description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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The invention relates to a pen or pencil sleeve, which absorbs sweat so that a person's fingers do not slip on the pen or pencil when handling the pen or pencil over an extended period.
The present invention is directed to a sweat absorbing finger-gripping device for use as a permanent or preferably a removable attachment to a writing implement. The finger-gripping device comprises a water or moisture absorbent sleeve to absorb sweat from the fingers of the person using the implement. The cylindrically-shaped sleeve has a formed internal bore or hollow portion sized to snugly fit around the writing instrument. The water absorbent sleeve forms a finger contacting surface when the sleeve is carried on a writing implement. The water absorbent layer absorbs sweat from the palm and/or fingers of the user sot the writing instrument does not slip in the user's palm and/or fingers.
The sleeve can be formed with an internal layer, which can be coated with an adhesive to prevent the finger-gripping device from sliding on the writing implement.
The sleeve also has an outer permeable fabric layer with a moisture absorbing layer sandwiched between the internal layer, which can also be coated with an adhesive layer, preferably a releasable adhesive layer.
The water absorbent sleeve can be formed from a layered or laminated material such as material used to make CAREFREE® panty liner feminine sanitary protection products.
The cylindrically-shaped sleeve can be perforated circumferentially at spaced intervals to allow removal of sections to compensate for reduced length of a pencil as the pencil is sharpened.
The water or moisture absorbent sleeve can be initially woven as a cylindrical fabric, or can be formed by bringing opposing edges of a flat sheet of layered material into contact and securing the opposing edges to form a cylindrical configuration. The seam or joint can be by bonding or stitching, or can be seamless.
As stated above, a water permeable layer is positioned on the finger contacting side of the cylindrical water absorbent sleeve to wick moisture from the fingers into the moisture absorbent layer.
The present invention further includes the permanent combination of a writing implement and a finger-gripping device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A shows a water absorbent sleeve on a writing implement (pencil shown);
FIG. 1B shows a water absorbent sleeve on a writing implement (pen shown);
FIG. 2 depicts one embodiment of the invention where sectional portion of the sleeve can be torn off (separated) as a pencil is shortened;
FIG. 3 depicts a cross-section view of a partial section of one of the sections from FIG. 2; and
FIG. 4 depicts a plan cross-section view of one of the sections from FIG. 2 .
DETAILED DESCRIPTION OF THE INVENTION
Turning now to FIGS. 1A and 1B, 2 , 3 and 4 , there is shown a water absorbent sleeve 10 having a finger contacting surface 12 , and a formed bore or hollow portion 14 designed to snugly fit around a writing implement. The sleeve can be formed as a multi-layered device, typically, three layers, a fabric layer 16 on the outside, a sleeve internal or inner layer 18 which is formed to snugly fit around the writing implement 20 a , 20 b , and an intermediate moisture absorbing layer 22 sandwiched in between. The sleeve internal layer 18 is generally made from an impervious material and can be coated with an adhesive 24 to prevent the water absorbent sleeve 10 from sliding on the writing implement 20 a , 20 b . Adhesive 24 can be a permanent adhesive for mechanical pencils 20 a or pens 20 b , although a releasable adhesive would be advantageous so as to be able to temporarily remove the sleeve 10 from the implement 20 a , 20 b for reuse on other writing implements.
The water absorbent sleeve's outer fabric layer 16 preferably has perforations 26 around its circumference at spaced-apart intervals to provide for reduction in length to correspond to reduction in length of the writing implement, when the writing implement is a pencil 20 a.
Outer layer 16 , which forms the finger contacting surface 12 , is typically a woven fabric such as nylon, cotton or synthetic material which will be sufficiently durable to be used repetitively. The outer layer 16 could also be preformed non-fabric material such as leather, elastomeric, polymeric, and synthetic materials, as long as the material selected is sufficiently permeable to allow any sweat to permeate into the sweat absorbing intermediate layer 22 . This intermediate sweat absorbing layer 22 can be a cotton fibrous or other loosely woven fibrous material sufficient to readily absorb the sweat moisture and the permeation in the outer layer 16 should be porous enough to allow for the intermediate layer to dry after a period of non-use.
Because pencils have to be sharpened, it is recommended that the sleeve 10 have spaced-apart circumferential perforations 26 , which allow for the tearing off or separation of sections as the pencil is shortened. These tear off perforations 26 can be typically spaced apart about very ½ inch to ¾ inches, although any increment spacing can be chosen. For mechanical pencils and pens, it is contemplated that the ability to tear off sections 28 is not necessary, and in fact, it is also contemplated that the sleeve 10 may be permanently adhered to the mechanical pencil or pen.
As can be ascertained from the above description, the inventive device 10 can be sized to fit any cross-sectionally shaped pen or pencil and can have any predetermined length to fit the pencil or pen.
It should be understood that the preceding is merely a detailed description of one or more embodiments of this invention and that numerous changes to the disclosed embodiments can be made in accordance with the disclosure herein without departing from the spirit and scope of the invention. The preceding description, therefore, is not meant to limit the scope of the invention. Rather, the scope of the invention is to be determined only by the appended claims and their equivalents.
Now that the invention has been described, | A water absorbent sleeve can be positioned on a writing implement to prevent the slipping of the writing instrument caused from a user's sweaty palm or fingers. | 0 |
FIELD OF THE INVENTION
The present invention relates generally to tubular fabric formed on small diameter circular knitting machines and, more particularly, to an apparatus and knitting machine that produces large rolls of such material.
BACKGROUND OF THE INVENTION
Small diameter circular knitting machines have been in use for many years in the textile industry. These machines are especially designed for knitting narrow tubular single jersey and rib knit polyester and cotton fabrics, and combinations thereof, to be used as cuffs on sleeves or trousers, as liners for specialty garments, etc.
While there are several types and models of small diameter circular knitting machines, they each operate on the same general principles. A small diameter knitting cylinder and dial assembly equipped with latch needles (knitting needles) receives ends of polyester or other yarn that are fed from surrounding creels. A small diameter tubular knitted fabric is thus formed on the latch needles and is continuously and synchronously drawn downward by the machine's takedown assembly. The takedown assembly includes two or more takedown rollers that frictionally engage and pull downward on the tubular fabric. As is conventional in machines of this type, a windup mandrel is positioned below the takedown rollers to form a narrow roll (like a coiled fire hose) of fabric having a width corresponding to the width of the tubular, but flattened, knitted fabric. The roll is wound around the mandrel, the mandrel being independently driven and controlled by a clutch assembly.
There are a number of problems inherent in this system of forming rolls of fabric. First, because these rolls are formed by a buildup of concentric layers, the rolls are limited in the diameter that can be formed. Thus the length of fabric on a roll must also be limited. As a result, these narrow rolls of fabric must be “doffed”, or removed, about every 35 to 40 minutes, depending upon the production rate of the machine. This translates to a substantial labor requirement wherein machine operators must frequently remove the full rolls and ready the machine for a new roll. Similarly, the end users of the narrow fabric rolls are forced to frequently interrupt the production of apparel or the like in which the tubular fabric is being incorporated in order to get a new roll.
In such machines, typically the mandrel, or core, of the narrow roll is driven independently by a clutch-controlled motion. As a result, the tension created in the fabric is not uniform throughout the roll. A great deal more tension tends to be induced on the inner, or first, layers than on the outer layers because the mandrel exerts a greater force on the inner layers and less force on the outer layers. This is caused by decreasing the angular velocity of the outer layers as the clutch tends to brake. Fabric, like any other material having a substantial elastic characteristic, develops a memory when held in a certain stretched or unstretched condition for any appreciable length of time. The problem that this creates is that the end users must produce apparel with a product that does not exhibit uniform characteristics throughout its length. For example, if the tubular fabric is being cut into specified lengths for use as cuffs on garments, the first cuffs, which are stretched less, will be more loosely fitting because the less stretched fabric will have less tendency to return to a narrow, stretched shape. On the other hand, the last cuffs formed will fit more tightly as the material that is stretched during the fabric formation tends to return to its narrow, stretched shape. This presents a quality dilemma for the end user who often must discard lengths of the knitted fabric as unusable.
Yet another problem inherent in the production of narrow rolls is wastage resulting from knitting machine failures such as sudden stoppage, which causes the very narrow rolls to collapse and unravel, rendering them useless.
SUMMARY OF THE INVENTION
The present invention is directed to an apparatus and method that addresses each of the problems described above.
The essence of the present invention is a takeup system that forms a larger, wider, roll of tubular knitted fabric and also maintains a constant tension on the fabric wound onto the takeup package. In its simplest form, the system includes a traversing mechanism that is positioned between the knitting cylinder and the takedown rollers. The traversing mechanism moves at a controlled rate across the path of the fabric tube to build a wound package of a substantially constant diameter. Secondly, the takeup package is surface driven to ensure a constant tension on the fabric on the package.
The traversing mechanism is mounted between the knitting cylinder and the takedown rollers and includes a traversing control spindle that extends substantially across the width of the machine's takedown assembly. The traversing control spindle is mounted by flange bearings at each end attached to the upper takedown bracket. A reversing nut is operatively mounted on the traversing control spindle and reciprocates along tracks in the traversing control spindle. Upon reaching the end of the track, the nut reverses direction and moves back to the opposite end, and so on. If the tracks were provided with a conventional, constant pitch, the reciprocating motion would be accelerated near the ends of the spindle. Therefore, an important aspect of the spindle track pattern in the present invention is that the pitch of the track pattern is steeper at the ends of the track and is more gradual in the middle of the track. This unique design causes the reversing nut to move more slowly when it approaches the ends of the track than it does at the middle of the spindle, which actually causes a more constant traversing speed. As a result, the fabric being pulled downwardly is more evenly wound across the width of the fabric roll.
A traversing plate is fastened to one end of the reversing nut so that, as the traversing control spindle rotates, the traversing plate moves with the reversing nut back and forth along the spindle. A guide rod extends through a slot in the traversing plate and is attached on opposite ends to the flange bearings. The guide rod keeps the traversing plate in a constant horizontal and vertical alignment with respect to the takedown rollers. Extending outwardly from the bottom of the traversing plate is a narrow, flat guide plate that is slightly wider than the width of the tubular fabric being processed. Small rollers having rotational axes perpendicular to the takedown rollers are attached on opposite sides of the guide plate and protrude forwardly outward so that they contact the vertical side edges of the tubular fabric. To stabilizethe fabric, a separate fabric spreader plate is inserted within the tubular fabric sleeve to spread and stabilize the fabric being pulled through by the takedown rollers. Thus, as the spindle rotates, the reversing nut with attached traversing plate moves back and forth along the length of the spindle. The guide plate, with rollers, moves the fabric with the spreader plate in similar fashion back and forth substantially along the length of the takedown rollers as the fabric is pulled through the takedown rollers.
A second aspect of the invention is to provide constant tension on the rolled fabric. Toward this end, the takeup mandrel and clutch assembly of the conventional machine are removed and replaced by a freely rotating takeup roller that extends across a substantial width of the lower takedown bracket. Opposite ends of the takedown roller shaft are held by spring-biased arms that are each mounted on opposing walls of the lower takedown bracket.
The independent drive system of the conventional machine is removed from the machine of the present invention and is replaced by a knurled, cylindrical surface driving windup roller that extends across the width of the lower takedown bracket. Opposite ends of the windup roller shaft are mounted within pillow block bearings. The windup roller is interconnected with the takedown rollers by a gear chain and driven in a ratioed relationship thereto. Thus, as the takedown rollers pull the fabric downward for winding upon the takeup roller, the windup roller is driven slightly slower, relaxing some of the tension in the fabric. The biasing arms holding the takeup roller and thus the fabric roll against the windup roller. The windup roller then drives the fabric roll from the roll's outer surface at a constant speed. This constant surface speed ensures that a constant tension is induced on the knitted fabric as it is being wound around the takeup roller. Therefore, a fabric roll is formed that has a substantially uniform outer shape, holds 5 to 10 times more fabric than a conventional, narrow roll, and delivers a fabric wound at a substantially uniform tension.
These and other aspects of the present invention will become apparent to those skilled in the art after a reading of the following description of the preferred embodiment when considered with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of the prior art small diameter circular knitting machine;
FIG. 2 is a front perspective view of the apparatus and small diameter circular knitting machine of the present invention;
FIG. 3 is a schematic of the drive system of the present invention shown in FIG. 2;
FIG. 4 is a front perspective view of the traversing mechanism of the present invention;
FIG. 5 is a rear perspective view of the traversing mechanism of the present invention;
FIG. 6 is a perspective view of the traversing control spindle of the present invention;
FIG. 7 is a front perspective view of the rollup and winding assembly of the present invention; and
FIG. 8 is a front view of the windup assembly of FIG. 7 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, shown generally as 10 is a representative small diameter circular knitting machine known in the art. The machine shown in FIG. 1 is manufactured by Tompkins Brothers Company, Inc. of Syracuse, New York as Model No. R0508. This type of machine is used for knitting inserts, cuffs, liners, etc., and is representative of other small diameter machines manufactured by other suppliers. In operation, the knitting cylinder and dial 11 equipped with knitting needles (not shown in detail) forms a tubular rib knit fabric 25 at the top of the machine, as a takedown assembly, shown generally as 12 , mounted within a stable frame 13 , rotates below. The takedown assembly 12 comprises upper and lower takedown brackets 14 a and 14 b, a plurality of take down rollers 15 , and a windup mandrel 16 . A drive system 17 controls the coordinated movement of the rollers 15 and mandrel 16 . The drive system 17 is interconnected to and driven by the rotation of the knitting cylinder and dial 11 . While a detailed description is not necessary for an appreciation of the present invention, the drive system basically includes a shaft 18 that links gear and chain assemblies 19 and 22 , and pulley assembly 24 . As shaft 18 is rotably driven, gear and chain assembly 19 causes the takedown assembly to rotate. The rotation of shaft 18 also drives gear and chain assembly 22 that engages a mechanical clutch 23 . The mechanical clutch 23 controls the rotation of the mandrel 16 .
As the knitting cylinder and dial 11 forms the tubular knitted fabric 25 and the takedown assembly 12 rotates, the takedown rollers 15 , which are driven by pulley assembly 24 , rotate to frictionally engage and pull the fabric 25 downwardly from cylinder 11 and flatten it for rolling up. The flattened fabric 25 is wound into a roll 27 rotably by mandrel 16 . The windup of the roll 27 is thus driven from the center of the roll 27 by the mandrel 16 . The resulting roll 27 , which is the width of the flattened fabric 25 , has a relatively large diameter to width ratio. As a result, roll 27 tends to be unstable and easily collapses due to machine stoppages or handling.
In a preferred embodiment of the present invention, the drive system and rollup assemblies for the small diameter circular knitting machine are substantially different from the prior art. As shown in FIG. 2, the present invention provides a small diameter circular knitting machine, shown generally as 100 . Knitting machine 100 comprises a knitting cylinder and dial 111 (not shown in detail) mounted atop a stable frame 113 . Mounted within the frame 113 is the takedown mechanism, shown generally as 112 . The takedown mechanism comprises a takedown bracket 114 having upper and lower bracket portions. The knitting cylinder 111 , frame 113 , and takedown bracket 114 are functionally the same as the prior art knitting machine shown in FIG. 1 . The takedown mechanism, however, is substantially different.
The takedown mechanism 112 of the present invention includes a traversing mechanism 120 , takedown rollers 115 , a takeup roller assembly 130 , a windup roller assembly 140 , and a drive system.
As seen by comparing the prior art machine of FIG. 1 with the present invention of FIG. 2, the drive system of the present invention is best understood. A schematic of the drive system of the present invention is shown in FIG. 3, in part. The gear and chain assembly 22 and mechanical clutch 23 of the prior art machines have been removed from the machine of the present invention. As shaft 118 is rotably driven, gear and chain assembly 119 causes the takedown assembly 112 to rotate. Shaft 118 is still connected to a pulley assembly 240 that drives the takedown rollers 115 . It is the rotation of the takedown rollers 115 that drives the takedown system 112 of the present invention. The rotation of the takedown rollers 115 drives the interconnected windup roller assembly 140 (and windup roller 141 ) and the traversing mechanism 120 (and traversing control spindle 122 ), each turning at a selected rotational speed. That is, an extension 116 a of one of the takedown roller 115 shafts has two sprockets affixed along its length. The first sprocket, 119 a, is interconnected to sprocket 119 d by a chain 129 a. Sprocket 119 d is rotably mounted to a shaft 116 b that is held in place by a bearing sleeve 116 c formed in the wall of the takedown bracket 114 . A second sprocket 119 c is rotably mounted on shaft 116 b and is interconnected by chain 129 b to sprocket 128 that is mounted on one end of the traversing control spindle 122 . Further, the second sprocket 119 b mounted on takedown roller shaft 116 a is interconnected to sprocket 145 on windup roller shaft 142 by chain 129 c. Sprocket gear ratios are selected such that the takedown roller shaft 116 a turns approximately 4.4 times for 1 turn of the traversing control spindle 122 . Traversing control spindle 122 moves a traversing plate, described in detail below. The takedown roller 115 surface turns 1.25 times faster than the windup roller 141 surface, ensuring that some of the tension is relaxed before being wound by windup roller 141 . Thus, as the gear and chain assembly 119 is driven, the takedown rollers 115 , traversing mechanism 120 , and windup roller assembly 140 are interconnectedly driven in unison.
In operation, as with the conventional small diameter machines, a tubular knitted fabric 150 is formed on knitting cylinder and dial 111 atop the machine. The frame 113 and knitting cylinder and dial 111 are taken from the Model R0508 knitting machine manufactured by Tompkins Brothers Company, Inc. Whereas in the conventional machine the fabric 25 first encounters the takedown rollers 15 on its straight vertical path downward, the knitted fabric 150 of the present invention first encounters the traversing mechanism 120 . FIGS. 4 and 5 show the front and rear perspective views of the traversing mechanism 120 . The traversing mechanism 120 comprises opposed flange bearings 121 a and 121 b, a traversing control spindle 122 , a reversing nut 125 , a traversing plate 123 , a guide rod 126 , and a sprocket 128 .
As the takedown rollers 115 rotate, the takedown roller shaft extension 116 a with sprockets 119 a and 119 b, and chains 129 a and 129 b connected thereto, drives the traversing mechanism 120 via sprocket 128 . The rotation of the traversing control spindle 122 causes reversing nut 125 to move back and forth along the length of the spindle 122 tracks 122 a. Tracks 122 a formed in spindle 122 , control the speed of movement of the reversing nut 125 along the spindle 122 . Conventional spindles used in other than textile operations typically have tracks that are uniformly spaced along their lengths; however, as will be understood by those skilled in the art, when the traversing nut 125 approaches and departs each end of the spindle track 122 a, less material (fabric) is deposited at the ends of the roll than in the middle, or center, of the roll. This effect results in a “football” shaped roll of fabric, which tends to be dimensionably unstable when packaged, shipped, and stored. Thus, the tracks 122 a formed in the spindle 122 of the present invention, are more widely spaced in the middle of the spindle 122 and are more closely spaced at the outer ends of the spindle 122 . This is best seen in FIG. 6 . The pattern of tracks 122 a are formed so that there is a variable lead with increasing dwell time on both ends of tracks 122 a. The optimal pattern was determined through testing and calculating the length of time the fabric 150 needed to dwell on the outer ends of the spindle track 122 a. As those skilled in the art will appreciate, if direction is reversed too quickly at the ends of the tracks 122 a, more fabric is deposited at the center of the roll. The spacing of the tracks at the center of the spindle 122 is 0.825 inches (see dimension A in FIG. 6) and tapers downward to a spacing of approximately 0.481 (see dimension B in FIG. 6) inches at the ends of spindle 122 tracks 122 a. The design of the spindle 122 tracks 122 a of the present invention effectively causes the reversing nut 125 to decrease speed at the ends of the spindle 122 track 122 a, which in turn ensures an even surface across the width of the roll 155 of knitted fabric. As those skilled in the art will appreciate, the spacing of the tracks may be varied depending upon the rate of fabric production, the type and shape of fabric, roller lengths, etc.
Connected to one end of the reversing nut 125 is the traversing plate 123 . As the reversing nut 125 moves back and forth along traversing control spindle 122 , the traversing plate 123 moves with it. Traversing plate 123 has a lower guide portion 123 a that is oriented generally parallel to the traversing control spindle 122 and parallel to the direction of travel of reversing nut 125 . Guide portion 123 a is dimensioned to be wider than the width of the fabric 150 being pulled down. On either side of the guide portion 123 a are guide rollers 123 b and 123 c. Guide rollers 123 b and 123 c are, in operation, configured so that they are positioned on either side of the knitted fabric tube being pulled downward by takedown rollers 115 . As the traversing plate 123 moves back and forth along the traversing spindle 122 , the guide rollers 123 b and 123 c urge the fabric sleeve 150 back and forth with the traversing plate 123 . To further ensure stability in this high speed knitting operation, a fabric spreader plate 127 is positioned inside the downwardly drawn knitted fabric sleeve 150 . The spreader plate is a thin, separate “floating” plate that spreads the knitted tube by approximately 10 percent so that the fabric 150 is more stable as it is engaged by the takedown rollers 115 . Further, the spreader plate 127 adds rigidity to the fabric 150 so that the fabric 150 may be more easily moved back and forth with the traversing plate 123 between guide rollers 123 b and 123 c, without becoming twisted or otherwise distorted.
As the fabric 150 is moved by the traversing plate 123 back and forth along the traversing control spindle 122 , the knitted fabric is engaged by the takedown rollers 115 along substantially the entire working length of the takedown rollers 115 . The working length of the takedown rollers 115 is approximately 4.5 inches to 5 inches. This, in turn, results in a fabric roll of approximately 4.5 inches to 5 inches in width.
As the takedown rollers engage the tubular knitted fabric 150 , a large, wide roll is thus formed as the fabric is wound. FIGS. 7 and 8 show the size and shape of the resulting large roll. As described above, the prior art rolls that are wound about a clutch-controlled mandrel 16 are limited to the width of a single, flattened, knitted fabric tube and weigh approximately 1.5 pounds to 2 pounds. The rolls of the present invention will hold 5 to 10 times more fabric because of their increased width. As shown in FIG. 7, a takeup roller assembly 130 replaces the mandrel 16 and clutch 23 of the conventional prior art machines. A generally cylindrical, freely rotating, takeup roller 135 that is longer than the width of the fabric roll 155 to be formed is held in place by opposed arms 131 that are pivotally attached at their ends to the lower takedown bracket 114 at points 132 a and 132 b ( 132 b not shown but identical to 132 a ) with fasteners 133 , such as pins. Springs (not shown) are connected to the riser blocks 144 and arms 131 so that the arms are spring-biased downward. Notches 131 a formed in the free ends of the arms 131 engage takeup roller extensions 134 on either end of takeup roller 135 . In operation, the arms 131 bias the empty takeup roller 135 downward against the windup roller 141 . As the windup roller 141 rotates, fabric 150 traverses from side to side to accumulate in the wide roll. As the diameter of the roll 155 increases, the takeup roller 135 moves upward aginst the bias as the arms 131 pivotally move upward as well about points 132 a and 132 b. In essence, then, the takeup roller 135 moves upward as the diameter of the roll 155 of fabric increases.
Referring to FIG. 8, the windup roller assembly 140 is shown in greater detail. As the takedown rollers 115 rotate, the shaft extension 116 a with sprocket 119 b and chain 129 c that is interconnected to the sprocket 145 on windup shaft 142 causes the windup shaft to rotate, turning the windup roller 141 . Windup roller 141 has a knurled surface along its length to frictionally engage the fabric roll 155 . The ends of the windup roller shaft 142 are rigidly mounted within pillow block bearings 143 . To provide sufficient clearance between windup roller 141 and the takedown bracket base, the pillow block bearings 143 are mounted atop riser blocks 144 , or spacers, well known in the art. As those skilled in the art will appreciate, there are a number of ways that the windup roller 141 and pillow block bearings 143 may be mounted, so long as the windup roller 141 is spaced from the takedown bracket base. Because windup roller 141 is rotating at a fixed rate and is rolling the fabric 150 from the outside of the roll, a constant tension is applied to the wound fabric from the very beginning of the roll to the end. The sprocket ratios between sprocket 119 b and sprocket 145 are fixed at a ratio of 1.25:1 so that the tension is less than the tension of the fabric 150 coming through the takedown rollers. As those skilled in the textile arts will appreciate, the amount of tension induced in the wound fabric is not critical as long as the same tension is applied throughout the entire roll of fabric.
Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. It should be understood that all such modifications and improvements have been deleted herein for the sake of conciseness and readability but are properly within the scope of the following claims. | A method and apparatus for producing large rolls of tubular fabric knitted on a small diameter circular knitting machine of the type having fabric takedown rollers for pulling the fabric from the knitting cylinder, and a takeup roller for winding up the fabric into a roll, including a traversing mechanism that is operatively associated with and positioned upstream of the tubular fabric takedown rollers so that the fabric is moved back and forth along the length of the take down rollers, so that the width of the fabric roll wound upon the takeup roller is substantially the length of the take down rollers. Further, the fabric leaving the takedown rollers is surface driven to provide constant speed and tension. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to a system for blending (mixing) textile fibers wherein a plurality of serially arranged hoppers, such as feed chutes, feed chambers or the like are charged with fibers in sequence by means of a common pneumatic conveying apparatus arranged overhead. The fibers are removed from the hoppers through the bottom end thereof and are introduced into a common conveying apparatus.
From a given fiber bale lot in a rational manner a fiber blend should be formed to continuously ensure an optimal distribution of the fiber material as regards staple length, fineness, degree of maturity, color, etc. A proper blend is not only fundamental for the manufacture of yarns of unchanging high quality as regards their uniformity, breaking strength and coloring but also improves the running properties of the material during the successive processing. A known apparatus for making such a homogeneous blend is, for example, the Multi-Mixer MPM model manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Federal Republic of Germany. This known apparatus may have six, eight, ten or twelve hoppers. The multiplier number (tuft blend multiplication or doubling) corresponds to the number of hoppers. By means of the blend doubling there is obtained a particular homogenization of the fiber tufts, that is, the blend doubling has the purpose of compensating for fluctuations in the fiber material.
The essential characteristics of blender efficiency are the hourly output quantities and the quality of blend. According to the blending process performed by the Multi-Mixer MPM, in case of six hoppers a production rate of 600 kg/hour and in case of twelve hoppers a production rate of 1200 kg/hour is achieved. The quality of the blend is decisively determined by how uniformly the defects in the introduced material are distributed in the fiber material mass. It is decisive of the quality of the blend and it is therefore the principal purpose of the blender to evenly distribute the defects in a large fiber quantity, that is, to achieve an equalization of medium and long wave defects in the composition of the introduced fiber material. The greater the fiber material mass in which the fiber defects are to be uniformly distributed the more successful an equalization and thus the better the quality of the blend. Short-wave defects, that is, defects related to small fiber material quantities are in part compensated for during the opening of the bales. Up-to-date bale openers such as the Blendomat BDT model manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Federal Republic of Germany, limit the error from the start by removing the smallest possible quantities in series from a plurality of bales forming a bale lot.
SUMMARY OF THE INVENTION
It is an object of the invention to provide an improved system for blending textile fibers, particularly for equalizing, at a high output rate, short wave defects in the fiber material.
This object and others to become apparent as the specification progresses, are accomplished by the invention, according to which, briefly stated, the fibers are pre-mixed by performing at least a two-fold doubling and are subsequently introduced into the hoppers of a main blender.
In the known blending methods the number of doubling corresponds to the number of hoppers. In the Multi-Mixer MPM which operates with twelve hoppers, a twelve-fold tuft doubling is effected. If the Multi-Mixer is additively extended by three hoppers, a fifteen-fold doubling may be effected. In contradistinction, according to the invention, a fiber tuft doubling may be multiplied by first at least twice doubling the fiber material and then introducing the doubled material into the hoppers of the blender. In a Multi-Mixer with twelve hoppers, for example, a thirty-six-fold doubling is effected by means of the upstream arrangement of three hoppers according to the invention. Thus, with the invention, particularly by the serial arrangements of the pre-mixer and the main blender, an over-additive effect is achieved in an advantageous manner.
Expediently, the fiber material which has been at least twice doubled is intermingled once more, prior to its introduction into the hoppers of the main blender. By such intermingling there is meant the blending of the contents of the various components of the doubled (pre-mixed) fiber material to obtain a mixture which is uniform in itself.
The system according to the invention has at least one pre-blender which has at least two hoppers and which is coupled by means of a pneumatic conveyor with the principal blender (for example, a Multi-Mixer MPM) situated downstream of the pre-blender. Thus, the pneumatic conveyor is coupled at least with one pre-blender, from the hoppers of which the fibers are supplied to the common pneumatic conveyor. The inlet openings of the hoppers forming part of the pre-blender are preferably alternately charged. Preferably, the hoppers are charged in a continuous operation so that an uninterrupted functioning can be achieved. Expediently, the hoppers are feed chutes which are charged from above and from which the fiber is removed at the bottom. Preferably, the hoppers have, in the zone of their side walls, photocells for controlling the filling height. Preferably, between the pre-mixer or, as the case may be, the pre-mixers and the principal blender there is provided an intermediate blending (intermingler) device for additionally homogenizing the fiber material. The intermingler may be, for example, a conventional Axi-flo model, manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Federal Republic of Germany which at the same time functions as a cleaner for the fiber material. Expediently, the intermingler is built into the pneumatic conveying apparatus.
According to a further feature of the invention, the inlet openings of the pre-blender are sequentially alternately charged with a predetermined fiber quantity from an upstream arranged fiber processing machine such as a bale opener, a scale box feeder or a multi-component scale.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic side elevational view of a preferred embodiment of the invention.
FIG. 2 is a schematic side elevational view of one part of another preferred embodiment of the invention.
FIG. 3 is a schematic side elevational view of still another preferred embodiment of the invention.
FIG. 4 is a schematic side elevational view of one part of still another preferred embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIG. 1, there is shown a principal blender 1 which may be a conventional Multi-Mixer MPM model. The principal blender 1 has six serially arranged hoppers 2, 3, 4, 5, 6 and 7 communicating with an overhead duct 8 through which fibers are conveyed by an airstream in a direction indicated by the arrow A. The hopper walls 9 have air outlet openings 10 in the zone of their upper portions. Each of the hoppers 2 through 7 may be closed at the top by means of respective pivotal closures 11 which, in their open position as shown for the closure 11 of the hopper 2, close the downstream side of the duct 8. In the zone of the lower end of each of the hoppers 2 through 7 a delivery roller pair 12 and an opening roller 13 are arranged. Underneath the hoppers 2 through 7 a common blending channel 14 is arranged from which the fiber tufts deposited therein are conveyed towards a suction funnel 15 which is coupled to a condenser (not shown).
The fiber material is, by means of a fiber driving impeller 15, drawn through a pipe conduit 16 from an upstream arranged pre-blender 17 and delivered to the hoppers 2 through 7 of the main blender 1.
The pre-blender 17 has three serially arranged hoppers 18, 19 and 20 which receive fiber material from an overhead arranged sieve drum 21. Between the sieve drum 21 and the inlet openings of the chutes 18, 19, 20 there is arranged a dual pivotal gate 22, 23 which is supported by pivots 24 and 25 having a horizontal axis. The fiber material is, from the sieve drum 21, introduced between the pivotal gates 22, 23 in their solid-line position into the hopper 18 and in the broken-line position 22a and 23a into the hopper 19. The hopper 20 is charged after the pivotal gate is pivoted counterclockwise from the position 22a, 23a into a third position. At the lower end of each hopper 18, 19 and 20 there is provided a respective delivery roller 26, 27 and 28 which may be a star or finger roller. Above each delivery roller 26, 27 and 28 there is positioned, for example, a deflecting element (such as 18b) affixed to a wall (such as 18a) of each hopper 18, 19 and 20. The upper end of the inside walls (such as wall 18a) is provided with a rounded part (such as 18c). Each hopper 18, 19 and 20 has, mounted on the respective hopper wall, a respective photocell 29, 30 and 31 which protects the hopper from overfilling and idle runs. The position of the pivotal gate 22, 23 with respect to the hoppers 18, 19 and 20 may be controlled by means of the associated photocell 29, 30 or 31. For this purpose, the photocells 29, 30 and 31 are operatively connected with a drive motor (not shown) for advancing the fiber material, such as a motor associated with a material supply apparatus arranged upstream of the pre-blender 17. Such a motor, as shown in FIG. 4, may be, for example, a drive motor 43 of a bale opener 37. Underneath the hoppers 18, 19 and 20 there is arranged a common conveyor belt 32 which advances the deposited fiber tufts in the direction of a suction funnel 33 which communicates with the suction side of the fan 15 by means of a conduit 16. The fiber material is drawn from an upstream arranged machine, such as a bale opener, through a conduit 34 and fed to the sieve drum 21.
The fibers are, in the direction designated by the arrow B introduced into the hoppers 18, 19 and 20 approximately up to the height of the respective photocells 29, 30 and 31. As soon as the height of the tuft level sinks below the level of the photocells 29, 30 and 31, resupply of the tufts is resumed. Fiber tufts are removed from all three hoppers 18, 19 and 20 simultaneously and continuously by the rollers 26, 27 and 28 and deposited on the conveyor 32. The thrice doubled fiber material leaving the pre-mixer 17 is, by means of the pneumatic conveyor formed of the duct 16, the fan 15 and the duct 8, sequentially introduced into the hoppers 2 through 7 of the main blender 1. The pre-blender 17 and the main blender 1 thus together achieve an eighteen-fold doubling (three pre-mixer hoppers times six main blender hoppers) of the fiber material.
Turning now to FIG. 2, downstream of the pre-blender 17 there is arranged a continuous mixer 35 (intermingler) which may be an Axi-flo model cleaner manufactured by Trutzschler GmbH & Co. KG, Monchengladbach, Federal Republic of Germany. The inlet of the mixer 35 is coupled to the outlet of the pre-mixer 17 whereas the outlet of the continuous mixer 35 is coupled to the duct 16. The thrice doubled fiber material discharged by the pre-blender 17 is thoroughly mixed in the intermingler 35.
Turning now to FIG. 3, there are shown two pre-blenders 17' and 17" having three hoppers 18', 19' and 20' and, respectively, 18", 19" and 20". The two pre-blenders 17' and 17" are arranged upstream of the main blender 1 having three chutes 2, 3 and 4 (the arrows in FIG. 3 indicate the direction of fiber material flow). The two pre-blenders 17' and 17" as well as the main blender 1 together achieve a twenty-seven-fold doubling of the fiber material (three times three times three).
Turning now to FIG. 4, the inlet openings of the hoppers 18, 19 and 20 of the pre-blender 17 may be charged sequentially in an alternating manner as described above. The sieve drum 21 of the pre-blender 17 is coupled by means of a pipe conduit 34 with a fiber tuft suction channel 36 of an upstream-arranged automatic bale opener 37, such as a Blendomat BDT. The bale lot is constituted by a plurality of serially arranged fiber bales 38 formed of three components A to B, B to C and C to D. Each component has a plurality of bales 38. The pivotal gates 22, 23 are coupled by setting devices 39, 40 to a setting apparatus 41 which is controlled, for example, by means of a time relay 42 and which, after a lapse of a predetermined period, pivots the gate from the hopper 18 to the hopper 19 or 20. The time relay 42 is so set that it switches when the component boundary between the components A through D is bridged by the opener. The setting apparatus 41 may be, in the alternative, controlled by measuring elements such as electric contacts which are arranged at the component boundaries A, B, C and D.
It will be understood that the above description of the present invention is susceptible to various changes, modifications and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims. | Textile fibers are blended by introducing them in a pre-blender; performing an at least two-fold doubling of the textile fibers in the pre-blender; pneumatically introducing the textile fibers in a principal blender from the pre-blender; performing a multiple doubling of the textile fibers in the principal blender; and removing the textile fibers from said principal blender. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of pending International patent application PCT/DK2007/000162, filed Mar. 30, 2007, which designates the United States and claims priority from Danish patent application no. PA 2006 00469, filed Apr. 2, 2006, the content of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a pitch bearing for a wind turbine, a wind turbine and a method for servicing a bearing.
BACKGROUND OF THE INVENTION
[0003] A typical bearing in a wind turbine has been the 4-point contact ball bearing e.g. in a blade pitch mechanism. This bearing design has shown its suitability to take the complexes load patterns the blade act on the bearing with.
[0004] As the blade rotates in the gravity field, the wind related loads are super positioned by gravity related loads. These gravity loads are cyclic and change directions during the rotation of the rotor. This causes the loads in some areas of the bearing to change directions to which the bearing will flex from one side of the play to the other. Such movements have been in favor for ball bearing as the ball can roll to absorb such movements.
[0005] However, by the increasing size of the modern wind turbine, the ball bearing lacks capacity to handle the increase in load.
[0006] Rollers have such properties; hence roller bearings are of interest. As the bearing sees large changes of loads and directions, there will be some flexure in the axial direction of the bearing. If the bearing has some axial play as well, this is added to the flexure from the loads. This flexure will cause sliding in the radial rollers and consequently deteriorate the bearing.
[0007] It is therefore an object of the present invention to provide a solution which is more efficiently adapted to the increasing loads of bearings for a modern wind turbine.
SUMMARY OF THE INVENTION
[0008] The invention provides a pitch bearing for a wind turbine comprising a first and second axial row of bearing rolling elements, said rows being positioned in a distance of each other, and one or more radial rows of bearing elements, where said one or more rows of bearing elements are positioned outside an area defined in between said first and second axial row.
[0009] Hereby are the abovementioned disadvantages of the prior art avoided in an advantageous manner.
[0010] In an aspect of the invention, said one or more radial rows of bearing elements are positioned on the upper side of the bearing above the first and second axial row e.g. close to the blade side of the pitch bearing or said one or more radial rows of bearing elements are positioned on the lower side of the bearing below the first and second axial row e.g. close to the hub side of the pitch bearing. If the radial row is relocated from in between the two axial races to the upper of the bearing, this part of the bearing becomes more access able from the outside on the blade side or from the inside on the hub side and thus easier to perform service on without having to remove the blade.
[0011] In an aspect of the invention, said one or more radial rows of bearing elements comprise sliding surfaces sliding on the roller end surfaces of at least one of said first and second axial row. Such a design would allow the bearing to be made more compact and with lower cost and of lower weight.
[0012] The invention further relates to a wind turbine comprising at least one blade, and at least one pitch mechanisms with one or more bearings according to any of claim 1 to 19 .
[0013] The invention also relates to a method for servicing a bearing according to any of claim 1 to 19 of a pitch bearing in a wind turbine, said method comprising the steps of:
removing any retaining means from the blade or the hub side of the pitch bearing lifting out the bearing elements of a radial row of bearing elements including the rolling elements and/or the raceways, inspecting, renovating or replacing the bearing elements, and positioning the bearing elements and retaining means in their work position.
[0018] If the radial row is relocated from in between the two axial races to the upper of the bearing, this part of the bearing becomes more access able from the outside on the blade side or from the inside on the hub side and thus easier to perform service on without having to remove the blade.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention will be described in the following with reference to the figures in which
[0020] FIG. 1 illustrates a large modern wind turbine,
[0021] FIG. 2 illustrates a cross sectional view of a well known bearing type in a wind turbine application such as a pitch mechanism,
[0022] FIGS. 3 a and 3 b illustrate a cross sectional view of a first embodiment of a bearing according to the invention,
[0023] FIG. 4 illustrates an upper part of a second embodiment of a bearing according to the invention,
[0024] FIG. 5 illustrates an upper part of a third embodiment of a bearing according to the invention,
[0025] FIG. 6 illustrates an upper part of a fourth embodiment of a bearing according to the invention,
[0026] FIG. 7 illustrates an upper part of a fifth embodiment of a bearing according to the invention,
[0027] FIG. 8 illustrates an embodiment of a bearing in a first and second section according to the invention,
[0028] FIG. 9 illustrates an embodiment of a bearing with rows of fixed bearing elements, and
[0029] FIG. 10 illustrates an embodiment of a bearing with rows of flexible bearing elements.
DETAILED DESCRIPTION OF THE INVENTION
[0030] FIG. 1 illustrates a modern wind turbine 1 . The wind turbine 1 comprises a tower 2 positioned on a foundation 6 . A wind turbine nacelle 3 with a yaw mechanism is placed on top of the tower 2 .
[0031] The wind turbine rotor comprises at least one rotor blade e.g. three rotor blades 5 as illustrated on the figure. The rotor blades 5 are pitchable in relation to the hub 4 by using pitch mechanisms.
[0032] FIG. 2 illustrates a well known bearing type (3RR configuration) in a wind turbine application such as a pitch mechanism.
[0033] The bearing comprises 3 rows of rolling elements. The first and second axial row 9 , 10 of rolling bearing elements is positioned between two different sets of horizontal raceways on an inner 8 and outer ring 7 . The two rows may especially handle and transfer axial loads. The third row 11 is a radial row of rolling bearing elements with a set of vertical raceways between the inner 8 and outer ring 7 and may especially handle and transfer radial loads of the bearing.
[0034] The first and second sealing means 12 , 13 are a steel or rubber component that has several important uses and are crucial to the functioning of the bearing. It separates the bearing rolling elements from the outside world, stops dirt and moisture from entering and prevents lubricants from leaking to the outside. The sealing means are integrated in the bearing and mounted between the outer and inner ring 7 , 8 at the upper and lower entrances of the bearing.
[0035] FIG. 3 a illustrates a cross sectional view of a first embodiment of a bearing according to the invention.
[0036] The bearing 14 comprises an outer and inner bearing ring 7 , 8 comprising sets of raceways.
[0037] Two horizontal sets of raceways hold two axial rows 9 , 10 of rolling elements such as rollers. The two axial rows 9 , 10 are separated by a horizontal extension part of the inner bearing ring 8 holding some of the horizontal raceways. Similarly the outer ring comprises an upper and lower extension part holding the further horizontal raceways for the two axial rows.
[0038] The radial row 17 , 18 of bearing elements is positioned above the two axial rows 9 , 10 at the blade side of the bearing 14 . The radial row comprises some kind of rolling element 17 and corresponding raceways 18 in opposite side of the inner and outer ring 7 , 8 . The raceways are illustrated as extending into the inner and outer ring and as such keeping the raceways vertically in place during normal use. The bearing rolling elements further keep the raceways horizontally in place during normal use.
[0039] The different rows of rolling elements are preferably positioned in rolling cages or any similar assemblies to retain the rolling elements in place. Further, the rolling elements may be part of a full compliance bearing i.e. rolling elements positioned side by side leaving no space in between.
[0040] The radial row 17 , 18 of bearing elements is protected from the outside by sealing means 12 which closes the opening between the inner and outer ring 7 , 8 at the surface of the bearing blade side.
[0041] The radial row 17 , 18 of bearing elements will be accessible from the outside at the blade side when the sealing means 12 is removed.
[0042] The raceways can be a solid part of the rings or loose inlays. Preferably in relation to loose inlays, each of the raceways is a broken ring or a number of ring segments e.g. 2*180 degrees, 4*90 degrees etc. Hereby it is possible to lift up the raceway or segments of raceway after the bearing rolling elements and the sealing means have been removed.
[0043] This change of position for the radial row gives following options:
The bearing can be inspected, services or replaced without the main bearing (the 2 axial races) are disconnected from the hub or blade. The wear fragments or debris from failure can be insulated from the primary bearing (by the seal 19 shown beneath the radial row of the bearing) The hub side of the bearing is very inflexible where the bearing flexibility increases with the distance from the hub. Thus the radial bearing can be preloaded more safely, as the height of the outer ring give some possibility for flexure. A spring can be built in behind one or both of the radial bearing rings to assure better control of pretension or to protect the bearing from excessive internal forces from geometrical deviations like out of roundness tolerances. The rolling elements can also be balls or cambered rollers as the space for the radial bearing is less constrained by the main bearing when on top of the bearing than inside. Plain bush bearing is a possibility.
[0050] These possibilities and embodiments according to the invention will be further explained below in connection with the accompanying figures.
[0051] It shall be emphasized that the inner T shape and outer C shape may just as well be reversed into an inner C shape and outer T shape.
[0052] Blade interface is the side of the bearing facing the wind turbine blade.
[0053] Hub interface is the side of the bearing facing the wind turbine hub.
[0054] FIG. 3 b illustrates the cross sectional view of the first embodiment in FIG. 3 a where the radial row is moved to a position below the first and second axial row 9 , 10 .
[0055] The radial row 17 , 18 of bearing elements is protected from the outside by sealing means 13 which closes the opening between the inner and outer ring 7 , 8 at the surface of the hub blade side.
[0056] The radial row 17 , 18 of bearing elements will be accessible from inside the hub when the sealing means 13 is removed.
[0057] Further, the radial row of bearing elements 17 , 18 is pre stressed or pre loaded by at least one of the raceways 18 being put in by flexible bearing means 28 e.g. spring means such as a helical spring. The flexible bearing means 28 creates flexibility at the radial row in relation to the very inflexible position at the hub side.
[0058] FIG. 4 illustrates an upper part of a second embodiment of a bearing according to the invention wherein the radial row is established with chambered rollers.
[0059] FIG. 5 illustrates an upper part of a third embodiment of a bearing according to the invention.
[0060] The radial row is established with a ball bearing with raceways shaped to guide the balls. A low conformity between the balls and the raceways may be preferred in order to allow axial movement within the radial ball bearing. The lower conformity may be obtained by oval shaped raceways or larger diameter on the relevant parts of the raceways in relation to the ball diameter.
[0061] Spring holding means 29 is positioned in a notch of the outer ring in order to retain the ball bearing in place during normal use. The notch is positioned in between the sealing means 12 and the ball bearing.
[0062] The spring holding means 29 may also be positioned in a notch of the inner ring or in notches of both the outer and inner ring.
[0063] The sealing means 12 are illustrated as having the width as the ball bearing including the raceways. Hereby it is possible to lift out the ball bearing as a whole after the spring holding means 29 have been removed.
[0064] FIG. 6 illustrates an upper part of a fourth embodiment of a bearing according to the invention.
[0065] The radial row is established with a plain bush bearing (glide bearing). The bush may be made in plastic or metal such as PTFE, POM, PA and steel. Further, the bush may be made in a combination of metal and plastic materials.
[0066] FIG. 7 illustrates an upper part of a fifth embodiment of a bearing according to the invention.
[0067] The radial row of bearing elements 17 , 18 may be pre stressed or pre loaded by at least one of the raceways 18 being forced by flexible bearing means 28 e.g. one or more spring means such as a helical spring.
[0068] FIG. 8 illustrates an embodiment of a bearing according to the invention. The bearing is made with a first and second separate part forced against each other by the blade and hub bolts.
[0069] The radial row of the bearing is illustrated in a separate part 22 of the bearing containing cylindrical roller, cambered roller or ball as rolling element or a plane bush bearing between an inner and outer ring. The lower part 23 of the bearing comprises the first and second axial row between another inner and outer ring.
[0070] FIG. 9 illustrates an embodiment of a bearing according to the invention with rows of fixed bearing elements in the form of ribs extending from the inner and outer ring.
[0071] Especially in blade applications it may be possible to use the ribs that guide the axial rows of rollers to provide the radial location and support function within the bearing.
[0072] To assist the good functioning of the rib-locating design, the design may include the following features:
i) tighter length tolerances on rollers ii) a modified end form on rollers iii) a small lean-back angle on the ribs
[0076] Such a design would allow the bearing to be made more compact and with lower cost and of lower weight.
[0077] FIG. 10 illustrates an embodiment of a bearing with rows of flexible bearing elements.
[0078] The figure illustrates the one or more radial rows as separate sliding bearing means 26 , 27 positioned on the inner and outer ring. The radial rows 24 - 27 may preferably be made in metal such as steel, brass or plastic such as POM or PA.
[0079] It shall be emphasized that any combination of the aspects in the above mentioned embodiments may be used in designing the bearing of the present invention.
[0080] Even further, the bearing may be designed in a multitude of varieties within the scope of the invention as specified in the claims.
REFERENCE LIST
[0081] In the drawings the following reference numbers refer to:
1 . Wind turbine 2 . Wind turbine tower 3 . Wind turbine nacelle 4 . Wind turbine rotor hub 5 . Wind turbine rotor blade 6 . Wind turbine foundation 7 . Outer bearing ring 8 . Inner bearing ring 9 . First axial row of rolling bearing elements for axial loads 10 . Second axial row of rolling bearing elements for axial loads 11 . Row of rolling bearing elements for radial loads 12 . First sealing means 13 . Second sealing means 14 . Bearing for a wind turbine application 15 . First through-going hole for a blade bolt 16 . Second through-going hole for a hub bolt 17 . Radial row of rolling bearing elements for radial loads 18 . Raceways for the radial row of rolling bearing elements 19 . Shielding means between radial and axial rows of rolling bearing elements 20 . First outer ring section of the bearing 21 . Second outer ring section of the bearing 22 . Upper bearing section 23 . Lower bearing section 24 . First row of fixed bearing elements 25 . Second row of fixed bearing elements 26 . First row of separate sliding bearing elements 27 . Second row of separate sliding bearing elements 28 . Flexible bearing means such as a spring 29 . Spring holding ring | The invention relates to a pitch bearing for a wind turbine comprising a first and second axial row of bearing rolling elements, said rows being positioned in a distance of each other, and one or more radial rows of bearing elements, where said one or more rows of bearing elements are positioned outside an area defined in between said first and second axial row. The invention also relates to a wind turbine and method for servicing a bearing hereof. | 5 |
RELATED APPLICATION
[0001] This application is a continuation-in-part of U.S. Ser. No. 10/515,264, filed Nov. 22, 2004 which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to a method for mass production of silk protein and gene recombinant silk-like protein with added functionality, and in particular, a method of mass producing gene recombinant silk-like protein with imparted cellular adhesiveness, elasticity or hardness.
BACKGROUND ART
[0003] Silk is a high strength, high elasticity fiber, and since it has aminoacids contained in living organisms as its structural unit, it is biocompatible and is used in various fields such as clothing, food and cosmetics.
[0004] A detailed structural analysis of silk has been made in order to explore the origin of these outstanding physical properties. The primary structure of silk is a block copolymer in which some kinds of regular aminoacid sequences (motifs) are repeated about ten times. Recently, now that the secondary structure of these motifs has been clarified, more information is coming to light regarding the correlation between the structure of silk fiber and its physical properties.
[0005] In recent years, research has been carried out on artificially synthesizing silk-like protein from synthetic DNA which codes for silk protein. Since silk protein has a repetitive structure of identical aminoacid sequences, the number of times a specific aminoacid appears, increases. Therefore, if some types of aminoacyl-tRNAs are depleted, there may be an error at the conclusion of protein synthesis. Moreover, since repetition of DNA sequences may lead to sequence recombination within E. coli , it was still difficult to obtain silk-like protein having a repetition sequence in large amounts by using E. coli.
[0006] In order to increase the expression efficiency, a vector which combines a powerful T7 promoter with an expression vector came into wide use, but there was the disadvantage that if the target protein was too stressful for E. coli on account of its powerful action, this protein affected the growth of the bacteria and the expression efficiency did not increase.
[0007] The Inventor therefore arbitrarily selected domesticated silkworm silk fibroin, wild silkworm silk fibroin, elastin and the functional motif of fibronectin to design four functional silk-like proteins. It was then found that, in the case of functional silk-like proteins with these four repetition sequences, by optimizing selection of expression vectors, host E. coli and expression conditions, it was possible to mass produce the functional silk-like proteins by using E. coli , and it was possible to apply this procedure also to common silk protein, which led to the present invention.
[0008] It is therefore an object of this invention to provide a procedure for mass production of silk protein and silk-like protein with functional properties.
SUMMARY OF THE INVENTION
[0009] According to this invention, a silk-like protein is produced by selecting one of domesticated silkworm silk fibroin, wild silkworm silk fibroin, elastin and fibronectin to design a silk-like polymer comprising a combination of two or more proteins requiring one of domesticated silkworm silk fibroin or wild silkworm silk fibroin, synthesizing the designed minimum unit of the polymer, and integrating the polymer having this synthesized minimum unit into at least one expression vector selected from expression vectors including T7 promoter. Subsequently, this expression vector was integrated into one of the E. coli BL21(DE3) pLysS and BLR(DE3) pLysS, and the E. coli was grown using a culture medium selected from composite culture media.
[0010] According to this invention, it is preferred to lower the temperature to 2-7° C. below the optimum growth temperature of E. coli , and in particular it is preferred to use an expression vector which contains a T71ac promoter as the expression vector which contains the T7 promoter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is the result of SDS-PAGE (sodium-dodecyl-sulfate-polyacrylamide gel electrophoresis) when SLP 2, 4, 6 are expressed in the E. coli strain BL21 (DE3) pLysS.
[0012] FIG. 2 is the result of detection by Western blot using His-Tag antibody, after separating SLPA4 by SDS-PAGE.
[0013] FIG. 3 is the result of detection by Western blot using His-Tag antibody, after separating SELP8 by SDS-PAGE.
[0014] FIG. 4 is the result of detection by Western blot using His-Tag antibody, after separating SLPF5 by SDS-PAGE.
DETAILED DESCRIPTION OF THE INVENTION
[0015] In this invention, domesticated silkworm silk fibroin means the protein secreted from the posterior silk gland of a domesticated silkworm ( Bombyx mori ), and wild silkworm silk fibroin means the protein secreted from the posterior silk gland of a wild silkworm.
[0016] These are described in the annals of the Silk Yarn Dictionary, Japanese Society of Sericultural Science (1979).
[0017] Elastin is a protein which is responsible for elasticity in the tissues of various organisms. In the primary structure of this elastin, there are regions where multiple sequences of 5 aminoacid residues, Val-Pro-Gly-Val-Gly (SEQ ID NO: 1), occur with high frequency (e.g., for chick elastin, Bressan, G. M., Argos, P. and Stanley, K. K., Repeating structure of chick tropoelastin revealed by complementary DNA cloning, Biochemistry 26, 1497-1503 (1987), and for bovine elastin, Raju, K and Anwar, R. A. Primary structures of bovine elastin a, b and c deduced from the sequences of cDNA clones, J. Biol. Chem. 262, 5755-5762 (1987)). Therefore, the functional motif of the elastin in this invention means the aminoacid sequence of the above-mentioned 5 residues.
[0018] Fibronectin is a protein having cellular adhesiveness which exists in the extra-cellular matrix of various organisms, and this cellular adhesiveness is related to an aminoacid sequence of 4 residues, i.e., Arg-Gly-Asp-Ser (SEQ ID NO: 2) contained therein (Reference: Pierschbacher MD, Rouslahti E, Nature 30930-33 (1984)). The aminoacid sequence of the 4 residues Arg-Gly-Asp-Ser (SEQ ID NO: 2) contained in fibronectin is the functional motif of fibronectin. Hence, in this invention, to support the secondary structure required for Arg-Gly-Asp-Ser (SEQ ID NO: 2) to express cellular adhesiveness, Thr-Gly-Arg-Gly-Asp-Ser-Pro-Ala (SEQ ID NO: 3) was used as the functional motif. Therefore, although this sequence of 8 residues is not limiting, the aforesaid extra part of the sequence was adopted as the aminoacid sequence surrounding the Arg-Gly-Asp-Ser (SEQ ID NO: 2) sequence in human fibronectin due to considerations of biocompatibility in case it is used as artificial skin.
[0019] According to this invention, the protein is designed based on the view, proposed by Lewis et al, that the physical properties and functionality of silk vary depending on the types of motif contained in silk protein, and their combinations. In this invention, the motifs contained in natural silk fibers, and the motif sequences considered to express functions specific to elastin and fibronectin (i.e., heat response (condensation when temperature is increased which stops dissolution in water), and cellular adhesiveness)), can be combined in various ways.
[0020] Specifically, to design a protein with novel physical properties and functionality not present in natural fibers, SLP (silk-like protein), SLPA (silk-like protein with polyalanine), SELP (silk and elastin-like protein), and SLPF (silk-like protein with fibronectin), were designed by variously rearranging the motifs in natural silk fiber, as follows.
[0000] SLP (Silk-Like Protein):
[0021] Combination of the aminoacid sequence in domesticated silkworm silk (GlyAlaGlySerGlyAla) 3 (SEQ ID NO: 4) and the aminoacid sequence GlyGlyAlaGlySerGlyTyrGlyGlyGlyTyrGlyHisGlyTyrGly SerAspGlyGly (SEQ ID NO: 5) of the glycine-rich region in wild silkworm silk.
[0022] SLPA (Silk-like Protein with Polyalanine): Combination of the aminoacid sequences GlyValGlyAlaGlyTyr (SEQ ID NO: 6), GlyAlaGlyAlaGlyTyr (SEQ ID NO: 7), GlyValGlyAlaGlyTyr (SEQ ID NO: 6) and GlyAlaGlyValGlyTyr (SEQ ID NO: 8) in domesticated silkworm silk, and the aminoacid sequence (A) 18 (SEQ ID NO: 9) similar to the polyalanine region in wild silkworm silk.
[0000] SELP (Silk and Elastin-Like Protein):
[0023] Combination of the aminoacid sequence (GlyAlaGlySerGlyAla) 3 (SEQ ID NO: 4) in domesticated silkworm silk, and the amino acid sequence (GlyValProGlyVal) 2 (SEQ ID NO: 10) in elastin.
[0024] SLPF: (Silk-like Protein with Fibronectine) Combination of the aminoacid sequence (GlyAlaGlySerGlyAla) 3 (SEQ ID NO: 4) in domesticated silkworm silk and the aminoacid sequence ThrGlyArgGlyAspSerProAla (SEQ ID NO: 11) in fibronectin.
[0025] The fibers must contain a crystalline region and an amorphous region, and when a new silk-like protein is designed, the motifs must be combined so that these regions are formed simultaneously. For example, in SLP and SLPA, in domesticated silkworm silk and silk from the Eri silkworm, which is a kind of wild silkworm, motifs which form crystalline regions or amorphous regions are respectively combined. In the case of SELP and SLPF, in addition to thermal stability and biodegradability, still more functions can be imparted by combining the functional motifs of elastin and fibronectin with silk protein for use not only as a fiber but also as a biopolymer.
[0026] In this invention, pET30a which contains T7 promoter as an expression vector, and the expression inductor BL21 (DE3)pLysS or BLR (DE3)pLysS as the host E. coli used for expression, are selected. Due to these combinations, as T7 RNA polymerase is not expressed until IPTG (isopropyl thio-β-D-galactoside) is added as an expression inductor, the target protein downstream of the T7 promoter is not expressed, therefore the stress on E. coli due to overexpression is reduced. Further, since Plasmid pLysS expresses T7 lysozyme and inactivates T7 RNA polymerase, a two-step inhibition can be expected. In this invention, it is preferred to select an expression vector from expression vectors including T7lac promoter, and it is particularly preferred to use pET30a.
[0027] After expression induction, the stress on E. coli is reduced using a culture medium selected from composite culture media by optimizing growth conditions, such as culture temperature, IPTG addition concentration and pH. In this invention, by deliberately removing the growth conditions which are optimal for the growth of E. coli , the expression of the target protein can be smoothly promoted, long-term growth is possible and the yield of target protein can be increased. Therefore, in this invention, it is preferred to set the culture temperature 2-7° C. lower than the optimum growth temperature of E. coli.
[0028] It is particularly preferred that the culture medium used in this invention is TB culture medium. The IPTG addition concentration is preferably 0.2-11.0 mM. The pH is preferably 6.7-7.0.
EXAMPLES
[0029] Hereafter, this invention will be described by means of specific examples, although the invention is not to be construed as being limited in any way thereby. In addition, unless otherwise stated, “%” means “weight %” and ratio means weight ratio. The meanings of the symbols in the text are as given below.
Example 1
[0000] <Construction of SLP Gene>
[0030] The four oligonucleotides shown in the SEQ ID NOS: 12-15 of Asahi TechnoGlass, were designed.
[0031] The synthesized film-like oligonucleotides were dissolved so that their concentration was 1 μg/μl using TrisEDTA (10 mM Tris-HCl (pH 8.0), 1 mM EDTA (pH 8.0): hereafter, TE). Two double-stranded DNAs which code for the aminoacids expressed in the SEQ ID NOS: 16 and 17 were constructed by equimolar mixing of complementary strands, heat-treating at 99° C. for 30 seconds, cooling at 37° C. for 1 hour, and settling for 30 minutes. After mixing equivalent amounts of the double-stranded DNAs, ligation was performed at 16° C. for 1 hour using Takara Ligation Kit ver2 solution I (product of TAKARA SHUZO CO., LTD.) so as to prepare double-stranded DNA which codes for the SLP monomer (SLP monomer sequence; ThrSer[GlyGlyAlaGlySerGlyTyrGlyGlyGlyTyrGlyHisGly TyrGlySerAspGlyGly(GlyAlaGlyAlaGlySer) 3 AlaSer] n (n=2, 4, 6) (see SEQ ID NO: 18 (for n=2)).
[0032] The cloning vector pUC118 (product of TAKARA SHUZO CO., LTD.) was digested at 37° C. for 1 hour 30 minutes using the restriction enzyme BamHI, CIAP (Calf Intestine Alkaline Phosphatase) (product of TAKARA SHUZO CO., LTD.) was added, and treatment was performed at 37° C. for 30 minutes (hereafter, “alkaline phosphatase treatment”). The reaction solution was extracted and purified with a mixture of phenol:chloroform:isoamyl alcohol in a ratio of 25:24:1 (weight ratio). Ethanol was added to the purified reaction solution, and the resulting precipitate was used as the vector sample.
[0033] The monomer DNA of SLP and a pUC118 vector sample were mixed in a ratio of 10:1 (weight ratio), and ligation was performed at 16° C. for 1 hour using Takara Ligation Kit ver2 solution I. After completion of the reaction, transformation was performed using competent cell DH5α. The presence or absence of an insert gene was verified by color selection using X-gal (5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside), DNA sequencing was performed on material containing the insert gene, and plasmid PUC-SLP (1) containing the monomer DNA of SLP was obtained by verifying the sequence.
[0000] <Construction of PUC-Link>
[0034] The cloning vector pUC118 used for this study does not include the regions digested with the restriction enzymes Nhe I and Spe I. Therefore, an adapter was designed for the purpose of adding the recognition regions of the restriction enzymes Nhe I and Spe I to pUC118 (SEQ ID NO: 19), and a pUC118-Link (plasmid containing the designed adapter) was constructed. Codons which code methionine residues other than the recognition regions of the restriction enzymes Nhe I and Spe I were arranged on both sides in the adapter. Methionine residues were thereby added on both sides of the insert gene of the expressed protein obtained, and a sample which did not include a sequence of plasmid origin was obtained by specifically cleaving the methionine residues using cyanogen bromide.
[0035] The synthesized film-like oligonucleotides were dissolved so that their concentration was 1 μg/μl using TE (10 mM Tris-HCl (pH 8.0), 1 mM EDTA (pH 8.0)). Double-stranded DNA which codes for the aminoacids expressed in the SEQ ID NOS: 16 and 17 was constructed by equimolar mixing of complementary strands, heat-treating at 99° C. for 30 seconds, cooling at 37° C. over 1 hour, and settling for 30 minutes. After mixing equivalent amounts of the respective double stranded DNAs, the cloning vector pUC118 (product of TAKARA SHUZO CO., LTD.) was digested at 37° C. for 1 hour 30 minutes using the restriction enzyme Xba I, CIAP was added, and treatment was performed at 37° C. for 30 minutes. The reaction solution was extracted and purified using phenol:chloroform:isoamyl alcohol in a ratio of 25:24:1 (weight ratio). Ethanol was added to the purified reaction liquid, and the precipitate produced was dissolved in sterilized water for use as the vector sample.
[0036] The pUC118 vector sample was mixed with Adapter DNA in a ratio of 10:1 (weight ratio), and ligation was performed at 16° C. for 1 hour using Takara Ligation Kit ver2 Solution I. After the reaction was complete, transformation was performed using competent cell DH5α. Plasmid pUC-Link containing the adapter was obtained by verifying the presence or absence of the insert gene, performing DNA sequencing on the material containing the insert gene, and verifying the sequence by color selection using X-gal.
[0000] <Construction of SLP(n)>
[0037] The restriction enzyme recognition regions of Spe I and Nhe I are included at both ends of the SLP monomer. The projecting ends of the fragments digested with restriction enzymes Spe I and Nhe I are all complementary and can be mutually combined. The newly combined sequences are all different from the restriction enzyme recognition regions of Spe I and Nhe I, and are not digested by Spe I and Nhe I. Using this property, plasmid pUC-Link SLP (n) containing DNA which polymerizes SLP monomer in one sense and codes SLP n times, was constructed.
[0038] Competent cell DH5α was transformed by PUC-SLP (1), and cultured in 2xYT culture medium at 37° C. for 18 hours. The plasmid was extracted from the liquid culture medium by the alkali-SDS method, and dissolved in TE. The sample was simultaneously digested by Nhe I and Spe I (both products of TAKARA SHUZO CO., LTD.) at 37° C. for 1 hour 30 minutes, and SLP (1) was isolated from the plasmid. After concentrating the reaction liquid to 5 μl using MicroCon (product of Millipore CO., LTD.), electrophoresis was performed using a 1.5% agarose gel, and the band of insert DNA was cut out. To extract DNA from the gel, the extract was again concentrated to 5 μl using Ultrafree DA (product of Millipore CO., LTD.), and this was used as the insert genetic material.
[0039] After digesting pUC-Link by Nhe I, CIAP was added and alkaline phosphatase treatment was carried out. The reaction solution was extracted and purified using a mixture of phenol:chloroform:isoamyl alcohol (weight ratio 25:24:1). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and this was used as the vector sample.
[0040] The DNA concentrations in the insert genetic material and vector sample were verified by electrophoresis using 1.5% agarose gel, the insert genetic material and vector sample were mixed in a ratio of 10:1, an equivalent amount of Takara Ligation Kit ver2 Solution I to the reaction mixture was added, and ligation was performed at 16° C. for 1 hour.
[0041] After the reaction was complete, transformation of competent cell DH5α was performed. It was then inoculated on a LB plate with added ampicillin, and screened. The colony produced was picked up, inoculated on 2xYT culture medium and grown at 37° C. for 18 hours. From the culture medium, the plasmid was extracted by the alkali-SDS miniprep method, dissolved in TE and used as a sample. After digesting the sample simultaneously using Nhe I and Spe I, the presence or absence and size of the insert gene were verified by the electrophoresis method. Then, DNA sequencing was performed and plasmid pUC-LinkSLP (1) was obtained by verifying the sequence.
[0042] After digesting pUC-Link SLP (1) by Nhe I, CIAP was added and alkaline phosphatase solution treatment was carried out. The reaction solution was extracted and purified using a mixture of phenol:chloroform:isoamyl alcohol (weight ratio 25:24:1), ethanol was added to the purified reaction solution, the precipitate obtained was dissolved in sterilized water, and this was used as the vector sample.
[0043] The DNA concentration in the insert genetic material and vector sample was verified by electrophoresis using 1.5% agarose gel, the insert genetic material and vector sample were mixed in a ratio of 10:1, an equivalent amount of Takara Ligation Kit ver2 Solution I to the reaction mixture was added, and ligation was performed at 16° C. for 1 hour.
[0044] After the reaction was complete, transformation of competent cell DH5α was performed. It was then inoculated on a LB plate with added ampicillin, and screened. The colony produced was picked up, inoculated on 2xYT culture medium and grown at 37° C. for 18 hours. From the culture medium, the plasmid was extracted by the alkali-SDS miniprep method, dissolved in TE and used as a sample. After digesting the sample simultaneously using Nhe I and Spe I, the presence or absence and size of the insert gene were verified by electrophoresis. Then, DNA sequencing was performed and plasmid pUC-Link SLP (2) (dimer) was obtained by verifying the sequence.
[0045] SLP (2) was inserted in pUC-Link SLP (2) to give pUC-Link SLP (4) (tetramer), then SLP (2) was inserted in pUC-Link SLP (4) to give pUC-Link SLP (6) (hexamer).
[0000] <Construction of Expression Vector pET-SLP (N)>
[0046] pUC-Link SLP (2, 4, 6) obtained as mentioned above was digested using the restriction enzymes BamHI and Hind III (both products of TAKARA SHUZO CO., LTD.). After concentrating the reaction liquid to 5 μl using MicroCon (product of Millipore CO., LTD.), electrophoresis was performed using a 1.5% agarose gel, and the band of insert DNA was cut out. To extract DNA from the gel, the extract was concentrated to 5 μl using Ultrafree DA and then MicroCon, and this was used as the insert genetic material.
[0047] After digesting the expression vector pET30a (product of Novagen CO., LTD.) by Nhe I, CIAP was added and alkaline phosphatase treatment was carried out. The reaction solution was extracted and purified using a mixture of phenol:chloroform:isoamyl alcohol (weight ratio 25:24:1). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and this was used as the vector sample.
[0048] The DNA concentrations in the insert genetic material and vector sample were verified by electrophoresis using 1.5% agarose gel, the insert genetic material and vector sample were mixed in a ratio of 10:1, an equivalent amount of Takara Ligation Kit ver2 Solution I to the reaction mixture was added, and ligation was performed at 16° C. for 1 hour.
[0049] After the reaction was complete, transformation of competent cell DH5α was performed. It was then inoculated on a LB plate with added kanamycin, and screened. The colony produced was picked up, inoculated on 2xYT culture medium and grown. From the culture medium, the vector was extracted by the alkali-SDS method, dissolved in TE and used as a sample. After digesting the sample simultaneously using Nhe I and Spe I, the presence or absence and size of the insert gene were verified by the electrophoresis method. Then, DNA sequencing was performed and the expression vector pET-SLP (2, 4, 6) was obtained by verifying the sequence.
[0000] <Expression of pET-SLP (2, 4, 6)>
[0050] Host E. coli BL21(DE3) pLysS (product of Novagen CO., LTD.) containing each of the aforesaid plasmids pET-SLP (2, 4, 6) obtained as mentioned above was grown at 37° C. for 16 hours in 1 ml of 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol) liquid culture medium. Next, 100 μl of the culture medium was added to a L-shaped tube containing 5 ml of 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol), and cultured at 37° C. for 1 hour (OD 600 =0.5−0.7 (Shimadzu UV 160)). In this case, to induce the expression of SLP, IPTG (final concentration 1 mM) was added, 100 μl of culture medium was sampled in an Eppendorf tube every other hour, and cultured for 3 hours. After performing centrifugal separation (14500 rpm, 5 minutes, 4° C.) of the sampled culture medium, the supernatant liquid was discarded, pellets were dissolved in 2× sample buffer (buffer solution for sample dissolution), and heat-treated at 100° C. for 5 minutes to give a SDS-PAGE sample. As shown in FIG. 1 , unique bands depending on IPTG were respectively observed at 19 kDa for SLP 2, 29 kDa for SLP 4 and 40 kDa for SLP 6. From this, it was confirmed that SLP genes were induced by IPTG addition, and mass-expressed strains could be obtained.
[0051] Next, host E. coli BL21(DE3) pLysS respectively containing the plasmids PET-SLP (2, 4, 6) was grown at 37° C. for 16 hours in 2.5 ml 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol) liquid culture medium. Next, this culture medium was added to a 500 ml flask containing 250 ml 2xTY(s) (25 μg/ml kanamycin, 25μ/ml chloramphenicol), and the culture medium was cultured at 37° C. for 1 hour (OD 600 =0.5−0.7 (Shimadzu UV-160)). In this case, to induce proteinic expression, IPTG (final concentration 1 mM) was added, and a bacteria was obtained by growing for a further 2 hours and collecting (5000 rpm, 10 minutes, 4° C.). The obtained bacteria was stored at −30° C.
[0052] This bacteria stored at −30° C. was slowly thawed on ice, suspended in Lysis buffer (buffer solution for protein dissolution) (50 mM Tris-HCl, 300 mM NaCl, 10 mM imidazole), and ultrasonic crushing (Output 3.5, Duty 60% (TOMY UD201)) was performed on ice 4 times, 1 minute at a time, with a cooling time of 1 minute. Centrifugal separation (10,000 rpm, 10 minutes, 4° C.) of the bacterial crushed solution was performed, and the supernatant liquid was collected.
[0053] The obtained supernatant liquid was used as an addition sample, and purified by affinity chromatography (flow velocity 15-20 ml/hour) using a column filled with nickel-NTA agarose beads equilibrated beforehand using the same buffer solution. The eluates were fractionated, and the fractions containing the target protein were verified and recovered by SDS-PAGE.
[0054] After dialyzing the obtained fractions while exchanging with distilled water as the outside liquid as required for 24 to 48 hours, a white powder was obtained by freeze-drying. The yields of each protein of molecular weight 19 kDa, 29 kDa, 40 kDa are shown in Table 1.
TABLE 1 Sample Yield (mg) Yield (%) SLP 6 21 52.5 SLP 4 24 60.0 SLP 2 15 50.0
<Identification of SLP>
[0055] For each protein, the aminoacid sequences of the N-terminal residues were determined by the N-terminal aminoacid sequences. The protein was dissociated from the surrounding proteins by the electrophoresis method using polyacrylamide gel, and transferred to a PVDF (polyvinylidene fluoride) film using SART BLOT 2-S (product of SARTORIUS CO., LTD.). After transfer, and staining with staining solution for 5 minutes, the target protein was cut out using scissors which had been bleached and rinsed with methanol. Using this sample, the N-terminal aminoacid sequence was determined using an ABI 473 gaseous-phase Edman sequencer. The result coincided with the expected aminoacid sequence, and it was confirmed that the expressed protein is a protein of plasmid origin.
[0000] <Cleavage of Tag Sequence by Cyanogen Bromide>
[0056] In the designed SLP 2, 4, 6, methionine residues are arranged on both sides of the insert gene by an adapter. Since SLP 2, 4, 6 do not themselves contain methionine residues, a protein which does not include an aminoacid sequence of plasmid origin, such as a tag, can be obtained by chemically cleaving amethionine residue. Proteinic methionine residues were cleaved, and the aminoacid sequences of the N terminal residues were determined by the N-terminal aminoacid sequence.
[0057] 10 mg of SLP6 was taken in an Eppendorf tube, and dissolved in 90% formic acid. After confirming that it had dissolved completely, it was diluted with milli Q water (ultrapure water) until the final concentration of formic acid was 70%. After adding 10 mg cyanogen bromide to the sample solution and dissolving, it was shaded completely with aluminum foil and left at room temperature for 12 to 48 hours. After adding 10 times the amount of milli Q water to the reaction solution and stopping the reaction, it was dialyzed with distilled water as the outside liquid, and a white powder was then obtained by freeze-drying. When the obtained white powder was dissolved in 2× sample buffer and the molecular weight was compared by SDS-PAGE, a reduction in molecular weight was found as compared with the sample before cyanogen bromide treatment.
[0058] The SLP 6 purified in this way was isolated from impure proteins by the electrophoresis method using polyacrylamide gel, and transferred to a PVDF film using SART BLOT 2-S (SARTORIUS). After transfer, and staining with staining solution for 5 minutes, the target protein was cut out using scissors which had been bleached and rinsed with methanol. Using this sample, the N-terminal aminoacid sequence was determined using an ABI 473 gaseous-phase Edman sequencer. The determined N-terminal aminoacid sequence coincided with the expected aminoacid sequence, and was confirmed to be the target protein SLP 6.
Example 2
[0000] <Construction of SLPA Gene>
[0059] The four oligonucleotides shown in the SEQ ID NOS: 20-23 synthesized by Asahi TechnoGlass CO., LTD., were designed.
[0060] The synthesized film-like oligonucleotides were dissolved so that their concentration was 1 μg/μl using TE (10 mM Tris-HCl (pH 8.0), 1 mM EDTA (pH 8.0): hereafter, TE). Two double-stranded DNAs which code for the aminoacids expressed in the SEQ ID NOS: 24 and 25 were constructed by equimolar mixing of complementary strands, heat-treating at 99° C. for 30 seconds, cooling at 37° C. for 1 hour, and settling for 30 minutes.
[0061] The cloning vector pUC118 (product of TAKARA SHUZO CO., LTD.) was digested at 37° C. for 1 hour 30 minutes using the restriction enzyme BamHI, CIAP (Calf Intestine Alkaline Phosphatase) (product of TAKARA SHUZO CO., LTD.) was added, and treatment was performed at 37° C. for 30 minutes (hereafter, “alkaline phosphatase treatment”). The reaction solution was extracted and purified with a mixture of phenol:chloroform:isoamyl alcohol in a ratio of 25:24:1 (weight ratio). Ethanol was added to the purified reaction solution, and the resulting precipitate was used as the vector sample.
[0062] The double-stranded DNA and pUC118 vector sample were mixed in a ratio of 10:1 (weight ratio), and ligation was performed at 16° C. for 1 hour using Takara Ligation Kit ver2 solution I to prepare double-stranded DNA which codes for the aminoacid sequences in SEQ ID NOS: 24 and 25. After completion of the reaction, transformation was performed using competent cell DH5 α. The presence or absence of an insert gene was verified by color selection using X-gal, DNA sequencing was performed on material containing the insert gene, and plasmid pUC-ALA containing the DNA sequence coding the polyalanine (SEQ ID NO: 24) with plasmid pUC-GX containing the DNA sequence coding the alternating copolymer of glycine (X=Ala, Tyr, Val) (SEQ ID NO: 25), were obtained by verifying the sequences.
[0063] pUC-ALA was transformed using competent cell DH5α, and cultured in 2xYT culture medium at 37° C. for 18 hours. The plasmid was extracted from the culture medium by the alkali-SDS method, and dissolved in TE. The sample was simultaneously digested by Nhe I and Spe I at 37° C. for 1 hour 30 minutes, and ALA was isolated from the plasmid. After concentrating the reaction liquid to 5 μl using MicroCon (product of Millipore CO., LTD.), electrophoresis was performed using a 1.5% agarose gel, and the band of insert DNA was cut out. To extract DNA from the gel, the extract was concentrated to 5 μl using Ultrafree DA and then MicroCon, and this was used as the insert genetic material.
[0064] After digesting pUC-GX by Spe I, CIAP was added and alkaline phosphatase treatment was carried out. The reaction solution was extracted and purified using a mixture of phenol:chloroform:isoamyl alcohol (weight ratio 25:24:1). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and this was used as the vector sample.
[0065] The DNA concentrations in the insert genetic material and vector sample were verified by electrophoresis using 1.5% agarose gel, the insert genetic material and vector sample were mixed in a ratio of 10:1, an equivalent amount of Takara Ligation Kit ver2 Solution I to the reaction mixture was added, and ligation was performed at 16° C. for 1 hour.
[0066] After the reaction was complete, transformation of competent cell DH5α was performed. It was then inoculated on a LB plate with added ampicillin, and screened. The colony produced was picked up, inoculated on 2xYT culture medium and grown at 37° C. for 18 hours. From the culture medium, the plasmid was extracted by the alkali-SDS miniprep method, dissolved in TE and used as a sample. After digesting the sample simultaneously using Nhe I and Spe I, the presence or absence and size of the insert gene were verified by the electrophoresis method. Then, DNA sequencing was performed and plasmid pUC-SLPA (1) was obtained by verifying the sequence (aminoacid sequence of SLPA: AlaSer [(Ala) 18 ThrSerGlyValGlyAlaGlyTyrGlyAlaGlyAlaGlyTyrGlyV alGlyAlaGlyTyrGlyAlaGlyValGlyTyrGlyAlaGlyAlaGlyTyrThrSer] n , SEQ ID NO: 26 (for n=4)).
[0000] <Construction of SLPA(n)>
[0067] Competent cell DH5α was transformed by pUC-SLPA (1), and cultured in 2xYT culture medium at 37° C. for 18 hours. The plasmid was extracted from the culture medium by the alkali-SDS method, and dissolved in TE. The sample was simultaneously digested by Nhe I and Spe I at 37° C. for 1 hour 30 minutes, and SLPA (1) was isolated from the plasmid. After concentrating the reaction liquid to 5 μl using MicroCon, electrophoresis was performed using 1.5% agarose gel, and the band of insert DNA was cut out. To extract DNA from the gel, the extract was concentrated to 5 μl using UltrafreeDA and then MicroCon, and this was used as the insert genetic material.
[0068] After digesting pUC-SLPA (1) by Nhe I, CIAP was added and alkaline phosphatase treatment was carried out. The reaction solution was extracted and purified using a mixture of phenol:chloroform:isoamyl alcohol (weight ratio 25:24:1). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and this was used as the vector sample.
[0069] The DNA concentrations in the insert genetic material and vector sample were verified by electrophoresis using 1.5% agarose gel, the insert genetic material and vector sample were mixed in a ratio of 10:1, an equivalent amount of Takara Ligation Kit ver2 Solution I to the reaction mixture was added, and ligation was performed at 16° C. for 1 hour.
[0070] After the reaction was complete, transformation of competent cell DH5α was performed. It was then inoculated on a LB plate with added ampicillin, and screened. The colony produced was picked up, inoculated on 2xYT culture medium and grown at 37° C. for 18 hours. From the culture medium, the plasmid was extracted by the alkali-SDS miniprep method, dissolved in TE and used as a sample. After digesting the sample simultaneously using Nhe I and Spe I, the presence or absence and size of the insert gene were verified by the electrophoresis method. Then, DNA sequencing was performed and plasmid pUC-SLPA (2) was obtained by verifying the sequence.
[0071] SLP (2) was inserted in pUC-SLPA (2) to give pUC-SLPA (4) (tetramer).
[0000] <Construction of Expression Vector pET-SLPA (4)>
[0072] pUC-SLAP (4) was digested with BamHI. After concentrating the reaction liquid to 5 μl using MicroCon, electrophoresis was performed using 1.5% agarose gel, and the band of insert DNA was cutout. To extract DNA from the gel, the extract was concentrated to 5 μl using UltrafreeDA and then MicroCon, and this was used as the insert genetic material.
[0073] After digesting pET30a by BamHI, CIAP was added and alkaline phosphatase treatment was carried out. The reaction solution was extracted and purified using a mixture of phenol:chloroform:isoamyl alcohol (weight ratio 25:24:1). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and this was used as the vector sample.
[0074] The DNA concentrations in the insert genetic material and vector sample were verified by electrophoresis using 1.5% agarose gel, the insert genetic material and vector sample were mixed in a ratio of 10:1, an equivalent amount of Takara Ligation Kit ver2 Solution I to the reaction mixture was added, and ligation was performed at 16° C. for 1 hour.
[0075] After the reaction was complete, transformation of competent cell DH5α was performed. It was then inoculated on a LB plate with added kanamycin, and screened. The colony produced was picked up, inoculated on 2xYT culture medium and grown at 37° C. for 18 hours. From the culture medium, the plasmid was extracted by the alkali-SDS miniprep method, dissolved in TE and used as a sample. After digesting the sample simultaneously using Nhe I and Spe I, the presence or absence and size of the insert gene were verified by the electrophoresis method. Then, DNA sequencing was performed and the expression vector PET-SLPA (4) was obtained by verifying the sequence.
[0000] <Expression of pET-SLPA (4)>
[0076] Host E. coli BL21 (DE3) pLysS containing each of the aforesaid plasmids pET-SLPA (4) was grown at 37° C. for 16 hours in 1.5 ml of 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol) liquid culture medium. Next, 100 μl of the culture medium was added to a test tube containing 5 ml of 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol), and cultured at 37° C. for 1 hour (OD600=0.5−0.7 (Shimadzu UV 160)). In this case, to induce the expression of SLP, IPTG (final concentration 1 mM) was added, 100 μl of culture medium was sampled in an Eppendorf tube every other hour, and cultured for 4 hours. After performing centrifugal separation (14500 rpm, 5 minutes, 4° C.) of the sample culture medium, the supernatant liquid was discarded, pellets were dissolved in 2× sample buffer (buffer solution for sample dissolution), and heat-treated at 100° C. for 5 minutes to give a SDS-PAGE sample.
[0077] After obtaining the SDS-PAGE sample, SPLA 4 was detected by Western Blot using His-Tag ( FIG. 2 ).
[0078] As can be seen from the figure, with SLPA 4, a band was observed at 29 kDa. From this, it was confirmed that SLP genes were induced by IPTG addition, and mass-expressed strains could be obtained.
[0079] Host E. coli BL21 (DE3) pLysS containing the plasmid pET-SLPA (4) was grown at 37° C. for 16 hours in 1.5 ml 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol) liquid culture medium. Next, this culture medium was added to a test tube containing 12 ml 2xTY (s) (25 μg/ml kanamycin, 25μ/ml chloramphenicol), and the culture medium was cultured at 37° C. for 16 hours. Next, it was added to a 21 fermenter containing 1.2 l 2xYT (25 μg/ml kanamycin, 25 μg/ml chloramphenicol) liquid culture medium), and cultured at 37° C. until OD600=0.5−0.7 (Shimadzu UV 160). In this case, IPTG (final concentration 1 mM) was added to induce expression of the protein, and a bacteria was obtained by growing for a further 4 hours and collecting (8500 rpm, 30 minutes, 4° C.). The obtained bacteria was stored at −20° C.
[0080] The aforesaid bacteria stored at −20° C. was slowly thawed on ice, suspended in Lysis buffer (50 mM Tris-HCl, 300 mM NaCl, 10 mM imidazole), and ultrasonic crushing (Output 3.5, Duty 60% (TOMY UD201)) was performed on ice 20 times, 2 minutes at a time, with a cooling time of 1 minute. Centrifugal separation (10,000 rpm, 40 minutes, 4° C.) of the crushed bacterial solution was performed, and a precipitate was recovered.
[0081] Buffer B (100 mM NaH 2 PO 4 , 10 mM Tris-Cl, 8M urea, pH 8.0) was added to the obtained precipitate, and ultrasonic crushing was performed. The crushed bacterial solution obtained here was centrifuged (10,000 rpm, 40 minutes, 4° C.), and the supernatant liquid was recovered.
[0082] The obtained supernatant liquid was used as an addition sample, and purified by affinity chromatography (flow velocity 15-20 ml/hour) using a column filled with Ni-NTA agarose beads equilibrated beforehand using the same buffer solution. The eluates were fractionated, and the fractions containing the target protein were verified and recovered by SDS-PAGE.
[0083] After dialyzing the obtained fractions while exchanging with distilled water as the outside liquid as required for 24 to 48 hours, a white powder was obtained by freeze-drying. The yield was 34.2 mg/L.
Example 3
[0000] <Construction of SELP Gene>
[0084] The four oligonucleotides shown in the SEQ ID NOS: 27-30 synthesized by Asahi TechnoGlass CO., LTD., were designed.
[0085] The synthesized film-like oligonucleotides were dissolved so that their concentration was 1 μg/μl using TE (10 mM Tris-HCl (pH 8.0), 1 mM EDTA (pH 8.0); hereafter, TE). Double-stranded DNAs which code for the aminoacids expressed in the SEQ ID NOS: 31 and 32 were constructed by equimolar mixing of complementary strands, heat-treating at 99° C. for 30 seconds, cooling at 37° C. for 1 hour, and settling for 30 minutes. After mixing equivalent amounts of the respective double-stranded DNAs, ligation was performed at 16° C. for 1 hour using Takara Ligation Kit ver2 Solution I to prepare a typical double-stranded DNA coding for the SELP monomer (aminoacid sequence of SELP: ThrSer[(Gly Val Pro Gly Val) 2 Gly Gly(Gly Ala Gly Ala Gly Ser) 3 Ala Ser] n , SEQ ID NO: 33 (for n=8)).
[0086] The cloning vector pUC118 was digested at 37° C. for 1 hour 30 minutes using the restriction enzyme BamHI, CIAP was added, and treatment was performed at 37° C. for 30 minutes. The reaction solution was extracted and purified with a mixture of phenol:chloroform:isoamyl alcohol in a ratio of 25:24:1 (weight ratio). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and used as the vector sample.
[0087] The SELP monomer DNA and pUC118 vector sample were mixed in a ratio of 10:1 (weight ratio), and ligation was performed at 16° C. for 1 hour using Takara Ligation Kit ver2 solution. After completion of the reaction, transformation was performed using competent cell DH5α. The presence or absence of an insert gene was verified by color selection using X-gal, DNA sequencing was performed on material containing the insert gene, and plasmid pUC-SELP (1) containing the SELP monomer DNA was obtained by verifying the sequence.
[0000] <Construction of SELP(n)>
[0088] Complement cell DH5α was transformed using PUC-SELP (1), and cultured in 2xYT culture medium at 37° C. for 18 hours. The plasmid was extracted from the culture medium by the alkali-SDS method, and dissolved in TE. The sample was simultaneously digested by Nhe I and Spe I at 37° C. for 1 hour 30 minutes, and SLP (1) was isolated from the plasmid. After concentrating the reaction liquid to 5 μl using MicroCon, electrophoresis was performed using 1.5% agarose gel, and the band of insert DNA was cut out. To extract DNA from the gel, the extract was concentrated to 5 μl using UltrafreeDA and then MicroCon, and this was used as the insert genetic material.
[0089] After digesting pUC-Link by Nhe I, CIAP was added and alkaline phosphatase treatment was carried out. The reaction solution was extracted and purified using a mixture of phenol:chloroform:isoamyl alcohol (weight ratio 25:24:1). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and this was used as the vector sample.
[0090] The DNA concentrations in the insert genetic material and vector sample were verified by electrophoresis using 1.5% agarose gel, the insert genetic material and vector sample were mixed in a ratio of 10:1, an equivalent amount of Takara Ligation Kit ver2 Solution I to the reaction mixture was added, and ligation was performed at 16° C. for 1 hour.
[0091] After the reaction was complete, transformation of competent cell DH5α was performed. It was then inoculated on a LB plate with added ampicillin, and screened. The colony produced was picked up, inoculated on 2xYT culture medium and grown at 37° C. for 18 hours. The plasmid was extracted from the culture medium by the alkali-SDS miniprep method, dissolved in TE and used as a sample. After digesting the sample simultaneously using Nhe I and Spe I, the presence or absence and size of the insert gene were verified by the electrophoresis method. Then, DNA sequencing was performed and plasmid pUC-Link SELP (1) was obtained by verifying the sequence.
[0092] Competent cell DH5α was transformed using pUC-SELP (1), and cultured in 2xYT culture medium at 37° C. for 18 hours. The plasmid was extracted from the culture medium by the alkali-SDS method, and dissolved in TE. The sample was simultaneously digested by Nhe I and Spe I at 37° C. for 1 hour 30 minutes, and SELP (1) was isolated from the plasmid. After concentrating the reaction liquid to 5 μl using MicroCon, electrophoresis was performed using 1.5% agarose gel, and the band of insert DNA was cutout. To extract DNA from the gel, the extract was concentrated to 5 μl using UltrafreeDA and then MicroCon, and this was used as the insert genetic material.
[0093] After digesting pUC-Link SELP (1) by Nhe I, CIAP was added and alkaline phosphatase treatment was carried out. The reaction solution was extracted and purified using a mixture of phenol:chloroform:isoamyl alcohol (weight ratio 25:24:1). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and this was used as the vector sample.
[0094] The DNA concentrations in the insert genetic material and vector sample were verified by electrophoresis using 1.5% agarose gel, the insert genetic material and vector sample were mixed in a ratio of 10:1, an equivalent amount of Takara Ligation Kit ver2 Solution I to the reaction mixture was added, and ligation was performed at 16° C. for 1 hour.
[0095] After the reaction was complete, transformation of competent cell DH5α was performed. It was then inoculated on a LB plate with added ampicillin, and screened. The colony produced was picked up, inoculated on 2xYT culture medium and grown at 37° C. for 18 hours. The plasmid was extracted from the culture medium by the alkali-SDS miniprep method, dissolved in TE and used as a sample. After digesting the sample simultaneously using Nhe I and Spe I, the presence or absence and size of the insert gene were verified by the electrophoresis method. Then, DNA sequencing was performed and plasmid pUC-Link SELP (2) was obtained by verifying the sequence.
[0096] SELP (2) was inserted in pUC-Link SELP (2) to construct pUC-Link SELP (4), and SELP (4) was inserted in pUC-Link SELP (4) to construct pUC-Link SELP (8).
[0000] <Construction of Expression Vector pET-SELP(n)>
[0097] PUC-SELP (8) was digested using BamHI and Hind III. After concentrating the reaction liquid to 5 μl using MicroCon, electrophoresis was performed using a 1.5% agarose gel, and the band of insert DNA was cut out. To extract DNA from the gel, the extract was concentrated to 5 μl using UltrafreeDA and then MicroCon, and this was used as the insert genetic material.
[0098] After digesting the expression vector pET30a by BamHI and Hind III, CIAP was added and alkaline phosphatase treatment was carried out. The reaction solution was extracted and purified using a mixture of phenol:chloroform:isoamyl alcohol (weight ratio 25:24:1). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and this was used as the vector sample.
[0099] The DNA concentrations in the insert genetic material and vector sample were verified by electrophoresis using 1.5% agarose gel, the insert genetic material and vector sample were mixed in a ratio of 10:1, an equivalent amount of Takara Ligation Kit ver2 Solution I to the reaction mixture was added, and ligation was performed at 16° C. for 1 hour.
[0100] Transformation of competent cell DH5α was performed using ligation reaction solution. It was then inoculated on a LB plate with added kanamycin, and screened. The colony produced was picked up, inoculated on 2xYT culture medium and grown. From the culture medium, the vector was extracted by the alkali-SDS method, dissolved in TE and used as a sample. After digesting the sample simultaneously using Nhe I and Spe I, the presence or absence and size of the insert gene were verified by the electrophoresis method. Then, DNA sequencing was performed and the expression vector pET-SELP 8 was constructed by verifying the sequence.
[0000] <Expression of pET-SELP (8)>
[0101] Host E. coli BL21(DE3) pLysS containing the respective plasmids pET-SELP (8) obtained as mentioned above was grown at 37° C. for 16 hours in 1.5 ml of 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol) liquid culture medium. Next, 100 μl of the culture medium was added to a test-tube containing 5 ml of 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol), and cultured at 37° C. until OD 600 =0.5−0.7. In this case, to induce the expression of SELP 8, IPTG (final concentration 1 mM) was added, 100 μl of culture medium was sampled in an Eppendorf tube every other hour, and cultured for 4 hours. After performing centrifugal separation (14500 rpm, 5 minutes, 4° C.) of the sampled culture medium, the supernatant liquid was discarded, pellets were dissolved in 2× sample buffer, and heat-treated at 100° C. for 5 minutes to give a SDS-PAGE sample.
[0102] After obtaining the SDS-PAGE sample, SELP 8 was detected by performing Western Blot using His-Tag antibody.
[0103] As shown in the figure, with SELP 8, a band was observed at 35 kDa. From this, it was confirmed that SLP genes were induced by IPTG addition, and mass-expressed strains could be obtained.
[0104] Host E. coli BL21(DE3) pLysS respectively containing the plasmids pET-SELP (8) was grown at 37° C. for 16 hours in 1.5 ml 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol) liquid culture medium. Next, this culture medium was cultured at 37° C. for 16 hours in 12 ml of 2 xYT (25 μg/ml kanamycin, 25u/ml chloramphenicol) liquid culture medium. Next, it was added to a 21 fermenter containing 1.2 l 2xYT (25 μg/ml kanamycin, 25 μg/ml chloramphenicol) liquid culture medium, and cultured at 37° C. until OD 600 =0.5−0.7. In this case, IPTG (final concentration 1 mM) was added to induce expression of the protein, and a bacteria was obtained by lowering the temperature to 30° C., culturing for a further 4 hours and collecting (8500 rpm, 30 minutes, 4° C.). The obtained bacteria was stored at −20° C.
[0105] The aforesaid bacteria stored at −20° C. was slowly thawed on ice, suspended in Lysis buffer (50 mM Tris-HCl, 300 mM NaCl, 10 mM imidazole), and ultrasonic crushing (Output 3.5, Duty 60% (TOMY UD201)) was performed on ice 20 times, 2 minutes at a time, with a cooling time of 1 minute. Centrifugal separation (10000 rpm, 30 minutes, 4° C.) of the crushed bacterial solution was performed, and the supernatant liquid was recovered.
[0106] The obtained supernatant liquid was used as an addition sample, and purified by affinity chromatography (flow velocity 15-20 ml/hour) using a column filled with Ni-NTA agarose beads equilibrated beforehand using the same buffer solution. The eluates were fractionated, and the fractions containing the target protein were verified and collected by SDS-PAGE.
[0107] After dialyzing the obtained fractions while exchanging with distilled water as the outside liquid as required for 24 to 48 hours, a white powder was obtained by freeze-drying. The yield of protein of 35 kDa was 38.8 mg.
Example 4
[0000] <Construction of SLPF Gene>
[0108] The four oligonucleotides shown in the SEQ ID NOS: 34-37 synthesized by Asahi TechnoGlass CO., LTD., were designed. The synthesized film-like oligonucleotides were dissolved so that their concentration was 1 μg/p 1 using TE (10 mM Tris-HCl (pH 8.0), 1 mM EDTA (pH 8.0)). Double-stranded DNAs which code for the aminoacids expressed in the SEQ ID NOS: 38 and 39 were constructed by equimolar mixing of complementary strands, heat-treating at 99° C. for 30 seconds, cooling at 37° C. for 1 hour, and settling for 30 minutes. After mixing equivalent amounts of the respective double-stranded DNAs, ligation was performed at 16° C. for 1 hour using Takara Ligation Kit ver2 Solution I to prepare a double-stranded DNA coding for SLPF monomer (aminoacid sequence of SLPF: Thr Ser [Thr Gly Arg Gly Asp Ser Pro Ala Gly Gly (Gly Ala Gly Ala Gly Ser) 3 Ala Ser] n , SEQ ID NO: 40 (for n=5)).
[0109] The cloning vector pUC118 was digested at 37° C. for 1 hour 30 minutes using the restriction enzyme BamHI, CIAP was added, and treatment was performed at 37° C. for 30 minutes. The reaction solution was extracted and purified with a mixture of phenol:chloroform:isoamyl alcohol in a ratio of 25:24:1 (weight ratio). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and used as the vector sample.
[0110] The SLPF monomer DNA and pUC118 vector sample were mixed in a ratio of 10:1 (weight ratio), and ligation was performed at 16° C. for 1 hour using Takara Ligation Kit ver2 solution. After completion of the reaction, a transformation was performed using competent cell DH5α. The presence or absence of an insert gene was verified by color selection using X-gal, DNA sequencing was performed on the material containing the insert gene, and plasmid pUC-SLPF (1) containing the SLPF monomer DNA was obtained by verifying the sequence.
[0000] <Construction of SLPF(n)>
[0111] The two termini of SLPF monomer contain regions for recognizing the restriction enzymes Spe I and Nhe I. The projecting ends of the fragments digested by Spe I and Nhe I are all complementary and can be mutually combined. Moreover, the new sequence produced by this combination is different from both of the regions for recognizing the restriction enzymes Spe I and Nhe I, and is not digested by Spe I and Nhe I. Using this property, pUC-Link SLPF(n) was constructed by polymerizing SLPF monomer in one direction.
[0112] Competent cell DH5α was transformed using pUC-SLPF (1), and grown in 2xYT culture medium at 37° C. for 18 hours. The plasmid was extracted from the culture medium by the alkali-SDS method, and dissolved in TE. The sample was simultaneously digested by Nhe I and Spe I at 37° C. for 1 hour 30 minutes, and SLPF (1) was isolated from the plasmid. After concentrating the reaction liquid to 5 μl using MicroCon, electrophoresis was performed using 1.5% agarose gel, and the band of insert DNA was cut out. To extract DNA from the gel, the extract was concentrated to 5 μl using UltrafreeDA and then MicroCon, and this was used as the insert genetic material.
[0113] The DNA concentration in the insert genetic material was verified by electrophoresis using 1.5% agarose gel, an equivalent amount of Takara Ligation Kit ver2 Solution I to the insert gene sample was added, and ligation was performed at 16° C. for 1 hour.
[0114] After digesting pUC-Link by Nhe I, CIAP was added and alkaline phosphatase treatment was carried out. The reaction solution was extracted and purified using a mixture of phenol:chloroform:isoamyl alcohol (weight ratio 25:24:1). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and this was used as the vector sample.
[0115] The DNA concentrations in the insert genetic material and vector sample were verified by electrophoresis using 1.5% agarose gel, the insert genetic material and vector sample were mixed in a ratio of 10:1, an equivalent amount of Takara Ligation Kit ver2 Solution I to the reaction mixture was added, and ligation was performed at 16° C. for 1 hour.
[0116] After the reaction was complete, transformation of competent cell DH5α was performed. It was then inoculated on a LB plate with added ampicillin, and screened. The colony produced was picked up, inoculated on 2xYT culture medium and grown at 37° C. for 18 hours. The plasmid was extracted from the culture medium by the alkali-SDS miniprep method, dissolved in TE and used as a sample. After digesting the sample simultaneously using Nhe I and Spe I, the presence or absence and size of the insert gene were verified by the electrophoresis method. Then, DNA sequencing was performed and plasmid pUC-Link SLPF (1) was obtained by verifying the sequence.
[0000] <Construction of Expression Vector pET-SLPF (5)>
[0117] pUC-SLPF (5) was digested using BamHI and Hind III. After concentrating the reaction liquid to 5 μl using MicroCon, electrophoresis was performed using a 1.5% agarose gel, and the band of insert DNA was cut out. To extract DNA from the gel, the extract was concentrated to 5 μl using UltrafreeDA and then MicroCon, and this was used as the insert genetic material.
[0118] After digesting the expression vector pET30a by BamHI and Hind III, CIAP was added and alkaline phosphatase treatment was carried out. The reaction solution was extracted and purified using a mixture of phenol:chloroform:isoamyl alcohol (weight ratio 25:24:1). Ethanol was added to the purified reaction solution, the precipitate produced was dissolved in sterilized water, and this was used as the vector sample.
[0119] The DNA concentrations in the insert genetic material and vector sample were verified by electrophoresis using 1.5% agarose gel, the insert genetic material and vector sample were mixed in a ratio of 10:1, an equivalent amount of Takara Ligation Kit ver2 Solution I to the reaction mixture was added, and ligation was performed at 16° C. for 1 hour.
[0120] Transformation of competent cell DH5α was performed using the ligation reaction solution. It was then inoculated on a LB plate with added kanamycin, and screened. The colony produced was picked up, inoculated on 2xYT culture medium and grown. The plasmid was extracted from the culture medium by the alkali-SDS method, dissolved in TE and used as a sample. After digesting the sample simultaneously using Nhe I and Spe I, the presence or absence and size of the insert gene were verified by the electrophoresis method. Then, DNA sequencing was performed and the expression vector pET-SLPF 5 was constructed by verifying the sequence.
[0000] <Expression of PET-SLPF (5)>
[0121] Host E. coli BL21 (DE3) pLysS containing the plasmid pET-SLPF (5) was grown at 37° C. for 16 hours in 1.5 ml of 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol) liquid culture medium. Next, 100 μl of the culture medium was added to a test-tube containing 5 ml of 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol), and cultured at 37° C. until OD 600 =0.5−0.7. In this case, to induce the expression of SLPF 5, IPTG (final concentration 1 mM) was added, 100 μl of culture medium was sampled in an Eppendorf tube every other hour, and cultured for 4 hours. After performing centrifugal separation (14500 rpm, 5 minutes, 4° C.) of the sampled culture medium, the supernatant liquid was discarded, pellets were dissolved in 2× sample buffer, and heat-treated at 100° C. for 5 minutes to give a SDS-PAGE sample.
[0122] After obtaining the SDS-PAGE sample, SLPF 5 was detected by performing Western Blot using His-Tag antibody.
[0123] As shown in FIG. 4 , with SELP 5, a band was observed at 23 kDa. From this, it was confirmed that SLPF genes were induced by IPTG addition, and mass-expressed strains could be obtained.
[0124] Host E. coli BL21 (DE3) pLysS respectively containing the plasmids pET-SLPF (5) was grown at 37° C. for 16 hours in 1.5 ml 2xTY (25 μg/ml kanamycin, 25 μg/ml chloramphenicol) liquid culture medium. Next, this culture medium was cultured at 37° C. for 16 hours in 5 ml of 2xYT (25 μg/ml kanamycin, 25 μg/ml chloramphenicol). Next, it was added to a 11 conical flask containing 250 ml of 2xYT (25 μg/ml kanamycin, 25 μg/ml chloramphenicol) liquid culture medium, and cultured at 37° C. until OD 600 =0.5−0.7. In this case, IPTG (final concentration 0.2 mM) was added to induce expression of the protein, and a bacteria was obtained by culturing for a further 4 hours and collecting (8500 rpm, 30 minutes, 4° C.). The obtained bacteria was stored at −20° C.
[0125] The aforesaid bacteria stored at −20° C. was slowly thawed on ice, suspended in Lysis buffer (50 mM Tris-HCl, 300 mM NaCl, 10 mM imidazole), and ultrasonic crushing (Output 3.5, Duty 60% (TOMY UD201)) was performed on ice 20 times, 2 minutes at a time, with a cooling time of 1 minute. Centrifugal separation (10000 rpm, 30 minutes, 4° C.) of the crushed bacterial solution was performed, and the supernatant liquid was recovered.
[0126] The obtained supernatant liquid was used as an addition sample, and purified by affinity chromatography (flow velocity 15-20 ml/hour) using a column filled with Ni-NTA agarose beads equilibrated beforehand using the same buffer solution. The eluates were fractionated, and the fractions containing the target protein were verified and collected by SDS-PAGE.
[0127] After dialyzing the obtained fractions while exchanging with distilled water as the outside liquid as required for 24 to 48 hours, a white powder was obtained by freeze-drying. The yield of protein of 23 kDa was 38.8 mg/L. | A method of producing silk or silk-like protein wherein silk or a silk-like polymer comprising at least one protein selected from among domestic silkworm fibroin, wild silkworm fibroin, elastin and fibronectin, and essentially comprising the aforesaid domesticated silkworm fibroin or silkworm fibroin is designed. The minimum unit of the silk or the thus designed polymer is synthesized, and the polymer of the minimum unit thus synthesized is integrated into at least one expression vector selected from among expression vectors containing T7 promoter. Then, the expression vector is integrated into E. coli BL21 (DE3) pLysS or BLR(DE3) pLysS, and the E. coli is grown in a medium selected from among composite media. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 61/945054, filed Feb. 26, 2014, which is incorporated herein by reference.
FIELD
[0002] The present invention is generally related to broad spectrum disinfectants using chlorine dioxide compositions, and more particularly, to methods for producing chlorine dioxide compositions that clean, disinfect and/or sterilize in one step with no harmful byproducts.
BACKGROUND
[0003] A hospital-acquired infection, also known as a HAI or in medical literature as a nosocomial infection, is an infection whose development is favored by a hospital environment, such as one acquired by a patient during a hospital visit or one developing among hospital staff. Such infections include fungal and bacterial infections and are aggravated by the reduced resistance of individual patients. [See “Nosocomial Infection”. A Dictionary of Nursing. Oxford Reference Online. 2008].
[0004] In the United States, the Centers for Disease Control and Prevention estimated roughly 1.7 million hospital-associated infections, from all types of microorganisms, including bacteria, combined, cause or contribute to 99,000 deaths each year. Nosocomial infections can cause severe pneumonia and infections of the urinary tract, bloodstream and other parts of the body. Many types are difficult to attack with antibiotics, and antibiotic resistance is spreading to Gram-negative bacteria that can infect people outside the hospital. [See Pollack, Andrew. “Rising Threat of Infections Unfazed by Antibiotics” New York Times, Feb. 27, 2010]. In March 2009, the CDC released a report estimating overall annual direct medical costs of healthcare-associated infections ranged from $28-45 billion. [See Scott RD. The direct medical costs of healthcare-associated infections in US hospitals and the benefits of prevention, 2008. CDC].
[0005] CRE, which stands for Carbapenem-Resistant Enterobacteriaceae, are a family of germs that are difficult to treat because they have high levels of resistance to antibiotics. Klebsiella species and Escherichia coli ( E. coli ) are examples of Enterobacteriaceae, a normal part of the human gut bacteria that can become carbapenem-resistant. Types of CRE are sometimes known as KPC ( Klebsiella Pneumoniae Carbapenemase ) and NDM (New Delhi Metallo-beta-lactamase). KPC and NDM are enzymes that break down carbapenems and make them ineffective.
[0006] Healthy people usually do not get CRE infections. In healthcare settings, CRE infections most commonly occur among patients who are receiving treatment for other conditions. Patients whose care requires devices like ventilators (breathing machines), urinary (bladder) catheters, or intravenous (vein) catheters, and patients who are taking long courses of certain antibiotics are most at risk for CRE infections. Some CRE bacteria have become resistant to most available antibiotics. Infections with these germs are very difficult to treat, and can be deadly—one report cites they can contribute to death in up to 50% of patients who become infected. [See “CDC: Action needed now to halt spread of deadly bacteria: Data show more inpatients suffering infections from bacteria resistant to all or nearly all antibiotics” (Press release). The Centers for Disease Control. Mar. 5, 2013].
[0007] Hospitals have sanitation protocols regarding uniforms, equipment sterilization, washing, and other preventive measures. Thorough hand washing and/or use of alcohol rubs by all medical personnel before and after each patient contact is one of the most effective ways to combat nosocomial infections. Despite sanitation protocol, patients cannot be entirely isolated from infectious agents. Furthermore, patients are often prescribed antibiotics and other antimicrobial drugs to help treat illness; this may increase the selection pressure for the emergence of resistant strains. [See McBryde ES, Bradley LC, Whitby M, McElwain DL (October 2004). “An investigation of contact transmission of methicillin-resistant Staphylococcus aureus”. J. Hosp. Infect. 58 (2): 104-8].
[0008] Sanitizing surfaces is an often overlooked, yet crucial, component of breaking the cycle of infection in health care environments. Modern sanitizing methods such as NAV-CO2 have been effective against gastroenteritis, MRSA, and influenza agents. Use of hydrogen peroxide vapor has been clinically proven to reduce infection rates and risk of acquisition. Hydrogen peroxide is effective against endospore-forming bacteria, such as Clostridium difficile, where alcohol has been shown to be ineffective. Ultraviolet cleaning devices may also be used to disinfect the rooms of patients infected with Clostridium difficile after discharge.
[0009] Micro-organisms are known to survive on inanimate ‘touch’ surfaces for extended periods of time. This can be especially troublesome in hospital environments where patients with immunodeficiencies are at enhanced risk for contracting nosocomial infections. Touch surfaces commonly found in hospital rooms, such as bed rails, call buttons, touch plates, chairs, door handles, light switches, grab rails, intravenous poles, dispensers (alcohol gel, paper towel, soap), dressing trolleys, and counter and table tops are known to be contaminated with Staphylococcus , MRSA (one of the most virulent strains of antibiotic-resistant bacteria) and Vancomycin-Resistant Enterococcus (VRE). Objects in closest proximity to patients have the highest levels of MRSA and VRE. This is why touch surfaces in hospital rooms can serve as sources, or reservoirs, for the spread of bacteria from the hands of healthcare workers and visitors to patients. [See Wilks, S. A., Michels, H., Keevil, C. W., 2005, The Survival of Escherichia Coli 0157 on a Range of Metal Surfaces, International Journal of Food Microbiology, Vol. 105, pp. 445-454; and U.S. Department of Defense-funded clinical trials, as presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Washington, D.C., Oct. 28, 2008].
[0010] When a patient is being treated in hospital with antibiotics, one side-effect is the increase in Clostridium difficile ( C. difficile ). When the bacteria are in a colon in which normal gut flora has been destroyed (usually after a broad-spectrum antibiotic such as clindamycin has been used), the gut becomes overrun with C. difficile . People are most often nosocomially infected in hospitals, nursing homes, or other medical institutions, although infection outside medical settings is increasing. C. difficile infection is a growing problem in healthcare facilities. The rate of C. difficile acquisition is estimated to be 13% in patients with hospital stays of up to two weeks, and 50% with stays longer than four weeks. [See Clabots, C. R.; Johnson, S.; Olson, M. M.; Peterson, L. R.; Gerding, D. N. (September 1992). “Acquisition of Clostridium difficile by hospitalized patients: evidence for colonized new admissions as a source of infection”. Journal of Infectious Diseases 166 (3): 561-7].
[0011] Chlorine dioxide has generated interest for control of microbiological growth. Unlike chlorine, chlorine dioxide remains a gas when dissolved in aqueous solutions and does not ionize to form weak acids. The biocidal activity of chlorine dioxide is believed to be due to its ability to penetrate bacterial cell walls and react with essential amino acids within the cell cytoplasm to disrupt cell metabolism. Unfortunately, chlorine dioxide in solution is unstable with an extremely short shelf life. Chlorine dioxide solutions must typically be generated at its point of use such as, for example, by a reaction between a metal chlorate or metal chlorite in aqueous solution and a liquid phase strong acid. However, the use of liquid phase strong acids poses handling issues and safety concerns.
[0012] In view of this, it would be desirable to develop a broad spectrum disinfectant that is safe, efficacious and fast, has no harmful byproducts, cleans and disinfects and/or sterilizes in one step, has a long shelf life, and does not cause and is not affected by pathogenic mutation.
SUMMARY
[0013] In one aspect, the invention is a method of making a chlorine dioxide disinfectant solution. The method includes adding a first amount of hydrochloric acid solution to a second amount of sodium chlorite; agitating the hydrochloric acid solution and sodium chlorite to mix the chemicals into a hydrochloric acid/sodium chlorite solution containing chlorine dioxide molecules; adding a third amount of one or more stabilizers to the hydrochloric acid/sodium chlorite solution; mixing the stabilizers and hydrochloric acid/sodium chlorite solution; and adding a fourth amount of deionized water.
[0014] In one aspect, a 100% L of chlorine dioxide disinfectant solution is produced using:
[0015] the first amount=1.0-10.0% L of hydrochloric acid solution;
[0016] the second amount=1.0-10.0% L of sodium chlorite;
[0017] the third amount=0.005-7.0% L of one or more stabilizers; and
[0018] the fourth amount=73.0-97.995% L of deionized water.
[0019] In another aspect, a 100% L of chlorine dioxide disinfectant solution is produced using:
[0020] the first amount=4.0-8.0% L of hydrochloric acid solution;
[0021] the second amount=4.0-8.0% L of sodium chlorite;
[0022] the third amount=0.005-0.60% L of hypochlorite and 0.005-6.0% L of surfactant; and
[0023] the fourth amount=77.40-91.99% L of deionized water.
[0024] In another aspect, a 100% L of chlorine dioxide disinfectant solution is produced using:
[0025] the first amount=4.0-8.0% L of hydrochloric acid solution;
[0026] the second amount=4.0-8.0% L of sodium chlorite;
[0027] the third amount=0.005-1.00% L of hypochlorite and 0.005-6.0% L of phosphate; and
[0028] the fourth amount=77.00-91.99% L of deionized water.
[0029] In another aspect, a 100% L of chlorine dioxide disinfectant solution is produced using:
[0030] the first amount=4.0-8.0% L of hydrochloric acid solution;
[0031] the second amount=4.0-8.0% L of sodium chlorite;
[0032] the third amount=0.005-0.60% L of hypochlorite and 0.005-6.0% L of phosphate; and
[0033] the fourth amount=77.40-91.99% L of deionized water.
[0034] In another aspect, a 100% L of chlorine dioxide disinfectant solution is produced using:
[0035] the first amount=4.0-8.0% L of hydrochloric acid solution;
[0036] the second amount=4.0-8.0% L of sodium chlorite;
[0037] the third amount=0.005-0.60% L of hypochlorite and 0.005-6.0% L of surfactant; and
[0038] the fourth amount=77.40-91.99% L of deionized water.
[0039] In some aspects, the one or more stabilizers form colloidal structures surrounding the chlorine dioxide molecules, the colloidal structures being suspended in the deionized water. The one or more stabilizers may include one or more hypochlorites, one or more surfactants or one or more phosphates.
DETAILED DESCRIPTION
[0040] Embodiments of the invention will now be described with reference to the figures, wherein like numerals reflect like elements throughout. The terminology used in the description presented herein is not intended to be interpreted in any limited or restrictive way, simply because it is being utilized in conjunction with detailed description of certain specific embodiments of the invention. Furthermore, embodiments of the invention may include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the invention described herein.
[0041] The present invention provides aqueous solution of chlorine dioxide (ClO 2 ) from various reactions. For example, from the reaction of: sodium chlorite (NaClO 2 ) and hydrochloric acid (HCl), shown in Formula (1); potassium chlorate (KClO 3 ) and oxalic acid (H 2 C 2 O 4 ), shown in Formula (2); chloric acid (HCO 3 ) and hydrochloric acid (HCl), shown in Formula (3); sodium chlorite (NaClO 2 ), hydrochloric acid (HCl) and sodium Hypochlorite (NaOCl), shown in Formula (4).
[0000] 4 HCL+5 NaClO 2 →4 ClO 2 +2 H 2 O+5 NaCl (1)
[0000] 2KClO 3 +2H 2 C 2 O 4 →K 2 C 2 O 4 +2ClO 2 +2CO 2 +2H 2 O (2)
[0000] HClO 3 +HCl→HClO 2 +HOCl (3)
[0000] 2NaClO 2 +2HCl+NaOCl→2ClO 2 +3NaCl+H 2 O (4)
[0042] Chlorine dioxide (ClO 2 ) decomposes in light, is temperature sensitive and it reacts with most organic compounds. Chlorine dioxide is a dissolved gas which means its ability to stay in solution is also affected by the sizes of exposed liquid surface areas and vapor spaces in containers. At atmospheric pressure and 20° C. the solubility in water is approximately 70 g/l.
[0043] The stability of chlorine dioxide in water is enhanced using two mechanisms, colloidal formations and buffering. The mechanism chosen depends on how the product is to be used. For disinfectants, a phosphate may be used, and in the proper amount forms a colloidal structure with the phosphate molecules surrounding the ClO 2 molecules. The durability of the colloid may be optimized by the colloidal wall design and the performance of the disinfectant may be enhanced with micelles. The mixture of the chemicals is important for shelf life. Tests revealed ClO 2 will remain stable for years if the solution has the proper amount of sodium polyphosphate.
[0044] Aqueous solutions of chlorine dioxide are prepared with pure reagents that are substantially free of undesirable contaminants. For stability, the chlorine dioxide is combined with one or more selected stabilizing compounds. The disclosed aqueous solutions of chlorine dioxide can maintain a stable concentration over many months or longer and minimize the deleterious effects of increased temperature and physical agitation, both in storage and in transport.
[0045] General Instructions
[0046] All bottles and cylinders shall be labeled with the chemicals that they contain. Each container shall be rinsed with deionized water and openings to the atmosphere shall be covered to avoid contamination. Always rinse any container with deionized water before reusing.
[0047] All processes and reactions are carried out at room temperature not exceeding (20° C.) unless otherwise specified.
[0048] The present invention may be used for various products, including, for example, a surface disinfectant. While the present application discloses embodiments for a surface disinfectant, it is contemplated that the same processes, methods and solutions may be used for the other products.
[0049] Basic Solutions
[0050] Below are examples of the Basic Solutions that may be used for the Broad Spectrum Disinfectant.
1. Hydrochloric acid solution (HCl). 2. Sodium chlorite (NaClO 2 ). 3. Stabilizers, such as:
3i Hypochlorite (OCl—), such as Calcium hypochlorite (Ca(OCl) 2 ), Sodium hypochlorite (NaOCl), Lithium hypochlorite (LiOCl), Hypochlorous acid (HOCl). Other examples may include Barium hypochlorite (Ba(OCl) 2 ), Potassium hypochlorite (KOCl), Strontium hypochlorite, (Sr(OCl) 2 ), Beryllium hypochlorite (Be(OCl) 2 ), Magnesium hypochlorite (Mg(OCl) 2 ), Methyl hypochlorite (CH 3 ClO), t-Butyl hypochlorite. 3ii Surfactant (for example, DOWFAX 3B2). 3iii Phosphate, such as: Sodium polyphosphate ((NaPO 3 ) n ), Sodium metaphosphate,
[0057] Sodium hexametaphosphate, Sodium tripolyphosphate, Sodium pyrophosphate, Sodium trimetaphosphate, Ammonium phosphate ((NH 4 ) 3 PO 4 ), Ammonium metaphosphate, Potassium phosphate (K 3 PO 4 ), Potassium polyphosphate, Potassium pyrophosphate, Potassium metaphosphate, Lithium phosphate (Li 3 PO 4 ), Lithium orthophosphate, Lithium polyphosphate, Cesium phosphate (Cs 3 PO 4 )
4 Deionized water (H 2 O).
[0059] Chlorine Dioxide Composition Products Types
[0060] Table 1 below shows a range of Basic Solutions used for a Broad Spectrum Disinfectant.
[0000]
TABLE 1
Basic Solutions (100% L)
Product type
1
2
3
4
Disinfectant
1.0-10.0%
1.0-10.0%
0.005-7.0%
73.0-97.995%
[0061] In a general embodiment of a Broad Spectrum Disinfectant, a 100% L of chlorine dioxide disinfectant solution is produced using the Basic Solutions as follows:
1. 1.0-10.0% L of Hydrochloric acid solution (HCl). 2. 1.0-10.0% L of Sodium chlorite (NaClO 2 ). 3. 0.005-7.0% L of one or more Stabilizers. 4. 73.0-97.995% L of Deionized water (H 2 O).
[0066] Table 2 below shows some example ranges of Basic Solutions that may be used for different embodiments of a Broad Spectrum Disinfectant.
[0000]
TABLE 2
Basic Solutions (100% L)
Disinfectant
1
2
3i
3ii
3iii
4
Embodiment 1
4-8%
4-8%
0.005-0.60%
0.005-6.0%
0
77.40-91.99%
Embodiment 2
4-8%
4-8%
0.005-1.00%
0
0.005-6.0%
77.00-91.99%
Embodiment 3
4-8%
4-8%
0.005-0.60%
0
0.005-6.0%
77.40-91.99%
Embodiment 4
4-8%
4-8%
0.005-0.60%
0.005-6.0%
0
77.40-91.99%
[0067] In Embodiment 1 of a Broad Spectrum Disinfectant, a 100% L of chlorine dioxide disinfectant solution is produced using the Basic Solutions as follows:
1. 4.0-8.0% L of Hydrochloric acid solution (HCl). 2. 4.0-8.0% L of Sodium chlorite (NaClO 2 ). 3i. 0.005-0.60% L of Hypochlorite. 3ii. 0.005-6.0% L of Surfactant. 4. 77.40-91.99% L of Deionized water (H 2 O).
[0073] In Embodiment 2 of a Broad Spectrum Disinfectant, a 100% L of chlorine dioxide disinfectant solution is produced using the Basic Solutions as follows:
1. 4.0-8.0% L of Hydrochloric acid solution (HCl). 2. 4.0-8.0% L of Sodium chlorite (NaClO 2 ). 3i. 0.005-1.00% L of Hypochlorite. 3iii. 0.005-6.0% L of Phosphate. 4. 77.00-91.99% L of Deionized water (H 2 O).
[0079] In Embodiment 3 of a Broad Spectrum Disinfectant, a 100% L of chlorine dioxide disinfectant solution is produced using the Basic Solutions as follows:
1. 4.0-8.0% L of Hydrochloric acid solution (HCl). 2. 4.0-8.0% L of Sodium chlorite (NaClO 2 ). 3i. 0.005-0.60% L of Hypochlorite. 3iii. 0.005-6.0% L of Phosphate. 4. 77.40-91.99% L of Deionized water (H 2 O).
[0085] In Embodiment 4 of a Broad Spectrum Disinfectant, a 100% L of chlorine dioxide disinfectant solution is produced using the Basic Solutions as follows:
1. 4.0-8.0% L of Hydrochloric acid solution (HCl). 2. 4.0-8.0% L of Sodium chlorite (NaClO 2 ). 3i. 0.005-0.60% L of Hypochlorite. 3ii. 0.05-6.0% L of Surfactant. 4. 77.40-91.99% L of Deionized water (H 2 O).
[0091] Chlorine dioxide (ClO 2 ) decomposes in light, is temperature sensitive and it reacts with most organic compounds. Clean production facilities and handling procedures, and material purity are essential to avoid reactions with organic contaminants.
[0092] Production Process
[0093] The production of chlorine dioxide solutions may be performed batch-wise or in continuous mode. Batch production is normally carried out in a single pot process, wherein the different components are added to a reaction container under a protocol as described in exact detail below. For continuous production, a special continuous mode reactor is used.
[0094] Preferably, the entire production process for the solution would be conducted under clean room conditions, in order to minimize the possibility of contamination of the solution by environmental contaminants, such as airborne particles. All contact surfaces, including without limitation surfaces of production equipment, filling equipment and packaging, should be thoroughly cleaned of particles prior to use.
[0095] Process for Preparation of the Stock Solutions
[0096] Ranges for the amounts of the Basic Solutions 1, 2, 3 and 4 to be used for each embodiment are shown in Tables 1 & 2 above.
1. Prepare the mixing process by decontaminating the container with chlorine dioxide followed by a rinse with deionized water. If the container is used regularly, the container may be rinsed with only deionized water. Ensure the container is empty before starting. 2. Add the hydrochloric acid solution to the container followed immediately by the sodium chlorite. When the hydrochloric acid and sodium chlorite solutions have been added, the funnel is removed and replaced with a cap. The cap should fit loosely in order to allow release of the gas formed in the container. Manually agitate the reagents back and forth a few times to help achieve proper mixing of the chemicals. CAUTION: Moderate gas formation is caused when mixing the hydrochloric acid and sodium chlorite solutions. 3. After 10 minutes, remove the cap and add the stabilizer for the individual product type being produced, Basic Solution 3 (one or more of 3A, 3B or 3C). Move the container back and forth a few times in order to achieve proper mixing of the chemicals. The reaction time after addition of the stabilizer is 12-15 minutes. During this time the mixture should be agitated at least two additional times. The reaction time should not exceed 20 minutes. CAUTION: Moderate gas formation is caused when mixing the stabilizer into the solution. 4. Add deionized water (basic solution for) to the container. The water temperature should not exceed 20° C., and the correct amount of water should be weighed in. WARNING: Very heavy gas formation is caused when adding the deionized water.
[0101] Batch Process Preparation of Stock Solution for a Broad Spectrum Disinfectant
[0102] Below shows one embodiment of a batch process for preparing N liters of Stock Solution for Surface Disinfectant.
A. Add the desired percentage of hydrochloric acid solution, for example 1.0-10.0%, to the container followed immediately by the desired percentage of sodium chlorite, for example 1.0-10.0%. Agitate the reagents back and forth a few times to help achieve proper mixing of the chemicals. B. After 10 minutes, add the desired percentage of stabilizers, for example 0.005-7.0%, to the container. Move the container back and forth a few times in order to achieve proper mixing of the chemicals. The reaction time after addition of the stabilizer is 12-15 minutes. During this time the mixture should be agitated at least two additional times. The reaction time should not exceed 20 minutes. C. Add the desired percentage of deionized water, for example 73.0-97.995%, preferably with a resistivity >10.0 MΩcm, to the container near the container bottom using the funnel with the extension tube. The water temperature should not exceed 20° C.
[0106] Continuous Process Preparation of Stock Solution for a Broad Spectrum Disinfectant
[0107] Below shows one embodiment of a continuous process for preparing chlorine dioxide Surface Disinfectant.
A. Turn on the water pump in the reactor unit and adjust the deionized water to the desired feed rate. B. Turn on the chemical solutions feed pumps and set the feed rates to the desired percentage of hydrochloric acid, sodium chlorite, and stabilizers. C. Assure proper mixing of the water and chemicals.
[0111] Dilution—Preparation Of Finished Product
[0112] The Solutions are diluted with deionized water in order to form the finished product solution. The concentration of chlorine dioxide in the finished product solution may vary. In one embodiment, the desired concentration of chlorine dioxide in the finished product solution is 5000 parts per million.
[0113] Handling of Stock Solution And Finished Product
[0114] When the stock solution has been prepared, it should be considered perishable. The Stock solution should be stored in a closed container, protected from light, at a temperature between 6-10° C. A storage temperature of 8° C. is recommended.
[0115] The maximum shelf life of the Stock Solution when stored under the above conditions is estimated to be 5 days when stored in a glass container or 2 days when stored in a polyethylene container.
[0116] After filling of the solution into the consumer containers, the filled Consumer Containers should be stored as described above for the Stock solution.
[0117] In some embodiments, the disinfectant solution is impregnated onto a cloth, such as paper or a fabric, to form disinfectant wipes. In some embodiments, the disinfectant solution is used to make disinfectant sprays.
[0118] It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims. In addition, where this application has listed the steps of a method or procedure in a specific order, it may be possible, or even expedient in certain circumstances, to change the order in which some steps are performed, and it is intended that the particular steps of the method or procedure claims set forth herebelow not be construed as being order-specific unless such order specificity is expressly stated in the claim. | Disclosed are devices, systems, and methods for producing broad spectrum disinfectants using a colloidal suspension of chlorine dioxide in deionized water, and more particularly, producing chlorine dioxide compositions that clean, disinfect and/or sterilize in one step with no harmful byproducts. | 2 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a substitute for U.S. patent application Ser. No. 07/743,484 which was filed Aug. 8, 1991 and which is now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to controlling the ignition rate of a solid propellant rocket grain and, more particularly, this invention relates to the vapor deposition of a thin polymer film on the surface of a rocket grain from a vaporized monomer.
2. Description of the Prior Art
The maximum performance of future missiles is limited by booster rocket and overall system constraints such as the ignition mass flow rise rate. This rate is typically controlled by an inhibitor on the surface of a solid propellant rocket grain.
For the purposes of the present invention, such a grain is defined as a relatively large mass of solid propellant material, which is shaped into a suitable geometric pattern and is used by itself or with only a few other corresponding and relatively large masses, rather than as one particle of a very large number of propellant particles which, for use, may be poured or packed into any suitable container or which are for subsequent incorporation in a binder. A grain of the present invention may be tubular or have a more complex centrally perforated shape or may have the configurations known in the art as cruciform, star, and multitubular.
U.S. Pat. No. 3,523,839, which issued Aug. 11, 1970 to Shechter et al and which is hereby incorporated by reference, describes the application of coatings of paraxylylene polymers to particulate propellant components by condensation thereon of monomers produced by pyrolytic cleavage of the corresponding dimer. However, this patent only discloses the application of such polymers to propellant components which are in particulate form and which are kept in continuous motion in a coating chamber during subjection of the particle exteriors to the monomer.
The general state of technology relating to the inhibition of ignition of a solid propellant rocket grain is either to paint some material on the surface of the grain, or to coat a mandrel with an inhibitor and cast the propellant onto it. The most common method is to paint a liner material on the grain surface. These methods are not uniformly controllable and are labor intensive. The liner material requires a separate cure and it is also very difficult to inspect the liner coating to ascertain whether it is uniformly applied and in the correct thickness. The liner coating formulations contain compounds that can react with and/or migrate into or out of the propellant surface, and thus cause degradation of underlying propellant over time.
It is particularly difficult and expensive to apply a uniformly thick liner coating to shaped or large rocket propellant grains so that the design of rocket motors has been constrained to special configurations to satisfy the limits imposed on the duration of the ignition transient.
BRIEF SUMMARY OF THE INVENTION
The present invention is a method of depositing a thin, uniform film of paraxylylene polymer as an ignition inhibitor on solid propellant rocket grain surfaces which may be large, internal, and of complex shape. The fabricated grain is disposed in a chamber, which may be the casing of a rocket motor incorporating the grain, and subjected to paraxylylene monomer vapors which condense on exposed surfaces of the grain and polymerize on the surfaces to form the film. The monomer is preferably prepared by vaporizing and thermally cracking the corresponding dimer, such as [2.2] paracyclophane or a halogenated derivative thereof.
The present invention thus provides a rocket motor inhibition system deposited in situ from vapor and spontaneously forming a uniform, thin coating on propellant grain surfaces which may be large and/or of complex shape. Due to the uniformity of the coating provided by the invention, the design of rocket motors need not be constrained to satisfy the limits imposed by ignition transients. The invention significantly reduces processing cost by requiring neither the processing of a mandrel for coating nor the labor intensive painting of an inhibitor coating onto an inner surface of a rocket grain and also reduces cost by requiring little labor for clean up.
The inhibition system is inert and does not interact with the propellant or cause migration of plasticizer therein. Also and since the vapor deposited coating of the invention polymerizes as the monomer condenses on the surface, there is no need to cure the coating so there is no plasticizer, curing agent, or unreacted monomer which could react with the propellant. The possibility of grain failure is thus reduced.
The inhibitor coating method of the present invention provides increased reliability in coating thickness by being makers of solid propellant rocket motors.
BRIEF DESCRIPTION OF THE DRAWING
These and many other features and attendant advantages of the invention will become apparent by reference to the following detailed description when considered in conjunction with the accompanying drawing wherein the FIGURE is a schematic view of a coating system for applying an inhibition coating to a solid propellant rocket motor grain by vapor deposition in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The vapor-deposition process of the invention utilizes a monomer material that can be vaporized and that then condenses at a moderate temperature below about 300° C. so that the monomer does not affect the solid propellants as it deposits. The vapor-deposited polymer coating is a non-energetic material so that it effectively inhibits the ignition of the propellant grain and does not enhance or contribute to the pressurization of the motor. The deposited polymer has an elongation greater than or equal to the elongation of the underlying solid propellant grain.
The method of the invention can deposit coatings having thicknesses from as low as 100 Angstroms to at least 7 mils. Coatings having thicknesses from 1-50 microns can be utilized as hydrophobic films to keep water off the surface of a propellant grain. However, ignition inhibition requires a thicker coating in the range of about 0.1 to about 7 mils, preferably about 2 mils. If the coating is too thick, the inhibition effect will unduly interfere with ignition and burning of the propellant.
Preferred materials for forming the vapor deposited inhibitor coatings are xylylene monomers. The paraxylylene monomer is a conjugated tetraolefin whose particular arrangement gives it extreme reactivity at its end carbons so as to form a linear paraxylylene polymer homopolymer. These monomers and their production and polymerization are well-known and are described in the above-identified U.S. Pat. No. 3,523,839.
In the present invention, solid propellant substrate at about room temperature is exposed to a controlled atmosphere of gaseous xylylene monomer so that a pin-hole free coating of xylylene polymer forms by vapor deposition polymerization (VDP). The xylylene monomer is thermally stable but kinetically unstable. Although the xylylene monomer is stable as a gas at low pressure, on condensation the monomer spontaneously polymerizes to produce a coating of high molecular weight polyxylylene.
The gaseous p-xylylene monomer (PX) can be generated by ultraviolet light plasma or glow discharges or by pyrolytic cleavage of the dimer. The polymers produced by the excitation of monomer by ultraviolet or electric discharges appear to be less linear, contain more branching and have lower molecular weights so that the preferred source of the reactive monomer is by pyrolytic cleavage of the dimer, di-p-xylylene (DPX).
In contrast to the extreme reactivity of the monomeric PX generated from the dimer DPX, the dimer is an exceptionally stable compound having extremely long shelf life. The diner can have varied substitutions which are known in the literature including the above-identified U.S. Pat. No. 3,523,839. Three commercially available dimers are DPXN, DPXC and DPXD which form polymers known as Parylene N, Parylene C and Parylene D, respectively. The unsubstituted C 16 hydrocarbon dimer, [2.2] paracyclophane is known as DPXN. Both DPXC and DPXD are prepared from DPXN by aromatic chlorination and differ only in the extent of chlorination. DPXC has an average of one chlorine per aromatic ring and DPXD has an average of 2 chlorines per aromatic ring. There may be more than 2 molecules per monomer of the above halogens. There are materials of similar nature containing other halogens such as fluorine and bromine, and future development could provide better materials for the practice of the present invention by use of these other halogens in combination with chlorine or without chlorine.
The paraxylyene polymers are produced from the dimer in two stages that are physically separate but adjacent. Referring now to the FIGURE, the dimer is placed in a vaporizer 10 which is heated to a temperature of about 150° C. to 200° C. at a pressure of about 100-150 Pa to vaporize the dimer. The vaporizer 10 contains a heating jacket 12 surrounding a tubular member 18 which receives the dimer. The tubular member 18 is connected to a heating chamber 20 of a pyrolyzer unit 22. Chamber 20 is surrounded by a heating furnace 24 which heats the vapor to a temperature from about 300 to about 750° C. at a pressure of from about 30 to about 100 Pa to thermally crack the dimer and thereby produce paraxylylene monomer with free radical ends. The gaseous, active monomer is then fed through an inlet pipe 26 through a plug 28 into a rocket motor chamber 31 containing a representative, solid rocket propellant grain 30. The grain is of centrally perforated, axially open-ended shape which provides an initial burning surface 42 disposed interiorly of the grain.
Plug 28 is received within a thrust nozzle 32 of a representative rocket motor 50 having grain 30 and chamber 31. An outlet tube 36 is connected to a trap 38 and to a vacuum pump 40 which maintains chamber 31 under vacuum of about 1 to 7 Pa. Grain 30 is at a colder temperature, usually at or near room temperature and, typically, from about 20 to 30° C. The active monomer vapors condense on the grain surface 42 to form thereon a thin coating 44 of paraxylylene polymer.
Since the monomer is gaseous and has free access to surface 42 or to any corresponding but more complex rocket propellant grain surface, it is evident that the polymer thickness resulting from condensation of the monomer will be uniform although the grain is stationary during subjection to the monomer.
Motor 50 includes a cylindrical casing 52 having a closed, upper end, not shown, and an open, lower end 56 to which is connected nozzle 32. Grain 30 is, typically, secured to the inside surface of casing 52 by means of adhesive and thermal insulating layers, not shown. When the grain is ignited by an igniter, also not shown, combustion gases create forward propulsion as they exit from the open end of the centrally perforated grain toward and through the nozzle 32.
The solid propellant grain 30 is typically formed from a combustible binder containing a high loading of an oxidizer salt and optional additives such as metal particles, a representative formulation being 10-15% elastomer, such as a cured hydroxyl terminated butadiene polymer (HTPB) or a cured carboxyl terminated butadiene polymer (CTPB), with the remainder being solids such as 60-80% ammonium perchlorate and 10-20% of aluminum powder.
EXAMPLES
In the following examples, cartridge loaded motor grains 2 inches diameter and 6 inches long with a 1 inch diameter center perforation were cast using a typical propellant containing 12% HTPB, 70% ammonium perchlorate, and 18% aluminum. The grains were ignited in a test chamber, and the pressure changes following ignition recorded to determine the ignition rate.
EXAMPLE 1
An uninhibited grain was fired for a baseline of comparison.
EXAMPLE 2
A grain was coated with a 0.0007 inch thick layer of Parylene C (DXPC) was vaporized at 150 to 160° C. and was thermally cracked into the monomer at 690° C.
The ignition time delay due to the inhibiting performance of this coating was 0.079 seconds.
EXAMPLE 3
A grain was coated with a 0.0019 inch thick layer of Parylene C according to the procedure of Example 2.
The ignition time delay from this thicker coating was 1.036 seconds.
In the above examples, comparison of the experimental results and the slopes of the pressure rise between the uninhibited and polyxylylene inhibited grains indicated the control of the ignition of the propellant when coated with a layer of polyxylylene. The deposition of polyxylene onto the initial burning surface of a rocket motor grain thus controls the ignition transient and pressurization of the motor.
The polyxylylene inhibited grains have increased reliability compared to other motor inhibition systems and should lower processing costs by at least 10%. There are decreased opportunities for chemical interactions with the propellant and the pure polyxylylene. Complex and large motor grains can be uniformly and consistently coated with a thin inhibiting film by the method of the invention since, by the very nature of the vapor deposition process, the coating is uniform over the exposed surface regardless of its geometrical complexity. This uniformity is highly advantageous since, in other methods, a complex grain shape causes a non-uniform coating of inhibitor. In the present method, the thickness can be precisely controlled, and witness strips provide a method to gauge the actual thickness of material deposited. Also, the Parylene material will not encourage the migration of any ingredients into or out of the grain.
It is to be realized that only preferred embodiments of the invention have been described and that numerous substitutions, modifications and alterations are permissible without departing from the spirit and scope of the invention as defined in the following claims. | A thin film of ignition inhibitor is applied uniformly to a rocket propelt grain which may be large and have a complex shape. The film is applied by condensation and polymerization of a vaporized monomer to which the grain is subjected. The monomer is prepared by thermally cracking the dimer of paraxylylene or a halogenated paraxylylene derivative. | 2 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of application Ser. No. 11/194,657, filed on Aug. 2, 2005, now U.S. Pat. No. 7,272,485 which is based upon and claims the benefit of priority of Japanese Patent Application No. 2004-23 0997, filed on Aug. 6, 2004, the contents of both applications are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a fuel nature measuring device for an internal combustion engine and an internal combustion engine having the same.
BACKGROUND OF THE INVENTION
A gasoline engine in an automobile generally has a fuel injection valve provided at an intake pipe, and fuel injected from the fuel injection valve is supplied to an intake port. However, during cold starting with no sufficient warm-up, part of the fuel injected from the fuel injection valve tends to stick to the inner wall surface of the intake port or the surface of the intake valve and fails to enter the combustion chamber. This substantially reduces the injection amount. In order to secure an air-fuel ratio equivalent to that in a sufficiently warmed-up state, the injection amount is often corrected by adding fuel in such a case.
The amount of fuel thus sticking, for example, to the inner wall surface of the intake port, without contributing to combustion varies depending on the nature of the fuel, especially the level of its volatility. Fuel nature varies among the manufacturers, the seasons, and the distribution areas even if the fuel is of the same kind. Therefore, fuel nature must be measured highly precisely in order to accurately correct the injection amount.
A known technique for measuring fuel nature takes advantage of the characteristic that the dielectric constant of fuel changes depending on the fuel nature. According to this technique, a capacitor-type detector is provided and determines whether the fuel is light gasoline or heavy gasoline based on a capacitance of the detector corresponding to the dielectric constant of the fuel (see Japanese Utility Model Laid-Open Publication No. Hei 4-8956). According to this technique, an oscillation circuit that generates a signal at a frequency corresponding to capacitance is provided to obtain the capacitance. Another known technique takes advantage of the characteristic that the refractive index, boiling point, and molecular heat of a fuel changes depending on the fuel nature (see Japanese Patent Laid-Open Publication No. Hei 4-1438). According to the disclosure of Japanese Patent Laid-Open Publication No. Hei 4-1438, an optical fiber is immersed in the fuel, and the quantity of light passed through the optical fiber is anazlyzed to obtain the refractive index.
In order to obtain the volatility of fuel based on the dielectric constant and the refractive index, a relation between the dielectric constant and refractive index of the fuel and the volatility of the fuel must be previously known. However, the relationship varies among the manufacturers of the fuel, the seasons, and the distribution areas and it is not necessarily easy to acquire accurate information between them.
SUMMARY OF THE INVENTION
The embodiments of the present invention are directed to solve the above-described and other problems and provide a fuel nature measuring device for use in an internal combustion engine that can simply determine the volatility of fuel and an internal combustion engine having the same.
A fuel nature measuring device according to one aspect of the present invention measures the nature of fuel stored in a fuel tank. The measuring device includes a measurement passage having an orifice; a gas flow generating means for generating a gas flow in the measurement passage; differential pressure detecting means for detecting a differential pressure between both ends of the orifice; evaporated fuel concentration operating means for determining the concentration of evaporated fuel based on the differential pressure detected when the measurement passage communicates with the fuel tank at its both ends and gas in the fuel tank is the gas for measurement let to flow in the measurement passage; temperature detecting means for detecting a temperature of the fuel in the fuel tank; and volatility calculation means for calculating volatility of the fuel in the fuel tank as the fuel nature based on the concentration of the evaporated fuel detected by the evaporated fuel concentration operation means and the temperature detected by the temperature detecting means.
When the volatility of the fuel changes, the characteristic line of the saturated concentration of the evaporated fuel relative to the temperature changes. Based on the evaporated fuel concentration at the present temperature, the volatility of the fuel stored in the fuel tank can be specified.
According to another aspect of the present invention, the internal combustion engine includes a canister storing an absorbent that temporarily absorbs the evaporated fuel guided from the fuel tank through a conduit; a purge passage that guides gas in the canister including evaporated fuel desorbed from the absorbent into the intake pipe of the internal combustion engine and purges the evaporated fuel; and a purge control valve provided in the purge passage to adjust a purge flow rate.
The configuration also includes another evaporated fuel concentration operation means for operating a concentration of the evaporated fuel in gas for measurement based on the differential pressure detected when the measurement passage communicates with the canister at its both ends and gas in the canister is the gas for measurement let to flow in the measurement passage.
The main means for measuring the concentration of the evaporated fuel such as the measurement passage and the differential pressure detecting means can also be used for measuring the concentration of the evaporated fuel purged from the canister. In this way, the concentration of the evaporated fuel in the purge gas as well as the volatility of the fuel can be measured without having to provide a complicated configuration.
Another aspect of the present invention includes measurement passage switching means for switching between first and second concentration measurement states. In the first concentration measurement state, the measurement passage is opened to the atmosphere at its both ends and the gas passed through the measurement passage is the air. In the second concentration measurement state, the measurement passage communicates with the fuel tank at its both ends through a gas phase portion of the fuel tank and the gas let to flow in the fuel measurement passage is the gas in the fuel tank. The evaporated fuel concentration operating means serves as operation means for operating the concentration of the evaporated fuel based on the detected differential pressures in the first and second concentration measurement states.
In addition to the differential pressure detected when the gas in the fuel tank is distributed in the measurement passage, the differential pressure detected when the concentration of the evaporated fuel is known (zero) is available, so that correction can be carried out based on the differential pressure detected in the state. In this way, the fuel nature can be obtained more accurately.
Another aspect of the present invention includes valve means for blocking the gas flow at the orifice, and the differential pressure detecting means includes a pair of lead passages having the orifice and the valve means therebetween. The configuration further includes a communication passage to allow a closed space including the canister (formed when the purge control valve is closed) to communicate with the measurement passage on the side of one of the leading passages; another valve means for blocking the communication passage; and leakage determining means for determining leakage in the closed space based on values detected by the differential pressure detecting means in first and second leakage detection states. In the first leakage detection state, the measurement passage is not blocked and the communication passage is blocked. In the second leakage detection state, the measurement passage is blocked and the communication passage is not blocked.
In the second leakage detection state, the value detected by the differential pressure detecting means changes according to the size of a leak hole in the closed space. Information on the leakage in the closed space can be obtained by comparing the detected value to the value detected in the first leakage detection state in which the air is distributed through the orifice whose cross sectional area in the passage is a prescribed value. In this way, the volatility of the fuel or the concentration of the evaporated fuel in the purge gas can be measured without having to provide a complicated configuration. In addition, the detection for the fuel leakage can be carried out.
Still another aspect of the present invention includes engine operation state detecting means for detecting the operation state of the internal combustion engine, and the fuel nature is measured provided that the internal combustion engine is in a stopped state.
When the internal combustion engine is in a stopped state, the concentration of the evaporated fuel in the gas in the fuel tank is stable, and the fuel nature can be known more accurately.
According to yet another aspect of the present invention, the engine operation state detecting means detects whether an ignition key is on or off.
Whether the internal combustion engine is in a stopped state can easily be detected.
Still another aspect of the present invention includes fuel tank state detecting means for detecting change in the state caused by fueling to the fuel tank, and the fuel nature is measured in response to the fueling to the fuel tank.
By the fueling, the fuel tank is filled with fuel supplied by a different manufacturer and distributed in a different area from the previous one and therefore, it is highly likely that the volatility of the fuel before and after the fueling changes in a discontinued manner. Therefore, the fuel nature can be obtained more accurately.
According to still another aspect of the present invention, the fuel tank state detecting means detects whether a fuel cap of the fuel tank is open or closed.
The fuel tank in the process of being filled can easily be detected.
According to still another aspect of the present invention, the fuel tank state detecting means detects an amount of the fuel in the fuel tank and it is determined that the tank is in the process of being filled when the fuel amount is increased to a predetermined reference amount.
In this way, the fuel tank in the process of being filled can easily be detected.
According to still yet another aspect of the present invention, the fuel nature is measured for every prescribed time period.
The fuel stored in the fuel tank evaporates with time starting from its low boiling point component and therefore, the volatility is gradually lowered. Since the fuel nature is measured for every prescribed period, the change with time in the volatility is available.
According to still yet another aspect of the present invention, the temperature detecting means detects a temperature at a location other than the fuel tank, and estimates the temperature of the fuel based on the temperature detected at the location other than the fuel tank.
Other temperature detecting means provided at the internal combustion engine can also be used as the temperature detecting means. In this case, the temperature is detected at a sufficient time after the internal combustion engine stops, so that the concentration of the evaporated fuel in the fuel tank can be stabilized. Since the temperatures at various parts of the internal combustion engine converge to the ambient temperature, estimation errors can be reduced.
Yet still another aspect of the present invention includes an internal combustion engine having the fuel nature measuring device according to any of the aspects described above.
Since the amount of the fuel not contributing to the combustion in the combustion chamber can accurately be determined, the air-fuel ratio can be controlled appropriately.
An internal combustion engine according to yet another aspect of the present invention includes fuel injection amount setting means for setting a fuel injection amount at the start of the internal combustion engine based on the measured fuel nature.
Since the amount of fuel coming into the combustion chamber during cold starting can accurately be determined, the optimum fuel amount can be injected, and the internal combustion engine can be started quickly. In addition, excess fuel is not injected and therefore, the amount of fuel sticking to the internal wall or the like of the intake port can be reduced, which can reduce exhaust emission at the start of the engine.
Other features and advantages of the present invention will be appreciated, as well as methods of operation and the function of the related parts from a study of the following detailed description, appended claims, and drawings, all of which form a part of this application. In the drawings:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a fuel nature measuring device according to a first embodiment of the invention adapted to an internal combustion engine;
FIG. 2 is a flowchart of a fuel nature measuring process according to the first embodiment of the present invention;
FIG. 3 is a second flowchart of a concentration detection routine of the fuel nature measuring process of FIG. 2 ;
FIG. 4 is a timing chart illustrating various transitional states of various components of the fuel nature measuring device of FIG. 1 during the concentration detection routine of FIG. 3 ;
FIG. 5 is a top view of a part of the fuel nature measuring device of FIG. 1 in a first concentration measurement state;
FIG. 6 is a top view of a part of the fuel nature measuring device of FIG. 1 in a second concentration measurement state;
FIG. 7 is a first graph illustrating the operation of the internal combustion engine according to the first embodiment of the present invention illustrating gas flow;
FIG. 8 is a flowchart of a fuel volatility calculation routine of the fuel nature measuring process of FIG. 2 ;
FIG. 9 is a reference map for use in the fuel volatility calculation routine of FIG. 8 ;
FIG. 10 is a fourth flowchart of a fuel injection correction amount routine according to the first embodiment of the present invention;
FIG. 11 is a schematic diagram of a fuel nature measuring device according to a second embodiment of the present invention;
FIG. 12 is a schematic diagram of a fuel nature measuring device according to a third embodiment of the present invention;
FIG. 13 is a flowchart of a fuel nature measuring process according to the third embodiment of the present invention;
FIG. 14 is a schematic view of a fuel nature measuring device according to a fourth embodiment of the present invention adapted to an internal combustion engine;
FIG. 15 is a flowchart of a fuel nature measuring process according to the fourth embodiment of the present invention; and
FIG. 16 is a schematic diagram of a fuel nature measuring device according to a fifth embodiment of the present invention adapted to an internal combustion engine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 illustrates a configuration of a fuel nature measuring device according to a first embodiment of the invention installed in an automobile engine. A fuel tank 11 for an internal combustion engine 1 is connected to a canister 13 through a conduit 12 , and the fuel tank 11 and the canister 13 are continuously in communication. The canister 13 is filled with an absorbent 14 and the fuel evaporated in the fuel tank 11 is temporarily absorbed by the absorbent 14 . The canister 13 is connected to an intake pipe 2 of the engine 1 through a purge passage 15 . The purge passage 15 is provided with a purge valve 16 serving as a purge control valve, and when the valve opens, the canister 13 and the intake pipe 2 communicate.
The purge valve 16 is an electromagnetic valve and has its valve travel controlled by duty control or the like using an electronic control unit (ECU) 51 that controls various parts of the engine 1 . Evaporated fuel desorbed from the absorbent 14 is purged into the intake pipe 2 by the negative pressure in the intake pipe 2 based on the valve travel and combusted together with fuel injected from an injector 5 . Hereinafter, the air-fuel mixture including the evaporated fuel to be purged is referred to as “purge gas.”
The canister 13 is connected to a purge air passage 17 that is open to the atmosphere at its tip end. The purge air passage 17 is provided with a close valve 18 .
The purge passage 15 and the purge air passage 17 can be connected through an evaporated fuel passage 21 , which serves as a measurement passage. The evaporated fuel passage 21 is connected to the purge passage 15 through a branch passage 25 . The branch passage 25 communicates with the purge passage 15 at a point that is closer to the canister 13 than the purge valve 16 . The evaporated fuel passage 21 is connected to the purge air passage 17 through a branch passage 26 that communicates with the purge air passage 17 at a point between the canister 13 and the close valve 18 . The evaporated fuel passage 21 is provided with a first selector valve 31 , an orifice 22 , a valve 33 , a pump 41 , and a second selector valve 32 in this order from the side of the purge passage 15 . The purge passage 15 can be connected to the conduit 12 through a communication passage 24 that communicates with the conduit 12 at a point closer to the canister 13 than the branch passage 25 . The purge air passage 17 can be connected to the fuel tank 11 by a communication passage 27 at the branch portion to the branch passage 26 . The communication passage 27 communicates with the fuel tank 11 above the level of the fuel regardless of the amount of fuel in the fuel tank 11 similar to the conduit 12 . Communication passages 24 and 27 are provided with valves 34 and 35 , respectively.
The purge air passage 17 and the evaporated fuel passage 21 communicate through a communication passage 28 . One end of the communication passage 28 communicates with the evaporated fuel passage 21 at a point between the valve 33 and the pump 41 , closer to the pump 41 . The other end of the communication passage 28 communicates with the purge air passage 17 at a point between the canister 13 and the communication passage 26 , closer to the communication passage 26 .
The first selector valve 31 is a three-way electromagnetic valve that selects between first and second concentration measurement states. In the first concentration measurement state, the evaporated fuel passage 21 is opened to the atmosphere at one end, which is the right end in FIG. 1 . In the second concentration measurement state, the evaporated fuel passage 21 communicates with the communication passage 25 at the end. The switching operation between the two states is controlled by the ECU 51 . When the first selector valve 31 is in a non-conductive state (off), the first concentration measurement state is attained to let the evaporated fuel passage 21 open to the atmosphere.
The second selector valve 32 is also a three-way electromagnetic valve that selects between first and second concentration measurement states. In the first concentration measurement state, the evaporated fuel passage 21 is opened to the atmosphere at the other end, which is the left end if FIG. 1 . In the second concentration measurement state, the evaporated fuel passage 21 communicates with the communication passage 26 . The switching operation between the two states is controlled by the ECU 51 . When the second selector valve 32 is in a non-conductive state (off), the first concentration measurement state is attained to let the evaporated fuel passage 21 open to the atmosphere.
The other valves 33 , 34 , 35 , and 36 are two-way electromagnetic valves, and block the respective passages in which they are provided.
The pump 41 , which serves as the gas flow generating means, is a motor pump that in operation allows gas to be distributed in and along the evaporated fuel passage 21 while the side of the first selector valve 31 serves as the intake side and has its on/off and revolution speed in operation controlled by the ECU 51 . The revolution speed is controlled to be stable at a previously set value, in other words, fixed revolution speed control is carried out.
The evaporated fuel passage 21 is connected to a differential pressure sensor 55 serving as the differential pressure detecting means through connecting pipes 231 and 232 at the ends of the orifice 22 and the valve 33 . The differential pressure sensor 55 detects the pressure difference between the ends of the orifice 22 . A detection signal for the differential pressure is output to the ECU 51 .
The fuel tank 11 is provided with a temperature sensor 56 , which serves as the temperature detecting means, that detects the temperature inside the fuel tank 11 . A detection signal for the temperature is output to the ECU 51 .
The ECU 51 has a general configuration for an engine and includes a microcomputer as a main part. The ECU 51 controls elements such as a throttle 4 that is provided at the intake pipe 2 to adjust the intake air amount, an injector 5 that injects fuel, and an ignition plug 6 that ignites an air fuel mixture. This is carried out based on the amount of intake air detected by the air flow sensor 52 provided at the intake pipe 2 , intake air pressure detected by an intake air pressure sensor 53 , and an air-fuel ratio detected by an air-fuel ratio sensor 54 provided at an exhaust pipe 3 and in response to an ignition signal, the engine speed, the temperature of engine cooling water, the accelerator opening and the like. Accordingly, an appropriate throttle opening angle, a fuel injection amount, an ignition timing and the like can be obtained. Note that the pressure detected by the intake air pressure sensor 53 is given in absolute pressure, and equal to atmospheric pressure in the subsequent description of the fuel volatility calculation routine.
FIG. 2 is a flowchart of the fuel nature determination process performed by the ECU 51 according to the principles of the first embodiment of the present invention. In step S 101 , it is determined whether a fuel volatility determining condition is established. The fuel volatility could change by fueling, or a passing of a prescribed time period or longer after the previous fueling or when the automobile having the engine is left unused for a long while in a high temperature environment and the low-boiling point component of the fuel in the fuel tank 11 is evaporated. The fuel volatility condition is so set that the volatility is to be determined when a change in the volatility is estimated for such a reason. The process of determining whether the fuel volatility determining condition is established will be described in more detail in connection with the subsequent third embodiment.
In general, when the result of the determination in step S 101 is affirmative, the process proceeds to step S 102 to carry out the concentration detection routine. When the result of the determination is negative, step S 101 is repeated. After the concentration detection routine is performed at step S 102 , the fuel volatility calculation routine is performed in step S 103 .
FIG. 3 shows the content of the concentration detection routine performed in step S 102 of FIG. 2 . FIG. 4 shows the transition of the states of various parts of the device during the concentration detection routine. In the initial state in the concentration detection routine, the purge valve 16 is “closed” and the close valve 18 is “open.” The first and second selector valves 31 and 32 are “off,” in other words, the first concentration measurement state is attained, as depicted in FIG. 5 . The valves 33 to 36 are closed or “off.” The pump 41 is “off” (A in FIG. 4 ). In FIG. 3 , in step S 201 , the valve 33 is opened to drive the pump 41 , and gas is allowed to flow through the evaporated fuel passage 21 (B in FIG. 4 ). The gas is the air distributed through the evaporated fuel passage 21 , as denoted by the arrow in FIG. 5 , and returned into the atmosphere. In step S 202 , the differential pressure ΔP 0 at the orifice 22 is detected. In step S 203 , the close valve 18 is closed and in step S 204 , the first and second selector valves 31 and 32 are turned on, while the valves 34 and 35 are opened (on) (C in FIG. 4 ). The state is therefore changed from the first concentration measurement state (shown in FIG. 5 ) to the second concentration measurement state (shown in FIG. 6 ). At this time, the purge valve 16 and the close valve 18 are closed and the valves 34 and 35 are open, so that the gas is circulated through a loop passage formed between the fuel tank 11 and the orifice 22 , as shown in FIG. 6 . The gas flow becomes an air-fuel mixture containing evaporated fuel as it is passed through the fuel tank 11 .
In step S 205 , the differential pressure ΔP 1 at the orifice 22 is detected.
The following steps S 206 and S 207 correspond to the process equivalent to the evaporated fuel concentration operation means, and the differential pressure ratio P is calculated in step S 206 based on the obtained two differential pressures ΔP 0 and ΔP 1 according to expression (1) provided below. In step S 207 , the fuel vapor concentration C is calculated based on the differential pressure ratio P according to expression (2) provided below, wherein k1 represents a constant pre-stored in the ROM of the ECU 51 together with a control program and other programs.
P=ΔP 1 /ΔP 0 (1)
C=k 1×( P− 1)(=.(Δ P 1−Δ P 0)/Δ P 0) (2)
The evaporated fuel is heavier than the air and therefore, if the gas from the fuel tank 11 contains the evaporated fuel, the density of the gas increases. For the same revolution speed and the same flow rate in the evaporated fuel passage 21 , the differential pressure at the orifice 22 is larger than the air based on the energy conservation law. As the fuel vapor concentration C increases, the differential pressure P increases. The characteristic line representing the fuel vapor concentration C and the differential pressure P is linear, as shown in FIG. 7 . Expression (2) provided above represents the characteristic line and the constant k1 is previously obtained from experiments and the like.
In the first concentration measurement state, which is shown in FIG. 5 , air distributes through the evaporated fuel passage 21 and the fuel vapor concentration is zero. Here, the differential pressure about the gas with known concentration and the differential pressure in the second concentration measurement state to allow the gas in the fuel tank 11 to be distributed in the evaporated fuel passage 21 are detected, so that detection errors can be cancelled, which results in highly precise detection.
In step S 208 , the obtained fuel vapor concentration C is temporarily stored.
The first and second selector valves 31 and 32 are turned off, and the valves 34 and 35 are closed (off) in step S 209 , the valve 33 is closed (off) in step S 210 , and the pump 41 is turned off. The state is the same as the state denoted by A in FIG. 4 , in other words, the state before the start of the concentration detection routine is regained.
FIG. 8 shows the fuel volatility calculation routine of step S 103 of FIG. 2 . First, in step S 301 of FIG. 8 , the fuel vapor concentration C obtained in the concentration routine is read.
In step S 302 , atmospheric pressure Patm is detected. The atmospheric pressure Patm is detected by the intake air pressure sensor 53 .
In step S 303 , fuel vapor pressure Pev is calculated according to expression (3) provided below. Expression (3) is based on the fact that the concentration of the evaporated fuel is the ratio of the saturated vapor pressure of the fuel to the atmospheric pressure.
Pev=Patm×C (3)
In step S 304 , the fuel temperature T is detected.
The following step S 305 is equivalent to the process performed by the volatility calculation means, and read vapor pressure RVP is calculated as the fuel volatility based on the fuel vapor pressure Pev and the fuel temperature T. As shown in FIG. 9 , the ECU 51 stores the characteristic line between the temperature T and the vapor pressure Pev in the form of a map. The fuel volatility RVP is calculated referring to the map. The obtained fuel volatility RVP is temporarily stored in a memory in step S 306 .
Now, referring to FIG. 10 , the routine of calculating a fuel injection correction amount at the start will be described. It is determined in step S 401 whether the ignition key is turned on, and if the result of this determination is affirmative, the process proceeds to step S 402 . If the result is negative, step S 401 is repeated.
Steps S 402 to S 406 are equivalent to the process carried out by the correction amount setting means, and in step S 402 , the fuel volatility RVP obtained in the fuel volatility calculation routine is read. In step S 403 , the fuel injection amount correction coefficient TAUe corresponding to the fuel volatility RVP is calculated. The calculation is carried out according to a map or the like in which the fuel volatility RVP and the fuel injection amount correction coefficient TAUe are associated with each other.
In step S 404 , the engine water temperature Tw is detected and a fuel injection correction coefficient TAUw according to the engine water temperature Tw is calculated in step S 405 . The calculation is carried out according to a map or the like in which the engine water temperature Tw and the fuel injection amount correction coefficient TAUw are associated with each other.
In step S 406 , the fuel injection correction amount KTAU is calculated according to expression (4) provided below. The fuel injection correction amount KTAU is multiplied by the injection amount TAU calculated based on the throttle opening angle and the engine speed to produce the final injection amount.
KTAU=TAUe×TAUw (4)
The map for producing the fuel injection amount correction coefficient TAUe is set so that as the fuel volatility RVP increases, the coefficient not less than 1 decreases toward 1. This is because there is little likelihood that injected fuel with high fuel volatility RVP sticks and does not contribute to combustion.
The map for producing the fuel injection amount correction coefficient TAUw is set so that as the engine water temperature Tw increases, the coefficient not less than 1 decreases toward 1. This is because when the engine water temperature Tw is high, the temperature of the intake pipe 2 is high, which makes easier the evaporation, so that there is little likelihood that injected fuel sticks and does not contribute to combustion.
In this way, the fuel injection amount is appropriately adjusted according to the volatility of the fuel, so that the air-fuel ratio can be controlled highly precisely.
Since the concentration of the evaporated fuel in the gas passing through the fuel tank 11 can be detected, the ECU 51 forms other evaporated fuel operation means at the evaporated fuel passage 21 . The operation means calculates the concentration of the evaporated fuel in the purge gas as follows. The valves 34 and 35 are closed based on the second concentration measurement state, so that the gas in the canister 13 is circulated between the canister 13 and the evaporated fuel passage 21 . Then, based on the differential pressure at the orifice 22 at the time, the concentration of the evaporated fuel in the purge gas is calculated. The concentration detection routine is substantially the same as the content shown in FIG. 3 except for how the valves 34 and 35 are set. More specifically, the concentration of the evaporated fuel in the purge gas is available based on the differential pressure ratio of the differential pressures at the orifice 22 when the air is passed through the evaporated fuel passage 21 and when the purge gas as the gas for measurement is passed through the evaporated fuel passage 21 .
In this way, the valve travel of the purge valve 16 can be set to an appropriate value, and the amount of the evaporated fuel in the purge gas can appropriately be adjusted.
The ECU 51 also forms the leakage determining means for checking leakage in a simple manner using an evaporator system as a detection space for leakage. The evaporator system defines a closed space from the fuel tank 11 through the canister 13 to the purge valve 16 in which the evaporated fuel is present while the purge valve 16 is closed. More specifically, the first and second selector valves 31 and 32 are off, the valve 33 as the valve means is opened, and the valve 36 as other valve means is closed. This defines the first leakage detection state. In this state, the pump 41 is driven, and the differential pressure detected by the differential pressure sensor 55 is obtained at prescribed intervals. The detection output represents the pressure in the evaporated fuel passage 21 toward the side of the pump 41 relative to the atmospheric pressure as the reference and gradually increases to the negative side as the pump 41 starts to be driven. When the differential pressure between the detected pressure and the previous value is not more than a predetermined reference value, the detection output (reference pressure) at the time is stored.
Then, valve 33 is closed, valve 36 is opened, and the close valve 18 is closed. This defines a the second leakage detection state. The pump 41 is driven in the state. Similarly, the differential pressure detected by the differential pressure sensor 55 is obtained at prescribed intervals. The detection output is a pressure in the evaporator system relative to the atmospheric pressure and serves as a reference. When the differential pressure between the detected pressure and the previous value is not more than the reference value, the detection output at the time is stored and compared to the reference pressure. When the evaporator system has a hole having an area as large as the orifice 22 , a pressure value equal to the reference pressure is obtained. When the evaporator system has a hole having an area larger than the orifice 22 , the detected pressure is smaller. Therefore, if the pressure is greater than the reference pressure value, it is determined that there is no leakage in the evaporator system. Otherwise it is determined that there is leakage.
Note that the difference between the detection output and the previous value, in other words, the amount of change must be at most the reference value in order to allow the detection pressure to converge.
In this way, as the air and the gas for measurement are distributed in the evaporated fuel passage having the orifice, not only the volatility of the fuel, but also the concentration of the evaporated fuel in the purge gas can be obtained. In addition, the evaporator system can be checked for leakage. Therefore, such a multi-function device can be implemented with low cost.
FIG. 11 shows a fuel nature measuring device according to the principles of a second embodiment of the present invention. The second embodiment is substantially the same as the first embodiment with except that a part of the configuration. The elements of the second embodiment that ate substantially the same as those of the first embodiment are denoted by the same reference characters, while the different elements will mainly be described.
A purge air passage 17 A is a simple passage unconnected to other conduits and closed by a close valve 18 provided therein.
An evaporated fuel passage 21 is provided with selector valves 31 and 32 at the ends similarly to the first embodiment. When the selector valves 31 and 32 are on, the evaporated fuel passage 21 communicates with the fuel tank 11 on one side, through a communication passage 28 , and, on the other side, through a communication passage 29 .
Similar to the first embodiment, an ECU 51 A can calculate the fuel volatility RVP by detecting the differential pressures at the orifice 22 . In a first measurement state, the ECU 51 A turns off the selector valves 31 and 32 to cause air to enter into the evaporated fuel passage 21 . In a second measurement state, the ECU 51 A turns on the selector valves 31 and 32 to distribute gas containing evaporated fuel from the fuel tank 11 into the evaporated fuel passage 21 .
FIG. 12 shows a fuel nature measuring device according to the principles of a third embodiment of the present invention. The third embodiment is substantially the same as the first embodiment except for a part of the configuration. The elements of the third embodiment that are substantially the same as those of the first embodiment are denoted by the same reference characters, while the different elements will mainly be described.
A fuel cap 19 at the fuel inlet of the fuel tank 11 has its open/closed state detected by a sensor 57 , which serves as the fuel tank state detecting means, so that the open/closed state of the fuel cap 19 is available to an ECU 51 B. The sensor 57 may be a switch type sensor, an optical type sensor, a capacitance type sensor, or any of various other kinds of sensors.
FIG. 13 partly shows how control is carried out by the ECU 51 B of the third embodiment of the present invention. It is determined in step S 501 whether or not the fuel cap 19 is “open.” If the result of determination is affirmative, the present time is stored in step S 505 as the concentration detection date and time. In the following step S 506 , the concentration detection routine is performed. In step S 507 , the fuel volatility calculation routine is performed. These concentration detection routine and fuel volatility calculation routine are performed similar to those of the first embodiment. After the fuel volatility calculation routine is performed at step S 507 , the process returns to step S 501 .
When the result of determination is negative in step S 501 , it is determined in step S 502 whether the ignition key is in an “on” state. If the result of determination is negative, the process returns to step S 501 . The concentration detection routine at step S 506 and the fuel volatility calculation routine at step S 507 are not performed.
When the result of determination in step S 502 is affirmative, it is determined in step S 503 whether a prescribed time period has elapsed after the previous concentration detection. This is determined based on the stored concentration detection date and time from step S 505 . If the result of determination is affirmative, the process from steps S 505 to S 507 is performed. Therefore, during the period before the next fueling, the volatility of the fuel is determined at intervals of the prescribed time period. The evaporation of the low boiling point component in fuel proceeds with time, which changes the volatility of the fuel and therefore, the fuel injection amount is adjusted appropriately in response to the change in the volatility.
If the result of determination is negative in step S 503 , it is determined in step S 504 whether the fuel temperature T is greater than the prescribed temperature T 0 . If the result of determination is affirmative, the process from steps S 505 to S 507 is performed. At the higher fuel temperatures T, the low boiling point component in combustion evaporates more easily, and the volatility of the fuel changes more rapidly. Therefore, if the prescribed time period has not elapsed after the previous concentration detection, it is highly likely that there is a significant change in the volatility. The fuel injection amount can be adjusted appropriately in response to the change in the volatility.
If the result of determination in step S 504 is negative, the process returns to step S 501 .
In this way, the fuel nature is determined in the timing when some significant change in the fuel nature is recognized, and the operation frequencies of the pump 41 , the selector valves 31 and 32 , and valves 33 to 35 can be lowered to reduce the power consumption from the batteries. This can also alleviate the calculation load.
Note that if the elapsed time after the previous concentration detection is greater than or equal to the prescribed time period, the ignition key must be on even at a temperature that is greater than or equal to the prescribed temperature T 0 . This is because the fuel is not injected during the ignition-off period, the result of fuel nature measuring process is not used for controlling the engine, and the power can be saved during the period. However, if the power consumption can be ignored, the operation may be carried out during the ignition-off period as will be described below in the fifth embodiment.
FIG. 14 shows a fuel nature measuring device according to a fourth embodiment of the present invention. The fourth embodiment is substantially the same as the first embodiment except for a part of the configuration. The elements of the fourth embodiment that are substantially the same as those of the first embodiment are denoted by the same reference characters, while the different elements will mainly be described.
A fuel level gauge 58 , which serves as the fuel tank state detecting means for detecting the fuel amount, is provided in the fuel tank 11 . The fuel level gauge 58 may be a float type device or any of other kinds of detecting devices. A detection signal from the fuel level gauge 58 is input to an ECU 51 C, so that the fuel amount is available.
FIG. 15 shows a part of the control carried out by the ECU 51 C of the fourth embodiment. It is determined in step S 601 whether the fuel amount has increased by a prescribed amount or more. If the result of determination is affirmative, steps S 605 to S 607 are performed. In steps S 605 to S 607 that are the same as the process from steps S 505 to S 507 , the present date and time are stored as concentration detection date and time (step S 605 ), the concentration detection routine is performed (step S 606 ), and the fuel volatility calculation routine is performed (step S 607 ). The fuel in the fuel tank 11 increases at the time of fueling, and the occurrence of fueling can be detected in the same manner as in step S 501 according to the third embodiment. If the result of determining whether the fuel amount increase is greater than or equal to the prescribed amount, in step S 601 , is negative, the process proceeds to step S 602 . Steps S 602 to S 604 are the same as the process from steps S 502 to S 504 according to the third embodiment. If the ignition key is “on” (step S 602 ) and the prescribed time has passed after the previous concentration detection (step S 603 ), or if the fuel temperature T attains the prescribed temperature T 0 or higher, the process of determining the fuel nature is performed (steps S 605 to S 607 ).
Note that the prescribed amount compared to the fuel amount in step S 601 must be set to a sufficiently large value, such that the appearance of a fuel increase due to the vehicle being parked on a slope is not mistaken for a fuel amount increase. The fueling is generally carried out when the fuel amount is reduced to half the full tank level and therefore, it is easy to set the prescribed value to a level that cannot allow such mistaken determination.
FIG. 16 shows a fuel nature measuring device according to the principles of a fifth embodiment of the present invention. The fifth embodiment is substantially the same as the first embodiment except for a part of the configuration. The elements of the fifth embodiment that are substantially the same as those of the first embodiment are denoted by the same reference characters, while the different elements will mainly be described.
An air flow sensor 52 in an intake pipe 2 has an intake air temperature sensor 59 that detects the temperature of intake air. The intake air temperature sensor 59 is formed as a unit in the air flow sensor 52 . A detection signal from the intake air sensor 59 is input to an ECU 51 D, so that the intake air temperature is available to the ECU 51 D.
The ECU 51 D performs control substantially the same as that by the ECU 51 according to the first embodiment, and the intake temperature sensor 59 is substituted for the temperature sensor 56 of the first embodiment. More specifically, immediately after the ignition key is turned “off,” the fuel tank 11 is approximately at the ambient temperature, while the intake pipe 2 provided in the engine room is at a high temperature. Then, the temperature of the intake pipe 2 converges toward to the ambient temperature after a sufficient period of time.
Therefore, after the elapse of a prescribed time period after the ignition key is turned “off,” the temperature detected by the intake temperature sensor 59 is considered substantially equal to the temperature of the fuel. Then, the concentration detection routine and the fuel volatility measuring routine are performed in the same manner as the first embodiment, so that the fuel nature can be determined. Note that the prescribed time period is, for example, a 5-hour period, in which the temperature of the intake pipe 2 is recognized to have converged to the ambient temperature. The convergence characteristic of the temperature of the intake pipe 2 may be obtained from experiments and the prescribed time period may be set based on the result. Therefore, it should be appreciated that the prescribed time period can be any time period less than or greater than 5 hours.
The use of the intake air temperature sensor 59 provided at the airflow sensor 52 simplifies the configuration. Any temperature detecting means provided in the vehicle having the engine may be used but the use of the intake air temperature sensor 59 is preferable because fresh air is distributed in the intake air passage 2 and therefore, the detected temperature is basically close to the temperature inside the fuel tank 11 as compared to the cooling water temperature.
It should be understood that the invention may be modified into other forms than those specifically described herein without departing from the spirit and scope of the present invention.
Furthermore, it should be appreciated that while the various processes and routines described herein have been described as including a sequence of steps, alternative embodiments including alternative sequences of these steps and/or including alternative or supplemental steps are intended to be within the scope of the present invention. | A fuel nature measuring device for measuring the nature of fuel stored in a fuel tank includes a measurement passage, a gas flow generator, a pressure detector, an concentration operator, a temperature detector, and a volatility calculator. The measurement passage has an orifice. The gas flow generator generates gas flow in the measurement passage. The pressure detector detects a differential pressure between opposite ends of the orifice. The concentration operator determines a concentration of evaporated fuel in the fuel tank based on the differential pressure detected when the opposite ends of the measurement passage communicate with the fuel tank and the fuel flows in the measurement passage. The temperature detector determines a temperature of the fuel in the fuel tank. The volatility calculator calculates a volatility of the fuel in the fuel tank based on the concentration of the evaporated fuel and the temperature of the fuel in the tank. | 5 |
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of and claims priority in U.S. patent application Ser. No. 14/018,113, filed Sep. 4, 2013, which claims priority in U.S. Provisional Patent Application No. 61/743,426, filed on Sep. 4, 2012, and which is a continuation-in-part of and claims priority in U.S. patent application Ser. No. 13/199,206, filed Aug. 23, 2011, which claims priority in U.S. Provisional Patent Application No. 61/402,536, filed Sep. 1, 2010, all of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This application relates to utility knife blades, and more particularly, to unconventional utility knife blades with multiple defined individual cutting edges that allow the user to have available on one blade, multiple individual cutting edges that will be used with special designed utility knives.
[0004] 2. Background and Description of the Related Art
[0005] Conventional disposable utility blades are well known in the art. These blades, along with their knives, have many industrial as well as home uses, such as for opening boxes, cutting cord or cutting wallboard. Typical utility blades are encased in a plastic or metal handle in either a fixed or retractable position. When in use, the blade is positioned to extend outwardly from the handle, exposing the cutting edge and one of the cutting points of the blade.
[0006] Utility knife blades come in a variety of shapes depending upon the intended use. A conventional utility blade has a generally trapezoidal shape that includes a back edge, a cutting edge and two side edges. The trapezoidal shaped blades have two cutting edges or tips formed at the intersections between the side edges and the cutting edge. These sharp points or tips enable a user to puncture through a material which is desired to be cut, such as sealing tape or a cardboard box. Once the object has been punctured and penetrated, the user can slice open the material by dragging the knife along the surface of the material allowing the cutting edge to cut through the material.
[0007] Existing prior art includes U.S. Pat. Nos.: 7,921,568; 5,557,852; 2,542,582; 4,592,113; 3,037,342; 5,636,845; and 4,745,653.
[0008] Although trapezoidal-shaped utility blades are widely used, they have only two usable cutting edges. They have the disadvantage that when the two edges get dull, the blade has to be replaced. The two-edged blade, therefore, requires more frequent replacement after the two cutting edges are worn out.
[0009] Break-off style blades with a multitude of cutting edges are not well suited for many applications and there is a greater safety or injury risk due to potential snap-off during usage when side loads are applied.
[0010] There is a need for an improved utility knife blade that overcomes one or more of the above-described drawbacks and/or disadvantages of conventional prior art utility knife blades.
SUMMARY OF THE INVENTION
[0011] The present invention provides a utility knife employing a blade having multiple cutting edges, and a means for quickly and simply swapping out one cutting edge for another.
[0012] In a preferred embodiment, a six-cutting-edge featured blade is employed. Each point of the generally triangular-shaped, multiple-cutting-edge featured blade features two distinct cutting edges, for a total of six cutting edges located on a single blade. The blade can be rotated about a central axis to expose new cutting edges as old edges wear and dull.
[0013] One embodiment of the present invention features a knife handle capable of holding a blade with multiple cutting edges, such that the blade can be turned or flipped to present a new cutting edge when the previous cutting edge has become dull.
[0014] Another embodiment features a hinged flap which bolts against the handle, thereby making it even simpler to install, flip, or exchange blades.
[0015] Another embodiment features a hinged flap and also a number of support pegs which provide additional support for the blade and may be used in situations where higher pressure is applied to the blade during the cutting process. The pegs may be removable or permanently attached to the handle.
[0016] The blades feature several different aspects, including curved or straight cutting edges, hooked cutting edges, and a plurality of connecting features for connecting the blades to a handle in such a way as to ensure the blade is secure and provides the best cutting performance.
[0017] Other aspects and advantages of the present invention will become more readily apparent in view of the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1A is an isometric view of a three-sided blade.
[0019] FIG. 1B is a front elevational view thereof.
[0020] FIG. 1C is a rear elevational view thereof, showing the blade edges located on the front face in hidden lines.
[0021] FIG. 2A is a side elevational view of a three-sided blade being fitted into a simplified knife handle and blade receiver head.
[0022] FIG. 2B is a second step in a series thereof.
[0023] FIG. 2C is a third step in a series thereof.
[0024] FIG. 2D is a top plan view thereof.
[0025] FIG. 3A is an isometric view of a three-sided blade of an alternative configuration.
[0026] FIG. 3B is a front elevational view thereof.
[0027] FIG. 3C is a rear elevational view thereof.
[0028] FIG. 4A is an isometric view of a three-sided blade of an alternative configuration.
[0029] FIG. 4B is a front elevational view thereof.
[0030] FIG. 4C is a rear elevational view thereof.
[0031] FIG. 5A is a side elevational view of a three-sided blade with notched receivers being fitted into a simplified knife handle and blade receiver head, the view including a cut-away view of the blade being contained within the handle.
[0032] FIG. 5B is a side elevational view thereof, showing the external face of the handle.
[0033] FIG. 5C is a top plan view thereof.
[0034] FIG. 5D is sectional view thereof, showing the blade being received by the handle in more detail.
[0035] FIG. 6A is an isometric view of a three-sided blade of an alternative configuration including hooked blade-ends.
[0036] FIG. 6B is a front elevational view thereof.
[0037] FIG. 6C is a rear elevational view thereof.
[0038] FIG. 7A is an isometric view of a three-sided blade of an alternative configuration including double-hooked blade-ends.
[0039] FIG. 7B is a front elevational view thereof.
[0040] FIG. 7C is a rear elevational view thereof.
[0041] FIG. 8A is an isometric view of a three-sided blade of an alternative configuration including notched receivers located between cutting edges which would be received by a handle as shown in FIGS. 5A-5D .
[0042] FIG. 8B is a front elevational view thereof.
[0043] FIG. 8C is a rear elevational view thereof.
[0044] FIG. 9A is an isometric view of a three-sided blade of an alternative configuration including notched receivers located between cutting edges and an alternative mounting hole located centrally within the blade.
[0045] FIG. 9B is a front elevational view thereof.
[0046] FIG. 9C is a rear elevational view thereof.
[0047] FIG. 10A is an isometric view of a three-sided blade of an alternative configuration including notched receivers located between cutting edges and etched gripping surfaces located at various locations on the face of the blade.
[0048] FIG. 10B is a front elevational view thereof.
[0049] FIG. 10C is a rear elevational view thereof.
[0050] FIG. 10D is a more detailed view taken about the circle in FIG. 10C .
[0051] FIG. 10E shows a blade featuring an alternative etching pattern from that shown in FIGS. 10A-10D .
[0052] FIG. 11A is an isometric view of a three-sided blade of an alternative configuration including mass-reducing cut-outs.
[0053] FIG. 11B is a front elevational view thereof.
[0054] FIG. 11C is a rear elevational view thereof.
[0055] FIG. 11D is an isometric view of an alternative orientation thereof, featuring additional mass-reducing cut-outs.
[0056] FIG. 11E is a front elevational view thereof.
[0057] FIG. 11F is a rear elevational view thereof.
[0058] FIG. 12A is an isometric view of an alternative embodiment multi-edged blade.
[0059] FIG. 12B is a front elevational view thereof.
[0060] FIG. 12C is a rear elevational view thereof.
[0061] FIG. 13A is an isometric view of an alternative embodiment multi-edged blade including mass-reducing spaces.
[0062] FIG. 13B is a front elevational view thereof.
[0063] FIG. 13C is a rear elevational view thereof.
[0064] FIG. 14 is a side elevational view of a handle receiving the blade shown in FIGS. 6A-6C .
[0065] FIG. 15 is a side elevational view of a handle receiving the blade shown in FIGS. 7A-7C .
[0066] FIG. 16 is an elevational view of an alternative blade.
[0067] FIG. 17 is an elevational view of another alternative blade.
[0068] FIG. 18 is an elevational view of yet another alternative blade.
[0069] FIG. 19 is an elevational view of yet another alternative blade.
[0070] FIG. 20 is an elevational view of yet another alternative blade.
[0071] FIG. 21 is an elevational view of yet another alternative blade.
[0072] FIG. 22 is an elevational view of yet another alternative blade.
[0073] FIG. 23 is an elevational view of yet another alternative blade.
[0074] FIG. 24A is a rear elevational view of a knife handle containing an embodiment of the present invention.
[0075] FIG. 24B is a front elevational view thereof, showing the hinged panel in an open position.
[0076] FIG. 25A is a rear elevational view of another knife handle containing another slightly-altered embodiment of the present invention.
[0077] FIG. 25B is a front elevational view thereof, showing the hinged panel in an open position.
[0078] FIG. 26A is a rear elevational view of another knife handle containing another embodiment of the present invention.
[0079] FIG. 26B is a front elevational view thereof, showing the hinged panel in an open position.
[0080] FIG. 27A is an elevational view showing an embodiment of the present invention which includes a wear coat shown in original condition.
[0081] FIG. 27B is an elevational view thereof showing the wear coat in a worn condition signifying that the blade should be rotated.
[0082] FIG. 28A is an elevational view showing an alternative embodiment of the present invention which includes a wear coat shown in original condition.
[0083] FIG. 28B is an elevational view thereof showing the wear coat in a worn condition signifying that the blade should be rotated.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
I. Introduction and Environment
[0084] As required, detailed aspects of the disclosed subject matter are disclosed herein; however, it is to be understood that the disclosed aspects are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art how to variously employ the present invention in virtually any appropriately detailed structure.
[0085] Certain terminology will be used in the following description for convenience in reference only and will not be limiting. For example, up, base, front, back, right and left refer to the invention as oriented in the view being referred to. The words “inwardly” and “outwardly” refer to directions toward and away from, respectively, the geometric center of the embodiment being described and designated parts thereof. Forwardly and rearwardly are generally in reference to the direction of travel, if appropriate. Said terminology will include the words specifically mentioned, derivatives thereof and words of similar meaning
[0086] A preferred embodiment features a generally planar blade featuring three distinct points, each point featuring at least one cutting edge. The blade is designed to be rotated amongst the cutting edges as the edges wear down from use.
II. Preferred Embodiment Knife Blade 3
[0087] FIGS. 1A-C show a typical three-sided knife blade 3 having six cutting edges 5 . Each edge can, in turn, be presented from a knife handle (see FIGS. 2A-D ) by flipping or turning the blade within the blade retaining head of the handle. The handle in the preferred embodiment would include a right portion 10 and a left portion 20 which join together to form the handle with a head portion 9 having a blade receiver gap 50 . Each cutting edge is labeled by an edge label 11 . A blade cutting edge indicator 13 distinguishes the cutting edge from the body of the blade. FIG. 1C shows the gap 17 located between two separate cutting edges 5 . The gap can be a flat space, a notch, or it could be a continuous cutting edge. The purpose of the gap 17 is to designate between two separate cutting edges.
[0088] FIGS. 2A-D show how a blade 3 would be inserted into a blade receiver slot 50 within the receiving head 9 of a knife handle having a right half 10 and a left half 20 . A handle mounting hole 8 located in the handle is aligned with the central mounting hole 7 of the blade 3 , and a mounting bolt 6 secures the blade within the handle.
III. First Alternative Embodiment Knife Blade 53
[0089] FIGS. 3A-C show an alternative arrangement of the three-sided blade which includes a secondary ring of mounting holes 62 which provides additional stability to a blade secured by those holes in addition to the blade retaining hole 57 . Here also, the cutting edge 55 , cutting edge indicator 63 and cutting edge identifier 61 may be used.
IV. Second Alternative Embodiment Knife Blade 103
[0090] As shown in FIGS. 4A-4C , an alternative embodiment three-tipped blade 103 includes six cutting edges 105 each labeled with a cutting edge identifier 111 and defined by a cutting edge indicator 113 . A centralized mounting hole 107 is used for mounting this blade 103 into a handle. This blade features angled edges, forming a 6-sided planar blade.
V. Third Alternative Embodiment Knife Blade 153
[0091] As shown in FIGS. 5A-5D , an alternative embodiment three-tipped blade 153 includes six cutting edges 155 each labeled with a cutting edge identifier 161 and defined by a cutting edge indicator 163 . A blade notch 154 is located between the two cutting edges 155 defining each side of the blade 153 . This notch provides greater stability and secures the blade 153 within the mounting head 159 of the handle comprising a right half 160 and a left half 170 . A mounting pin 156 secures the blade 153 to the mounting head 159 via the central mounting hole 157 .
[0092] The blade notches relieve pressure on the cutting blade 153 when the blade is actively cutting an object. This prevents the edge of the blade from being pressed against the interior of the utility knife receiving head, which can cause inactive cutting edges to become dulled. The receiving head of the utility knife handle includes notched posts which receive the blade notches 154 . These notches also assist in manufacturing purposes, indexing, and assuring that the blade is properly located within the knife handle.
VI. Fourth Alternative Embodiment Knife Blade 203
[0093] FIGS. 6A-6C show another embodiment of a knife blade 203 having a generally planar shape and featuring three hooked tips 204 each having a cutting edge 205 located along the inside of the hook feature. Each cutting edge is identified by a cutting edge identifier 211 . Blade notches 206 help to secure the blade to a blade handle (not shown). A central mounting hole 207 features multiple radiating arms which help to lock the blade in place when mounted within a blade handle. Additional mounting holes 212 are located around the central mounting hole 207 to receive mounting pegs or other securing elements when the blade is inserted into a handle.
[0094] FIG. 14 shows a handle 210 receiving the blade 203 . Three pegs 220 are inserted through the secondary mounting holes 212 . A panel 214 closes over the blade 203 once it is inserted into the handle. The panel has peg receivers 218 and a central locking element receiver 216 which secure the blade between the panel and the handle 210 .
[0095] The mounting pegs relieve pressure on the cutting blade 203 when the blade is actively cutting an object. This prevents the edge of the blade from being pressed against the interior of the utility knife receiving head, which can cause inactive cutting edges to become dulled. The mounting holes which are associated with the pegs also assist in manufacturing purposes, indexing, and assuring that the blade is properly located within the knife handle.
VII. Fifth Alternative Embodiment Knife Blade 253
[0096] FIGS. 7A-7C show another embodiment of a knife blade 253 having a generally planar shape and featuring three double-hooked tips 254 each having two cutting edges 255 located along the inside of the hook feature. Each cutting edge is identified by a cutting edge identifier 261 . Blade notches 256 help to secure the blade to a blade handle (not shown). A central mounting hole 257 features multiple radiating arms which help to lock the blade in place when mounted within a blade handle. Additional mounting holes 262 are located around the central mounting hole 257 to receive mounting pegs or other securing elements when the blade is inserted into a handle
[0097] FIG. 15 shows a handle 260 receiving the blade 203 . Three pegs 270 are inserted through the secondary mounting holes 262 . A panel 264 closes over the blade 253 once it is inserted into the handle. The panel has peg receivers 268 and a central locking element receiver 266 which secure the blade between the panel and the handle 260 .
VIII. Sixth Alternative Embodiment Knife Blade 303
[0098] FIGS. 8A-8C show another embodiment of a knife blade 303 having a generally planar shape and featuring three tips each having two cutting edges 305 . Each cutting edge is identified by a cutting edge identifier 311 and a cutting edge indicator 313 . Blade notches 304 help to secure the blade to a blade handle (not shown). A central mounting hole 307 features multiple radiating arms or spokes which help to lock the blade in place when mounted within a blade handle. Additional mounting holes 312 are located around the central mounting hole 307 to receive mounting pegs or other securing elements when the blade is inserted into a handle
IX. Seventh Alternative Embodiment Knife Blade 353
[0099] FIGS. 9A-9C show another embodiment of a knife blade 353 having a generally planar shape and featuring three tips each having two cutting edges 355 . Each cutting edge is identified by a cutting edge identifier 361 and a cutting edge indicator 363 . Blade notches 354 help to secure the blade to a blade handle (not shown). A central mounting hole 357 features a large geometric opening having three long sides and three short sides to lock the blade in place when mounted within a blade handle. Additional mounting holes 362 are located around the central mounting hole 357 to receive mounting pegs or other securing elements when the blade is inserted into a handle.
X. Eighth Alternative Embodiment Knife Blade 403
[0100] FIGS. 10A-10D show another embodiment of a knife blade 403 having a generally planar shape and featuring three tips each having two cutting edges 405 . Each cutting edge is identified by a cutting edge identifier 411 and a cutting edge indicator 413 . Blade notches 404 help to secure the blade to a blade handle (not shown). A central mounting hole 407 and secondary mounting holes 412 receive mounting pegs or other securing elements when the blade is inserted into a handle. A grip surface 416 including a hole 417 is located in proximity to each of the three points of the cutting blade 403 . The grip surface enhances the ability to grasp the blade for replacement or when turning the blade to use a new cutting edge.
[0101] FIG. 10E shows a slightly altered version wherein the pattern of the grip surface 420 is based upon concentric rings instead of the pattern shown in FIGS. 10A-10D .
XI. Ninth Alternative Embodiment Knife Blade 453
[0102] FIGS. 11A-11C show another embodiment of a knife blade 453 having a generally planar shape and featuring three tips each having two cutting edges 455 . Each cutting edge is identified by a cutting edge identifier 461 . Blade notches 454 help to secure the blade to a blade handle (not shown). A central mounting hole 457 and secondary mounting holes 462 receive mounting pegs or other securing elements when the blade is inserted into a handle. A number of mass-reducing cutouts 466 are punched through, cut out, or otherwise removed from the body of the blade 453 . An example pattern is shown in FIGS. 11A-11C and an alternative pattern is shown in FIGS. 11D-11F featuring additional mass-reducing cutouts 466 ; however, any pattern, shape, or variation of mass-reducing cutouts could be used to reduce the weight of the blade 453 . The purpose of the mass-reducing elements is to reduce friction while cutting using the blade.
XII. Tenth Alternative Embodiment Knife Blade 503
[0103] FIGS. 12 A- 12 DC show another embodiment of a knife blade 503 having a generally planar shape and featuring three tips each having two cutting edges 505 . Blade notches 504 help to secure the blade to a blade handle (not shown). A central mounting hole 507 for mounting the blade to a handle (not shown) is centrally located in the blade 503 .
XIII. Eleventh Alternative Embodiment Knife Blade 553
[0104] FIGS. 13A-13C show a slightly altered embodiment of a knife blade 553 having a generally planar shape and featuring three tips each having two cutting edges 555 . Blade notches 554 help to secure the blade to a blade handle (not shown). A central mounting hole 557 for mounting the blade to a handle (not shown) is centrally located in the blade 553 . Mass-reducing cutouts 566 are shown removed symmetrically from each point of the blade 553 , but the cutouts could be any shape and located anywhere on the blade's surface.
XIV. Additional Alternative Embodiment Knife Blades 603
[0105] FIGS. 16-23 present additional knife blade 603 variations to those blades described in detail above. Each includes blade cutting edge identifiers, many ( FIGS. 16-21 ) include cutting edge indicators, and all present three or six cutting edges. FIG. 23 shows a knife blade 603 featuring a blade notch.
[0106] FIG. 16 presents a knife blade 603 having a 3-spoke center mounting hole 606 . FIG. 17 presents a knife blade 603 having a triangular shaped center mounting hole 608 . FIG. 19 presents a knife blade 603 having a six-pointed star shaped center mounting hole 610 . FIG. 20 presents a knife blade 603 having scalloped cutting edges 616 and a six-spoked center mounting hole 612 . FIG. 21 presents a knife blade 603 having a triangular-shaped center mounting hole 614 with rounded points.
[0107] Any variation of a three-pointed blade, from the general shape, placement of cutting edges, location and/or shape of mounting holes, and type of cutting edge surface, could be possible in an embodiment of the present invention.
XV. Alternative Embodiment Knife Blade 653 and Knife Handle 660 Assembly
[0108] FIGS. 24A-24B show a handle 660 including a hinged panel 664 receiving another embodiment of a three-pointed knife blade 653 of generally planar shape. The blade 653 includes six cutting edges 655 each having a cutting edge identifier 661 and a cutting edge indicator 663 . A central mounting hole 657 and three surrounding mounting holes 662 are used to secure the blade within the handle. The panel includes peg receiver holes 668 which receive pegs 670 passing through the secondary mounting holes 662 of the blade 653 . A center mounting bolt receiver 666 is also located in the panel and is aligned with the center mounting hole 657 of the blade 653 . In this orientation, the secondary mounting holes 662 closest to the two points not exposed from the handle are engaged with pegs 670 , and the third secondary mounting hole associated with the point of the blade exposed from the handle is not engaged with a peg.
[0109] FIGS. 25A-25B show a slightly altered embodiment of the same knife blade 653 wherein the secondary mounting holes 662 are oriented such that all three are engaged with pegs 670 whenever the panel 664 is closed over the blade 653 .
XVI. Alternative Embodiment Knife Blade 703 and Knife Handle 710 Assembly
[0110] FIGS. 26A-26B show a handle 710 including a hinged panel 714 receiving another embodiment of a three-pointed knife blade 703 of generally planar shape. The blade 703 includes six cutting edges 705 each having a cutting edge identifier 711 and a cutting edge indicator 713 . A central mounting hole 707 is used to secure the blade within the handle. The central mounting hole is of an abnormal shape featuring three short sides interspaced amongst three long sides which matches a similarly-shaped peg located on the handle. The shape of the mounting hole 707 and the peg does not matter, as long as it allows for the blade 703 to be rotated amongst the cutting edges and secures the blade from rotating when the peg is placed through the mounting hole. A mounting bolt receiver 720 is located in the center of the peg. The panel 714 includes a peg receiver 716 and a mounting bolt receiver hole 717 .
XVII. Alternative Embodiment Knife Blade 753 Featuring a Wear Coat Layer 768
[0111] FIGS. 27A-27B show a handle 760 including a blade receiver head 761 receiving another embodiment of a three-pointed knife blade 753 of generally planar shape. The blade 753 includes three or six cutting edges 755 . A central mounting hole 757 is used to secure the blade within the handle.
[0112] The wear coat 768 , possibly of an ink-like substance or other semi-permanent marking agent, may cover any or all portions of the blade 753 . This would include the cutting edges 755 and any portion of the blades that would come in contact with the already cut material. The wear coat may be designed in any configuration, such as a circle, square or others. The wear-coat may consist of a Logo or company name, or may include cutting edge indicators in the forms of letters or numbers.
[0113] The wear-coat will allow the user the ability to distinguish between the used and the unused cutting surfaces 755 of the blade 753 . As the blade is cutting through material, only that portion of the blade's wear-coat will sustain and visually show wear. Once the wear coat has been worn significantly away to a clean, smooth surface 770 , it will be an indication to the user that the cutting edge should be swapped for a new cutting edge. Of course the user will make the ultimate determination based upon the dullness of the blade. Unused cutting edges on the blade will be immediately recognizable by the un-worn finish of the wear coat along those particular edges.
[0114] In some embodiments, the wear coat could double as a lubricant which would reduce the friction of the knife blade against the cutting surface. This could be particularly useful in certain fields of industry. The wear coat indicates both when the blade is likely becoming dull and when the lubricant is running low.
XVIII. Alternative Embodiment Knife Blade 803 Featuring a Wear Coat 818
[0115] FIGS. 28A-28B show an alternative method of establishing a wear coat, wherein the wear coat 818 consists of a raised or otherwise altered surface of the knife blade 803 along the cutting edge 805 of the blade. The blade 803 is mounted to a knife handle 810 via a central mounting hole 807 and multiple secondary mounting holes 812 using features disclosed elsewhere above. As the cutting edge is used, the surface area of the wear coat 818 becomes worn down and wears away to a smooth surface 820 , indicating that the cutting edge is dull and should be switched.
[0116] For all of the above-mentioned embodiments, simple variations may be incorporated. For example, the blade's cutting edge can be straight, serrated, wave shaped or can have micro serration's and other shapes as needed. The blade can be of different materials such as steel alloys, bimetallic, tri-metallic, and ceramics and it can have different types of coatings to enhance its surface properties, hardness and to resist corrosion. The blade can be of different sizes and thickness.
[0117] All of the blade variations introduced in this application could be made of any appropriate material, such as stainless steel. However, these blades are also suitably made of carbide, ceramic, powder metal, or other non-typical materials. This is due to the novel features as discussed, such as the mounting pegs and mounting notches which relieve pressure on the actual blade during cutting action, thereby increasing the cutting edge's durability.
[0118] It is to be understood that while certain aspects of the disclosed subject matter have been shown and described, the disclosed subject matter is not limited thereto and encompasses various other embodiments and aspects. | A three-sided, multi-edged disposable cutting blade for use within a utility knife. The cutting blade features between three and six distinct cutting edges. The cutting blade may be rotated and flipped such that each cutting edge may be presented from the utility knife as the active cutting edge. Features of the cutting blade include a wear-coat indicator which is located at or near each cutting edge and indicates when an edge has been used; grippable locations on the body of the blade to increase the grippibility of the blade when removing and handling the blade; multiple mounting-hole orientations; and mass-reducing punch-outs which reduce cutting friction of the blade against the object being cut. | 8 |
CROSS-REFERENCE
This is a continuation-in-part of Copending Application Ser. No. 581,740 filed May 29, 1975 now abandoned.
BACKGROUND OF THE INVENTION
This invention is in the field of movable wall panels and space dividers which may be made to conform and fit a desired functional usage. There are in the prior art many types of wall panels and designs useful in designing and arranging floor plans for buildings to meet various functional needs of offices, homes or the like.
Typical of such prior art is that shown in the following patent references:
______________________________________U.S. Pat. Nos.______________________________________1,154,622 2,730,209 2,787,8122,832,101 3,694,975 3,713,2573,049,197 3,492,766 3,429,6013,488,908 3,852,926 2,107,6243,299,594 3,075,253 2,371,3003,194,361 3,377,756 3,643,395Great Britain Patents Nos.______________________________________179,840 (1922) 197,184 (1923)Italy Patent No. 553,280 (1956)Sweden Patent No. 129,429 (1950)______________________________________
These movable walls and dividers are of such construction, however, that they are not adaptable to quick assembly or to new and changing material and design concepts for decorating or redecorating. In addition, the prior known wall panels are burdensome to assemble and, in some instances, do not provide sufficient separations of office functions to prevent noise or other distracting influences from the next adjacent areas, and do not have the appearance of a permanent wall.
SUMMARY OF THE INVENTION
This invention has for its object to provide a free standing wall or vertical divider which is capable of placement within any building complex to form cubicles or areas for different functional purposes in accordance with a desired floor plan.
The invention permits the utilization of identically pre-constructed elements such as frames and panels which can be quickly assembled in desired patterns of functional usage in building spaces, and which can be readily moved with changes in floor plan or decor.
Generally the invention is directed to a free-standing vertical divider wall useful in separating or dividing areas, especially within buildings, to form offices, classrooms and the like. The structure of the invention basically incorporates a quadrilateral frame, of desired thickness, the inside space defined by the frame being filled with one or more decorative panels. First vertical support members of thickness less than the thickness of the frame extend internally along each of the inside vertical frame sections. These first support members may be movable in a horizontal direction and include apertures for the placement of hidden locking devices, keepers or brackets for the support of shelves or other appurtenances. If a plurality of panels are used, there is at least one second vertical support member positioned to the upper and lower horizontal frame sections so as to be movable in a horizontal direction yet retained to the upper and lower horizontal frame sections. The vertical second support members divide the space horizontally between the first supports being movable to permit a plurality of panels to substantially fill the divided space inside the frame. The panels have grooves or recesses along their vertical edges into which the support members are caused to operate and thus permit the insertion of each of the panels. The second vertical support members are then moved to a mid-position relative to the edges of adjacent panels and temporarily locked in place by hidden keeper members inserted into apertures in the support members. Each of the panels includes a resilient peripheral edge that, in essence, makes the panel slightly larger than the space it is to fill, thus being compressible to the actual dimensional space when in place. Because of the resiliency, the aforementioned keepers and/or shelf brackets are readily insertable into apertures vertically formed in the support members. The bottom of the frame member may include a hollow box into which appropriate utility lines may be carried to appropriate outlets within the walls. Appropriate openings are provided, prior to insertion of the panel members, to level the framework in its desired position. Once the panels have been inserted these openings are unseen.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the wall or divider of this invention.
FIG. 2 is a front elevational view of the wall or divider of this invention, including shelves supported thereon.
FIG. 3 is a side sectional view taken along the line 3--3 of FIG. 8.
FIG. 4 is a side sectional view taken along the line 4--4 of FIG. 2.
FIG. 5 is a sectional view taken along the line 5--5 of FIG. 8.
FIG. 6 is a sectional view along the lines 6--6 of FIG. 10.
FIG. 7 is a partial sectional frontal view of a corner wall frame construction without panels.
FIGS. 8, 9 and 10 are front elevational views showing the method of assembling a three-panel wall or divider of this invention.
FIG. 11 is a partial sectional frontal view of an alternate construction for retaining vertical wall supports used in the invention.
FIG. 12 is a perspective view of a panel locking and alignment member.
FIGS. 13 and 14 are perspective views of shelf support brackets.
FIG. 15 is a perspective view of a shelf bracket keeper.
FIG. 16 is a partial side sectional view depicting means to attach transverse walls or dividers together.
FIG. 17 is an exploded perspective view of FIG. 16.
FIG. 18 is a perspective view of a bracket used in the connections shown in FIGS. 16 and 17.
FIG. 19 is a perspective view of a modified panel embodiment.
FIG. 20 is a top elevational view depicting the drawstring means to lock fabric type cover panels in place.
DETAILED DESCRIPTION
Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in the various ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation.
Referring now to the drawings, where like numbers are used for like elements throughout and, in particular, reference is made to FIG. 1 wherein the wall or divider unit of this invention is generally indicated by the numeral 10. The wall generally comprises a basic frame having upper and lower horizontal members 12 and 14 and vertical members 16 and 17. Additional vertical structural members 18 and 19 may be made a part of the frame as shown. The frame will be made of a desired wall thickness 20. In one embodiment of the invention a basement box 21 extends below the lower horizontal frame 14 and is adapted to contain levelling legs and utility lines, e.g., telephone, electricity, or fluids, not shown in this view. Appropriate outlets 22 are provided for connection therewith. The box, in another embodiment may be made a part of the other frame members with the same functional usage. Interiorly of the frame and described in greater detail hereafter are a plurality of decorative panel units designated 24A, 24B and 24C.
In the front elevational view of FIG. 2 shelves 25 and 26 are shown as they would be hung on the wall of this invention, in manners hereinafter described. As shown the wall is assembled in such a manner that only the outer frame members 12, 14, 16, 17, 18, 19 and 21, and the desired ornamental replaceable panels 24A, 24B and 24C are exposed to view, with the internal structural members substantially hidden as shown by the dotted lines. As such a novel wall is provided wherein the panels substantially fill the space within the defined frame, yet are easily assembled, removed or replaced as hereinafter described.
The internal structural members are described in reference to FIGS. 3, 4, 5 and 6. FIG. 3 is the right-hand side while a mirror image thereof will comprise the left-hand side.
The inner end framework includes first tubular support members 30, which are of a thickness less than the thickness 20 of the frame. These first support members 30 are vertically positioned to the inside of said frame within a vertical recess 32 within the respective vertical frames 16 and 17. The member includes a plurality of vertically aligned apertures 31. The vertical first support members are movable in a horizontal direction being retained within their recessed 32 by upper and lower corner plates 34 and 36 which are attached to frames 16 and 17. (See FIG. 10) The frontal width of said first support members is designated as "X".
As shown in FIG. 3 the horizontal leg of said lower corner plates include opening 37 aligned with opening 38 of the base frame to permit a tool to engage levelling screw 39 which may include a foot pad as shown in FIG. 4. The upper and lower horizontal frames include respective recesses 40 and 42 particularly described hereafter relative to the secondary support members.
Cover plates 43 and 44 comprise identical members or strips which cover respective recesses 40 and 42 being attached to respective frame members 12 and 14 as shown in FIGS. 4 and 5 yet spaced to create therebetween upper and lower guide slots 45 and 46 with enlarged openings 47 (Shown in FIG. 5).
Intermediate the frame members 16 and 17 is at least one second vertical support member 50, each having a plurality of vertically aligned apertures 51 such as universal slots capable of accepting universal fixtures. In the embodiments shown two of such members are necessary. These vertical supports are preferably made of rectangular or square tubing of a dimension less than the thickness of the frame (preferably equal to the thickness of the first support members 30 and have a frontal width 52 which is no greater than twice the width (2X) of a first support member. Each of the second support members 50 are identical in construction and include upper and lower bolts 54 and 56 threaded to the respective top and bottom support member 50 and which operate within appropriate and respective upper and lower guide slots 45 and 46. The respective bolt heads 55 and 57 are insertable in one or more enlarged openings, as 47 in FIG. 5, of the cover plates. Lock nuts 58 and 60 retain the bolts fixed in position. The second vertical support members are adapted for horizontal sliding movement (See arrows in FIGS. 5 and 11) either side of a division line (e.g., one-half, one-third as shown, etc.) between the interior space formed by frame members 12, 14, 16 and 17. In the embodiment shown, this space is divided into three equal spaces.
The base member 21' in FIG. 4 is to show another embodiment including levelling screw 62, associated nut 64, and a foot pad 66 formed as a part of the screw. Suitable openings 68 are provided for screwdriver or other tool to permit adjustment through the lower frame 14. The openings in all embodiments are fully hidden from view when the panels 24 are in place and may have temporary dust covers as desired and not shown.
Panel members 24A, 24B and 24C are identically constructed. In this embodiment, as shown in FIG. 6, the panels describe a basic quadrilateral framework 70 interconnected by a central plate 72. Suitable filler 74, e.g. acoustic or other insulation materials is received between the frame structure 70 and 72. Around the outer periphery of frame 70 are strips of resilient material (e.g., sponge rubber, vinyl or soft plastics) 76 and 78. Preferably the strips increase the outer peripheral dimension of the frame slightly greater than the frame opening to receive the panel. Thus, the panels are compressibly retained to each other and the frame members without further movement but yet will permit the panels to be readily inserted and removed. Covering the framework is fabric 80. It is to be understood, however, that the outer covering may be any decorative material, albeit wood, fabric, masonry, or other decorative designs and materials, all of which are within the purview of this invention and dictated by an interior designer's skill. The framework of panels is adapted to substantially fill each of the horizontally divided areas inside the frame. Each of the panels includes vertical grooves 82 and 84 on each side thereof, each of the grooves being of a thickness slightly larger than the thickness of the vertical support members but having a frontal width that is no less than the frontal width of the second support members 50.
The support members 50 are movable either side of the imaginary division line for each space for a distance equal to at least the width 52 of said second vertical supports. Although grooves 85 and 86 are shown in the upper and lower horizontal portions of the panel frames 70 (See FIG. 4) this is not absolutely necessary (e.g., see FIG. 16).
The horizontal basement box portion 21 is adapted to receive, as best shown in FIG. 3, appropriate utility (telephone and electrical, communication, and fluid) which are adapted to be connected to suitable outlets 22. Connections are made to utility usages within the panels for other appurtenances attached therewith, e.g., as shown in FIG. 20. Conduit means is provided in the panel, e.g., via the vertical grooves 82 and 84 or through the vertical support members 30 and/or 50.
FIGS. 12, 13, 14 and 15 describe typical devices for attachment to the apertures in vertical supports 30 and 50. Keeper 90 is used to retain the vertical supports in the assembled position relative to panels 24 and are insertable through aligned apertures 31 or 51 as necessary. Shelf bracket 92 includes support mounting clips 94 for insertion within the apertures 31 or 51 between adjacent panels 24. Shelf 25 or other apurtenances are attached to shelf mounting clips 96 as shown in FIG. 4. The shelf clips comprise upper and lower parts spaced a distance 97 and 97' slightly larger than the vertical dimension of the lower shelf rod 120. Grooves 99 and 99' in both upper and lower parts are slightly larger than the horizontal dimension of the shelf rods. The upper part is rounded as shown while the lower part is square cut. The spacings prevent the shelf rods from coming out of the clips if accidentally raised vertically. FIG. 14 describes a bracket 92 that will straddle a panel joint. In FIG. 15 a locking keeper 98 is depicted as being used to prevent vertical movement of the bracket 92 as shown in FIG. 4.
OPERATION
Referring now to FIGS. 8, 9 and 10, a typical operation is shown for constructing the wall and/or divider of this invention. A first panel unit 24A is placed into position as shown by first moving a second support member 50L to its extreme position to the right of its imaginary division line. The wall panel 24A is then placed such that its vertical groove 84 will straddle the first vertical support, designated 30L in these views. In the event said first vertical support 30L is movable, further locking of the panel is achieved by moving same to the right to straddle the panel groove 84. One or more keepers 90 are inserted into the support apertures 31 between the left edge of panel 24A and frame 17. Thereafter the movable support 50L is then moved horizontally to the left into the appropriate groove 82 of the panel 24A. As a second step a similar procedure occurs on the right hand side of the wall of this invention by moving the support 50R to the left of its center division inserting the panel 24C such that its vertical groove 82 straddles the first support member 30R. If member 30R is movable, then it may be moved to the left to lock panel 24C in place using keepers 90. Thereafter second support 50R is moved to the right of its imaginary division line so as to be enclosed within the groove 84 of the panel 24C. In this position, as shown in FIG. 9, the third panel 24B may then be inserted into the space provided. Thereafter an appropriate spatula or thin blade-like tool or instrument is placed between the panels and the frame to move the second supports 50L and 50R to the right and to the left, respectively, so as to be centered at the panel division line as shown in FIG. 10, thus locking the panels with keepers 90 or shelf brackets 92 in ultimate desired position.
Openings 31 and 51 at parallel locations on the other supports are adapted to receive brackets 92 or 92' appropriately placed by the insertion of clips 94 or 94' between the panels or panel and frames in the matching apertures to the position shown in FIG. 4. Shelf clips 96 or 96' are adapted to receive, retain and support shelf units as generally indicated by the numerals 25 and 26. Horizontal rods 120 are adapted to fit, lock, and be retained by the retaining clips 96 or 96'. The bracket 92 or 92' is then locked into place so as not to be movable vertically by keeper 98 positioned above the bracket 92 in the manner shown.
MODIFICATIONS
FIG. 11 described a modified vertical support construction. Vertical supports 30 and 50 include respective upper and lower "L" and "T" sections 130 and 132 movable in appropriated recesses covered by respective plates 131 and 133.
FIGS. 16, 17 and 18 describe means whereby one or more second walls can be attached transversely or angularly to a first wall or divider. A transverse wall bracket 110 includes a lip 112 insertable in upper and lower guide slots 45 and 46 while panel 24 is removed. Fasteners 114 are used to connect to the transverse wall frame 19. The panel of the first frame may be replaced and the operation of assembly for the transverse panel commences as described. The panel of the transverse frame may be of different height as shown.
FIG. 19 depicts an assembly view of a typical office or room cubicle formed with the walls or dividers of this invention as may be modified for different functional purposes. As shown a two-panel unit is transversely attached to a three-panel unit at the corners thereof in distinction to the construction of FIGS. 16 and 17. One of the panels is divided horizontally to include an audio-visual panel insert 140 which is coverable by hinged doors 142 and 144. Panel 24B would be thus modified. The panels could be divided vertically too. A general utility shelf or credenza 146 (glass or wood) is also shown attached to the two-panel wall using universal shelf brackets 147. Typically, 1/2" long slots are spaced 1" center to center. An insertable panel 148 modifies panel 24A' into three sections. Panel 148 providing further means to connect with utility line needs such as means 150 to connect with a telephone, for example, or other needs to eliminate exposed lines from the floor connectors 22. The wall is also readily adaptable to connect with utility line connectors from floor connectors 22' as shown or to outlets 152 above the floor in panel 148.
When using a fabric panel member 80 one means for readily removing same for cleaning or changing is with a drawcord 87 and 88 formed in the outer peripheral edge. FIG. 20 depicts a preferred manner of attaching the rings 88 of drawstring ends 87A and 87B of a fabric panel 80 to the screw heads 89 in the recess groove 85.
Although a plurality of panels 24 have been shown the concepts of the invention include a single panel design omitting the need for a secondary divisional support 50, but utilizing movable first supports 30 in the vertical end. | A free-standing fabricatable vertical wall or space divider is useful for partitioning buildings and/or office complexes. The wall is made up of a plurality of individualized and decorative flush panel units which are interchangeable and which are adapted to be readily inserted within a wall frame and locked into place without any visual showing of vertical supports used to lock the panels in place. The panels may be removed, redecorated and replaced as needed. Shelving or other appurtenances are attachable to the hidden vertical supports. The entire wall panel and/or divider is capable of replacement when it is desired to rearrange or enlarge or change a given floor space. Identical walls or dividers of the same basic construction are transversely connectable to each other. | 4 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application No. 62/290,733, filed on, filed on Feb. 3, 2016.
FIELD OF THE INVENTION
This invention relates to a pulley joint assembly potentially suited for various applications but in a preferred implementation is utilized in an automotive window regulator assembly.
BACKGROUND
Passenger car and a light truck motor vehicles feature movable side door glass. A mechanism is required to move the glass between the upper closed position and the lower opened position. These mechanisms are generally known as window regulators. Window regulators can be manually operated, or can be driven by a power actuator, most commonly employing an electric motor. One type of window regulator uses a pulley arrangement having a metal cable wrapped around a drum driven by an electric motor. These devices use a carrier movable along a guide rail which engages the door glass which is a driven by the metal cable to control its motion.
The pulley components provided for cable driven window regulator systems are available in numerous configurations. A typical arrangement is to provide a stud or shaft which acts as a bearing journal for supporting and permitting rotation of the pulley. The drive cable is wrapped around the outer perimeter of the pulley wheel. These devices work well and are implemented in a wide range of machines, articles and mechanisms. Despite the satisfactory performance of conventional pulley arrangements, there is constantly a desire to reduced cost, simplify assembly, and reduce weight of automotive components, while providing a desirable durability, low warranty claims, and compliance with performance requirements. This invention is related to a pulley joint assembly which addresses the above-referenced desirable attributes.
SUMMARY
The pulley joint assembly in accordance with the present invention utilizes a simple pulley arrangement which is snap-fit into a pulley housing. The joint assembly includes features for maintaining the pulley in an assembled condition while providing required performance attributes. The described arrangement may be implemented with a conventional guide rail type window regulator, or in an alternative implementation, can be integrated into a door module structure. Moreover other applications of the described pulley joint assembly in various structures and machines are available.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a window regulator assembly incorporating a pulley joint assembly in accordance with the present invention;
FIG. 2 is an exploded view of the pulley joint assembly components;
FIGS. 3A and 3B are enlarged illustrations of the pulley joint assembly;
FIGS. 4A and 4B are pictorial views illustrating an assembly process of the pulley ring into the pulley joint housing;
FIGS. 5A and 5B illustrate the completed assembly condition of the pulley joint assembly;
FIG. 6 is a top view of pulley assembly showing contact and clearance segments of the bearing post;
FIG. 7A is a cross-sectional view of the pulley joint assembly taken along line 7 A- 7 A of FIG. 6 and FIG. 7B is an elongated view taken from FIG. 7A ; and
FIG. 8A is a side view of a module plate incorporating the pulley joint assembly of the present invention, and FIG. 8B is an enlargement from FIG. 8A .
DETAILED DESCRIPTION
With reference to FIG. 1 window regulator assembly 10 is illustrated, which includes as principal components, guide rail 12 , window carrier 14 , pulley assembly 16 , motor drive assembly 18 , and drive cable 20 . Guide rail 12 is typically made from sheet-metal stock fabricated by a stamping or rolling process, or as an extrusion. Window carrier 14 is caused to travel up and down along guide rail 12 and includes a window clamp arrangement which attaches to the lower edge of the vehicle side door glass (not illustrated). Pulley assembly 16 is positioned at the top of guide rail 12 and acts to redirect and tension drive cable 20 . Motor drive assembly 16 is powered electrically and includes internal reduction gears and a cable drum to move drive cable 18 . Drive cable 20 wraps around pulley assembly 16 at the top of the assembly and wraps around the drive pulley which is part of motor drive assembly 18 . Ends of drive cable 20 terminate at window carrier 14 .
Motor drive assembly 18 is shown in FIG. 1 affixed to the bottom of guide rail 12 but could be positioned at other locations depending on application requirements. Similarly, pulley assembly 16 is shown at the top of guide rail 12 but may be implemented in various other positions depending on the application. Window regulator assembly 10 is shown as a single rail type system. Alternate implementations may use a pair of separated guide rails provided for control of the movable glass or other panel, based on application requirements.
This invention is particularly related to the design configuration of pulley assembly 16 . As noted previously, such a pulley arrangement may be found in numerous automotive and other vehicle applications and other mechanisms and devices. Although this description treats pulley assembly 16 as part of window regulator assembly 10 , the pulley assembly may be implemented in such alternative applications. For example pulley assembly 16 is described as usable for controlling the motion of side door glass, but could be readily implemented for other motor vehicle movable panels including closure panels.
With particular reference to FIGS. 2A, 2B, 3A and 3B , features of components of pulley assembly 16 are illustrated. Pulley ring 22 is hoop shaped with an outer external grooved perimeter 24 for receiving and guiding drive cable 20 . Inside cylindrical bearing surface 26 is provided for allowing rotation of pulley ring 22 , as will be described in further detail. Between perimeter 24 and bearing surface 26 is a reduced thickness circular central hub portion 25 . Pulley ring 22 is preferably formed of a polymeric resin material.
Pulley housing 28 is an injection molded unitary plastic component and features slot 30 to enable it to be slid on and attached to the upper end of guide rail 12 , as best illustrated in FIG. 2 . Once assembled, a locking feature may be implemented to maintain the components in an assembled condition. For example, a pierced hole or tab formed in guide rail 12 can be provided to interact with an interlocking feature of pulley housing 28 , or a discrete fastener may be used for attachment of the components. Pulley housing 28 further integrally forms projecting bearing post 32 within a circular clearance area 34 provided for accommodating pulley ring 22 for rotation. Projecting from bearing post 32 is retention tab 36 which extends in a radially outward direction to overlie a portion of clearance area 34 . Retention tab 38 is also provided which is positioned radially outside clearance area 34 and extends in a radially inward direction toward bearing post 32 and overlies clearance area 34 . An additional tab 40 extends from is supported by flexible arm 42 , and in a normal relaxed condition, positions tab 40 to project radially inwardly to overlie circular clearance area 34 . In this illustrated embodiment, central clearance bore 44 is provided at the center of bearing post 32 and receives bolt 46 which is used to fasten the upper end of the unit to associated structure. Retention tabs 36 and 40 confront each other and are positioned along a radial line vertical with respect to the top of the assembly and tension applied by the drive pulley, and tab 38 is located at a diametrically opposed radial position from tabs 36 and 40 .
Now with reference to FIGS. 4A, 4B, 5A and 5B , additional design features and an assembly process for pulley assembly 16 is described. As shown in FIGS. 4A and 4B , in a first assembly step, pulley ring 22 is positioned over bearing post 32 and its upper edge is placed in the gap between tabs 36 and 40 . As shown pulley ring 22 is tipped from the plane of its final installed position. Tab 40 is deflected as shown in FIG. 5A and this portion of the ring 22 is placed in position. Thereafter, the bottom edge of ring 22 closest to hook 38 can be displaced over tab 38 and placed into its final assembled condition. Arm 42 resiliently biases tab 40 to maintain pulley ring 22 in its installed condition, interlocked with tabs 36 , 38 and 40 which overlie circular clearance area 34 and trap the pulley ring in position. Bearing post 32 is shaped such that an upper portion 48 makes direct contact with pulley ring bearing surface 26 over an arcuate contact surface when tension upon is applied by drive cable 20 , whereas lower clearance segment 50 is provided to allow vertical displacement of pulley ring 22 during the installation process, as described previously. A clearance gap 53 shown in FIG. 6 allows pulley ring 22 to be displaced over retention tab 36 during installation. During operation of window regulator assembly 10 , tension on drive cable 22 presses pulley ring 22 against the bearing portion of bearing post 32 .
Assembly of pulley ring 22 and pulley housing 28 may occur before or after the assembly is affixed to guide rail 12 . In the embodiment described above, bolt 46 is provided to support the upper end of regulator assembly 10 to an associated structure. However, bolt 46 is not provided to act as a bearing component for pulley ring 22 . In an alternate design without bolt 46 , the central area of pulley housing 28 can be solid, with other features provided for supporting window regulator assembly 10 .
FIGS. 7A and &B illustrate a feature for reducing friction in the sliding contact between pulley bearing surface 26 and bearing post 32 . As shown by the figures, the bearing surface 26 may be relieved or chamfered from a cylindrical surface such that contact does not occur along its entire axial length but is rather concentrated to a line of contact 52 . Reduction of the contact area may provide lower friction, allowing more free movement of pulley ring 22 during operation of the window regulator assembly 10 .
FIGS. 8A and 8B illustrate an embodiment of window regulator assembly 52 in which pulley assembly 26 is integrated into a module plate 56 which provides for mounting of various hardware components or functional features of the regulator assembly 54 . Such implementations may not require a discrete guide rail 12 and the features of pulley housing 28 may be molded into a larger module plate provided for the other functions described above. The regulator assembly shown in FIG. 8A has its motor drive assembly 18 a at a central location with a pair of pulley assemblies 16 a positioned at the top and bottom of the guide rail 12 a , as an example of alternate implementations of pulley assembly 16 . Pulley assemblies 16 a are functionally identical to assembly 16 described previously. Guide rail element 12 a can be molded as part of module plate 56 , or can be made of a metal component attached to the module plate or molded in position. Pulley housing 28 a may be separately formed and affixed to module plate 56 , or its features can be directly molded as an integral feature of the module plate.
While the above description constitutes the preferred embodiment of the present invention, it will be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims. | A window regulator assembly particularly adapted for motor vehicle applications having a pulley assembly featuring snap in insulation of a pulley ring into a pulley housing. The pulley housing features the clearance area and a number of retention tabs and hooks which enable the pulley ring to be snap fit into position. The assembly may be implemented with a discrete window regulator or as part of a modular inner door plate as well as and for other applications. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electromagnetic fuel injection valve and to a method for assembling the nozzle assembly, and more particularly to an electromagnetic fuel injection valve that allows the amount of lift in a needle valve to be established with high precision in electromagnetic fuel injection valves used for high pressure fuel injection such as cylinder injection of gasoline, as well as to a method for assembling the nozzle assembly.
2. Description of the Related Art
In the conventional establishment of the amount of lift in needle valves for electromagnetic fuel injection valves employed in cylinder injection of gasoline, electromagnetic fuel injection valves have a configuration that is designed to establish the amount of needle valve lift by having the armature come into direct contact with the lift stopper in response to magnetization of the electromagnetic coil. Examples include Japanese Patent Nos. Hei.5-504181 and Hei.5-504182.
FIG. 5 is a vertical cross section illustrating an example of a conventional electromagnetic fuel injection valve 1. This electromagnetic fuel injection valve 1 comprises a connector 2, a valve housing 3, a nozzle holder 4, a fuel supply pipe 5 consisting of a magnetic substance, a spring seat 6, a valve seat 7, and an electromagnetic coil 8 that is magnetized and demagnetized by means of control signals from the connector 2.
An armature 9 in the form of a tube and a needle valve 10 that is integrally movable with this armature 9 are provided downwardly in the figure and are opposite the fuel supply pipe 5.
An injection hole 12 is formed in a steel plate 11 located at the tip of the valve seat 7, and the needle valve 10 is always energized in the direction of this injection hole 12 by the valve spring 13 so as to be seated in the seat portion 7A of the valve seat 7.
A lift amount adjusting shim 14 is provided on the upstream side of the valve seat 7, and the steel plate 11 is held between the valve seat 7 and a holding plate 15 on the downstream side.
Fuel such as gasoline is fed from the upper part (in the figure) of the fuel supply pipe 5 to the first fuel channel 16, from the first fuel channel 16 through the second fuel channel 17 inside the armature 9, through the third fuel channel 18 between the nozzle holder 4 and the armature 9 or needle valve 10, through the fourth fuel channel 19 inside the lift amount adjusting shim 14, and to the fifth fuel channel 20 between the valve seat 7 and the needle valve 10.
The interval between the fuel supply pipe 5 and the armature 9 is used as the amount of lift L for the needle valve 10. As a result of the magnetization of the electromagnetic coil 8, the armature 9 and the needle valve 10 are integrally lifted against the urging force of the valve spring 13, and the fuel is sprayed from the injection hole 12 into the engine cylinder 21.
With the demagnetization of the electromagnetic coil 8, the armature 9 and the needle valve 10 are returned to their original positions by the urging force of the valve spring 13, and the injection hole 12 is closed off.
The amount of lift L for the needle valve 10 is established in the following manner.
That is, the lift amount adjusting shim 14, valve seat 7, steel plate 11, and holding plate 15 are inserted in that order from the downstream side of the tubular tip 4A of the nozzle holder 4, and the leading end portion of the tubular tip 4A is crimped to form a crimped portion 22, thereby fixing these parts.
If a thicker lift amount adjusting shim 14 is inserted, the valve seat 7 is located further downstream, allowing a greater amount of lift L to be established, whereas the insertion of a thinner lift amount adjusting shim 14 allows a smaller amount of lift L to be established.
The dimensions of the valve housing 3, needle valve 10, and the like are thus determined, a lift amount adjusting shim 14 is selected for use to allow the prescribed amount of lift L to be obtained, and the leading end portion of the tubular tip portion 4A is crimped, so that the lift amount adjusting shim 14, valve seat 7, steel plate 11, and holding plate 15 are fixed to the tubular tip portion 4A.
The amount of lift L in such an electromagnetic fuel injection valve 1, however, usually requires extremely high dimensional precision of, say, 50±5 μm. In the conventional electromagnetic fuel injection valve 1 described above, a large number of parts are connected with the amount of lift L, and since the crimped part 22 is formed after the selection of the lift amount adjusting shim 14 used to determine the final amount of lift L, there is a possibility that the very act of crimping results in the deformation of the various parts in the tubular tip portion 4A, with many problems arising in accurately establishing the amount of lift L.
During the manufacturing process, moreover, the problem of loose parts in the tubular tip portion 4A makes it difficult to avoid the problems in precision described above because the portion is invariably crimped firmly, so that the amount of lift L cannot be adjusted after the crimping.
FIG. 6 is a vertical cross section illustrating an example of another conventional electromagnetic fuel injection valve 30. The same parts are indicated by the same symbols, and their description is thus omitted. Only the different parts are described. In this electromagnetic fuel injection valve 30, a ball valve 10A which allows a fuel channel to be formed, with the surface 5 cut flat, is attached to the tip of the needle valve 10, and the ball valve 10A is seated in the seat portion 7A of the valve seat 7.
A steel plate 31 in the form of a cross-sectional arc, in which a steel plate 11 has been bent on the upstream side, is used, the resilience resulting from its tension is utilized in bringing it under pressure into the tubular tip portion 4A, and two prescribed locations in the peripheral portion adjacent to the tubular tip 4A and in the central portion adjacent to the valve seat 7 (peripheral weld location 32 and central weld location 33) are fixed by electronic seal welding such as laser welding.
The seal welding is done, however, after the steel plate 31 as been fixed in a location greater than the prescribed amount of lift L (for example, greater than 50 μm).
A probe M for measuring the amount of lift L is then attached to the upstream side of the armature 9, and the steel plate 31 is pushed in, with the probe set up in a state allowing the amount of lift L to be measured, as a prescribed load is applied from the downstream side to the upstream side. The amount of lift L is gradually reduced, and when the prescribed amount of lift L has been obtained, the plate is no longer pushed in, so as to conclude the establishment of the amount of lift L.
That is, the load is applied on the steel plate 31 from the downstream side to the upstream side, and as the amount of lift L is measured, the steel plate 31 is reversibly deformed in establishing and adjusting the prescribed amount of lift L.
In this method for assembling the nozzle assembly (ball valve 10 A, needle valve 10, and valve seat 7), the amount of lift L can be adjusted as it is directly measured, so the precision of the amount of lift L is greater than in the case of the electromagnetic fuel injection valve 1 shown in FIG. 5.
Since, however, the steel plate 31 has a thin plate thickness of 0.2 to 0.25 mm, it can be used for low pressure fuel injection valves with a fuel pressure of about 3 kg/cm 2 , but it cannot be used for high pressure cylinder injection of fuel in fuel injection valves for cylinder injection of gasoline, where the fuel pressure is extremely high at 40 to 100 kg/cm 2 . The high fuel pressure would cause the steel plate 31 to fly off in the direction of the engine cylinder 21.
When the plate thickness of the steel plate 31 is increased to make it resistant to such high pressure, greater welding energy is needed to join the parts, and the resulting heat leads to the problems of poor roundness in the seat portion 7A of the valve seat 7 and poor oil-tightness.
Problems in conventional electromagnetic fuel injection valves 1 and 30 and the like are that they are difficult to make resistant to high pressure fuel injection such as in cylinder injection of gasoline and that the amount of lift is difficult to adjust and establish with good precision.
SUMMARY OF THE INVENTION
With the foregoing in view, it is an object of the present invention to provide an electromagnetic fuel injection valve that is suitable for high pressure cylinder injection of fuel and that allows the amount of lift to be established with high precision, as well as a method for assembling the nozzle assembly.
It is another object of the present invention to provide an electromagnetic fuel injection valve that allows the amount of lift to be adjusted and established after assembly of the nozzle assembly, as well as a method for assembling the nozzle assembly.
It is yet another object of the present invention to provide an electromagnetic fuel injection valve in which the valve seat does not fly off in the direction of the engine cylinder in the unlikely event of defective welding, as well as a method for assembling the nozzle assembly.
That is, the present invention is the outcome of attention to the fact that a thin-walled skirt portion is formed at the nozzle holder, with the valve seat introduced therein under pressure, the fact that the skirt portion and valve seat are welded, and the fact that the amount of lift is preferably finally established following the welding by applying a load from the outside to the nozzle holder to irreversibly deform the nozzle holder or valve seat. The first invention is an electromagnetic fuel injection valve comprising a valve housing, an electromagnetic coil located in the valve housing, an armature responding to the magnetization of the electromagnetic coil, a valve seat in which a fuel injection hole for fuel has been formed, a nozzle holder for fixing the valve seat, and a needle valve allowing fuel to be sprayed from the injection hole when the valve seat is lifted from the seat portion along with the armature in response to the magnetization of the electromagnetic coil, wherein a thin-walled skirt portion is formed in a protruding manner at the nozzle holder, the valve seat is introduced under pressure to the skirt portion, and the valve seat and nozzle holder are welded and joined at the skirt portion.
A protruding step portion can also be formed along the outer peripheral surface of the valve seat, and a stopper portion that can be engaged with the protruding step portion can be formed along the inner circumferential surface of the nozzle holder.
The second invention is a method for assembling the nozzle assembly of an electromagnetic fuel injection valve having a valve housing, an electromagnetic coil located in the valve housing, an armature responding to the magnetization of the electromagnetic coil, a valve seat in which a fuel injection hole for fuel has been formed, and a needle valve allowing fuel to be sprayed from the injection hole when the valve seat is lifted from the seat portion along with the armature in response to the magnetization of the electromagnetic coil, and a nozzle holder for fixing the valve seat by combining the needle valve and the valve seat in the form of a nozzle assembly, comprising a pressurized introduction step in which the valve seat is introduced under pressure to the thin-walled skirt portion formed in a protruding manner at the nozzle holder, and a welding step in which the valve seat and the nozzle holder are integrated by being welded and joined at the skirt portion.
A lift amount adjusting step can also be included, wherein a load is applied to the outer peripheral portion while the nozzle assembly is fixed, so as to adjust the amount of lift for the needle valve.
In the electromagnetic fuel injection valve and the method for assembling the nozzle assembly in the present invention, a thin-walled skirt is formed at the nozzle holder, the valve seat is introduced under pressure to the skirt portion, and the nozzle holder and the valve seat are then welded at the skirt portion, so the valve seat is introduced under pressure by estimating the contraction of the nozzle holder and the valve seat caused by the welding. The amount of lift can thereby be established. The crimped portion formed after the amount of lift has been established as in the case of the conventional electromagnetic fuel injection valve 1 (FIG. 5) is not needed thus allowing problems of deviation in the amount of lift from the established value to be avoided.
The precision of the amount of lift can be enhanced when the amount of lift is finally established by applying a load from the outside of the nozzle holder to irreversibly deform the nozzle holder after the nozzle holder and the valve seat have been welded.
A thin-walled skirt portion can also be formed at the tip of the nozzle holder, and the parts can be welded and joined at the skirt portion, so that, unlike the conventional electromagnetic fuel injection valve 30 (FIG. 6), no steel plate 31 is used, allowing the device to be adapted for high pressure fuel injection and allowing the thermal effects on the valve seat to be greatly reduced.
When a stopper portion that can be engaged with the protruding step portion formed along the outer peripheral surface of the valve seat is formed along the inner circumferential surface of the nozzle holder, the valve seat can be prevented from separating from the nozzle holder and flying off in the direction of the engine cylinder in the unlikely event of a defective welding.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a vertical cross section of an electromagnetic fuel injection valve 40 in a preferred embodiment of the present invention;
FIG. 2 is an enlarged vertical cross section of the valve seat 7 and the needle valve 10 portions in particular of this same electromagnetic fuel injection valve;
FIG. 3 is a schematic illustrating the lift amount adjusting step when tensile external force is allowed to act on the upstream side step portion 56 and the downstream side step portion 57;
FIG. 4 is a vertical cross section illustrating an electromagnetic fuel injection valve 60 of a reference example, depicting the disadvantages when the skirt portion 44 of the present invention is not formed;
FIG. 5 is a vertical cross section illustrating an example of a conventional electromagnetic fuel injection valve 1; and
FIG. 6 is a vertical cross section illustrating an example of another conventional electromagnetic fuel injection valve 30.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An electromagnetic fuel injection valve 40 in a preferred embodiment of the present invention and a method for assembling the nozzle assembly are described next with reference to FIGS. 1 through 3. Parts which are the same as those in FIGS. 5 and 6 are indicated by the same symbols, and their description is thus omitted.
FIG. 1 is a vertical cross section of an electromagnetic fuel injection valve 40, and FIG. 2 is an enlarged vertical cross section view in particular of the parts of the valve seat 7 and the needle valve 10 of the electromagnetic fuel injection valve 40. The electromagnetic fuel injection valve 40 has a flat plate-shaped armature 41 corresponding to the armature 9 described above, and the needle valve 10 can be moved integrally with the armature 41.
A communication hole 42 connecting the second fuel channel 17 and the third fuel channel 18 is formed in the needle valve 10.
A method for assembling the needle valve 10 and the valve seat 7 in the form of a nozzle assembly 43 in the nozzle holder 4 is described below along with the structure.
As shown in the enlargement in FIG. 2 in particular, a thin-walled skirt portion 44 is formed in a protruding manner from the valve seat 7 at the tip of the nozzle holder 4.
The skirt portion 44 has sufficient axial resistance against the fuel pressure and the combustion pressure from the engine cylinder 21, and it is formed with walls thin enough to allow for electronic seal welding such as laser welding, while it is long enough to fix the valve seat 7.
A welding groove 45 is formed around an outer periphery at a prescribed location in the skirt portion 44.
The nozzle assembly 43 is inserted into the skirt portion 44 while the needle valve 10 is inserted in the valve seat 7, so as to introduce the valve seat 7 under pressure (pressurized introduction step).
A protruding step portion 46 is formed along the upper outer peripheral surface of the valve seat 7, a stopper portion 47 that can be formed with the protruding step portion 46 is formed along the inner circumferential surface of the nozzle holder 4, and an adjusting stroke S portion of a prescribed length is left in the stopper portion 47 to allow an amount of lift L slightly greater (60 μ, for example) than the prescribed amount of lift L (50 μm, for example) to be maintained in the pressurized introduction step described above,
In this state, laser welding is effected in the welding groove 45 to form laser welded parts 48, and the nozzle holder 4 and the valve seat 7 are integrated at the skirt portion 44 (welding step).
Since, however, the amount of lift L shrinks because of the contraction of the skirt portion 44 and the valve seat 7 due to welding holes following heat radiation during the welding operations, an excess amount of lift L is set during the pressurized introduction step, as described above, by estimating the welding deformation.
The welding deformation is thus estimated, and the pressurized introduction step and welding step are carried out, allowing the prescribed amount of lift L to be obtained.
In general, however, because of the possibility of the contraction of the skirt portion 44 and valve seat 7 resulting in an amount of lift L that is shorter than prescribed (20 to 40μm, for example, with respect to the prescribed 50 μm amount of lift), the following step for adjusting the amount of lift based on compression operations should be carried out.
That is, a compression load is applied to an outer peripheral compression portion 49 on the upstream side from the skirt portion 44 of the nozzle holder 4, with the aforementioned probe M attached to the top of the needle valve 10 to measure the amount of lift L (compression step or lift amount adjusting step).
Specifically, these compression operations can be selected from operations in which a number of prescribed locations in the outer peripheral compression portion 49 are pressed, operations in which pressure is applied in the circumferential direction around the outer peripheral compression portion 49, and the like.
Because the nozzle holder 4 can be made of SUS 304 and the valve seat 7 can be made of SUS 440 or the like, they can be irreversibly deformed by such compression operations.
These compression operations allow the amount of lift L to be increased since the nozzle holder 4 is axially extended and thus irreversibly deformed, so that the amount of lift L can be adjusted and set to the prescribed value, and the final amount of lift L can be established with good precision after the valve seat 7 has been fixed to the nozzle holder 4.
A swell-absorbing outer peripheral groove 50 can be formed on the downstream side of the outer peripheral compression portion 49 to prevent swelling from being produced by the compression operations in the seal surface 51 of the nozzle holder 4.
In other words, a seal ring 54 can be provided between the seal surface 53 of the engine cylinder block 52 and the seal surface 51 of the nozzle holder 4 to seal off combustion gas from the engine cylinder 21. Since a defective seal resulting from irregularities caused by swelling on the seal surface 51 can be avoided, leakage of combustion gas from the engine cylinder 21 can be reliably prevented.
As shown in the partial enlargement in FIG. 2, moreover, a prescribed number of expansion-preventing grooves 55 were formed in the plane of contact between the nozzle holder 4 and the valve seat 7, so that with these compression operations, part of the nozzle holder 4 can penetrate into the expansion-preventing grooves 55, and the deformation portions in the nozzle holder 4 from the compression operations can be absorbed with the outer peripheral groove 50.
In the unlikely event that the laser welded parts 48 in the welding groove 45 are broken, the protruding step portion 46 and the stopper portion 47 can be engaged. Thus, even when the laser welded parts 48 are broken by high pressure fuel in the third fuel channel 18 through the fifth fuel channel 20, or for some other reason, resulting in the detachment of the nozzle assembly 43, the valve seat 7 is engaged and stopped by the stopper portion 47, and accidents in which the nozzle assembly 43 flies off into the engine cylinder 21 can be prevented.
As an alternative to the compression step in which the outer peripheral compression member 49 is compressed in the present invention, a tensile external force can be allowed to act on a downstream side step portion 57 of the swell-absorbing outer peripheral groove 50 and an upstream side step portion 56 of the outer peripheral compression portion 49 to pull the nozzle holder 4 in the axial direction as a lift amount adjusting step.
FIG. 4 is a vertical cross section illustrating an electromagnetic fuel injection valve 60 as a reference example, depicting the disadvantages of not forming the skirt portion 44 in the present invention. In this electromagnetic fuel injection valve 60, no skirt portion 44 is formed as in the electromagnetic fuel injection valve 40 shown in FIG. 1. As a result, a seal weld can be done only at the outermost tip of the nozzle holder 4.
That is, during seal welding, the nozzle holder 4 and the valve seat 7 must be brought into close contact by being introduced under pressure to the welding parts, but when they are introduced with the structure shown in FIG. 4, the valve seat 7 is inwardly deformed in the nozzle holder 4, and the needle valve 10 cannot slide.
The welding must thus be done with a loose fit between the nozzle holder 4 and the valve seat 7. As a result, welding is done only in the welding parts 61 of the outermost tip of the nozzle holder 4.
The external load on the valve seat 7 is thus applied only to the welding parts 61, resulting in the problem of extremely weak mechanical strength. Pressurized introduction operations to a thin-walled portion such as the skirt portion 44 in the nozzle holder 4 and welding operations should be implemented as shown in FIGS. 1 and 2.
As described above, the present invention involves forming a skirt portion on a nozzle holder and introducing the nozzle assembly under pressure for welding. As such, it can be adapted to fuel injection in high pressure cylinders, and the amount of lift can be adjusted and set with the prescribed precision.
Additionally, a load can be applied to the outer peripheral portion of the nozzle holder by means of compression, tension, or the like to the external compression portion of the nozzle holder, so that the nozzle holder can be extended and the precision of the amount of lift can be further enhanced. | An electromagnetic fuel injection valve is provided, which allows the amount of lift to be adjusted and established following the assembly of the nozzle assembly so that it is suitable for high pressure cylinder injection of fuel and which also allows the amount of lift to be established with high precision. A method for assembling the nozzle assembly is also offered.
This invention comprises a thin-walled skirt portion formed in a protruding manner at the nozzle holder, a valve seat that is introduced under pressure to the skirt portion, with the valve seat and the nozzle holder welded and joined at the skirt portion, and, preferably, the application of a load from the outside of the nozzle holder following welding to bring about the irreversible deformation of the nozzle holder and establish the final amount of lift. | 5 |
RELATED PATENTS
This Application is related to U.S. Pat. No. 6,141,903, entitled TREE STAPLE, issued on Nov. 7, 2000, and to U.S. Pat. No. 6,065,243, entitled TREE AND SHRUB STABILIZING DEVICE, issued on May 23, 2000. Each related patent has common ownership herewith.
FIELD OF THE INVENTION
The present invention relates generally to an apparatus for stabilizing newly planted trees and shrubs to prevent them from shifting or toppling while their root systems are first developing, and more particularly to devices and methods for securing the root balls of the newly planted trees or shrubs into proper position.
BACKGROUND OF THE INVENTION
In the initial period, newly planted trees or shrubs typically require some level of assisted support to avert tilting or toppling. Strong winds and excessive moisture can cause a poorly supported tree or shrub to lean excessively or fall to the ground. Adequate support not only enhances the survival of the tree or shrub during the critical growth period, but also reduces the risks of injury to people and of damage to property. The support is usually maintained until the roots have sufficiently established themselves in the ground. The time required for the roots to establish themselves can vary depending on tree or shrub type, growth conditions, soil type and condition, moisture and nutrient level and other factors. Adequate support is necessary for larger trees or shrubs especially those planted during wet or freezing weather.
Conventional methods for supporting trees or shrubs typically include driving two or more stakes into the ground adjacent to the trunk or the tree or shrub and tethering the trunk to the stakes with guy wires to provide the support. The stakes are usually composed of wood or other suitable material in the form of short spikes a few inches in length to elongate poles a few feet in length. The stakes can deteriorate rapidly and are typically limited to single use. Such conventional methods are generally limited to stabilizing small to moderate sized trees and shrubs, and are not recommended for supporting substantially larger trees and shrubs.
There are several disadvantages associated with using stakes and guy wire systems. The stakes and guy wires are typically exposed above grade level of the ground, and can pose hazards to passing traffic such as pedestrians, children, ground maintenance equipment such as lawnmowers and the like. The presence of such components are usually displeasing to the eye and often undesirably detract from the appearance of the tree or shrub and the surrounding area. The stakes and guy wires also need frequent attention and adjustment, since they can become loosened, vandalized, damaged, shifted or simply outgrown by the tree or shrub. Once the roots of the tree or shrub have become established, the stakes and guy wires require prompt disassembly and removal to prevent potentially fatal disfigurement or injury to the tree or shrub.
For the foregoing reasons, there is a need for developing an improved device and method for providing a tree or shrub with adequate support at the time of planting that avoids the limitations associated with conventional devices and methods as highlighted above.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a unitary multi-pronged device, fabricated from a single piece of material, of sufficient size to engage both the root ball and the surrounding undisturbed earth, that can provide stabilizing support for any size tree or shrub.
Another object of the invention is to provide a tree and/or shrub stabilizing support without potentially hazardous cables, ropes, or wires, or stakes.
Another object of the invention is to provide a tree and/or shrub stabilizing support apparatus that is not difficult to mow or to trim around.
Another object of the invention is to provide a tree and/or shrub stabilizing support apparatus that is not unsightly.
Yet another object of the invention is to provide a stabilizing support apparatus that after a period of time in which the planting becomes self-supporting, the components of the apparatus can remain in the ground.
Another object of the invention is to provide a stabilizing support apparatus that can be made permanent, or can be removed and used again.
Another object of the invention is to provide a tree and/or shrub stabilizing support apparatus including a device that is applicable to small trees and shrubs, and equally applicable to larger plantings.
Another object of the invention is to provide a tree and/or shrub stabilizing support apparatus that provides superior physical stabilization in comparison to conventional systems.
Another object is to provide a tree and/or shrub stabilizing support apparatus comprising a unitary multi-grouped tubular device and tool for driving the device into the ground without damage.
A further object of the invention is to provide a tree and/or shrub stabilizing support apparatus that is quicker and easier to install than the conventional methods.
Another object of the invention is to provide an improved tree and/or shrub stabilizing support apparatus including a device that facilitates the application of water and/or fertilizer to the root system of the tree or shrub.
In one embodiment of the invention, with the problems of the prior art in mind, various objects of the invention are provided by a novel unitary tree stabilizing device, fabricated from a single piece of material, having a cross member, and two side portions of prongs perpendicularly depending or bent from proximate the ends of the horizontal cross member. The embodiment typically has a vertical outer prong bent from proximate one end of the horizontal cross member, and a vertical inner prong bent from the other end of the cross member. The free ends of the outer and inner prongs include tapered ground penetrating tips that can be formed, for example, by cutting the free ends at an angle relative to the horizontal.
In a second embodiment, the angles and orientation of the ground penetrating tips at the respective free ends of the prongs are selected to substantially prevent the prongs from breaking up the root ball as the present device is driven into the ground.
In all of the embodiments described, the unitary tree stabilization devices may consist of material such as iron, steel, or other metal, preferably free of harmful platings or coatings. Typically, an inexpensive material such as metal or plastic polymer in the form of a reinforcement bar (rebar) or a tubular member can be used. Other suitable materials can also be used for fabricating the device of the present invention. Optionally, the device can include a through cavity or hollow core extending from an inlet in the cross member to a plurality of holes in the prongs through which a substance such as water or fertilizer can be conveniently irrigated directly to the roots of the tree or shrub beneath the ground.
In all of the embodiments described, the unitary tree stabilizing device is preferably installed at the time the tree or shrub is planted. After the root ball of the tree or shrub is set into an appropriate sized hole, the tree is positioned to the proper vertical position and desired orientation, and the surrounding hole space is filled with soil, the tree stabilizing device is driven into the ground such that the outer prong engages the soil around the root ball, and the inner prong engages the root ball. The outer prong is of a sufficient length to be held permanently and securely into the earth, and the shorter inner prong is arranged both in position and length to engage the root ball securely. The unitary tree stabilization device is typically driven into the earth deep enough so that the cross member will be recessed into the root ball and adjacent soil to ensure a secure anchoring engagement of the device with the root ball. By recessing the cross member into the root ball, the tree stabilization device is positioned below the finished grade of the ground. Since the tree stabilization device is established below the finished grade, the disadvantages of the prior art including hazards to passing traffic, unappealing appearance and the like, are avoided.
BRIEF DESCRIPTION OF THE DRAWINGS
The various embodiments of the invention are described in detail below with reference to the drawings, in which like items are identified by the same reference designation, wherein;
FIG. 1 is a pictorial view of one embodiment of the invention in which a tree stabilization device is provided from a single piece of material, making it unitary, having an outer prong and a shorter inner prong, each bent vertically from a cross member;
FIG. 2 illustrates a newly planted tree stabilized by a pair of the present unitary tree stabilization devices in one embodiment of the present invention;
FIG. 3A illustrates a newly planted tree stabilized by three unitary tree stabilization devices arranged in one of many possible support configurations in accordance with the principles of the present invention;
FIG. 3B is a top view of the newly planted tree stabilized by the three unitary tree stabilization devices as shown in FIG. 3A;
FIG. 4 is a side elevational view of a unitary tree stabilization device in accordance with second embodiment of the present invention;
FIG. 5 is a side elevational view of a unitary tree stabilization device in accordance with a third embodiment of the present invention;
FIG. 6A is a perspective view of a unitary tree stabilization device in accordance with a fourth embodiment of the present invention;
FIG. 6B is a top plan view of the unitary tree stabilization device of FIG. 6A operatively engaged with a root ball of a tree or shrub;
FIG. 7 is a front perspective view of a tool for driving the inner and outer prongs into the ground without damaging the portions of the associated cross members that is impacted or struck in accordance with the present invention;
FIG. 8 is a rear perspective view of the tool of FIG. 7;
FIG. 9 is a perspective view of the tool operatively coupled to one embodiment of the unitary tree stabilization device in accordance with the present invention; and
FIG. 10 is a perspective view of a tool for another embodiment of the present invention shown operatively coupled to the unitary tree stabilization device for the embodiments of the present invention of FIGS. 1 and 4 .
DETAILED DESCRIPTION OF THE INVENTION
The present invention is generally directed to an apparatus for stabilizing a tree or shrub which comprises a unitary stabilization device adapted for providing structural support to trees and/or shrubs, and optionally a tool for installing the stabilization device. The stabilization device of the present invention provide safe and effective support for a range of plantings in all types of soils and conditions, while being relatively inexpensive and simple to fabricate and install. The stabilization device is further adapted for effective concealment during use to avoid obstructing passing traffic including pedestrians, and avoid detracting from the appearance of the tree or shrub and the surrounding area. The stabilization device is also designed to prevent or at least minimize any injury to the tree and/or shrub during planting.
FIG. 1 shows a preferred embodiment of a tree stabilization device 10 in accordance with the principles of the present invention. The tree stabilization device 10 includes in this embodiment a single piece of tubing material bent into a substantially squared-off U-shaped configuration having a horizontal cross member 12 . A vertically oriented outer prong 14 is bent from one end of the cross member 12 , and a vertically oriented inner prong 16 is bent from the other end of the cross member 12 . The inner prong 16 is shorter than the outer prong 14 , in this example. It is noted that the lengths of the outer and inner prongs 14 and 16 can vary with respect to one another depending on the needs of the application at hand, the depth of the planting hole, soil conditions, terrain features, and the like.
The outer and inner prongs 14 and 16 each include ground penetrating tips 22 and 24 , respectively, at respective ends 18 and 20 . The ground penetrating tips 22 and 24 are each cut at substantially parallel angles with respect to one another. The ground penetrating tip 24 is formed by making a cut proceeding from the inside surface of the prong 16 downward to its outside surface at the end 20 at an angle sufficient to form a sharp point. The ground penetrating tip 22 is formed by making a cut proceeding from the outside surface of the prong 14 downward to its inside surface at the end 18 at a substantially equivalent angle for forming the tip 24 of the prong 16 . The cuts form point edges that are angled in a manner to cause the prongs 14 and 16 to slightly shift towards the tree as the device 10 is being driven into the ground. The tendency for the prongs 14 and 16 to shift towards the tree helps to prevent or at least minimize the break-up of or injury to the root ball. Optionally, the ends of the prongs 14 and 16 can be further modified through suitable methods such as by pinching or welding to seal the tips 22 and 24 , respectively. It is further noted that the form of the ground penetrating tips and the method of fabricating them are not limited to those disclosed herein, and can include other suitable configurations and methods as known in the art.
The tree stabilization device 10 of the present invention can be fabricated with a solid or tubular construction using a durable, rigid material that is impact resistant including wood, plastic polymers, metal such as ferrous-based alloys or other suitable material that is at least minimally safe for plants including trees and shrubs, and free from harmful plating or coatings.
In another embodiment of the present invention, the tree stabilization device can be fabricated from a plastic polymer material preferably one that is biodegradable. The plastic polymer can be extruded, molded or reinforced, and is capable of withstanding the rigors associated with installation and implementation. The plastic polymer material can be further impregnated with a soil enriching or conditioning agent that can be released into the surrounding soil and provide beneficial sustenance for the growth of plants including trees and shrubs. Such soil enriching agent can include minerals, ions, fertilizers including nitrogen sources, and other suitable plant nutrients.
The tree stabilization device 10 can be driven into the ground using conventional mallets, sledge hammers or other appropriate means for driving the device 10 into the ground. During installation, the shorter inner prong 16 is positioned for penetration into the root ball of the planting, and the outer prong 14 is positioned for penetration into the more stable ground extending around the perimeter of the root ball. Once the device 10 is so positioned, a mallet or hammer can be used to strike the upper portions of the cross member 12 , preferably near the prong 14 or 16 , to drive the device 10 into the ground.
In FIG. 2, two unitary tree stabilization devices 10 are installed for stabilizing a newly planted tree 100 having a root ball 110 . Generally, a planting hole having a diameter twice that of the root ball 110 is prepared. The root ball 110 is placed into the planting hole with the base of the tree trunk even with or above the grade level of the surrounding soil 112 . As the root ball 110 is placed into planting hole, a quantity of fill soil 114 is added to fill the space under the root ball 110 and elevate the tree 100 to a suitable planting height. The devices 10 are positioned at opposite sides of the tree 100 to provide a dimensionally-equalized anchoring support. The inner prongs 14 are placed over the root ball 110 , while the outer prongs 14 are placed on the soil along the edge of the root ball 110 . With the tree 110 held in the desired positioned, each of the devices 10 is driven fully into the ground until the cross member 12 is recessed into the root ball 110 . Recessing the cross member 12 into the root ball 110 ensures that the device 10 is firmly secured to the root ball 110 and that the device 10 is installed below the finished grade of the ground for effective concealment. Preferably, the cross member 12 is recessed about an inch or more into the root ball 110 . It is noted that the number, shape, and size of the stabilization devices can be modified as required depending on the size and type of tree, the planting hole and root ball, the features of the terrain, the soil conditions, the soil type, the moisture content of the soil, the wind conditions, space constraints and the like.
The inner prongs 16 of the devices 10 are adapted to efficiently penetrate into the root ball 110 of the tree 100 . The respective pointed inner prong tips 24 include sharp points that can penetrate the root ball 110 to provide a secure anchoring engagement. The outer prongs 14 each comprise a length sufficient to extend through the fill dirt 114 beyond the depth of the planting hole into the surrounding undisturbed soil 112 for deep anchoring engagement. In order for the outer prongs 14 to penetrate the undisturbed soil 112 , the outer prongs 14 are preferably longer than the depth of the planting hole.
In the preferred embodiment, the devices 10 are each positioned with the outer prongs 14 positioned adjacent to the root ball 110 and the inner prongs 14 positioned at a distance halfway between the edge of the root ball 110 and the tree 100 . The inner prongs 16 and the respective cross members 12 are each offset at an angle from the extended radius of the tree 100 . The respective cross members 12 are each oriented substantially parallel with one another. Preferably, the angle can range from about 0° to 90°, preferably from about 30° to 45°.
With reference to FIG. 3A, a plurality of unitary tree stabilization devices 10 are shown employed in a spatial configuration or arrangement to securely anchor a tree or shrub 140 having a root ball 150 planted in the ground. The root ball 150 includes a top portion 151 . The plurality of devices 10 are arranged radially around the tree or shrub 140 and spaced apart by about 120° from one another to provide a firm dimensionally-equalized support in all directions. The root ball 150 is separated from the undisturbed soil 152 by the fill dirt 154 . The inner prongs 16 of the devices 10 are securely anchored into the root ball 150 , while the outer prongs 14 extending through the fill dirt 154 are embedded in the undisturbed soil 152 . Each of the devices 10 is driven into the ground until the cross member 12 is recessed into the top portion 151 of the root ball 150 to provide a firm engagement therebetween and to ensure that the device 10 is positioned below the finished grade of the ground. Preferably, the cross member 12 is recessed about an inch or more into the root ball 150 .
With reference to FIG. 3B, the devices 10 are each positioned with the outer prongs 14 positioned adjacent to the root ball 150 and the inner prongs 14 positioned at a distance halfway between the edge of the root ball 150 and the tree 140 . The inner prong 14 and respective cross member 12 of each device 10 are oriented at an angle, α, measured from the extended radius 142 of the tree 140 . The angle, α, can range from about 0° to 90°, preferably from about 30° to 45°.
Referring to FIG. 4, a tree stabilization device 30 is shown for a second embodiment of the present invention. The device 30 consists in this example of a single piece of tubing material, and includes a cross member 12 , an inner prong 16 formed by bending one end portion of the tubing from one end of the cross member 12 at substantially a right angle, and an outer prong 14 formed by bending the other end portion of the tubing from the other end of the cross member 12 at substantially a right angle. The inner prong 16 includes a ground penetrating tip 24 at its end 20 and the outer prong 14 includes a ground penetrating tip 22 at its end 18 , each formed in the same manner as described above for the device 10 . As previously indicated, the device 30 includes a tubular wall 32 typically constructed from a rigid, impact resistant material such as metal or other suitable material for defining an interior cavity or hollow pathway therein.
The device 30 further includes an opening 36 in the tubular wall 32 at the upper portion of the cross member 12 , and a plurality of irrigation through holes 34 in the tubular wall 32 of the cross member 12 , and the outer and inner prongs 14 and 16 , respectively, in communication with the hollow pathway, thus permitting fluid passage from the opening 36 to the through holes 34 . Once the device 30 is set in the ground, the user can introduce a liquid such as water or a fertilizer solution into the hollow pathway of the tubing 32 via the opening 36 , wherein the fertilizer or water is able to exit from the irrigation holes 34 into the surrounding soil.
Optionally, the opening 36 can further be adapted to receive the threaded end of a hose to provide a secure fluid coupling therebetween during irrigation. In this manner, the newly established roots of the planting can be fertilized and/or watered directly without undesirably disturbing the soil surface and the fill soil. The device 30 can further include a soil enriching or conditioning agent such as in the form of water-soluble fertilizer granules captively retained in the hollow pathway. The user adds water through the opening 36 into the device 30 where the retained fertilizer is dissolved and carried into the surrounding soil.
Optionally, the device 30 can further include a projection 38 (shown in phantom in FIG. 4) securely attached to the cross member 12 proximate the outer prong 14 . The projection 38 can be attached to the cross member 12 through any suitable means including welding and the like. The projection 38 includes a notch portion 40 located proximately to the distal end thereof A guy wire can be used to encircle the trunk or body of the planting and then tied to the notched portion 40 of the projection 38 to provide additional anchoring support, if required.
With reference to FIG. 5, a tree stabilization device 42 is shown for a third embodiment of the present invention. The device 42 includes a cross member 44 , an inner prong 46 attached near one end of the cross member 44 , and an outer prong 48 attached near the other end of the cross member 44 . The prongs 46 and 48 can be attached to the cross member 44 through any suitable means including welding and the like. The inner and outer prongs 46 and 48 include ground penetrating pointed tips 50 and 51 , respectively, a tubular wall 52 defining a through cavity or open pathway in each prong 46 , 48 , and a plurality of irrigation through holes 54 in the tubular walls 52 in communication with the pathway. The device 42 further includes a pair of irrigation openings 56 each located proximate to the upper end of the cross member 44 in communication with the respective pathways of the inner and outer prongs 46 and 48 . Once the device 42 is installed, fluid such as water or fertilizer can be introduced through the corresponding openings 56 and passed through the respective pathways where it exits the irrigation holes 54 , respectively, to irrigate the surrounding soil. The irrigation openings 56 can further be adapted to receive the threaded end of an irrigation hose for secure fluid coupling therebetween.
The device 42 can further includes a projection 55 with a notch 57 attached at the end of the cross member 44 proximate the outer prong 48 . Once the device 42 is established in the ground, a guy wire can be tied to the projection 55 at the notch 57 with the other end secured to the trunk of the tree, thereby providing additional support as needed.
With reference to FIGS. 6A and 6B, a tree stabilization device 58 is shown for a fourth embodiment of the present invention. The tree stabilization device 58 can be constructed from tubular material, flat stock, rebar and the like. It is noted that although the tree stabilization device 58 is illustrated as a unitary piece, it can be comprised of individual components assembled by suitable means including welding and the like. The tree stabilization device 58 includes an outer prong 14 with a ground penetrating tip 22 , and a pair of cross members 12 A and 12 B each connected at a common end to the top of the outer prong 14 .
As shown in FIG. 6A, the cross members 12 A and 12 B are separated from one another by an angle, θ. The cross members 12 A and 12 B each include an inner prong 16 A and 16 B, respectively, with ground penetrating tips 20 A and 20 B, respectively. The prongs 14 , 16 A and 16 B in one embodiment can be welded together or can be made from a single casting, for example.
As shown in FIG. 6B, the cross members 12 A and 12 B are adapted to position the respective inner prongs 16 A and 16 B for penetration into a root ball 110 of a tree. The inner prongs 16 A and 16 B are positioned apart to spread the hold over a wider area, thus improving the anchoring to the root ball 110 . The angle, θ, between the inner prongs 16 A and 16 B can vary depending on the dimensions of the root ball, soil conditions and the like. Preferably, the angle, θ, can range from about 10° to 80°. It is understood that the number of inner prongs is not limited to two, and can include more than two.
With reference to FIGS. 7 and 8, an optional impact tool 70 for installing the tree stabilization device of the present invention is shown for one embodiment of the present invention. The tool 70 is adapted for flush mating engagement with the tree stabilization device 10 of FIG. 1 as further described below. The tool 70 includes a body portion 72 , a curved grooved portion 74 , an upper retainment portion 76 proximate one end thereof, a lower retainment portion 78 proximate the other end thereof, and a striking protrusion 80 . The upper retainment portion 76 includes a vertical width which is preferably less than the diameter of the device 10 to facilitate mounting and removal from the device 10 . The tool 70 is adapted to be struck by the user and to effectively focus and direct the generated impact force through the prongs of the tree stabilization device of the present invention, while minimizing any damage to the device. The tool 70 is constructed as a solid piece from an impact resistant, high-strength material such as steel, for example. Applicants note that the tool can be modified to operate with different embodiments of the tree stabilization device in accordance with the present invention as understood by one skilled in the art.
In FIG. 9, the tool 70 is shown operatively coupled to the tree stabilization device 10 . The curved groove portion 74 in combination with the retainment portions 76 and 78 , respectively, are adapted to fit with the contours of the stabilization device 10 preferably along the portion between the cross member 12 and the outer prong 14 . The tool 70 is adapted to be attached to the stabilization device 10 so that the impact area or the striking protrusion 80 is positioned in axial alignment with the outer prong 14 . In this manner, the user can strike the striking protrusion 80 with a mallet to efficiently drive the stabilization device 10 into the ground. As noted above, the tool 70 is designed to direct and to focus the impact force into the outer prong 14 , while preventing or at least minimizing any damage to the physical integrity and exterior portion of the device 10 . Applicant notes that the striking protrusion 80 can be omitted from the tool 70 , and the user can strike along the top surface of the tool 70 to drive the device 10 into the ground.
In FIG. 10, an optional impact tool 82 is shown for a second embodiment of the present invention. The impact tool 82 is similar to the impact tool of FIGS. 7-9. In this embodiment, the impact tool 82 is adapted to fit over the length of the cross member 12 . The tool 82 can be slipped over the cross member 12 as shown. The user can strike along a top surface 84 of the tool 82 or at the strike points 86 provided thereon to drive the device 10 into the ground.
Although various embodiments of the invention have been shown and described, they are not meant to be limiting. Those of skill in the art may recognize various modifications to these embodiments, which modifications are meant to be covered by the spirit and scope of the appended claims. | A unitary device for securing the root ball of newly planted trees and/or shrubs into proper position, for stabilizing the trees and/or shrubs to prevent shifting or toppling while the tree and/or shrub root systems are first developing. The device includes a horizontal cross member, and a couple of prongs perpendicularly depending from the horizontal cross member, all formed from a single piece of rod or tubing material. At the time of planting, after the root ball of the tree is set into an appropriate hole and the tree is in proper position, the free ends of the prongs of the device are driven into the ground such that the outer prong is retained in the firm portion of the soil, and the inner prong engages the root ball. The outer prong is of a sufficient length to be held securely in the soil, and the inner prong is both arranged in position and sized in length to engage the root ball securely. The device is driven into the soil deep enough for the cross member to be recessed into the root ball to provide a firm engagement therebetween and to ensure that the device is established below the finished grade of the ground. | 0 |
TECHNICAL FIELD
[0001] The present invention relates to an electronic cipher code lock, particularly, to an input device of the electronic cipher code lock, an input method used for the electronic cipher code lock, and the application of the input device of the electronic cipher code lock.
BACKGROUND ART
[0002] To enable and to set the cipher code of a prior mechanical dial type cipher code lock are implemented by the mechanical linkage mechanism inside the cipher code lock. Accurate positioning is required for enabling the cipher code and setting the cipher code of such cipher code lock, particularly, it is more complicated to modify the cipher, in addition to that the lock body is required to disassemble, it is very difficult for the person who have not been trained professionally to complete the operation of setting the code. Furthermore, the amount of the cipher code keys of said method depends on the amount of the directive wheels inside the mechanical linkage mechanism. In order to obtain a large amount of cipher code keys, the amount of the directive wheels shall be increased so that the volume and the complexity of the structure will be increased. Therefore, people attempt more and more to use the electronic cipher code lock, which can be operated conveniently and has a compact structure.
[0003] It has been disclosed in the U.S. Pat. No. 6,420,958 an electronic digital lock, it uses a dial coupled to a step motor, when rotating the dial, the signals are generated by the step motor, and are outputted to a microcomputer for counting process via a shaping circuit, and are displayed by a display device. When the rotation of the dial is stopped, the numbers displayed are inputted as a part of the cipher code combination. Since the structure of the step motor is complicated and the price is rather high, and the peripheral circuits, such as the shaping circuit, and the like, are required, therefore the manufacturing cost of such electronic digital lock is relatively high.
[0004] Additionally, the input devices of dial type electronic cipher code locks have been disclosed in U.S. Pat. No. 4,745,784 and U.S. Pat. No. 4,899,562 respectively, they have the similar structure. The input device of the electronic cipher code lock comprises a dial, a contact tip which is fixed inside the dial and can be rotated together with the dial, and ten contact points which are distributed as a circle or a half circle corresponding to the moving track of the contact tip and connected to a circuit board. The dial is depressed axially when the dial is rotated to a certain calibration position, and an electrical signal is produced by the contact between the contact tip thereon and a certain contact point corresponding to said calibration position. The electrical signal of each of the contact points corresponds to a different number, and this number is confirmed as an element of the cipher code.
[0005] An input device of the dial type electronic cipher code lock has also been disclosed in Japanese Patent P2000-73632. It comprises a conducting sheet fixed on the dial, and two groups of contact points, which contact with the conducting sheet and are distributed intermittently as a circle, and a conducting ring, which is connected electrically with the contact point groups and supplies the power thereto. When rotating the dial, the above two contact point groups are contacted and are turned on intermittently with and by the conducting sheet, and two groups of electrical pulse signals can be obtained from the output leads of the two groups of the contact points. The signals are processed and displayed as the cipher code elements. In this technical scheme, a confirmation device for confirming the cipher code is a button switch installed on the dial.
[0006] The electrical signals representing the cipher codes are produced directly by employing the electrical contact method in the above said three kinds of input devices of the electronic cipher code lock, therefore a problem of the contact reliability may be caused. Particularly, in the input device of the electronic cipher code lock of the Japanese Patent P2000-73632, there is also the problem of the abrasion due to the contact friction. Furthermore, since the electrical signals representing the cipher code are inputted directly without isolation, the security protection performance is also insufficient.
[0007] Furthermore, most of the prior cipher code locks are in the form of numeral keyboard, in most of the cases, the keyboard is installed on the panel of the lock body above the handle of the door lock. However, for a handle of cipher code lock disclosed in U.S. Pat. No. 6,378,344, the numeral keyboard is embedded in the handle of the lock, and the cipher code is inputted through the keyboard. Since the plane size of the keyboard is large, the volume of the handle is larger than that of a normal handle, thus, it will bring about an uncomfortable feeling when using said handle.
[0008] Most of the prior cipher code locks used for the chests and bags are in the form of mechanical roller, as described above, the structure of the mechanical cipher code lock is complicated, and it is inconvenient to operate it. For example, for a mechanical combination lock used for the chests and bags as disclosed in the Chinese Patent ZL00261865.6, though it has four digit wheels and employs new structure to simplify the operation for changing the cipher code, but the disadvantages, such as the amount of the cipher code keys being small, the mechanical operation for changing the cipher code being complicated, still exist.
SUMMARY OF THE INVENTION
[0009] The object of the invention is to overcome the disadvantages in the prior art and to provide an input device of the electronic cipher code lock, which has a high reliability and an excellent security protection performance, and the input and the set of the cipher code is simple and convenient.
[0010] The invention also provides a cipher code lock handle including said input device of the electronic cipher code lock, and a panel for the cipher code lock used for the chests and bags, their structures are simple and compact, the amount of the cipher code keys is large, the volume is small and the operation for inputting the cipher code is intuitional and convenient.
[0011] Another object of the invention is to provide an input method used for inputting the cipher code of an electronic cipher code lock, and the cipher code can be inputted reliably, safely and conveniently by this method.
[0012] According to the first aspect of the invention, it provides an input device of an electronic cipher code lock, comprising: a signal device for producing cipher code input information and for converting said information into two groups of electrical pulse signals; a measurement and control device connected with said signal device for measuring the electrical pulse signals outputted from the signal device, deciding the order of the electrical pulse signals and calculating correspondingly such that said signals are converted into character sequences including the cipher code elements, and deciding whether said cipher code elements are confirmed to be inputted or not and deciding whether the input of all the cipher code elements is completed or not; a confirmation device connected with said measurement and control device and used for producing a conformation signal for inputting the cipher code elements to indicate that the input of the current cipher code element is confirmed; and a display device connected with said measurement and control device for displaying said character sequences and preset prompt information in a rolling and refreshing manner by the driving of said measurement and control device.
[0013] Preferably, in the input device of the electronic cipher code lock of the invention, said confirmation device is a switch device, an electrical signal produced when it is closed allows said measurement and control device to confirm the current cipher code element displayed by said display device as a part of the input cipher code.
[0014] Preferably, in the input device of the electronic cipher code lock of the invention, the measurement and control device is also used for deciding whether during a given timing period which starts each time when a signal is produced by a switch device, the timing period expires or not. If the timing period expires, then it decides that the input is during overtime.
[0015] The preset information displayed by said display device is indicated by symbols, wherein the close and open states of the lock are indicated by a symbol having a padlock shape, the time at which the lock is opened on time or is delayed to be opened is indicated by a symbol having a clock shape, the code setting state is indicated by a symbol having a key shape, and low power of battery is indicated by a symbol having a battery shape, and the confirmation states of the respective parts of the cipher code are indicated in turn by the remaining dot symbols.
[0016] The above input device of the electronic cipher code lock may be an input device of a dial type electronic cipher code lock. Wherein the signal device comprises: a panel body, a dial which is installed on said panel body and can be rotated freely, a drive shaft fixed at the center of said dial, a set of driving gears installed on said drive shaft, a driven gear which meshes with said driving gears, and a rotating coder connected with said driven gear on the same shaft. Wherein the measurement and control device is a programmed microcontroller, the display device is an information display screen, and the switch device is a photoelectric switch. Said microcontroller, coder, information display screen and photoelectric switch are provided on the same circuit board, said circuit board is provided within said panel body, and said microcontroller is connected electrically with said coder, information display screen and photoelectric switch respectively.
[0017] Preferably, in the above said input device of the dial type electronic cipher code lock, the outer edge of said dial is a circular skirt-like fringe, the position of said photoelectric switch corresponds to the skirt-like fringe of said dial, when said dial is depressed, the light transmitted to the photoelectric switch is blocked by said skirt-like fringe, thereby a signal is produced by said photoelectric switch.
[0018] Optionally, in the above said input device of the dial type electronic cipher code lock, the upper part and lower part of said panel body have a hunched ear edge like shape, and said panel body further comprises: grooves provided in back of said ear edge and matched with the fingers; a display window, which matches with the shape and size of said information display screen, and forms a oblique angle together with said information display screen for viewing effectively; and a guiding hole provided at the display window side of said panel body for inserting an emergency key.
[0019] In the above said input device of the dial type electronic cipher code lock, it further comprises a reset spring installed axially within an internal hole provided in the drive shaft of said dial.
[0020] Alternatively, in the above said input device of the electronic cipher code lock, concentric circle plane gullets are provided on the internal end face of said driving gear, and a blind hole is provided on said plane gullet at a position corresponding to said panel body, and a steel ball and a spring are installed in said blind hole, under the action of the spring, said steel ball contacts and matches with the concentric circle plane gullet of said driving gear.
[0021] Furthermore, the above said input device of the electronic cipher code lock can also be an input device of a roller type electronic cipher code lock. Wherein the signal device is a roller device, it comprises: a roller, a coder which is coaxial with the roller, and an elastic bracket for supporting said roller. Wherein the measurement and control device is a programmed microcontroller, the display device is an information display screen, the switch device is a microswitch provided below the shaft extension of the roller. Said microcontroller is connected electrically with said coder, information display screen and microswitch, respectively.
[0022] Preferably, in the above said input device of the roller type electronic cipher code lock, 1-bit or 2-bit number is displayed on the information display screen in an ascending order or descending order circularly rolling manner according to the rotation direction and angle of said roller. When the roller is depressed, the microswitch is actuated by the shaft extension of said roller, thereby the rolling display of said information display screen is stopped, so that the current number displayed is confirmed as a part of the cipher code. After releasing the depressed roller, said roller is reset by the elastic bracket.
[0023] According to the second aspect of the invention, it provides a handle of the cipher code lock, which is hollow, and comprises: an input device of the roller type electronic cipher code lock of the invention, which is fixed within a cavity in said handle; a first window, which corresponds to said roller thereby said roller may be dialed and depressed, provided on the surface of the handle, a second window, which corresponds to said information display screen thereby the contents displayed may be viewed, provided on the surface of the handle; and a rotation shaft fixed in the handle with a through-hole used for the wires to be passed through provided therein. The input device of the electronic cipher code lock is connected with a cipher code identification device of the lock and a power supply, which are installed inside the core mechanism of the lock or installed at other position inside the door, via the wires.
[0024] The invention further provides another handle of the electronic cipher code lock, said handle is hollow and comprises: a handle body, a panel and a transparent window cover. Said handle body comprises a rotation shaft fixed therein, and a through-hole provided inside said rotation shaft for allowing the connection wires to be passed through. The input device of the roller type electronic cipher code lock of the invention is installed within the panel body, a first window, which corresponds to said roller thereby said roller may be dialed and depressed, and a second window, which corresponds to said information display screen thereby the contents displayed may be viewed, are provided on said panel. Said transparent window cover is provided on a plane on which there is said second window. A hollowed region, which has the size and shape matching with said panel, is provided on the front surface of the handle body, thereby said panel can be embedded therein. Said handle of the cipher code lock is connected to a cipher code identification device and a power supply of the cipher code lock which are installed inside the core mechanism of the lock or installed at other positions inside the door via the wires.
[0025] The invention further provides yet another handle of the cipher code lock, and it comprises: a handle body, a handle base and a panel. The microcontroller and information display screen in the above input device of the roller type electronic cipher code lock are installed inside the handle base, and the second window, which corresponds to said information display screen thereby the displayed contents may be viewed, is provided on the front surface of the base. The roller device in the input device of the electronic cipher code lock of the invention is fixed inside the panel body, and the first window having the size and shape matching with the roller thereby said roller may be dialed and depressed is provided on the surface of said panel. Wherein said handle is hollow, and a cavity matching with the size and shape of said panel is provided on its front surface, thereby said panel can be embedded therein. Said input device of the roller type electronic cipher code lock is connected to a cipher code identification device and a power supply of the cipher code lock which are installed inside the core mechanism of the lock or installed at other positions inside the door via the wires.
[0026] According to the third aspect of the invention, it provides a panel of a cipher code lock for the chests and bags, the panel of the cipher code lock for the chests and bags is fixed on the external surface of the chest body. It comprises: an input device of the electronic cipher code lock of the invention installed within said panel body; a first window, matching with the size and shape of said roller thereby said roller may be dialed and depressed, provided on the surface of said panel; and a second window, matching with the size and shape of said information display screen and having a transparent window cover provided thereon thereby the displayed contents may be viewed, provided on said panel. Wherein said input device of the cipher code lock is connected to a cipher code identification device and a power supply of the cipher code lock which are installed inside the chest body via the wires.
[0027] According to the fourth aspect of the invention, it provides a method for inputting the cipher code of a cipher code lock, and the method comprises the following steps: receiving rotation information of the dial or roller via a signal device and converting it into two groups of electric pulse signals; measuring, deciding and calculating said two groups of electric pulse signals by a measurement and control device, and further converting them into element sequence constituted by the cipher code; displaying character sequences including cipher code elements and preset information by a display device, wherein the rolling refreshing rate for displaying the character sequences including cipher code is a function of the signal frequency of said two groups of electric pulse signals, the element sequence of the cipher code is rolling refreshed in an ascending order or descending order manner, which corresponds to the rotation direction and angle of said dial or roller; when the input of the current cipher code element is confirmed, a confirmation signal for inputting the cipher code element is produced by a confirmation device; after said electrical signal is detected by the measurement and control device, the currently inputted cipher code element is confirmed; and the measurement and control device further decides whether the input of all of the cipher code elements is completed or not.
[0028] Preferably, the above said input method for the cipher code further comprises the following steps: when a signal is produced by said confirmation device, a given timing period is started, after that, whether the timing period expires or not is decided by the measurement and control device, if the timing period expires, then it decides that the input is during overtime.
[0029] By using the above said input device and input method of the electronic cipher code lock, it makes the input device of the electronic cipher code lock of the invention have simple structure, the input cipher code signals be isolated by using mechanic-electric or optical-electric isolation, no electrical contact exist between the operating parts and the circuits, therefore it improves significantly the reliability and the security protection performance. Furthermore, the operation for inputting cipher code and the operation for modifying cipher code are also very simple and intuitional.
[0030] Particularly, when the input device of the electronic cipher code lock of the invention is a dial type, the above advantages will be more outstanding. Furthermore, the structure of the input device of the dial type electronic cipher code lock is novel and inimitable, and the way for the open operation of the cipher code lock further accords with the conventional operation custom.
[0031] When the input device of the electronic cipher code lock of the invention is a roller type, its structure is more compact and its volume is smaller, it is convenient for applying it in a variety of situations. After applying it to the handle of the lock, the handle function and the cipher code input function as well as the display function of the cipher code and information can be integrated in one so that the disadvantage of the large volume of the handle of the electronic cipher code lock of the prior art is overcome. After applying it to the chests and bags, not only the amount of the cipher code key is large and the operation for modifying the cipher code becomes more simple and convenient, but also the comfortable feeling of the operation will be better than that of the mechanical roller type cipher code lock used for the chests and bags.
BRIEF DESCRIPTION OF APPENDED DRAWINGS
[0032] The invention will be further described in detail by referring to the drawings and embodiments as follows. In the drawings, the same reference number indicates the same or corresponding parts. The above and other objects, features and advantages of the invention will become more apparent through the following description.
[0033] FIG. 1 is a structure block diagram according to a first embodiment of the invention;
[0034] FIG. 2 is a flow chart according to the first embodiment of the invention;
[0035] FIG. 3 is a schematic structure diagram according to a second embodiment of the invention;
[0036] FIG. 4 shows a structure of a driving gear in the second embodiment of the invention;
[0037] FIG. 5 shows a structure of a dial in the second embodiment of the invention;
[0038] FIG. 6 is a schematic plan diagram showing an information display screen in the second embodiment of the invention;
[0039] FIG. 7 is a schematic structure diagram according to a third embodiment of the invention;
[0040] FIG. 8 shows another alternative structure form according to the third embodiment of the invention;
[0041] FIG. 9 shows an enlarged cross section structure of an elastic bracket in the third embodiment of the invention;
[0042] FIG. 10 shows an enlarged cross section structure of an elastic bracket at another state in the third embodiment of the invention;
[0043] FIG. 11 shows an external structure of a handle of cipher code lock according to the invention;
[0044] FIG. 12 and FIG. 13 exhibit commonly an internal structure of the handle of a cipher code lock as shown in FIG. 11 ;
[0045] FIG. 14 shows an external structure of another handle of cipher code lock according to the invention;
[0046] FIG. 15 exhibits an internal structure of the handle of cipher code lock shown in FIG. 14 ;
[0047] FIG. 16 shows an external structure of another handle of cipher code lock according to the invention;
[0048] FIG. 17 exhibits an internal structure of the handle of cipher code lock as shown in FIG. 16 ;
[0049] FIG. 18 shows an external structure of the panel of the lock for the chests and bags according to the invention; and
[0050] FIG. 19 exhibits an internal structure of the panel of the lock for the chests and bags as shown in FIG. 18 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0051] The input device, input method and the application of the electronic cipher code lock of the invention will be further described by incorporating several specific embodiments as follows.
[0052] Input Device of the Electronic Cipher Code Lock
[0053] FIG. 1 shows an input device of the electronic cipher code lock according to the first embodiment of the invention. As shown in the drawing, said input device of the electronic cipher code lock is composed of a signal device 2 , a measurement and control device 3 , a display device 4 and a confirmation device 5 .
[0054] The signal device 2 can employ an electromechanical rotation coder, the rotor of the coder has a mechanical driving relationship with the dial and rotates following the dial. The coder has two code signal output terminals, when the dial rotates in a clockwise direction, the electrical pulse signal 11 outputted from the first output terminal keeps ahead; when the dial rotates in a counterclockwise direction, the electrical pulse signal 12 outputted from the second output terminal keeps ahead. The number of the pulses included in the two groups of electrical pulse signals is proportional to the angle through which the rotor of the coder has rotated, and the frequency of the pulse signals is proportional to the rotation rate of the rotor of the coder.
[0055] The measurement and control device 3 is composed of a single-chip microcomputer and the peripheral circuits thereof, and a single-chip microcomputer having integrated RAM and ROM therein can be used for measuring the electrical pulse signals 11 and 12 outputted by the signal device 2 , deciding the order of said electrical pulse signals, and calculating correspondingly such that said signals are converted into character sequences including the cipher code elements, and deciding whether the current cipher code elements are confirmed to be inputted or not and deciding whether the input of all of the cipher code elements is completed or not. ROM stores the control program and the preset data information, RAM stores the data information, such as the measuring data, displaying data and other intermediate data; EEPROM is required to be set further, and the cipher code for opening the lock, the setting cipher code and the verification cipher code are stored therein in advance. The single-chip microcomputer comprises several I/O ports P 2 ˜P 6 , wherein the measurement and control device 3 receives the two groups of electrical pulse signals 11 and 12 converted by the signal device 2 via the ports P 2 and P 3 , the port 6 is connected with the confirmation device 5 , the port P 4 is connected with the display device 4 , the port P 5 can be connected optionally with the implementation device 7 of the electronic cipher code lock.
[0056] As shown in FIG. 1 , in order to achieve preferably the technical results of the invention, the confirmation device 5 in the present embodiment is a switch device, the close of the switch device 5 is controlled by the axial motion of the dial, when the dial is not depressed the switch device 5 is in a disconnection state, and when the dial is depressed the switch device 5 is closed, and the close action produces an electrical signal 13 at two terminals of the switch device 5 , said signal is directed to I/O port P 6 of the measurement and control device 3 as a confirmation signal for inputting an element of the input cipher code.
[0057] Furthermore, in the input device of the electronic cipher code lock as shown in FIG. 1 , each time when a signal is produced by the switch device 5 thereby starting a given timing period, said measurement and control device 3 decides whether a timing period expires or not, if the timing period expires, then it decides that the input is overtime.
[0058] Said character sequence and preset prompt information are displayed by the display device 4 under the driving of the measurement and control device 3 in a roll refreshing manner. Wherein the preset information is indicated by symbols, with reference to FIG. 6 , the close state and open state of the lock are indicated by a symbol having a padlock shape, the time at which the lock is opened on time or is delayed to be opened is indicated by a symbol having a clock shape, the code setting state is indicated by a symbol having a key shape, and low power of battery is indicated by a symbol having a battery shape, and the confirmation states of the respective parts of the cipher codes are indicated in turn by the remaining dot symbols.
[0059] The operation principle and flow process of the input device of the electronic cipher code lock of the invention will be described in detail with reference to FIG. 2 , they can be achieved by the program stored in ROM.
[0060] As shown in FIG. 2 , in step S 21 , the signal device 2 is rotated by the dial and electrical pulse signals 11 and 12 are produced, the two groups of signals are directed to the I/O ports P 2 and P 3 of the measurement and control device 3 , the measurement and control device 3 will be waked up from a low power consumption state regardless of which direction the dial rotates and changed to an operation state thereby turning on the display device 4 . Then, the first group of electrical pulse signals 11 and the second group of electrical pulse signals 12 are received by the I/O ports P 2 and P 3 of the measurement and control device 3 , and the measurement and control device 3 proceeds to the timing period under the control of the program, and the timing program begins timing from zero. Meanwhile, the input flow process of the entire electronic cipher code lock proceeds to step S 22 .
[0061] As shown in the drawing, in step S 22 , the received electrical pulse signals 11 and electrical pulse signals 12 are measured by the measurement and control device 3 . Next, in step S 23 , the successive order of the electrical pulse signals 11 and 12 are decided by the measurement and control device 3 . If the electrical pulse signals 11 keep ahead, then an add operation will be performed for the change amount of the pulses measured currently and the accumulation sum of the amount of the pulses measured previously; if the electrical signals 12 keep ahead, then an subtraction operation will be performed for the change amount of the pulses measured currently and the accumulation sum of the amount of the pulses measured previously. Next, in steps S 24 and S 25 , after the above operation results are data processed by the measurement and control device 3 , the display device 4 is driven via the I/O port P 4 to display in a decimal number manner, and the display refresh rate of the above operation results is adjusted according to the proportional relationship of the measured frequency of the electrical pulse signals, meanwhile, the flow process proceeds to step S 26 .
[0062] In step S 26 , the measurement and control device 3 detects firstly whether a signal is inputted at I/O port P 6 , if the electrical level signal 13 outputted from the switch device 5 is not detected, then the measurement and control device 3 detects in step S 27 whether the time counted by the overtime counting program expires or not. If the time counted by the overtime counting program has not expired, then it proceeds to step S 22 . If the time counted by the overtime counting program has expired, then it proceeds to step S 32 , and an overtime alarm signal is issued, meanwhile, an input overtime information is displayed by the display device 4 . If the measurement and control device 3 detects the electrical level signal 13 outputted by switch device 5 , after the cipher code element displayed currently on display device 4 is confirmed and stored into RAM, a cipher code receiving confirmation information is displayed by the display device 4 under the driving of the I/O port P 4 , meanwhile, the flow process proceeds to step S 28 to enter a new timing period.
[0063] In step S 29 , the measurement and control device 3 counts the received cipher code elements which have been confirmed, and compares the counting result with a preset number, if the counting result is less than the set number, then it proceeds to step S 30 . In step 30 , the measurement and control device 3 stores the number displayed currently into RAM as a cipher code element, and next in step S 31 , the display device 4 is driven to display the cipher code input confirmation information, meanwhile, the flow process goes back to step S 22 . In step S 33 , after the measurement and control device 3 performs the operation of linking several cipher code elements, which have been inputted and confirmed, in sequence and they are stored into RAM again, the display device 4 displays the cipher code receiving completion information under the driving of the I/O port P 4 . At this time, the entire input flow process for the electronic cipher code lock is completed, other operation flow process can be entered selectively from step 34 as required.
[0064] For example, the cipher code can be set through the above method steps for inputting the cipher code. The preset cipher code is inputted firstly such that the input device of the electronic cipher code lock of the invention enters a cipher code setting state, then a new cipher code for opening the lock can be inputted under said state to substitute the old cipher code, and the new cipher code can be used for opening the lock afterwards. The details can be referred to FIG. 2 . In step S 34 , the cipher code for opening the lock and set cipher code, which are preset, are read from EEPROM, and are compared with the inputted cipher code. Then in step S 35 , whether the inputted cipher code is the same as the cipher code for opening the lock or not is decided. If they are the same, then it will proceed to step S 36 , and an open lock command will be issued to the implementation device 7 . Then in step S 37 , the implementation device 7 opens the closed lock device. If it is decided in step S 35 that they are different, then it will proceed to step S 38 , whether the inputted cipher code and the preset cipher code are the same or not is decided. If they are the same, then it will proceed to the cipher code setting flow process, otherwise, the display device 4 will display a cipher code error information in step S 39 .
[0065] Input Device of the Dial Type Electronic Cipher Code Lock
[0066] The input device of the electronic cipher code lock of the invention can also be produced specifically as a dial form as required, just as shown in the second preferred embodiment of the invention. As shown in FIG. 3 , when it is produced as an input device of a dial type electronic cipher code lock, a signal device 2 comprises: a panel body 111 , a dial 101 which is installed on said panel body 111 and can be rotated freely, a drive shaft 102 fixed at the center of said dial 101 , a set of driving gears 103 installed on said drive shaft 102 , a driven gear 115 which meshes with said driving gear 103 , and a rotating coder 108 connected with said driven gear 115 on the same shaft. A measurement and control device 3 is a programmed microcontroller (hereinafter refer to as MCU) 106 , a display device 4 is an information display screen 110 , and a switch device 5 is a photoelectric switch 107 .
[0067] In the above drawing, the MCU 106 , coder 108 , information display screen 110 and photoelectric switch 108 are provided on a circuit board 109 , said circuit board 109 is provided within said panel body 111 . A mechanical-electrical rotation coder can be used as the coder 108 . An infrared photoelectric switch is used as the photoelectric switch 107 , comprising a transmitter tube and a receiver tube. A single-chip microcomputer having ROM, RAM and several I/O ports is employed as the microcontroller, and the control program being installed in the ROM. The I/O ports on MCU are connected with the coder 108 , photoelectric switch 107 , and information display screen 110 respectively, wherein one I/O port is connected with the cipher code identification device of the cipher code lock for data communicating.
[0068] The dial 101 , drive shaft 102 , driving gears 103 , driven gear 115 , and the rotor of the coder 108 constitute a simple driving system. Specifically, the cross section of drive shaft 102 is a regular polygon, one end of the shaft being fixed at the center of the dial 101 , a internal regular polygon hole is provided on the driving gears 103 for adapting the other end of the drive shaft 102 to be inserted into. A movable fit exists between a cylindrical face at one side of the driving gears 103 and the corresponding internal hole of the panel body 111 . The driven gear 107 meshes with the driving gears 115 , and a movable fit exists between two cylindrical faces of the driven gear 115 and the internal hole of the gear pressboard 117 , another internal hole of the panel body 111 respectively, the gear pressboard 117 is snapped on two supporting posts of the panel body 111 , the cross section of the shaft extension of the driven gear 115 is a regular polygon, the shaft extension as the drive shaft of the rotor of the coder 108 is inserted into the internal regular polygon hole of the rotor of the coder 108 . In this driving system, the function of the panel body 111 , gear pressboard 117 , and the like is supporting and the positioning.
[0069] The dial 101 and drive shaft 102 can displace axially 2 to 4 mm, an internal hole 122 is provided axially at the movable end of the drive shaft 102 , and a reset spring 104 is provided in the hole. Two slot openings 118 , corresponding to the transmitter tube and receiver tube of the photoelectric switch 107 , are provided on the panel body 111 .
[0070] FIG. 5 shows a structure of the dial in the second embodiment of the invention. As shown in the drawing, the internal edge of the dial 101 has a circular skirt-like fringe 123 , said skirt-like fringe corresponds to a position between the transmitter tube and the receiver tube of the photoelectric switch 107 on the circuit board 109 . When the dial 101 is depressed, the light signal of the photoelectric switch 107 is blocked by the skirt-like fringe 123 , causing the electrical signal outputted from the photoelectric switch 107 to change, and the electrical signal is transmitted to MCU 106 , when the change of the signal is detected by MCU 106 , the number displayed currently is confirmed and stored as a part of the cipher code. After releasing the external force for depressing the dial 101 , the dial 101 and drive shaft 102 are reset under the reset function of the reset spring 104 .
[0071] The shape of driving gears 103 is shown in FIG. 4 , a simple mechanism is constituted by a concentric circle plane gullet 121 provided on the internal end face of said driving gear, and a steel ball 114 , a spring 113 and a corresponding blind hole provided on said panel body 111 . Under the action of the spring 113 , said steel ball 114 contacts and matches with the concentric circle plane gullet 121 of said driving gear 103 , the function of which is: during the procedure of rotating the dial 101 , as the displayed number changes dynamically, a hand feeling, which synchronizes with the refresh of the displayed number, will be produced.
[0072] An eight-segment nixie tube for displaying the prompt information symbols and two seven-segment nixie tubes for displaying number are provided on the information display screen 110 , as shown in FIG. 6 , wherein the close state and open state of the lock are indicated by a symbol having a padlock shape, the time at which the lock is opened on time or is delayed to be opened is indicated by a symbol having a clock shape, the code setting state is indicated by a symbol having a key shape, low power of battery is indicated by a symbol having a battery shape, and the confirmation states of the respective parts of the cipher code are indicated in turn by the remaining dot symbols.
[0073] The display face of the information display screen 110 is an oblique face, the oblique angle thereof makes user's line of sight be approximately perpendicular to the display face of information display screen 110 so that it accords with the principle of the human body engineering. The plane of the display widow of the panel body, which corresponds to the display face of the information display screen 110 , is also an oblique face having the same angle. A transparent window cover 116 is snapped on the plane on which there is the display window of said panel body.
[0074] The upper part and lower part of said panel body 111 have a hunched ear like edge 105 to serve as a handle, and grooves are provided on the internal side (back part) of said ear like edge 105 and matched with the fingers so that the operation of opening the door is easy. Furthermore, an isomerism guiding hole 112 is provided at the display window side of said panel body for inserting a mechanical emergency key.
[0075] During assembling, the circuit board 109 is fixed at other side of the panel body 111 , the cylindrical face of the driving gears 103 is installed into a corresponding hole on the panel body 111 , the cylindrical face at one end of the driven gear 115 which is meshed with the driving gears 103 is installed into a corresponding hole of the panel body 111 , the shaft extension thereof is inserted into an internal hole of the rotor of the coder 108 , a middle hole of the gear pressboard 117 is fitted with the cylindrical face at another end of the driven gear 115 , and the gear pressboard 117 is snapped by two supporting post on the panel body 111 , the steel ball 114 and spring 113 are installed into a corresponding hole on the panel body 111 , the drive shaft 102 is inserted into a polygon hole of the driving gears 103 , the position of another end of the reset spring 104 in the axial internal hole is limited by the face of the door of the safe, the circular skirt-like fringe at the internal edge of the dial 101 corresponds to the transmitter tube and receiver tube of the photoelectric switch 107 through two slot openings of the panel body 111 .
[0076] The specific application of the input device of the dial type electronic cipher code lock of the present embodiment will be described as follows.
[0077] The dial 101 is turned when it requires to open the lock, when the displayed two bits of number are the same as the first part of the preset cipher code for opening the lock, the turning will be stopped and the dial 101 will be depressed axially, at this time, the dot symbols distributed at the most lower part of the half circle on the information display screen 110 are illuminated, it indicates that the first part of the cipher code is confirmed and inputted, and the other parts of the cipher code is inputted according to the same method, during the procedure of confirming and inputting each part of the cipher code, the dot symbols distributed as a half circle on the information display screen 110 are illuminated in turn, after the last part of the cipher code is inputted, the entire cipher code is sent to the cipher code identification device of the cipher code lock by MCU 106 , the received cipher code is identified and decided by the cipher code identification device, if the decided cipher code result is true, then the lock will be opened by an electromotive driving device under the control of the cipher code identification device, and an open lock signal will be sent to MCU 106 , after the open lock signal is received by MCU 106 , the symbol having the padlock shape on the information display screen 110 is illuminated under its control.
[0078] When it is required to reset the cipher code for opening the lock, firstly, the set cipher code is inputted via the above said steps of inputting and confirming the cipher code, when the set cipher code inputted is decided as true, the symbol having the key shape is illuminated, it indicates that it enters the cipher code setting state, at this time, a new cipher code for opening the lock can be inputted.
[0079] When the voltage of the power supply of the cipher code lock measured by MCU 106 is lower than a prescribed value, the symbol having a battery shape is illuminated, prompting that it is required to change the battery.
[0080] Input Device of the Roller Type Electronic Cipher Code Lock
[0081] The input device of the electronic cipher code lock of the invention can also be produced specifically as a roller form as required, just as shown in the third preferred embodiment of the invention. As shown in FIG. 7 , when it is produced as an input device of a roller type electronic cipher code lock, a signal device 2 is a roller device 201 (a part inside the dash line block in FIG. 7 ), comprising: a roller 202 , a coder 212 which is coaxial with the roller 202 , and an elastic bracket 204 for supporting the roller 202 ; a measurement and control device 3 is a programmed microcontroller 208 ; a display device 4 is an information display screen 209 , and a switch device 5 is a microswitch 206 provided below the shaft extension of the roller 202 . The microcontroller 208 is connected electrically with the coder, the information display screen 209 and the microswitch 206 respectively.
[0082] A photoelectric coder can be used as the rotation coder, it is composed of a photoelectric wheel 203 , and a light emitting diode and a phototriode 207 which are disposed at two sides of the photoelectric reel.
[0083] The microcontroller 208 is composed of a single-chip microcomputer MCU, a memory RAM, and peripheral circuits. The control program are contained in MCU, several I/O ports of MCU are connected electrically with the roller device 201 and the information display screen 209 respectively, wherein another I/O port is connected electrically to the cipher code identification device of the cipher code lock for data communicating.
[0084] Furthermore, a connector can be provided on the circuit board 211 so that MCU may be connected with the cipher code identification device of the cipher code lock and the power supply via the connector 210 .
[0085] The roller device 201 , microcontroller 208 , information display screen 209 , and microswitch 206 can be installed on the same circuit board 211 , as shown in the drawing. And it may be also as shown in FIG. 8 that the information display screen 209 and microcontroller 208 are installed on one circuit board 214 , and the roller device 201 and microswitch 206 are installed on another circuit board 217 , to adapt to different installation conditions. The connector 210 can also be disposed on the circuit board 214 as shown in FIG. 7 , and meanwhile, the connectors 215 and 216 can also be disposed on the circuit board 217 , and the connectors 215 and 216 can be connected to each other via the wires 213 . Those skilled in the art should understand that the technical results of these two installation forms are the same.
[0086] Returning back to FIG. 7 , in the roller device 201 , the rotation direction and the rotated angle of the roller 202 are converted into electrical pulse signals via the photoelectric wheel 203 and light emitting diode and a phototriode 207 , said signals are directed into the I/O ports of MCU in the microcontroller 208 , and after processing by MCU program, the information display screen 209 is controlled to display in a rolling manner the numbers 0 - 9 . While the roller device 201 is depressed, the microswitch 206 disposed below its shaft extension 205 is actuated, then the electrical signals produced by the actuated microswitch 206 is directed to another I/O port of MCU as an input confirmation signal of the cipher code element, after deciding by the MCU program, the rolling display of information display screen 209 is stopped by the control of the microcontroller 208 , and the current displayed number is confirmed as a part of the cipher code.
[0087] In the input device of the roller type electronic cipher code lock in the present embodiment, customized nixie tubes or liquid crystal display panel can be used as the information display screen 209 . As shown in FIG. 7 , the displayed contents displayed and the function are the same as those in the input device of the dial type electronic cipher code lock in the second embodiment, only the bits of the displayed number and the order and the arrangement of the graphic symbols are different.
[0088] FIG. 9 and FIG. 10 show the enlarged cross section diagram of the elastic bracket 204 under two states, respectively. The structures of these two elastic brackets 204 are substantially the same.
[0089] As shown in FIG. 9 , the elastic bracket 204 is composed of a base 225 , a reset spring 227 , a Y type bracket 220 , wherein a circular shaft slot 221 matching with the shaft is provided on the top of the Y type bracket 220 , the size of an opening 222 of the shaft slot 221 is slightly smaller than the diameter of the shaft, when installing the shaft, the opening shall be spread slightly, after installing the shaft, the radial displacement is restricted by the opening, but it can rotate freely, shoulders provided on both ends of the roller 202 match the shaft slot 221 to restrict the axial displacement of the roller 202 . The base 225 is fixed on the circuit board 211 , and the reset spring 227 and the Y type bracket 220 are installed inside the base 225 , two snap hooks 224 are provided at the bottom of a cylindrical face where the Y type bracket 220 matches with the base 225 , two slide slots 226 for the Y type bracket 220 and the snap hooks 224 to go through favorably and two snap slots 228 (in FIG. 10 ) arranged at an angle of 90 degrees with respect to the slide slots 226 are provided above a hole where the base 225 matches with the Y type bracket 220 .
[0090] As shown in FIG. 10 , the Y type bracket 220 and its snap hooks 224 are inserted into the hole in the base along the slide slot 226 , when arriving the bottom, the Y type bracket 220 is rotated by an angle of 90 degrees so that the snap hooks 224 and the snap slots 228 to be aligned, and under the action of the reset spring 227 , the snap hooks 224 move upwardly and is snapped into the snap slots 228 . In this way, the Y type bracket 220 is fixed.
[0091] When the roller 202 is depressed, the Y type bracket 220 moves downwardly by 1-2 mm along the snap slots 228 , the shaft extension 205 at one end of the roller 202 actuates the microswitch 206 provided below it. When the depressing is released, the Y type bracket 220 is reset by the reset spring 227 .
[0092] Furthermore, if it is desired to produce the effect of a ratchet wheel during the rotation procedure of the roller 202 , there are two schemes: the first one is that one end face of the roller 202 is fabricated in a corrugation shape, a spring having a ratchet wheel form (not shown) is installed on a base 225 near the corrugation end face of the roller 202 , one end of said spring is fixed by the slot and hole on the base 225 , and another end of the spring is bent to form a circle and contacts elastically with the corrugation end face of the roller 202 , when the roller 202 rotates, it brings about a hand felling of a ratchet wheel. And the second one is that a blind hole (not shown in the drawing) is provided on the Y type bracket 220 with a spring and a steel ball installed therein, and fabricating a segment of the surface of the roller shaft which fits with the Y type bracket 220 as teeth form, the steel ball contacts and fits with said teeth under the function of the spring, and when the roller 202 rotates, it can also bring about a hand felling of a ratchet wheel.
[0093] Preferably, a buzzer can be installed on the circuit board 211 , it may incorporate with the information display screen 209 , a prompt information can be issued by them.
[0094] The use of the above roller type cipher code lock assembly will be explained as follows.
[0095] When it is desired to open the lock, the roller 202 is rotated, and the information display screen 209 displays the numbers 0 - 9 in a rolling manner as the rotation of the roller, the rolling order of the numbers (ascending order or descending order) corresponds to the rotation direction of the roller (clockwise or counterclockwise). When one bit of the currently displayed number and the first element of the preset open lock cipher code are the same, the rotation is stopped and the roller 202 is depressed at a time. At this time, the first dot symbol on the information display screen 209 is illuminated, indicating that the first bit of the cipher code is confirmed and inputted. The other bits of the cipher code are inputted in the same manner, during the procedure for confirming each bit of the cipher code, the dot symbols are illuminated in turn on the information display screen 209 .
[0096] After the last bit of the cipher code is inputted, if the inputted cipher code is completely true, then a symbol having a padlock shape will be illuminated, indicating that the lock has been opened.
[0097] If the inputted cipher code is wrong, then prompt information will be issued by the information display screen 209 and the buzzer (if installed), and the program proceeds to an error processing flow.
[0098] If it requires to enable the lock open function of the timing or delay timing, then the timing set state and delay timing set state can be entered by inputting special cipher code, said function can be enabled after inputting the time.
[0099] When it requires to reset the cipher code for opening the lock, firstly, the set cipher code is inputted by the above said steps for inputting the cipher code and confirming, when the inputted set cipher code is decided as true, the symbol having a key shape is illuminated, indicating that it enters the cipher code setting state, at this time, new cipher code for opening the cipher code lock can be inputted.
[0100] When the voltage of the power supply of the cipher code lock is lower than a prescribed value, a symbol having a battery shape is illuminated, prompting that the changing battery is needed.
[0101] The Handle of Cipher Code Lock
[0102] When the above said input device of the roller type electronic cipher code lock is applied to a handle of the door lock, it constitutes a novel handle of the cipher code lock. The external structure of such handle of cipher code lock is shown in FIG. 11 .
[0103] As shown in the drawing, the handle body 301 is hollow, and the above said input device of the roller type electronic cipher code lock is disposed inside the cavity. The input device of the roller type electronic cipher code lock assumes a form as shown in FIG. 7 , a roller device 201 , a microcontroller 208 , a information display screen 209 and a microswitch 206 are installed on one circuit board 211 , then the circuit board 211 can be fixed inside the cavity of the handle by screws. A first window 302 , which corresponds to the roller 202 thereby the roller can be dialed and depressed conveniently, is provided on the front surface of the handle. Similarly, a second window 303 , which corresponds to the information display screen 209 thereby the contents displayed by said information display screen 209 can be viewed conveniently and clearly, is further provided on the front surface of said handle.
[0104] In order to show the internal structure of the above said handle of the cipher code lock more clearly, FIG. 12 and FIG. 13 show a cross section of the handle of the cipher code lock shown in FIG. 11 .
[0105] As shown in FIG. 12 , the handle of the cipher code lock further comprises a rotation shaft 304 fixed within the handle body 301 . It is known from FIG. 13 that a through hole 305 for allowing the connection wires to pass through is provided inside the rotation shaft 304 . The installed input device of the roller type electronic cipher code lock can be connected to a cipher code identification device and a power supply of the cipher code lock, which are installed inside the core mechanism of the lock or installed at other position inside the door, via the connector 210 and the wires 218 .
[0106] An external structure of another handle of the cipher code lock is shown in FIG. 14 . It is composed of a handle body 401 , a panel 402 and a transparent window cover 403 . A cross section structure of said handle of the cipher code lock is shown in FIG. 15 . It is known from the drawing that a hollowed region 405 , which has the size and shape that match with those of the panel 402 thereby the panel 402 being able to be embedded in, is provided on the handle body 401 , the external surface of the panel 402 fits with the curved external surface of the handle body 401 smoothly. Common known snap structure can be used to fix the panel 402 on the handle body 401 . It can also be seen form the drawing, the input device of the roller type electronic cipher code lock assumes the form as shown in FIG. 8 , that is, it employs two circuit boards, wherein the microcontroller 208 and the information display screen 209 are installed on the circuit board 214 , and the roller device 201 and the microswitch 206 are installed on the circuit board 217 , and these two circuit boards are connected with each other via connectors 215 and 216 and wires 213 . The circuit boards 214 and 217 are installed inside the panel 402 , common known snap structure can be used to fix them, and the structure of using screws and nuts can also be used. A first window, which has the size and position that match the roller 202 thereby a part of the roller 202 is exposed and can be dialed and depressed conveniently by fingers, is provided on panel 402 . Similarly, a second window, which has the size and position that match the information display screen 209 thereby the contents displayed on the information display screen 209 can be viewed clearly, is provided on the panel 402 . A transparent window cover is snapped on the plane on which the second window is located at so that the displayed cipher code and information can be viewed while operating. The handle body 401 further comprises a rotation shaft 404 fixed therein, a through hole, for allowing the connection wire 215 to pass through such that the input device of the roller type electronic cipher code lock may be connected with the cipher code identification device of the cipher code lock and a power supply, which are installed inside the door, is provided in the rotation shaft 404 .
[0107] Yet another handle of the cipher code lock is shown in FIG. 16 , it is composed of a handle body 501 , a handle base 502 and a panel 504 . It is known by referring to FIG. 15 in which its internal structure is shown, the input device of the roller type electronic cipher code lock employs the form as shown in FIG. 8 , it is composed of two circuit boards, wherein the information display screen 209 and the microcontroller 208 are installed on a circuit board 214 which is fixed within the base 502 , and the roller device 201 and the microswitch 206 are installed on a circuit board 217 which is fixed below the panel 502 , and these two circuit boards are connected with each other via connectors 215 and 216 and wires 213 . The base 502 is a housing having a cylindrical shape, a second window 505 used for viewing the contents displayed by the information display screen 209 is provided on its front face. A first window, which has the size and position that match with those of the roller 202 thereby a part of the roller 202 can be exposed so that it may be dialed and depressed by the fingers, is provided on the surface of the panel 504 . The handle body 501 is hollow, and a cavity matching with the shape of said panel 504 is provided on the front surface of the handle body, and said panel is snapped on the internal edge of the cavity. A rotation shaft 506 is provided in the handle body 501 , and through holes 507 and 508 are provided in the rotation shaft 506 to allow the connection wires 218 to pass through the through holes 507 and 508 thereby the input device of the roller type electronic cipher code lock is connected with the cipher code identification device and power supply of the cipher code lock installed inside the door.
[0108] The rotation shaft of the above said three types of the handles of the cipher code lock incorporates with the lock core mechanism or clutch device of the cipher code lock, and the lock core mechanism or clutch device is driven by a electromotive implementation mechanism of the cipher code lock, the electromotive implementation mechanism is controlled by the cipher code identification device of the cipher code lock, the cipher code identification device of the cipher code lock is connected electrically and communicates the data with the input device of the roller type electronic cipher code lock. Before the correct cipher code for opening the lock is inputted, the lock core mechanism or the clutch device are separated from the handle of the cipher code lock (is abbreviated to handle), at this time, the handle can not be rotated, and the lock pin linked therewith is in a protruding state. After a correct cipher code for opening the lock is inputted according to the input method of the electronic cipher code lock of the invention, the electromotive implementation mechanism is operated by the control of the cipher code identification device, and the lock core mechanism or the clutch device is combined with the handle, at this time, the handle is turned downwardly for a angle, (not more than 90 degrees) so that the lock pin is retracted into the lock body, and the lock is opened.
[0109] The Panel of the Cipher Code Lock for the Chests and Bags
[0110] When the above said input device of the roller type electronic cipher code lock is applied to the lock for the chests and bags, it constitutes a novel panel of a cipher code lock for the chests and bags. FIG. 18 shows an external structure of such panel of a cipher code lock for the chests and bags applied to a chest body, the panel 603 of the cipher code lock for the chests and bags is fixed on the chest body 601 , and the reference number 602 is a chest cover.
[0111] It can be known from FIG. 19 in which the internal structure is shown that the input device of the roller type electronic cipher code lock employs a form as shown in FIG. 7 , the roller device 201 , microcontroller 208 , information display screen 209 , and microswitch 206 are installed on the same circuit board 211 , and the circuit board 211 is fixed within the panel 603 by using screws or a snapping structure. The panel 603 has a housing form, a second window 606 , which has a rectangle shape and its shape and size matches with those of the information display screen 209 , is provided on the panel. A transparent cover 607 is provided on said window 606 so that the user may view the displayed cipher code and information. A first window 605 , the position and size of which match the roller 202 thereby a part of the roller 202 is exposed so that the roller may be dialed and depressed by the fingers, is also provided on the panel 603 . The panel 603 can be fixed on the chest body by the rivets 604 , and other fixing method that those skilled in the art are familiar with can also be used. The input device of the roller type electronic cipher code lock is connected with the cipher code identification device and the power supply which are installed within the chest by the wires 218 . The electromotive implementation device and the mechanical lock mechanism of the chest and bag lock operate in a linkage manner, when a correct cipher code for opening the lock is inputted, the implementation device is driven by the control of the cipher code identification device, the lock mechanism is opened, thus the cover 602 of the chest can be opened.
[0112] Although the input device, input method and the application of the electronic cipher code lock of the invention have been described by referring to the above embodiments, however, those skilled in the art shall understand, it is apparent that the form and details thereof can be modified without departing the scope and the spirit of the invention. Therefore, the above described embodiments are only illustrative rather than restrictive, under a condition without departing the spirit and scope of the invention, all the changes and modifications are within the protection scope of the invention. | The invention provides an input device of the electronic cipher code lock and a corresponding input method thereof, wherein a signal device produces cipher code input information and converts said information into two groups of electrical pulse signals; a measurement and control device measures the electrical pulse signals, decides the order of the electrical pulse signals and calculates correspondingly such that said signals are converted into character sequences including the cipher code elements, and decides whether the current cipher code elements are confirmed to be inputted or not and decides whether the input of all the cipher code elements is completed or not; a confirmation device produces a conformation signal for inputting the cipher code elements; and a display device displays said character sequences and preset prompt information in a rolling and refreshing manner. The invention also provides a door lock handle and a panel of the cipher code lock for the chests and bags applying the above said input device of the electronic cipher code lock. In said input device of the electronic cipher code lock and the application thereof, the operation parts do not contact with the circuit, the reliability and the security protection performance have been improved significantly. Furthermore, the operation for inputting the cipher code and the operation for changing the cipher code are very convenient and intuitional. | 4 |
CROSS REFERENCE
[0001] This application is a continuation of U.S. Ser. No. 13/722,535 filed Dec. 20, 2012 which is a divisional of U.S. Ser. No. 12/608,489 filed Oct. 29, 2009, now U.S. Pat. No. 8,367,331, which claims priority from U.S. provisional application Ser. No. 61/111,499 filed Nov. 5, 2008, herein incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The task of epigenomic mapping is inherently more complex than genome sequencing since the epigenome is much more variable than the genome. While an individual only has one genome, one's epigenome varies in time and space with age, tissue type, exposure to environmental factors, and shows aberrations in diseases especially in cancer. With methylated CpG's only accounting for ˜ 2-6% of the genome (18), large scale shotgun sequencing efforts will require some form of purification of short CpG methylated sequences. Many current enrichment technologies fall short of the dynamic range necessary to capture minute changes in CpG methylation that can have large repercussions in gene expression.
[0003] In the mammalian genome, 60-80% of relatively infrequent (1 per 100 bp on average) CpG dinucleotides are methylated at the carbon 5 position (1). In contrast, dense clusters of unmethylated CpG sequences ( ˜ 1 per 10 bp) are found at the transcription start sites of genes (2). In certain circumstances, these CpG islands are heavily methylated with the concomitant silencing of the promoter and the silencing of gene activity (3). These modifications are considered to be important for development (4), genomic imprinting (5), and X chromosome inactivation through gene silencing (6, 7). Aberrant DNA methylation of CpG islands has been frequently observed in cancer cells (8).
[0004] Many techniques exist for the enrichment of heavily methylated CpG islands from genomic DNA. One protocol relies on methylation-sensitive restriction endonucleases such as HpaII (CCGG) and HhaI (GCGC) followed by PCR identification, Southern Blot analysis or microarray profiling (9). Another approach utilizes the ability of an immobilized methyl-CpG-binding domain (MBD) of the MeCP2 protein to selectively bind to methylated double-stranded DNA sequences. Restriction endonuclease-digested genomic DNA is loaded onto the affinity column and methylated-CpG island-enriched fractions are eluted by a linear gradient of sodium chloride. PCR, microarray, DNA sequencing and Southern hybridization techniques are used to detect specific sequences in these fractions (10). These techniques are limited due to the specific cleavage moiety of the restriction enzyme and therefore will not completely reflect all combinations of bases flanking the methylated CpG dinucleotide.
[0005] There are several additional methods for analysis of methylation patterns. In the bisulfite method, single-stranded DNA (ssDNA) is exposed to a deamination reagent (bisulfite) that converts unmethylated cytosines to uracils while methylated cytosines remain relatively intact (11). After cleanup, the resultant treated DNA of interest must be PCR amplified (converting the uracils to thymines) and analyzed by a myriad of techniques that can distinguish between methylated and unmethylated DNA. If the PCR products are cloned and sequenced, alignment analysis of the untreated and treated nucleotide sequences can reveal the in vivo methylation status of the amplified region. The PCR products can also be analyzed by combined bisulfite-restriction analysis (COBRA assay) and methylation-specific PCR (MSP) (12, 13).
[0006] Recently, direct shotgun ultra-high-throughput sequencing of bisulfite-converted DNA using the Illumina 1G Genome Analyzer and Solexa sequencing technology have yielded insights of the methylation state of the small ( ˜ 120 Mbp) genome of the mustard plant Arabidopsis (14). This new technology allowed the exact identification and quantification of 5-methylcytosines at the single-nucleotide level in genes. Although highly specific and reasonably sensitive, it required at least 20-fold coverage to theoretically cover all potential methylated cytosines. Currently, no method exists to enrich bisulfite-converted CpG methylated DNA, which by the nature of the deamination reaction, is single-stranded, from total genomic DNA.
SUMMARY
[0007] Methods and compositions are described herein that include the embodiments listed below.
[0008] In one embodiment, an isolated first polypeptide is provided that includes an amino acid sequence having at least 90% homology or identity with SEQ ID NO:3 and is capable of binding single-stranded methylated polynucleotides. The first polypeptide may be fused to a second polypeptide and may be immobilized on a solid substrate by means of the second polypeptide if the second polypeptide is a substrate-binding domain such as maltose-binding domain (MBP). A property of the isolated first polypeptide may include an ability to bind a methylated CpG in a single-stranded polynucleotide.
[0009] Examples of the first polypeptide are human UHRFI, and mouse NP95 SRA. Either of these polypeptides may be used in series or in parallel with a methyl-binding domain (MBD), which binds double-stranded methylated DNA and thus recovery of methylated DNA may be enhanced. For example, the sample may be applied to a MBD column, eluted, denatured and then applied to an SRA column. Additionally, one aliquot of a sample may be applied to an MBD column and one aliquot of sample applied to an SRA column.
[0010] The above-described polypeptides either alone or as a fusion protein, either in solution or immobilized on a substrate, may be used for differentially binding a single-stranded methylated polynucleotide to a solid substrate, for example at a CpG site in a low salt solution.
[0011] In an embodiment of the invention, a method is provided for enriching for CpG methylated single-stranded polynucleotides from a mixture containing methylated and unmethylated polynucleotides. This method includes: binding the mixture to the first polypeptide described above; eluting the unmethylated polynucleotide from the isolated polypeptide in a solution containing a low concentration of a salt; and eluting the methylated polynucleotide from the isolated polypeptide in a solution containing a high concentration of a salt. The eluted methylated polynucleotide can then be sequenced and the methylation site analyzed.
[0012] In embodiments of the invention, a low concentration of the salt is less than 0.4 M salt and a high concentration of the salt is 0.4 M-0.6 M salt. The salt may be, for example, sodium chloride.
[0013] In an embodiment of the invention, a method is provided which can be applied to determining the existence of pre-cancerous cells. The method includes: (a) comparing the methylation pattern for selected polynucleotide sequences in both pre-identified transformed eukaryotic cells and non-transformed eukaryotic cells by differential binding of methylated polynucleotides to the first polypeptide of claim 1 ; (b) determining the presence of abnormal methylation patterns associated with alteration of tumor suppressor function; and (c) utilizing the abnormal methylation patterns as a diagnostic tool for determining whether any eukaryotic cells in a sample are transformed. (In this context “transformed” is intended to mean converted to a pre-cancerous state where the cell is immortalized.)
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIGS. 1A-1C show a GST-SRA-domain resin with bound and eluted methylated, and unmethylated dsDNA at low NaCl; and eluted methylated ssDNA at high NaCl.
[0015] FIG. 1A is a chromatogram profile at A280 of human chromatin DNA spiked with a small amount of FAM-labeled methylated (M) and unmethylated (U) CpG-containing oligonucleotides. Both the unmethylated and methylated oligos co-eluted with the bulk of the chromatin DNA between 0.2 M and 0.3 M NaCl.
[0016] FIG. 1B shows a gel containing individual column fractions in each lane. At higher NaCl, a faint band (*) on the gel was observed corresponding to single-stranded methylated DNA.
[0017] FIG. 1C shows a side-by-side comparison of the methylated and unmethylated oligos confirming that the band (*) corresponded to methylated CpG-containing ssDNA.
[0018] FIGS. 2A-2B show a DNA preparation with significantly altered elution characteristics of the GST-SRA-domain column.
[0019] FIG. 2A is a comparison of chromatogram profiles at A280 of 100 μg of MseI-digested HeLa DNA spiked with 3 μg of MseI digested M.SssI-labeled 3 H-Adomet HeLa DNA. The DNA composition was heated to 98° C. for one minute and quickly chilled prior to loading onto the column. A large portion of the 3 H-labeled DNA eluted off the column at 0.15 M NaCl, however, three distinct peaks that eluted at 0.3 M, 0.35 M and 0.4 M NaCl were observed with a small peak of 3 H-labeled DNA co-eluted with the 0.4 M NaCl peak. The gel shows the content of each fraction.
[0020] FIG. 2B shows the same DNA load preparation, which was sonicated for 1 minute followed by heating of the sample to 98° C. for 1 minute, chilled, and loaded onto the column. Three peaks were observed at 0.35 M, 0.4 M and 0.45 M NaCl with the bulk of the 3 H-labeled DNA co-eluted with the 0.4 M and 0.45 M peaks, respectively. The gel shows the content of each fraction.
[0021] FIG. 3 shows a flowchart of the procedures used to enrich single-stranded methylated CpG-containing DNA. Total genomic DNA was sonicated to 50-150 base fragments. The sample was heated to 98° C., chilled and loaded onto the GST-SRA-domain column (or magnetic beads), or bisulfite-converted (which made the sample single-stranded and converted all non-methyl cytosines to uracils) prior to loading. The column/beads were washed with buffer containing 0.3 M NaCl, which eluted the active gene fraction. Methylated CpG-containing DNA remained on the column matrix and can be eluted with 0.5 M NaCl or alternatively equilibrated with low NaCl buffer prior to the addition of the “fourN” cloning/sequencing primer (SEQ ID NO:1). The sample was heated to 98° C., chilled to 4° C., and then slowly raised to 37° C. Sequenase was introduced into the reaction, allowed to extend the ssDNA fragments, heated and chilled, with more Sequenase added to label the other end of the DNA fragment. The defined-ends DNA was further amplified by a complementary PCR primer without the random nucleotides, purified and digested with BamH1, purified and cloned into a sequencing vector.
[0022] FIGS. 4A-4D show a simplified step salt gradient of GST-SRA-domain column yielded reproducible elution profiles.
[0023] FIGS. 4A-4B show a comparison of two chromatogram profiles at A280 of 100 μg of sonicated, heated HeLa genomic DNA FIG. 4A or 200 μg initial concentration of sonicated, bisulfite-converted genomic DNA FIG. 4B . The 0.3 M and 0.5 M fractions were characterized by qRT-PCR or cloned and sequenced.
[0024] FIG. 4C shows the bisulfite-converted fractions which were labeled and extended with a random “fourN” oligonucleotide, and PCR amplified. Ethidium-stained 20% TBE polyacrylamide gel analysis of the PCR products before (−) and after (+) BamH1 treatment showed the size distribution of fragments from the two peaks.
[0025] FIG. 4D shows GST-SRA-domain coupled magnetic beads only retained methylated (M) ssDNA lambda DNA after extensive washing with 0.3M NaCl as assayed on an ethidium-stained 20% TBE polyacrylamide gel.
[0026] FIG. 5 shows active and inactive gene enrichment from GST-SRA-domain column. Active genes showed at least a 2-fold enrichment over input DNA in the 0.3 M peak. Single copy inactive genes showed a direct correlation of the fold enrichment and CpG occupancy in the 0.5 M peak. As the copy number increased, satellite and line elements showed an inverse correlation between CpG occupancy and enrichment.
[0027] FIG. 6 shows a cartoon of the UHRFI gene illustrating the location of the different domains in the protein. The inset shows an amino acid alignment of the SRA domains from mouse and human (SEQ ID NOS:2 and 3, respectively), revealing that the sequences are 90% identical.
[0028] FIG. 7 shows the DNA sequences of mouse and human (SEQ ID NOS:4 and 5, respectively).
[0029] FIG. 8 shows how SRA domain can be used in sequencing platforms (e.g. Helicos sequence platform) to detect methylated CpG DNA. 1. Methylated ssDNA (SEQ ID NO:6) annealed to polyT on a slide. 2. Methylated cytosine detected by fluorescence labeled NP95 SRA domain and 3. SRA is washed off. DNA is sequenced.
[0030] Within the flow cells, billions of single molecules of ssDNA are captured on a solid surface. These captured strands serve as templates for the sequencing-by-synthesis process. Prior to the addition of polymerase and one fluorescently labeled nucleotide (C, G, A or T), the cell is flooded with MBP-SRA domain protein, which binds specifically to methylated CpG sequences. The cell is washed with a 100 mM NaCl wash buffer, and fluorescently labeled Anti-MBP antibody couples to the MBP-NP95 SRA domain/methylated CpG DNA complexes. After a wash step, which removes free Anti-MBP antibody, the cell is imaged and the positions of the methylated CpG-containing DNA strands are recorded. A high wash step (500 mM NaCl) removes the Antibody-MBP-NP95 SRA domain and the sequencing process continues with a polymerase catalyzing the sequence-specific incorporation of fluorescent nucleotides into nascent complementary strands on all the templates. Multiple cycles result in complementary strands greater than 25 bases in length synthesized on billions of templates, providing a sequence read on the methylated CpG templates.
[0031] FIG. 9 shows a flowchart of the procedure used to compare a commercially available methylated CpG DNA enrichment system (e.g. Invitrogen) with MBP-NP95 SRA domain. Total HeLa genomic DNA was sonicated to 50-150 base fragments. Half of the sample was heated to 95° C. for 5 minutes and chilled on ice. The other half of the sample was not heated. To 1 μg of unheated sample, 1 μg of biotinylated (bt) MBD and buffer were added. Similarly, to 1 μg of heated DNA, 1 μg of MBP-NP95 SRA domain and buffer were added. Both samples were incubated at room temperature for 20 minutes. To the bt-MBD sample 100 μl (1 mg) of Streptavidin Magnetic Beads was added. To the MBP-NP95 SRA domain sample 100 μl (1 mg) of Anti-MBP Magnetic Beads was added. The samples were then incubated overnight at 4° C. with rotation. The bound complexes were then washed 3× with 100 mM NaCl, 1% Triton, 0.1% Tween buffer, with magnetic separation and aspiration of buffer and 1× with TE buffer containing 0.1% Tween. Finally, a small quantity of water was added to the aspirated samples, and the enriched methylated DNA complexes were eluted from the magnetic beads by heat. The complexes were then assayed by qPCR using primer sets to known active and inactive genes in HeLa DNA.
[0032] FIG. 10 shows the number of fold enrichment values of known methylated (inactive) and unmethylated (active) genes comparing a commercially available methyl CpG enrichment system (e.g. Invitrogen) with MBP-NP95 SRA domain protein. Both techniques resulted in similar enrichment of the inactive genes rDNA and MYOD, with no enrichment of the active gene RPL30.
DETAILED DESCRIPTION OF EMBODIMENTS
[0033] UHRFI is a ubiquitin-like protein that improves fidelity of maintenance of methylation and has a histone methyltransferase function. It contains multiple domains (see FIG. 6 ). Two adjacent domains in the protein are named SET and RING and together are called the SRA domain. The SRA domain has a sequence shown in FIG. 7 . The SRA domain is capable of binding methylated CpG in a salt-dependent manner. In an embodiment of the invention, the SRA is immobilized on a matrix and can be used to bind methylated and unmethylated ssDNA or bisulfite-converted genomic DNA at low salt conditions (for example 0.15 M NaCl). The unmethylated DNA can be eluted from the SRA protein in conditions of increased salt concentration such as 0.3 M NaCl while methylated DNA can be eluted at 0.5 M NaCl.
[0034] Human UHRFI is an example of a family of DNA-binding proteins that are associated with regulating gene expression via methylation. Other examples include DNMTI and mouse NP95 SRA. This family of related proteins are shown here to be effective in differentiating methylated from unmethylated DNA.
[0035] These proteins can be produced in high yield and are relatively stable, which makes them suitable for attaching to solid substrates such as agarose resin or carbohydrate-coated beads or magnetic beads (NEB) without loss of binding activity. The immobilized protein can easily be integrated in a high-throughput bisufite sequencing setup. With just one wash step, mild elution characteristics, sensitivity and accuracy are enhanced. Thus, the reusable matrix provides valuable information on the methylome, providing insights into aging and disease.
[0036] There are a variety of approaches by which the SRA-like proteins can be immobilized on a matrix. The matrix may include beads, 96 well plastic dishes, columns or any other support material. Where beads are selected, these can be magnetic, colored and/or coated with a carbohydrate or other ligand suitable for binding the SRA. To facilitate binding of the SRA-like proteins to a matrix, the SRA-like protein can be synthesized as a fusion protein by standard molecular biology techniques in prokaryotic or eukaryotic host cells. For example, the SRA-like proteins may be synthesized as SRA-chitin-binding domain for binding chitin or SRA-MBP for binding to amylose. Examples of suitable fusion proteins are provided for example in U.S. Pat. No. 5,643,758.
[0037] Other examples of fusion proteins include SRA-AGT or SRA-ACT proteins (using the SNAP-Tag® or CLIP-Tag™ technology provided commercially by New England Biolabs). These fusion proteins can be labeled as required for detection of purification of polynucleotides for example by using fluorescent labels after covalent binding of the ACT/AGT in the fusion protein to labeled substrates such as benzyl guanine or benzyl cytosine, leaving available the SRA to bind methylated DNA in vitro or in vivo.
[0038] The SRA may also be bound to a matrix or solid substrate such as beads, columns, glass, plastic or polymer surfaces, etc. Binding can be achieved by any ligand/ligand-binding molecule system including antibody/antigens or biotin/strepavidin, chitin-binding domain, maltose-binding domain, etc. SRA-like proteins may be synthesized as intein fusions to facilitate certain separation methods (U.S. Pat. Nos. 5,496,714 and 5,834,247).
[0039] In an embodiment of the invention, a binding preference for methylated single-stranded polynucleotides by SRA-like proteins was demonstrated. This property can be exploited for detection, purification and analysis of the polynucleotides using immobilized SRA bound to the matrix. The methylated polynucleotides can then be sequenced to identify the location of the methylated CpG. In another embodiment, a double stranded polynucleotide can be bound to SRA where methylation if present can be detected on one strand or the other.
[0040] Mammalian UHRF1 SRA domains (such as human UHRF1 or murine NP95) can be used to augment high-throughput sequencing methodologies, for example, True Single Molecule Sequencing (tSMS)™ technology (Helicos Biosciences) by binding and identifying single-stranded methylated CpG-containing DNA prior to a series of nucleotide additions and detection cycles that will then determine the sequence of each fragment ( FIG. 8 ). By integrating the UHFR1-SRA domain into this instrumentation setup, additional epigenetic information can be layered on top of rapid and inexpensive resequencing of genomes to facilitate the understanding of methylation states in complex organisms.
[0041] The mammalian UHRF1 SRA domains can be displaced from the polynucleotide by adding cations that neutralize the charge on the DNA and thereby release the electrovalently bound protein. In embodiments of the invention, the protein binding to the polynucleotide is disrupted using NaCl. However, the use of this salt is not intended to be limiting. Moreover, it was found that protein binds to polynucleotide at methylated CpGs more tightly so that a high salt concentration was required to release CpG methylated polynucleotides and a low salt concentration was required to release CpG unmethylated polynucleotides. In an embodiment of the invention, the low salt concentration was 0.3 M NaCl whereas the high salt concentration was 0.5 M NaCl. Table 1 provides the results of a two-step salt gradient.
[0042] Table 1 shows a sequence analysis of the two NaCl peaks from the GST-SRA-domain column. Greater than 10-fold enrichment of methylated CpG-containing DNA was observed. 19/30 reads with an average size of 63 bases in the high (0.5 M) NaCl fraction contained at least one methylated CpG. 44/1900 bases were methylated CpG or 2.32% of the total. 3/22 reads with an average size of 105 bases in the low salt 0.3M peak contained methylated CpG. 5/2327 bisulfite-converted bases were identified as methylated CpG or 0.215% of the total.
[0043] All references cited herein, as well as U.S. provisional application Ser. No. 61/111,499 filed Nov. 5, 2008 and U.S. Ser. No. 12/608,489 filed Oct. 29, 2009 are incorporated by reference.
EXAMPLES
Example 1
SRA-Domain Protein Purification and the Covalent Coupling of the Protein to Solid-State Matrixes
[0044] The SRA domain (386-618) was amplified from full-length human UHRF1 cDNA synthesized using total RNA from HeLa cells. The product was cloned into pENTR-TEV (GST Tag Invitrogen) and recombined into pDEST15 (Invitrogen, Carlsbad, Calif.) to create the GST fusion. The construct was propagated in T7 Express E. coli (NEB) to an OD 590 of 0.5 at 37° C. and induced with 0.1 mM IPTG overnight at 16° C. Cells were spun, broken open by French press, spun again and the supernatant layered over a 10 ml Glutathione Separose High Performance column (GE Healthcare). After a 10-column wash, the protein was eluted with a 10 mM L-Glutathione (Sigma) solution. The yield was 12 mg total of purified SRA-domain from 8 liters shake flasks.
GST-SRA Column
[0045] 9 μls of 1.2 mg/ml (10.8 mg total) of previously purified and dialyzed GST-SRA-domain protein in 10 mM Tris pH. 7.5, 1 mM EDTA and 0.2 M NaCl was layered onto a 4.5 ml Glutathione Sepharose matrix equilibrated with the above buffer. Of the 10.8 mg load, 7.83 mg remained bound to the column. The resin was washed with 10 column volumes of the above buffer, then cycled twice with the above buffer supplemented with 1 M NaCl before final equilibration at 0.05 M NaCl. Sequences of the methylated oligonucleotides were FAM-GTAGG5GGTGCTACA5GGTTCCTGAAGTG top strand (SEQ ID NO:7), FAM-CACTTCAGGAAC5GTGTAGCAC5GCCTAC bottom strand with 5=5 methyl cytosine. Sequences of the unmethylated oligonucleotides were GTCACTGAAGCGGGAAGGGACTGGCTGCTCCCGGGCGAAGTGCCGGGGCAGGATCT-FAM top strand (SEQ ID NO:8), AGATCCTGCCCCGGCACTTCGCCCGGGAGCAGCCAGTCCCTTCCCGCTTCAGTGAC-FAM bottom strand.
[0000] qPCR Analysis of NaCl Fractions from GST-SRA-Column
[0046] DNA from the high and low salt fractions were characterized by real-time PCR on a Bio-Rad MyiQ iCycler using Bio-Rad iQ SYBR Green Supermix and the following primer sets: hsALDOA TCCTGGCAAGATAAGGAGTTGAC forward (SEQ ID NO:9), ACACACGATAGCCCTAGCAGTTC reverse (SEQ ID NO:10), hsSERPINA GGCTCAAGCTGGCATTCCT forward (SEQ ID NO:11), GGCTTAATCACGCACTGAGCTTA reverse (SEQ ID NO:12), hsRPL30 CAAGGCAAAGCGAAATTGGT forward (SEQ ID NO:13), GCCCGTTCAGTCTCTTCGATT reverse (SEQ ID NO:14), hsRASSF1 TCATCTGGGGCGTCGTG forward (SEQ ID NO:15), CGTTCGTGTCCCGCTCC reverse (SEQ ID NO:16), hsMYO-D CCGCCTGAGCAAAGTAAATGA forward (SEQ ID NO:17), GGCAACCGCTGGTTTGG reverse (SEQ ID NO:18), hsMYT1 TGAAACCTTGGGTGTCGTTGGGAA forward (SEQ ID NO:19), TTGCGGGCCATTGTTCCATGATGA reverse (SEQ ID NO:20), rDNA CGTACTTTATCGGGGAAATAGGAGAAGTACG forward (SEQ ID NO:21), GTGCTTAGAGAGGCCGAGAGGA reverse (SEQ ID NO:22), hsSAT ATCGAATGGAAATGAAAGGAGTCA forward (SEQ ID NO:23), GACCATTGGATGATTGCAGTCA reverse (SEQ ID NO:24), LINE CGGAGGCCGAATAGGAACAGCTCCG forward (SEQ ID NO:25), GAAATGCAGAAATCACCCGTCTT reverse (SEQ ID NO:26). Cycle program was as follows: cycle 1: (1×) 95° C., 5 minutes, cycle 2 (40×) step 1: 95° C. 10 seconds, step 2: 61° C. 30 seconds, step 3 72° C. 30 seconds.
[0000] Cloning and Sequencing of NaCl DNA Fragments from GST-SRA-Column
[0047] Eluted and de-salted DNA fragments were cloned into BamH1 cut and alkaline phosphatase (CIP) treated LITMUS 28i cloning vector using the “fourN” procedure (17) with the exception of the sequence of the oligonucleotide: GTTTCCCAGTCAGGATCCNNNN (SEQ ID NO:1) and PCR primer GTTTCCCAGTCAGGATCC (SEQ ID NO:27). PCR products were purified using Qiagen columns cut with BamH1, purified again, ligated to the vector and cloned as stated.
Results
GST-SRA-Domain of Human UHFR1 Coupled to a Solid Matrix Enriched Single-Stranded Methylated CpG-Containing DNA
[0048] To determine the preference of the SRA-domain for unmethylated, fully methylated or hemi-methylated double-stranded or ssDNA in a solid state matrix, the following experiment was performed. 7.83 milligrams of purified GST-SRA domain was bound to a 4.5 ml GST column. 1.68 milligrams of MNase digested chromatin ( ˜ 150-1000 bp) from human Jurkat cells spiked with 1 μg each of fluorescein (FAM)-labeled double-stranded methylated CpG oligonucleotide and unmethylated CpG oligonucleotide of different sizes were layered onto the column in buffer A (10 mM Tris pH. 7.5, 1 mM EDTA, 0.05 M NaCl). After a 10 volume column wash with buffer A, the column was developed with a 100 ml NaCl gradient to 1 M and the fractions were assayed by gel electrophoresis ( FIGS. 1A-1C ). Both the methylated and unmethylated DNA oligos co-eluted with the bulk of the chromatin DNA between 0.2 M and 0.3 M NaCl. Interestingly, a faint fluorescent band that was smaller than the two annealed oligos was eluted off the column at ˜ 0.4 M NaCl. It was speculated that this band might contain unannealed methylated ssDNA.
[0049] To further investigate the binding preferences of the SRA-domain resin for ssDNA, 100 μg of MseI-digested HeLa DNA spiked with 3 μg of MseI-digested M.SssI-labeled 3 H-Adomet HeLa DNA was applied to the above equilibrated GST-SRA domain column. After column wash in buffer A, a 30 ml step gradient from 0.1 M to 0.6 M NaCl was initiated and fractions collected. The double stranded DNA and the 3 H-labeled fully methylated double-stranded DNA eluted off the column in the first two fractions at 0.15 M NaCl. Next, another DNA preparation of the same composition was heated to 98° C. for 1 minute and quickly chilled on ice for 5 minutes prior to loading on the equilibrated column. The above step gradient was used to elute the DNA and the fractions were analyzed as before. A large portion of the 3 H-labeled DNA eluted off the column at 0.15 M NaCl; however, three distinct peaks that eluted at 0.3 M, 0.35 M and 0.4 M NaCl were observed with a small peak of 3 H-labeled DNA co-eluted with the 0.4 M NaCl peak. Finally, a third DNA load preparation was sonicated for 1 minute followed by heating of the sample to 98° C. for 1 minute, chilled, and loaded onto the column. Three peaks were observed at 0.35 M, 0.4 M and 0.45 M NaCl with the bulk of the 3 H-labeled DNA co-eluted with the 0.4 M and 0.45 M peaks, respectively ( FIGS. 2A and 2B ). It was concluded that sonication plus heating of the sample fully fractionated the genomic DNA into a single-stranded form that facilitated binding of the DNA to the resin and greatly improved the resolving power of the matrix to discriminate between unmethylated and fully methylated CpG DNA.
Simplified Elution Profile Enriched Active and Inactive Genes
[0050] A new DNA preparation containing 100 μg of sonicated, heated HeLa genomic DNA was layered onto the above equilibrated column in buffer A. To simplify the elution protocol, a 0.15 M wash step and a 0.3 M and 0.5 M elution steps were employed. Fractions containing the 0.3 M and 0.5 M peaks were collected, desalted and concentrated using a Qiagen miniprep column ( FIG. 3 flow chart and FIGS. 4A-4D ). The products from the salt fractions were characterized by qPCR on a BioRad iCycler using primers to known active and inactive genes in HeLa cells ( FIG. 5 ). The actively transcribed genes Aldolase A (ALDOA), serpin peptidase inhibitor (SERPINA) and 60S ribosomal protein L30 (RPL30) showed a consistent two-fold enrichment in the 0.3 M peak over input DNA. The high salt peak, presumably containing the inactive gene fraction, revealed little or no enhancement of these genes.
[0051] Six known repressed areas of the HeLa genome were interrogated in a similar fashion. Single-copy genes RAS association domain family protein 1 (RASSF1), myogenic differentiation 1 (MYO-D), and myelin transcription factor 1 (MYT1) as well as tandem repetitive ribosomal DNA (rDNA) showed a direct correlation of fold enrichment and CpG occupancy in the 0.5 M peak. Highly repetitive satellite DNA (hsSAT) showed less enrichment in the high salt peak. In spite of high CpG content, long interspersed nuclear (LINE) elements that are transcribed by RNA polymerase II into mRNA (16) showed little difference between the low and high salt fractions, suggesting that the SRA-domain column may accurately reflect the extent of methylation of these sequences in the genome.
[0000] Random Sequencing of Cloned Fragments Derived from NaCl Eluted Fractions
[0052] Sodium bisulfite conversion of genomic DNA, while highly degrading as a consequence of the reaction, can yield very high-resolution information about the methylation state of a given segment of DNA. As the SRA-domain resin favored fragmented ssDNA, it was ideally suited to bind and resolve bisulfite-converted DNA. To explore the characteristics of the SRA-domain column when bisulfite DNA is applied, 200 μg of HeLa genomic DNA converted by the Epitect Bisulfite Kit (Qiagen) was applied to the equilibrated column, washed and eluted as before. As in previous runs, two peaks were observed at the 0.3 M and 0.5 M NaCl step elutions. Fractions were collected, concentrated and de-salted by Qiagen columns. Cloning of the fragments was accomplished using a modification of the “fourN” procedure (17) in which a small oligonucleotide containing four random bases followed by a BamHI restriction site were annealed to the fragments at both ends and extended with Sequenase. Primers complementary to known sequences introduced during the random priming reaction were added and a PCR reaction amplified the products. After cleavage with BamHI restriction enzyme, the DNA was cloned into a BamHI linearized Litmus 28i vector and plated on AMP/IPTG/XGAL plates ( FIG. 3 flow chart).
[0053] The DNA from 100 white colonies of the 0.5 M peak and 50 colonies of the 0.3 M peak were submitted for sequencing. Of those 100 reads from the 0.5 M peak, 30 were deemed suitable for analysis by the following criteria: 1) Contained viable sequences that could be identified by NCBI BlastN as human; 2) Showed evidence of non-methyl cytosine conversion (C to T or G to A, depending on orientation); and 3) unconverted C that was followed by G or unconverted G followed by C, again depending on forward or reverse sequencing orientation. Out of these 30 reads (Table 1) with an average size of 63 bases, 19 contained at least one methylated CpG. Of the 1900 bases sequenced, 44 were methylated CpG or 2.32% of the total. Amazingly, out of the 19 methylated CpG sequences, 10 mapped to known CpG methylation sites: nuclear receptor subfamily 4 (19), Fanconi anemia (20), von Willebrand factor (21), coagulation factor XIII and transglutaminase (22), chromodomain protein Y-like (23), spectrin repeat (24), HECTD1 (25), zinc finger and BTB domain containing 46 (26), and pumilio (27). Out of 22 reads with an average size of 105 bases in the low salt 0.3M peak, 3 contained methylated CpG. Of these 2327 bisulfite-converted bases, 5 were identified as methylated CpG or 0.215% of the total. Although limited in scope, these data showed a better than 10-fold enrichment of methylated CpG from the high NaCl peak versus the low NaCl peak. Additional sequencing efforts will be required to fully determine the potential fold enrichment by the SRA-domain resin as compared to random sequencing of genomic DNA or to CpG methylated DNA that was augmented by other means such as an MBD column.
GST-SRA-Domain Protein Covalently Coupled to Magnetic Beads Showed Similar Binding and Elution Characteristics
[0054] An alternative to column chromatography, GST-SRA-domain protein covalently coupled to a nonporous paramagnetic particle was tested for its suitability as a high-throughput purification matrix for methylated CpG sequences. To compare the binding characteristics of the GST-SRA-domain magnetic beads, 5 μg of sonicated unmethylated lambda DNA or 5 μg of sonicated fully enzymatically methylated (M.SssI) lambda DNA was added to a 50 μl of a 50% slurry of 10 mg/ml SRA-domain magnetic beads in 150 mM NaCl, 0.1% Tween 20, 10 mM Tris pH 7.5, and 1 mM EDTA and allowed to mix end over end for 30 minutes at room temperature. The tubes were placed on a magnetic separation rack and the supernatant was aspirated. The samples were washed and magnetically separated three times by the above buffer supplemented with 150 mM NaCl. The beads were then loaded directly on a 20% native TBE acrylamide gel for analysis. Similarly, sonicated methylated and unmethylated lambda DNA samples were heated to 98° C. and chilled prior to binding on the magnetic beads, followed by washes as stated above. Based on the ethidium stained DNA gel, it was determined that only the methylated heated lambda DNA remained on the beads after the 0.3 M NaCl washes ( FIGS. 4A-4D ). Additional work is needed to characterize the DNA fragments that remain bound to the beads by direct linker addition and DNA sequencing.
Example 2
Common Properties Shared by Sra Domains from Different Sources
[0055] MBP-NP95 SRA-domain fusion protein effectively enriched single-stranded methylated CpG DNA using a small amount of input DNA. This was demonstrated as described below.
[0056] The SRA domain of mouse NP95, which is 90% identical to human UHRF1, bound and enriched fragmented methylated ssDNA using 1 μg of input DNA. In addition, mouse NP95 SRA domain purified methylated CpG-containing DNA by 20-25 fold from 1 μg of fractionated ssDNA, and was comparable to methyl binding domain in yield and sensitivity.
[0057] An alternative to column chromatography, a MBP-NP95 SRA-domain fusion protein in conjunction with Anti-MBP monoclonal antibody coupled to a paramagnetic bead was tested for its suitability as a high-throughput purification matrix for methylated CpG sequences. To compare the binding and elution characteristics of the NP95 SRA-domain with a commercially available methylated CpG enrichment system employing biotinylated MBD (MethylMiner™ Methylated DNA Enrichment Kit from Invitrogen), 1 μg of sonicated, heated HeLa DNA (NP95 SRA) and 1 μg of sonicated HeLa DNA (MBD) was added to 1 μg of MBP-NP95 SRA (15 μl) or 1 μg of biotinylated MBD (2 μl), in a 200 μl total reaction mix containing 20 μl 10× NEBuffer 4 (50 mM potassium acetate, 20 mM Tris-acetate, 10 mM magnesium acetate, 1 mM dithiothreitol pH 7.9) and 2 μl 100 μg/ml BSA was incubated for 30 minutes at room temperature. To the MBP-NP95 SRA reactions, 100 μl (1 mg) of Anti-MBP magnetic beads (NEB) was added. To the MBD reactions, 100 μl ( ˜ 1 mg) of streptavidin magnetic beads (Invitrogen) was added. Both reactions were allowed to mix end over end overnight at 4° C. The tubes were placed on a magnetic separation rack and the supernatant was aspirated. The samples were washed and magnetically separated 3× by 15 ml of wash buffer (20 mM Tris-HCl pH 7.5, 100 mM NaCl, 1 mM EDTA, 1% Triton X-100, 0.1% Tween 20) followed by a final 15 ml wash in low salt buffer (20 mM Tris-HCL, 1 mM EDTA, 0.1% Tween 20 (see FIG. 9 ). 140 μl of water was added to the bead complexes and the DNA samples were heated to 98° C. to liberate the enriched methylated DNA. The products from this heat step were characterized by qPCR on a BioRad iCycler using primers to known active and inactive genes in HeLa cells. The actively transcribed gene ribosomal protein L30 (RPL30) showed no enrichment in the MPB-NP95 SRA samples or the bt-MBD samples. The methylated genes myogenic differentiation 1 (MYO-D), and tandem repetitive ribosomal DNA (rDNA) showed a 20-25 fold enrichment in MPB-NP95 SRA samples, and is comparable to the enrichment values in the bt-MBD samples ( FIG. 8 ). Additional work is needed to characterize the DNA fragments that remain bound to the beads by direct linker addition and DNA sequencing.
[0000]
TABLE 1
High Salt 0.5M (enriched) peak, no CpG
1
1-33.5 TGTGGGGTTGTTGTTTTGAGAGGGTTTTTTTTTGGGGTTTTTATTAATGATG (SEQ ID NO: 79)
6-33.5 AAACATTGGGAATATAGTATTTATTTTTGGTGATTATGTGTTTAGTTAAGTATTAGAGG
ATATTTTTA (SEQ ID NO: 28)
7-33.5 AATTTTTGTAGTTTTAGTAGAGATGGAGTTTTATTATGTTGGTTAGGTTGG (SEQ ID NO: 29)
8-33.5 GAAACAGGAGAATTTTTTGAATTTGGGTGGTAGAGG (SEQ ID NO: 30)
9-33.5 AGAAAATATGGTTTGTTAATGAATGATAGGTTAATTTTAGTATGTTGGTTATTTTAATA
TTTTGTTATTAGTTGGTTTGG(SEQ ID NO: 31)
H19-33.5 CAGGTATAGTGGTAAGAATTTGTAGTTTTAGTTATTTGGGAGGTTGAGTTAGGA (SEQ ID NO: 32)
H76-33.5 AAACTTTTGGTTGGGGGTGGTGGTTTATGTTTGTAATTTTAGTATTTTGGGAGGTCAAGGTGAGTGGAT
(SEQ ID NO: 33)
H2-33.5 AGGTAGTTTTATTTTGGGTTTTAGGGAATAGGAGGGAATTAGAAGGA (SEQ ID NO: 34)
H5-33.5 CAGTATTTTGGGAGGTTAAGGTAGGTGGATTATGAGGTTAGGAGATTGAGA (SEQ ID NO: 35)
H21-33.5 GATGGATTGTTTGAGTTTAGGAGTTTGAGATTAG (SEQ ID NO: 36)
H24-33.5 TGAGTTTAGTTTAAGTTGATTGGGTAGGTAAATGTTTGTTATGAATTTGGAAGTGAGAGA
(SEQ ID NO: 37)
High Salt 0.5M (enriched) peak, CpG
3-33.5 725439 bp at 3′ side: nuclear receptor subfamily 4, group A, member
2 isoform a
CAGGTGTTGAGTGGTGAGGGATGTGTAAATAAGTAAGTGTGGGGTTCGGTTATTGCGTATAGTTAGGTATATTGG
TTGTT
GTGGGGTGGGGTAGGTAATTTAAGTATTAGTATGGGTATTGGTTTTTTGTGAGGC (SEQ ID NO: 38)
4-33.5 Fanconi anemia, complementation groupM
ACAAAAATTAGTTAGGTATAGTGGTATGTATTTGTAGTTTTAGTTAATCGGGATCCTGA (SEQ ID NO: 39)
5-33.5 GENE ID: 10692 RRH | retinal pigment epithelium-derived rhodopsin
homolog
GAATGGCAAGTATTGGATTATTTACGGTCGTGGTTGTGGATCGATA (SEQ ID NO: 40)
10-33.5 transglutaminase 2 isoform b
AGTTTGTACGGTGAAGTTTAGGTTTTATTGTGGATACGGTTGAAATAGAAGAGTGATGGG (SEQ ID NO: 41)
H6-33.5 31781 bp at 5′ side: von Willebrand factor preproprotein 46059 bp
at 3′ side: CD9 antigen
TGAACGCGGGAGGCGGAGTTTGTAGTGAGTTAAGATCGCGTTATTGTATTTTAG (SEQ ID NO: 42)
H7-33.5 ref|NW_001838799.1|H52_WGA192_36
GGAAACGAATGAAATTATCGAATGGAATCGAATGGTGTTATCGAACGGA (SEQ ID NO: 43)
H12-33.5 coagulation factor XIII A1 subunit precursor
CGGATAGGAGGGGTTGTTATGAAG (SEQ ID NO: 44)
H15-33.5 545337 bp at 5′ side: EGF-like repeats and discoidin I-like
domains-containing TAGTTAATTATATGTGTTCGTTATTTGTGTATGTGG (SEQ ID NO: 45)
H45-33.5 114563 bp at 5′ side: similar to hCG2036843
ATGAAAGTGTTTTGGGGATGGATGGGGGATATGGTTGTATAATGTGGCGGACG (SEQ ID NO: 46)
H55-33.5 B-cell novel protein 1 isoform a
AGAATCGTTTGAGTTTAGGAGTTTAAGATTAGTTTGGGTAATATAGTGAGATTTTGTTGTTACGAAAATAAAT
AAAAAAT
TAGTTAGGTGTGGTGGTGTATGTTTGTGGT (SEQ ID NO: 47)
H64-33.5 17408 bp at 5′ side: musashi 2 isoform b
TGTTTGTTGAGTGTACGTNTNNNGTATTTGTGTTGGGTGTATGTGGATGTGTGNGNTGAG
(SEQ ID NO: 48)
H74-33.5 Homo sapiens HECT domain containing 1 (HECTD1), mRNA
AGTTTGAAGTTTTTATAGAAGAAGGTTATGATTTATTTTCGGTAGGAAGTTTTGAAGAG
(SEQ ID NO: 49)
H15a-33.5 62438 bp at 5′ side: D-amino acid oxidase activator
AGGAAAGTTGGAAGGATGAGGATAACGTAGTGTTTTGTTGAAGAAGGAAGAGANNNNGGATTAAATTGAAATTGA
TTGGG
TTTYTAAAATGGATGGGAT (SEQ ID NO: 50)
H27-33.5 unc-51-like kinase 4 AGTTTGATTTTAGATTGTTGTGTTAGTAATGAGCGAGG
(SEQ ID NO: 51)
H30-33.5 spectrin repeat containing, nuclear envelope 2 isoform 1
TTATTTTTATAAAAATAAAAAAATTAGTTGGGTGTAGTGGCGTATGTTTGTNGTTTTAGT (SEQ ID NO: 52)
H H31-33.5 256834 bp at 5′ side: alpha 1 type IV collagen
preproprotein AACGATAAAGAAAATAAAAGGAGTGAGGGAGGATAGATGGG (SEQ ID NO: 53)
H35-33.5 pumilio 1 isoform 1
ATTAGTTAGGCGTGGGGGTGGGTGTTTGTAGTTTTAGTTATTTAGGAGGTTGAGGTAGGA (SEQ ID NO: 54)
H7a-33.5 zinc finger and BTB domain containing 46
AAGGTGGGGGTTGGGGGGNTNGTTTTTTCGGGNTGTTGTCGCGGNGGAGGAGCGTTTTAGAGTTTACGGCGTA
GTTTTATTCGTCGGNATTTAGGTGGACGTTGATCGGGGGAGAGAATTGAGTATCGGGATC
(SEQ ID NO: 55)
H9-33.5 259088 BP AT 3′ SIDE: CHROMODOMAIN PROTEIN, Y-LIKE 2
AGAGTAGAGAGATGATTAAATTTATGTTAATTTTATTATTTTGGTTTTGAGGTTGTTGTRYAAGTTTTTTAGA
ATGTGAGTCGGGTATTGTTTTTGAGGTTAACGTTATTTGGTTTGCGTTT (SEQ ID NO: 56)
Low Salt 0.3M(control) peak, CpG
13-33.3 GGGAGGTAGTGATGAGAGTAATAGATAGGGTTTAGGTGTTTGTGTATGATATGTTTG
(SEQ ID NO: 57)
L9-33.3
GATGTTATTAAATAATTAGATTATTTGTATTCGAATTGGGTAAGTAGTATAAAGGANAANGATATTATTAAAT
AATTAGACTATTTGTATTCGAATTGGGTAAGTAGTACAAAGGAGAAGTGGGGNAA(SEQ ID NO: 58)
3-2-33.3 19744 bp at 3′ side: Myc-binding protein-associated protein
TTTGTAGAAGGATGTGAGAGGAGAAGTGAGCGGTTTTATAGGTATGATGTTAGTTATAAGGGGTTGGTGAGTTGA
TGTGGGAGGATTATTTG
GTTTAGGAGTTTAAGGTTGCGGTGAGT (SEQ ID NO: 59)
L-17.33 dihydrouridine synthase 3-like
TGAGGGTTGGGTTTAGGATAGAGTATAGAGAGGGAGATTTAGTTAGGAGTTTTTTTAAGGTATATAGTTTTTG
ATTTTTAGGTAGTTAGAATAGGAACGTGGATATAGTTGGTATTTAATAGACGTATATTAGATGGATAGATTTG
TTATTGA (SEQ ID NO: 60)
Low Salt 0.3M(control) peak, no CpG
3-5-33.3
TAGTAGTATGATGTTAGTTTTTTTTAAATTATAGATTCAATAAAATTCAGTTAAAATTTTATTAGTTTTATTT
ATTTATTGATTTAGTAGAGATGGATATAGTACTGT (SEQ ID NO: 61)
3-6-33.3
GTGTTATCGTATTGGGGTTATTTGTGTAATTAATATGTGTTATTTAGTTTTAGGGTGTATGTTTATTGTTTTA
ATTATGATGGAGGTGTAGTTTGGAGATTTTGTGTTAGGAGATTAGTAGAGTTTGGGGTTTTAAGGGGATTTTT
TGTGGGGGAGAGGGATAGTTGTGTAGTAGAGTGATAATGAAGGTTTTTGATTTAATGTGTAGTTTTTAGGTTA
TGTGT (SEQ ID NO: 62)
3-8-33.3 TTTGGGAGGTTGAGGTGGGTAGATTATGATGTTAAGAGATTGAGATTAT(SEQ ID NO: 63)
L1-33.3
GATGAAAGGTTAAAAATTGAGATAGAAGATGTGATTTGGAAGGTTATAAGAGAAGTTGGATAAAGTTAAATAAGGAAA
GGAATTTAGAAAAAAGTGTTTAATGTTGTAGAAGG (SEQ ID NO: 64)
L1-19.3
CTATTCTTCCCATTCTCAACATAACTCTAACCTTCCTTCATCCTCACACCCAACAATCATTCACTCATTTATCTA
(SEQ ID NO: 65)
L-1.33
GATAAAGTTGTGNGTAGGGATTTTTGGTAGAGGGAATAGAAAGATGGAGGTGTTGAGGTAGGAGTGATGGGTAGG
TTTGAAGAGTAGAGTTTAGTGTAGTGAGGGGGTTATTAGTAAGGG (SEQ ID NO: 66)
L-11.33
ATATTTTATGGAGGAGTAATTTTTAGAGTATATGAATTGGTTTTATGGAGGAAGATTGTTATTTATAGGTTGGTG
TAAGTGATGGTAGTAGTGGTTTGTC (SEQ ID NO: 67)
L-12.33 AGAAGATAAGGAGAAGATAATTATTNTTTTGGTAGAGGTAATTGATTTGATTATTAGGA
(SEQ ID NO: 68)
L-15.33 ATGTGTATTTAAAGTAAGGTTATGAGATTTTGGATTGTTTTTTGTTTAGGATGATATGTG
(SEQ ID NO: 69)
L-16.33 AAGTAAAATAATTTTGTTTTTATTTATTTTANAGGATTGTT
(SEQ ID NO: 70)
L-18.33
AAAATTTTAAGATTAGGTAAAAATATTGTGTAAAGTGAGAGGGATGTGATGGTTAAAAAGTGATTTAAGATTT
TTGTAATTTTTAGTTATAATTTAAGA (SEQ ID NO: 71)
L-2.33
GAGATAATAGTGAGTATGATATTTTTTGTTTTTTTTATTATGTGTTAAGTATTGTTTAGGGATTAAGTGGGGT
TGTGTTTATTGTAGATGTTGTAGGTATGGAGTTAGTA (SEQ ID NO: 72)
L-20.33
ATGTATTTAGTTGTTTATTGAATATTATTTTAATATTGTATTATGAATATTGTTATGTTATGGATTTTAGGTT
TTATTAGATTGGTATTAGTATCATTTAGGAATATTTTATGATGTGTGTTGATAAATTTTTAAGATAAATGAAT
TTGAGATATGTGTGAGTATTTTATAAAATAAATTTTGTTGGA (SEQ ID NO: 73)
L-23.33 ATGGTTTGTTTGTTTTTGTGGAAAATGGTATGAAGATTGGGTTTGTATTGAATTTG (SEQ ID
NO: 74)
L-24.33
TGTAGTTTTAGTTATTTAGGAGGTTGAGATATGAGAATTATTTGAATTTGGGGGGGGAAGGTTGTAGTGA
(SEQ ID NO: 75)
L-27.33
TGAGAAGGGGGTAGTGGGGATGGTTTTGTGGGTTTATGTTGTTTTTGATTTTAGAAAATAAAGTTTTTTGTAG
GAAGTAGGTGGGAAGTAATTTGTTGATAAGTGTAAAGATTTGGGAATTATATTAAGGGGTAAATGGAGGANAG
GTGTTGGTGTTAANGAGGTAGACNTATGGGAGTTNGGTTTTAGGAANGGNNGTGGNTAGAAAGG
((SEQ ID NO: 76)
L-28.33 GGTAGGTAGATTATTTGAGGTTAGGAGTTTAAG (SEQ ID NO: 77)
L-4.33
ATATTTTTTTATTGAAGAATGTAGTTTTTTAAAATTAAAATGTATTTTTAAAATTTATTTATTATTTTTT--
GAGATAAGGTTTTGTTTTGTTGTTTAAGTTAGAGTATAGTATGTGATTATAGTTTATTGTAGTTTTGAATTTT
TGGGTTTAAG (SEQ ID NO: 78)
[0058] Table 1 above shows the results of sequence analysis of the two NaCl peaks from the SRA-domain column showed a better than 10-fold enrichment of methylated CpG DNA. Out of 30 reads with an average size of 63 bases in the high (0.5 M) NaCl fraction, 19 contained at least one methylated CpG. Of the 1900 bases sequenced, 44 were methylated CpG or 2.32% of the total. Out of 22 reads with an average size of 105 bases in the low salt 0.3M peak, 3 contained methylated CpG. Of these 2327 bisulfite-converted bases, 5 were identified as methylated CpG or 0.215% of the total. | Compositions and methods are provided for facilitating the enrichment of single-stranded DNA containing methylated CpG in a mixture containing methylated and unmethylated DNA. The compositions relate to methylation-binding protein domains that selectively bind to methylated single strand DNA. In embodiments of the invention, the methylated DNA is eluted in 0.4M-0.6M NaCl while the unmethylated single strand DNA is eluted in less than 0.4M salt. The ability to readily enrich for methylated DNA permits high throughput sequencing of the methylated DNA and identification of abnormal methylation patterns associated with disease. | 2 |
FIELD OF THE INVENTION
[0001] The present invention relates to cookware. In particular, the invention relates to improvements in baking dish design.
BACKGROUND OF THE INVENTION
[0002] Baking is a well known cooking process. During the baking process, the article to be baked is placed upon cookware and heated to the desired temperature for the desired amount of time.
[0003] Two main cookware shape configurations are used in the baking process. The first type of configuration is a walled dish generally used to bake foods containing juices or liquids that need to be contained during the baking process. These types of dishes have enclosing walls around the entire perimeter of the dish that prevent food from flowing outside of the dish during baking. Baking dishes with enclosing walls are not suitable for certain types of crusted foods that require heat to convect freely around all portions of the food. Enclosing walls block the free flow of heat and prevent crust or bread portions of food from becoming crispy.
[0004] A second cookware shape configuration is generally used to bake foods such as pizza or other crusted foods. This second configuration is a generally flat tray that does not have enclosing walls to contain the food during the baking process.
[0005] Both types of cookware can be made from a variety of materials. Cooking sheets made from metal are know in the art. For example, U.S. Pat. No. 4,176,591 teaches a metal cooking pan, and U.S. Pat. No. 4,429,625 teaches a cooking sheet made from stamped aluminum foil. Cookware made of non-metallic materials such as stone, earthenware, clay and pottery is also known in the art. For example, U.S. Pat. No. 6,190,450 teaches a baking stone composition for use in temperatures exceeding 500 degrees F.
[0006] Non-metallic bakeware without walls is known in the art, but such bakeware has several disadvantages. Many of the known baking trays made from stone or clay contain some metallic portions. For example, U.S. Pat. No. 4,805,526 teaches a baking plate made from a stone slab inserted into a metal support. This mixture of metal and non-metal materials creates different heat conductivity in different portions of the bakeware, and different rates of heat expansion during baking. This difference in material characteristics reduces the bakeware's ability to cook food evenly, and increases the bakeware's susceptibility to cracking or wearing unevenly.
[0007] Known non-metallic baking trays contain handles made from materials different from the material used to make the tray itself. For example, known baking stones contain handles made from metal or wood, rather than from stone. Handles made from such materials increase the difficulty of moving a hot baking tray, and increase the risk of burning the hand or arm of a person removing the baking tray from an oven.
[0008] Consequently, there has been a continuing need for an improved design of non-metallic bakeware lacking enclosing walls. It is an object of the present invention to provide a baking dish unitarily constructed from single non-metallic material. It is a further object of the present invention to provide a baking dish having unitarily constructed handles made from the same non-metallic material as the body of the baking dish.
[0009] The present invention provides such an improved bakeware design and overcomes the disadvantages and limitations of the bakeware designs in the prior art.
SUMMARY OF THE INVENTION
[0010] The present invention satisfies the foregoing objects and needs by way of a unitarily constructed baking dish having handles. The baking dish is made from a non-metallic material such as stone, clay, pottery, or earthenware. The baking dish is a generally flat tray that is substantially free of enclosing walls around the perimeter of the dish. The baking dish contains handles made from the same material as the other portions of the baking dish. The handle is unitarily constructed with the baking dish such that the handle portion and flat tray portion of the baking dish are of a single continuous construction.
[0011] The baking dish of the present invention can have a variety of shapes, including circular or rectangular. The present invention can have various designs on the bottom surface of the baking dish if so desired, but these designs must be unitarily formed from the same material as the baking dish itself.
[0012] The unitary design of the present invention provides a structure having a consistent thermal conductivity, which heats food evenly and decreases the likelihood of cracking or uneven wear. The handle design of the present invention eases the transport of the baking dish and decreases the likelihood that a user will be burned when removing the baking dish from an oven. The lack of enclosing walls in the design allows for convection heat to move freely around food during baking.
[0013] These and other features, aspects, objects, and advantages of the present invention will become better understood upon consideration of the following detailed description and appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0014] FIG. 1 is a top view of a baking dish according to one preferred embodiment of the present invention;
[0015] FIG. 2 is a front view of the baking dish of FIG. 1 ;
[0016] FIG. 3 is a rear view of the baking dish of FIG. 1 ;
[0017] FIG. 4 is a side view of the baking dish of FIG. 1 ;
[0018] FIG. 5 is a bottom view of the baking dish of FIG. 1 ;
[0019] FIG. 6 is a top view of a baking dish according to a second preferred embodiment of the present invention;
[0020] FIG. 7 is a front view of the baking dish of FIG. 6 ;
[0021] FIG. 8 is a side view of the baking dish of FIG. 6 ;
[0022] FIG. 9 is a bottom view of the baking dish of FIG. 6 .
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIGS. 1 through 5 show a first embodiment of a baking dish according to the present invention. As shown in FIG. 1 , the baking dish 10 includes a flat tray 12 having a rectangular outer edge formed from four sides 14 , 16 , 18 , 20 . Flat tray 12 has a thickness of about ⅛ inch to about 2 inches, and preferably about ¼ inch to about ¾ inch. The thickness of the flat tray affects the thermal properties of the baking dish. Increasing the thickness of the flat tray increases the amount of time and heat needed to increase the temperature of the dish, and also increases the amount of time that the dish will retain heat after a heat source has been removed.
[0024] Extending from side 14 is first handle 22 , and extending from side 18 is second handle 24 . As shown in FIGS. 2 and 3 , first handle 22 extends outward from one side of flat tray 12 and extends slightly above flat tray 12 . Second handle 24 extends from an opposite side of flat tray 12 and extends slightly above flat tray 12 . Handles 22 , 24 extend about 1 inch to about 5 inches outward and about ½ inch to about 4 inches upward from the outer edge of the flat tray 12 . Handle 22 extends at obtuse angle A from flat tray 12 , and handle 24 extends at obtuse angle B from flat tray 12 . Handles 22 , 24 are slightly curved and contain rounded end portions.
[0025] First handle 22 and second handle 24 are located on opposite sides of flat tray 12 approximately 180 degrees apart as shown in FIGS. 1-3 . In other embodiments of the present invention (not shown), the first and second handles can be located at different portions of the tray. For example, the handles could be offset such that the first handle 22 could be located on the front portion of side 14 adjacent to side 16 and the second handle 24 could be located on rear portion of side 18 adjacent side 20 . In another embodiment of the present invention (not shown), additional handles could be located along the outer edge of the flat tray 12 so that one or several handles extend from any one or more of sides 14 , 16 , 18 or 20 . In another embodiment of the present invention (not shown), handles 22 , 24 can be shaped differently than the curved and rounded shape shown in FIGS. 1-3 .
[0026] As further shown in FIGS. 2-3 , flat tray 12 has an upper surface 26 and a bottom surface 28 . Both surfaces 26 , 28 are substantially planar. During normal operation, food is placed upon upper surface 26 of flat tray 12 , and baking dish 10 is placed into an oven to cook the food as desired.
[0027] As shown in FIG. 4 , side 18 of flat tray 12 contains an upturned lip 30 . Lip 30 prevents food from sliding off of the back edge of the tray when inserting or removing the baking dish 10 into or out of an oven. The height of the lip is low relative to the food being baked, and is preferably lower than the height of the food. This low height allows for heat to convect around the food while at the same time preventing food from sliding from the back of the tray. In another embodiment (not shown), none of the sides of the flat tray 12 contain an upturned lip.
[0028] None of the sides of the flat tray contain enclosing walls that extend above or below the surface of the flat tray 12 . Baking dish 10 does not contain an enclosing wall structure that would contain liquid or juices during the baking process. Aside from handles 22 , 24 and upturned lip 30 , the sides 14 , 16 , 18 , 20 are free from such structures.
[0029] The bottom surface 28 can contain surface designs if desired. Any surface designs are unitarily formed from the same material as the rest of baking dish 10 . Alternatively, bottom surface 28 can be free of designs and substantially flat.
[0030] FIGS. 6 through 9 show a second embodiment of a baking dish according to the present invention. As shown in FIG. 6 , the baking dish 110 includes a flat tray 112 having a circular outer circumference 114 . Flat tray 112 has a thickness of about ⅛ inch to about 2 inches, and preferably about ¼ inch to about ¾ inch.
[0031] Extending from outer circumference 114 is first handle 122 and second handle 124 . As shown in FIGS. 7 and 8 , first handle 122 extends outward from one side of flat tray 112 and extends slightly above flat tray 112 . Second handle 124 extends from an opposite side of flat tray 112 and extends slightly above flat tray 12 . Handles 122 , 124 extend about 1 inch to about 5 inches outward and about ½ inch to about 4 inches upward from the outer edge of the flat tray 112 . Handle 122 extends at obtuse angle C from flat tray 112 , and handle 124 extends at obtuse angle D from flat tray 112 . Handles 122 , 124 are slightly curved and contain rounded end portions.
[0032] First handle 122 and second handle 124 are located on opposite sides of flat tray 112 approximately 180 degrees apart as shown in FIGS. 6 and 7 . In other embodiments of the present invention (not shown), the first and second handles can be located at different portions of the flat tray, and additional handles could be located along the outer circumference 114 of the flat tray 112 .
[0033] As further shown in FIGS. 7 and 8 , flat tray 112 has an upper surface 126 and a bottom surface 128 . Both surfaces 126 , 128 are substantially planar. During normal operation, food is placed upon upper surface 126 of flat tray 112 , and baking dish 110 is placed into an oven to cook the food as desired.
[0034] None of the sides of the flat tray 112 contain enclosing walls that extend above or below the surface of the flat tray 12 . Baking dish 110 does not contain an enclosing wall structure that would contain liquid or juices during the baking process.
[0035] The bottom surface 128 can contain surface designs if desired. Any surface designs are unitarily formed from the same material as the rest of baking dish 110 . Alternatively, bottom surface 128 can be free of designs and substantially flat.
[0036] In the foregoing description, certain terms have been used for brevity, clarity and understanding, however, no unnecessary limitations are to be implied therefrom because such terms are for descriptive purposes and are intended to be broadly construed. Moreover, the descriptions and illustrations given are by way of example and the invention is not limited to the exact details shown or described. | The present invention is directed to a baking dish formed from a unitary non-metallic material. The baking dish comprises a flat tray portion of various shapes with handles extending from the sides of the flat tray portion. The handles are formed from the same non-metallic material that forms the other portions of the baking dish. | 0 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 12/291,443, filed on Nov. 10, 2008.
BACKGROUND OF DISCLOSURE
[0002] 1. Field of the Disclosure
[0003] The embodiments herein relate generally to rotary directional drilling apparatuses for downhole steering of a drill bit and methods for steering a drill string.
[0004] 2. Background Art
[0005] During rotary drilling, a drill bit is rotated from the surface of a well by rotating a drill string. It is often desirable to control the direction in which the drilling proceeds through use of a downhole steerable drilling apparatus. Steerable drilling apparatuses include hydraulic devices that apply a lateral bias to a drill string, bent or bendable housing members for drilling at angles, and rotary devices that use a rotatable member, actuators, and/or retractable members to control the direction of the drill string.
[0006] Conventional downhole rotary directional drilling assemblies use gravity and compression to force an under gauge stabilizer to the bottom side of a hole, with a drill collar acting as a lever, and a near bit stabilizer acting as a fulcrum. This lever-like motion pushes the drill bit upward, causing the drill bit to drill on the top of a hole, thereby increasing the angle of the hole. The angle of the drilling can be modified through changes in the length of the drill collar, the diameter of the stabilizers, or modifying one or more drilling parameters.
[0007] Conventional rotary directional drilling assemblies can steer a drill bit only within a single plane, and not along the azimuth.
[0008] A need exists for a rotary directional drilling apparatus that can allow an operator to steer a drill string in any direction, controlling directional changes both in hole angle and along the azimuth.
[0009] A need also exists for a rotary directional drilling apparatus that can utilize fixed steering elements without use of actuators, rather than conventional retractable and movable biasing and thrusting members.
[0010] A further need exists for a rotary directional drilling apparatus able to selectively adjust the orientation of a drill bit through control of the flow of drilling fluid or mud through the mud motor.
[0011] The present embodiments meet these needs.
SUMMARY OF DISCLOSURE
[0012] In an embodiment, the present apparatus for steering a drilling string includes a downhole drilling motor having a rotor for imparting rotational movement to the drill bit, and a stator rotatably disposed about the rotor. The stator can be freely rotatable about the rotor, enabling counter rotation of the stator relative to the rotor. One or more bearings, rollers, and/or seals, as known in the art, can be disposed between the rotor and the stator to enable this rotation.
[0013] It should be noted that the drill string is connected to the rotor, rather than to the stator, while conventional rotary directional drilling assemblies typically utilize a connection between the drill string and the stator. Rotation of the drill string, such as when drilling, as known in the art, thereby imparts rotation to the rotor without imparting this rotation to the stator. Various bearings, rollers, and/or seals, as known in the art, can be disposed at each end of the motor to facilitate this rotation and prevent the loss of drilling fluid from the stator. In an embodiment, the drill string can have a concentric stabilizer connected thereon.
[0014] A first passage is disposed through the rotor for flowing drilling fluid through the rotor to the drill bit. One or more fluid passages are disposed through the rotor to flow drilling fluid between the first passage and the stator. The stator can include a fluid passage having vanes, lobes, or similar protrusions, as known in the art, adapted to enable the flow of fluid to impart rotational motion to the stator in a direction counter to the rotation of the rotor imparted by the drill string. The flow rate of drilling fluid or mud to the stator controls the rate of rotation of the stator. In an embodiment, the rotor can include an upper diverter passage disposed through a first end of the rotor and a lower diverter passage disposed through a second end of the rotor.
[0015] In a further embodiment, the first passage can include a flow restrictor for facilitating the flow of drilling fluid to at least one of the fluid passages to cause counter rotation of the stator relative to the rotor.
[0016] One or more seals can be disposed between the rotor and the stator, exterior to each of the fluid passages.
[0017] A valve is disposed in communication with the first passage and one of the fluid passages to the stator for selectively controlling the flow of drilling fluid between the first passage and the stator. The flow rate of drilling fluid conveyed to the stator can be controlled by the valve, thereby controlling the rotational speed of the stator.
[0018] In an embodiment, the valve can be in communication with a measurement while drilling device and can be controlled responsive to data from the measurement while drilling device. In a further embodiment, the valve can include an actuator, a power supply, or combinations thereof.
[0019] One or more blades can be fixedly disposed on the exterior surface of the stator. The one or more blades are usable to orient the drill bit and steer the drill string by providing an asymmetrical moment to the drill string. By selectively controlling the rate of counter rotation of the stator relative to the rotor, the direction of drilling operations can be controlled. The stator can be counter rotated at an equal rate with respect to the rotation of the rotor to maintain the one or more blades in a stationary orientation with respect to a fixed position within a borehole. The one or more blades thereby offset the apparatus' rotational center from the center of the borehole by providing the apparatus with an asymmetrical moment, thereby enabling reorientation of the drill bit in any horizontal or vertical direction through selective positioning of the blades. In an embodiment, the one or more blades can be over-gauge blades.
[0020] The blades are also usable to maintain the orientation of the drill bit and continue drilling in a straight direction by selectively controlling the flow rate of drilling fluid through the stator to maintain constant rotation of the one or more blades with respect to the rotor.
[0021] In an embodiment, the apparatus can include an electronic member in communication with the measurement while drilling device and with the valve for determining the current position of the one or more blades and controlling the valve in response to data obtained from the measurement while drilling device.
[0022] The present embodiments also relate to methods for steering a drill string using similar rotatable asymmetrical moments about a drill string. In an embodiment, a rotary directional drilling assembly, which can include a motor, valve, and blade, as described previously, is provided, coupled with a measurement while drilling device in communication with a drill string.
[0023] Data from the measurement while drilling device is received, and a position of the blade necessary to orient the drill bit in a desired direction is determined. The current location of the blade can be determined using the measurement while drilling device.
[0024] The valve is then controlled to achieve the necessary flow of drilling fluid to the stator, to cause counter rotation of the stator relative to the rotor until the desired position of the blade is reached. The valve can then be adjusted to change the rotational speed of the stator to maintain the blade in the desired position with respect to the borehole. The position of the blade causes reorientation of the drill bit. The valve can then be readjusted to change the rotational speed of the stator to cause drilling to continue in a generally straight direction.
[0025] The valve can be controlled to enable fluid flow to the stator such that the blade remains stationary with respect to a fixed point within the bore hole, thereby causing the drill string to change direction through reorientation of the drill bit. Alternatively, the valve can be controlled to regulate the flow of drilling fluid to the stator such that the stator continuously rotates relative to the rotor, thereby causing the drill string to drill in a constant direction.
[0026] The present embodiments thereby enable steering of a drill string through control of a rotatably moveable asymmetrical moment about a drill string, which can be rotated about the drill string through selective control of the flow of drilling fluid.
[0027] Other aspects and advantages of the disclosure will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
[0028] In the detailed description of the embodiments presented below, reference is made to the accompanying drawings, in which:
[0029] FIG. 1 depicts a cross-sectional view of an embodiment of the present rotary directional drilling apparatus attached to a drill string.
[0030] FIG. 2 depicts a cross sectional view of an embodiment of the motor of the rotary directional drilling apparatus of FIG. 1 .
[0031] FIG. 3 depicts a cross sectional view of the diverter valve of the rotary directional drilling apparatus of FIG. 1 .
[0032] FIGS. 4A and 4B depict an end view of an embodiment of the present rotary directional drilling apparatus showing the rotation of the rotor and the stator.
[0033] FIG. 5 depicts an isometric cross sectional view of the downhole motor of FIG. 2 .
[0034] The present embodiments are detailed below with reference to the listed Figures.
DETAILED DESCRIPTION
[0035] Before explaining the present embodiments in detail, it is to be understood that the embodiments are not limited to the particular descriptions and that the embodiments can be practiced or carried out in various ways.
[0036] Referring now to FIG. 1 , a cross-sectional view of an embodiment of the present rotary directional drilling apparatus is depicted, usable to orient a drill bit 36 for steering a drill string 32 .
[0037] The apparatus is shown having a downhole motor 10 , which includes a rotor 12 and a stator 14 . A passage 16 is shown extending through the rotor 12 , which is depicted extending along the central axis of the rotor 12 .
[0038] An upper diverter passage 18 and a lower diverter passage 20 are shown extending through the rotor 12 between the passage 16 and the stator 14 . A blade 22 , which in an embodiment, can include an over-gauge blade, is shown disposed on the exterior surface of the stator 14 . The blade 22 offsets the apparatus' rotational center from the center of a borehole, thereby enabling reorientation of the drill bit 36 through selective placement of the blade 22 .
[0039] The stator 14 is freely rotatable about the rotor 12 , such that the blade 22 can be selectively maintained in a stationary position with respect to a bore hole, to reorient the drill bit 36 , or selectively maintained in constant counter rotational motion with respect to the rotor 12 , to maintain a straight drilling direction. One or more bearings, rollers, or similar devices, as known in the art, can be used to enable the stator 14 to rotate independent of the rotor 12 . Due to the ability of the blade 22 to be positioned on any side of the drill string 32 through rotation of the stator 14 , the blade 22 is usable to orient the drill bit 36 in any horizontal or vertical direction.
[0040] A valve 24 is shown disposed within the upper diverter passage 18 of the rotor 12 , in communication with the passage 16 . A sub 26 , shown connected to the rotor 12 , can contain electronic controls and/or a power supply for the valve 24 and/or a measurement while drilling device, or other similar devices in communication with the drill string 32 .
[0041] The valve 24 is controllable to regulate the flow of drilling fluid from the passage 16 , through the upper diverter passage 18 , to a stator passage ( 25 , FIG. 2 ) disposed in the stator 14 . The stator passage can include one or more interior vanes 14 A (e.g., lobes or similar protrusions), as known in the art, such that the flow of drilling fluid through the stator passage imparts rotation to the stator 14 as fluid impacts one or more of the vanes 14 A. The flow rate of drilling fluid to the stator 14 controls the rate of counter rotation of the stator 14 with respect to the rotor 12 .
[0042] FIG. 1 also depicts a measurement while drilling device 30 attached to the sub 26 . The drill string 32 is depicted attached to the measurement while drilling device 30 . A concentric stabilizer 34 is depicted attached to the drill string 32 . Data from the measurement while drilling device 30 is usable to control the valve 24 for positioning of the blade 22 to reorient the drill bit 36 .
[0043] It should be noted that the drill string 32 is attached to the rotor 12 , via the measurement while drilling device 30 and the sub 26 , rather than to the stator 14 , while a conventional rotary directional drilling apparatus utilizes a connection between the drill string and the stator. The rotor 12 is also shown attached to a near-bit stabilizer 35 , which is in turn attached to the drill bit 36 . In an embodiment, the near-bit stabilizer 35 can include a reamer. Bearings and/or rollers, as are known in the art, can be disposed at each end of the rotor 12 to facilitate rotation of the rotor 12 . Bearings and/or seals, as known in the art, can be disposed at each end of the stator 14 to facilitate rotation of the stator 14 and prevent the exodus of drilling fluid from the stator passage into the annulus.
[0044] Referring now to FIG. 2 , a cross-sectional view of the downhole motor 10 is shown.
[0045] The stator 14 , having the blade 22 disposed thereon, is shown rotatably disposed about the rotor 12 . Bearings and/or rollers, as known in the art, can be disposed between the rotor 12 and the stator 14 to facilitate rotation of the stator 14 . The passage 16 is shown in communication with the upper diverter passage 18 and lower diverter passage 20 for conveying drilling fluid to and from a stator passage 25 within the stator 14 . The stator passage 25 can include various vanes 14 A (and/or other similar protrusions) adapted to enable rotation of the stator 14 as drilling fluid is flowed through the stator passage 25 . The valve 24 is shown disposed within the upper diverter passage 18 in communication with the passage 16 , for controlling the flow of drilling fluid from the passage 16 through the upper diverter passage 18 to the stator 14 , thereby controlling the rotational speed of the stator 14 relative to the rotor 12 .
[0046] An upper seal 38 is shown disposed between the rotor 12 and the stator 14 above the upper diverter passage 18 . A lower seal 40 is shown disposed between the rotor 12 and the stator 14 below the lower diverter passage 20 .
[0047] Referring briefly to FIG. 5 , a partial isometric cross sectional view of the downhole motor 10 is shown, which further illustrates the components of the motor 10 shown in FIG. 2 , and as described herein.
[0048] Referring again to FIG. 2 , there may also be a flow restriction 42 within the passage 16 , which facilitates the flow of drilling fluid to the upper diverter passage 18 via the valve 24 , while allowing excess fluid to flow through the passage 16 to the drill bit.
[0049] Referring now to FIG. 3 , a cross-sectional view of the valve 24 is depicted. FIG. 3 depicts an actuator and power supply 44 usable to actuate a movable member 46 until partially or fully aligned with the valve passage 48 . While the actuator and power supply 44 are depicted in close proximity to the valve 24 , in an embodiment, the actuator and power supply could be remote from the motor, such as disposed within an adjacent sub. Through selective actuation of the valve 24 , the flow rate of drilling fluid to the stator can be controlled to achieve a desired rate of counter rotation of the stator relative to the rotor.
[0050] The present rotary directional drilling apparatus is thereby able to use the flow rate of drilling mud to selectively position an exterior blade with respect to a bore hole to orient the direction of a drill bit, without use of thrusting, actuatable, or retractable steering members, by enabling counter rotation of the stator and blade relative to the rotor.
[0051] FIGS. 4A and 4B depict end views of the rotor 12 having the fluid passage 16 extending therethrough, with the stator 14 rotatably disposed about the rotor 12 . FIG. 4A depicts the blade 22 disposed on the exterior surface of the stator 14 in a first position, while FIG. 4B depicts the blade 22 in a second position rotationally displaced from the first position. A bearing surface 15 , which can include various bearings and/or rollers as known in the art, can be disposed between the rotor 12 and stator 14 to facilitate the rotation of the stator 14 relative to the rotor 12 . As a drill string connected to the rotor 12 is rotated, such as when drilling, rotation is imparted to the rotor 12 in a first direction 23 .
[0052] Selectively, fluid that flows through the fluid passage 16 to the drill bit can be diverted through diverter passages (shown in FIGS. 1 and 2 ) to a stator passage 25 disposed within the stator 14 , which can include vanes 14 A (or similar protrusions) adapted to provide counter rotation to the stator 14 in a second direction 27 opposite the first direction 23 . The blade 22 disposed on the exterior of the stator 14 can thereby be rotated to any position about the drill string, as illustrated.
[0053] While the present disclosure has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments may be devised which do not depart from the scope of the disclosure as described herein. Accordingly, the scope of the disclosure should be limited only by the attached claims. | An apparatus for steering a drill string that includes at least one blade fixedly disposed on an exterior surface of the drill string, such that the at least one blade is rotatable about the drill string in response to fluid flow through a fluid passage in association with said at least one blade, and the at least one blade rotates independent of the drill string for imparting an asymmetrical moment to the drill string in a selected direction for orienting a drill bit attached to the drill string, thereby steering the drill string. | 4 |
RELATED APPLICATIONS
This is a continuation-in-part of Ser. No. 08/095,006, filed Jul. 23, 1993, now abandoned, which is a continuation-in-part of Ser. No. 08/041,498, filed Apr. 1, 1993, now abandoned.
FIELD OF INVENTION
The present invention relates to an apparatus and a method for securing objects, particularly, mobile trailer and motor homes against gale-force winds, and more particularly to a containment and protective apparatus and method for securing such objects to the ground and protecting and containing them in gale-force winds.
BACKGROUND OF THE INVENTION
Objects such as aircraft, small sail and motor boats, vehicles and particularly, trailer and motor homes, due to their light construction, large surface area and relatively low mass, are highly susceptible to damage and destruction from gale-force winds. Notably, gale-force winds have commonly been known to overturn such objects, or worse yet, lift and/or blow them a distance, resulting in severe damage and sometimes complete destruction of the object.
Aircraft are typically anchored to the ground by lines, straps, chains and the like to specific parts associated with the wheels or struts of the aircraft.
Objects such as small watercraft, power and sail boats, typically, rest on cradles or blocks formed of wood or steel when stored on land or are merely restrained by lines secured to an adjacent dockside or buoy when afloat. No other restraining means to prevent the boat from being hurled inland in the event of gale-force winds are employed.
Buildings, including residential homes and commercial and retail properties which typically rest on the ground by means of concrete footings and the like are often damaged by gale-force winds. In particular, roofs of buildings may be blown away. Further, the above objects are often damaged by flying debris created by the gale-force winds. Yet further, glasshouses for example, commercial greenhouses, are very susceptible to damage from windborne debris.
Vehicles are also often flung into the air and damaged by such winds.
Although netting has been used to embrace objects such as vehicles and aircraft, particularly as a means of carrying camouflage material, such netting has not been provided over the object as a secure retaining means sufficient to withstand gale-force winds and/or impact from flying debris.
Numerous prior art apparatus exist for securing mobile or trailer homes to the ground in the event of hurricane, flood, or gale-force winds. The majority of these prior art apparatus use a combination or anchor means, elongate strap members and tightening turnbuckles, whereby such strap members are placed over and encircle a mobile home and are affixed to anchor means via turnbuckles to anchor the mobile home to the ground.
U.S. Pat. Nos. 4,148,162, 4,070,802, 3,054,151, 3,335,531, 3,644,192, 3,747,288, 3,848,367 and 3,937,437 are all examples of such apparatus which secure a mobile home to the ground via elongate strap members placed over and encircling the mobile home.
For example, U.S. Pat. No. 3,054,151 and 4,070,802 each disclose "elongate metallic web-like hold-down straps 12 and 14" (U.S. Pat. No. '802) or "lashings 15" which bridge the roof of the mobile home and are secured at their ends to anchors.
Indeed, in some states within the United States of America where the incidence of hurricanes is high, such as in the State of Florida, State legislation requires that mobile homes be anchored to the ground in a stipulated manner requiring utilization of one or more of the above prior art apparatus and methods for securing mobile homes to the ground.
The above prior art apparatus, however, are often unsuccessful in preventing damage to mobile homes and small boats due to gale-force winds, since they completely fail to protect these objects from another source of damage, namely, damage due to impact with airborne debris, such as uprooted trees, bricks, flotsam, and the like which may impact the object at high velocity during a hurricane. For example, despite the utilization of such prior art apparatus, such prior art apparatus was unable to prevent the extensive damage and destruction to mobile homes which occurred in the state of Florida due to Hurricane Andrew in August of 1992. During this hurricane, trailer homes, despite being secured to the ground by prior art apparatus, suffered mass destruction due to being impacted by airborne projectiles such as trees, bricks, debris and the like, which so damaged trailer homes that the elongate strap members were completely ineffective in providing containment of the damaged trailer home. This often, and generally without exception, resulted in the damaged trailer home and its contents being completely blown away.
Accordingly, prior art apparatus do nothing to shield a mobile home from bombardment by airborne debris which frequently impacts a trailer home with such force so as to cause the break-up and disintegration of the mobile home. This is extremely undesirable, not only because of the destruction of the subject mobile home, but also because the resultant debris from the destroyed mobile home, including the mobile home's contents such as TV's, appliances, and the like, further add to the airborne debris circulating in a hurricane and in turn become airborne and impact and bombard other mobile homes, causing further resultant damage and destruction. Accordingly, the elongate strap members utilized with the apparatus of the aforementioned patents not only do nothing to shield a trailer home from airborne bombardment, but they further do nothing to prevent debris from damaged trailer homes and their contents from becoming airborne in a hurricane and causing further damage and destruction, both to human life and other property.
Use of canvas or nylon tarps or tarpaulins to protect property from wind and rain is also generally known. However, use of canvas tarps or tarpaulins, for the purpose of protecting mobile homes from damage from airborne debris in a hurricane, even if employed in the novel and inventive manner disclosed herein, would highly be unsuitable and indeed unworkable. In particular, to resist large volumes of wind, any canvas or nylon tarpaulins need to be of such thickness that their weight makes them extremely difficult to work with in placing over a trailer home, not to mention the increased expense in the number and size of ground anchor means necessary to retain the tarpaulin in high winds. In addition, once becoming rain-soaked, tarpaulins tend to sag, thereby trapping water and placing additional weight on the trailer, which, if such water were allowed to accumulate, may result in structural damage to the trailer home.
Accordingly, there exists a real need for a novel apparatus and method to shield and anchor property such as aircraft, boats, buildings and particularly, mobile homes from destruction in gale-force winds. In addition, there exists a further real need to contain resultant debris from any of such property which may be destroyed due to impact from airborne debris to prevent such debris from itself becoming airborne and causing further destruction.
SUMMARY OF THE INVENTION
In order to overcome the disadvantages of the prior art, the present invention discloses a means/apparatus for simultaneously shielding, anchoring, and containing objects such as aircraft, boats, buildings, vehicles and trailer homes in the event of gale-force winds.
Advantageously, the apparatus of the present invention uses wind-permeable perforate sheets means, which in the preferred embodiment consists of flexible webbed netting, which may be placed in a prescribed manner over or around an object which is sought to be protected against impending gale-force winds or a hurricane. The flexible netting extends outwardly and downwardly at an acute angle from an upper part, preferably the top of the object and is affixed to ground anchors interspersed around the periphery of the object, to thereby anchor the net in place. In such manner, the object is contained within an enclosure, and each of the sides of the object are surrounded by an inclined sloped surface of the net.
Advantageously, by providing an inclined, substantially planar, sloped surface around the sides of the object, the object may thereby be protected from impact and bombardment by airborne debris during a hurricane, thereby preventing structural damage to the object. The inclined sloped surfaces of the net means allow substantial passage of wind therethrough, but prohibit passage of windborne debris such as bricks, stones, such as B3 gravel, trees, flotsam, wood spars and the like, which would otherwise impact and destroy or at least seriously damage, by penetration thereof or otherwise, the object. The perforate sheet means or net is of sufficient strength to resist impact with such projectiles, but further assists in preventing airborne debris from impacting the sides of the object by its sloped configuration, which assists in deflecting such airborne matter away from the sides of the object.
Accordingly, in its broadest aspect, the apparatus of the present invention comprises the combination of:
(i)an oversize wind-permeable perforate sheet means of a surface area substantially greater than the combined surface area of the top and sides of an object over which it is adapted to be placed, wherein such sheet means is extendable downwardly and outwardly from the top at an acute angle to the sides of the object;
(ii)a plurality of ground anchor means adapted for placement in the ground surrounding said object; and
(iii)attachment means, attachable to the periphery of the perforate sheet means, to allow the perforate sheet means to be secured to the ground anchor means.
In a further aspect of the present invention, there is disclosed a method of simultaneously shielding, anchoring, and containing an object in the event of gale-force winds. Such method comprises the steps of:
1 casting an oversize, substantially wind-permeable flexible net means over said object so as to substantially cover the top of the object; and
2 attaching the wind-permeable net means proximate an outer peripheral edge thereof to ground anchor means, so that the net extends downwardly and outwardly from the top at an acute angle to each of the sides of the object, so as to surround at least a substantial portion of each of the sides with an inclined, wind-permeable surface.
In a preferred embodiment, the apparatus of the present invention further comprises the combination of:
1 an oversize wind-permeable perforate sheet means of a surface area substantially greater than the combined surface area of a roof and outer side walls of a trailer home over which it is adapted to be placed, wherein such sheet means is extendable downwardly and outwardly from the roof at an acute angle α to the outer side of the walls of the mobile home;
2 a plurality of ground anchor means adapted for placement in the ground surrounding said home; and
3 attachment means, attachable to the periphery of the perforate sheet means, to allow the perforate sheet means to be secured to the ground anchor means.
In a further preferred embodiment of the present invention, there is disclosed a method of simultaneously shielding, anchoring, and containing a trailer home or motor home in the event of gale-force winds. Such method comprises the steps of:
1 casting an oversize, substantially wind-permeable flexible net means over a mobile home so as to substantially cover the roof of the home; and
2 attaching the wind-permeable net means proximate an outer peripheral edge thereof to ground anchor means, so that the net means extends downwardly and outwardly from the roof at an acute angle α to each of outer side walls of the trailer home, so as to surround at least a substantial portion of each of the outer side walls with an inclined, wind-permeable surface.
Surprisingly, I have found that by providing a net formed of a resiliently flexible material, such as a flexible thermoplastics material, sufficiently taut around the object as to give the net one or more flat stationary planes, acutely angled to the object, that windborne debris can be restrained and deflected from the object to prevent damage thereto. I have found that when such debris hits the net with appreciable force, the net is temporarily deformed at an area of at least one of these flat, stationary planes under the impact of the flying debris. The resilient net material absorbs the energy of impact and surprisingly, this energy is distributed throughout the net adjacent the impact site and transferred to the restraining anchor means. The extent of this impact energy distribution throughout the net to the anchors allows of the unexpectedly high degree of efficacy of the net in restraining and deflecting the debris.
Thus, the invention provides a combination and method as hereinabove defined wherein a side or face of the net is so formed as to be deformable from its stationary plane and so biased as to deflect or restrain windborne flying debris by absorbing impact energy by distribution thereof through said material.
The net is, thus, so formed and taut as to constitute resiliently flexible deflection means to deflect and restrain flying debris.
While it is desirable to have the net fully covering the object to be protected, for example, in the case of a building, trailer or mobile home, the roof and sides, the invention is applicable to those situations where only one or more sides need to be protected. One edge of the sheet may be attached to only one side of a structure to protect a window or the like, with the opposite edge being secured to the adjacent ground or surface at a distance from the base of the structure. Also within the scope of the present invention are those embodiments wherein the net is spaced away from, but adjacent an upper part of the object, structure and the like, to be protected. The net may be directly or indirectly supported on or by a frame so spaced away from the object but to be effective in providing the desired protection from windborne debris. Such arrangements in this specification and claims are embraced by the terms "adapted for placement around said object" and "adapted for placement over the roof" and the like.
Thus, the system of the invention in one aspect has the net fully covering the top of the object, for example the roof of a trailer home. This provides a means of restraining and containing the home and any contents contained therein should the sides of the home be penetrated to allow air pressure build up within the home. In an alternative embodiment, the home may be contained and restrained by the system notwithstanding the net does not fully cover the top or roof of the home.
The substantially wind-permeable, flexible netting extends outwardly and downwardly at an acute angle from an upper part to provide a stationary substantially planar inclined sloped surface around the sides of the object and is of sufficient strength and resilience so as to effect distribution of the energy of impact between windborne debris and the netting throughout the netting and, optimally, as far as the anchor means. Such efficacious distribution of the impact energy reduces the likelihood of a breakthrough of the net to allow airborne debris to pass therethrough.
Preferred flexible materials are resiliently flexible thermoplastics such as the polyolefins, polyesters and polyamides. Preferred polyolefins are polymers and copolymers of the ethylene, propylene and polybutadiene families with for example other olefins and vinyl acetate. As examples, high density, low density and linear low density polyethylenes and 1,2-polybutadienes may be mentioned. The term "polyethylene" includes ethylene homopolymers, and copolymers of, such as for example vinyl acetate, acrylic acid, methyl methacrylate, butene, n-hexene, 4-methyl-1-pentene and octene polymers with ethylene and blends thereof. Most preferred polyethylenes have oriented molecular structures, such as gel spun oriented polyethylenes sold under the trade marks of SPECTRA, DYNEEMA, MIKELOW. A preferred polyester is polyethylene terephthalate. By the term "nylon" as used in this specification is meant melt-processable thermoplastic polyamides whose chain structure features repeating amide groups, such as, for example, amorphous nylon, nylon-6, 6 (polyhexamethylene adipamide), nylons-6,9,-6,10 and -6,12, nylon 6 (polycapromide), nylon 11, nylon 12, polymers, copolymers and blends thereof. A preferred polyamide material is Nylon 6,6 copolymer of 1,6-diaminohexene and adipic acid.
I have found that one of the benefits of the protective net system of the invention is a reduction in wind pressure on the windward surface of the object protected by the net, due to reduced passage of wind through the net.
I have found that when preferred nets of use in the invention were tested to failure by the impact on the net of either a heavy test weight in a drop test or by a projectile fired from an air cannon to effect breakthrough, that the resulting hole caused by the impact was so localized that the efficacy of the net in continuing to provide a protective membrane around an object was not substantially affected. A protective system capable of such continued efficacy is most valuable. This should be contrasted with systems formed of non-resiliently flexible materials such as tempered and heat strengthened glass, wood, such as plywood, chipboard and the like, aluminum sheeting and steel wire, which are most likely to break, shatter or collapse under comparable impact energies.
The mechanical characteristics of the net of use in the practice of the invention, such as mesh size, fabric denier and fabric and net construction may be readily and suitably determined from the physical characteristics of the flexible material in view of the desired efficacy.
The size of the mesh of the net not only influences the range of projectile sizes which the net will stop, but also is a factor in the capability to absorb the energy of an impact. Smaller mesh sizes allow objects to strike more net elements, which better dissipates the impact energy. In order to withstand a given impact, a net with larger mesh size has to weigh more than a net with smaller mesh size.
The net of a typical 4 m×4 m dimension, preferably, should be able to withstand an impact energy of at least 400 Joules, more preferably more than 500 Joules and most preferably at least 800 Joules.
Table 1 shows the energy to break (MJ/m 3 ) values for several thermoplastic fibres of use in the practice of the invention.
The area under the curve of a graph of tensile strength (MPa) plotted against elongation L/L is a rough measure of the energy to break the fibre i.e. the breaking energy per unit volume of fiber material. These values have been divided by the density of the fiber to obtain the equivalent specific fracture energies in J/g.
TABLE 1______________________________________ Elongation Tensile Strength to Break Energy to (MPa) (ΔL/L) Break AB/2Fibre A B (MJ/M.sup.2)______________________________________Nylon 66 300-960 0.16-0.66 75-100Nylon 6 400-910 0.16-0.5 73-100Polyethylene 270-1160 0.12-0.55 70-75Terephihalate(PET)Polypropylene 240-640 0.14-0.8 45-95Polyethylene 290-590 0.1-0.45 30-65Kevlar (Dupont) 2760 0.03 42E-Glass 2100-4500 0.03-0.05 55-70______________________________________
The following explanation is given by way of guidance in determining the configuration of the thermoplastics material constituting the net.
The specific energies of most synthetic fibres are approximately 50-100 Joules/gram. In the case of, for example, a 4.09 kg projectile impacting at 15 meters/second, a kinetic energy of impact of approximately 460 Joules is imparted to the net. A net having a mass and configuration resulting in a distribution of 0.033 g/cm 2 thermoplastics material will thus require about 3.3 Joules/cm 2 to effect breakage. For a projectile impacting on an area of 34 cm 2 the net will withstand a load of up to 112.2 Joules.
The force on the impact area will be distributed over the entire area of the net such that the stress will decay outwardly from the area of impact wherein approximately half the impact energy will be dissipated outside the periphery of the contact zone. Some energy may be converted to heat by plastic flow and friction.
Thus, a heavy object, travelling at a high velocity and impacting a small area will exceed the breaking energy, eg. a steel rod impacting at one end. A solid spherical rock (density 2.8 g/cm 3 , a diameter of about 10 cm) travelling at 15 m/s would impart about 165 kJ to the net. About half of this energy 82.5 J is concentrated on an area of 78.5 cm 2 , with the remainder being largely dissipated over the entire structure.
However, the net will support more than 240 J for an area of 78.5 cm 2 assuming a net fabric weight of 0.033 g/cm 2 . This is a worst case scenario which assumes all energy is transmitted to this small area of the net. In practice, some of the energy is spread out over the whole net and to the anchors. This example suggests that stones, even large ones, cannot penetrate the net at 15 m/s but might penetrate at velocities above 24 m/s for a fabric having an areal weight of 0.033 g/cm 2 . Thus, the weight/unit area of the fabric net determines the resistance to penetration. Since stones/masonry are the most likely source of damage, a 0.066 g/cm 2 fabric should prevent penetration at a velocity of 30 m/s.
Table 2 below gives the approximate minimum weight/unit area of a plastics net material derived to prevent breakthrough at the given velocities for a spherical object weighing 4.09 kg and having a density of 2.89 g/cm 2 . The specific energy to break of 100 J/g of the fibre is assumed to be a reasonable average for synthetic fibres.
TABLE 2______________________________________Impact Rating of Net for a Spherical Object(mass: 4.09 kg; density 2.8 g/cm.sup.3)Velocity Kinetic Energy of 4.09 kgm.p.h. m/s object (Joules) Weight of Net, kg/m.sup.2______________________________________50 22 990 0.760 27 1490 1.070 31 1965 1.3100 45 4141 2.6120 54 5963 3.8150 67 9180 5.9______________________________________
The net may optionally be formed, for example, of an extruded, woven or non-woven, knotted, knitted, crocheted or braided, knotless web. Preferred configurations are those known as a raschel crocheted knit or as a lockstitch configuration.
A woven i.e. interlocked perpendicular threads configuration is less preferred in the practice of the invention. Intersections can easily slip to allow relatively large holes to be formed without actual breakage of any fibres.
In extruded netting, net elements are solid strands of material, instead of assemblages of fibres having solid intersections. Extruded netting can be very cheap, but strength is low due to the lack of the alignment of molecules and stiffness may be quite high.
Knotted netting is efficacious but is less preferred and is generally formed with pre-assembled cord. However, preferred small mesh sizes are generally impractical to manufacture, and strength is lost in the knots. Thus, use of such a configuration requires a heavier net with reduced ability to stop small debris.
Braided netting, where yarns cross each other in a regular pattern, allows for high strength and a high degree of stretch. Intersections can be knotless (e.g. Ultra Cross configuration), giving no reduction in strength. Intersections allow some limited slip, which may allow failure to a limited degree to propagate from one element to another.
One edge of net arrangement of use in the invention consists of reinforcement with either 5 cm wide nylon, polyester or polypropylene webbing folded over the edge of the net and stitched on, typically with two rows of stitches, to leave a 2.54 cm strip of webbing along the edge. The net may itself be reinforced at the edge by increasing the amount of material used in the raschel knit. This is a straightforward procedure with raschel machines. Rings are attached to the edging using 2.54 cm webbing, and straps are used to attach these rings to a peripheral cable, which is in turn attached to ground anchors.
Further objects and advantages of this invention will appear from the following detailed description of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be better understood, preferred embodiments will now be described by way of example only with reference to the accompanying drawings, wherein:
FIG. 1 is a perspective view of the apparatus of the present invention, in its intended-use position to shield, anchor, and contain a trailer home in gale-force winds;
FIG. 2 is a plan view of the apparatus of the present invention, in the direction of arrow "A" in FIG. 1;
FIG. 3 is a section view of the apparatus of the present invention, taken along plane B--B of FIG. 2;
FIG. 4 is an enlarged cross-sectional view of the attachment means and anchor means of the present invention shown in FIG. 3;
FIG. 5 is a view of an arrow `c` of FIG. 4;
FIG. 6 is a perspective view of another embodiment of the apparatus of the present invention, in its intended-use position to shield, anchor, and contain a trailer home in gale-force winds; and
FIG. 7 is an enlarged view on the area designated as `F` in FIGS. 1 and 6 showing coupling means for joining sections of perforate sheet together.
FIG. 8 is a plan view of an alternative apparatus of the invention;
FIG. 9 is a sectional view of an alternative embodiment of the invention showing an alternative net deployment system;
FIG. 10 is a sectional view of an alternative embodiment of the invention showing a further alternative net deployment system;
FIG. 11 is a sectional view of an alternative embodiment of the invention showing a still further alternative net deployment system; and wherein the same numerals denote like parts throughout the drawings.
FIG. 12 is an illustration of a net useful in the present invention; and
FIG. 13 is an enlarged view of an intersection of the net of FIG. 12.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 6 show a perspective view of two different embodiments of the apparatus 10 and method of the present invention for securing trailer homes and motor homes 12 (hereinafter mobile homes) against gale-force winds.
An oversized, substantially wind-permeable perforate sheet means 14, capable of being cast or placed over the roof 16 of a mobile home 12, is contemplated as an essential component of the apparatus 10 of the present invention. In the preferred embodiment, the perforate sheet means 14 is a flexible woven net, preferable formed of a water-resistant braided polyethylene.
The surface area of the sheet means or net 14 of the present invention is greater than the combined surface area of the roof 16 and side walls 18 of the trailer home 12. This excess size is important, since a necessary requirement of the invention is that net 14 when placed over the roof 16 of the mobile home be adapted to extend downwardly and also outwardly from the roof 16 at an acute angle α to the outer side wails 18 of the mobile home so as to create a protective inclined sloped surface 25 around each outer wall 18, as shown in FIGS. 1, 2 and particularly FIG. 3.
In a preferred embodiment, net 14 extends downwardly and outwardly so that the outer peripheral edge 20 thereof extends to at least the level of the lowermost portion 22 (floor) of the mobile home 12, so as to provide a protective inclined surface 25 proximate the entire surface of each outer wall 18 of the mobile home, as shown in FIG. 3.
Attachment means 24 are further provided, as shown in FIG. 1 and in greater detail in FIGS. 4 and 5, attachable to the perforate sheet means 14 proximate the outer peripheral edge 20 thereof. Such attachment means 24 allow net 14 to be attached to ground anchor members 30 located in the earth surrounding the mobile home 12 (see FIGS. 4 and 5), to thereby maintain net 14 in the angular outwardly extending position as shown in FIG. 3 around all outer sides 18 of mobile home 12. More particularly, it is desirous that the anchor means 30 be interspersed about the periphery of mobile home 12, as shown in FIGS. 1 and 2, and the dimensions of net 14 be such that net 14 is maintained at an outwardly extending angle α from the outer walls 18, as shown in FIG. 3. In a preferred embodiment angle α so formed between the net and the outer side walls is between 15°-60° and preferably between 20°-35°. Angle α should be a compromise between as high a value as possible to thereby afford as a "shock-absorbing" distance between net 14 and outer walls 18 to allow net 14 to protect walls 18 from airborne debris, while at the same time being as low a value as possible to thereby minimize the size of the net means 14 required.
Since mobile homes are generally of sizes ranging from 30 ft.-70 ft. in length, by 10 ft. in width, net 14 needs to be of a general rectangular shape of at least 30'×50' (1,500 sq. ft.) for the smallest trailer home size of 30'×8'×10', in order to have a protective inclined sloped surface 25 extending outwardly and angularly downwardly to protect substantially all of the outer side walls 18 of mobile home 12 to the level of the floor 22 of the trailer home. Dimensions of this size will permit an angular slope α of net 14 of up to approximately 30°. Angle α should be the greatest value possible at which net 14 will extend with its peripheral edge 20 to a position level with the floor surface 22 of the mobile home, to thereby ensure walls 18 are entirely protected from horizontally-moving airborne debris.
Mobile home sizes greater than 30'×8'×10' require nets 14 of dimensions larger than 1,500 sq.ft. if an angle α is to be maintained and if peripheral edge 20 of net 14 is to extend to a level of floor 22 to thereby protect all of the surface area of the outer walls 18 from impact damage due to airborne debris.
Notably, in order that net 14 when placed over the mobile home be adapted to extend evenly and uniformly downwardly and outwardly with a minimum of bunching and folding in a preferred embodiment the perforate sheet means is comprised of two or more irregular shaped perforate sheets or nets 14' joinable along various seams 40, as shown for example in FIGS. 1, 2 and 7. Accordingly, when a perforate sheet means 14 assembled in the preceding manner is placed over mobile home 12 and attached to the anchor means 30, a wrinkle and bunch-free sloped surface 25 is thereby formed proximate each of outer walls 18 of mobile home 12, as shown in FIGS. 1, 2 and 6.
To accomplish the joining of each of the various perforate sheets 14' which comprise entire net 14 releasable coupling means 42 may be utilized to join the perforate sheets along a seam 40 thereof, as shown in FIG. 7. These coupling means 42 may be of any type commonly known in the art, but in a preferred embodiment are a steel `D`-shaped snap-ring.
Advantageously, releasable coupling means 42 along one or more seams 40 allows entry by a person in and out of the mobile home 12 when the apparatus 10 of the present invention is assembled about the mobile home.
Notably, the force exerted by gale-force winds of up to 150-160 miles per hour, as was recently experienced in Hurricane Andrew which struck the eastern seaboard of the State of Florida and some of the other states surrounding the Gulf of Mexico, including Louisiana, in August 1992, can be quite significant.
Utilizing the formulas:
P=C×V 2 and
F=P×A
where:
P is pressure in lbs. force exerted on an area,
C is a constant of ##EQU1## (assuming air at a specified density at standard temperature and pressure) V is velocity in miles per hour, and
A is the surface area,
the maximum force exerted by a wind of a given velocity against a perpendicularly-disposed outer wall 18 of a trailer home of a given area A can easily be calculated.
From Table 3, it can be seen that the force exerted by a gale-force wind of 160 miles per hour on a mobile home size of 45'×8' (×10') can exceed 24,000 pounds.
TABLE 3______________________________________ Wall SizeWind Speed Pressure of Mobile(mph) (lb/ft.sup.2) Home (ft.sup.2) Force (lbs)______________________________________50 6.75 280 (35' × 8') 1890 6.75 360 (45' × 8') 243060 9.72 280 (35' × 8') 2722 9.72 360 (45' × 8') 349970 13.23 280 (35' × 8') 3704 13.23 360 (45' × 8') 476380 17.28 280 (35' × 8') 4838 17.28 360 (45' × 8') 622190 21.87 280 (35' × 8') 6124 21.87 360 (45' × 8') 7873100 27 280 (35' × 8') 7560 27 360(45' × 8') 9720110 32.67 280 (35' × 8') 9148 32.67 360 (45' × 8') 11761120 38.88 280 (35' × 8') 10886 38.88 360 (35' × 8') 13997______________________________________
To resist a force of such magnitude applied by a 160 mile per hour wind perpendicularly contacting a wall of a mobile home, the net means 14 is affixed to suitable anchoring means 30. It is contemplated that anchor means 30 of the present invention be comprised of elongate multi-helix screwable anchors 30, which may be mechanically screwed into the ground (see FIG. 3).
A number of such anchor members 30 are commercially available. One such product is multi=helix anchor manufactured by Dixie Electrical manufacturing Company of Birmingham, Ala., under Cat. No. D-284 for a tandem 8" helix anchor. According to information supplied by said company, such anchor depending on soil type and length of anchor, when inserted into the soil can resist a load of between 10,000 to 30,000 lbs. Using such information, knowing of the appropriate soil conditions, the necessary approximate spacing of such anchor means 30 around the periphery of a mobile home can be determined to secure net 14 about a mobile home 12. The anchors may be installed ahead of net deployment and constitute capped sub-ground members.
To avoid anchor means 30 protruding upwardly and creating a safety hazard, it is contemplated in a preferred embodiment that anchor means 30 be recessed below the surface of the earth, as shown in FIGS. 3, 4 and 5. To facilitate this, a recessed well 70 may be further provided to surround anchor means 30, within which a cylindrical hollow canister 50 may be placed level with the surface of the ground, as shown in FIGS. 3, 4 and 5. When anchor means 30 and apparatus 10 of the present invention is not in use, a cylindrical cover plate (not shown) may be placed over the cylindrical canister 50, to thereby conceal and hide anchor means 30 from view.
Commercial cylindrical canister devices 50 and cover plates suitable for such purposes are available. For example, Brooks Products Inc., Polyplastic Division, of Cucamonga, Calif. provides a "60 series Valve Box" which is ideally suited to this purpose.
The attachment means 24 of the present invention may simply comprise a releasable attachment mechanism, such as a snap-ring, for releasably attaching the net 14 at any point proximate the peripheral edge thereof directly to anchor means 30, as shown in FIG. 6. In a preferred embodiment, however, it is contemplated that the attachment means 24 further comprise means for tightenably securing flexible net 14 to anchor members 30.
Accordingly, it is further contemplated that attachment means 24 comprise a pair of releasably securable hooks 60, 62, one of which may be secured to anchor 30 and the other to net 14 as shown in FIGS. 4 and 5. Rollable webbing connects the two hooks 60, 62, and crankable tightening means 70 is further provided to wind the webbing 72 onto a spool 74, thereby bringing hooks 60, 62 together to thereby tighten net 14 to anchor 30, as shown in FIGS. 4 and 5. An example of such a commercially available tightening means ideally suited to this purposes is model FE 400 (P/N802) Ratchet Strap, sold by Kinedyne Corporation of North Branch, N.J., having a breaking strength of 11,000 lbs., with a 2" cranking handle, and hooks 60, 62 interposed at each end.
An extremely lightweight and water resistant high-strength fibre particulary suited for net means 14 of the present invention is a braided line netting comprised of a polyethylene homopolymer having a high modulus of elasticity and a molecular weight of over 500,000. An example of such a commercially available fibre is SPECTRA* 1 manufactured by Allied Fibers, a division of Allied Signal Inc. of Petersburg, Va. In "single braid format, such fiber has a break strength of approximately 48,000 lbs., and a weight of approximately 22 lbs. per 100 ft. of rope.
In one embodiment, two netting configurations are preferred and are commercially available. One is the Ultra Cross Spectra (a registered trademark of Allied-Signal Inc.) available from NET and the other is Raschel Nylon from Polytech. Nylon is not quite as strong as the "Spectra" fiber.
The net sold as Ultra Cross Spectra comprises four bundles of fibers to make the twine. Intersections are formed by braiding the two twines through each other. This will avoid the stress concentrations seen in knotted netting. This net is illustrated in FIG. 12 and the braid and intersection in the enlargement of FIG. 13.
FIG. 8 shows an embodiment of the invention wherein the net 16 does not fully cover the top of home 12 but has peripheral net covering strips 80 taped and sewn to transverse restraining straps 82 formed of a plastics webbing material, such as nylon. Such an arrangement provides partial roof covering which allows protrusions such as vent pipe 84, air conditioning unit 86 and television arial to extend above the net, if so required.
FIG. 9 shows an embodiment having a pair of displacing members 90 formed of a suitable material, such as, for example, polystyrene foam or rubber blocks arranged lengthwise of the roof line to provide a means of deploying the net away from the home at its upper parts to provide less risk of impact damage to these parts should a wind-borne object hit the net with sufficient force to produce extensive permanent or transient deformation of the net.
FIG. 10 shows an alternative means of providing for the net to be deployed away from the upper reaches of the object. Angled support and deployment poles 92 are arranged around the home and engage the net so as to produce a wider angle at the upper reaches of the home between the net and the home. Poles 22 may be formed of any suitable material, such as aluminum, fibre glass or wood and each may comprise individual lengths or several smaller members suitable connectable one to another, such as by bayonet fittings, screw-in mechanism or telescopic spring loaded means.
FIG. 11 shows a further alternative means of separating the net from the home at the upper reaches thereof. A plurality of resiliently flexible poles 92 formed of, say, fibre glass, bamboo or like material are joined end to end and disposed over the home in the form of an arch. Each end of pole 92 is retained in a base plate 94. The upper curved portions of pole 92 may be fixed to the top of the roof by a suitable fixing means (not shown) or merely held under tension by the embracing net.
EXAMPLES
1. Raschel Nylon Tension Tests
In order to accurately model the impact of a projectile on the netting, data regarding the stiffness and strength of the netting was obtained. Simple static tension tests were performed, with load and strain data recorded at several points for each sample.
Sample Preparation
Specimens of nylon fibres were cut from a large section of netting. A single strand (0.25 cm diameter) of the netting was followed through a series of intersections. To avoid adverse effects on the test strand, intersection strands were cut roughly five diameters away from the intersection. All cuts were made with a soldering iron to eliminate unravelling. Typical sample lengths were 1.2 m.
To facilitate gripping of the specimen, and to ensure that failure occurred in the test section of the sample, the ends of each sample were threaded through the hollow core of a short length of 0.5 cm braided nylon rope. A clamp on the end of the rope nearest the test section, along with a knot a short distance away, eliminated the possibility of slippage of the specimen through the rope.
Experimental Procedure
The test apparatus used was a Tinius-Olsen tension/compression test rig. Samples (inside the rope) were wound around a 4 cm dia. steel pipe to avoid stress concentrations and tied off to a post. Elastic strands were attached to each sample at the end of the test section as references for strain measurements.
Typical crosshead separation rate was 20 mm/min. Deflections were manually measured at specific loads (e.g. every 4 kg).
Maximum load supported by each sample was also recorded.
Results
A typical plot of load vs. deflection is shown in Table 4.
TABLE 4______________________________________Load (N) Strain (no. units)______________________________________0 049 0.0990 0.15140 0.20175 0.24225 0.27260 0.28310 0.30355 0.32400 0.33______________________________________
2. Dropped Projectile Impact Tests
(A) Large samples of netting were tested for impact absorption capability through drop tests. The sample to be tested was securely fastened to a rigid frame, and a projective of measured weight and dimensions was dropped onto the specimen from a range of measured heights.
Apparatus
The netting used was 210/20 twine, (Hafner Fabrics, Toronto, Ontario Canada), 1.27 cm length of stretched mesh 100% Nylon 6,6 (Du Pont) raschel knit configuration. The raschel knit is a knotless configuration, with strands and intersections `crocheted` together. The designation 210/20 indicates that 20 ends of 210 denier fibre form the yarn. The resulting twine was roughly 1 mm in diameter. The mesh had a breaking strength of 25 kgs. and the mesh squares were roughly 6 mm wide.
Breaking strength is an indication of the net's capabilities. Breaking strength is measured by pulling apart one square of the finished product, so the element strength is half the breaking strength. Denier is a measure of a fibre's weight. One denier is equivalent to the weight in grams of a 9000 m length of the fibre. Thus, a 9000 m length of 210 denier fibre would weigh 210 grams. Stretched mesh size indicates the distance between intersections, along two sides of a square. Thus 1.27 cm stretched mesh corresponds to roughly 0.635 cm squares.
The raschel knit construction technique consists of essentially crocheting the yarns (three yarns together at a time) and forming loops in the net elements. Intersections between elements of the net are accomplished without knots; the crochet process continues through the intersection, with one yarn being exchanged between the intersecting elements. A main advantage of the raschel knit is its ability to stretch to a large degree: as much as 50% strain-to-failure for an element.
Another advantage of raschel is that, if one element of the net is damaged, there is no tendency for adjacent intersections, or adjacent elements, to unravel. This avoids single-point failures.
A third advantage is that intersections cannot slip significantly, due to the exchange of yarns. Thus an opening cannot be stretched wider by wind or impacts.
One more advantage is that no significant strength is lost in intersections. Knotted netting configurations lose significant performance due to the stress concentrations of the knots.
A system for edge attachment was installed on each sample of netting to be tested. Earlier versions of this consisted of a rope or cable strung through the outside squares of the netting, the latter version consisted of a length of 5 cm webbing sewn onto the edge of the netting, with D-rings attached to this webbing using small 2.54 cm pieces of webbing
A rigid frame, roughly 4 m square, was constructed from 10 cm angle iron to support the test samples. 2.5 cm eye bolts were attached to the inside corners and at the centres of each side of the frame. A 0.6 cm cable was strung through the eye bolts and tightened with a turnbuckle. The netting was attached to this cable by stringing a rope between the edge attachment system and the cable every foot or so along the perimeter of the sample.
The degree to which the test specimen was stretched into place depended on the type of edge attachment--the webbing allowed for very little stretch, whereas the rope strung through the edge allowed for ample pre-stressing (approximately 13.7%).
The projectile used was a steel cylinder roughly 9 cm diameter, roughly 20 cm long, and 11.7 kg weight. As the projectile had fairly sharp edges, tape was placed around the bottom edge to avoid cutting the test specimen. A ring was attached to the top of the weight to support it from the crane.
Experimental Procedure
The hook of a crane was placed above the centre of the net. A rope was strung through the hook and attached to the projectile. A tape measure attached to the hook was used to measure the height of the projective above the net. The projectile was dropped from increasing heights until the net failed. A video camera recorded all tests, and was used to measure displacement of the net, as indicated by a scale on the far side of the frame.
Results
The maximum height from which a projectile could be dropped without damaging the net ranged from 9.3 m (for the pre-stretched sample) to 10.21 m (for the unstretched sample), which corresponds to an impact energy of 1100 to 1200 Joules. The maximum displacement of the pre-stretched sample was approximately 1.0 m whereas the maximum displacement of the unstretched sample was approximately 1.3 m. The holes left by impacts from a greater height were typically 20 cm in diameter. The force of impact was sufficient to do significant damage to the corner eyebolts. After the series of roughly 15 tests, the eyes had been forced open, leaving gaps as large as 2 cm.
The nets were tested to failure. After the first intentional failure of the netting, several subsequent drop tests were performed on the netting. Results from these tests and direct observations indicate that damage to the net was limited to the immediate vicinity of the actual hole; outside a small distance (15 cm) away from the hole, the net performed as well as it had before being damaged.
(B) Comparative drop tests were conducted with approximately 1.25 m×1.25 m samples of netting formed of various materials in various notted, knitted or raschel construction. The samples were attached by webbing and D-rings to the frame as outlined under A. The same test weight iron cylinder (11.8 kg) of 9 cm diameter was dropped from various heights until the net was penetrated.
The following materials were tested.
Sample
1. White polypropylene monofilament knit netting. Mesh size 1.5×4 mm. Roughly 50% open. From Roxford Fordell.
2. Black polyethylene monofilament and tape simple weave shade cloth. Mesh size 2.3 mm. 60% open.
3. Orange polypropylene multifilament knotted netting. Mesh size 13/8" (stretched mesh). Roughly 80% open. Redden 210/27.
4. Black nylon multifilament raschel knit netting. Mesh size 2" (stretched mesh). Roughly 85% open. Redden 210/42.
5. White polyester (high tenacity) multifilament knit netting. Mesh size 1.5×3 mm. Roughly 25% open. Much more fibre in one direction. Tek-knit 2059.
6. White nylon multifilament knotted netting. 31/2" stretched mesh. Roughly 90% open. First Washington Net #18 nylon.
7. Black nylon multifilament knotted netting. 17/8" stretched mesh. Roughly 90% open. From First Washington Net.
8. White nylon multifilament raschel knit netting. 1/2" stretched mesh. Roughly 70% open. Hafner 210/20.
The results are shown in Table 5, wherein areal density means the weight per unit area of net and the maximum impact energy is the maximum impact energy without failure.
TABLE 5______________________________________Mesh Areal Densities and Impact ResistanceImpact energies stated are the maximum impactenergies without net failure Areal Maximum Maximum Energy Areal Density Impact Impact CapacityMaterial Density lb/ft.sup.2 Energy (J) Energy (ft-lb) (Jcm.sup.2 /g)______________________________________1 0.0212 4.34 197 131 8442 0.00967 1.98 undetermined undetermined --3 0.258 52.8 429 315 16634 0.122 24.9 107 79 8775 0.469 96.0 1286 946 27426 0.0659 13.5 71 53 10777 0.544 111 143 105 26298 0.221 45.2 643 473 2910______________________________________ Note: 2 failed at the edges (weave pulled apart).
Maximum Impact Energy is the maximum kinetic energy of the projectile as it strikes the net, without failure of the net during that particular test. It is calculated by multiplying projectile mass×gravitational acceleration×height of drop. Units are kgm 2 /s 2 =Joules (J), or ft-lb. These data apply to this set of tests only: 11.95 kg (26.3) lb), 31/2" diameter cylindrical projectile, striking a 1.25 square test specimen.
Energy Capacity is the maximum impact energy absorbable by a particular netting sample, compensated for the density of the sample. This enables comparisons of netting configurations to be made as if all had equal areal density. Energy capacity is calculated by dividing the Maximum Impact Energy by the Areal Density. Units are Jm 2/kg (or ft-lb/(lb/fit 2)). As with Maximum Impact Energy, these data apply only to the given test conditions.
Table 5 shows that to protect a given area with a given weight of material, the decreasing order of preference of the materials is No.8, No.5, No.7. Although Specimen No.8, 210/20 raschel nylon, performed best, other materials may be superior when modified to make them better suited to the application.
Specimen 5, for example, is much stronger in having more fibres in one direction than the other. It would likely have improved performance if strength was more equal in the warp and weft directions. The directional difference in strengths led to a "tear" type of failure, rather than the usual "punch-through" failure. Also, No.7 would probably perform better with a smaller mesh size, allowing the impacter to strike more twines in the mesh.
It will be readily understood in the art that very many varieties of knits are possible and which may be considered if the material selected has the desired high degree of stretch, high strength and high initial stiffness. Alternative monofilament construction rather than multifilament offers acceptable efficacy in being cheaper to manufacture while being only 20% weaker. It will be realised that for a given areal density of fabric netting, a smaller mesh size allows of greater impact resistance.
3. Air Cannon Tests
Impact tests were performed using a standardised air-propelled wood projectile at American Test Laboratory in Pompano Beach, Fla., U.S.A., to simulate hurricane force winds-windborne debris.
Apparatus
Similar netting--Nylon 6,6 raschel knit, was used for this test as in the previous drop-tests. The edge attachment system used was a 5 cm webbing sewn around the edge of the samples, with D-rings attached with 2.54 cm webbing, spaced roughly 30 cm apart.
A bolted wooden frame of approximately 4 m square was used as part of the restraining means. 1.3 cm eye bolts were mounted through the wood at each corner of the frame and in the centres of the sides. A 0.6 cm cable was strung through the eye bolts and tightened with a turnbuckle. Rope was used to attach the D-rings to the cable. Tension in the netting was low.
The cannon used to propel the projectile consisted of an air compressor, an air reservoir with a pressure gauge, a 10 cm air line, a manually activated butterfly valve, and a 10 cm PVC tube as a barrel of the cannon. The end of the cannon was approximately 7.5 m from the flat, vertical stationary plane of net.
The projectile was a 4 kg, 5 cm×10 cm×2.4 m Southern Pine member having its front end slightly rounded. A 10 cm diameter disc was attached to the back end to provide a pressure seal for the barrel of the air cannon.
Procedure
Four tests were performed at increasing speeds: 65, 80, 90, and 100 feet per second (fps). Speed had been previously calibrated to reservoir pressure at pressures up to 80 fps, and an extrapolation was made from this data to calculate the pressure required to provide the higher speeds. The tests were recorded on videotape and also provided the displacement of the netting during impact.
Results
The net withstood the impact of the 5 cm×10 cm×2.4 m rectangular wood projective at the aforesaid selected three speeds of up to 90 fps, with net deformation from its flat stationary plane of up to 1.1 m. At 100 fps, the net failed, leaving a 33 cm×30 cm rectangular hole. Surprisingly, the eyebolts in each of the comers of the frame showed significant alteration in that their eyes had been pried open and the bolt shanks bent by as much as 15 degrees. This indicated that the cumulative force of impacts of the four speeds had been significantly large and had been transferred through the net material to each of the bolts. It should also be noted that the 90 fps test success indicates that the net is capable of withstanding more than three times the energy of the standard impact test of 50 fps.
Similar air cannon impact tests with the 5 cm×10 cm×2.4 m wood member conducted on 1.5 cm thick plywood and on 6 mm thick tempered and heat strengthened glass produced penetration of the plywood and breakage of the glass at 50 fps.
The degree of resiliency of the material element of the net was measured for two netting configurations: 210/20 nylon, and 18/80 polypropylene raschel. Maximum elongation for the nylon was roughly 34%, whereas the polypropylene stretched as much as 50%. Tests showed that in one test an impact energy of approximately 800 joules on the above nylon 210/20 netting was readily absorbed by the net system while providing a displacement of approximately 0.7 m. A 18/18 polypropylene net of 65% of the areal weight of nylon 210/20 also withstood the same impact of the wooden member at 20 m/s and provided a deformation of approximately 1 m.
Although the disclosure describes and illustrates preferred embodiments of the invention, it is to be understood that the invention is not limited to these particular embodiments. Many variations and modifications will now occur to those skilled in the art. | Method for shielding, anchoring and containing an object such as a trailer or motor home in gale-force winds. A wind-permeable perforate sheet extends downwardly and outwardly from the top of the object or the roof of a home at an acute angle so as to surround a substantial portion of each of the sides with an inclined wind-permeable planar surface. The sheet is anchored to helical ground anchors via mechanical attachments which may also be used to tighten the sheet over the object or home. Apparatus for shielding, anchoring and containing an object such as a trailer or motor home in gale-force winds is also disclosed. | 4 |
BACKGROUND AND SUMMARY OF THE INVENTION
In the construction industry, particularly with respect to house construction, there has long been a need for reduced costs of construction, shortened time period for construction, and improved insulation with minimum heat transfer between the exterior and interior of a constructed house.
The present invention provides construction assemblies or modules, improved components and improved methods for rapid construction, excellent insulation, and durability. A construction module comprises foam blocks, preferably formed of polystyrene in end-to-end array, with adjacent blocks separated by back-to-back studs secured together, as by welding, and with flanges thereof extending oppositely into the adjacent blocks. Elongate studs, preferably of steel, extend above and below the array of blocks with flanges thereof extending into the blocks.
The term “studs” with respect to steel components, is used herein because the term has long been used in the construction art to denote studs, typically of wood, which have been widely used for vertical members, etc., in building and home construction.
A construction assembly or module, typically for use as a beam, comprises a plurality of foam blocks disposed end-to-end, with elongate studs along the upper and lower surfaces of the plurality of blocks with flanges extending into the foam blocks. Between each adjacent pair of blocks are two studs secured back-to-back and extending oppositely into the adjacent blocks.
In a construction module typically for use as a wall section, the end-to-end array of blocks, longitudinally extending studs above and below the blocks with flanges extending into the blocks, are utilized. Between each pair of adjacent blocks are back-to-back studs secured together by welding with flanges extending oppositely into the adjacent blocks.
A construction module for use as a header above a door or window opening, has a first row of end-to-end blocks, and elongated studs extending along the upper and lower surfaces of the end-to-end blocks. Both studs have edge flanges extending into the blocks. A second row of end-to-end blocks is disposed normally below the first array of blocks. Elongated studs extend along the upper surfaces and the bottom surfaces of the blocks. The second or lower row of blocks may be narrower than the blocks of the upper row and a relatively narrower row of end-to-end blocks may be disposed on either side of the lower array of blocks.
The construction assemblies or modules according to the invention provides great structural strength, and excellent insulation with respect to heat transfer between the interior and exterior of a house built utilizing the modules of the invention.
The steel studs, etc., utilized according to the invention, provide substantially greater strength than structures comprised of wooden members, and have the highest strength-to-weight ratio among building materials. Outer surfaces of the construction modules, typically wall and header modules, preferably have applied thereto an adhesive coating, a matting layer applied atop the adhesive coating, and a second adhesive coating applied atop the matting. A hard, cementous coating and tough fire barriers are thus provided. The present invention enables the erection of a house in a single day, with an additional day or longer required for finish work and details. A house structure is preferably secured to a slab by appropriate metal foundation straps together with other securement arrangements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a house wall frame structure including vertical studs and defining a door opening and a window opening;
FIG. 2 is a perspective view of a construction section or module according to the invention which is adapted as a header for mounting above a door or window;
FIG. 3 is an enlarged sectional view taken at line 3 — 3 in FIG. 1;
FIG. 4 is an enlarged sectional view taken at line 4 — 4 in FIG. 1;
FIG. 5 is an elevational view of a construction module for use typically as a beam; and
FIG. 6 is an enlarged perspective view of the construction module of FIG. 5, showing structural features thereof.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, FIGS. 1 and 3 show an embodiment of the present invention which may typically be used, as in house construction, as a header associated with doors and windows. FIGS. 4 and 1 show an embodiment of the invention which serves as a wall portion or section in such construction. FIGS. 5 and 6 illustrate an embodiment in the form of a beam.
The beam 10 of FIGS. 5 and 6 comprises a plurality of foam blocks 12 disposed in end-to-end relation, and an elongate steel stud 14 extending along the first or upper side of the foam blocks, and a second elongate stud 16 extending along a second or bottom side of the plurality of blocks, as shown.
Between each respective adjacent pair of the end-to-end foam blocks is a pair of transverse steel studs 18 , 20 , each having a pair of flanges therebetween, with flange portions 22 thereof extending oppositely into respective foam blocks, the flange portions being spaced inwardly from the outer side surfaces of the foam blocks, as shown. Slots are preferably cut or machined into the foam blocks to receive the flanges of the studs.
The construction module of FIGS. 5 and 6 typically serves as a beam in construction, such as in a house. Such a beam may be secured to other construction members or components as by threaded fasteners and end components 24 and 26 (FIG. 5 ).
Referring to FIGS. 1 and 4, wherein FIG. 4 is a sectional view taken at line 4 — 4 in FIG. 1, there is shown an embodiment 30 of the invention which may typically serve as a wall section. As in the embodiment of FIGS. 5 and 6, the construction module includes the plurality of foam blocks 31 disposed end-to-end with a pair of steel studs 32 , 34 disposed between each adjacent pair of foam blocks, and having oppositely extending edge flanges 36 , 38 extending oppositely into respective adjacent blocks. As shown, the flanges extend normally at right angles to, the flat body surfaces of the respective studs.
A layer of adhesive 40 may preferably be applied to the outer side walls of the module, and a layer of matting 42 may preferably be applied atop the adhesive. A second layer of adhesive 44 is applied. The coatings provide structural strength and strong solid surfaces.
Referring to FIGS. 1 and 3, wherein FIG. 3 is a sectional view taken at line 3 — 3 in FIG. 1, there is shown a construction module 50 , typically utilized as a header above a door or window, as indicated in the drawings.
The construction module 50 , like the earlier-described construction modules, has a plurality of foam blocks 52 with an elongate stud 54 extending along a first or upper side and a second elongate stud 56 extending along a second or lower side of the plurality of blocks.
The elongate stud 54 extends atop the end-to-end array of foam blocks 52 , and a second elongate stud 56 extends along the bottom sides of the plurality of foam blocks 52 , as shown. Both the upper stud 54 and the lower stud 56 have edge flanges 58 extending into the end-to-end foam blocks and spaced inwardly from the outer side surfaces of the blocks, as shown.
A second plurality of foam blocks 59 is disposed below the array of foam blocks 52 . An elongate steel stud 60 extends above the lower stud array and has edge flanges 62 extending into the foam blocks 59 . A lower stud 64 extends along the lower surfaces of the foam blocks, and has flanges 66 extending into the foam blocks and spaced inwardly of side surfaces of the blocks, as shown.
Both end portions 68 of the lower stud 64 are bent downwardly, as by cutting the flanges 66 , thus to provide panels for securement of the header to other structural members, as by means of threaded fasteners or other means.
Relatively narrower pluralities of foam blocks 70 are mounted on respective sides of the lower array of the end-to-end foam blocks 59 , as best shown in FIG. 3, and are secured to the foam blocks, preferably by threaded fasteners 72 (FIG. 3 ).
As with the embodiment of FIGS. 4 and 1, the construction module may preferably have on its outer surfaces a layer of adhesive 80 , a layer of matting 82 disposed atop said adhesive layer, and a second layer of adhesive 84 applied atop the layer of matting, thus to provide a strong, rugged, durable structure.
It will be understood that various changes and modifications may be made from the preferred embodiments discussed above without departing from the scope of the present invention, which is established by the following claims and equivalents thereof. | Construction assemblies or modules comprising headers, wall sections and beams, are formed of end-to-end arrays of plastic foam blocks and steel studs extending above and below the foam blocks, with flanges thereof extending into the blocks. Steel studs are disposed between each pair of adjacent blocks with flanges thereof extending may be utilized for strength and durable surfaces. | 4 |
RELATED APPLICATION(S)
[0001] This application claims priority from European Patent Application No. 13165005.3, filed Apr. 23, 2013, which is incorporated herein by reference in its entirety. This application is also a continuation of and claims priority to U.S. patent application Ser. No. 14/258,435, entitled “DRYER OR WASHER DRYER AND METHOD FOR THIS OPERATION” filed Apr. 22, 2014, currently allowed, which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] In conventional dryers and washer-dryers, the use of thermoelectric devices implies exchanging heat on both sides of a planar object thus meaning that process air has to flow in two opposite directions, thereby leading to a complex air path design and to a trade-off between space and performance that may be in practice not acceptable.
SUMMARY
[0003] Disclosed example drying appliances (e.g., a dryer, a washer-dryer, a refresher, etc.) having a closed process air circuit including a drum, a condenser downstream from the drum for dehumidifying warm moist air, and a thermoelectric device having a cold side arranged in the process air circuit downstream from the drum are disclosed. Example disclosed thermoelectric devices have a warm side cooled by a fluid which is circulated in a liquid/air heat exchanger arranged in the process air circuit downstream from the condenser.
[0004] It is an object of this disclosure to provide drying appliances that do not present the above drawbacks and in which the Peltier thermoelectric module can be used without modifying the traditional process air path of a condenser dryer.
[0005] Another object of this disclosure is to provide drying appliances with increased energy efficiency compared to prior art.
[0006] The above objects are reached thanks to the features disclosed herein and listed in the appended claims.
[0007] The novel dryer architectures disclosed herein solve at least the above problems by simplifying appliance design without decreasing the overall system performance that indeed may take benefit of a reduced pressure drop in the process air circuit.
[0008] Another advantage of the appliances disclosed herein is that the energy saving performances are similar to the performance of more expensive condensing dryers with a heat pump device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Further advantages and features will become clear from the following detailed description, with reference to the attached drawings in which:
[0010] FIG. 1 is a schematic view of an example household tumble dryer according to this disclosure;
[0011] FIG. 2 illustrates a portion of the tumble dryer of FIG. 1 in more detail;
[0012] FIG. 3 is a graph showing energy balances in a prior-art condensing dryer;
[0013] FIG. 4 is a graph showing energy balances in an example dryer according this disclosure; and
[0014] FIG. 5 is a another graph showing energy balances in another dryer according this disclosure not having an electrical heating element in addition to the thermoelectric device.
DETAILED DESCRIPTION
[0015] With reference to the drawings, an example tumble dryer comprises a rotating drum 1 containing a certain amount of clothes, actuated by an electric motor, a heating element 2 that heats the air going inside, an air channel 3 that conveys the air to a condenser 6 (condensing dryer) which is an air/air heat exchanger, a temperature sensor 4 a that measures the temperature of the air after the heater 2 before entering the drum 1 , a temperature sensor 4 b measuring the temperature of the exhaust air, and a screen 5 that collects the lint detaching from the tumbling clothes. While the examples disclosed herein refer to a dryer, it should be understood that the disclosed architectures can be used for other drying appliances such as, but not limited to, a washer-dryer, a refresher, etc.
[0016] Condenser dryer functionality is based on condensing the evaporated water from the clothes without throwing the humidity directly into the environment as a conventional air vented dryer does. For this reason, condensing dryers normally have a closed loop process air and the humid air, after passing into the drum 1 through the moist clothes, goes into the condenser 6 where the vapor condenses, then the air is heated and returned to the drum 1 .
[0017] Traditional condensing dryers use an electrical heater to heat the process air in order to evaporate moisture from the clothes, and then release such energy through the process air condenser in the cooling air into the environment. This means almost all energy released for condensing is wasted into the environment and has to be reintroduced into the system to keep the desired temperature operating point by means of the electric heater. An example of such energy balance is shown in FIG. 3 , wherein the heat exchanged on the heating element is depicted in the solid line whereas the heat exchanged on the air cooled condenser is shown in the dashed line.
[0018] In the examples disclosed herein, the process air circuit includes a thermoelectric device 15 and a liquid/air circuit 10 capable of transferring heat from a warm side 16 of the thermoelectric device 15 to the process air downstream from the condenser 6 , by means of a liquid and/or air heat exchanger 12 . The cold side 14 of the thermoelectric device 15 is in direct heat exchange relationship with the process air by means of a heat sink 18 in order to cool it downstream or, as in some embodiments, upstream from the condenser 6 . The overall architecture of a dryer according to this disclosure is therefore similar to that of a traditional air cooled condensing dryer, however, the thermoelectric device 15 that exchanges heat across the condenser 6 , more specifically by cooling the process air upstream (so starting condensation) or downstream (so ending condensation) the air cooled condenser 6 and heating the air downstream from the condenser 6 and upstream from the electric heater 2 . By using the example structures, a portion of the condensation energy is transferred by the thermoelectric device 15 from one side to the other side of the condenser 6 , so it is not wasted in the ambient.
[0019] With reference to FIG. 2 , the cold side 14 of the thermoelectric device 15 directly exchanges heat through a finned heat sink 18 into the process air channel just downstream from the drum output. In such position the air is close to saturation, so condensation occurs onto the heat sink 18 .
[0020] The heat removed by the heat sink 18 , plus the electrical energy supplied to the thermoelectric device 15 is released to the circulating water passing into a water tank 16 that in a small volume ensures a very high performance and limits the thermoelectric device thermal gradient allowing such device to work at a higher efficiency operating point. The process air leaving the heat sink 18 passes into the condenser 6 , where it loses additional water and thermal energy that is released to the cooling air. The heat released to the liquid/water circuit 10 can now be transferred to the process air by means of the heat exchanger 12 before passing through the electric heater 2 , that in such system will need to provide less energy to keep the required temperature operating point, thus increasing the overall system efficiency with respect to conventional air cooled only condenser dryers. Moreover the particular architectures proposed herein (cold side of thermoelectric device 15 —“TEC”—upstream from the air cooled condenser) allows for lower temperature differences between the two sides of the TEC 15 leading to additional increase in the efficiency of the device.
[0021] As a comparison to FIG. 3 , in FIG. 4 is shown an example of the energy balance that can be obtained by using the example architectures disclosed herein; the heat exchanged on the heating element is depicted in the solid line 405 , the heat exchanged on the air cooled condenser is shown in the dashed line 410 , the heat exchanged on cold side of TEC is in the bold dashed line 415 , and the heat exchanged on warm side of TEC is in the bold solid line 420 . As discussed above, the heat exchanged on warm side of TEC 15 is the sum of electrical power provided to such device and the heat exchanged on cold side 14 to condense water that is therefore not wasted as happens in traditional condensing dryers.
[0022] Another possible embodiment takes into consideration the removal of the electrical heating element. By designing the system in order to keep constant the energy efficiency, the cycle length increases but overall cost of the dryer decreases giving a possible solution for implementing low cost machines. An example of the energy balances that can be obtained in such embodiment is shown in FIG. 5 ; the heat exchanged on the air cooled condenser is shown in dashed line 505 , the heat exchanged on cold side of TEC is in bold dashed line 510 , and the heat exchanged on warm side of TEC is in bold solid line 515 . As mentioned, this solution has the disadvantage of increasing cycle length but can be implemented with reduced cost.
[0023] In the liquid/air circuit 10 water, or a mixture of water and alcohol or glycol ether can be used, and the circulation can be either due to natural convection or forced by a circulation pump 17 .
[0024] To increase furthermore the heat exchange efficiency, a phase changing liquid (so called “phase changing material” or PCM) at design temperatures can be used taking the benefit of an almost constant temperature heat exchange with high performances; even in this case the circulation can be either due to natural convection or forced by the circulation pump 17 .
[0025] The liquid/air heat exchanger 12 is preferably provided with fins or similar devices in order to increase the heat transfer coefficient. | Example dryers and washer-dryers having a closed process air circuit having a drum, a condenser downstream from the drum for dehumidifying warm moist air, and a thermoelectric device having a cold side arranged in the process air circuit downstream from the drum are disclosed. Example thermoelectric devices have a warm side cooled by a fluid which is circulated in a liquid/air heat exchanger arranged in the process air circuit downstream from the condenser. Using the disclosed architectures, appliance design can be simplified without decreasing overall system performance. | 3 |
FIELD OF INVENTION
[0001] The present invention relates to a synthetic immunogen useful for generating long lasting immunity and protection against pathogens and a process for the preparation thereof. The developed immunogen is able to circumvent HLA restriction in humans. The invention further relates to a vaccine comprising the said immunogen for generating long lasting immunity and protection against various diseases. The said vaccine is targeted against intracellular pathogens, more particularly the pathogen Mycobacterium tuberculosis ( M. tuberculosis ), in this case. The pathogen M. tuberculosis the subject matter of this invention is the causative agent of tuberculosis. The vaccine is also useful against the intracellular pathogens, which are causative agents of brucellosis, leishmaniasis, listeriosis, leprosy, malaria, typhoid, trypanosomiasis, streptococcus, acquired immunodeficiency syndrome (AIDS), and also for diseases like cancer, allergy, autoimmunity, etc. In the present invention, promiscuous epitopes of M. tuberculosis are conjugated to Toll-like receptor (TLR) ligands to target them to antigen presenting cells (APCs), in particular to dendritic cells (DCs) and therefore elicit enduring protective immunity.
BACKGROUND OF INVENTION & DESCRIPTION OF PRIOR ART
[0002] According to the World Health Organization (WHO) report (2000), 100 million newborns and children received BCG in 1992 through WHO/UNICEF program. Even though majority of the global population is vaccinated with BCG, tuberculosis continues to kill some 3 million people a year. Further, about one-third of the world population remains latently infected with M. tuberculosis . Hence, the only available vaccine BCG is both unpredictable and highly variable. Doubtful efficacy of BCG vaccination has put the scientific community to challenge to urgently develop effective means of vaccination against M. tuberculosis.
[0003] Unfortunately, the global problem of tuberculosis is compounded by the additional problems of AIDS and emergence of Multi Drug Resistant (MDR) strains of M. tuberculosis . Moreover, a new question has arisen regarding the safety of BCG in HIV-infected individuals. A small number of cases of disseminated BCG-osis have been reported among children who received BCG vaccine and were subsequently found to be HIV seropositive (Von Reyn, et. al. Lancet 1987:ii:669-672; Braun, et. al., Pedietr. Infect. Dis. J. 1992:11:220-227; Weltman, et. al., AIDS 7:1993:149). WHO currently recommends discontinuing the use of BCG vaccine in children showing overt signs of immunodeficiency (World Health Organization. Tuberculosis fact sheet number 104, August 2002).
[0004] BCG has been extensively utilized globally and in spite of its intrepid use, tuberculosis has still become the fastest spreading disease not only in developing countries but also in the industrialized world. Its doubtful efficacy in controlled trials has increased the concern about its use as a vaccine (Bloom, B. R. et. al., Annu. Rev. Immunol. 10:1992:453). Furthermore, the extensive clinical trials done in Chenglepet, India showed similar extent of protection in BCG-vaccinated and unvaccinated individuals, indicating that it induced zero protection (Narayanan Indian J Med Res. 2006, 123 (2): 119-124). Thus it is obvious that BCG vaccination does not prevent transmission.
[0005] Another insight for BCG failure is provided by the intracellular location of the mycobacterium. Electron microscopic findings indicate that BCG remains essentially within the phagolysosomes after in vitro infection of macrophages, whereas virulent M. tuberculosis (strain H37Rv) can escape from the phagolysosome and enter the cytoplasm (McDonough, et. al., Infect. Immun. 61:1993:2763). This may be relevant insofar as it is the antigens in the endosomal compartment of antigen-presenting cells that are presented in conjunction with MHC class II determinants to CD4 + T helper cells, whereas cytoplasmic antigens are presented in association with the Major Histocompatibility Complex (MHC) class I determinants to CD8 + Cytotoxic T cells (CTL). This explains why M. tuberculosis is more dependent for its elimination on MHC class I-restricted CTL than BCG and suggests that BCG may not be very effective in eliciting MHC class I-restricted CTL (Stover, et. al., Nature 351:1991:456). In this context, Rich, 1951, Kaufman et al 2008, commented that recovery from infection with M. tuberculosis provided stronger protection against future tuberculosis than could BCG. Hence, the effective resistance to M. tuberculosis infection will require participation both of specific CD8 + CTL to lyse macrophages or parenchymal cells unable to restrict their infection and of specific CD4 + T cells able to produce IL-2, IFN-γ, TNF-α, and other lymphokines involved in macrophage activation.
[0006] Recent series of studies have suggested that M. tuberculosis /environmental mycobacteria actively inhibit bacterial antigen processing and presentation by MHC-I and MHC-II pathways, thus slowing the emergence of protective adaptive immunity (Wolf et al. 2007). Furthermore, M. tuberculosis also impairs in vivo antigen processing of dendritic cells (Wolf et al. 2007). Hence failure of BCG in endemic areas like India can be suggested to be due to the extensive mycobacterial load in the environment. Consequently, antigen processing pathways might be seriously compromised. To overcome these problems, a suitable approach in TB-endemic areas may be to devise a vaccine that bye pass antigen processing. Hence peptides can be suitable alternative since they do not require extensive antigen processing.
[0007] Peptides can be potentially used as vaccines. They bypass antigen processing because they can directly bind to MHC class I and II molecules; hence can be presented to both CD4 and CD8 T cells. Therefore the environmental mycobacterial load will not affect their efficacy. Unfortunately, conventional peptide vaccines have been plagued by two problems. Firstly, peptides are poorly immunogenic. They have to be administered with powerful adjuvants to elicit an immune response. The number of adjuvants available for humans are not only extremely limited but are also very expensive. Therefore such a strategy is economically not viable for mass vaccination, especially in developing countries, where tuberculosis incidence is maximal. Secondly, most of the antigenic peptides derived from mycobacterial antigen's binding is restricted to just one or two Human Leukocyte Antigen (HLA) alleles. HLA is the most polymorphic gene system in the entire human genome. Therefore it is difficult for the peptides to elicit an immune response in a genetically diverse human population, which is thoroughly polymorphic. These reasons have mired progress in peptide vaccinology. But if these problems are circumvented, peptide vaccine can be extremely effective than any other potential candidates; particularly in a situation where antigen processing is stalled by environmental agents. Further, promiscuous peptides, which can bind to many HLA alleles, can solve the problem of HLA restriction. Therefore identification of promiscuous peptides from antigens of M. tuberculosis , especially secretory antigens, would be of great importance in developing a vaccine. Promiscuous T cell epitopes are peptides that bind to more than one HLA allele and hence may elicit a T cell response overcoming MHC restrictions. They can be identified by conventional biochemical in vitro HLA binding assays, immunologic assays such as T cell proliferation, and activation or effector response such as secretion of cytokines (Agrewala and Wilkinson, 1997, 1998, 1999). They may also be selected based on bioinformatic analysis using T cell epitope prediction programs.
[0008] The pre-requisite for the effective priming of the adaptive immune system is the maturation of APCs, whose function is to engulf the pathogens, process and present it to T cells. Antigen presenting cells possess Pattern Recognition Receptors (PRRs) which recognize the conserved motifs known as Pathogen Associated Molecular Patterns (PAMPs) of the pathogens. Triggering of PRRs by PAMPs acts as a “danger signal” (Medzhitov & Janeway, 1997), which results in maturation of APCs and culminates in mounting an adaptive immune response against that pathogen. Toll-Like Receptors are one such critical PRRs which link the innate and adaptive arms of immunity. Adjuvants functions by binding to TLRs and thereby delivering signals necessary for the activation of APCs. Recently, it has been demonstrated very elegantly that there is robust increase in the immune response if TLR triggering moiety and the antigen are physically associated (Blander & Medzhitov 2006).
[0009] Expression of costimulatory molecules, enhanced antigen presentation and production of cytokines and chemokines is also upregulated when APCs are engaged with TLRs. In essence, TLRs are a family of transmembrane receptors by which APCs recognize the conserved PAMPs that distinguish the infectious agents from self. Over the past few years, the macromolecules recognized by TLRs have been identified. Agonists for TLRs include the inflammatory mediators tri-acyl lipopeptides (TLR1), lipoteichoic acid (TLR2), dsRNA (TLR3), lipopolysaccharide (TLR4), flagellin (TLR5), diacyl lipopeptides (TLR6), imidazoquinolines (TLR7, TLR8) and CpG oligonucleotides (TLR9) (Akira, 2003). Toll like receptors constitute an essential part of the innate immune system but they have also been equally important in adaptive immune system. Antigen presentation without this danger signal leads to anergy or tolerance.
[0010] Hence, an analysis of the hitherto reported literature reveals that free peptides may not elicit an optimum immune response. Since TLR triggering is essential for activation of the APCs, physically coupling (covalent or encapsulated form) promiscuous peptides/epitopes to TLR ligands to trigger effective immune response may be an exceptional proposition. Most of the TLR ligands are lipid moieties but TLR 3, 7 and 9 are triggered by nucleic acids. Triggering of TLRs especially, TLRs 2, 4 and 9 results in Th1 responses. Hence, it is specially proposed that these peptide-TLR ligands for 2 or 4 or 9 would be very effective in protecting against M. tuberculosis.
[0011] Despite several potential advantages none of the totally synthetic peptide epitope-based vaccines are yet licensed/available for human or animal use. The poor immunogenicity of peptides in the absence of co-administered adjuvants and the paucity of adjuvant systems suitable for human use has limited the development of viable epitope-based vaccines.
[0012] Accordingly, it may be summarized that non-living vaccines fails to impart protection against tuberculosis due to the use of inadequate adjuvants. The currently-used adjuvants for human vaccines (based on aluminum salts) are only effective in vaccines that require a humoral response since they bias the immune response towards the Th2 pole, which can only help in protecting against extra-cellular infections. The available adjuvants have limited use due to their very high cost. Thus, an effective way to overcome this predicament is to incorporate lipid groups into the promiscuous-peptides/subunit vaccines which will then have self-adjuvanting properties.
OBJECTS OF THE INVENTION
[0013] The main object of the present invention is thus to develop an immunogen that obviates the drawbacks as detailed above.
[0014] Another object of the present invention is to provide an immunogen that is useful for generating long lasting protective immunity against intracellular pathogens, which are the causative agents of tuberculosis, brucellosis, leishmaniasis, listeriosis, leprosy, malaria, typhoid, trypanosomiasis, streptococcus, AIDS, and also diseases like cancer, allergy and autoimmunity.
[0015] Yet another object of the present invention is to provide an immunogen which is able to circumvent HLA restriction in humans.
[0016] Yet another object of the present invention is to provide an immunogen comprising of promiscuous peptides/epitopes from M. tuberculosis proteome coupled to TLR ligands.
[0017] Still another object of the present invention is to provide lipidated promiscuous peptides/epitopes from M. tuberculosis that enhances enduring CD4 + and CD8 + T cell memory and impart protective immunity against tuberculosis.
[0018] Another object of the present invention is to provide lipidated promiscuous peptides/epitopes from M. tuberculosis that can mainly induce the secretion of cytokines interferon-gamma (IFN-γ) and interleukin-12 (IL-12).
[0019] Another object of the present invention is to provide lipidated promiscuous peptides/epitopes from M. tuberculosis that can reduce the bacterial burden from pulmonary and extra-pulmonary regions of the body.
[0020] Another object of the present invention is to provide a pharmaceutical composition comprising the said immunogen.
[0021] A further object of the present invention is to provide a vaccine based on surface coating or encapsulation of the promiscuous peptides/epitopes of M. tuberculosis to nanoparticles.
SUMMARY OF THE INVENTION
[0022] The present invention relates to a process for eliciting an effective immune response against intracellular pathogens, especially M. tuberculosis . This is achieved by developing a synthetic immunogen comprising of promiscuous peptides/epitopes from M. tuberculosis linked to a TLR ligand. The said immunogen can either be in a free form or encapsulated in nanoparticles and/or liposomes so that it can effectively elicit a robust and long-lasting protective immune response. The invention further relates to a pharmaceutical composition in the form of a vaccine based on surface coating or encapsulation of the promiscuous peptides/epitopes of M. tuberculosis to nanoparticles for imparting long-lasting immunity against M. tuberculosis . The developed immunogen may also be covalently coupled to/entrapped in mannosylated liposomes or liposomes tagged with anti-DEC-205 antibody for evoking the desired immune response.
[0023] The developed synthetic immunogen comprises of promiscuous peptides/epitopes from M. tuberculosis proteome represented by SEQ ID Nos. 1 to 103 (Table 1). The promiscuous peptides are identified based on binding to FILA class I (HLA-A, B, C) and HLA class II (HLA-DR, DP, DQ) molecules, T cell proliferation, cytokines (IL-2, IL-4, IL-12, IFN-γ) secretion and in silico methods.
[0024] The identified MHC I and MHC II binding promiscuous peptides are either covalently coupled to TLR ligands selected from TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, TLR11, TLR12, TLR13 (such as diacyl lipopeptides, triacyl lipopeptides, lipoarabinomanan, lipoteichoic acid, dsRNA, lipopolysaccharide, flagellin, diacyl lipopeptides, imidazoquinolines and CpG oligonucleotides, etc) that are amenable to such coupling through a serine and/or lysine linker. Further, the peptides may be encapsulated in synthetic nanoparticles or liposomes, so that they are effectively presented to CD4 and CD8 T cells by APCs, especially the dendritic cells ( FIG. 1 ).
[0025] Accordingly, the present invention provides a synthetic immunogen useful for generating long-lasting immunity against M. tuberculosis , wherein the said immunogen is represented by the general formula I:
[0000]
[0000] wherein, X 1 =a promiscuous CD4 T helper epitope selected from SEQ ID No. 1 to 980R nil; X 2 =a promiscuous CD8 T cytotoxic epitope selected from SEQ ID No. 99 to 103 OR nil; when X1=nil; X2=SEQ ID No. 99 to 103 and when X2=nil; X1=SEQ ID No. 1 to 98; Y=Lysine; and S=Serine.
[0026] In an embodiment, the present invention provides a synthetic vaccine comprising of promiscuous peptides (capable of binding to several MHC I and MHC II molecules) selected from M. tuberculosis linked to TLR2 ligand Pam2Cys and targeted to dendritic cells for eliciting both CD4 and CD8 T cell response.
[0027] In another embodiment, the present invention provides a synthetic vaccine comprising of promiscuous peptides of M. tuberculosis linked to TLR2 ligand Parn3Cys.
[0028] In yet another embodiment, the present invention a synthetic vaccine comprising of promiscuous peptides of M. tuberculosis linked to TLR2, ligand lipopeptide MALP-2.
[0029] In still another embodiment, the present invention a synthetic vaccine comprising of promiscuous peptides of M. tuberculosis linked to TLR4 ligand lipopolysaccharide (LPS).
[0030] In yet another embodiment, the present invention a vaccine comprising of promiscuous peptides of M. tuberculosis linked to TLR9 ligand CpG oligonucleotides (CpG ODN).
[0031] In still another embodiment, the present invention provides a vaccine based on surface coating or encapsulation of promiscuous peptides of M. tuberculosis to nanoparticles.
[0032] In still another embodiment, the present invention provides a vaccine based on surface coating or encapsulation of promiscuous peptides of M. tuberculosis to liposomes.
[0033] In yet another embodiment, the present invention provides a vaccine by mixing promiscuous CD4 and CD8 epitopes of M. tuberculosis with TLR agonists.
[0034] In another embodiment, the present invention provides a process for the preparation of the vaccine by mixing promiscuous CD4 and CD8 epitopes of M. tuberculosis with nanoparticles.
[0035] In another embodiment, the present invention provides a process for the preparation of the vaccine by mixing promiscuous CD4 and CD8 epitopes of M. tuberculosis with liposomes.
[0036] In another embodiment, the present invention provides a process for preparation of a vaccine, wherein the main rationale for encapsulation is for those situations where covalent coupling is not very amenable as in case of nucleic acids (ligands for TLRs 3, 7, 9) and when the TLR ligands are predominantly intracellular. However, the same strategy can be applied to TLRs 2, 4 and 5 as well because though they are predominantly expressed on the surface, they are also expressed in the endosomal compartments.
[0037] In another embodiment, the present invention provides an immunogen represented by the formula:
[0000]
wherein, X 1 =a promiscuous CD4 T helper epitope selected from SEQ ID No. 1 to 98; and Y=Lysine; and S=Serine.
[0039] In yet another embodiment, the present invention provides an immunogen represented by the formula:
[0000]
wherein, X 2 =a promiscuous CD8 T cytotoxic epitope selected from SEQ ID No. 99 to 103; and Y=Lysine; and S=Serine.
[0041] In still another embodiment, the present invention provides an immunogen represented by the formula:
[0000]
[0000] wherein, Y=Lysine and S=Serine.
[0042] In yet another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes represented by SEQ ID No. 1 to 103 are from Mycobacterium tuberculosis.
[0043] In still another embodiment, the present invention provides an immunogen wherein the TLR ligand is selected from the group consisting of TLR1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, TLR11, TLR12 and TLR13 ligands.
[0044] In yet another embodiment, the present invention provides an immunogen wherein the TLR ligand is selected from the group consisting of diacyl lipopeptides, triacyl lipopeptides, lipoarabinomanan and lipopolysacharides.
[0045] In still another embodiment, the present invention provides an immunogen wherein the TLR ligand is S-[2,3-bis(palmitoyloxy)propyl]cysteine (Pam2Cys).
[0046] In yet another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes from M. tuberculosis are identified based on binding to HLA class I (HLA-A, B, C) and HLA class II (HLA-DR, DP, DQ) molecules.
[0047] In still another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes from M. tuberculosis are identified based on T cell proliferation and secretion of IFN-γ, IL-2, IL-4 and IL-12.
[0048] In yet another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes from M. tuberculosis enhances MHC/HLA expression.
[0049] In still another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes from M. tuberculosis enhances the expression of co-stimulatory molecules selected from CD80, CD86 and CD40.
[0050] In yet another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes enhance the proliferation of CD4 + and CD8 + T cells and up regulates the expression of CD69 and CD44.
[0051] In still another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes from M. tuberculosis modulates the secretion of cytokines IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, IFN-γ and TNF-α.
[0052] In yet another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes enhance CD4 + and CD8 + T cell memory, including both central and effector T cell memory.
[0053] In still another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes modulates the expression of CD44, CD62L and CD127 on memory CD4 + and CD8 + T cells.
[0054] In still another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes boosts pulmonary and extra-pulmonary immunity against M. tuberculosis.
[0055] In yet another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes down regulate the expression of immune suppressive molecule like PD-1.
[0056] In still another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes inhibit the generation of regulatory T cells.
[0057] In yet another embodiment, the present invention provides an immunogen wherein the promiscuous epitopes can induce proliferation of human lymphocytes from healthy and tuberculosis patients by inducing the secretion of IFN-γ.
[0058] In still another embodiment, the present invention provides an immunogen wherein it exploits TLR ligands as adjuvants and hence extra adjuvants are not required.
[0059] In yet another embodiment, the present invention provides an immunogen wherein it is targeted to antigen presenting cells like dendritic cells, macrophage and B cells.
[0060] In still another embodiment, the present invention provides an immunogen wherein it is coated to/encapsulated in nanoparticles.
[0061] In yet another embodiment, the present invention provides an immunogen wherein it is covalently coupled to/entrapped in mannosylated liposomes or liposomes tagged with anti-DEC-205 antibody.
[0062] In a further embodiment, the present invention provides a pharmaceutical injectable composition comprising the said immunogen optionally along with a pharmaceutically acceptable carrier, diluent or excipient.
[0063] In still further embodiment, the present invention provides a method of inducing an immune response against M. tuberculosis in a subject, comprising administering to the subject a therapeutically effective amount of the said immunogen optionally along with a pharmaceutically acceptable carrier, diluent or excipient.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0064] FIG. 1 . Mechanism of action of the immunogen. (A) As soon as the immunogen is administered, it seeks DCs due to their high expression of TLR2 ligands and MHC molecules. (B) due to high affinity for MHC and TLR2, the construct containing TLR2 ligand (Pam2cys), CD8 and CD4 epitopes binds to TLR2 and MHC molecules on DCs. (C) This activates DCs and makes them upregulate co-stimulatory and MHC molecules. (D) When peptides bind MHC-I and MHC-II, CD8 and CD4 T cells recognize their respective peptides presented in context with MHC-I and MHC-II molecules on activated DCs. (E) This activates antigen specific T cells. (F) This results in clonal expansion of CD4 T-helper cells and CD8 cytotoxic T cells and secretion of cytokines and results in promoting amplification of the immune response.
[0065] FIG. 2 . Lipidated Promiscuous Peptides [developed immunogen] works permissively in different laboratory strains of mice. Genetically distinct strains of mice (BALB/c, C57BL/6, C3He) were used to test the ability of the developed immunogens to trigger T cell proliferation. Splenocytes from antigen exposed mice were stimulated with lipidated peptides [immunogen] and free peptides. T cell proliferation was measured using incorporation of 3 H-thymidine after 48 hrs of in vitro challenge. Abbreviations used in the drawings: p21: free peptide SEQ ID No. 2, p91: free peptide SEQ ID No. 1, L21: lipidated peptide SEQ ID No. 2, L91: lipidated peptide SEQ ID No. 1.
[0066] FIG. 3 . Effect of promiscuous peptides/epitopes on the peripheral blood mononuclear cells obtained from different PPD + human subjects. Human peripheral blood mononuclear cells (PBMCs) were isolated from healthy donors and they were stimulated in vitro using different immunogenic constructs. T cell proliferation was measured by incorporating 3 H-thymidine after 48 hrs.
[0067] FIG. 4 . Lipidated peptides [immunogens] enhance DC maturation. (A) BALB/c mice were immunized with lipidated peptides [immunogen] and free peptides. Total splenocytes were recovered and in vitro stimulated with the lipidated and free peptides. After 48 hrs of incubation, they were harvested and stained for DC population (CD11c + /CD40 + ). CD11c + /CD40 + population indicates mature DCs. Lipidated immunogen constructs were able to induce DC maturation compared to their unlipidated counterparts. (B) Bone marrow derived DCs from C57BL/6 mice were cultured using standard protocol. On day 7 of culture they were treated with free or lipidated peptides for 12 hrs and then the cells were harvested and stained for activation markers. There was enhanced expression of CD80, CD86, CD40 in L91 treated cells compared to p91 treated cells. (C) On day 7 of culture, bone marrow derived DCs were treated with free or lipidated peptides for 12 hrs. Later on, the cells were harvested and stained for CD74 (immature MHC) and IA b (mature MHC). There was enhanced expression IA b and decrease in expression of CD74 when treated with L91 compared to free peptide.
[0068] FIG. 5 . Lipidated peptides [developed immunogen] induce the production of IFNγ in T cells. (A) Gamma irradiated M. tuberculosis was injected in mice and splenocytes were in vitro challenged with developed immunogens for 48 hrs. Later on, levels of IFN-γ were estimated from the culture supernatants by ELISA. Lipidated peptides induced significantly higher IFN-γ production compared to free peptides. This indicates a Th1 phenotype of these cells. (B) Lipidated peptide L91 was injected in mice and splenocytes were in vitro challenged with constructs for 48 hrs. Later on, levels of IFNγ were estimated from the culture supernatants by ELISA. Lipidated peptides induce significantly higher IFN-γ production compared to free peptides and this indicates a Th1 phenotype of these cells.
[0069] FIG. 6 . CD4 T cells from mice immunized with immunogen containing SEQ ID No. 1 produced IFN-γ on in vitro peptide restimulation. Mice were immunized with lipopeptide containing SEQ ID No. 1. Splenocytes from the immunized mice were cultured with A) medium; B) Pam2Cys; C) non-lipidated peptide (SEQ ID No. 1); D) lipopeptide (containing SEQ ID No. 1) for 48 h. Cells were restimulated for 6 h and stained for surface CD4 and intracellular for IFN-γ. Representative flow cytometry contours depict IFN-γ producing CD4 T cells and numbers indicate their percentage.
[0070] FIG. 7 . The developed immunogen imparts better protection than BCG. The protection studies in mouse model were performed as described. Mycobacterial load in lungs was enumerated by CFU plating. Results are depicted as bar graphs with mean±SD (log 10 value). Mice were immunized with A) PBS; B) BCG; C) immunogen containing SEQ ID No. 1. D) un-related lipopeptide containing peptide from influenza hemagglutinin virus. ‘*’ indicates p<0.05, ‘**’ p<0.01, ‘***’ p<0.001.
[0071] FIG. 8 . Immunization with developed immunogenic lipopeptide results in protection against M. tuberculosis in guinea pigs. The protection studies in guinea pig model were performed as described. Mycobacterial load in lungs was enumerated by colony forming units (CFU) plating. Results are depicted as bar graphs with mean±SD (log 10 value). Animals were immunized with A) PBS; B) BCG; C) immonogen containing SEQ ID NO. 1; D) un-related lipopeptide from influenza hemagglutinin virus. ‘*’ indicates p<0.05, ‘**’ p<0.01, ‘***’ p<0.001.
[0072] FIG. 9 . The developed immunogenic lipopeptide induces proliferation of human peripheral blood mononuclear cells. Human peripheral blood mononuclear cells were obtained from sputum positive tuberculosis patient and incubated with A) medium alone; B) immunogen (containing the SEQ ID NO. 1); C) free peptide (SEQ ID NO. 1); D) immunogen (containing the SEQ ID NO. 103); E) non-lipidated peptide (SEQ ID NO. 103); F) immunogen (containing both the sequences SEQ ID NO. 1 and SEQ ID NO. 103); non-lipidated peptide (containing both the sequences SEQ ID NO. 1 and SEQ ID NO. 103) for 48 h. T cell proliferation was measured with 3 H-thymidine incorporation.
DETAILED DESCRIPTION OF THE INVENTION
Abbreviations Used
[0073] TB: tuberculosis, M. tuberculosis: Mycobacterium tuberculosis
BCG: Bacillus Calmette-Guérin
TLR: Toll like receptor
HLA: Human leukocyte antigen
MHC: Major histocompatibility complex
DC: Dendritic cells
APC: Antigen Presenting Cells
[0074] L21: immunogen wherein X 1 =SEQ ID. No. 2 and X 2 =0
L91: immunogen wherein X 1 =SEQ ID. No. 1 and X 2 =0
p21: promiscuous epitope represented by SEQ ID No. 2
p91: promiscuous epitope represented by SEQ ID No. 1
PBMC: Peripheral Blood Mononuclear Cells
[0075] PBS: phosphate buffered saline
PPD + : Purified protein derivative
Pam2Cys: S-[2, 3-bis (palmitoyloxy) propyl] cysteine
BMDCs: bone marrow derived DCs
Ab: antibodies
p.i.: post-immunization.
[0076] The terms “peptides” and “epitopes” from M. tuberculosis have been used interchangeably in the invention.
[0077] The present invention exploits promiscuous peptides from M. tuberculosis and the biology of TLR ligands [TLRs] to design a synthetic immunogen wherein promiscuous CD4 and/or CD8 peptides/epitopes are physically associated with TLR ligands (TLR1 to TLR13) via a lysine and/or serine linker. These are prepared in a pharmaceutically administrable form either by covalent coupling or by encapsulating them in synthetic nanoparticles or liposomes that would ultimately be effectively presented by antigen presenting cells; especially dendritic cells to helper and cytotoxic T cells. Optionally, the said immunogen is also prepared in a vaccine form by combining it with pharmaceutically acceptable carriers, diluents or additives. Promiscuotis peptides from M. tuberculosis proteome were identified using in silico tools and/or experimental methods and were found to be 103 in number, which are enlisted in table 1 illustrating the SEQ IDs and sequences of all the 103 CD4 and CD8 promiscuous epitopes of M. tuberculosis used in the invention. Then the identified peptides were either covalently coupled to TLR ligands that are amenable to such coupling followed by mixing and/or encapsulation in synthetic nanoparticles and liposomes.
[0078] The promiscuous T cell epitopes that are used as selective examples in the patent application have been identified employing peptide binding assays (using a reference binding peptide) and/or T cell proliferation and IFN-γ, IL-2, IL-4 secretion (Agrewala and Wilkinson 1997, 1998, 1999; Weichold et al 2007). The listed peptide sequences were predicted computationally using the IEDB prediction servers and were selected on the basis of binding cut off of IC50<500 and the ability of peptides to bind to a minimum of three HLA alleles. A few peptides were also selected based on the in vitro binding assays and CD8 T cell lysis assays (Axelsson-Robertson et al, 2009; Masemola et al 2004). The sequences of the promiscuous peptides/epitopes from M. tuberculosis which were tested in the aforesaid manner are represented by SEQ ID Nos. 1 to'103 [Table 1].
[0079] Covalent Coupling of TLR Ligands to Promiscuous Peptides:
[0080] The peptides/epitopes represented by SEQ ID Nos. 1 to 103 were synthesized using standard Fmoc techniques. If the construct has two or more peptides, they were linked with a lysine residue and then two serine residues were added to enhance immunogenecity and also for enabling the peptides to be linked to the TLR ligands. The peptides (along with the serine linker) were coupled to the TLR ligand using an established methodology (Jackson et al 2004). In short, excess of synthetic TLR ligand, O_benzotriazole-N,N,N_,N_-tetramethyluronium-tetrafluoroborate, and 1-hydroxy benzotriazole were dissolved in dichloromethane [DCM], and a 3-fold excess of diisopropylethylamine was added. Then this solution was added to resin bound peptide (pre-synthesized) to generate the lipopeptide, which was cleaved from the resin and purified using reverse phase chromatography. Two serine residues were added following the peptide to increase the immunogenecity of the immunogen.
[0081] The above prepared immunogen was bound to TLRs expressed on the surface of APCs and to MHC class I and II molecules. The triggering of the TLRs resulted in maturation of the APCs and upregulation of costimulatory molecules and cytokines. The matured APCs effectively present the peptides to CD4 + and CD8 + T cells and elicit a robust immune response against M. tuberculosis ( FIG. 1 ). This strategy can be used directly in vivo or alternatively the DCs can be pulsed and triggered with this immunogen in vitro and can be adoptively transferred to the host for inducing protective immunity.
[0082] Encapsulation of the Peptides and TLR Ligands:
[0083] Encapsulation is performed where covalent coupling is not amenable, as in the case of nucleic acids (ligands for TLRs 3, 7, 9) and when the TLR ligands are predominantly intracellular. However, the same strategy can be applied to TLRs 2, 4 and 5 because they are also expressed in the endosomal compartments. Promiscuous CD4 and CD8 epitopes from M. tuberculosis were mixed with TLR ligands like nucleic acids that cannot be covalently coupled to these peptides or the covalently coupled TLR2, 4 ligands—promiscuous epitopes were encapsulated with poly γ-glutamic acid, poly(d,l-lactic-co-glycolic acid), poly(ethylene glycol) dimethacrylate, 2-diethylamino ethyl methacrylate, aminoethyl methacrylate, methyl methacrlate etc. in the form of nanoparticle like complexes for the uptake by dendritic cells.
[0084] Moreover, this strategy can be specially modified to target dendritic cells. All APCs can take up antigen avidly. Among the APCs, dendritic cells can take up large sized particles up to 500-700 nm in diameter. However, for the effective immunization of antigens encapsulated in nanoparticles, the size should not be more than 200 nm. Hence for direct immunization, 200 nm diameter particles and for in vitro addition of encapsulated material and then adoptive transfer in to living systems, 500 nm encapsulated particles would be ideal. Promiscuous CD4 and CD8 T cell epitopes from M. tuberculosis were mixed with TLR ligands like nucleic acids that cannot be covalently coupled to these peptides and the covalently coupled TLR-2, TLR-4 ligands—promiscuous epitopes were encapsulated in the form of nanoparticles like complexes for the uptake by dendritic cells.
[0085] The APCs will take up the encapsulated constructs avidly and once it reaches the endosomal compartments, the TLR ligands will activate the APCs and the CD4 T cell epitopes will be loaded on to the MHC II molecules and presented to CD4 T cells. CD8 T cell epitopes will be loaded on to MHC I molecules and will elicit effective CD8 T cell priming and would eventually lead to a robust CD4 and CD8 T cells response.
[0086] Based on the data, lipidated promiscuous peptides, give robust T cell response in many strains of mice ( FIG. 2 ). Moreover, it is also able to circumvent HLA restriction in humans ( FIG. 3 ). Further, it enhances DC maturation and predominantly results in Th1 response ( FIGS. 4 , 5 ).
[0087] Using this strategy, effective immune response can be generated against many pathogenic organisms and an array of diseases like cancer, allergies.
EXAMPLES
[0088] The following examples are given by way of illustration only and therefore should not be construed to limit the scope of the present invention.
[0089] Experimental Animals.
[0090] 6-8 weeks old female BALB/c, C3He, and C57BL/6 mice were used for the experiments. All experiments were carried out on BALB/c, unless mentioned. Female Duncan-Hartley Guinea pigs (6-8 weeks old) were used for protection studies. Animals were housed in Biosafety Level-3 facility of Institute of Microbial Technology, Chandigarh and National JALMA Institute for Leprosy and Other Mycobacterial Diseases (NJIL & OMD), Agra, India. Animals were offered ad libitum pellet feed and water.
[0091] Patients and Healthy Volunteers.
[0092] PBMCs were separated from the blood of the sputum positive pulmonary tuberculosis patients and PPD + healthy volunteers.
[0093] Immunization.
[0094] Mice were immunized with the developed immunogenic lipopeptides (20 nmol/animal). Twenty-one days later, a booster dose (10 nmol) was administered. Animals were sacrificed 45 days post booster immunization.
[0095] For long-term T cell memory and protection studies, lipopeptides or control non-lipidated peptides were immunized (20 nmol/mouse or 100 nmol/Guinea pig) intraperitonially, and 21 days later, a booster (10 nmol/mouse and 50 nmol/Guinea pig) was inoculated. For comparison, animals were immunized with BCG (1×10 6 CFU/animal). The animals were rested for 75 days before aerosol challenge with live M. tuberculosis . The animals were sacrificed 30 days post-challenge.
Example 1
Synthesis of Lipidated Peptides
[0096] The synthesis, purification, and characterization of peptides and lipopeptides were done as per the procedure detailed below:
[0097] To enable lipid attachment between the CD4 T cell epitopes and CD8 T cell epitopes, F-moc-lysine (Mtt)-OH was inserted at a point between the two epitopes in the approximate center of the resin-bound peptide. Following completion of peptide synthesis, the Mtt group was removed by continual flow washing with 1% TFA in DCM over a period of 30-45 min. Pam2Cys was then coupled to the exposed ε-amino group according to the procedure described previously (Zeng et al., 1996). The presence of serine between the Pam2Cys and peptide moieties improves immunogenicity. Hence, two residues of serine were incorporated between the peptide and lipid moieties of the Pam2Cys-containing peptide immunogen. This was simply done by sequential addition of two serine residues to the peptide before covalent attachment of the lipid moiety.
[0098] Employing this methodology, constructs that contained single promiscuous CD4 or CD8 T cell epitopes or containing both CD4 and CD8 T cell epitopes were synthesized. The immunogenicity was experimentally validated in mice, guinea pigs and with human lymphocytes.
[0099] It was found that although the use of an automatic synthesizer can save time and be relatively unproblematic for simple sequences, the synthesis of peptides manually allows for more flexibility and control over the assembly process. This is particularly important for the synthesis of difficult sequences as it permits quick and easy intervention at any point. The apparatus routinely used in this laboratory for the manual synthesis of peptides consists of a flask attached to a glass manifold that can support up to four sintered funnels, thereby permitting the simultaneous synthesis of up to four peptides. The side arm of the flask is attached to a vacuum pump to allow for solvents to be aspirated from each funnel. The manifold also contains valves that are arranged so that a vacuum can be applied universally either to all four funnels or restricted to individual funnels.
[0100] There are a very large number of choices of solid phase supports available for peptide synthesis, and the prospective peptide chemist should spend a little time familiarizing themselves with the possibilities: For the purposes of the T-helper cell epitopes designed to bind MHC II and cytotoxic T-cell epitopes designed to fit in the groove of MHC I molecules, however, resins should be used to assemble peptides containing a free carboxyl, COOH group, at the C-terminus (i.e.; Tentagel S PHB resin, Rapp Polymere).
[0101] For the synthesis of immunogen comprising SEQ ID No. 1 [SEFAYGSFVRTVSLPVGADE]-K-SEQ ID No. 2 [FVRSSNLKF], weighed 1 g Tentagel S RAM resin into a sintered funnel and allowed to swell in DMF at room temperature for at least 30 min.
1. To expose the Fmoc-protected NH2 group on the resin, treated with either piperidine or 2.5% DBU in DMF for 2×5 min, followed by four washes with DMF. 2. Weighed 0.92 mmol of Fmoc-amino acid (i.e., a fourfold excess of amino acid relative to the substitution level of the support) into clean and dry plastic tubes (Sarstedt, Germany); [Tubes with a 10-mL volume capacity are ideal]. Added an equimolar amount of HOBT and HBTU relative to the amount of amino acid to 2 mL of DMF and a six-fold excess of DIPEA over the substitution level of the solid phase support. Dissolved fully by vortexing and sonication. 3. Removed DMF from the swollen resin in the glass sinter filter funnel by aspiration using the vacuum pump and added the activated amino acid solution. Stirred with a spatula and incubated at room temperature for 30-45 min, stirring occasionally. 4. After 30-45 min, aspirated the amino acid solution followed by two washes of the resin with DMF. 5. Transferred a few beads of resin with a Pasteur pipette into an Eppendorf tube and added two drops of DIPEA followed by five drops of TNBSA solution. Inspected the beads by eye or under a microscope. If the beads were colorless after 1 min, then acylation was complete and the next step was carried out. Any trace of orange color in the beads indicates the presence of free amino groups and incomplete coupling. In those cases steps 2-5 should be repeated until a negative TNBSA test is returned. 6. Removed the N-Fmoc group of the coupled amino acid by carrying out step 1. Confirmation of the removal of the Fmoc group was determined by performing a TNBSA test that resulted in a positive orange color change. 7. Repeated steps 2-6 with the next amino acid until completion of the SEQ ID. No. 103. 8. To enable lipid attachment, repeated steps 3-6 using (Fmoc)-K(Mtt)-OH to enable lipid attachment between the two epitopes. 9. Repeated steps 2-6 with the amino acids corresponding to the SEQ ID. No. 1. 10. Repeated steps 3-6 using (Boc)-Gly-OH to temporarily block the N-terminus of the peptide. The Boc-protective group is resistant to removal by the conditions used for lipid attachment until cleavage of the assembled product from the resin and concomitant removal of the side-chain-protecting groups. 11. At this point, the completed peptide on resin was washed sequentially in DMF, DCM, and methanol, dried under vacuum, and stored in a desiccated atmosphere at room temperature until ready to be cleaved for use as a non-lipidated peptide control. 12. Continuing from step 11, the resin was treated with 1% TFA in DCM5×12 min to remove the Mtt group from the side chain of the lysine residue situated between the two epitopes. 13. Repeated steps 2-6 in order to couple the two serines to the exposed e-amino group of the intervening lysine residue and removed the Fmoc group from the second serine residue. The peptide is now ready for lipid attachment.
Attachment of the TLR ligand Pam2Cys to Peptide
Synthesis of S-(2,3-dihydroxypropyl) Cysteine
[0000]
1. Triethylamine (6 g, 8.2 mL, 58 mmol) was added to 1-cysteine hydrochloride (3 g, 19 mmol) and 3-bromo-propan-1,2-diol (4.2 g, 2.36 mL, 27 mmol) in water. This homogeneous solution was kept at room temperature for 3 d.
2. The solution was reduced in vacuum at 4 degree C. to a white residue which was washed three times with acetone and dried to give S-(2,3-dihydroxypropyl) cysteine as a white amorphous powder (2.4 g, 12.3 mmol, 64.7%). This product was used for the next step without further purification.
Synthesis of N-Fluorenylmethoxycarbonyl-S-(2,3-dihydroxypropyl) Cysteine (Fmoc-Dhc-OH)
[0000]
1. Dissolved S-(2,3-dihydroxypropyl)cysteine (2.45 g, 12.6 mmol) in 20 ml of 9% sodium carbonate.
2. Added a solution of fluorenylmethoxycarbonyl-N-hydroxysuccinimide (3.45 g, 10.5 mmol) in acetonitrile (20 mL) and stirred the mixture for 2 hours. Diluted with water (240 mL), and extracted with diethyl ether (25 mL×3).
3. Acidified the aqueous phase to pH 2 with concentrated hydrochloric acid and then extracted with ethyl acetate (70 mL×3).
4. Washed the extract with water (50 mL×2) and saturated sodium chloride solution (50 mL×2). Dried over sodium sulfate and evaporated to dryness. Recrystallized from ether and ethyl acetate at minus 20 degree C. to yield a colorless powder (2.8 g, 6.7 mmol, 63.8%).
Coupling of Fmoc-Dhc-OH to Resin-Bound Peptide
[0000]
1. Activated Fmoc-Dhc-OH (100 mg, 0.24 mmol) in DMF (3 mL) with HOBT (36 mg, 0.24 mmol) and DICI (37_al, 0.24 mmol) at 0 degree C. for 5 min.
2. Added this mixture to a vessel containing the resin-bound peptide (0.06 mmol, 0.25 g amino-peptide resin). After shaking for 2 h removed the solution by filtration and washed the resin with DCM and DMF (3×30 mL). Completeness of the reaction was monitored using the TNBSA test.
Palmitoylation of the Two Hydroxy Groups of the Fmoc-Dhc-Peptide Resin
[0000]
1. Dissolved palmitic acid (307 mg, 1.2 mmol), DICI (230_L, 1.5 mmol) and DMAP (14.6 mg, 0.12 mmol) in 3 mL of DCM.
2. Suspended the resin-bound Fmoc-Dhc-peptide resin (0.06 mmol, 0.25 g) in the above solution and kept under shaking for 16 h at room temperature. Removed the supernatant by filtration and thoroughly washed with DCM and DMF to remove any residue of urea. The removal of the Fmoc group was accomplished with 2.5% DBU (2×5 min).
Cleavage of Lipopeptide from Solid Phase Support
[0125] This procedure simultaneously cleaves the lipopeptide or peptide from the solid phase support and removes side-chain-protecting groups from those amino acids that have them.
1. Transferred the vacuum-dried resin into a clean dry McCartney glass bottle and added 3 mL cleavage reagent (88% TFA, 5% phenol, 5% water, and 2% TIPS). 2. Gently flushed with nitrogen and left for at least 3 h with occasional mixing. 3. Transferred the mixture into the barrel of a 5-mL syringe plugged with non-adsorbent cotton wool and used the plunger to drive the peptide-containing supernatant into a clean dry 10-mL centrifuge tube. 4. Evaporated the solution to a volume of approximately 500 microL under a gentle stream of nitrogen. 5. Added 10 mL cold diethyl ether to the peptide, solution and vortexed vigorously to precipitate the peptide. 6. Centrifuged to sediment the peptide material, washed by aspirating the diethyl ether, and resuspended the precipitate in cold diethyl ether followed by washing twice in cold diethyl ether. 7. After the final wash, aspirated the remaining diethyl ether and allowed the pellet to dry in a fume hood for approximately 1 h. 8. Dissolved the precipitate in 0.1% aqueous TFA and lyophilized. 9. Assessed the product purity using reversed-phase chromatography and fidelity of the target sequence by mass spectrometry.
[0135] Briefly, T cell epitopes were conjugated to lipid moiety Pam2Cys, corresponding to the lipid component of macrophage-activating lipopeptide 2 (MALP-2) from mycoplasma. CD4 T cell promiscuous peptides represented by SEQ ID No. 1 to 98 were selected from the 16 kDa secretory protein of M. tuberculosis and conjugated to Pam2Cys to make immunogen L91. The CD8 promiscuous T cell epitopes represented by SEQ ID No. 99 to 103 were selected from antigen 85B of M. tuberculosis . The control lipopeptide was synthesized with an epitope from influenza hemagglutinin virus (HA) containing sequence KYVKQNTLKL. All the peptides were modified at the N-terminus with two serine residues followed by the lipid moiety Pam2Cys to obtain the synthetic lipopeptide.
Example 2
Protection Studies in Mice and Guinea Pigs
[0136] Animals were immunized as described above and rested for 75 days. They were then exposed to M. tuberculosis H37Rv through aerosol route at 100 CFU (mice) or 30 CFU (Guinea pigs) and sacrificed 30 days later. Mycobacterial burden in lungs was estimated by CFU plating. For histopathological analysis, formalin fixed tissues were processed and stained with hematoxylin and eosin.
Results
Immunization of Lipopetides Results in Robust Th1 Immune Response
[0137] Mice immunized with immunogenic lipopeptide containing SEQ ID No. 1, were rested for 45 days and checked for recall responses. Upon restimulation with peptides, predominant production of IFN-γ in CD4 T helper T cells ( FIG. 6 ) was observed.
[0000] Immunization of Lipopeptides Results in Protection Against M. tuberculosis in Mice.
[0138] It was explored whether with prepared immunogen lipopeptide containing SEQ ID No. 1 (SEFAYGSFVRTVSLPVGADE), protection from experimental tuberculosis could be rendered. Mice were vaccinated with lipopeptide or controls (BCG, free peptide, un-related lipopeptide from influenza hemagglutinin, and placebo). Later, the mice were aerosol challenged with M. tuberculosis on day 75 post vaccination and sacrificed 30 days later. It was observed that mice immunized with immunogen lipopeptide containing SEQ ID No. 1 restricted the growth of mycobacterium significantly as compared to BCG (p<0.05) and other controls ( FIG. 7 ).
[0000] Immunization with Lipopeptide Results in Protection Against M. tuberculosis in Guinea Pigs.
[0139] The next set of experiments was performed to demonstrate whether vaccination with immunogen lipopeptide containing SEQ ID No. 1 (SEFAYGSFVRTVSLPVGADE) could render protection from experimental tuberculosis in guinea pigs. Duncan-Hartley guinea pigs were vaccinated with prepared lipopeptide or controls (placebo, BCG, free peptide and un-related lipopeptide from influenza hemagglutinin virus). Later, the animals were aerosol challenged with M. tuberculosis on day 75 post vaccination and sacrificed 30 days later. It was observed that animals immunized with immunogen lipopeptide containing SEQ ID No. 1 harbored significantly lower bacterial load in lungs as compared to BCG and other controls ( FIG. 8 ).
Example 3
Aerosol Infection and Mycobacterial Burden in Lungs
[0140] Frozen stocks of M. tuberculosis H37Rv were thawed quickly at 37° C. and centrifuged at 10000×g for 10 min and washed 2× with PBS-Tween-80. Peptide/BCG/placebo immunized animals were challenged with a standardized low-dose of aerosol infection, using an inhalation exposure system (Glas-Col, Terre Haute, Ind.) to deposit approximately 100 (mice) or 30 (Guinea pigs) live bacteria in the lungs (as checked by CFU plating after 24 h of exposure). Thirty days post-infection, lungs were harvested and homogenized in 7H9 supplemented with Tween-80 (0.05%). Serially diluted homogenates of individual lungs were plated onto Middlebrook 7H11 containing thiophene carboxylic hydrazide (TCH, 2 μg/ml) and OADC. CFUs were counted after 3-4 weeks of incubation at 37° C.
Immunization of Lipopetides Results in Protection Against Tuberculosis in Mice.
[0141] It was explored whether with prepared immunogen lipopeptide containing SEQ ID No. 1 (SEFAYGSFVRTVSLPVGADE), protection from experimental tuberculosis could be rendered. Mice were vaccinated with lipopeptide or controls (BCG, free peptide, un-related lipopeptide from influenza hemagglutinin, and placebo). Later, the mice were aerosol challenged with M. tuberculosis on day 75 post vaccination and sacrificed 30 days later. It was observed that mice immunized with immunogen lipopeptide containing SEQ ID No. 1 restricted the growth of mycobacterium significantly as compared to BCG (p<0.05) and other controls ( FIG. 7 ).
[0000] Immunization with Lipopeptide Results in Protection Against Tuberculosis in Guinea Pigs.
[0142] The next set of experiments were performed to demonstrate whether vaccination with immunogen lipopeptide containing SEQ ID No. 1 (SEFAYGSFVRTVSLPVGADE) could render protection from experimental tuberculosis in guinea pigs. Duncan-Hartley guinea pigs were vaccinated with prepared lipopeptide or controls (placebo, BCG, free peptide and un-related lipopeptide from influenza hemagglutinin virus). Later, the animals were aerosol challenged with M. tuberculosis on day 75 post vaccination and sacrificed 30 days later. It was observed that animals immunized with immunogen lipopeptide containing SEQ ID NO. 1 harbored significantly lower bacterial load in lungs as compared to BCG and other controls ( FIG. 8 ).
Example 4
[0143] Isolation of Lymphocytes from Spleen
[0144] Spleens were removed aseptically and single cell suspensions were prepared. RBCs were lysed by ACK lysis buffer (NH 4 Cl 0.15M, KHCO 3 10 mM, EDTA 88 μM), washed thrice with PBS and resuspended in complete medium [CM; RPMI-1640 containing FBS-10%]. Splenocytes (2×10 5 /well) were cultured in 96 well U bottom plates for 48-72 h. Different concentrations of peptides were added to the cultures. A pretitrated dose (50 or 100 ng/ml) of commercially available ultrapure Pam2Cys (Invivogen) was used as controls.
[0145] Lymphocytes from lipopeptide immunized mice responded to the recall stimulation with peptides effectively through T cell proliferation and IFN-γ secretion ( FIGS. 2 and 5B ).
Example 5
Proliferation Assays
[0146] T cell proliferation assays were set by incubating human PBMCs or mouse splenocytes with peptides for 72 h and 48 h respectively. Later, [ 3 H]-thymidine (0.5 μCi/well) was incorporated. After 16 h, plates were harvested and radioactivity incorporated was measured. Cell proliferation assays were set as described previously (Singh et al., 2011). Briefly, lymphocytes (2×10 5 cells/well) isolated from spleen and/or lymph nodes were cultured in triplicates in 200 μl of complete RPMI-1640 with different concentrations of L91/F91 in 96 well U bottom plates. After 48 h and 72 h, the cultures were pulsed with 0.5 μCi of [ 3 H]-thymidine. The plates were harvested after 16 h using Tomtec-Harvester-96 (Tomtec, Hamden, Conn.). Radioactivity incorporated was measured by Wallac 1450 Microbeta Trilux β-scintillation counter (Perkin Elmer, Waltham, Mass.). For human lymphoproliferation, Blood (20 ml) was drawn in vacutainers from PPD + volunteers or sputum positive tuberculosis patients. Peripheral mononuclear cells (PBMCs) were isolated by density gradient method using Histopaque-1077 following manufacturer's instructions. Purified PBMCs were washed 4× in PBS containing 1% FBS. Cells (2×10 5 cells/well) were cultured in triplicates with CM (without 2-mercaptoethanol), in U-bottom 96w plates with peptides. Cells were incubated for 72 h and later pulsed with 0.5 μCi of [ 3 H]-thymidine. The plates were harvested after 16 h, as mentioned above.
[0147] The influence of lipopeptides in stimulating peripheral blood mononuclear cells of tuberculosis patient is illustrated in FIG. 9 . Immunogenic lipopeptide containing SEQ Id No. 1 (SEFAYGSFVRTVSLPVGADE) enhanced the proliferation of human PBMCs as compared to non-lipidated peptide counterparts. Interestingly, it was observed that the best response was obtained with the lipopeptide immunogen constructs that contained both the CD4 helper epitope (SEQ ID No. 1) and the CD8 cytotoxic epitope (SEQ ID No. 103).
Example 6
Intracellular Staining
[0148] Lymphocytes (2×10 6 cells/ml) were cultured with peptides in triplicates in 96w plate for 48 h. Cells were pooled and washed twice with wash buffer (PBS containing FBS-1%). Cells were re-stimulated with PMA (50 ng/ml) and ionomycin (1 μg/ml) for 6 h/37° C. and in the last 4 h brefeldin A (10 μg/ml) was added in cultures. After 6 h of activation, cells, were washed twice with staining buffer (BSA-1%, NaN 3 -0.01% in PBS). Fc receptors were blocked with 2.4G2 and then stained with anti-mouse fluorochrome labeled mAbs for CD4. Cells were washed twice with staining buffer and fixed in paraformaldehyde-2%. Then they were permeabilized with saponin-0.01% in PBS-FCS-1% (permeabilization buffer). This was followed by incubation with fluorochrome labeled anti-cytokine Abs (or its isotype control) in permeabilization buffer staining buffer containing (saponin—0.01%). The incubation period for each step was 30 min/4° C. or otherwise mentioned. Finally, cells were fixed in parafolmaldehyde-1% and acquired on FACS Aria II and data was analyzed by FACS DIVA (BD Biosciences, San Jose, Calif.).
[0149] Lymphocytes from lipopeptide immunized mice responded to the recall stimulation with peptides effectively through secretion IFN-γ ( FIG. 6 ). Notably, the secretion of IFN-γ was specific to CD4 T cells. Pam2Cys alone in absence of the peptide component did not elicit production of IFN-γ in CD4 T cells.
Statistical Analysis.
[0150] Data were analyzed by unpaired students ‘t’ test and Student-Newman-Keuls multiple comparisons test by GraphPad InStat 3 software.
Advantages of the Invention
[0000]
The epitopes are precisely defined; can avoid autoreactive portions in the antigen
Requires no extensive processing
The developed immunogen does not require any adjuvant
Totally synthetic
Can activate both CD4 and CD8 T cells
Skews immune response to Th1 type
Can activate naïve T cells
Can induce the generation of long-lasting memory T cells
Can reduce the bacterial burden from pulmonary and extra-pulmonary regions of the body
[0000]
TABLE 1
Sequence ID Numbers and the respective sequences
LIST of promiscuous epitopes [peptides] used
Promiscuous CD4 epitopes
Sl. No.
Sequence ID. No.
from M . tuberculosis
1
SEQ ID No. 1
SEFAYGSFVRTVSLPVGADE
2
SEQ ID No. 2
LFAAFPSFAGLRPTFDTRLM
3
SEQ ID No. 3
TYGIASTLLGVLSVAAV
4
SEQ ID No. 4
VVEKLRTHSSGRIEA
5
SEQ ID No. 5
QTVHWNLRLDVSDVD
6
SEQ ID No. 6
LLAVLIALALPGAAV
7
SEQ ID No. 7
PISGLQAIGLMQAVQG
8
SEQ ID No. 8
TLVQIIRWLRPGAVIAI
9
SEQ ID No. 9
GYKVFPVLNLAVGGSG
10
SEQ ID No. 10
LRQRISQQLFSFGDPT
11
SEQ ID No. 11
ILRAGAAFLVLGIAAATF
12
SEQ ID No. 12
RYMIDFNNHANLQQA
13
SEQ ID No. 13
FAWVNHMKIFFNNKGVVAKGT
14
SEQ ID No. 14
QWGSLPSLRVYPSQV
15
SEQ ID No. 15
FLQRNLPRGTTQGQAFQFLGAAIDH
16
SEQ ID No. 16
AKVVVVGGLVVVLAVVAAAA
17
SEQ ID No. 17
LYRKLTTTTVVAYFS
18
SEQ ID No. 18
DKVQIMGVRVGSIDK
19
SEQ ID No. 19
VTLHYSNKYQVPATATA
20
SEQ ID No. 20
LVASRTIQLSPPYTG
21
SEQ ID No. 21
DFVAITRSLALFVSA
22
SEQ ID No. 22
TALHVLPTYASNFNNL
23
SEQ ID No. 23
PIQLICSAIQAGSRL
24
SEQ ID No. 24
ALKFNYLPFGSNPFSS
25
SEQ ID No. 25
VLLDANVLIALVVAEH
26
SEQ ID No. 26
SLVRFLVRSGQSAAAAR
27
SEQ ID No. 27
MTARSVVLSVLLGAHPA
28
SEQ ID No. 28
VRSADGYRLSDRLLAR
29
SEQ ID No. 29
WHMLIVTSIGTDART
30
SEQ ID No. 30
FVVAAAMVRHLLTDPML
31
SEQ ID No. 31
MVLRSRKSTLGVVVCLALVLGGP
32
SEQ ID No. 32
SLRVSWRQLQPTDPRTLP
33
SEQ ID No. 33
GMRLTLRVYAYSSCCKAS
34
SEQ ID No. 34
YVQTKDPVVAALRQRLAT
35
SEQ ID No. 35
DVIRYHVSMTSSVNFPD
36
SEQ ID No. 36
KWVPGYRLVDSTGQVVRTLPAAV
37
SEQ ID No. 37
VVNYPPMLLSRDGRDD
38
SEQ ID No. 38
MRLSLTALSAGVGAVAMSLTVGA
39
SEQ ID No. 39
FNASPVAQSYLRNFLAAPPP
40
SEQ ID No. 40
MIIPDINLLLYAVITGFP
41
SEQ ID No. 41
LFGFLRIATSARVLAAP
42
SEQ ID No. 42
YVREWLSQPNVDLLTAGPRHL
43
SEQ ID No. 43
ALGLLDKLGTASHLTT
44
SEQ ID No. 44
QYLGSGHAVIVSINAEMIWG
45
SEQ ID No. 45
MTTMITLRRRFAVAVAGVA
46
SEQ ID No. 46
AYFVVDATKAYCPQYASQL
47
SEQ ID No. 47
LALRASAGLVAGMAMAA
48
SEQ ID No. 48
PLILVFGRVSELSTCS
49
SEQ ID No. 49
LRLVGGVLRVLVVVGAVFDVA
50
SEQ ID No. 50
VNIGNALWARLQPCVNW
51
SEQ ID No. 51
LVFLAVLVIFAIIVVAKSVALIP
52
SEQ ID No. 52
LNIDTVVYFQVTVPQAA
53
SEQ ID No. 53
LRVARVELRSIDPPPSIQ
54
SEQ ID No. 54
AALQGFTRLLGKPGEDG
55
SEQ ID No. 55
YQQITDVVIARGLSQRG
56
SEQ ID No. 56
GMTPYLVRVLGTQPTPVQQ
57
SEQ ID No. 57
MRVVSTLLSIPLMIGLAVPAHAGP
58
SEQ ID No. 58
MITNLRRRTAMAAAGLG
59
SEQ ID No. 59
GAALGLGILLVPTVDAHLA
60
SEQ ID No. 60
RWFVVWLGTANNPVDKG
61
SEQ ID No. 61
GYWVISYPLYGVQQVG
62
SEQ ID No. 62
NQLGILNGLLGPTGG
63
SEQ ID No. 63
EATATVNAIRGSVTPAVS
64
SEQ ID No. 64
VVAYLVNVTVRPGYNF
65
SEQ ID No. 65
YQASYLLSQAVNELC
66
SEQ ID No. 66
QYGILTGVFHTDIAS
67
SEQ ID No. 67
NGFGISLKIGSVDYQMPYQP
68
SEQ ID No. 68
VVYQMQPVVFGAPLPLDP
69
SEQ ID No. 69
FVNQGGWMLSRASAME
70
SEQ ID No. 70
IRVAENVLRSQGIRAWPVC
71
SEQ ID No. 71
VRTVPSAVALVTFAGAALS
72
SEQ ID No. 72
DLMANIRYMSADPPSMAA
73
SEQ ID No. 73
FNADSSKYMITLHTPIAGG
74
SEQ ID No. 74
GIVAVAIAVVLMFGLANTPRA
75
SEQ ID No. 75
FVGIATRADVGAMQSFVSKYNLNF
76
SEQ ID No. 76
VFYRADGTSTFVNNPTAAMS
77
SEQ ID No. 77
MRSYLLRIELADRPGSLGSLAVALG
78
SEQ ID No. 78
LQVLVNEAPRVLRVSWCTVLR
79
SEQ ID No. 79
MRYLIATAVLVAVVLVGW
80
SEQ ID No. 80
TWYKAFNYNLATSQPITFDTLFVP
81
SEQ ID No. 81
IYPIVQRELARQTGF
82
SEQ ID No. 82
IFYFAQGELLPSFVGACQAQV
83
SEQ ID No. 83
MHRRTALKLPLLLAAGTVLG
84
SEQ ID No. 84
LARFHGFNTVRVFLHDLLWAQD
85
SEQ ID No. 85
FVAIAARYHIKPLFVLFDSCWD
86
SEQ ID No. 86
HPNGRPYRDGEVQTIRKLNGMPS
87
SEQ ID No. 87
MRPYYIAIVGSGPSAFFAAAS
88
SEQ ID No. 88
RFRFFGNVVVGEHVQPGEL
89
SEQ ID No. 89
LESLRPRGIQEVVIVGRRGPLQA
90
SEQ ID No. 90
VFRFLTSPIEIKGKRK
91
SEQ ID No. 91
LVVRSVGYRGVPTPGLP
92
SEQ ID No. 92
WRGSARSYRGTIPKLSLTGL
93
SEQ ID No. 93
WLRLVRATSSSRNLMAIM
94
SEQ ID No. 94
VLLNAAVRRIDRHGAGV
95
SEQ ID No. 95
FVIVAIPPAHRVAIEFDPPLPP
96
SEQ ID No. 96
WRAYALPVLMVLTTVVVYQTVTGTS
97
SEQ ID No. 97
FVRIDSGKPDFRISLVSPT
98
SEQ ID No. 98
YRQYVINHEVGHAIGYL
Promiscuous CD8 epitopes
from M . tuberculosis
99
SEQ ID No. 99
QIMYNYPAM
100
SEQ ID No. 100
IMYNYPAML
101
SEQ ID No. 101
AMLGHAGDM
102
SEQ ID No. 102
AMEDLVRAY
103
SEQ ID No. 103
FVRSSNLKF | The present invention relates to a synthetic immunogen represented by the general formula 1, useful for generating long lasting protective immunity against various intracellular pathogens which are the causative agents of tuberculosis, leishmaniasis, AIDS, trypanosomiasis, malaria and also allergy, cancer and a process for the preparation thereof. The developed immunogen is able to circumvent HLA restriction in humans and livestock. The invention further relates to a vaccine comprising the said immunogen for generating enduring protective immunity against various diseases. The said vaccine is targeted against intracellular pathogens, more particularly the pathogen M. tuberculosis in this case. In the present invention, promiscuous peptides of M. tuberculosis are conjugated to TLR ligands especially; Pam2Cys to target them mainly to dendritic cells and therefore elicit long-lasting protective immunity. (The formula (I) should be inserted here) General formula (I) wherein, X 1 =a promiscuous CD4 T helper epitope selected from SEQ ID No. 1 to 98 OR nil; X 2 =a promiscuous CD8 T cytotoxic epitope selected from SEQ ID No. 99 to 103 OR nil; when X1=nil; X2=SEQ ID No. 99 to 103 and when X2=nil; X1=SEQ ID No. 1 to 98; Y=Lysine; and S=Serine. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of copending U.S. patent application Ser. No. 06/644,581 filed Aug. 24, 1984, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a method of transmitting a pulse code modulated (PCM) signal in a biphase code including a complete sequence of level changes and a sequence of level changes containing gaps. More particularly the present invention relates to such a method utilizing a novel synchronizing pattern for the transmitted signal.
At the 12th meeting of the 8-mm Video Conference, Audio Workgroup, on Mar. 28th, 1983, in Tokyo, Japan, a biphase signal synchronizing pattern comprising two mutually inverted bits each having a length of 1.5 clock pulse periods was proposed.
By definition, the maximum ratio of level change intervals in a biphase signal is fixed at 2:1. Increasing this ratio to 3:1 has a significant influence on the biphase spectrum. To compensate for this drawback, different equalizer circuits are required as well as a broader transmission channel. The above mentioned biphase signal is described in "Fairchild: The Interface Handbook, 1975, Page 4-18".
SUMMARY OF THE INVENTION
It is an object of the present invention to provide for the transmission of PCM signals in biphase code with a biphase signal synchronizing pattern which has little influence on the biphase spectrum.
The above object is basically achieved according to the present invention in that in a method of transmitting a pulse code modulated data signal train in biphase code having a complete sequence of level changes and a sequence of level changes containing gaps, and including inserting a synchronizing pattern into the data signal train, the synchronizing pattern comprises a biphase signal of at least one bit which has been shifted by one-half bit period relative to the data signal.
The synchronizing pattern according to the present invention can be used for a biphase level signal, for a biphase mark signal or for a biphase space signal, and preferably includes two, and more preferably at least three, bits.
According to the present invention, the interval or space between level changes within the synchronizing pattern is 0.5 or 1.0 bit periods as it is in the biphase code signal. At both sides of at least one long halfwave of the synchronizing pattern, there is always an odd number of successive short halfwaves. The deviation from the biphase signal is merely that the number of the short, successive halfwaves is odd. For an uninterfered biphase signal this number must always be even.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the invention, several embodiments thereof will be described in greater detail below with the aid of drawing figures.
FIG. 1 shows a synchronizing pattern according to the invention for a biphase level signal.
FIG. 2 shows a synchronizing pattern according to the invention for a biphase mark or biphase space signal, respectively.
FIG. 3 shows a circuit for generating a block synchronizing signal from a signal including a synchronizing signal according to the invention.
FIG. 4 shows the pulse diagram for the circuit of FIG. 3.
FIG. 5 shows the first two signal lines of FIG. 4 and is used to explain the biphase signal.
FIG. 6 is a block circuit diagram of one embodiment of a modulator circuit used to insert a synchronizing signal according to the invention into a biphase code data stream.
FIG. 7 shows the time sequence of the signals in the circuit of FIG. 6.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a synchronizing pattern 8 for a biphase level signal. In line a, one bit of the value 0 precedes the synchronizing pattern 8. Synchronizing pattern 8 is shifted by one-half bit clock pulse. A level change in the middle of a bit cell, i.e., during a bit clock pulse, is thus no longer present. A decoder circuit designed for a biphase level signal detects this bit sequence as a nonbiphase level signal. In the embodiment illustrated in FIG. 1, synchronizing pattern 8 is composed of three bits. The first two bits f L f L are inverted with respect to one another and each has a length of one bit clock pulse. The third bit of the synchronizing pattern 8 is identical with the bit immediately preceding the synchronizing pattern 8, i.e., a zero in line a and a one in line b. To enable the same oscillation train (1a or 1b) to always be generated as the synchronizing pattern, a zero or a one preceding the synchronizing pattern 8 may be provided as part of the actual synchronizing pattern. In the case of FIG. 1, the synchronizing pattern according to the invention would then consist of four bits.
FIG. 2 shows a synchronizing pattern 9 for a biphase mark or biphase space signal. The bit preceding synchronizing pattern 9 is here not decisive for the course of the synchronizing pattern; instead it is the direction of the level change between the last data bit x and the first bit of the synchronizing pattern 9. Depending on the direction of this level change, the pattern shown in line b or the one in line c is produced. By placing an additional bit ahead of the actual synchronizing pattern, it is possible here as well to produce a defined sequence for the synchronizing pattern. This additional bit must always be selected in such a manner that the level change determinative for the sequence of the synchronizing pattern 9 has the desired direction. Demodulation of line b or c, respectively, according to biphase mark would produce the bit pattern shown in line a, while demodulation of line b or c according to biphase space would produce the bit pattern shown in line d.
FIG. 3 shows a circuit for generating a block synchronizing signal from a signal train including a synchronizing pattern according to the invention. The circuit includes an input 1 to which is fed any desired biphase signal. Input 1 leads to one input of an exclusive-OR gate 4 and to the signal input of a D-flip-flop 5. As shown, flip-flop 5 is clocked via its clock input at 2f T , i.e., twice the clock pulse frequence f T . Output 2 of D-flip-flop 5, at which appears a biphase signal which is shifted in phase by one-half bit period with respect to the biphase signal at input 1, is connected to the other input of exclusive-OR gate 4. Output 3 of exclusive-OR gate 4 is connected with one input of a NOR gate 6. The other input of NOR gate 6 receives the bit clock pulse signal f T . At the output 7 of NOR gate 6, a block synchronizing signal can be obtained.
FIG. 4 shows a pulse diagram to illustrate the operation of the circuit of FIG. 3. The first line shows the NRZ (non-return to zero) signal for the biphase signal at input 1 for the case where the biphase input signal is a biphase level signal (FIG. 1a). As shown, synchronizing pattern 8 is composed of three bits, f L , f L and 0. The identifications of the signal sequences in FIG. 4 correspond to those of FIG. 3, where 1 is the biphase signal at input 1, 2 is the biphase signal at output 2 of flip-flop 5, 3 is the output signal of the exclusive-OR gate 4, and 7 is the resulting synchronizing signal. As can clearly be seen from line 7, an output signal, i.e., a synchronizing signal, exists only in the section of synchronizing pattern 8.
FIG. 5 shows that, in principle, each biphase signal has two sequences 10, 11 of level changes 12 which occur at the spacing of one bit period 13 or a whole number multiple thereof i.e., nT. The first sequence 10 is complete, i.e., sequence 10 has a level change 12 at every point in time T1, T2, T3, . . . T8, which occur at the spacing of one bit period 13. The second sequence 11 occurring at times T10-T17, has gaps in it, i e., sequence 11 has no level changes at times T10, T13, T14, T15 and T17, and has level changes 12 only at T11, T12 and T16. In biphase level, the complete sequence contains the information and the sequence with gaps, i.e., the incomplete sequence, is produced as required. In biphase mark or biphase space, however, the sequence with the gaps carries the information. The direction of the level changes in the complete sequence is thus a result of requirements to provide the necessary coding.
A biphase signal synchronizing pattern according to the invention containing halfwaves and being shifted by one-half bit period produces as many gaps in the complete level change sequence as there are long halfwaves. With a circuit according to FIG. 3, these gaps and thus the position of the synchronizing signal according to the invention can be detected. The minimum length for the synchronizing signal is preferably two bits: one bit for producing a gap and one bit for insertion into the given signal so that no halfwaves of undue length are produced. If the synchronizing signal is always to have the same sequence, then as indicated above, it is necessary to insert two additional bits.
Since synchronizing signals can be simulated by interference, the use of longer synchronizing signals may be advisable which then produce several gaps in the complete sequence of level changes. Accordingly, the synchronizing signals according to the previously illustrated and disclosed embodiments of the invention each includes two long halfwaves and each produces two gaps in the complete sequence of level changes of the total or transmitted signal.
Referring now to FIG. 6 there is shown a modulator circuit for inserting a synchronizing signal or word according to the invention, and which produces more than two gaps, into a stream of NRZ data. As shown, the NRZ data signal, which is to be modulated to a biphase-level (B-L) signal in the illustrated example, is fed to a buffer 23 provided in a clock pulse generator 14. The clock pulse generator 14 receives its basic clock pulse from the NRZ signal and, in a known manner, calculates, on the basis of the synchronizing word, clock pulse signals fT, 2fT and SY (see first three lines of FIG. 7), with clock pulse frequency fT being the frequency sum of the frequencies of the NRZ signal and the clock pulse steps of the synchronizing word. From the buffer 23, the NRZ signal is fed via a switch 15, which is controlled by the synchronizing clock pulse signal SY, to the input of a delay flip-flop (DFF) 16 which is controlled or clocked by a clock pulse signal fT 2 (see line (e) of FIG. 7) and whose complimentary output is connected to the alternate position of the switch 15. The normal output of the delay flip-flop 16, i.e., the NRZ1 signal as indicated, is fed to one input of an exclusive OR-gate 17 to whose other input is fed the clock pulse signal fT. The output signal of the exclusive OR-gate 17, which is a biphase level (B-L) plus synchronizing signal, is in turn fed to the input of a further delay flip-flop 18 which is clocked by the clock pulse signal 2fT. In FIG. 6, the output signal from flip-flop 18 is fed or transmitted to a magnetic head 19 which records the signal on a passing magnetic tape 20. Of course, if desired, the output signal from flip-flop 18 can be transmitted in any known manner.
In order to produce the clock pulse signal fT 2 (line (e) of FIG. 7) for the flip-flop 16, the clock pulse signal fT and the synchronizing clock pulse SY are fed to the respective inputs of a further exclusive OR-gate 21 to produce an output signal fT 1 (line (d) of FIG. 7) which is fed to the input of a further delay flip-flop 22. This flip-flop 22 is in turn controlled or clocked by the clock pulse signal 2fT to produce the signal fT 2 .
With the circuit of FIG. 6, the insertion of a biphase signal shifted by one-half bit is effected during the synchronizing clock pulse SY. While synchronizing bits are being transmitted, information bits are intermediately stored in the buffer 23.
Turning now to FIG. 7, there is shown the time sequence of the various signals produced in the circuit of FIG. 6 for a biphase level signal. Lines (a)-(e) show the various clock pulse signals generated in the circuit of FIG. 6 as described above. In order to indicate the biphase level signal mode of operation for the circuit of FIG. 6 when the synchronizing word SYNC is preceded by a "1" or by a "0" in the NRZ data signal, two illustrative NRZ signals are shown in lines (f) and (i) of FIG. 7. In the NRZ signal (1NRZ) of line (f), the bit preceding the synchronizing word, which is indicated by the bits marked S during which no information is transmitted, is a "1", whereas in the NRZ signal (ONRZ) of line (i) the bit preceding the synchronizing word is a "0". The respective signals appearing at the outputs of flip-flop 16 and gate 17 are shown in lines (g) and (h) of FIG. 7 for the 1NRZ signal of line (f), and in lines (j) and (k) of FIG. 7 for the ONRZ signal of line (i).
It will be understood from the above description that the present invention is susceptible to various modifications, changes and adaptations which are intended to be comprehended within the meaning and range of equivalents of the invention within the bounds of the appended claims. | For the transmission of synchronizing information for a PCM signal transmitted in biphase code, a synchronizing pattern is provided which is composed of a biphase signal that has been shifted by one-half bit period relative to the data portion of the transmitted signal. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a pedicure basin, specifically a pedicure basin with overflow protection.
2. Description of the Related Art
Professional salons today allow customers to receive numerous services, such as facials, manicures, and pedicures. To facilitate these services, spa chairs are often used to allow clients to sit and relax while they receive facials, manicures, and pedicures. Such spa chairs often include a pedicure basin at the foot of the chair to facilitate pedicure services and foot massages. The pedicure basin generally includes warm water for cleaning, comfort and to complement the massaging affect.
Reference is made to U.S. Pat. No. 7,950,979 issued May 31, 2011 to the present Applicant, the disclosure of which is incorporated herein by reference.
FIG. 1 in that patent is reproduced herein and is a diagram showing a prior art spa chair with a pedicure basin for the client's feet to soak in. This conventional pedicure basin has a drain at the bottom for draining the water present in the pedicure basin. However, although the water is drained out of the pedicure basin, residual is ultimate left behind, including possible bacteria, germs and other contaminates from the client's feet. If not thoroughly washed and sanitized, the next client to use the pedicure basin is exposed to the left behind bacteria and germs from the previous client. This poses a serious sanitation issue.
The potential of spreading germs among clients through various tools and equipment, including the pedicure basin, is well known within the manicure and pedicure industries. As such, it is common practice in the industry to apply a liner over the pedicure basin, which may be easily replaced for the next client. The liner is typically either a plastic bag type (like a trash bag) or a harder plastic that has been molded to fit like a shell in the pedicure basin. Utilizing a liner around the pedicure basin is cost effective and efficient, compared to the alternative of having to thoroughly clean and sanitize the pedicure basin after each use. With a liner applied over the pedicure basin, the drain is blocked. As such, a water-filled pedicure basin with a liner will commonly require that the plastic be punctured to drain the water into the drain hole of the pedicure basin. Alternatively, and less common, the water may be drained by pouring the water out over a sink. Thereafter, the used liner will be replaced, and the pedicure basin will be filled with new water for the next client.
The blockage of the drain by the liner poses another challenge. The drain is convenient for not only draining the water completely from pedicure basin, but also for partially draining the water from the pedicure basin. This may be convenient in the scenario where one client may want to adjust the temperature of the water in the pedicure basin. One easy means of doing this is by draining some of the water through the drain and adding additional warm water or cool water to adjust the water temperature within the pedicure basin. If some of the water is not drained, there is the possibility of overflowing the pedicure basin through the addition of the desired warm or cool water. Of course, with a liner, the drain is blocked, and thus the pedicure basin cannot be easily drained.
BRIEF SUMMARY OF THE INVENTION
The design for a new and improved pedicure basin is disclosed. This design may be applied to spa chairs with an integrated pedicure basin or removal pedicure basin. The design is particularly useful for pedicure basins where a liner blocks the drain hole.
This pedicure basin design is comprised of a main basin and a secondary basin that accommodates overflow of fluids (typically water) from the main basin. A portion of the rim, where the main basin is interconnected with a secondary basin, has a lower edge, thus allowing the fluid from the main basin to overflow to the secondary basin.
In another embodiment of this pedicure basin design, the secondary basin completely surrounds the main basin (, the secondary basin forming a ring shape if the main basin and secondary basin are circular), and allows for overflow of fluids from any part of the rim of the main basin to the secondary basin.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the advantages thereof will be readily obtained as the same becomes better understood by reference to the detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 (PRIOR ART) shows a perspective view of a conventional spa chair with an integrated pedicure basin.
FIG. 2A shows a perspective view of an embodiment of a square-like pedicure basin with a secondary basin.
FIG. 2B shows a perspective view of an embodiment of a square-like pedicure basin incorporated into a spa chair.
FIG. 3A shows a perspective view of an embodiment of a round pedicure basin with a secondary basin.
FIG. 3B shows a perspective view of an embodiment of a round pedicure basin with a liner.
FIG. 4A shows a perspective view of an embodiment of a pedicure basin with a secondary basin where no walls are shared.
FIG. 4B shows a perspective view of an embodiment of a pedicure basin with a liner and a secondary basin where no walls are shared.
DETAILED DESCRIPTION
FIG. 1 shows a conventional spa chair 100 with a pedicure basin. Though FIG. 1 shows a spa chair with an integrated pedicure basin 110 , and the pedicure basin 110 may be removable. In the case where the pedicure basin 110 is removable, the spa chair 100 will typically have a pedicure basin base 108 for holding the pedicure basin 110 . In this case, the pedicure basin base 108 will allow for the water to drain from the pedicure basin's drain hole, through the pedicure basin base's drain hole (not shown). The spa chair 100 will typically also have a water inlet and faucet head for adding cold or hot water. Pedicure basins may take a variety of shapes and sizes. For example, they may be circular, square, and a variety of other shapes, mainly for aesthetic purposes.
The spa chair 100 includes a seat 102 connected to a backrest 104 and a pair of arm rests 106 . The seat 102 of the spa chair 100 is further connected to a spa chair base 108 , which also houses a pedicure basin 110 . The pedicure basin 110 is located with the spa chair base 108 , below and forward of the seat 102 . The pedicure basin 110 is designed to hold a liquid such as water, and generally includes a drain in the bottom panel of the pedicure basin 110 . A faucet (not shown) can optionally be attached to the pedicure basin 110 to allow liquid to be easily flowed into the pedicure basin 110 .
In addition to the drain, there are some pedicure basins with an overflow drain, much like one would find in a standard sink. The overflow drain is usually in the side wall and near the top of the pedicure basin, and it's purpose is to allow water to drain before it can overflow. Both the drain and overflow drain would generally be blocked if a liner were used to cover the pedicure basin.
FIG. 2A shows a preferred embodiment of a pedicure basin with a secondary basin. The shape of this pedicure basin 200 is square-like with rounded corners. There is a main basin 210 and a secondary basin 220 . The main basin 210 has four side walls and a bottom portion. There is a drain 270 A at or near the bottom of this main basin 210 . Attached to one side of the main basin is a secondary basin 220 . This secondary basin 220 has four walls and a bottom portion. There is a drain 270 B at or near the bottom of this secondary basin 220 . In this embodiment, the secondary basin 220 shares a side wall with the main basin 210 . In other embodiments, it is possible for the main basin 210 and secondary basin 220 to not share a side wall. It is also possible for the main basin and/or secondary basin to not have a drain.
In the pedicure basin of FIG. 2 , a portion of the rim 240 on the main basin is intentionally lower. This is referred to as the lowered rim 230 . The lowered rim 230 results in fluids overflowing from the main basin 210 to the secondary basin 220 . The flow area is the area calculated from the shape comprised of the imaginary normal rim line and the lowered rim 230 . The flow area determines the rate of fluid overflow that can be handled, which should be sufficiently large enough to accommodate the rate of fluid inflow into the main basin 210 . As water overflows to the secondary basin 220 , it will be drained through the drain hole 270 B at or near the bottom of this secondary basin 220 .
In this embodiment, the outer walls of the secondary basin have a lower height then the outer walls of the main basin. It can also be said that the rim 240 of the main basin is higher than the rim 250 of the secondary basin. However, in other embodiments, the rim of the secondary basin may be higher or the same than the main basin.
FIG. 2A also shows a liner 280 within the main basin 210 . The liner 280 covers the inside portion of the main basin 210 and may also wrap around the rim 240 and lowered rim 260 of the main basin 210 . The liner 280 is usually easily replaceable and prevents the sharing of contaminated liquids within the main basin from one user to another.
FIG. 2B shows the pedicure basin of FIG. 2A integrated into a general spa chair. As can be seen, in this embodiment, the person sitting within the spa chair would have their feet placed within the main basin 210 . As water is added to the main basin 210 , it will overflow through the lowered rim 230 and into the secondary basin 220 .
FIG. 3A shows another embodiment where the shape of the main basin 420 is round, and where the secondary basin 410 is also round and encompasses the entire portion of the main basin 420 . In this embodiment, the entire rim 440 of the main basin 420 can be considered lowered, and thus overflow can occur at any portion of the lowered rim for the fluid to overflow from the main basin 420 to the secondary basin 410 . The height of the rim 430 of the secondary basin can be higher or lower than the height of the rim 440 of the main basin. In this embodiment, a drain hole 450 A is shown for the main basin, as well as a drain hole 450 B for the secondary basin. Both of these drain holes 450 A 450 B may or may not be present. When a liner 460 is used to cover the main basin 420 , as displayed in FIG. 3B , the drain hole 450 A of the main basin is rendered useless. Here, the drain hole 450 B of the secondary basin may still be utilized.
FIG. 4A shows another embodiment where the main basin 510 and secondary basin 520 do not share a side wall. In this embodiment, a lowered rim 560 exists on the main basin, and the same principle of having the overflow of fluids from the main basin 510 to the secondary basin 520 at the lowered rim 560 applies. In this embodiment, the fluid enters a slide (or spout) 550 from the lowered rim 560 , and is led to the secondary basin 520 . The rim 530 of the main basin 510 is higher than the rim 540 of the secondary basin in this embodiment.
FIG. 4B demonstrates the addition of a liner 580 to the main basin 510 . The liner renders the drain hole 570 A of the main basin useless, and the drain hole 570 B of the secondary basin may still be used. Both of these drain holes 570 A 570 B are optional.
As discussed above, a disposable liner is commonly used for sanitation purposes. The liner generally goes around the rim of the main basin. The liner may be utilized with a lowered rim, where the liner wraps around the entire rim of the main basin, including the lowered rim. For a plastic bag style liner, conforming the liner to the lowered rim occurs easily enough. A hard shell style liner requires that the liner be molded to conform to the rim, including the lowered rim. When the liquid overflows over the lowered rim, it would only be in contact with the liner, and would generally not have to come in contact with the main basin.
Having a secondary basin for overflow protection has many advantages. In case of accidental overflow, it will prevent the overflow from the main basin from hitting the floor. Also, as described above, there may be the desire for intentional overflow, where additional water is being added to the main basin for various purposes, including the intent to warm or cool the water in the main basin. The overflow system accommodates the use of a liner in the main basin, which is being performed in the industry due to sanitation needs.
The present invention has been described in an illustrative manner. It is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than of limitation. While there have been described herein, what are considered to be preferred and exemplary embodiments of the present invention, other modifications of the invention shall be apparent to those skilled in the art from the teachings herein and, it is, therefore, desired to be secured in the appended claims all such modifications as fall within the true spirit and scope of the invention. | A spa chair with a novel pedicure basin is disclosed. The pedicure basin has a main basin and a secondary basin. The main basin is where the feet of the person sitting in the spa chair goes. This main basin is generally filled with water. In one embodiment, the main basin has water overflow protection through a lowered rim, directing the overflow of water to a secondary basin. This method of overflow protection is especially useful where the main basin has a liner blocking the drain hole within the main basin. | 0 |
[0001] This application claims the benefit of the Oct. 2, 1997 filing date of provisional application No. 60/060,858.
FIELD OF THE INVENTION
[0002] The present invention relates, in general, to automotive fuel leak detection methods and systems and, in particular, to a temperature correction approach to automotive evaporative fuel leak detection.
BACKGROUND OF THE INVENTION
[0003] Automotive leak detection systems can use either positive or negative pressure differentials, relative to atmosphere, to check for a leak. Pressure change over a given period of time is monitored and correction is made for pressure changes resulting from gasoline fuel vapor.
[0004] It has been established that the ability of a leak detection system to successfully indicate a small leak in a large volume is directly dependent on the stability or conditioning of the tank and its contents. Reliable leak detection can be achieved only when the system is stable. The following conditions are required:
[0005] a) Uniform pressure throughout the system being leak-checked;
[0006] b) No fuel movement in the gas tank (which may results in pressure fluctuations); and.
[0007] c) No change in volume resulting from flexure of the gas tank or other factors.
[0008] Conditions a), b), and c) can be stabilized by holding the system being leak-checked at a fixed pressure level for a sufficient period of time and measuring the decay in pressure from this level in order to detect a leak and establish its size.
SUMMARY OF THE INVENTION
[0009] The method and sensor or subsystem according to the present invention provide a solution to the problems outline above. In particular, an embodiment of one aspect of the present invention provides a method for making temperature-compensated pressure readings in an automotive evaporative leak detection system having a tank with a vapor pressure having a value that is known at a first point in time. According to this method, a first temperature of the vapor is measured at substantially the first point in time and is again measured at a second point in time. Then a temperature-compensated pressure is computed based on the pressure at the first point in time and the two temperature measurements.
[0010] According to another aspect of the present invention, the resulting temperature-compensated pressure can be compared with a pressure measured at the second point in time to provide a basis for inferring the existence of a leak.
[0011] An embodiment of another aspect of the present invention is a sensor subsystem for use in an automotive evaporative leak detection system in order to compensate for the effects on pressure measurement of changes in the temperature of the fuel tank vapor. The sensor subsystem includes a pressure sensor in fluid communication with the fuel tank vapor, a temperature sensor in thermal contact with the fuel tank vapor, a processor in electrical communication with the pressure sensor and with the temperature sensor and logic implemented by the processor for computing a temperature-compensated pressure based on pressure and temperature measurements made by the pressure and temperature sensors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 shows, in schematic form, an automotive evaporative leak detection system in the context of an automotive fuel system, the automotive leak detection system including an embodiment of a temperature correction sensor or subsystem according to the present invention.
[0013] [0013]FIG. 2 shows, in flowchart form, an embodiment of a method for temperature correction, according to the present invention, in an automotive evaporative leak detection system.
DETAILED DESCRIPTION
[0014] We have discovered that, in addition to items a), b), and c) set forth in the Background section above, another condition that affects the stability of fuel tank contents and the accuracy of a leak detection system is thermal upset of the vapor in the tank. If the temperature of the vapor in the gas tank above the fuel is stabilized (i.e., does not undergo a change), a more reliable leak detection test can be conducted.
[0015] Changes in gas tank vapor temperature prove less easy to stabilize than pressure. A vehicle can, for example, be refueled with warmer than ambient fuel. A vacuum leak test performed after refueling under this condition would falsely indicate the existence of a leak. The cool air in the gas tank would be heated by incoming fuel and cause the vacuum level to decay, making it appear as though there were a diminution of mass in the tank. A leak is likely to be falsely detected any time heat is added to the fuel tank. If system pressure were elevated in order to check for a leak under a positive pressure leak test, and a pressure decay were then measured as an indicia of leakage, the measured leakage would be reduced because the vapor pressure would be higher than it otherwise would. Moreover, measured pressure would also decline as the vapor eventually cools back down to ambient pressure. A long stabilization period would be necessary to reach the stable conditions required for an accurate leak detection test.
[0016] The need for a long stabilization period as a precondition to an accurate leak detection test result would be commercially disadvantageous. A disadvantageously long stabilization period can be compensated for and eliminated, according to the present invention, by conducting the leak detection test with appropriate temperature compensation even before the temperature of the vapor in the gas tank has stabilized. More particularly, a detection approach according to the present invention uses a sensor or sensor subsystem that is able to either:
[0017] 1) Provide information on the rate of change of temperature as well as tank vapor pressure level, and correct or compensate for the change in temperature relative to an earlier-measured temperature reference; or
[0018] 2) Provide tank pressure level information corrected (e.g., within the sensor to a constant temperature reference, the result being available for comparison with other measured pressure to conduct a leak-detection test.
[0019] In order to obtain the data required for option 1), two separate values-must be determined (tank temperature rate of change and tank pressure) to carry out the leak detection test. These values can be obtained by two separate sensors in the tank, or a single sensor configured to provide both values.
[0020] Alternatively, if tank pressure is to be corrected in accordance with option 2), then a single value is required. This single value can be obtained by a new “Cp” sensor (compensated or corrected pressure sensor or sensor subsystem) configured to provide a corrected pressure.
[0021] To obtain this corrected pressure, P c , the reasonable assumption is made that the vapor in the tank obeys the ideal gas law, or:
PV=nRT
[0022] where:
[0023] P=pressure;
[0024] V=volume;
[0025] n=mass;
[0026] R=gas constant; and
[0027] T=temperature.
[0028] This expression demonstrates that the pressure of the vapor trapped in the tank will increase as the vapor warms, and decrease as it cools. This decay can be misinterpreted as leakage. The Cp sensor or sensor subsystem, according to the present invention, cancels the effect of a temperature change in the constant volume gas tank. To effectuate such cancellation, the pressure and temperature are measured at two points in time. Assuming zero or very small changes in n, given that the system is sealed, the ideal gas law can be expressed as:
P
1
V
1
/RT
1
=P
2
V
2
/RT
2
[0029] Since volume, V, and gas constant, R, are reasonably assumed to be constant, this expression can be rewritten as:
P 2 =P 1 ( T 2 /T 1 ).
[0030] This relation implies that pressure will increase from P 1 to P 2 if the temperature increases from T 1 to T 2 in the sealed system.
[0031] To express this temperature-compensated or -corrected pressure, the final output, P c , of the Cp sensor or sensor subsystem will be:
P c =P 1 −( P 2 −P 1 )
[0032] where P c is the corrected pressure output. Substituting for P 2 , we obtain:
P c =P 1 −( P 1 ( T 2 /T 1 )− P 1 ).
[0033] More simply, P c can be rewritten as follows:
P c =P 1 (2− T 2 /T 1 ).
[0034] As an example using a positive pressure test using the Cp sensor or sensor subsystem to generate a temperature-compensated or -corrected pressure output, the measured pressure decay determined by a comparison between P c and P 2 (the pressure measured at the second point in time) will be a function only of system leakage. If the temperature-compensated or -corrected pressure, P c , is greater than the actual, nominal pressure measured at the second point in time (i.e., when T 2 was measured), then there must have been detectable leakage from the system. If Pc is not greater than the nominal pressure measured at T 2 , no leak is detected. The leak detection system employing a sensor or subsystem according to the present invention will reach an accurate result more quickly than a conventional system, since time will not be wasted waiting for the system to stabilize. The Cp sensor or subsystem allows for leakage measurement to take place in what was previously considered an unstable system.
[0035] [0035]FIG. 1 shows an automotive evaporative leak detection system (vacuum) using a tank pressure sensor 120 that is able to provide the values required for leak detection in accordance with options 1) and 2) above. The tank pressure/temperature sensor 120 should be directly mounted onto the gas tank 110 , or integrated into the rollover valve 112 mounted on the tank 110 .
[0036] Gas tank 110 , as depicted in FIG. 1, is coupled in fluid communication to charcoal canister 114 and to the normally closed canister purge valve 115 . The charcoal canister 114 is in communication via the normally open canister vent solenoid valve 116 to filter 117 . The normally closed canister purge valve 115 is coupled to manifold (intake) 118 . The illustrated embodiment of the sensor or subsystem 120 according to the present invention incorporates a pressure sensor, temperature sensor and processor, memory and clock, such components all being selectable from suitable, commercially available products. The pressure and temperature sensors are coupled to the processor such that the processor can read their output values. The processor can either include the necessary memory or clock or be coupled to suitable circuits that implement those functions. The output of the sensor, in the form of a temperature-compensated pressure value, as well as the nominal pressure (i.e., P 2 ), are transmitted to processor 122 , where a check is made to determine whether a leak has occurred. That comparison, alternatively, could be made by the processor in sensor 120 .
[0037] In an alternative embodiment of the present invention, the sensor or subsystem 120 includes pressure and temperature sensing devices electronically coupled to a separate processor 122 to which is also coupled (or which itself includes) memory and a clock. Both this and the previously described embodiments are functionally equivalent in terms of providing a temperature-compensated pressure reading and a nominal pressure reading, which can be compared, and which comparison can support an inference as to whether or not a leak condition exists.
[0038] [0038]FIG. 2 provides a flowchart 200 setting forth steps in an embodiment of the method according to the present invention. These steps can be implemented by any processor suitable for use in automotive evaporative leak detection systems, provided that the processor: (1) have or have access to a timer or clock; (2) be configured to receive and process signals emanating, either directly or indirectly from a fuel vapor pressure sensor; (3) be configured to receive and process signals emanating either directly or indirectly from a fuel vapor temperature sensor; (4) be configured to send signals to activate a pump for increasing the pressure of the fuel vapor; (5) have, or have access to memory for retrievably storing logic for implementing the steps of the method according to the present invention; and (6) have, or have access to, memory for retrievably storing all data associated with carrying out the steps of the method according to the present invention.
[0039] After initiation, at step 202 (during which any required initialization may occur), the processor directs pump 119 at step 204 , to run until the pressure sensed by the pressure sensor equals a preselected target pressure P 1 . (Alternatively, to conduct a vacuum leak detection test, the processor would direct the system to evacuate to a negative pressure via actuation of normally closed canister purge valve 115 ). The processor therefore should sample the pressure reading with sufficient frequency such that it can turn off the pump 119 (or close valve 115 ) before the target pressure P 1 has been significantly exceeded.
[0040] At step 206 , which should occur very close in time to step 204 , the processor samples, and in the memory records, the fuel vapor temperature signal, T 1 , generated by the temperature sensor. The processor, at step 208 , then waits a preselected period of time (e.g., between 10 and 30 seconds). When the desired amount of time has elapsed, the processor, at step 210 , samples and records in memory the fuel vapor temperature signal, T 2 , as well as fuel vapor pressure, P 2 .
[0041] The processor, at step 212 , then computes an estimated temperature-compensated or corrected pressure, P c , compensating for the contribution to the pressure change from P 1 to P 2 attributable to any temperature change (T 2 −T 1 ).
[0042] In an embodiment of the present invention, the temperature-compensated or corrected pressure, P c , is computed according to the relation:
P c =P 1 (2− T 2 /T 1 )
[0043] and the result is stored in memory. Finally, at step 214 , the temperature-compensated pressure, P c , is compared by the processor with the nominal pressure P 2 . If P 2 is less than P c , then fuel must have escaped-from the tank, indicating a leak, 216 . If, on the other hand, P 2 is not less than P c , then there is no basis for concluding that a leak has been detected, 218 .
[0044] The foregoing description has set forth how the objects of the present invention can be fully and effectively accomplished. The embodiments shown and described for purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments, are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the spirit of the following claims. | A method and sensor or sensor subsystem permit improved evaporative leak detection in an automotive fuel system. The sensor or sensor subsystem computes temperature-compensated pressure values, thereby eliminating or reducing false positive or other adverse results triggered by temperature changes in the fuel tank. The temperature-compensated pressure measurement is then available for drawing an inference regarding the existence of a leak with reduced or eliminated false detection arising as a result of temperature fluctuations. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on U.S. Provisional filing No. 60/175,809 filed Jan. 12, 2000 and claims the benefit thereof.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to children's crayons and, in particular, to a device for sharpening and reforming broken or dull crayons using heat from the sun.
[0003] Children's crayons employ a binder of wax to carry a non-toxic colored pigment. Although crayons offer a versatile and safe media for children, they have several drawbacks. The first is that the wax matrix is relatively soft so the crayon tip rapidly dulls. Further the crayon is easily broken, especially once the outer paper wrapper is removed.
[0004] Mechanical sharpeners may be used to sharpen crayons. One form employs a canted blade hidden in a cavity. The crayon is sharpened by inserting the tip of the crayon into the cavity and rotating it against the blade. Repeated sharpenings reduce the length of the already short crayon, limiting the number of times the crayon can be resharpened.
[0005] It has been proposed to sharpen crayons with a heated conical cavity. The crayon tip is pressed against the cavity, which melts its surface into a point. Whether or not such devices are practical, they are relatively expensive and require both a connection to an electrical source and the use of a heating element, both of which may be make the device unsuitable for young children. In any case, the drawback to mechanical sharpening, that of the crayon getting shorter, is not avoided.
BRIEF SUMMARY OF THE INVENTION
[0006] The present invention provides a safe, entertaining and educational way to sharpen dull crayons and to mold crayon fragments into complete crayons using single or multiple colors. The need for electricity or dangerous heat source is eliminated by a design that uses sunlight passing through a window as the sole energy source. While the sun provides sufficient heat to melt the crayons, the total amount of energy remains relatively small ensuring that the molten wax presents relatively little danger to a child both in temperature and heat capacity.
[0007] A device for practicing the invention may be inexpensively molded from a clear plastic such as polystyrene and may assembled from two molded mirror image shells so as to reduce molding costs. The shells may be held together by rubber bands to provide a safe and effective clamping. A suction cup may be used to hang the shells directly on a window eliminating the need for a nearby table or other support. The necessary insulation may be provided solely by air gaps within the shells eliminating the need for insulating foam or the like.
[0008] The crayons may be formed in an elastomeric mold flexing to provide for easy release of the molded crayons. Interlocking ridges and sockets flexibly engage to provide a good seal against leakage of molten wax during operation. The mold may be longer than a standard crayon to accommodate the inevitable gaps between the fragments from which the crayons are molded and thus to produce a crayon of full length. The mold may provide an internal ridge to allow excess sprue to be snapped off.
[0009] A temperature sensor composed of a liquid crystal device or a trap holding a fragment of wax may provide an indication of the temperature of the system.
[0010] By orienting the broad face of the toy vertically, year round use may be provided in which low angled sun provides more direct illumination during winter months and high angled sun has a high angle of incidence, which reduces its heating effect.
[0011] The entire toy may be readily formed by vacuforming or thermoforming techniques. A single piece thermoform shell may be used in conjunction with thermoformed front and rear panels to provide the necessary insulating and light transmitting properties or simple thermoformed shells may be used in combination with an opaque or other shroud. Molds may be thermoformed trays positioned so as to eliminate the need for tight sealing against the liquid wax. Forms other than crayons may also be formed such as medallions or the like.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a perspective view of the toy of the present invention supported via a suction cup and hook on the inside face of a window;
[0013] [0013]FIG. 2 is an exploded perspective view of the toy of FIG. 1 showing hooks by which the components of the toy are held together with elastic bands;
[0014] [0014]FIG. 3 is a cross-section taken along line 3 - 3 of FIG. 2 of the assembled toy showing the sandwiching of an elastomeric mold within transparent opposed insulating shells;
[0015] [0015]FIG. 4 is a detailed cross-section perpendicular to the cross-section of FIG. 3 showing a score line incorporated into the mold to facilitate the removal of the crayons sprue after molding;
[0016] [0016]FIG. 5 is a cross-sectional view similar to that of FIG. 3 showing a cavity in the mold for supporting a temperature indicating material between the mold and one panel of the shell;
[0017] [0017]FIG. 6 is a side elevational view of an alternative embodiment formed from a thermoformed tri-fold having laminated front and rear panels to provide for a double pane construction;
[0018] [0018]FIG. 7 is a front elevational view of the embodiment of FIG. 6 when assembled showing placement of thermoformed tray molds within the cavity so produced; and
[0019] [0019]FIG. 8 is a vertical cross section of the embodiment of FIG. 6 as placed against a window and having an opaque covering shroud in lieu of the front and back panels.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Referring now to FIG. 1, the molding toy 10 of the present invention has a generally rectangular body 20 such as may lie against an inner surface of a vertically oriented residential glass window 12 as held by a vinyl suction cup 14 having a metal hook. The hook of the suction cup may attach to an upwardly extending ear 18 positioned at a front edge of the body 20 and having a hole 22 for receiving the hook therethrough. A window-facing portion of the body 20 is transparent to allow sunlight to pass through to its inner volume.
[0021] Referring now to FIG. 2, the ear 18 may be an extension of a front cover plate 24 a being generally a six-inch rectangle of 0.055-inch polystyrene plastic. The front cover plate 24 a, as shown in FIG. 3, includes an offset lip 26 allowing it to fit into an open face of generally rectangular front mold support 30 a. The front mold support 30 (when it is installed on the front cover plate 24 a ), presents a central face behind and parallel to the front cover plate 24 a approximately 0.4 inches away from the front surface of front mold support 30 a.
[0022] The central face of the front mold support 30 is in turn surrounded on four sides by channel 32 extending away from the front cover plate 24 a. The channel 32 is in turn surrounded by walls 34 extending toward the front cover plate 24 a and engaging its offset lip 26 . The walls 34 thus support the front cover plate 24 a. Front cover plate 24 a and front mold support 30 a may both be molded of the same polystyrene.
[0023] The front cover plate 24 a and front mold support 30 a, when assembled, form a shell 42 a enclosing an airtight volume. A second identical shell 42 b formed by rear cover plate 24 b and rear mold support 30 b may be rotated 180 degrees with respect to its vertical axis so that a now front facing surface of channel 32 b of shell 42 b (corresponding to channel 32 a of shell 42 a ) abuts the rear facing surface of channel 32 a of shell 42 a. The rear facing surface of the channel 32 a and the front facing surface of channel 32 b include a key and socket joint 38 having interengaging portions extending in or out of surfaces to align the shells 42 a and 42 b for assembly. In this joint, keys 38 a of one-half of the perimeter of the channel 32 a engaging the sockets 38 b on an opposite one half of the perimeter of the channel 32 b of sides of the shell 42 b and key sockets 38 b of the remaining-half of the perimeter of the channel 32 a engaging the keys 38 a on a remaining opposite one half of the perimeter of the channel 32 b of sides of the shell 42 b. In this way the shells 42 a and 42 b can be identical.
[0024] The outer surfaces of the walls 34 of each of the shells 42 a and 42 b have outwardly extending hooks 36 such as may engage elastic bands 54 to hold the shells 42 a and 42 b together. The necessary pressure between the plate shells 42 a and 42 b may be adjusted by providing additional hooks 36 and elastic bands 54 as needed. Reinforcing ribs may be added to either of the front or rear cover plates 24 and mold support 30 a or 30 b to provide for additional rigidity in the body 20 .
[0025] When assembled together, front mold support 30 a of shell 42 a and the corresponding rear mold support 3 b of shell 42 b are separated by their respective channels 32 a and 32 b to enclose an inner volume 51 . Extending into this volume from the mold supports 30 a and 30 b are guide ridges 40 a and 40 b, respectively, aligning and supporting an elastomeric mold 44 .
[0026] The elastomeric mold 44 may be constructed of an opaque rubber material such as silicone rubber and may separate into a front mold half 47 a and a rear mold half 47 b. The front mold half 47 a and rear mold half 47 b join along a vertical interface to define four crayon-shaped mold cavities 48 , each being substantially 0.3 inches in diameter and 4.0 inches long to be approximately half an inch longer than a commercially available wax crayon but of equal diameter. The mold cavities terminate in a frusto-conical tip of the type adopted by commercial crayon manufacturers.
[0027] Troth and ridge joints 50 are positioned around each of the mold cavities 48 to prevent the migration of molten wax from one cavity to the other or into the volume between front mold support 30 a and rear mold support 30 b.
[0028] In use, fragments of crayons or crayons in need of sharpening are placed within the mold cavities 48 which are then clamped between the shells 42 a and 42 b as held by elastic bands 54 on each of four sides of the shells 42 a and 42 b. The assembled molding toy 10 is then placed on the window 12 as supported by the suction cup 14 .
[0029] Approximately one hour of noonday sun will melt the contents of the elastomeric mold 44 causing the molten wax to descend toward the frusto-conical tips of the mold cavities 48 of elastomeric mold 44 which are preferably pointed downward.
[0030] Referring now to FIG. 4, some separation of the pigment from the wax matrix will cause a concentration of pigment toward the tip rendering an upper sprue 56 substantially free of pigment. The portion of the mold cavity 48 below the sprue 56 conforms substantially to the outline of a standard wax crayon 3.5 inches in length and includes beyond that point an inwardly extending annular ridge 58 which produces a circumferential groove between the sprue 56 and the remainder of the crayon to provide a point at which the sprue may snapped off. A circular bore (not shown) may be provided in one of the shells or both of the shells 42 a and 42 b to provide leverage for this snapping operation.
[0031] Referring now to FIG. 5, a portion of one of the mold halves 46 a or 46 b may have a concave depression 60 to form a pocket between the mold 46 b and rear mold support 30 b that may be used to hold a fragment of crayon 62 whose melting will indicate the temperature of the elastomeric mold 44 . Likewise a thermometer or liquid crystal-type display may be placed at this point.
[0032] Black paper collectors 64 may be placed within the volume between the shells 42 a and 42 b so as to provide additional heat absorbing capacity in winter months.
[0033] The side of the collectors 64 toward the sun may be black and the side away from the sun may be a low emissivity surface such as white or foil.
[0034] It will be understood that the elastomeric mold 44 may be used to make other shapes as well as conventional crayons out of wax and thus the toy forms a general purpose-molding device.
[0035] Standoffs (not shown) may be molded into the front and rear cover plates 24 a and 24 b to hold the toy 10 away from the window during periods of low outside temperature so as to provide an additional insulating layer between the toy 10 and the window 12 .
[0036] Instead of a two-part elastomeric mold 44 , the mold may comprise sleeves of highly elastic material that may be rolled back without seam to release the crayons.
[0037] Alternatively, only the tips of the crayons may be molded using a small elastomeric mold and reusable handles embedded in the molten tips by projecting hooks. A high expansion co-efficient of these hooks would ensure the wax tips are held in tension against the handles, a mode of great strength for wax.
[0038] As an alternative to the elastomer, the molds may be formed directly out of a rigid plastic or semi-rigid plastic with a suitable release surface or having a sufficient flexure to allow release of the molded crayons. Sleeves may be provided to roll about the crayons when they are formed or may be molded in place. Different colored crayons may be put into the molds to provide for various effects including streaking and/or laminated crayons of different colors depending on the mobility of the pigments.
[0039] Referring now to FIG. 6, in an alternative embodiment of the molding toy 10 , a thermoformed tri-fold shell 70 of a type well known in the art, may provide two outwardly concave shells 72 and 74 joined at lower outer edges 76 by means of living hinge members 76 to a base 78 so that bottom surfaces 80 of the shells 72 and 74 may hinge together and be held abutting by post and socket members 82 of a type well known in the art of thermoforming.
[0040] The abutting bottom surfaces 80 may be formed to produce inwardly facing cavities 84 such as may enclose molds 86 for holding crayon or other wax fragments.
[0041] Referring now also to FIG. 7, the thermoformed material may be a transparent material to provide for the necessary influx of solar energy. Extending laterally inward from the sidewalls of the cavities 84 may be rails 88 also thermoformed as support the edges of the molds 86 .
[0042] Referring again to FIG. 6, the molds 86 may have covering flaps 90 such as provide additional heat retention and are transparent to allow the influx of solar energy.
[0043] Transparent front plates and rear plates 90 and 92 may be adhered to the outwardly facing lips of shells 72 and 74 to trap air about the cavities 84 so as to reduce heat loss.
[0044] Referring now to FIG. 8, in an alternative embodiment, the tri-fold 70 of FIG. 6 may be used without front and rear plates 90 and 92 but attached directly to the window 12 by suction cup 14 so that the window itself provides a trapping of air between the cavity 84 and the window 12 . An opaque shroud 96 such as a cardboard box or the like may be placed over flanges 73 of the tri-fold shell 70 providing trapped insulating spaces 97 at the top and bottom of the toy and 98 to its rear. The opaque quality of the shroud 96 ensures complete capture of solar influx. | A wax molding toy uses a heat retaining housing with a transparent surface to provide wax melting temperatures with typical indoor solar flux intensities. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method and mechanical locking device suitable for securing the closure position of an overhead door having hinged panels carried on rollers that are guided along a pairs of channeled roller tracks.
[0003] 2. Description of Related Art
[0004] Portal closures such as overhead opening doors of the type typically used for residential garages and commercial vehicle stalls generally comprise a plurality of horizontal panels that are hinged together along adjacent panel edges for articulation about parallel axes. Each panel is supported at opposite horizontal ends by rollers confined within a channeled track.
[0005] Numerous locking appliances for overhead opening doors of the type described rely on direct or indirect radio-controlled electrical or electronic actuation and are subject to compromise with sophisticated radio communication methods. U.S. Pat. Nos. 4,668,899 and 4.819,379 provide examples of this category of locking systems. Mechanical locks having manually sliding deadbolts that may be emplaced on the interior of the overhead door are also available in many designs. U.S. Pat. Nos. 4.031,719 and 5,458,383 describe mechanical locks suitable for the exterior side of overhead garage doors.
[0006] A suitable mechanical locking appliance designed for use with a traditional padlock and for placement on the interior side of the door has not been available heretofore. Such a device would be immune to those methods employed to defeat electrically or electronically actuated locks. Emplacement of the lock on the interior side of the door would protect the lock from physical tampering and compromise—the invader would have to break and enter the building via another entryway before he could attack such a garage door lock.
[0007] A type of locking appliance that takes advantage of mechanical design features that are widely used in overhead door systems is desirable. Further to this, it is desirable that such a locking device should require only minimum mechanical installation preparation and be suitable for widely used overhead door systems. A locking device that relies on commonly available padlocks combined with a unique, robust and easy-to-use mechanical appliance is also desirable. Finally, the locking device should be simple and easy-to-manufacture and thus available at relatively low cost.
SUMMARY OF THE INVENTION
[0008] A preferred embodiment of the present invention which overcomes the limitations of prior overhead door locking systems features two unequal-length arms linked in a U configuration as an integral unit by a bight section. The first, shorter, arm is inserted axially within a rotation tube that serves as a hinge joint between two overhead door panels. The second, longer, arm is inserted through a suitably positioned aperture in the web of the roller track that carries the door.
[0009] The locking device is equipped with a tip on the second arm that protrudes through the aperture in the roller track web of the overhead door, away from the door. The second arm tip features an aperture through which a padlock may be reversibly secured. An intermediate length portion of the second arm may have a section between the tip and the bight section having a larger diameter than the rest of the arm to provide additional structural strength to deter mechanical attacks. The locking device may be constructed of stainless steel or other material of suitable strength and hardness, either metallic or non-metallic.
[0010] The preferred embodiment provides a higher level of security than normally available in prior art systems because the lock is simply emplaced on the interior side of the door without requirement of special preparations—other than to drill a hole in the roller track web in any and all suitable positions at which a secure door position is desired. The lock cannot be defeated by electromagnetic or electro-mechanical means.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Other features and advantages of the invention will be recognized and understood by those of skill in the art from reading the following description of the preferred embodiments and referring to the accompanying drawings wherein like reference characters designate like or similar elements throughout the several figures of the drawings and wherein: FIG. 1 is a partially sectioned elevation view of a prior art overhead door showing the panel hinge and roller and track assembly; FIG. 2 is a pictorial view of the panel hinge and roller track assembly with the track web drilled to receive the present locking device FIG. 3 is a schematic profile view of the overhead door locking device; and, FIG. 4 is a view of the interior margin of the overhead door and roller track assembly with the locking device and padlock emplaced.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] FIG. 1 is a partially sectioned end view of a prior art overhead door and roller track assembly 200 showing two adjacent, horizontally aligned door panels 210 and 220 . One panel 210 may be designated the “upper” panel relative to a vertical panel alignment, for example. The adjacent panel 220 may be designated as the “lower” panel. At opposite distal ends of the horizontal panels are respective carrier brackets. A roller bracket 222 is secured to the lower panel 220 by cap screws 226 . Normally upstanding from the bracket 222 base plane are a pair of roller carrier plates 224 . Bridging a space between the two roller carrier plates 224 is a roller axle confinement tube 228 and a hinge axis tube 218 . The axis 219 of the hinge axis tube is usually positioned within an extension of the edge juncture plane 202 common to the adjacent panel edges.
[0013] A hinge bracket 212 is secured to the opposite distal ends of the upper panel 210 by cap screws 216 . Normally upstanding from the hinge bracket base plane are a pair of hinge carrier plates 214 . The hinge axis tube 218 passes through the carrier plates 214 to secure rotation of the carrier plates 214 , and hence, hinge bracket 212 about the hinge axis 219 . Notably, the hinge axis tube 218 comprises an annular wall around an axial hollow space 205 .
[0014] A roller wheel 230 is secured to an outside end of the axle 232 . The axle 232 is usually inserted loosely within the axial bore space formed within the tubular wall of the axial confinement tube 228 to permit limited axial displacement of the axle 232 relative to the confinement tube 228 . The wheel 232 rotational plane is normally perpendicular to the axle 232 axis. Wheel 230 rolling alignment is confined between and along two channels 242 of a roller track 240 . The track channels 242 are secured in constant, parallel alignment by the roller track web 244 .
[0015] The prior art overhead door assembly of FIG. 1 is modified to practice the present invention in the manner illustrated by FIG. 2 which differentially shows an aperture 246 through the roller track web 244 . The web 244 may be perforated by a multiplicity of apertures 246 at locations along the track 2 length corresponding to predetermined holding positions of the door when the locking device of the present invention is engaged.
[0016] Referring to FIG. 3 , a U-shaped locking device 100 is shown in schematic profile view. The locking device is designed for emplacement on the interior side of an overhead door assembly as typically utilized for vehicle garages in or in proximity to homes. The U-shaped locking device 100 has a first arm 110 , a second arm 120 and a bight portion 160 that links the first and second arms. The first arm 110 is shorter than the second arm 120 . The second arm 120 preferably has an enlarged section 140 with a significantly greater cross-sectional area than the remainder of the arm. The enlarged section 140 preferably bridges the joint between the lateral edges of the garage door and the adjacent door jams where, in some structures, a saw may be inserted in an attempt to sever the second arm 120 . Alternatively, the enlarged section 140 may be given or replaced by a suitable hard-face treatment such as with carbide, titanium or diamond chips
[0017] The two arms and linking bight member are preferably constructed with circular cross-section although other appropriately dimensioned cross-sectional geometries may be substituted such as squares, hexagons or octagons. The tip 130 of the second arm 120 extends beyond the end of the enlarged section 140 and may have a cross-sectional that is preferably intermediate between the diameters of the enlarged section 140 of the second arm and the bight portion 160 . A tip-hole 150 penetrates through the tip 130 and is also preferably circular in cross-section. The tip-hole 150 is given a sufficient inside diameter to receive a standard lock shank 252 ( FIG. 4 ).
[0018] Suitable dimensions for the locking device 100 are coordinated with dimensions of the overhead door and its roller track and associated components. One dimensional criterion is a coordination of the first arm 110 outside dimension to the inside dimension of the hinge axis hollow space 205 for an easily nested sliding fit of the first arm 110 inside of the hollow hinge axis tube 218 . Another dimensional criterion is a coordination of the second arm tip section 130 outside dimension to the inside dimension of the web aperture 246 for a effortless penetration of the aperture by the tip section 130 .
[0019] Typically, an overall length of approximately 5.75 inches, a cross-sectional diameter of 0.25 inches for the arms 110 and 120 , a cross-sectional diameter of 1.0 inches for the enlarged section 140 , and a cross-sectional diameter of 0.625 inches for the tip of the second arm 150 are suitable dimensions.
[0020] The locking device 100 may be constructed of 304 stainless steel or equivalent. Because of its simplicity of form and small size, the locking device is easy and economical to manufacture. It may be manufactured from component pieces or as a single piece but in the former case the component pieces will be permanently bonded together to form an effective single piece. Alternatively to 304 stainless steel, a different material of suitable strength and hardness, either metallic or non-metallic, may be used. Suitable strength and hardness are defined as of sufficient strength and hardness to successfully resist deformation or breakage of the locking device, from either outside or inside of the locked overhead door, by a determined predatory adult not equipped with specialized tools for the purpose.
[0021] FIG. 4 shows the present invention locking device 100 as positioned for locking an overhead door from translational movement along the roller track 240 thereby preventing movement of all depicted elements of the interior margin of the overhead door and roller track assembly 200 . The installation procedure begins by inserting the first arm 110 into the hollow interior 205 of the hinge axis tube assembly 218 as he simultaneously inserts the tip 130 of the second arm 120 through a selected web aperture 246 in the roller track web 244 . The user then secures the locking device 100 by inserting a shear pin or the shank 252 of an open padlock 250 through the tip-hole 150 and closed.
[0022] Unlocking is accomplished simply by the reverse process. Thus the locking device is simple and easy to use, both in the locking and in the unlocking process.
[0023] The position of the locked door is determined directly by the position of the aperture 246 in the roller track web 244 . Consequently, the user must place this hole correctly to achieve the desired door position when locked. Normally this would be the fully closed position. If he wishes a slightly raised position for purposes such as pet access he may position the circular hole slightly higher in the roller track. Multiple holes may be prepared for multiple locked positions. The hole may be easily drilled with an electric drill and appropriate drill bits, available to the average homeowner.
[0024] Because the locking device 100 and padlock 250 are not accessible or even viewable except from the interior of the garage (or other enclosure) an illicit entry is better prevented than with exterior mechanical locking devices. No electro-magnetic or electrical methods are capable of defeating the lock.
[0025] For the intruder, entering the garage by another entry way is necessary before he can attack the locking device 100 and padlock 250 . For the illicit intruder this should require breaking before entering (if other entryways are appropriately secured).
[0026] For the user, the garage also must be accessible by another entryway to allow access to the locking device 100 for installation and removal. This requirement is met by the vast majority of home garages. The user may wish to employ the locking device 100 together with other prior-art locking devices for increased security. For an increased measure of security the user may elect to utilize two locking devices 100 —one on each of the two roller tracks of the overhead door. Although the locking device 100 may be secured from external invasion by a simple shear pin through the tip-hole 150 , an intruder who enters the structure interior by an alternative route may easily remove a shear pin and open the overhead door. For this reason, use of a padlock 250 is preferred.
[0027] The invention has been described for overhead garage doors; however it may also be utilized with any overhead door having the essential features of rotating panels and roller tracks, providing there is suitable alternative access to the interior of the structure, other than via the entry protected by the overhead door, as required for operating the locking device.
[0028] While preferred embodiments of this invention have been shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit or teaching of this invention. The embodiments described herein are exemplary only and are not limiting. Many variations and modifications of the system and apparatus are possible and are within the scope of the invention. Accordingly, the scope of protection is not limited to the embodiments described herein, but is only limited by the claims that follow, the scope of which shall include all equivalents of the subject matter of the claims. | An overhead opening door lock device for use with existing types of door systems having horizontally hinged panels carried on rollers confined within channeled roller tracks is attached on the interior side of the door and fixes the door in position relative to the roller track. One leg of a U-shaped device is inserted in the hollow interior of a tube that serves as an articulation axis for a pair of hinged panels. The other leg of the U-shaped device penetrates a suitably positioned aperture in the web of the adjacent channeled roller track. A shear pin or padlock shank may be inserted through an aperture in a tip portion of the other leg that projects past the outside plane of the roller track web. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] “Not Applicable”
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] “Not Applicable”
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISK
[0003] “Not Applicable”
FIELD OF THE INVENTION
Background of the Invention
[0004] To clarify the description of the invention, certain dental terms should be understood. Upper and lower teeth are termed maxillary and mandibular teeth, respectively. Front teeth are anterior teeth and back teeth are posterior teeth. Anterior teeth are incisors and are named centrals, laterals, and cuspids in order from the anterior midline to the posterior. The posterior teeth, from anterior to posterior, are first and second premolars and first, second, and third molars. Distal refers to the direction towards the last posterior tooth, as opposed to mesial, which refers to the direction towards the anterior midline.
[0005] Orthodontists and dental researchers are constantly searching for new and improved ways to correct malocclusion problems. Corrective movement of teeth may be accomplished utilizing a variety of orthodontic appliances. One such commonly used orthodontic appliance is orthodontic braces, wherein brackets are bonded to teeth and an arch wire is attached to the brackets in known ways. The arch wire exerts pressure on the brackets and teeth whereby the positioning of teeth relative to each other can be controlled and adjusted. The adjustment of the position of teeth is accomplished by providing forces in a desired direction. For many desired forces, there are unwanted reciprocal forces that often move teeth from their correct position.
[0006] Attempts have been made to try to secure teeth from moving, rotating, or torquing from their correct positions in response to such unwanted forces. However, often these attempts are expensive, or involve surgery typically requiring significant healing time. Thus, there exists a need for an orthodontic system to position and adjust a tooth or teeth of a patient that is able to withstand occlusal, biomechanic or other reciprocal forces applied thereto, is less expensive and time consuming to install, and is less invasive to the patient. It is to the provision of such an improved orthodontic anchor system that the present invention is primarily directed.
SUMMARY OF THE INVENTION
[0007] A palatal t-bar for preventing movement of selected teeth during corrective movement of other teeth through the use of an orthodontic appliance such as orthodontic braces is provided. The t-bar comprises an elongate stem having an anchorage end arranged for affixation to the palatal bone of a patient by means of a temporary bone anchorage device, e.g., a miniscrew implant, and a free end extending in an anterior direction from the anchorage end. The stem is shaped to conform to the palatal surface of the patient. A cross-bar extends laterally from the free end of the stem and is arranged to engage one or more selected maxillary anterior teeth to retain the teeth non-mobile and non-rotational during corrective movement of other teeth utilizing an orthodontic appliance such as orthodontic braces.
DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is an isometric view of a preferred embodiment of the palatal t-bar of the present invention;
[0009] FIG. 2 is a view of the preferred embodiment of the palatal t-bar of the present invention installed in the roof of the mouth of a patient, the patient also wearing orthodontic braces;
[0010] FIG. 3 is a view of the preferred embodiment of the palatal t-bar of the present invention installed within the roof of the mouth of a patient, the patient also wearing orthodontic braces;
[0011] FIG. 4 is an elevational view, partially in cross-section, illustrating the preferred embodiment of the palatal t-bar of the present invention installed within the roof of the mouth of a patient;
[0012] FIG. 5 is a view of the stem portion of the palatal t-bar of the present invention;
[0013] FIG. 6 is another view of the stem portion of the palatal t-bar of the present invention;
[0014] FIG. 7 is an elevational view, partially in cross-section, illustrating a second embodiment of the palatal t-bar of the present invention installed within the roof of the mouth of a patient; and,
[0015] FIG. 8 is an isometric view of a third embodiment of the palatal t-bar of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] Referring now in greater detail to the drawings in which like numerals represent like components throughout the several views, FIGS. 1-4 illustrate a first preferred embodiment of the palatal t-bar 10 of the present invention. As best shown in these figures, the palatal t-bar 10 is intended for placement within the mouth of a patient to serve as an anchorage to prevent one or more selected teeth (as an example here shown on teeth 14 ) anchored within the t-bar 10 from rotating, torquing, or moving distally during corrective movement of other teeth. Such other teeth may include lateral incisors 18 , canines 22 , or posterior teeth 26 . As shown in FIGS. 1-4 , corrective movement of teeth 14 , 18 , 22 , and 26 is shown as being accomplished utilizing orthodontic braces, wherein brackets 30 are bonded to teeth 14 , 18 , 22 , and 26 and an arch wire 34 is attached to the brackets 30 in known ways. The arch wire 34 exerts pressure on the brackets 30 and teeth 14 , 18 , 22 , 26 whereby the positioning of teeth relative to each other can be controlled and adjusted. The adjustment of the position of the teeth is accomplished by providing forces in a desired direction.
[0017] Referring now to FIG. 2 , the orthodontic braces are shown mounted to the patient's maxillary teeth at the start of a corrective orthodontic procedure to provide corrective forces to move the posterior teeth 26 , e.g., premolars and molars, anteriorly in the direction of arrows 38 to fill in gaps 42 existing between the teeth 22 and 26 . During movement of the posterior teeth 26 in the mesial direction of arrows 38 , undesired forces may inadvertently be applied to the teeth 14 providing a tendency for them to rotate, torque, or move in an undesired direction.
[0018] To prevent such unwanted rotation, torque or movement of these teeth 14 , the palatal t-bar 10 is provided. Referring again to FIGS. 1-4 , the palatal t-bar 10 includes a cylindrical elongate stem 46 having a first end arranged to be affixed to the palatal surface 50 of the patient and a second end to which a cross-bar 54 is attached. Alternatively, the cross-bar 54 may be integral with the elongate stem 46 . As best shown in FIGS. 1 and 4 , the elongate stem 46 is comfortable for the patient and generally cylindrical in shape. The elongate stem 46 can be contoured, molded or shaped to roughly match the palatal surface 50 . The cross-bar 54 is shaped to match the contour of the posterior surface of one or more anterior teeth 14 , 18 and/or 22 in their correct position. In this manner, the cross-bar 54 will prevent movement, rotation and torquing of the anchored teeth. In addition, the cross-bar 54 includes curved ends 54 a ( FIG. 1 ) arranged for bending around the edges of the anchored teeth 14 to prevent movement of the anchored teeth 14 . As best shown in FIGS. 2 and 3 , the cross-bar 54 is bonded or held to one or more anchored teeth 14 , 18 and/or 22 utilizing a suitable dental adhesive 57 to provide support for teeth 14 against the aforementioned undesired forces.
[0019] Although the cross-bar 54 is illustrated in FIGS. 1-4 as anchoring only the two frontmost teeth 14 , i.e., the upper central incisors, it should be understood that the cross-bar 54 could be configured to anchor a smaller or larger number of teeth during the application of corrective orthodontic forces to other teeth. For example, the cross-bar 54 could be lengthened and suitably configured to anchor the upper lateral incisors 18 in addition to the upper central incisors 14 to prevent unwanted distal movement, rotation or torquing of these teeth during the application of corrective forces. Likewise, the cross-bar 54 could be lengthened and configured to anchor upper canines 22 in addition to the central and lateral incisors, 14 and 18 .
[0020] The palatal t-bar 10 is formed from a metal such as titanium, titanium alloys, stainless steel, a nickel-titanium alloy, titanium-molybdenum alloy, a chromium-nickel alloy, or combinations thereof, or alternatively, could be formed from synthetic polymer materials, such as an acrylic or by stereolithography. In the embodiment shown in FIGS. 1-4 , the palatal t-bar 10 is illustrated as including an elongate stem 46 that is contoured to the shape of the maxilla, but it will be understood that other shapes or configurations can be used.
[0021] As best shown in FIG. 4 , the palatal t-bar 10 includes an anchor mechanism for anchoring the t-bar 10 to the patient's palatal surface 50 , i.e., the roof of the patient's mouth. As shown in FIGS. 4 and 6 , under the present embodiment, the anchor mechanism includes an anchoring miniscrew implant 58 to which one end of the palatal t-bar is fixed. As an optional feature, in case it is necessary, a washer 62 can be used to provide a small amount of space or separation, e.g., 1 mm, between the palatal t-bar 10 and the palatal surface 50 when the t-bar 10 is anchored to the maxillary bone. In this manner, the palatal t-bar 10 will not contact the roof of the patient's mouth during use which will increase the patient's level of comfort, thus allowing for saliva to pass over the t-bar and facilitating hygiene around the miniscrew implant 58 . The anchoring miniscrew implant 58 and washer 62 are minimal in size so as to be unobtrusive of eating and to likewise minimize the trauma to the tongue and palate of the patient during insertion and thereafter while the palatal t-bar 10 is worn by the patient. Accordingly, the anchoring miniscrew implant 58 typically will be approximately 8 to 21 mm in length with approximately 2 to 6 mm of the anchoring miniscrew implant 58 being exposed outside the palatal surface 50 when inserted in the patient's mouth. However, it is possible to use anchors of other, varying dimensions and types. Therefore, while the present anchor mechanism is being disclosed with reference to a preferred range of sizes, such a preferred range is for illustrative purposes only and it will be understood by those skilled in the art that various other types of conventional dental implants and varying sizes also may be used.
[0022] As shown, the anchoring miniscrew implant 58 typically includes a body 66 that is inserted or drilled into the palatal surface 50 of the mouth of the patient so as to be embedded into the palatal bone 70 , and a head or upper portion 74 exposed from the palate. The shank portion 66 of the anchoring miniscrew implant 58 further typically include threads to enable the anchoring miniscrew implant 58 to be drilled into the palatal surface 50 , although it will be understood by those skilled in the art that the anchoring miniscrew implant 58 also can have substantially smooth sided shanks. As best shown in FIGS. 2-4 , a coating or bonding material 78 is utilized to mechanically hold the elongate stem 46 of the t-bar 10 to the miniscrew implant 58 . Also, a mechanical retention can be obtained by using metallic ligature wire to hold the elongate stem 46 of the t-bar 10 to the miniscrew implant 58 .
[0023] As best illustrated in FIGS. 3-6 , a portion of the elongate stem 46 may be configured as a bendable spine 82 formed in a notched or zig-zag pattern to provide a plurality of retention surfaces to enable mechanical retention with the bonding material 78 . The bendable spine 82 may be integral with or attached to the elongate stem 46 and may be fabricated of the same or different materials as the elongate stem 46 . The bendable spine 82 is bendable in proximity to the anchoring miniscrew implant 58 , which serves as a locator. As best shown in FIGS. 4-6 , the spine 82 is bent around the head, neck or body 66 of the anchoring miniscrew implant 58 . Thereafter, it is secured to the miniscrew implant 58 by using a ligature wire, bonding material or composite 78 . The bonding material 78 flows within the retention grooves of the bendable spine 82 to create a solid mechanical retention between the t-bar 10 and the miniscrew implant 58 . By providing a bendable spine 82 , the palatal t-bar 10 is provided with a degree of adjustability to assure that anchorage can occur while the cross-bar 54 engages the teeth 14 to be anchored.
[0024] FIG. 3 illustrates the patient's maxillary teeth at the conclusion of the corrective orthodontic procedure wherein the posterior teeth 26 have been moved mesially to eliminate gaps between teeth 22 and 26 . As illustrated in FIG. 3 , the t-bar 10 anchoring the maxillary teeth 14 has prevented these teeth 14 from rotating, torquing, or moving distally during corrective mesial movement of the posterior teeth 26 . The above example illustrates use of the t-bar 10 for anchoring teeth 14 during mesial movement of other teeth, e.g., molars. However, it should be understood that the t-bar 10 would be equally effective for anchoring teeth 14 during distal movement of other teeth, such as molars, utilizing dental appliances such as braces.
[0025] Referring now to FIG. 7 , there is shown a second embodiment of the palatal t-bar of the present invention. As with the first embodiment, the second embodiment t-bar 100 is intended for placement within the mouth of a patient to prevent teeth 114 anchored within the second embodiment t-bar from rotating, torquing, or moving mesially or distally during corrective movement of other teeth 118 . As with the first embodiment, the second embodiment palatal t-bar includes a cross-bar 154 that is attached to, or integral with an elongate stem. The cross-bar 154 is bonded or held to one or more anchored teeth, e.g., the anchored teeth 114 shown in FIG. 7 , utilizing a suitable dental adhesive 57 to provide support for the teeth against the undesired forces discussed above.
[0026] However, under the embodiment 100 , the elongate stem is formed of a multi-piece construction, e.g., a two-piece construction, including an outer portion 146 a and an inner portion 146 b that are in telescoping relation to each other to enable adjustability of the overall length of the elongate stem to accommodate different sized palates. Once the overall length has been determined, the inner and outer portions may be crimped, glued or soldered together to retain the elongate stem at a defined length. The elongate stem includes a contour that roughly matches the maxilla 150 and includes a fixed end that is arranged to be anchored to the maxilla 150 utilizing anchoring hardware, e.g., an anchoring screw 158 . A washer 162 may be used to provide a small amount of separation between the second embodiment palatal t-bar and the maxilla 150 for the reasons previously discussed. Likewise, the anchoring screw 158 may be coated with a coating or bonding mechanism similar to that shown in the first embodiment for the reasons previously discussed.
[0027] Referring now to FIG. 8 , there is shown a third embodiment 200 of the present invention. This third embodiment 200 of the palatal t-bar is similar to prior embodiments in that it is intended for placement within the mouth of a patient to serve as an anchorage for preventing teeth anchored therein from rotating, torquing, or moving distally during corrective movement of other teeth. As with the prior embodiments, the third embodiment palatal t-bar 200 includes a cross-bar 254 that is attached to, or integral with an elonagate stem 246 . However, under this embodiment 200 , the elongate stem 246 includes an anchorage end that will fit two anchors, as opposed to one, and includes two semi-circular anchoring openings 258 that serve as points for anchoring the third embodiment palatal t-bar 200 within the maxilla utilizing suitable anchorage hardware as previously discussed. By providing two anchoring openings 258 , as opposed to one, lateral support for the anchored teeth will be increased to further reduce the possibility of torquing, rotation, or distal movement of the anchored teeth during application of corrective orthodontic forces.
[0028] In the foregoing specification, specific embodiments of the present invention have been described. However, one of ordinary skill in the art appreciates that various modifications and changes can be made without departing from the scope of the present invention. Thus, while preferred embodiments of the invention have been illustrated and described, it is clear that the invention is not so limited. Numerous modifications, changes, variations, substitutions, and equivalents will occur to those skilled in the art without departing from the spirit and scope of the present invention. Accordingly, the specification and figures are to be regarded in an illustrative rather than a restrictive sense, and all such modifications are intended to be included within the scope of present invention. | A palatal t-bar for preventing movement of selected teeth during corrective movement of other teeth through the use of an orthodontic appliance such as orthodontic braces. The t-bar comprises an elongate stem having an anchorage end arranged for affixation to the palatal bone of a patient by means of a temporary bone anchorage device, e.g., a miniscrew implant, and a free end extending in an anterior direction from the anchorage end. The stem is shaped to conform to the palatal surface of the patient. A cross-bar extends laterally from the free end of the stem and is arranged to engage one or more selected maxillary anterior teeth to retain the teeth non-mobile and non-rotational during corrective movement of other teeth utilizing an orthodontic appliance such as orthodontic braces. | 1 |
TECHNICAL FIELD
The present disclosure relates to storage bins for motor vehicles.
BACKGROUND
Motor vehicles typically include storage bins disposed on or in various interior trim components, such as center consoles, dash boards, door panels and arm rests. The storage bins are utilized to hold beverages, cell phones, and other personal items. Traditional storage bins have a fixed size that may be either too large, or too small, for many items.
SUMMARY
According to one embodiment, a cup holder includes a base, a plurality of pins supported by the base, and a locking plate spaced away from the base. Each of the pins are biased in an extended position and movable to a depressed position in response to a downward force. The locking plate defines openings. Each of the pins extend through one of the openings. The locking plate is engageable with the pins to prevent movement of the pins.
According to another embodiment, a vehicle interior component includes a panel defining a recess. A storage bin is disposed within the recess and includes a base, a plurality of pins supported by and movable relative to the base, and a locking plate. The locking plate is movable relative to the pins and includes a plurality of sidewalls that are each engageable with one of the pins to lock the pins relative to the base in response to movement of the locking plate.
According to yet another embodiment, a storage bin includes a base, a plurality of pins supported by and moveable relative to the base, and a locking plate. The locking plate includes a plurality of sidewalls that each define an opening for one of the pins to pass therethrough. Each of the sidewalls are configured to engage one of the pins to lock the pins relative to the base in response to movement of the locking plate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a perspective view of a center console including a storage bin.
FIG. 2 illustrates a side view, in cross-section, of the storage bin of FIG. 1 .
FIG. 3 illustrates a perspective view of a locking plate of the storage bin of FIG. 1 .
FIG. 4 illustrates a side view of a pin assembly of the storage bin of FIG. 1 .
FIG. 5 illustrates a side view of another pin assembly.
FIG. 6 illustrates a side view of yet another pin assembly.
DETAILED DESCRIPTION
Embodiments of the present disclosure are described herein. It is to be understood, however, that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could 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. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.
Referring to FIGS. 1, 2, and 3 a vehicle cabin 20 includes a center console 22 having at least one storage bin 24 built into the center console. The storage bin 24 may include a housing 26 having sidewalls 28 and a finished panel (or top surface) 32 . The housing 26 defines a storage area 30 where items can be stored. The housing 26 includes a base 34 that may be connected to each of the sidewalls 28 . A mid-plate 36 is disposed above the base 34 and below the finished panel 32 . The mid-plate 36 may be attached to the sidewalls 28 and oriented parallel to the base 34 . The mid-plate 36 may include holes 41 , and the base 34 may include holes 43 . The holes 41 are aligned with holes 43 such that a plurality of vertical pins 40 are each receivable through one of the holes in the mid-plate and a corresponding hole of the base 34 . The mid-plate 36 and the base 34 provide lateral support for each of the vertical pins 40 while allowing the pins to freely move up and down. The storage bin 24 may be located on other components of the vehicle cabin—such as the dash, door panels, seat backs, and/or arm rests.
Each of the pins 40 is individually vertically displaceable relative to the base 34 between an extended position and a depressed position. The pins are spring biased to rest in the extended position. The pins 40 form a floating pin floor within the storage area 30 . When an item is received within the storage area, the weight of the item causes the pins in contact with the item to depress downwardly. The surrounding pins not in contact with the item remain in the extended position. This creates a depression—in the floating pin floor—that is in the shape of the item. The surrounding pins that are not depressed define a ministorage area that prevents the item from sliding around the storage area 30 , which could cause damage to the object or spills if the object is a beverage. Traditional cup holders have a fixed size that may be too large or too small for many different beverage containers or cups. The floating pin floor of storage bin 24 is able to take on many shapes and sizes to effectively secure a variety of different sized beverage containers.
A locking plate 38 is disposed between the base 34 and the mid-plate 36 . The locking plate 38 may include a plurality of lower arms 54 connected to the mid-plate 36 to suspend the locking plate 38 above the base 34 . The locking plate 38 may be pivotably attached to the mid-plate 36 allowing the locking plate 38 to displace horizontally. For example, the locking plate 38 may include a hub 56 disposed on an axle 58 projecting from the mid-plate 36 . The locking plate 38 also includes an upper surface 42 , a lower surface 44 , and a plurality of slots 46 extending between the upper and lower surfaces. The slots 46 may be aligned in parallel rows. Each of the slots 46 may be defined by at least one sidewall 48 . The slots 46 may be aligned with the holes 41 , 43 . Each of the pins 40 is disposed within one of the slots 46 when assembled. The locking plate 38 may be horizontally displaceable between a locked position and an unlocked position. When in the unlocked position, the slots 46 align with the holes 41 , 43 allowing the pins 40 to vertically displace relative to the base 34 . When in the locked position, at least a portion of each of the sidewalls 48 engages with one of the pins 40 to frictionally lock the pins 40 in a vertical position relative to the base 34 . The locking plate 38 allows the floating pin floor to remain in a desired shape after the force on the pins 40 is removed.
The locking plate 38 may be actuated between the locked and unlocked positions by any mechanism known to a person skilled in the art. For example, an upper arm 52 may extend upwardly from one of the hubs 56 to a slide button 60 . Movement of the slide button 60 causes the hubs 56 to pivot about the axles 58 causing the locking plate 38 to move horizontally and engage, or disengage, with the pins 40 . The finished panel 32 may include a slot providing the upper arm 52 space to move. The slide button 60 and the finished panel 32 may include features for holding the slide button 60 in the locked position. For example, the finished panel 32 may include an L-shaped slot, a slot with a detent, or a tapered slot.
FIG. 4 illustrates a detail view of the pins 40 according to one embodiment. Each of the pins 40 may include an upper portion 62 having a head 64 defining an upper end, and a shaft 66 extending downwardly from a lower end of the upper portion 62 . The upper portion 62 , the head 64 , and the shaft 66 may be integrally formed. The pin 40 may be arranged in the housing 26 with the upper portion 62 received through the mid-plate 36 and with the shaft 66 received through the locking plate 38 and the base 34 . The head 64 may have a diameter larger than the hole 41 in the mid-plate to prevent the head 64 from traveling below the mid-plate 36 . The pin 40 may include a shoulder 68 where the upper portion 62 and the shaft 66 meet. A spring 72 may be disposed on the shaft 66 between the shoulder 68 and the upper surface 42 of the locking plate 38 . The shaft 66 may include a flared end 70 that is larger than the hole 43 in the base 34 to prevent the shaft 66 from dislodging from the base 34 . Alternatively, a clip (or similar feature) may be used to retain the shaft 66 in the base 34 .
In another embodiment, the locking plate may be arranged closer to the mid-plate 36 and engage with the upper portion 62 . Here, the spring 72 is disposed below the locking plate 38 and is disposed between the base 34 and the shoulder 68 .
FIGS. 5 and 6 illustrate alternative embodiments of the pins 40 . Referring to FIG. 5 , a pin 80 includes a head 82 and an internal sleeve 84 . A projection 86 is connected to the base 34 and extends vertically upward therefrom. The projection 86 may include a clip 90 for retaining the projection in the base 34 . Alternatively, the projection 86 and the base 34 may be integrally formed. The pin 80 may be received onto the projection 86 such that the sleeve 84 and the projection 86 can telescopically slide relative to each other. A spring 88 may be disposed between a lower end 92 of the pin 80 and an upper surface 94 of the base 34 .
Referring to FIG. 6 , a pin 100 includes a head 102 and an internal sleeve 104 . A projection 106 is connected to the base 34 and extends vertically upward therefrom. The projection 106 may include a lower portion 108 and an upper portion 110 . The lower portion 108 may have a larger diameter than the upper portion 110 creating a shoulder 112 . The lower portion 108 may have a diameter that is substantially the same as the internal sleeve 104 . The outer surface of the lower portion 108 may form the bearing surface upon which the pin 100 slides. A spring 114 may be disposed on the upper portion 110 between a ceiling 116 of the sleeve 104 and the shoulder 112 .
The shapes of the pins and projection have been shown and described as cylindrical cylinders. But, the pins and the projections may have a different cross-sectional shape in other embodiments. For example, the pins and projections could have a square cross-section. The shape of the holes in the mid-plate and the locking plate correspond to the shape of the pins and vary according to the cross-sectional shape of the pins. The shape of the heads may be the same shape as the main body of the pins or may be a different shape. For example, the pins may have a circular cross-section while the heads may have a square cross-section. A number of different head shapes and sizes may be used. The density of pins 40 varies according to design needs and cost.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms encompassed by the claims. The words used in the specification are words of description rather than limitation, and it is understood that various changes can be made without departing from the spirit and scope of the disclosure. As previously described, the features of various embodiments can be combined to form further embodiments of the invention that may not be explicitly described or illustrated. While various embodiments could have been described as providing advantages or being preferred over other embodiments or prior art implementations with respect to one or more desired characteristics, those of ordinary skill in the art recognize that one or more features or characteristics can be compromised to achieve desired overall system attributes, which depend on the specific application and implementation. These attributes can include, but are not limited to cost, strength, durability, life cycle cost, marketability, appearance, packaging, size, serviceability, weight, manufacturability, ease of assembly, etc. As such, embodiments described as less desirable than other embodiments or prior art implementations with respect to one or more characteristics are not outside the scope of the disclosure and can be desirable for particular applications. | A storage bin includes a base, a plurality of pins supported by and moveable relative to the base, and a locking plate. The locking plate includes a plurality of sidewalls that each define an opening for one of the pins to pass therethrough. Each of the sidewalls are configured to engage one of the pins to lock the pins relative to the base in response to movement of the locking plate. | 1 |
BACKGROUND OF THE INVENTION
The present invention broadly relates to machine drives and, more specifically, pertains to a new and improved construction of an orbital drive for a machine table.
Generally speaking, the drive of the present invention is a drive fo a machine for the manufacture of an electrode-workpiece by means of a form grinding tool of a similar spatial shape, which drive generates the orbital movement necessary for an abrading or grinding operation between the form grinding tool and the electrode-workpiece and changes the eccentricity of such orbital movement.
In other words, the drive means of the present invention is for generating between a blank for an electrode-workpiece having a first spatial configuration and a form-operating tool having a second spatial configuration similar to said first spatial configuration a relative orbital motion requisite for fabricating the electrode-workpiece from the blank by an abrading operation in an abrading machine and for altering a predetermined degree of an eccentricity of the relative orbital motion and comprises at least one motion-generating means for generating the relative orbital motion.
The construction of moulds encompasses the manufacture of moulds for pressure casting, injection molding, punching, hot forming, cold forming, and forging of materials formed of steel or other metals, plastics, and rubber as well as their respective alloys and mixtures. These moulds are frequently complicated and exhibit a three-dimensional construction. The aircraft and automobile industries especially require such type of difficult-to-manufacture forms or moulds which must be manufactured to very close tolerances. By the same method, there are also fabricated tools or construction parts (e.g. in the engine industry) of difficult to machine materials (e.g. high temperature alloys). Such moulds or complex three-dimensional parts such as engine parts are manufactured by spark erosion or electrochemical machines. The electrodes used for this purpose have the same complicated three-dimensional surface as the respective moulds or parts to be manufactured. During the course of the most recent developments, such electrodes have been manufactured on special machines. The manufacture occurs in a manner such that the electrodes are made from the solid material by means of a grinding or abrading operation or a filing operation. The material, could for instance, be graphite. The tool required for this purpose already has substantially the shape of the electrode with an over-dimensional allowance. The grinding or abrading operation or filing operation is accomplished due to a relative movement between the tool and the electrode that is to be machined from the solid piece. A grinding or abrading agent is introduced on to the surface of the tool to support the grinding or filing operation, or the tool already has a rough surface (steel with an eroded surface). Further, a fluid is introduced into the gap between the tool and the workpiece.
The relative movement is composed of two types of movement. The one type is a feed movement of the grinding or filing tool toward or away from the electrode-workpiece (usually vertical). This feed movement can also be circular (usually vertical). The other type is a circular movement of the electrode-workpiece in the horizontal plane, i.e. in a plane substantially perpendicular to the direction of the feed movement. This circular movement can also be termed orbital or planetary movement, and it can be also be spherical
The radius, respectively the eccentricity, of the circular movement can be adjusted. The grinding or abrading operation is carried out until the electrode-workpiece assumes a spatial shape similar to the tool. Then the relative movements are stopped. This is achieved by a gauge, also termed depth gauge, mounted on the machine. The spatial shape of the electrode-workpiece can be made larger or smaller than the spatial shape of the tool. This is accomplished by setting the desired eccentricity of the circular or orbital movement. This known manner of manufacture of the spatial shape of the electrodes has the following disadvantages:
The eccentricity of the relative circular or orbital movement cannot be altered during the grinding or abrading operation. For this purpose the machine must be stopped.
The setting of the eccentricity is not accurately accomplished. This is so because the eccentricity has to be set at two locations of the workpiece support successively and independently of one another. Despite great care on the part of the operator, a certain amount of play cannot be avoided, so that the setting of the eccentricity at the second point will differ from that at the first point.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind, it is a primary object of the present invention to provide a new and improved construction of a drive means which does not exhibit the aforementioned drawbacks and shortcomings of the prior art constructions.
Another and more specific object of the present invention aims at providing a new and improved construction of a drive means of the previously mentioned type which does not display the disadvantages of the known machines for the manufacture of electrodes.
Yet a further significant object of the present invention aims at providing a new and improved construction of a drive means of the character described which is relatively simple in construction and design, extremely economical to manufacture, highly reliable in operation, not readily subject to breakdown or malfunction and requires a minimum of maintenance and servicing. By using a special drive the eccentricity can be altered during the working operation, and additionally continuously, the spatial shape of the finished-machined electrode-workpiece is complementary in every way to that of the tool. With the use of a single tool it is possible to manufacture a number of workpieces of complicated spatial shape.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
FIG. 1 shows as a first exemplary embodiment a transmission arranged between the drive motor and the drive, that generates the relative and orbital motion between the tool and the workpiece;
FIG. 2 shows a top plan view of the transmission taken along the section line A--A of FIG. 1;
FIG. 3 shows the device for performing the relative orbital movement between the tool and the workpiece;
FIG. 4 shows a top plan view of the complete drive with a different exemplary embodiment of the invention; and
FIG. 5 shows as a further exemplary embodiment of the invention, an electrical control circuit for the device that carries out the relative, orbital movement between the tool and the workpiece.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that to simplify the showing thereof only enough of the structure of the drive means has been illustrated therein as is needed to enable one skilled in the art to readily understand the underlying principles and concepts of this invention. Turning now specifically to FIG. 1 of the drawings, the apparatus illustrated therein by way of example and not limitation will be seen to comprise a transmission 1 shown in partial sectional view. A driving wheel or pulley 2, which constitutes a first mechanical power take-off means, driven by an electric motor 3 (FIG. 4) by means of a transmission belt or first connection means 4. A shaft 6, mounted in bearings 5, is connected to the driving wheel or pulley 2 by means of a key, and rotates an outer gear wheel 7 which sets idler gears 8 and 9 in rotation (FIG. 2). These idler gears 8 and 9 rotate about shafts 10 which are fixed to a construction part or machine member 11. The construction part or machine member 11 and the gears 7 and 8, 9 and an inner gear 15 are arranged in a housing 12 of the transmission 1. The construction part or machine member 11 is rotatably mounted in bearings 13 and is set into stepwise or incremental rotation by an electric stepping-motor 14. Assuming now that the stepping-motor is not in operation, the rotational shafts 10 of the idler gears 8 and 9 are in the position shown in FIG. 2. The idler gears 9 set the inner gear wheel 15 in rotation. The inner gear 15 rotates a power take-off wheel or pulley 17, which constitutes a second mechanical power take-off means fixed to its shaft 16. The power take-off wheel or pulley 17 is as shown in FIG. 4, connected to devices or motion-generating means 20 by means of a transmission belt or second connection means 18, which imparts to a machine table 21 of the grinding machine an orbital motion. Instead of a transmission belt 18 there can also be used gears to make the connection between the power take-off wheel or pulley 17 of the transmission 1, and driving wheels or pulleys 26 of the device or motion-generating means 20. The machine table 21 has either a tool or a workpiece fixed to it. Tool and workpiece perform a relative orbital motion. This will be further discussed later.
The eccentricity of this orbital movement is adjusted in the transmission or motion-altering means 1 shown in FIGS. 1 and 2. For this purpose the stepping-motor 14 is activated by means of electrical signals, either from a numerically controlled installation or by the machine operator, in order to rotate the construction part or machine member 11 and the shafts 10 of the idler gears 8 and 9 by one or more steps. Consequently, there is altered the relative rotational speed of the inner gear 15 relative to the outer gear 7. The power take-off wheel or pulley 17 experience the same change of the relative rotational speed relative to that of the driving wheel or pulley 2. The change of rotational speed between the two wheels or pulleys 2 and 17 occurs during the period in which the stepping-motor 14 moves the shafts 10. In this time period the desired amount of the eccentricity of the orbital movement is adjusted. In an example, one step of the stepping-motor 14 brings about a rotational movement of the shafts 10. This brings about an alteration of the orbital movement in the order of magnitude of less than 1 μm related to the radius of the chosen eccentricity. The eccentricity can be adjusted larger or smaller. The direction of the rotational movement of the shafts 10 relative to the rotational movement of the power take-off wheel or pulley 17 determines the setting of the eccentricity in the direction of larger or smaller values.
In FIGS. 1 a sensing means or sensor 32 is shown placed between both of the wheels or pulleys 2 and 17. Such a sensor, which determines the rotational speed of the two wheels or pulleys 2 and 17 and transmits the actual values through lines 33 to a not particularly shown but conventional control circuit, are commercially available. Therefore they will only be described in sufficient detail for understanding the described arrangement. This sensor detects the rotational speed of the two wheels or pulleys 2 and 17 magnetically, capacitatively, inductively or optically. When the rotational speed of the power take-off wheel or pulley 17 no longer coincides with the rotational speed of the drive wheel or pulley 2, due to the setting of the eccentricity, the sensing means or sensor 32 reports the change of the rotational speed through the lines 33 to the control circuit, in which the actual value of the eccentricity is compared with a predetermined reference value. When the two values coincide there is set the required eccentricity. The arrangement of the sensing means or sensor 32 at the transmission 1 of FIG. 1 does not give a very precise indication of the actual value, since the driving belts 4 and 18 and the device 20 and a device 35 can undesirably influence the eccentricity effective at the machine table 21. Therefore it is better if the sensing means 32 is mounted at the devices 20 and 35. This will be discussed in connection with FIG. 3.
FIG. 2 shows an arrangement of three pairs of idler gears 8 and 9. Each pair is offset at an angle of 120° from the other. An arrangement of two pairs with an offset of 180° is also readily possible. Three idler gears may also be placed between the gears 7 and 15.
FIG. 3 shows the device 20 which imparts to the machine table 21 its eccentric orbital movement. The principle is described in the book "INGENIOUS MECHANISMS for designers and inventors", volume 3, fifth edition, 1959, published by the Industrial Press, New York, FIG. 28, page 294. The device comprises a housing 22, fixed to a machine frame 23, a sleeve 24 rotatably mounted in the housing 22, and a shaft 25 rotatably mounted in the sleeve 24. The sleeve 24 is set in rotation by the transmission wheels or pulleys 26 which constitute second drive means. The driving wheel or pulley 26 is connected through the driving belt 4 to the driving wheel or pulley 2 of the transmission 1, with the driving wheel or pulley of the transmission motor 3 and, if desired, with the driving wheels or pulleys 26 of the other devices 20. The shaft 25 is asymmetrically mounted in the sleeve 24 which is shown by the mutually offset rotational axes 27 and 28 of the sleeve 24 and the shaft, 25 respectively. The upper end of the shaft 25 has a crank pin 29 which is rotatably mounted in a mechanical bearig 30 of the machine table 21. A driving wheel or pulley 31, which constitutes first drive means is fixed to the lower end of the shaft 25 and connected by the transmission belt 18 with the power take-off wheel or pulley 17 of the transmission 1 and, if desired, with the wheels or pulleys 31 of the other devices 20. The shaft 25 is set in rotation by the driving wheel or pulley 17 of the transmission 1.
As long as the stepping-motor 14 of the transmission 1 is not in operation, the rotational speeds of the sleeve 24 and the shaft 25 are the same. In this condition nothing is altered.
If, the eccentricity of the orbital movement of the machine table 21 is required to be set, or is to be altered, then, as already described in connection with FIG. 1, the stepping-motor 14 is activated. The altered rotational speed of the power take-off wheel or pulley 17 of the transmission 1 is transmitted to the driving wheel or pulley 31 of the device 20 in FIG. 3, so that the shaft 25 no longer has the same rotational speed as before, but rather has a different rotational speed in relation to the sleeve 24. The shaft 25 rotates relative to the sleeve 24, so that the crank pin 29 takes up a new position. This new position is the amount of the set eccentricity. The sensing means or sensor 32 placed between the wheels or pulleys 26 and 31, detects this and sends corresponding electrical signals over the lines 33 to the control circuit in which the actual value of the eccentricity is compared to the reference value. When the two values are in agreement the required eccentricity has been set. Since the sensing means or sensor 32 has already been discussed in connection with FIG. 1, it will not be discussed further in relation to FIG. 3. The machine table 21 now carries out an orbital movement with the adjusted amount of the eccentricity. The setting or alteration of the eccentricity is accomplished while the machine is in operation, in infinitesimal steps, as often as required, and in larger or smaller increments. The eccentricity is adjusted or changed from only one point. This is particularly advantageous when a number of devices 20 are to impart an orbital motion to the machine table 21. It is unnecessary, as in the known constructions, to individually set at each device 20 the desired value of the eccentricity. In this manner the invention prevents inaccuracies from arising.
In place of the mechanical bearing 30 for the crank pin 29 in the machine table 21 as shown in FIG. 3, there can be used the known hydrostatic bearings. These have not been shown in FIG. 3 to maintain the clarity of the illustration. The advantage of the hydrostatic bearings lies in their ability to provide an automatic equalization when the value of the set eccentricity of the one device 20 differs from the value set at the other device 20. This could occur through aging after long years of service. The result of such differences of the values of the eccentricity, during the orbital movements of the machine table 21, is to introduce large differential forces, at the crank pin 29 and the mechanical bearing 30. The hydrostatic bearings 30 are connected to each other by means of a conduit and equalize these forces. This connecting line can contain a throttle with a pressure sensor that detects the pressure differences and is connected to a not particularly known but conventional control circuit that moves two tension rollers 38 and 39 toward or away from the transmission belt 18 until the pressure differences in the connecting line of the hydrostatic bearing 30 disappear and thus, the eccentricity in the devices is identical.
At this point an explanation will be given of the differing diameters of the wheels or pulleys 2 and 17 of the transmission 1 and the driving wheels or pulleys 26 and 31 of the device 20. As in the illustrated exemplary embodiment of the transmission 1, the speed of revolution of the power take-off wheel or pulley 17, because of the chosen translation, is double the speed of the driving wheel or pulley 2, this rotational speed difference is compensated by different diameters of the wheels or pulleys 2, 17, 26 and 31.
FIG. 4 shows various features. Firstly, there is shown the complete transmission 1 with a number of devices 20 for the orbital movement of the machine table 21. Here the different diameters of the various wheels or pulleys, the necessity of which was explained above, can be clearly seen. A device 35 is shown, constructed in the same way as the device 20, but with its crank pin 29 not mounted in the machine table 21, but in a not particularly shown but conventioal counterweight. This counterweight, which is placed under the machine table 21, acts as an automatic mass compensation when heavy and large workpieces are machined during such time as the radius of the orbital motion of the work table 21 is changed. FIG. 4 also shows freely movable idling rollers or pulleys 36, 37, 38 and 39. The idling rollers or pulleys 36, 37, 38 and 39 can fulfill two functions. Firstly, they serve as tension rolls that assure that the transmission belts 4 and 18 always have the proper tension. By means of weights or springs, the tension rolls can exert a continuous static force on the two transmission belts 4 and 18. Secondly, these rolls or pulleys 36, 37, 38 and 39 can be used to set or alter the eccentricity. In this case, only the rollers or pulleys 38 and 39 are required, which are fixed to a not particularly shown but conventional plunger. The plunger, which could be triggered by a numerical control circuit, and which could be displaced pneumatically, by an electro-motor, magnetically, or hydraulically, pushes the wheels or rollers or pulleys 38, 39 into or against the transmission belt 18, so that the speed of revolution of the driving wheel or pulley 31 and the shaft 25 changes relative to the speed of revolution of the sleeve 24. This occurs only in the device 20 which is in close proximity to the wheels or rollers or pulleys 38 and 39. Depending on which direction the wheels or rollers or pulleys are displaced (either towards the transmission belt 18 or away from it), the eccentricity is altered in the direction of a larger or smaller amounts. Here too, the eccentricity can be changed in infinite manner and as often as desired, in the direction of larger or smaller amounts. Since with this method only small values of the eccentricity can be set, the transmission 1 cannot altogether be dispensed with.
FIG. 5 shows an exemplary embodiment of the invention that is different from the exemplary embodiment of FIGS. 1 and 4 in important aspects. In FIG. 5 no drive motor 3 for the whole drive and no transmission 1 are used; instead a frequency transformer 41 is used that is powered by a supply voltage 40. The supply voltage 40 can be the usual line voltage with an alternating current of 50 Hz or 60 Hz, or a direct-current voltage. In the latter case, in place of the frequency transformer 41, a rectifier is used. Both frequency transformers and rectifiers are well known and are offered in the marketplace by relevant manufacturers. Therefore they will not be described any further here. Both can deliver at their outputs a predetermined power at a predetermined frequency. In the exemplary embodiment of FIG. 5, a frequency transformer 41 is provided. This generates an alternating-current having a power output of 10-20 KW and a frequency of, for example 100 Hz and powers through a line 42, a synchronous motor 43, which by means of power take-off wheel or pulley 44, moves, by means of the drive belt 4, the driving wheels 26 and sleeves 24 of the devices 20 and 35 (FIGS. 3 and 4). The rotational speed of the synchronous motor 43 is controlled by the frequency transmitted through the line 42. The frequency transformer 41 supplies the same frequency, for example, 100 Hz, with a smaller power through an other line 45, to a second frequency transformer 46. If no signals appear on a control line 47, which is connected to a not particularly shown but conventional control circuit, then the second frequency transformer 46 transmits the frequency unaltered to a second synchronous motor 49 by means of the line 48. The second synchronous motor 49, via a power take-off wheel or pulley 50, the transmission belt 18, the transmission wheel or pulley 31 and the shaft 25, rotates the devices 20 and 35 (FIGS. 3 and 4). The sleeves 24 and the shafts 25 of the devices 20 and 35 have the same rotational speed, since the two motors 43 and 49 are powered with the same frequency. At this point it must be mentioned that the transmission wheels or pulleys 26 and 31 of the device 20 shown in FIG. 3, and the power take-off wheels or pulleys 44 and 50 of the synchronous motors 43 and 49 shown in FIG. 5, have the same diameter. The mentioned wheels or pulleys could have grooves which engage teeth of the drive belts 4 and 18.
To set or change the eccentricity of the orbital movement of the machine table 21, a control signal appears on the control line 47 for altering the frequency of the second frequency transformer 46. A control circuit that can generate a control signal is, for instance, described in the Swiss patent application No. 7432/82-6 (82-110). The second synchronous motor 49 receives, through the line 48, the altered frequency and therefore has a different rotational speed at the power take-off wheel or pulley 50 relative to the power take-off wheel or pulley 44 of the first synchronous motor 43. Through the transmission belt 18, the shafts 25 of the devices 20 and 35 have a different rotational speed relative to the sleeves 24, so that the crank pins 29 of the shafts 25 take up a different position. As the eccentricity is only set or changed during the time of the differing rotational speeds of the sleeve 24 and the shaft 25, the control signal is sent through the control line 47 to the second frequency transformer 46 only until the necessary eccentricity is achieved. The detection of this actual value is accomplished by the sensors 32 of FIG. 3, which transmit the actual value to a not particularly shown but conventioal comparator in the control circuit. As soon as the actual value is equal to the reference value of the eccentricity, the control signal on line 47 is removed. The second frequency transformer 46 then supplies the second synchronous motor 49 with the same frequency as the first synchronous motor 43 receives from the first frequency transformer 41, so that the sleeve 24 and the shaft 25 of the devices 20 and 35 once again have the same speed.
With the circuit arrangement of FIG. 5 it is possible to cyclically change the eccentricity in accordance with a predetermined pattern. For instance, if the workpiece is to be ground less on the side located on the X-axis side of the machine table 21 than on the side located on the Y-axis side, then during every revolution the eccentricity in the Y-axis direction must have a larger value than in the X-axis direction. The machine table 21 then carries out an orbital movement in the form of an ellipse. For every revolution of the machine table 21, two different values of eccentricity are set. In this manner the orbital movement can follow the larger part of the curves of Lissajou patterns.
While there are shown and described present preferred embodiments of the invention, it is to be distinctly understood that the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims. | A transmission is provided for a machine that manufactures a workpiece, later to serve as an electrode, by means of a form grinding tool. The tool has a similar spatial shape to that of the workpiece. The drive generates between the tool and the workpiece an orbital motion with changeable eccentricity and which orbital motion is necessary for a grinding or abrading process. A device, which can be structured as a transmission, an electrical control circuit, or as displaceable idling rollers, alters the eccentricity and is in constant operative connection with the driving side and power take-off side of the transmission. In this way there is obtained a constant setting or a cyclical adjustment of the eccentricity throughout the orbital movement. Furthermore, the orbital movement can describe non-circular patterns so that Lissajou patterns can be generated. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is based on and claims the benefit of priority of Japanese Patent Application No. 2005-309906 filed on Oct. 25, 2005, the disclosure of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention generally relates to a vehicular navigation system.
BACKGROUND OF THE INVENTION
[0003] In recent years, a navigation system uses an application software for retrieving map data from information medium such as DVD-ROM or the like and displaying it on a display unit. In this case, the application software has to be switched depending on a format of the map data provided by the DVD-ROM. For example, when the map data is prepared by using a format 1.0 in a region A and by using a format 2.0 in a region B, different types of application software have to be used respectively in each of the region A and region. B to accommodate the difference of data format. The map data in each of the format 1.0 and format 2.0 is retrieved from the medium such as the DVD-ROM, a HDD or the like and is loaded in a memory under a control of a CPU when a user, or a driver of a vehicle, uses the navigation system. The application software used in the navigation system is also retrieved from the medium to the memory of the navigation system.
[0004] The application software executed in, for example, a substrate 1 of the navigation system in FIG. 7A is conventionally determined based on an input of a divided voltage Vd that is applied to a reference input terminal of a CPU 2 after dividing a source voltage Vc by using a series circuit of resistors 3 , 4 . That is, the CPU 2 determines the application software to be used in the navigation system based on the input of a signal that is derived from A/D conversion of the divided voltage Vd. The input to the CPU 2 may be provided as an ID code from a ROM 5 coupled with the CPU 2 when the navigation system is initialized.
[0005] Thus, the conventional navigation system has to have a different product series for respective regions (i.e., for respective data formats) due to above-described operation scheme. That is, the navigation system having the application software designated for each region has to be produced as a different series of products because the application software for a specific region (i.e., for a specific data format) is selected and determined based on a product code of the navigation system. As a result, an increased number of versions of the navigation system leads to a complicated situation such as a version control in a production operation, an inventory operation or the like.
[0006] The navigation system disclosed in Japanese patent document JP-A-H10-208194 has an operation scheme that the navigation system in operation determines and switches product specifications based on a current position of the navigation system detected by using map data.
[0007] However, the navigation system in the above disclosure suffers from difference of map data format. That is, the navigation system does not work properly when the map data for the current position is provided in a format that is not compatible with the application software used in the navigation system.
SUMMARY OF THE INVENTION
[0008] In view of the above-described and other problems, the present disclosure provides an application control system that uses different types of application software for different regions without compromising usability in trans-regional use and simplicity in product version control.
[0009] In one aspect of the present disclosure, the application control system for use in a vehicle includes a current region detector for detecting a current region where the vehicle is operating, an application storage for storing a regional application software in association with a preset region and a control unit for retrieving and executing the regional application software stored in the application storage based on the current region detected by the current region detector. The control unit retrieves and executes the regional application software when the current region is identified as the preset region.
[0010] The application control system having the operation scheme described above can retrieve a different type of the application software for different region, thereby enabling a single model of a specific product (e.g., a navigation system) to cover multiple regions that requires respectively different types of application software. Therefore, production cost of the product is reduced.
[0011] Further, the control unit controls the retrieval of the application software that is suitable to the region where the specific product is operated for the first time. In this manner, the suitability of the application software to the region of the operation is securely guaranteed.
[0012] In another aspect of the present disclosure, the application software is adaptively switched by the application control system according to the region where the application software is operated. In this manner, execution of the application software is always suitably maintained to the region of the operation even when a parent system of the application software travels from region to region.
[0013] In yet another aspect of the present disclosure, the switching timing of the application software is adaptively controlled based on a predetermined condition such as a travel distance, a travel time of the parent system. In this manner, stable execution of the application software and the parent system is guaranteed even when the parent system of the application software frequently crosses a border of the different regions. In addition, the predetermined condition can be controlled to achieved an improved operation condition of the application software and/or the parent system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings, in which:
[0015] FIG. 1 shows a block diagram of an application control system in a first embodiment of the present disclosure;
[0016] FIG. 2 shows a flowchart of a control process of the application control system;
[0017] FIG. 3 shows a table of relationship between regions and application types;
[0018] FIG. 4 shows a flowchart of the control process of the application control system in a traveling condition;
[0019] FIG. 5 shows a flowchart of the control process of the application control system in a traveling condition in a second embodiment;
[0020] FIG. 6 shows a flowchart of the control process of the application control system in a traveling condition in a third embodiment; and
[0021] FIGS. 7A and 7B shows illustrations of a substrate in a conventional system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Embodiments of the present disclosure are described with reference to the drawings. The embodiments of the present disclosure are not necessarily limited to the types/forms in the present embodiment, but may take any form of the art or technique that is regarded within the scope of the present disclosure by artisans who have ordinary skill in the art.
[0023] (First Embodiment)
[0024] A first embodiment of an application control system in the present disclosure is described as a vehicle navigation system with reference to FIGS. 1 to 4 .
[0025] FIG. 1 shows a block diagram of the navigation system 11 in a first embodiment of the present disclosure. The block diagram shows an electrical connection between components in the navigation system 11 . The navigation system 11 has a control unit 12 including a CPU, a ROM, a RAM, an interface circuit and programs for navigation functions stored therein for providing route navigation for a user based on a user input.
[0026] The control unit 12 has a connection to a GPS receiver 13 and various sensors such as a speed sensor 14 , an angular speed sensor 15 , a G sensor (an acceleration sensor) 16 and the like. The control unit 12 detects and calculates a current region (a current position) of the vehicle based on a GPS signal from a satellite received by the GPS receiver 13 . The current position of the vehicle is accurately determined by employing signals from the speed sensor 14 , the angular velocity sensor 15 , the G sensor 16 .
[0027] The control unit 12 also has a connection to a communication unit 17 , a display unit 18 , an operation switch 19 , a speaker 20 , a memory 21 , and a storage medium 22 . The storage medium 22 is used as a medium for provision of application software. The communication unit 17 has a function of a cellular phone for providing communication with an external network and the like. The display unit 18 has a liquid crystal display panel and the like for displaying a signal from the control unit 12 . The display unit 18 also has a touch panel disposed thereon for implementing the operation switch 19 . The operation switches 19 are also implemented as a mechanical switches arranged around the display unit 18 .
[0028] The speaker 20 is used to output navigation guidance voice synthesized by the navigation system, and other guidance voices for notification or the like. The memory 21 is used to store setting information and other information. The memory 21 is also used to as a database for storing travel condition information. The memory 21 uses non-volatile memory device such as an EEPROM or the like for storing information. The storage medium 22 is, for example, information medium such as a CD-ROM, a DVD-ROM or the like for storing map data and-application software for displaying the map data. The information in the storage medium 22 is retrieved by using a data reader (not shown in the figure).
[0029] The operation of the navigation system 11 is described with reference to FIGS. 2 to 4 . Functions of the navigation system beside route navigation function accompanied by map display based on an inputted destination and a current position of the vehicle are omitted from the description for brevity, while characteristics of the present disclosure are described in detail in the following.
[0030] The navigation system 11 starts its operation in the following manner. That is, when a power of the navigation system 11 is turned on, the control unit 12 starts its operation and executes an operation instruction stored in a loader in the ROM of the memory 21 . The execution process of the operation instruction is described as a flowchart in FIG. 2 .
[0031] In step S 1 , the process in the control unit 12 detects a current position of the vehicle based on the GPS signal received by the GPS receiver 13 . The current position is used to determine a current region where the vehicle is traveling. In steps S 2 and S 3 , the process determines whether the current position is detected and displays a progress message on the display unit 18 during detection of the current position (step S 2 :NO). The process returns to step S 1 after step S 3 . The process proceeds to step S 4 when the current position is detected (step S 2 :YES).
[0032] In step S 4 , the process determines application software to be retrieved according to the current position detected in step S 1 . In this case, relationship between the current region and the application software are defined by, for example, a table shown in FIG. 3 . That is, the region A is associated with the application software V1.5, the region B is associated with the application software V2.5, and the region C is associated with the application software V3.5. Each of the application software having various versions is stored in the storage medium 22 .
[0033] In step S 5 , the process in the control unit 12 determines whether the application software already used in the navigation system 11 is in concord with the definition in the table in FIG. 3 . The process proceeds to step S 6 when the application software is already used in the navigation system 11 (step S 5 :YES). The process proceeds to step S 7 when the application software in use is different from the definition (step S 5 :NO).
[0034] In step S 6 , the process executes the application software already in use.
[0035] In step S 7 , the process determines whether a suitable version of the application software is found in the storage medium 22 . The process proceeds to step S 8 when the suitable version in found in the storage medium 22 . The process proceeds to step S 9 when the suitable version is not found in the storage medium 22 .
[0036] In step S 8 , the process retrieves the suitable application software and returns to step S 5 . After passing step S 8 , the determination in step S 5 always becomes affirmative (YES), and the process proceeds to step S 6 .
[0037] In step S 9 , the process displays an error message for notifying a condition that the suitable software is not found in the storage medium 22 due to, for example, a mismatch, an absence of the medium 22 or the software on the medium 22 . The process returns to step S 1 after displaying the error message.
[0038] The operation of the navigation system 11 in a traveling condition is described with reference to a flowchart in FIG. 4 . In this flowchart, the control process executed in parallel with a navigation function switches the application software that suitably handles the map data of a region where the vehicle is currently traveling so as to accommodate different map data format in each of the plural regions, that is, in each of the plural countries or the like when the vehicle is traveling across country borders.
[0039] In steps P 1 to P 3 , the process detects and determines the current position of the vehicle as in steps S 1 to S 3 described before.
[0040] In step P 4 , the process determines whether the application software in use is suitable for the current region. The process proceeds to step P 5 when the software is suitable (step P 4 :YES), and the process proceeds to step P 7 when the software is not suitable (step P 4 :NO).
[0041] In steps P 5 and P 6 , the process executes the application software and determines whether navigation process ends. The process proceeds to step P 10 when the navigation process ends (step P 6 :YES), or the process returns to step P 1 when the navigation process is not ending (step P 6 :NO).
[0042] In step P 7 , the process determines whether the suitable version of the application software is found in the storage medium 22 . The process proceeds to step P 8 when the suitable version in found in the storage medium 22 . The process proceeds to step P 9 when the suitable version is not found in the storage medium 22 .
[0043] In step P 8 , the process retrieves the suitable application software and returns to step P 4 . After passing step P 8 , the determination in step P 4 always becomes affirmative (YES), and the process proceeds to step P 5 .
[0044] In step P 9 , the process displays an error message for notifying a condition that the suitable software is not found in the storage medium 22 due to, for example, a mismatch, an absence of the medium 22 or the software on the medium 22 . The process returns to step P 1 after displaying the error message.
[0045] In step P 10 , the process performs an end process for ending the navigation process. In this manner, the application software is switched whenever the traveling vehicle causes change of the current region.
[0046] The navigation system 11 having the operation scheme of the above description is capable of retrieving the application software that is suitable for the current region when the navigation system 11 is turned on, and is capable of switching the application software when required application software is different from the current application software in use due to the travel of the vehicle across the boundary of the current region. Therefore, a single model of the navigation system 11 can be adaptively used in various regions and/or countries by switching the versions of the application software. In addition, manufacturing process of the navigation system 11 is simplified because of the decrease of the number of the models to cover different countries.
[0047] (Second Embodiment)
[0048] FIG. 5 shows a flowchart of a control process in a second embodiment of the present disclosure. The description of the second embodiment is focused to a portion of the process that is different from the first embodiment.
[0049] The second embodiment assumes the travel of the navigation system 11 around the border of the different regions. That is, the travel of the navigation system 11 along a road that frequently crosses the border of the different regions causes a frequent switching of the application software, thereby causing an unstable condition in the navigation system 11 .
[0050] Therefore, the process in FIG. 5 has an additional step P 11 after the suitability of the application software is determined in step P 4 . Then, in step P 11 , the process determines whether the vehicle has proceeded for more than A km from the boundary of the region. The process proceeds to step P 7 to switch the application software when the vehicle has proceeded for A km or more from the boundary (step P 11 :YES). The process proceeds to step P 5 when the vehicle stays within the A km from the boundary (step P 1 :NO). In this manner, the control unit 12 stably controls the operation of the navigation system 11 when the vehicle travels along the boundary of the different regions.
[0051] (Third Embodiment)
[0052] FIG. 6 shows a flowchart of a control process in a third embodiment of the present disclosure. The difference of the third embodiment from the second one exists in that the process determines whether the vehicle has proceeded B minutes after crossing the boundary. That is, in step P 12 , the process determines a travel time after crossing the boundary of the different regions. The process proceeds to step P 7 when the travel time reaches a predetermined value (step P 12 :YES). The process proceeds to step P 7 when the travel time is less than the predetermined value (step P 12 :NO).
[0053] In this manner, the control unit 12 can stably controls the operation of the navigation system 11 when the vehicle travels along the boundary of the different regions.
[0054] Although the present disclosure has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications will become apparent to those skilled in the art.
[0055] For example, the application software controlled by the application control system may not only control the map data, but also control information such as travel guide information and/or other additional information.
[0056] The current position of the vehicle may not necessarily be determined by the GPS signal, but may be detected and determined based on, for example, a signal that conveys positional information provided by an external source. Further, the current position is detected based on an address, a region name or the like.
[0057] The storage medium 22 may be different from the CD-ROM, the DVD-ROM or the like. That is, the storage medium 22 may be non-volatile memories such as a hard disk device, a flash memory device, or a storage device such as an IC card or the like. Further, the information may be stored in an external storage by using a radio communication or the like.
[0058] The application control system may also be applicable to a portable information terminal that is carried by a user, or applicable to a system such as a personal computer, a cellular phone or the like.
[0059] Further, use of a so-called hysteresis function for controlling the switching timing of the application software in the second and third embodiment may be selected by the user. The amount of the hysteresis may also be selected and/or determined by the user for the improved adaptability.
[0060] Such changes and modifications are to be understood as being within the scope of the present invention as defined by the appended claims. | An application control system for use in a vehicle includes a current region detector for detecting a current region where the vehicle is operating, an application storage for storing a regional application software in association with a preset region and a control unit for retrieving and executing the regional application software stored in the application storage based on the current region detected by the current region detector. The control unit retrieves and executes the regional application software when the current region is identified as the preset region. | 7 |
BACKGROUND OF THE INVENTION
1. Technical Field
The present invention relates to a valve system for an internal combustion engine having nonrotatable rocker shafts for mounting rocker arms or finger followers which actuate intake and exhaust popper valves.
2. Description of Prior Art
In designing a valve system or valve train mechanism for an internal combustion engine which is expected to operated at high engine speed, it is necessary to limit component deflections at the maximum rated speed. As an approximation, limiting values could comprise 0.0015 inches deflection for a rocker arm, measured at the valve tip, and 0.00075 inches of deflection of the rocker shaft, measured at the location of the rocker arm. In engines using cylindrical rocker shafts, a typical way of mounting the shafts involves placing the shaft as a slip-fit in a round mounting bore formed in the cylinder head. This causes problems because tolerances permit movement of the rocker shaft of the magnitude recited above. This is undesirable because, as noted above, any loss of stiffness due to wobble or movement of the parts of the valve system will reduce the maximum satisfactory operating speed of the valve system. The present invention mitigates this problem because it provides support for a rocker shaft at three circumferential locations which are approximately equally spaced. The rocker shaft is supported with a robustness which is essentially independent of dimensional tolerances of the rocker shaft and the mounting saddles. In conventional saddle mounting systems in which a nonrotatable rocker shaft is placed in a semicircular saddle, the diameter of the saddle must be sufficient so that the shaft neither touches solely at the bottom of the saddle, in which case the shaft would be free to rock back and forth in the presence of side loading imposed by the rocker arms and valve springs. Also, the shaft should not be pinched between the upper edges of the saddle because this will produce unwanted stresses in both the saddle and the shaft. As a result, it is exceedingly difficult to produce a semicircular saddle and shaft having appropriately sized diameters during mass production of engines. This manufacturing problem, which is present in other systems, is solved by the present invention.
SUMMARY OF THE INVENTION
A valve system for an internal combustion engine includes a plurality of intake and exhaust poppet valves, a plurality of rocker arms for actuating the poppet valves, a cylinder head having the popper valves mounted therein, at least one fixed rocker shaft for mounting the rocker arms, with the rocker shaft having a cylindrical outer surface, and a plurality of saddles formed in an outer surface of the cylinder head for nonrotatably mounting the rocker shaft, with the saddles each having opposing arcuate pads which form a generally semicircular mount for the rocker shaft. Each of the mounting pads is concave and has a radius of curvature which is greater than the outside radius of curvature of the rocker shaft, with the center of the radius of curvature of each of the pads being offset in opposite directions from the centerline of the shaft such that the shaft and the pads make line contact in a region proximate to the arc midpoint of each pad. The arcuate pads preferably have a circular form generated by an invariant radius of curvature.
According to yet another aspect of the present invention, a lubricant supply subsystem comprises a lubricant passage extending from a lubricant supply system of the engine through the concave surface of at least one of the pads at the location of the line contact between the pad and the rocker shaft, with the lubricant then passing through a port formed in the rocker shaft and into an inner volume of the rocker shaft.
According to a preferred embodiment, the rocker shaft comprises a hollow cylinder having an axially extending interior passage for conveying lubricating oil to the rocker arms.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a cylinder head having a valve system according to the present invention.
FIG. 2 is a partially schematic representation of a rocker shaft mounting system according to the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
As shown in FIG. 1, a valve system for an internal combustion engine includes a multitude of components which are attached to cylinder head 10. In this case, each cylinder is serviced by two intake valves 12 and a single exhaust poppet valve 14. Each pair of intake valves 12 for a given cylinder is actuated by a single intake rocker arm 17, which is bifurcated and which contacts both of intake valves 12 for a single cylinder. Each of intake rocker arms 17 is driven in conventional fashion by means of a pushrod (not shown) which extends up from a camshaft located in a lower part of the engine. Intake rocker arms 17 are mounted upon intake rocker shaft 16, which is shown with greater clarity in FIG. 2.
Exhaust valves 14 are driven by exhaust rocker arms 19, which are actuated by means of secondary pushrods 25 which extend across the top of the cylinder head between exhaust rocker arm 19 and intermediate rocker arm 21. The sole function of intermediate rocker arm 21 is to act as a bellcrank between secondary pushrod 25 and a primary pushrod (not shown) extending between intermediate rocker arm 21 and the camshaft.
As is readily understood by those skilled in the art, the present system causes considerable side loading on both intake rocker shaft 16 and exhaust rocker shaft 18. As noted above, it is necessary to maintain precise mounting geometry of both of the rocker shafts so as to maintain precision operation of both intake and exhaust valves, particularly during higher engine speeds. This precise geometry is promoted by the structure in FIG. 2. A plurality of saddles 20 is formed in the upper surface of cylinder head 10. Saddles 20 provide a means for nonrotatably mounting intake rocker shaft 16 and exhaust rocker shaft 18. Each saddle has a pair of arcuate pads 22 and 24. Arcuate pad 22 has a concave surface 22a, whereas arcuate pad 24 has a concave surface 24a. Both of these concave surfaces may be formed by a longitudinal pass of a forming tool such as a milling cutter or other type of cutter capable of producing a circular surface. Arcuate pad 22 has a radius R 22 and arcuate pad 24 has a radius R 24 . These radii of curvature are, in this case, equal, and both have a value greater than the outside radius of rocker shaft 16.
As seen in FIG. 2, center C 1 of arcuate pad 22 is offset from the center lines C 3 and C 4 of rocker shaft 16 such that the contact patch between the outer surface of rocker shaft 16 and concave surface 22a is a line contact occurring at location L 22 which is the arc midpoint of concave surface 22a. Similarly, center C 2 of arcuate surface 24a is offset in an opposite direction from the center line of shaft 16 to achieve the line contact labeled L 24 . As is the case with L 22 , line contact L 24 is situated 45° from the vertical centerline of rocker shaft 16. Because contact between saddle 20 and shaft 16 is two lines L 22 and L 24 , situated at the arc midpoints of arcuate pads 22 and 24, shaft 16 may be reliably, repeatably, and robustly placed in its desired position--a position which may be maintained largely independent of manufacturing tolerance stackup. This obviates the problems encountered with other mounting systems in which engineers and engine builders attempted to keep the outside diameter of a shaft, such as shaft 16, closely matched to the inside diameter of a bed plate or saddle such as saddle 20. Such a scheme was often destined for failure because of the tendency for the shaft to either be positioned tightly against the bottom of the saddle or at the top edges of the saddle. With the rocker shaft at the bottom, the shaft would tend to rock in the saddle; when wedged at the top of the saddle, the rocker shaft and its fastening system could induce excessive stress in both the saddle and the rocker shaft itself.
Each of rocker shafts 16 and 18 are maintained in their respective saddles by means of retaining bolts 34 and clamps 36. Each of bolts 34 has a load bearing surface 34a in contact with clamp 36, which itself has an arcuate contact surface 36a providing contact with the outer surface of rocker shaft 16. Fastener 34 passes through relief groove 26, which is milled, of formed in any other acceptable manner, in the lower surface of saddle 20. The combination of the arcuate engagement of clamp 36 with shaft 16 as well as engagement of shaft 16 with arcuate surfaces 22a and 24a solidly mounts shaft 16 to cylinder head 10. Those skilled in the art will appreciate in view of this disclosure that the contact pattern between rocker shaft 16 and clamp 36 need be only a line contact on one side of fastener 34 in order to securely fasten the rocker shaft to saddles 20. Those skilled in the art will further appreciate, in view of this disclosure, that clamps 36 may be located precisely by bolts 34 by piloting clamps 36 upon the upper portions of the shanks of bolts 34. Clamps 36 not only maintain rocker shafts 16 in their saddles, but also provide thrust surfaces for maintaining the various rocker arms in their desired axial locations.
The present cylinder head advantageously uses bolt bosses 38, through which cylinder head bolts 40 pass, for the dual purpose of providing a place for saddles 20 along with threaded bores 35 for fasteners 34.
According to another aspect of the present invention, cylinder head lubricant passage 28 provides lubricant, in this case, engine oil, through port 30 formed in intake rocker shaft 16. After flowing through port 30, lubricant flows into bore 32, which forms the interior of rocker shaft 16. Lubricant is allowed to flow through bore 32 and then through suitably located outlet ports (not shown) so as to lubricate intake rocker arms 17. Exhaust rocker shaft 18 has a similar axially directed bore for the purpose of providing oil to exhaust rocker arms 19.
While the invention has been shown and described in its preferred embodiments, it will be clear to those skilled in the arts to which it pertains that many changes and modifications may be made thereto without departing from the scope of the invention. For example, the present invention may be employed with overhead camshaft engines having followers which are journaled to a common rocker shaft. | A valve system for an internal combustion engine with multiple intake and exhaust valves driven by rocker arms includes a fixed, nonrotatable, rocker shaft for mounting the rocker arms, with the rocker shaft being mounted in saddles formed in an outer surface of the cylinder head. Each of the saddles has opposing pads forming a generally semicircular mount for the rocker shaft, with the mounting pads being offset in opposite directions such that the rocker shaft and the pads make line contact in a region proximate the arc midpoint of each pad. | 5 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 09/806,834, filed Apr. 5, 2001, which is incorporated herein by reference in its entirety. U.S. application Ser. No. 09/806,834 is the National Stage of PCT/FR99/02375, filed Oct. 5, 1999, which claims priority to French application FR 98-12435, filed Oct. 5, 1998.
BACKGROUND
[0002] The present invention relates to a cosmetic method for preventing and/or treating skin stretchmarks, and to the use of a composition to prepare a dermatological medicinal product for preventing and/or treating stretchmarks.
[0003] Stretchmarks are visible marks on the skin resulting from the skin being stretched due to a gain in weight or mechanical stresses, which usually concern women, after puberty or a first pregnancy. About 50% of pregnant women develop stretchmarks, on the thighs, the abdomen and/or the breasts. Stretchmarks may also appear during physiological or pathological states such as obesity, tuberculosis and typhoid fever, and also during a relatively intensive dietary regime. The treatment of stretchmarks has been described, for example, in the article by P. Zheng et al., “Anatomy of striae”, British Journal of Dermatology 112:185-193 (1985), in which it is especially reported that stretchmarks are scars resulting from an inflammation process which destroys elastic fibers.
[0004] Since then, many compounds have been proposed as active principles for treating stretchmarks, such as, for example, tretinoin (or all-trans-retinoic acid). According to the article by R. E. B. Watson et al., “Fibrillin microfibrils are reduced in skin exhibiting striae distensae”, British Journal of Dermatology 138:931-937 (1998), it would appear that tretinoin has an anti-stretchmark action with a tendency toward essentially restoring the network of fibrillins, which are the main constituent of the microfibrils within elastic fibers, when compared with other constituents of the extracellular matrix.
[0005] However, although the active compounds of the prior art produce a stretchmark-regressing effect, it nevertheless remains that the results obtained are not entirely satisfactory, in particular given the well-known skin intolerance problem of tretinoin. There has thus hitherto been a real demand for the development of a product for efficiently preventing and/or treating, with acceptable skin tolerance, this complex and particularly unattractive problem of stretchmarks.
[0006] It has now been found, entirely surprisingly and unexpectedly, that the use of certain peptides makes it possible entirely significantly to prevent and/or treat skin stretchmarks, in a manner which is acceptable as regards skin tolerance.
SUMMARY
[0007] A subject of the present invention is thus a cosmetic method for preventing and/or treating skin stretchmarks, characterized in that a composition is applied to the areas of skin liable to form or comprising stretchmarks, this composition comprising, in a suitable vehicle, at least one anti-stretchmark agent chosen from the group consisting of soya peptides and tripeptides consisting of the amino acids glycine, histidine and lysine, and mixtures of these peptides.
[0008] According to the present invention, the expression “prevention of skin stretchmarks” means an action which prevents or at least reduces the formation of stretchmarks, i.e. their length, width and/or depth, in the context of a cosmetic or dermatological treatment, by applying the composition before and during an event known to cause the appearance of stretchmarks, such as pregnancy. According to the present invention, the expression “treatment of skin stretchmarks” means an action which visibly and measurably regresses, i.e. resorbs, in the context of a cosmetic or dermatological treatment, already-formed stretchmarks, i.e. their length, width and/or depth.
[0009] Thus, the composition used according to the invention may be applied to areas of skin liable to form stretchmarks, comprising stretchmarks in the process of being formed or even comprising already-formed stretchmarks.
[0010] The soya peptides in the composition used according to the present invention may be any peptide obtained by hydrolysis of proteins extracted from soya, under operating conditions known to those skilled in the art, in other words any soya protein hydrolysate. These soya peptides are preferably peptides which have also undergone a fermentation with a strain of microorganism. In general, a fermented soya peptide is obtained by placing a soya peptide in a fermenter in the presence of glucose, mineral salts and a given strain of microorganism, under controlled temperature, pH, oxygenation and time conditions. After the fermentation, the fermented soya peptide is obtained by conventional separating and filtering operations. This technique is especially used by the company Coletica which thus sells various fermented plant protein hydrolysates. The fermented or unfermented soya peptides in the composition used according to the present invention preferably have a molecular weight of between about 200 and about 20,000 daltons, as measured, for example, by electrophoresis.
[0011] One soya peptide which is particularly preferred for the composition used according to the invention is the fermented peptide known as “Phytokine®” as sold by the company Coletica.
[0012] This specific fermented soya peptide, with an average molecular weight of about 800 daltons, is obtained by fermenting a soya peptide with the Lactobaccillus microorganism strain, and its amino acid composition is as follows:
Number of residues per 100 Hyp . . . 0.39 Asp . . . 12.64 Thr . . . 2.93 Ser . . . 4.29 Glu . . . 20.08 Pro . . . 7.31 Gly . . . 7.95 Ala . . . 7.76 Cys . . . ND* Val . . . 5.59 Met . . . 0.96 Ile . . . 4.46 Leu . . . 7.42 Tyr . . . 1.38 Phe . . . 3.39 His . . . 2.12 Hyl . . . 0.09 Lys . . . 5.73 Trp . . . ND* Arg . . . 5.53 βAla . . . ND
[0013] The expression “tripeptide consisting of the amino acids glycine, histidine and lysine” in particular means tripeptides of Gly-His-Lys sequence, the amino acids of which may be in D, L or DL form, which may be conjugated with a carboxylic acid such as acetic acid, in the form of a complex with a metal such as zinc or copper.
[0014] Among the tripeptides consisting of the amino acids glycine, histidine and lysine, it is preferred to use the tripeptide “Kollaren-CPP” whose INCI name is “tripeptide-1”, as sold by the company Seporga. “Kollaren-CPP” is a tripeptide having the sequence Gly-His-Lys conjugated with acetic acid (acetate) in the form of a complex with zinc.
[0015] Thus, more particularly, the present invention relates to a cosmetic method for preventing and/or treating skin stretchmarks, characterized in that the anti-stretchmark agent is chosen from the group consisting of the soya peptide Phytokine® and the tripeptide Kollaren-CPP®, and mixtures of these peptides.
[0016] In the composition used according to the invention, the proportion of anti-stretchmark agent is between about 0.1% and about 10% by weight relative to the total weight of the composition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] According to one preferred embodiment, the composition used according to the present invention also comprises at least one α-hydroxy acid, in combination with the anti-stretchmark agent. The reason for this is that it has been found, surprisingly, that the joint use of an α-hydroxy acid makes it possible at least to potentiate the activity of the anti-stretchmark agent, if not, in certain cases, to obtain a synergistic effect in preventing and/or treating stretchmarks.
[0018] The α-hydroxy acid used according to the invention may be any α-hydroxy acid which produces an exfoliation and/or moisturization effect on the skin, such as, for example, citric acid, pyruvic acid, glycolic acid or lactic acid.
[0019] One α-hydroxy acid which is particularly preferred for the composition used according to the invention is lactic acid.
[0020] The proportion of α-hydroxy acid is preferably between about 0.1% and about 20% by weight relative to the total weight of the composition.
[0021] Preferably, the composition used according to the invention comprises an anti-stretchmark agent chosen from the group consisting of the soya peptide Phytokine® and the tripeptide Kollaren-CPP®, and mixtures of these peptides, in combination with lactic acid as α-hydroxy acid. The reason for this is that it has been found that such a combination provides a particularly advantageous effect as regards the anti-stretchmark activity of the composition used according to the invention.
[0022] Finally, the composition used according to the invention also advantageously comprises a compound intended to adjust the pH of the composition according to the invention to a value of between about 2 and about 4, and preferably to a value of about 3.5, in particular to partially neutralize the α-hydroxy acid. In particular, arginine or an alkanolamine such as triethanolamine may be used.
[0023] According to one particularly preferred embodiment, the composition used according to the invention also comprises a substance-P and neuropeptide-Y (or NPY hereinbelow) inhibitor compound. This additional compound may be chosen from the substance-P and NPY inhibitor compounds known to those skilled in the art.
[0024] However, one substance-P and NPY inhibitor compound that is particularly preferred is a specific extract comprising an active peptide fraction, obtained from green algae (or chlorophycea) known as “ Enteromorpha compressa ” (or “Ao-nori” or “yellow green nori”), such as the product sold by the company Secma under the name “Enteline 2” (INCI name: “butylene glycol, glycerol, Enteromorpha compressa extract; CAS No. 92128-82-0).
[0025] Specifically, it has been observed that the use of this specific substance-P and neuropeptide-Y inhibitor compound makes it possible to obtain a particularly advantageous tolerance effect of the composition used according to the invention, in particular given the irritant effects of the α-hydroxy acid, in particular of lactic acid.
[0026] The proportion of substance-P and NPY inhibitor compound in the composition used according to the invention is preferably between about 0.1% and about 5% by weight relative to the total weight of the composition.
[0027] Preferably, the composition used according to the invention comprises an anti-stretchmark agent chosen from the group consisting of the soya peptide Phytokine® and the tripeptide Kollaren-CPP® and mixtures of these peptides, in combination with lactic acid and the Enteromorpha compressa extract.
[0028] The composition used according to the invention also comprises a suitable vehicle, which may be any vehicle among those known to a person skilled in the art, in order to obtain a cosmetic or dermatological composition which may be used according to the invention, in the form of a cream, a lotion, a gel, an ointment, etc., optionally in the form of an emulsion, also with components known to those skilled in the art for improving, modifying or stabilizing the composition from a cosmetic or dermatological point of view.
[0029] In particular, the composition used according to the invention may also comprise compounds contributing secondarily to the anti-stretchmark action, such as the extract of Sophora japonica which contributes toward controlling the vascularization of stretchmarks and thus their color, or alternatively silanol compounds such as methylsilanyl lactate, or trace elements based on copper and zinc which are constituents of dermal proteins, such as zinc gluconate and copper gluconate.
[0030] The operating conditions for preparing the composition used according to the invention form part of the general knowledge of a person skilled in the art.
[0031] Finally, a subject of the present invention is also the use of a composition as defined above to prepare a dermatological medicinal product for preventing and/or treating skin stretchmarks.
[0032] The examples which follow are intended to illustrate the present invention and should not in any way be interpreted as restricting its scope.
EXAMPLE 1
[0033] Anti-stretchmark cream with a pH of 3.5.
% Cetyldimethicone, sold under the name “Albilwax 9801” 2 by the company Goldschmitt Octyl sebacate 5 Isononyl isononanoate 7 Mixture of glyceryl stearate, cetearyl alcohol, cetyl 2.5 palmitate and cocoglycerides, sold under the name “Cutina CBS” by the company Sidobre Sinnova Methyl paraben 0.1 Propyl paraben 0.1 Water qs 100 PEG 300 5 Triethanolamine 4.8 Sepigel 305 ® (thickener sold by the company SEPPIC) 5.5 Phytokine ® 2 Lactic acid 10 Enteline 2 ® 0.4 Sophora japonica 3 Methylsilanyl lactate 3 Zinc gluconate 0.2 Copper gluconate 0.2 Fragrance 0.35
EXAMPLE 2
[0034] Anti-stretchmark cream with a pH of 3.5.
% Cetyldimethicone, sold under the name “Albilwax 9801” 2 by the company Goldschmitt Octyl sebacate 5 Isononyl isononanoate 7 Mixture of glyceryl stearate, cetearyl alcohol, cetyl 2.5 palmitate and cocoglycerides, sold under the name “Cutina CBS” by the company Sidobre Sinnova Methyl paraben 0.1 Propyl paraben 0.1 Water qs 100 PEG 300 5 Triethanolamine 4.8 Sepigel 305 ® (thickener sold by the company SEPPIC) 5.5 Kollaren CPP ® 2.5 Lactic acid 10 Enteline 2 ® 0.4 Sophora japonica 3 Methylsilanyl lactate 3 Zinc gluconate 0.2 Copper gluconate 0.2 Fragrance 0.35
EXAMPLE 3
[0035] Clinical study to evaluate the effect of the compositions of Examples 1 and 2 on the regression of stretchmarks, on the basis of an instrumental evaluation combined with a clinical evaluation, after repeated applications to the skin, under the normal conditions of use, for 6 weeks, in 9 adult female volunteers.
1. Object of the Study
[0036] The object of the present study is to evaluate and compare the effect of the compositions of Examples 1 and 2 above on the “regression” of stretchmarks, by calorimetric measurements of stretchmarks on the skin of the thighs, combined with measurements of biomechanical parameters and with a clinical evaluation, after repeated applications to the skin for 6 weeks, under the normal conditions of use, in 9 adult female volunteers.
2. Relevance of the Test
[0037] Measurement of the viscoelastic parameters of the skin using a Cutometer® makes it possible to determine the effect of a product on the skin's biomechanical properties, after repeated applications. This apparatus measures the deformation of an area of skin subjected to a mechanical'suction stress, and its power of recovery (Wilhelm et al., 1993). Specifically, the viscoelastic properties of the skin are correlated with the notions of suppleness, elasticity and firmness of the tegurment.
[0038] Measurements using a Chromameter moreover make it possible to evaluate objectively the effect of a product on skin coloration, in an area with stretchmarks, compared with a control area (normal skin).
[0039] When combined with a clinical evaluation on the basis of scores by the Study Director, these instrumental techniques make it possible to evaluate the effect of a product on stretchmarks, in a panel of 9 adult female volunteers, after 6 weeks of twice-daily applications, under the normal conditions of use.
3. Volunteers
[0040] 9 panel members were finally accepted by the Study Director on the basis of a clinical examination specific to the study, carried out just before the start of the trial. They all participated in the entire trial.
[0041] The analysis of the results was thus made on a panel of 9 adult female volunteers (or 8 for the colorimetric measurements) from 20 to 31 years old (average age: 26 years old), showing stretchmarks dating back less than 8 months.
4. Protocol
[0042] 4.1 Initial Clinical and Instrumental Evaluations:
[0043] 4.1.1. Determination of the Viscoelastic Parameters:
[0044] These parameters were evaluated on the skin of both thighs using a Cutometer™ (Courage+Khazaka, Germany), on two diametrically opposite areas delimited on the left and right thighs of each of the adult female volunteers specifically selected and recruited to carry out and objectivize this type of trial. These measurements were taken on an area showing stretchmarks, and also on an adjacent area without stretchmarks (“normal skin”), after marking the areas using a transparent plastic card bearing anatomical markers.
[0045] 4.1.2. Coloration Measurement
[0046] The evaluation of the coloration of a stretchmark was carried out on the skin of both thighs and of an adjacent control area (free of stretchmarks) by analysis of the clarity variable “L*” and the chromaticity coordinates “a*” and “b*”, using a CR 321 Chromameter (Minolta) fitted with a cone for colorimetric measurements on an area 3 mm in diameter.
[0047] These measurements were carried out after a rest period of about 20 minutes, in an air-conditioned room with an ambient temperature maintained at 22±2° C. and a relative humidity of 50±5%, by means of a microprocessor connected to temperature and humidity sensor-transmitters so as to achieve a stable equilibrium of water exchange between the skin of each panel member and the surrounding environment. The stability of these parameters was monitored and printed out continuously using a multipath recorder.
[0048] 4.13. Clinical Evaluation
[0049] The following judgement criteria were evaluated, by the Deputy Study Director, on the basis of 9-point clinical scores (1 to 9), on both thighs, for each of the volunteers:
[0050] size of the stretchmarks,
[0051] color of the stretchmarks,
[0052] relief of the stretchmarks.
[0053] 4.1.4. Photographs
[0054] Color macrophotographs of an area of skin of each thigh were taken, using a Nikon F-801S camera fitted with a Nikon 105 MM macro objective lens, under lighting of “daylight” type (6500° K.).
[0055] 4.2. Determination of the Efficacy of the Products After Repeated Applications
[0056] 4.2.1. Application Methods
[0057] The products studied were applied twice a day for 6 consecutive weeks, under the normal conditions of use, by the volunteer herself at home, on the skin of both thighs (1 product for each thigh according to a randomization—binomial law).
[0058] In order to achieve the maximum standardization of the study conditions, the products studied were applied once a week, in the presence of the laboratory staff.
[0059] 4.2.2. Effect on the Viscoelastic Properties of the Skin (Tonicity, Firmness, Suppleness, Elasticity)
[0060] The viscoelastic parameters of the skin of both thighs (areas with and without stretchmarks) marked out accurately relative to the first day of the test and according to the same principle, were determined after the sixth week of use of the products. This evaluation was carried out 16 to 24 hours after the last application of the products, by the laboratory staff, so as to specifically measure the variations in the elastic parameters of the skin tissue that are induced by the repeated uses.
[0061] 4.2.3. Effect on the Coloration of the Skin
[0062] The skin coloration measurements were carried out using a Chromameter® after the 6 weeks of use, on the areas determined during the first day of the study and accurately marked out, according to the same principle (areas with and without stretchmarks).
[0063] 4.2.4. Clinical Evaluations and Self-evaluations
[0064] The evaluations of the skin of both thighs were carried out by the Study Director, on the basis of 6-35 point clinical scores, according to the same principle as that followed during the initial determination, after the 6 weeks of application.
[0065] 4.2.5. Photographs
[0066] Color macrophotographs of the areas determined during the first day of the study and accurately marked out were taken, according to the same principle, after the 6 weeks of application.
[0067] 4.3. Analysis and Interpretation of the Results
[0068] 4.3.1. Biomechanical Parameters
[0069] The mean values of the viscoelastic parameters determined on D1 and D43 on the 2 thighs (areas with stretchmarks and areas without stretchmarks) were calculated by determining the arithmetic mean and the error obtained relative to the mean (S.E.M.) of the individual measurements taken on all of the panel members.
[0070] The initial values obtained on the right and left thighs (before the first application of the products) were compared by an analysis of variance (ANOVA, significance: p<0.05).
[0071] The values obtained after using the products for 6 weeks were compared with the initial values, determined before the first application, by the paired serial Student “t” test (“one-tail”, significance: p<0.05), for each of the areas (right and left thighs, areas with and without stretchmarks).
[0072] The effects obtained on the right and left thighs (areas with and without stretchmarks) were compared by an analysis of variance (ANOVA, significance: p<0.05) and by the multiple comparison test (“L.S.D.”), relating to the differences calculated between the values acquired after the 6 weeks of use and the initial values (ΔD43-D1).
[0073] The mean variation percentages of the parameters evaluated during the trial were calculated for each area of skin, after the 6 weeks of application, relative to the initial value, starting with the mean values obtained for all of the panel members.
[0074] 4.3.2. Colorimetric Measurements
[0075] The mean values of the colorimetric parameters, determined at each stage of the study, were calculated by determining the arithmetic mean and the error relative to the mean (S.E.M.) of the individual measurements taken on all of the panel members.
[0076] These determinations relate to the clarity variable “L*”, the chromaticity coordinates “a*” and “b*” and the Individual Typological Angle ITA°, calculated according to the following formula:
ITA°=[arc tangent (L*−50)/b*]180/3,14159
[0077] The initial values obtained on the right and left thighs (before the first application of the products) were compared by an analysis of variance (ANOVA, significance: p<0.05).
[0078] The values obtained after using the products for 6 weeks were compared with the initial values, determined before the first application, by the paired serial Student “t” test (“one-tail”, significance: p<0.05), for each of the areas (right and left thighs, areas with and without stretchmarks).
[0079] The effects obtained on the right and left thighs (areas with and without stretchmarks) were compared by an analysis of variance (ANOVA, significance: p<0.05) and by the multiple comparison test (“L.S.D.”), relating to the differences calculated between the values acquired after the 6 weeks of use and the initial values (ΔD43-D1).
[0080] The mean variation percentages of the parameters evaluated during the trial were calculated for each area of skin, after the 6 weeks of application, relative to the initial value, from the mean values obtained for all of the panel members.
[0081] 4.3.3. Clinical Scores
[0082] The mean values of the judgement criteria determined at each stage of the study on the basis of the clinical scores were calculated by determining the arithmetic mean and the standard deviation (Sd) of the individual data acquired for all of the panel members.
[0083] The values obtained, after applying the products, were compared with the values determined during the first day of the trial (initial evaluations) by the paired serial Wilcoxon test (“one-tail”, significance: p<0.05), for each area treated.
[0084] The effect of the products was compared by a paired serial Wilcoxon test (“one-tail”, significance: p<0.05) relating to the values obtained before and after repeated applications.
[0085] The mean variation percentages of each of the evaluation criteria were calculated relative to the initial data, starting with the mean values obtained for all of the volunteers.
5. Results and Conclusion
[0086] 5.1. Cutometric Measurements
[0087] The statistical analysis previously demonstrated that the initial values of the biomechanical parameters were identical, firstly on each of the areas without stretchmarks, and secondly on each of the areas with stretchmarks. Statistically significant differences were moreover revealed between the areas with and without stretchmarks, reflecting a skin which is slacker and less elastic in the areas with stretchmarks.
[0088] 5.1.1. Anti-stretchmark Cream of Example 1
[0089] The analysis of the results made it possible to reveal, after 6 weeks of application, relative to the initial measurement:
[0090] On the area without stretchmarks:
[0091] a tendency toward decreasing the Uf (final elongation), by about 4% during the 1st and 3rd stress,
[0092] a statistically significant decrease in Uv/Ue (degree of viscoelasticity determining the size of the viscous response relative to the elastic response), of about 14%.
[0093] On the area with stretchmarks:
[0094] a tendency toward decreasing the Uf (final elongation), by about 2% during the 1st and 3rd stress,
[0095] a stabilization of Ua/Uf (degree of recovery after stress)
[0096] a statistically significant decrease in Uv/Ue (degree of viscoelasticity determining the size of the viscous response relative to the elastic response) of about −17%.
[0097] A significant improvement in the firmness and tonicity components is thus found, on the area with stretchmarks.
[0098] 5.1.2. Anti-stretchmark Cream of Example 2
[0099] The analysis of the results made it possible to reveal, after 6 weeks of application, relative to the initial measurement:
[0100] On the area without stretchmarks:
[0101] a statistically significant decrease in Uf (final elongation), of about 6% during the 1 st and 3rd stress,
[0102] a stabilization in Ua/Uf (degree of recovery after stress)
[0103] a stabilization of Uv/Ue (degree of viscoelasticity).
[0104] On the area with stretchmarks:
[0105] a tendency toward decreasing the Uf (final elongation), by about 2% during the 1 st stress,
[0106] a stabilization of Ua/Uf (degree of recovery after stress),
[0107] a tendency toward decreasing the Uv/Ue (degree of viscoelasticity), by about 9%.
[0108] A marked tendency (non-significant for the 9 panel members) toward improving the tonicity and firmness components of the skin in the area with stretchmarks is thus found.
[0109] 5.2. Colorimetric Measurements
[0110] The statistical analysis previously demonstrated that the initial values of the calorimetric parameters were identical, firstly on each of the areas without stretchmarks, and secondly on each of the areas with stretchmarks. It should be noted that the skin of the areas with stretchmarks (before and after using the products for 6 weeks) was paler than that of the areas without stretchmarks (higher clarity variable L* and higher I.T.A.°).
[0111] No favorable and statistically significant improvement in the colorimetric parameters was recorded, after using each of the products, irrespective of the areas (with and without stretchmarks).
[0112] 5.3. Clinical Evaluations by the Study Director
[0113] The analysis of the results made it possible to reveal a statistically significant improvement in the following criteria, with the exception of the length of the stretchmarks. A significant difference was moreover noted between the two products studied for this criterion, reflecting a greater regression of stretchmarks on the area treated with the anti-stretchmark cream of Example 2.
TABLE 1 Anti-Stretchmark Cream Example 1 Example 2 Width of the Stretchmarks −17%* −14% (thin → broad) Length of the Stretchmarks −8% −14%• (short → long) Color of the Stretchmarks −18% −26%* (abnormal → normal) (tendency close to the significant level) Relief of the Stretchmarks −26%* −16%* (hollow/puffy → normal)
[0114] 5.4. Tolerance of the Cosmetic Product Assessed by the Volunteer
[0115] Skin sensations experienced:
[0116] none: 100%
[0117] Best-tolerated product:
[0118] no difference: 100%
[0119] No pathological irritation reaction significant 20 of a skin intolerance was noted. The 9 volunteers also indicated that they did not observe any irritation and/or discomfort sensations during the trial.
6. Conclusion
[0120] In conclusion, the anti-stretchmark creams of Examples 1 and 2, which differ from each other only in the anti-stretchmark active agent used, applied for 6 consecutive weeks under the normal conditions of use, to 9 adult female volunteers, made it possible to obtain a regression of stretchmarks, demonstrated by instrumental methods and on the basis of clinical scores.
[0121] This effect is reflected:
[0122] for the cream of Example 1 (use of “Phytokine®”):
[0123] by a statistically significant improvement in the tonicity and firmness components of the skin;
[0124] by statistically significant regression of the width of the stretchmarks (−17%) and of their relief (−26%), with a non-significant tendency on their color (−18%);
[0125] for the cream of Example 2 (use of “Kollaren-CPP®”):
[0126] by a marked, non-significant tendency toward improving the tonicity and firmness components of the skin;
[0127] by a statistically significant decrease in the length of the stretchmarks, compared with the cream of Example 1;
[0128] by a statistically significant improvement in the color (−26%) and the relief (−16%) of the stretchmarks.
Bibliographic References
[0129] Leveque J. L., Corcuff P. The Surface of the Skin—The Microrelief In Non Invasive Methods for the Quantification of Skin Functions: An Update on Methodology and Clinical Applications. Frosch P. J., Kligman A. M. Eds, Springer-Verlag, Berlin, New York, Paris 1993; 3-24.
[0130] Wilhelm K. P., Cua A. B. and Maibach H. I. In vivo study on age-related elastic properties of Human skin. In “Noninvasive Methods for the Quantification of Skin. Functions: An Update on Methodology and Clinical Applications”. Frosch P. J. and Kigman A. M. Ed., Springer-Verlag, 1993: 190-203. | A method for reducing the formation of and/or treating skin stretchmarks is described. The method is characterized in that a composition is applied to the areas of skin liable to form or comprising stretchmarks, including skin of the thighs, abdomen, and/or breast. The applied composition includes a soya peptide, a tripeptide consisting of the amino acids glycine, histidine, and lysine, and/or mixtures of the soya peptide and tripeptide in a suitable application vehicle. The composition displays good skin tolerance. | 0 |
BACKGROUND TO THE INVENTION
[0001] The World Health Organisation's 2014 report on global surveillance of antimicrobial resistance reveals that antibiotic resistance is a global problem that is jeopardising the ability to treat common infections in the community and hospitals. Without urgent action, the world is heading towards a post-antibiotic era, in which common infections and minor injuries, which have been treatable for decades, can once again kill (WHO, 2014), Antibiotic resistance complicates patients' recovery from even minor operations and is increasingly causing treatment failures. In fact, there are now strains of some genera of bacteria circulating globally which are resistant to all available antibiotics. Such strains commonly fall within the scope of the so-called ESKAPE pathogens— Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa and Enterobacter species (Boucher et al., 2009). The term ESKAPE pathogens was coined by Boucher et al. to emphasize that these bacteria currently cause a majority of hospital infections in the US and Europe and can effectively “escape” the majority, if not all, available antibiotics with panantibiotic-resistant infections now occurring. The death rate for patients with serious infections caused by common bacteria treated in hospitals is approximately twice that of patients with infections caused by the same non-resistant bacteria, e.g. people with methicillin-resistant Staphylococcus aureus (MRSA) infections are estimated to be 64% more likely to die than people with a non-resistant form of the infection (WHO, 2014). Of the Gram positive bacteria, methicillin resistant S. aureus continues to be a major cause of morbidity and mortality in hospitals in the US and Europe. However, in more recent years, several highly resistant Gram negative pathogens, including Acinetobacter species, multidrug resistant (MDR) P. aeruginosa , and carbapenem-resistant Klebsiella species and Escherichia coli, have emerged as major pathogens causing serious, and sometimes untreatable, infections. Advances in medicine mean that increasingly complex procedures take place: and these advances are leading to a growing number of elderly patients and patients undergoing surgery, transplantation, and chemotherapy all of which will produce an even greater number of immunocompromised individuals at risk of these infections Walker et al., 2009. This phenomenon has led to a greater dependence on, and requirement for, effective antibiotics.
[0002] P. aeruginosa is one bacterium which is frequently multi-drug resistant (MDR) having intrinsic resistance due to low permeability of its outer membrane limiting drugs getting into the cell, and a multitude of efflux pumps to expel any drugs that successfully manage to enter the cell. P. aeruginosa is also acquiring additional resistance mechanisms, including resistance to the “antibiotics of last resort” for Gram negatives, the carbapenems. P. aeruginosa causes approximately 10% of all hospital acquired infections and is the second leading cause of hospital-acquired pneumonia, which accounts for 50% of all hospital-acquired infection prescribing. P. aeruginosa infections in hospitals commonly require intravenous (IV) treatment with current standard of care for P. aeruginosa infections dictating that patients are treated with at least two antibiotics. Unfortunately, resistance frequently develops in patients during therapy. With so few new classes of antibiotic developed and approved for market within the last 30-40 years, there is a critical need for novel, safe and effective antibacterial agents.
[0003] As an alternative to conventional antibiotics, one family of proteins which demonstrate broad spectrum antibacterial activity inside bacteria comprises the α/β-type small acid-soluble spore proteins (known henceforth as SASP). Inside bacteria, SASP bind to the bacterial DNA: visualisation of this process, using cryoelectron microscopy, has shown that SspC, the most studied SASP, coats the DNA and forms protruding domains and modifies the DNA structure (Francesconi et al., 1988; Frenkiel-Krispin et al., 2004) from B-like (pitch 3.4 nm) towards A-like (3.18 nm; A-like DNA has a pitch of 2.8 nm). The protruding SspC motifs interact with adjacent DNA-SspC filaments packing the filaments into a tight assembly of nucleo-protein helices. In 2008, Lee et al. reported the crystal structure at 2.1 Å resolution of an α/β-type SASP bound to a 10-bp DNA duplex. In the complex, the α/β-type SASP adopt a helix-turn-helix motif, interact with DNA through minor groove contacts, bind to approximately 6 bp of DNA as a dimer and the DNA is in an A-B type conformation.
[0004] In this way DNA replication is halted and, where bound, SASP prevent DNA transcription. SASP bind to DNA in a non-sequence specific manner (Nicholson et al., 1990) so that mutations in the bacterial DNA do not affect the binding of SASP. Sequences of α/β-type SASP may be found in appendix 1 of WO02/40678, including SASP-C from Bacillus megaterium which is the preferred a/B-type SASP.
[0005] WO02/40678 describes the use as an antimicrobial agent of bacteriophage modified to incorporate a SASP gene. In order to provide effective production of the modified bacteriophage in a bacterial host, WO02/40678 aims to avoid expression of the SASP gene during proliferation of the production host. To this end, the SASP gene was put under the control of an inducible promoter. In one arrangement, the SASP gene was put under the control of a lysis gene promoter which is active only at the end of the bacteriophage life cycle by insertion into the lysis genes of a temperate bacteriophage. In doing so the phage remains viable as a prophage. In another arrangement, the SASP gene could be located elsewhere on the bacteriophage chromosome and placed under the control of a bacteriophage or bacterial promoter whereby the lytic cycle could be left to run its course. In this arrangement, the bacterial promoter would be non-constitutive and could be up-regulated by environmental cues. It was thought that proliferation of the bacterial production host would otherwise be prevented owing to the presence of the SASP gene product, particularly if the SASP gene was under the control of a constitutive promoter.
[0006] WO2009019293 describes that effective production of bacteriophage may be achieved where the bacteriophage has been modified to carry a gene encoding a SASP under the control of a promoter which is controlled independently of the bacteriophage, and which is constitutive with no exogenous or in trans regulation necessary or provided. An example is the fbaA promoter from S. aureus which is used to drive expression of the SASP-C gene from Bacillus megaterium and which, when present in multiple copies, for example following infection of target cells, drives toxic levels of SASP expression.
[0007] Bacteriophage vectors modified to contain a SASP gene have generally been named SASPject vectors. Once the SASP gene has been delivered to a target bacterium, SASP is produced inside those bacteria where it binds to bacterial DNA and changes the conformation of the DNA from B-like towards A-like. Production of sufficient SASP inside target bacterial cells causes a drop in viability of affected cells.
[0008] Bacteriophage have been used as medicines for the treatment of bacterial infections since the 1920s or 30s. Generally, bacteriophage are specific to their bacterial host. Some bacteriophage are temperate and others non-temperate. Temperate phage are able to infect the host cell and integrate into the host cell genome becoming a prophage which is generally harmless to the host cell in this state. Non-temperate or “lytic” phage are only able to replicate in a lytic lifestyle by making new bacteriophage progeny and ending in lysis of the host cell and release of mature phage particles. For useful medicines, the challenge is to provide bacteriophage compositions which can be used to treat infection from a variety of different bacteria in an effective way. It is commonly thought that this is achieved using the most potent bacteriophage compositions available: those with a broadened host range, possibly as a mixture or “cocktail” of bacteriophage, which are obligately lytic and retain viability through replication and release during treatment (Carlton, 1999; Kutateladze and Adamia, 2010). Cocktails of wild type phage have been used to ensure sufficient spectrum of activity against clinical strains of bacteria (Burrowes and Harper, 2012). Such cocktails can consist of up to 20 different and unrelated phage (Abedon 2008). As an alternative to the cocktail approach, E. coli bacteriophage K1-5 has been isolated. This is a naturally-occurring obligately lytic phage which carries more than one host range determinant allowing it to infect and replicate on both K1 and K5 strains of E. coli (Scholl et al, 2001). These phage are considered to be extra potent.
[0009] There remains a need to provide improved bacteriophage for use in treating bacterial infections in medicine as well as inhibiting or preventing bacterial cell growth in medical and non-medical situations.
SUMMARY OF THE INVENTION
[0010] In a first aspect, the present invention provides a modified bacteriophage capable of infecting a plurality of different target bacteria, which bacteriophage includes an α/β small acid-soluble spore protein (SASP) gene encoding a SASP which is toxic to the target bacteria; wherein the bacteriophage is non-lytic; wherein the bacteriophage expresses a plurality of different host range determinants (HRD); and wherein each HRD has a different bacterial host specificity. The bacterial host specificity of the HRD is advantageously within the same bacterial species.
[0011] It has surprisingly been found that a modified bacteriophage may be produced which is capable of infecting a variety of different target bacteria and which is effective for use in medicine even though the bacteriophage is non-lytic. The bacteriophage has an enhanced host range because it expresses a plurality of different HRD, wherein each HRD has a different bacterial host specificity. Such phage may be produced by genetic engineering, for example by selecting HRD from phage which infect the same bacterial species. Having created such an extra-potent phage, it can then be rendered non-lytic, and hence non-viable and yet still be suitable as a SASPject vector.
[0012] In one aspect, the term ‘SASP’ as used in the present specification refers to a protein with α/β-type SASP activity, that is, the ability to bind to DNA and modify its structure from its B-like form towards its A-like form, and not only covers the proteins listed in appendix 1 of WO02/40678, but also any homologues thereof, as well as any other protein also having α/β-type SASP activity. In an alternative aspect, the term ‘SASP’ as used in the specification refers to any protein listed in appendix 1 of WO02/40678, or any homologue having at least 70%, 75%, 80%, 85%, 90%, 92%, 94%, 95%, 96%, 98% or 99% sequence identity with any one of the proteins listed in appendix 1 of WO02/40678. In another alternative aspect, the term ‘SASP’ as used in the specification refers to any protein listed in appendix 1 of WO02/40678.
[0013] The modified bacteriophage may be non-lytic because it comprises an inactivated lysis gene. Insertion of sequence into the lysis gene or removal of the lysis gene would render this gene inactive. The lysis gene may conveniently be inactivated by insertion of the SASP gene. The SASP gene may be chosen from any one of the genes encoding the SASP disclosed in Appendix 1 of WO02/40678. In a preferred arrangement the SASP is SASP-C. The SASP-C may be from Bacillus megaterium.
[0014] It is preferred that the SASP gene is under the control of a constitutive promoter which is advantageously sufficiently strong to drive production of toxic levels of SASP when the modified bacteriophage is present in multiple copies in the target bacterium. Useful constitutive promoters include pdhA for pyruvate dehydrogenase E1 component alpha sub units, rpsB for the 30S ribosomal protein S2, pgi for glucose-6-phosphate isomerase and the fructose bisphosphate aldolase gene promoter fda. Preferred regulated promoters, active during infection, are lasB for elastase. These promoters are typically from P. aeruginosa . Promoters having a sequence showing at least 90% sequence identity to these promoter sequences may also be used.
[0015] The present invention is generally applicable to bacteriophage infecting a variety of different target bacteria. In one arrangement at least one of the target bacteria is Pseudomonas. Advantageously, the plurality of different target of bacteria is a plurality of different Pseudomonas bacteria. An important target is Pseudomonas aeruginosa.
[0016] It was not previously considered obvious that use of an obligate lytic phage would be suitable as a SASPject vector since a requirement of a SASPject vector is that it is specifically not lytic for optimal therapeutic use, giving an increased time window for SASP expression and enabling prevention of rapid lysis upon treatment in vivo, thus limiting the potential release of antibiotic resistance genes and toxic cell wall components which can lead to a dangerous inflammatory response.
[0017] The approach described in the present invention is advantageous as compared to the cocktail approach described previously. Mixtures of modified bacteriophage, such as SASPject vectors are identical in structure and genome sequence, other than carrying one or more extra HRD. One advantage is that control of the manufacturing process for the mix of SASPjects will be straightforward, which is an important aspect of a pharmaceutical preparation: the process will be materially the same for phage modified to carry one or more heterologous HRD as they share identical or near-identical biophysical properties. Another advantage is that the in vivo characteristics of the SASPject vectors are likely to be similar, e.g. pharmacokinetics/pharmacodynamics, as each vector is structurally the same or similar.
[0018] In the present invention it has been found that phage can be created which are extra-potent obligately-lytic bacteriophage carrying one or more extra HRD. Surprisingly, such phage can be used to make enhanced SASPject vectors by rendering these phage non-lytic and non-viable, by insertion or replacement of a lytic gene(s) with a gene for a SASP. Phage suitable for such modification may be isolated by screening for phage capable of infecting a chosen bacterial species. For instance, phage may be isolated which infect Pseudomonas aeruginosa, by screening for phage from environmental sources which are able to form plaques on representative P. aeruginosa strains (Gill and Hyman, 2010). Isolated phage may have their whole genomes sequenced and annotated. HRD may be tail fibre proteins, which are commonly found to be proteins responsible for the initial recognition/binding to the host bacterium, for instance in phage T4, T5 and T7 (Rakhuba et al., 2010). Alternatively other HRD may be baseplate proteins. Phage genomes may be searched for potential HRD sequences by assessing the homology of all proteins in the phage genome to known sequences, using BLAST searches.
[0019] According to the present invention it is preferred that each HRD has a broad host range. This may be defined as the ability to infect >50% of a diverse collection or clinical isolates, totalling at least 35, preferably at least 40, more preferably at least 44, and most preferably >50 in number. Such isolates should be from a range of geographical locations, including Europe, the Americas, and Asia, should carry a diverse range of antibiotic resistance phenotypes, including multi-drug resistant (MDR) strains, and should be from a diverse range of infection sites, such as strains cultured from blood, lung and skin infections. Such isolates can be obtained from public strain collections such as the American Type Culture Collection (ATCC) and the National Collection of Type Cultures (NCTC). HRD proteins have at least one region involved in structural incorporation into the phage and at least one region involved in host recognition. Generally, in the case of tail fibre proteins, each comprises a C-terminal receptor binding region for binding to the target bacteria and an N-terminal region linking the C-terminal receptor binding region to the body of the bacteriophage. In one arrangement, taking Phi33 and related phage as an example, the N-terminal region comprises amino acids 1 to 628 of the tail fibre protein and the C-terminal region comprises the amino acids 629 to 964 of the tail fibre protein.
[0020] The C-terminal region may have no more than 96% amino acid sequence identity with the C-terminal region of bacteriophage Phi33 and may be from any one of the bacteriophage Phi33, LBL3, SPM-1, F8, PB1, KPP12, LMA2, SN, 14-1, JG024, NH-4, PTP47, C36, PTP92 and PTP93. Lower amino acid sequence identities in the C-terminal region are preferred. Advantageously the sequence identity is less than 90%, more advantageously less than 80%, preferably less than 70%, more preferably less than 60%, still more preferably less than 50%, particularly preferably less than 40%, more particularly preferably less than 30%. The N-terminal region may have at least 90% and advantageously at least 95% amino acid sequence identity with the N-terminal region of bacteriophage Phi33 and may be from any one of bacteriophage Phi33, LBL3, SPM-1, F8, PB1, KPP12, LMA2, SN, 14-1, JG024, NH-4, PTP47, C36, PTP92 and PTP93. The N-terminal region and the C-terminal region may be from the same bacteriophage to provide a homologous tail fibre protein. Alternatively, the N-terminal region and the C-terminal region may be from different bacteriophage tail fibre proteins to provide a heterologous tail fibre protein. In one arrangement where the phage tail fibre protein is homologous, each tail fibre protein is from a bacteriophage selected from Phi33, LBL3, SPM-1, F8, PB1, KPP12, LMA2, SN, 14-1, JG024, NH-4, PTP47, C36, PTP92 and PTP93.
[0021] It is advantageous to identify phage tail fibre proteins which share sequence identity of greater than 90% in the N-terminal region. For example several phage—Phi33, PTP47, PTP92 and C36—with a broad host range for P. aeruginosa strains (all of these phage infect >60%, when analysed against 260 strains), have been isolated/identified and their genomes sequenced. Analysis of the genome sequences of Phi33, PTP47, PTP92 and C36 reveals that they contain genes encoding putative tail fibre proteins with a high level of sequence identity in the N-terminal region (>95% amino acid sequence identity), following a 2 sequence BLAST alignment, compared to the Phi33 tail fibre amino acids 1-628 (amino acid identity in parentheses): C36 (96%), PTP47 (98%), PTP92 (97%). BLAST searches have shown that these 4 phages are related to 10 other deposited phage genome sequences which, together, form the family of PB1-like phage: PB1, SPM1, F8, LBL3, KPP12, LMA2, SN, JG024, NH-4, 14-1 (Ceyssens et al., 2009). The homology of these putative tail fibre proteins was assessed. Following a 2 sequence BLAST alignment, compared to the Phi33 tail fibre protein (amino acid identity in parentheses): LBL3 (96%), SPM-1 (95%), F8 (95%), PB1 (95%), KPP12 (94%), LMA2 (94%), SN (87%), 14-1 (86%), JG024 (83%), NH-4 (83%), C36 (96%), PTP47 (86%), PTP92 (83%). An alignment of all 14 of the aforementioned phage is shown in FIG. 14 .
[0022] Analysis of the annotated tail fibre protein sequences from these 14 phages reveals that the N-terminal region of the proteins—equivalent to Phi33 tail fibre amino acids 1-628—show an even higher level of sequence identity at the amino acid level than the sequence identity of these proteins over their entire length, in the range of 96-100% for all 14 proteins. Following a 2 sequence BLAST alignment, compared to the N-terminal amino acids 1-628 of the Phi33 tail fibre protein (amino acid identity in parentheses): LBL3 (96%), SPM-1 (96%), F8 (96%), PB1 (96%), KPP12 (98%), LMA2 (99%), SN (99%), 14-1 (97%), JG024 (97%), NH-4 (97%), PTP47 (98%), C36 (96%), PTP92 (97%). However, the C-terminal region of the protein - equivalent to Phi33 tail fibre amino acids 629-964—is not as conserved as the N-terminal region in some of the proteins, the range of sequence identity being typically 57-96%. Following a 2 sequence BLAST alignment, compared to the C-terminal 629-964 amino acids of the Phi33 tail fibre protein (amino acid identity in parentheses): LBL3 (94%), SPM-1 (93%), F8 (93%), PB1 (94%), KPP12 (87%), LMA2 (85%), SN (65%), 14-1 (65%), JG024 (57%), NH-4 (57%), PTP47 (64%), C36 (96%), PTP92 (57%). Analysis of phage tail fibres from other, well characterised, phage has shown that they possess an N-terminal tail base plate binding region and a C-terminal receptor binding region (Veesler and Cambillau, 2011). In experimental analysis of their bacterial strain host range, using plaque assay or growth inhibition tests, the phage Phi33, PTP47, PTP92 and C36 have overlapping but non-identical host range (Table 1). Taken together with the established evidence for the role of the C-terminal region of phage tail fibres being involved in bacterial host receptor binding, and the sequence variation in the C-terminal region of these 4 phage, and their similar but non-identical host range, it is postulated that the C-terminal variation is associated with host range in the phage assessed.
[0023] It is further provided, according to this invention, that the genes for homologous tail fibre proteins can be taken from one phage and added to another, based upon their high level of sequence identity in the N-terminal region. The N-terminal region is thought to be involved in the binding of the tail fibre to the phage tail (Veesler and Cambillau, 2011), allowing the formation of viable phage with the host range associated with donor phage's tail fibre. Alternatively hybrid tail fibre genes may be made, carrying the conserved N-terminal tail attachment region of the tail fibre from a recipient phage, together with the variable C-terminal receptor-binding region from a heterologous donor phage tail fibre protein, using tail fibres genes such as those described herein. Such tail fibre hybrid genes could be used to replace some of the tail fibres of the phage. This provides an N-terminal region of the hybrid tail fibre (from the recipient phage) and allows the formation of viable phage with the host range associated with donor phage's tail fibre C-terminal receptor-binding region. Transplantation of engineered tail fibre hybrid genes into a recipient phage has been demonstrated in the present invention. Using standard molecular genetic techniques, Phi33 has been modified to carry heterologous tail fibre hybrids from the following phage: PTP92, PTP47, LBL3, SPM-1, F8, PB1, KPP12, LMA2, SN, 14-1, NH-4. All modified phage have been shown to be viable and able to plaque on P. aeruginosa . (The nomenclature of tail fibre hybrids is as follows: As an example, a hybrid gene such that the N-terminal tail attachment region of Phi33 is hybridised with the C-terminal receptor binding region of PTP47 is Phi33(N)PTP47(C).)
[0024] In one such modified phage, Phi33 was engineered such that its tail fibre gene carries the C-terminal receptor binding region of PTP92, creating PTP93 (Phi33(N)PTP92(C)). This was assessed in more detail, by testing the host range against 35 diverse P. aeruginosa clinical isolates. Comparing host range of the progenitor phage (Phi33), the tail fibre donor (PTP92) and the hybrid phage (PTP93), the host range of the PTP93 hybrid phage is equivalent to that of the tail fibre donor phage (PTP92) rather than Phi33, but it was surprisingly found that in some instances PTP93 possesses the host range of Phi33 on strains that PTP92 cannot infect, thus inheriting the host range of both phages (Table 2). Indeed, PTP93 possesses a broader host range (92%) than either Phi33 (74%) or PTP92 (66%) (Table 2). PTP93 is an example of an obligately lytic bacteriophage which can be considered as “extra-potent” as it possesses a characteristic above and beyond those exhibited in their unmodified state. Such extra potent phage are suitable for further modification to make SASPject vectors.
[0025] A preferred approach according to the present invention is to use one or more obligately lytic phage engineered to express 2 or more host range determinants (extra potent obligately lytic phage), each engineered to carry a SASP gene expressed from a constitutive promoter, each phage being genetically identical other than carrying different tail fibre genes, or tail fibre hybrid genes, and whereby a lytic gene(s) is inactivated. Such phage may be propagated in strains carrying the deleted lytic gene in trans. Preferred obligately lytic phages for modification and for provision of tail fibre genes to create phages carrying multiple tail fibre genes or tail fibre hybrid genes are phages carrying tail fibre genes which encode predicted proteins that possess ≧90% amino acid sequence identity in their N-terminal regions compared to N-terminal regions of the tail fibre of other isolated or identified phage. Preferred obligate lytic phage meeting this criterion are Phi33, PTP92, PTP47, LBL3, SPM-1, F8, PB1, KPP12, LMA2, SN, 14-1, NH-4, PTP93, JG024, PTP47 and C36. Such phage can be identified by a simple PCR assay, by subjecting plaques of isolated phage to PCR with primers specific to highly conserved regions in the N-terminal region of the tail genes. In such a way, suitable phage can be identified without whole genome sequencing. Phage PB1 can be obtained from a public strain collection. Phages need not be isolated or provided in order to generate tail fibre sequences as such sequences may be identified in DNA sequence databases, or other sources of DNA sequences, which may provide the information necessary in order to synthesise and clone, by standard methods, such sequences, or to create hybrid tail fibre sequences.
[0026] Particularly preferred phage for modification are PTP92, PTP93, Phi33, PTP47 and C36. Particularly preferred extra-potent obligate lytic phage are PTP93, modified to carry the tail fibre from Phi33 and/or the tail fibre hybrid Phi33(N)PTP47(C), and Phi33 modified to carry the hybrid tail fibre Phi33(N)PTP47(C). A particularly preferred extra-potent non-lytic SASPject derivative of PTP93 is: PTP93 carrying the Phi33 tail fibre gene and the Phi33(N)PTP47(C) tail fibre hybrid gene, carrying SASP-C from Bacillus megaterium under the control of the P. aeruginosa ribosomal subunit protein S2 (rpsB) gene promoter, in place of the endolysin gene.
[0027] A mixture of different modified bacteriophage as described above may also be provided. Mixtures of modified extra-potent non-lytic obligately lytic SASPject vectors may be used. A particularly preferred mixture of such SASPjects is: PTP93 carrying the Phi33 tail fibre gene, carrying SASP-C from Bacillus megaterium under the control of the P. aeruginosa ribosomal subunit protein S2 (rpsB) gene promoter in place of the endolysin gene, together with PTP93 carrying the Phi33(N)PTP47(C) tail fibre hybrid gene, carrying SASP-C from Bacillus megaterium under the control of the P. aeruginosa ribosomal subunit protein S2 (rpsB) gene promoter in place of the endolysin gene, together with Phi33 modified to carry the hybrid tail fibre Phi33(N)PTP47(C) carrying SASP-C from Bacillus megaterium under the control of the P. aeruginosa ribosomal subunit protein S2 (rpsB) gene promoter in place of the endolysin gene.
[0028] The host range of one such modified phage (PTP213) is shown in Table 3. PTP93 carrying the Phi33 tail fibre gene, carrying SASP-C from Bacillus megaterium under the control of the P. aeruginosa ribosomal subunit protein S2 (rpsB) gene promoter in place of the endolysin gene (PTP213) shows activity against a broader range of strains than either Phi33 or PTP92.
[0029] In another embodiment, an obligately lytic phage engineered to carry a SASP gene expressed from a constitutive promoter, in place of or inactivating a lytic gene, may be propagated in a host strain carrying the gene(s) for heterologous tail fibre protein(s) or hybrid tail fibre protein(s) in trans under the control of a suitable promoter, and the lytic gene in trans expressed from a suitable promoter. Suitable promoters for the tail fibre or tail fibre hydrid gene(s) may be a phage promoter, particularly the promoter which drives expression of the tail fibre gene in the engineered obligately lytic phage. Other suitable promoters are inducible promoters, such as lac, and trp, together with their cognate regulatory proteins. Suitable promoters for the lytic gene may be a phage promoter, particularly the promoter which usually drives expression of the lytic gene in the engineered obligately lytic phage. Other suitable promoters are inducible promoters, such as lac, and trp, together with their cognate regulatory proteins. The SASPject progeny obtained from such strains are extra-potent and non-lytic, carrying the tail fibre(s) or tail fibre hybrid(s) expressed from the strain in trans as well as their own. Alternatively the tail fibre gene from the obligately lytic phage may be deleted altogether, providing that a strain is used for propagation in which tail fibre gene(s) or tail fibre hybrid gene(s) are expressed in trans, and the lytic gene is expressed in trans, allowing for the formation of derivative SASPjects. In such an instance, the SASPject progeny from such a strain would carry multiple tail fibres, yet would lack in their genomes any tail fibre or tail fibre hybrid gene(s).
[0030] In a further aspect, the present invention provides a composition for inhibiting or preventing bacterial cell growth, which comprises a modified bacteriophage or mixtures thereof as defined herein and a carrier therefor. The modified bacteriophage may be provided in a mixture with at least one other modified bacteriophage which is capable of infecting target bacteria, which includes a SASP gene encoding a SASP which is toxic to the target bacteria and which is non-lytic. The at least one other modified bacteriophage may or may not express a plurality of different HRDs. Such compositions may have a wide range of uses and are therefore to be formulated according to the intended use. The composition may be formulated as a medicament, especially for human treatment and may treat various conditions, including bacterial infections. Among those infections treatable according to the present invention are localised tissue and organ infections, or multi-organ infections, including blood-stream infections, topical infections, oral infections including dental carries, respiratory infections, and eye infections. The carrier may be a pharmaceutically-acceptable recipient or diluent. The exact nature and quantities of the components of such compositions may be determined empirically and will depend in part upon the routes of administration of the composition.
[0031] Routes of administration to recipients include intravenous, intra-arterial, oral, buccal, sublingual, intranasal, by inhalation, topical (including ophthalmic), intra-muscular, subcutaneous and intra-articular. For convenience of use, dosages according to the invention will depend on the site and type of infection to be treated or prevented. Respiratory infections may be treated by inhalation administration and eye infections may be treated using eye drops. Oral hygiene products containing the modified bacteriophage are also provided; a mouthwash or toothpaste may be used which contains modified bacteriophage according to the invention formulated to eliminate bacteria associated with dental plaque formation.
[0032] A modified bacteriophage according to the invention may be used as a bacterial decontaminant, for example in the treatment of surface bacterial contamination as well as land remediation or water treatment. The bacteriophage may be used in the treatment of medical personnel and/or patients as a decontaminating agent, for example in a handwash. Treatment of work surfaces and equipment is also provided, especially that used in hospital procedures or in food preparation. One particular embodiment comprises a composition formulated for topical use for preventing, eliminating or reducing carriage of bacteria and contamination from one individual to another. This is important to limit the transmission of microbial infections, particularly in a hospital environment where bacteria resistant to conventional antibiotics are prevalent. For such a use the modified bacteriophage may be contained in Tris buffered saline or phosphate buffered saline may be formulated within a gel or cream. For multiple use a preservative may be added. Alternatively the product may be lyophilised and excipients, for example a sugar such as sucrose may be added.
DETAILED DESCRIPTION OF THE INVENTION
[0033] The invention will now be described in further detail, by way of example only, with reference to the accompanying figures and the following Examples.
[0034] FIG. 1 is a schematic diagram showing construction of plasmids containing lacZΔM15 and the Phi33 endolysin gene for the creation of transgenic P. aeruginosa strains;
[0035] FIG. 2 is a schematic diagram showing construction of plasmids encoding hybrid tail fibre genes, including the lacZα marker;
[0036] FIG. 3 is a schematic diagram showing construction of plasmids encoding hybrid tail fibre genes, which do not include the lacZα marker;
[0037] FIG. 4 is a schematic diagram showing construction of phage with hybrid tail fibre genes;
[0038] FIG. 5 is a schematic diagram showing construction of plasmids for the genetic modification of phage to introduce an additional tail fibre gene or tail fibre hybrid gene, utilising a lacZα marker;
[0039] FIG. 6 is a schematic diagram showing genetic modification of phage to add an extra tail fibre gene, utilising a lacZα marker, and then to replace endolysin with rpsB-SASP-C, also utilising a lacZα marker;
[0040] FIG. 7 is a schematic diagram showing genetic modification of further phage to add an extra tail fibre hybrid gene, utilising a lacZα marker, and then to replace endolysin with rpsB-SASP-C, also utilising a lacZα marker;
[0041] FIG. 8 is a schematic diagram showing genetic modification of further phage to add an extra tail fibre hybrid gene, utilising a lacZα marker, and then to replace endolysin with rpsB-SASP-C, also utilising a lacZα marker;
[0042] FIG. 9 is a schematic diagram showing construction of plasmids for the genetic modification of phage to add a third tail fibre hybrid gene, utilising a lacZα marker;
[0043] FIG. 10 is a schematic diagram showing genetic modification of phage carrying three tail fibre genes, utilising a lacZα marker, and then to replace endolysin with rpsB-SASP-C, also utilising a lacZα marker;
[0044] FIG. 11 is a schematic diagram showing construction of plasmids for the genetic modification production of phage to replace the endolysin gene with rpsB-SASP-C, utilising a lacZα marker;
[0045] FIG. 12 is a schematic diagram showing production of bacteriophage that carry multiple tail fibre genes or tail fibre hybrid genes, and in which the endolysin gene has been replaced with rpsB-SASP-C, according to the invention;
[0046] FIG. 13 is a schematic diagram showing production of further bacteriophage that carry multiple tail fibre genes or tail fibre hybrid genes, and in which the endolysin gene has been replaced with rpsB-SASP-C, according to the invention; and
[0047] FIG. 14 is a multiple sequence alignment of tail fibre genes from related phages.
GENERIC PRODUCT COVERING MULTIPLE TAIL FIBRES WITHIN AN INDIVIDUAL PHAGE, OR A MIX OF PHAGES EACH CONTAINING MULTIPLE TAIL FIBRES
[0048] Summary of the genetic modification of a lytic bacteriophage to render it non-lytic, and such that it carries more than one tail fibre gene, in addition to SASP-C under the control of a promoter that usually controls expression of the 30S ribosomal subunit protein S2 gene (rpsB).
[0049] Genes can be removed and added to the phage genome using homologous recombination. There are several ways in which phages carrying foreign genes and promoters can be constructed and the following is an example of such methods.
[0050] For the construction of Phi33 derivatives, it is shown how, using an E. coli/P. aeruginosa broad host range vector, as an example only, Phi33-based bacteriophage carrying alternative tail fibre genes may be made, via homologous recombination. It is also shown how Phi33 derivatives may be constructed, using an E. coli/P. aeruginosa broad host range vector, as an example only, in which an additional tail fibre gene is added to the bacteriophage genome via homologous recombination, such that the resulting bacteriophage carry two tail fibre genes. In a subsequent step, it is shown how, using an E. coli/P. aeruginosa broad host range vector, as an example only, a third tail fibre gene may be added to the bacteriophage genome via homologous recombination, such that the resulting bacteriophage carry three tail fibre genes.
[0051] As an example, for the construction of recombinant lytic bacteriophage, an E. coli lacZα marker may be included as a means of identifying recombinant bacteriophage. In order to use this marker, the bacteriophage host strains must first be modified to carry the E. coli lacZΔM15 allele at a suitable location in the bacterial genome, to complement the lacZα phenotypes of the desired recombinant bacteriophage. As an example, the construction of this P. aeruginosa strain may be achieved via homologous recombination using an E. coli vector that is unable to replicate in P. aeruginosa. The genomic location for insertion of the lacZΔM15 transgene should be chosen such that no essential genes are affected and no unwanted phenotypes are generated through polar effects on the expression of adjacent genes. As an example, one such location may be immediately downstream of the P. aeruginosa strain PAO1 phoA homologue.
[0052] The E. coli lacZΔM15 allele may be cloned into an E. coli vector that is unable to replicate in P. aeruginosa , between two regions of P. aeruginosa strain PAO1 genomic DNA that flank phoA. This plasmid may be introduced into P. aeruginosa and isolates having undergone a single homologous recombination to integrate the whole plasmid into the genome selected according to acquisition of tetracycline (50 μg/ml) resistance. Isolates which have undergone a second homologous recombination event may then be isolated on medium containing 10% sucrose (utilising the sacB counterselectable marker that is present on the plasmid backbone).
[0053] As an example by which Phi33 derivatives may be made that possess an alternative tail fibre gene, a tail fibre gene comprising the region encoding the N-terminal region of the Phi33 tail fibre, followed by the region encoding the C-terminal, receptor-binding region of the tail fibre from phage PTP92 (Phi33(N)PTP92(C)), may be constructed, and cloned next to a lacZα marker, in between two regions of homology that flank the native tail fibre gene of Phi33. This plasmid may be introduced into P. aeruginosa, and the resulting strain infected with Phi33. Following harvesting of progeny phage, double recombinants may be isolated by plaquing on a suitable P. aeruginosa (lacZΔM15 + ) host, using medium containing S-gal as a chromogenic indicator of β-galactosidase activity. The resulting phage will have had the native Phi33 tail fibre replaced by the gene encoding the Phi33(N)PTP92(C) tail fibre, plus a lacZα marker.
[0054] In a subsequent step, the lacZα marker may be removed from the Phi33(N)PTP92(C) tail fibre phage via another homologous recombination step. The region of homology downstream of the native Phi33 tail fibre may be cloned next to the gene encoding the C-terminal, receptor-binding region of PTP92. This plasmid may be introduced into a suitable P. aeruginosa strain, and the resulting strain infected with the Phi33 derivative carrying the gene encoding the Phi33(N)PTP92(C) tail fibre, plus lacZα. Following harvesting of progeny phage, double recombinants may be isolated by plaquing on a suitable P. aeruginosa (lacZΔM15 + ) host, using medium containing S-gal as a chromogenic indicator of β-galactosidase activity. The resulting Phi33 derivative (PTP93) will have had the native Phi33 tail fibre replaced by the gene encoding the Phi33(N)PTP92(C) tail fibre, and will no longer carry the lacZα marker.
[0055] As an example by which tail fibre genes may be added to a bacteriophage genome, the tail fibre gene from bacteriophage Phi33 may be cloned next to the E. coli lacZα marker, between two regions of Phi33 DNA that flank the 5′ end of orf57 (ectopic position 1; this is the beginning of the predicted operon containing the native tail fibre gene), in a broad host range E. coli/P. aeruginosa vector. This plasmid may be introduced into P. aeruginosa , and the resulting strain infected with PTP93. Following harvesting of progeny phage, double recombinants may be isolated by plaquing on a suitable P. aeruginosa (lacZΔM15 + ) host, using medium containing S-gal as a chromogenic indicator of β-galactosidase activity. The resulting phage will contain two tail fibre genes: the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position and the gene encoding the native Phi33 tail fibre (plus a lacZα marker) at an ectopic position (ectopic position 1).
[0056] In an alternative example, a gene encoding a tail fibre comprising the N-terminal region of the Phi33 tail fibre and the C-terminal receptor-binding region of the tail fibre from bacteriophage PTP47 (Phi33(N)PTP47(C)), may be constructed and cloned next to the E. coli lacZα marker, between two regions of Phi33 DNA that flank the 5′ end of orf57 (ectopic position 1; this is the beginning of the predicted operon containing the native tail fibre gene), in a broad host range E. coli/P. aeruginosa vector. This plasmid may be introduced into P. aeruginosa , and the resulting strain infected with PTP93. Following harvesting of progeny phage, double recombinants may be isolated by plaquing on a suitable P. aeruginosa (lacZΔM15 + ) host, using medium containing S-gal as a chromogenic indicator of β-galactosidase activity. The resulting phage will contain two tail fibre genes: the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position and the gene encoding the Phi33(N)PTP47(C) tail fibre (plus a lacZα marker) at an ectopic position (ectopic position 1).
[0057] In an alternative example, a gene encoding a tail fibre comprising the N-terminal region of the Phi33 tail fibre and the C-terminal receptor-binding region of the tail fibre from bacteriophage PTP47 (Phi33(N)PTP47(C)), may be constructed and cloned next to an E. coli lacZα marker, between two regions of Phi33 DNA that flank orf57 (ectopic position 1; this is the beginning of the predicted operon containing the native tail fibre gene), in a broad host range E. coli/P. aeruginosa vector. This plasmid may be introduced into P. aeruginosa , and the resulting strain infected with Phi33. Following harvesting of progeny phage, double recombinants may be isolated by plaquing on a suitable P. aeruginosa (lacZΔM15 + ) host, using medium containing S-gal as a chromogenic indicator of β-galactosidase activity. The resulting phage will contain two tail fibre genes: the gene encoding the Phi33 native tail fibre at the native position and the gene encoding the Phi33(N)PTP47(C) tail fibre (plus a lacZα marker) at an ectopic position (ectopic position 1).
[0058] In subsequent steps, the lacZα marker may be removed from these Phi33 derivatives by another homologous recombination step. The lacZα marker may be deleted from the previously-described recombination plasmids that were used to introduce the gene encoding the Phi33 native tail fibre, or the Phi33(N)PTP47(C) tail fibre at ectopic position 1. These ΔlacZα plasmids may be introduced into suitable P. aeruginosa strains, and the resulting strains infected, as appropriate, with Phi33 derivatives carrying either the wild type Phi33 tail fibre gene plus the lacZα marker, or the gene encoding the Phi33(N)PTP47(C) tail fibre plus the lacZα marker, at ectopic position 1. Following harvesting of progeny phage, double recombinants may be isolated by plaquing on a suitable P. aeruginosa (lacZΔM15 + ) host, using medium containing S-gal as a chromogenic indicator of β-galactosidase activity. The resulting Phi33 derivatives will contain two tail fibre genes (Phi33(N)PTP92(C) at the native position and Phi33 native tail fibre at ectopic position 1, OR Phi33(N)PTP92(C) at the native position and Phi33(N)PTP47(C) at ectopic position 1, OR Phi33 native tail fibre at the native position and Phi33(N)PTP47(C) at ectopic position 1), and will no longer carry the lacZα marker.
[0059] In a subsequent step, another homologous recombination may be used to add a third tail fibre gene to the bacteriophage genome. As an example, a gene encoding a tail fibre comprising the N-terminal region of the Phi33 tail fibre and the C-terminal receptor-binding region of the tail fibre from bacteriophage PTP47, under the control of the native tail fibre promoter (orf57 promoter), may be constructed and cloned next to a lacZα marker, between two regions of Phi33 DNA that flank an intergenic region between orf28 and orf29 (ectopic position 2), in a broad host range E. coli/P. aeruginosa vector. This plasmid may be introduced into P. aeruginosa , and the resulting strain infected with Phi33 carrying the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position and the gene encoding the native Phi33 tail fibre at ectopic position 1 (ΔlacZα). Following harvesting of progeny phage, double recombinants may be isolated by plaquing on a suitable P. aeruginosa (lacZΔM15 + ) host, using medium containing S-gal as a chromogenic indicator of β-galactosidase activity. The resulting phage will contain three tail fibre genes: the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position, the native Phi33 tail fibre gene at ectopic position 1, and the gene encoding the Phi33(N)PTP47(C) tail fibre (plus a lacZα marker) at ectopic position 2.
[0060] In a subsequent step, the lacZα marker may be removed from this Phi33 derivative carrying three tail fibre genes (the gene encoding the Phi33(N)PTP92(C) tail fibre at the native locus, the native Phi33 tail fibre gene at ectopic position 1, and the gene encoding the Phi33(N)PTP47(C) tail fibre, plus the lacZα marker, at ectopic position 2) by another homologous recombination step. The lacZα marker may be deleted from the previously-described recombination plasmid used to introduce the gene encoding the Phi33(N)PTP47(C) tail fibre at ectopic position 2. This ΔlacZα plasmid may be introduced into a suitable P. aeruginosa strain, and the resulting strain infected with the Phi33 derivative carrying the gene encoding the Phi33(N)PTP92(C) tail fibre at the native locus, the native Phi33 tail fibre gene at ectopic position 1, and the gene encoding the Phi33(N)PTP47(C) tail fibre, plus the lacZα marker, at ectopic position 2. Following harvesting of progeny phage, double recombinants may be isolated by plaquing on a suitable P. aeruginosa (lacZΔM15 + ) host, using medium containing S-gal as a chromogenic indicator of β-galactosidase activity. The resulting phage will contain three tail fibre genes: the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position, the native Phi33 tail fibre gene at ectopic position 1, and the gene encoding the Phi33(N)PTP47(C) tail fibre at ectopic position 2, and will no longer carry the lacZα marker.
[0061] In subsequent steps, a similar homologous recombination may be used to replace the endolysin gene of any of the Phi33 derivatives, or similar bacteriophage, with the gene for SASP-C, under the control of a P. aeruginosa rpsB promoter, while simultaneously adding the E. coli lacZα marker for the identification of recombinant phage. Since the bacteriophage to be modified is lytic (rather than temperate), another requirement for this latter step of bacteriophage construction is the construction of a derivative of a P. aeruginosa host strain that carries the Phi33 endolysin gene and the E. coli lacZΔM15 allele at a suitable location in the bacterial genome, to complement the Δendolysin and lacZα phenotypes of the desired recombinant bacteriophage. As an example, the construction of this P. aeruginosa strain may be achieved via homologous recombination using an E. coli vector that is unable to replicate in P. aeruginosa. The genomic location for insertion of the endolysin and lacZΔM15 transgenes should be chosen such that no essential genes are affected and no unwanted phenotypes are generated through polar effects on the expression of adjacent genes. As an example, one such location may be immediately downstream of the P. aeruginosa strain PAO1 phoA homologue.
[0062] The Phi33 endolysin gene and the E. coli lacZΔM15 allele may be cloned into an E. coli vector that is unable to replicate in P. aeruginosa , between two regions of P. aeruginosa strain PAO1 genomic DNA that flank phoA. This plasmid may be introduced into P. aeruginosa and isolates having undergone a single homologous recombination to integrate the whole plasmid into the genome selected according to acquisition of tetracycline (50 μg/ml) resistance. Isolates which have undergone a second homologous recombination event may then be isolated on medium containing 10% sucrose (utilising the sacB counter-selectable marker that is present on the plasmid backbone).
[0063] A region consisting of SASP-C controlled by the rpsB promoter, and the E. coli lacZα allele, may be cloned between two regions of Phi33 that flank the endolysin gene, in a broad host range E. coli/P. aeruginosa vector. This plasmid may be transferred to the previously constructed P. aeruginosa (endolysin + lacZΔM15 + ) strain, and the resulting strain infected by any of the Phi33 derivatives that have already been genetically modified to carry more than one tail fibre gene, as exemplified above in the previous steps. Progeny phage may be harvested and double recombinants identified by plaquing on P. aeruginosa (endolysin + lacZΔM15 + ), looking for acquisition of the lacZα reporter on medium containing a chromogenic substrate that detects the action of β-galactosidase.
[0064] In a subsequent step, the lacZα marker may be removed from the previously-constructed phage that carry rpsB-SASP-C and lacZα in place of the endolysin gene, by homologous recombination. A region consisting of rpsB-SASP-C may be cloned in between two regions of homology that flank the Phi33 endolysin gene, in a broad host range E. coli/P. aeruginosa vector. This plasmid may be transferred to the previously constructed P. aeruginosa (endolysin + lacZΔM15 + ) strain, and the resulting strain infected by any of the Phi33 derivatives that have already been genetically modified to carry rpsB-SASP-C in place of the endolysin gene, as exemplified above in the previous steps. Progeny phage may be harvested and double recombinants identified by plaquing on P. aeruginosa (endolysin + lacZΔM15 + ), looking for loss of the lacZα reporter on medium containing a chromogenic substrate that detects the action of β-galactosidase. The resulting phage will carry multiple tail fibre or tail fibre hybrid genes, and carry rpsB-SASP-C in place of endolysin, according to the invention.
[0065] Experimental Procedures
[0066] PCR reactions to generate DNA for cloning purposes may be carried out using Herculase II Fusion DNA polymerase (Agilent Technologies), depending upon the melting temperatures (T m ) of the primers, according to manufacturers instructions. PCR reactions for screening purposes may be carried out using Taq DNA polymerase (NEB), depending upon the T m of the primers, according to manufacturers instructions. Unless otherwise stated, general molecular biology techniques, such as restriction enzyme digestion, agarose gel electrophoresis, T4 DNA ligase-dependent ligations, competent cell preparation and transformation may be based upon methods described in Sambrook et al., (1989). Enzymes may be purchased from New England Biolabs or Thermo Scientific. DNA may be purified from enzyme reactions and prepared from cells using Qiagen DNA purification kits. Plasmids may be transferred from E. coli strains to P. aeruginosa strains by conjugation, mediated by the conjugation helper strain E. coli HB101 (pRK2013). A chromogenic substrate for β-galactosidase, S-gal, that upon digestion by β-galactosidase forms a black precipitate when chelated with ferric iron, may be purchased from Sigma (S9811).
[0067] Primers may be obtained from Sigma Life Science. Where primers include recognition sequences for restriction enzymes, additional 2-6 nucleotides may be added at the 5′ end to ensure digestion of the PCR-amplified DNA.
[0068] All clonings, unless otherwise stated, may be achieved by ligating DNAs overnight with T4 DNA ligase and then transforming them into E. coli cloning strains, such as DH5α or TOP10, with isolation on selective medium, as described elsewhere (Sambrook et al., 1989).
[0069] An E. coli/P. aeruginosa broad host range vector, such as pSM1080, may be used to transfer genes between E. coli and P. aeruginosa . pSM1080 was previously produced by combining a broad host-range origin of replication to allow replication in P. aeruginosa, oriT from pRK2, the tetAR selectable marker for use in both E. coli and P. aeruginosa, from plasmid pRK415, and the high-copy-number, E. coli origin of replication, oriV, from plasmid pUC19.
[0070] An E. coli vector that is unable to replicate in P. aeruginosa , pSM1104, may be used to generate P. aeruginosa mutants by allelic exchange. pSM1104 was previously produced by combining oriT from pRK2, the tetAR selectable marker for use in both E. coli and P. aeruginosa , from plasmid pRK415, the high-copy-number, E. coli origin of replication, oriV, from plasmid pUC19, and the sacB gene from Bacillus subtilis strain 168, under the control of a strong promoter, for use as a counter-selectable marker.
[0071] Detection of Phi33-like phage (PB1-like phage family) conserved N-terminal tail fibre regions by PCR
[0072] 1. Primers for the detection of Phi33-like phage-like tail fibre genes in experimental phage samples may be designed as follows:
[0073] The DNA sequences of the tail fibre genes from all sequenced Phi33-like phage (including Phi33, PB1, NH-4, 14-1, LMA2, KPP12, JG024, F8, SPM-1, LBL3, PTP47, C36, PTP92 and SN) may be aligned using Clustal Omega, which is available on the EBI website, and the approximately 2 kb-long highly conserved region mapping to the gene's 5′ sequence may be thus identified (positions 31680-33557 in the PB1 genome sequence, Acc. EU716414). Sections of 100% identity among the 11 tail fibre gene sequences may be identified by visual inspection. Three pairs of PCR primers targeting selected absolutely conserved regions, and amplifying PCR products no longer than 1 kb may be chosen as follows: pair B4500 and B4501, defining a 194 bp-long region; pair B4502 and B4503, defining a 774 bp-long region; and pair B4504 and B4505, defining a 365 bp-long region.
[0074] Primer B4500 consists of sequence of PB1 phage genome (Acc. EU716414) ranging from position 31680 to 31697. Primer B4501 consists of sequence of PB1 phage genome (Acc. EU716414) ranging from position 31851 to 31872. Primer B4502 consists of sequence of PB1 phage genome (Acc. EU716414) ranging from position 31785 to 31804. Primer B4503 consists of sequence of PB1 phage genome (Acc. EU716414) ranging from position 32541 to 32558. Primer B4504 consists of sequence of PB1 phage genome (Acc. EU716414) ranging from position 32868 to 32888. Primer B4505 consists of sequence of PB1 phage genome (Acc. EU716414) ranging from position 33213 to 33232.
[0000]
B4500
(SEQ ID NO: 1)
5′-GTGATCACACCCGAACTG-3′
B4501
(SEQ ID NO: 2)
5′-CGATGAAGAAGAGTTGGTTTTG-3′
B4502
(SEQ ID NO: 3)
5′-ACGCCGGACTACGAAATCAG-3′
B4503
(SEQ ID NO: 4)
5′-TCCGGAGACGTTGATGGT-3′
B4504
(SEQ ID NO: 5)
5′-CCTTTCATCGATTTCCACTTC-3′
B4505
(SEQ ID NO: 6)
5′-TTCGTGGACGCCCAGTCCCA-3′
[0075] 2. Phi33-like tail fibre genes may be detected in experimental phage samples as follows:
[0076] Plaques of isolated phage of environmental origin may be picked from agar plates and added to water and incubated for 30 minutes, making plaque soak outs. The plaque soak outs may be diluted and a portion added to PCR reactions containing one or all of the above primer pairs, and PCR may be performed according to a standard protocol. PCR products may be visualised on a 1.5% agarose gel with ethidium bromide staining, and evaluated for their size. PCR products of the correct size for the primer pair used may be gel-extracted and submitted to an external facility for sequencing. Sequencing results may be compared with the available tail fibre gene sequences in order to confirm the identity of the PCR product.
[0077] Construction of a Plasmid to Introduce the Escherichia coli lacZΔM15 Allele into the Genome of P. aeruginosa , Downstream of phoA
[0078] 1. Plasmid pSMX400 ( FIG. 1 ), comprising pSM1104 carrying DNA flanking the 3′ end of the P. aeruginosa PAO1 phoA homologue, may be constructed as follows.
[0079] A region comprising the terminal approximately 1 kb of the phoA gene from P. aeruginosa may be amplified by PCR using primers B4400 and B4401 ( FIG. 1 ). The PCR product may then be cleaned and digested with Spel and BglII. A second region comprising approximately 1 kb downstream of the phoA gene from P. aeruginosa, including the 3′ end of the PA3297 open reading frame, may be amplified by PCR using primers B4402 and B4403 ( FIG. 1 ).This second PCR product may then be cleaned and digested with BglII and Xhol. The two digests may be cleaned again and ligated to pSM1104 that has been digested with Spel and XhoI, in a 3-way ligation, to yield plasmid pSMX400 ( FIG. 1 ).
[0080] Primer B4400 consists of a 5′ Spel restriction site (underlined), followed by sequence located approximately 1 kb upstream of the stop codon of phoA from P. aeruginosa strain PAO1 ( FIG. 1 ). Primer B4401 consists of 5′ BglII and AflII restriction sites (underlined), followed by sequence complementary to the end of the phoA gene from P. aeruginosa strain PAO1 (the stop codon is in lower case; FIG. 1 ). Primer B4402 consists of 5′ BglII and Nhel restriction sites (underlined), followed by sequence immediately downstream of the stop codon of the phoA gene from P. aeruginosa strain PAO1 ( FIG. 1 ). Primer B4403 consists of a 5′ Xhol restriction site (underlined), followed by sequence within the PA3297 open reading frame, approximately 1 kb downstream of the phoA gene from P. aeruginosa strain PAO1 ( FIG. 1 ).
[0000]
Primer B4400
(SEQ ID NO: 7)
5′-GATA ACTAGT CCTGGTCCACCGGGGTCAAG-3′
Primer B4401
(SEQ ID NO: 8)
5′-GCTC AGATCT TC CTTAAG tcaGTCGCGCAGGTTCAG-3′
Primer B4402
(SEQ ID NO: 9)
5′-AGGA AGATCT GA GCTAGC TCGGACCAGAACGAAAAAG-3′
Primer B4403
(SEQ ID NO: 10)
5′-GATA CTCGAG GCGGATGAACATTGAGGTG-3′
[0081] 2. Plasmid pSMX401 ( FIG. 1 ), comprising pSMX400 carrying lacZΔM15 under the control of a lac promoter, may be constructed as follows.
[0082] The lacZΔM15 gene under the control of a lac promoter may be amplified by PCR from Escherichia coli strain DH10B using primers B4408 and B4409 ( FIG. 1 ). The resulting PCR product may then be digested with BglII and Nhel, and ligated to pSMX400 that has also been digested with BglII and Nhel, to yield plasmid pSMX401 ( FIG. 1 ).
[0083] Primer B4408 consists of a 5′ BglII restriction site (underlined), followed by sequence of the lac promoter ( FIG. 1 ). Primer B4409 consists of a 5′ Nhel restriction site (underlined), followed by a bi-directional transcriptional terminator and sequence complementary to the 3′ end of lacZΔM15 (underlined, in bold; FIG. 1 ).
[0000]
Primer B4408
(SEQ ID NO: 11)
5′-GATA AGATCT GAGCGCAACGCAATTAATGTG-3′
Primer B4409
(SEQ ID NO: 12)
5′-GATA GCTAGC AGTCAAAAGCCTCCGGTCGGAGGCTTTTGAC TTTATT
TTTGACACCAGACCAAC -3′
[0084] Genetic Modification of Pseudomonas Aeruginosa to Introduce the Escherichia Coli LaczΔM15 Gene Immediately Downstream of the phoA Locus of the Bacterial Genome
[0085] 1. Plasmid pSMX401 ( FIG. 1 ) may be transferred to P. aeruginosa by conjugation, selecting for primary recombinants by acquisition of resistance to tetracycline (50 μg/ml).
[0086] 2. Double recombinants may then be selected via sacB-mediated counter-selection, by plating onto medium containing 10% sucrose.
[0087] 3. Isolates growing on 10% sucrose may then be screened by PCR to confirm that lacZΔM15 has been introduced downstream of the P. aeruginosa phoA gene.
[0088] 4. Following verification of an isolate (PAX40), this strain may then be used as a host for further modification of bacteriophage, where complementation of a lacZα reporter is required.
[0089] Construction of Plasmids for Recombination with Phi33, to Generate PTP93, Utilising a lacZα Screening Process
[0090] 1. pSMX402 ( FIG. 2 ), comprising pSM1080 carrying the region immediately downstream of the Phi33 tail fibre gene, may be constructed as follows.
[0091] A 1 kb region of Phi33 sequence covering the terminal 20 bases of the Phi33 tail fibre, and the adjacent downstream region, may be amplified by PCR using primers B4422 and B4449 ( FIG. 2 ). The resulting PCR product may then be cleaned and digested with Nhel, and ligated to pSM1080 that has also been digested with Nhel and then treated with alkaline phosphatase prior to ligation, yielding plasmid pSMX402 ( FIG. 2 ).
[0092] Primer B4422 consists of a 5′ Nhel restriction site (underlined), followed by sequence from Phi33, approximately 1 kb downstream of the end of the Phi33 tail fibre gene ( FIG. 2 ). B4449 consists of 5′ NheI-KpnI-AvrII restriction sites (underlined), followed by sequence complementary to the 3′ end of the Phi33 tail fibre and sequence immediately downstream of the tail fibre open reading frame ( FIG. 2 ).
[0000]
B4422
(SEQ ID NO: 13)
5′-GATA GCTAGC ATGGTTTTCACGACCATG-3′
B4449
(SEQ ID NO: 14)
5′-GATA GCTAGC GA GGTACC GA CCTAGG TTTTCCAGCGAGTGACGTAA
AATG-3′
[0093] 2. pSMX403 ( FIG. 2 ), comprising pSMX402 carrying lacZα, a tail fibre gene consisting of a 3′ section of PTP92 DNA that encodes the C-terminal receptor-binding region of the tail fibre and the 5′ section of the Phi33 tail fibre gene sequence that encodes the N-terminal region, and sequence located immediately upstream of the Phi33 tail fibre gene, may be constructed as follows.
[0094] The lacZα open reading frame may be amplified by PCR from pUC19 using primers B4450 and B4452 ( FIG. 2 ). The region of the PTP92 tail fibre gene that encodes the C-terminal receptor-binding region, may be amplified by PCR from PTP92 using primers B4451 and B4454 ( FIG. 2 ). The lacZα open reading frame may then be joined to the section of PTP92 DNA that encodes the tail fibre C-terminal receptor-binding region, by SOEing PCR using the outer primers, B4450 and B4454. A region comprising sequence of Phi33 tail fibre gene that encodes the N-terminal region, and sequence located immediately upstream of the Phi33 tail fibre gene, may be amplified by PCR using primers B4453 and B4429 ( FIG. 2 ). This PCR product may then be joined to the PCR product comprising lacZα and the PTP92 tail fibre gene section, by SOEing PCR using the outer primers B4450 and B4429. The resulting PCR product may then be cleaned and digested with AvrII and KpnI, and ligated to pSMX402 that has also been digested with AvrII and KpnI, yielding plasmid pSMX403 ( FIG. 2 ).
[0095] Primer B4450 consists of a 5′ AvrII restriction site, followed by sequence complementary to the 3′ end of the lacZα open reading frame ( FIG. 2 ). Primer B4452 consists of a 5′ section of sequence that overlaps the 3′ end PTP92 tail fibre region that encodes the C-terminal receptor-binding region, followed by sequence of the 5′ end of the lacZα open reading frame ( FIG. 2 ). Primer B4451 is the reverse complement of primer B4452 ( FIG. 2 ). Primer B4454 consists of 5′ sequence from within the region of the Phi33 tail fibre gene that encodes the N-terminal region (underlined), followed sequence within the region of the PTP92 tail fibre gene that encodes the C-terminal receptor-binding region ( FIG. 2 ). Primer B4453 is the reverse complement of Primer B4454. Primer B4429 consists of a 5′ KpnI restriction site (underlined), followed by sequence that is complementary to a region approximately 1 kb upstream of the tail fibre gene in Phi33 ( FIG. 2 ).
[0000]
Primer B4450
(SEQ ID NO: 15)
5′-GATA CCTAGG TTAGCGCCATTCGCCATTC-3′
Primer B4452
(SEQ ID NO: 16)
5′- CTATTCCAGCGGGTAACGTAAA ATGACCATGATTACGGATTC-3′
Primer B4451
(SEQ ID NO: 17)
5′-GAATCCGTAATCATGGTCAT TTTACGTTACCCGCTGGAATAG -3′
Primer B4454
(SEQ ID NO: 18)
5′- CAAGCGGGCCGGCTGGTCTCTC GGCAATAACTCCTATGTGATC-3′
Primer B4453
(SEQ ID NO: 19)
5′-GATCACATAGGAGTTATTGCC GAGAGACCAGCCGGCCCGCTTG -3′
Primer B4429
(SEQ ID NO: 20)
5′-GATA GGTACC GCGACCGGTCTGTACTTC-3′
[0096] 3. pSMX404 ( FIG. 3 ), comprising pSM1080 carrying a region of the gene encoding the C-terminal receptor-binding region of the PTP92 tail fibre, and a region of Phi33 sequence located immediately downstream of the Phi33 tail fibre gene, may be constructed as follows.
[0097] The region of Phi33 sequence located immediately downstream of the Phi33 tail fibre may be amplified by PCR using primers B4422 and B4455 ( FIG. 3 ). The region of the gene encoding the C-terminal receptor-binding region of the PTP92 tail fibre may be amplified by PCR using primers B4456 and B4457 ( FIG. 3 ). These two PCR products may then be joined by SOEing PCR, using the two outer primers B4422 and B4457. The resulting PCR product may then be cleaned, digested with Nhel, cleaned again, and ligated to pSM1080 that has also been digested with Nhel and then treated with alkaline phosphatase prior to ligation, to yield plasmid pSMX404 ( FIG. 3 ).
[0098] Primer B4455 consists of a 5′ section of the region of the gene encoding the C-terminal receptor-binding region of the PTP92 tail fibre gene (underlined), followed by sequence immediately downstream of the Phi33 tail fibre gene ( FIG. 3 ). Primer B4456 is the reverse complement of primer B4455 ( FIG. 3 ). Primer B4457 consists of a 5′ Nhel restriction site (underlined), followed by sequence of a region within the section of the tail fibre gene of PTP92, that encodes the C-terminal, receptor-binding region ( FIG. 3 ).
[0000]
Primer B4455
(SEQ ID NO: 21)
5′- CTATTCCAGCGGGTAACGTAA AATGAAATGGACGCGGATCAG-3′
Primer B4456
(SEQ ID NO: 22)
5′-CTGATCCGCGTCCATTTCATT TTACGTTACCCGCTGGAATAG -3′
Primers B4457
(SEQ ID NO: 23)
5′-GATA GCTAGC GGCAATAACTCCTATGTGATC-3′
[0099] Genetic Modification of Phi33 to replace the 3′ Region of the Tail Fibre Gene, Encoding the C-Terminal Receptor-Binding Region, with that of PTP92, to form the Phi33(C)PTP92(N) Tail Fibre Gene, at the Native Position within the Phi33 Genome
[0100] 1. Plasmid pSMX403 ( FIG. 2 ; FIG. 4 ) may be introduced into P. aeruginosa strain PAX40 by conjugation, selecting transconjugants on the basis of tetracycline resistance (50 μg/ml), yielding strain PTA40.
[0101] 2. Strain PTA40 may be infected with phage Phi33, and the progeny phage harvested.
[0102] 3. Recombinant phage in which the region of the Phi33 gene encoding the C-terminal, receptor-binding region of the tail fibre has been replaced by that of PTP92, and to which lacZα has been added, may be identified by plaquing the lysate from step (2) on P. aeruginosa strain PAX40, onto medium containing S-gal, looking for black plaques, which are indicative of β-galactosidase activity.
[0103] 4. PCR may be carried out to check that the tail fibre gene has been replaced, and that lacZα is present.
[0104] 5. Following identification of a verified isolate (PTPX40; FIG. 4 ), this isolate may be plaque purified twice more on P. aeruginosa strain PAX40, prior to further use.
[0105] Genetic Modification of PTPX40 to Remove the lacZα Marker, Generating PTP93 (Phi33, Carrying the Phi33(N)PTP92(C) Tail Fibre Gene)
[0106] 1. Plasmid pSMX404 ( FIG. 3 ; FIG. 4 ) may be introduced into P. aeruginosa strain PAX40 by conjugation, selecting transconjugants on the basis of tetracycline resistance (50 μg/ml), yielding strain PTA41.
[0107] 2. Strain PTA41 may be infected with phage PTPX40, and the progeny phage harvested.
[0108] 3. Recombinant phage in which the lacZα marker has been removed may be identified by plaquing the lysate from step (2) on P. aeruginosa strain PAX40, onto medium containing S-gal, looking for white plaques, which is indicative of loss of β-galactosidase activity.
[0109] 4. PCR may be carried out to check that the tail fibre gene has been retained, and that lacZα has been removed.
[0110] 5. Following identification of a verified isolate (PTP93; FIG. 4 ), this isolate may be plaque purified twice more on P. aeruginosa strain PAX40, prior to further use.
[0111] Construction of Plasmids for the Genetic Modification of PTP93 to Introduce either the Phi33 Tail Fibre Gene, or the Gene Encoding the Phi33(N)PTP47(C) Tail Fibre at Ectopic Position 1
[0112] 1. Plasmid pSMX405 ( FIG. 5 ), comprising pSM1080 containing a 2.8 kb fragment of Phi33 spanning a continuous ‘orf60 to orf57’ stretch (neither orf60 nor orf57 were complete), may be constructed as follows. FIG. 5 shows the priming sites for the oligonucleotides described below for amplification of regions from the Phi33 genome.
[0113] PCR amplification of Phi33 DNA may be carried out using primers B4410 and B3332 ( FIG. 5 ), to yield a 2.9 kb fragment, which may be cleaned and digested with PciI. Following digestion, the DNA may be cleaned and ligated to pSM1080 that has been digested with Ncol and treated with alkaline phosphatase, to yield pSMX405 ( FIG. 5 ).
[0114] Primer B4410 consists of a 5′ Pcil site (underlined; FIG. 5 ), followed by sequence that anneals approximately 240 bp downstream of the start codon of Phi33 orf60, in the sense orientation. Primer B3332 consists of sequence complementary to Phi33 orf57, and anneals approximately 120 bp downstream of an intrinsic PciI site within orf57.
[0000]
B4410
(SEQ ID NO: 24)
5′-CGCG ACATGT CCTACAGCAGCGATGGAG-3′
B3332
(SEQ ID NO: 25)
5′-TTACTCCCCCTTCAGGTAGATG-3′
[0115] 2. Plasmid pSMX406 ( FIG. 5 ), comprising pSMX405 carrying the complete tail fibre gene from Phi33 and a promoterless lacZα marker, may be constructed as follows.
[0116] The complete tail fibre gene from Phi33 ( FIG. 5 ) may be amplified by PCR using primers B3324 and B4411. A promoterless lacZα marker may be amplified by PCR from pUC19 using primers B4412 and B4413 ( FIG. 5 ). The two PCR products may be joined together by SOEing PCR using the two outer primers, B3324 and B4413. The resulting PCR product may then be digested with BstBI, and ligated to pSMX405 that has also been digested with BstBI and treated with alkaline phosphatase prior to ligation. Plasmid pSMX406 may be isolated following screening of clones to identify a clone in which the Phi33 tail fibre has been cloned in the same orientation as orf57 ( FIG. 5 ).
[0117] Primer B3324 consists of a 5′ BstBI site (underlined), followed by sequence that anneals to the ribosome binding site just upstream of the Phi33 tail fibre gene ( FIG. 5 ). Primer B4411 consists of 5′ sequence complementary to the beginning of the lacZα marker from pUC19, followed by sequence complementary to the end of the tail fibre gene from Phi33 (underlined; FIG. 5 ). Primer B4412 is the reverse complement of Primer B4411 ( FIG. 5 ). Primer B4413 consists of a 5′ BstBI site (underlined), followed by sequence complementary to the region between the native Phi33 BstBI site and orf57, followed in turn by sequence complementary to the end of the lacZα marker from pUC19 ( FIG. 5 ).
[0000]
Primer B3324
(SEQ ID NO: 26)
5′-ACTC TTCGAA TTAACGGGATCCTCATTCAGGAGTAATGAC-3′
Primer B4411
(SEQ ID NO: 27)
5′-GTGAATCCGTAATCATGGTCATT TTACGTCACTCGCTGGAAAAG -3′
Primer B4412
(SEQ ID NO: 28)
5′- CTTTTCCAGCGAGTGACGTAA AATGACCATGATTACGGATTCAC-3′
Primer B4413
(SEQ ID NO: 29)
5′-GATA TTCGAA GAGTCGTGGTTAGCGCCATTCGCCATTC-3′
[0118] 3. Plasmid pSMX407 ( FIG. 5 ), comprising pSMX405 carrying a tail fibre gene consisting of the 5′ section of Phi33 DNA encoding the N-terminal region of the Phi33 tail fibre, and the 3′ section of PTP47 DNA encoding the C-terminal, receptor-binding region of the PTP47 tail fibre, in addition to a promoterless lacZα marker, may be constructed as follows.
[0119] The DNA region encoding the N-terminal region of the Phi33 tail fibre may be amplified by PCR using primers B3324 and B4417 ( FIG. 5 ). The DNA region encoding the C-terminal, receptor-binding region of the PTP47 tail fibre may be amplified by PCR using primers B4416 and B4414 ( FIG. 5 ). The two PCR products may be joined together by SOEing PCR using the outer primers B3324 and B4414. The lacZα marker from pUC19 may be amplified by PCR using primers B4415 and B4413 ( FIG. 5 ). The lacZα marker may be joined to the constructed tail fibre PCR product by SOEing PCR using the outer primers B3324 and B4413. The resulting PCR product may then be digested with BstBI and ligated to pSMX405 that has been digested with BstBI and treated with alkaline phosphatase prior to ligation. Plasmid pSMX407 may be isolated following screening of clones to identify a clone in which the Phi33(N)PTP47(C) tail fibre has been cloned in the same orientation as orf57 ( FIG. 5 ).
[0120] Primer B4417 consists of a 5′ section of sequence complementary to part of PTP47 encoding the C-terminal, receptor-binding region of the PTP47 tail fibre (underlined), followed by sequence complementary to part of Phi33 encoding the N-terminal region of the Phi33 tail fibre ( FIG. 5 ). Primer B4416 is the reverse complement of B4417 ( FIG. 5 ). B4414 consists of 5′ sequence complementary to the beginning of the lacZα marker from pUC19, followed by sequence complementary to the end of the tail fibre gene from PTP47 (underlined; FIG. 5 ). Primer B4415 is the reverse complement of primer B4414 ( FIG. 5 ).
[0000]
Primer B4417
(SEQ ID NO: 30)
5′- GATCACATAGGAGTTATTGCC GAGAGACCAGCCGGCCCGCTTG-3′
Primer B4416
(SEQ ID NO: 31)
5′-CAAGCGGGCCGGCTGGTCTCTC GGCAATAACTCCTATGTGATC -3′
Primer B4414
(SEQ ID NO: 32)
5′-GTGAATCCGTAATCATGGTCATT TTACGTCACTCGCTGGAAAAG -3′
Primer B4415
(SEQ ID NO: 33)
5′- CTTTTCCAGCGAGTGACGTAA AATGACCATGATTACGGATTCAC-3′
[0121] Genetic Modification of PTP93 to Add the Phi33 Tail Fibre Gene and a lacZα Marker, Upstream of orf57
[0122] 1. pSMX406 ( FIG. 5 ; FIG. 6 ) may be introduced into P. aeruginosa strain PML14 by conjugation, selecting transconjugants on the basis of tetracycline resistance (50 μg/ml), yielding strain PTA42.
[0123] 2. Strain PTA42 may be infected with PTP93, and the progeny phage harvested.
[0124] 3. Recombinant phage, which have acquired the Phi33 tail fibre and lacZα marker upstream of orf57, may be identified by plaquing on P. aeruginosa strain PAX40 using medium containing S-gal, a chromogenic substrate that detects β-galactosidase activity, looking for black plaques.
[0125] 4. PCR may be carried out to confirm that the Phi33 tail fibre and lacZα marker have been introduced upstream of orf57 in PTP93, and to confirm that the native PTP93 tail fibre region is still intact.
[0126] 5. Following identification of a verified isolate (PTPX41; FIG. 6 ), the new recombinant phage may be plaque purified twice more on P. aeruginosa strain PAX40, before further use. PTPX41 is therefore a Phi33 derivative carrying the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position, and the Phi33 wild type tail fibre gene along with a lacZα marker at ectopic position 1.
[0127] Genetic Modification of PTP93 to Add the Phi33(N)PTP47(C) Tail Fibre Gene and a lacZα Marker, Upstream of orf57
[0128] 1. pSMX407 ( FIG. 5 ; FIG. 7 ) may be introduced into P. aeruginosa strain PML14 by conjugation, selecting transconjugants on the basis of tetracycline resistance (50 μg/ml), yielding strain PTA43.
[0129] 2. Strain PTA43 may be infected with PTP93, and the progeny phage harvested.
[0130] 3. Recombinant phage, which have acquired the gene encoding the Phi33(N)PTP47(C) tail fibre, in addition to the lacZα marker, upstream of orf57, may be identified by plaquing on P. aeruginosa strain PAX40 using medium containing S-gal, a chromogenic substrate that detects β-galactosidase activity, looking for black plaques.
[0131] 4. PCR may be carried out to confirm that the gene encoding the Phi33(N)PTP47(C) tail fibre, in addition to the lacZα marker, has been introduced upstream of orf57 in PTP93, and to confirm that the native PTP93 tail fibre region is still intact.
[0132] 5. Following identification of a verified isolate (PTPX42; FIG. 7 ), the new recombinant phage may be plaque purified twice more on P. aeruginosa strain PAX40, before further use. PTPX42 is therefore a Phi33 derivative carrying the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position, and the gene encoding the Phi33(N)PTP47(C) tail fibre along with a lacZα marker at ectopic position 1.
[0133] Genetic Modification of Phi33 to Add the Phi33(N)PTP47(C) Tail Fibre Gene and a lacZα Marker, Upstream of orf57
[0134] 1. pSMX407 ( FIG. 5 ; FIG. 8 ) may be introduced into P. aeruginosa strain PML14 by conjugation, selecting transconjugants on the basis of tetracycline resistance (50 μg/ml), yielding strain PTA43.
[0135] 2. Strain PTA43 may be infected with Phi33, and the progeny phage harvested.
[0136] 3. Recombinant phage, which have acquired the gene encoding the Phi33(N)PTP47(C) tail fibre, in addition to the lacZα marker, upstream of orf57, may be identified by plaquing on P. aeruginosa strain PAX40 using medium containing S-gal, a chromogenic substrate that detects β-galactosidase activity, looking for black plaques.
[0137] 4. PCR may be carried out to confirm that the gene encoding the Phi33(N)PTP47(C) tail fibre, in addition to the lacZα marker, has been introduced upstream of orf57 in Phi33, and to confirm that the native Phi33 tail fibre region is still intact.
[0138] 5. Following identification of a verified isolate (PTPX43; FIG. 8 ), the new recombinant phage may be plaque purified twice more on P. aeruginosa strain PAX40, before further use. PTPX43 is therefore a Phi33 derivative carrying the native Phi33 tail fibre gene at the native position, and the gene encoding the Phi33(N)PTP47(C) tail fibre along with a lacZα marker at ectopic position 1.
[0139] Construction of Plasmids to Remove the lacZα Markers from the Double-Tail Fibre Phage, PTPX41, PTPX42 and PTPX43
[0140] 1. Plasmid pSMX408 ( FIG. 5 ), consisting of pSMX405 carrying the Phi33 tail fibre gene, may be constructed as follows.
[0141] The Phi33 tail fibre gene may be amplified by PCR using primers B3324 and B3333 ( FIG. 5 ). The resulting PCR product may then be digested with BstBI and ligated to pSM405 that has been digested with BstBI and treated with alkaline phosphatase prior to ligation, to yield plasmid pSMX408.
[0142] Primer B3333 consists of a 5′ BstBI site (underlined), followed by sequence complementary to the region between the native Phi33 BstBI site and orf57, followed in turn by sequence complementary to the 3′ end of the tail fibre gene from Phi33 ( FIG. 5 ).
[0000]
Primer B3333
(SEQ ID NO: 34)
5′-GCGC TTCGAA GAGTCGTGGTTACGTCACTCGCTGGAAAAG-3′
[0143] 2. Plasmid pSMX409 ( FIG. 5 ), consisting of pSMX405 carrying the gene encoding the Phi33(N)PTP47(C) tail fibre, may be constructed as follows.
[0144] The gene encoding the Phi33(N)PTP74(C) tail fibre may be amplified by PCR from pSMX407 using primers B3324 and B4418 ( FIG. 5 ). The resulting PCR product may then be digested with BstBI and ligated to pSM405 that has been digested with BstBI and treated with alkaline phosphatase prior to ligation, to yield plasmid pSMX409 ( FIG. 5 ).
[0145] Primer B4418 consists of a 5′ BstBI site (underlined), followed by sequence complementary to the region between the native Phi33 BstBI site and orf57, followed in turn by sequence complementary to the 3′ end of the tail fibre gene from PTP47 ( FIG. 5 ).
[0000]
Primer B4418
(SEQ ID NO: 35)
5′-GATA TTCGAA GAGTCGTGGTTACGTCACTCGCTGGAAAAG-3′
[0146] Removal of lacZα Marker from the Double-Tail Fibre Phage PTPX41
[0147] 1. pSMX408 ( FIG. 5 ; FIG. 6 ) may be introduced into P. aeruginosa strain PML14 by conjugation, selecting transconjugants on the basis of tetracycline resistance (50 μg/ml), yielding strain PTA44.
[0148] 2. Strain PTA44 may be infected with PTPX41, and the progeny phage harvested.
[0149] 3. Recombinant phage, from which the lacZα marker has been removed, may be identified by plaquing on P. aeruginosa strain PAX40 using medium containing S-gal, a chromogenic substrate that detects β-galactosidase activity, looking for clear plaques.
[0150] 4. PCR may be carried out to confirm that the lacZα marker has been removed, and that the two tail fibre genes are still intact.
[0151] 5. Following identification of a verified isolate (PTPX44; FIG. 6 ), the new recombinant phage may be plaque purified twice more on P. aeruginosa strain PAX40, before further use. PTPX44 is therefore a Phi33 derivative carrying the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position, and the Phi33 tail fibre gene at ectopic position 1 (AlacZα).
[0152] Removal of lacZα Marker from the Double-Tail Fibre Phage PTPX42 and PTPX43
[0153] 1. pSMX409 ( FIG. 5 ; FIG. 7 ; FIG. 8 ) may be introduced into P. aeruginosa strain PML14 by conjugation, selecting transconjugants on the basis of tetracycline resistance (50 μg/ml), yielding strain PTA45.
[0154] 2. Strain PTA45 may be infected with PTPX42 ( FIG. 7 ) or PTPX43 ( FIG. 8 ), as appropriate, and the progeny phage harvested.
[0155] 3. Recombinant phage, from which the lacZα marker has been removed, may be identified by plaquing on P. aeruginosa strain PAX40 using medium containing S-gal, a chromogenic substrate that detects β-galactosidase activity, looking for clear plaques.
[0156] 4. PCR may be carried out to confirm that the lacZα marker has been removed, and that the two tail fibre genes are still intact.
[0157] 5. Following identification of verified isolates, the new recombinant phage may be plaque purified twice more on P. aeruginosa strain PAX40, before further use. PTPX45 ( FIG. 7 ) is therefore a Phi33 derivative carrying the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position and the gene encoding the Phi33(N)PTP47(C) tail fibre at ectopic position 1 (AlacZα). PTPX46 ( FIG. 8 ) is therefore a Phi33 derivative carrying the Phi33 tail fibre gene at the native position and the gene encoding the Phi33(N)PTP47(C) tail fibre at ectopic position 1 (AlacZα).
[0158] Construction of a Plasmid to Add a Third Tail Fibre Gene to PTPX44, at Ectopic Position 2, in the Intergenic Region Between orf28 and orf29
[0159] 1. Plasmid pSMX410 ( FIG. 9 ), comprising pSM1080 carrying sequences of Phi33 DNA that flank the orf28-29 intergenic region, may be constructed as follows.
[0160] A region of Phi33 DNA flanking the end of orf28 may be amplified by PCR using primers B4419 and B4420 ( FIG. 9 ). A region of Phi33 DNA flanking the beginning of orf29 may be amplified by PCR using primers B4421 and B4422 ( FIG. 9 ). The resulting PCR products may then be joined by SOEing PCR using the outer primers, B4419 and B4422. The joined PCR product may be cleaned, digested with Nhel and ligated to pSM1080 that has been digested with Nhel and treated with alkaline phosphatase prior to ligation, to yield plasmid pSMX410 ( FIG. 9 ).
[0161] Primer B4419 consists of a 5′ Nhel restriction site (underlined), followed by Phi33 sequence within orf28 ( FIG. 9 ). Primer B4420 consists of 5′ sequence complementary to that of the Phi33 orf28-orf29 intergenic region, KpnI and AflII restriction sites (underlined), followed by sequence complementary to more of the Phi33 orf28-orf29 intergenic region ( FIG. 9 ). Primer B4421 is the reverse complement of Primer B4420 ( FIG. 9 ). Primer B4422 consists of a 5′ Nhel restriction site (underlined), followed by Phi33 sequence complementary to the region downstream of orf29 ( FIG. 9 ).
[0000]
Primer B4419
(SEQ ID NO: 36)
5′-GATA GCTAGC CTGGGATTCGAAGGTTCC-3′
Primer B4420
(SEQ ID NO: 37)
5′-CGAGAAAACCCGGATCGCCTGTA GGTACC TC CTTAAG TAGGATAAGG
CGTCCGGGTTTATC-3′
Primer B4421
(SEQ ID NO: 38)
5′-GATAAACCCGGACGCCTTATCCTA CTTAAG GA GGTACC TACAGGCGA
TCCGGGTTTTCTCG-3′
Primer B4422
(SEQ ID NO: 39)
5′-GATA GCTAGC TATTCGCCCAAAAGAAAAG-3′
[0162] 2. Plasmid pSMX411 ( FIG. 9 ), comprising pSMX410 carrying a gene constructed to encode the Phi33(N)PTP47(C) tail fibre, under the control of the native tail fibre promoter (Porf57), in addition to a lacZα marker, may be constructed as follows.
[0163] The DNA region comprising [Porf57-Phi33(N)PTP47(C) tail fibre gene-lacZα] may be amplified from plasmid pSMX407 ( FIG. 5 ), by PCR using primers B4423 and B4424 ( FIG. 9 ). The resulting PCR product may be digested with AflII and KpnI, and ligated to pSMX410 that has also been digested with AflII and KpnI, to yield plasmid pSMX411 ( FIG. 9 ).
[0164] Primer B4423 consists of a 5′ AflII restriction site (underlined), followed by sequence of the Phi33 orf57 promoter ( FIG. 9 ). Primer B4424 consists of a 5′ KpnI restriction site (underlined), followed by sequence that is complementary to the end of the lacZα marker ( FIG. 9 ).
[0000]
Primer B4423
(SEQ ID NO: 40)
5′-GATA CTTAAG TACTGAGAAAAATCTGGATTC-3′
Primer B4424
(SEQ ID NO: 41)
5′-GATA GGTACC TTAGCGCCATTCGCCATTC-3′
[0165] Genetic Modification of PTPX44 to Add the Phi33(N)PTP47(C) Tail Fibre Gene and a lacZα Marker, in the Intergenic Region Between orf28 and orf29 (Ectopic Position 2), to Generate a Bacteriophage Carrying Three Tail Fibre Genes
[0166] 1. pSMX411 ( FIG. 9 ; FIG. 10 ) may be introduced into P. aeruginosa strain PML14 by conjugation, selecting transconjugants on the basis of tetracycline resistance (50 μg/ml), yielding strain PTA46.
[0167] 2. Strain PTA46 may be infected with PTPX44, and the progeny phage harvested.
[0168] 3. Recombinant phage, which have acquired the gene encoding the Phi33(N)PTP47(C) tail fibre, in addition to the lacZα marker, in the orf28-29 intergenic region, may be identified by plaquing on P. aeruginosa strain PAX40 using medium containing S-gal, a chromogenic substrate that detects β-galactosidase activity, looking for black plaques.
[0169] 4. PCR may be carried out to confirm that the gene encoding the Phi33(N)PTP47(C) tail fibre, in addition to the lacZα marker, has been introduced into the orf28-29 intergenic region and to confirm the presence of the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position, and the native Phi33 tail fibre gene at ectopic position 1.
[0170] 5. Following identification of a verified isolate (PTPX47; FIG. 10 ), the new recombinant phage may be plaque purified twice more on P. aeruginosa strain PAX40, before further use. PTPX47 is therefore a Phi33 derivative carrying the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position, the native Phi33 tail fibre gene at ectopic position 1, and the gene encoding the Phi33(N)PTP47(C) tail fibre along with a lacZα marker at ectopic position 2.
[0171] Construction of a Plasmid to Remove the lacZα Marker from the Triple-Tail Fibre Bacteriophage, PTPX47
[0172] 1. Plasmid pSMX412 ( FIG. 9 ), comprising pSMX410 carrying the gene encoding the Phi33(N)PTP47(C) tail fibre, under the control of the native promoter (Porf57) may be constructed as follows.
[0173] The [Porf57-Phi33(N)PTP47(C) tail fibre gene] region from pSMX407 ( FIG. 5 ) may be amplified by PCR using primers B4423 and B4425 ( FIG. 9 ). The resulting PCR product may be digested with AflII and KpnI and ligated to pSMX410 that has also been digested with AflII and KpnI, to yield plasmid pSMX412 ( FIG. 9 ).
[0174] Primer B4425 consists of a 5′ KpnI site (underlined), followed by sequence complementary to the end of the PTP47 tail fibre gene ( FIG. 9 ).
[0000]
Primer B4425
(SEQ ID NO: 42)
5′-GATA GGTACC TTACGTCACTCGCTGGAAAAG-3′
[0175] Genetic Modification of the Triple-Tail Fibre Bacteriophage, PTPX47 to Remove the lacZα Marker
[0176] 1. pSMX412 ( FIG. 9 ; FIG. 10 ) may be introduced into P. aeruginosa strain PML14 by conjugation, selecting transconjugants on the basis of tetracycline resistance (50 μg/ml), yielding strain PTA47.
[0177] 2. Strain PTA47 may be infected with PTPX47, and the progeny phage harvested.
[0178] 3. Recombinant phage, from which the lacZα marker has been removed, may be identified by plaquing on P. aeruginosa strain PAX40 using medium containing S-gal, a chromogenic substrate that detects β-galactosidase activity, looking for clear plaques, indicative of loss of β-galactosidase activity.
[0179] 4. PCR may be carried out to confirm that the lacZα marker has been removed, and that the gene encoding the Phi33(N)PTP47(C) tail fibre is still present in the orf28-29 intergenic region (ectopic position 2), and to confirm the presence of the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position, and the native Phi33 tail fibre gene at ectopic position 1.
[0180] 5. Following identification of a verified isolate (PTPX48; FIG. 10 ), the new recombinant phage may be plaque purified twice more on P. aeruginosa strain PAX40, before further use. PTPX48 is therefore a Phi33 derivative carrying the gene encoding the Phi33(N)PTP92(C) tail fibre at the native position, the native Phi33 tail fibre gene at ectopic position 1, and the gene encoding the Phi33(N)PTP47(C) tail fibre (AlacZα) at ectopic position 2.
[0181] Construction of a Plasmid to Generate a P. aeruginosa Strain Carrying the Phi33 Endolysin Gene and the Escherichia coli lacZΔM15 Immediately Downstream of the phoA Locus of the Bacterial Genome
[0182] 1. Plasmid pSMX413 ( FIG. 1 ), comprising pSMX400 carrying the endolysin gene from Phi33, under the control of the native endolysin promoter, may be constructed as follows.
[0183] The endolysin promoter may be amplified by PCR from Phi33 using primers B4404 and B4405 ( FIG. 1 ). The endolysin gene itself may be amplified by PCR from Phi33 using primers B4406 and B4407 ( FIG. 1 ). The two PCR products may then be joined together by Splicing by Overlap Extension (SOEing) PCR, using the two outer primers, B4404 and B4407. The resulting PCR product may then be digested with AfLII and BglII, and ligated to pSMX400 that has also been digested with AflII and BglII, to yield plasmid pSMX413 ( FIG. 1 ).
[0184] Primer B4404 consists of a 5′ AflII restriction site (underlined), followed by a bi-directional transcriptional terminator (soxR terminator, 60-96 bases of genbank accession number DQ058714), and sequence of the beginning of the endolysin promoter region (underlined, in bold) ( FIG. 1 ). Primer B4405 consists of a 5′ region of sequence that is complementary to the region overlapping the start codon of endolysin from Phi33, followed by sequence that is complementary to the end of the endolysin promoter region (underlined, in bold; FIG. 1 ). Primer B4406 is the reverse complement of primer B4405 (see also FIG. 1 ). Primer B4407 consists of a 5′ BglII restriction site (underlined), followed by sequence complementary to the end of the Phi33 endolysin gene ( FIG. 1 ).
[0000]
Primer B4404
(SEQ ID NO: 43)
5′-GATA CTTAAG AAAACAAACTAAAGCGCCCTTGTGGCGCTTTAGTTTTA
TAC TACTGAGAAAAATCTGGATTC -3′
Primer B4405
(SEQ ID NO: 44)
5′-GATTTTCATCAATACTCCTGGATCC CGTTAATTCGAAGAGTCG -3′
Primer B4406
(SEQ ID NO: 45)
5′- CGACTCTTCGAATTAACG GGATCCAGGAGTATTGATGAAAATC-3′
Primer B4407
(SEQ ID NO: 46)
5′-GATA AGATCT TCAGGAGCCTTGATTGATC-3′
[0185] 2. Plasmid pSMX414 ( FIG. 1 ), comprising pSMX413 carrying lacZΔM15 under the control of a lac promoter, may be constructed as follows.
[0186] The lacZΔM15 gene under the control of a lac promoter may be amplified by PCR from Escherichia coli strain DH10B using primers B4408 and B4409 ( FIG. 1 ). The resulting PCR product may then be digested with BglII and Nhel, and ligated to pSMX413 that has also been digested with BglII and Nhel, to yield plasmid pSMX414 ( FIG. 1 ).
[0187] Primer B4408 consists of a 5′ BglII restriction site (underlined), followed by sequence of the lac promoter ( FIG. 1 ). Primer B4409 consists of a 5′ Nhel restriction site (underlined), followed by a bi-directional transcriptional terminator and sequence complementary to the 3′ end of lacZΔM15 (underlined, in bold; FIG. 1 ).
[0000]
Primer B4408
(SEQ ID NO: 11)
5′-GATA AGATCT GAGCGCAACGCAATTAATGTG-3′
Primer B4409
(SEQ ID NO: 12)
5′-GATA GCTAGC AGTCAAAAGCCTCCGGTCGGAGGCTTTTGACT TTATT
TTTGACACCAGACCAAC -3′
[0188] Genetic Modification of Pseudomonas aeruginosa to Introduce the Phi33 Endolysin Gene and the Escherichia coli lacZΔM15 Allele Immediately Downstream of the phoA Locus of the Bacterial Genome
[0189] 1. Plasmid pSMX414 may be transferred to P. aeruginosa by conjugation, selecting for primary recombinants by acquisition of resistance to tetracycline (50 μg/ml).
[0190] 2. Double recombinants may then be selected via sacB-mediated counter-selection, by plating onto medium containing 10% sucrose.
[0191] 3. Isolates growing on 10% sucrose may then be screened by PCR to confirm that endolysin and lacZΔM15 have been introduced downstream of the P. aeruginosa phoA gene.
[0192] 4. Following verification of an isolate (PAX41), this strain may then be used as a host for further modification of bacteriophage, where complementation of a Δendolysin, lacZα + genotype is required.
[0193] Construction of a Plasmid to Replace the Endolysin Gene of the Double-Tail Fibre Phage (PTPX44, PTPX45, PTPX46), or Similar Bacteriophage, or the Triple-Tail Fibre Phage (PTPX48), or Similar Bacteriophage, with rpsB-SASP-C and lacZα
[0194] 1. Plasmid pSMX415 ( FIG. 11 ), comprising pSM1080 containing regions of Phi33 flanking the endolysin gene, may be constructed as follows.
[0195] The region of Phi33 sequence immediately downstream of the endolysin gene may be amplified by PCR using primers B4465 and B4466 ( FIG. 11 ). This PCR product may then be cleaned and digested with NdeI and Nhel. The region of Phi33 sequence immediately upstream of the endolysin gene may be amplified by PCR using primers B4467 and B4468 ( FIG. 11 ). This second PCR product may then be cleaned and digested with NdeI and Nhel. The two PCR product digests may then be cleaned again and ligated to pSM1080 that has been digested with Nhel and treated with alkaline phosphatase prior to ligation. Clones carrying one insert of each of the two PCR products may be identified by PCR using primers B4465 and B4468, and by restriction digest of the purified plasmid DNA with NdeI, to identify plasmid pSMX415 ( FIG. 11 ).
[0196] Primer B4465 consists of a 5′ Nhel restriction site (underlined), followed by Phi33 sequence located approximately 340bp downstream of the Phi33 endolysin gene ( FIG. 11 ). Primer B4466 consists of 5′ NdeI and KpnI restriction sites (underlined), followed by sequence of Phi33 that is located immediately downstream of the endolysin gene ( FIG. 11 ). Primer B4467 consists of a 5′ NdeI restriction site (underlined), followed by sequence that is complementary to sequence located immediately upstream of the Phi33 endolysin gene ( FIG. 11 ). Primer B4468 consists of a 5′ Nhel site (underlined), followed by Phi33 sequence that is located approximately 340 bp upstream of the endolysin gene ( FIG. 11 ).
[0000]
Primer B4465
(SEQ ID NO: 47)
5′-GATA GCTAGC TTGGCCAGAAAGAAGGCG-3′
Primer B4466
(SEQ ID NO: 48)
5′-GATA CATATG TC GGTACC TATTCGCCCAAAAGAAAAG-3′
Primer B4467
(SEQ ID NO: 49)
5′-GATA CATATG TCAATACTCCTGATTTTTG-3′
Primer B4468
(SEQ ID NO: 50)
5′-GATA GCTAGC AATGAAATGGACGCGGATC-3′
[0197] 2. Plasmid pSMX416 ( FIG. 11 ), comprising pSMX415 containing SASP-C under the control of an rpsB promoter, may be constructed as follows.
[0198] The SASP-C gene from Bacillus megaterium strain KM (ATCC 13632) may be amplified by PCR using primers B4469 and B4470 ( FIG. 11 ). The resulting PCR product may then be digested with KpnI and Ncol. The rpsB promoter may be amplified by PCR from P. aeruginosa using primers B4471 and B4472 ( FIG. 11 ). The resulting PCR product may then be digested with Ncol and NdeI. The two digested PCR products may then be cleaned and ligated to pSMX415 that has been digested with KpnI and NdeI, yielding plasmid pSMX416 ( FIG. 11 ).
[0199] Primer B4469 comprises a 5′ KpnI restriction site, followed by a bi-directional transcriptional terminator, and then sequence complementary to the 3′ end of the SASP-C gene from B. megaterium strain KM (ATCC 13632) (underlined, in bold; FIG. 11 ). Primer B4470 comprises a 5′ Ncol restriction site (underlined), followed by sequence of the 5′ end of the SASP-C gene from B. megaterium strain KM (ATCC 13632) ( FIG. 11 ). Primer B4471 comprises a 5′ Ncol restriction site (underlined), followed by sequence complementary to the end of the rpsB promoter from P. aeruginosa PAO1 ( FIG. 11 ). Primer B4472 comprises a 5′ NdeI restriction site (underlined), followed by sequence of the beginning of the rpsB promoter from P. aeruginosa PAO1 ( FIG. 11 ).
[0000]
Primer B4469
(SEQ ID NO: 51)
5′-GATA GGTACC GATCTAGTCAAAAGCCTCCGACCGGAGGCTTTTGACT
TTAGTACTTGCCGCCTAG -3′
Primer B4470
(SEQ ID NO: 52)
5′-GATA CCATGG CAAATTATCAAAACGCATC-3′
Primer B4471
(SEQ ID NO: 53)
5′-GATA CCATGG TAGTTCCTCGATAAGTCG-3′
Primer B4472
(SEQ ID NO: 54)
5′-GATA CATATG CCTAGGGATCTGACCGACCGATCTACTCC-3′
[0200] 3. Plasmid pSMX417 ( FIG. 11 ), comprising pSMX416 containing lacZα, may be constructed as follows.
[0201] lacZα may be PCR amplified using primers B4473 and B4474 ( FIG. 11 ). The resulting PCR product may then be digested with KpnI and ligated to pSMX416 that has also been digested with KpnI and treated with alkaline phosphatase prior to ligation, to yield pSMX417 ( FIG. 11 ).
[0202] Primer B4473 consists of a 5′ KpnI restriction site (underlined), followed by sequence complementary to the 3′ end of lacZα ( FIG. 11 ). Primer B4474 consists of a 5′ KpnI restriction site (underlined), followed by sequence of the lac promoter driving expression of lacZα ( FIG. 11 ).
[0000]
Primer B4473
(SEQ ID NO: 55)
5′-GATA GGTACC TTAGCGCCATTCGCCATTC-3′
Primer B4474
(SEQ ID NO: 56)
5′-GATA GGTACC GCGCAACGCAATTAATGTG-3′
[0203] Genetic Modification of the Double-Tail Fibre Phage (PTPX44, PTPX45, PTPX46), or Similar Bacteriophage, or the Triple-Tail Fibre Phage (PTPX48), or Similar Bacteriophage, to Replace Endolysin with rpsB-SASP-C and lacZα
[0204] 1. Plasmid pSMX417 ( FIG. 11 ) may be introduced into P. aeruginosa strain PAX41 by conjugation, selecting transconjugants on the basis of tetracycline resistance (50 μg/ml), yielding strain PTA48.
[0205] 2. Strain PTA48 may be infected in individual experiments with one of the double-tail fibre phage (PTPX44 ( FIG. 6 ), PTPX45 ( FIG. 7 ), PTPX46 ( FIG. 8 )), or similar bacteriophage, or the triple-tail fibre phage (PTPX48; FIG. 10 ), or similar bacteriophage, and the progeny phage harvested.
[0206] 3. Recombinant phage, in which the endolysin gene has been replaced by rpsB-SASP-C and lacZα, may be identified by plaquing the lysate from step (2) on P. aeruginosa strain PAX41, onto medium containing S-gal, looking for black plaques, which are indicative of β-galactosidase activity.
[0207] 4. PCR may be carried out to check that the endolysin gene has been replaced, and that rpsB-SASP-C and lacZα are present.
[0208] 5. Following identification of verified isolates (for example, PTPX49 ( FIG. 6 ), PTPX50 ( FIG. 7 ), PTPX51 ( FIG. 8 ), PTPX52 ( FIG. 10 ), the isolates may be plaque purified twice more on P. aeruginosa strain PAX41, prior to further use.
[0209] Genetic Modification to Remove the lacZα Marker from PTPX49, PTPX50, PTPX51, PTPX52 and Similar Derivatives of Phi33 that Carry rpsB-SASP-C in Place of the Endolysin Gene
[0210] 1. Plasmid pSMX416 ( FIG. 11 ) may be introduced into P. aeruginosa strain PAX41 by conjugation, selecting transconjugants on the basis of tetracycline resistance (50 μg/ml), yielding strain PTA49.
[0211] 2. Strain PTA49 may be infected in individual experiments with phage PTPX49, or PTPX50, or PTPX51, or PTPX52, or other similar phage, and the progeny phage harvested.
[0212] 3. Recombinant phage, in which lacZα marker has been removed, may be identified by plaquing the lysate from step (2) on P. aeruginosa strain PAX41, onto medium containing S-gal, looking for clear plaques, which are indicative of loss of β-galactosidase activity.
[0213] 4. PCR may be carried out to confirm removal of the lacZα marker, while ensuring that rpsB-SASP-C is still present.
[0214] 5. Following identification of verified isolates (for example, PTP213 ( FIG. 11 ; FIG. 12 ), PTPX53 ( FIG. 11 ; FIG. 12 ), PTPX54 ( FIG. 11 ; FIG. 13 ), PTPX55 ( FIG. 11 ; FIG. 13 )), the isolates may be plaque purified twice more on P. aeruginosa strain PAX41, prior to further use.
[0000]
TABLE 1
Host range of Phi33, PTP92, C36 and PTP47 against 44 European
clinical isolates of Pseudomonas aeruginosa .
Bacterial Strain no.
Phi33
PTP47
PTP92
C36
2019
+
+
−
+
2020
+
+
−
+
2021
+
+
+
+
2029
+
+
−
+
2031
+
+
+
+
2039
+
+
+
+
2040
+
+
−
+
2041
+
+
+
+
2042
+
+
+
+
2045
−
−
+
−
2046
+
+
+
+
2047
+
+
+
+
2048
+
+
+
+
2049
+
+
+
+
2050
+
+
+
+
2051
+
+
−
−
2052
−
−
−
−
2053
+
+
−
+
2054
−
+
−
+
2055
+
+
−
+
2056
+
+
+
+
2057
+
+
+
+
2058
+
+
+
+
2483
−
−
+
−
2484
+
+
−
+
2705
+
+
−
+
2706
+
+
−
+
2707
+
+
+
+
2708
+
+
+
+
2709
+
+
+
+
2710
−
+
+
−
2711
+
+
+
+
2712
+
+
−
+
2713
−
+
+
+
2714
+
+
+
+
2715
+
+
+
+
2716
+
+
−
−
2717
−
+
+
+
2718
−
+
+
+
2719
+
+
−
+
2720
+
+
+
+
2721
+
+
+
+
2722
+
+
+
+
2723
+
+
−
+
Strains were tested for sensitivity to each phage by dropping 10 μl of crude phage lysate onto a soft agar overlay plate inoculated with bacteria. Plates were grown overnight at 32° C. and the strains were scored for sensitivity to each phage by assessing clearance zones at the point of inoculation. Where phage inhibited growth, as seen by clearance of the bacterial lawn, the strain was marked as sensitive (+), and where no inhibition of growth was seen, the strain was marked as not-sensitive (−)
[0000]
TABLE 2
Host range of Phi33, PTP92 and PTP93 against 35 European
clinical isolates of Pseudomonas aeruginosa .
Isolate
Phi33
PTP93
PTP92
2019
+
+
−
2020
+
+
−
2029
+
+
−
2040
+
+
−
2045
−
+
+
2053
+
+
−
2483
−
+
+
2484
+
+
−
2705
+
−
−
2710
−
+
+
2711
+
+
+
2712
+
+
−
2713
−
+
+
2716
+
+
−
2717
−
+
+
2718
−
+
+
2720
+
+
+
2721
+
+
+
2722
+
+
+
2723
+
−
−
2728
−
+
+
2733
+
+
−
2734
+
+
+
2740
−
+
+
2741
+
+
+
2742
+
+
+
2743
+
+
+
2747
+
+
+
2748
+
+
+
2749
+
+
−
2750
+
+
+
2752
+
+
+
2753
−
+
+
2754
+
+
+
2756
+
+
+
Strains were tested for sensitivity to each phage by dropping 10 μl of crude phage lysate onto a soft agar overlay plate inoculated with bacteria. Plates were grown overnight at 32° C. and the strains were scored for sensitivity to each phage by assessing clearance zones at the point of inoculation. Where phage inhibited growth, as seen by clearance of the bacterial lawn, the strain was marked as sensitive (+), and where no inhibition of growth was seen, the strain was marked as not-sensitive (−)
[0000]
TABLE 3
Host range of PTP213, Phi33, and PTP92 against 9
clinical isolates of Pseudomonas aeruginosa .
Isolate
PTP213
Phi33
PTP92
2055
+
+
−
2710
+
−
+
2948
+
+
−
2967
+
−
+
2975
+
−
+
2992
+
−
+
3183
+
−
+
3193
+
−
+
3207
+
+
+
Strains were tested for sensitivity to each phage by dropping 10 μl of crude phage lysate onto a soft agar overlay plate inoculated with bacteria. Plates were grown overnight at 32° C. and the strains were scored for sensitivity to each phage by assessing clearance zones at the point of inoculation. Where phage inhibited growth, as seen by clearance of the bacterial lawn, the strain was marked as sensitive (+), and where no inhibition of growth was seen, the strain was marked as not-sensitive (−)
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[0231] WHO (2014) Antimicrobial resistance: global report on surveillance 2014. | Modified bacteriophage, uses thereof, and compositions containing the modified bacteriophage are described. The compositions are useful for human treatment and may treat various conditions, including bacterial infections. | 2 |
FIELD OF THE INVENTION
[0001] The present invention is related to the field of optical systems.
[0002] More specifically, the invention is related to the filed of thermal compensation of an optical system.
[0003] Still more specifically, the invention is related to an apparatus for the thermal compensation of an optical system, comprising a housing, at least one optical element adapted to be displaced relative to the housing, and at least one piston-and-cylinder unit positioned directly between the housing and the optical element, the piston-and-cylinder unit acting on the position of the optical element within the housing and containing a fluid, wherein the coefficients of volumetric thermal expansion of the piston, the cylinder and the fluid are selected such that for a predetermined change in temperature of the apparatus a defined relative displacement between the piston and the cylinder takes place which compensates the change of the optical properties of the optical system caused by the change in temperature.
BACKGROUND OF THE INVENTION
[0004] Optical systems are temperature sensitive. Under the influence of temperature the geometry of lenses (radii, thickness, diameter) changes as well as the refractive index of the lens material used. The surrounding structure (the mounts and the barrel supporting the optical elements) change likewise. These changes effect a deterioration of the imaging quality.
[0005] In this context various approaches have become known for compensating this negative influence of changes in ambient temperature.
[0006] A first approach consists in purposefully combining materials for the components of the optical system with different coefficient of volumetric thermal expansion, such that the different volumetric thermal expansions just compensate one another. This approach, however, has substantial effects on the design of the components. It is, moreover, quite limited in its efficiency because the thermal coefficients of solids only differ little, and, therefore, the components have to be quite voluminous for obtaining noticeable compensation effects. Further, the selection of materials becomes limited thereby.
[0007] A second approach works with actuators which purposefully change the position of one or several optical elements within the system during a change in temperature, such that the imaging errors caused by the temperature change are compensated.
[0008] In this context one has already used apparatuses in which a bi-metallic element changes its shape as a function of temperature and an actuating force is derived therefrom. The forces generated thereby are, however, quite small and allow only small amounts of displacement for the optical elements.
[0009] On the other hand one has also been working with temperature sensors for controlling an actuator, for example a motor in connection with a pinion-and-rack drive unit, a spindle drive unit, a piezo drive unit or the like. By doing so one may obtain high actuating forces and long distances of displacement, however, one has to put up with the fact that the dimensions of the units require substantial space. Moreover, such systems require an electrical power supply which is not available for many optical systems, for example telescopes, and which is not desired either.
[0010] Finally, apparatuses have become known utilizing a piston-and-cylinder unit in which one takes advantage of the substantial difference in thermal coefficients between solids on the one hand and liquids on the other hand.
[0011] Document EP 1 081 522 B1 discloses a temperature-compensated objective lens for a film camera. In this objective lens the optical components are not displaced. Only the index ring is rotated relative to the rotatable distance setting ring for compensating the scale values on the distance setting ring which would be faulty otherwise. The actuator used for that purpose comprises a wax motor with a cylinder and a piston moving temperature-dependent with the coefficient of volumetric thermal expansion of the wax, and thereby rotates the ring. The wax motor rotates the ring in dependence of the temperature acting on it which expands or contracts, respectively, a liquid contained therein. The ring is biased in a circumferential direction by a compression spring, thereby overpowering by pressure any play that might exist.
[0012] This prior art apparatus has the disadvantage that the adjustment of the optical elements required for focusing is effected indirectly because the wax motor acts on the adjustment ring, and, therefore, also influences its reading.
[0013] Document U.S. Pat. No. 4,525,745 A discloses a similar apparatus for the thermal compensation of a focusing unit in a projection objective lens. The apparatus comprises a piston-and-cylinder unit with a cylinder and a piston that is likewise biased by springs. Her, too, the optical elements are adjusted indirectly, namely by means of a lever or a cam drive.
[0014] Document U.S. Pat. No. 3,162,664 A discloses still another such apparatus having likewise a spring-biased piston and an indirect adjustment via coupling elements.
[0015] Document U.S. Pat. No. 4,919,519 A discloses a fluid thermal compensation system for an objective lens. This system provides for a piston-and-cylinder unit directly between the housing and a lens of the objective lens. A liquid, namely a mixture of 66% ethylene glycol (with inhibitors) and 34% water is contained in the piston-and-cylinder unit cavity. This liquid is selected because of its low freezing point of −65° C. The liquid has a coefficient of volumetric thermal expansion of 540×10 −6 /°C.
[0016] In such systems liquids have substantial drawbacks. These draw-backs of liquids in particular consist in that already a small loss of liquid results in the formation of little gas bubbles so that the thermal compensation system becomes inoperable as a whole, and, on the other hand, the leaking liquid contaminates optical surfaces.
SUMMARY OF THE INVENTION
[0017] It is, therefore, an object underlying the invention to improve an apparatus of the type specified at the outset, such that the afore-mentioned drawbacks are avoided. In particular, an apparatus shall be provided that has a reliable thermal compensation over long time use, and which is simple to manufacture.
[0018] In an apparatus of the type specified at the outset this object is achieved in that the fluid is a polymer system.
[0019] The object underlying the invention is, thus, entirely solved.
[0020] The use of a polymer system instead of a liquid namely has the advantage that due to the higher viscosity, as compared to that of prior art hydraulic fluids, fluid will practically not escape in case of a leakage, such that one has not to be afraid of either an impairment to the thermal compensation system due to the formation of gas bubbles, or a contamination of the optical elements.
[0021] In particularly preferred embodiments of the invention the polymer system is a reactive polymer system being liquid in the non-cured state, and having a consistency between that of a gel and that of an elastomer in the cured state.
[0022] This measure has the advantage that during the manufacture of the optical system the polymer system, due to its low viscosity in the non-cured state, may be filled into the thermal compensation system in a simple manner, and that after curing it assumes the desired higher viscosity in situ.
[0023] It is, further, preferred when the polymer system is selected from the group consisting of: silicones, polyurethanes, acrylates, epoxies, urethaneacrylates, epoxyacrylates, polysulfides, hot-melt adhesives, hot-melt resins, ketone resins, colophonium derivates, waxes.
[0024] These substances, the enumeration of which being not to be understood as a limitation, have turned out to be particularly appropriate during practical tests.
[0025] In embodiments of the invention the polymer system is an addition crosslinking two-component casting compound.
[0026] This measure has the advantage that during the manufacture of the optical system the polymer system may be produced in a simple manner by mixing the two components with each other.
[0027] According to the invention, a particularly good effect is achieved in that fillers are admixed to the polymer system.
[0028] This measure has the advantage that the properties of the polymer system may be purposefully adjusted.
[0029] Preferred as fillers are nano particles, in particular SiO 2 particles having a particle size of between 5 and 20 nm, preferably of 10 nm.
[0030] The preferred optical elements are lenses or groups of lenses. The invention, however, may likewise be used in connection with other optical elements, for example aperture stops or mirrors.
[0031] The optical system, preferably, is an objective lens, for example for a camera or a telescope.
[0032] In embodiments of the invention the piston and the cylinder are each configured sleeve-shaped and coaxial to the optical element.
[0033] This measure has the advantage that a particularly compact design is obtained which, as compared to conventional apparatuses without thermal compensation requires only a very small additional space.
[0034] In this context it is particularly preferred when the piston and the cylinder surround the optical element.
[0035] In the context of the present invention the kinetic alternative is preferred in which the optical element is connected to the cylinder and the housing is connected to the piston.
[0036] In a further group of embodiments the piston is biased relative to the cylinder by means of a spring.
[0037] This measure has the advantage that a remaining play, likewise a play caused by the required gaskets within the piston-and-cylinder unit is suppressed.
[0038] Another embodiment of the invention is characterized in that the piston-and-cylinder unit comprises a cavity for the fluid, and that the cavity is subdivided into a plurality of axial chambers in a circumferential direction.
[0039] This measure has the advantage that in the case of unfavorable length conditions one avoids that the piston tilts within the cylinder because the fluid expands homogenously within the chambers.
[0040] Moreover, a measure is preferred, according to which the piston-and-cylinder unit comprises a cavity for the fluid, and the cavity is connected to an auxiliary cavity.
[0041] This measure has the advantage that the expanding fluid volume may be positioned at an arbitrary location within the optical system. This results in additional design options, and, due to a larger volume, larger expansions to be exploited.
[0042] Further advantages will become apparent from the description and the enclosed drawings.
[0043] It goes without saying that the features mentioned before and those that will be explained hereinafter may not only be used in the particularly given combination but also in other combinations, or alone, without leaving the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] Embodiments of the invention are shown in the drawing and will be explained in further detail throughout the subsequent description.
[0045] FIG. 1 is a schematic depiction of a piston-and-cylinder unit for explaining the invention; and
[0046] FIG. 2 is a partial, cross-sectional view, of an embodiment of the apparatus according to the invention, exemplified with respect to an objective lens.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] In FIG. 1 reference numeral 10 as a whole designates a hydraulic adjustment unit. Adjustment unit 10 comprises a sleeve-shaped piston 12 which slides within a likewise sleeve-shaped cylinder 16 via gaskets or seals 14 a, 14 b. With corresponding annular shoulders piston 12 and cylinder 14 define an annular cavity 18 containing a fluid 20 . According to the invention, fluid 20 is a polymer system.
[0048] Preferably, the polymer system is selected from the group consisting of: silicones, polyurethanes, acrylates, epoxies, urethaneacrylates, epoxyacrylates, polysulfides, hot-melt adhesives, hot-melt resins, ketone resins, colophonium derivates, waxes.
[0049] Further preferred is the use of 2K silicone rubber.
[0050] By using within the thermal compensation system a reactive polymer system having a consistence between that of a gel and that of an elastomer, the essential drawbacks of conventional hydraulic fluids are avoided. These drawbacks of liquids for example consist in that in view of sealing problems only highly fluorinated liquids may be used which in the long run behave indifferently in relation to the elastomers of the gaskets. A good sealing effect is essential in the present context because on the one hand already a small loss of liquid results in the formation of little gas bubbles so that the thermal compensation system becomes inoperable as a whole, and, on the other hand, the leaking liquid contaminates optical surfaces.
[0051] The polymer system used according to the invention, preferably, is an addition crosslinking two-component casting compound. This casting compound is filled into the thermal compensation system in its non-cured state which is highly facilitated by the low viscosity in that state. Only after the filling in the casting compound is crosslinked, for example with the help of heat or of ultraviolet light.
[0052] By properly selecting the casting compound and guiding the crosslinking process, the consistency of the cured polymer system may be set in wide ranges from gel-like over elastomer-like to brittle. For each individual application, the modulus of elasticity, the glass transition range, and the coefficient of volumetric thermal expansion are of importance.
[0053] The following coefficients of volumetric thermal expansion (each in 10 −6 /° C. units) have roughly been determined for the present application:
Silicones: 250-300 Silicone gels: 300-350 Polyurethane: 200-300 Epoxy resin: 60-80 Polycarbonate (CR 39): 100-120
[0054] wherein, as is well known, the coefficients of volumetric thermal expansion for aluminum are about 25, for steel are about 10-14, and for optical glass (BK 7) are about 7-8, also in 10 −6 /° C. units.
[0055] The properties of the polymer system may be purposefully modified by the admixing of fillers. Preferred as fillers are nano particles, for example SiO 2 particles having a particle size of between 5 to 20 nm, preferably of 10 nm.
[0056] Piston 12 and cylinder 14 consist of a solid material, in particular a metal. It is assumed that they both consist of the same material having a coefficient of volumetric thermal expansion designated α. The coefficient of volumetric thermal expansion of fluid 20 is designated β. In FIG. 1 , further, the axial length of cavity 18 is designated as L, the outer diameter of piston 12 as D 1 and the inner diameter of cylinder 16 as D 2 .
[0057] As the coefficient of volumetric thermal expansion β of fluid 20 is essentially higher as compared to the coefficient of volumetric thermal expansion α of piston 12 and cylinder 16 , a change in temperature causes a relative axial movement between piston 12 and cylinder 16 . In order to obtain a desired change in length ΔL for a predetermined temperature change ΔT, one has to calculate the required axial length L of cavity 18 .
[0058] The volume V of cavity 18 is:
V=π/ 4( D 2 2 −D 1 2 ) L [1]
[0059] The change in volume ΔV F of fluid 20 (coefficient of volumetric thermal expansion β) for a change in temperature ΔT is:
Δ V F =βΔTV=βΔTπ/ 4( D 2 2 −D 1 2 ) L [2]
[0060] The change in volume ΔV H of cavity 18 (coefficient of volumetric thermal expansion α) for a change in temperature ΔT is:
Δ V H =(π/4( D 2′ 2 −D 1′ 2 ) L ′)−(π/4( D 2 2 −D 1 2 ) L ), [3]
[0061] wherein D‘′ and D 2 ′ are the diameters of piston 12 and cylinder 16 , and L′ is the length of cavity 18 at the temperature having changed by ΔT.
[0062] With
D 1 ′=D 1(1 +αΔT ) und D 2 ′=D 2(1 +αΔT ) [4]
and
L′=L+ΔL [5]
[0063] one obtains
Δ V H = ( π / 4 ( ( 1 + α Δ T ) 2 ( D 2 2 - D 1 2 ) ( L + Δ L ) - ( D 2 2 - D 1 2 ) L ) = = π / 4 ( D 2 2 - D 1 2 ) ( ( 1 + α Δ T ) 2 ( L + Δ L ) - L ) = = π / 4 ( D 2 2 - D 1 2 ) L ( ( 1 + α Δ T ) 2 ( 1 + Δ L / L ) - 1 ) [ 6 ]
[0064] As the changes in volume ΔV F and ΔV H are equal, [3] and [6] may be equated, too, and one obtains for L:
L=ΔL /((βΔ T+ 1)/(1 +αΔT ) 2 −1) [7]
[0065] For the design of FIG. 1 the diameters D 1 und D 2 , and, hence, their tolerances, have no influence on the thermal compensation. The length L required for a change in length ΔL when temperature changes by ΔT solely depends on α and β.
[0066] Because the contribution from a is small, [7] may be simplified to read:
L=ΔL /(βΔ T ). [8]
[0067] Example: when piston 12 and cylinder 16 are made from aluminum (α=24×10 −6 /K) and fluid 20 is oil (β=10 −3 /K), then for a desired change in length ΔL=0.2 mm for a temperature change ΔT=20K the required length is obtained from equation [7] as L=10.54 mm, and from equation [8] as L=10 mm. The deviation of about 5% is acceptable, such that in practice one may calculate with simpler equation [8]. The example shows that length L for the desired change in length ΔL is very short, thus enabling a compact design.
[0068] FIG. 1 shows an apparatus with two O-ring seals 14 a and 14 b. Instead of these O-rings one may of course also use other kinds of slide seals or gaskets as are known in the field of hydraulics. Moreover, membrane seals, which do not slide, may likewise be used.
[0069] Irrespective of the kind of seal used, the problem of lost motion may arise which results in a hysteresis within the thermal compensation. The O-rings used are namely compressed in a radial direction for obtaining a sufficient sealing effect. Thereby, the elastic O-rings are broadened in an axial direction. For enabling such an axial broadening to happen, the groove housing the O-Ring must be axially broader as the O-Ring diameter. Accordingly, when the fluid becomes warmer or colder, respectively, the O-rings first move to the respective opposite groove wall before the piston and the cylinder start to move relatively to one another.
[0070] In the apparatus shown in FIG. 2 , this disadvantage is avoided.
[0071] FIG. 2 shows an optical system 30 , namely an objective lens. System 30 has a housing 31 . An optical element 32 , being a group of lenses in the embodiment shown, is housed axially displaceable within housing 31 .
[0072] The lens group is held on opposite ends by means of holding rings 34 a and 34 b which are bolted to a sleeve 36 surrounding the lens group. Sleeve 36 , in turn, is bolted to a sleeve-shaped cylinder 38 which is journalled axially displaceable within housing 31 . A sleeve-shaped piston 40 is provided between sleeve 36 and cylinder 38 . Piston 40 and cylinder 38 , together with seals 42 a and 42 b surround a cavity 44 . A fluid 46 is contained within cavity 44 . Fluid 46 may be filled into cavity 44 via an opening which may be closed by a closure bolt 48 . Piston 40 is bolted to housing 31 .
[0073] Axial and circumferentially distributed pull springs 52 are provided between piston 40 and cylinder 38 .
[0074] For the piston-and-cylinder unit 38 , 49 the same holds true as already explained in connection with FIG. 1 . The above discussed problem in connection with the lost motion caused by the seals is solved through the pull springs 52 because they bias piston 40 , and, thereby, overpower the lost motion or the hysteresis, respectively, by compression.
[0075] In the case of a change of temperature, cylinder 38 together with the lens group move relative to piston 40 being rigidly connected to housing 31 .
[0076] Starting from the system of FIG. 2 , various advancements may be provided.
[0077] According to a first advancement one takes into account that under unfavorable length conditions, in particular for very short lengths of guide, cylinder 38 and piston 40 may tilt relative to one another. In order to avoid that, cavity 44 may be subdivided into several, preferably three or four axial chambers by providing several circumferentially distributed and radially meshing axial ridges. When fluid 46 gets warmer, it expands simultaneously and uniformly within all such chambers, thereby generating a parallel movement and, hence, an axial guide without the risk of tilting.
[0078] According to a second advancement an additional cavity is provided being connected to cavity 44 . The additional cavity may be positioned at an arbitrary location within system 30 . The larger volume, thus obtained results in a bigger expansion amount of the fluid, such that longer distances and/or higher forces of displacement may be obtained. The above calculation would, of course, have to be modified accordingly. | An apparatus for the thermal compensation of an optical system is disclosed. The apparatus comprises a housing, at least one optical element adapted to be displaced relative to the housing, and at least one piston-and-cylinder unit positioned directly between the housing and the optical element. The piston-and-cylinder unit acts on the position of the optical element within the housing. It contains a fluid. The coefficients of volumetric thermal expansion of the piston, the cylinder and the fluid are selected such that for a predetermined change in temperature of the apparatus a defined relative displacement between the piston and the cylinder takes place which compensates the change of the optical properties of the optical system caused by the change in temperature. The fluid is a polymer system. | 6 |
TECHNICAL FIELD
The present invention relates to a medium processing apparatus such as a banknote telling machine, and in particular relates to a medium processing apparatus equipped with detachable medium storage cassettes for storing a medium such banknotes.
BACKGROUND ART
As a related medium processing apparatus there is, for example, the apparatus described in Japanese Patent Application Laid-Open (JP-A) No. 2009-098835.
FIG. 14 is a side view illustrating an internal structure of a related apparatus described in JP-A No. 2009-098835, and FIG. 15 is a side view illustrating the apparatus in a state in which banknote storage cassettes have been pulled out.
In an apparatus as shown in FIG. 14 and FIG. 15 , a customer interface section 31 , a checking and authentication section 32 , a temporary holding section 33 , conveying paths 34 a , 34 b , 34 c , 34 d , 34 e , and a conveying path (sorting conveying path) 3 including a sorting section are provided in an upper portion of the apparatus, and plural banknote storage cassettes (medium storage cassettes) 5 to 8 and a medium storage cassette (integrated stacking box type) 9 are loaded in a lower portion of the apparatus, in a row from the near side to the far side of the apparatus.
The conveying paths 34 a , 34 b , 34 c configure a loop shaped path from the customer interface section 31 , via the checking and authentication section 32 and the temporary holding section 33 , and back again to the customer interface section 31 , the conveying path 3 is provided in a straight line along the row of the banknote storage cassettes 5 to 8 and the medium storage cassette 9 , and the conveying path 34 d connects the conveying path 34 a and the conveying path 3 together at a position at the near side of the checking and authentication section 32 , and the conveying path 34 e connects the conveying path 34 b and the conveying path 3 together at a position at the far side of the checking and authentication section 32 .
The following processing for banknote (medium) depositing and dispensing is performed by such a configuration. First, when depositing, banknote(s) that have been introduced by a customer into the customer interface section 31 are separated and conveyed one-by-one by the conveying path 34 a to the checking and authentication section 32 where the banknotes are checked and authenticated for denomination, and such irregularities as counting and conveying irregularities are detected. Resulting banknotes deemed suitable for depositing are conveyed by the conveying path 34 b to the temporary holding section 33 where they are temporarily held, however, banknotes whose denomination is not clear or which have been detected as having an irregularity and are therefore not deemed suitable for depositing are conveyed by the conveying paths 34 b , 34 c to the customer interface section 31 and returned to the customer.
When all of the introduced banknotes have been checked and authenticated, the amount of the checked banknotes is then displayed on a display section, not shown in the drawings, and when a customer acknowledges this amount and authorizes transaction to proceed, the banknotes that are being temporarily stored in the temporary holding section 33 are fed out one-by-one and conveyed back to the checking and authentication section 32 by the conveying path 34 b and a denomination check is again performed in the checking and authentication section 32 . After checking, the banknotes are then conveyed from the conveying path 34 a into the conveying path 3 via the conveying path 34 d , sorted according to the identified denominations by the sorting section on the conveying path 3 and then stored separately by denomination in the banknote storage cassettes 5 to 8 .
In dispensing processing, banknote(s) are fed out according to the denomination and amount input by a customer from at least one of the banknote storage cassettes 5 to 8 to an operation section, not shown in the drawings, and the banknotes that have been fed out are conveyed to the checking and authentication section 32 by the conveying path 3 , the conveying path 34 d , and the conveying path 34 a . After performing checks on such aspects as the denomination and count in the checking and authentication section 32 , the banknotes are then conveyed to the customer interface section 31 by the conveying paths 34 b , 34 c and stacked, and when banknotes of the customer-input denomination and amount have been stacked in the customer interface section 31 , a shutter on the customer interface section 31 is opened and the banknotes are paid out to the customer.
Banknote replenishment and collection for the banknote storage cassettes 5 to 8 is performed utilizing the medium storage cassette 9 , however further explanation thereof is omitted.
DISCLOSURE OF INVENTION
Technical Problem
However, there are the following issues with related apparatuses as described above.
Namely, in a related apparatus a box shaped cassette loading frame 35 having an open face on the top face side is provided, and the plural banknote storage cassettes (medium storage cassettes) 5 to 8 and the medium storage cassette 9 are loaded into the cassette loading frame 35 . An upper portion and a lower portion inside of the apparatus are also divided with banknote transfer sections (medium transfer sections) provided between the conveying path 3 and each of the cassettes 5 to 9 , configuration is made such that the cassettes 5 to 9 are pulled out towards the near side of the apparatus together with the box shaped cassette loading frame 35 that has an open face on the top face side, as shown in FIG. 15 , and configuration is made such that each of the cassettes 5 to 9 can be removed from the cassette loading frame 35 by then lifting each of the cassettes 5 to 9 upwards.
When each of the cassettes 5 to 9 have been loaded into the apparatus together with the cassette loading frame 35 , there is a need to align their respective banknote transfer sections with the banknote transfer sections on the conveying path 3 side, therefore, the height h of the cassette loading frame 35 is accordingly made as high as possible, and a structure is adopted such that positioning of each of the cassettes 5 to 9 is performed by positioning sections, not shown in the drawings, at the upper end portion side, thereby suppressing vibration of the cassettes 5 to 9 .
In the related apparatus, since the height of the cassette loading frame is high, each of the heavy cassettes 5 to 9 needs to be lifted upwards in order to remove each of the cassettes 5 to 9 from the cassette loading frame 35 , and there are accordingly resulting issues of the handling characteristics being extremely awkward, and the accompanying danger of dropping the cassettes 5 to 9 during removal.
If the height h of the cassette loading frame 35 is lowered in order to facilitate removal of the cassettes 5 to 9 , then since the positioning of each of the cassettes 5 to 9 is performed at an upper portion of the cassette loading frame 35 , the separation distance between the positioning sections and the banknote transfer section provided to each of the cassettes 5 to 9 becomes large, and as a result banknote jams (medium jams) occur due to resulting vibration of the cassettes 5 to 9 or due to misalignment between the banknote transfer sections of the conveying path 3 and the banknote transfer sections of the cassettes 5 to 9 when the cassettes 5 to 9 are loaded into the apparatus together with the cassette loading frame 35 .
The present invention is directed towards addressing these issues.
Solution to Problem
To do this, the present invention is a medium processing apparatus including: plural medium storage cassettes for storing a medium; a conveying path for conveying medium for storing in each of the medium storage cassettes, for sorting conveyed medium into each of the medium storage cassettes and for conveying medium fed out from each of the medium storage cassettes; medium transfer sections provided on the medium storage cassettes side and on the conveying path side, for performing transfer of medium for storing in each of the medium storage cassettes and performing transfer of medium fed out from each of the medium storage cassettes; and a cassette loading frame for loading with each of the medium storage cassettes, wherein the cassette loading frame has a structure in which the height of a side panel on the cassette loading frame on a cassette handling side is the height of each of the medium storage cassettes or less and plural dividing plates are further provided that divide a lower portion of the cassette loading frame into cassette storage positions.
Furthermore, the medium processing apparatus of the present invention is structured such that the conveying path is disposed in a conveying path frame, and the conveying path frame is rendered capable of being pulled out together with the cassette loading frame by attaching the conveying path frame to the cassette loading frame such that the conveying path frame is capable of opening and closing; and a positioning section is further provided such that when mutually opposing faces of each of the medium storage cassettes and the conveying path frame are fitted together positioning is performed to the medium transfer sections on the medium storage cassettes side and the medium transfer sections on the conveying path side.
Advantageous Effect of Invention
In the thus configured present invention, the height of the side panel on the cassette handling side of the cassette loading frame is low, and the positioning sections are provided in the vicinity of the banknote transfer sections of the conveying path and the banknote transfer sections of each of the cassettes so as to fit together, consequently, improved handling characteristics are achieved for loading or removing the medium storage cassettes to or from the cassette loading frame even though the medium storage cassettes are heavy, and positioning of the banknote transfer section of the conveying path side and the banknote transfer sections on the medium storage cassette side can be performed with good precision.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a side view of an exemplary embodiment illustrating a cassette in a pulled out state from an apparatus.
FIG. 2 is a perspective view of a cassette loading frame with opened conveying path frame in a first exemplary embodiment.
FIG. 3 is a perspective view of a cassette loading frame with closed conveying path frame in the first exemplary embodiment.
FIG. 4 is a perspective view of relevant portions of a banknote storage cassette with open conveying path frame in the first exemplary embodiment.
FIG. 5 is a back view of relevant portions with closed conveying path frame in the first exemplary embodiment.
FIG. 6 is a cross-section taken on line X-X of FIG. 5 .
FIG. 7 is a perspective view illustrating operation of the first exemplary embodiment.
FIG. 8 is a perspective view of a cassette loading frame with opened conveying path frame in a second exemplary embodiment.
FIG. 9 is a perspective view of a cassette loading frame with opened conveying path frame in a third exemplary embodiment.
FIG. 10A is a back view of a cassette loading frame illustrating the operation of the third exemplary embodiment.
FIG. 10B is a back view of a cassette loading frame illustrating the operation of the third exemplary embodiment.
FIG. 11 is a perspective view of a cassette loading frame with opened conveying path frame in a fourth exemplary embodiment.
FIG. 12 is a perspective view of relevant portions of the fourth exemplary embodiment.
FIG. 13 is a perspective view illustrating another example of a cassette loading frame.
FIG. 14 is a side view illustrating internal structure of a related apparatus.
FIG. 15 is a side view of a related apparatus illustrating a state in which cassettes have been pulled out.
DESCRIPTION OF EMBODIMENTS
Explanation follows regarding an exemplary embodiment of a medium processing apparatus of the present invention, with reference to the drawings.
First Exemplary Embodiment
FIG. 1 is a side view of the internal structure of an exemplary embodiment, illustrating an example applied to a banknote telling machine, and showing a banknote storage cassette in a state pulled out from the apparatus. In FIG. 1 , an upper unit 1 is provided with a customer interface section 31 , a checking and authentication section 32 , a temporary holding section 33 , conveying paths 34 a , 34 b , 34 c , 34 d , 34 e , and a conveying path 3 .
A lower unit 2 includes: a conveying path 3 ; a cassette loading frame 4 that has a top face open; banknote storage cassettes (medium storage cassettes) 5 to 8 set out in a single row in the cassette loading frame 4 from the apparatus near side to the apparatus far side; and a medium storage cassette 9 , the conveying path (sorting conveying path) 3 that includes a sorting section is disposed housed in a box shaped conveying path frame 36 having an open top face, and the conveying path frame 36 is attached to the cassette loading frame 4 so as to be able to open and close, and further details regarding this aspect are explained later.
A sliding rail is provided to a bottom section of the cassette loading frame 4 , with the sliding rail engaged with a sliding rail on the apparatus side while not shown in the drawings, and the lower unit 2 including the cassette loading frame 4 , the cassettes 5 to 9 and the conveying path frame 36 can be pulled out towards the apparatus near side or pushed into the apparatus using the two sliding rails.
Note that the customer interface section 31 , the checking and authentication section 32 , the temporary holding section 33 , the conveying paths 34 a , 34 b , 34 c , 34 d , 34 e , the conveying path 3 and the banknote storage cassettes 5 to 8 and the medium storage cassette 9 are similar configuration elements to those of a related apparatus illustrated in FIG. 14 and FIG. 15 .
FIG. 2 to FIG. 6 are drawings illustrating the first exemplary embodiment, FIG. 2 is a perspective view of the cassette loading frame 4 shown when the conveying path frame 36 is opened, FIG. 3 is a perspective view of the cassette loading frame 4 shown when the conveying path frame 36 is closed, FIG. 4 is a perspective view of relevant portions of the banknote storage cassette 6 shown when the conveying path frame 36 is opened, FIG. 5 is a back view of relevant portions shown when the conveying path frame 36 is closed, and FIG. 6 is a cross-section taken on line X-X of FIG. 5 .
As shown in FIG. 2 and FIG. 3 , the cassette loading frame 4 has a side panel 4 a (as used herein, the side panel 4 a may also be referred to as a first side panel) on a first side, this being the cassette handling side, of height h that is half the height of the cassettes 5 to 9 or less, and preferably about ⅓ the height thereof, the height of a side panel 4 b (as used herein, the side panel 4 b may also be referred to as a second side panel), on a second side that is the opposite side to the cassette handling side, is about the same as the height of the cassettes 5 to 9 , plural lower dividing plates 21 to 24 are provided between a front panel 4 c and a back panel 4 d so as to divide up the lower portion of the cassette loading frame 4 into respective cassette storage positions, and the lower dividing plates 21 to 24 have heights that are about the same as the height of the side panel 4 a , and are disposed at a separation from each other of the front-rear direction dimension of the cassettes 5 to 9 .
The conveying path frame 36 is attached to the upper edge portion of the side panel 4 b of the cassette loading frame 4 , as shown in FIG. 2 , so as to swing open or closed about support points 31 , 32 . Elongated guide holes 10 to 15 that are longer than the banknote width in a direction orthogonal to the banknote conveying direction are provided parallel to each other in the bottom face side of the conveying path frame 36 , a respective banknote transfer section (transfer guide) 37 a of the conveying path 3 is provided at each of the guide holes 10 to 15 , as shown in FIG. 6 , so as to be exposed to the cassette side, and banknote transfer sections 37 b corresponding to the banknote transfer sections 37 a are provided to the top face of the respective cassettes 5 to 9 so as to be exposed on the conveying path frame 36 side. Guide holes 16 , 17 are also provided in the top face side of the conveying path frame 36 so as to correspond to banknote transfer sections of the conveying paths 34 b , 34 c , and banknote transfer sections similar to those of the banknote transfer sections 37 a also provided to the guide holes 16 , 17 .
Positioning pins (positioning sections) 43 , 44 are provide to the bottom face of the conveying path frame 36 at a specific separation from each other, so as to be positioned in the vicinity of for example the guide hole 11 , namely in the vicinity of the banknote transfer sections 37 a , as shown in FIG. 4 and FIG. 5 , and positioning holes (positioning sections) 41 , 42 are provided in the top face side of the banknote storage cassette 6 so as to align with the positioning pins 43 , 44 . Namely the positioning pins 43 , 44 and the positioning holes (positioning sections) 41 , 42 are provided to the mutually opposing faces of the conveying path frame 36 and the banknote storage cassette 6 , respectively.
Circular conical profiled leading ends are provided to the positioning pins 43 , 44 , and the positioning hole 41 corresponding to the positioning pin 43 furthest from the pivot point of the conveying path frame 36 has a diameter lightly larger than the diameter of the positioning pin 43 , and opening of the hole widens out in a taper profile. Further, the positioning hole 42 corresponding to the positioning pin 44 nearest to the pivot point of the conveying path frame 36 is formed as an elongated hole that widens out to the left and right in a taper shaped profile such that the movement path of the positioning pin 44 is permitted when the conveying path frame 36 is swung open or closed about the support points 31 , 32 .
Note that while not shown in the drawings, positioning pins 43 , 44 provided at a specific separation from each other are similarly positioned in the vicinity of the guide holes 10 , 12 to 15 of the conveying path frame 36 , namely in the vicinity of the respective banknote transfer sections 37 a , and similarly, there are positioning holes 41 , 42 corresponding to positioning pins 43 , 44 provided in the banknote storage cassettes 5 , 7 , 8 and the medium storage cassette 9 .
Explanation follows regarding operation of the first exemplary embodiment configured as described above. FIG. 7 is a perspective view illustrating operation of the first exemplary embodiment, and in order to load each of the cassettes 5 to 9 into the cassette loading frame 4 the conveying path frame 36 is swung open about the support points 31 , 32 as illustrated, and the banknote storage cassette 6 , for example, is lifted up and placed down in the cassette loading frame 4 between the lower dividing plates 21 , 22 . When performing this action the height h of the side panel 4 a of the cassette loading frame 4 on the cassette handling side is half or less than half the height of each of the cassettes 5 to 9 , for example about ⅓ the height of the cassettes 5 to 9 , hence, the loading operation of lifting up the banknote storage cassette 6 and placing it down between the lower dividing plates 21 , 22 of the cassette loading frame 4 can be easily performed. The removal operation when lifting up and removing the banknote storage cassette 6 from the cassette loading frame 4 can also be easily performed due to the low height h of the side panel 4 a . It is possible to perform similar operations to load and remove the other cassettes 5 , 7 to 9 into and out of the cassette loading frame 4 .
When the conveying path frame 36 is swung closed about the support points 31 , 32 , as illustrated in FIG. 3 , after each of the cassettes 5 to 9 have been loaded into the cassette loading frame 4 , the positioning pins 43 , 44 of the conveying path frame 36 fit into the positioning holes 41 , 42 of the banknote storage cassette 6 , as shown in FIG. 5 and FIG. 6 . When this is performed, even if the banknote storage cassette 6 is somewhat misaligned in the left-right direction indicated by arrow A and/or in the front-rear direction indicated by arrow B, such misalignment in the cassette loading frame 4 is absorbed since the leading ends of the positioning pins 43 , 44 is profiled in a conical cone shape and each of the insertion openings of the positioning holes 41 , 42 is configured so as to widen out in taper profile. Further, the positioning pins 43 , 44 and the positioning holes 41 , 42 are also provided in the vicinity of the banknote transfer sections 37 a of the conveying path 3 and the vicinity of the banknote transfer sections 37 b of the cassettes 5 to 9 , respectively, hence, positioning of the banknote transfer sections 37 a and 37 b with each other can be achieved with good precision by the positioning pins 43 , 44 fitting into the positioning holes 41 , 42 .
After the above operation, the conveying path frame 36 , the cassette loading frame 4 , the banknote storage cassettes 5 to 8 and the medium storage cassette 9 are loaded into the apparatus by pushing the lower unit 2 into the apparatus, thereby the banknote transfer sections provided to the guide holes 16 , 17 of the conveying path frame 36 with the banknote transfer sections of the conveying paths 34 b , 34 c are connected.
Cash depositing processing and cash withdrawal processing is performed in this state similarly as conventionally performed, however jams can be prevented from occurring in this section due to the banknote transfer sections 37 a of the conveying path 3 and the banknote transfer sections 37 b of the cassettes 5 to 9 each being positioned with good precision.
As explained above, in the first exemplary embodiment the height of the side panel on the cassette handling side of the cassette loading frame is made low, and the positioning sections for positioning the banknote transfer sections of the conveying path and the banknote transfer sections of each of the cassette are provided on the opposing faces of each cassette and the conveying path frame. Accordingly an effect is exhibited of obtaining a medium processing apparatus with good handling characteristics achieved for loading and removing the cassettes into and out of the cassette loading frame, and capable of positioning the banknote transfer sections of the conveying path and the banknote transfer sections of the cassettes with good precision.
Second Exemplary Embodiment
FIG. 8 is a diagram illustrating a second exemplary embodiment, and shows a perspective view of a cassette loading frame 4 when a conveying path frame 36 has been opened. The second exemplary embodiment is an embodiment in which the left and right hand side heights of lower dividing plates 21 to 24 provided in the cassette loading frame 4 are made different from each other. More specifically, the height of the lower dividing plates 21 to 24 on the side panel 4 b side of the cassette loading frame 4 is set higher than the height on the side panel 4 a side on the cassette handling side of the cassette loading frame 4 , so as to configure right-angled triangular shaped guide portions 21 a to 24 a.
Other parts of the structure are similar to those of the first exemplary embodiment, and, while not shown in the drawings, the guide holes 10 to 15 are provided with respective banknote transfer sections (transfer guides) 37 a of a conveying path 3 as illustrated in FIG. 6 , and banknote transfer sections 37 b corresponding to the banknote transfer sections 37 a are provided on the top face side of the respective cassettes 5 to 9 . Guide holes 16 , 17 are also provided on the top face side of the conveying path frame 36 so as to correspond with the banknote transfer sections of the conveying paths 34 b , 34 c . Banknote transfer sections similar to the banknote transfer sections 37 a are also provided to the guide holes 16 , 17 .
The bottom face of the conveying path frame 36 is also provided with positioning pins 43 , 44 at a specific separation so as to be positioned in the vicinity of the guide hole 11 , for example as shown in FIG. 4 and FIG. 5 , namely in the vicinity of the banknote transfer section 37 a . Provision of positioning holes 41 , 42 in the banknote storage cassette 6 so as to align with the positioning pins 43 , 44 is also similar to in the first exemplary embodiment.
In the thus configured second exemplary embodiment, in order to load each of the cassettes 5 to 9 into the cassette loading frame 4 , the individual cassettes 5 to 9 are lifted up to the height of the side panel 4 a of the cassette loading frame 4 . When then pressed towards the side panel 4 b side in this state, since the cassettes 5 to 9 are guided while being positionally restricted by the respective guide portions 21 a to 24 a of the lower dividing plates 21 to 24 , the cassettes 5 to 9 can be loaded into their respective assigned positions. Similarly, when removing the cassettes 5 to 9 from the cassette loading frame 4 , since the lower end of each of the cassettes 5 to 9 is positionally restricted by the guide portions 21 a to 24 a , cassettes being removed can be prevented from hitting and damaging adjacent cassettes.
Note that in the present exemplary embodiment too, obviously, positioning is performed by the positioning pins 43 , 44 of the conveying path frame 36 fitting into the positioning holes 41 , 42 of the cassettes 5 to 9 when the conveying path frame 36 is swung closed.
The second exemplary embodiment configured as explained above exhibits a similar effect to that of the first exemplary embodiment. In addition, since positional restriction and guiding is performed by the guide portions formed on the lower dividing plates when loading the cassettes into the cassette loading frame and when removing the cassettes from the cassette loading frame 4 , an effect is exhibited of enabling the handling characteristics during loading and during removing each of the cassettes to be improved further.
Third Exemplary Embodiment
FIG. 9 is a diagram illustrating a third exemplary embodiment and is a perspective view of a cassette loading frame 4 when a conveying path frame 36 is open, and FIGS. 10A and 10B are rear face views of the conveying path frame 36 and the cassette loading frame 4 illustrating operation of the third exemplary embodiment. The third exemplary embodiment is an embodiment in which upper dividing plates 81 to 84 are provided on the bottom face of the conveying path frame 36 so as to be aligned with lower dividing plates 21 to 24 provided in the cassette loading frame 4 . Each of the upper dividing plates 81 to 84 is formed in a substantially right angled triangular shape, with projections 81 a to 84 a at the leading ends (bottom ends) thereof. Relief holes 85 to 88 are provided to the side panel 4 b of the cassette loading frame 4 for the projections 81 a to 84 a to escape into.
Other parts of the structure are similar to those of the second exemplary embodiment. In the third exemplary embodiment too, while not shown in the drawings, guide holes 10 to 15 are provided with respective banknote transfer sections (transfer guides) 37 a of the conveying path 3 as illustrated in FIG. 6 , and banknote transfer sections 37 b corresponding to the banknote transfer sections 37 a are provided on the top face side of the respective cassettes 5 to 9 . Guide holes 16 , 17 are also provided on the top face side of the conveying path frame 36 so as to correspond with the banknote transfer sections of the conveying paths 34 b , 34 c . Banknote transfer sections similar to the banknote transfer sections 37 a are also provided to the guide holes 16 , 17 .
The bottom face of the conveying path frame 36 is also provided with positioning pins 43 , 44 at a specific separation to each other so as to be positioned in the vicinity of the guide hole 11 , for example as shown in FIG. 4 and FIG. 5 , namely positioned in the vicinity of the banknote transfer section 37 a . Provision of positioning holes 41 , 42 in the banknote storage cassette 6 so as to align with the positioning pins 43 , 44 is also similar to in the first and the second exemplary embodiment.
Thus in the third exemplary embodiment, similarly to in the second exemplary embodiment, when the conveying path frame 36 is swung closed about the support points 31 , 32 after each of the cassettes 5 to 9 have been loaded into the cassette loading frame 4 , the positioning pins of the conveying path frame 36 fit into the positioning holes 41 , 42 of the cassettes 5 to 9 and positioning is accordingly performed. However when this occurs, the upper dividing plates 81 to 84 act to restrict the upper portions of the cassettes 5 to 9 as the conveying path frame 36 is being closed, as shown in FIG. 10A and FIG. 10B , enabling the positioning pins to be fitted smoothly into the positioning holes 41 , 42 . In a closed state of the conveying path frame 36 , each of the projections 81 a to 84 a of the upper dividing plates 81 to 84 is inserted into the respective relief holes 85 to 88 provided to the side panel 4 b of the cassette loading frame 4 , accordingly suppressing vibration of the conveying path frame 36 such as due to external vibration.
In the third exemplary embodiment configured as explained above similar effects are exhibited to those of the second exemplary embodiment. In addition, the positioning pins are able to smoothly fit into the positioning holes due to providing the upper dividing plates provided to the conveying path frame, such that the upper dividing plates restrict the upper portion of the cassettes when the conveying path frame is being closed. An effect is obtained as a result of enabling positioning of the banknote transfer sections of the conveying path and the banknote transfer sections of the cassettes to be stably performed with good precision.
Fourth Exemplary Embodiment
FIG. 11 is a diagram illustrating the fourth exemplary embodiment in a perspective view of a cassette loading frame 4 when a conveying path frame 36 has been opened, and FIG. 12 is a perspective view of relevant portions of the fourth exemplary embodiment. As shown in FIG. 11 , in the fourth exemplary embodiment, the cassette loading frame 4 is configured with dividing plates 92 to 97 provided to a side panel 4 b on the opposite side of the cassette loading frame 4 to the cassette handling side and separated from each other by the front-rear direction dimension of cassettes 5 to 9 . The conveying path frame 36 is attached to the top edge portion of the side panel 4 b so as to open and closed by swinging about support points 31 , 32 .
In the fourth exemplary embodiment, each of the cassettes 5 to 9 is loaded by inserting the upper portion of each of the cassettes 5 to 9 respectively between the dividing plates 92 and 93 , between the dividing plates 93 and 94 and so on up to between the dividing plates 96 and 97 . However, protruding portions 98 are provided with a specific length to the both faces of each of the dividing plates 92 to 97 in order to hang each of the cassettes 5 to 9 therefrom, and groove portions 99 are formed to the front and rear faces of each of the cassettes 5 to 9 for the protruding portions 98 to slidably fit into.
Jack style electrical contacts 90 , 91 are provided on the top face of each of the cassettes 5 to 9 and on the bottom face of the conveying path frame 36 for fitting together. A slide rail 110 is also provided on the face of the side panel of the cassette loading frame 4 on the opposite side to the cassette installation face of the cassette loading frame 4 . The slide rail 110 is provided for pulling out the lower unit 2 containing the cassette loading frame 4 , the cassettes 5 to 9 and the conveying path frame 36 towards the near side of the apparatus or for pushing the lower unit 2 into the apparatus. The slide rail 110 engages with a slide rail, not shown in the drawings, on the apparatus side.
Other parts of the structure are similar to those of the first and second exemplary embodiment, and in the fourth exemplary embodiment too, while not shown in the drawings, guide holes 10 to 15 are provided with respective banknote transfer sections (transfer guides) 37 a of the conveying path 3 as illustrated in FIG. 6 , and banknote transfer sections 37 b corresponding to the banknote transfer sections 37 a are provided on the top face side of the respective cassettes 5 to 9 . Guide holes 16 , 17 are also provided on the top face side of the conveying path frame 36 so as to correspond to the banknote transfer sections of the conveying paths 34 b , 34 c . Banknote transfer sections similar to the banknote transfer sections 37 a are also provided to the guide holes 16 , 17 .
The bottom face of the conveying path frame 36 is also provided with positioning pins 43 , 44 at a specific separation from each other so as to be positioned in the vicinity of, for example, the guide hole 11 as shown in FIG. 4 and FIG. 5 , namely the banknote transfer section 37 a . Provision of positioning holes 41 , 42 to the banknote storage cassette 6 so as to align with the positioning pins 43 , 44 is also similar to in the first and the second exemplary embodiment.
In the thus configured fourth exemplary embodiment, each of the cassettes 5 to 9 is lifted up slightly, the protruding portions 98 of the dividing plates 92 to 97 are fitted into the groove portions 99 of each of the cassettes 5 to 9 , and each of the cassettes 5 to 9 is loaded between the respective dividing plates 92 to 97 by pushing each of the cassettes 5 to 9 in against the side panel 4 b of the cassette loading frame 4 . Then when the conveying path frame 36 is swung closed about the support points 31 , 32 the positioning pins of the conveying path frame 36 fit into the positioning holes 41 , 42 such that positioning is performed. When this is being performed, the respective electrical contacts 90 provided on the top face of each of the cassettes 5 to 9 and the respective electrical contacts 91 provided on the bottom face of the conveying path frame 36 fit together so as to make a connection. Accordingly, when the lower unit 2 containing the cassette loading frame 4 , the cassettes 5 to 9 and the conveying path frame 36 has been pushed into the apparatus then driving power can be supplied a banknote feed-out section or storing section provided on the respective cassette 5 to 9 side by, for example connecting the electrical contacts 91 on the conveying path frame 36 side to an apparatus power source.
In order to remove each of the cassettes 5 to 9 from the cassette loading frame 4 , the conveying path frame 36 is opened and each of the cassettes 5 to 9 can then be easily removed by pulling out towards the near side.
Note that while in the fourth exemplary embodiment the cassette loading frame 4 is configured with only the side panel 4 b on the opposite side of the cassette loading frame 4 to the cassette handling side, configuration may be made with a structure such as that illustrated in FIG. 13 . FIG. 13 is a perspective view illustrating another example of the cassette loading frame 4 , with the cassette loading frame 4 configured with a side panel 4 b and a bottom panel 4 e.
Due to such provision of the bottom panel 4 e , in order to load each of the cassettes 5 to 9 , each of the cassettes 5 to 9 is placed on the bottom panel 4 e and the protruding portions 98 of the respective dividing plates 92 to 97 are fitted into the groove portions 99 of the cassettes 5 to 9 . The cassettes 5 to 9 can then be simply loaded between the respective dividing plates 92 to 97 by pressing each of the cassettes 5 to 9 in against the side panel 4 b of the cassette loading frame 4 .
In the fourth exemplary embodiment, the jack style electrical contacts 90 , 91 are provided to the top face of each of the cassettes 5 to 9 and to the bottom face of the conveying path frame 36 for fitting together. However, the electrical contacts 91 may be provided to the side panel 4 b of the cassette loading frame 4 so as to be positioned between the respective dividing plates 92 to 97 , as illustrated in FIG. 13 , and the electrical contacts 90 may be provided on the side face of each of the cassettes 5 to 9 that faces the side panel 4 b . Accordingly, the electrical contacts 90 , 91 can be fitted together and connected when each of the cassettes 5 to 9 has been loaded into the cassette loading frame 4 .
Furthermore, for pulling out the lower unit 2 containing the cassette loading frame 4 , the cassettes 5 to 9 and the conveying path frame 36 towards the near side of the apparatus or pushing the lower unit 2 into the apparatus, the handling characteristics for pulling out from the apparatus and pushing into the apparatus can be stabilized further by providing the slide rail 110 at both upper and lower levels of the face of the side panel of the cassette loading frame 4 that is on the opposite side to the cassette operation face, as shown in FIG. 13 .
In the fourth exemplary embodiment as explained above, configuration is made with dividing plates provided separated from each other by the front-rear direction dimension of each of the cassettes on at least one of side panel of the cassette loading frame, protruding portions are provided with a specific length on each of the dividing plates, and groove portions are provided on the front and rear faces of each of the cassettes into which the protruding portions are capable of sliding and fitting. Since configuration is made such that each of the cassettes is can be loaded or removed by fitting the protruding portions into the groove portions and pushing each of the cassettes towards the side panel side of the cassette loading frame or pulling out the cassette therefrom, an excellent effect is exhibited in which superior handling characteristic are achieved due to each of the cassettes only needing to be lifted up slightly when loading or removing each of the cassettes.
Obviously, in the fourth exemplary embodiment too, the banknote transfer sections on the conveying path and the banknote transfer section on the cassettes can be positioned with good precision similarly to in the first to the third exemplary embodiments, due to provision of the positioning sections in the vicinity of the banknote transfer sections of the conveying path and the banknote transfer sections of the cassettes for fitting together.
Note that while in each of the exemplary embodiments described above the positioning pins 43 , 44 for positioning the banknote transfer sections of the conveying path and the banknote transfer sections of the cassettes are provided to the conveying path frame 36 , and the positioning holes 41 , 42 corresponding to the positioning pins 43 , 44 are provided to the cassettes 5 to 9 , configuration may be made in which the positioning pins 43 , 44 are provided to the cassettes 5 to 9 and the positioning holes 41 , 42 are provided to the conveying path frame 36 .
Furthermore, it is not essential to provide plural of the positioning pins and the positioning holes. Configuration is possible with a positioning section of a single elongated shaped positioning pin and a single elongated shaped positioning hole. Furthermore configuration is possible in which a small tab shaped plate and a slit are provided as a positioning section in place of a positioning pin and positioning hole.
Electrical contacts 90 , 91 similar to those of the fourth exemplary embodiment may also be provided in the first to the third exemplary embodiments as described above.
Furthermore, while explanation has been given above of examples in which the above exemplary embodiments are applied to a banknote telling machine, application is possible to various types of apparatus that a medium processing apparatus equipped with plural medium storage cassettes and a conveying path. | Disclosed is a media processing device that offers ease of use in loading and removal of cartridges and is capable of aligning paper currency delivery units upon conveyance paths and paper currency delivery units upon cartridges with a high degree of precision. A cartridge loading frame ( 4 ) is configured such that the height of the lateral plate upon the cartridge handling side is less than or equal to half the height of the respective cartridges, and a plurality of partitions, which partition the storage positions of the respective cartridges, is disposed upon the lower portion thereof; a conveyance path ( 3 ) is located within a conveyance path frame ( 36 ) so as to expose media delivery units; and alignment pins and alignment apertures, which align the media delivery units upon each respective cartridge ( 5 - 9 ) and the media delivery units upon the conveyance path ( 3 ), are disposed upon the facing surfaces of each respective cartridge ( 5 - 9 ) and of the conveyance path frame ( 36 ), and fit respectively therewith. | 1 |
FIELD OF THE INVENTION
The present invention is directed to a system for more accurately indicating if a spark and a flame are being produced in a fuel ignitor.
BACKGROUND
In typical gas and light oil-fueled utility burners, the gas/oil is ignited from a pilot flame on an ignitor. The ignitor must start this pilot flame. Therefore, it creates a spark from a spark rod connected to a high voltage transformer. The transformer provides high voltage electrical power (about 8 kV) to the spark rod that is adjacent to a grounded metal housing. The electrical power causes an arc (spark) to be produced between the spark rod and housing (ground). This arc occurs for a predefined time (typically 10 seconds) when the ignitor is first turned on. In prior art devices there are no external verifications that arcing is actually occurring.
The ignitor also has a flame rod located near a small fuel source, the spark rod and the housing. The spark rod creates arcing that lights the fuel from the small fuel source creating the pilot flame. The pilot flame spans the area between the flame rod and the housing. Since fire conducts electricity, this causes current to flow from the flame rod to the housing through the flame.
This current is monitored by an externally mounted electronic device. The electronic device and flame rod are referred to as a flame-proving device. The flame-proving device analyzes the flow of current from the flame rod to the housing to determine the presence of a pilot flame.
The arc from the high voltage transformer sometimes interferes with the ignitor flame-proving device, causing it to falsely indicate flame while the arc is on.
When an ignitor will not correctly light a pilot flame, the technician diagnosing the problem will usually remove the ignitor from the boiler and activate it without fuel to visually determine if an arc is being produced. This takes time and effort.
Currently, there is a need for a device that automatically determines if an ignitor is producing arcing and more accurately determines if a pilot flame is being produced.
SUMMARY OF THE INVENTION
The present invention may be embodied as an ignitor diagnostic device 100 for detecting the presence of arcing between an energized spark rod 23 and a housing 11 . It employs a flame rod 25 for sensing an electromagnetic (EM) signal radiated by the spark rod 23 when energized.
A sensing device 50 is coupled to the flame rod 25 and receives the EM signal from the flame rod 25 and processing the EM signal to create a spark indication signal.
A user interface 90 adapted to provide output to a user.
A logic unit 60 is coupled to the user interface 90 . The logic unit 60 is adapted to receive the spark indication signal from the sensing device 50 , determine if arcing is occurring based upon the strength of the spark indication signal. The logic unit 60 provides this information to the user interface 90 to cause an output to be displayed to the user.
The spark indication signal is comprised by a plurality of periodic lobes separated by low voltage timer periods, and the logic unit 60 monitors the low voltage time periods in the spark indication signal and measures the spacing between lobes to indicate ‘health’ of the spark producing equipment.
The present invention may also be embodied as an ignitor diagnostic device 100 for more accurately determining if a pilot flame is present.
It includes a flame rod 25 for sensing an electromagnetic (EM) signal radiated by the spark rod 23 when the spark rod 23 is energized,
a sensing device 50 coupled to the flame rod 25 for receiving the EM signal from the flame rod 25 and processing the EM signal to create a spark indication signal;
a logic unit 60 adapted to receive the spark indication signal from the sensing device 50 , determine if arcing is occurring based upon the strength of the spark indication signal and provide a logic signal indicating when arcing is occurring; and
a flame-proving device 70 coupled to the logic unit 60 adapted to receive the logic signal from the logic unit 60 and only test for a pilot flame when the logic signal indicates that no arcing is occurring.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide a system that accurately determines if an ignitor is producing a spark.
It is another object of the present invention to indicate to a flame detector that an arc is currently being produced.
It is another object of the present invention to aid a flame detector in more accurately determining if there is currently a pilot flame burning.
It is another object of the present invention to indicate when there are problems with the spark apparatus.
It is another object of the present invention to predict failures of the spark apparatus.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings in which:
FIG. 1 is a perspective view of a pipe ignitor compatible with the present invention with its housing removed.
FIG. 2 is a perspective view from a different angle of a pipe ignitor compatible with the present invention with its housing removed.
FIG. 3 is a partially cut-away diagram of a pipe ignitor compatible with the present invention.
FIG. 4 is a schematic block diagram of the general elements for one embodiment of a circuit according to the present invention for processing a signal received from the flame rod.
FIG. 5 is an illustration of a waveform monitored at test point “A” of the circuit of FIG. 4 .
FIG. 6 is an illustration of a waveform monitored at test point “B” of the circuit of FIG. 4 .
FIG. 7 is an illustration of a waveform monitored at test point “C” of the circuit of FIG. 4 .
FIG. 8 is an enlargement of a portion of the waveform shown in FIG. 7 .
FIG. 9 is a cross sectional, elevational view of a side ignitor compatible with the present invention as it would appear installed within a boiler.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a perspective view of a pipe ignitor 10 compatible with the present invention with its housing removed.
FIG. 2 is a perspective view from a different angle of a pipe ignitor 10 compatible with the present invention with its housing removed.
FIG. 3 is a partially cut-away diagram of a pipe ignitor 10 compatible with the present invention.
The following description is made with reference to FIGS. 1 , 2 and 3 . Pipe ignitor 10 has an elongated housing 11 having an internal end 13 passing inside of a combustion chamber of a boiler and an external end 12 extending outside of the combustion chamber.
The external end 12 has a spark rod cable 33 and a flame rod cable 35 extending out to external equipment. Internally, the spark rod cable 33 connects to an electrically conductive spark rod 23 . Spark rod 23 extends from the spark rod cable 33 to the internal end 13 . It extends parallel to, but does not come in contact with, the outer housing 11 . The outer housing 11 is electrically connected to ground. There is a predetermined gap between spark rod 23 and outer housing 11 .
High voltage electric power source 3 provides electric power, preferably in the form of alternating current, through the spark rod cable 33 and to the spark rod 23 . This causes pulsating arcing between the spark rod 23 and the internal end 13 of housing 11 . This arcing produces high frequency electro-magnetic radiation and induces current flow in nearby conductors.
A flame rod 25 is enclosed within the outer housing 11 and extends to the internal end 13 of the pipe ignitor 10 . It is positioned between the fuel tube 40 and the end of spark rod 23 . This allows the flame rod 25 to be immersed in a pilot flame when the pilot flame is burning.
Flame rod 25 is connected to a flame rod cable 35 that connects ultimately to a flame-proving device that detects the presence of a pilot flame.
Referring now also to FIG. 4 , one type of flame-proving device 70 measures electrical current passing through a flame. Flame-proving device 70 applies a voltage difference between the flame rod 25 and the housing (ground). Since the pilot flame (fire) conducts electricity, the pilot flame between the fuel tube 40 and the housing 11 creates a circuit allowing current to flow from the flame rod through the pilot flame and to the housing 11 . This is typically about 30 volts. This current is measured by the flame-proving device 70 . The presence of electrical current flow indicates that a pilot flame is present. Conversely, the absence of current flow indicates that a pilot flame is not present.
The present inventors discovered that the flame rod 25 could act as an antenna as well as functioning to provide current through the pilot flame. It was also determined that the arcing produced by the spark rod 23 creates high frequency RF ‘splatter’ radiation that was being sensed by the flame rod 25 . The characteristic AC pulsing is sensed by the flame rod 25 . Therefore, it was determined that the signal sensed by the flame rod 25 can be monitored to indicate when the spark rod 23 is creating arcing. This signal also indicates that a spark is being produced. This information may also be used to determine when the spark rod and associated power source are not functioning properly. It also may be used to cause the flame-proving device to sense the flame only when no arcing is being produced, and therefore detect the flame more accurately.
The theory of the present invention is to monitor electrical signals sensed by the flame rod 25 , filter out the DC and low frequencies in the sensed signal, rectify the signals, filter out the high frequencies and digitize the signal. This leaves a low frequency envelope signal that is twice the frequency of the AC current used (100 Hz. or 120 Hz.). When this signal is detected, the spark rod 23 is arcing.
The arcing of the spark rod 23 creates current that may be mistaken by the flame-proving device 70 as originating from a flame and incorrectly indicates that a flame is present when it is not. This is a false positive. Therefore, the sensing device 50 of the present invention must communicate with the flame-proving device 70 to indicate when arcing is occurring.
The flame-proving device 60 must then test for a flame only when the spark rod is not operating to detect if there is a flame.
This eliminates the interference and false-positives that occur due to the inadvertent detection of arcing and confusing the arcing with the presence of a pilot flame. This results in a more accurate flame-proving device.
FIG. 4 shows a schematic block diagram of the general elements for one embodiment of a sensing device 50 according to the present invention for sensing when arcing is occurring. The signal from the flame rod 25 is received through the flame rod cable 35 and provided to a high pass filter 51 . High pass filter 51 employs a capacitor C 1 and resistor R 1 connected to ground that will block lower frequencies in the signal caused by flame impingement on the flame rod 25 . High pass filter 51 passes the higher frequency signal due to the arcing radiation “splatter”. One such signal is that shown in FIG. 5 .
The filtered signal passes through a rectifier D 1 that rectifies the signal to flip the negative lobes to make them all positive. This signal is shown in FIG. 6 .
The rectified signal is provided to a low pass filter 55 . Low pass filter 55 in this embodiment employs a resistor R 2 and capacitor C 2 that block the high frequency arcing signal to produce an envelope signal. The envelope signal has a frequency that is twice the frequency produced by the AC power supply. The signal is shown in FIG. 7 .
An analog to digital converter 57 receives the analog envelope signal and digitizes it to create a set of digital samples approximating the analog envelope signal of FIG. 7 . This may be in the form of a series of measured amplitude values, or a block or table of such data.
A logic unit 60 senses the digitized signal provided by the ND converter 55 . Logic unit 60 may be a standalone device with its own microprocessor or be part of a calculation device 80 that has a microprocessor that runs several different programs and performs several different functions. One embodiment compares the amplitude of the digitized signal with a minimum amplitude, such as a 2 of FIGS. 7 and 8 .
Logic unit 60 then monitors the digitized signal to identify if the signal is at periodic peaks that exceed the threshold with a regular frequency. This frequency should be double the frequency of the signal provided by the spark power supply ( 3 of FIGS. 1 , 2 ) to the spark rods ( 23 of FIGS. 1 , 2 ). If so, arcing is being produced. If not, then no arcing is being produced.
Logic unit 60 receives the signal from the sensing device 50 and calculates information that there is, or is not, arcing being produced. This information is provided from the logic unit 60 to the flame-proving device 70 . Flame-proving device 70 is modified in this embodiment to operate when the output of the logic unit 60 indicates that no arcing is being produced. It is not allowed to operate when the logic unit 60 indicates that arcing is being performed.
In an alternative embodiment, the flame-proving device 70 is allowed to operate at all times, but readings indicating that there is a flame present while logic unit 60 indicates that arcing is being performed are ignored.
FIG. 5 is an illustration of a waveform monitored at test point “A” of the circuit of FIG. 4 . Here the high frequency signal has an envelope with a frequency that follows the AC input frequency.
FIG. 6 is an illustration of a waveform monitored at test point “B” of the circuit of FIG. 4 . Here the signal of FIG. 5 has been rectified, flipping the signal lobes to the positive side.
FIG. 7 is an illustration of a waveform monitored at test point “C” of the circuit of FIG. 4 . Here the resultant signal is only the envelope of the rectified AC input frequency. The high frequency signal due to the arcing has been filtered out.
FIG. 8 is an enlargement of a portion of the waveform shown in FIG. 7 .
This is a time vs. amplitude plot of the envelope of the rectified waveform. As the waveform envelope reduces amplitude (input voltage), it reaches a point at time t 1 that the curve drops to zero amplitude.
Similarly, as voltage is provided by the power source 3 to the spark rod 23 during the period from time=t 2 to time just before t 3 , there is no measurable amplitude response. It is only at time=t 3 that arcing begins and increases its amplitude rapidly until it follows the normal waveform envelope.
It has been determined that the health of the power source 3 , spark rod 23 , the spark rod cable 33 and the remainder of the connections between these units can be determined by the distances between t 1 and t 3 .
The probability of failure may be determined not only by these distances, but by how these distances change over time.
Referring now to FIGS. 4 and 8 , optionally, logic unit 60 measures the amplitudes and times shown in FIG. 8 . It then compares these measurements to predetermined thresholds or optimum measurements to determine health of the system. Based on the deviations from the thresholds, one can determine how ‘healthy’ the system is.
Also, if the logic unit 60 is capable of storing historic data, the change over time can be determined and a prediction may be made as to when the system will fail. This can be very useful in the maintenance and repair of these ignitors.
FIG. 9 shows a variation of the pipe ignitor 10 . This is a side ignitor. All of the parts have the same function as those with the same reference numbers that have been previously described. Housing 21 is different since this is intended to be mounted in the sidewall of a boiler. Also, spark plug 24 is employed instead of a spark rod 23 . This is due to the different geometry that makes it difficult to be close to the housing. Therefore, spark plug 24 has both a positive and negative electrode spaced by a gap to create a spark similar to spark plugs in an average automobile.
It should be emphasized that the above-described embodiments of the present invention, particularly any “preferred” embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the invention. Many variations and modifications may be made to the above-described embodiment(s) of the invention without departing substantially from the spirit and principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention. | An ignitor spark indicator 100 is described that monitors RF signals within a flame rod 25 located near a spark rod 23 . The signal from the flame rod 25 is processed to provide a waveform that indicates when electrical arcing is occurring. The indication when arcing is occurring is also provided to flame-detecting equipment. The flame-proving device 60 only operates when the arcing is not produced so that the flame-detecting device 60 does not confuse the arcing with a flame reducing the false positive determinations. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a color proofing apparatus which utilizes an electronic signal input, and more particularly, to a method and apparatus for focusing a writing beam in a thermal printer using lasers to provide thermal energy to a dye-donor which causes the dye to selectively transfer to a receiver to form the proof image.
2. Description of the Prior Art
Color-proofing is the procedure used by the printing industry for creating representative images that replicate the appearance of printed images without the cost and time required to actually set up a high-speed, high-volume printing press to print an example of the images intended. Ideally, these representative images, or proofs, are generated from the same color-separations used to produce the individual color printing plates used in printing presses so that variations in the resulting images can be minimized. Various color-proofing systems have been devised to create the proofs and have included the use of smaller, slower presses as well as means other than presses, such as photographic, electrophotographic, and non-photographic processes.
The proofs generated are judged for composition, screening, resolution, color, editing, and other visual content. The closer the proof replicates the final image produced on the printing press, as well as the consistency from image to image, from press to press, and from shop to shop, the better the acceptance of the proofing system by the printing industry. Other considerations used in judging proofing systems include reproducibility, cost of the system as well as cost of the individual proofs, speed, and freedom from environmental problems. Further, since nearly all printing presses utilize the half-tone process for forming pictorial images, wherein the original image is screened, i.e. photographed through a screen to produce one or more printing plates containing an image formed of a plurality of fine dots that simulate the varying density of the original image, proofing processes that employ the half-tone process to form an image are more acceptable to the printing industry than are continuous tone systems.
In recent years a variety of processes have been developed and implemented to electronically form, store, and manipulate images both for the actual printing as well as the proofing of images. While such electronic systems can handle and produce analog images, the most widely used systems employ digital processes because of the ease of manipulation of such digital images. In each of these electronic processes it is possible to display the resulting image on a CRT display, but it is generally necessary to produce a "hard copy" (i.e. an image actually formed on a sheet of paper or other material) before it can be fully assessed for approval of the final printing operation. Thus, each of these electronic systems requires the use of some form of output device or printer which can produce a hard copy of the image for actual evaluation. It is to the field of proofing output devices that the present invention is directed.
While purely photographic processes can provide accurate reproductions of images, they do not always replicate the reproduction resulting from printing presses. Further, most photographic processes do not produce half-tone images that can be directly compared to the printed images they are supposed to simulate. Moreover, they are almost universally incapable of reproducing the images on the wide variety of paper or other material that can be run through a press. It is known that the appearance of the final printed image is affected by the characteristics of the paper or other material upon which it is printed. Thus, the ability to form the proof image on the material actually to be used in the press can be a determining factor in the selection of the proofing system.
Other continuous tone proofing systems, such as thermal processes and ink-jet systems have been developed, but they do not replicate the half-tone images so desired by the printing industry.
Electrophotographic proofing systems with half-tone capability have been introduced over the past few years which employ either wet or dry processes. The electrophotographic systems that use dry processes suffer from the lack of high resolution necessary for better quality proofing, particularly when the images are almost of continuous tone quality. This results from the fact that dry electrophotographic processes cannot employ toner particles which have a sufficiently small size to provide the requisite high image resolution. While wet electrophotographic processes do employ toners with the requisite small particle size, they have other disadvantages such as the use of solvents that are environmentally undesirable.
In commonly assigned U.S. patent application Ser. Nos. 451,655 and 451,656, both filed Dec. 18, 1989, a thermal printer is disclosed which may be adapted for use as a direct digital color proofer with half-tone capabilities. This printer is arranged to form an image on a thermal print medium in which a donor element transfers a dye to a receiver element upon receipt of a sufficient amount of thermal energy. This printer includes a plurality of diode lasers which can be individually modulated to supply energy to selected areas of the medium in accordance with an information signal. The printhead of the printer includes one end of a fiber optic array having a plurality of optical fibers coupled to the diode lasers. The thermal print medium is supported on a rotatable drum, and the printhead with the fiber optic array is movable relative to the drum. The dye is transferred by sublimation to the receiver element as the radiation, transferred from the diode lasers to the donor element by the optical fibers, is converted to thermal energy in the donor element.
A direct digital color proofer utilizing a thermal printer such as that just described must be capable of consistently and accurately writing minipixels at a rate of 1800 dots per inch (dpi) and higher to generate half-tone proofs having a resolution of 150 lines per inch and above, as is necessary to adequately proof high quality graphic arts images such as those found in high quality magazines and advertisements. Moreover, it is necessary to hold each dot or minipixel to a density tolerance of better than 0.1 density unit from that prescribed in order to avoid visible differences between the original and the proof. This density control must be repeatable from image-to-image and from machine-to-machine. Moreover, this density control must also be maintained in each of the colors being employed in multiple passes through the proofer to generate a full color image.
Aspects of the apparatus which affect the density of the dots that make up the image include such things as variations and randomness of the intensity and frequency of the laser output, and variations in the output of the fiber optics which can vary from fiber to fiber and even within a single fiber as it is moved during the writing process. Variations in the finish of the drum surface as well as drum runout and drum bearing runout and variations in the parallelism of the translation of the printhead with respect to the axis of the drum will also affect the density of the image dots. The difference in the distance between the ends of individual fibers and the drum surface also affects image density because of the fact that the end of the fiber bundle is flat while the surface of the drum is curved. Temperature variations in the printhead due to the ambient temperature of the machine as well as the fact that the writing process itself heats the printhead also influence the image density.
Variations in the print medium elements, such as variations in the thickness of the donor and receiver elements as well as the various layers that are a part thereof, can also affect the image density as it is being written.
SUMMARY OF THE INVENTION
Thus, it has been found necessary to continuously focus the writing beam as the image is being formed to assure that variations in the thickness of the donor and receiver elements, as well as other perturbations in the system, do not defocus the writing beam and adversely affect the image density or the sharpness of the image. Attempts have been made to utilize reflections of the writing beam from the top surface of the donor element to affect an autofocus control of the writing beam but variations in the thickness of the donor element itself have led to less than satisfactory results. Further, because of the total power being produced by the multi-channel writing array, e.g. 20 channels, each operating at a power level of 200 milliwatts, it is easy to overwhelm any focusing beam reflected from the writing element and to flood the photo-detector with the reflected writing beam. Still further, it has been found that, in thermal writing systems such as presently described, the process of writing or generating an image by heating the donor element can adversely affect the optical characteristics of the donor sheet through which the focusing beam must be transmitted. Thus, it has been discovered that improved focusing of the writing beam can be obtained if the focusing beam is directed to the donor element ahead of the writing beam. In this manner, the focusing beam can be transmitted through the donor element before it has been distorted by the thermal writing process. Accordingly, the focusing beam may more accurately determine the focusing position if it does not have to pass through a donor element that may have been optically distorted by the writing process.
Thus, a method and apparatus for separating the focusing beam from the writing beam at the focusing photo-detector of such a digital proofing apparatus would be technologicaly desirable and economically advantageous in that it facilitates the discrimination of the focusing beam from the writing beam. This is accomplished by physically separating the focusing beam from the writing beam at the writing head, at the writing element, and at the photo-detector. Moreover, this separation of the focusing beam from the writing beam permits the focusing beam to be projected onto the writing element ahead of the writing beam with the above-mentioned advantageous results.
Accordingly, the present invention provides, in an imaging apparatus utilizing a writing element, a movable writing head including means for generating a writing beam of light to be projected onto the writing element to generate an image, means for focusing the writing beam with respect to the writing element. The focusing means comprises means for generating a focusing beam of light to be projected onto the writing element and means for detecting the focusing beam. The improvement comprises means for spatially separating the focusing beam of light at the writing element from the writing beam of light at the writing element.
According to another embodiment of the present invention, in an imaging apparatus utilizing a writing element, a source of light is arranged to project a writing beam of light onto the writing element to generate an image. The source of light includes means for transferring the light to a movable writing head from whence it is projected onto the writing element. Means is provided for focusing the writing beam with respect to the writing element, with the focusing means comprising means for generating a focusing beam of light to be projected onto the writing element and means for detecting the focusing beam. The focusing beam generation means includes means for transferring the focusing beam of light to the movable writing head, with the improvement comprising means for spatially separating at the writing head the focusing beam transferring means and the writing beam transferring means whereby the focusing beam is projected onto the writing element in spaced relation with respect to the projection of the writing beam onto the writing element.
According to still another embodiment, in an imaging apparatus utilizing a rotating carrier member arranged to carry a writing element, a source of light is provided which is movable with respect to the writing element and is arranged to project a writing beam of light onto the writing element to generate an image. The source of light comprises a plurality of laser diodes and a plurality of optical fibers connecting the diodes to a movable writing head adjacent the carrier member, with the optical fibers in the writing head having output ends arranged in a linear array. The method of focusing the writing beam with respect to the writing element comprises the steps of generating a focusing beam of light, projecting the focusing beam from a location in the writing head spatially separated from but substantially centrally of the linear array onto the writing element, aiming the focusing beam ahead of the writing beam at the writing element, and reflecting the focusing beam from the writing element to a photocell where it remains separated from the writing beam.
According to yet another embodiment, in an imaging apparatus utilizing a rotating carrier member arranged to carry a writing element, a source of light is provided which is movable with respect to the writing element to project a writing beam of light onto the writing element to generate an image. The source of light comprises a plurality of laser diodes and a plurality of optical fibers connecting the diodes to a movable writing head adjacent the carrier member, with the optical fibers in the writing head having output ends arranged in a linear array. The improvement comprises a substantially planar support substrate disposed in the writing head arranged to support the output ends of the optical fibers on a first surface thereof. The substrate is provided with a plurality of grooves on the first surface with each groove receiving the output end of each fiber. Means is provided for focusing the writing beam with respect to the writing element, comprising a laser diode for generating a focusing beam of light to be projected onto the writing element and a photocell. A focusing optical fiber connects the focusing diode to the writing head, with the end of the focusing optical fiber at the writing head being supported on the opposite surface of the substrate from the first surface substantially centrally of the linear array of the writing beam optical fibers. Thus, the focusing beam is projected onto the writing element ahead of the writing beam and is separated from the writing beam when it is detected by the photocell.
Various means for practicing the invention and other features and advantages thereof will be apparent from the following detailed description of illustrative, preferred embodiments of the invention, reference being made to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the imaging apparatus of the present invention, partially cut-away to reveal hidden portions thereof;
FIG. 2 is a sectional view of the writing head and lens taken along line 2--2 of FIG. 1;
FIG. 3 is a greatly enlarged end view of the print head assembly; and
FIG. 4 is a perspective view of an optical fiber supporting substrate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a thermal printer 10 comprising a drum member 12 mounted for rotation about an axis 15 in frame member 14. The drum member 12 is adapted to support a thermal print medium, not shown, of a type in which a dye is transferred by sublimation from a donor element to a receiver element as a result of heating the dye in the donor. The donor element and the receiver element are superposed in relatively intimate contact and are held onto the peripheral surface of the drum member by means such as by vacuum applied to the superposed elements from the drum interior. A thermal print medium for use with the printer 10 can be, for example, the medium disclosed in U.S. Pat. No. 4,772,582, which includes a donor sheet having a material which strongly absorbs at the wavelength of the exposing light source. When the donor element is irradiated, this absorbing material converts light energy to thermal energy and transfers the heat to the dye in the immediate vicinity, thereby heating the dye to its vaporization temperature for transfer to the receiver element. The absorbing material may be present in a layer beneath the dye, or it may be admixed with the dye and is strongly absorptive to light having wavelengths in the range of 800 nm-880 nm. An example of a preferred embodiment of a receiver element that can be used with the present invention is disclosed in co-pending, commonly assigned U.S. patent application Ser. No. 606,404, entitled Intermediate Receiver Opaque Support, and filed Oct. 31, 1990. The receiver element disclosed therein incorporates a reflective layer which improves the efficiency of the dye transfer to the receiver element.
The light source is movable with respect to the drum member and is arranged to direct a beam of actinic light to the donor element. Preferably the light source comprises a plurality of laser diodes (not shown) which can be individually modulated by electronic signals which are representative of the shape and color of the original image, so that each dye is heated to cause volatilization only in those areas in which its presence is required on the receiver to reconstruct the color of the original object. In the preferred embodiment, the laser diodes are mounted remotely from the drum member 12, on the stationary portion of the frame 14, and each direct the light produced thereby to the input end of a respective optical fiber which extends to and transfers the light to a movable writing head 20 adjacent the drum member. The laser diodes are selected to produce a first beam of light having wavelengths in the range of 800 nm-880 nm, and preferably predominately at a wavelength of 830 nm.
The writing head 20 is moveably supported adjacent drum member 12 and is mounted on a moving translator member 16 which, in turn, is supported for slidable movement on bars 22 and 24. The bars 22 and 24 are sufficiently rigid that they do not sag between the mounting points at their ends and are arranged as exactly parallel with the axis of the drum member as possible. The upper bar 22 is arranged to locate the writing head precisely adjacent the axis of the drum with the axis of the writing head perpendicular to the drum axis. The upper bar 22 locates the translator in the vertical and the horizontal directions with respect to the axis of the drum member. The lower bar 24 locates the translator member only with respect to rotation of the translator about the bar 22 so that there is no over-constraint of the translator which might cause it to bind, chatter, or otherwise impart undesirable vibration to the writing head during the generation of an image. The translator member 16 is driven by means of a motor (not shown) which rotates a lead screw 26 parallel to bars 22 and 24 to move the writing head parallel with the axis of the drum member. The coupling (not shown) which connects the translator member to the lead screw is carefully chosen so that the only force imparted to the translator by the lead screw is parallel to the drum axis.
The writing head 20 is removably mounted on the translator member 16 so that it automatically adopts the preferred orientation with respect to the drum axis noted above. The writing head is selectively locatable with respect to the translator, and thus with respect to the drum surface and axis, with regard to its distance from the drum surface, and with respect to its angular position about its own axis. Accordingly, a pair of adjustable locating means are provided to accurately locate the writing head with respect to these two axes on the translator member 16. Only one of the adjustable locating means, a micrometer adjustment screw 25, is illustrated, A torsion and compression spring 27 is provided to load the writing head against these locating means.
The end of the writing head 20 adjacent the drum member 12 is provided with a pair of photosensors 29 aimed at the surface of the drum member. The photosensors are disposed on diametrically opposite sides of the optical axis of the writing head in a fixed relationship thereto.
A cross section of the writing head 20 is illustrated in FIG. 2 and comprises a generally cylindrical barrel portion 50 having a flange 52 at the drum end thereof. The interior of the barrel portion is arranged to accept a stationary lens barrel 54 at the writing end, containing a stationary lens 56. A printhead assembly 58 is selectively oriented within and at the opposite end of the barrel from the writing end. The printhead assembly comprises a tubular member selectively oriented within barrel portion 50 and contains a linear array of optical fibers which includes a planar fiber-supporting wafer or substrate 34 having a plurality of writing optical fibers 60 mounted on one face thereof and focusing optical fibers 62 on the opposite face thereof, as will be more thoroughly described hereinbelow. The writing optical fibers 60 have a writing end 36 facing the drum member 12 at one end of the barrel and extend from the other end of the printhead assembly out of the writing head barrel through a protective sheath 64 to the diode lasers, not shown.
A cup-shaped closure member 66 is arranged to mate with the flange 52 of the writing head barrel 50 and forms a housing for the focusing drive means, as will be described hereinbelow. The end of the closure member adjacent drum member 12 is provided with an axially disposed opening which is bridged by a pair of sheet flexure members, 68 and 70, mounted at the outer periphery thereof by annular plate means 72 and 74 to the closure member 66. The central portions of the sheet flexure members are mounted to a movable rigid cylindrical lens housing 76 which contains moveable lens 80. A cylindrical bobbin 82 is disposed around the end of stationary lens barrel 54 and is connected to the moveable lens housing 76 via equally spaced arms 84 which extend between the legs of the flexure members 68 and 70. A voice coil 86 is wound about the cylindrical portion of the bobbin 82 and is connected to a driving circuit, to be further described hereinbelow.
Also enclosed between the end closure 66 and flange 52 is a high power, toroidal magnet 90 and an annular magnetic plate 92 which are both disposed about and spaced from the end of stationary lens barrel 54. The voice coil portion of the bobbin 82 is disposed in the gap between the inner circumference of plate 92 and the outer circumference of stationary lens barrel 54. The dimensions of the magnet, the annular plate, the stationary lens barrel, and the bobbin are such that the bobbin can move freely axially of the lens barrel. The bobbin is supported in the gap by its attachement to the moveable lens housing 76 which is held in position by the plate flexures 68 and 70. It will be noted that the barrel portion 50, flange 52, the stationary lens barrel 54, and annular plate 92, are all formed of magnetic material, such as ordinary steel, so that in combination with the toroidal magnet 90, a strong magnetic field is created between the inner periphery of the annular plate 92 and the end of the stationary lens barrel 54. As a result, when a current is introduced into the voice coil 86 of the bobbin 82, as by a lens focusing circuit (not shown), an axial force is imparted to the bobbin and to the moveable lens housing 76, thereby selectively moving the moveable lens 80 along the optical axis of the assembly. Thus, with an appropriate focus detection system, to be described hereinbelow, the moveable lens assembly may be driven to assure that the output of the fiber optic array is maintained in focus at the appropriate position on the drum member 12, or on or within the writing element (not shown) mounted thereon.
The fiber optic array (see FIGS. 2 and 3) comprises a plurality of fibers 60 which are each connected to a respective, remotely mounted diode laser, not shown. The diode lasers can be individually modulated to selectively project light from the writing end 36 of the optical fibers through the lens assembly, consisting of stationary lens 56 and movable lens 80, onto the thermal print medium carried by the drum member 12. The fiber optic array can be of the type shown in FIG. 3 and comprises optical fibers 60 which are supported on a first surface of the substantially planar substrate 34. The array may be of the type shown in co-pending, commonly assigned U.S. application Ser. No. 451,656, filed Dec. 18, 1989. Each of the optical fibers includes a jacket, a cladding, and a core, as is well known in the art. As disclosed in the copending application, the fibers extend from the laser diodes to the array and are mounted in sets of V-grooves 100 (FIG. 4) which are formed in the first surface of the substrate 34 so that the fibers at the writing end 36 are disposed as a linear array, substantially parallel and adjacent to each other in very close proximity, with the ends disposed in a common plane perpendicular to the fiber axes. In a preferred embodiment of the array, twenty writing fibers 60 are employed. As illustrated in FIG. 3, the substrate 34 is disposed in the tubular member 54 of the printhead assembly 58. The tubular member is provided with a keyway 59 which mates with a corresponding key (not shown) on the inner surface of barrel portion 50 so that the orientation of the linear array 60 is at a preselected angle Θ with respect to the drum axis 15. The orientation of the keyway 59 in the outer surface of the printhead assembly 58, the corresponding key on the interior of the barrel portion 50, and the photosensors 29 (see FIG. 1) disposed on diametrically opposite sides of the writing head axis, all correspond so that when the line connecting the two photosensors 29 is exactly parallel with the axis 15 of drum member 12, the writing angle of the linear array 60 is that which has been preselected for the particular apparatus.
The focus detection system comprises a second array of optical fibers 62 mounted in V-grooves 101 on the opposite surface of the substrate 34 with respect to the writing array 60. The focusing array 62 requires only a single fiber, but in practice, three fibers may be provided, with two as extras in case the first fiber fails. The focusing fiber is connected at its inlet end to a laser diode (not shown) which may be mounted in the same region with the writing diodes, but which is selected to produce a second beam of light having a wavelength different from the wavelength of the writing beam and preferably outside the range of 800 nm-880 nm. In the preferred embodiment the focusing light source produces a beam of light having a predominant wavelength of 960 nm. The writing and the focusing fibers, 60 and 62, are held in the respective V-grooves 100 and 101 by cover plates, 63 and 65, respectively, which extend over all of the fibers and are glued or otherwise adhered to the surfaces of the substrate 34.
In the preferred embodiment, the writing array is provided with power from laser diodes, each operating at a power level of 200 milliwatts. The writing array consists of twenty laser diodes, which supply twenty optical fibers, each with a core diameter of 50 μm, that are mounted on a first surface of the planar support substrate 34 at the writing head. The substrate has a thickness of approximately 1 mm, or about 1000 μm. The focusing beam is produced by a laser diode producing approximately 10 milliwatts of power which is transferred to the writing head through a focusing optical fiber 62, also having a diameter of approximately 50 μm, which is mounted on the opposite surface of the support substrate from the writing array. The focusing optical fiber is preferably centered along the length of the linear writing array, as will be further described hereinbelow. Thus, the focusing fiber is spaced from the closest writing fiber by a distance of approximately twenty diameters. Moreover, in the preferred embodiment, the support substrate is oriented so that the focusing fiber, with respect to the writing array, is disposed so that the focusing beam is projected onto the writing element ahead of the writing beam. As a result, the focusing beam is relatively unaffected by any thermal distortions of the donor element resulting from the heating thereof during the thermal writing process. Also, since the focus laser diode is of such a relatively low power output, there is little chance that the donor element will be thermally distorted by the focusing beam itself.
The focusing system also includes a beam splitter 120, having a semi-reflective buried surface 122, which is disposed between the writing end 36 of the linear array 60 and the stationary lens 56. A split cell photodetector 130 is disposed in the sidewall of barrel 50 and is arranged to receive the portion of the focusing beam which is reflected from the writing element and by the buried layer of the beam splitter. The photodetector is provided with a mask to shield the split cell from any part of the writing beam which may be reflected to the photodetector. The focusing fiber 62 is arranged to project the focusing beam through the image splitter 120, the focusing assembly comprising lenses 56 and 80, and onto the drum surface or the writing element disposed thereon. Because of the spatial separation of the focusing fiber from the linear array of the writing fibers at the writing head, the focusing beam is spaced from the writing beam at the writing element and, subsequently, at the photodetector. The focusing beam is reflected from the reflective surface of the receiver element back through the focusing assembly and into the beam splitter 120 wherein a portion of the reflected focusing beam is deflected by the buried layer into the split cell photodetector 130. In the preferred embodiment, photodetector 130 has a preferential wavelength sensitivity to the wavelength of the focusing beam, i.e. 960 nm. The signal from the photocell 130 is fed to a focusing circuit, not shown, which then generates an appropriate current which is supplied to the voice coil 86 on the bobbin attached to the movable lens element 80. In this way the focus detection system constantly monitors the location of a surface closely adjacent the surface of the writing element on which the writing beam is to be concentrated.
As noted above, the focusing fiber is preferentially located opposite the center of the writing array on the opposite surface of the support substrate. This assures that the focusing fiber is spaced from the writing element a distance which is substantially the same as the central writing fiber. Moreover, since the location of the focusing fiber is substantially closer to the axis of the focusing lens than would be the case were the focusing fiber mounted on the same surface of the substrate but spaced from the end of the writing array, a smaller, less expensive lens may be utilized with no loss of performance.
Further, it will be appreciated that, in an image writing apparatus according to the preferred embodiment, the writing array produces a total power at the writing element of 4 watts while the focusing beam has a power of only 10 milliwatts at the laser diode. After all of the losses of the two beams passing through the various elements of the writing and focusing system are considered, the power of the writing beam at the photodetector is approximately 1 milliwatt, while the focusing beam has a power of only 25 microwatts, one-fortieth the power of the writing beam. Yet the separation of the focusing beam from the writing beam makes it possible for the photodetector to be unable to determine whether or not the writing beam is turned on. Accordingly, the spacing of the focusing beam from the writing beam permits the focusing photocell to have a sensitivity that would not otherwise be possible without a significant increase in the output power of the focusing laser diode, with the attendant problems of increased power requirements and undesirable heat generation.
The invention has been described in detail with particular reference to a presently preferred embodiment, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. | In an imaging apparatus utilizing a rotating carrier member arranged to carry a writing element, a source of light is provided which is movable with respect to the writing element to project a writing beam of light onto the writing element to generate an image. The source of light comprises a plurality of laser diodes and a plurality of optical fibers connecting the diodes to a movable writing head adjacent the carrier member, with the optical fibers in the writing head have output ends arranged in a linear array. The improvement comprises a substantially planar support substrate disposed in the writing head arranged to support the output ends of the optical fibers on a first surface thereof. The substrate is provided with a plurality of grooves on the first surface with each groove receiving the output end of an individual fiber. A focusing arrangement is provided for focusing the writing beam with respect to the writing element and comprises a laser diode for generating a focusing beam of light to be projected onto the writing element, and a photocell. A focusing optical fiber connects the focusing diode to the writing head, with the end of the focusing optical fiber at the writing head being supported on the opposite surface of the substrate from the first surface substantially centrally of the linear array of the writing beam optical fibers. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rate control method whereby a system for providing a multimedia service across a network, such as video on demand (hereinafter referred to as a VOD), transmits to the network multimedia data, such as video/audio data, at a requested speed.
2. Related Arts
Because of the standardization of digital audio/video coding systems, such as ISO/MPEG (Moving Picture Expert Group)-2, and the expansion of networks using B-ISDN and ATM (Asynchronous Mode Transfer)-LAN, VOD service and various other bidirectional multimedia services can be realized.
VOD is a system that is constituted by a server (video server) for storing in a cumulative medium, such as a hard disk, a larger quantity of video data that are encoded in advance, and for distributing video data to a client upon the client's request, a client for displaying contents of a request for information issued by a subscriber and video data that are supplied; and a wide network (an ATM network) that can cope with a transfer and an exchange of video data.
FIG. 11 is a diagram illustrating the general configuration of a VOD service system. A video server 100 and a client 200 are connected to an ATM network 300, and upon receipt of a request from the client, MPEG2 data is transmitted by the server 100.
The video server 100 includes a storage device 101, such as a hard disk; a data transfer section 102; and a controller 103 for controlling these components. The client 200 includes a data receiver 210; an MPEG decoder 202; and a controller 203 for controlling these components.
A mapping method (MPEG over ATM) for mapping MPEG data over an ATM cell, which is used to transfer MPEG2 data, has been standardized by an ATM forum. The contents of the mapping are shown in FIGS. 12A, 12B and 12C. This standard will also be adopted by DAVIC, which is an organization established for the standardization of VOD systems.
Every two TS packets AA (188 bytes) (see FIG. 12A) of MPEG2 data are defined as a packet AAL5 (CPCS-PDU), and a trailer BB of eight bytes is added to the packet AAL5 to define a CPCS-PDU (AAL5 packet) (see FIG. 12B). Thereafter, the CPCS-PDU is disassembled to form eight ATM cells for transmission to a network. It should be noted that an ATM header DD of five bytes is provided for each ATM cell (see FIG. 12C).
To realize the video server 100, the MPEG data must be transmitted in the format shown in FIG. 12 that conforms to the system determined by the MPEG over ATM method. Another important function is control of the rate at which the ATM cells are transmitted to the network. This is the control for maintaining the speed at which the video contents are coded for transmission of the ATM cells to the network.
When this control is not performed precisely (clock precision: on an order of several tens of ppm, if available), a one-hour program, for example, will be ended within 59 minutes.
Taking the function of the video server 100 into account, since a conversion process between the AAL/ATM layers in FIGS. 12A through 12C is performed and an ATM cell is transmitted, a transmission queue is so controlled that it is never empty in order to maintain communication with a fixed rate.
A problem encountered here is that the value for a rate that can be set for the AAL/ATM layer conversion is a discrete value. That is, since cell transmission timing is generated by counting source clocks that are input for such control, the rate value can not help but be a discrete value.
In general, when the transfer speed does not match the data coding speed, stuff data (a packet) is inserted to absorb a difference in the speeds. An example structure is shown in FIG. 13. In FIG. 13, a buffer circuit 50, a multiplexer 51 and a stuff packet generator 52 are provided in the structure.
The buffer circuit 50 reads and fetches coded data in consonance with a coding clock timing, and transmits that data in consonance with a transmission clock timing. The stuff packet generator 52 detects an underflow for the data accumulated in the buffer circuit 50 and transmits stuff data (a packet) to the multiplexer 51 for insertion in the data.
If the same structure is to be applied for the coded data sent from the video server 100, however, a clock for coding can not be reproduced because the coded data from the video server 100 is stored in the storage device 101. Therefore, the configuration in FIG. 13 can not be applied.
In order to match the MPEG coding rate for information contents and the transmission rate for ATM cells, either (a) the information contents are coded at a coding rate that corresponds to the ATM cell transmission rate, or (b) an analog adjustment of an oscillator is performed that provides for the transmission rate a reference frequency that is in consonance with the coding speed.
With the remedial process (a), however, various vendors can not cope with the data contents, and the flexibility of the system will be lost. With the remedial process (b), since the coding rates for a number of different types of data contents are supported, a plurality of ATM interface sections, on which are mounted oscillators having different frequencies, must be provided for the individual transmission rates, with the result that there will be an increase in the system costs.
SUMMARY OF THE INVENTION
Focusing on the fact that a CPU in an ATM interface section controls the transmission of an AAL5 packet, it is one object of the present invention to provide a data transfer rate control method, and an apparatus therefor, whereby a CPU inserts the transmission of a stuff packet in real time, thereby resolving the above shortcomings.
To achieve the above object, according to the present invention, a method, for controlling a data transfer rate at which coded data are transferred in an asynchronous transfer mode, includes the steps of:
forming the coded data for an AAL layer;
calculating an insertion timing for insertion of a NULL packet;
inserting the NULL packet into the coded data of the AAL layer in consonance with the insertion timing, obtained by the calculation, for the NULL packet; and
transferring, in the asynchronous transfer mode, the coded data of the AAL layer into which the NULL packet is inserted.
Other objects of the present invention will become obvious during the course of the following explanation of the preferred embodiment of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating an example arrangement for a video server to which the present invention is applied;
FIG. 2 is a block diagram illustrating an example arrangement for an ATM interface circuit 6 in FIG. 1;
FIG. 3 is a diagram for explaining the structure of an MPEG2 transport stream;
FIGS. 4A and 4B are diagrams for explaining the concept of the insertion of a TS-NULL packet according to the present invention;
FIGS. 5A, 5B and 5C are diagrams showing an insertion example for a TS-NULL packet according to the present invention;
FIG. 6 is a diagram illustrating a logic model for a NULL packet insertion operation;
FIG. 7 is a flowchart for one control method for acquiring a packet interval for the insertion of an NULL packet;
FIG. 8 is a diagram for explaining the module configuration for the processing performed by a CPU of a video server, including the processing for the present invention shown in FIG. 7;
FIG. 9 is a diagram for explaining the processing performed by a schedular module;
FIG. 10 is a diagram illustrating an example arrangement for a PLL circuit on the reception side;
FIG. 11 is a diagram illustrating the general structure of a VOD service;
FIGS. 12A, 12B and 12C are diagrams for explaining the standards of a method for the mapping of MPEG data to an ATM cell (MPEG over ATM method); and
FIG. 13 is a diagram illustrating an example arrangement for the insertion of stuff data (packet) into coded data and the absorption of a speed difference.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention will now be described while referring to the accompanying drawings. The same reference numerals are used throughout to denote corresponding or identical components in the drawings.
FIG. 1 is a block diagram illustrating an example arrangement for a video server to which the present invention is applied. Under the control of a CPU 1, coded MPEG data that are stored on a disk 2 are read by a disk interface circuit 3. Buffering is performed for the data when it is transferred to a memory 5 via a bus 4.
An ATM interface circuit 6 employs the MPEG data for which buffering is performed when transferred to the memory 5 to form an ALL-5 packet (see FIG. 12B) and an ATM cell (FIG. 12C), which in turn are transmitted to an ATM network 300 (see FIG. 11).
In order to obtain a high throughput, a fast bus, e.g., a PCI bus, is employed as the bus 4, and a SCSI (Small Computer System Interface) is used for the disk interface circuit 3.
To accommodate more subscribers, the arrangement in FIG. 1 is developed in parallel, so that a video server providing a higher throughput and having a larger storage capacity can be provided.
The MPEG over ATM processing, i.e., the processing during which the MPEG data is formed into an AAL-5 packet and an ATM cell and the rate of transmission is controlled, is performed by the ATM interface circuit 6, as is described above. The example arrangement for the ATM interface circuit 6 is shown in FIG. 2.
The ATM interface circuit 6 includes a bus interface circuit 60, which functions as an interface with an upper host bus 4; a controller 62 for performing an AAL/ATM layer conversion process; a TC layer controller 63 for performing a TC layer process, such as SONET SDH; a transmitter/receiver 64 for functioning as an interface with a network; and a CPU 61.
The CPU 61 may be mounted in the ATM interface circuit 6, as is shown in FIG. 2, or it may be the host CPU 1 in FIG. 1. The AAL/ATM layer controller 62, the TC layer controller 63, and the transmitter/receiver 64 can be constructed of commercially available chips that are supplied by several makers, and therefore, no detailed explanation for them will be given.
The MPEG over ATM process and the rate control are performed by the AAL/ATM layer controller 62. When the CPU 61 adds the units of AAL5 packets (CPCS-PDU) to a transmission queue, the AAL/ATM layer process is performed and an ATM cell is output. For data transmission at a specific fixed rate, the rate is so controlled that the transmission queue is not emptied. Details concerning the rate control operation are contained in the user's manual for [ATM Adaptation Layer] Controller MB86686A, which is an AAL/ATM controller produced by Fujitsu Limited, the assignee of the present invention.
The problem that was maintained previously is that an available value for a rate set in the AAL/ATM layer controller 62 is a discrete value.
The present invention, therefore, focused on the fact that a NULL packet is prepared for a packet layer for MPEG2 (see FIG. 12A), and an AAL5-NULL packet, in which two NULL packets (NULL packet×2) are mounted in a payload for an AAL5 packet, is prepared. This AAL5-NULL packet is inserted at a proper location in coded data, which is then transmitted, so that the transmission of the contents at a desired coding rate is enabled.
FIG. 3 is a diagram for explaining the contents of a plurality of transport packets that are to be transmitted as an MPEG2 transport stream TS. The transport packet of 188 bytes, which has been explained while referring to FIG. 12, has a packet identification PID of 13 bits. The packet identification PID carries the attribute for the packet for each stream.
When the packet identification PID is 0×1fff, i.e., when 13 bits are all "1s," this means that the pertinent packet is a NULL packet. From the packet identification PID, the reception side can identify a received packet as either a normal packet or a NULL packet. When the received packet is an NULL packet with a TS packet layer, it is abandoned by the MPEG2 decoder at the reception side, so that no particular influence attributable to the insertion occurs.
The concept of the present invention involving the insertion of a TS-NULL packet is shown in FIGS. 4A and 4B. A set of two 188 byte TS packets (see FIG. 4A) and an eight byte trailer form an AAL5 packet of 384 bytes. A TS-NULL packet of 384 bytes is inserted between such AAL5 packets (see FIG. 4B). The actual problem is determining the AAL5 packet count interval at which an AAL5-NULL packet is to be inserted.
FIGS. 5A, 5B and 5C depict an example where a NULL packet is inserted. Data packets to be transmitted are shown in FIG. 5A, and transmission clocks are shown in FIG. 5B. When there is a difference between the data packet to be transmitted (FIG. 5A) and the transmission clock (FIG. 5B), the clocks for the data packets to be transmitted are advanced, as is shown in FIG. 5B.
According to the present invention, therefore, as is shown in FIG. 5C, NULL packets (N), whose packet identification PIDs are all ls, are inserted to maintain the clock timing for the data packets to be transmitted.
The actual problem here again is determining the AAL5 packet count interval at which a NULL packet should be inserted. This calculation method will be now explained.
Assuming that a coded bit rate for the information contents is X and a bit rate for an ATM layer that can be set is Y, the transmission bit rate for the MPEG-TS layer is represented as follows. ##EQU1##
A value 48 is obtained by subtracting a header of five bytes from an ATM cell of 53 bytes (see the ATM layer in FIG. 12C), and a value 376 is obtained by subtracting a trailer of eight bytes from an AAL5 packet of 384 bytes (see FIG. 4B).
A logic model for a NULL packet insertion operation is shown in FIG. 6. An underflow occurs in the buffer memory 5 of 376 bytes at a speed of (αy-x) bits. Thus, the time interval at which the underflow occurs is (376×8)/(αy-x).
The number of packets P that can be transmitted in this interval is represented as follows. ##EQU2##
Assuming that a desired coded bit rate x=6 Mbps and a set bit rate y=7 Mbps, P=29.9090909 . . . In this case, the AAL5-NULL packet generator 10 changes a NULL packet insertion interval between the packet values 29 and 30 to adjust the average packet value to 29.9090909 . . .
Such a control method is shown in the flowchart in FIG. 7. As the initial setup, a packet count value c is 0; an obtained interval q for packet insertion is 30; and current packet count values are cs and cl, which are both set to 0 initially.
For this processing, the packet insertion interval q for the insertion of a NULL packet is set to 30. Each time the NULL packet is inserted, the packet insertion intervals cl and cs in the past are recorded. Based on the cl and cs, the average packet insertion interval v up to the present is calculated, and in consonance with the average interval, the succeeding NULL packet insertion interval q is determined.
More specifically, in the flowchart in FIG. 7, when the packet count value c does not equal the obtained packet insertion interval q (step S1: N), the common AAL packet transmission process is performed (step S2). Then, the packet count value is incremented by one (step S3). The above described process is repeated until the packet count value c equal the obtained packet insertion interval q.
When the packet count value c equals the obtained packet insertion interval q (step S1: Y), a NULL-AAL packet is transmitted (step S4).
When q=30, the count value cl is incremented by one, and When q≠30, the count value cs is incremented by one (step S5). The average packet insertion interval v up to the present is calculated (step S6). The average packet insertion interval v is represented by the following expression:
v=(cl×30+cs×29)/(cl+cs).
Then, the average insertion interval v for the packets that have been inserted is compared with the packet insertion interval P that was previously acquired as the average value. When v>P, the obtained packet insertion interval q is set to 30 (step S7).
Thereafter, the packet count value c is set to 0 (step S8) and program control then returns to step S1 to repeat the above processing.
FIG. 8 is a diagram for explaining the module structure for the processing performed by the CPU 1 of the video server 100, including the processing for the present invention in FIG. 7. An upper command interface module 11 has an interface function for commands and messages that are exchanged with the upper controller.
A master control module 12 controls the individual modules (generation and deletion of tasks), and generates a system message. A file system module 13 manages a logic format, information contents, a file directory and data.
A schedular module 14 determines the order in which a disk interface device driver module 15 and an ATM interface device driver module 16 will be accessed so as to guarantee data quality and provide efficient service.
The disk interface device driver module 15 and the ATM interface device driver module 16 are respective groups of device drivers for a disk interface device and for an ATM interface driver.
Only the portion of the above modules that is directly related to the present invention is shown in FIG. 9. In FIG. 9, when the processing is begun, the initial setup is performed (MO). When the initial setup has been completed, service is begun in accordance with commands originating at the upper level.
There are commands for starting and for terminating service, a special reproduction command, etc.; commands for which individual service processors 20 perform specified processes. When the service for a setup/change of a schedule parameter is begun, on each occasion after data held in the buffer memory 5 is transmitted (the system falls into the idle state: M1), scheduling is performed (M2), data is read from the disk 2 (M3), and the data is transmitted (M4).
For the data transmission process (M4), the ATM interface device driver 16 is called for each AAL packet, and the data in the buffer memory 5, which have been read from the disk 2, are placed in the transmission queue for the ATM interface 6 and transmitted.
The present invention is employed to register a NULL packet in the transmission queue using the above described method.
Further, as an expansion of the present invention, it is possible to include auxiliary data in the above described NULL packet that is to be inserted and to transfer the packet. The reception side can obtain the auxiliary data by extracting it in the course of abandoning the NULL packet.
When the reception side is to decode the stream in which the NULL packet is inserted, in consonance with the transmission clock, in the above described manner, the value of synchronous data (STC) to be used as reference data must be set to a desired value by an encoder on the transmission side.
To do this, a PCR (Program Clock Reference) is included in the transport stream, which is the system for assembling a plurality of programs into one stream (data string). The PCR is located in the adaptation field in the stream in FIG. 3, and consists of six bytes in the MPEG2 data. The PCR value is incremented in consonance with the elapse of transmission time.
Since by itself the PCR value is insufficient, the decoder sets a value indicated by the PCR when the final byte of the 6-byte PCR carried in the transport stream has arrived.
In FIG. 10 is shown an example arrangement of a PLL (Phase Lock Loop) that is located on the reception side, so that the decoder can obtain an STC having a frequency that matches the system clock of the coder. A phase comparator 70, a digital/analog converter 71, a low-pass filter 72, a voltage control oscillator 73, and a counter 74 constitute a closed feedback circuit.
As is described above, a value carried by the PCR a stream is set to a counter 74 when the final byte of the PCR has arrived. The value set to the counter 74 is incremented in consonance with a frequency of 27 MHz provided by the voltage control oscillator 73.
Therefore, the above described closed feedback circuit can provide a system reference clock having a frequency that completely matches the system clock of the coder.
As is described above in the embodiment of the present invention, according to the rate control method, data contents that have been coded at any rate can be transmitted at a desired rate by using the same hardware. As a result, this method contributes greatly to the reduction of system operating costs. | A data transfer rate control method inserts a stuff packet in real time to resolve the problem present in an ATM transmission for MPEG data. The method, for controlling a data transfer rate at which coded data are transferred in an asynchronous transfer mode may include the steps of: forming the coded data for an AAL layer (ATM Adaptation Layer); calculating an insertion timing for insertion of a NULL packet; inserting the NULL packet into the coded data of the AAL layer in consonance with the insertion timing, obtained by the calculation, for the NULL packet; and transferring, in the asynchronous transfer mode, the coded data of the AAL layer into which the NULL packet is inserted. | 7 |
TECHNICAL FIELD
This invention relates to a cream deodorant composition containing methyl salicylate as the surface active agent.
BACKGROUND OF THE INVENTION
Odor from a human body constitutes a problem. It has long been recognized that certain chemical compositions will prevent human body odor without adversely affecting the health of the applicant. Foot odor has presented a particularly severe problem, and many attempts have been made to solve it.
Traditionally, sprays, powders, and other deodorant application have attempted to eliminate foot odor. Sprays and powders have left residual particles on the feet of the consumer, thereby causing a maintenance problem within the socks and shoes. Other products have met with similar unsuccessful results.
U.S. Pat. No. 4,278,658 issued on July 14, 1981 to Hooper, et al., in which a deodorant composition is described for application to regions of the human body where apocrine sweat glands are located, such as in the groin, axilla, anal and genital regions and in the aureola of the nipple. Described therein is a deodorant composition containing at least five components, including phenolic substances in combination with oils, aldehydes and ketones, polycyclic compounds, esters and alcohols.
SUMMARY OF THE INVENTION
A deodorant composition comprises a cosmetically acceptable vehicle for the deodorant composition, methyl salicylate as the surface active agent, and a solubility enhancing oil in sufficient amounts to dissolve the methyl salicylate into the composition vehicle. Further components are included for emulsification, fragrance, preservation, and for the enhancement of its general properties. This composition results in a deodorant cream easily applicable to feet.
The composition of the deodorant includes the following constituents: from about 0.01 to about 0.10 percent by weight of methyl salicylate, up to 99.9 percent by weight of a cosmetically acceptable vehicle for the composition, and a solubility enhancing oil in sufficient amounts to dissolve the methyl salicylate into the composition vehicle.
An object of the present invention is to provide an improved deodorant composition for the topical application to the foot of a consumer. This deodorant composition may include a cosmetically acceptable vehicle, such as water, in combination with glycerine, oleyl alcohol, stearic acid, lanolin, peanut oil, polyethylene glycol stearate, dimethicone, triethanolamine, polyethylene ether, methyl salicylate, propylparaben, methylparaben and fragrances and colorings.
DESCRIPTION OF THE INVENTION
The present invention is directed to a cream deodorant composition useful in the prevention of foot odor in consumers. The composition includes a commercially acceptable vehicle, such as water, combined with glycerine and a deodorant composition containing methyl salicylate dissolved in a solubility enhancing oil, such as peanut oil.
Preferably, the composition contains methyl salicylate and up to 80% water, up to 15% glycerine, up to 10% oleyl alcohol, up to 10% stearic acid, up to 5% polawax, up to 5% lanolin, and up to 5% peanut oil. These percentages are expressed in percentage by weight. Methyl salicylate is preferably present between 0.01% by weight 0.10% by weight.
Methyl salicylate, commonly referred to as oil of wintergreen, is the surface-active agent in creams prepared in accordance with the present invention. The U.S. Food and Drug Administration requires compliance with FDA regulations if the concentration of methyl salicylate is greater than 0.10 percentage by weight. However, the preferred concentration for topical applications is up to 0.10 percentages by weight.
Peanut oil is added in amounts from about 0.5% and 5% by weight to aid the solubility of the methyl salicylate into the vehicle. Peanut oil is the preferred solubility enhancing oil because the methyl salicylate completely dissolves in its presence, while maintaining the neutrality of the fragrance of the cream composition. Other oils alter the fragrance in a disadvantageous manner, rendering the preparation unpleasant to use. Creams prepared according to the present invention have a mild, minty odor, both pleasant and effective.
In the examples described hereinbelow, the amounts are given in percentages by weight. Illustrative compositions of the present invention are disclosed, but the examples are not meant to limit the invention in any manner.
EXAMPLE 1
A cream deodorant composition was prepared with the following constituents:
______________________________________ Percentage by Weight______________________________________Water 71.00Glycerine 10.00Oleyl Alcohol 5.00Stearic Acid 3.00Polawax 3.00Lanolin 3.00Peanut Oil 2.00PEG-50 1.00Dimethicone 1.00Triethanolamine 1.00Laneth-15 .60Methyl Salicylate .10Propylparaben .10Methylparaben .10Camphor .05D&C Red #19 traceFragrance trace______________________________________
The methyl salicylate and the other oil soluble ingredients were dissolved into the peanut oil before dissolution into the vehicle. The glycerine and oleyl alcohol were mixed with the water and then all ingredients were combined to form the deodorant cream. Upon testing on human feet, the cream was effective in reducing odor.
EXAMPLE 2
A cream deodorant composition was prepared with the following constituents:
______________________________________ Percentage by Weight______________________________________Water 77.75Stearic Acid 3.00Propylene Glycol 3.00Glyceryl Stearate 2.00Sorbitol 2.00Polyethylene Laureth-4 2.00Peanut Oil 2.00Isopropyl Palmitate 1.00Dimethicone 1.00Hydrolyzed Animal Protein 1.00Methylparaben 1.00Imidazolidinyl Urea 1.00PEG-8 1.00PEG-12 1.00Quaternium-15 0.60Eucalyptus Oil 0.50Methyl Salicylate 0.10Camphor 0.05Red No. 33 traceFragrance trace______________________________________
Once again, the methyl salicylate and the other oil soluble ingredients were dissolved into heated peanut oil before dissolution into the vehicle. The other constituents were mixed with the water and all ingredients were combined to form the deodorant cream. Upon testing on human feet, this composition was effective in reducing odor.
While the best modes have been described in detail, those familiar with the art to which this invention relates will recognize various alternative compositions and methods for practicing the invention as defined by the following claims. | A deodorant composition comprises a cosmetically acceptable vehicle containing methyl salicylate and a solubility enhancing oil, preferably peanut oil. The composition is externally applied to the skin, generally to the feet of the user, and provides protection against development of odor. | 8 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/494,202 filed Jun. 7, 2011. The disclosure of the above application is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present invention generally relates to roofing materials and, more particularly, to roofing trim strips for in situ type of attachment to a roof.
BACKGROUND
[0003] It is generally known in the art to apply one-piece decorative thermoplastic strips to underlying thermoplastic roofing membranes. Current strips have several disadvantages.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a perspective view of an exemplary embodiment of a roofing trim base strip for application to a surface;
[0005] FIG. 2 is a cross-sectional view of the roofing trim base strip of FIG. 1 taken along line 2 - 2 thereof;
[0006] FIG. 3 is a perspective view of an exemplary embodiment of a roofing trim cap strip for assembly to the roofing trim base strip of FIG. 1 ;
[0007] FIG. 4 is a cross-sectional view of the roofing trim cap strip of FIG. 3 taken along line 3 - 3 thereof;
[0008] FIG. 5 is a cross-sectional view of a multi-piece roofing trim product including the roofing trim cap strip of FIG. 3 assembled to the roofing trim base strip of FIG. 1 ;
[0009] FIG. 6 is a perspective view of another exemplary embodiment of a roofing trim cap strip for assembly to the base strip of FIG. 1 ;
[0010] FIG. 7 is a cross-sectional view of the roofing trim cap strip of FIG. 6 taken along line 7 - 7 thereof; and
[0011] FIG. 8 is a cross-sectional view of a multi-piece roofing trim strip product including the roofing trim cap strip of FIG. 6 assembled to the roofing trim base strip of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0012] FIGS. 1 and 2 show one exemplary embodiment of a roofing trim base strip 10 that may be applied in situ to any suitable roofing surface. The roofing surface may include a sheet of material, for example, a roofing membrane of single or multiple ply construction. In one embodiment, the membrane may be molded from polyvinyl chloride, or may be produced in any other suitable manner of any other suitable thermoplastic material. Suitable membranes are available from Duro-Last Roofing, Inc., of Saginaw, Mich. In one embodiment, the material of the surface is identical to the material of the strip 10 . The strip 10 may be molded, extruded, or otherwise formed or produced in any other suitable manner and may be composed of polyvinyl chloride, or any other suitable thermoplastic material. In other embodiments, the materials of the base strip 10 and the roofing membrane may be similar or may be dissimilar. If any given strip 10 is not long enough for a particular application, a plurality of the strip 10 may be laid end-to-end, and may be butt-welded or otherwise coupled together in end-to-end fashion.
[0013] The base strip 10 extends longitudinally along a longitudinal axis A 1 and perpendicularly to a base axis B 1 that is perpendicular to the longitudinal axis A 1 and perpendicularly to a projection axis C 1 that is perpendicular to the longitudinal and base axes A 1 , B 1 . The base strip 10 includes a base portion 12 including opposed flanges 14 , 16 extending in opposite directions, and a cap coupling portion 18 extending in a direction transversely away from the base portion 12 a location between the flanges 14 , 16 . As used herein, the term “opposed” includes face-to-face opposition or back-to-back opposition. The flanges 14 , 16 may extend transversely away from the projection axis C 1 , and generally parallel to the base axis B 1 . The base strip 10 may be of generally inverted T-shape as shown wherein the cap coupling portion 18 forms a central or vertical leg of the “T” and the base flanges 14 , 16 form a transverse or horizontal leg or legs of the “T.” The base portion 12 may be generally planar and includes a base surface 20 that may include flange base surfaces 22 , 24 of the flanges 14 , 16 and also may include another portion 23 extending between the flange base surfaces 22 , 24 . The base portion 12 also may include angled sides 26 , 28 on the flanges 14 , 16 , and shoulder surfaces 30 , 32 on the flanges 14 , 16 oppositely disposed from the flange base surfaces 22 , 24 . The shoulder surfaces 30 , 32 may be flat or of any other suitable shape.
[0014] The cap coupling portion 18 may be a solid or hollow rib or projection extending away from the base portion 12 , for example, at a central portion 13 thereof wherein the flange portions 14 , 16 extend in a direction away therefrom. The cap coupling portion 18 may include cap engagement features 34 , 36 . The engagement features 34 , 36 may extend in a direction away from the projection axis C 1 , and generally parallel to the base axis B 1 . In one example, the cap coupling portion 18 also may include side surfaces 38 , 40 extending away from the surfaces 30 , 32 of the flanges 14 , 16 , a terminal surface 42 , and the cap engagement features 34 , 36 therebetween. The cap engagement features 34 , 36 may include outwardly extending barbs. For example, the cap engagement features 34 , 36 may include ramp surfaces 44 , 46 and shoulder surfaces 48 , 50 extending between the ramp surfaces 44 , 46 and the side surfaces 38 , 40 . The cap engagement features 34 , 36 may be spaced from the flanges 14 , 16 in a direction along the projection axis C 1 .
[0015] The cap engagement features 34 , 36 and the side surfaces 30 , 32 may be shaped to form engagement slots 52 , 54 between the cap engagement features 34 , 36 and the opposed flanges 14 , 16 . For example, the side surfaces 38 , 40 may be semi-circular, as shown, or may be of any other suitable shape. Also, the terminal surface 42 may be flat, as shown, or may be of any other suitable shape. Moreover, the ramp surfaces 44 , 46 may be angled or straight, as shown, or may be curved, radiused, or of any other suitable shape. Additionally, the shoulder surfaces 48 , 50 may be flat, as shown, and may extend generally parallel to the base axis B 1 , forming acute angles with respect to the ramp surfaces 44 , 46 .
[0016] More particularly, the cap coupling portion 18 itself also may be generally T-shaped. For example, the cap engagement features 34 , 36 may form a transverse or horizontal leg or legs of the “T.” Likewise, a central or vertical portion of the “T” may be formed between the side surfaces 38 , 40 .
[0017] FIGS. 3 and 4 show an exemplary embodiment of a roofing trim cap strip 310 that may be assembled to the base strip 10 of FIGS. 1 and 2 , or to any other suitable roofing trim base strip. The cap strip 310 extends longitudinally along a longitudinal axis A 2 and perpendicularly to a base axis B 2 that is perpendicular to the longitudinal axis A 2 and perpendicularly to a projection axis C 2 that is perpendicular to the longitudinal and base axes A 2 , B 2 . The cap strip 310 may be extruded from polyvinyl chloride or may be produced in any other suitable manner of any other suitable thermoplastic material. In other embodiments, the materials of the cap strip 310 and the base strip 10 may be similar or may be dissimilar. The cap strip 310 includes a web portion 312 , and a base coupling portion 314 extending from the web portion 312 . The cap strip 310 may be of generally inverted V shape in cross-section.
[0018] The web portion 312 includes two side walls 316 , 318 extending at an inward angle from the base coupling portion 314 at one end of the web portion 312 , and forming an apex 320 at another end of the web portion 312 . The web portion 312 may be triangular shaped and the apex 320 may rounded or radiused.
[0019] The base coupling portion 314 includes legs 323 , 325 with fixed ends 322 , 324 and free ends 326 , 328 . The legs 323 , 325 may be spaced apart in a direction extending parallel to the base axis B 2 , and disposed on either side of the projection axis C 2 . The base coupling portion 314 extends from the fixed ends 322 , 324 at corresponding portions of the web portion 312 in a direction away from the web portion 312 and includes base engagement features 330 , 332 proximate the free ends 326 , 328 . As used herein, the term “proximate” includes being relatively closer to the free ends 326 , 328 than to the fixed ends 322 , 324 . The base engagement features 330 , 332 may include barbs extending inwardly from inward surfaces of the base coupling portion 314 . For example, the base engagement features 330 , 332 may include ramp surfaces 334 , 336 and shoulder surfaces 338 , 340 extending from the ramp surfaces 334 , 336 . The ramp surfaces 334 , 336 may be curved, or radiused or semi-circular, as shown, or may be or angled or straight, or of any other suitable shape. The shoulder surfaces 338 , 340 may be flat as shown and may extend in a direction parallel with the transverse axis B 2 , forming acute angles with respect to the ramp surfaces 334 , 336 .
[0020] FIG. 5 shows one exemplary embodiment of a roofing trim cap assembly 300 . The assembly 300 may include the cap strip 310 of FIGS. 3 and 4 assembled to the base strip 10 of FIGS. 1 and 2 that may be applied to a roof R in any suitable manner.
[0021] For example, the base strip 10 may be laid over the roof R and adhered, bonded, welded, fastened, or coupled to the roof R in any suitable in situ application. In one example embodiment, the base strip 10 may be applied to the roof R in accordance with the METHOD AND APPARATUS FOR APPLYING STRIPS TO SURFACES of U.S. Provisional Patent Application Ser. No. 61/352,193, filed Jun. 7, 2010 and assigned to the assignee hereof. The content of the above application is incorporated herein by reference in its entirety.
[0022] Then, the cap strip 310 may be oriented over the base strip 10 and assembled thereto. For example, the base coupling portion 314 of the cap strip 310 may be forced over the cap coupling portion 18 of the base strip 10 . The cap strip ramp surfaces 334 , 336 may cam or ride over the base strip ramp surfaces 44 , 46 until the cap strip shoulder surfaces 338 , 340 move past the base strip shoulder surfaces 48 , 50 ( FIG. 2 ). The cap strip engagement features 330 , 332 interengage the cap strip 310 to the base strip 10 , wherein the cap strip engagement features 330 , 332 are retained in the base strip slots 52 , 54 ( FIG. 2 ) between the base strip engagement features 34 , 36 and the base strip flanges 14 , 16 . The cap strip engagement features 330 , 332 may be sized to occupy substantially the entire slots 52 , 54 . Accordingly, the cap strip 310 may be coupled directly to and in contact with the base strip 10 with nothing in between. Also, if any given strip 310 is not long enough for a particular application, a plurality of the strip 310 may be laid end-to-end, and may be butt-welded or otherwise coupled together in end-to-end fashion.
[0023] The assembly 300 is a multiple piece or multi-piece product that may provide an aesthetic, architectural appearance to a roof. For example, the assembly 300 may simulate a standing-seam rib of a metal roof. The assembly 300 forms an interior space or void 302 between interior surfaces of the cap strip 310 and exterior surfaces of the base strip 10 . The void 302 may be generally triangular in shape, as shown, or of any other suitable shape. The assembly 300 may be customized. For example, a common base strip may be used with cap strips of other colors and/or other shapes different from the base strip.
[0024] For instance, FIGS. 6 and 7 show another exemplary embodiment of a roofing trim cap strip 410 that may be assembled to the base strip 10 of FIGS. 1 and 2 or to any other suitable roofing trim base strip. This embodiment is similar in many respects to the embodiment of FIGS. 3 and 4 , and like numerals between the embodiments generally designate like or corresponding elements throughout the several views of the drawing figures. Additionally, the descriptions of the embodiments are incorporated by reference into one another and the common subject matter generally may not be repeated here.
[0025] The cap strip 410 extends longitudinally along a longitudinal axis A 3 and perpendicularly to a base axis B 3 that is perpendicular to the longitudinal axis A 3 and perpendicularly to a projection axis C 3 that is perpendicular to the longitudinal and base axes A 3 , B 3 . The cap strip 410 may be extruded from polyvinyl chloride or may be produced in any other suitable manner of any other suitable thermoplastic material. In other embodiments, the materials of the cap strip 410 and the base strip 10 may be similar or may be dissimilar. The cap strip 410 includes a web portion 412 , and a base coupling portion 414 extending from the web portion 412 . The cap strip 410 may be of generally “Pi” shape in cross-section.
[0026] The web portion 412 includes a wall 413 extending across the base coupling portion 414 . The wall 413 may have an arcuate outer surface 416 and a corresponding arcuate inner surface 417 . The arcuate surfaces 416 , 417 may be semi-circular. The wall 413 may terminate in extensions 418 , 420 that may extend past portions of the base coupling portion 414 .
[0027] The base coupling portion 414 includes opposed legs 423 , 425 including fixed ends 422 , 424 and free ends 426 , 428 . The legs 423 , 425 may be spaced apart in a direction extending parallel to the base axis B 3 , and disposed on either side of the projection axis C 3 . The base coupling portion 414 extends from the fixed ends 422 , 424 at corresponding portions of the web portion 412 in a direction away from the web portion 412 and includes base engagement features 430 , 432 proximate the free ends 426 , 428 . The base engagement features 430 , 432 may include barbs extending inwardly from inward surfaces of the base coupling portion 414 . For example, the base engagement features 430 , 432 may include ramp surfaces 434 , 436 and shoulder surfaces 438 , 440 extending from the ramp surfaces 334 , 336 . The ramp surfaces 434 , 436 may be curved, or radiused or semi-circular, as shown, or may be or angled or straight, or of any other suitable shape. The shoulder surfaces 438 , 440 may be flat as shown and may extend in a direction parallel with the transverse axis B 3 , forming acute angles with respect to the ramp surfaces 434 , 436 .
[0028] FIG. 8 shows another exemplary embodiment of a roofing trim cap assembly 400 . This embodiment is similar in many respects to the embodiment of FIG. 5 , and like numerals between the embodiments generally designate like or corresponding elements throughout the several views of the drawing figures. Additionally, the descriptions of the embodiments are incorporated by reference into one another and the common subject matter generally may not be repeated here.
[0029] The assembly 400 may include the cap strip 410 of FIGS. 6 and 7 assembled to the base strip 10 of FIGS. 1 and 2 that may be applied to a roof R in any suitable manner. Then, the cap strip 410 may be oriented over the base strip 10 and assembled thereto, for example, by forcing the base coupling portion 414 of the cap strip 410 over the cap coupling portion 18 of the base strip 10 . The cap strip ramp surfaces 434 , 436 may cam or ride over the base strip ramp surfaces 44 , 46 until the cap strip shoulder surfaces 438 , 440 move past the base strip shoulder surfaces 48 , 50 ( FIG. 2 ). The cap strip engagement features 430 , 432 interengage the cap strip 410 to the base strip 10 , wherein the cap strip engagement features 430 , 432 are retained in the base strip slots 52 , 54 ( FIG. 2 ) between the base strip engagement features 34 , 36 and the base strip flanges 14 , 16 . The cap strip engagement features 430 , 432 may be sized to occupy substantially the entire slots 52 , 54 . Accordingly, the cap strip 410 may be coupled directly to and in contact with the base strip 10 with nothing in between. Also, if any given strip 410 is not long enough for a particular application, a plurality of the strip 410 may be laid end-to-end, and may be butt-welded or otherwise coupled together in end-to-end fashion.
[0030] The assembly 400 is a multiple piece or multi-piece product that may provide an aesthetic, architectural standing-seam appearance to a roof. The assembly 400 forms an interior space or void 402 between interior surfaces of the cap strip 410 and exterior surfaces of the base strip 10 . The void 402 may be generally rectangular in shape, as shown, or of any other suitable shape.
[0031] The foregoing description is considered illustrative only. The terminology that is used is intended to be in the nature of words of description rather than of limitation. Many modifications and variations will readily occur to those skilled in the art in view of the description. Thus, the foregoing description is not intended to limit the invention to the embodiments described above. Accordingly the scope of the invention as defined by the appended claims. | A roofing trim strip and multi-piece trim strip product is provided. There is shown a roofing trim strip base that may be applied to a suitable roofing surface, such as a thermoplastic membrane roof. The trim strip base includes a cap coupling portion extending away from a base portion. The cap coupling portion includes cap engagement features. A roofing trim cap strip includes a web portion and a base coupling portion. The base coupling portion of the cap strip may be placed over the cap coupling portion to couple the cap strip with the base strip. The cap strip may take any suitable configuration and may be particularly adapted to simulate a standing seam metal roof. | 4 |
This is a continuation of application Ser. No. 886,904, filed July 16, 1986, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a novel voltage control module which may be mounted in a standard wall box.
Large scale dimming systems generally comprise a control panel having a series of levers or other operating members each connected to a potentiometer. A control signal, which is typically a steady DC signal, is sent to a dimmer module remotely located from the control panel. A dimmer module normally must be housed in a custom panel or electrical box which requires the provision of adequate space for the same. Also, the prior custom dimmer modules were expensive to manufacture and to install.
In addition, many facilities where lighting dimming is required entail a number of circuits with modest load requirements. Typical custom dimming enclosures used heretofore possessed a large capacity which far exceeded the requirements of these facilities. Consequently, the installation of existing lighting dimming equipment became uneconomical.
The provision of a compact dimmer or voltage control module which is mountable in a standard wall box would be a great advance in the lighting industry.
SUMMARY OF THE INVENTION
In accordance with the present invention a novel and useful voltage control module is provided.
The module of the present invention utilizes a housing which easily fits in a standard wall box. The housing contains circuitry which controls the passage of AC electrical power from a source, thereof, to a load such as a lamp, fan, motor, and the like. Such means for determining the quantity of power passing from the source of AC electrical power to the load may include a power semi-conductor which possesses power leads between the source and the load, heretofore described. Typically, power semi-conductors of this type have a gate for controlling the delivery of power from the source to the load using phase control through a triggering circuit.
The module of the present invention also employs means for rectifying the AC electrical power signal from the source and transforming the resultant pulsating DC signal to a lower voltage.
Comparitor means may be employed for generating an output signal for triggering the gate of the power semi-conductor in accordance with the low voltage pulsating DC signal and the remotely generated low voltage DC control signal. The comparator means further includes voltage compensation means for substantially maintaining the delivery of a constant quantity of power from the source to the load through the power semi-conductor with variations of the voltage of the AC electrical power from the source. In the case where the load is a lamp, the dimming level of the lamp would remain unchanged with fluctuations of the voltage of the AC electrical power source.
The module of the present invention also may be provided with an optically coupled semi-conductor device connected between the AC power source and the comparator. Also, another optically coupled semi-conductor device may be connected between the output terminal of the comparator and the power semi-conductor. Thus, the comparator, which operates at low voltage, is effectively isolated from the high voltage portions of the electrical circuitry.
The voltage control module of the present invention may further include means for compensating the pulsating DC power signal for changes in the ambient temperature. The temperature compensation means may include a pair of optically coupled transistors having light emitting diode portions. Further, the light emitting diode portion of the first optically coupled transistor may be connected in parallel with the means for rectifying the source AC signal. The second optically coupled transistor light emitting diode portion is connected in series with the transistor of the first optically coupled transistor. Also, the transistor of the second optically coupled transistor could be connected in parallel with the light emitting diode of the first optically coupled transistor.
An offset diode may also be placed in series with the emitter of the transistor of the first optically coupled transistor. This offset diode would insure the proper reset of one of the comparator imputs during generation of the triggering signal.
A further aspect of the module of the present invention is the provision of a chassis having a front and rear portion. A magnetic breaker is mounted to the chassis herein and an indicator of the on-off state of the breaker is visible of the front portion of the chassis. The magnetic breaker extends to the rear portion of the chassis and serves to interrupt current flow from the AC electrical source to the load when a certain current level is exceeded.
It may be apparent that a novel and useful wall box mounted voltage control module has been described.
It is therefore an object of the present invention to provide a voltage control module which is sufficiently compact to fit within a standard wall box.
It is another object of the present invention to provide a voltage control module which utilizes remotely generated DC signals from a variety of control panels with or without demultiplexing.
Another object of the present invention is to provide a voltage control module which may be packaged alone or in combination with a group of like modules and is simple to install at a site.
Yet another object of the present invention is to provide a voltage control module which may be employed with incandescent, low voltage incandescent, fluorescent, or neon/cold cathode lighting and with a variety of motors.
Another object of the present invention is to provide a voltage control module which is durable and less susceptible to electronic interference than prior dimmer modules.
A further object of the present invention is to provide a voltage control module which utilizes a fully magnetic circuit breaker which has an illuminated accessible operator for mechanically overriding the magnetically operated on/off function of the breaker.
Yet another object of the present invention is to provide a voltage control module which includes a silent, electronic, on-off switching relay which controls the activation of the dimmer circuit in the module.
Another object of the present invention is to provide a voltage control module which includes voltage compensation means to eliminate flicker in lamps being dimmed by the module dimming circuit caused by source AC voltage fluctuations.
A further object of the present invention is to provide a voltage control module which includes temperature compensation means for eliminating load output variations caused by changes in the ambient temperature surrounding the module.
Another object of the present invention is to provide a voltage control module which possess high and low trim adjustment controls in the dimming circuit.
The invention possesses other objects and advantages especially as concerns particular characteristics and features thereof which will become apparent as the specification continues.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view showing a physical embodiment of the present invention;
FIG. 2 is a front elevational view of the physical embodiment of the present invention of FIG. 1 in its assembled state;
FIG. 3 is a rear elevational view of the present invention in its assembled state;
FIG. 4 is a schematic view of the circuit of the present invention;
FIG. 5 is a series of graph depicting signal characteristics at certain points in the schematic view shown in FIG. 4;
FIG. 6 is a graph indicating the voltage compensation feature of the present invention;
For a better understanding of the invention reference is made to the hereinafter description of the preferred embodiments of the present invention which should be referenced to the hereinabove described drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Various aspects of the present invention will evolve from the following detailed description of the preferred embodiments thereof which should be referenced to the hereinabove drawings.
The invention as a whole is represented in the drawings by reference character 10. The dimmer module or dimmer pack 10 includes a removable face plate 12 having a plurality of springy legs 14 which rest against the wall 16 of channel 18 found on heat sink body 20.
A magnetic circuit breaker 22 is mounted to stand-off 24 which is itself riveted to heat sink body 20 by the use of a pair of grovets 26. Heat sink body includes a rear surface 28 which serves as a mounting surface for SCR tabs 30 and 32 which aid in the mounting of SCR1 and SCR2 to surface 28. Likewise, tab 34 holds triac U2 to surface 28. Printed circuit boards 36 and 38 mount to tabs 30, 32, and 34 by solder or other fastening means. Various circuit components 40 are mounted to printed circuit boards 36 and 38, resistor R-29 being exemplar thereof. Choke 40 is also included for the suppression of RF1 interference, as is known in the art. Choke 40 is attached to printed circuit board 36 by solder or other fastening means. Back box 42 encloses the electrical and electronic components found on the rear surface 28 of heat sink body and on the printed circuit boards 36 and 38 which are also enclosed by back box 42. Plurality of openings 44 permit wires to extend to the exterior of back box 42. Adjustment tools 46 and 47 extend through openings and 50 of heat sink body 20 and openings 52 and 54 of standoff 24. Adjustment tools 46 and 47 are employed to permit manual adjustment of the high and low trim of the voltage controlling or dimming function of module 10. These adjustments are accessible by removal of face plate 12 from heat sink 20. It should be noted that magnetic circuit breaker 22 may be of the type sold as the AIRPAX 203 manufactured by AIRPLAX, Corp, Cambridge, Md. The terminals 52 of breaker 22 interconnect with appropriate conductors on printed circuit boards 30 and 32.
With reference to FIG. 2, it may be apparent that circuit breaker 22 extends to the front portion 54 of heat sink body or chassis 20. Also, the circuit breaker 22 extends to the rear portion 26 of chassis 20 when assembled. Circuit breaker 22 includes operator 58 for mechanically turning the breaker "on" and "off". Operator 58 manually overrides the magnetically operated portion of the operator 22 and is illuminated, as will be discussed hereinafter.
Turning attention to FIG. 3, rear surface 28 of chassis 20 is depicted. As heretofore discussed, backbox 42 includes a plurality of openings 44. Wires or conductors 60, 62, 64, 66, 68, 70, 72, and 74 extend through plurality of openings 44 for use in electrically wiring module 10 within a standard single gang wall box, standard in the industry. Conductors 62, 64., 70 and 72 represent low voltage DC wires while conductors 60, 66, 68 and 74 represent high voltage AC wires.
With reference to FIG. 4, a circuit diagram is represented. The heretofore described conductors appearing in. FIG. 3 have been identified in FIG. 4 with indicia further clarifying the same.
Conductors 68 and 74 represent the NEUTRAL and LINE AC voltage conductors and constitute the source 76 of AC electrical power to module 10. Resistors R1 and R2 and diode bridge 78 having diodes D1, D2, D3, and D4 generate a full-wave rectified signal. Graph A, FIG. 5 represents the sine wave AC current across conductors 68 and 74. Graph B of FIG. 5 depicts the "camel hump" full-wave rectified signal coming from diode bridge 78.
It should be noted that the graphs shown in FIG. 5 are included to generally show the wave shapes encountered in the circuit shown in FIG. 4 and are not to be construed as accurately portraying voltage and time values.
U1 and U5 are optically coupled or opto-coupled transistors. The emitter current of the transistor of U1 is the same as the light emitting diode of transistor U-1 (LED) current multiplied by some gain. Graph C describes the emitter curren of U1. Graph D depicts the wave form of the voltage on R5. R5 includes the trim resistor R-29 to adjust the voltage across R5 as desired. The voltage flowing from the emitter of U-1 enters pin 9 of U4C which is a comparator. Thus, GRAPH D also represents the wave form found on pin 9 of comparator U4C. It should be noted that all pins will be designated by the letter "P", with a particular number, hereinafter. The voltage at P9 of comparator U4C generally ranges between 0 and 15 volts DC.
U5 is also an opto-coupled transistor whose LED portion is connected in series with the collector of transistor U1. The transistor portion of opto-coupled transistor U5 is connected in parallel with resistor R28 and the LED of opto-coupled transistor U1.
As the ambient temperature relative to module 10 varies, the amplitude of the signal from the emitter of transistor U-1 also varies. Generally, as temperature increases the voltage of the signal from U1 increases and vice-versa. However, the U5 transistor will compensate for temperature variations. For example, if the ambient temperature at device 10 increases, the U5 LED will increase its output as the U1 opto-coupled transistor current increases. The current through the transistor of U5 added to the current through R28 and the LED of opto-coupled transistor U1 will become a fixed value, e.g. 3 milliamps. As the current through the transistor of U5 increases a current through the LED of opto-coupled transistor U1 will decrease. Thus, through this feed back mechanism the emitter current of U1 decreases to a value existing prior to the temperature increase. Thus the U1 and U5 combination serves as means 82 for temperature compensation.
The CONTROL signal through conductor is generally a steady DC signal of some value; in the embodiment shown, between 0 and 15 volts. The CONTROL voltage is generated remotely from a dimmer or voltage control module (not shown) and may be demultiplexed, if the original signal is a digital signal. The control signal passes through limiting resistor R17 which is a part of a voltage divider formed therewith and with resistor R18. Resistor R18 is found in leg 84 which terminates in conductor 72, the COMMON lead of the DC power reference. It should be noted that conductor 70 leading into leg 86 serves as the supply voltage or "hot" DC lead. Conductors 70 and 72 originate with a DC lead power supply (not shown). In the embodiment shown, leg 86 is at a level of about 15 volts DC.
U4D is an operating amplifier having inputs at P12 and P13. P12 originates between resistors R17 and R18 while P13 comes from variable resistor RV1, the high trim adjustment for the module 10. Thus, the gain of U4D is RV1. P4 and P11 serve as the DC supply voltage and COMMON leads to U4D respectively. P14, the output of U4D, passes through gain setting resistor R19 and to P3 of U4A. U4A is a current generator also receiving an input at P2 from COMMON leg 84. Resistors R20, R21 and R22 are gain setting resistors. The output at P1 of U4A feeds back through R22 into P2. RV2 and parallel resistors R23 and R24 set the low trim for the resistor dimmer module 10. The output of current generator at P1 of U4A is proportional to the CONTROL signal through R17.
The DC signal from U4A is sent to node 88 and charges capacitor C2. Graph E of FIG. 6 depicts a typical variety of steady DC signals into capacitor C-2. Again, the constant DC current signals to capacitor C-2 are proportional to the CONTROL signal entering through conductor 64. Graph F, FIG. 6, depicts the typical ramps corresponding to the inputs to C-1, shown in Graph E. Thus, comparator U4C possesses inputs at P9 and P10 corresponding to the wave form shown in Graphs D and F. When the voltage of P9 is greater than P10, the output of comparator U4C, P8, equals zero. However, when P9 is less then P10, P8 goes to a certain DC voltage determined by P4, in the embodiment shown being 10 volts DC. Graph G represents the voltage at P5 and P6 of U4B. Graph H depicts the output, P7, of U4B i.e.: when the voltage at P6 exceeds the voltage at P5. Graph I, FIG. 6, depicts the input voltages at P9 and P10 to U4C. This DC current from P-8 passes to R6 and to the LED of U-2, an opto-coupled triac (switch). Graph J, FIG. 6, depicts the output of P8 of U4C as well as the configuration of the current to the LED of opto-coupled triac U-2. When P8 of U4C plateaus, capacitor C-2 is reset to zero. P9 of U4C also feeds into P6 of operational amplifier U4B. P5 of U4B connects to capacitor C2 and lies between voltage dividing resistors R14 and R16. When the voltage on P6 is less than the voltage on P5, P7 goes to a high value and travels the base of Q1 via resistor R15. At this point Q1 is turned "off" and capacitor C-2 may again charge. The values of resistor R14 and R16 are chosen to synchronize the resetting of capacitor C-2 with the zero crossing of the AC line frequency from source 76. Thus, U4B and Q1 serve as a portion of a reset circuit for capacitor C2.
The width of the plateau of the square wave form shown in Graph J, FIG. 5 depends on the steepness of the ramp of P10 entering comparator U4C. In turn, these signals are proportional to the CONTROL signal entering conductor 64, previously described. SCR1 and SCR2 serves as the positive and negative gate to LOAD which is a portion of conductor 66. The output of SCR1 and SCR2 to the LOAD is shown by Graph K. Where the load is a lamp, the light emanating from such a lamp will be less than its full intensity depending on the level of the CONTROL signal through conductor 64.
It should be noted that offset diode D6 insures that capacitor C2 is fully discharged when reset to zero, since a residual charge on C2 could cause full conduction of anti-parallel SCRs'1 and 2 and full conduction of the AC power to the load, thereby. R8 and C3 provide a snubber circuit which eliminates "noise" in the firing of SCR1 and SCR2.
Comparitor U4C also serves as a portion of means 90 for compensating for variations in the AC voltage across conductors 68 and 74. With reference to FIG. 6 it may be seen that LOAD voltages are depicted at 90%, 100% and 110% of LINE voltage from source 76. When the LINE voltage from source 76 increases the ramp from capacitor C2 crosses later in the half cycle of the signal at P9 of U4C. Thus, the "on" time of SCR1 and SCR2 is shorter, but the peak value of the voltage is higher. Conversely, at 90% LINE voltage from source 76, the ramp produced by capacitor C2 crosses the P9 waveform sooner in the half cycle. The "on" time of anti-parallel SCR1 and SCR2 is longer but the peak voltage value is less. The areas, beneath the graphs (representing the power to the LOAD) formed by each of the three wave forms depicted in FIG. 6, substantially equal each other. The symbols X1, X0, and X2 represent corresponding initiation times of the ramps produced by capacitor C2 at 90%, 100% and 100 % values of LINE AC voltage, respectively.
Returning to FIG. 4 it may be seen that ON-OFF conductor 62 represents a DC control signal of a certain value which appears at current limiting resistor R9 by the actuation of a switch (not shown). When a current flows through R9 to the base of opto-coupled transistor U3, no current travels through diode D9 and R13 to the base of transistor Q1. Thus, the system for controlling the power to the LOAD functions according to the signal arriving at the CONTROL lead 64. R10 serves as a "cool down" resistor between the base and emitter of the transistor portion of U3. However, when no signal is fed through conductor 62, Q3 and R13 provide a predetermined DC signal to this base of Q1. With Q1 in the "on" condition, capacitor C2 is incapable of charging. Thus, comparator U4C is in the "off" condition. In addition, when Q3 is "on" the LED 92 passes a signal from the COMMON conductor 72 through current limiting resistor R12 to transistor U3. LED 92 is optically coupled to triac U3. Triac U3 U4 is then turned on to produce a constant AC voltage through conductor 60. Typically, this voltage is employed to feed a ballast in a fluorescent lighting fixture. However, conductor 60 may feed to other electrical units requiring a constant AC voltage.
Lamp 94 connects to conductor 68 via current limiting transistor R27. Lamp 94 illuminates operator 58 of magnetic circuit breaker 22. As heretofore discussed, the switch depicted in FIG. 4 may be operated magnetically when excessive current passes through conductor 74 or overridden mechanically by the use of operator 58.
In operation, module 10 is connected to a source 76 of AC voltage represented by conductors 68 and 74. A source of DC power is fed into module 10 though conductors 70 and 72 representing the DC voltage and COMMON leads. A CONTROL signal enters module 10 through conductor 64 from a remote source. Typically the CONTROL signal is a steady DC signal at a certain voltage. The CONTROL signal through the circuit depicted in FIG. 4 determines the power delivered to the LOAD through conductor 66 using a phase control technique with power semi-conductor SCR1 and SCR2. The circuit depicted in FIG. 4 includes means 82 to compensate for variations in ambient temperature as well as means 90 for compensating for variations in the AC voltage from source 76. Module 10, in part by the usage of opto-coupled transistors, has been miniaturized to fit in standard wall box. As heretofore noted, the CONTROL signal entering conductor 64 may be a demultiplexed digital signal, in which case a demultiplexer is required.
The following table lists typical values for the various components shown in FIG. 4.
TABLE 1______________________________________C-1 0.1 mic.fC-2 0.1 mic.fC-3 0.047 mic.fD-1 1N4148D-2 1N4148D-3 1N4148D-4 1N4148D-5 1N4148D-6 1N4148D-9 1N4148Q-1 MPS 8097 (Motorola)Q-3 MPS 8097Q-4 Q-2015 (Teccor)R1 20 KOHMR2 20 KOHMR5 10 KOHMR6 390 OHMR7 100 OHMR8 100 OHMR9 10 KOHMR10 1 MOHMR12 390 OHMR13 1 MOHMR15 100 KOHMR16 10 KOHMR17 1 MOHMR18 1 MOHMR19 1 MOHMR20 1 MOHMR21 1 MOHMR22 620 KOHMR23 1 MOHMR24 620 KOHMR25 20 KOHMR26 1 KOHMR27 33 KOHMR27 33 KOHMR28 68 KOHMR29 VariableRV-1 10 KOHMRV-2 10 KOHMSCR 1 S112 (Teccor)SCR 2 S112 (Teccor)U-1 4N37U-2 MOC-3021 (Motorola)U-3 MOC-3021 (Motorola)U-5 4N37U4A, U4B, U4C, U4D Integ. Cir. LM 324______________________________________
While in the foregoing embodiments of the present invention have been set forth in considerable detail for the purposes of making a complete disclosure of the invention, it may be apparent to those of skill in the art that numerous changes may be made in such detail without departing form the spirit and principles of the invention. | A wall box mounted remotely operated voltage module utilizing a low voltage DC control signal which is remotely generated. A power semi conductor device is triggered to deliver a predetermined amount of power from the source of AC electrical power to a load. The AC electrical power is rectified and transformed to produce a low voltage rectified DC signal. A comparator generates a triggering signal to the power semi conductor utilizing the low voltage rectified DC signal and remotely generated low voltage DC control signal as imputs. The comparator also serves as a compensator for changes in the voltage of the AC electrical power from the source. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to the recovery of plastic for re-use.
SUMMARY OF THE INVENTION
Among the objects of the present invention are the provision of novel methods and apparatus for recovering used plastic.
Additional objects of the present invention are treatments for recovering plastic from compact discs that are defective or damanged or surplus.
The foregoing as well as still further objects will be more fully understood from the following description of several embodiments of the present invention, reference being made to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged transverse sectional detail view of a compact disc used for audio recordings and the like; and
FIG. 2 is a plan view of the details of a recovery treatment pursuant to the present invention.
DETAILED DESCRIPTION
Plastics are generally re-usable after they have been formed into commercial products. They can in many cases be remelted and formed again.
Such re-use of plastics is particularly significant where the plastics are of the more expensive kind such as polycarbonates. Compact discs used for audio recording or the like are made of such more expensive plastics, and their production is accompanied by rejects as well as damaged discs. Such discs are aluminized and coated during their production, and these treatments complicate the recovery.
According to the present invention, the salvaging of a compact disc is effected by shaving off the coatings with a specially arranged surface mill.
According to another aspect of the present invention, salvaging of plastics is effected by shaving down a face of the plastic with a shaving machine having rotating rubbery rollers that engage a face of the disc and feed it through an entrance slot, a shaving mill that engages and shaves a face of the disc after it passes through the entrance slot, a resiliently mounted centering pin that engages and centers the disc as it feeds forward, and means for brushing the disc edge and rotating the disc about the centering pin as it feeds forward.
Turning now to the drawings, FIG. 1 illustrates a currently manufactured compact disc 20, in enlarged detail. It can be a disc of transparent polycarbonate resin about one millimeter thick and about 12 centimeters in diameter. The disc's under face 22 is generally flat and provided with a multiplicity of generally cylindrical pockets 24 which are configured in a pattern that records an audio signal which can be played back by rotating the disc around its axis while the pockets are illuminated by laser beams.
The upper face of the disc is coated with a thin layer of specular metal 28--generally by aluminizing. The metal layer is in turn protected by a thin resin covering layer 30.
Both the metal layer and the resin coating need to be removed before the expensive plastic of the disc can be re-used most economically.
FIG. 2 is a diagrammatic illustration of an effective removal technique according to the present invention. A transporting assembly 50 is arranged to convey discs 20,20 from an entrance position 52 to an exit position 54 through a passageway 56 that closely fits the disc. The passageway floor has a rubbery first feed roller 60 spaced from and followed by a surface mill 62 and then similarly followed by a second rubbery feed roller 64, ending with a set of spring loaded guide rolls 71,73 that urge a transported disc toward a side 74 of the passageway and also hold that disc against the disc behind it in the passageway.
The passageway side 74 has an edge opening through which each passing disc projects its outer edge. A motor-driven rotary brush 80 engages the projecting edges and brushes them clean of any shavings and debris. The disc is then pushed past the spring-loaded rollers by the next disc, and thus discharged.
The passageway 56 is covered by a closely fitting roof, as noted, and through that roof a centering plunger 82 projects downwardly and is spring-urged toward the line along which the disc centers are carried. When an open disc center moves under the plunger, the plunger penetrates into the opening and momentarily holds the disc so that for a fraction of a second, the disc is rotated around its center by the very rapidly rotating brush 80. Brushing action at two to ten thousand rpm is effective.
To feed the discs, the passageway floor is provided with rubbery feed rollers that pinch against feed rollers 60 and 64 to effect the feeding action. Only one of the first set of rollers 60 need be power driven. A vacuum cleaning suction input can be placed under the floor as well as near the brush to suck off the shavings and debris. Spaces 68, 69 between the rollers and the mill are provided to permit the suction to remove shavings. If desired, the rubbery rollers can be backed up by all metal rolls that stiffen the pinching action of the rubbery rollers.
The surface mill 62 is held between bearing blocks 84, 86, adjacent a section 72 of the floor so that the mill can be rotated around its axis at high speed, generally over 2,000 revolutions per minute, and also raised or lowered a little to control the shaving depth. That depth is generally about 2 to 5 thousandths of an inch, and can be adjusted if necessary, by inspection of the brushed output, without interrupting the shaving.
The surface mill can be an end mill, one end of which is ground to form a bearing projection. A four-flute end mill one inch in diameter is typical, but its sharp flutes are desirably dulled to minimize the heat generation caused by the shaving. Removing the outermost two to three thousandths of an inch from the flutes by simple grinding is very effective and permits the shaving to be conducted at 60 to 70 discs per minute, without interruption and with little or no cooling. The drive for the shaving mill can be fixed to the bearing blocks 84, 86 so that it moves up and down with the blocks, or it can be a flexible drive in which event it can generate heat that needs controlling as by jets of cooling air when shaving at 3000 or more rpm.
Using a mill which is not dulled, significantly increases the heating and requires correspondingly significant cooling when the shaving is as low as 15 discs per minute.
Spacings 68,69 are preferably about 1/2 to about 5/8 inch wide in the feed direction although they can be somewhat narrower. A guide panel 87 can extend into opening 68 to help guide an incoming disc to the bight position of the mill and thus prevent a misdirected feed. However the panel is arranged to leave at least about half of opening 68 unblocked as by making the panel triangular in plan view, as illustrated. The triangle can be pointed up-feed or down-feed, and should leave about 1/8 inch gap in the feed. The shavings generated during operation are generally long, twisted and threadlike so that much of the unblocked portion of opening 68 should extend from one edge of the floor to the other. The shavings can be used for radar chaff or the like.
A vibratory feeder can be connected to supply the discs to the input rolls 60 from a bin in which the discs are collected for treatment. It may be desirable to equip such a feeder with a turnover station to turn over any discs that it feeds upside down. The turnovers can be manually controlled, or can be automatically responsive to the differences in reflectivity between the opposite faces of a disc or responsive to laser scanning that will show which face is being scanned.
Instead of shaving, the discs can be cleaned up by dissolving their plastic coatings and the aluminum layer. Strong aqueous caustic like a hot 20% NaOH solution in water loosens the plastic coating and dissolves the aluminum, but the coating removal is speeded by mixing a resin solvent like toluene with the caustic. Resin solvents that attack the plastic disc body should not be permitted to contact a disc for more than a minute or so.
In general, the discs can be scrubbed with an appropriate resin solvent and then with caustic, or with a mixture of the two, for about 20 to 30 seconds, or even less if the scrubbing is effected hot. The scrubbed disc is then rinsed with water and dried for packaging.
Dilute acid like 0.1N aqueous hydrochloric acid can be used instead of caustic, in which event care should be taken to keep the equipment from the corroding effects of the acid.
The resin coating can also be removed by blasting the discs with jets of superheated steam hot enough to melt that resin and blow the melt off the disc. Adding a little caustic or acid to the steam jets will cause them to also remove the aluminum.
Sputtered or ion-implanted metals like titanium can also be removed by the shaving treatment or the chemical treatment using the dilute acid or superheated steam that reacts with titanium and other metals.
Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described. | Plastics having coatings are reused by first removing the coatings as by shaving or treatment with solvents or jets of hot liquid or vapor that melt the coatings and blow them away. Thin plastic pieces like compact discs are passed through surface milling apparatus which shaves off the coatings. After the shaving, the discs are brushed while rotating around their centers. | 8 |
BACKGROUND OF THE INVENTION
It is known to electrolytically reduce nitrate and nitrite from solutions of alkali metal hydroxides. This procedure is disclosed in U.S. Pat. No. 3,542,657 to Mindler and Tuwiner, the disclosure of which is incorporated herein by reference.
It has recently been found that this procedure is inoperative when the solution of nitrate and nitrite in sodium hydroxide is contaminated with oxidizing transition metal ions such as chromium ion. The chromium contamination which will give rise to this interference may be as low as 60 parts per million (as Na 2 CrO 4 ).
The reason for this interference is that in the electrolysis, nitrate is reduced to a nitrite at the cathode:
NO.sub.3.sup.- +2H→NO.sub.2.sup.- +H.sub.2 O (I)
However, the presence of chromate proximate to the cathode will reverse this reaction:
2NO.sub.2.sup.- +CrO.sub.4.sup.-- →2NO.sub.3.sup.- +CrO.sub.2.sup.-(II)
at the anode the chromate is reoxidized:
CrO.sub.2.sup.- +2O→CrO.sub.4.sup.-- (III)
here, a trace of chromate will, as found, make the prior art process inoperative.
It is generally known that bismuth will react with chromate to form a water insoluble pearlescent pigment compound. When it was first found that the chromium interfered with the regular process of the prior art procedure, it was attempted to remove the chromium by reacting the same with bismuth ion.
4CrO.sub.4.sup.-- →2Cr.sub.2 O.sub.7.sup.-- +O.sub.2 (IV)
O.sub.2 +2Bi.sup.+++ +Cr.sub.2 O.sub.7.sup.-- →(BiO).sub.2 Cr.sub.2 O.sub.7 (V)
The expected precipitation of the bismuth/chromium compound did not occur although a temporary operability of the process, for a very brief period of time, was noted.
It is furthermore known that when bismuth ion is subjected to electrolysis in an aqueous medium, black metallic bismuth will be formed on the cathode and purple/brown bismuth pentoxide (which is an insulator) is formed on the anode.
SUMMARY OF THE INVENTION
It has been found that where solutions of nitrate in caustic solution are contaminated with oxidizing transition metal ions such as chromium ion and thus cannot be subjected to the conventional electrolytic reduction of U.S. Pat. No. 3,542,657, the procedure can be made operable by adding a small amount of bismuth ion, suitably but not minimally 250 parts per million by weight of the entire solution and, preferrably periodically reversing the direction of direct current flow.
In the operation of the process, a black metallic coating of bismuth is formed on the cathode and a purple/brown bismuth pentoxide is formed on the anode:
Bi.sup.+++ +3e→Bi↓(cathode) (VI)
2Bi.sup.+++ +50→Bi.sub.2 O.sub.5 +4e (anode) (VII)
During current reversal the bismuth is sloughed off from the cathode and some is converted to bismuth pentoxide on the new anode surface:
2Bi+50→B.sub.2 O.sub.5 +10e (new anode) (VII)
Bi→Bi.sup.+++ +3e (new anode) (IX)
Bi.sub.2 O.sub.5 +10e→2Bi+50 (new cathode) (X)
BiO.sub.3.sup.- +5e+6H→Bi+3H.sub.2 O (new cathode) (XI)
At the same time some of the bismuth pentoxide which was on the anode is solubilized to sodium bismuthate and the remainder reduced to metallic bismuth on the new cathode.
Bi.sub.2 O.sub.5 +2NaOH→2NaBiO.sub.3 +H.sub.2 O
At the end of the procedure a small amount of sludge is noted, which is mainly bismuth metal and bismuth pentoxide, but also contains nickel and chromium.
At the end of the electrolytic procedure, the remaining solution contains some traces of chromium since a yellow tinge was noted.
The reason why this procedure avoids the chromate reoxidation of nitrite to nitrate is not understood. Some reductive action by the metallic bismuth is probably involved since, as stated above, the sludge contains some black bismuth metal and chromium and after standing after the end of the process, the residual yellow tinge eventually disappears indicating some form of reductive action. Thus, the process is surprising and unexpected in its result.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of an embodiment of the present invention.
FIG. 2 is an exploded elevational crossectional partial schematic representation of another embodiment of the present invention showing a bipolar cell.
FIG. 3 is a plot of percentage currency efficiency on an ammonia basis against amp hours of an experimental run in accordance with the present invention.
FIG. 4 is another graphical representation as for FIG. 3 of another run of the process of the present invention showing higher levels of current efficiency.
It should be noted that since the calculations are based upon efficiency on an ammonia basis rather than other bases, efficiencies exceeding 100% are possible. Much of the gas involved is nitrogen. Ammonia and nitrogen are products of the decomposition of hydroxylamine, which is manufactured by electrolysis of nitrate; it is very likely an intermediate product.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The process of the present invention is carried out as illustrated in FIG. 1 in a substantially conventional electrolysis tank having one or more plates of nickel connected to one pole of a direct current source and a similar number of plates connected to a direct current source of opposite polarity. Intermediate between the direct current source and the plates of the cell there is provided a polarity reversor of conventional construction which may be set to reverse the polarity either manually or automatically at a predetermined period. The outlet gases from the cell contain a mixture of ammonia, nitrogen, and oxygen. The ammonia may, if desired, be scrubbed out in a conventional acid containing scrubber or it may be collected and liquified, equally in a conventional manner.
In one embodiment of the invention, in place of utilizing a cell with the plates of a given polarity connected in parallel as shown in the drawing of FIG. 1, there may equally be used a bi-polar cell as illustrated in FIG. 2.
The substrate upon which the process is carried out is an industrial waste product. Therefore, it will have varying amounts of components. The substrate solutions comprise water, nitrate, hydroxide, and oxidizing transition metal ion, usually chromium ion. The amount of nitrate in the initial solution may be between 5 and 30% by weight, usually it will be about 15 to 20% by weight and the amount of hydroxide will be between 2 and 25%, usually about 5% (initial). The process is operative whatever the ratio of these two components may be. The water content is usually between 50 and 80%. The amount of chromium contamination may of course vary, however, it has been found that a chromium contamination of the order of 60 parts per million is sufficient to inihibit the conventional Mindler and Tuwiner process. In order for the invention to be operative, a sufficient amount of bismuth must be added to permit the optically detectable presence of bismuth pentoxide on an anode during the operation of the process. While there appears to be no upper limit (other than solubility) for bismuth to be present in the solution, it has been found that the process is always operative using an amount of bismuth which would, in theory, react with the amount of chromium or other oxidizing transition metal ion known to be present and form bismuth chromate or the like, (which of course is not formed). For a solution which contains 60 parts per million of chromium, it has been found that this criterium is satisfied by the use of 250 parts per million of bismuth ion. It should be stressed that this amount is a known operative amount and should under no circumstances be considered to be a limiting amount, either as a maximum or a minimum. The bismuth may be added as sodium bismuthate, bismuth nitrate or bismuth subnitrate. The subnitrate submicro particles are produced by diluting the nitrate and neutralizing with dilute ammonium hydroxide.
In the operation of the process the applied voltage across the plates of the cell will lie between about 2 to about 4 volts, generally it has been found that the actual voltage between the plates is between about 2.5 and about 3.5 volts. The current flowing will generally be of the order of 10 to 20 amps, usually about 15 amps. The bath temperature will also vary between about 35° and about 90° C. A temperature range of between about 70° and about 85° C. being generally preferred. The time between current direction reversal can be anywhere from 2 minutes to about 30 hours. It is preferred to operate the the process on a reversal schedule of between about 2 to about 5 minutes. If the time period in a given direction is substantially shorter than 2 minutes efficiency is impaired because the time is insufficient to permit the bismuth to be "deplated" from the cathode on the one hand and the bismuth pentoxide to be sloughed off or redissolved from the anode. On the other hand, if the time period is too long, the bismuth pentoxide which is an insulator, will substantially insulate the anode, thus cutting down the efficiency of current flow.
All experiments reported herein were carried out on a simulated decontaminated salt solution, whose composition is set forth below in Table 1.
TABLE 1______________________________________Simulated Decontaminated Salt Solution (SDSS)COMPONENT WEIGHT %.sup.1______________________________________H.sub.2 O 68.7NaNO.sub.3 15.6NaOH 4.2NaNO.sub.2 3.9NaAl(OH).sub.4 3.6Na.sub.2 SO.sub.4 1.9Na.sub.2 CO.sub.3 1.7Na.sub.3 PO.sub.4 0.13NaCl 0.12Na(C.sub.6 H.sub.5).sub.4 BO.sub.3 0.05NaSiO.sub.3 0.007Na.sub.2 CrO.sub.4 0.006NaF 0.004Na.sub.2 MoO.sub.4 0.004NaHgO(OH) 2.4 × 10.sup.-6______________________________________ .sup.1 Nominal weight percent.
RUN 1
This run is tabulated on Table 2 below and comprises the electrolysis of an SDSS solution as set forth above without the chromium contaminant. This is added after neutralization with nitric acid and restart. This run shows that the prior art method of Mindler and Tuwiner gives a current efficiency of approximately 70% when free of chromium. This efficiency drops to 26.5% when chromium is added.
TABLE 2______________________________________Electrolysis DataArea of Electrodes 0.3 sq. ft. Cum. OH Amp Amp CE Temp.Hrs. Volts Amps Hrs. Hrs. % °C. Remarks______________________________________Synthetic NaNO.sub.3 /NaOH - 1.8 liters 1,81 N OH.sup.- ; 2.2 NNO.sub.3.sup.-3.5 15 0 0 Start - NO CrO.sub.4.sup.=2.8 15 45 3822 2.5 10 358 358 73.5 5250 2.5 10 334 692 66.7 52.5 Overall CE 70.0Neutralize with acid and add 60 ppm Na.sub.2 CrO.sub.42.6 15 0 0 58 Start3.0 19 350 350 5.6 822.5 15 142 492 14.8 712.6 10 194 686 35.0 45 Overall CE 26.5______________________________________
RUN 2
This long scale run of SDSS solution shows an overall current efficiency of 11% in Table 3.
The run as made with 1.8 l of SDSS containing 60 ppm Na 2 CrO 4 by weight in a single cell with 0.3 sq.ft. each cathode and anode surface exposed, spaced 2 inches apart.
TABLE 3__________________________________________________________________________Electrolysis Data Cum. OH Amp Amp CE Temp.Hrs. Volts Amps Hrs. Hrs. % °C. Remarks__________________________________________________________________________ 2.2 1.5-5.0 4 Start NaNO.sub.2 is 18.1% - 2.12 N 3.2 11.8 24 28 31 Shut Down22 3.7 12.0 36 64 50 Restart 2.6 6.0 36 100 40 2.7 6.1 --46 2.8 6.0 150 250 3957 2.8 5.6 150 400 3676 2.8 5.7 114 514 18 3795 3.2 15 225 739 57116 3.5 12 252 991 48140 3.2 15 345 1336 18.1 44171 3.0 13 400 1736195 3.0 15 252 1986218 2.1 4/2.5 68 2054239 2.4 5.0 105 2159 32 NaOH 2.62 N Overall CE 13.0 0 3.1 15 2159 Replace 2/3 of bath with 15% NaOH 6 2.8 12 45 NaOH 3.86 N21 2.8 12.5 288 2447 43 40 Add PE Beads to45 2.8 13 312 2759 14.2 47 reduce mist 2.8 15 47 3.0 15 360 3119 45 NaOH 4.09 N Overall CE 9.2Effect of Bismuth Addition:69 2.9 15 3119 54.5 Add 400 mg NaBiO.sub.3 OH.sup.- 4.13 N 2.6 15 93 63.5 Shut down93 2.5 14.5 360 3479 111 57 NaOH 4.89 N Overall CE 81.5__________________________________________________________________________
The effectiveness of bismuth in promoting the electrolytic reduction of nitrate to nitrogen and ammonia may be shown in terms of milliequivalents of hydroxyl ion produced per 100 ampere hours. Thus, for the first 2159 amp hrs., 33.8 meq/100 amp hrs. resulted. For the next 960 amp hrs., 43.1 meq/100 amp hrs. was produced. After adding 400 mg sodium bismuthate, the next 360 asmpere hrs. produced 380 meq/100 amp hrs.
(466 meq OH - is equal to 100% current efficiency).
RUN 3
Shows a cumulative run of 1,020 ampere hours on 1.8 liters SDSS solution containing 100 milligrams of bismuth showing an overall current efficiency of 94.6%.
TABLE 4______________________________________ Cum. OH Amp Amp CE Temp.Hrs. Volts Amps Hrs. Hrs. % °C. Remarks______________________________________0 3.5 15 0 0 -- -- NaOH 1.99 N2 3.3 15 -- -- --17.5 2.8 15 241 241 1154.5 2.8 15 68 309 1313.5 2.8 15 53 362 86 7915.5 2.8 15 232 594 73 81 Add 100 mg Bi5.5 2.8 15 82 676 84 763 2.8 15 45 721 103 --16 2.7 16 256 977 89 843.5 2.7 16 43 1020 90 74 Stop - OH.sup.- 4.49 N441 meq. OH.sup.- produced per 100 amp hrs.______________________________________
RUN 4
Shows a 1558 ampere hour run showing current reversal after 151, 566, 686, 746, and 1296 hours, given overall current efficiency of 87.8%.
TABLE 5__________________________________________________________________________ Cum. OH Amp Amp CE Temp.Hrs. Volts Amps Hrs. Hrs. % °C. Remarks__________________________________________________________________________0 5.8 30 0 0 -- 20 Start - OH.sup.- 2.16 N 1.8 liters1.25 4.2 30 38 38 408 70 1.3 × Theory Bi.sup.++3.75 3.8 30 113 151 85 89 Reverse current4.25 3.5 30 105 256 169 10110.25 3.5 29-30 310 566 46 98 "2 3.4 30 60 626 103 --2 3.4 30 60 686 0 -- Reverse current2 3.4 31-30 60 746 71 -- Reverse 15 min.2 3.1 30 60 806 136 935.50 3.3 30 175 981 97 9810.50 3.5 30 315 1296 81 99.5 "10.50 3.0 30-20 262 1558 110 80 Stop - OH.sup.- 6.89 N 1.44 liters409 meq OH.sup.- produced per 100 amp hrs.__________________________________________________________________________
RUN 5
This run is illustrated by Table 6 and FIG. 3. Different rates of current reversal were utilized. 49 amps/sq.ft. bipolar mode seven cells 2" spacing. Overall efficiency 57.3%. 5.075 gms. Bi added as NaBiO 3 .
TABLE 6______________________________________Current Reversal______________________________________0 to 451 Amp Hrs. 80 sec. Forward 15 sec. Reverse451 to 596 Amp Hrs. 120 sec. Forward 120 sec. Reverse596 to 1081 Amp Hrs. 1800 sec. Forward 120 sec. Reverse1081 to END Amp Hrs. 24 hours Reversal______________________________________
(N.B. It should be noted that while the current was reversed as stated above, analyses were only taken at the points illustrated. Therefore this figure is probably not an accurate reflection of the actual currency efficiency at a particular moment, but gives a true general indication thereof.)
RUN 6
As illustrated in FIG. 4, there is shown a run in excess of 4,000 ampere hours utilizing a current pattern of 55 minutes in one direction and 5 minutes in the reverse direction.
Conclusions
It is clear from Runs 5 and 6 that the best efficiencies are obtained where the current in one direction does not exceed 55 minutes and where the reversal time is at least 120 seconds, it will be seen from Run 5 that a serious drop-off in efficiency occurs where the current flows for less than 120 seconds in any given direction. Similarly, where the current flows for 24 to 30 hours in one direction, there is also a serious drop-off in operating efficiency.
The very best efficiencies appear to be noted in bipolar cells (Run 5) with a flow time in each direction of the order of 120 seconds.
While the principle purpose of the present invention is to permit the reduction of nitrate to hydroxide in the presence of a chromium contaminant, the invention is not limited thereto. The invention would be equally operative in the presence of other multi-valent transition metals which form oxidizing anions, for example, vanadium, manganese, molybdenum and the like, although chromium, at the present time, causes the most serious industrial problems. | Alkali metal hydroxide solutions containing substantial amounts of nitrate and nitrite which are contaminated by chromate are electrolytically converted to the corresponding hydroxides. The interference of the chromate with the normal electrolytic process is voided by adding bismuth ion to the solution and reversing the current direction at predetermined intervals. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application is a continuation-in-part of U.S. patent application Ser. No. 13/382,207, filed on Jan. 4, 2012, which is a national phase application of International Application No. PCT/DE2010/000685, filed on Jun. 18, 2010, which claims priority to German Patent Application No. 10 2009 033 572.2, filed on Jul. 16, 2009, and the present application also claims priority to German Patent Application No. 10 2012 003 087.8, filed on Feb. 18, 2012, each of which is hereby incorporated herein in its entirety by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a hydraulic circuit for longwall support by means of a support device (support shield) for use in underground mining.
2. Description of Related Art
Such circuits are well known from PCT/DE2010/000685 (the publication of which is W02011006461A2). The proposed pressure monitoring system prevents unforeseen operating conditions where pressure conditions may occur that are sufficient to manipulate the hydraulic pilot control, i.e. the opening of essential valves even in case of failures to the pumping system, or if in case of an emergency the overall electric and hydraulic control systems are switched off, or in case of extremely high pressures from the rock which the load maintaining valves are not capable of handling.
The arrangement of W02011006461A2 according to one embodiment also monitors the annular piston line for each cylinder/piston assembly by means of a pressure sensor. When a pre-determined maximum pressure is achieved, the entire longwall is depressurized so that particularly the unlocking process for the check valves that retain the rock pressure is disabled. This can, however, cause operating conditions that may require the system to be controlled either manually or automatically.
The purpose of the invention is to design the circuit in such a manner that a comprehensive monitoring of the system as well as any necessary manipulation of the control system is possible.
SUMMARY OF VARIOUS EMBODIMENTS
This is achieved by means of the various embodiments described herein.
An alternate embodiment includes a supplementary improvement that allows for a so-called negative emergency operation, and therefore enables the control if, due to a pressure signal activated by the pressure monitor, an emergency signal would cause a system failure.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The invention is hereafter described by means of a preferred embodiment. Explicit reference is made to the drawing descriptions relating to FIGS. 1A, 1B and 2 of W02011006461A2 and particularly to FIG. 1B and its description.
The terms used and their reference signs are also taken up in this application. Any divergences will be expressly noted in the following detailed description of the invention.
FIG. 1 is an electrical/hydraulic circuit of a support shield in a longwall mine in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
The electric/hydraulic circuit of a support unit in a longwall according to W02011006461A2 comprises the following elements, which are also illustrated or indicated in the drawing:
1. the longwall supply line 1 (pumps—manifold, flow pipe), which extends through a portion of the longwall or the entire length of the longwall and which is connected to the pump station—without reference mark. 2. the return flow manifold 2 (return flow—manifold, return flow), which extends through a portion of the longwall or the entire length of the longwall and which is connected to the tank—without reference mark—of the pump station. 3. the hydraulic control device of the shield control device for a support shield. Shown is one of the power transmitters 4 . The hydraulic control device 3 is connected through the feed line stub 12 with the feed line and through the return line stub 13 with the return line. 4. A power transmitter, which is here illustrated as cylinder-piston unit. 5. The electrical control device 5 of the shield control unit for controlling the hydraulic control device 3 . The hydraulic control device 3 and the electrical control device 5 together comprise the excavation control device, which is designed for inputting switching and control commands, however, may also receive its switching and control commands from the central longwall control device 15 .
Other existing secondary valves, particularly check valves, have not been illustrated or further described.
The hydraulic control device comprises multiple valves. The connection for each power transmitter 4 with the pump manifold of the longwall between the power transmitter outlet, which is acted upon by the rock pressure, and the hydraulic control device 5 is generally blocked by a pressure holding valve 14 which is designed as an unlockable check valve so that in case the pump pressure fails or is turned off the load pressure of the power transmitter acts upon the tightly locking check valve 14 . This check valve 14 can be unblocked by means of hydraulic pilot operation through the system pressure when the pressure variation between load pressure and pilot pressure fall below a value that is predetermined by the valve construction. The check valve 14 is hydraulically designed in such a manner that when it is hydraulically unblocked the working space of the power transmitter is through outlet 6 and the return line stub connected with the return line manifold. Such unlockable check valve is, for example, well known through DE 38 04 848 A1.
The pressure monitoring device 19 prevent the pressure between the unlockable check valve 14 and the cylinder annular space and/or the hydraulic control device 3 from reaching a level that could cause the check valve 14 , which acts as a load maintaining valve, from being unintentionally unlocked (turned on). See also W02011006461A2.
The detailed drawing of FIG. 1 illustrates the individual valves of the hydraulic control device 3 .
The pilot control valve 16 . 1 for setting the power transmitter and the pilot control valve 16 . 2 for removing the power transmitter are both activated through bus line 20 by means of the electric control device 5 of the support shield and/or by means of the central longwall control unit 15 through the signal line 21 and hydraulically activate the main valve 17 . 1 for setting the power transmitter and main valve 17 . 2 for removing the power transmitter between two settings.
The encoding of the switching signals causes the magnet of the pilot control valves to be interlocked in the following manner:
when hydraulically actuated in the course of setting (lifting):
Main valve 17 . 1 opens the connection (feed line stub 12 , setting line 22 ) between longwall supply line (pump line, pressure line) 1 and power transmitter input 6 ; Main valve 17 . 2 releases the connection (annular piston line 10 , return line stub 13 ) of the annular space 24 to the return line manifold 2 . The piston of power transmitter 4 and the load acting upon it are elevated.
at standstill:
Main valve 17 . 1 blocks the connection between connection 6 of the power transmitter and longwall supply line (pump line, pressure line) 1 and opens the connection to the return line manifold 2 . Main valve 17 . 2 releases the connection of the annular space 23 to the return line manifold 2 . The load acting upon the piston of the power transmitter is held by the blocked check valve 14 /load maintaining valve.
when hydraulically actuated in the course of removing the timbering (lowering the piston):
Main valve 17 . 1 blocks the connection between longwall supply line (pump line, pressure line) 1 and opens the connection to the return line manifold 2 . Main valve 17 . 2 releases the connection of the annular space 23 to the longwall supply line (pump line, pressure line) 1 . The load acting upon the piston of the power transmitter is held by the blocked check valve 14 /load maintaining valve until the check valve 14 is unblocked by the rising pressure in the annular piston line 10 through line stub 24 . The load acting upon the piston of the power transmitter is thus lowered.
Standstill is a critical condition since persons staying inside the longwall are subject to injury or death from the unintentional movement of the expansion equipment. This hazard is prevented by the pressure sensor 19 which is installed into annular piston line 10 of each cylinder/piston assembly 4 . Each of these pressure sensors 19 is switched through another bus line 20 to the longwall shutoff valve 11 through the central longwall control device 15 in such a manner that upon reaching a predetermined maximum pressure in the annular piston line 10 the entire longwall is pressureless switchable. This also ensures that internal pressure, which could cause the unblocking of the check valves that are holding the rock pressure, is no longer present. Therefore the maximum allowable pressure at which all support units of the longwall are depressurized is set significantly lower, in fact at least 20% lower, for example, at 50 bar, than the inherent pressure of, for example, 80 bar that is sufficient to unlock the check valve.
It is, however, possible for operating conditions to occur for which it may become desirable or even necessary to manually adjust the control system. For this reason it is intended that the longwall shutoff valve 11 can only be activated when a triggering signal for the main valves 16 . 1 , 16 . 2 is no longer present. For this reason the central longwall control device 15 is activated through a UND—member 25 , which only sends a positive output signal if the pressure signal of the pressure sensor 19 is positive and at the same time the signal for triggering the pilot control valves 16 . 1 , 16 . 2 is negative. This is here illustrated by means of a negative (NANO) member 26 , which is connected with the signal line 21 and only sends a positive output signal to the UND member 25 of the longwall control device 15 when a negative input signal is present. This prevents the possibility that the pressure sensor 19 interferes with any intentional manually or automatically controlled operating condition or process of the power transmitter. Such a situation could cause serious hazards.
It is furthermore intended that the function of the pressure sensor 19 can be completely disabled. For this purpose a push button switch 28 is installed in the line between longwall control device 15 and longwall shutoff valve 11 . If necessary, this push button switch can be opened when it is disadvantageous that the entire longwall is shut off accidentally. It is also possible to bypass the pressure sensor by means of a circuit which is not illustrated here. | A hydraulic circuit for longwall support for use in underground mining for supporting a longwall by means of a plurality of support shields includes in the annular piston line of each cylinder/piston unit a pressure sensor. The pressure sensor, upon reaching a predetermined maximum pressure activates a pressure deviation signal, causes the entire longwall to be depressurized by means of a longwall shut-off valve. The pressure deviation signal is blocked for one of the hydraulic valves against each triggering signal. | 4 |
FIELD OF THE INVENTION
[0001] The present invention relates to data processing systems. More particularly, the present invention relates to the use of browser for large image and/or small window size applications.
BACKGROUND OF THE INVENTION
[0002] In years past, computer system technology was used primarily by engineers, scientists, or computer-oriented individuals who supported large businesses. With the proliferation of personal computers in the 1980s and 1990s and the more recent acceptance of the internet, many different types of computer systems are now used by a wide variety of individuals.
[0003] In today's computer system world, a specific type of computer program, called a browser, is arguably the most widely used computer system tool. This wide acceptance is largely attributable to the standardized protocol and file format used on the internet. Computer system users are able to access and view a significant amount of information. As is commonly understood, this information comes to the user in the form of pages (called web pages in the internet context). Each page includes information elements that come in a variety of forms, including textual information (i.e., text) and images.
[0004] When the browser retrieves a page for the user, the browser considers the window size, formats the page's information elements in a particular way, and presents the page to the user as one large image (called a page image). If the user adjusts the size of his or her window, the browser considers the new window size, formats the information elements anew, and again presents the page to the user. The user can then point to and select different locations on the page to cause the browser to retrieve another page. Of course, this process can continue for as long as the user chooses.
[0005] Existing browsers are designed to operate using a fairly large display screen (i.e., a computer monitor), such as those commonly used with personal computers. For this reason, the information elements that make up a page (e.g., text and image information) are specified as being a particular size. Text, for example, is specified to be a specific font size and images are provided having a specific height and width. The chosen size of these information elements is established ahead of time for each page, which generally works well on display screens that are more or less standard in size.
[0006] While browser technology is not new, and in fact predates the internet's popularity, the internet has driven the wide spread use of browser technology on different devices. Herein lies two problems. First, standard size information elements are too big to work well with small display screen devices. The ever-popular cell phones, personal digital assistants (PDAs), and pocket personal computers are but a few examples. Second, standard size information elements are too small for sight-impaired users who want to make the information elements bigger, but can't.
[0007] While existing browser technology does not include a comprehensive solution to these problems, existing browsers do provide certain user adjustments represent partial solutions. As mentioned, browser users can adjust the window size of their browser. However, this only affects the size of the page background and possibly how the information elements are organized on the page, but does not affect the size of the information elements themselves. Some browsers similarly allow the user to manually adjust the font size of text information elements, but not image information elements. While this manual adjustment can help sight-impaired users read text, it does not help sight-impaired users view images. Moreover, the ability to reduce font size does not solve the small window/screen problem because reducing font size to the point where it can fit into a small window or screen often makes the text too small to read.
[0008] The overall usefulness of small display screen devices will continue to be impaired without a comprehensive solution to the problems identified above.
SUMMARY OF THE INVENTION
[0009] An enhanced browser is disclosed. The browser essentially operates in two different modes. These modes are referred to as “thumbnail mode” and “non-thumbnail mode.” In thumbnail mode, the browser of the present invention presents the user with a small window, called a thumbnail. The thumbnail is presented in addition to the user's normal window or as a small window on the user's screen in the case of a small screen device. The page image presented by the browser is logically divided into segments through use of the thumbnail. The size of each segment is based upon the size of the user's window or screen and the size of the page image. The thumbnail window contains a scaled-down version of the page image. The thumbnail image is divided into cells, one cell for each page image segment. When taken together the cells form a grid. Each cell is encoded with hotspot information to form a mapping between it and the associated page image segment. When the user selects a cell on the thumbnail, the browser of the present invention presents the associated segment of the page image to the user via the user's window or screen. As a further feature, the page image used can be adjusted in size to be larger than the original retrieved page image (e.g., web page image) as an aid to sight-impaired individuals.
[0010] In non-thumbnail mode, the browser of the present invention automatically scales the original page image to fit into the user's display window or screen. This scaling is performed on all of the information elements within the original page image, making for a uniform presentation of the page to the user.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a block diagram of the computer system used in the preferred embodiment of the present invention.
[0012] [0012]FIGS. 2A through 2C are mock-up screen shots showing the thumbnail window and display window used in the preferred embodiment.
[0013] [0013]FIGS. 3A through 3C are flow diagrams depicting the steps used to carryout the HTTP Browser of the preferred embodiment.
[0014] [0014]FIG. 4 is a block diagram showing the image record used in the preferred embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Turning now to the drawings, FIG. 1 shows a block diagram of the computer system of the preferred embodiment. The computer system of the preferred embodiment is an enhanced IBM Personal Computer 300PL. While computer system 100 of the preferred embodiment is a particular type of computer system, those skilled in the art appreciate that the benefits and advantages of the present invention apply equally to any computer system, regardless of whether the computer system is a complicated multi-user computing apparatus, a single user workstation, or a handheld device. In addition, the benefits and advantages are similarly applicable regardless of whether the computer system stands alone or participates in a computer system network. As shown in the exploded view of FIG. 1, computer system 100 comprises main or central processing unit (CPU) 105 connected to memory 135 and network adapter 110 . These system components are interconnected through the use of system bus 130 .
[0016] Computer system 100 of the preferred embodiment utilizes well-known virtual addressing mechanisms, allowing its programs to work against a large virtual storage aggregate instead of against multiple, smaller storage entities. Memory 135 is, however, shown on FIG. 1 as a monolithic entity because the programs of the preferred embodiment are not dependent upon any one type of memory management arrangement.
[0017] There are two programs shown to reside in memory 135 . Operating system 140 of the preferred embodiment is the multitasking operating system known in the industry as Windows 2000 ®, which is licensed by Microsoft Corporation. However, those skilled in the art will appreciate that the spirit and scope of the present invention is not limited to any one operating system. The browser of the preferred embodiment, shown in memory 135 as HTTP Browser 160 , operates using the HTTP protocol. As such, HTTP Browser 160 operates within internet and/or intranet networks. However, those skilled in the art will appreciate that the present invention is not limited to any particular protocol or to any particular network type. Also shown are image records 150 , which are used in the preferred embodiment to store information about page images received by HTTP Browser 160 . HTTP Browser 160 and image records 150 are described in more detail in the text accompanying FIGS. 3A through 4.
[0018] Also shown within computer system 100 is network adapter 110 . Network adapter 110 is used to allow computer system 100 to be part of different networks (e.g., internet/intranet networks).
[0019] It is important to note that while the present invention has been (and will continue to be) described in the context of a fully functional computer system, the mechanisms of the preferred embodiment are capable of being distributed as a program product in a variety of forms, and there is no limitation as to the particular type of signal bearing media used to actually carry out such distribution. Examples of signal bearing media include: recordable type media such as floppy disks and CD ROMs and transmission type media such as digital and analog communications links.
[0020] [0020]FIGS. 2A through 2C are mock-up screen shots showing the thumbnail window and display window used in the preferred embodiment. FIG. 2A shows a display window 202 as it would appear without use of the mechanisms of the preferred embodiment. Using the terminology of the preferred embodiment, this figure shows original page image 200 as it would be portrayed to the user via display window 202 . FIG. 2B shows thumbnail 205 and display window 202 . As shown, thumbnail 205 is an image grid that is made up of six cells. While dashed grid lines are used in the preferred embodiment, options include other types of visual separators or no separators at all. The user has selected cell 210 and therefore is presented with associated segment 215 in display window 202 . FIG. 2C again shows thumbnail 205 and display window 202 . In this case, the user has selected cell 220 and therefore is presented with associated segment 225 in display window 202 .
[0021] [0021]FIGS. 3A through 3C are flow diagrams depicting the steps used to carryout the HTTP Browser of the preferred embodiment. Turning first to FIG. 3A, HTTP Browser 160 begins processing in block 300 where it retrieves an HTML page, scans the page, and constructs what is referred to herein as the original page image or “original image” for short.” This original image is that which would at this point be presented to the user. It is also important here to note that the source of the HTML page is not important vis-à-vis the logic of HTTP Browser 160 . The page may be loaded via the internet or an intranet or be loaded directly from memory 135 .
[0022] In processing block 301 , HTTP Browser 160 saves the original page image and link and hot spot information into one of image records 150 . Within the nomenclature of the preferred embodiment, the term “link” refers to hypertext links, which are well understood in the art. The term “hot spot” refers to a section or area of an image that is given navigation capabilities to allow the user to move to a different location (e.g., to another page or to another location within the current page). Turning now to FIG. 4, shown is image record 400 . In the preferred embodiment, image record 400 is a separate storage record that is used by HTTP Browser 160 ; however, it should be understood that the information stored within image record 400 could be stored in some other browser-accessible data structure. Image field 401 is used to store the original page image itself while image width and height fields ( 402 and 405 respectively) are used to store the width and height of the original page image once it has been created from the received HTML by HTTP Browser 160 . Universal Resource Locator (URL) fields 410 are used to store the URL locations in x, y coordinate form and to store the width and height of URLs found on the original page image. Similarly, hot spot fields 415 are used to store the hot spot locations in x, y coordinate form and to store the width and height of the hot spots found on the original page image.
[0023] Decision block 302 represents the option of having or not having a thumbnail as part of the presentation to the user. In the preferred embodiment, a thumbnail is used as a map to provide context and navigation in the case where that which is to be displayed to the user is larger than the user's screen or window size. When applicable, the user has the option of using a thumbnail window in addition to his or her normal window or screen. (The exact way in which this selection is accomplished by the user and made available to HTTP Browser 160 is not important and is, therefore, not addressed here.) Assuming first that a thumbnail window is not an option because that which is to be displayed is not larger than the user's screen or window size or because the thumbnail option is not selected by the user, HTTP Browser 160 proceeds to block 303 where the window size or screen size is acquired. The window size is acquired in the case where the preferred embodiment is being practiced in a window-oriented environment. That is, where different programs render information to the user via different windows. The screen size is acquired in an environment where the small size of the screen typically dictates that the entire screen is needed to adequately render the information (e.g., a PDA, cell phone, or other handheld device).
[0024] After the applicable size has been determined (i.e., window or screen), HTTP Browser 160 proceeds to scale the original page image such that it fits into the window or screen [processing block 305 ]. It is important to note that the original image may be scaled down to fully fit into a smaller window or screen or scaled up to fully fit into a larger window or screen. This image is referred to herein as the “window image” because it is equal in size to the user's window or screen. In the preferred embodiment, scaling is accomplished using well-known pixel expansion and compression techniques. After the image has been scaled, the URL link and hot spot locations are transferred from the original image location to the corresponding window image location [processing block 313 ]. The links and hotspots are similarly scaled to a size appropriate for given window or screen size. Table 1 below shows the calculations used in the preferred embodiment to accomplish this transfer.
TABLE 1 New Location/Dimension Calculation URL or hot spot x coordinate (original x)*(new image width)/(original page image width) URL or hot spot y coordinate (original y)*(new image height)/(original page image height) URL or hot spot width (original width)*(new image width)/ (original image width) URL or hot spot height (original height)*(new image height)/ (original page image height)
[0025] After the URLs and hot spots have been transferred onto the window image, the window image is copied into the user's display window or screen [processing block 307 ] and smoothed [processing block 309 ]. Standard smoothing techniques are used in the preferred embodiment to enhance the presentation of the image to the user. Other techniques such as edge detection/enhancement and anti-aliasing can also be used. HTTP Browser 160 then waits for a user event in processing block 311 . The user may choose to terminate execution of HTTP Browser 160 , in which case processing simply ends (not shown), or the user may choose to navigate elsewhere by selecting a URL or a hot spot, in which case HTTP Browser 160 proceeds to processing block 300 to begin the process anew.
[0026] Assuming now that a thumbnail window is an option and is selected by the user, HTTP Browser 160 proceeds to block 306 instead of block 303 and constructs what is termed herein as the “desired page image” or “desired image” for short. As used herein, the desired page image can be larger or smaller than the original page image, but must be larger than the ultimate window image. This restriction is not a technical one but instead stems from the observation that there is no real benefit associated with a desired page image that was smaller than the window image. Thus, a user may decide that he or she would like the desired image page to be smaller than the original page image, but larger than the window image, or the user (particularly a sight-impaired user) may decide that the desired image size should be larger than the original image size. Moreover, the user may decide that the desired image should be the same size as the original image, which is the default selection used in the preferred embodiment. (The exact way in which the user specifies the desired image size is not important, and accordingly, not discussed here.) In any case, the desired page image is constructed (i.e., scaled) using the techniques described above.
[0027] The URL and hot spot locations are scaled and transferred as described in Table 1 [processing block 308 ] and the window/screen size is acquired [processing block 310 ].
[0028] Turning now to FIG. 3B, the thumbnail image is created by scaling the desired image to the size of the thumbnail window [processing block 314 ]. The width and height for thumbnail cells are then calculated in block 316 . As discussed above, the thumbnail of the preferred embodiment is an image grid that is split up into two or more cells. These cells act as navigation aids for the user. The number of cells depends on the degree to which the desired image size is larger than the window image size. For example, if the desired image is four times larger than the window image, the thumbnail image will be split into four cells. Thus, each cell in the thumbnail grid corresponds to a segment of the desired image. This correspondence creates a logical mapping between the thumbnail grid and the desired image grid. Generally speaking, each segment is the same size as the display window or screen. However, it should be noted that the desired image size may not be evenly divisible by the window or screen size, meaning that cells and segments which terminate rows and/or columns may be narrower or shorter respectively than other cells and segments. The following calculations are used in the preferred embodiment to arrive at the cell width and height.
TABLE 2 Cell Dimension Calculation Cell Width (display window width)*(thumbnail window width)/ (desired image width) Cell Height (display window height)*(thumbnail window height)/ (desired image height)
[0029] The display window and thumbnail window coordinates are then initialized to zero in processing block 316 . These coordinates are represented on FIG. 3B by the variables x and y for the thumbnail window and by the variables r and s for the display window.
[0030] Processing blocks 320 through 328 represent the logic used in the preferred embodiment to define the thumbnail grid and thereby logically segment the desired image into a grid of segments. In decision block 320 , HTTP Browser 160 determines whether the y coordinate is greater than the thumbnail window height. On this first pass though the logic, the y coordinate will still be zero. Thus, HTTP Browser 160 proceeds to block 326 where it determines whether the x coordinate of the thumbnail window is greater than the thumbnail window width. The x coordinate will similarly be zero, meaning that HTTP Browser 160 proceeds to block 328 where a hot spot in the thumbnail image for the first cell is created. The hot spot area for the cell is defined by its lower left corner (x,y) and its upper right corner (x+(cell width)−1, y+(cell height)−1). The hot spot on the thumbnail image corresponds to a particular segment of the desired image, which is defined by its lower left corner (r,s) and its upper right corner (r+(display window width)−1, s+(display window height)−1).
[0031] After the first cell has been created, HTTP Browser 160 proceeds to the next cell in the row by incrementing the x coordinate by the cell width and by incrementing the r coordinate by the width of the display window [processing block 324 ]. HTTP Browser 160 then checks to see whether it has past the last cell in the row. If not, blocks 328 and 324 are repeated. If HTTP Browser 160 has reached the last cell in the row, it proceeds to the next row in the thumbnail grid by incrementing the y and s coordinates [processing block 322 ]. When all the cells in all the rows have been created, decision block 320 evaluates to TRUE, which causes HTTP Browser 160 to move on to the logic set forth on FIG. 3C.
[0032] Turning now to FIG. 3C, HTTP Browser 160 sets the window image to be the segment of the desired image which corresponds to the upper left most cell of the thumbnail grid [processing block 330 ]. HTTP Browser 160 then determines which links and or hot spots should be made visible in the window image, and proceeds to extract and then enable those links and hot spots through reference to image record 400 . Once the links and hot spots have been processed, the window image is copied into the user's display window [block 334 ] and smoothed [block 335 ]. HTTP Browser 160 then waits for a user event in block 336 . If the user selects a link or a hot spot or resizes the display or the thumbnail windows, HTTP Browser 160 will repeat the above-described processing beginning with processing block 300 of FIG. 3A. If the user selects one of the hot spot areas within the thumbnail grid, HTTP Browser 160 sets the new window image based on the coordinates of the user's selection within the thumbnail (i.e., the selected cell in the grid) [processing block 344 ] and proceeds to block 332 to display the image as has been described above.
[0033] The embodiments and examples set forth herein were presented in order to best explain the present invention and its practical application and to thereby enable those skilled in the art to make and use the invention. However, those skilled in the art will recognize that the foregoing description and examples have been presented for the purposes of illustration and example only. The description as set forth is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching without departing from the spirit and scope of the following claims. | The browser of the present invention presents the user with a small window, called a thumbnail, in addition to the user's normal window, or in the case of a small screen device, as a small window on the user's screen. A retrieved page image presented by the browser is logically divided into segments through use of the thumbnail. The size of each segment is based upon the size of the user's window or screen and upon the size of the page image. The thumbnail window contains a scaled-down version of the page image. The thumbnail image is divided into cells, one cell for each page image segment. When taken together, the cells form an image grid. Each cell is encoded with hotspot information to form a mapping between it and the associated page image segment. When the user selects a cell on the thumbnail, the browser of the present invention presents the associated segment of the page image to the user via the user's window or screen. As a further feature, the page image used can be adjusted in size to be larger than the original retrieved page image (e.g., web page image) as an aid to sight-impaired individuals. | 6 |
TECHNICAL FIELD
[0001] This invention relates to automatic vehicle transmissions that are characterized by closed-loop control of an off-going clutch pressure command to maintain a predetermined slip threshold, and that exploit data from the first and second derivatives of the off-going clutch pressure command to determine when an on-coming clutch gains torque capacity.
BACKGROUND OF THE INVENTION
[0002] In general, a motor vehicle automatic transmission includes a number of gear elements and selectively engageable friction elements (referred to herein as clutches) that are controlled to establish one of several forward speed ratios between the transmission input and output shafts. The input shaft is typically coupled to the vehicle engine through a fluid coupling such as a torque converter, and the output shaft is coupled to the vehicle drive wheels through a differential gear set.
[0003] Shifting from a currently established speed ratio to a new speed ratio involves, in most cases, disengaging a clutch (off-going clutch) associated with the current speed ratio and engaging a clutch (on-coming clutch) associated with the new speed ratio. Each such shift includes a fill or preparation phase during which an apply chamber of the on-coming clutch is filled in preparation for torque transmission. Once filled, the on-coming clutch transmits torque in relation to the clutch pressure, and the shift can be completed using various control strategies.
[0004] In a clutch-to-clutch transmission, disengagement of the off-going clutch and engagement of the on-coming clutch is accomplished by a transmission controller transmitting pressure commands to alter the pressure and fluid volume in the respective apply chambers. The transmission controller must take into account such variables as the volume of fluid necessary to fill each clutch's respective apply chamber, fluid flow rates, fluid temperature, etc., in generating the pressure commands to ensure proper timing of the clutches. If an on-coming clutch gains torque capacity prior to disengagement of the off-going clutch, then transmission tie-up may occur. If an on-coming clutch gains torque capacity too long after the off-going clutch disengages, then engine flare will occur.
[0005] The prior art includes clutch-to-clutch transmissions that employ closed loop control of the off-going clutch during a shift event such that the off-going clutch maintains a predetermined slip threshold. As the on-coming clutch gains torque capacity, the speed of the input shaft drops. The transmission controller, as a result of the closed loop control of the off-going clutch, will compensate by reducing the pressure command for the off-going clutch as the on-coming clutch gains capacity until the off-going clutch torque capacity is zero.
SUMMARY OF THE INVENTION
[0006] A method and apparatus for use with an automatic transmission having an off-going clutch and an on-coming clutch during a speed ratio shift event is provided. The method enables accurate determination during vehicle operation of when, in the course of a shift event, an on-coming clutch gains torque capacity. The method includes controlling the off-going clutch using closed loop control to maintain a predetermined slip threshold. Controlling the off-going clutch includes generating an off-going clutch pressure command to which the off-going clutch is responsive and that varies with respect to time. The method also includes causing the on-coming clutch to gain torque capacity while controlling the off-going clutch, determining the first derivative with respect to time of the off-going clutch pressure command, and determining when the on-coming clutch gained torque capacity using the first derivative.
[0007] In the preferred embodiment, a k-means neural network algorithm is employed in determining when the on-coming clutch gains torque capacity. More specifically, the method preferably includes generating a set of data points corresponding to local minima and local maxima of the first derivative. Each of the data points includes a time value and a first derivative value (i.e., the rate of change of the commanded pressure in the off-going clutch apply chamber) for one of the local minima or maxima. The method also preferably includes using a k-means algorithm to classify each of the data points into one of a first group and a second group, the data points in the second group having later time values than the data points in the first group, and determining the data point having the earliest time value in the second group.
[0008] The ability to determine, during vehicle operation, when in the course of a shift event the on-coming clutch gains torque capacity enables a transmission controller to determine the accuracy of the variables and calculations employed in generating pressure commands and to make appropriate adjustments as necessary to optimize the timing of the on-coming clutch.
[0009] A corresponding apparatus is also provided.
[0010] The above objects, features and advantages, and other objects, features and advantages of the present invention are readily apparent from the following detailed description of the best mode for carrying out the invention when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a schematic illustration of an automatic transmission;
[0012] FIG. 2 is a truth table indicating a relationship between transmission clutch activation and corresponding speed ratio;
[0013] FIG. 3 is a graphical depiction of an off-going clutch pressure command and the first derivative with respect to time of the off-going clutch pressure command;
[0014] FIG. 4 is a schematic depiction of a buffer storing a set of data generated from the off-going clutch pressure command; and
[0015] FIG. 5 is a block diagram illustrating a k-means neural network algorithm for processing the data in the buffer of FIG. 4 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] The control of this invention is described in the context of a multi-ratio power transmission having a planetary gear set of the type described in the U.S. Pat. No. 4,070,927 to Polak, and having an electro-hydraulic control of the type described in U.S. Pat. No. 5,601,506 to Long et al, both of which are hereby incorporated by reference in their entireties. Accordingly, the gear set and control elements shown in FIG. 1 hereof have been greatly simplified, it being understood that further information regarding the fluid pressure routings and so on may be found in the aforementioned patents.
[0017] Referring to FIG. 1 , the reference numeral 10 generally designates a vehicle power train including engine 12 , transmission 14 , and a torque converter 16 providing a fluid coupling between engine 12 and transmission input shaft 18 . A torque converter clutch 19 is selectively engaged under certain conditions to provide a mechanical coupling between engine 12 and transmission input shaft 18 . The transmission output shaft 20 is coupled to the driving wheels of the vehicle in one of several conventional ways. The illustrated embodiment depicts a four-wheel-drive (FWD) application in which the output shaft 20 is connected to a transfer case 21 that is also coupled to a rear drive shaft R and a front drive shaft F, but any driven wheel configuration is within the scope of the present invention. Typically, the transfer case 21 is manually shiftable to selectively establish one of several drive conditions, including various combinations of two-wheel-drive and four-wheel drive, and high or low speed range, with a neutral condition occurring intermediate the two and four wheel drive conditions.
[0018] The transmission 14 has three inter-connected planetary gear sets, designated generally by the reference numerals 23 , 24 and 25 . The planetary gear set 23 includes a sun gear member 28 , a ring gear member 29 , and a planet carrier assembly 30 . The planet carrier assembly 30 includes a plurality of pinion gears rotatably mounted on a carrier member and disposed in meshing relationship with both the sun gear member 28 and the ring gear member 29 . The planetary gear set 24 includes a sun gear member 31 , a ring gear member 32 , and a planet carrier assembly 33 . The planet carrier assembly 33 includes a plurality of pinion gears rotatably mounted on a carrier member and disposed in meshing relationship with both the sun gear member 31 and the ring gear member 32 . The planetary gear set 25 includes a sun gear member 34 , a ring gear member 35 , and a planet carrier assembly 36 . The planet carrier assembly 36 includes a plurality of pinion gears rotatably mounted on a carrier member and disposed in meshing relationship with both the sun gear member 34 and the ring gear member 35 .
[0019] The input shaft 18 continuously drives the sun gear 28 of gear set 23 , selectively drives the sun gears 31 , 34 of gear sets 24 , 25 via clutch C 1 , and selectively drives the carrier 33 of gear set 24 via clutch C 2 . The ring gears 29 , 32 , 35 of gear sets 23 , 24 , 25 are selectively connected to ground 42 via clutches (i.e., brakes) C 3 , C 4 and C 5 , respectively.
[0020] As diagrammed in FIG. 2 , the state of the clutches C 1 -C 5 (i.e., engaged or disengaged) can be controlled to provide six forward speed ratios ( 1 , 2 , 3 , 4 , 5 , 6 ), a reverse speed ratio (R) or a neutral condition (N). For example, the first forward speed ratio is achieved by engaging clutches C 1 and C 5 . Shifting from one forward speed ratio to another is generally achieved by disengaging one clutch (referred to as the off-going clutch) while engaging another clutch (referred to as the on-coming clutch). For example the transmission 14 is shifted from first to second by disengaging clutch C 5 while engaging clutch C 4 .
[0021] The torque converter clutch 19 and the transmission clutches C 1 -C 5 are controlled by an electro-hydraulic control system, generally designated by the reference numeral 44 . The hydraulic portions of the control system 44 include a pump 46 which draws hydraulic fluid from a reservoir 48 , a pressure regulator 50 which returns a portion of the pump output to reservoir 48 to develop a regulated pressure in line 52 , a secondary pressure regulator valve 54 , a manual valve 56 manipulated by the driver of the vehicle and a number of solenoid-operated fluid control valves 58 , 60 , 62 and 64 .
[0022] The electronic portion of the electro-hydraulic control system 44 is primarily embodied in the transmission control unit 66 , or controller, which is microprocessor-based and conventional in architecture. The transmission control unit 66 controls the solenoid-operated fluid control valves 58 - 64 based on a number of inputs 68 to achieve a desired transmission speed ratio. Such inputs include, for example, signals representing the transmission input speed TIS, a driver torque command TQ, the transmission output speed TOS, and the hydraulic fluid temperature Tsump. Sensors for developing such signals may be conventional in nature, and have been omitted for simplicity.
[0023] The control lever 82 of manual valve 56 is coupled to a sensor and display module 84 that produces a diagnostic signal on line 86 based on the control lever position; such signal is conventionally referred to as a PRNDL signal, since it indicates which of the transmission ranges (P, R, N, D or L) has been selected by the vehicle driver. Finally, fluid control valves 60 are provided with pressure switches 74 , 76 , 78 for supplying diagnostic signals to control unit 66 on lines 80 based on the respective relay valve positions. The control unit 66 , in turn, monitors the various diagnostic signals for the purpose of electrically verifying proper operation of the controlled elements.
[0024] The solenoid-operated fluid control valves 58 - 64 are generally characterized as being either of the on/off or modulated type. To reduce cost, the electro-hydraulic control system 44 is configured to minimize the number of modulated fluid control valves, as modulated valves are generally more expensive to implement. To this end, fluid control valves 60 are a set of three on/off relay valves, shown in FIG. 1 as a consolidated block, and are utilized in concert with manual valve 56 to enable controlled engagement and disengagement of each of the clutches C 1 -C 5 with only two modulated valves 62 , 64 . For any selected ratio, the control unit 66 activates a particular combination of relay valves 60 for coupling one of the modulated valves 62 , 64 to the on-coming clutch, and the other one of the modulated valves 62 , 64 to the off-going clutch.
[0025] The modulated valves 62 , 64 each comprise a conventional pressure regulator valve biased by a variable pilot pressure that is developed by current controlled force motors (not shown). Fluid control valve 58 is also a modulated valve, and controls the fluid supply path to converter clutch 19 in lines 70 , 72 for selectively engaging and disengaging the converter clutch 19 . The transmission control unit 66 determines pressure commands for smoothly engaging the on-coming clutch while smoothly disengaging the off-going clutch to shift from one speed ratio to another, develops corresponding force motor current commands, and then supplies current to the respective force motors in accordance with the current commands. Thus, the clutches C 1 -C 5 are responsive to the pressure commands via the valves 58 - 64 and their respective actuating elements (e.g., solenoids, current-controlled force motors).
[0026] As indicated above, each shift from one speed ratio to another includes a fill or preparation phase during which an apply chamber of the on-coming clutch is filled in preparation for torque transmission. Fluid supplied to the apply chamber compresses an internal return spring (not shown), thereby stroking a piston (not shown). Once the apply chamber is filled, the piston applies a force to the clutch plates, developing torque capacity beyond the initial return spring pressure. Thereafter, the clutch transmits torque in relation to the clutch pressure, and the shift can be completed using various control strategies. The usual control strategy involves commanding a maximum on-coming clutch pressure for an empirically determined fill time, and then proceeding with the subsequent phases of the shift. The volume of fluid required to fill an apply chamber and thereby cause the clutch to gain torque capacity is referred to as the “clutch volume.”
[0027] If the predetermined fill time is too short, and the apply chamber is not filled sufficiently, the on-coming clutch does not have sufficient torque capacity when the off-going clutch is released, resulting in engine flare prior to the next phase of the shift; if the predetermined fill time is too long, the on-coming clutch will develop significant torque capacity before the off-going clutch is released, resulting in an early pull-down or a clutch overlap condition (i.e., a tie-up).
[0028] The controller 66 determines the timing of the pressure commands based on an estimated on-coming clutch volume, i.e., an estimated volume of fluid required to fill the on-coming clutch apply chamber and thereby cause the oncoming clutch to gain torque capacity. An estimated on-coming clutch volume must be used because the actual on-coming clutch volume may vary over time as a result of wear, and may vary from transmission to transmission because of build variations and tolerances.
[0029] The controller 66 calculates an estimated volume of fluid supplied to the on-coming clutch apply chamber as the chamber is being filled based on a mathematical model of the transmission hydraulic system, and compares the estimated volume of fluid supplied to the estimated clutch volume. When the estimated volume of fluid supplied to the apply chamber equals the estimated clutch volume, then the on-coming clutch should gain capacity. A hydraulic flow model for use in estimating the volume of fluid supplied to an apply chamber is described in U.S. Pat. No. 6,285,942, issued Sep. 4, 2001 to Steinmetz et al, which is hereby incorporated by reference in its entirety. The model inputs include the fill pressure, the shift type ST (for example, a 1-2 upshift), the speed of pump 46 , and the temperature Tsump of the hydraulic fluid. The output of the model is the on-coming clutch flow rate. The flow rate is integrated by an integrator to form the estimated cumulative volume of fluid supplied to the apply chamber. In a preferred embodiment, the controller 66 subtracts the estimated volume of fluid supplied from the estimated clutch volume to determine an estimated clutch volume remaining. If the controller is accurate, the estimated clutch volume remaining will be zero at the time the on-coming clutch gains torque capacity.
[0030] The controller 66 is programmed to effect a clutch-to-clutch shift by lowering the torque on an off-going clutch to the point of allowing slip, and then closed loop controlling the off-going clutch to maintain a predetermined slip threshold. More specifically, during a shift event, the controller 66 generates an off-going clutch pressure command to which the off-going clutch's actuating elements are responsive to affect the off-going clutch pressure. The controller uses the input shaft speed signal TIS and the output shaft speed signal TOS to determine the amount of slip on the off-going clutch, and adjusts the magnitude of the off-going clutch pressure command to maintain the predetermined slip threshold, thereby effectuating the closed loop control.
[0031] During the shift event, the controller 66 also generates an on-coming clutch pressure command sufficient to cause the on-coming clutch to gain torque capacity during the closed loop control of the off-going clutch at the predetermined slip threshold. As the on-coming clutch gains torque capacity, it resists the rotation of the input shaft, causing a reduction in input shaft speed. The controller 66 detects the reduction in input shaft speed, and, because of the closed loop control of the off-going clutch, reduces the magnitude of the off-going clutch pressure command in an effort to maintain the predetermined slip threshold. As the on-coming clutch gains torque capacity, the magnitude of the off-going clutch pressure command becomes smaller until the off-going clutch has no torque capacity and the shift event is completed.
[0032] The off-going clutch pressure command is therefore responsive to the on-coming clutch gaining torque capacity, and thus may be advantageously analyzed to obtain information about the on-coming clutch. Referring to FIG. 3 , the off-going clutch pressure command 100 , as measured by the commanded off-going clutch fill pressure, is graphically depicted with respect to time during a shift event. The controller is programmed to determine the first derivative 104 with respect to time of the off-going clutch pressure command 100 , and the second derivative (not shown) with respect to time of the off-going clutch pressure command 100 . Local minima and maxima 108 A-R of the first derivative 104 are found where the second derivative is equal to zero.
[0033] Each local minimum and maximum 108 A-R is a data point comprising the time value at which the local minimum or maximum occurred and the corresponding value of the first derivative. The controller is programmed to generate a set of data containing the data points 108 A-R for each local minimum and maximum, and a corresponding estimated clutch volume remaining for each of the data points. The data is stored in a buffer 110 , as shown in FIG. 4 .
[0034] The closed loop control of the off-going clutch results in a reduction in magnitude of the off-going clutch pressure command when the on-coming clutch gains torque capacity. Accordingly, the first derivative will change from a positive value to a negative value, or from a negative value to a more negative value, when the on-coming clutch gains torque capacity. Thus, data points with a time value earlier than a negative to positive transition in the first derivative are discarded or ignored. In FIGS. 3 and 4 , the first derivative at local minimum 108 E is negative, and first derivative at local maximum 108 F is positive. Accordingly, all data points associated with local minima and maxima occurring prior to 108 F are ignored or discarded.
[0035] The controller then performs a k-means neural network algorithm to assign each of the data points 108 F- 108 R into one of two clusters or groups, where one group, “Group 1,” consists of those local minima and maxima that occur before on-coming clutch torque capacity, and where the other group, “Group 2,” consists of those local minima and maxima that occur after on-coming clutch torque capacity. The k-means neural network method employed by the controller is depicted in the flow chart of FIG. 5 . The method includes selecting a first data point to function as an initial Group 1 Mean (step 112 ). In the preferred embodiment, the controller selects the data point 108 F having the earliest time value of all the remaining data points in the buffer as the initial Group 1 Mean. The method also includes selecting a second data point to function as an initial Group 2 Mean (step 116 ). In the preferred embodiment, the controller selects the data point 108 R having the latest time value of all the data points in the buffer as the initial Group 2 Mean.
[0036] The method also includes calculating, for each data point 108 F-R in the buffer, the distance between the data point and the Group I Mean (step 120 ). The method also includes calculating, for each data point 108 F-R in the buffer, the distance between the data point and the Group 2 Mean (step 124 ). The distance between a data point and a mean may be the Euclidean distance from the data point to the mean. That is,
D ={square root}{square root over (( M m −M DP ) 2 +( t m −t DP ) 2 )}
[0037] Where D is the distance between the mean and the data point, M m is the value of the first derivative at the mean, M DP is the value of the first derivative at the data point, t m is the time value at the mean, and t DP is the time value at the data point. Alternatively, the distance may be non time based, where the distance is simply the difference between the first derivative value of the data point and the first derivative value of the mean.
[0038] The method further includes classifying the data points that are closer to the Group 1 Mean than the Group 2 Mean into Group 1 (step 128 ), and classifying the data points that are closer to the Group 2 Mean than the Group 1 Mean into Group 2 (step 132 ). Using the data points in Group 1 , a New Group 1 Mean is calculated (step 136 ). 1 f the distances calculated in steps 120 and 124 are Euclidean distances, then the New Group 1 Mean will comprise the mean first derivative value and the mean time value of all the data points classified as Group 1 . 1 f the distances calculated are non time based, i.e., the difference between a data point's first derivative value and the mean's first derivative value, then the New Group 1 Mean will comprise the mean first derivative value of all points classified as Group 1 . Similarly, using the data points in Group 2 , a New Group 2 Mean is calculated (step 140 ).
[0039] In decision block 144 , the controller determines whether the Group 1 Mean is equal to the New Group 1 Mean, and whether the Group 2 Mean is equal to the New Group 2 Mean. 1 f not, then the controller designates the New Group 1 Mean as the Group 1 Mean, designates the New Group 2 Mean as the Group 2 Mean (step 148 ), and then repeats the clustering process at step 120 . If so, the k-means neural network algorithm is successfully completed.
[0040] After the controller has processed the data in the buffer according to the k-means neural network algorithm, the controller determines the data point 108 I in the second group having the earliest time value. Data point 108 I is considered the point at which the on-coming clutch gained capacity, and, accordingly, the point at which the on-coming clutch's apply chamber is completely filled. The estimated volume remaining associated with point 108 I should be zero, that is, the estimated volume of fluid supplied to the on-coming clutch apply chamber should be equal to the estimated clutch volume. If the estimated volume remaining associated with point 108 I is not zero, then the controller can adapt its volume remaining calculations accordingly. For example, referring again to FIG. 4 , the estimated clutch volume remaining at data point 108 I is −20 cc. The controller may increase the estimated clutch volume accordingly since the estimated volume of fluid supplied exceeds the estimated clutch volume by 20 cc.
[0041] While the best mode for carrying out the invention has been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention within the scope of the appended claims. | A method for determining when in the course of a shift event an on-coming clutch gains torque capacity is provided. The method includes closed-loop controlling an off-going clutch to maintain a predetermined slip threshold by generating an off-going clutch pressure command, causing the on-coming clutch to engage during the closed loop control of the off-going clutch, generating a first derivative with respect to time of the off-going clutch pressure command, and using the first derivative to determine when the on-coming clutch gained torque capacity. A neural network method is preferably employed in analyzing the first derivative to locate a transition in the rate of commanded pressure indicative of off-going clutch release. A corresponding apparatus is also provided. | 5 |
BACKGROUND OF THE INVENTION
This invention relates to a cut-off control system for variable displacement pumps and more particularly to a control system for preventing the generation of excessive pressure by reducing the displacement volume of such pumps.
In conventional control devices of the type specified, the arrangement is made such that when the delivery pressure of the pump has become more than a predetermined cut-off pressure set by a spring of a cut-off control valve, the spool thereof is urged against the biasing force of the spring so that the pump pressure is transmitted to the chamber of a variable displacement device so as to urge a piston mechanically connected to the variable displacement pump thereby reducing the delivery volume of the pump.
In this conventional system, there are following problems.
(1) Improvement in response to control system renders the system unstable. Such unstable condition is caused by overdisplacement of the variable displacement device.
(2) Because the displacement volume of the pump reaches its maximum when the pump is stopped, the prime mover for the pump cannot be easily started.
(3) Since the fluid pressure source for the control valve varies depending on the load applied, it becomes difficult to provide other types of displacement controls than the cut-off control.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a displacement control system for a variable displacement pump which is capable of overcoming the above noted problems.
Another object of the present invention is to provide a displacement control system for a variable displacement pump wherein a stable and reliable displacement control can be achieved by reducing an overmovement of a servo piston due to inertia to a minimum.
A further object of the present invention is to provide a displacement control system for a variable displacement pump wherein displacement volume can be kept a minimum when a charge pump is out of operation thereby improving starting-up characteristic of a prime mover for driving the variable displacement pump.
A still further object of the present invention is to provide a displacement control system for a variable displacement pump wherein in addition to a cut-off displacement control, other types of displacement controls can be easily combined therewith.
Still another object of the present invention is to provide a displacement control system for a variable displacement pump which is capable of reducing a warming-up time for the system.
In accordance with an aspect of the present invention, there is provided a displacement control system for a variable displacement pump comprising charge pump means; cut-off control valve means connected to said charge pump means, said cut-off control valve means comprising a valve body having a first and a second pump ports and a first outlet port formed therein, the first pump port being connected to said charge pump means and the second pump port being connected to said variable displacement pump, sleeve means mounted within said valve body, a pin slidably mounted within said sleeve means, a spool slidably mounted within said sleeve means, the cross-sectional area of which is larger than that of said pin, a cylindrical cap member fixedly secured to said valve body defining a spring chamber therein, and spring means disposed within said spring chamber for urging said spool toward connecting said first pump port with said first outlet port; and servo booster means connected to said first outlet port for controlling the displacement of said variable displacement pump.
The servo booster means comprises servo pilot-operated spool valve means connected with said first outlet port and operated by the hydraulic fluid therefrom, said servo pilot-operated spool valve means being connected to said charge pump means, and servo cylinder means having a piston mounted therein, the piston being mechanically connected to said variable displacement pump for controlling the displacement therefrom. The rod-side chamber of said servo cylinder means is connected to the charge pump means and the head-side chamber thereof is connected to the servo pilot-operated spool valve means.
According to a second embodiment of the present invention, warming-up cock means is provided in the hydraulic system for reducing a warming-up time of the system when it is opened.
The above and other objects, features and advantages of the present invention will be readily apparent from the following description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a hydraulic circuit of a displacement control system for a variable displacement pump according to the present invention wherein a cut-off control valve is shown in cross-section;
FIG. 2 is a hydraulic circuit of another embodiment of the present invention;
FIG. 3 is a cross-sectional view of a cut-off control valve used in the hydraulic circuit of FIG. 2;
FIG. 4 is a diagram showing characteristic feature of a cut-off control valve wherein Pp is the output pressure of a variable displacement pump and Pi is the output pressure of the cut-off control valve;
FIG. 5 is a diagram explaining how the cut-off displacement control is performed according to the present invention wherein Pp is the output pressure of a variable displacement pump and Q is the displacement volume thereof; and
FIG. 6 is a cross-sectional view of a servo booster means.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described below by way of example only with reference to the accompanying drawings. Reference numeral 5 denotes a variable displacement pump the delivery side of which is connected through a selector valve to an actuator (not shown). Reference numeral 2 denotes a servo booster which adjusts the displacement of the variable displacement pump 5. The servo booster 2 comprises a servo cylinder 9 and a servo pilot spool valve 10. Reference numeral 11 indicates a cut-off control valve.
The delivery side of a charge pump 12 is connected through the servo pilot spool valve 10 to a head-side chamber 9b of the servo cylinder 9 and also directly connected to a rod-side chamber 9c of the servo cylinder 9. Reference numeral 13 denotes a relief valve which leads to a tank 14.
The above-mentioned cut-off control valve 11 has a valve body 15 having a pump port 16, outlet ports 18, 19 and a drain port 23 formed therein. The outlet port 19 communicates through a feedback circuit 20 with the outlet port 18. The valve body 15 has a bore hole 21 at one end of which is fitted a plug member 22. The plug member 22 has a pump port 24 formed therein.
Sleeves 25 and 27 are fitted in the bore hole 21. The sleeve 27 has formed therein a passage 26 communicating with the port 19. Fixedly secured to an end of the valve body 15 is a cylindrical member 28. A pin 29 is slidably mounted in the sleeve 25 and a spool 31 is slidably mounted in the sleeve 27. A spring retainer 32 is fitted to an end of the spool 31. Movably mounted in the cylindrical member 28 is a piston-shaped stopper 33. The cylindrical member 28 is provided with an adjusting screw 34 which abuts against the stopper 33. A spring 35 extends between the spring retainer 32 and the stopper 33. Spring chamber 41 communicates through a passage 39 of the spool 31 with drain.
The sleeve 27 has ports 36, 37 and 38 formed therein, and the spool 31 has a restriction 39a formed therein.
The aforementioned pump port 24 is connected to the delivery side of the variable displacement pump 5, and the pump port 16 is connected to the delivery side of the charge pump 12. The outlet port 18 communicates through a restriction 40 with an actuating port 10a of the servo pilot spool valve 10.
The operation of the present invention will now be described below.
The servo cylinder 9 includes a servo piston 9a which is mechanically connected with a yoke or swash plate (not shown) of the variable displacement pump 5. With the rightward movement of the servo piston 9, the displacement volume Q cc/Rev of the variable displacement pump 5 will increase. When the delivery pressure Pp of the variable displacement pump 5 is low, the pin 29 and the spool 31 of the cut-off control valve 11 is pushed leftwards by the force of the spring 35 so as to allow the port 16 to communicate with the port 18 so that the pilot pressure Pi becomes equal to the charge pressure Ps of the charge pump 12 set by the relief valve 13. In response to increase in the pilot pressure Pi, the spool of the pilot spool valve 10 is urged rightwards against the biasing force of the spring 10b and will assume its actuated or offset position. Consequently, the head-side chamber 9b of the servo cylinder 9 is connected to the drain, and so the servo piston 9a is move rightwards by the charge pressure Ps introduced into the rod-side chamber 9c thereby increasing the displacement volume of the variable displacement pump 5.
Since the weight of the spool of the pilot spool valve 10 is extremely light as compared with the weight of the yoke or swash plate of the variable displacement pump 5 or the weight of the servo piston 9a, the movement of the spool of the pilot spool valve 10 due to inertia can be extremely reduced.
With an increase in the pump delivery pressure Pp, the spool 31 is moved rightwards through the pin 29 against the biasing force of the spring 35 so as to cut off the communication between ports 16 and 18 and allow communication between port 18 and drain port 23 thereby lowering the pilot pressure Pi. With the lowering of the pilot pressure Pi, the pilot spool valve 10 is returned to its neutral position by the force of the spring 10b and will strike against a stop 47 which is fitted to a member 45 mechanically connecting the servo piston 9a and the pilot spool valve 10 so as to move the servo piston 9a leftwards thereby reducing the delivery volume of the variable displacement pump 5.
When the delivery pressure Pp of the pump 5 becomes low as compared with the force of the spring 35 preset by the adjusting screw 34, the spool 34 is moved to the left so as to intercommunicate the ports 16 and 18 thereby increasing the pilot pressure Pi and the displacement volume of the pump.
Because the charge pressure Ps will decrease when the charge pump 12 is stopped, the pilot pressure Pi will decrease. Consequently, as mentioned hereinabove, the servo piston 9a is moved leftwards so that the displacement volume of the pump 5 reaches its minimum. Because the charge pressure Ps will increase when the charge pump 12 is started to be driven, the pilot pressure Pi will increase and the displacement volume of the pump 5 will reach its maximum.
One of the features of the present invention resides in that the displacement volume of the variable displacement pump 5 can be controlled by the charge pressure Ps generated by the charge pump 12 which is provided separately from the pump 5 so that displacement controls other than the aforementioned cutoff control can be easily made.
If the control gain of the cut-off control valve 11 is increased in order to increase the response characteristic of the displacement control for the pump 5, the pilot pressure Pi tends to become excessively overshoot and unstable so that hunting of the variable displacement pump 5 may occur.
In order to prevent an excessive overshoot of the pilot pressure Pi, the feedback circuit 20 is provided to introduce the pilot pressure Pi between the pin 29 and the spool 31. Since the diameter of the spool 31 is larger than that of the pin 29, when the pilot pressure Pi becomes excessively high the spool 31 is moved rightwards against the biasing force of the spring 35 so as to cut off the communication between the ports 16 and 18 and allow the port 18 to communicate with the drain port 23. As a result, the pilot pressure Pi is released into the drain and the generation of excessive pressure overshoot and hunting can be avoided.
Referring to FIGS. 2 and 3, there is shown another embodiment of the present invention which differs from the embodiment of FIG. 1 in that a warming-up cock 30 is provided on the delivery side of the charge pump 12 and is connected to the port 17 of the cut-off control valve 11. Other structures of this embodiment are same as those of the embodiment of FIG. 1.
FIG. 4 shows a characteristic diagram of the cut-off control valve 11 in which its abscissa shows the pump delivery pressure Pp and its ordinate shows the pilot pressure Pi. When the warming-up cock 30 is closed, the operation of the cut-off control valve of FIG. 3 will be same as that of the control valve of FIG. 1. In brief, when the pump delivery pressure Pp is increased and reaches Pm in FIG. 4, the spool 31 is moved through the pin 29 to the right against the biasing force of the spring 35. As a result, the communication between the ports 16 and 18 is cut off and the port 18 is allowed to communicate with the drain port 23 so that the outlet pressure of the cut-off control valve will decrease. The pressure Pm is determined by the biasing force of the spring 35 preset by the adjusting screw 34.
When the warming-up cock 30 is opened, the charge pressure Ps is introduced into the spring chamber 41, and due to the provision of the restriction 39a formed between the passage 39 and the drain port 23, the pressure within the spring chamber 41 will increase up to the charge pressure Ps. Consequently, the force urging the spool 31 leftwards will increase and so Pp will increase to Pw (Pw>Pm) and then move the spool 31 rightwards.
In this case, when the pump delivery pressure Pp reaches Pw, the pilot pressure Pi will decrease.
Since the outside diameter of the spool 31 is larger than that of the pin 29 and the outlet pilot pressure Pi is introduced through the feedback circuit 20 between the spool 31 and the pin 29, when Pi becomes excessively high, the spool 31 is moved rightwards thereby automatically reducing Pi so that automatic pressure compensation can be effected.
Since the servo booster 2 controls the displacement volume Q cc/rev of the variable displacement pump 5 in response to the valve of Pi, the cut-off displacement controls of the pump as shown in FIG. 5 can be effected by combining the aforementioned cut-off control valve 11 and the servo booster 2. In FIG. 5, dotted line shows characteristic curve of a main relief valve 42.
If the cracking pressure of the main relief valve 42 is set at Pm and when the warming-up cock 30 is closed, the cut-off displacement controls of the pump is made prior to cracking of the main relief valve 42 and so the energy loss due to the main relief valve 42 can be reduced.
In the case the warming-up cock 30 is opened, cracking of the main relief valve 42 occurs before the cut-off displacement control of the pump is made so that the energy loss due to the main relief valve 42 is increased thereby reducing the time required for warming up the hydraulic system.
Therefore, according to the second embodiment, when warming-up of the hydraulic system is required, the warming-up time can be remarkably reduced by opening the warming-up cock 30, and once the warming-up has been completed, the cut-off displacement control of the pump can be made prior to cracking of the main relief valve 42 by closing the warming-up cock 30 so that the energy loss due to the main relief valve 42 can be reduced.
Referring to FIG. 6, there is shown an embodiment of servo booster 2 adapted to be used in the hydraulic circuit of the present invention.
Reference numeral 50 denotes a servo cylinder in which a servo piston 52 is slidably mounted. Fixedly secured to one end of the servo cylinder 50 is an end cover 57, and also fixedly secured to the other end thereof is a sleeve 56.
The servo cylinder 50 has an axially extending hole 60 formed therein in which servo pin 58 is inserted. The servo pin 58 is fixedly secured to the servo piston 52 (9a in FIGS. 1 and 2).
The servo piston 52 has a spool hole 61 formed therein in which a pilot spool 53 and a guide tube 54 are inserted. One end of the guide tube 54 is fixedly secured to an end cover 57 by means of a retainer member 62 and a snap ring 63, and the inside of the guide tube 54 communicates with a port k formed in the end cover 57.
The servo piston 52 has a drain port j extending from the peripheral face and communicating with the spool hole 61, a port 65 communicating with a pressure chamber "a" and a port 66 communicating with a pressure chamber b. A restriction 67 is formed in the drain port j. The servo piston 52 has a stopper 68 located between lands 53a and 53b of the pilot spool 53.
One end of a slide tube 55 is fitted to an end of the pilot spool 53 and the other end thereof is slidably mounted in the sleeve 56.
The inside of the slide tube 55 communicates with a passage 69 of the pilot spool 53 which opens in the peripheral surface thereof.
Further, the slide tube 55 has a spring seat 70 formed in the other end thereof. A spring 59 is mounted between the spring seat 70 and a spring seat 71 of the sleeve 56.
The aforementioned servo pin 58 is connected to the yoke or swash plate (not shown) of the variable displacement pump 5.
Reference numeral 72 denotes an inlet port for the change pressure Ps.
Thus, charge pressure Ps is supplied through the inlet port 72 into the pressure chamber "a" defined in one end of the servo piston 52. Pilot pressure Pi is supplied by way of the port k into a pressure chamber c defined between the guide tube 54 and the pilot spool 53. A chamber g within the sleeve 56 communicates with the drain port j.
The above-mentioned pressure chamber "a" communicates through a port 65 with a chamber d, and a pressure chamber b formed in the end of the servo piston 52 communicates with the port 66.
With an increase in the pilot pressure Pi, the pilot spool 53 is moved rightwards against the biasing force of the spring 59 so as to allow the port 66 and the drain port j to communicate so that the working fluid within the pressure chamber b is drained through the restriction 67 of the port j and the servo piston 52 will move or follow after the pilot spool 53.
Since the pilot spool 53 is moved rightwards against the biasing force of the spring 59 in response to increase in the pilot pressure, the displacement volume of the pump can be set by the pilot pressure.
When the pilot pressure Pi is suddenly increased, the pressure within the chamber e is increased by the restriction 67 of the drain port j, and the pressure rise is transmitted to the chamber g within the sleeve 56.
Therefore, as the rightward moving speed of the servo piston increases, the force tending to return the pilot spool 53 leftwards will increase thereby limiting the speed of increasing the displacement volume of the pump.
On the contrary, when the pilot pressure Pi is suddenly reduced, the pilot spool 53 is returned or moved leftwards by the force of the spring 59 so as to allow the ports 65 and 66 to communicate so that the charge pressure Ps is supplied into the pressure chamber b and the servo piston 52 will move or follow after the pilot spool 53.
In this case, because the quantity of the fluid passing through the restriction 67 of the drain port j is extremely limited, the pressure within the chamber g of the sleeve 56 is maintained at the drain pressure regardless of the speed of movement of the servo piston 52.
Accordingly, the pilot spool 53 is not subjected to the influence of the servo piston 52 and so the speed of reduction in the displacement volume of the pump is not limited.
When the pump is stopped, the displacement volume of the pump is kept at its minimum by the action of the spring 59.
It is to be understood that the above description is by way of example only, and that details for carrying the invention into effect may be varied without departing from the scope of the invention claimed. | A displacement control system for a variable displacement pump comprising a charge pump; a cut-off control valve connected to the charge pump, the cut-off control valve including a valve body having a first and a second pump ports and an outlet port formed therein, the first pump port being connected to the charge pump and the second pump port being connected to the variable displacement pump, a sleeve mounted within the valve body, a pin slidably mounted within the sleeve, a spool slidably mounted within the sleeve, a cylindrical cap member fixedly secured to the valve body defining a spring chamber therein, and a spring disposed within the spring chamber for urging the spool toward connecting the first pump port with the outlet port; and a servo booster connected to the outlet port for controlling the displacement of the variable displacement pump. | 5 |
FIELD OF THE INVENTION
The present invention relates generally to millimeter imaging systems and in particular to a realtime millimeter imaging system for detecting millimeter wave radiation and generating a corresponding image.
BACKGROUND
Millimeter-wave imaging systems produce a picture of a scene by detecting thermally generated radiation in the 30-300 GHz range, which is emitted or reflected by objects in the field of view of the instrument. Such systems offer advantages over equivalent instruments detecting infrared and visible light, because the millimeter-wave radiation can penetrate low visibility and obscuring conditions (e.g., caused by clothing, walls, clouds, fog, haze, rain, dust, smoke, sandstorms) without the high level of attenuation that occurs at the other noted wavelengths. This is particularly the case in specific “windows” for atmospheric transmission of radio waves that occur between 90 and 110 GHz and between 210 and 250 GHz.
Millimeter-wave imaging systems may be used in a range of important applications such as: aids to aircraft landing; collision warning in air, land and sea transport; detection and tracking of ground based vehicular traffic; covert surveillance for intruders, contraband and weapons. In such applications, the availability of real-time, “movie-camera” like imaging is highly desirable. However, for such systems to find wide acceptance in the commercial market-place, the sensing instrumentation must be light in weight, small in size, and affordable in cost.
A range of millimeter-wave imaging systems have been reported, but fail to meet the size, weight, and cost requirements for wide commercial acceptance of the technology, while at the same time offering real-time moving images. Such systems use two distinct technologies: mechanical scanning of the beam of a single antenna, and two-dimensional arrays.
Mechanical scanning of the beam of a single antenna connected to a single receiving system is performed in a raster pattern over a scene to detect the emitted radiation and produce a map or image of the brightness. The angular resolution of the resultant image is determined by the width of the antenna beam, whereas the scan angle determines the field of view. Rapid real-time imaging is difficult or inadequate, because physically large and cumbersome antenna elements (required to achieve high angular resolution) must be moved quickly at high rates.
Two-dimensional arrays of electrically-small antennas and integrated receivers sample the magnitude of the received millimeter-wave signal at the focal plane of an antenna system. This information is then used to produce a snap-shot of the brightness in the field of view of the instrument. In any given plane, the angular resolution of the resultant image is determined by the number of elements across the array and the outer dimensions of the array. In contrast, the field of view is determined by the beam-width of the individual antenna-array elements. Rapid real-time imaging can be achieved with these systems. However, this occurs at the expense of large numbers (1000's) of millimeter-wave receiving sub-systems and complex electronic phase shifting and amplitude weighting networks. Because of the large number of receivers required, heterodyne systems are avoided (in view of the local oscillator distribution problems) in favour of direct detection systems, with the attendant problems of gain stability and poorer sensitivity. Coherent local oscillator distribution to such a large number of millimeter-wave heterodyne receivers presents significant difficulties.
Thus, a need clearly exists for an improved real-time millimeter-wave imaging system capable of producing real-time, movie-like imaging, in which the system is more compact, less complex, and less expensive to produce.
SUMMARY
In accordance with a first aspect of the invention, an image is formed from millimeter waves. To do so, a field of view is scanned using two geometrically orthogonal, intersecting co-polarized fan beams to receive millimeter-wave radiation. The components of received millimeter-wave radiation from the two fan beams are cross-correlated. The polarizations of the electric fields of the two fan beams are arranged to be substantially parallel in alignment. This may be achieved by polarization rotation filtering of the millimeter-wave radiation received in one of the fan beams. The two fan beams may be scanned in azimuth and elevation defining a scan range. The intersection region of the two fan beams is able to cover any point in the scan range. The scan range determines the field of view and a beam width of each fan beam in the narrow direction determines an angular resolution of the image. The cross-correlated output is measured at each point in the field of view to produce a map of the brightness. The position of the two geometrically orthogonal, intersecting fan beams may be controlled to generate the cross-correlated output at each fan beam intersection point in the field of view. Preferably, the scanning is implemented using a dual fan-beam antenna The dual fan-beam antenna may have two modified pill-box antennas and a polarization rotator to change the direction of the incident polarization for one of the modified pill-box antennas. An image may be formed from millimeter waves of a different polarization by having a polarization rotator to change the direction of the incident polarization for a different modified pill-box antenna, only one polarization rotator being used at any time.
In accordance with a second aspect of the invention, millimeter-wave radiation is received. A field of view is scanned using a fan beam to receive millimeter-wave radiation. Polarization of incident millimeter-wave radiation is rotated through 90 degrees, and the field of view is scanned using another fan beam to receive the polarization-rotated millimeter-wave radiation. The fan beams intersect and are geometrically orthogonal to each other, yet the radiation is co-polarized. The fan beams are provided by respective fan-beam antennas. Each such antenna may include a modified pill-box antenna. Preferably, the modified pill-box antenna includes: a metal housing with an elongated aperture in at least one side of the housing, a curved primary reflector surface located within the housing and opposite the aperture, a feed horn within the housing, and one or more sub-reflectors for coupling the feed horn to the primary reflector surface. At least one of the sub-reflectors is designed to rotate, providing one-dimensional beam scanning in the narrow direction of the fan beam. The polarization rotation for a fan beam may be implemented using a polarization rotating transreflector.
Preferably, the transreflector includes: a planar metallic reflector, and a grid of closely spaced wires. The wires are preferably spaced n×λ/4 from the planar metallic reflector, where n is an odd integer and λ is a wavelength of the millimeter-wave radiation. The polarization rotating transreflector may be positioned at a 45 degree angle relative to the aperture of the second fan-beam antenna and at a substantially 45 degree angle relative to the direction of incident millimeter-wave radiation. The polarization rotation for a fan beam may be switched by exchanging a polarization rotating transreflector and a planar metallic reflector, both aligned in the same way. An exchange may be effected by turning a polarization rotating transreflector by 180 degrees to use its back surface as a planar metallic reflector. An exchange may be effected by making the wires of a polarization rotating transreflector out of a material that has a switchable conductivity.
In accordance with a third aspect of the invention, millimeter wave radiation is received for generating an image. To do so, millimeter wave radiation is received in accordance with first and second fan beams. The first and second fan beams are geometrically orthogonal to each other and intersecting. The millimeter wave radiation received in accordance with the second fan beam is co-polarized with the millimeter wave radiation received in accordance with the first fan beam. Components of the millimeter wave radiation received in accordance with the first and second beams are downconverted to generate respective intermediate frequency (IF) signals. The IF signals are cross-correlated. The resulting cross-correlated signal is filtered to provide a value proportional to brightness at each point in the scene. The received millimeter wave radiation may be amplified in accordance with the first and second beams prior to the step of downconverting.
In accordance with a fourth aspect of the invention, millimeter-wave imaging is disclosed. To do so, millimeter-wave radiation is received. The receiving includes: receiving millimeter-wave radiation by scanning a field of view using a fan beam, rotating the polarization of incident millimeter-wave radiation through 90 degrees, and receiving the polarization-rotated millimeter-wave radiation by scanning a field of view using another fan beam. The fan beams intersect and are geometrically orthogonal to each other. The received millimeter-wave radiation is processed. The processing step includes: receiving components of millimeter-wave radiation from the antenna received in accordance with the fan beams, downconverting respective components of the received millimeter wave radiation received to generate respective intermediate frequency (IF) signals, cross-correlating the IF signals; and filtering the resulting cross-correlated signal. The filtered, cross-correlated signal is proportional to the brightness at each point in the field of view as the antenna beams are scanned. In this way, an image of the scene may be built up. The scanning of each fan beam may be independently controlled as required so that the image can be generated from the filtered, cross-correlated output signal which provides a value proportional to the brightness of the scene at each point in said field of view.
BRIEF DESCRIPTION OF THE DRAWINGS
A small number of embodiments are described hereinafter with reference to the drawings, in which:
FIG. 1 is a radiation pattern of two crossed fan beam antennas in accordance with the embodiments of the invention;
FIG. 2 is a simplified block diagram of a real-time millimeter-wave imaging system in accordance with an embodiment of the invention;
FIG. 3 is a perspective view of an example of a pill-box antenna for implementing a scanned-beam imaging system in accordance with another embodiment of the invention;
FIG. 4 is a perspective view of a combination of two pill-box antennas and a metallic reflector for producing a dual-scanning beam antenna with co-polarized far-field response in accordance with a further embodiment of the invention;
FIG. 5 is a perspective view of a combination of two pill-box antennas and two polarization rotating transreflectors that may be exchanged for planar metallic reflectors, for producing a dual-scanning beam antenna with co-polarized far-field response of either of two polarizations, in accordance with a further embodiment of the invention; and
FIG. 6 is a block diagram illustrating a real-time cross-correlating millimeter-wave imaging system in accordance with a further embodiment of the invention, incorporating the dual fan-beam antenna of FIG. 4 or FIG. 5 in a modified millimeter-wave imaging system of FIG. 2 .
DETAILED DESCRIPTION
A method and an apparatus for forming an image from millimeter waves, a method and an antenna for receiving millimeter wave radiation, a method and an apparatus for receiving millimeter wave radiation for generating an image, and a method and a system for millimeter wave imaging are disclosed. In the following description, numerous specific details are set forth. In the other instances, details well known to those skilled in the art may not be set out so as not to obscure the invention. It will be apparent to those skilled in the art in the view of this disclosure that modifications, substitutions and/or changes may be made without departing from the scope and spirit of the invention.
The embodiments of the invention involve improved imaging methods, antennas, and systems that enable the realization of a simple, low-cost instrument, capable of realtime imaging of moving targets. In broad terms, the embodiments produce a map or image of the millimeter-wave brightness in the field of view of the instrument by cross-correlating the signal received from two orthogonal, intersecting fan-beams.
Fan-Beam Antennas Generally
An antenna with a fan-beam radiation pattern detects radiation from a region in the field of view that is of narrow angular extent in one direction only, while possessing a broad pattern in the orthogonal plane. Typically, a fan-beam can be generated by an antenna, or array of antennas, which is essentially one-dimensional (e.g., a long narrow slot, a linear array of slots, or a linear array of patch antennas). The width of the beam in the narrow direction is inversely proportional to the electrical length of the aperture or array. In contrast, the beam-width in the broad direction is inversely proportional to the width of the aperture or an individual element of the array. The angular position of the fan-beam in the narrow direction may be scanned across the field of view by producing a varying linear gradient in the phase of the electrical excitation across the aperture or across the elements of the array.
In accordance with embodiments of the invention, two such fan beams are arranged so that the beams intersect at right angles in the field of view of the instrument. FIG. 1 is a plot illustrating the radiation pattern 100 of two crossed fan beam antennas. The pattern 100 includes an E-plane, fan-beam antenna pattern 110 and an H-plane, fan-beam antenna pattern 120 , and a pencil beam pattern 130 . The polarization of the electric field in each beam is arranged to be parallel in alignment. As the fan-beams 110 , 120 are scanned in azimuth and elevation, the intersection region 130 can be made to cover any point in the scan range. Thus, the scan range determines the field of view of the instrument and the beam-width of the fan-beam in the narrow direction determines the angular resolution of the image. The millimeter-wave brightness at any point in the image is proportional to the cross-correlation between the signals received by the two antenna systems.
Imaging Receiver System
A significant component of the imaging system is the receiver, which takes the output from the antennas, amplifies the signals, and then down-converts the amplified signals to a convenient intermediate frequency at which the cross-correlation can take place. There are a number of possible implementations for such receiving systems, depending upon the design of the fan-beam antenna.
An imaging receiver system 200 in accordance with an embodiment of the invention shown in FIG. 2 uses only two receivers, one connected to an antenna 202 scanning in the vertical direction and the other to an antenna 204 scanning in the horizontal plane, to sample the whole image. The antenna 202 is an E-plane antenna, and the antenna 204 is an H-plane antenna. The E-plane antenna is coupled to one or more radio frequency (RF) low noise amplifiers (LNAs) 212 a , 212 b . The output of the one or more low noise amplifiers 212 b is coupled to a respective block down converter 232 . Similarly, the H-plane antenna 204 is coupled to one or more LNAs 214 a , 214 b . The output of the LNA 214 b is coupled to a further block down converter 234 . A local oscillator 220 provides an input to both block down converters 232 , 234 .
The respective block down converters 232 , 234 produce respective intermediate frequency (IF) signals that are both provided to a correlator 240 . The output of the correlator 240 is provided to a low pass filter 250 , which produces the output signal 260 . A map of the millimeter-wave brightness at each point in the field of view is produced by scanning the antenna beams over the field and at each field point measuring the cross correlation between the receiver outputs using a broadband analogue multiplier 240 .
A polarization rotating filter (not shown) may be placed in front of one of the antenna apertures so that both fan beams operate in the same polarization.
Antenna for Imaging System
In accordance with an embodiment of the invention, a simple, inexpensive implementation uses a multiple reflector “pill-box” style antenna 300 shown in FIG. 3 . In this simplified example, a shaped primary reflector 334 is coupled to a single feed-horn 330 , 332 via a rotating sub-reflector 320 , which provides beam scanning as the sub-reflector 320 spins. More than one sub-reflector may be practiced, with at least one sub-reflector rotating to provide beam scanning. With careful mechanical and electrical design, in which the rotating sub-reflector 320 rotates about its center of mass, high speed scanning can be achieved. Preferably, the sub-reflector 320 is disc-like in form. A significant advantage of this system is that only a single heterodyne receiver per beam is needed. This is advantageous from the point of view of system simplicity and cost and also because a simple local oscillator distribution system is possible without the need for complex array phasing.
In a conventional “pill-box” antenna, a parabolic cylinder is used as the reflector. The “pill-box” is formed by two parallel planes which cut through the parabolic cylinder perpendicular to the cylinder elements. Typically, the focal line of the cylinder is positioned in the center of the aperture formed by the open ends of the parallel plates. When a feed horn is placed at the focal line, the feed horn blocks a significant portion of the aperture, resulting in large sidelobes in the far-field pattern of the antenna as well as standing waves within the “pill-box” itself.
Much improved performance can be obtained when an offset feeding arrangement is used, so that only one side of the “pill-box” is illuminated. The arc of the parabola does not include its vertex, and the feed horn points to illuminate this arc. Even though the illumination is asymmetric, good sidelobe performance is obtained. Alternatively, the “pill-box” antenna may be symmetrical about the axis of the parabola, but arranged as a folded lens to avoid blockage. Such an antenna, however, is more difficult to manufacture than an unfolded design.
The millimeter-wave fan-beam antenna 300 shown in FIG. 3 includes a metal housing 310 with a radiating aperture 312 formed in one side of the metal housing. The length of the radiating aperture 312 is approximately 200 wavelengths (λ) and the width of the aperture 312 is approximately one wave length (1λ). These measurements are preferred and other dimensions may be practiced without departing from the scope and spirit of the invention. The direction of the electric field at the aperture is indicated by an arrow 314 . Located within the metal housing 310 is the primary reflector surface 334 coupled to the tapered wave guide feed-horn 330 with a wave guide input/output 332 oppositely positioned relative to the radiating aperture 312 within the housing 310 . At the bottom of the tapered wave guide feed-horn 330 within the metal housing 310 is the rotating sub-reflector 320 for one dimensional beam scanning.
The antenna 300 uses one or more sub-reflectors 320 to couple the feed horn 330 , 332 in an offset “pill-box” structure. The primary reflector 334 is shaped away from the traditional parabola to provide enhanced off-axis scanning angle with good sidelobe performance over the widest possible range of scan. The primary reflector 334 is coupled to the single feed-horn 330 via one or more sub-reflectors 320 , which are also designed to have a profile that enhances the scan performance of the complete antenna assembly 300 . One of these secondary mirrors 320 is arranged so that this sub-reflector 320 rotates, providing main beam scanning as the sub-reflector 320 spins. With careful mechanical and electrical design, in which the rotating sub-reflector 320 rotates about its center of mass, high speed scanning can be achieved.
For the imaging system, a pair of independently-scanned, orthogonally-oriented fan beams are required, with the sense of electric polarization aligned in each beam. Two “pill-box” antennas 410 , 420 of the type shown in FIG. 3 are used, configured 400 as shown in FIG. 4 . The antenna 410 has an aperture 414 oriented lengthwise in a horizontal sense, while the other antenna 420 has an aperture 424 lengthwise in a vertical sense, as depicted in FIG. 4 . The direction 412 , 422 of the electric field in the respective apertures 414 , 424 are shown. Thus, the aperture 424 couples directly to the observed scene, while the other aperture 414 is arranged at a right angle so that the aperture 414 is coupled via a passive reflecting screen 430 , 440 and is oriented so that the narrow dimension of the far-field pattern of the aperture 414 is at right angles to the pattern of the other antenna 420 .
The passive reflecting screen 430 , 440 is generally configured at an angle of 45° relative the surface of the fan-beam antenna 410 having the aperture 414 . The passive reflecting screen preferably has a planar metallic reflector 430 spaced apart by a multiple of a quarter wavelength (nλ/4) from a closely spaced, fine wire grid 440 . The grid 440 is located between the reflector 430 and the antenna 410 . The wires of the grid 440 are aligned at 45° to the direction of incident field polarization. This arrangement 400 results in orthogonal polarization in the far-field, if a standard plane reflector 430 is used.
Another way to achieve a co-polarized far-field response may be to modify the feed for the “pill-box” antenna 410 , 420 , so that the E-field vector is rotated through 90 degrees and aligned parallel to the long direction of the aperture. For this configuration, small variations in the surface quality and spacing of the metallic walls may cause significant degradation in antenna performance. However, for this arrangement, the polarization rotating filter 430 , 440 is no longer required to be included.
The preferred way to achieve co-polarization is by the use of a “transreflector” 430 , 440 . The transreflector 430 , 440 consists of the wire grid 440 , with wires aligned at 45 degrees to the incident electric field vector, backed by the planar metallic mirror 430 spaced away by an odd-multiple of a quarter wavelength at the operating frequency. The wire spacing and wire diameter must both be small compared to the operating wavelength. Over a limited bandwidth determined by the spacing between the grid 440 and the reflector 430 (the higher the number of quarter wavelengths, the narrower the bandwidth), this arrangement results in a rotation of the polarization of the incident wave through 90 degrees, without significantly altering the far-field radiation pattern of the antenna system.
Two “pill-box” antennas 510 , 520 of the type shown in FIG. 3 configured 500 in an alternative manner are shown in FIG. 5 . Generally, FIG. 5 shows how two pill-box antennas can be placed with their flat sides parallel and the apertures oriented 90 degrees apart. In front of both apertures is a polarization rotating transreflector that can be exchanged with a planar metallic reflector, such that only one aperture receives polarization-rotated radiation at any time. This leads to a more compact structure than FIG. 4 that is capable of forming an image of either of two polarizations. The axes of the rotating sub-reflectors are parallel, so a simple gearing mechanism can be used to give the relative rotation rates needed for the intersection of the fan beams to perform a raster scan.
The antenna 510 has an aperture 530 oriented lengthwise in a horizontal sense, while the other antenna 520 has an aperture 540 oriented lengthwise in a vertical sense, as depicted in FIG. 5 . In front of both apertures is a polarization rotating transreflector that can be exchanged with a planar metallic reflector, such that only one aperture receives polarization-rotated radiation at any time. In FIG. 5 the horizontal aperture 530 is coupled to the observed scene via a transreflector 550 , while the vertical aperture 540 is coupled to the observed scene via a planar metallic reflector 560 . The transreflector 550 may be exchanged with a planar metallic reflector, and the planar metallic reflector 560 may be exchanged with a transreflector, as indicated by the dotted lines on the reflector 560 . An exchange may be effected by turning a polarization rotating transreflector by 180 degrees to use its back surface as a planar metallic reflector. An exchange may be effected by making the wires of a polarization rotating transreflector out of a material that has a switchable conductivity. The advantages of this configuration 500 over the configuration 400 in FIG. 4 are that the configuration 500 occupies a smaller overall volume and is capable of forming an image from either of two polarizations. The axes of the rotating sub-reflectors 320 are parallel in this configuration 500 , so a simple gearing mechanism (not shown) can be used to achieve relative rotation rates that cause the intersection 130 of the fan beams 110 , 120 to perform a raster scan of the field of view.
FIG. 6 is a block diagram illustrating an implementation of a real-time, cross-correlating, millimeter-wave imaging system 600 in accordance with a further embodiment of the invention. For purposes of illustration only, the system is shown in FIG. 6 with a tree 602 as the object of imaging in the field of view. A dual, fan-beam antenna 610 is used to scan the object 602 and respective horizontal and vertical scans 604 , 606 generated by the antenna 610 are shown. The dual fan-beam antenna 610 is of the type 400 shown in FIG. 4 . Alternatively, the dual fan-beam antenna 610 may be of the type 500 shown in FIG. 5 . The dual fan-beam antenna 610 provides respective E-plane and H-plane outputs to an imaging receiver system, similar to that shown in FIG. 2 .
The E-plane output is provided to a low noise amplifier 612 and the H-plane output is provided to a different low noise amplifier 614 . In turn, the low noise amplifiers 612 , 614 , acting as RF amplifiers, are coupled to respective mixers 620 , 622 . Further, a local oscillator 630 is coupled to both of mixers 620 and 622 . The respective outputs of mixers 620 and 622 are provided as inputs to IF amplifiers 640 , 642 . The output of the IF amplifiers 640 , 642 are provided to a cross-correlator 652 .
The output of the cross-correlator 652 is provided to a base band filter 660 . The base band filter 660 provides the output signal for the system. The output of the base band filter 660 is provided to an analogue to digital (A/D or ADC) converter 670 . The ADC 670 produces digital data from the output signal that is provided as input to a computer 680 . The computer 680 using hardware and/or software can produce a computer image 682 using the digital data from the ADC 670 . In turn, using the digital data, the computer 680 can provide scan control signals 690 (indicated by dashed lines) to the dual fan-beam antenna 610 . As shown in FIG. 6 , the scan control signals 690 are preferably provided to each of the pill-box antennas.
The embodiments of the invention have various advantages including one or more of:
Use of a “pill-box” antenna to implement a scanned-beam imaging system;
A “pill-box” antenna in which the beam is scanned in one dimension using a rotating sub-reflector;
Use of a wire-grid transreflector to achieve a dual-scanning-beam system with co-polarized far-field response;
Use of two wire-grid transreflectors, exchangeable for planar metallic reflectors, to achieve switchable polarisation of the far-field response.
Use of a mechanically scanned beam so that only a single heterodyne receiver per beam is needed.
Use of two intersecting fan beams so that each antenna is required to scan only in one direction.
Thus, a method and an apparatus for forming an image from millimeter waves, a method and an antenna for receiving millimeter wave radiation, a method and an apparatus for receiving millimeter wave radiation for generating an image, and a method and system for millimeter wave imaging have been disclosed. In the light of this disclosure, it will be apparent to those skilled in the art that modifications, substitutions and/or changes may be made without departing from the scope and spirit of the invention. | A method and apparatus are disclosed for forming an image from millimeter waves. A field of view scanned using two geometrically orthogonal, intersecting copolarized fan beams ( 110, 120 ) to receive millimeter wave radiation. The received millimeter wave radiation from said fan beams are then cross-correlated ( 250, 650 ). Also, a method and antenna ( 400, 610 ) for receiving millimeter wave radiation are disclosed. The antenna includes first and second fan beam antennas ( 410, 420 ) for receiving millimeter wave radiation and a filter ( 430, 440 ) for rotating polarization of incident millimeter wave radiation through 90 degrees received by the second fan beam antenna ( 410 ). The respective first and second beams ( 110, 120 ) intersect and are co-polarized and geometrically orthogonal to each other. Still further, a millimeter wave imaging system ( 600 ) and method are also disclosed, which utilise an antenna ( 610 ) for receiving millimeter wave radiation, process the received millimeter wave radiation from the antenna ( 610 ), and build up the image ( 682 ) using a filtered, cross-correlated signal. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a process for producing 1,1,1-trifluoroacetone that is useful as an intermediate of pharmaceuticals and agricultural chemicals, or as a reagent for introducing fluorine-containing groups.
1,1,1-trifluoroacetone is known to be obtained by various methods. It is described in J. Chem. Soc. (Lond.) 1956, 835 that 1,1,1-trifluoroacetone is synthesized by a Grignard reaction between trifluoroacetic acid and magnesium methyliodide. This Grignard reaction must be conducted in an anhydrous state. In addition, it is also described in Tetrahedron, 20, 2163 (1964) that trifluoroacetone can be synthesized by decarbonating trifluoroacetoethyl acetate in sulfuric acid. It is described in Tetrahedron Lett. Vol. 24 (No. 5), 507-510, 1983 that difluoromethylketones are obtained at considerably high yield as a result of reducing chlorodifluoroketones, which are represented by CF 2 ClC(═O)R (wherein R is a group not containing halogen) by zinc and methanol in tetrahydrofuran.
Japanese Patent Publication 2000-336057A, corresponding to Japanese Patent Application 11-147670, discloses a process for producing 1,1,1-trifluoroacetone by reacting 3,3-dichloro-1,1,1-trifluoroacetone with zinc in a solvent of a proton donor. In this process, it is necessary to have a relatively large amount of zinc.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a process for producing 1,1,1-trifluoroacetone, which is suitable for an industrial-scale production.
According to the present invention, there is provided a process for producing 1,1,1-trifluoroacetone. This process comprises conducting a hydrogenolysis of a halogenated trifluoroacetone, which is represented by the general formula (1), by a hydrogen gas in the presence of a catalyst comprising a transition metal,
where X represents a chlorine, bromine or iodine, and n represents an integer from 1 to 3.
According to the present invention, it is possible to obtain 1,1,1-trifluoroacetone with a high yield by using the above special catalyst in hydrogenolysis of the halogenated trifluoroacetone (e.g., 3,3-dichloro-1,1,1-trifluoroacetone) by a hydrogen gas.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The hydrogenolysis can be conducted by a gas phase reaction between the halogenated trifluoroacetone (gas) and a hydrogen gas using a reactor for flow method.
The halogenated trifluoroacetone used as a starting material in the process of the present invention may be a hydrate, alcohol addition product, gem-diol, acetal or hemiacetal, or their aqueous or alcohol solutions, of a halogenated trifluoroacetone represented by the general formula (1), as indicated in the following formulas, although an aqueous solution of the hydrate is preferable due to its ease of handling:
where X and n are the same as previously defined in the general formula (1), m represents an integer, R 1 represents an alkyl group, and each R 2 independently represents a hydrogen atom or alkyl group.
The halogenated trifluoroacetone can be 3-chloro-1,1,1-trifluorocetone, 3,3-dichloro-1,1,1 -trifluoroacetone, or 3,3,3-trichloro-1,1,1-trifluoroacetone. These compounds can be synthesized by known processes. For example, they can be obtained by fluorinating pentachloroacetone by hydrogen fluoride in the presence of a transition metal or the like as a catalyst. Furthermore, decarboxylation of a trifluoroacetoacetic ester is known.
As stated above, the halogenated trifluoroacetone used as a starting material in the process of the present invention may be a hydrate in which a halogenated trifluoroacetone represented by the general formula (1) has hydrated to have an arbitrary number of water molecules. In the process, it is preferable to use the halogenated trifluoroacetone in the form of an aqueous solution, since its handling is easy and thereby the reaction procedures can be simplified. The existence of water is not an obstacle to the reaction, but the existence of unnecessary water is not preferable from the viewpoint of energy consumption.
As stated above, the catalyst used in the hydrogenolysis comprises a transition metal. This transition metal is preferably a noble metal such as ruthenium, palladium, platinum, iridium, and rhodium. Further examples of the transition metal other than noble metal are nickel, copper and iron. Of these, palladium and platinum are preferable. The transition metal is preferably supported on a support such as activated carbon, alumina, silica-alumina, and silica. Of these, activated carbon is preferable. It is particularly preferable to use a catalyst containing an activated carbon supporting thereon palladium or platinum. The way of making the transition metal to be supported on the support is not particularly limited. For example, it is possible to immerse a support in a solution of a transition metal compound or to spray this solution to a support, followed by drying and then reduction with hydrogen gas. The transition metal compound may be in the form of chloride, bromide, fluoride, oxide, nitrate, sulfate or carbonate. The transition metal may be in an amount of about 0.1-10 g, preferably 0.2-5 g, per 100 ml of the support. If it is less than 0.1 g, both conversion of the halogenated trifluoroacetone and yield of 1,1,1-trifluoroacetone may become too low. An amount of greater than 5 g may not be preferable from the economical viewpoint.
The reaction temperature may be 50° C. or higher, preferably 70° C. or higher, more preferably 90° C. or higher, still more preferably 100° C. or higher, further preferably 105° C. or higher. Furthermore, the reaction temperature may be 350° C. or lower, preferably 250° C. or lower, more preferably 200° C. or lower, still more preferably 150° C. or lower, further preferably 120° C. or lower. Therefore, the reaction temperature range may be 50-350° C., preferably 70-250° C., more preferably 90-120° C. If it is lower than 50° C., both conversion of the halogenated trifluoroacetone and yield of 1,1,1-trifluoroacetone may be lowered. If it is higher than 350° C., fluorine atom hydrogenolysis and/or hydrogenation of carbonyl group may proceed. With this, yield of 1,1,1-trifluoroacetone may be lowered.
The molar ratio of hydrogen (hydrogen gas) to the halogenated trifluoroacetone may be varied depending on the number of the halogen atoms (other than fluorine) of the halogenated trifluoroacetone. This ratio may be in a range of 1.5-50, preferably 2-10, more preferably 2.5-5. If it is less than 1.5, conversion of the halogenated trifluoroacetone may not be sufficiently high. Even if it is greater than 50, conversion of the halogenated trifluoroacetone may not improve further. Furthermore, this is not preferable from the economical viewpoint, due to the necessity of recovering the unreacted hydrogen gas. It is optional to make nitrogen gas coexistent with the other reagents in the reaction system in order to adjust the reaction and to suppress the catalyst deterioration.
It is preferable that the hydrogenolysis is conducted by using a reactor made of a material lined with a lining material selected from of borosilicate glasses, tetrafluoroethylene resins, chlorotrifluoroethylene resins, vinylidene fluoride resins, perfluoroalkyl vinyl ether (PFA) resins and carbon, when water exists in the reaction system. When water does not exist in the reaction system by using a halogenated trifluoroacetone that is not hydrated, it is possible to use iron, stainless steel, nickel and Hastelloy (trade name) for the reactor in addition to the above-mentioned lining material.
The way of conducting the hydrogenolysis is not particularly limited. For example, it can be conducted by the following flow method. At first, a reactor for flow method, which is resistant against the reaction conditions of the hydrogenolysis, is charged with a transition metal supported catalyst. Then, the reactor is heated from outside, and hydrogen gas is allowed to flow through a reaction tube. When the reaction tube's inside temperature reaches a predetermined temperature, the halogenated trifluoroacetone is introduced into a vaporizer for vaporizing the same and then into the reaction tube together with the hydrogen gas. A mixture of gas and/or liquid flowing out of the reaction tube is absorbed into water. Alternatively, it is cooled down and collected in the form of liquid. It is optional to separately introduce the halogenated trifluoroacetone and water into the reaction tube.
The resulting 1,1,1-trifluoroacetone can be purified by a conventional purification method used for hydrogenolysis products obtained from fluorinated compounds. For example, a reaction product containing 1,1,1-trifluoroacetone (in the form of liquid or gas), which has flowed out of the reactor together with hydrogen chloride, is cooled down. After that, hydrogen chloride is removed from the reaction product by distillation or gas-liquid phase separation. Then, the remaining acid component is removed from the product with a basic substance or the like. After that, the target product, 1,1,1-trifluoroacetone of high purity, is obtained by rectification.
The following nonlimitative catalyst preparations are illustrative of the present invention.
Catalyst Preparation 1
At first, a 200-ml eggplant-type flask was charged with 35 g of a granular activated carbon (a coconut husk carbon of a particle diameter of 4-6 mm) made by Takeda Chemical Industries, Ltd. having a trade name of GRANULAR SHIRO SAGI G2X-4/6. Then, about 120 ml of an about 20% nitric acid aqueous solution was added to the flask. After that, the flask was allowed to stand still for about 3 hr, thereby to conduct a nitric acid treatment of the activated carbon. Separately, 0.83 g of palladium (II) chloride, PdCl 2 , was dissolved in 5 g of a 24% hydrochloric acid, to prepare a palladium chloride solution. This palladium chloride solution was poured on the activated carbon contained in the flask. Then, this flask was allowed to stand still for 2 days. Then, the activated carbon, impregnated with the palladium chloride solution, was subjected to vacuum drying with an evaporator by increasing the bath temperature to 150° C. Then, the dried activated carbon was put into a reaction tube having a diameter of 25 mm, an axial length of 400 mm, and a capacity of about 200 ml. Then, while nitrogen was allowed to flow through the reaction tube at a rate of 200-300 ml/min, the reaction tube was heated from 150° C. to 300° C. by increasing the set temperature of the reaction tube stepwise by 50° C., in order to bake the activated carbon. The reaction tube temperature was maintained at 300° C. for 1 hr in order to further bake the same, and then the set temperature was decreased to 150° C. After that, while nitrogen and hydrogen were allowed to flow therethrough at respective rates of 50 ml/min and 50 ml/min, the reaction tube temperature was increased again to 300° C. by increasing its set temperature stepwise by 30° C. for conducting reduction. With this, there was prepared a first catalyst having an activated carbon carrying thereon 0.5% of palladium, based on the weight of the activated carbon.
Catalyst Preparation 2
At first, a 200-ml eggplant-type flask was charged with 35 g of the same granular activated carbon as that of Catalyst Preparation 1. Separately, 0.46 g of hexachloroplatinic (IV) acid hexahydrate, H 2 PtCl 6 .6H 2 O, was dissolved in 100 ml of 30% hydrochloric acid, to prepare a hexachloroplatinic acid solution. This solution was poured on the activated carbon contained in the flask. Then, this flask was allowed to stand still for 2 days. Then, the same procedures as those of Catalyst Preparation 1 were conducted, thereby preparing a second catalyst having an activated carbon carrying thereon 0.5% of platinum, based on the weight of the activated carbon.
The following nonlimitative examples are illustrative of the present invention.
EXAMPLE 1
At first, a tubular reactor made of glass was charged with 50 ml of the first catalyst (0.5% Pd on activated carbon) obtained in Catalyst Preparation 1. Then, the reactor was heated to 110° C., while hydrogen gas was allowed to flow through the reactor at a rate of 80 ml/min by downflow. A 3,3-dichloro-1,1,1-trifluoroacetone aqueous solution (water content: 25%) was introduced into a vaporizer at a rate of 0.2 g/min, thereby vaporizing this solution. The resulting vapor was mixed with hydrogen, and the mixture was introduced into the reactor after the reactor's inside temperature became stable. Then, the reaction was conducted for 5 hr. During the reaction, liquid and gas flowing out of the reactor were introduced into 10 g of water cooled at 0° C., thereby collecting them. The collected product in an amount of 47.2 g was found by Karl Fischer's method to contain 52.4% of water. Furthermore, it was found by gas chromatography to contain organic components of 98.4% of 1,1,1-trifluoroacetone, 0.1% of 1,1-difluoroacetone, 0.5% of 1-fluoroacetone, 0.4% of acetone and others. These percentages are areal percentages in chromatogram.
EXAMPLE 2
Example 1 was repeated except in that the flow rate of hydrogen gas was 65 ml/min, thereby collecting 53.8 g of a product. The collected product was found by Karl Fischer's method to contain 42.3% of water. Furthermore, it was found by gas chromatography to contain organic components of 97.7% of 1,1,1-trifluoroacetone, 0.4% of 1,1-difluoroacetone, 1.3% of 1-fluoroacetone, 0.3% of acetone and others.
EXAMPLE 3
Example 1 was repeated except in that the flow rate of hydrogen gas was 100 ml/min, thereby collecting 49.1 g of a product. The collected product was found by Karl Fischer's method to contain 52.8% of water. Furthermore, it was found by gas chromatography to contain organic components of 97.5% of 1,1,1-trifluoroacetone, 1.1% of 1,1-difluoroacetone, 0.5% of 1-fluoroacetone, 0.4% of acetone and others.
EXAMPLE 4
At first, a tubular reactor made of glass was charged with 50 ml of the first catalyst (0.5% Pd on activated carbon) obtained in Catalyst Preparation 1. Then, the reactor was heated to 110° C., while hydrogen gas was allowed to flow through the reactor at a rate of 80 ml/min by downflow. An aqueous solution (water content: 15%) of a raw material mixture containing 8.2% of 3-chloro-1,1,1-trifluoroacetone, 88.8% of 3,3-dichloro-1,1,1-trifluoroacetone, and 2.4% of 3,3,3-trichloro-1,1,1-trifluoroacetone was introduced into a vaporizer at a rate of 0.2 g/min, thereby vaporizing this solution. The resulting vapor was mixed with hydrogen, and the mixture was introduced into the reactor after the reactor's inside temperature became stable. Then, the reaction was conducted for 5 hr. During the reaction, liquid and gas flowing out of the reactor were introduced into 20 g of water cooled at 0° C., thereby collecting them. The collected product in an amount of 56.9 g was found by Karl Fischer's method to contain 45.6% of water. Furthermore, it was found by gas chromatography to contain organic components of 97.9% of 1,1,1-trifluoroacetone, 0.4% of 1,1-difluoroacetone, 0.5% of 1-fluoroacetone, 0.6% of acetone and others.
EXAMPLE 5
Example 1 was repeated except in that the first catalyst was replaced with the second catalyst (0.5% Pt on activated carbon) obtained in Catalyst Preparation 2 and that the water cooled at 0° C. was in an amount of 14 g, thereby collecting 64.2 g of a product. The collected product was found by Karl Fischer's method to contain 46.3% of water. Furthermore, it was found by gas chromatography to contain organic components of 99.0% of 1,1,1-trifluoroacetone, 0.1% of 1,1-difluoroacetone, 0.1% of 1-fluoroacetone, 0.3% of acetone and others.
EXAMPLE 6
At first, a tubular reactor made of glass was charged with 500 ml of the first catalyst (0.5% Pd on activated carbon) obtained in Catalyst Preparation 1. Then, the reactor was heated to 95° C., while hydrogen gas was allowed to flow through the reactor at a rate of 500 ml/min by downflow. A raw material mixture containing 9.6% of 3-chloro-1,1,1-trifluoroacetone, 84.0% of 3,3-dichloro-1,1,1-trifluoroacetone, and 3.9% of 3,3,3-trichloro-1,1,1-trifluoroacetone was introduced into a vaporizer at a rate of 1.5 g/min, thereby vaporizing the mixture. The resulting vapor was mixed with hydrogen, and the mixture was introduced into the reactor after the reactor's inside temperature became stable. Then, the reaction was conducted for 6 hr. During the reaction, liquid and gas flowing out of the reactor were introduced into 500 g of water cooled at 0° C., thereby collecting them. The collected product in an amount of 909 g was found by Karl Fischer's method to contain 55.0% of water. Furthermore, it was found by gas chromatography to contain organic components of 98.1% of 1,1,1-trifluoroacetone, 0.7% of 1,1-difluoroacetone, and others.
EXAMPLE 7
At first, a tubular reactor made of glass was charged with 10 ml of the second catalyst (0.5% Pt on activated carbon) obtained in Catalyst Preparation 2. Then, the reactor was heated to 110° C., while hydrogen gas was allowed to flow through the reactor at a rate of 80 ml/min by downflow. An aqueous solution (water content: 15%) of a raw material mixture containing 8.2% of 3-chloro-1,1,1-trifluoroacetone, 88.8% of 3,3-dichloro-1,1,1-trifluoroacetone, and 2.4% of 3,3,3-trichloro-1,1,1-trifluoroacetone was introduced into a vaporizer at a rate of 0.16 g/min, thereby vaporizing the mixture. The resulting vapor was mixed with hydrogen, and the mixture was introduced into the reactor after the reactor's inside temperature became stable. Then, the reaction was conducted for 1 hr. During the reaction, liquid and gas flowing out of the reactor were introduced into 10 g of water cooled at 0° C., thereby collecting them. The collected product in an amount of 16.1 g was found by Karl Fischer's method to contain 61.2% of water. Furthermore, it was found by gas chromatography to contain organic components of 96.7% of 1,1,1-trifluoroacetone, 1.5% of 3-chloro-1,1,1-trifluoroacetone, and others.
EXAMPLE 8
At first, a tubular reactor made of glass was charged with 50 ml of the second catalyst (0.5% Pt on activated carbon) obtained in Catalyst Preparation 2. Then, the reactor was heated to 110° C., while hydrogen gas was allowed to flow through the reactor at a rate of 80 ml/min by downflow. 3,3-dichloro-1,1,1-trifluoroacetone was introduced into a vaporizer at a rate of 0.18 g/min, thereby vaporizing this compound. The resulting vapor was mixed with hydrogen, and the mixture was introduced into the reactor after the reactor's inside temperature became stable. Then, the reaction was conducted for 1 hr. During the reaction, liquid and gas flowing out of the reactor were introduced into 10 g of water cooled at 0° C., thereby collecting them. The collected product in an amount of 17.4 g was found by Karl Fischer's method to contain 55.9% of water. Furthermore, it was found by gas chromatography to contain organic components of 95.4% of 1,1,1-trifluoroacetone, 3.0% of 3-chloro-1,1,1-trifluoroacetone, and others.
The entire disclosure of each of Japanese Patent Applications No. 2000-043869 filed on Feb. 22, 2000 and No. 2000-309649 filed on Oct. 10, 2000, including specification, claims and summary, is incorporated herein by reference in its entirety. | A process for producing 1,1,1-trifluoroacetone includes the step of conducting a hydrogenolysis of a halogenated trifluoroacetone, which is represented by the general formula (1), by a hydrogen gas in the presence of a catalyst containing a transition metal,
where X represents a chlorine, bromine or iodine, and n represents an integer from 1 to 3. It is possible to obtain 1,1,1-trifluoroacetone with a high yield by using the special catalyst. | 2 |
FIELD OF THE INVENTION
The present invention relates generally to an interlocking masonry unit. One embodiment of the invention comprises an interlocking masonry unit for use in mortared or similar wall construction which reduces the need for constant measurements and alignment, resulting in a wall with increased strength.
BACKGROUND OF THE INVENTION
The creation of buildings by utilizing walls made of concrete or similar stonework is a popular method of construction. Many traditional masonry walls are created using masonry units commonly referred to as cinder blocks. A cinder block is a masonry unit in the shape of a rectangular prism with two vertical chambers. A wall is constructed by creating successive rows of cinder blocks. Often each row of cinder blocks is offset by half a block from the previous row to increase stability. Some form of mortar or similar bonding material is placed between each row of blocks to bond the blocks into a solid structure.
One of the primary difficulties of creating cinder block walls is that constant measurements and adjustments must be made as the construction process is undertaken. Bonding material must be laboriously applied between each new block and all adjacent blocks. The craftsman must constantly adjust the wall as each block is placed to ensure that each row is level and straight. Failure to make constant adjustments often results in a wall that is uneven, non-level, angular, or otherwise unstable and not ascetically pleasing. This process is both time consuming for the craftsman and subject to significant human error. The resulting wall is also only as strong as the weakest bonded joint between two adjacent blocks.
Therefore, what is needed is an interlocking masonry unit. The interlocking masonry unit should connect with adjacent masonry units in a standard way that reduces the need for precision and skill. The interlocking masonry unit should also be designed to accept bonding material that is poured into the wall after each course of the wall is completed in order to reduce overall construction time. The interlocking masonry unit should also be designed to allow the bonding material to pour inside of and between the masonry units in both the horizontal and vertical dimensions to create a strong wall that is bonded together internally in all directions forming a matrix. Furthermore, other desirable features and characteristics of the present invention will become apparent when this background of the invention is read in conjunction with the subsequent detailed description of the invention, appended claims, and the accompanying drawings.
SUMMARY OF THE INVENTION
The present invention provides an interlocking masonry unit that advantageously overcomes the aforementioned deficiencies. Each interlocking masonry unit may be placed in connection with an adjacent masonry unit in a standard manner that reduces the need for constant measurement and adjustment for alignment purposes. Additionally, bonding material may be poured as the wall is created so that the need for adjustment is clear to the craftsman before the units become permanently bonded together. The interlocking masonry unit also provides both horizontal and vertical cavities to accept bonding material in order to create a matrix of bonding material to increase the overall strength of the wall.
The present invention is described more fully hereinafter with reference to the accompanying drawings, which are intended to be read in conjunction with both this summary, the detailed description, and any preferred and/or particular embodiments specifically discussed. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of illustration only and not limitation.
BRIEF DESCRIPTION OF THE DRAWINGS
The drawings contained herein illustrate an embodiment of the invention. The invention is not limited to the particular embodiment shown in the drawings. The embodiment shown is an example, and the invention is capable of many variations of said embodiment in the drawings;
FIG. 1 illustrates a perspective view of the concave upper surface and a side surface of an interlocking masonry unit according to an embodiment of the present invention;
FIG. 2 illustrates a perspective view of the concave lower surface of the interlocking masonry unit of FIG. 1 ;
FIG. 3 illustrates an end plan view of two vertically adjacent interlocking masonry units according to an embodiment of the present invention. The masonry unit may be offset by one half block as desired to increase the strength and stability of a stack or wall;
FIG. 4 illustrates a top plan view of a complete and a partial horizontally adjacent interlocking masonry unit according to an embodiment of the present invention; and
FIG. 5 illustrates perspective view of a wall comprising multiple masonry units according to an embodiment of the invention. FIG. 5 also shows the use and placement of rebar reinforcement in the wall system for added strength.
The first digit of each reference numeral in the above figures indicates the figure in which an element or feature is most prominently shown. The second digit indicates related elements or features, and a final letter (when used) indicates a sub-portion of an element or feature.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 illustrate a masonry unit according to a preferred embodiment of the invention, and is shown generally at reference numeral 100 . FIG. 1 illustrates a perspective view of the concave upper surface and a side surface of the masonry unit 100 . The masonry unit 100 comprises a generally rectangular prism shape with a concave upper surface 10 as shown in FIG. 1 ., a concave lower surface 20 as shown in FIG. 2 , two side surfaces 11 as shown in FIG. 1 , and two end surfaces 30 as shown in FIG. 3 . One skilled in the art will recognize that any three dimensional object with a rectangular prism shape generally comprises six surfaces. The surface names, as used throughout the application, are chosen for purposes of designation rather than functionality and should not be considered limiting. The purpose of the concave shape of the upper surface 10 and lower surface 20 is discussed below in reference to FIG. 3 .
The masonry unit 100 comprises one or more central vertical cavities 12 , as shown in FIGS. 1 and 2 . The central vertical cavities 12 should extend between the lower surface 20 and the upper surface 10 of the present invention and should be capable of accepting bonding material. In the preferred embodiment, two central vertical cavities 12 are employed, and each of the central vertical cavities 12 comprise the same shape mirrored about an axis passing through the center of the unit and perpendicular to the side surfaces 11 . In the preferred embodiment, the central vertical cavities 12 comprise a rounded triangular shape, however, many central vertical cavity 12 shapes could be substituted. When two or more interlocking masonry units 100 , 100 ′ are placed in a vertically adjacent position relative to one another, also referred to hereinafter as a stack as shown in FIG. 3 ., the central vertical cavities 12 of each masonry unit should be generally aligned with the central vertical cavities 12 of the other units. So long as the central vertical cavities 12 of each unit are generally the same shape and are generally aligned, any bonding material poured into a central vertical cavity 12 of the uppermost unit 100 will also pour through the corresponding central vertical cavity 12 of each unit below in the stack due to the force of gravity. This allows a craftsman to quickly create a wall by stacking the masonry units, one on top of one another, and then pouring bonding material through each vertical cavity as the wall is completed and judged to be in the proper shape and alignment. In the preferred embodiment, the central vertical cavities 12 are surrounded by a sloped edge 12 A as shown in FIGS. 1 and 2 , preferably at or near a forty five degree angle from the horizontal plane, to act as a funnel creating a larger void between the upper and lower masonry units, thus assisting the bonding material in its movement into the lower portions of the stack.
As shown in FIG. 2 ., the masonry unit 100 comprises a plurality of support members 21 projecting vertically out from the lower surface 20 of the masonry unit. Preferably, eight support members 21 are employed, however, a greater or fewer number of support members 21 can be employed. As shown in FIG. 1 , the masonry unit comprises a plurality of receiving port depressions 13 each projecting vertically into the upper surface 10 of the masonry unit 100 . Preferably, eight receiving port depressions 13 are employed. Each receiving port depression 13 can be shaped and positioned to be capable of receiving a corresponding support member 21 from another masonry unit. As such, multiple masonry units can be stacked one on top of another. When creating the stack, the support members 21 of the upper masonry unit are received by the receiving port depressions 13 on the upper surface 10 of the masonry unit immediately below it. In this manner, each masonry unit is effectively interlocked into position relative to the masonry units below. Absent manufacturing defects or variable terrain, the resulting stack is straight and level without requiring the user to undertake efforts to adjust or otherwise level the stack. As variable terrain and manufacturing irregularities are possible, the user can rapidly create a stack and quickly observe and correct any alignment concerns prior to pouring bonding material through the vertical cavities. Preferably, each receiving port depression 13 is larger than the support members 21 to allow the user to make minor adjustments to the wall as it is completed.
In a preferred embodiment, each end surface 30 as shown in FIG. 3 further comprises two end projections 14 . As shown in FIG. 4 ., the end projections 14 can be shaped and positioned so that when two interlocking masonry units are placed in a horizontally adjacent configuration, an intermediate vertical cavity 40 , as shown in FIG. 4 , extending between the masonry units is created. When the masonry units are stacked in rows, the intermediate vertical cavity 40 can accept bonding material. So long as the masonry units are not offset, the bonding material can be capable of poured through an intermediate vertical cavity 40 , as shown in FIG. 5 , that is placed in a higher position in the stack to intermediate vertical cavities 40 that are placed lower in the stack due to the force of gravity. However, even in an offset configuration, as can be seen in FIG. 5 , the bonding material can be poured into each intermediate vertical cavity 40 from the central cavity 12 above it, due to the shape and positioning of the central cavities 12 . Each of the end projections 14 include a sloped edge 14 A, as shown in FIG. 1 , preferably at or near a forty five degree angle from the horizontal plane, to act as a funnel and assist the bonding material in its movement into the lower portions of the stack. The end projections 14 should be omitted on the end surface 30 of any masonry unit that is to be used at the corner of a wall. It should also be noted that, in the preferred embodiment, portions of each block end come in contact with an adjacent block. This allows for proper alignment and spacing which maximizes amount of bonding material to attach between each unit to strengthen the bond. It should also be noted that, preferably, the shape of the intermediate vertical cavity 40 is irregular. This configuration increases the surface area available for the bonding material to attach to for a stronger bond. This configuration also ensures that the end projections 14 each attach around the cured bonding material contained in the vertical cavity 40 , which further reduces the possibility of a breach in the wall, even if the bonding material should become separated from the associated masonry unit.
As shown in FIGS. 1 and 4 , the masonry unit 100 can include one or more vertical depressions 15 in one or both of the side surfaces 11 . Preferably, each vertical depression 15 has a width greater than one-half inch and less than two inches. Preferably, each vertical depression 15 projects into the masonry unit 100 between one-half inch and two and a half inches, and each vertical depression 15 also preferably extends down the entire side surface 11 of the masonry unit. When crafted to these preferred dimensions, each vertical depression 15 is capable of accepting a wall stud. The vertical depressions can further comprise a plurality of stud support notches 17 , as shown in FIGS. 1 and 2 . Each of the stud support notches 17 can be capable of accepting a peg to hold a wall stud in place. When a wall is finalized, a wall stud can be inserted into the vertical depression 15 and secured in position by means of plurality of pegs or similar items hammered or screwed into the stud support notches 17 . In an alternate embodiment, no support notches 17 are provided and the wall studs can be secured by a toggle bolt or other securing means. This allows the user to create a wooden wall, capable of accepting drywall or similar finishing material without the structure that is typically associated with a standard wall. Referring to FIG. 4 , the end projections 14 may also be shaped and positioned to create a vertical depression 15 in the side surface 11 between two horizontally adjacent interlocking masonry units 100 , 100 ″ that are capable of accepting a wall stud. This ensures that in the case of stacked rows where one or more rows are offset by half a masonry unit from one another, the vertical depression 15 in the side surface 11 of a masonry unit lines up with the vertical depression 15 created between two horizontally adjacent masonry units on a different row. This allows a wall stud to be accepted into all of the rows at once. Preferably, the vertical depressions 15 are positioned to create a distance of eight inches between the center of each wall stud and the center of the horizontally adjacent wall studs, once said wall studs are accepted. This allows the user to easily attach standard building materials to the wall studs.
FIG. 3 illustrates an end plan view of two vertically adjacent interlocking masonry units 100 , 100 ′. In the preferred embodiment, the concave upper surface 10 of the lower masonry unit and the concave lower surface 20 of the upper masonry are shaped to create a horizontal cavity 31 which extends between the two masonry units. The horizontal cavity 31 is capable of accepting bonding material poured from upper rows through the vertical cavities and channeling the bonding material horizontally between two rows in the wall. The channel created by the horizontal cavity 31 and the vertical cavities 12 create a matrix of cured bonding material which increases the overall strength of the wall in relation to standard cinderblock walls. The channel created by the horizontal cavity 31 also allows bonding material to pour into the intermediate vertical cavities 40 in cases where the rows of the wall are offset. An end surface 30 of any masonry unit that is to be used at the corner of a wall can include an additional projection on the upper surface 10 and the lower surface 20 capable of closing the horizontal cavity 31 and vertical cavity 40 preventing any bonding material from escaping from the channel created by the horizontal cavities 31 of the masonry units 100 , 100 ′ in the wall.
In a preferred embodiment, the upper surface 10 further comprises a plurality of upper projections 32 as shown in FIG. 3 . The upper projections 32 can accept one or more reinforcing elements 16 , as shown in FIG. 1 and FIG. 5 , such as concrete reinforcing bar, also known as rebar, and/or similar items. The vertical channels created by the central vertical cavities 12 are also capable of accepting one or more reinforcing elements 16 . The presence of the reinforcing elements 16 increases the overall structural integrity of the resultant wall after the bonding material is poured inside and allowed to cure. The matrix of vertical and horizontal channels associated with a wall constructed with the interlocking masonry units, as described herein, along with associated reinforcing elements 16 , creates a structural integrity that is significantly increased over a standard cinder block wall.
In a preferred embodiment, the masonry unit 100 has sharp edges 35 at the outer perimeter at the top and bottom and on both ends of the masonry unit 100 , as shown in FIGS. 1 and 2 . The sharp edges 35 form one-half of a mortar seam. The edge 35 slopes inward, toward the center of the masonry unit 100 to form a V or pinch point 45 , as shown in FIG. 4 , between masonry units 100 , 100 ″, when the units are stacked end to end and/or one on top of the other. This pinch point 45 preferably should be approximately one-sixteenth to one eighth inch in width. This pinch point 45 is shaped similar to a funnel to guide the bonding material from a wide area or space to the narrow space where the grit, sand and gravel of the bonding material fill in, forcing out air from the masonry units and sealing the space, bonding the units together. In addition, the masonry unit 100 can have sloped, concave outer edges 34 , as shown in FIG. 3 .
In a preferred embodiment, each end projection 14 further comprises a bumper projection 33 . As can be seen in FIG. 4 , each bumper projection 33 is shaped and positioned to come in contact with a bumper projection 33 of an equivalent horizontally adjacent interlocking masonry unit when the masonry units are being placed by the user. In this manner, the user may place each masonry unit, verify the bumper projections 33 of each masonry unit are properly touching, and thereby verify that the row of masonry units being created is level and aligned. The bumper projections 33 hold the blocks of the masonry units apart a pre-determined distance, as shown at reference numeral 45 in FIG. 4 . Preferably, the bumper projections 33 create a space 45 of approximately one-sixteenth to one-eighth inch wide. This space 45 lets the air out when the masonry units are being filled with bonding material. The grit, rock and sand that is part of the bonding material fills the internal block voids are stopped from exiting at this point
FIG. 5 illustrates perspective view of a wall comprising multiple masonry units according to a preferred embodiment of the invention. A method of assembling a wall comprising interlocking masonry units as depicted in FIG. 5 is now more fully described. A row of interlocking masonry units can be created by placing a plurality of interlocking masonry units on a prepared surface in a manner that causes the end surface 30 of each masonry unit to come in contact with an end surface 30 of one or more adjacent masonry units. Subsequent rows of interlocking masonry units can be positioned on top of the previously created row of interlocking masonry units by placing the support members 21 of the masonry units in the subsequent row into the receiving port depressions 13 of the previously placed row. This process can be repeated until a wall or structure of the desired height is created. Reinforcing elements 16 can be placed into the horizontal cavities 31 between each row. Depending on the embodiment, the user may shift each subsequent row by half of the length of a masonry unit in the horizontal axis from the previously placed row to increase the stability of the resultant wall. The reinforcing elements 16 can be placed in the horizontal cavities 31 prior to placing any associated corner units. Reinforcing elements 16 should also be placed into the central vertical cavities 12 and 40 of each masonry unit for greater structural integrity. Bonding material can be poured into the vertical cavities and allowed to spread and seep into the horizontal cavities to create a matrix of bonding material throughout the cavities of the wall. A mechanical means may be employed to vibrate and to assist the bonding material in its spread throughout the matrix of cavities in the structure. The bonding material should then be allowed to cure in the wall. In an alternate embodiment, bonding material can be poured into the cavities after each row is positioned.
While the present invention has been described above in terms of specific embodiments, it is to be understood that the invention is not limited to these disclosed embodiments. Many modifications and other embodiments of the invention will come to mind of those skilled in the art to which this invention pertains, and which are intended to be and are covered by both this disclosure and the appended claims. The foregoing description of the preferred embodiment of the invention and the best mode for practicing the invention are provided for the purpose of illustration only and not for the purpose of limitation—the invention being defined by the following claims and equivalents thereof. | A multi-purpose interlocking masonry unit includes support members extending from its lower surface and port depressions formed in its upper surface. Each masonry unit can be placed on top of a previously placed masonry unit. The interlocking masonry unit allows for the rapid creation of a wall that is substantially straight and aligned while minimizing the need to perform precise measurements and make alignment adjustments during the creation process. Bonding material can be poured through the resultant wall ports, creating a matrix pattern of bonding material throughout the wall, which results in a stronger more durable construction. | 4 |
FIELD OF THE INVENTION
The present invention relates generally to semiconductor device fabrication and more particularly to the formation of dummy features and inductors in semiconductor device fabrication.
BACKGROUND OF THE INVENTION
In a conventional semiconductor chip, the presence of dummy features often has a detrimental impact on the operation of an inductor of the semiconductor chip. Therefore, there is a need for a structure for the dummy features and the inductor (and a method for forming the same) in which the detrimental impact of the dummy features on the operation of the inductor is minimized.
SUMMARY OF THE INVENTION
The present invention provides a structure, comprising (a) a substrate which includes a top substrate surface which defines a reference direction perpendicular to the top substrate surface; (b) N semiconductor regions on the substrate, N being a positive integer, wherein the N semiconductor regions comprise dopants; (c) P semiconductor regions on the substrate, P being a positive integer, wherein the P semiconductor regions do not comprise dopants; and (d) M interconnect layers on top of the substrate, the N semiconductor regions, and the P semiconductor regions, M being a positive integer, wherein the M interconnect layers include an inductor, wherein the N semiconductor regions do not overlap the inductor in the reference direction, wherein the P semiconductor regions overlap the inductor in the reference direction, and wherein a plane perpendicular to the reference direction and intersecting a semiconductor region of the N semiconductor regions intersects a semiconductor region of the P semiconductor regions.
The present invention provides a structure of dummy features and inductors (and a method for forming the same) in which the detrimental impacts of the dummy features on the yield of the die containing the features and to the operation of the inductor are minimized.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1R illustrate a fabrication process for forming a semiconductor structure, in accordance with embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1A-1Q show cross-section views used to illustrate a fabrication process for forming a semiconductor structure 100 , in accordance with embodiments of the present invention. More specifically, with reference to FIG. 1A , the fabrication process starts with an SOI (Silicon On Insulator) substrate 110 + 120 + 130 . The SOI substrate 110 + 120 + 130 comprises a silicon layer 110 , a silicon dioxide layer 120 on top of the silicon layer 110 , and a silicon layer 130 on top of the silicon dioxide layer 120 . The SOI substrate 110 + 120 + 130 can be formed by a conventional method.
Next, with reference to FIG. 1B , in one embodiment, shallow trench isolation (STI) regions 122 are formed in the silicon layer 130 resulting in silicon regions 130 a, 130 b, and 130 c. The STI regions 122 can comprise silicon dioxide. The STI regions 122 can be formed by a conventional method. In one embodiment, the silicon regions 130 a and 130 c are actual active silicon regions on which transistors will later be formed, whereas the silicon region 130 b is a dummy active silicon region to provide a uniform pattern density of silicon regions across the semiconductor structure 100 . It should be noted that no transistor will be formed on the dummy active silicon region 130 b.
Next, with reference to FIG. 1C , in one embodiment, a gate dielectric layer 140 is formed on top of the semiconductor structure 100 of FIG. 1B . The gate dielectric layer 140 can comprise silicon dioxide. The gate dielectric layer 140 can be formed by thermal oxidation, nitridation, or CVD (Chemical Vapor Deposition), atomic layer deposition (for high-k dielectrics) or other known means.
Next, with reference to FIG. 1D , in one embodiment, a gate electrode layer 150 is formed on top of the gate dielectric layer 140 . The gate electrode layer 150 can comprise poly-silicon, or a suitable metal, or metal/polysilicon stack. The gate electrode layer 150 can be formed by CVD, sputtering, or other means of deposition.
Next, in one embodiment, the gate dielectric layer 140 and the gate electrode layer 150 are patterned resulting in (i) gate dielectric regions 140 a, 140 b, and 140 c and (ii) gate electrode regions 150 a, 150 b, and 150 c, respectively, as shown in FIG. 1E . More specifically, the gate dielectric layer 140 and the gate electrode layer 150 can be patterned using lithographic and etching processes. In one embodiment, the patterning of the gate electrode layer 150 ( FIG. 1D ) described above results in not only the gate electrode regions 150 a, 150 b, and 150 c ( FIG. 1E ) but also resistor regions (not shown) which can be used as resistors in semiconductor structure 100 . In one embodiment, with reference to FIG. 1E , the actual active silicon region 130 a and the gate electrode region 150 a (also called an actual gate electrode region) are later used to form a PFET (p-channel field effect transistor), whereas the actual active silicon region 130 c and the gate electrode region 150 c (also called an actual gate electrode region) are later used to form an NFET (n-channel field effect transistor). In one embodiment, the gate electrode region 150 b is used as a dummy gate electrode region to provide a uniform pattern density of gate electrode regions across the semiconductor structure 100 . It should be noted that the dummy gate electrode region 150 b will not be used to form any transistor. It should be noted that the locations of the dummy active silicon region 130 b and the dummy gate electrode region 150 b are independent from each other. It just happens that, in FIG. 1E , the dummy gate electrode region 150 b overlaps the dummy active silicon region 130 b in the vertical direction (i.e., the direction which is perpendicular to a top surface 131 of silicon layer 130 of FIG. 1A ).
Next, with reference to FIG. 1F , in one embodiment, a photoresist layer 160 is formed on top of the gate electrode regions 150 b and 150 c and the silicon regions 130 b and 130 c such that the actual active silicon region 130 a and the actual gate electrode region 150 a are exposed to the surrounding ambient. The photoresist layer 160 can be formed by a conventional lithographic process.
Next, in one embodiment, halo regions 134 a 1 and 134 a 2 and extension regions 132 a 1 and 132 a 2 are formed in the actual active silicon region 130 a. More specifically, the halo regions 134 a 1 and 134 a 2 and the extension regions 132 a 1 and 132 a 2 can be formed by implanting ions (p-type dopants for extension regions 132 a 1 and 132 a 2 and n-type dopants for halo regions 134 a 1 and 134 a 2 ) in the actual active silicon region 130 a using the photoresist layer 160 as a blocking mask.
Next, in one embodiment, the photoresist layer 160 is removed resulting in the semiconductor structure 100 of FIG. 1 G. The photoresist layer 160 can be removed by wet etching.
Next, with reference to FIG. 1H , in one embodiment, a photoresist layer 170 is formed on top of the gate electrode regions 150 b and 150 a and the silicon regions 130 b and 130 a such that the actual active silicon region 130 c and the actual gate electrode region 150 c are exposed to the surrounding ambient. The photoresist layer 170 can be formed by a conventional lithographic process.
Next, in one embodiment, halo regions 134 c 1 and 134 c 2 and extension regions 132 c 1 and 132 c 2 are formed in the actual active silicon region 130 c. More specifically, the halo regions 134 c 1 and 134 c 2 and the extension regions 132 c 1 and 132 c 2 can be formed by implanting ions (n-type dopants for extension regions 132 c 1 and 132 c 2 and p-type dopants for halo regions 134 c 1 and 134 c 2 ) in the actual active silicon region 130 c using the photoresist layer 170 as a blocking mask.
Next, in one embodiment, the photoresist layer 170 is removed resulting in the semiconductor structure 100 of FIG. 1I . The photoresist layer 170 can be removed by plasma etching.
Next, with reference to FIG. 1J , in one embodiment, spacer regions 180 a 1 , 180 a 2 , 180 b 1 , 180 b 2 , 180 c 1 , and 180 c 2 are formed on side walls of the gate electrode regions 150 a, 150 b, and 150 c. The spacer regions 180 a 1 , 180 a 2 , 180 b 1 , 180 b 2 , 180 c 1 , and 180 c 2 can comprise silicon nitride. The spacer regions 180 a 1 , 180 a 2 , 180 b 1 , 180 b 2 , 180 c 1 , and 180 c 2 can be formed by (i) depositing a spacer layer (not shown) on top of the semiconductor structure 100 of FIG. 1I and then (ii) anisotropically (vertically) etching the spacer layer resulting in the spacer regions 180 a 1 , 180 a 2 , 180 b 1 , 180 b 2 , 180 c 1 , and 180 c 2 .
Next, with reference to FIG. 1K , in one embodiment, a photoresist layer 190 is formed on top of the silicon regions 130 b and 130 c and the gate electrode regions 150 b and 150 c such that the actual active silicon region 130 a and the actual gate electrode region 150 a are exposed to the surrounding ambient. The photoresist layer 190 can be formed by a conventional lithographic process.
Next, in one embodiment, source/drain regions 136 a 1 and 136 a 2 are formed in the actual active silicon region 130 a. More specifically, the source/drain regions 136 a 1 and 136 a 2 can be formed by implanting ions (p-type dopants such as boron ions) in the actual active silicon region 130 a using the photoresist layer 190 as a blocking mask.
Next, in one embodiment, the photoresist layer 190 is removed resulting in the semiconductor structure 100 of FIG. 1L . The photoresist layer 190 can be removed by wet etching.
Next, with reference to FIG. 1M , in one embodiment, a photoresist layer 192 is formed on top of the silicon regions 130 b and 130 a and the gate electrode regions 150 b and 150 a such that the actual active silicon region 130 c and the actual gate electrode region 150 c are exposed to the surrounding ambient. The photoresist layer 192 can be formed by a conventional lithographic process.
Next, in one embodiment, source/drain regions 136 c 1 and 136 c 2 are formed in the actual active silicon region 130 c. More specifically, the source/drain regions 136 c l and 136 c 2 can be formed by implanting ions (n-type dopants such as phosphorous ions) in the actual active silicon region 130 c using the photoresist layer 192 as a blocking mask.
Next, in one embodiment, the photoresist layer 192 is removed resulting in the semiconductor structure 100 of FIG. 1N . The photoresist layer 192 can be removed by wet etching. It should be noted that because of the photoresist layers 160 ( FIG. 1F ), 170 ( FIG. 1H ), 190 ( FIG. 1K ), and 192 ( FIG. 1M ), the dummy active silicon region 130 b and the dummy gate electrode region 150 b are protected from ion bombardment that formed halo regions, extension regions, and source/drain regions of the PFET and the NFET mentioned above.
Next, with reference to FIG. 1O , in one embodiment, a dielectric cap region 194 is formed on top of the dummy active silicon region 130 b and the dummy gate electrode region 150 b. More specifically, the dielectric cap region 194 can comprise a dielectric material such as silicon nitride. The dielectric cap region 194 can be formed by (i) depositing a dielectric cap layer (not shown) on top of the semiconductor structure 100 of FIG. 1N and then (ii) patterning the dielectric cap layer resulting in the dielectric cap region 194 . In one embodiment, said patterning the dielectric cap layer results in not only the dielectric cap region 194 but also other dielectric cap regions covering resistor regions (which are described above with reference to FIG. 1E ) such that no surface of the resistor regions is exposed to the surrounding ambient. Because of the dielectric cap region 194 , it is more difficult for the dummy active silicon region 130 b and the dummy gate electrode region 150 b to fall off the semiconductor structure 100 under subsequent etching processes. In an alternative embodiment, the dielectric cap region 194 can be formed earlier. In one embodiment, the dielectric cap region 194 can be formed on top of the dummy active silicon region 130 b and the dummy gate electrode region 150 b in FIG. 1E .
Next, with reference to FIG. 1P , in one embodiment, (i) silicide regions 138 a 1 , 138 a 2 , and 152 a are formed on the source/drain regions 136 a 1 and 136 a 2 and the actual gate electrode region 150 a, respectively, as shown, and (ii) silicide regions 138 c 1 , 138 c 2 , and 152 c are formed on the source/drain regions 136 c 1 and 136 c 2 and the actual gate electrode region 150 c, respectively, as shown. The silicide regions 138 a 1 , 138 a 2 , 152 a, 138 c 1 , 138 c 2 , and 152 c can be formed by (i) depositing a metal layer (not shown) on top of the semiconductor structure 100 of FIG. 1O , then (ii) heating the semiconductor structure 100 resulting in the metal chemically reacting with silicon of the source/drain regions and the actual gate electrode regions, and then (iii) removing unreacted metal resulting in the silicide regions 138 a 1 , 138 a 2 , 152 a, 138 c 1 , 138 c 2 , and 152 c. It should be noted that because of the dielectric cap region 194 , no silicide region is formed on top of the dummy active silicon region 130 b and the dummy gate electrode region 150 b. Also, because of other dielectric cap regions covering resistor regions (described above) such that no surface of the resistor regions is exposed to the surrounding ambient, no silicide region is formed on top the resistor regions as a result of the silicidation described above. It should be noted that the other dielectric cap regions covering resistor regions do not prevent the resistor regions from being doped during the formation of the halo regions, the extension regions, and the S/D regions of the structure 100 (described above).
Next, with reference to FIG. 1Q , in one embodiment, a dielectric layer 196 is formed on top of the semiconductor structure 100 of FIG. 1P . More specifically, the dielectric layer 196 can be formed by CVD of a dielectric material on top of the semiconductor structure 100 of FIG. 1P .
Next, in one embodiment, contact regions (not shown) are formed in the dielectric layer 196 to provide electrical access to the source/drain regions 136 a 1 , 136 a 2 , 136 c 1 , and 136 c 2 and the gate electrode regions 150 a and 150 b.
In summary, with reference to FIG. 1N , in the process for forming the PFET and the NFET mentioned above, (i) no dopant enters and (ii) no silicide is formed on top of the dummy active silicon region 130 b and the dummy gate electrode region 150 b. As a result, the dummy active silicon region 130 b and the dummy gate electrode region 150 b have higher resistances than the case in which the dummy active silicon region 130 b and the dummy gate electrode region 150 b are not protected from ion bombardments and silicidation during the formation of the PFET and the NFET mentioned above.
Next, in one embodiment, one interconnect layer after another (not shown) is formed on top of the structure 100 of FIG. 1Q . In one embodiment, the formation of the interconnect layers also results in an inductor (not shown in FIG. 1Q but can be seen as an inductor 220 in FIG. 1R ).
FIG. 1R shows a top-down zoom-out view of the resulting structure 100 after the formation of the interconnect layers including the inductor 220 , in accordance with embodiments of the present invention. In addition to the actual active silicon regions 130 a and 130 c, the structure 100 comprises other actual active silicon regions similar to the actual active silicon regions 130 a and 130 c. In addition to the actual gate electrode regions 150 a and 150 c, the structure 100 comprises other actual gate electrode regions similar to the actual gate electrode regions 150 a and 150 c. In addition to the dummy active silicon region 130 b, the structure 100 comprises other dummy active silicon regions similar to the dummy active silicon region 130 b. In addition to the dummy gate electrode region 150 b, the structure 100 comprises other dummy gate electrode regions similar to the dummy gate electrode region 150 b.
In one embodiment, with reference to FIG. 1R , each actual feature 230 can represent any one region of (i) the actual active silicon regions and (ii) the actual gate electrode regions of the structure 100 , whereas each dummy feature 240 can represent any one region of (i) the dummy active silicon regions and (ii) the dummy gate electrode regions of the structure 100 . Although the actual and dummy gate electrode regions and the actual and dummy active silicon regions can (i) overlap one another in the vertical direction, (ii) be of different sizes and shapes, and (iii) be not distributed uniformly across the structure 100 as shown in FIG. 1Q , but in FIG. 1R , for simplicity, the features 230 and 240 (i) do not overlap one another in the vertical direction, (ii) are of the same size and shape, and (iii) are distributed uniformly across the structure 100 of FIG. 1R . In one embodiment, contact regions 222 a and 222 b are used to provide electrical access to the inductor 220 .
In one embodiment, all the actual features 230 do not overlap the inductor 220 in the vertical direction. In one embodiment, all the dummy features 240 were protected from ion bombardments and silicidation during the formation of the PFET and the NFET mentioned above. In one embodiment, some dummy features 240 overlap the inductor 220 in the vertical direction, whereas other dummy features 240 do not overlap the inductor 220 in the vertical direction. Alternatively, all the dummy features 240 overlap the inductor 220 in the vertical direction.
Assume that an electric current flows in the inductor 220 . As a result, the current creates around the inductor 220 a magnetic field (not shown) in which the dummy features 240 reside. Because the dummy features 240 were protected from the ion bombardments and the silicidation resulting in the resistances of the dummy features 240 not being reduced as in the prior art, (i) the loss of the inductance of the inductor 220 due to the presence of electrically conductive regions in the magnetic field is minimized and (ii) the energy dissipation caused by eddy currents induced by the magnetic field of the inductor 220 in the dummy features 240 is also minimized.
In summary, as a result of (i) the actual features 230 being away (i.e., not overlapping in the vertical direction) from the inductor 220 and (ii) the resistances of the dummy features 240 not being reduced, (i) the loss of the inductance of the inductor 220 due to the presence of electrically conductive regions in the magnetic field is minimized and (ii) the energy dissipation caused by eddy currents induced by the magnetic field of the inductor 220 in the dummy features 240 is also minimized.
In one embodiment, the entire inductor 220 resides in a single interconnect layer. In an alternative embodiment, the inductor 220 resides in multiple interconnect layers of the structure 100 . More specifically, the inductor 220 comprises multiple segments which are electrically coupled together by vias (not shown).
In the embodiments described above, the actual features 230 do not overlap the inductor 220 in the vertical direction. In an alternative embodiment, the distance from any actual feature 230 to the inductor 220 in the horizontal direction (i.e., the direction which is perpendicular to the vertical direction) is at least a pre-specified minimum distance (e.g., 3 μm).
While particular embodiments of the present invention have been described herein for purposes of illustration, many modifications and changes will become apparent to those skilled in the art. Accordingly, the appended claims are intended to encompass all such modifications and changes as fall within the true spirit and scope of this invention. | A structure and a method for forming the same. The structure includes (a) a substrate which includes a top substrate surface which defines a reference direction perpendicular to the top substrate surface, (b) N semiconductor regions on the substrate, and (c) P semiconductor regions on the substrate, N and P being positive integers. The N semiconductor regions comprise dopants. The P semiconductor regions do not comprise dopants. The structure further includes M interconnect layers on top of the substrate, the N semiconductor regions, and the P semiconductor regions, M being a positive integer. The M interconnect layers include an inductor. (i) The N semiconductor regions do not overlap and (ii) the P semiconductor regions overlap the inductor in the reference direction. A plane perpendicular to the reference direction and intersecting a semiconductor region of the N semiconductor regions intersects a semiconductor region of the P semiconductor regions. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates method and model for regulating the computational and memory requirements of a compressed bitstream in a video decoder. This invention is useful in the field of multimedia audio-visual coding and compression techniques where the encoder needs to regulate the complexity requirements of the bitstreams it generates. This ensures that decoders conforming to the complexity specification of the standard can successfully decode these bitstreams without running short of resources.
2. Description of the Related Art
In the past, implementers of video decoders that conform to a certain performance capability of a standard are required to ensure that the decoders have sufficient resources to support the worse case scenario that is possible according to the specification. This is not a good engineering practice as usually the worse case scenario represents a case that almost impossible under normal operating conditions. This leads to over engineering and a waste of resources.
Currently within the MPEG-4 standardization, there is an effort to specify complexity bounds for the decoder based on the complexity of the bitstream rather than the worse case scenario. This is a statistical method based on a common unit of complexity measure. The standard will specify a fixed value for the maximum complexity allowed in a compliant bitstream. The decoder is required to provide resources sufficient to decode all compliant bitstreams. The encoder is required to ensure that all bitstreams that are generated do not exceed the maximum complexity bounds and are therefore complaint.
FIG. 1 shows graphically the above concept. In FIG. 1, valid bitstreams are distributed to the left of the fixed value of the standard and all compliant encoder are distributed to the right of the fixed value of the standard. The complexity bound is indicated by the straight line in the graph. The abscissa is given in complexity units. On the left of the line are all the conformant bitstreams. The typical distribution of the bitstream is depicted here. The majority of the bitstreams would have a complexity that is much lower than the complexity bound. A few bitstreams will approach this bound. When a bitstream exceeds this bound it is no longer a conformant bitstream and therefore not shown. On the right side of the complexity bound is the distribution of decoders. Most decoders would be designed as closed to the complexity bound as possible in order to save cost. A few decoders may have more resources that are required and these lie further to the right of the graph. A decoder that does not have enough resources to satisfy the complexity requirements of a compliant bitstream will lie to the left of the complexity bound and will be considered non-compliant.
FIG. 2 show a simple complexity measure method where the encoder counts the number of each macroblock type selected and evaluates the complexity of the bitstream based on some predefined cost function given to each of the macroblock type. FIG. 2 shows a simple method of counting the cost function of the bitstream being generated by calculating the equivalent I-MB units. However, this has the problem of not being able to give the instantaneous complexity measure and does not consider other resource such as memory. Information about the current macroblock is passed to the Macroblock Type Decision, module 201 , where the decision to encode the macroblock in a particular method is made. This decision is then counted by the Cost Function Generator, module 202 , which converts this information into a complexity cost function. The complexity cost function is then fed back to the Macroblock Type Decision module for the future decision.
Modules, 203 to 210 are the typical modules required for a hybrid transform coder. The input picture is partitioned into blocks that are processed by the motion estimation and compensation modules 210 and 209 , respectively. Note that this step is skipped if there is no motion prediction. The motion compensated difference signal is then processed by the DCT transform module 203 . The transform coefficients are then Quantized in the Quantization module 204 , The quantized coefficients are then entropy coded together with the overhead information of the macroblock type and motion vectors in the Variable Length Coding module 205 . The local decoder comprising of modules 206 to 209 reconstructs the coded picture for use in prediction of future pictures. The Inverse Quantization, module 206 , inverse quantizes the coefficients before it is fed into the Inverse DCT, module 207 , where the difference signal is recovered. The difference signal is then added with the motion prediction to form the reconstructed block. These blocks are then stored in the Frame Memory, module 208 , for future use.
Also, in video coding it is inherent that the compression process results in a variable bitrate bitstream. This bitstream is commonly sent over a constant bitrate channel. In order to absorb the instantaneous variation in the bitrate it is common to introduce buffers at the output of the encoder and at the input of the decoder. These buffers serve as reservoir for bits and allow a constant bitrate channel to be connected to an encoder that generates variable bitrate bitstreams as well as to a decoder that consumes bitstreams at a variable bitrate.
The buffer occupancy changes in time, because the rate at which the buffer is being filled and the rate at which it is being emptied are different. However, over a long period of time, the average rate for filling the buffer and the average rate of emptying the buffer can be defined to be the same. Therefore, if we allow a large enough buffer the steady state operation can be achieved. To work correctly the buffer must not become empty (underflow) or be totally filled up (overflow). In order to ensure this constraint, models of the buffer have been presented in the literature such as MPEG-1 and MPEG-2 where the video buffer model allow the behaviour of the variable bitrate decoder connected to a constant bitrate channel. The remainder of the decoder does not need to be model because the video decoding method has been defined at a constant frame rate and each frame having a constant size. Therefore, the constant rate of decoding and the consumption of buffer are well defined in time and the video buffering verifier (VBV) is used to verify whether the buffer memory required in a decoder is less than the defined buffer size by checking the bitstream with its delivery rate function, R(t).
Defining the complexity measure is not sufficient to ensure that the decoder can be designed in a unambiguous way. There are two reasons for this.
The first reason is that the complexity is measured in time. Since the time is sufficiently large, it can accommodate several frames of pictures. The complexity distribution may be such that the resources of the decoder may be exhausted in the instantaneous time while the average complexity is below the limit set. Restricting the window to a shorter time would then restrict the variability of the complexity of the pictures. This means that all pictures must have the constant complexity. This is not good since by the nature of the coding modes different picture types should have different complexities.
The second reason is that the complexity is not just related to the computation time. A second element, which is not captured in the complexity measure, is the memory requirements.
The problem to be solved is therefore to invent a method for regulating the complexity requirements of the bitstream in terms of computational and memory requirements.
Also, in recent developments in the video compression process, a more flexible encoding method that is object oriented has been defined by MPEG. This flexible encoding scheme supports variable number of macroblocks within a video picture and different picture rate such that the rate of decoding and the rate of consumption of the memory are no longer constant. It becomes necessary to measure these rates over time to ensure them not violate the maximum capability of the decoder.
Also, the problem to be solve is how to define new verifiers and algorithms to measure the parameters of a compressed video bitstream to ensure the generated bitstream can be decoded with defined capability and resources.
SUMMARY OF THE INVENTION
In order to solve the above problem, a joint computational and memory requirement model is designed. By considering the computational as well as the memory requirements of the bitstreams we can accurately constraint the resource requirements in the decoder.
The memory requirements are well defined by the amount of memory available. The usage and release of the memory is also well defined in time by the decoding and presentation time stamps of the video sequence. This time stamps are embedded in the bitstreams.
By linking the computation complexity units to the memory usage, it is therefore possible to solve the first problem where the window for defining the complexity bound is ambiguous. By linking these requirements, the computational and memory requirements can be bounded based on the decoding and presentation time stamps. There is no longer the need for defining a sliding window for measurement of complexity. At the same time the pictures are not constrained to have constant complexity.
Furthermore, the VCV model 130 provides the computational requirements to determine the start and end time of the decoding of the macroblocks. The VMV 140 model describes the behavior of the reference memory and the occupancy of the reference memory. The VPV 105 defines an algorithm to check the bitstream and verify the amount of presentation buffer.
This invention links the models in terms of the memory consumption, which allows the bitstreams to be constrained by a physical limitation of the decoder. The apparatus to implement the verification is also provided in this invention.
Furthermore, a complete new set of verifier models is developed: Video Complexity Verifier (VCV), Video memory Verifier (VMV) and Video Presentation Verifier (VPV). The models specify the behavior of a decoder for variable VOP size and rate and define new parameters and bounds to measure and verify the computational and memory resources that the bitstream demands, see.
The operation of the invention is as follows. The encoder monitors the complexity of the bitstream being generated by counting the macroblock type. Each macroblock type is assigned a predefined cost in some complexity units. Each macroblock decoded also consumes a predefined amount of memory space. Depending on the type of the VOP the memory is occupied for different duration. Memory is released when the macroblock in the VOP is no longer required for display or prediction.
The virtual decoder is assigned the maximum bound of complexity units and memory. The virtual decoder is allowed to decode the bitstream as fast as is possible subject to the limit of the complexity bound. However, in doing so the decoder would have to have extra memory to keep the decoded VOPs until it is time for them to be displayed or until it is no longer needed for prediction. So it is clear that the virtual decoder is bounded both by the amount of processing capability and memory available.
Therefore by monitoring the complexity units requirements of the bitstream and adjusting the decoding time stamp of the VOP the virtual decoder is able to prevent the memory usage from exceeding its bound. Thus the virtual decoder is allowed to use less time on a simple VOP and more time on a complex VOP. The virtual decoder is defined by the following rules:
a) The amount of memory required for decoding the current VOP is defined by the number of macroblocks in the VOP and is consumed at a constant rate between the decoding time stamp of the current VOP and the next VOP.
b) At the presentation time of an I- or P-VOP the total memory allocated to the previous I- or P-VOP in decoding order is released instantaneously.
c) At the presentation time of a B-VOP the total memory allocated to that B-VOP is released instantaneously.
d) At any time, the decoding time stamp of the (n+1) th VOP in decoding order, DTS n+1 , must be less than or equal to the presentation time stamp of the n th VOP in decoding order, PTS n .
DTS n+1 ≦PTS n (1)
where n is in decoding order.
e) At any time, the sum of the memory consumed must not exceed the maximum memory resources available, M Max . Otherwise, the virtual decoder is said to have memory overflow.
f) At any time, the ratio of the decoding complexity of the current VOP, C n , to the decoding time available, DTS n+1 −DTS n , must be less than the maximum complexity resources available per second, C′ Max . Otherwise, the virtual decoder is said to have complexity overflow.
C n /(DTS n+1 −DTS n )< C′ Max (2)
where n is in decoding order.
A valid bitsteam is thus one where the values in the bitstream satisfy the conditions in d), e) and f) and does not cause the vertual decoder to overflow in memory or complexity resources.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a distribution of bitstream complexity and decoder resources in complexity units of prior art.
FIG. 2 is a complexity measure and control in video encoder of prior art.
FIG. 3 is a complexity measure and control with vertual decoder in video encoder according to the first embodiment.
FIG. 4 is a block diagram for the vertual decoder of the first embodiment.
FIG. 5 is a graph showing the functionality of the vertual decoder with the decoding and presentation time stamps without frame reordering.
FIG. 6 is a graph showing the functionality of the vertual decoder with the decoding and presentation time stamps, and particularly showing an example of the embodiment of the vertual decoder.
FIG. 7 is a block diagram showing a complexity measure and verification with hypothetical virtual complexity verifier in video encoder according to the present invention.
FIG. 8 is a block diagram showing a complexity measure and verification using hypothetical virtual complexity verifier
FIG. 9 is a block diagram of a video verifier model, particularly showing the interrelationship between the VBV, VCV, VMV and the VPV.
FIG. 10 is a block diagram of a video buffer verifier, particularly showing the layout of the video buffer verifier connected to the output of the encoder.
FIG. 11 is a graph showing an operation of a video buffer verifier occupying time.
FIG. 12 is a block diagram of a video complexity verifier, particularly showing the layout of the video complexity verifier connected to the output of the encoder.
FIG. 13 is a graph showing an operation of the video complexity verifier occupying time.
FIG. 14 is a block diagram of a video memory verifier, particularly showing the layout of the video memory verifier connected to the output of the encoder.
FIG. 15 is a graph showing an operation of the video memory verifier occupying time.
FIG. 16 is a block diagram of a video presentation verifier, particularly showing the layout of the video presentation verifier connected to the output of the encoder.
FIG. 17 is a graph showing an operation of the video presentation verifier occupying time.
FIG. 18 is a block diagram of a video verifier model used in video encoder.
FIG. 19 is a flowchart of the video bitstream verification showing the operation of a standalone video bitstream verifier.
FIG. 20 is a graph showing a VBV buffer occupancy.
FIG. 21 is a graph showing VCV, VMV and VPV buffer occupancy.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First Embodiment
The first embodiment is shown in FIGS. 3, 4 , 5 and 6 . FIG. 3 shows the same diagram as in the prior art of FIG. 2, but with new portions added according to the present invention. The first embodiment uses a vertual decoder 303 . The output of the cost function generator 302 is not directly fed back to the macroblock type decision module 301 , but via the vertual decoder 303 . The vertual decoder 303 also receives the presentation time stamps of the pictures being coded. The vertual decoder 303 performs the function as described above. It is a hypothetical model that simulates a decoder that has a bounded computational and memory resources. These resources are consumed according to the encoding information found in the cost function generator and the presentation time stamps.
FIG. 4 illustrates the functions of the vertual decoder 303 . The complexity cost function from the cost function generator 302 is passed to the Virtual VOP memory buffer 401 , and the decoding time stamp (DTS) generator 402 . The virtual VOP memory buffer 401 also receives the presentation time stamp (PTS) and the decoding time stamp (DTS) signals. It then simulates the memory buffer usage. The output of the virtual VOP memory buffer 401 is the memory buffer occupancy. This information is passed to the DTS generator 402 to enable it to generate the next DTS.
The generation of the DTS is dependent on the memory buffer occupancy and the complexity cost function. As the memory is being filled up, the next DTS may be delayed to allow more time for decoding the current picture and thus fill the memory buffer later. Similarly, as the complexity cost function of the current picture goes up, the DTS of the next picture can also be delayed to allow the decoder more time to decode the current picture. A possible function is given below:
DTS n+1 =DTS n +c 1 ×buffer 13 fullness+ c 2 ×complexity_cost (3)
where c 1 and c 2 are constant factors that are determined by the frame rate of the sequence.
The DTS cannot be too quick, as if two consecutive DTS are too close the denominator in equation (2) will become small and the left-hand side of the equation would exceed the limits of the right-hand side. When this happen the decoder has run out of computational resource. See rule f) explained above.
Similarly, the DTS cannot be delayed indefinitely, since the picture will have to be displayed at a particular time given by the PTS. See rule d) above. This check is done in the PTS/DTS comparator 403 , where difference between the PTS and DTS is checked. The result is passed to the macroblock type weight factor generator 404 , where the weighting factor for each macroblock type is generated. These weights are used to regulate the decision made in the macroblock type decision module 301 .
The Virtual VOP Memory Buffer implements rules a) to c) and ensures that rule e) is not violated. There are two examples of this embodiment which are shown in FIGS. 5 and 6. FIG. 5 shows the case where the VOP coding type consists of I and P-VOPs only. Therefore the VOPS are decoded and displayed in the same order. FIG. 6 shows the case where the VOP coding types consists of I, P and B-VOPs. Due to the bidirectional prediction of the B-VOPs, there is a need to reorder the VOPS for encoding such that the coding order and the display order of the VOPs are different. Therefore, in the model the VOPs are decoded and displayed in different order.
Case1: I and P-VOPs Only
The following describes the operation virtual VOP memory buffer when there are only I and P-VOPs. The horizontal axis shows the time and the corresponding time stamps when an event starts. The vertical axis shows the memory usage. The limit of the memory resources is marked by the maximum memory resource available.
According to rule a), at time DTS 0 the virtual decoder starts decoding the first VOP, I-VOP 0 . It completes the decoding at DTS 1 . The virtual decoder, or model, assumes that the memory used by VOP 0 is linear in time, thus the straight line shown between DTS 0 and DTS 1 . Between DTS 1 and DTS 2 the decoded decodes the P-VOP 1 and consumes VOP 1 worth of memory. This process is repeated for all intervals of DTS i to DTS i+1 and is shown in FIG. 5 as the linearly increasing lines.
Rule b) is shown at each PTS except at PTS 0 where it does not have a previous VOP. At PTS 1 , the memory that is consumed by VOP 0 is released instantaneously. This is shown as the vertical line on the graph. Similar vertical drop in the memory consumed is shown at time PTS i through out the graph.
As long as the graph stays between the limits of the maximum memory resources available and that, the DTS and PTS satisfy the conditions of rule e), then the model is operation within its limits. The model has overflowed when one or more of rule d), e) or f) is violated.
Case2: I, P and B-VOPs
FIG. 6 shows the case where there are I, P and B-VOPs. When there are B-VOPs in the sequence then there is a need for reordering the decoding order. In this example the encoded sequence contains VOPs 0 , 1 , 2 , 3 , 4 , . . . VOP 0 is and I-VOP, VOPs 1 and 3 are P-VOPs and VOPs 2 and 4 are B-VOPS. The actual display order of these VOPs is 0 , 2 , 1 , 4 , 3 , . . . Notice the reorder of VOPs 1 and 2 as well as 3 and 4 . This is because the B-VOP 2 needs the P-VOP 1 for prediction therefore the P-VOp is decoded first although its display order comes after the B-VOP 2 .
According to rule a), at time DTS 0 the Virtual Decoder starts decoding the first VOP, I-VOP 0 . It completes the decoding at DTS 1 . The model assumes that the memory used by VOP 0 is linear in time, thus the straight line shown between DTS 0 and DTS 1 . Between DTS 1 and DTS 2 the decoded decodes the P-VOP 1 and consumes VOP 1 worth of memory. Between DTS 2 and DTS 3 the decoded decodes the B-VOP 2 and consumes VOP 2 worth of memory.
Rules b) and c) are applied at each PTS except at PTS 0 where it does not have a previous VOP. At PTS 2 , the memory that is consumed by VOP 2 is released instantaneously. This is shown as the vertical line on the graph. Similar vertical drop in the memory consumed is shown at time PTS i through out the graph.
As long as the graph stays between the limits of the maximum memory resources available and that, the DTS and PTS satisfy the conditions of rule e), then the model is operation within its limits. The model has overflowed when one or more of rule d), e) or f) is violated.
Virtual Complexity Verification
In a separate embodiment, the vertual decoder 303 is used not for controlling the complexity of the encoded bitstream but for verifying that the bitstream conforms to the complexity specification. There are two methods of verification. One is done internally in the encoder while the bitstream is being generated and the other external of the encoder after the bitstream has been generated. These are shown in FIGS. 7 and 8, respectively.
In FIG. 7, the hypothetical virtual complexity verifier calculates the cost function through the cost function generator 702 , as well as receives the PTS and DTS from the PTS, DTS generator 701 . This information is then applied through the vertual decoder 703 , as described above. The verifier ensures that the rules a) to f) are satisfied for the bitstream to be valid.
FIG. 8 shows the case where the hypothetical virtual complexity verifier is attached to the output of the encoder 801 . The Parser 802 , parses the bitstream from the output of the encoder to obtain the PTS, DTS and macroblock encoding type. The macroblock encoding type is then passed to the cost function generator 803 , where the cost function is evaluated. The cost function together with the PTS and DTS is applied through the vertual decoder 804 , as described in the previous section. The verifier ensures that the rules a) to f) are satisfied for the bitstream to be valid.
With the first embodiment, the encoder is capable of controlling and regulating the complexity of the coded bitstreams that it generates. At the same time, the decoder is ensured that streams that are too complex will not be created. The effect of this invention is that the design of the decoders no longer have to be based on the worse case scenario but based on the common complexity measure that is specified by the standard. The cost of these products can therefore be reduced, as there is no need for over engineering.
Second Embodiment
The second embodiment describes the general operation of the present embodiment.
A model is a simulation of the actions of a target decoder and its modules such as the bitstream buffer, the central processing unit (CPU), or the memory storage device. A model may be used as and embedded video verifier in the encoder during the creation of the encoded bitstream in order to ensure that a typical decoder can decode the bitsteam that the encoder creates. A model may also be used as a stand-alone video verifier. A stand-alone video verifier is used to check and verify a bitstream that have already been encoded by some means to ensure that a typical decoder is able to decode it.
This embodiment presents a video verifier, shown in FIG. 9, which comprises the following models:
1) A video buffer model 120 ,
2) A video complexity model 130 ,
3) A video reference memory model 140 , and
4) A video presentation model, 150 .
Each of the models is shown individually in FIGS. 10, 12 , 14 , and 16 , respectively.
FIG. 10 shows a video buffer model 120 , which is has a video buffer verifier 202 . Video buffer verifier 202 is required in order to bound the memory requirements for the bitstream buffer needed by a video decoder, with which, the video encoder can be constrained to make bitstreams which are decodable with a predetermined buffer memory size. The video buffer verifier 202 attached to the output of the encoder 201 is used to simulate the bitstream buffer 204 present in an actual decoder 203 .
The video buffer verifier 202 works in the following way as illustrated by the graph in FIG. 11 . It simulates the bitstream buffer of the decoder by making the following assumptions. First it assumes a certain maximum buffer size 251 and initial occupancy 252 of the virtual buffer verifier. Next it is assumed that the virtual buffer verifier is filled 253 with bits from the bitstream that is produced by the encoder. It is assumed that the virtual buffer verifier is filled at a specific rate that is governed by the channel that is used to transport the bitstream. Then by interpreting the timing information embedded in the bitstream, the video buffer verifier works out the time at which the decoder is expected to start the decoding of the individual pictures of the input data coded in the bitstream 254 . At the time at which the decoder is suppose to complete the decoding of the individual pictures of the input data the number of bits representing the current picture are removed from the virtual buffer verifier 255 . It is assumed that the bits are removed instantaneously from the buffer.
The virtual buffer verifier 202 content is checked at the instant before and after the bits are removed from it. If the occupancy virtual buffer verifier exceed the maximum buffer size then the virtual buffer verifier is said to have overflowed. If the bits to be removed are more that what is available in the virtual buffer verifier then the virtual buffer verifier is said to have underflowed. For normal operation the buffer is not allowed to overflow. In the case of underflow the decoder is assumed to idle until the required bits arrive at the virtual buffer verifier.
By implementing this model and using it to regulate and check the bitstreams that are created by the encoder, we can be sure that any decoder that is compliant to the specifications of the standard can decode the bitstreams so generated. The bitstream will not overflow or underflow the bitstream buffer of the decoder.
FIG. 12 shows a video complexity model 130 , which has a video complexity verifier 302 . The video complexity verifier 302 is required in order to bound the processing speed requirements needed by a video decoder, with which, the video encoder can be constrained to make bitstreams which are decodable with a predetermined decoder processor capability. The video complexity verifier 302 attached to the output of the encoder 301 is used to simulate the processor 305 present in an actual decoder 303 .
The video complexity verifier 302 works in the following way as illustrated by the graph in FIG. 13 . It simulates the processor of the decoder by making the following assumptions. The picture is segmented into smaller processing units called macroblocks. First it assumes that there is a certain maximum number of macroblocks 351 that the processor can accumulate in its buffer for processing. This puts a bound on the amount of delay the processor is allowed to have before the picture has to be decoded. Next the video complexity verifier determines the start of the decoding time by inspecting the information encoded in the bitstream. At the time the decoder is expected to start the decoding of the individual pictures of the input data coded in the bitstream 352 , the virtual complexity verifier determines the complexity of the picture to be decoded in terms of number of macroblocks 353 . This number of macroblocks is then placed in the video complexity verifier queue for processing. The video verifier then processes the macroblocks at a given maximum rate of macroblocks per unit time 354 . This maximum rate is based on the specification of the standard. Using these assumptions the time of the completion of the decoding of the pictures is calculated 535 . A simple formula of dividing the size of the queue by the processing rate will give the time it takes to complete the decoding of the picture just submitted into the queue.
The video complexity verifier queue is checked at the start time of the decoding to ensure that the queue does not exceed the maximum number of macroblocks limit. This is to ensure that all the pictures can be decoded within certain decoder latency.
In a different variation of the video complexity verifier, the complexity of the bitstream is further measured in terms of the different types of macroblocks. The coding types of the macroblocks are used to classify the macroblocks into different categories of complexity. The complexity is then normalised with respect to the simplest type of macroblock, which is given a unit of one macroblock complexity. The remainder categories are given a weight of w times one macroblock complexity where w varies for each of the categories depending on the complexity and is always a value greater than one. The weighted sum of the macroblock complexity is then used in the video complexity verifier.
By implementing this model and using it to regulate and check the bitstreams that are created by the encoder, we can be sure that any decoder that is compliant to the specifications of the standard can decode the bitstreams so generated. The bitstream will not be too complex for the processor in the decoder.
FIG. 14 shows a video memory model 140 , which has a video memory verifier 402 . The video memory verifier 402 is required in order to bound the reference memory requirements needed by a video decoder, with which, a video encoder can be constrained to make bitstreams which are decodable with a predetermined reference memory size. The video memory verifier 402 attached to the output of the encoder 401 is used to simulate the reference memory 406 present in an actual decoder 403 .
The video memory verifier 402 works in the following way as illustrated by the graph in FIG. 15 . It simulates the memory consumption of the decoder by making the following assumptions. First it assumes a certain maximum reference memory in terms of macroblocks is available 451 . During the decoding time 452 , the reference memory is consumed at a constant rate given by the rate of decoding of the picture 453 . The rate can be in terms of macroblocks per unit time. At the presentation time of the current picture 454 the memory occupied by the previous picture is instantaneously released 455 .
The reason the memory occupied by the previous picture is released and not the current picture, is because the reference memory of the previous picture is used for the decoding of the current picture. It can be released only when it is no longer needed. The display time of the current picture is used to determine that the current picture has been decoded and therefore the previous picture is no longer needed and can be released. In the case of bidirectional prediction the release of the memory is more complicated. Since the bidirectional predicted pictures are not used for the prediction of future pictures, they are released from memory at their presentation time without any delay.
The video memory verifier is checked at the presentation time of each picture to see if it has exceeded the maximum reference memory. This is to ensure that there is always enough reference memory for the storage of the decoded picture.
By implementing this model and using it to regulate and check the bitstreams that are created by the encoder, we can be sure that any decoder that is compliant to the specifications of the standard can decode the bitstreams so generated. The bitstream will not occupy more reference memory than is available in the decoder.
Video Presentation Model
FIG. 16 shows a video presentation model 150 , which has a video presentation verifier 502 . The video presentation verifier 502 is required in order to bound the presentation memory requirements needed by a video display, with which, a video encoder can be constrained to make bitstreams which are displayable with a predetermined display memory size. The video presentation verifier 502 attached to the output of the encoder 501 is used to simulate the presentation memory 507 attached to the output of the actual decoder 503 .
The video presentation verifier 502 works in the following way as illustrated by the graph in FIG. 17 . It simulates the presentation memory buffer of the display by making the following assumptions. First it assumes a certain maximum presentation memory in terms of macroblocks is available 551 . During the presentation time 552 , the presentation memory is filled with the complete decoded picture. This memory is then release at a constant rate as the picture is displayed 553 . The presentation verifier is checked to ensure that the accumulated macroblocks in the buffer does not exceed the maximum available memory.
The video verifier model presented individually above can be combined to form a complete video verifier, FIG. 18 shows a complete solution including all the modules in the encoder. It shows the video verifier models and the various encoder modules that are controlled by the feedback mechanism of the verifier. The present invention of the video verifier models can be used in the video encoder and in the verification of pre-encoded video bitstream.
When used in a video encoder, the VBV model 613 is used to check the bitstream rate. If the rate is larger than the defined bound, a feedback signal will be sent to the Rate Controller 610 to control the quantization 604 and VLC 605 . The VCV model 612 is used to check the complexity or the decoding cost of the generated bitstream. If the complexity is over the defined bound, a feedback signal will be sent to the Macroblock Type Controller 611 to control the Macroblock Type Decision 601 . T he VMV 614 and VPV 615 are used to check the reference memory 608 requirement. If it is overflowed, a feedback signal will be also sent to the Macroblock Type Controller 611 to change the Macroblock Type Decision 601 .
As show in FIG. 19 the verifier models can also be used to check the conformance of video bitstreams. With the flowchart, the video bitstream is checked with the VBV, VCV, VMV, and VPV one-by-one. If any of the bounds can not be satisfied, the bitstream is not compliant and must be rejected.
Third Embodiment
The third embodiment is a generalized cased of the present invention. It describes an example of a complete specification of the video verifier model. It is sectioned into the following definitions:
Video Buffer Model Definition
The video buffering verifier (VBV) is an algorithm for checking a bitstream with its delivery rate function, R(t), to verify that the amount of rate buffer memory required in a decoder is less than the stated buffer size. Originated from MPEG-2, the new VBV is defined with new features of the object-oriented video coding. If a visual bitstream is composed of multiple Video Objects (VOs) each with one or more Video Object Layers (VOLs), the rate buffer model is applied independently to each VOL (using buffer size and rate functions particular to that VOL).
The VBV applies to natural video coded as a combination of Intra, Predicted and Bi-directional Video Object Planes (I, P and B-VOPs). The following section refers to FIG. 20 . The coded video bitstream shall be constrained to comply with the requirements of the VBV defined as follows:
1. When the vbv_buffer_size and vbv_occupancy parameters are specified by systems-level configuration information, the bitstream shall be constrained according to the specified values. When the vbv_buffer_size and vbv_occupancy parameters are not specified (except in the short video header case as described below), this indicates that the bitstream should be constrained according to the default values of vbv_buffer_size and vbv_occupancy. The default value of vbv_buffer_size is the maximum value of vbv_buffer_size allowed within the profile and level. The default value of vbv_occupancy is 170×vbv_buffer_size, where vbv_occupancy is in 64-bit units and vbv_buffer_size is in 16384-bit units. This corresponds to an initial occupancy of approximately two-thirds of the full buffer size.
2. The VBV buffer size is specified by the vbv_buffer_size field in the VOL header in units of 16384 bits. A vbv_buffer_size of 0 is forbidden. Define B−16384×vbv_buffer_size to be the VBV buffer size in bits.
3. The instantaneous video object layer channel bit rate seen by the encoder is denoted by R vol (t) in bits per second. If the bit_rate field in the VOL header is present, it defines a peak rate (in units of 400 bits per second; a value of 0 is forbidden) such that R vol (t)<=400×bit_rate Note that R vol (t) counts only visual syntax for the current VOL (refer to the definition of d i below). If the channel is a serial time mutiplex containing other VOLs or as defined by ISO/IEC 14496-1 with a total instantaneous channel rate seen by the encoder of R(t), then R vol ( t ) = { R ( t ) if t ∈ { channel bit duration of a bit from VOL vol } 0 otherwise
4. The VBV buffer is initially empty. The vbv_occupancy field specifies the initial occupancy of the VBV buffer in 64-bit units before decoding the initial VOP. The first bit in the VBV buffer is the first bit of the elementary stream.
5. Define d i to be size in bits of the i-th VOP plus any immediately preceding GOV header, where i is the VOP index which increments by 1 in decoding order. A VOP includes any trailing stuffing code words before the next start code and the size of a coded VOP (d i ) is always a multiple of 8 bits due to start code alignment.
6. Let t i be the decoding time associated with VOP i in decoding order. All bits (d i ) of VOP i are removed from the VBV buffer instantaneously at t i . This instantaneous removal property distinguishes the VBV buffer model from a real rate buffer. The method of determining the value of t i is defined in item 7 below.
7. τ i is the composition time (or presentation time in a no-compositor decoder) of VOP i. For a video object plane, τ i defined by vop_time_increment (in units of 1/vop_time_increment_resolution seconds) plus the cumulative number of whole seconds specified by module_time_base In the case of interlaced video, a VOP consists of lines from two fields and τ i is the composition time of the first field. The relationship between the composition time and the decoding time for a VOP is given by:
t i =τ i if ((vop_coding_type of VOP i==B-VOP)∥low_delay∥scalability)
t i =τ i −m i otherwise
where low_delay is true (‘1’) if the elementary stream contains no B-VOPs. If low_delay is ‘0’ and scalability is also ‘0’, then the composition time of I and P VOP's is delayed until all immediately temporally-previous B-VOPs have been composed. This delay period is m i =τ f −τ p , where f, for an I or P VOP is the index of the VOP itself, and for a B-VOP is the index of the nearest temporally-future non-B VOP relative to VOP i, and p is the index of the nearest temporally-previous non-B VOP relative to vop i. In order to initialize the model decoder when m i is needed for the first VOP, it is necessary to define an initial decoding time t 0 for the firs VOP (since the timing structure is locked to the B-VOP times and the first decoded VOP would not be a B-VOP). This defined decoding timing shall be that to t 0 −2t 1 −t 2 (i.e., assuming that t 1 −t 0 −t 2 −t 1 ).
The following example demonstrates how m i is determined for a sequence with variable numbers of consecutive B-VOPs:
Decoding order: I 0 P 1 P 2 P 3 B 4 P 5 B 6 P 7 B 8 B 9 P 10 B 11 B 12
Presentation order: I 0 P 1 P 2 B 4 P 3 B 6 P 5 B 8 B 9 P 7 B 11 B 12P 10
Assume that vop_time_increment=1 and modulo_time_base=0 in this example. The sub-index i is in decoding order.
TABLE 1
An example that demonstrates how m i is determined
i
τ i
t i
m i
0
0
0 − 1 = −1
1
1
1
1 − 1 = 0
1
2
2
2 − 1 = 1
1
3
4
4 − 2 = 2
2
4
3
3
2
5
6
6 − 2 = 4
2
6
5
5
2
7
9
9 − 3 = 6
3
8
7
7
3
9
8
8
3
10
12
12 − 3 = 9
3
11
10
10
3
12
11
11
3
8. Define b i as the buffer occupancy in bits immediately following the removal of VOP i from the rate buffer. Using the above definitions, b i can be iteratively defined
b o =64×vbv_occupancy− d o
b
i
+
1
=
b
i
+
∫
t
i
t
i
+
1
R
vol
(
t
)
t
-
i
+
1
for
i
≥
0
9. The rate buffer model requires that the VBV buffer never overflow or underflow, that is
0 <b i and b i +d i <B for all i
Real-valued arithmetic is used to compute b i so that errors are not accumulated.
A coded VOP size must always be less than the VBV buffer size, i.e., d i <B for all i.
10. If the short video header is in use (i.e., when short_video_header=1), then the parameter vbv_buffer_size is not present and the following conditions are required for VBV operation. The buffer is initially empty at the start of encoder operation (i.e., t=0 being at the time of the generation of the first video plane with short header), and its fullness is subsequently checked after each time interval of 1001/30000 seconds (i.e., at t=1001/30000, 2002/30000, etc.). If a complete video plane with short header is in the buffer at the checking time, it is removed. The buffer fullness after the removal of a VOP, b i , shall be greater than zero and less than (4·Rmax·1001)/30000 bits, where Rmax is the maximum bit rate in bits per second allowed within the profile and level. The number of bits used for coding any single VOP, d i , shall not exceed k·16384 bits, where k=4 for QCIF and Sub-QCIF, k=16 for CIF, k=32 for 4CIF, and k=64 for 16CIF, unless a larger value of k is specified in the profile and level definition. Furthermore, the total buffer fullness at any time shall not exceed a value of B=k·16384+(4·Rmax·1001)/30000.
It is a requirement on the encoder to produce a bitstream which does not overflow or underflow the VBV buffer. This means the encoder must be designed to provide correct VBV operation for the range of values of R vol,decoder (t) over which the system will operate for delivery of the bitstream. A channel has constant delay if the encoder bitrate at time t when particular bit enters the channel, R vol,encoder (t) is equal to R vol,decoder (t+L), where the bit is received at (t+L) and L is constant. In the case of constant delay channels, the encoder can use its locally estimated R vol,encoder (t) to simulate the VBV occupancy and control the number of bits per VOP, d i , in order to prevent overflow or underflow.
The VBV model assumes a constant delay channel. This allows the encoder to produce an elementary bitstream which does not overflow or underflow the buffer using R vol,encoder (t)—note that R vol (t) is defined as R vol,encoder (t) in item 2 above.
Video Complexity Model Definition
The video complexity verifier (VCV) is an algorithm for checking a bitstream to verify that the amount of processing capability required in a decoder is less than the stated complexity measure in cost function equivalent of I-MB/sec. If a visual bitstream is composed of multiple VOs each with one or more VOLs, the video complexity model is applied jointly for all VOLs (using one cumulative vcv_buffer_size for all the VOLs).
The VCV applies to natural video coded as a combination of I, P and B-VOPs. The coded video bitstream shall be constrained to comply with the requirements of the VCV defined as follows:
1. A vcv_buffer_size is defined as the number of equivalent I-MBs which can be contained in the VCV-buffer. These equivalent I-MBs are consumed by the decoder at the cost function equivalent I-MB decoding rate vcv_decoder_rate. A vcv_decoder_latency is defined as the processing time needed for the decoder to decode a full VCV-buffer (vcv_buffer_size MBs) with the MB-decoding rate (equivalent I-MB/s). Thus the relation vcv_buffer_size=vcv_decoder_latency*vcv_decoder_rate holds. The VCV-buffer is initially empty at the start of decoding.
2. When the vcv_decoder_latency parameter is specified by vol_control_parameters, the bitstream shall be constrained according to the specified values. When the vcv_decoder_latency parameter is not specified, the bitstream shall be constrained according to the default values of vcv_decoder_latency.
3. The complexity cost of a vop, M i , in units of equivalent I-MB is calculated based on the following formula:
M i is the new amount of macroblocks at time stamp t i . M i can include I-, P- and B-macroblocks. The “decoding cost” for these macroblocks are based on the macroblock type and are given by the weights w i , w P , w B , w SI and w SP .
M i =w I ·W Ii +w P ·M Pi +w B ·M Bi +w SI ·M SIi +w SP ·M SPi
where I, P and B refer respectively to I-, P- and B-macroblocks while SI and SP refer respectively to I- and P-macroblocks including object boundary (shape).
4. At time t i −vcv_decoder_latency the complexity cost of the vop is added to the VCV-buffer, where t i is the decode time calculated in section 0 .
5. The complexity model requires that the VCV buffer never overflows, that is the decoding process must be completed within the decoder latency time. In that case the only stringent requirement of the model is fulfilled: the decoding end time must be before the decoding time calculated in section 0 . This constraint is always fulfilled if no VCV-buffer overflow occurs.
6. The complexity model allows the VCV buffer to underflow, in which case the decoder simply remains idle, while the VCV-buffer is empty.
Video Reference Memory Model Definition
The video memory verifier (VMV) is an algorithm for checking a bitstream to verify that the amount of reference memory required in a decoder is less than the stated maximum total reference memory in units of MB. If a visual bitstream is composed of multiple VOs each with one or more VOLs, the video reference memory model is applied jointly for all VOL (since this model assumes a shared memory space).
The VMV applies to natural video coded as a combination of I, P and B-VOPs. The coded video bitstream shall be constrained to comply with the requirements of the VMV defined as follows:
1. The reference memory is initially empty. It is filled with the decoded data as each macroblock is decoded.
2. The amount of reference memory required for the decoding of the i th vop is defined as the number of macroblocks in the vop, n i , and is consumed at a constant rate during the decoding duration of the vop, T i . The decoding duration of the i th vop, T i , occurs between s i and e i , where s i and e i are the decoding start time and the decoding end time of the i th vop and are obtained from the intersection of the decoder processing slope and the decode time axis of the VCV model in FIG. 21 .
3. At the composition time (or presentation time in a no-compositor decoder), τ i , of an I- or P-VOP the total memory allocated to the previous I- or P-VOP in the decoding order is released instantaneously.
4. At the composition time (or presentation time in a no-compositor decoder), τ i , of a B-VOP the total memory allocated to that B-VOP is released instantaneously.
5. The reference memory model requires that the VMV buffer never overflows.
The buffer occupancy of the video memory verifier is shown in FIG. 21 . In FIG. 21, arrow A 1 points a place where the reference memory is consumed during decoding period, and arrow A 2 points a place where the reference memory released at composition time or presentation time in a no-compositor decoder.
Interaction Between VBV, VCV and VMV.
The rate buffer model defines when the bitstream is available for the decoding and is removed from the buffer. The complexity model defines the speed at which the macroblocks are decoded. The reference memory model defines the amount of reference memory that is consumed and released. Obviously, it is advantageous for the video decoder to decode as far in advance as possible. However, this is constraint by the VBV and the VMV. The decoder can only start decoding if the bits are available for decoding. At the same time as the decoder decodes the bitstream, it generates macroblocks which consumes the reference memory. So if it decodes too fast it will overflow the reference memory.
On the other hand if the decoder start decoding too late, then it will not be able to complete the decoding in time and the bitstream will be removed from the VBV before it could be processed. Similarly the reference memory required for the prediction of the current VOP may also be removed from the VMV.
Therefore, the encoder will have to adjust the vbv_buffer_size, vbv_occupancy and vcv_decoder_latency parameters such that the resulting bitstream does not violate any of the VBV, VCV and VMV models. Besides adjusting these parameters, the encoder can also adaptively adjust its encoding parameters such that the resulting bitstream does not violate the models.
Video Presentation Model Definition
The video presentation verifier (VPV) is an algorithm for checking a bitstream to verify that the amount of presentation buffer required in a decoder is less than a given amount of memory in units of MB. It is also used to constraint the speed of the compositor in terms of maximum number of MB/sec.
The VPV operates in the same manner as the VCV:
1. At the composition time of the i th VOP, τ i , the VOP is placed in the presentation buffer.
2. The data in the presentation buffer is consumed by the compositor at a rate equivalent to the maximum number of MB/sec.
3. At τ i +compositor_latency the VOP should be composited.
4. The presentation memory model requires that the VPV buffer never overflows
With the third embodiment of the present invention, the encoder is capable of controlling and regulating the complexity of the coded bitstreams that it generates. At the same time, the decoder is ensured that streams that are too complex will not be created. The effect of this invention is that the design of the decoders no longer have to be based on the worse case scenario but based on the common complexity measure that is specified by the standard. The cost of these products can therefore be reduced, as there is no need for over engineering.
The present disclosure relates to subject matter contained in priority Japanese Patent Application Nos. HEI 10-328767, filed on Oct. 13, 1998, and HEI 11-41406, filed on Feb. 19, 1999, the contents of both being herein expressly incorporated by reference in their entireties. | An apparatus for the verification of compressed objected-oriented video bitstream includes a set of verifier models: Video Complexity Verifier (VCV), Video memory Verifier (VMV) and Video Presentation Verifier (VPV). The models specify the behavior of a decoder for variable VOP size and rate and define new parameters and bounds to measure and verify the computational and memory resources that the bitstream demands. They can be used in the video encoder or in the verification of pre-compressed video distribution. | 7 |
RELATED APPLICATION
[0001] This application is a division of U.S. patent application Ser. No. 10/386,145 filed Mar. 11, 2003 which is relied on and incorporated herein by reference.
FIELD OF THE INVENTION
[0002] This invention relates to a floating screed asphalt paver, and more particularly, relates to a floating screed paver having a floating screed and an auger/cut off assembly. The auger/cut off assembly includes an auger mechanism for distributing asphalt paving material evenly in front of the floating screed and a cut off mechanism for cutting off the flow of paving material to the floating screed when the cut off mechanism is in a closed cut off position and for striking off the paving material in front of the floating screed when the cut off mechanism is in an open strike off position.
BACKGROUND OF THE INVENTION
[0003] Most asphalt pavers employ a floating screed in which asphalt paving material is distributed in front of the floating screed as the paver moves along the roadbed to be paved. Particularly, such a conventional floating screed paver consists of a self-propelled power unit, a floating screed connected at the rear end of the power unit, a hopper at the forward end of the power unit for receiving paving material from a dump truck, a gravity feed hopper or a conveyor system for moving the paving material from the hopper to the roadbed in front of the floating screed, an auger assembly between the conveyor system and the floating screed for evenly distributing the paving material across the width of the floating screed, and a fixed strike off plate between the auger and the floating screed to control buildup of paving material in front of the floating screed.
[0004] The self-propelled power unit is typically mounted on tracks or rubber tires. The self-propelled power unit thereby provides the motive force for the paver along the roadbed as well as power for the operation and control of the various paving functions of the paver including functions associated with the hopper, the conveyor system, the auger, and the floating screed.
[0005] The hopper, mounted at the front end of the power unit, contacts the dump truck, and the power unit of the paver pushes the dump truck along the roadbed as the dump truck progressively dumps its load of paving material into the hopper.
[0006] The conveyor system on the paver or gravity moves the paving material from the hopper for discharge onto the roadbed. The screw auger spreads the paving material in front of and across the width of the floating screed. The fixed strike off plate controls the buildup of paving material in front of the floating screed.
[0007] The floating screed is commonly connected to the power unit by pivoting tow or draft arms, which allow the screed to float on the paving material. The depth of the paving material is controlled by a depth screw at each end of the screed. The screed functions to level, compact, and set the width of the paving material thereby leaving the finished asphalt slab with a uniform and smooth surface.
[0008] At the end of a paving pass with a conventional floating screed paver, the loose paving material that has been discharged by the conveyor system to the auger in front of the floating screed will remain on the roadbed and must be removed with a shovel by hand. In order to eliminate the labor involved in such a cleanup, prior art floating screed pavers have employed a cut off gate comprising a hinged cut off plate located in front of and below the auger. When the conventional cut off plate was activated by a hydraulic cylinder, the cut off plate would swing rearwardly into contact with the fixed strike off plate to eliminate the discharge of loose paving material onto the roadbed below the auger. The swinging cut off plate below the auger required additional ground clearance for its operation and thereby restricted how low the auger could be positioned.
[0009] In order for the auger to be lowered with minimum ground clearance, there is a need for a paving material cut off mechanism that does not require additional ground clearance. Moreover, there is a need for a cut off mechanism that is adjustable to vary the degree of strike off of paving material ahead of the floating screed and that can eliminate the deposit of loose paving material at the end of a paving pass.
[0010] In addition, there is a need for a auger/cut off assembly which may be divided into sections across the width of the paver. The auger sections can be independently operated, and the cut off mechanism sections can be independently opened and closed to control of the feed of paving material to the floating screed in discrete sections across the width of the floating screed.
SUMMARY OF THE INVENTION
[0011] The present invention satisfies the above-described need for an improved auger/cut off assembly by providing an auger/cut off assembly consisting of an auger mechanism and a cut off mechanism. The auger mechanism consists of a auger support member for supporting an auger for rotation about an axis. The cut off mechanism consists of at least one concave cut off panel that is rotated by means of an actuator about the axis of the auger between an open strike off position and a closed cut off position. Because the concave cut off panel closely conforms to a portion of the circumference of the auger, the auger/cut off assembly allows low ground clearance.
[0012] With the concave cut off panel in the open strike off position, the bottom of the auger is exposed so that the paving material can be discharged from the auger onto the roadbed. In addition, when the cut off panel is in the open strike off position, the leading edge of the concave cut off panel functions as a strike off edge. Moreover, because the cut off panel can be rotated between the open strike off position and the closed cut off position, the degree of engagement of the strike off edge can be continuously varied by the actuator to insure that the proper amount of paving material is removed by the strike off edge of the concave cut off panel.
[0013] In the closed cut off position, the concave cut off panel forms a trough beneath the auger to catch the loose paving material so that the loose paving material is not deposited on the roadbed at the end of a paving pass. Because the ends of the concave cut off panel are open, the loose paving material can be moved along the trough formed by the concave cut off panel and discharged through the open ends outboard of the floating screed paver for filling potholes or trenches for example.
[0014] Consequently, the concave cut off panel performs the dual function of striking off the paving material when the concave cut off panel is in the open strike off position and cutting off discharge of the paving material in front of the floating screed when the concave cut off panel is in the closed cut off position. In one embodiment of the invention, the auger/cut off assembly comprises a single auger mechanism and a single cut off mechanism. In another embodiment of the invention, the auger cut off assembly comprises a plurality of auger mechanisms and a plurality of cut off mechanisms. Particularly, in one embodiment, the concave cut off panel comprises two independently controlled concave cut off panels, and the auger comprises two independently controlled augers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a side elevation view of a floating screed asphalt paver in accordance with the present invention.
[0016] FIG. 2 is a top plan view of a floating screed asphalt paver in accordance with the present invention.
[0017] FIG. 3 is a rear perspective view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with the cut off mechanism in an open strike off position.
[0018] FIG. 4 is a rear perspective view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with the cut off mechanism in a partially closed cut off position.
[0019] FIG. 5 is a side elevation view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with the cut off mechanism in the open strike off position.
[0020] FIG. 6 is a side elevation view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with the cut off mechanism in the closed cut off position.
[0021] FIG. 7 is a front elevation view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with the cut off mechanism in the partially closed cut off position.
[0022] FIG. 8 is a rear perspective view of an auger/cut off assembly for a floating screed asphalt paver in accordance with the present invention with one section of the cut off mechanism in a closed cut off position and a second section of the cut off mechanism in the open strike off position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] The present invention is an auger/cut off assembly for a floating screed paver. The auger/cut off assembly comprises an auger mechanism and a cut off mechanism. The auger mechanism consists of an auger support member attached to the floating screed paver which supports an auger for rotation about an axis. The cut off mechanism consists of at least one concave cut off panel that is rotated by means of an actuator about the axis of the auger between an open strike off position and a closed cut off position. In one embodiment, the auger mechanism consists of two independently controlled augers, and the cut off mechanism consists of two concave cut off panels that are independently rotated by means of independent actuators about the axis of the augers between an open strike off position and a closed cut off position.
[0024] Turning to the figures, FIG. 1 is a side elevation view of a floating screed asphalt paver 10 in accordance with the present invention. The floating screed paver 10 is designed to lay a finished slab of asphalt on a roadbed 12 . In connection with the following description of the floating screed paver 10 , references to “left” and “right” will be from the perspective of an operator at the rear of the paver 10 facing forward. Consequently, the elements shown in FIG. 1 are the left hand elements of the paver 10 . By contrast in FIG. 7 , the left side of the drawing represents the right hand side of the paver 10 and vice versa. With further reference to FIG. 1 , the floating screed paver 10 comprises a self-propelled power unit 14 , an operator deck 20 , a hopper 24 with a left wing 26 and a right wing 28 , a floating screed 30 , an asphalt material conveyor system 52 , and an auger/cut off assembly 58 .
[0025] The self propelled power unit 14 includes a frame 15 , a motor 16 , generally a diesel engine, a hydraulic system (not shown), and crawler tracks 18 . The motor 16 provides the prime motive power for the self propelled power unit 14 . Typically, the motor 16 drives a hydraulic pump (not shown) which in turn drives hydraulic motors and cylinders to power the various functions of the floating screed paver 10 . For example, a pair of hydraulic motors (not shown) propel the paver 10 along the roadbed 12 on the crawler tracks 18 . In other embodiments of the paver 10 , rubber tires may be used instead of the crawler tracks 18 .
[0026] The floating screed paver 10 is controlled by an operator from the operator deck 20 by means of a control panel 22 .
[0027] The hopper 24 receives asphalt paving material from a dump truck (not shown) at the front end of the paver 10 . The wings 26 and 28 are controlled by means of hydraulic cylinders (not shown) to open in order to expand the width of the hopper 24 in order to receive paving material and to close in order to minimize the width of the hopper during transportation and maneuvering.
[0028] As shown in FIG. 2 , the conveyor system 52 along the bottom of the hopper 24 delivers the paving material from the hopper 24 to the roadbed 12 in front of the floating screed 30 . The conveyor system 52 is divided in half across the width of the hopper and consists of a left conveyor 54 and a right conveyor 56 . Each conveyor 54 and 56 consists of the series of slats mounted at each end on a continuous chain. Each conveyor 54 and 56 is independently driven by a hydraulic motor to control the amount of paving material delivered to each half of the roadbed 12 in front of the floating screed 30 . The conveyor system 52 could also consist of a single conveyor instead of the left conveyor 54 and the right conveyor 56 . Alternatively, the conveyor system 52 could also consist of multiple conveyors extending across the width of the hopper 24 . Moreover, the conveyor system 52 may comprise a gravity feed from the hopper.
[0029] The floating screed 30 is attached to the power unit 14 by means of a left draft arm 40 , a right draft arm 42 , a left pivot pin 32 , and a right pivot pin 34 so that the floating screed 30 is pulled by the power unit 14 along the roadbed 12 . The floating screed 30 is raised for transportation by means of hydraulic cylinders such as left side hydraulic cylinder 36 . The floating screed 30 is supported on a left side skid 48 and on a right side skid 50 which contact the roadbed 12 when the paver 10 is not involved in a paving operation. During a paving operation, the relative height of the floating screed 30 with respect to the roadbed 12 , and therefore the thickness of the finished slab, is controlled by a left side depth screw 44 and a right side depth screw 46 . Particularly, the left side depth screw 44 and the right side depth screw 46 very the angle of attack of the floating screed 30 on each end of the floating screed 30 .
[0030] In order to insure proper operation of the floating screed 30 , the auger/cut off assembly 58 includes an auger mechanism 59 and a cut off mechanism 104 . The auger mechanism 59 receives the paving material from the conveyor system 52 and distributes the paving material evenly across the width of the floating screed 30 including any screed extensions for producing wider paving widths. The cut off mechanism 104 has an open strike off position ( FIGS. 3 and 5 ) and a closed cut off position ( FIGS. 4 and 6 ). In the open strike off position, the cut off mechanism 104 strikes off the paving material in order to control buildup of the paving material in front of the floating screed 30 . In the closed cut off position, the cut off mechanism cuts off the flow of paving material from the conveyor system 52 to the roadbed 12 in front of the floating screed 30 thereby eliminating the deposit of loose paving material on the roadbed 12 at the end of a paving pass.
[0031] Turning to FIGS. 3 and 5 , the auger/cut off assembly 58 is shown in the open strike off position. As previously stated, the auger/cut off assembly 58 consists of the auger mechanism 59 and the cut off mechanism 104 . With reference to FIG. 7 , the auger mechanism 59 consists of an auger support member 60 and a left auger 80 and a right auger 90 . The auger support member 60 has a left mounting bracket 62 and a right mounting bracket 64 for mounting the auger support member 60 to the self-propelled power unit 14 between the outlet of the conveyor system 52 and the floating screed 30 . Auger bearing supports 66 , 68 , and 70 extended below the auger support member 60 and carry auger bearings 72 , 74 , 76 , and 78 . The left auger 80 is journaled for rotation in auger bearings 72 and 74 , and the right auger 90 is journaled for rotation in auger bearings 76 and 78 . The left auger 80 and the right auger 90 both rotate about a common auger axis of rotation 100 . The left auger 80 is driven by a left hydraulic motor 82 by means of a left motor sprocket 84 , a left auger sprocket 86 , and a left drive chain 88 . Likewise, the right auger 90 is driven by a right hydraulic motor 92 by means of a right motor sprocket 94 , a right auger sprocket 96 , and a right drive chain 98 . Each of the hydraulic motors 82 and 92 are independently controllable in the forward or reverse direction by the operator from the controlled panel 22 . Also, the speed of each of the hydraulic motors 82 and 92 is independently controlled by the operator from the control panel 22 . Consequently, the augers 80 and 90 can be independently controlled to move paving material at different and variable rates from the center outward, from the sides inward, to the left, or to the right.
[0032] With reference to FIG. 3 , the auger support member 60 is hollow with a series of inlet vents 65 along the length of the bottom of the support member 60 and outlets vents 67 along the front of the support member 60 . A source of vacuum (not shown) is attached to outlets vents 67 in order to draw fumes from the paving material into inlet vents 67 and away from of paving material in close proximity with the operator of the paver. In that way, the fumes can be collected and processed before being released to the atmosphere away from the operator of the paver.
[0033] The cut off mechanism 104 of the auger/cut off assembly 58 consists of a left concave cut off panel 106 and a right concave cut off panel 118 . As can best be seen in FIG. 4 , the left concave cut off panel 106 has a partial hub 108 attached at one end and a partial hub 110 attached at the other end. Likewise, the left concave cut off panel 118 has a partial hub 120 attached at one end and a partial hub 122 attached at the other end. The partial hubs 108 , 110 , 120 , and 122 are all journaled for rotation about the augers axis of rotation 100 . The partial hubs 108 and 122 at the end of each of the concave cut off panels 106 and 118 are open. The concave cut off panels 106 and 118 have a circumference that closely matches of the circumference of the augers 80 and 90 . In addition and as shown in FIG. 7 , the left concave cut off panel 106 has a left strike off edge 112 . Likewise, the right concave cut off panel 118 has a right strike off edge 124 .
[0034] The rotation of the left cut off panel 106 about the axis of rotation 100 is independently controlled by a left actuator which includes a hydraulic cylinder 114 connected between a left upper bracket 115 and a left lower bracket 117 . Likewise, the rotation of the right cut off panel 118 about the axis of rotation 100 is independently controlled by a right actuator which includes a hydraulic cylinder 126 connected between a right upper bracket 127 and a right lower bracket 129 . The upper brackets 115 and 127 are fixed to the support member 60 and the lower brackets 117 and 129 are connected to the left concave cut off panel 106 and the right concave cut off panel 118 respectively.
[0035] FIGS. 3 and 5 illustrate the open strike off position of the cut off mechanism 59 , and FIGS. 4 and 6 illustrate the closed cut off position of the cut off mechanism 59 . During the continuous paving operation, the concave cut off panels 106 and 118 are rotated by means of the hydraulic cylinders 114 and 126 to the open strike off position shown in FIGS. 3 and 5 . In the open strike off position, the strike off edges 112 and 124 of the concave cut off panels 106 and 118 strike off the paving material delivered from the conveyors 54 and 56 to the augers 80 and 90 . The depth of engagement of the strike off edges 112 and 124 can be varied by extending and retracting the hydraulic cylinders 114 and 126 thereby allowing more or less paving material to reach the leading edge of the floating screed 30 .
[0036] Once the paver reaches the end of paving run, the hydraulic cylinders 114 and 126 are extended so that the concave cut off panels 106 and 118 rotate to the fully closed cut off position shown in FIG. 6 . If paving material remains in the augers 80 and 90 at the time the concave cut off panels 106 and 118 are move to the closed cut off position, the augers 80 and 90 may continue to run thereby delivering the paving material to the outside ends of the concave cut off panels 106 and 118 . Because the partial end hubs 108 and 122 are open, the paving material is carried along the concave cut off panels 106 and 118 by the augers 80 and 90 , and the paving material is thus expelled from the concave cut off panels 106 and 118 on either side of the paver 10 . In that manner, loose paving material is not left on the roadbed 12 at the end of the finished slap at the end of the paving run. Any excess material is either carried in the concave cut off panels 106 and 118 or is extruded out of the ends of the cut off panels 106 and 118 to the side of the slab and out of the way. By extruded paving material out of the ends of the cut off panels 106 and 118 , the paver can be used to deliver paving material to potholes or trenches along the side of the paver.
[0037] Because the concave cut off panels 106 and 118 are closely fit to the diameter of the augers 80 and 90 and because the concave cut off panels 106 and 118 rotate about the augers' axis of rotation 100 , the concave cut off panels 106 and 118 extend below the augers 80 and 90 only by the thickness of the concave cut off panels 106 and 118 themselves. Consequently, the configuration of the concave cut off panels 106 and 118 and their rotation about the augers' axis of rotation 100 allows the augers 80 and 90 to be position close to the roadbed 12 .
[0038] FIG. 8 illustrates the auger/cut off assembly 58 with the left cut off panel 106 in the closed cut off position and the right cut off panel 118 in the open strike off position. With the cut off panels 106 and 118 independently position by the actuators 114 and 126 as shown in FIG. 8 , the paver 10 can be used to pave a strip that is half the width of the paver.
[0039] The present invention thus contemplates an auger/cut off assembly with a single auger and single cut off panel, an auger/cut off assembly with two independently controlled augers (such as augers 80 and 90 ) and two independently controlled cut off panels (such as cut off panels 106 and 118 ), and an auger/cut off assembly with multiple independently controlled augers and multiple independently controlled cut off panels.
[0040] Alternative embodiments will become apparent to those skilled in the art to which the present invention pertains without departing from its spirit and scope. Accordingly, the scope of the present invention is defined by the appended claims rather than the foregoing description. | An auger/cut off assembly for a floating screed asphalt paver. The auger/cut off assembly consists of an auger mechanism with an axis of rotation and a cut off mechanism. The cut off mechanism has a concave cut off panel that rotates about the axis of the auger mechanism from an open strike off position to a closed cut off position. Because the concave cut off panel closely conforms to a portion of the circumference of the auger mechanism, the cut off mechanism provides for low ground clearance. The concave cut off panel serves the dual function of striking off the paving material when in the open strike off position and cutting off the deposit of paving material when in the closed cut off position. | 4 |
BACKGROUND OF THE INVENTION
[0001] The invention relates to a device for continuous drying of a pulp web, particularly a tissue web, with a drying drum and an air circulating system, where the drying drum has a cylindrical shell designed as a honeycombed body.
[0002] In conventional tissue plants, the drying process begins at an ingoing dryness of some 40 to 45%. In order to achieve higher paper volume, papermakers now dispense with preliminary mechanical dewatering, and the ingoing dryness of this newer type of device is around 20 to 25%. These plants operate with through-air drying. During the heating process, one or more consecutive through-air drying drums at ambient temperature are exposed abruptly to the supply air temperature of approximately 300° C. The drying drums currently in use have a thin-walled shell, for example a perforated or honeycombed body, that is joined to thick-walled end flanges. Due to the substantial differences in mass between drum shell and end flange, there is excessive stress at the transition points that leads to deformation and even structural damage. The same damage occurs if the drums are cooled down abruptly from operating to ambient temperature during an emergency shutdown, when they are sprayed with cold water in order to prevent the plastic wires enclosing the drums from being damaged.
SUMMARY OF THE INVENTION
[0003] The invention now aims to eliminate this disadvantage and is characterized by the honeycombed cylinder shell of the drying drum having an annular, flexible transition profile at the edges. Thus, any changes occurring in diameter and any resulting thermal stress can be reduced.
[0004] An advantageous further development of the invention is characterized by the transition profile being designed as a U-profile and preferably being butt-welded onto the honeycombed cylinder shell. With this design of transition piece, continuous heat transition is guaranteed during both the heating and the cooling process of the machine. The special type of joint leads to a reduction of the stresses in the welds to such extent that the welds suffer no deformation or structural damage at all.
[0005] A favorable embodiment of the invention is characterized by the cross-section of the transition profile, preferably a U-profile, narrowing towards its center. As a result, the heat flow can be influenced particularly well. In addition, this design creates a flexible connection, which also guarantees that the cylinder shell is centered and thus, runs exactly true.
[0006] It is an advantage if the honeycombed cylinder shell is wider than the paper web to be dried, thus allowing a defined variation of the paper web width.
[0007] A favorable further development of the invention is characterized by an endless ring being shrunk on at each end and which extends beyond the transition profile and into the honeycombed cylinder shell. This prevents dust or fibers from entering the cavity of the U-profile.
[0008] It has proved favorable to make the cylinder shell out of longitudinal ribs that are connected to upright, edged profiles. This achieves good stability in the cylinder shell.
[0009] A favorable embodiment of the invention is characterized by the longitudinal ribs of the honeycombed cylinder shell being spaced at a distance of between 20 and 80 mm from one another, preferably between 30 and 40 mm. If the spacing is narrower, there is also less specific load and thus, reduced risk of marks on the paper web.
[0010] An advantageous embodiment of the invention is characterized by the edged connecting profiles mounted in a honeycombed pattern protruding beyond the longitudinal ribs and supporting the paper web and the conveying wire. This results in a large supporting surface and a further reduction in the risk of marks on the paper web.
[0011] It is particularly favorable it the honeycombed cylinder shell has an open area of at least 85%. The through-air drying process can thus be implemented particularly well.
[0012] A particularly favorable further development of the invention is characterized by covers being provided on the face ends to stabilize the cylinder shell and by these covers being bolted to the cylinder shell, particularly to the transition pieces. This design guarantees improved stability of the drum shell; in particular, it prevents any sliding movement by the end cover and the drum shell if there is radial expansion caused by the temperature.
[0013] An advantageous embodiment of the invention is characterized by the drying drum having a fully welded drum body. This design virtually excludes the risk of any areas where cracks could occur.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The invention will now be described in examples and referring to the drawings, where
[0015] FIG. 1 shows a variant of a configuration of a through-air drying unit;
[0016] FIG. 2 is a sectional view through FIG. 1 along the line marked II-II;
[0017] FIG. 3 shows a drying drum according to the invention;
[0018] FIG. 4 shows detail IV in FIG. 3 ;
[0019] FIG. 5 shows detail V in FIG. 3 ; and
[0020] FIG. 6 a sectional view along the line marked VI-VI in FIG. 3 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] FIG. 1 shows a possible configuration of a through-air drying process. The figure shows the drum 1 with its bearings 2 and 3 , and the drive 4 .
[0022] Beneath the drum there is a two-part hood 5 and 6 (see FIG. 2 ) from which the hot supply air flows through the paper web, through a conveying wire 8 , then through the drying drum 1 into the inside of the drum, and is removed from the drum on the drive side through an annular channel 10 . The hot supply air at a temperature of approximately 300° C. is cooled down to approximately 120° C. by the drying process. The exhaust air cooled in this way is then returned to its entry status in a processing system. At the outlet, the paper web 7 with the conveying wire 8 is carried over a deflection roll 11 . The cover device 12 is clearly visible here, covering the area of the drum 1 from the inside outwards in the sector that does not come into contact with the tissue web 7 and which also is not enclosed by the hood 5 and 6 . This prevents additional air from being drawn into the drying drum, which would greatly reduce the suction effect through the paper web. In principle, the air can also be conveyed from the inside of the drying drum 1 through the cylinder shell 9 to the outside.
[0023] FIG. 3 show a sectional view through a drying drum 1 , comprising a perforated, preferably honeycombed cylinder shell 9 with a flexible ring 13 rolled into a horizontal U-profile, butt-welded onto the edges of the shell on both the operator and the drive side. Due to this U-shaped transition profile 13 between cylinder shell 9 and end covers 14 , 15 , the maximum stresses in the connecting weld are reduced to approximately one third of those occurring in conventional designs, which guarantees damage-free operation of the drying drum over its entire service life.
[0024] FIG. 4 shows a sectional view of the connection between the drum shell and the flexible ring 13 , as well as the weld joint itself and the bolted connection 17 to the drum cover 14 . As viewed in section, each flexible ring 13 is preferably a unitary (or two half-ring) member having a radially extending, relatively rigid inner rim portion that is butt welded to the outer edges of the longitudinal ribs 18 (see FIG. 6 ), and a radially extending, relatively rigid outer rim portion that forms a flange for the bolted connection to a mating flange portion of the cover. A relatively thin, flexible, web portion extends axially between the inner and outer rim portions, forming the preferred “U” profile in section. As used herein, “flexible” should be understood in the context as semi-rigid with the capability to bend or flex under thermal or mechanical stresses, while retaining sufficient rigidity to transmit the rotational drive torque between one or both covers 14 , 15 and the shell body 9 . A cavity or channel is formed by the flange portions and the web, and can be considered as having a center C that lies on an imaginary circle around the drum axis. Likewise, the web can be considered as having a center that lies in radial alignment with the center of the channel, and preferably has a varying width along the direction between the flange portions, which narrows toward the center.
[0025] The external flanges of these flexible rings 13 are bolted to the drum covers 14 and 15 , which have journals to hold the two bearing assemblies 2 and 3 that are designed to take account of the changing length of the drying drum 1 in cross-machine direction, caused by the differences in temperature during heating up and cooling down. The temperature of the exhaust air is normally around 120° C., while the supply air entering the drying drum has a temperature of approximately 300° C. The two ends of the drum including flexible ring 13 are covered by an endless imperforate protective ring 16 from the outer edge of the outer flange portion inwardly beyond the inner flange portion to the edges P of the paper web. This arrangement prevents any dust or fibers from entering the cavity in the U-profile. This endless ring 16 is shrunk on in such a way that it cannot detach itself from the drum surface during the heating and cooling process, nor during drying operation.
[0026] A view of the peripheral sector of the drum 1 is illustrated in FIG. 5 . This drawing shows the covering ring 16 , which extends inwardly beyond the outer edges of the honeycombed cylinder shell 9 a distance D and marks the edges P of the paper web.
[0027] FIG. 6 shows the supporting structure of the cylinder shell 9 with longitudinal ribs 18 , with advantageous spacing a of approximately 30 to 40 mm and the connecting profiles 19 protruding beyond the longitudinal ribs in radial direction to form the honeycomb and support the paper web 7 and the conveying wire 8 . | A device for continuous drying of a pulp web, particularly a tissue web, with a drying drum ( 1 ) and an air circulating system, where the drying drum ( 1 ) has a cylindrical shell ( 9 ) designed as a honeycombed body with an annular, flexible transition profile ( 13 ) at the edges of the shell and connected to the end covers. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a contact-free double-sheet control device in a printing press.
2. Description of Related Art including information disclosed under 37 CFR 1.97-1.99
A double-sheet control device which operates contact-free has become known heretofore in German Published Non-prosecuted Patent Application (DE-OS) 33 44 842. This heretofore known device has two serially connected plate-like precision capacitors which are connected to one another by a bridge circuit. The precision capacitors are fastened onto a common carrier plate to compensate for operating influences, such as machine vibrations, for example, the opposing plates of the capacitors being formed by a conveyor table.
The respective serially-connected precision capacitors of the foregoing published German application, however, are only able to measure the thickness of the sheets. Consequently, a measurement is attainable only at an overlap border of two consecutive sheets. Furthermore, the spacing between two overlap borders must correspond to at least the capacitor length.
SUMMARY OF THE INVENTION
It is accordingly an object of the invention to provide an improved contact-free sheet control device for printing presses for measuring mis-fed sheets, which prevents interruptions in production runs by recognizing faulty or erroneous double sheets.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a contact-free double-sheet control device for a printing press having a capacitively-operating measuring sensor for determining sheet count, a counter-electrode adjacent thereto, and an evaluation circuit connected to the sensor, comprising an eddy-current measuring sensor assigned to the capacitive measuring circuit for compensating for operating influences.
In accordance with another feature of the invention, the counter-electrode is a feeding table of a printing press.
In accordance with a further feature of the invention, the counter-electrode is disposed above a feeding table of a printing press.
In accordance with an added feature of the invention, the counter-electrode is a sheet smoother.
In accordance with an additional feature of the invention, the capacitive measuring sensor and the eddy-current measuring sensor are disposed opposite one another in a spacing.
In accordance with yet another feature of the invention, the capacitive measuring sensor and the eddy-current measuring sensor are assembled into a combisensor.
In accordance with yet a further feature of the invention, the combisensor is disposed freely in the vicinity of a feeding table of a printing press.
In accordance with yet an added feature of the invention, the control device includes a traverse on which the combisensor is disposed.
In accordance with yet an additional feature of the invention, the traverse is disposed at an end of the feeding table facing towards a sheet pile.
In accordance with still another feature of the invention, the capacitively-operating measuring sensor and the eddy-current measuring sensor coaxially within one another.
In accordance with still a further feature of the invention, the combisensor has one of an elliptical, a triangular, a polygonal and a circular cross section.
In accordance with a concomitant feature of the invention, an electric signal of the capacitive measuring sensor and a measuring signal of the eddy-current measuring sensor are combinable by subtraction by means of the evaluation circuit.
The measuring device of the invention occupies a relatively small structural space and is installable freely in a region of the feeding table which forms the counter-electrode. Due to this construction, the measuring device can be disposed at a relatively great distance or spacing from the front lays, so that adequate time remains for switching off the press when a mis-printed or faulty sheet is recognized or detected, even at relatively high press speeds.
Due to the free selection of the type of arrangement, a changeover or conversion as well as a retrofitting or upgrading, respectively, is always readily possible.
The measuring device may also be integrated in and cooperate with a counter-electrode spaced from the conveyor or feeding table and disposed above the measuring device. The measuring device or the counter-electrode can thereby be fastened to an overlay rake or sheet smoother cooperating with the feeding table. It is also possible for the counter-electrode to be formed by the sheet smoother.
In an advantageous manner, the sensors of the measuring device are disposed coaxially within one another, due to which they are applied to virtually the same, relatively small measurement location. Disruptive mechanical effects, such as tilting or tipping movements of the measuring device, are thereby minimized.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in a contact-free double-sheet control device, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic side elevational view of a feeding table of a printing press;
FIG. 2 is a much-enlarged fragmentary cross-sectional view of FIG. 1 showing diagrammatically an embodiment of a so-called combisensor forming part of the control device according to the invention;
FIG. 3 is a plot diagram from top to bottom of a measurement signal variation or pattern from a capacitive measuring sensor, from an eddy-current measuring sensor, and from the combination of both of the foregoing measuring sensors as a function of the angular position of the printing press during sheet in-feed;
FIG. 4 is a schematic circuit diagram of an evaluating circuit for the combisensor of FIGS. 1 and 2; and
FIG. 5 is a view like that of FIG. 1 of the feeding table with a different embodiment of the conbisensor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and particularly to FIG. 1 thereof, there is shown therein, on a sheet feeder 1 of a printing press and in the vicinity of a feeding table 2 thereof, a so-called combisensor 3 for detecting, without contact, mis-fed sheets, such as double sheets, for example. The combisensor 3 is formed of a capacitive measuring sensor 4 and an eddy-current measuring sensor 6. The sensors 4 and 6 are connected via electric lines to an evaluation 7 (note FIG. 2). In the embodiment shown in greater detail in FIG. 2, the capacitive measuring sensor 4 is surrounded coaxially by the eddy-current sensor 6, insulation 8 being provided at the common contact surfaces thereof. The combisensor 3 is arranged so as to be slidable and swivelable on a traverse or crosstie rod 11 at a spaced distance a, approximately equal to from two to ten mm from an upper side 9 of the feeding table 2. The traverse 11 is supported in side frames of the sheet feeder 1. It is also possible to fasten the combisensor 3, for example, to an overlay guide or sheet smoother 12. A bipartite bracket 13 surrounds and is secured to the traverse 11. The two parts 16 and 17 of the bracket 13 are held together by fastening screws or setscrews 18 and 19 and clamped to the traverse 11. By means of two additional fastening screws 21 and 22, a supporting beam 23 is fastened to the part 17 of the bracket 13 which, as viewed from the traverse 11, extends in a direction towards the feeding table 2. At the end of the beam 23 facing towards the feeding table 2, a holder 24 for carrying the combisensor 3 is provided. The combisensor 3 has a large spacing b in sheet transport direction, which is represented by the associated arrow in FIG. 1, towards front lays 26 which are located in the immediate vicinity of the cylinders of the printing press, the distance b being greater than a sheet overlap length, as shown in FIG. 2. The combisensor 3 is preferably disposed on an end of the feeding table 2 facing towards a sheet pile 29.
In the the embodiment according to FIG. 2, the combisensor 3 is formed as a coaxial bearing of two cylindrical bodies 4 and 6, with a circular cross-sectional surface area resulting therefrom. It is also possible, however, to provide elliptical, triangular or polygonal cross-sectional surface areas. The possibility furthermore exists of arranging the capacitive measuring sensor 4 and the eddy-current measuring sensor 6 adjacent to one another, preferably directly near one another, i.e., separated only by the insulation 8.
The capacitive measuring sensor 4 detects or measures a total thickness of a sheet stream 27 acting as a dielectric, which is fed through the spacing a between the capacitive sensor 4 and the feeding table 2. The sheet stream 27 can have a plurality of single sheets 28, such as five, for example, depending upon the overlap length. In accordance with the total thickness of the sheet stream 27, an electric signal Ec is generated and passed on to the evaluation circuit 7. Even with only one sheet 28, an electric signal Ec is generated which is sufficient for reliably displaying or indicating the thickness of the individual sheet 28. By means of the double-sheet control device according to the invention, it is therefore possible to provide an effective monitoring even starting from the sheet in-feed. Mechanical disturbances, such as vibrations, for example, occur due to the machine run. The combisensor 3 accordingly performs a a movement relative to the feeding table 2. The electric signal Ec generated by the capacitive sensor 4 can have such great fluctuations that an error message may result which can shut the press operation down. For this reason, the eddy-current measuring sensor 6 has been assigned to the capacitive measuring sensor 4, and continuously generates an electric signal Ew corresponding to the spacing a, which is also transmitted to the evaluation circuit 7. The electric signals Ec and Ew are combined thereat by subtraction. An advantage derived from the eddy-current measuring sensor 6 is that it is not dependent upon the total thickness of the sheet stream 27, but rather, only upon the actual spacing a between the combisensor 3 and the counter-electrode, such as the feeding table 2, for example. It is thereby of outstanding value for compensating for spacing variations.
FIG. 3 shows qualitatively the course or variations of the electric signals Ew and Ec and the combination Ew-Ec thereof.
In the vicinity of the phase angle 0° of the printing press, only one single sheet 28 is measured. The signal Ec has sharp variations in this region and would result in a mis-fed sheet message without compensation by the signal Ew. The compensated signal Ew-Ec is clear and accurate, in contrast. A further electric signal E M is generated in accordance with or as a function of the angular setting of the cylinders of the printing press, i.e., the press cycle, and likewise fed to the evaluation circuit 7. By means of the combination of the signals Ew, Ec and E M , the evaluation circuit 7 recognizes how many single sheets 28 and how thick the sheet stream 27, respectively, should measure for a given angle setting of the cylinders of the press in order that no mis-fed sheets be present. A deviation of about a factor d, which is equal to 1.8 times the sheet thickness, from the recognized value results in a signal "mis-fed sheet" and a shutdown of the press and sheet transport circuits, respectively connected therewith.
In a second embodiment of the control device according to the invention shown in FIG. 5, the combisensor 3 is integrated with the feeding table 2. A metal plate 32 is disposed as a counter-electrode above the feeding table 2. In this regard, it is also possible that the sheet smoother 12 is formed as the counter-electrode. FIG. 4 is a block circuit diagram of the evaluation circuit 7. The combisensor 3 delivers the electric signals Ew and Ec to the evaluation circuit 7. The electric signal Ew of the eddy-current measuring sensor 6 is fed to a demodulator 33, which simultaneously receives a signal from an oscillator 34. A signal resulting therefrom is then fed to an analog computer 39. The electric signal Ec of the capacitive measuring sensor 4 is amplified by a pre-amplifier 36 and transmitted to a second demodulator 37 and subjected thereat to a signal from a second oscillator 38. A signal resulting therefrom is likewise fed to the analog computer 39 which combines by subtraction the signals generated by the demodulators 33 and 38 and produces a measurement signal Ew-Ec. This is thereafter combined with the electric signal E M . In a further, non-illustrated embodiment of the invention, the capacitive measuring sensor 4 is disposed opposite the eddy-current measuring sensor 6 in the spacing a. In this regard, both the capacitive measuring sensor 4 and the eddy-current measuring sensor 6 can be disposed in the feeding table 2 and respectively located opposite one another, preferably on a common axis. | Contact-free double-sheet control device for a printing press having a capacitively-operating measuring sensor for determining sheet count, a counter-electrode adjacent thereto, and an evaluation circuit connected to the sensor, includes an eddy-current measuring sensor assigned to the capacitive measuring circuit for compensating for operating influences. | 6 |
FIELD OF THE INVENTION
The present invention relates generally to a radio receiving apparatus and, more particularly, to a system and method for automatically adjusting the volume of an audio source.
BACKGROUND OF THE INVENTION
Listening to radio and television broadcasts, whether they are music, news, or discussion-based programming, consumes a large amount of time of the average individual. As people's lives become busier, there is more of a tendency for multi-tasking. It is quite common for an individual to perform one or more tasks while watching television or listening to the radio. These tasks may involve the individual moving from one location to another (e.g., from the living room to the kitchen). As a result, the individual may be forced to constantly adjust the audio level of the radio or television in order to maintain a comfortable listening level.
For example, suppose that a person is listening to a radio or stereo that is playing from a fixed location, such as the living room. As the listener moves throughout the house, the perceived volume at the listener's location does not remain constant but varies based on the listener's distance from the audio source. It would be impractical to constantly go back to the radio or stereo system to manually adjust the volume to retain a relatively constant volume as perceived by the listener as he or she moves throughout the house.
As another example, suppose that an automobile driver is listening to the car radio while driving. The noise level inside the car is constantly changing. For example, most drivers find that they have to adjust the volume of the radio to different levels as the car changes from highway to city driving speeds. As a result, the automobile radio listener is repeatedly required to manually adjust the volume of the radio to keep it at a perceived constant volume.
Suppose, as a further example, that a telephone with hands-free speaker operation is being used by a consumer in the kitchen of a house. As the consumer moves away from the telephone and moves about the kitchen, it may become difficult to hear the caller out of the telephone's speaker due to either the distance from the telephone or the noise in the kitchen, or both.
Accordingly, there is a need in the art for a system and method that will allow the perceived volume of an audio source to remain at a constant level irrespective of a listener's location.
SUMMARY OF THE INVENTION
Systems and methods consistent with the present invention address this and other needs by providing a mechanism through which an audio source and an associated local sensor can maintain a constant perceived volume level for a user in close proximity to the local sensor.
In accordance with the purpose of this invention as embodied and broadly described herein, a method adjusts an audio level of an audio device. The method includes receiving a first audio signal from the audio device; receiving a data packet from the audio device, the data packet comprising a second audio signal; determining whether a difference between the first audio signal and the second audio signal exceeds a threshold value; and adjusting the audio level of the audio device when the difference between the first audio signal and the second audio signal exceeds the threshold value.
In another implementation consistent with the present invention, a system for adjusting an audio level includes a sensor and an audio device. The sensor receives at least one first audio signal, generates a data packet, the data packet comprising the at least one first audio signal, and transmits the data packet. The audio device receives the data packet, retrieves at least one second audio signal, determines average volume levels of the at least one first audio signal and the at least one second audio signal, multiplies the average volume level of the at least one second audio signal with a volume setting value to produce an adjusted average volume level, compares a difference between the average volume level of the first audio signal and the adjusted average volume level to a threshold value, and adjusts the audio level when the difference exceeds the threshold value.
In yet another implementation consistent with the present invention, a computer-readable medium having a packet data structure is provided. The packet data structure includes a volume setting field that stores a value representing a volume setting of an audio device and an audio sample field that stores at least one audio sample.
In still yet another implementation consistent with the present invention, a computer-readable medium having a packet data structure is provided. The packet data structure includes a destination address field that stores a destination address and a volume adjustment command field that stores a value indicating that a volume of an audio device is to be adjusted.
In yet a further implementation consistent with the present invention, a method adjusts an audio level of an audio device. The method includes receiving a first audio signal, the first audio signal comprising a plurality of sub-bands; receiving a data packet, the data packet comprising a second audio signal comprising a plurality of sub-bands; determining, for each sub-band, whether a difference between a sub-band of the first audio signal and a corresponding sub-band of the second audio signal exceeds a threshold value; and adjusting the audio level of a sub-band at the audio device when the difference between a sub-band of the first audio source and the corresponding sub-band of the second audio signal exceeds the threshold value.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, explain the invention. In the drawings,
FIG. 1 illustrates an exemplary system in which systems and methods consistent with the present invention may be implemented;
FIG. 2 illustrates an exemplary configuration of the elements of the local sensor of FIG. 1 ;
FIG. 3 illustrates an exemplary configuration of the elements of the audio source of FIG. 1 ;
FIGS. 4–9 illustrate an exemplary process, consistent with the present invention, for maintaining a constant perceived audio level at a user;
FIG. 10 illustrates an exemplary configuration, consistent with the present invention, of a data packet generated by audio source;
FIG. 11 illustrates an exemplary comparison operation consistent with the present invention;
FIG. 12 illustrates an exemplary configuration, consistent with the present invention, for the data packet transmitted by local sensor;
FIGS. 13–17 an alternative exemplary process, consistent with the present invention, for maintaining a constant perceived audio level at a user; and
FIG. 18 an exemplary configuration, consistent with the present invention, for the data packet transmitted by local sensor.
DETAILED DESCRIPTION
The following detailed description of implementations consistent with the present invention refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. Also, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims and equivalents.
Implementations consistent with the present invention provide a process by which an audio level at a user may be maintained at a constant level. A local sensor is positioned in close proximity to the user. The local sensor interacts with the audio source in order to adjust the volume level of the audio source so that the user perceives a constant audio level.
Exemplary System Configuration
FIG. 1 illustrates an exemplary system 100 in which systems and methods, consistent with the present invention, for maintaining a constant perceived audio level may be implemented. System 100 includes a local sensor 110 and an audio source 120 . A single local sensor 110 and audio source 120 have been shown for simplicity. It will be appreciated that the techniques described herein are equally applicable to systems having multiple local sensors 110 and audio sources 120 .
Local sensor 110 may include components for receiving sound waves, performing calculations on audio signals, and receiving and transmitting data packets to other devices or systems, such as audio source 120 . Local sensor 110 may be employed as a small device attached to a listener's body, such as a watch-like device, a pager-like device, or a small microphone-like unit clipped to one's clothing. Alternately, local sensor 110 may be incorporated into a personal electronic device, a piece of clothing worn by a listener, or may be mounted near a listener, such as in an automobile or airplane.
Audio source 120 may include components for broadcasting audio signals in the form of sound waves and transmitting and receiving data packets to/from other devices or systems, such as local sensor 110 . Audio source 120 may include the components of a portable personal radio, a stereo system, a car radio, an intercom system, or any other audio device. Audio source 120 may also include any device that broadcasts audio signals of any nature to a listener, such as a computer-like device or a telephone-like device.
Exemplary Local Sensor
FIG. 2 illustrates an exemplary local sensor 110 configuration consistent with the present invention. In FIG. 2 , the local sensor 110 includes a power supply 210 , a communications interface 220 , a central processing unit (CPU) 230 , a memory 240 , a converter 250 , and an input device 260 .
The power supply 210 may include all the components necessary to supply local sensor 110 with operating power. Power supply 210 may include a battery, fuel cell, solar collector, A/C adapter, or any other device capable of powering the components of local sensor 110 . Alternately, power supply 210 may include a combination of devices capable of supplying power to local sensor 110 .
The communications interface 220 may include any transceiver-like mechanism that enables local sensor 110 to communicate with other devices and/or systems, such as audio source 120 , via a wired, wireless, optical, or any other type of connection. For example, communications interface 220 may include a modem or an Ethernet interface to a network. In an implementation consistent with the present invention, communications interface 220 may include an antenna, radio frequency (RF) transceiver, and modem by which local sensor 110 may transmit and receive data packets.
The CPU 230 may include any type of conventional processor or microprocessor that interprets and executes instructions in a well-known manner. Alternately, CPU 230 may consist of multiple processors or microprocessors, or some combination thereof. In general, CPU 230 may control the operation of local sensor 110 .
The memory 240 may include a random access memory (RAM) or another type of dynamic storage device that stores information, such as information associated with the audio signals and data packets received by the local sensor, and instructions for execution by the CPU 230 . In addition to RAM, memory 240 may also include a read only memory (ROM) or another type of static storage device that stores static information and instructions for use by the CPU 230 , and/or some type of magnetic or optical recording medium and its corresponding drive.
The converter 250 may include components necessary to translate audio signals from an analog format to a digital format in a well-known manner. The input device 260 , which may interact directly with converter 250 , may include any conventional mechanism that allows local sensor 110 to receive information, such as a keypad, a mouse, a microphone, and the like.
Local sensor 110 operates in response to CPU 230 executing sequences of instructions contained in a computer-readable medium. A computer-readable medium may include one or more memory devices or carrier waves. Execution of the sequences of instructions causes CPU 230 to perform process steps that will be described hereafter.
In alternate embodiments, hard-wired circuitry may be used in place of or in combination with software instructions to implement the present invention. Thus, the present invention is not limited to any specific combination of hardware circuitry, software, and/or firmware.
Exemplary Audio Source
FIG. 3 illustrates an exemplary audio source 120 configuration consistent with the present invention. In FIG. 3 , the audio source 120 includes a CPU 310 , a memory 315 , a volume input device 320 , a volume controller 325 , a converter 330 , a communications interface 335 , a reactivity input device 340 , a reactivity controller 345 , an amplifier 350 , and an audio output device 355 .
The CPU 310 may include any type of conventional processor or microprocessor that interprets and executes instructions. Alternately, CPU 310 may consist of multiple processors or microprocessors, or some combination thereof. In general, CPU 310 may control the operation of audio source 120 .
The memory 315 may include a RAM or another type of dynamic storage device that stores information, such as data packets, and instructions for execution by the CPU 310 . In addition to RAM, memory 315 may include a read only memory (ROM) or another type of static storage device that stores static information and instructions for use by the CPU 310 , and/or some type of magnetic or optical recording medium and its corresponding drive.
Volume input device 320 may include a user interface for adjusting the volume of the audio emanating from audio source 120 . Volume input device 320 may consist of a dial, switch, or button that can be manually adjusted by a listener. In other applications, volume input device 320 may consist of an audio input device that receives verbal commands or an input device that receives signals transmitted from a remote control. Volume controller 325 may include one or more components that allow CPU 310 to sense the setting of volume input device 320 .
Converter 330 may include all the components necessary to translate audio signals from an analog format to a digital format in a well-known manner. The communications interface 335 may include any transceiver-like mechanism that enables audio source 120 to communicate with other devices and/or systems, such as local sensor 110 , via a wired, wireless, optical, or any other type of connection. For example, communications interface 335 may include a modem or an Ethernet interface to a network. In an implementation consistent with the present invention, communications interface 335 may include an antenna, radio frequency (RF) transceiver, and modem by which audio source 120 may transmit and receive data packets.
Reactivity input device 340 may include a user interface that allows a listener to adjust the rate at which the volume of audio source 120 is automatically changed in either a positive or negative direction. As used herein, a positive change in the volume of audio source 120 causes the sound level at the output of audio source 120 to increase (i.e. become louder) in contrast a negative change in the volume of audio source 120 causes the outputted sound to decrease (i.e. become quieter). Reactivity input device 340 may, for example, consist of a dial, switch, or button that can be manually adjusted by a listener. In other applications, reactivity input device 340 may consist of an audio input device that receives verbal commands or a device that receives signals transmitted from a remote control. Reactivity controller 345 may include one or more components that allow CPU 310 to sense the setting of reactivity input device 340 .
Amplifier 350 may process the audio input signals in a well-known manner and provide them to audio output device 355 . Audio output device 355 may include one or more components that convert audio signals into sound waves in a well-known manner. In an implementation consistent with the present invention, audio output device 355 may include one or more speakers.
It will be appreciated that audio source 120 may include additional hardware, software, and/or firmware components (not shown) to perform the functions associated with the operation of various types of audio sources 120 , such as radios, stereos, televisions, telephones, and the like. Audio source 120 operates in response to CPU 310 executing sequences of instructions contained in a computer-readable medium. A computer-readable medium may include one or more memory devices or carrier waves. Execution of the sequences of instructions causes CPU 310 to perform the process steps that will be described hereafter.
In alternate embodiments, hard-wired circuitry may be used in place of or in combination with software instructions to implement the above components. Thus, the present invention is not limited to any specific combination of hardware circuitry, software, and/or firmware.
Exemplary Processing
FIGS. 4–9 illustrate an exemplary process, consistent with the present invention, for maintaining a constant perceived audio level at a user location. Processing begins with the audio source 120 sampling an incoming audio signal, such as the audio input in FIG. 3 [step 410 ]. Since the audio signal is sampled at its source, the signal may be considered “ideal.” The audio source 120 may store a predetermined number of ideal audio samples in, for example, memory 315 [step 420 ]. As will be appreciated later, the audio source 120 may store a predetermined number of ideal audio samples to allow the local sensor 110 to determine whether a volume adjustment is necessary. If the predetermined number of samples has not yet been stored [step 430 ], the audio source 120 may collect additional samples.
When the predetermined number of ideal audio samples has been collected [step 430 ], the audio source 120 may obtain the current volume setting [step 440 ]. The audio source 120 may obtain the current volume setting from the volume controller 325 . Once obtained, the audio source 120 may store that information in memory 315 [step 450 ]. The audio source 120 may also obtain the current reactivity setting from reactivity controller 345 [step 460 ], and may store that information in memory 315 [step 470 ].
After retrieving the ideal audio samples, the volume setting, and the reactivity setting, the audio source 120 may generate a data packet for transmission to the local sensor 110 [step 480 ]. FIG. 10 illustrates an exemplary configuration, consistent with the present invention, of a data packet 1000 generated by audio source 120 . As illustrated, the data packet 1000 may include a header 1020 and a data field 1030 .
The header 1020 may contain the overhead information associated with the process of transmitting data over a communications channel. The header 1020 may include a source address 1022 and a destination address 1024 . Source address 1022 may include a unique identifier that represents the address of the source transmitting data packet 1000 . In this case, the source address may identify the audio source 120 . Destination address 1024 may include a unique identifier that represents the address of the recipient of data packet 1000 (i.e., local sensor 110 ). It will be appreciated that a typical packet header may include additional fields (not shown), such as a length field, an error correction field, and the like.
Data field 1030 may represent the portion of data packet 1000 that contains the actual data for which the transmission is being made. Data field 1030 may include multiple fields of information, such as a volume setting 1032 , a reactivity setting 1034 , and an ideal audio sample 1036 . The volume setting 1032 may include an indication of a current setting of volume input device 320 . The reactivity setting 1034 may include an indication of a current setting of reactivity input device 340 . The ideal audio sample 1036 may contain the ideal audio signals sampled by audio source 120 .
While a packet structure having a header has been set forth, it will be appreciated that the above description is equally applicable to a packet structure having a trailer or any other similar or equivalent format.
After generating the data packet 1000 , audio source 120 may then transmit the data packet 1000 to the local sensor 110 [step 490 ]. The data packet 1000 may be transmitted via communications interface 335 to the local sensor 110 in any well-known manner, such as by any wireless, wired, or optical technique.
The local sensor 110 may receive data packet 1000 via, for example, communications interface 220 [step 510 ] ( FIG. 5 ). The local sensor 110 may then extract the ideal audio sample 1036 transmitted in data packet 1000 [step 520 ] and store this information in memory 240 [step 530 ].
Local sensor 110 may extract the volume setting information 1032 transmitted in data packet 1000 [step 540 ]. As indicated above, this information may represent a current volume setting value of the volume input device 320 . Local sensor 110 may store the volume setting value in, for example, memory 240 [step 550 ].
Local sensor 110 may extract the reactivity setting information 1034 transmitted in data packet 1000 [step 560 ]. As indicated above, this information may represent a current reactivity setting value of the reactivity input device 340 . Local sensor 110 may store the reactivity setting value in memory 240 [step 570 ].
To determine whether a volume adjustment is necessary, the local sensor 110 may sample the audio signals transmitted by audio source 120 via its audio output device 355 [step 610 ] ( FIG. 6 ). The local sensor 110 may receive the audio samples via, for example, its input device 260 . These audio samples are referred to hereinafter as “local audio samples.” The local sensor 110 may then store the local audio samples in, for example, memory 240 [step 620 ].
The local sensor 110 may determine the best correlation between the local audio samples received through input device 260 , and the ideal audio samples received in data packet 1000 [step 630 ]. In general, there may be some delay between the two samples, and the local audio sample may be corrupted from the ideal audio samples due to extraneous noise picked up by the local sensor's input device 260 . The local sensor 110 may use any of the conventional techniques well known in the art to correlate or line-up the two corresponding samples. The local sensor 110 may then determine the average volume of the ideal audio samples [step 640 ] and the local audio samples [step 650 ] in a well-known manner. The average volumes may be determined in any number of classical ways, such as simple averaging, time series averaging, or any other standard method.
The local sensor 110 may multiply the average value for the ideal audio samples by the volume setting value 1032 received in the data packet 1000 in order to adjust the desired value to a level consistent with the user's volume setting [step 640 ].
The local sensor 110 may then compare the average volumes of the ideal audio sample and the local audio sample in a well-known manner [step 710 ] ( FIG. 7 ). FIG. 11 illustrates an exemplary comparison operation consistent with the present invention. As illustrated, the local sensor 110 determines an average volume level 1110 for the ideal audio sample received in data packet 1000 . The local sensor 110 also determines an average volume level 1120 for the local audio samples captured by input device 260 . The local sensor 110 may then compare the two average volumes to arrive at a delta volume 1130 as illustrated by the difference between the dashed lines in FIG. 11 . The delta volume may represent the average difference between the ideal audio sample and the local audio sample.
Local sensor 110 may then determine if the average difference between the ideal audio sample and the local audio sample (i.e., the delta volume 1130 ) is greater than a threshold value [step 720 ]. The threshold value may represent a value, below which it is determined that the two audio samples are close enough such that no volume adjustments are necessary. This threshold value may be set, for example, by the user or manufacturer of local sensor 110 .
If the local sensor 110 determines that the average difference between the local audio samples and the ideal audio samples is below or less than the threshold value, then no immediate volume adjustment is necessary and local sensor 110 may return to step 510 [step 730 ]. If the average difference between the local audio samples and the ideal audio samples is greater than the threshold value, local sensor 110 may set a flag or indicator that a volume adjustment at audio source 120 is warranted [step 740 ]. The local sensor 110 may store this flag in memory 240 until needed.
Local sensor 110 may then determine if the average volume of the local audio signal is less than the average volume of the ideal audio sample [step 750 ]. This may be determined, for example, by subtracting one average volume from the other. If the average volume of the local audio sample is less than the average volume of the ideal audio sample, then local sensor 110 may set a flag to indicate that a volume increase is warranted [step 760 ]. If the average volume of the local audio sample is greater than the average volume of the ideal audio sample, then local sensor 110 may set a flag to indicate that a volume decrease is warranted [step 770 ].
Once local sensor 110 determines that a volume adjustment is necessary, the local sensor 110 may then determine if it is time to adjust the volume of audio source 120 [step 810 ] ( FIG. 8 ). The local sensor 110 may query memory 240 to obtain the reactivity setting 1034 that was transmitted from the audio source 120 in data packet 1000 . The local sensor 110 may then determine how long it has been since the last volume adjustment command has been sent to the audio source 120 , and based on that time along with the reactivity setting 1034 may determine if it is time to send the another volume adjustment command. If a predetermined amount of time has not elapsed since the last volume adjustment, local sensor 110 may delay any future adjustments until the appropriate time.
If the delay since the last volume adjustment command was sent is consistent with the value of the reactivity setting, then local sensor 110 may determine if a flag is set indicating that either an increase or decrease in the volume is warranted [step 820 ]. If a flag is not set, indicating that no volume adjustment is necessary, then local sensor 110 may wait until the end of the next time period before looking again for the flag indicating whether an adjustment is necessary.
If a flag is set to indicate that a volume adjustment is necessary, then local sensor 110 may generate a data packet containing the volume adjustment command [step 830 ]. FIG. 12 illustrates an exemplary configuration 1200 , consistent with the present invention, for the data packet transmitted by local sensor 110 . As illustrated, data packet 1200 may include a header 1220 and a data field 1230 .
The header 1220 may contain overhead information associated with the process of transmitting data over a communications channel. As illustrated, the header 1220 may include a source address 1222 and a destination address 1224 . Source address 1222 may include a unique identifier that represents the address of the source transmitting data packet 1200 . In this case, the source address would identify the local sensor 110 . Destination address 1224 may include a unique identifier that represents the address of the recipient of data packet 1200 (i.e., audio source 120 ). It will be appreciated that a typical packet header may include additional fields (not shown), such as a length field, an error correction field, and the like.
Data field 1230 may represent the portion of data packet 1200 that contains the actual data for which the transmission is being made. Data field 1230 may include, for example, a volume adjustment command 1232 . The volume adjustment command 1232 may include a command to either increase or decrease the volume of audio source 120 . The volume adjustment command 1232 may include a value (not shown) representing the amount that the volume of audio source 120 is to be adjusted.
While a packet structure having a header has been set forth, it will be appreciated that the above description is equally applicable to a packet structure having a trailer or any other similar or equivalent format.
Local sensor 110 may then transmit data packet 1200 to audio source 120 [step 840 ]. The local sensor 110 may transmit the data packet 1200 in any well-known manner, such as by any wireless, wired, or optical technique.
The audio source 120 may receive the data packet 1200 from local sensor 110 via, for example, communications interface 335 [step 910 ] ( FIG. 9 ). Audio source 120 may extract the volume adjustment command 1232 from the data packet 1200 in a well-known manner [step 920 ]. After extracting the volume adjustment command 1232 , audio source 120 may determine whether the volume needs to be increased [step 930 ]. For illustration purposes, the volume adjustment command 1232 could consist of a single binary digit. A value of “0” may indicate that the volume needs to be decreased, and a value of “1” may indicate to audio source 120 that the volume needs to be increased.
If audio source 120 determines that an increase in volume is warranted, the audio source 120 may increase the volume incrementally [step 940 ]. CPU 310 may increase the gain of amplifier 350 and hence the volume of audio output device 355 which may, for example, consist of one or more standard speakers. If audio source 120 determines that a decrease in volume is warranted, the audio source 120 may decrease the volume incrementally [step 950 ]. In this case, for example, CPU 310 may reduce the gain of amplifier 350 , and hence the volume of audio output device 355 .
Alternative Exemplary Processing
FIGS. 13–17 illustrate an alternative exemplary process, consistent with the present invention, for maintaining a constant perceived audio level at a user. Processing may begin with the audio source 120 sampling an incoming audio signal, such as the audio input in FIG. 3 [step 1310 ]. Since the audio signal is sampled at its source, the signal may be considered “ideal.” The audio source 120 may store a predetermined number of ideal audio samples in, for example, memory 315 [step 1320 ]. As will be appreciated later, the audio source 120 may store a predetermined number of ideal audio samples to determine whether a volume adjustment is necessary. If the predetermined number of samples has not been stored [step 1330 ], the audio source 120 may collect additional samples.
When the predetermined number of ideal audio samples has been collected [step 1330 ], the audio source 120 may obtain the current volume setting [step 1340 ]. The audio source 120 may obtain the current volume setting from the volume controller 325 . Once obtained, the audio source 120 may store that information in memory 315 [step 1350 ]. The audio source 120 may also obtain the current reactivity setting from reactivity controller 345 [step 1360 ], and may store that information in memory 315 [step 1370 ]. Once this information is stored, the audio source 120 may transmit a request to the local sensor 110 for local audio sample [step 1380 ].
The local sensor 110 may receive the request from the audio source 120 [step 1410 ] ( FIG. 14 ). In response thereto, the local sensor 110 may sample local audio signals in the form of sound waves from audio source 120 via, for example input device 260 [step 1420 ] ( FIG. 14 ). In other implementations consistent with the present invention, the local sensor 110 may automatically sample the local audio signals at predetermined periods of time. The local sensor 110 may store the local audio samples in memory 240 [step 1430 ].
Local sensor 110 may then generate a data packet containing the local audio samples [step 1440 ]. FIG. 18 illustrates an exemplary configuration 1800 , consistent with the present invention, for the data packet transmitted by local sensor 110 . As illustrated, data packet 1800 may include a header 1820 and a data field 1830 .
The header 1820 may contain overhead information associated with the process of transmitting data over a communications channel. As illustrated, the header 1820 may include a source address 1822 and a destination address 1824 . Source address 1822 may include a unique identifier that represents the address of the source transmitting the data packet. In this case, the source address would identify the local sensor 110 . Destination address 1824 may include a unique identifier that represents the address of the recipient of data packet 1800 (i.e., audio source 120 ). It will be appreciated that a typical packet header may include additional fields (not shown), such as a length field, an error correction field, and the like.
Data field 1830 may represent the portion of data packet 1800 that contains the actual data for which the transmission is being made. Data field 1830 may include, for example, the local audio samples 1832 . The local audio samples 1832 may include the audio samples received by local sensor 110 from audio source 120 in the form of sound waves. These samples may be received, for example, via input device 260 , and may represent the state of the local audio signals in the proximity of the user.
While a packet structure having a header has been set forth, it will be appreciated that the above description is equally applicable to a packet structure having a trailer or any other similar or equivalent format.
Local sensor 110 may then transmit data packet 1800 to audio source 120 [step 1450 ]. The local sensor 110 may transmit the data packet 1800 in any well-known manner, such as by any wireless, wired, or optical technique.
The audio source 120 may receive the data packet 1800 from local sensor 110 via, for example, communications interface 335 [step 1510 ] ( FIG. 15 ). Audio source 120 may extract the local audio samples 1832 from the data packet 1800 in a well-known manner, and may store this information in memory 315 [step 1520 ].
The audio source 120 may then determine the best correlation between the local audio samples and the ideal audio samples now stored in memory 315 [step 1530 ]. In general, there may be some delay between the two samples, and the local audio sample may be corrupted from the ideal audio samples due to extraneous noise picked up by the local sensor's input device 260 . The audio source 120 may use any of the conventional techniques well known in the art to correlate or line-up the two corresponding samples. The audio source 120 may then determine the average volume of the ideal audio samples [step 1540 ] and the local audio samples [step 1550 ] in a well-known manner. The average volumes may be determined in any number of classical ways, such as simple averaging, time series averaging, or any other standard method. The audio source 120 may multiply the average value for the ideal audio samples by the volume setting value previously stored in memory 315 , or obtained from the volume controller 325 , in order to adjust the desired value to a level consistent with the user's volume setting [step 1540 ].
The audio source 120 may then compare the average volumes of the ideal audio sample and the local audio sample in a well-known manner [step 1610 ] ( FIG. 16 ). FIG. 11 , as described previously, illustrates an exemplary comparison operation consistent with the present invention. As illustrated, the audio source 120 determines an average volume level 1110 for the ideal audio sample. The audio source 120 also determines an average volume level 1120 for the local audio samples captured by local sensor 110 and transmitted to audio source 120 in data packet 1800 . The audio source 120 may then compare the two average volumes to each other to arrive at a delta volume 1130 as illustrated by the difference between the dashed lines in FIG. 11 . The delta volume may represent the average difference between the ideal audio sample and the local audio sample.
Audio source 120 may then determine if the average difference between the ideal audio sample and the local audio sample (i.e., the delta volume 1130 ) is greater than a threshold value [step 1620 ]. The threshold value may represent a value, below which it is determined that the two audio samples are close enough such that no volume adjustments are necessary. This threshold value may be set, for example, by the user or manufacturer of audio source 120 .
If the audio source 120 determines that the average difference between the local audio samples and the ideal audio samples is below the threshold value, then no immediate volume adjustment is necessary and audio source 120 may return to step 1310 [step 1630 ]. If the average difference between the local audio samples and the ideal audio samples is greater than the threshold value, audio source 120 may set a flag or indicator that a volume adjustment at audio source 120 is warranted [step 1640 ]. The audio source 120 may store this flag in memory 315 until needed.
Audio source 120 may then determine if the average volume of the local audio signal is less than the average volume of the ideal audio sample [step 1650 ]. This may be determined, for example, by subtracting one average volume from the other. If the average volume of the local audio sample is less than the average volume of the ideal audio sample, then audio source 120 may set a flag to indicate that a volume increase is warranted [step 1660 ]. If the average volume of the local audio sample is greater than the average volume of the ideal audio sample, then audio source 120 may set a flag to indicate that a volume decrease is warranted [step 1670 ].
Once audio source 120 determines that a volume adjustment is necessary, the audio source 120 may then determine if it is time to adjust its volume [step 1710 ] ( FIG. 17 ). The audio source 120 may query memory 315 to obtain the reactivity setting stored there. The audio source 120 may then determine how long it has been since the last volume adjustment was made, and based on that time, along with the reactivity setting, may determine if it is time to make another volume adjustment. If a predetermined amount of time has not elapsed since the last volume adjustment, audio source 120 may delay any future adjustments until the appropriate time. If the delay since the last volume adjustment is consistent with the value of the reactivity setting, then audio source 120 may determine if a flag is set indicating that either an increase or decrease in the volume is warranted [step 1720 ]. If a flag is not set, indicating that no volume adjustment is necessary, then audio source 120 may wait until the end of the next time period before looking again for the flag indicating whether an adjustment is necessary.
If a flag is set indicating that a volume adjustment is necessary, then audio source 120 may then determine whether the volume needs to be increased [step 1730 ]. Audio source 120 may, for example, query memory 315 to determine if a flag is set to indicate that an increase in volume is warranted. If audio source 120 determines that an increase in volume is warranted, then audio source 120 may increase the volume incrementally [step 1740 ]. CPU 310 may increase the gain of amplifier 350 and hence the volume of audio output device 355 which may, for example, consist of one or more standard speakers.
If audio source 120 determines that a decrease in volume is warranted, then audio source 120 may decrease the volume incrementally [step 1750 ]. Audio source 120 may, for example, query memory 315 to determine if a flag is set to indicate that a decrease in volume is warranted. In this case, for example, CPU 310 may reduce the gain of amplifier 350 , and hence the volume of audio output device 355 .
CONCLUSION
Systems and methods, consistent with the present invention, provide a mechanism by which an audio source can maintain a constant perceived volume level at a local sensor. A local sensor in close proximity to a user provides feedback to the audio source to raise, lower, or maintain its volume level so as to maintain that perceived constant volume level at the local sensor.
The foregoing description of exemplary embodiments of the present invention provides illustration and description, but is not intended to be exhaustive or to limit the invention to the precise form disclosed. Modifications and variations are possible in light of the above teachings or may be acquired from practice of the invention. For example, while the above-described processing is directed to adjusting the volume of audio signals, it will be appreciated that the present invention is equally applicable to adjusting sub-bands of an audio signal. In such an implementation, the local sensor may sample audio signals from each of a plurality of sub-bands. The local sensor may then instruct the audio source whether an adjustment of any or all of the sub-bands is necessary. This would allow, for example, local sensor to boost the bass of the audio source, while keeping the treble constant.
While series of steps have been described with regard to FIGS. 4–9 and 13 – 17 , the order of the steps may be varied in other implementations consistent with the present invention. No element, step, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly described as such.
The scope of the invention is defined by the claims and their equivalents. | A system adjusts audio levels so as to maintain a constant perceived audio level at a user's location. The system includes a sensor ( 110 ) and an audio device ( 120 ). The sensor ( 110 ) receives a first audio signal, receives at least one data packet ( 1000 ) comprising a second audio signal, determines whether a difference between an average volume level of the first audio signal and the second audio signal exceeds a threshold value, generates a response data packet ( 1200 ) including a volume adjustment command when the difference between the average volume level of the first audio signal and the second audio signal exceeds the threshold value, and transmits the response data packet ( 1200 ). An audio device ( 120 ) transmits the first audio signal, transmits the at least one data packet ( 1000 ) to the sensor ( 110 ), receives the response data packet ( 1200 ), and adjusts an audio level based on the response data packet ( 1200 ). | 7 |
This application is a continuation of application Ser. No. 07/719,096 filed Jun. 20, 1991 now abandoned, which is a continuation of Ser. No. 07/453,549 filed Dec. 20, 1989 now abandoned.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is related by subject matter to U.S. patent application Ser. No. 07/453,543 now abandoned, having common title, inventor, and assignee as the instant application and filed concurrently herewith.
FIELD OF THE INVENTION
The invention concerns methods and apparatuses for etching copper layers, especially copper layers overlying a layer of a second material, such as found in printed circuit fabrication and the seed copper layers used in printed circuit fabrication and in integrated circuit metallization layers, by photo-formed and photo-activated halogen radicals.
BACKGROUND OF THE INVENTION
Patterning of a relatively thick copper layer or a thinner seed copper layer has been a requirement of printed circuit fabrication techniques. More recently, it has been desired to pattern thin copper layers in integrated circuit fabrication technology. Aluminum has been commonly used successfully in integrated circuit technology to form conductive leads between and across active elements of the integrated circuits, partly because aluminum has been found to be easily patterned by several techniques. However, as discussed by Hu, et al., in "Diffusion Barrier Studies for CU", 1986 IEEE V-MIC Conference, Jun. 9-10, 1986, pages 181-187, copper offers several advantages over aluminum metallization layers in integrated circuits such as higher conductivity, better electromigration resistance, and reduced power consumption. As further discussed, however, in the same article, copper has a greater tendency to diffuse into silicon than aluminum. Satisfactory solution to this problem has, nevertheless, been found by the use of diffusion barriers between the silicon and other layers of integrated circuits and the copper metallization layers.
Patterned etching of copper films has been accomplished, primarily in printed circuit fabrication, by wet processes wherein a protective, patterned film, such as a photoresist is applied to a copper layer and then a strong liquid etchant, usually an acid, is applied to etch the exposed copper down to the base material. This process presents several problems when applied to integrated circuit fabrication, such as the following. The wet processes are inherently "dirty" in that contaminants in the etchant can be introduced to the integrated circuit wafer. The wet etchants required are generally hazardous to operators by contact and inhalation of vapors produced thereby. Etching of copper requires etchants, high temperatures, or both which may damage the other layers of an integrated circuit. Etching of copper by wet processes is isotropic, making copper metallization for VLSI circuits extremely difficult. Disposal of the waste products of wet etch processes is becoming more expensive.
Therefore, because of the increased desire to utilize copper metallization in integrated circuits and the problems inherent in known wet etch techniques, it has become more important to develop more effective etching processes and equipment for etching copper layers, especially as used in integrated circuit fabrication.
Sputtering techniques are utilized presently to remove copper from copper-doped aluminum films and therefore may have application to removing copper films. However, sputtering, the physical dislodging of copper atoms and clusters by high energy ion bombardment, does not exhibit selective removal of various films and will result in extreme build-up of residue in the reaction chamber, since copper is not converted to a volatile species. Also, sputter removal techniques are relatively slow, difficult to control, and exhibit insufficient selectivity to masking layers.
Dry etch processes involving a plasma to form reactive agents such as a halogen, an amine, or an organic radical which react and form volatile copper products could be an approach to an effective etch process for copper which solves some of the problems encountered in other processes, particularly the redeposit of residue on reaction chambers. However, due to the known high melting and boiling points of the copper compounds that would be formed, coupled with the normal range of substrate temperatures associated with these plasma processes, it has been thought that volatilization would not occur and that these processes would be unsuccessful. Moreover, a plasma discharge produces a wide range of disassociated, reactive products that can combine homogenously or heterogeneously to form a polymer residue. For example, hydrocarbon and chlorocarbon can produce heavy residues of polymer generating many particles. Also, if the reaction product of these processes does not volatize, it has been thought that the surface reaction would prevent further reaction of the copper bulk material below this surface. Some investigation of the reaction of chlorine with copper has been done as discussed by W. Sesselmann, et al., in "The Interaction of Chlorine with Copper", Surface Science, vol. 176(1986) pages 32-90. Some early investigation of ion etching of copper films is discussed by Schwartz, et al, in "Reactive Ion Etching of Copper Films", Journal of the Electochemical Society, Vol. 130, No. 8 (1983), pages 1777-1779.
SUMMARY OF THE INVENTION
The Inventor has found that dry or dry/wet processes using halogen ions generated and activated or energized by light and exposed to a copper film are effective processes for etching copper metallization layers, even in the environment of integrated circuit fabrication.
The Inventor has discovered that, especially at higher substrate or chamber temperatures, anisotropic volatilization of the copper halide reaction product from unmasked areas is possible. And, further, even when the copper halide product is not volatile, complete reaction of a bulk copper film with the halide ion occurs directionally or anisotropically to produce a copper halide reaction product which is easily removed anisotropically by a solvent or water wash. In either case the reaction product is removed anisotropically.
It is therefore an object of the invention to provide an etch process for copper films that is useful in fabrication processes for integrated circuits.
It is a further object of the invention to sustained patterned critical dimension definition and control in a copper etch process.
It is an object of the invention to provide an etch process for copper films which does not require a strong wet etchant.
It is a further object of the invention to provide a copper etch process that is anisotropic and can be used in integrated circuit fabrication.
It is also an object of the invention to provide for photo-induced directional diffusion of a radical through copper.
It is a further object of the invention to provide an etch process for copper films which avoids the contamination of process chambers caused by sputtering techniques.
It is a further object of the invention to provide an etch process for copper which is, essentially, a dry process. These and further benefits of the invention will be evident to one of ordinary skill in view of the drawing figures and detailed description of the embodiments to follow.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
FIG. 1 is a schematic drawing of an embodiment of a reaction chamber as used in the process according to the instant invention.
FIGS. 2a and 2b are drawings representative of side views by electron microscopy of a semiconductor wafer during two stages of the etch process according to the instant invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, there is shown a sealed chamber 6 having a substrate holder 8, which normally has temperature controlled heating elements (not shown) for heating a substrate placed thereon. Shown on the substrate holder 8, is a drawing representation, not to scale, of a typical integrated circuit wafer having a substrate 9, for example a single crystal silicon substrate, a copper metal layer 10, and a patterned mask 11. Mask 11, in integrated circuit fabrication processes, would typically be a photo sensitive mask material of known types which is patterned and etched according to well-known photolithographic techniques. However, mask 11 may also be fabricated by techniques other than photolithography. Substrate holder 8 may contain controlled heating elements (not shown) for the purpose of heating the substrate 9 to a desired process temperature, preferably above 200° C. The process temperature desired may be determined according to several factors. If a high degree of volatilization or complete volatilization of the combinative copper product is desired, a high process temperature is required. The exact temperature required is dependent upon the radical agent used. However, factored against utilization of such high process temperatures is the fact that the integrated circuit wafers processed may be damaged or destroyed by the temperatures required for significant volatilization. Of course, printed circuit substrates may not be so damaged by high process temperatures.
Again, referring to FIG. 1, a high intensity light source 4, such as a filtered ultra violet source, e.g., a 1000 watt Hg/Xe lamp, is located above the chamber 6. Focusing elements 2 and 4 are arranged to direct the high intensity light through transparent window 7, which may be a quartz window, onto the surface of the masked copper layer 10 and 11. The window 7 is sealed, as by "O"-ring 14. It is pointed out that, although FIG. 1 shows the high intensity light directed perpendicularly to the wafer, it has been found to be also effective if the chamber is arranged so that the light is directed at other angles to, and even parallel to, the wafer.
Inlet port 12, having valve 13, allows reactant R to enter the chamber 6 and contact the wafer 9, 10 and 11. Reactant R is a halogen radical-chlorine, fluorine, bromine or iodine. The halogen radical may be produced from a halogen compound, e.g., CF 4 by photochemical dissociation, microwave afterglow dissociation or plasma discharge dissociation, for example, as is known in the art. Also the halogen radical may be produced within the chamber by photochemical dissociation by, for example, introducing CL 2 to the high intensity ultraviolet light 5 from source 4. The halogen radical R may be light activated by high intensity light 5 and contacts the copper layer 10 and mask layer 11.
The etch process which occurs within the chamber 6, using a halogen radical R which may be light activated will follow two different methodologies, depending primarily upon the temperature at which the process occurs and the reactant used. As the copper layer 10 is contacted by light activated reactant R*, the copper and halogen atoms react at the surface to form a halogen copper compound. These reactions may be represented as:
I. Radical Formation
P(gas)+hν→R (or R*), where P is a Parent molecule, R is an amine or organic radical, and R* is a light-activated radical.
II. Radical Formation with Cu
R+Cu.sub.(s) →CuR or,
R*+Cu.sub.(s) →CuR or,
R ads . . . Cu.sub.(s) +hν→CuR, where (g) is gas, (s) is solid.
III. CuR Removal
CuR+S→CuR(soln) or,
CuR.sub.(ads) →CuR(g) or,
CuR.sub.(ads) +hν→CuR.sub.(g), where S is solvent, (soln) is solution, and (ads) is absorbed.
If CuR, under the conditions of the reaction, is volatile, then the product CuR is released as a vapor and may be pumped as a vapor from the chamber 6.
If however, product CuR is not volatile, the product remains on the copper layer surface. Surprisingly however, the Inventor has found that the reaction continues throughout the copper layer to form CuR. The surface reaction does not block reaction beneath the surface under the process conditions disclosed. After the reaction has then occurred throughout the copper layer 10, the resulting copper halogen product CuR can be washed away using an appropriate solution such as water or acetone. The copper halogen product will easily enter into solution. Moreover, the diffusion of R, in CuR to react further with copper is believed to be photo-induced directional diffusion.
FIGS. 2a and 2b show a representation of an integrated circuit wafer using a copper metallization layer during two stages of the process according to the invention as has been observed by electron microscopy. The wafer of FIG. 2a is shown before the etch process showing a silicon substrate 9, a silicon dioxide layer 9a, a titanium tungsten barrier layer 10a, and a copper layer 10.
A mask layer 11 is applied and patterned by well-known photolithography methods, for example, or by other known means. In this instance, a cantilevered resist overhang 11a is generated by an image-reversal development process.
FIG. 2b depicts the same wafer after etch processing steps have been accomplished, as in the chamber of FIG. 1 under the following conditions. The wafer (9, 10 and 11) may be deglazed as by a dilute nitric acid. A 1000 watt Mercury-Xenon lamp with a water filter was directed upon the wafer 9, 10 and 11. The water filter serves to extract most of the infrared light above 1.3 nm while passing the deep ultraviolet light, down to about 200 nm. The light was directed orthogonally to the wafer. The wafer was heated to a temperature of 200 C. Molecular chlorine, Cl 2 , was introduced to the chamber, at 10 torr, at the rate of 100 sccm. The Cl 2 was photo-dissociated by the photo energy of the light source to generate Cl ion radicals. The wafer was exposed to the chlorine radical for 10 minutes. After this time, FIG. 2b shows that the entire copper layer which was not masked has reacted and expanded to about three times its previous thickness. The resulting product layer film 12 was found to be CuCl 2 . Further, a void 14, due to the initial resist profile, can be noted. The resulting film may be removed by a simple wash step. The reaction products are typically removed with an acetone or water wash. Note that the copper is not etched laterally where the resist contacts the copper film surface.
It is pointed out that the invention has been disclosed with respect to embodiments which are not intended to be limiting. It is intended that the parameters suggested in these embodiments may be varied within certain latitudes to achieve desired results. The scope of the invention, therefore, is intended to be limited only by the appended claims and equivalent modifications. | An etch process for etching copper layers that is useable in integrated circuit fabrication is disclosed which utilizes halides to react with copper, preferrably using photoenergizing and photodirecting assistance of high intensity ultraviolet light, to produce a product which is either volatile or easily removed in solution. The process is anisotropic. | 2 |
This is a continuation of PCT application No. PCT/SE98/00303, filed Feb. 20, 1998, the entire content of which is hereby incorporated by reference in this application.
TECHNICAL FIELD
The present invention relates to a pressure sensor element comprising built-in temperature measuring means, in particular a ceramic capacitive pressure sensor element having capacitor electrodes on tile bottom side of a house part and on the top side of a diaphragm.
BACKGROUND
A ceramic capacitive sensor element 1 for sensing pressures is usually built of mainly two parts, see FIG. 9 . These parts comprise a stable circular base plate 3 having a diameter of typically 20-30 mm and a thickness of typically 4-5 mm, also called a housing or house part, and a thinner circular plate 5 , also called a diaphragm, applied to one of the large surfaces of the base plate 3 and joined thereto by means of for example glass joints 6 at its circular edge. The diaphragm 5 is attached so that its central portion can move, bend or be deflected in relation to the base plate, i.e., the basically flat shape of the diaphragm can change for varying pressures acting thereon. The diaphragm has the same diameter as the base plate and has a thickness, which is adapted to the magnitude of the load, i.e., the pressure, to which the diaphragm is intended to be subjected. The change of the position of the central portion of the diaphragm 5 is detected as a change of the capacitance between two parallel and opposite electrodes 7 , 9 of, e.g., gold, which are applied by means of thin film methods on the central portions of the inner, opposite surfaces of the base plate 3 and the diaphragm 5 respectively. In the measurement of pressure the variable searched for is the pressure P meas , which acts on the bottom, free surface of the diaphragm 5 , and it is measured in relation to a reference pressure P ref acting on the inner surface of the diaphragm, i.e., the surface facing the base plate 3 . Temperature measurement elements can be applied to the interior side of the diaphragm 5 , see German publication document DE-A1 41 36 999. However, this involves a large disadvantage due to the fact that additional surface coatings on the diaphragm will always to some extent influence the mechanical characteristics of the diaphragm and in particular temperature induced movements in the diaphragm can increase. This can be particularly embarrassing when measuring using thin diaphragms.
SUMMARY
It is an object of the invention to provide a pressure sensor comprising integrated measurement of temperature and having a high accuracy and repeatability.
It is another object of the invention to provide a capacitive pressure sensor, which comprises temperature measurement elements which have a minimal influence of the mechanical characteristics of the measurement diaphragm and also on the electric fields at the capacitor electrodes of the pressure sensor.
The general problem solved by the invention is thus how to arrange temperature measurement means inside a compact ceramic pressure sensor of the capacitive type allowing an accurate temperature measurement at the place where it is needed, i.e. as near the capacitor electrodes as possible, and at the same time not interfering with the electric characteristics of the capacitor electrodes and not interfering with the movement of the measurement diaphragm.
The sensor element is designed to comprise an integrated temperature measurement bridge, which makes a compensation of the drift of the sensor element possible for a change of the ambient temperature and for temperature changes of the measurement medium. The signal from the measurement bridge can be processed digitally, what increases the applicability of the temperature measurement bridge. Resistive bridge elements of thin film type are coated on an interior surface inside a sensor housing comprising a thick base plate and a thin plate, the interior surface being located between the base plan and the thin plate, so that the bridge is separated from the measurement electrodes only by the relatively thin plate.
A pressure sensor of substantially ceramic material thus comprises a rigid and stable, non-deformable house part consisting of a thicker base plate and an interior shielding plate, and furthermore it comprises a diaphragm having a portion movable with the pressure which is to be sensed or measured. A cavity comprising a reference pressure is formed between the shielding plate and the diaphragm. On the opposite walls of the cavity electrodes are arranged, which form a capacitor, the capacity of which can be sensed by electronic circuits. A temperature sensor comprises a bridge circuit. This circuit includes thermistors arranged inside the house part, between the base plate and the shielding plate, and reference resistors on that surface of the base plate which faces outwards. The shielding plate is thin, e.g., having a thickness substantially between the thickness of the diaphragm and twice that thickness. Thereby the thermistors are located near the diaphragm and are sensitive to the temperature thereof. This position of the thermistors also results in that the temperature sensor elements, particularly the thermistors, give a minimum influence on the electric properties of the pressure sensor and in particular on the mechanical properties of the diaphragm.
Generally, a pressure sensor can comprise a pressure sensor house assembly made of substantially ceramic materials. The assembly comprises a substantially rigid house part having no movable portions and an at least partly movable diaphragm. A cavity is formed between the house part and the diaphragm. At least one temperature sensor or temperature sensing element is arranged in the interior of the house part, i.e inside the material of the house part. The temperature sensing element is thus not in contact with the exterior of the assembly and not in contact with the cavity. The temperature sensing element is preferably located at or very near the cavity and can be separated therefrom only by a ceramic plate. This ceramic plate is advantageously a thin plate, having a thickness substantially equal to the thickness of the diaphragm or at most equal to twice that thickness. Preferably, the temperature sensor is also located at the periphery of the house part in order not to interfere with electrical fields at central portions of the house part and the diaphragm.
The temperature sensing element can be arranged between a thicker base plate and a thinner shielding plate, the latter of which has a surface, which forms a wall in the cavity, wand in particular it can be arranged between an interior surface of the base plate and a joint, which attaches the base plate to the shielding plate
An electrically conducting, shielding layer can be located between the base plate and the shielding plate and preferably centrally in the contact surface between the base plate and the shielding plate. Then the shielding layer and the temperature sensor may be located separately from each other, as seen in directions in the contact surface between the base plate and the shielding plate.
The area of an electrode, which is centrally located on the surface of the housing part at the cavity, may be somewhat smaller the e area of an opposite electrode, which is located centrally on the surface of the diaphragm at the cavity. An electrode, which is centrally located on the surface of the diaphragm at the cavity, is preferably surrounded by a substantially annular shielding layer made of an electrically conducting material.
The pressure sensor has typically the shape of a plate such as a substantially circular plate and then house part also has the shape of a plate with the same exterior form. Then two temperature sensor elements are advantageously arranged opposite each other along a diameter and symmetrically in the house part in relation to a central axis of the house part, the central axis being perpendicular to the large surface of the house part.
Furthermore, at least one reference resistor can be applied to or at an exterior surface of the house part. For a plate-shaped pressure sensor such as a substantially circular plate two reference resistances can be applied opposite each other along a diameter and symmetrically on or at the house part respectively in relation to a central axis of the house part.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention The objects and advantages of the invention may be realized and obtained by means of the methods, processes, instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
While the novel features of the invention are set forth with particularly in the appended claims, a complete understanding of the invention, both as to organization and as content, and of the above and other features thereof may be gained from and the invention will be better appreciated from a consideration of the following detailed description of non-limiting embodiments presented hereinbelow with reference to the accompanying drawings, in which:
FIG. 1 a is a sectional view of a pressure sensor element of the ceramic, capacitive type adapted to be provided with integrated, accurate temperature measuring means,
FIG. 1 b is an exploded perspective view as seen obliquely from above of the pressure sensor element in FIG. 1 a comprising temperature measuring means,
FIG. 2 a is a view from above of a base plate included in the pressure sensor element having an applied protective film,
FIG. 2 b is a view similar to FIG. 2 a but without a protective film,
FIG. 3 a is a view of the base plate in FIGS. 2 a and 2 b as seen from below,
FIG. 3 b is a partial section taken through the region at the mouth at a through-hole intended for electrical through-connections,
FIG. 3 c is a detail view of a contact area adjacent a through-hole for electrical trough-connections as seen in a direction perpendicular to the contact surface,
FIG. 4 is a view from above of a shielding plate included in the pressure sensor element,
FIG. 5 is a view of the shielding plate in FIG. 4 as seen from below,
FIG. 6 is a view of a diaphragm included in the pressure sensor element as seen from above,
FIG. 7 is a view of the diaphragm in FIG. 6 as seen from below,
FIG. 8 is a view of a support ring included in the pressure sensor element as seen from above, and
FIG. 9 is a sectional view of a prior an sensor element of ceramic, capacitive type
DETAILED DESCRIPTION
In FIG. 1 a a cross-sectional view and in FIG. 1 b an exploded perspective view of a pressure sensor element are shown, which are generally constructed as is disclosed in the published International patent application WO 95/28624. The housing or house part 11 comprises here two ceramic parts, a thicker base plate 13 and thinner shielding plate 15 . Between these parts an electrically conducting shielding layer 81 is arranged, i.e., at the inner bottom surface of the base plate 13 and at the top surface of the shielding plate 15 . The ceramic diaphragm 19 is attached by means of a glass joint 21 at the opposite bottom surface of the shielding plate 15 , which joint is annular and is located at the periphery of the opposite surfaces of the shielding plate 15 and the diaphragm 19 . The glass joint 21 thus attaches the top surface of the diaphragm 19 to the bottom surface of the shielding plate 15 in a hermetic, helium impermeable and stable way. A stabilizing front ring 22 of ceramics is applied to the bottom surface of the diaphragm 19 . The base plate 13 , the shielding plate 15 , the diaphragm 19 and the front ring 22 have all substantially the same outer diameter and the three first part are low circular-cylindrical bodies whereas the fourth component is a low, circular-cylindrical ring.
Between the bottom surface of the shielding plate 15 and the top surface of the diaphragm 19 a cavity 23 is formed owing to the glass joint 21 , which is made so thick as to provide a distance between these surfaces. The cavity 23 has the shape of a very low cylinder, to which a channel 24 extends, see also FIGS. 3 a , 4 and 5 , up to the top surface of the base plate 13 . This channel 24 is closed by a lid 25 inside which a getter body, not shown, is located, as is described in the simultaneously filed International patent application “A sensor element having an integrated reference pressure”, so tat in the cavity 23 a very low reference pressure exists. Such a high quality integrated reference pressure increase the stability, the repeatability and the technical life-time of the sensor element and in particular this is true in the case where the diaphragm 19 , which is used the pressure sensing element, is thin or very thin.
On the bottom side of the shielding plate 15 a top measurement electrode or capacitor electrode 27 is applied as a gold layer coated by means of thin film methods. The bottom measurement electrode or the capacitor electrode 29 is also made of gold and is in the same way coated on the top side of the diaphragm 19 . The diameter of the top measurement electrode 27 is somewhat smaller than the diameter of the bottom measurement electrode 29 , see FIGS. 5 and 6. Typically they can have diameters of 5.0 and 5.5 mm respectively. Channels 31 , 33 are arranged for conducting electrical wires to the measurement electrodes 27 , 29 and a channel for conducting electrical wires to an interior bottom shielding layer, see FIG. 6, which is coated on the top surface of the diaphragm 19 . The channels 31 , 33 extend through the base plate 13 and the shielding plate 15 perpendicularly to the large surfaces thereof and are located in the cylindrical ring region thereof which is located at their envelope surface and which corresponds to the glass joint 21 having a circular ring shape. These channels thus end at their lower end in the glass joint 21 and at their upper ends mouth at the top surface of the base plate 13 and at the top surface of the shielding plate 15 respectively. The glass joint 21 encloses but does not cover the contact surfaces of the electrical through-connections, as will be described hereinafter. Conductor paths of gold applied by means of thin film methods on the opposite surfaces of the shielding plate 15 and the diaphragm 19 extend from the measurement electrodes to the contact surfaces around the channels 31 , 33 of the measurement electrode and are then partly covered by the glass joint material.
The construction of the different plates of the sensor element which are placed on top of each other to form a sensor element having integrated temperature measuring means will now be described in detail.
In FIG. 2 a the base plate 13 is shown as seen from above comprising an electrically isolating protective film, which is applied to its top surface and which covers screen printed electrical conductor paths but has holes for the connection lid 25 , for the electrical conductors to the electrodes and for electrical connections to the temperature measurement bridge and to interior shielding. Seven holes extending through the base plate 13 and having small diameters are arranged for these electrical conductors. Two of these holes are the upper portion or the mouths of the channels 31 , 33 , which extend to the measurement electrodes 27 , 29 . Around all these holes concentric circular ring shaped regions 43 , 45 , 47 , and 49 are arranged comprising silver layers applied by means of thick film methods, see FIG. 2 b , in which the base plate 13 is shown as seen from above without the protective film 41 . Conducting shielded pins, not shown, are intended to be placed in the channels 31 , 33 for the electrodes. Four through-holes 51 are arranged for electrical conductors comprising surrounding ring-shaped silver regions 47 to temperature sensitive elements, which are screen printed on the bottom side of the base plate 13 , as will be described hereinafter in conjunction with FIG. 3 a . In the holes for electrical conductors these conductors can be arranged in principle the same way, which is described in the International patent application WO 95/28624, cited above, see in particular the description of FIG. 4 .
These temperature sensitive elements are together with two reference resistors 52 on the top surface of the base plate 13 components of a temperature measurement bridge. The legs of the measurement bridge are through, the screen printed conductor paths connected to rectangular solder areas 53 which are intended for exterior electrical connection and which are located along a diameter of the base plate 13 . The screen printed conductors are in contact with the respective silver rings 47 located around the holes 51 for the conductors. Further out from the center, along the same diameter of the top surface of the base plate are the reference resistors 52 located. Centrally another rectangular solder area 55 is located, which through a screen printed electrically conducting line and the termination thereof at the circular silver ring 49 has contact with an electric conductor in the through-hole 57 to an inner shielding layer located on the top surface of the shielding plate 15 and the top surface of the diaphragm 19 , see the detailed description of these plates hereinafter. At the same diameter and farthest out, near the periphery of the base plate 13 , are the holes 31 , 33 for the electrical conductor to the electrodes located.
The bottom surface of the base plate 13 , see FIG. 3 a , has a dotted pattern, the dots being configured as hexagons 58 , made of some glass material suited for joining the plates. Around the holes 51 , 57 for the electrical conductors to the temperature measurement bridge and interior shielding layer circular rings 59 of gold are coated as thin films, see the partial sectional view in FIG. 3 b , which shows a cross-section of the region at the mouth of a hole 51 , 57 at the bottom surface. On top of these circular rings 59 of gold circular rings 61 of silver having the same diameter are applied. The circular rings 59 of gold are thin films whereas the circular rings 61 of silver are thick films having a thickness, which is adapted, so that their surfaces, which are opposite the surfaces, which are in contact with the gold rings 59 , are located in the same plane as or in the same level a the exterior surface (the bottom surface as seen in FIGS. 1 a and 1 b ) of the glass joint material in the hexagons 58 . Outside these circular rings of gold/silver surrounding circular rings 63 are arranged made of the same glass joint material as the dotted hexagon pattern 58 and having the same height as this. The channel 24 corresponds here to a through-hole 65 which has only a circular ring 67 of glass material around its mouth in the bottom surface of the base plate 13 .
The glass, which is here used on the bottom surface of the base plate 13 in the hexagon pattern 58 , can be another type than the glass material, which is coated on the bottom side of the shielding plate 15 and on the top surface of the front ring 22 , compare the discussion hereinafter.
Around the channels 31 , 33 extending to the measurement electrodes oblong gold/silver rings 69 , 71 are arranged which have elongated shapes but otherwise are the same type as the gold/silver rings 59 , 61 around the other holes 51 , 57 for electric conductors. These oblong gold/silver rings 69 , 71 act as contact points for pins for connection to the measurement electrodes, see FIG. 3 c . Around these gold/silver rings 69 , 71 oblong glass material rings 73 having an elongated shape are arranged.
Two thermistors 75 are applied as thin or thick film regions on the bottom surface of the base plate 13 directly on the ceramic surface thereof. Conductors of gold applied by means of thin film methods exend from the thermistors 75 to the contact surfaces, i.e., the silver rings 62 , for the electrical through-connecting to the top surface of the base plate 13 . The thin film conductors are applied directly to the ceramic surface and they are covered by the dotted glass pattern 58 . The thermistors 75 are also surrounded by the dotted glass pattern 58 . The thermistor material can be platinum or a PTC-material, which is compatible with the glass material. If the shielding plate 15 opposite the base plate 13 is thin, the thermistors 75 will be located in a direct vicinity of the diaphragm 19 , the central portion of which is movable with the pressure, and still the thermistors are not applied to or located on or in the diaphragm. Elements applied to the diaphragm 19 can influence the central mechanical function of the diaphragm acting as an element having a portion which is movable with the exterior pressure. The thermistors 75 are located at the periphery of the bottom surface of the base plate 13 , in parallel to the periphery and are located opposite each other at a diameter and at an angular distance of 90° from the reference resistors 52 on the top surface of the base plate 13 .
Against the bottom surface of the base plate 13 the top surface of the shielding plate 15 is located, see FIG. 4, It has two contact surfaces 77 , 79 of gold/silver films for the pins, which are used for conducting the signal from the measurement electrodes. The contact surfaces 77 , 79 can be made in principle in the same way as the contact surfaces 69 , 71 at the corresponding holes 31 , 33 on the bottom surface of the base plate 13 . A screen printed gold surface 81 of gold coated by means of thin films methods on the top side of the shielding plate 15 forms an upper portion of the interior electrical shielding. On this top shielding layer 81 a contact surface 83 is arranged which is made of sliver applied by means of thick film methods and which is located, so that it is placed at the bottom mouth of the channel 57 through the base plate 13 . The top shielding layer is along a radius prolonged by a conductor of gold, which extends to a contact area 85 located near the periphery of the late. This contact area 85 is by an electrical conductor in a through-hole 87 in the shielding plate connected to the bottom portion of the interior shielding, see more details hereinafter. The top shielding layer 81 has generally a circular shape comprising Free approximate semicircular cut-outs located in the two directions, in which the holes 31 , 33 for the electrical conductors to the electrodes are located, and in the direction in which the channel 89 , which is arranged for the channel 24 to the reference cavity and is a prolongation of the corresponding hole 65 in the base plate 13 , start at the top surface of the shielding plate 15 in order to continue into the cavity 23 at the measurement electrodes. The cut-outs of the shielding layer 81 are like said holes located at an angular distance of 90° from each other. The main portion of the shielding layer 81 , which as described has a generally circular shape, is located centrally on the top surface of the shielding plate 15 ,
On the bottom surface of the shielding plate 15 the top measurement electrode 27 is applied and is made of gold applied by means of thin film methods, see FIG. 5 . The holes 31 , 33 for the electrical conductors to the top measurement electrode 27 and to the bottom measurement electrode applied to the top side of the diaphragm 19 and the hole 87 for electrical connection to the bottom portion of the interior shielding mouth at the bottom surface of the shielding plate in the glass joint 21 , which forms a circular ring located at the periphery. The glass joint 21 encloses but does not cover the contact areas 90 , 91 which are intended for the electrical conductors and are located around the holes 31 , 33 and 87 respectively. An electrical conductor of gold applied by means of thin film methods extends from the top measurement electrode 27 , which has the shape of a centrally located, circular region, up to the contact surface 90 surrounding the corresponding hole 33 for the electrical signal conductor through the plates. The gold conductor from the top measurement electrode 27 is covered by the glass joint within the region thereof at the periphery of the shielding plate 15 .
The surface located opposite and close to the bottom surface of the shielding plate 15 is the top surface of the diaphragm 19 , see FIG. 6 . The bottom measurement electrode 29 , which also comprises a main portion having a centrally located circular shape, is made of gold applied by thin film methods and is prolonged by a radially extending electrical conductor. This radial conductor extends to an electrical contact surface 93 , which is located under the hole 31 for the electrical connection through the plates to the bottom measurement electrode. A region 95 of gold applied by means of thin film methods is also provided on the corresponding place for the hole 33 for the top measurement electrode. The lower portion of the interior shielding is a an electrically conducting layer 97 , which is located as a circular ring around the bottom measurement electrode 29 , only interrupted for the conductor between the electrode and the contact area thereof, and which through a radial portion is prolonged up to a contact area 99 , which is located under the hole 87 for the electrical connection from the top shielding layer 81 on the top surface of the shielding plate 15 . The contact areas 93 , 95 , 99 on the top surface of the diaphragm 19 are thus located opposite contact surfaces on the bottom surface of the shielding plate 15 .
The bottom surface of the diaphragm 19 , see FIG. 7, can be coated with a layer 101 of an electrically well conducing material, such as gold, covering the whole surface and applied by means of thin film methods. To the bottom side of the diaphragm a stabilizing front ring 22 or front plate can be applied, see the view of the top surface thereof in FIG. 8 . The top surface of the front ring 22 , which is engaged with the bottom surface of the diaphragm 19 , is coated with glass joint material 103 . It covers all of the circular ring surface of the front ring.
Thus a pressure sensor has been described having temperature measurement means allowing an accurate temperature measurement near the capacitor electrodes and not to any noticeable extent interfering with the electric fields of the capacitor electrodes and not interfering with the pressure-induced movements of the measurement diaphragm.
While specific embodiments of the invention have been illustrated and described herein, it is realized that numerous additional advantages, modifications and changes will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, representative devices and illustrated examples shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes as fall within a true spirit and scope of the invention. | A pressure sensor of substantially ceramic material comprises a rigid housing having a thick base plate, an interior shielding plate, and a movable diaphragm. A cavity providing a reference pressure is formed between the shielding plate and the diaphragm and on the opposite walls thereof are electrodes, which form a capacitor, the capacity of which is sensed. A temperature sensor comprises thermistors positioned inside the housing, between the base plate and the shielding plate, with the reference resistors on the surface of the base plate facing outwards. The shielding plate is thin, so that the thermistors are located near the diaphragm and are sensitive to the temperature thereof. Therefore the temperature sensor element has minimum influence on the electric properties of the pressure sensor and in particular on the mechanical properties of the diaphragm. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to operation of ambient air-cooled heat exchangers, and more particularly to monitoring the operation of such heat exchangers during very cold weather.
Heat exchangers using ambient air as the cooling medium are used in many industrial processes. For example, the overhead stream from petroleum refinery fluid catalytic cracker main fractionators is often condensed and cooled by air-cooled heat exchangers. The overhead stream from these fractionators typically contains a substantial amount of water, such as from 5 to 10 weight percent. These heat exchangers may be single pass units having a large number of parallel tubes. In a typical unit, upflow induced-draft fans pull cooling air over the tube bundles, and some means of controlling the airflow, such as adjustable louvers, is generally used in conjunction with fan control to regulate the cooling.
In very cold climates, where ambient air temperatures reach -20° C. and lower, there is a potential problem of freeze-up in the tubes due to the very cold air causing freezing of water in the tubes. This can lead to rupturing of a tube with serious consequences. Hydrocarbons leaking from a ruptured tube can present a serious fire hazard.
2. The Prior Art
Several methods have been considered or actually tried in an effort to eliminate the problem of tube freeze-up.
One proposed solution involved attaching thermocouples to the outside of the tubes which are subjected to the coldest air. The thermocouples are located near the outlet ends of the tubes as this was the coldest part of each tube. These thermocouples were connected to a monitor to provide operators with an indication of potentially freezing conditions. However, even when the thermocouples were heavily insulated, the readings obtained were unreliable and the technique was considered unsatisfactory.
Another proposed solution involved controlling the inlet air louvers in response to the bulk outlet temperature. This was not satisfactory as the relation between bulk outlet temperature and individual tube temperature was indefinite.
Another proposed solution involved partial air recirculation to hold air temperature above the freezing point. However, this would require extensive ductwork and control to provide the proper amount of warm outlet air for mixing with cold inlet air.
Still another proposal involved use of steam coils in the air inlet. This was rejected as expensive and energy inefficient.
Finally, it was proposed to install additional piping which permits shutting off a portion of the tubes during very cold weather. However, this would have required considerable work each time the temperature changed, and for that reason was rejected.
Thus, there has been a long-standing need for an improved method of controlling the operation of an air-cooled heat exchanger in very cold conditions.
SUMMARY OF THE INVENTION
According to the present invention, thermocouples are placed in the outlet ends of those tubes of an air-cooled heat exchanger which are subjected to the coldest air, and the thermocouple readings are monitored to enable an operator to take appropriate action in the event of a potential freeze-up. The thermocouples are contained in elongated thermocouple wells having a small cross section area so that flow through the tubes is hindered a minimum amount.
It is an object of this invention to provide an improved method of controlling the operation of an air-cooled heat exchanger during cold weather.
It is a further object to provide such a method that is relatively inexpensive, convenient and reliable.
The accomplishment of the foregoing objects as well as additional objects and advantages is obtained by the present invention as will be apparent from the following detailed description of the preferred embodiment thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view, partially cut away, of an air cooler of the type to which the present invention is directed.
FIG. 2 is an end view, partially cut away, of the air cooler shown in FIG. 1.
FIG. 3 is a side view, partially cut away, showing a thermocouple well for use in the invention.
FIG. 4 is an isometric view, partially cut away, showing the arrangement of the thermocouples and tubes in accordance with the invention.
FIG. 5 is a schematic view showing thermocouple leads connected to a scanner for monitoring conditions in the tubes.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, an air-cooled heat exchanger is shown generally at 10. The exchanger 10 includes inlet piping 11 which conducts a hot process stream to be cooled and condensed to an inlet header box 12. From header box 12, the hot fluid enters tubes 13 and passes to outlet header box 14. The condensed and cooled fluid from outlet header box 14 is then removed through outlet piping 15.
Cooling air is drawn over tubes 13 by induced draft fans 16 mounted above the tube bundle. Louver control 17 can be used to regulate the airflow over the tube bundle by opening or closing louvers (not shown) located below the tube handle.
It will be apparent that the lowermost row of tubes will be contacted by the coldest air, so the freeze-up problem is essentially limited to these lowermost tubes. Also, any water which condenses in the inlet header box 12 will tend to gravitate into the lowermost tubes.
Referring to FIG. 4, cleanout plugs 18 in the outer all of outlet header box 14 are provided in line with the tubes. Only the lower plugs are shown in FIG. 4, but in practice each of the tubes preferably has an associated cleanout plug. This facilitates cleaning the interior of the tubes. If the outlet header does not have cleanout plugs, then openings must be formed in the header box wall in order to practice this invention.
Referring to FIG. 3, a thermocouple well 19 of the type preferred for use in this invention is shown. Thermocouple well 19 includes an elongated small diameter section 20. This section 20 should have a cross-sectional area of not more than twenty percent, and preferably not more than ten percent, of the cross-sectional area of the tube in which it is to be placed. This is so the fluid flow interference through the tubes will be minimized. The small diameter section 20 should extend into the outlet end of tube 13 sufficiently far that the effect of the bulk temperature in outlet header box 14 will not significantly influence the reading from the thermocouple.
As best seen in FIG. 4, thermocouple well 19 threads into a cleanout hole in alignment with a tube 13. A packing nut 21 over thermocouple lead 22 secures the thermocouple in the thermocouple well.
As shown schematically in FIG. 5, a series of thermocouple leads 22 extends from each of the bottom row of tubes of an air-cooled heat exchanger to a scanner 23. The scanner preferably is an automatic electronic scanner with an adjustable alarm. The scanner may have a readout or printout, or both, preferably with an audible or visible alarm indicator. Such devices are readily available.
The alarm can be set at a reasonable level above the freezing point of water, such as about 10° C. This provides ample time for control action to be taken in the event that one or more tubes reach this temperature. Appropriate control action might include stopping or slowing one or more fans, or closing the inlet air louvers. It will be appreciated that controlling the operation by measurement of the bulk outlet temperature from outlet header box 14 would be less precise, since colder liquid from the bottom row of tubes would be blended with warmer liquid from the other rows of tubes, making it difficult to determine the actual danger point.
The operation of a heat exchanger in accordance with the invention will now be generally described. First, thermocouples are installed in the row of tubes first contacted by incoming cold air. The thermocouples are installed in thermocouple wells in the outlet end of the tubes and extend into the tubes a sufficient distance to be substantially unaffected by the warmer temperature in the outlet header box. The thermocouple wells block off less than twenty percent of the flow area of the tubes. Thermocouple leads from each thermocouple are connected to a scanning alarm device set to give an alarm upon a preset low temperature being reached. An operator would then take appropriate control action in the event of the alarm being given, preventing the temperature from going lower. Without this control action, freezing up and possibly bursting of one or more tubes would be likely.
The foregoing description is directed to a method of controlling an air cooler having top mounted induced flow fans and a series of rows of tubes carrying a mixture of water and hydrocarbons. It will be appreciated that the invention is equally appropriate for numerous modifications and variations in the equipment utilized and the process stream compositions being treated. Such modifications and variations, even if not specifically described, are intended to be included within the scope of the invention, which is defined in the appended claims. | Cold weather operation of a heat exchanger which utilizes ambient air to cool a process stream containing water is monitored by a series of thermocouples placed in the heat exchanger tubes subjected to the coldest air. A scanner monitors the thermocouples and alerts operators to unsafe or potentially freezing temperature conditions in the tubes. | 8 |
[0001] This application is the national phase under 35 U.S.C. §371 of PCT International Application No. PCT/DE01/02018 which has an International filing date of May 28, 2001, which designated the United States of America and which claims priority on German Patent Application number DE 100 26 651.7 filed May 29, 2000, the entire contents of which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention generally relates to a vacuum-tight and thermal shock-resistant material composite comprising an aluminum oxide sapphire and an aluminum oxide ceramic. The invention also generally relates to a process for producing this material composite and to a use thereof.
[0003] In this context, the term aluminum oxide sapphire is understood as meaning the crystalline corundum structure, with titanium dioxide impurities, of aluminum oxide (α-Al 2 O 3 ). By contrast, an aluminum oxide ceramic is understood as meaning a ceramic material which has been produced substantially by firing clays (aluminum silicates). This ceramic material includes, as its main constituent, aluminum oxide in the corundum modification which is incorporated in a vitreous phase. In addition, further metal oxides may be present in this ceramic.
BACKGROUND OF THE INVENTION
[0004] A transparent aluminum oxide ceramic is used, for example, in high-pressure gas discharge lamps, as described, for example, in EP-A-0 327 049 and DE-A-23 07 191. A metallic conductor has to be guided into the aluminum oxide ceramic, which is generally tubular and provided as a discharge vessel, and has to be connected to the aluminum oxide ceramic in a vacuum-tight manner. For this purpose, there is provision for a metallization paste to be sintered onto the aluminum oxide ceramic, so that a metal layer is obtained. The metallic conductor is then sealed to the metal layer in a vacuum-tight manner, for example by means of a brazing solder. U.S. Pat. No. 3,590,468 has described a process for forming a seal between a pure aluminum oxide and a metal. Therefore, the prior art has only disclosed a material composite comprising an aluminum oxide ceramic and a metal, but not a material composite comprising an aluminum oxide sapphire and an aluminum oxide ceramic.
SUMMARY OF THE INVENTION
[0005] Since the coefficients of thermal expansion of an aluminum oxide sapphire and of an aluminum oxide ceramic differ, it is extremely difficult to make a thermal shock-resistant, secure join between these two materials. A satisfactory, permanent and vacuum-tight join between the two materials mentioned above, which would be necessary, for example, for a transparent leadthrough into a vacuum, has not hitherto been disclosed in the prior art. Numerous tests have shown that all known joins between these materials are not permanent in the event of fluctuating thermal loads.
[0006] It is an object of an embodiment of the invention to provide a vacuum-tight and thermal shock-resistant material composite comprising an aluminum oxide sapphire and an aluminum oxide ceramic, in which the aluminum oxide sapphire is joined to the aluminum oxide ceramic securely and in such a manner as to withstand thermal shocks. Furthermore, it is an object of an embodiment of the invention to provide a process for producing a material composite of this type. Finally, another object of an embodiment of the invention is to provide a use of a material composite of this type.
[0007] According to an embodiment of the invention, the first object may be achieved by the fact that the aluminum oxide sapphire and the aluminum oxide ceramic are sintered to one another via a first joining layer and via a second joining layer, the first joining layer being adjacent to the aluminum oxide ceramic and comprising a manganese silicate glass which includes at least one of the metals selected from the group consisting of molybdenum, tungsten, palladium and platinum, and the second joining layer being adjacent to the aluminum oxide sapphire and comprising a manganese silicate glass. In this case, the manganese silicate glass of the first joining layer may contain aluminum oxide and/or titanium dioxide. The manganese silicate glass of the second joining layer contains aluminum oxide and/or titanium dioxide, the total content by weight of the oxides aluminum oxide and titanium oxide in the manganese silicate glass of the second joining layer being higher than in the manganese silicate glass of the first joining layer.
[0008] An embodiment of invention may be based on the consideration that by introducing metals into the manganese silicate glass it is possible to match the coefficient of thermal expansion of the first joining layer to the coefficient of thermal expansion of the aluminum oxide ceramic. The coefficient of thermal expansion of manganese silicate glass per se is in turn similar to the coefficient of thermal expansion of the aluminum oxide sapphire. To this extent, the first and second joining layers gradually match the coefficient of thermal expansion of the aluminum oxide sapphire to the coefficient of thermal expansion of the aluminum oxide ceramic. The stresses at the material joins which occur under fluctuating temperature loads are reduced.
[0009] Furthermore, extensive tests have now shown that by enriching the manganese silicate glass of the first joining layer with at least one of the abovementioned metals, during sintering onto the aluminum oxide ceramic fixed intermeshing and partial vitrification of the first joining layer to the aluminum oxide ceramic take place. Intermeshing and partial vitrification of the two joining layers also take place between the first joining layer and the second joining layer. The high glass content in the second joining layer results in a surface solid solution, i.e. a permanent chemical bond, being formed during sintering in the boundary layer between the aluminum oxide sapphire and the second joining layer.
[0010] As tests have shown, if the first joining layer is omitted, the aluminum oxide sapphire flakes off the aluminum oxide ceramic under fluctuating temperature loads. On the other hand, if the second joining layer is dispensed with, the aluminum oxide sapphire simply fails to adhere at all to the metal-enriched manganese silicate glass of the first joining layer.
[0011] If the aluminum oxide sapphire is sintered to the aluminum oxide ceramic via the first joining layer and via the second joining layer in the manner described, a material composite of this type will withstand fluctuating temperature loads within a wide range. It was impossible to detect any fracture in the material composite with fluctuating temperature loads between −60° C. and +200° C.
[0012] In an advantageous configuration of the invention, the sum of the contents of the metals in the manganese silicate glass of the first joining layer is 65 to 85% by weight. If the content of the said metals lies within this range the coefficient of thermal expansion of the first joining layer can be matched to the coefficient of thermal expansion of the aluminum oxide ceramic of the most widespread composition without the bonding of the first joining layer to the aluminum oxide ceramic being reduced.
[0013] Furthermore, it is advantageous if the manganese silicate glass of the first joining layer additionally comprises a content of up to 6% by weight of aluminum oxide and/or titanium dioxide. This type of content can further improve the joining of the first joining layer to the aluminum oxide ceramic.
[0014] In a further advantageous configuration, the manganese silicate glass of the second joining layer comprises a content of up to 30% by weight, in particular of 15 to 25% by weight, of aluminum oxide and/or titanium dioxide. The addition of a content of this level to the manganese silicate glass of the second joining layer allows the coefficient of thermal expansion of the second joining layer to be varied and to this extent allows the thermal shock resistance of the material composite to be optimized with regard to various levels of impurities in the aluminum oxide sapphire and with regard to a very wide range of compositions of the aluminum oxide ceramic.
[0015] The second object, relating to the production of the material composite referred to in the introduction, may be achieved, according to an embodiment of the invention, through the fact that a) a first screen-printing paste is produced by a 1 ) mixing the powder of a first manganese silicate glass with a powder of at least one of the metals selected from the group consisting of molybdenum, tungsten, palladium and platinum, to form a powder mixture, and a 2 ) combining the powder mixture with a suspending agent and/or with an adhesive, that b) a second screen-printing paste is produced by b 1 ) combining a powder of a manganese silicate glass, which contains a higher level of aluminum oxide and/or titanium dioxide than the first manganese silicate glass, with a suspending agent and/or with an adhesive, that c) a sequence of materials comprising aluminum oxide ceramic, first joining layer, second joining layer, the aluminum oxide sapphire is produced by screen-printing the first screen-printing paste and the second screen-printing paste, and that, finally, d) a firing operation takes place at 1200 to 1500° C.
[0016] The powder of the manganese silicate glass can either be obtained commercially as a finished product or can be produced by mixing the powders of Braunstein MnO 2 and silica solidifying the molten material and finally milling the solidified molten material itself. The proportions by weight in the powder mixture are 55-63% of MnO 2 and 45-37% of SiO 2 .
[0017] During the production of the powder mixture for the first screen-printing paste, the powders of the manganese silicate glass and at least one of the abovementioned metals are intimately mixed to form the powder mixture.
[0018] The addition of a suspending agent and/or an adhesive to the powder mixture or to the powder is necessary in order to be able to produce a screen-printing paste which can be screen printed from the powders. Screen printing makes it simple to achieve uniform application with a defined layer thickness of the subsequent interlayers. To produce the material composite, first of all the first screen-printing paste and then the second screenprinting paste can be applied to the aluminum oxide ceramic by screen printing. Finally, the aluminum oxide sapphire is placed on top and the layer sequence which has been formed in this way is fired, i.e. sintered, at 1200 to 1500° C. Of course, the reverse order of process sequences is also possible, i.e. first of all the second screen-printing paste and then the first screen-printing paste are applied to the aluminum oxide sapphire, and then the aluminum oxide ceramic is placed on top. However, since in a material composite of this type the aluminum oxide ceramic is generally the larger workpiece rather than the aluminum oxide sapphire, the procedure which was outline first is generally easier to implement.
[0019] In addition to the advantages which have already been outlined in connection with the specific contents by weight of the metals or of aluminum oxide and titanium oxide (for which a titanium hydride can also be used as starting substance) which have been mentioned in patent claims 6 to 8, with regard to the process it is furthermore advantageous if, after the screen printing with the first screen-printing paste and/or after the screen printing with the second screen-printing paste, in each case a separate firing operation takes place at 1200 to 1500° C. In this way, it is possible to avoid solvent effects between the two screen-printing pastes which have been applied.
[0020] With a view to processing, it is advantageous if a powder with a mean grain size of less than 10 μm, in particular of less than 2 μm, is used for the powder of the manganese silicate glass.
[0021] Furthermore, for the same reason it is advantageous if the powder of one or more of the abovementioned metals is used with a mean grain size of less than 15 μm, in particular less than 5 μm.
[0022] Furthermore, with regard to the screen-printing paste it is advantageous if vegetable oil or terpineol oil is used as suspending agent. Ethylcellulose has proven advantageous as the adhesive. The abovementioned additives are commercially available and the firing operation does not produce any decomposition products which are harmful to the environment.
[0023] With regard to the durability and thermal shock resistance of the material composite, it has proven expedient if the first screen-printing paste is applied in a thickness of from 2 to 20 μm and the second screen-printing paste is applied in a thickness of from 2 to 200 μm.
[0024] According to an embodiment of the invention, the final object is achieved by the fact that the material composite is used to insert a window made from the aluminum oxide sapphire into a housing for a light-triggerable thyristor. As the name would suggest, a light-triggerable thyristor is switched or triggered not by a voltage signal but rather by light. A thyristor is generally used to switch high currents. A thyristor as what is known as a power semiconductor is for this purpose generally inserted between two metallic contact pieces into a housing with a surrounding wall made from an insulating aluminum oxide ceramic. The aluminum oxide ceramic is used to electrically isolate the high electric voltage which is present at the two poles of the thyristor, i.e. at the two metallic contact pieces. The interior of the housing is generally evacuated.
[0025] For a light-triggerable thyristor which is fitted in a housing of this type, there is now the problem of introducing light through the housing to the light-sensitive point in the thyristor. In this context, a window of an aluminum oxide sapphire arranged in the housing is recommended for this introduction of light, an optical waveguide being led to the window from the outside. Since the housing is evacuated in the interior and, in addition, after insertion of the thyristor one or both of the abovementioned contact pieces has to be soldered to the wall made from aluminum oxide ceramic, the material composite formed between the window made from the aluminum oxide sapphire and the housing has to be permanent, strong, vacuum-tight and resistant to thermal shocks. For this reason, the material composite described is recommended in particular for this type of use.
[0026] For this use, the window made from the aluminum oxide sapphire is advantageously inserted into the partial area of the housing which consists of aluminum oxide ceramic. For this purpose, the window, at its edge regions, is fixedly sintered to the aluminum oxide ceramic via the first joining layer and the second joining layer in the manner described above.
[0027] In a further advantageous configuration of the use, the window is inserted into a partial area of the housing which includes a first metal. This partial area may, for example, be one of the abovementioned metallic contact pieces. For this purpose, the window, at its edge regions, is fixedly joined to a first piece of material made from aluminum oxide ceramic via the first joining layer and the second joining layer, and the first piece of material is fixedly soldered to the first metal of the partial area of the housing via a metal solder. In this case, therefore, the material composite is used to join the window made from the aluminum oxide sapphire to the first metal of the partial area of the housing. The join between the aluminum oxide ceramic of the first piece of material and the first metal of the partial area of the housing is known per se and corresponds to the method in which the metallic partial area of the housing or the metallic contact pieces of the housing are soldered to the surrounding wall made from the aluminum oxide ceramic.
[0028] In a further advantageous configuration of the use, the aluminum oxide ceramic of the first piece of material is fixedly joined to a second piece of material made from a second metal via a metal solder, and the second piece of material is soldered to the first metal of the partial area of the housing via a metal solder. In this way, the coefficients of thermal expansion of the window made from the aluminum oxide sapphire and of the first metal of the partial area of the housing are compensated for via the first and second pieces of material. The first and second pieces of material produce a gradual transition from the coefficient of thermal expansion of the aluminum oxide sapphire to the coefficient of thermal expansion of the first metal.
[0029] A particularly suitable metal solder is a eutectic silver/copper solder (L-Ag72, DIN 8513), although it is also possible to use a different solder.
[0030] The metallic contact pieces of a housing for receiving a power semiconductor are generally made from copper. With a view to achieving good soldering between the second piece of material and the metallic partial area of the housing, it is advantageous if the second metal is a nickel/iron alloy.
[0031] In a further advantageous configuration of the use, the first and second pieces of material are joined to one another at an angle which is such that differences in length between the partial area made from the first metal and the window made from the aluminum oxide sapphire which occur as the result of temperature changes are compensated for by relative movements of the first piece of material and of the second piece of material with respect to one another, substantially without any load on the joins.
[0032] The “angled join” results in the formation of a lever structure which allows relative movements of the first and second pieces of material with respect to one another. Differences in length which occur in the event of fluctuating temperature loads on account of the different coefficients of thermal expansion of aluminum oxide sapphire and metal are then compensated for as a result of relative movements of the first and second pieces of material with respect to one another. The joining of the window to the metal of the metallic partial area itself is exposed to lower mechanical loads. As a result, the join between the window made from the aluminum oxide sapphire and the metal of the metallic partial area of the housing is able to withstand even high loads caused by fluctuating temperatures, which occur in particular when the metallic partial areas are soldered to the partial areas of the housing made from aluminum oxide ceramic.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Exemplary embodiments of the invention are explained in more detail with reference to the drawings, in which:
[0034] [0034]FIG. 1 shows a section through a material composite comprising an aluminum oxide sapphire and an aluminum oxide ceramic,
[0035] [0035]FIG. 2 diagrammatically depicts the process for producing a material composite as shown in FIG. 1,
[0036] [0036]FIG. 3 shows a partially cut-away, perspective illustration of a housing for a light-triggerable thyristor having a window for light to pass through which is inserted into a metallic contact piece,
[0037] [0037]FIG. 4 shows a section corresponding to that shown in FIG. 3 illustrating the joining of the inserted window made from aluminum oxide sapphire to the metallic contact piece, and
[0038] [0038]FIG. 5 shows a section illustrating a window made from aluminum oxide sapphire which has been inserted into an aluminum oxide ceramic of a surrounding insulating wall of a housing for a light-triggerable thyristor.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] [0039]FIG. 1 shows a section through a material composite 1 including an aluminum oxide ceramic 5 which is joined to an aluminum oxide sapphire 2 via a first joining layer 3 and a second joining layer 4 . The first joining layer 3 comprises a manganese silicate glass which has 70% by weight of included molybdenum. The second joining layer 4 likewise comprises a manganese silicate glass, but it has 20% by weight of included aluminum oxide. The material composite 1 illustrated has been produced by sintering the individual materials to one another. Both intermeshing of the materials and partial vitrification of the materials occurs between the aluminum oxide sapphire 2 and the second joining layer 4 and between the first joining layer 3 and the second joining layer 4 . After the sintering operation, the aluminum oxide ceramic 5 has been securely joined to the first joining layer 3 via a surface solid solution which has formed.
[0040] [0040]FIG. 2 diagrammatically depicts the process used to produce a material composite as shown in FIG. 1. In this process, first of all a powder G of a manganese silicate glass and a powder M of one or more of the refractory metals molybdenum, tungsten, palladium or platinum are provided. A powder mixture P is produced by mixing and screening the powders G and M. Since the powder of a manganese silicate glass is commercially available, the production of this powder is not illustrated in more detail. However, as has already been mentioned, a powder of this type can be produced from Braunstein MnO 2 and crystalline silicon dioxide SiO 2 .
[0041] A first screen-printing paste SP 1 is produced by combining 9 the powder mixture P with a suspending agent S and adhesive K. Furthermore, a second screen-printing paste SP 2 is produced by combining the powder G of the manganese silicate glass with a suspending agent S and adhesive K.
[0042] The first screen-printing paste SP 1 is applied to an aluminum oxide ceramic by means of screen printing 10 . Then, the aluminum oxide ceramic with the applied first screen-printing paste SP 1 is fired 11 at a temperature of 1300° C. Following this firing operation 11 , the second screen-printing paste SP 2 is applied 12 , by use of screen printing, to the first joining layer which has been produced from the first screen-printing paste SP 1 as a result of the firing operation 11 . Then, the aluminum oxide sapphire is placed on top, 13 .
[0043] The sequence of materials which has formed is finally sintered together by a final firing operation 15 , once again carried out at 1300° C.
[0044] [0044]FIG. 3 shows a perspective, partially cut-away illustration of a housing 16 for a power semiconductor. The housing 16 has a metallic housing cover 17 , which is electrically insulated from a metallic housing base 19 by an insulating wall 18 . The housing cover 17 and the housing base 19 are made from copper, the surface of which is nickel-plated. Both the housing cover 17 and the housing base 19 are each formed of a metallic contact piece and for this purpose each have at thickened portion 20 and 22 , respectively, which projects into the interior of the housing and is used to receive the power semiconductor. A light-triggerable thyristor 24 is clamped between housing cover 17 and housing base 19 via the thickened portions 20 and 22 as the power semiconductor. The insulating wall 18 is made from aluminum oxide ceramic in order to provide voltage isolation of housing cover 17 with respect to the housing base 19 .
[0045] To trigger the light-triggerable thyristor 24 , the housing cover 17 has a bore 27 into which (not visible in FIG. 3) a window made from an aluminum oxide sapphire has been inserted. An optical waveguide 28 , the output of which ends before the window of aluminum oxide sapphire which has been inserted into the bore 27 , is guided via a recess 26 formed in the housing cover 17 . The light which emerges from the optical waveguide 28 passes via the window made from the aluminum oxide sapphire into the interior of the housing 16 , where it is incident on the light-sensitive point of the light-triggerable thyristor 24 . The emission of a light pulse via the optical waveguide 28 in this way switches the light-triggerable thyristor 24 .
[0046] [0046]FIG. 4 shows an enlarged view of part of the section on line IV-IV in FIG. 3. The housing cover 17 with the introduced bore 27 is visible once again. The output of the optical waveguide 28 , which ends in the immediate vicinity of the window 29 made from aluminum oxide sapphire, is also visible.
[0047] Toward the interior of the housing, the bore 27 has a recess 30 with a larger diameter in order to receive the securing materials for the window 29 . The window 29 made from the aluminum oxide sapphire is designed as a disk which at the edge regions is joined to a hollow-cylindrical first piece of material 31 made from an aluminum oxide ceramic. The first piece of material 31 made from the aluminum oxide ceramic is in turn soldered to the housing cover 17 via a disk-like second piece of material 32 made from a nickel/iron alloy.
[0048] The window 29 made from the aluminum oxide sapphire is fixedly joined (not illustrated in more detail in FIG. 4) via a first and a second joining layer 35 to the first piece of material in accordance with the material composite shown in FIG. 1. The first piece of material 31 made from the aluminum oxide ceramic is in turn soldered via a metal solder 36 to the piece of material 32 made from the nickel/iron alloy. Finally, the second piece of material 32 is soldered via a metal solder 37 to the housing cover 17 . The metal solder used is in each case a silver/copper solder.
[0049] The window 29 made from the aluminum oxide sapphire has a thickness of 0.55 mm. The hollow-cylindrical first piece of material 31 has a wall thickness of 1.3 mm. The disk-like second piece of material in turn is approximately 0.25 mm thick. The nickel/iron alloy which is commercially available under the name Vacodil from Vakuumschmelze Hanau was used as the nickel/iron alloy of the second piece of material.
[0050] Joining the first piece of material 31 at an angle to the second piece of material 32 allows a relative movement of the two pieces of material 31 , 32 in the event of a reduction or increase in the diameter of the bore 27 in the event of fluctuating temperature loads on the housing cover 17 . In this way, the different coefficient of thermal expansion of the window 29 than the metal of the housing cover 17 is compensated for. The join between the window 21 made from aluminum oxide sapphire and the housing cover 17 remains vacuum-tight and secure, even if the housing cover is soldered to the insulating wall 18 at a soldering temperature of approx. 600° C.
[0051] The use of the material composite shown in FIG. 1 for inserting the window 29 made from the aluminum oxide sapphire into the housing cover 17 of a housing for a light-triggerable thyristor for the first time allows a permanent, vacuum-tight and thermal shock-resistant join between the window 29 and the housing cover 17 and therefore the introduction of light via a window into the interior of the housing. In this way, it is possible to dispense with complex vacuum-tight leadthroughs for guiding the optical waveguide into the evacuated interior of the housing.
[0052] Finally, FIG. 5 shows the use of the material composite shown in FIG. 1 for direct insertion of the window 29 made from the aluminum oxide sapphire into the insulating wall 18 made from the aluminum oxide ceramic. For this purpose, the insulating wall 18 is flattened at a suitable point and the window is inserted 29 at this point.
[0053] [0053]FIG. 5 clearly shows the aluminum oxide ceramic 40 of the insulating wall 18 of the housing 16 shown in FIG. 3. The aluminum oxide ceramic 40 has been sintered to the window 29 made from the aluminum oxide sapphire via a first joining layer 3 and a second joining layer 4 , as described in the description associated with FIG. 1. Even with a use of this type, the material composite shown in FIG. 1 allows a reliable, vacuum-tight and thermal shock-resistant joining of the window 29 made from the aluminum oxide sapphire to the aluminum oxide ceramic of the insulating wall 18 of the housing 16 . In this relatively simple way, it is once again possible to eliminate the need for a complex leadthrough passing the optical waveguide into the interior to the light-sensitive area of the light-triggerable thyristor.
[0054] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | The invention relates to a material composite ( 1 ) that is vacuum-tight and resistant to thermal shocks, to a method for the production thereof and to its use. A permanent connection between an aluminum oxide sapphire ( 2 ) and an aluminum oxide ceramic ( 5 ) is attained by a first connecting layer ( 3 ) comprised of a manganese-silicate glass, in which at least one of the metals molybdenum, tungsten, palladium or platinum is incorporated, and by a second connecting layer ( 4 ) comprised of a manganese-silicate glass. To this end, the individual materials are fused by sintering. The material composite ( 1 ) is used for inserting a window comprised of aluminum oxide sapphire ( 2 ) into a housing ( 16 ) for a light-ignitable thyristor ( 24 ). | 2 |
FIELD OF THE INVENTION
[0001] The invention relates to electric direct current (DC) motor systems, and, more particularly, to cordless electric DC motor systems that may be used in portable devices such as vacuum cleaners and hand-controlled lawn equipment and power tools.
BACKGROUND OF THE INVENTION
[0002] Historically, battery operated brush-type DC motors have been around and used in a variety of applications for many years, including in small vacuum cleaners. These generally consist of a stator which includes some form of permanent magnets and a rotor having a winding energized through brush contacts. However, such configurations have been criticized for being inefficient and requiring maintenance mainly due to the replacement of the brushes. This has led to the advent of motors that do not include any brushes, commonly known as “brushless” motors. However, the present invention may provide increased efficiency in brush motors, while also reducing maintenance issues.
[0003] The motor may provide high torque and efficiency while maintaining a small size and minimizing heat generation.
[0004] The term “cordless” is generally used to refer to electrical or electronic devices that are powered by a battery or a battery pack and can operate without a power cord or cable attached to a fixed electricity supply, such as an outlet, generator, or other centralized power source, thereby allowing greater mobility. The development of more powerful rechargeable batteries in recent years has allowed the production of battery-powered versions of power tools and appliances that once required a power cord, and these are distinguished by the term “cordless,” as in cordless drills, cordless saws, cordless irons, cordless vacuums and the like.
[0005] Numerous types of DC motors have been provided in the prior art in an attempt to address the shortcomings with the traditional design but each fails to address them like the present invention. For example, U.S. Pat. Nos. 4,873,463; 7,728,479; 8,324,775; U.S. Application 2013/0147311 and European Patent 106,002 are all illustrative; however, these inventions are not as suitable for the purposes of the present invention described herein.
SUMMARY
[0006] The present invention relates to an Electric DC Motor System and method of manufacture. The Electric DC Motor System is accomplished by an improved battery management system, new stator design incorporating high permanent magnetism (HPM) magnets and a unique controller, all of which are synchronized to maximize efficiency and lower operating temperature. The method of manufacture discloses how the present invention is made.
[0007] The invention provides a battery powered electric DC motor system and method of manufacture thereof. The present invention takes advantage of a novel design for a battery powered DC motor, which also incorporates improved battery management, HPM magnets, and improved circuitry/controls, all of which increase efficiency by, among other things, eliminating wasted energy and optimizing motor and battery performance, yielding a motor that can operate, at a minimum, very close to the same length of time in which the battery might be charged (e.g., 30 minutes of charge time yields nearly 30 minutes of use at full power). The motor of the present invention, with its increased efficiency and size, provides an advancement in cordless electric motor technology. The present invention may make a variety of cordless devices and machines more practical. In particular, the present invention is uniquely suited for use in a cordless upright vacuum cleaner and other portable power tools and equipment.
[0008] In one embodiment, the present invention provides a battery operated Electric DC Motor System that features improved efficiency and reliability as a result of the novel arrangement of components noted herein. Unlike some improvements seen in the past, the present invention enables cooperation of all the components (e.g., motor, battery, and controller) in such a way that all these components work together more efficiently than heretofore achieved in the art.
[0009] The invention comprises, in one form thereof, an electric DC motor system for a cordless vacuum cleaner, including a rotor and a stator having a plurality of permanent magnets. Each of the magnets includes six substantially flat and rectangular faces.
[0010] The invention comprises, in another form thereof, an electric DC motor system, including a rotor, a stator having a plurality of permanent magnets, and a housing containing and supporting the magnets. The housing is formed of a non-magnetic material.
[0011] The invention comprises, in yet another form thereof, an electric DC motor system for a cordless vacuum cleaner, including a rotor, a stator including at least two permanent magnets disposed opposite to each other relative to an axis of the rotor, and at least two brushes. Each of the brushes is disposed at angles relative to each of the magnets of approximately between eighty-five degrees and ninety-five degrees in circumferential directions defined by the axis of the rotor.
[0012] The invention comprises, in still another form thereof, an electric DC motor system for a cordless device including a rotor and a stator including at least two permanent magnets disposed opposite to each other relative to an axis of the rotor. Each of the magnets spans less than forty-five degrees in a circumferential direction defined by the axis.
[0013] Yet other embodiments include the features described in any of the three previous paragraphs as combined with:
(i) one or more of the features described in one or more of the four previous paragraphs, (ii) one or more of the following aspects, or (iii) one or more of the features described in one or more of the four previous paragraphs and one or more of the following aspects:
wherein each of the six faces is parallel to a respective other one of the six faces; wherein each of the six faces is oriented at an angle of about ninety degrees relative to each of four other ones of the faces; wherein a respective gap is defined between each of the magnets and the rotor in a radial direction, each said gap being approximately between 0.025 inch and 3 inches, preferably approximately between 0.035 inch and 2 inches, more preferably approximately between 0.05 inch and 0.1 inch, and, in one embodiment, about 0.078 inch; wherein the system includes at least one brush, an angle between at least one of the magnets and at least one of the brushes being approximately between eighty degrees and one hundred degrees in a circumferential direction defined by an axis of the rotor; wherein the angle is about ninety degrees; wherein the plurality of permanent magnets comprises two permanent magnets disposed opposite to each other relative to an axis of the rotor, the two magnets being oriented parallel to each other; wherein the system further includes at least one brush and a battery pack electrically coupled to the brush and configured to provide power thereto, the battery pack including at least two batteries connected to each other in parallel and at least two batteries connected to each other in series; wherein the housing is formed of a plastic material; wherein the housing is formed of a non-ferrous metal material; wherein the housing contains and supports at least one brush and/or at least one magnet; wherein the gap may be adjustable as a means of achieving a desired target motor torque and/or a desired target rotational speed of the rotor; wherein the system includes a battery pack electrically coupled to the brushes and configured to provide power thereto, the battery pack including at least two batteries connected to each other in parallel and at least two other batteries connected to each other in series; wherein the angles are each between a first centerline bisecting a corresponding brush and a second centerline bisecting a corresponding magnet; wherein the system includes a housing containing and supporting the magnets and the brushes, the housing being formed of a non-magnetic material; wherein the brushes are driven via pulse width modulation; and wherein the system includes a processor coupled to the brushes and configured to control the pulse width modulation.
[0032] Traditionally, upright vacuum cleaners, with their torque and storage requirements, have primarily been “corded.” However, the present invention opens the door to having a battery operated power tool, such as but not limited to an upright vacuum cleaner. The numerous advantages are, firstly, the fact that the user need not struggle with finding an outlet in which to plug the unit, and, secondly, when the unit is being used, a cordless unit avoids the troubles in dealing with the power cord, not to mention the issue of accidental unplugging of the unit, which sometimes occurs. These advantages are multiplied when considering cleaning (and/or groundskeeping) in a commercial environment, such as a hotel or commercial office setting and the reduced labor costs brought about by the present invention.
[0033] As used throughout this specification and claims, reference is made to magnets formed of one or more materials that display a “high permanent magnetism” denoted as “HPM” herein. These magnets, such as Neodymium magnets, are deemed to be those which, when compared to typical ferrite magnets as commonly known in the art, display three (3×) or more times the magnetic flux density, and three (3×) or more times the coercive force, to give approximately ten (10×) times the total energy per unit volume. Further, when the term “Electric DC Motor System” is used in this specification (including as the title of this invention), it is understand that this includes all components in which to make the invention operate, to wit: a motor, which may include a stator and rotor; a controller, which may be attached to the motor; and a battery, which may be attached to the controller. This term should not be confused with the more generic use of the term “motor,” which includes only a stator, rotor and associated hardware.
[0034] An advantage of the invention is that it may provide a high level of electromagnetic force and increased battery capacity, resulting in longer operation between battery re-charging than is known in the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] A better understanding of the present invention will be had upon reference to the following description in conjunction with the accompanying drawings.
[0036] FIG. 1 is a schematic view of one embodiment of the motor of the present invention in a configuration for use with an upright vacuum cleaner.
[0037] FIG. 2 is a schematic, expanded, partially cross-sectional view one embodiment of the stator and commutator of the motor.
[0038] FIG. 3 is a schematic diagram of one embodiment of the motor.
[0039] FIG. 4 is a schematic circuit diagram of one embodiment of the motor.
[0040] FIG. 5 is a schematic block diagram of another embodiment of an electric DC motor system provided by the present invention.
[0041] FIG. 6 is a schematic circuit diagram of one embodiment of the motor and driver circuit of the system of FIG. 5 .
[0042] FIG. 7 is a schematic circuit diagram of one embodiment of the battery pack of the system of FIG. 5 .
[0043] FIG. 8 a schematic block diagram of yet another embodiment of an electric DC motor system provided by the present invention.
[0044] FIG. 9 is an exploded perspective view of one embodiment of a motor suitable for use in an electric DC motor system of the invention.
[0045] FIG. 10 is a perspective view of the motor of FIG. 9 .
[0046] FIG. 11 is a side view of the motor of FIG. 9 .
[0047] FIG. 12 is a schematic top view of the motor of FIG. 9 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0048] For the purpose of promoting an understanding of the principles of the present invention, reference will now be made to the embodiment illustrated in specific language contained herein. It will, nevertheless, be understood that no limitation of the scope of the invention is thereby intended; any alterations and further modifications of the described or illustrated embodiments, and any further applications of the principles of the invention as illustrated therein are contemplated as would normally occur to one skilled in the art to which the invention relates.
[0049] Battery system 1 ( FIG. 1 ) may provide energy to the motor, and may be a high-capacity, high-use battery. Battery system 1 may be selected and tuned to meet the specific requirements of the motor itself in conjunction with the controller's efforts to minimize draw on the battery, while still maintaining the amount of energy needed for the motor to complete its appointed task. Battery system 1 may include multiple independent battery packs 2 ( FIG. 3 ) each having its own circuitry 4 that limits the rate at which energy is discharged from each battery pack 2 , thus limiting heat generation, and also limiting the total amount of discharge allowed from any such battery pack 2 . Limiting deep discharge from a battery pack may extend the useful life of the battery pack by virtue of the pack and the associated battery chemistry never being stressed outside the normal peak operating limits. In the illustrated embodiment of FIG. 3 , two battery packs 2 with associated circuitry 4 are included.
[0050] The battery may be recharged from an outside source 5 dependent upon a position of a switch 6 . The switch 6 enables the device to be turned ON or OFF, or may enable the selection of a different setting of operation, e.g., high speed versus low speed. The switch 6 may be connected to a controller 7 , which, in turn, is connected to the motor 8 .
[0051] Controller 7 controls the flow of electricity from the battery to the motor and manages the energy used by the motor. Part of this management is an electrical pulse means 9 ( FIG. 4 ). This pulse means operates intermittently and may maintain a constant speed of the rotor, sending the pulse only when the rotor needs additional rotational velocity. In this way, only the minimally required amount of energy is sent to the motor in order to drive, in a pulsating manner, the motor. Further, the controller also includes a means 10 in which to recapture energy generated by the movement of the motor, and this energy is returned to the motor, as necessary. This arrangement may therefore minimize the energy that is drawn from the battery, thus increasing battery use-time.
[0052] The motor may include a stator 11 ( FIG. 2 ) having magnets 12 and a rotor 13 having a winding 14 energized through brush contacts 15 that touch a commutator 16 . Unlike traditional DC motors, the motor of the present invention has a stator exterior 11 that is made of plastic versus metal. This helps reduce heat and eliminates possible distortion in the magnetic fields involved in the operation of the motor.
[0053] Also, unlike the arrangement of most magnets in a traditional DC motor, which are curved and extend around almost the entire circular interior of the stator, the present invention provides magnets arranged in a linear fashion taking up only approximately ten percent (10%) of the curved interior circumference of the stator or housing. This amount of coverage may vary depending upon the requirements of the motor, but may generally be less that the amount of coverage seen in traditionally built DC motors. Further, the magnets used are HPM magnets and in one embodiment may be neodymium in nature.
[0054] The HPM magnets may be placed in the stator in linear fashion as shown in FIG. 2 . As noted above, these magnets are smaller than traditionally used and only so many are used as is necessary to facilitate continued movement of the rotor via the relationship with the windings, which are fixedly attached to the rotor and commutator. The rotor, windings and commutators all move in a circular fashion around a center point of the rotor shaft 17 . In this way, the magnetic field in the stator created by the HPM magnets is tuned specifically to that created by the rotor. This results in increased efficiency as the two magnetic fields do not end up fighting against each other. In the embodiment shown in FIG. 2 , the number of HPM magnets is two, and they are arranged such that they are not of curved design, to mimic the arc of a circle, but are rather linear.
[0055] The invention also includes a method of manufacturing the Electric DC Motor System. This method begins with determining the requirements of the use for the Electric DC Motor System, which includes determining the amount of torque and speed, or speeds, which would be required from the motor. Once determined, then a motor, of the type disclosed in this invention, is made using the novel elements disclosed herein, such that the motor meets the necessary requirements. Thereafter, the controller is made, as disclosed herein, in light of the requirements of motor in conjunction with the energy needs (e.g., volts and amps) necessary to meet the requirements. Next, a battery system may be selected in light of the controller and consistent with its energy needs as determined by the requirements, which may include the amount of battery packs and their respective circuitry. A method of manufacture as indicated may ensure that all three components of the Electric DC Motor System work at maximum efficiency, which may result in significantly improved operating time, as well as lower operating temperature and a minimization of wasted energy.
[0056] Another embodiment of an electric DC motor system of the present invention is shown in FIG. 5 , including a battery pack 502 , a motor and driver circuit 504 , a plug-in external battery charger 506 , a diode 508 , an ON/OFF switch 510 and a circuit breaker 512 . The detail of battery pack 502 is shown in FIG. 7 , including charge controllers PMC 1 and PMC 2 . Each of these charge controllers may be on its own dedicated circuit board. As shown, some of the batteries may be connected in series with each other, and some of the batteries may be connected in parallel with each other. Parallel combinations of batteries may be connected in series with other batteries or with other parallel combinations of batteries.
[0057] The detail of motor and driver circuit 504 is shown in FIG. 6 , including a motor 602 and various electronic components including an LM555CN timer controller 604 . The general function of the motor driver circuit is to limit the total current available to the motor from the battery and improve overall system efficiencies by reducing some potential losses. By eliminating the field coil of the motor and adding permanent magnets as in this embodiment, the motor's magnetic field does not require AC wall-power in order to be present. This permanent-magnet motor may function as a typical DC motor, relying on the commutation of the rotor windings to move the aiding and opposing magnetic forces that spin the rotor with respect to the fixed magnetic forces of the stator. With DC current applied to the rotor, and with the magnetic field fixed at the stator, when voltage is applied to the rotor, through the commutator, the current in the selected rotor winding may rise as the magnetic field builds in that rotor winding. Once the rotor winding has reached its peak in magnetic field generation, or the point of magnetic saturation, the current in the winding may rapidly rise and approach the limit imposed by the rotor winding resistance. Commutation may also provide some limit to the maximum current possible, but at the risk of switching during a peak current condition in the rotor winding, which creates arcs, high electrical noise and electromagnetic radiation, which can contribute to wear and reduced life for the commutator and rotor windings.
[0058] Because the rotor winding DC resistance is very low, nearly zero Ohms, the current can be extremely high and yet produce no work at the motor shaft, only converting this energy to heat. The pulse width modulation (PWM) circuit, including LM555CN timer controller 604 , allows the output of the battery to be current limited by only applying DC power for 70-90% of the time, allowing the rotor-generated magnetic field to relax in the off-time, and keeping the rotor windings out of saturation. This may elevate the overall efficiency rating by reducing the potential losses of applying power to the rotor when it is potentially saturated. This percentage can be manually adjusted for best performance under nominal load conditions. It can also be improved such that the duty cycle could be made relative to commutation allowing the efficiency to remain optimized throughout motor startup, from low-speed to high-speed, and under various load conditions.
[0059] The LM555 timer controller 604 may be used to set the duty-cycle of its output as a function of the time constant created by R6, R9, and C8. The LM555 timer controller 604 may generate a constant pulse width that may serve to extend battery life. The digital output of LM555 timer 604 may be level converted by U2 operational amplifiers 606 , 608 to create the appropriate switching levels for the gate of MOSFET (Q 1 ) 610 to reach the fully-saturated on and off levels required for minimum switch losses. MOSFET Q 1 (e.g., part no. IRF250) 610 may work as a sinking switch to the motor by pulling one of the motor rotor leads to BATTERY-MINUS, while the other rotor lead is permanently affixed to BATTERY-PLUS.
[0060] Illustrated in FIG. 8 is an embodiment of an electric DC motor system in which the PWM drive may be controlled by a microprocessor 802 . In the illustrated embodiment, microprocessor is a model PIC16C73 processor marketed by Microchip Technology Inc., and its pinout is well known to those of skill in the art. The microprocessor can monitor motor current, battery voltage, and may additionally monitor battery current and motor shaft rotation to improve the application of energy to the motor in a manner that further improves efficiency.
[0061] Microprocessor 802 may use firmware to control an on-chip timer that creates a pulse-width-modulated (PWM) drive signal. This PWM signal is amplified by Q 1 (MOSFET) 804 and applied to the motor 806 . Current flowing through the motor windings is measured across a shunt resistance (R7) 808 and monitored by amplifiers 810 , 812 and 814 . Amplifiers 812 , 814 provide a shutdown signal to MOSFET 804 through transistor Q 3 816 as the current in the motor winding approaches a designated maximum. Similarly, an interrupt is transmitted to microprocessor 802 to signal to the microprocessor that the maximum allowed current is being reached. Microprocessor 802 also monitors the average current to the motor, which is represented as a DC level by amplifier 810 .
[0062] In this diagram of FIG. 8 the battery voltage is monitored by microprocessor 802 providing an ability to shut the drive off when the battery level becomes critically low. This same signal also enables evaluation of the discharge rate of the battery over time to better manage the current delivered by the PWM and transistor 804 and achieve better run times for the system while in use.
[0063] Illustrated in FIGS. 9-12 is an embodiment of a motor suitable for use in an electric DC motor system of the present invention. The motor includes brushes, permanent magnetics and a rotor. A housing or casing 902 of the magnets and/or a housing or casing 904 of the motor may be formed of non-ferrous metal or some non- metal material such as plastic. This helps reduce heat and eliminates possible distortion in the magnetic fields involved in the operation of the motor.
[0064] Magnets 906 may be linear in that they may have no curved surfaces, but instead have six rectangular, flat faces and twelve line segment edges. In the embodiment shown, each of the two magnets 906 may span less than 45 degrees of the interior circumference of the magnetics housing 908 . In another embodiment, each of the two magnets 906 may span less than 30 degrees of the interior circumference of the magnetics housing 908 . In yet another embodiment, each of the two magnets 906 may span approximately between 10 degrees and 30 degrees of the interior circumference of the magnetics housing 908 . This relatively small circumferential span of the magnets may provide a narrower magnetic focus which allows the pulse to push past the point of magnetism and then better enable the magnets to do some pushing and pulling to better utilize their power. The result is greater efficiency and more torque in some applications. Magnets 906 may be aligned in that they are disposed opposite each other (e.g., 180 degrees apart in a circumferential direction defined by the axis of the rotor) within housing 908 .
[0065] FIG. 12 illustrates a 90-degree angular difference between the center line of the permanent magnets and the center line of the brushes. However, it is to be understood that this angle may vary from 90 degrees.
[0066] A gap between the permanent magnets and the rotor is shown in FIG. 12 to be preferably about 0.078 inch. This relatively small gap may advantageously produce a high level of torque with the magnets being relatively close to the armature. However, if more torque is needed for a particular application (e.g., a cordless chain saw), then the motor's rotational speed may be sacrificed (i.e., reduced) by further reducing the gap. Conversely, if more rotor speed is needed (e.g., for a cordless vacuum cleaner), then the motor's torque may be sacrificed (i.e., reduced) by increasing the gap. Thus, this invention provides a DC motor of variable design that affords the user to custom design and manufacture a DC motor depending on its intended field of use.
[0067] Another advantage of the above-described motor configuration is that it may enable magnetism to push the rotation of the rotor through the cycles rather than electricity providing the pushing force.
[0068] Although the invention has been described herein as being implemented with linear magnets, it is to be understood that it is within the scope of the invention to use C-shaped magnets, and particularly rare earth C-shaped magnets.
[0069] The foregoing detailed description is given primarily for clearness of understanding and no unnecessary limitations are to be understood therefrom for modifications can be made by those skilled in the art upon reading this disclosure and may be made without departing from the spirit of the invention. | An electric DC motor system for a cordless powered device includes a rotor and a stator having a plurality of non-curved permanent magnets. Each of the magnets includes six substantially flat and rectangular faces. The cordless powered device may be a vacuum cleaner, power tool, garden tool, lawn tool or the like. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The subject matter described herein relates generally to switches and, more particularly, to switches for sourcing electrical energy.
2. Related Art
Electrical switches for switching a source of electrical energy are known. For example, automatic transfer switches function to switch a main source of power that is reduced or cut off to another source of power. One particular automatic transfer switch is a bypass isolation automatic transfer switch that has an additional feature for preventing non-main source energy from leaking back into the main source.
Starting in the mid 1980s and onward, bypass isolation automatic transfer switches have been widely used in the power industry. As the need for critical power installations continues to grow and as power sensitive equipment continues to be developed and installed in locations throughout the U.S. and the world, it continues to become more apparent how important power dependency has become. Current bypass isolation automatic transfer switches have a “top-down” structure that includes an isolation panel affixed to a frame and disposed above an automatic transfer switch. Connection between the isolation panel and the automatic transfer switch is accomplished through movement of the two in a vertical direction.
Though highly effective for the given cost, bypass isolation automatic transfer switches have a disadvantage in that the “top-down” structure leads to an enhanced equipment footprint that, in turn, keeps it from being a more popular choice in the market. With the upgrade of power to existing installations, these large bypass units are sometimes too big to fit through existing doorways thus forcing contractors to perform demolition and repair activities on doorways and entry halls.
Accordingly, to date, no suitable switch is available which overcomes the above and other disadvantages of the prior art.
BRIEF DESCRIPTION OF THE INVENTION
In accordance with an embodiment of the present invention, a shutter device is provided for a bypass isolation automatic transfer switch. The shutter device comprises a frame, a shutter that is movably supported by the frame and that is configured to selectively cover and uncover conductors. At least one cam is movably supported by the frame and at least one shutter lever is interposed between the shutter and the at least one cam. The shutter lever is configured to move the shutter in response to movement of the cam.
In another aspect of the present invention, a method of connecting an automatic transfer switch to a shuttered bypass panel comprises providing a movable automatic transfer switch; fixing a bypass panel to a frame; shuttering receptacles of the bypass panel in response to movement of the automatic transfer switch; and moving the automatic transfer switch to connect the automatic transfer switch to the bypass panel.
In a further aspect of the invention, a bypass isolation automatic transfer switch comprises a frame, a bypass panel supported by the frame, a movable automatic transfer switch and a shutter device supported by the frame. The shutter device comprises a frame, a shutter that is movably supported by the frame and that is configured to selectively cover and uncover conductors. At least one cam is movably supported by the frame and at least one shutter lever is interposed between the shutter and the at least one cam. The shutter lever is configured to move the shutter in response to movement of the cam.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description is made with reference to the accompanying drawings, in which:
FIG. 1 is a perspective view of a switch comprising a frame, an isolation panel and an automatic transfer switch in accordance with one embodiment of the present invention;
FIG. 2 is an enlarged, perspective view showing one side of the isolation panel of FIG. 1 ;
FIG. 3 is another enlarged, perspective view showing another side of the isolation panel of FIG. 1 ;
FIG. 4 is an enlarged, perspective view showing one side of the automatic transfer switch of FIG. 1 ;
FIG. 5 is another enlarged, perspective view showing another side of the automatic transfer switch of FIG. 1 ;
FIG. 6 is a perspective view of a portion of the switch of FIG. 1 showing a shutter shield and a cart for supporting the automatic transfer switch which is omitted;
FIG. 7 is another perspective view of a portion of the switch of FIG. 1 showing a shutter, a shutter lever and a pusher cam in an open position;
FIG. 8 is an enlarged view, in perspective, of the shutter lever and the pusher cam of FIG. 7 ;
FIG. 9 is a further enlarged view, from a side, of the shutter lever of FIG. 7 in a first position;
FIG. 10 is another view, similar to that of FIG. 9 , with the shutter lever in a second position;
FIG. 11 is a further enlarged view, from a side, of the pusher cam of FIG. 7 ;
FIG. 12 is another perspective view of the switch of FIG. 1 showing the shutter in the open position;
FIG. 13 is a further perspective view of the switch of FIG. 1 showing the shutter in the closed position; and
FIG. 14 is an enlarged view of a portion of the switch of FIG. 1 showing automatic transfer switch bus bars adjacent an open window of the shutter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
One embodiment of the present invention concerns a switch that includes dimensions of both reduced height and depth thus yielding a smaller more compact package for easier installation and use while also providing an enhanced safety feature for the switch. In one particular embodiment, a shutter is provided for covering bus bars of an isolation panel when not connected to bus bars of an automatic transfer switch.
Referring now to FIG. 1 , a switch in accordance with one embodiment of the present invention is illustrated generally at 10 . In this embodiment, the switch 10 comprises a frame 12 , a bypass panel 14 , a movable automatic transfer switch 16 , a racking mechanism 18 for moving the automatic transfer switch 16 into contact with the bypass panel 14 and a shutter mechanism 20 .
The frame 12 may comprise any suitably strong and durable sheet material such as a steel or aluminum and may comprise a base 22 , two pairs of upright portions 24 and 26 extending from the base and stabilizing members 28 and 30 interconnected with the upright portions. As shown, each of the base 22 , upright portions 24 and 26 and stabilizing members 28 may comprise appropriate cross-sectional configurations for enhanced strength to support, e.g., the bypass panel 14 , the racking mechanism 18 , and the shutter mechanism 20 .
Referring now to FIGS. 2 and 3 , and 5 , the bypass panel 14 comprises baskets or receptacles 32 , 34 and 36 that are connectable with blade connectors 50 , 52 , and 54 ( FIG. 5 ) and are in an exemplary four-pole configuration. In the shown configuration, bus bars 38 and 42 provide power while bus bar 40 provides line return via receptacles 32 , 34 , and 36 when connected. Mounting plates 44 function to support the bypass panel 14 when fastened to the frame 12 .
The automatic transfer switch 16 is best seen in FIGS. 4 and 5 and comprises blade connectors 50 , 52 and 54 . The blade connectors 50 , 52 and 54 are arranged to mate with the receptacles 32 , 34 and 36 of the bypass panel 14 ( FIG. 2 ) when not covered by the shutter mechanism 20 ( FIG. 1 ) as described in more detail below.
Referring again to FIG. 1 , the automatic transfer switch 16 is mounted to, and supported by, a movable cart 62 that includes handles 64 , support structure 66 and wheels 68 . The handles 64 are provided so that an operator may move the automatic transfer switch 16 , where necessary.
The racking mechanism 18 is provided for moving the cart 62 and, in turn, the automatic transfer switch 16 , e.g., for a scheduled maintenance. Upon completion of maintenance, the blade connectors 50 , 52 and 54 of the automatic transfer switch may be urged together with the receptacles 32 , 34 and 36 by the racking mechanism 18 .
Referring now to FIGS. 6 and 7 , the shutter mechanism 20 may be connected to the frame 12 and comprises a mounting frame 70 , a shutter shield 72 , a shutter 74 , pusher cams 76 and shutter levers 78 . The mounting frame 70 comprises any suitably strong and durable material such as a steel and may be connected with the frame 12 via suitable fasteners 80 and mounting brackets 82 . Support strips 84 may support a central open portion of the mounting frame 70 as described below.
The shutter shield 72 functions to protect the end user against incidental or accidental contact with live parts or the bus systems 32 , 34 , and 36 and comprises an insulative material such as a polycarbonate or a compressed and treated fiber board. Apertures 86 extend through the shutter shield 72 at appropriate locations to provide for passage of the blade connectors 50 , 52 and 54 for connection with the receptacles 32 , 34 and 36 . Mounting slides 88 and 90 may extend along and generally parallel to opposing end portions 92 and 94 of one side (not numbered) of the shutter shield 72 .
The shutter 74 may comprise a generally thin sheet of insulative material such as a polymeric substance and, as illustrated, is slidably supported by the mounting slides 88 and 90 . The shutter 74 may comprise apertures 96 and slots 98 . Fasteners 100 may extend through the slots 98 for engagement with the shutter shield 72 and to provide for support and sliding movement of the shutter 74 .
Referring now also to FIG. 8 , in the exemplary embodiment, two pusher cams 76 are illustrated and each may comprise a plate 102 that may comprise mounting slots 104 and a cam surface 106 . The plate 102 may comprise any suitably strong material such as a steel and is configured to be engaged by strike plates 108 of the cart 62 . Fasteners 110 , extend through mounting slots 104 , and stops 112 may be provided for closing reciprocal movement of the pusher cams 76 . The pusher cams 76 extend through apertures 114 in the mounting frame 70 and the shutter shield 72 with the cam surface 106 disposed adjacent the shutter lever 78 .
The cam surface 106 (also seen in FIG. 11 ) may be angled at an angle A that is acute and, in one optional embodiment, angle A may be in the range of between about 38° degrees to about 42° degrees. In one particular embodiment, angle A is approximately 40°. The cam surface 106 functions to urge the shutter lever 78 upon movement of the pusher cam 76 , as described in more detail below.
The shutter levers 78 may be disposed in opposing directions or in a mirrored manner as illustrated and each may comprise a strong metallic substance such as a steel. Each shutter lever 78 is rotatable about a pivot portion 115 and each comprises a lever arm 116 and a roller arm 118 .
The pivot portion 115 may be pinned by a fastener 120 and a bearing 122 to provide for rotational movement in the direction of arrow 124 . A spring 126 may be provided to bias the shutter lever in one direction that, in turn, biases the shutter 74 in a “closed position”. A couple 128 and stiffening member 130 may be interposed between the shutter lever 78 and the shutter 74 .
The lever arm 116 may be rotatably connected to the couple 128 via a bearing 132 and a fastener 134 .
The roller arm 118 may extend from the lever arm 116 and may comprise a support bracket 136 that, in turn, comprises members 138 and a roller 140 . The roller 140 may extend through apertures (not numbered) in the members 138 that support bearings 142 . The roller 140 is biased by spring 82 against the cam surface 106 .
As shown in FIGS. 9 through 11 , linear movement of the pusher cam 76 causes movement of the roller 140 along cam surface 106 and, in turn, rotation of the lever arm 116 in the directions of arrows 144 and 146 . The rotation of lever arm 116 may be on the order of between approximately −12° in a clockwise direction and approximately +4° in a counterclockwise direction for a total of about 16° of angular rotation. Rotation of the lever arm 116 causes reciprocal movement of the shutter 72 as illustrated by an arrow 147 in FIG. 7 .
FIGS. 12 and 13 illustrate a racked in position and a racked out position of the automatic transfer switch 16 . Upon movement of the automatic transfer switch 16 in the direction of arrow 148 , blade connectors 50 will be separated from the receptacles 32 ( FIG. 14 ) and the shutter 72 will close.
FIG. 14 illustrates a position of the automatic transfer switch 16 just after the shutter 72 has reciprocated out of the way revealing the receptacles 32 .
While the present invention has been described in connection with what are presently considered to be the most practical and preferred embodiments, it is to be understood that the present invention is not limited to these herein disclosed embodiments. Rather, the present invention is intended to cover all of the various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | A shutter device is provided for a bypass isolation automatic transfer switch. The shutter device comprises a frame and a shutter that is movably supported by the frame and that is configured to selectively cover and uncover conductors. At least one cam is movably supported by the frame and at least one shutter lever is interposed between the shutter and the at least one cam. The shutter lever is configured to move the shutter in response to movement of the cam. | 8 |
This is a division of application Ser. No. 08/393,103, filed Feb. 22, 1995, now U.S. Pat. No. 5,485,818.
BACKGROUND OF THE INVENTION
Air pollution is a serious problem especially in large cities. In the U.S. the Environmental Protection Agency has the primary responsibility for carrying out the requirements of the Clean Air Act, which specifies that air-quality standards shall be established for hazardous substances. There are also state laws and international Protocols that set standards.
Some air pollutants are formed through the action of sunlight on previously emitted reactive materials (called precursors). For example, ozone, a pollutant in smog, is produced by tile interaction of hydrocarbons and nitrogen oxides under the influence of sunlight. Although many types of combustion contribute to this problem, trucks and buses have been identified as a significant source of both oxides of nitrogen (NO x ) and particulate matter (PM). Pollution from internal combustion engines has been significantly reduced by burning the fuel as completely as possible, by recirculating fumes and by using catalytic converters. However, standards are constantly being changed in an attempt to lower exhaust emissions. Current standards propose NO x emissions limits of between 1.5 and 2 grams per brake horse power per hour (g/bhp-hr). The state of California has adopted an Ultra Low Emission Vehicle (hereinafter ULEV) regulation, which will become effective in 1998, for medium-duty vehicles that limits NO x plus hydrocarbons at 2.5 g/bhp-hr and caps particulates at 0.05 g/bhp-hr. In addition this California regulation restricts the emissions of formaldehyde (HCHO) to 0,025 g/bhp-hr and Carbon Monoxide (CO) emissions to 7.2 g/bhp-hr. Meeting such standards will be difficult for spark ignited (SI) engines and even more difficult.
Trying to meet such standards alternative fuels such as Methanol and Ethanol have been tried. Dimethyl ether, CH 3 --O--CH 3 hereinafter DME, is currently used as a propellant for spray cans. DME was adopted for this use as a replacement for chlorofluorcarbons. DME has been used in experiments, as an ignition enhancer, for Methanol-fueled Diesel Engines. However, even when the ratio of DME to Diesel Fuel is as high as 60%, satisfactory operation was not obtained. Recently, a limited test was conducted using pure DME as an alternative fuel in a single cylinder, four stroke, direct injection Diesel Engine. This test yielded very promising combustion, performance and emissions results. Although the fuel injection system used in this test was designed for standard diesel fuel, when using DME the thermal efficiency of the engine was equivalent to when diesel fuel is used. Furthermore, as compared to standard diesel fuel the NO x , were low and the smoke emissions were extremely low. Reference is made to a soon to be published paper by S.C. Sorenson entitled, Performance and Emissions of a 0.273 Liter Direct Injection Diesel Engine with a New Alternative Fuel, in which this test are discussed.
The use of DME as an alternative fuel does have obstacles that must be overcome. DME is a gas at ambient temperature and pressure and thus the fuel storage and delivery system must be pressurized to maintain the DME in a liquid state. DME must be pressurized to about five bar to keep it in a liquid state under ambient conditions. At the elevated temperatures present on an internal combustion engine higher pressures (12-30 bar) are required to maintain DME in a liquid state.
The energy density of DME, although higher than the alternative fuels Methanol (CH 3 OH) and Ethanol (CH 3 --CH 2 --OH) it is much lower than conventional Diesel Fuel. As a result to obtain the same power from an engine fueled by DME obtained when fueling with Diesel Fuel the volume of DME must be increased by a factor of about 1.8. To accommodate this increased volume the fuel injector must have a larger orifice opening. A single hole pintle type nozzle, rather than a multi hole nozzle, has been found to function well to provide this increased fuel flow.
A fuel's Cetane number, which is a measure of the fuel's ability to auto-ignite, has an important influence on diesel combustion and is a meaningful indicator of a fuel's value for diesel engines. Fuels with a high Cetane number will ignite quicker and thus will have a short ignition delay. This lowers premixed burning of the fuel, which in turn lowers NO x and noise emissions. DME has a higher Cetane number than Diesel Fuel and thus it will ignite quicker and will have a relatively short ignition delay. By throttling the amount of fuel injected during the initial portion of the injection cycle the quantity of fuel in the combustion chamber when ignition occurs has been diminished which significantly lowers NO x and noise emissions. The mechanism for throttling the fuel injected during the initial portion of the injection cycle should be time dependent such that it can be coordinated with ignition delay that is also time dependent.
Also the vapor pressure of DME is higher than most other fuels. At 38° Centigrade, the vapor pressure of DME is 8 bar as compared to 0.0069 bar and 0.35 bar respectively for Diesel fuel and Methanol. Thus DME will boil at a lower atmosphere pressure than Diesel fuel or Methanol. The system must be pressurized to prevent the fuel from flashing to vapor in the engine's fuel manifolds or fuel injection system.
The viscosity of DME is estimated to be about 5% to 10% of diesel fuel. This relatively low viscosity of DME portends fuel leakage in a system designed for fuels higher viscosities. Thus, standard fuel storage and delivery systems will not be suitable for DME.
Test results, such as those described in the above referred to Sorenson paper, are obtained in carefully controlled and monitored operating environments and conditions. It is often difficult to duplicate such test results outside the laboratory. As a result further developments are required to obtain the same results in a production situation where many and changing conditions are experienced.
Internal combustion engines and especially Diesel engines represent large capital investments and have long useful lives. The current process for producing DME would result in a price that would render it unacceptable as an alternative fuel. A new less costly manufacturing method has been developed to produce "raw DME" which is a form of DME that includes small amounts of water and Methanol. Large capital investments would be required to build the necessary facilities to produce raw DME at volumes that would meet its demand as an alternative fuel. Even greater capital investments would be required to provide the necessary refueling system. Large capital investments of this magnitude are unlikely to be made if the alternative fuel can only be used in newly produced special designed engines. Thus, a very important consideration for an alternative fuel is whether economic field conversions can be made to existing engines to enable them to use the alternative fuel.
For these reasons, there is a need for a fuel storage and delivery system that will enable internal combustion engines to be powered with DME fuel in a broad range of environmental conditions. The new and improved fuel storage and delivery system must also permit existing internal combustion engines to be economically converted in the field to be fueled by DME.
SUMMARY OF THE INVENTION
The present invention is directed to the use of DME as a fuel in internal combustion engines and a DME storage and delivery system for internal combustion engines. Experimental work done by Sorenson yielded test results that suggest that the use of DME as an alternative fuel for internal combustion engines may enable the current ULEV standards to be met or even exceeded. This invention will enable the test results seen in the laboratory work described in the Sorenson paper to be achieved in production internal combustion engines that operate in many conditions and in environments that are constantly changing. The present invention will also enable existing engines fueled by conventional fuel to be economically converted to use DME as a fuel.
The present invention is directed to a fuel storage and delivery system including a fuel pump that has low internal leakage to accommodate the low viscosity of the DME.
The injector of this invention utilizes a pintle type nozzle that can provide the increased volume of DME fuel required in the same cylinder rotation arc required in an engine using diesel fuel.
This invention uses a characteristic of the pintle nozzle, to gradually increase its orifice area as the nozzle is lifted, to damp the fuel flow during the initial portion of the injection cycle. This improved injector, with damping, can be used with engines using diesel fuels and also engines that are powered by DME.
The injection system of this invention controls the rate at which the DME is injected and thus reduces the premixed fuel quantity and avoids noisy combustion and high NO x emissions.
The nozzle orifice area of this invention is relatively large to accommodate for the lower density and heating value of DME.
This invention provides flexible injection timing to optimize the tuning of the engine and gain low emissions.
For the foregoing reasons there is a need for a DME storage and delivery system for internal combustion engines that will enable the favorable emission properties of DME to be exploited in new and existing engines.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of an embodiment of the invention in which a common rail injection system is provided for the DME.
FIG. 2 is a detailed, partially cut away, view of an embodiment of a unit injector.
FIG. 3 is a perspective view of the damping piston of FIG. 2.
FIG. 4 is a lift/time diagram illustrating the nozzle needle lift with and without the damper.
FIG. 5 is a lift/time diagram illustrating the effect of high and low viscosity fluid.
FIG. 6 is a detailed view of an embodiment of a pintle nozzle in the closed position.
FIG. 7 is a detailed view of the pintle nozzle of FIG. 6 in a slightly raised or open position.
FIG. 8 is a detailed view of the pintle nozzle of FIG. 6 in a greater raised or open position then shown in FIG. 7.
FIG. 9 is a detailed view of the pintle nozzle of FIG. 6 in a fully raised or open position.
FIG. 10 is cross sectional view of a unit injector, of the type disclosed in FIG. 2, mounted in the injector cavity of a conventional engine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
There is shown in FIG. 1 a schematic view of an embodiment of the invention in which the fuel for an internal combustion engine is stored in a pressurized fuel tank 10 from which it is fed by a pump 14 to a rail 22 which functions as an accumulator system from which fuel is distributed to unit injectors 40. DME must be pressurized to about 5 bar to keep it in a liquid state under ambient conditions. At the elevated temperatures present on an internal combustion engine the fuel tank 10 should be pressurized to about 9 bar to insure that the DME is maintained in a liquid state.
The fuel pump 14 must be able to provide DME to the rail 22 at a pressure in the range of 100-300 bar. The fuel supply pump 14 can be driven by the engine, at a speed ratio of engine speed to pump speed in the range of 1:1 to 1:0.5. Pump 14 must have the capacity to meet the engine's peak torque requirements. At peak torque an engine is rotating at a relatively high rate, and accordingly drives the fuel pump at a relatively high rate. At this relatively high speed a gear type pump would have high efficiency even when pumping DME which has a very low viscosity. The viscosity of DME is about 10% of the viscosity of Diesel fuel. Thus, a gear type pump would perform adequately when the engine is operating at peak torque speeds. However, another critical requirement for the fuel pump 14, is that it must be able to supply sufficient fuel to the engine during start-up. At start-up the engine and therefore the pump 14 will be running at a relatively low speed. A diesel engine that delivers peak torque at speeds of 2,000 rpm will have a start-up speed of about 200 rpm. At 200 rpm the efficiency of a gear type pump will be very low and inadequate to start the engine when pumping a fluid having a viscosity as low as that of DME. The low speed combined with the low viscosity of DME fuel affords time for the fuel to leak internally around the gears of the pump. This internal leakage is an inefficiency in the pump and if it is too high the pump can't manage the critical engine start-up requirements. As the engine speed and the corresponding pump speed increases there is less time for internal leakage and consequently there is less leakage. For these reasons a highly efficient pump is necessary when using DME as a fuel. A piston type pump with seals to minimize leakage, that has an efficiency of about 50% at starting speed when pumping DME has been found suitable.
A filter 12 and a shut-off valve 13 are provided in the line 11 that extends from the fuel tank 10 to the pump 14. The Rail Pressure Modulator Valve (RPMV) 18 functions to control the output pressure of the pump 14 that determines the pressure of the DME in the common rail 22. The RPMV also functions as a relief valve to prevent DME, at excess pressures, from being sent to the rail 22. A pressure transducer 16 is provided in the line 15 that extends from the pump 14 to the rail 22. As will be discussed in more detail, transducer 16 can be used to monitor the rail pressure and transmit data back to the ECM through a line 23.
A common rail 22, which dispenses fuel to all of the engine's cylinders, is necessary to ensure a constant fuel pressure to all injector's. In FIG. 1 the rail 22 has been illustrated to have eight fuel passages 21. It should be understood that if the rail 22 is being used on a four or six cylinder engine the rail would have one passage 21 for each cylinder. Although the rail 22 is shown as a separate component it could be an integral part of the engine.
One unit injector 40 has been illustrated in FIG. 1, however it should be understood that there is a unit injector 40 for each of the engine's combustion cylinders. The body of the injector 40 has an upper bore 44 that extends longitudinally from its upper end as seen in FIG. 2. The upper bore 44 is closed by a plug 48 at its upper end. A damping piston 70 is contained in the chamber 67 defined by the upper bore 44 and the plug 48. There is silicone fluid 120 or other suitable viscous fluid in the chamber 67. The fuel passage 21 from the rail 22 is secured to a side extension 38 of the injector 40 such that the DME fuel enters the injector through an inlet passage 36. An injector solenoid 30 is carried by the extension 38, which when energized opens a valve 32 that is normally held closed by a spring 34 or by a magnetic force. When the valve 32 is opened by the solenoid 30, the DME fuel flows through the inlet passage 36 into the fuel passage 50 that extends longitudinally through the body of the injector 40. Injector 40 carries a pintle nozzle 90 at its bottom end, as seen in FIG. 1. An optional fuel return vent line 24 can be provided.
The Electronic Control Module (ECM) 20 includes a microprocessor that receives inputs from various engine monitors such as fuel temperature, fuel rail pressure, throttle position, engine revolutions per minute and cam angle. The ECM 20 is programmed with the operating strategy of the system and controls the operation of the entire fuel system. Other engine conditions that can be monitored and input to the ECM are, for example, oil temperature, ambient air temperature, barometric pressure and exhaust back pressure. The pressure transducer 16 in line 15 is an example of one such monitor.
The ECM 20 computes output control signals 19 and 17. The outputs signals 17 are sent to the solenoids 30 and cause the solenoids to be actuated at a precise time. Output control signal 17 determines the time for starting fuel injection and the duration of each injection.
The output signal 19 represents the desired rail pressures for the specific engine conditions calculated according to the operating strategy of the system and in response to the data collected by the various monitors. Signal 19 is directed to a Rail Pressure Modulator Valve (RPMV) 18. The RPMV 18 functions to control the output pressure of the pump 14 that determines the pressure of the DME in the common rail 22.
Referring now to FIGS. 2 through 9 the injector 40 will be discussed in more detail.
The injector 40 includes a generally cylindrical shaped body portion 42. The injector 40 disclosed herein conforms to the shape and dimensions of a standard 17 millimeter injector that is currently used in diesel engines available from most engine sources. Thus existing conventional diesel engines can receive injector 40 by simply replacing the conventional injectors. The other modifications necessary to convert a conventional diesel engine from diesel fuel to DME are relatively minor and it will be possible to convert existing diesel engines to DME fuel.
The injector 40 has been provided with a pintle type nozzle 90, at its bottom or first end, rather than a multi hole nozzle. The single hole design feature of a pintle nozzle functions well to provide the increased fuel flow necessary when using DME. Pintle type nozzles have the characteristic of increasing the flow area as the pintle is lifted. This feature is best illustrated in FIGS. 6 through 9. In FIG. 6 a first beveled portion 92 of the pintle nozzle 90, located at the discharge end of the pintle nozzle, is seated on a corresponding beveled portion 56 of the body 42 and the flow area is zero and accordingly there is no flow. It should be noted that there is a slight clearance between the corresponding cylindrical portions of the pintle and body below the first beveled portion 92 and the beveled portion 56. In FIG. 7 the pintle 90 has been lifted slightly, indicated by the letters PL, and the orifice, indicated by the letter O, has opened slightly. In FIG. 8 the pintle 90 has been further lifted and the flow area of the orifice has increased. In FIG. 9 the pintle 90 is fully lifted and the flow area of the orifice is at its maximum.
Referring now to FIG. 2, lifting of the pintle nozzle 90 will be described. The pressurized DME fuel enters the injector 40, at the top or second end of the injector body 42, through the inlet passage 36 when the injector solenoid 30 is energized and flows longitudinally through a fuel passage 50 formed in the injector body 42. Fuel passage 50 opens into a cavity 58. The pintle nozzle 90 includes first and second piston like portions 94 and 96 respectively that slide in corresponding cylindrical bores in the injector body 42 to thus guide and allow the pintle nozzle 90 to reciprocate longitudinally in the injector body 42. First piston like portion 94 is of a smaller diameter than second piston like portion 96 and these piston like portions are connected by a second beveled portion 98. The second beveled portion 98 of the pintle nozzle is located in the cavity 58 and when the pressurized DME fuel enters cavity 58 it exerts a force on the second beveled portion 98, a component of which is directed upward. This upward directed force lifts the pintle nozzle. The upper end of the pintle nozzle extends into a lower bore 46 formed in the injector body 42 where it bears against a spring seat 60 biased downwardly by a spring 64. The upper end of spring 64 engages the top surface of the lower bore 46. The upper portion of the spring seat 60 is in contact with the lower end of a lower push rod 52 that slides in a cylindrical opening 62 that connects the upper bore 44 with the lower bore 46. The upper end of lower push rod 52 extended through a seal 66, secured to the bottom surface of the upper bore 44, and bears against the bottom surface of the damping piston 70. The volume of the upper bore 44 that is not occupied by the damping piston 70 is filled with silicone fluid 120 or other suitable viscous fluid. An upper push rod 54 bears against the circular top surface 74 of the damping piston 70 and extends into a bore 68 formed in the plug 48. The upper end of upper push rod 54 engages a spring 69 contained in the bore 68. Spring 69 exerts, through the upper push rod 54, a downward force on the damping piston 70.
An isolated perspective view of the damping piston 70 is shown in FIG. 3. The damping piston 70 has a generally cylindrical shape and includes a flat circular top surface 74. A pair of rectangular shaped flat surfaces 76 are formed on opposite sides of the damping piston 70. The flat surfaces 76 do not; extend to the top circular surface 74 and there remains part of the damping piston at its upper end that is a complete cylinder. The damping piston 70 and upper bore 44 are dimensioned to allow the damping piston 70 to reciprocate with a close sliding relationship in the upper bore 44. The longitudinal length of the true cylinder portion is represented by L in FIG. 3. As shall be discussed in more detail the duration of the throttling of the fuel injection during the initial portion of the injection can be controlled or changed by utilizing damping pistons 70 in which the dimension L is different.
A damping orifice 72, is formed by a bore having a relatively small diameter that extends from the top surface 74 to the bottom surface of the damping piston 70.
A reverse flow check valve 75 is provided in the damping piston 70 by a bore 78 having a larger diameter than the diameter of the damping orifice 72. At the top surface 74 the flow check valve bore 78 is enlarged to form a check ball cage. When the damping piston 70 is being forced upward through the silicone fluid the check ball 77 seats and closes the bore 78 and thus prevents silicone fluid from passing through the bore 78. However, when the damping piston 70 moves downward the silicone fluid can pass upward through the bore 78 raising the check ball 77 off its seat. The check ball 77 is retained in the enlarged portion of bore 78 by the check ball cage but permits free passage of the silicone fluid. When the damping piston 70 moves downwardly, the silicone fluid 120 is also free to pass unencumbered through the damping orifice 72.
When the damping piston 70 is forced into the silicone fluid, above the damping piston, the silicone fluid is forced to flow through the damping orifice 72. Thus upward movement of the damping piston 70 and the pintle nozzle is slowed or restricted. As the damping piston 70 raises in upper bore 44 a distance equal to the dimension L, the flats 76 become uncovered which opens a path for the silicone fluid to flow from above the damping piston 70 to below the damping piston 70. This ends damping and the velocity of the damping piston 70 and the pintle nozzle increases. The pintle nozzle lift L at which the flats 76 are exposed can be varied by using a damping piston 70 having a different dimension L.
FIG. 4, is a graph plotting pintle nozzle lift on the Y axis and time on the X axis. The thin line on the graph represents the lift over time for a pintle nozzle that is not damped and the heavy line represents the lift over time for a pintle nozzle that is damped. The lift of the pintle nozzle with damping is gradual to the point where the flats 76 are exposed at which point the lift is accelerated until maximum lift is achieved.
The velocity of the pintle nozzle lift can be adjusted by using silicone fluids having different fluid viscosities. FIG. 5 is a graph in which pintle nozzle lift is shown on the Y axis and time on the X axis. In this graph the thin line represents a low viscosity silicone fluid and the heavy line represents a high viscosity silicone fluid. This graph illustrates that as the viscosity of the silicone fluid is increased the throttling or damping effect on the lift increases. This graph also illustrates, through the broken lines, how the combination of using silicone fluids of different viscosity and changing the length of dimension L effects the lift of pintle nozzle. Thus, the lift of the pintle nozzle can be customized for a particular engine or environment.
FIG. 10 shows a cross section of a conventional cylinder head 100 that has a common rail 22, of the type previously described, secured thereto by bolts 102. An injector 40 incorporating the invention of this patent is mounted in the conventional injector aperture 104. A fuel passage line 21 is shown extending from the common rail to the injector 40. The injector portion of this invention has been built into a standard size injector body that can be inserted into the standard size injector aperture that is found in many existing diesel engines. In addition this Figure shows that the injector of this invention could be mounted in a conventional diesel engine that is fueled by conventional diesel fuel. When the injector of this invention is used in an engine fueled by diesel fuel, the concept of damping the initial portion of the injection cycle will reduce the NO x and the noise pollution.
While the invention has heretofore been described in detail with particular reference to an illustrated apparatus, it is to be understood that variations, modifications and the use of equivalent mechanisms can be effected without departing from the scope of this invention. It is, therefore, intended that such changes and modifications are covered by the following claims. | An internal combustion engine that is driven by dimethyl ether (DME) and a storage and delivery system for the DME that will reduce considerably the emissions of NO x and particulate. Existing internal combustion engines, fueled by conventional fuels can be economically converted to the use of DME as a fuel. | 8 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a display device, for example, a liquid crystal display device.
[0002] A typical liquid crystal display device is configured such that, on one surface of a substrate thereof, a plurality of signal lines are juxtaposed in the longitudinal direction as well as in the lateral direction, and respective pixels are driven in response to signals supplied to these signal lines. The respective pixels are arranged in a matrix array, and a liquid crystal display part is constituted by these pixels. Liquid crystal is sandwiched between one substrate and another substrate such that the liquid crystal is disposed at positions which correspond to the pixels.
[0003] The signal lines extend to regions outside the liquid crystal display part and are provided with terminals at the extended ends thereof. These terminals are made to face down, and they constitute portions which are connected with bumps of a semiconductor device on which the liquid crystal display part is mounted. The signals are supplied to the signal lines from the semiconductor device.
[0004] Here, in a typical case, the signal lines are covered with an insulation film inside of a region of the liquid crystal display part, and the insulation film is formed such that it extends to the outside of the liquid crystal display part. Accordingly, the terminals are formed by exposing portions of the signal lines by forming holes in the insulation film and by stacking, for example, conductive layers, which exhibit the strong resistance against electrolytic corrosion, on these exposed portions.
[0005] Further, even inside of the liquid crystal display part, conductive layers are provided so as to be arranged as separated layers; and, when these conductive layers are to be connected with each other, an operation is carried out to form holes (through holes) in an insulation film which is formed between the conductive layers. In this case, the formation of the above-mentioned holes (through holes) in the terminal parts is usually performed simultaneously. Such simultaneous hole forming operations are performed with a view toward achieving a reduction in the manufacturing man-hours.
[0006] Further, as the insulation film, there is a known insulation film which is formed of a sequentially stacked film, which is constituted of an inorganic material layer and an organic material layer, for reducing the capacitance at a portion where the conductive film, which constitutes a layer below the insulation is film, and the conductive film, which constitutes a layer above the insulation film, are overlapped relative to each other (for example, see JP-A-2000-171817).
SUMMARY OF THE INVENTION
[0007] In the liquid crystal display device having such a constitution, it is desirable to provide a side wall surface of the through hole in the insulation film formed at the terminal part with a gentle inclination. This is so because, since the connection of the bump of the semiconductor device and the terminal is established via an anisotropic conductive film or the like, for example, it is necessary to ensure a good reliability in such a connection. This factor is not limited to the provision of an anisotropic conductive film, but the same goes for a case in which the connection is established via a blazing material.
[0008] However, in forming these through holes simultaneously with the formation of other through holes inside of the liquid crystal display part, it is inevitably necessary to make the inclination of the side wall surfaces of the other through holes inside of the liquid crystal display part gentle, thus giving rise to a drawback in that the so-called numerical aperture is reduced.
[0009] Further, when the connection of the semiconductor device with the substrate is not favorable, after mounting the semiconductor device on the substrate, it is usually necessary to perform an operation to remove the semiconductor device from the substrate and to newly mount the semiconductor device on the substrate (repair).
[0010] Here, when an organic material layer or the like is formed as the upper layer of the protective film, as mentioned above, the organic material layer is peeled off at the time of removing the semiconductor device from the substrate, and this brings about a drawback in that the reliable connection environment is broken in the terminal part.
[0011] Although it is desirable that the organic material layer is not formed on the terminal part and the periphery thereof, the reduction of the number of manufacturing man-hours is impeded when an attempt is made to achieve selective removal.
[0012] The present invention has been made under such circumstances, and one object of the present invention is to provide a display device in which the inclination of the side wall surfaces of the through holes in an insulation film formed at a terminal part is made gentler than the corresponding inclination of other through holes.
[0013] It is another object of the present invention to provide a display device in which through holes at a terminal part exhibit a good reliability in connection.
[0014] A brief explanation of representative aspects and features of the invention disclosed in this specification will be presented in the following.
(1) The present invention is, for example, directed to a display device in which a semiconductor chip is mounted on a substrate, wherein terminals, which are connected with respective bumps of the semiconductor chip, are formed by first openings formed in a first insulation film, which openings expose portions of signal lines which are formed below the first insulation film; portions of the signal lines which extend to a display part are exposed by second openings, which penetrate a second insulation film and the first insulation film, which is formed below the second insulation film, and are connected with other conductive layers, which are formed on the second insulation film; the angle of the side wall surfaces of the first openings in the first insulation film, which angle is formed with respect to the substrate, is set so as to be smaller than the angle of the side wall surfaces of the second openings in the first insulation film, which angle is formed with respect to the substrate; and the angle of the side wall surfaces of an edge of the second insulation film on a terminal side, which angle is formed with respect to the substrate, is set so as to be smaller than the angle of the side wall surfaces of the second openings in the second insulation film, which angle is formed with respect to the substrate. (2) The display device according to the present invention is, for example, characterized in that respective regions of a display part and a terminal part are formed on a liquid-crystal-side surface of a substrate; a first insulation film is formed on the display part and the terminal part and a second insulation film is formed on other regions, except for at least the terminal part and a periphery thereof, sequentially; first through holes are formed in the display part so that the first through holes penetrate the second insulation film and the first insulation film; second through holes are formed in the terminal part so that the second through holes penetrate the first insulation film; the angle of the side wall surfaces of the second through holes in the first insulation film, which angle is formed with respect to the substrate, is set so as to be smaller than the angle of the side wall surfaces of the first through holes in the first insulation film, which angle is formed with respect to the substrate; and the angle of a side wall surface of an edge of the second insulation film on a terminal part side, which angle is formed with respect to the substrate, is set so as to be smaller than the angle of the side wall surfaces of the first through holes in the second insulation film, which angle is formed with respect to the substrate. (3) The display device according to the present invention is, for example, on a premise of the constitution (1) or (2), characterized in that the first insulation film is formed of an inorganic material layer and the second insulation film is formed of an organic material layer. (4) The display device according to the present invention is, for example, on a premise of the constitution (3), characterized in that signals are supplied to respective pixels of the display part via thin film transistors, and the first insulation film and the second insulation film are provided to function as a protective film, which is formed so that the protective film covers the thin film transistors. (5) The display device according to the present invention is, for example, on a premise of the constitution (2), characterized in that in the terminal part, portions of the signal lines which are formed below the first insulation film are exposed via the second through holes that are formed in the first insulation film, and an oxide conductive film is formed so as to cover at least the exposed portions. (6) The display device according to the present invention is, for example, on a premise of the constitution (5), characterized in that the oxide conductive film extends to an upper surface of the first insulation film on the peripheries of the second through holes, with a second insulation film interposed therebetween. (7) The display device according to the present invention is, for example, on a premise of the constitution (5) or (6), characterized in that the oxide conductive film is made of ITO. (8) The display device according to the present invention is, for example, on a premise of the constitution (2), characterized in that the signal lines are drain signal lines which supply signals to the respective pixels of the liquid crystal display part. (9) The display device according to the present invention is, for example, on a premise of the constitution (2), characterized in that the signal lines are gate signal lines which supply signals to turn on the thin film transistors for the purpose of supplying the signals to the respective pixels of one group of the display part with a thin film transistor therebetween. (10) The display device according to the present invention is, for example, a display device with a first contact hole formed in a display region and a second contact hole formed in a terminal region; a first insulating layer and a second insulating layer formed in that order; and wherein the taper angle of the first insulating layer at the first contact hole is larger than the taper angle of the first insulating layer at the second contact hole, and the taper angle of the second insulating layer at the first contact hole is larger than the taper angle of the second insulating layer around the second contact hole.
[0025] The present invention is not limited to the above-mentioned constitutions and various modifications can be made without departing from the technical concept of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1A and FIG. 1B are diagrams showing the constitution of a characteristic part of a display device according to one embodiment of the present invention;
[0027] FIG. 2A is a diagram showing one embodiment of the display device, and FIG. 2B is an equivalent circuit diagram showing one pixel;
[0028] FIG. 3A is a cross-sectional view showing the constitution of a pixel of the display device according to the present invention and FIG. 3B is a cross-sectional view showing the constitution of an end part of the display device according to the present invention;
[0029] FIG. 4 is a flow chart showing one example of a method of manufacture of the terminal part of the display device according to the present invention;
[0030] FIG. 5 is a flow chart showing another of a method of manufacture of the terminal part of the display device according to the present invention;
[0031] FIG. 6 is a flow chart showing another example of a method of manufacture of the terminal part of the display device according to the present invention;
[0032] FIG. 7 is a flow chart showing another example of a method of manufacture of the terminal part of the display device according to the present invention;
[0033] FIG. 8 is a flow chart showing another example of a method of manufacture of the terminal part of the display device according to the present invention;
[0034] FIG. 9 is a flow chart showing another example of a method of manufacture of the terminal part of the display device according to the present invention; and
[0035] FIG. 10A and FIG. 10B are plan views showing another embodiment of the terminal part of the display device according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0036] Hereinafter, various embodiments of the present invention will be explained in conjunction with the drawings by taking a liquid crystal display device as an example.
Embodiment 1
[0037] FIG. 2A and FIG. 2B show one embodiment of a liquid crystal display device according to the present invention, wherein FIG. 2A is a diagram of the whole liquid crystal display device, and FIG. 2B is an equivalent circuit diagram of one pixel. FIG. 2B is a view which corresponds to a part surrounded by a circle B in FIG. 2A .
[0038] In FIG. 2A , a pair of transparent substrates SUB 1 , SUB 2 are arranged to face each other in an opposed manner with liquid crystal disposed therebetween, wherein the liquid crystal is sealed by a sealing material SL, which is also used for fixing the other transparent substrate SUB 2 to the one transparent substrate SUB 1 .
[0039] On a liquid-crystal-side surface of the one transparent substrate SUB 1 , which is surrounded by the sealing material SL, gate signal lines GL extend in the x direction and are arranged in parallel in the y direction, and drain signal lines DL which extend in the y direction and are arranged in parallel in the x direction.
[0040] Regions which are surrounded by adjacent gate signal lines GL and adjacent drain signal lines DL constitute pixel regions, and a matrix array of the respective pixel regions constitute a liquid crystal display part AR.
[0041] Further, the respective pixel regions, which are arranged in parallel in the x direction, are provided with a common counter voltage signal line CL, which runs in the inside of the respective pixel regions. The counter voltage signal line CL constitutes a signal line for supplying a voltage, which becomes a reference with respect to a video signal, to counter electrodes CT of the respective pixel regions, as will be explained later.
[0042] In each pixel region, there is a thin film transistor TFT, which is driven by a scanning signal transmitted from the one-side gate signal line GL, and a pixel electrode PX, to which the video signal is transmitted from the one-side drain signal line DL through the thin film transistor TFT.
[0043] An electric field is generated between the pixel electrode PX and the counter electrode CT, which is connected with the counter voltage signal line CL, and the optical transmissivity of the liquid crystal is controlled in response to the electric field.
[0044] One end of the respective gate signal lines GL extends over the sealing material SL, and the extending ends of the gate signal line GL constitute terminals GLT, to which output terminals of a scanning signal drive circuit V are connected. Further, input terminals of the scanning signal drive circuit V are configured to receive the inputting of the signals from a printed circuit board (not shown in the drawing), which is arranged outside a liquid crystal display panel.
[0045] The scanning signal drive circuit V is constituted of a plurality of semiconductor devices, wherein a plurality of gate signal lines GL, which are arranged close to each other, are formed into a group, and one semiconductor device is allocated to each group of gate signal lines GL.
[0046] In the same manner, one end of the respective drain signal lines DL extends over the sealing material SL, and these extending ends of the drain signal lines DL constitute terminals DLT, to which output terminals of a video signal drive circuit He are connected. Further, input terminals of the video signal drive circuit He are configured to receive signals from a printed circuit board (not shown in the drawing), which is arranged outside the liquid crystal display panel.
[0047] The video signal drive circuit He is also constituted of a plurality of semiconductor devices, wherein a plurality of drain signal lines DL, which are arranged close to each other, are formed into a group, and one semiconductor device is allocated to each group of drain signal lines DL.
[0048] Further, the counter voltage signal lines CL are connected in common at an end portion on the right side, as seen in the drawing, and a connection line extends over the sealing material SL, and an extending end constitutes a terminal. A voltage which becomes the reference with respect to the video signal is supplied from the terminal.
[0049] The respective gate signal lines GL are sequentially selected one after another in response to the scanning signal received from the scanning signal drive circuit V. Further, to the respective drain signal line DL, a video signal is supplied at the timing of selecting the gate signal line GL by the video signal drive circuit He.
[0050] FIG. 3A is a cross-sectional view showing the region of a typical pixel, and FIG. 3B is a cross-sectional view showing the terminal DLT of the drain signal line DL.
[0051] First of all, in the region of the pixel, the gate signal lines GL are formed on a surface of the transparent substrate SUB 1 , and an insulation film GI is formed on the surface of the transparent substrate SUB 1 such that the insulation film GI also covers the gate signal lines GL. On an upper surface of the insulation film GI, a semiconductor layer AS, which is made of amorphous Si, for example, is formed such that the semiconductor layer AS overlaps a portion of the gate signal line GL.
[0052] The semiconductor layer as forms a part of the thin film transistor TFT, which thin film transistor TFT is constituted of a MIS (Metal Insulator Semiconductor) transistor having a so-called inversely staggered structure, which uses a portion of the gate signal line GL as a gate electrode and the insulation film GI as a gate insulation film, and further includes a drain electrode SD 1 and a source electrode SD 2 to be described later.
[0053] Further, the drain electrodes SD 1 and the source electrodes SD 2 are formed simultaneously at the time of forming the drain signal lines DL, wherein the drain electrode SD 1 and the source electrode SD 2 are connected with the semiconductor layer AS at one end and another end of the semiconductor layer AS, respectively. Here, the source electrode SD 2 is connected with the pixel electrode PX and is provided with an extending portion which slightly extends in the direction toward the center of the pixel to provide a connecting portion.
[0054] Then, on the surface of the transparent substrate SUB 1 , on which the drain signal lines DL (drain electrodes SD 1 ) and the source electrodes SD 2 are formed, a protective film PCV is formed such that the protective film PCV also covers the drain signal lines DL and the like. The protective film PCV is a film which avoids direct contact between the thin film transistor TFT and the liquid crystal so as to prevent deterioration of the properties of the thin film transistor TFT.
[0055] Further, the protective film PCV is formed as a sequentially stacked structure which is constituted of a protective film PAS, which is formed of an inorganic material layer made of SiN, for example, and a protective film OPAS, which is formed of an organic material layer made of resin, for example. Such a structure is provided for imparting reliability in the form of a protective function to the protective film PCV by the protective film PAS and for reducing the capacitance of the whole protective film PCV by the protective film OPAS.
[0056] In portions of the protective film PCV, through holes are formed which penetrate the protective film OPAS and the protective film PAS, so that the pixel electrodes PX, which are formed on an upper surface of the protective film PCV, can be connected with the source electrodes SD 2 of the thin film transistors TFT via the through holes.
[0057] Here, although the counter electrode CT (and the counter voltage signal line CL), which is used to generate an electric field between the counter electrode CT and the pixel electrode PX, is not shown in the drawing, the counter electrode CT may be formed on the same layer as the pixel electrode PX, or it may be formed between other layers, for example, between the insulation film INS and the protective film PAS. It is needless to say that the counter electrode CT may be formed on the other substrate and be arranged to face the pixel electrode PX in an opposed manner.
[0058] Further, in a region where the terminals DLT shown in FIG. 3B are formed, the drain signal line DL extends on an upper surface of the insulation film GI, and a portion of the extending portion is exposed by a through hole formed in the protective film PAS, through which the exposed portion is connected with a conductive layer CD, which is formed on the portion or in the periphery thereof.
[0059] Provided that the pixel electrodes PX are formed of, for example, ITO (Indium Tin Oxide), ITZO (Indium Tin Zinc Oxide), IZO (Indium Zinc Oxide), SnO 2 (Tin Oxide), In 2 O 3 (Indium Oxide) or the like, the conductive layers CD are formed simultaneously with the formation of the pixel electrodes PX; and, hence, the manufacturing man-hours can be reduced, and, at the same time, it is is possible to form terminals which exhibit a desired reliability against electrolytic corrosion.
[0060] The protective film OPAS is not formed on the terminals DLT and on the peripheries of the terminals, and it has edges which are arranged in the vicinity of the terminals DLT and extend from the liquid crystal display part AR.
[0061] The relationship between the through hole portion of the protective film PAS in the pixel portion, as seen in the drawing (circled frame A in FIG. 3A ), and the through hole portion of the protective film PAS in the terminal DLT portion (circled frame B in FIG. 3B ), will be explained in detail in conjunction with FIGS. 1A and 1B .
[0062] FIG. 1A is a detailed view of the portion shown in the circled frame A in FIG. 3A , and FIG. 1B is a detailed view of the portion shown in the circled frame B in FIG. 3B .
[0063] As can be clearly understood from FIG. 1A and FIG. 1B , an angle θ 2 of a side wall surface of the through hole formed in the protective film PAS at the terminal part, which is formed with respect to the transparent substrate SUB 1 (an angle which is formed with respect to a plane of the substrate or an angle which is formed with respect to an upper surface of the drain signal line DL) is set so as to be smaller than an angle θ1 of a side wall surface of the through hole formed in the protective film PAS at the pixel portion, which angle is formed with respect to the transparent substrate SUB 1 (an angle which is formed with respect to a plane of the substrate or an angle which is formed with respect to an upper surface of the drain signal line DL).
[0064] Further, with respect to the angle of the side wall surface of the protective film OPAS, an angle θ4 of the side wall surface of the protective film OPAS at the edge of the terminal part side, which angle is formed with respect to the transparent substrate SUB 1 , is set so as to be smaller than the angle θ3 of the side wall surface of the protective film OPAS in the through hole of the pixel portion, which angle is formed with respect to the transparent substrate SUB 1 .
[0065] In a display device having such a constitution, the inclination of the side wall surface of the through hole at the terminal part is formed gently, and, hence, the coating of the conductive layer CD can be performed reliably, whereby the connection of the terminal parts with the bumps of the semiconductor device can be established favorably.
[0066] Further, in the through holes formed in the terminal part, the inclination of the side wall surfaces is formed so as to be gentler compared to the inclination of the side wall surfaces of the through hole formed in the pixel portion. Accordingly, the size of the through holes formed in the pixel portion can be reduced, whereby a lowering of the numerical aperture of the pixel portion can be obviated.
[0067] Further, since the protective film OPAS is not formed in the terminal part and the periphery thereof, even when a repair of the semiconductor device is required, it is no longer necessary to worry about the drawback attributed to the peeling-off of the protective film OPAS.
[0068] In this case, the constitution, in which the inclination of the side wall surface of the edge on the terminal part side of the protective film OPAS is set so as to be gentler than the inclination of the side wall surfaces of the through holes in the inside of the pixel portion, indicates that the protective film OPAS can be used as a mask at the time of forming the through holes in the terminal part.
[0069] FIG. 4 shows one example of the steps which may be employed in the manufacture of the terminal part DLT of the drain signal line DL. In FIG. 4 , respective steps (a) to (e) are shown in left column along with the names of the steps; plan views of the terminal part at the time of the corresponding steps are shown in the center column; and cross-sectional views taken along a line A-A′ in the plan views shown in the center column are shown in the right column. Hereinafter, the manufacturing method of the manufacture will be explained in order the of the steps thereof.
[0000] Step (a)
[0070] The terminals which are connected with the drain signal lines DL by way of the insulation film GI are formed on the upper surface of the transparent substrate SUB 1 ; and, thereafter, the protective film PAS made of the inorganic material and the protective film OPAS made of the organic material are formed sequentially on the upper surface of the transparent substrate SUB 1 such that the protective film PAS and the protective film OPAS also cover the drain signal lines DL and the terminals.
[0000] Step (b)
[0071] To form holes for the contacts in the protective film OPAS, the protective film OPAS is subjected to a half light exposure. As a mask PM which is used for the half light exposure, a mask is used which completely shields portions, which correspond to the formation of the contacts, from light, partially allows light to transmit, while blocking the remaining light at the peripheries of the portions, and allows sufficient light to pass through in further areas of the peripheries.
[0072] Corresponding to such a constitution, with respect to the protective film OPAS, the light is blocked in the regions where the holes for contacts are formed, and the light is allowed to transmit in other regions, while an exposure which partially blocks the light is provided at the peripheries of the regions where the holes are formed.
[0000] Step (c)
[0073] The protective film OPAS is etched. The protective film OPAS is removed corresponding to the degree of light shielding; and, hence, holes are formed in the regions where the contacts are formed to an extent that the surface of the protective film PAS which is arranged below the protective film OPAS is exposed, while the surface of the protective film PAS is not yet exposed on the peripheries of the regions where the contacts are formed and only the recessed portions are formed.
[0000] Step (d)
[0074] Using the protective film OPAS as a mask, the protective film PAS, which is arranged below the protective film OPAS, is etched. The holes are formed in the protective film PAS in the regions where the contacts are formed and the terminals which are arranged below the protective film PAS are exposed. Here, the surface of the protective film OPAS is also uniformly etched, and the protective film OPAS is removed until the surface of the protective film PAS is exposed in the portions in the peripheries of the regions where the contacts are formed (the portions corresponding to the recessed portions).
[0000] Step (e)
[0075] The ITO film is formed and is selectively etched, thus forming the conductive layers which are connected with the terminals of the drain signal lines DL in the regions where the contacts are formed. The conductive layers are formed in the inside of the regions where the protective film OPAS is removed and is not formed such that the conductive layers bridge over the protective film OPAS.
[0076] In the description of the above-mentioned embodiment, the constitution of the terminal parts of the drain signal lines DL was based on the relationship of the terminal parts with the through holes formed in the pixel portions. However, it is needless to say that the above-mentioned embodiment is applicable to the terminal portions GLT of the gate signal lines GL in the constitution shown in FIG. 3A .
[0077] FIG. 5 shows one example of a manufacturing method that may be used when the invention is applied to the terminal portions GLT of the gate signal line GL, and it corresponds to the method shown in FIG. 4 . Hereinafter, the method of manufacture will be explained in the order of the steps thereof.
[0000] Step (a)
[0078] The terminals which are connected with the gate signal lines GL are formed on the upper surface of the transparent substrate SUB 1 ; and, thereafter, the insulation film GI is formed on the upper surface of the transparent substrate SUB 1 so that the insulation film GI also covers the gate signal lines GL. Further, on upper surfaces of the insulation films GI, a protective film PAS made of an inorganic material and a protective film OPAS made of an organic material are sequentially formed.
[0000] Step (b)
[0079] To form holes for the contacts in the protective film PAS, the protective film OPAS is subjected to a half light exposure. As a mask PM which is used for the half light exposure, a mask is used which completely shields portions which correspond to the formation of the contacts from light, partially allows light to transmit, while blocking the remaining light at the peripheries of the portions, and allows sufficient light to pass through in further areas of the peripheries is used.
[0080] Corresponding to such a constitution, with respect to the protective film OPAS, the light is blocked in the regions where the holes for contacts are formed, and the light is allowed to transmit in other regions, while an exposure which partially blocks the light is carried out at the peripheries of the regions where the holes are formed.
[0000] Step (c)
[0081] The protective film OPAS is etched. The protective film OPAS is removed corresponding to the degree of light shielding; and, hence, holes are formed in the regions where the contacts are formed to an extent that the surface of the protective film PAS is exposed, while the surface of the protective film PAS is not yet exposed at the peripheries of the regions where the contacts are formed and only the recessed portions are formed.
[0000] Step (d)
[0082] Using the protective film OPAS as a mask, the protective film PAS, which is arranged below the protective film OPAS, and the insulation film GI, which is arranged below the protective film OPAS, are etched. The holes are formed in the protective film PAS and the insulation film GI in the regions where the contacts are formed, and the terminals which are arranged below the insulation film GI are exposed. Here, the surface of the protective film OPAS is also uniformly etched, and the protective film OPAS is removed until the surface of the protective film PAS is exposed in the portions in the peripheries of the regions where the contacts are formed (the portions corresponding to the recessed portions).
[0000] Step (e)
[0083] The ITO film is formed and is selectively etched, thus forming the conductive layers CD, which are connected with the terminals of the gate signal lines GL in the regions where the contacts are formed. The conductive layers are formed in the inside of the regions where the protective film OPAS is removed and is not formed such that the conductive layers bridge over the protective film PAS.
[0084] In the method shown in FIG. 4 , at the time of forming the through holes in the protective film PAS using the protective film OPAS as a mask, care is taken to prevent the surface of the protective film PAS that is exposed from the protective film OPAS from being lightly etched gradually. However, it is needless to say that the present invention is not limited to such a technique, and a light etching may be performed.
[0085] FIG. 6 shows one example of a manufacturing method in which a portion of the surface of the protective film PAS, which is exposed from the protective film OPAS, is etched. Hereinafter, the manufacturing method will be explained in the order of the steps thereof.
[0000] Step (a)
[0086] The terminals which are connected with the drain signal lines DL by way of the insulation film GI are formed on the upper surface of the transparent substrate SUB 1 and, thereafter, the protective film PAS made of the inorganic material and the protective film OPAS made of the organic material are formed sequentially on the upper surface of the transparent substrate SUB 1 such that the protective film PAS and the protective film OPAS also cover the drain signal lines DL and the terminals.
[0000] Step (b)
[0087] To form holes for the contacts in the protective film OPAS, the protective film OPAS is subjected to a half light exposure. As a mask PM which is used for the half light exposure, a mask is used which completely shields portions which correspond to the formation of the contacts from light, partially allows light to transmit while blocking the remaining light at the peripheries of the portions, and allows sufficient light to pass through in further areas of the peripheries.
[0088] Corresponding to such a constitution, with respect to the protective film OPAS, the light is blocked in the regions where the holes for contacts are formed, and the light is allowed to transmit in other regions, while an exposure which partially blocks the light is provided at the peripheries of the regions where the holes are formed.
[0000] Step (c)
[0089] The protective film OPAS is etched. The protective film OPAS is removed corresponding to the degree of light shielding; and, hence, holes are formed in the regions where the contacts are formed to an extent that the surface of the protective film PAS is exposed, while the surface of the protective film PAS is not yet exposed at the peripheries of the regions where the contacts are formed and only the recessed portions are formed.
[0000] Step (d)
[0090] Using the protective film OPAS as a mask, the protective film PAS, which is arranged below the protective film OPAS, is etched. The holes are formed in the protective film PAS in the regions where the contacts are formed and the terminals which are arranged below the protective film PAS are exposed. Here, the surface of the protective film OPAS is also uniformly etched and the protective film OPAS is removed until the surface of the protective film PAS is exposed in the portions in the peripheries of the regions where the contacts are formed (the portions corresponding to the recessed portions). Then, the etching is continued to slightly etch the surface of the protective film PAS which is exposed from the protective film OPAS.
[0000] Step (e)
[0091] The ITO film is formed and is selectively etched, thus forming the conductive layers which are connected with the terminals of the drain signal lines DL in the regions where the contacts are formed. The conductive layers are formed in the inside of the regions where the protective film OPAS is removed and are not formed such that the conductive layers bridge over the protective film OPAS.
[0092] Using substantially the same technical concept, it is possible to execute the steps in the same manner in the method shown in FIG. 5 . FIG. 7 shows one embodiment of such a manufacturing method, which will be explained in the order of the steps thereof hereinafter.
[0000] Step (a)
[0093] The terminals which are connected with the gate signal lines GL are formed on the upper surface of the transparent substrate SUB 1 , and the insulation film GI is formed on the upper surface of the transparent substrate SUB 1 so that the insulation film GI also covers the gate signal line GL. Further, the protective film PAS made of the inorganic material and the protective film OPAS made of the organic material are formed sequentially on the upper surface of the insulation film GI.
[0000] Step (b)
[0094] To form holes for the contacts in the protective film PAS, the protective film OPAS is subjected to a half light exposure. As a mask PM which is used for the half light exposure, a mask is used which completely shields portions which correspond to the formation of the contacts from light, partially allows light to transmit, while blocking the remaining light at the peripheries of the portions, and allows sufficient light to pass through in further areas of the peripheries.
[0095] Corresponding to such a constitution, with respect to the protective film OPAS, the light is blocked in the regions where the holes for contacts are formed and the light is allowed to transmit in other regions, while the exposure which partially blocks the light is carried out at the peripheries of the regions where the holes are formed.
[0000] Step (c)
[0096] The protective film OPAS is etched. The protective film OPAS is removed corresponding to the degree of light shielding; and, hence, the holes are formed in the regions where the contacts are formed to an extent that the surface of the protective film PAS, which is arranged below the protective film OPAS, is exposed, while the surface of the protective film PAS is not yet exposed at the peripheries of the regions where the contacts are formed and only the recessed portions are formed.
[0000] Step (d)
[0097] Using the protective film OPAS as a mask, the protective film PAS, which is arranged below the protective film OPAS, and the insulation film GI, which is arranged below the protective film PAS, are etched. The holes are formed in the protective film PAS and the insulation film GI in the regions where the contacts are formed, and the terminals which are arranged below the insulation film GI are exposed. Here, the surface of the protective film OPAS is also uniformly etched, and the protective film OPAS is removed until the surface of the protective film PAS is exposed in the portions in the peripheries of the regions where the contacts are formed (the portions corresponding to the recessed portions). Further, the etching is continued so as to lightly etch the surface of the protective film PAS exposed from the protective film OPAS.
[0000] Step (e)
[0098] The ITO film is formed and is selectively etched, thus forming the conductive layers CD which are connected with the terminals of the gate signal lines GL in the regions where the contacts are formed. The conductive layers are formed in the inside of the regions where the protective film OPAS is removed and are not formed such that the conductive layers bridge over the protective film PAS.
[0099] In the manufacturing method shown in FIG. 4 , care is taken to prevent the protective film OPAS from remaining in the peripheries of the through holes at the time of forming the through holes in the protective film PAS using the protective film OPAS as a mask. However, it is needless to say that the present invention is not limited to such a case, and the protective film OPAS may slightly remain. This is because such a constitution can also obtain the substantially the same advantageous effect.
[0100] FIG. 8 shows one example of a manufacturing method which will be explained hereinafter in the order of the steps thereof.
[0000] Step (a)
[0101] The terminals, which are connected with the drain signal lines DL by way of the insulation layer GI, are formed on the upper surface of the transparent substrate SUB 1 ; and, thereafter, the protective film PAS made of the inorganic material and the protective film OPAS made of the organic material are formed sequentially on the upper surface of the transparent substrate SUB 1 such a way that the protective film PAS and the protective film OPAS also cover the drain signal lines DL and the terminals.
[0000] Step (b)
[0102] To form holes for the contacts in the protective film OPAS, the protective film OPAS is subjected to half light exposure. As a mask PM which is used for the half light exposure, a mask which completely shields portions which correspond to the formation of the contacts from light, partially allows light to transmit, while blocking the remaining light in peripheral portions, and allows the sufficient light to pass through in further areas of the peripheries is used.
[0103] Corresponding to such a constitution, with respect to the protective film OPAS, the light is blocked in the regions where the holes for contacts are formed, and the light is allowed to transmit in other regions, while an exposure which partially blocks the light is carried out at the peripheries of the regions where the holes are formed.
[0000] Step (c)
[0104] The protective film OPAS is etched. The protective film OPAS is removed corresponding to the degree of light shielding; and, hence, the holes are formed in the regions where the contacts are formed to an extent that the surface of the protective film PAS which is arranged below the protective film OPAS is exposed, while the surface of the protective film PAS is not yet exposed in the peripheries of the regions where the contacts are formed and only the recessed portions are formed.
[0000] Step (d)
[0105] Using the protective film OPAS as a mask, the protective film PAS, which is arranged below the protective film OPAS, is etched. The holes are formed in the protective film PAS in the regions where the contacts are formed, and the terminals which are arranged below the protective film PAS are exposed. Here, although the surface of the protective film OPAS is also substantially uniformly etched, the etching is not performed to such an extent that the surface of the protective film PAS is exposed, and the etching is stopped at a stage in which the protective film OPAS is allowed to remain in the peripheries of the through holes as a thin layer.
[0000] Step (e)
[0106] The ITO film is formed and is selectively etched, thus forming the conductive layers which are connected with the terminals of the drain signal lines DL in the regions where the contacts are formed. The conductive layers are formed such that the protective film OPAS is interposed as a layer in the vicinity thereof.
[0000] Step (f)
[0107] By ashing the protective film OPAS using a gas, such as O 2 plasma, the following structure is formed. That is, the protective film OPAS partially remains below the ITO film; and, thereafter, the region where the protective film PAS is exposed is present; and, thereafter, the region where the protective film OPAS is formed on the protective film PAS is present.
[0108] Using substantially the same technical concept, it is possible to modify the manufacturing method shown in FIG. 5 in the same manner. FIG. 9 shows one embodiment of such a method, which will be explained in the order of the steps thereof.
[0000] Step (a)
[0109] The terminals which are connected with the gate signal lines GL are formed on the upper surface of the transparent substrate SUB 1 , and the insulation film GI is formed on the upper surface of the transparent substrate SUB 1 in such a way that the insulation film GI also covers the gate signal lines GL. Further, the protective film PAS made of the inorganic material and the protective film OPAS made of the organic material are formed sequentially on the upper surface of the insulation film GI.
[0000] Step (b)
[0110] To form holes for the contacts in the protective film PAS, the protective film OPAS is subjected to half light exposure. As a mask PM which is used for the half light exposure, a mask which completely shields portions which correspond to the formation of the contacts from light, partially allows light to transmit, while blocking the remaining light in peripheral portions, and allows the sufficient light to pass through in further areas of the peripheries is used.
[0111] Corresponding to such a constitution, with respect to the protective film OPAS, the light is blocked in the regions where the holes for contacts are formed, and the light is allowed to transmit in other regions, while an exposure which partially blocks the light is carried out at the peripheries of the regions where the holes are formed.
[0000] Step (c)
[0112] The protective film OPAS is etched. The protective film OPAS is removed corresponding to the degree of light shielding; and, hence, the holes are formed in the regions where the contacts are formed to such an extent that the surface of the protective film PAS which is arranged below the protective film OPAS is exposed, while the surface of the protective film PAS is not yet exposed in the peripheries of the regions where the contacts are formed and only the recessed portions are formed.
[0000] Step (d)
[0113] Using the protective film OPAS as a mask, the protective film PAS, which is arranged below the protective film OPAS, and the insulation film GI, which is arranged below the protective film PAS, are etched. The holes are formed in the protective film PAS and the insulation film GI in the regions where the contacts are formed, and the terminals which are arranged below the insulation film GI are exposed. Here, although the surface of the protective film OPAS is also substantially uniformly etched, the etching is not performed to such an extent that the surface of the protective film PAS is exposed, and the etching is stopped at a stage in which the protective film OPAS is allowed to remain in the peripheries of the through holes as a thin layer.
[0000] Step (e)
[0114] The ITO film is formed and is selectively etched, thus forming the conductive layers which are connected with the terminals of the gate signal lines GL in the regions where the contacts are formed. The conductive layers are formed in such a way that the protective film OPAS is interposed as a layer in the vicinity thereof.
[0000] Step (f)
[0115] By ashing the protective film OPAS using a gas, such as O 2 plasma, the following structure is formed. That is, the protective film OPAS partially remains below the ITO film; and, thereafter, the region where the protective film PAS is exposed is present; and, thereafter, the region where the protective film OPAS is formed on the protective film PAS is present.
[0116] In the terminal parts having the structures shown in FIG. 8 and FIG. 9 , it is possible to increase the size of stepped portions of recessed portions of the ITO. Accordingly, it is possible to obtain an advantageous effect in that, at the time of connecting the terminal and the semiconductor element using the anisotropic conductive film, it is possible to suppress the flow-out of the anisotropic conductive film to the outside of the terminal part.
[0117] In the above-mentioned manufacturing method, by adjusting the quantity of the exposure to the protective film OPAS, it is possible to control the etching rate of the protective film OPAS. This is an advantageous effect that is brought about by a manufacturing method which uses a half exposure. It is no longer necessary to form the protective films OPAS having a plurality of thicknesses individually, and so the number of processing steps can be reduced, thus giving rise to an advantageous effect in that the manufacturing cost can be reduced.
[0118] On the other hand, when the exposure of the protective film OPAS is a half exposure, irregularities in the exposure are liable to be easily generated due to reflection light (the reflection caused by the signal lines) in the parallel direction of the terminals in the vicinity of the terminal part (corresponding to the parallel direction of the signal lines which are connected with the terminals) to a greater extent than in the extending direction of the terminals. Accordingly, it is desirable to carry out deliberate control of the exposure quantity to perform a uniform exposure. This is because the time necessary for exposure processing is prolonged, and, hence, the cost lowering effect is slightly reduced.
[0119] Accordingly, inventors of the present invention have further invented a terminal structure in which irregularities in the exposure are hardly generated.
[0120] FIG. 10A shows one example. For example, at the time of forming the drain signal lines DL, signal lines DML are simultaneously formed between the respective drain signal lines DL, which are arranged in parallel. Due to such a constitution, the reflectance of light in the direction indicated by an arrow A in the drawing becomes substantially uniform; and, hence, it is possible to achieve an exposure with no irregularities.
[0121] Further, the exposure to the protective film OPAS is performed by the above-mentioned half exposure. With respect to a photo mask PM, which is used for the half exposure, in a portion which performs a partial transmission of light and a partial blocking of light, a plurality of strip-like light blocking portions are formed, which extend in one direction and are arranged in a direction which intersects the one direction.
[0122] In using such an exposure mask, due to the relationship with the light blocking portions of the exposure mask, there may be a case in which is interference fringe is formed in the extending direction of the terminals. Accordingly, as shown in FIG. 10B , dummy signal lines DML are intermittently formed along the longitudinal direction, wherein the pitch thereof is set to a value which avoids an integer times the pitch of the strip-like light blocking portions.
[0123] Here, the application of the constitutions shown in FIG. 10A and FIG. 10B is not limited to a so-called COG method, and these constitutions are widely applicable to general connection terminals for connecting a printed circuit board and films on which terminals are formed.
[0124] The above-mentioned respective embodiments may be used in a single form or in combination. This is because it is possible to obtain the advantageous effects of these embodiments individually or synergistically.
[0125] Further, in the above-mentioned embodiments, the through holes which are formed in the pixel portion are connected with the conductive layers, which are positioned below the pixel electrodes. However, it is needless to say that the counter electrodes may replace the pixel electrodes. This is because the electric field applied to the liquid crystal has a relative value, and, hence, there is no difference in designating either one of the electrodes as the pixel electrode or the counter electrode.
[0126] Here, although an explanation has been given by taking a liquid crystal display device as an example in all if the above-mentioned embodiments, it is needless to say that the present invention is applicable to other types of display device, such as an organic EL display device or the like, for example. This is because, that although an organic EL display device may differ from a liquid crystal display device with respect to the constitution that in which emitting layers made of a solid body are sandwiched between pixel electrodes and counter electrodes in place of the liquid crystal and an electric current is supplied to the light emitting layers through these electrodes, there is no difference with respect to the other constitution compared with the above-mentioned constitution. Further, the organic EL display device also has the above-mentioned drawbacks with the respect to at least the through holes formed in the pixel portion and the through holes formed in the terminal part. | A display device is provided with a first contact hole formed in a display region and a second contact hole formed in a terminal region, and a first insulating layer and a second insulating layer are formed in that order. The taper angle of the first insulating layer at the first contact hole is larger than the taper angle of the first insulating layer at the second contact hole, and the taper angle of the second insulating layer at the first contact hole is larger than the taper angle of the second insulating layer around the second contact hole. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/413,719, filed on Nov. 15, 2010, entitled “CONTROLLED NOZZLE INJECTION METHOD AND APPARATUS,” which is hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates in general to a controlled nozzle injection method and apparatus, and deals more particularly with a controlled nozzle injection method and apparatus which operates to reduce the amount of polluting contaminants emitted by an internal combustion engine.
BACKGROUND OF THE INVENTION
[0003] Internal combustion engines are well known power generating devices which may have any number of differing configurations in dependence upon the type of fuel utilized, their size and the particular environment in which they are designed to operate.
[0004] Although several electronic fuel delivery systems for internal combustion vehicles are known to provide adequate performance characteristics, these systems tend to be expensive and do not address those motorized vehicles which include non-electronic fuel delivery systems. In those systems which utilize standard mechanical pumps for this purpose, there exists several inherent inefficiencies which the present invention seeks to address.
[0005] As can be seen in FIG. 1 , a known fuel delivery system 10 of a typical high pressure, diesel engine utilizes a mechanical pump 12 (also referred to as a jerk pump or a block pump), and an unillustrated arrangement of camshafts and plungers, to intermittently provide a predetermined amount of fuel from a fuel supply 14 to a fuel injector 16 via an injection line. The nozzle of the fuel injector 16 operates to atomize the fuel as it enters the high pressure air combustion chamber of the engine.
[0006] In operation, pressure within the fuel injector 16 continues to build as the pump 12 provides fuel to the fuel injector 16 at the onset of a given fuel delivery cycle. A spring biased injector valve 22 , typically a needle valve or the like of the fuel injector 16 , opens in response to the pressure building within the fuel injector 16 , thereby causing fuel to be dispensed through a series of passageways and into the vehicle's combustion chamber.
[0007] FIG. 2 is a graph illustrating the pressure at the nozzle portion of the fuel injector 16 during the fuel delivery cycle, wherein a slight drop in pressure can be seen to occur at the start of the injection process (in certain instances a slight change in the slope of the pressure curve may be seen, rather than an actual drop in pressure), although pressure continues to build at a desired rate after fuel injection has begun. Fuel will therefore continue to be delivered to the combustion chamber of the vehicle until the pressure within the fuel injector falls below the return spring biasing force of the injector valve 22 . In these known systems, residual fuel which is left in the nozzle portion of the fuel injector 16 after the injector valve 22 closes is typically vented from the nozzle portion via a nozzle leak-off valve, conduit or the like. In other systems, such as that of the present invention, the residual fuel is not vented and remains in the line until the next injection.
[0008] In such systems as described in conjunction with FIGS. 1 and 2 above, the pressure of the fuel has a direct effect on how the fuel atomizes as it leaves the fuel injector 16 and enters the combustion chamber, and hence on how the fuel burns within the combustion chamber of the vehicle. Larger droplets of fuel are provided to the combustion chamber of the vehicle during those times when the pressure at the nozzle portion of the fuel injector 16 is comparatively low. These larger droplets tend to take longer to evaporate, mix and burn and therefore may not be able to completely combust within the combustion chamber before being exhausted therefrom. In addition, such large, low pressure and low velocity droplets may not make it to the distal side of the combustion chamber to mix with all the air. Such incomplete mixing and combustion aggravates pollution concerns, including the production of increased particulates, smoke, odor, hydrocarbons, carbon monoxide and the like.
[0009] It would therefore be advantageous to modify existing fuel delivery systems so as to reduce the generation of pollutants while increasing the efficiency of the fuel delivery system as a whole. Towards this end, the present invention seeks to raise the closing pressure of the injected fuel, while holding the starting pressure of the fuel injection at an elevated level.
[0010] It has been determined that by raising the closing pressure, the needle valve in the nozzles starts to close earlier as the pressure in the injection line begins to drop. The nozzle therefore tends to close completely before the line pressure goes to zero, thereby reducing the quantity of fuel injected at an undesirably low pressure. A problem exists in incorporating this pressure architecture with standard mechanical, or jerk, pumps because known mechanical pumps cannot reach the desired high opening and closing pressures to start at typical cranking speeds.
[0011] With the forgoing problems and concerns in mind, the present invention seeks to provide a controlled nozzle injection method and apparatus which operates in conjunction with known mechanical fuel pumps to reduce the amount of polluting contaminants emitted by an internal combustion engine.
SUMMARY OF THE INVENTION
[0012] It is an object of the present invention to provide a controlled nozzle injection device.
[0013] It is another object of the present invention to provide a controlled nozzle injection device which operates to reduce the amount of polluting contaminants emitted by an internal combustion engine.
[0014] It is another object of the present invention to provide a controlled nozzle injection device which elevates the pressure at the beginning of the fuel delivery cycle.
[0015] It is another object of the present invention to provide a controlled nozzle injection device which maintains higher pressures at the end of the fuel delivery cycle.
[0016] It is another object of the present invention to provide a controlled nozzle injection device that allows for the pressure at each nozzle to be independently, dynamically and selectively controlled.
[0017] According to one embodiment of the present invention, a nozzle injection apparatus for use in internal combustion engines includes a fuel pump for intermittently pressurizing fuel and an injection conduit in fluid communication with the fuel pump, the injection conduit permitting the pressurized fuel to be communicated to a fuel injection nozzle. A high pressure manifold in fluid communication with the fuel pump and the nozzle is also provided to accumulate the pressurized fuel which is residually left in the injection conduit between intermittent pressurizations of the fuel.
[0018] According to another embodiment of the present invention, a nozzle injection apparatus for use in internal combustion engines includes a fuel pump for intermittently pressurizing fuel, an injection conduit in fluid communication with the fuel pump, the injection conduit permitting the pressurized fuel to be communicated to a fuel injection nozzle a control valve in fluid communication with the nozzle, wherein the control valve dynamically and selectively controls a pressure of said pressurized fuel within the injection conduit.
[0019] These and other objectives of the present invention, and their preferred embodiments, shall become clear by consideration of the specification, claims and drawings taken as a whole.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below:
[0021] FIG. 1 is a block diagram of a known fuel delivery system for internal combustion engines.
[0022] FIG. 2 is a graph illustrating the pressure at the nozzle portion of a fuel injector during the fuel delivery cycle according to the fuel delivery system of FIG. 1 .
[0023] FIG. 3 illustrates a controlled nozzle injection apparatus according to one embodiment of the present invention.
[0024] FIG. 4 is an enlarged, partial cross-sectional view of a valve assembly utilized in the injection apparatus of FIG. 3 .
[0025] FIG. 5 is a graph illustrating the pressure at the nozzle portion of a fuel injector during the fuel delivery cycle according to the nozzle injection apparatus of FIG. 3 .
[0026] FIG. 6 illustrates a controlled nozzle injection apparatus according to another embodiment of the present invention.
[0027] FIG. 7 is an enlarged, partial cross-sectional view of a dual valve assembly utilized in the injection apparatus of FIG. 6 .
[0028] FIG. 8 illustrates a controlled nozzle injection apparatus according to another embodiment of the present invention.
[0029] FIG. 9 is an enlarged, partial cross-sectional view of a dual valve assembly utilized in the injection apparatus of FIG. 8 .
[0030] FIG. 10 is an enlarged view of area “A” of FIG. 8 and depicts a control valve assembly utilized in the injection apparatus of FIG. 8 .
[0031] FIG. 11 is partial cross-sectional view of a controlled nozzle injection apparatus according to one embodiment of the present invention.
[0032] FIG. 12 is a schematic view of a controlled nozzle injection system according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] FIG. 3 illustrates a controlled nozzle injection apparatus 100 according to one embodiment of the present invention. As illustrated in FIG. 3 , a fuel injection pump 112 is provided to intermittently supply the injection apparatus 100 with a pressurized stream of fuel, typically a hydrocarbon fuel comprising gasoline, diesel fuel or the like. The pump 112 operates to send streams of pressurized fuel through, in succession, a plurality of fuel transport conduits 114 , a high pressure manifold 116 , a plurality of fuel injection conduits 118 and, finally, to a plurality of fuel injector nozzles 120 which exhaust the fuel streams into an unillustrated combustion chamber of a vehicle. A fuel return conduit 122 is also provided for depressurizing the high pressure manifold 116 , as will be described in more detail later.
[0034] Each of the nozzles 120 typically include a known arrangement of needle valves or the like which, when subjected to a threshold pressure, will permit passage of the pressurized fuel into the combustion chamber. The nozzles 120 do not, however, include leak off valves, conduits or the like which are typically provided to known nozzle assemblies to evacuate residual fuel therefrom like (as discussed previously). The present embodiment utilizes such leakless nozzles in order to trap residual, pressurized fuel within the spring chamber of the needle valves for subsequent use, as will be described in more detail later. Moreover, although there are a discreet number of conduits and fuel injector nozzles shown in FIG. 3 , it will be readily appreciated that the present invention contemplates the incorporation of any number of conduits or nozzles without departing from the broader aspects of the present invention.
[0035] Returning to FIG. 3 , the high pressure manifold 116 is provided with a plurality of differing valve sets 125 which are utilized to control the flow and pressure of the fuel streams provided by the fuel pump 112 . FIG. 4 is an enlarged, partial cross-sectional view of the valve sets 125 utilized to control the flow and pressure of the fuel streams in accordance with the present invention.
[0036] As shown in FIG. 4 , a check valve assembly 126 works in concert with a spool valve assembly 128 and a pressure relief valve assembly 130 to bootstrap residual pressure left in the injection apparatus 100 at the conclusion of each fuel cycle back into the injection apparatus 100 . By doing so, the present invention seeks to maintain high fuel injection pressures at the end of the fuel delivery cycle, similar to the high injection pressures present at the beginning of the fuel delivery cycle.
[0037] Operation of the injection apparatus 100 will now be described in conjunction with FIGS. 3 and 4 . At the beginning of an initial fuel delivery cycle, the fuel pump 112 pressurizes a predetermined amount of fuel from an unillustrated fuel supply. As best seen in FIG. 4 , the pressurized fuel travels through the transport conduit 114 and pools in a spring chamber 124 of a check valve assembly 126 . Once the pressure within the spring chamber 124 overcomes the reverse biasing force of a check spring 132 , a check ball valve 134 will be displaced, thereby allowing the pressurized stream of fuel to pass through the injection conduit 118 on the way to the nozzles 120 where a needle valve, or the like, opens and releases an atomized fuel stream into the combustion chamber of a motorized vehicle.
[0038] As pressure within the spring chamber 124 lessens at the end of the initial fuel delivery cycle, the check ball valve 134 will reassume its blocking position leaving a measured amount of residual fuel, and therefore pressure, trapped in the injection conduits 118 . While known systems remove this residual pressure, the present invention redirects the remaining pressurized fuel to the high pressure manifold 116 for later use. Returning to FIG. 4 , the residual pressurized fuel in the injection conduits 118 forces the spool valve assembly 128 to shift against the biasing force of a return spring 136 housed within the spring chamber 124 . A passageway is thereby created which allows the pressurized fuel to be redirected to the high pressure manifold 116 for later use, the spool valve assembly 128 subsequently reassuming its original position. At this point, the needle valves of the nozzles 120 are also exposed to the residual fuel pressure in the injection conduits 118 and, therefore, a small amount of pressurized fuel will leak into an unillustrated spring chamber of the nozzles 120 , and so the opening and closing pressures of the nozzles 120 will be somewhat higher for subsequent fuel deliver cycles.
[0039] As subsequent fuel delivery cycles are performed, the residual pressurized fuel will continue to be ‘boot-strapped’ into the high pressure manifold 116 , as described above, until the injection conduits 118 and the high pressure manifold 116 have reached and stabilized at a predetermined elevated pressure. In one particular design embodiment, the pressure of the injection lines 118 and the high pressure manifold 116 are designed to stabilize at approximately 4000 psi, whereby detrimentally higher pressures are guarded against through the action of the pressure relief valve assembly 130 which shunts excessive pressure back to the fuel pump 112 for later use via the fuel return line 122 .
[0040] As will now be appreciated, once a state has been reached in which the injection conduits 118 and the fuel manifold 116 have stabilized at a predetermined elevated pressure, each subsequent fuel delivery cycle will begin and end at a scaled pressure which is substantially higher than normal and higher than the predetermined elevated pressure. A graph illustrating the forgoing pressure architecture during operation of the injection apparatus 100 is shown in FIG. 5 . As can be seen from FIG. 5 , subsequent to the pressure within the injection conduits 118 and the fuel manifold 116 having stabilized, the pressure curve 150 has similar characteristics to the pressure curve of known fuel delivery systems, as illustrated previously in FIG. 2 . In the present invention, however, FIG. 5 illustrates how the pressure of the injected fuel remains high even during the later stages of each fuel delivery cycle, owing to the elevated pressure maintained in the high pressure manifold 116 and the injection conduits 118 as a result of the bootstrapping of pressurized fuel.
[0041] In particular, when comparing the pressure curve 50 of FIG. 2 to the pressure curve 150 of FIG. 5 , it will be apparent that the pressure at the nozzle at the onset of fuel injection may be represented by X that is, the dynamic pressure provided by the fuel pump which is sufficient to open the needle valve of the nozzle. In FIG. 5 , owing to the bootstrapping of pressure and the use of leakless nozzles 120 (as described previously), the pressure at the nozzles 120 is represented by the residual pressure in the system, 4000 psi in FIG. 5 , plus the dynamic pressure X provided by the fuel pump 112 . In this manner, the present invention ensures that high opening and closing pressures may be maintained at the nozzles 120 during operation of the vehicle, resulting in a more complete combustion of injected fuel and a corresponding reduction in the pollutants exhausted therefrom.
[0042] It is therefore an important aspect of the present invention that the fuel streams provided to the combustion chamber of a motorized vehicle are maintained at an elevated pressure, especially at the nozzles 120 , thereby ensuring a more complete combustion of these fuel streams and an associated reduction in exhausted polluting contaminants.
[0043] It is another aspect of the present invention that the injection apparatus 100 illustrated in FIGS. 3 and 4 may be incorporated onto existing motorized vehicles without incurring significant expenses. In order to accommodate the present invention into existing fuel delivery systems, an electrically actuated valve 140 , typically a solenoid or the like, is provided to the pressure relief valve assembly 130 . The solenoid valve 140 is actuated to vacate pressure within the high pressure manifold 116 during the initial cranking of the motorized vehicle's engine, to be in conformance with the motorized vehicle's original pressure design parameters. Once the vehicle has started, the solenoid valve would again be actuated to enable the fuel delivery routine as described above. While the primary function of the solenoid valve 140 is to reduce the build-up of pressure during a starting operation, the present invention also contemplates actuating the solenoid valve 140 in order to lower the opening and closing pressures of the nozzles 120 during low idle to reduce idling noise and the like.
[0044] Moreover, it should be noted that any additional expense incurred as a result of the incorporation of the more intricate valve assemblies of the present invention, as shown in FIG. 4 , may be substantially offset by a reduction in other fuel delivery system components. In particular, as no ‘leak-off’ capability must be directly attributed to the nozzles 120 , as is standard in known fuel delivery systems, there is no need to drill leak-off holes in the nozzles 120 and the associated tubing and hoses for such are correspondingly eliminated. The present invention is therefore less expensive to produce and install than existing systems, as well as being more efficient.
[0045] In certain circumstances, it may be necessary to adjust the tubing or conduit sizes, as well as the size of the nozzles 120 themselves, in order to make the injection apparatus 100 work as designed at all engine operating speeds and for all fuel delivery demands, and the present invention contemplates such modifications without departing from the broader aspects of the present invention. In particular, the present invention may require that the injection conduits have as much as a 40% larger diameter than is typically present in those systems which utilize hydraulic mechanical fuel pumps. This may be required to ensure that the total pressure at the fuel pump does not get too high. In operation, the pressure at the pump end of the injection conduits is approximately equal to the residual pressure within the conduits plus the dynamic pressure required to propagate the fuel wave down the conduits. The dynamic pressure therefore needs to be reduced, and since the dynamic pressure is approximately inversely proportional to the injection conduits' internal area, the internal area of the injection conduits may need to be made larger, as mentioned above.
[0046] It is therefore another important aspect of the present invention that by increasing the internal area of the injection conduits, enhanced performance may be readily obtained at the nozzle end of the injection conduits as well. In practice, the pressure available to inject the pressurized fuel into the combustion chamber is again the sum of the residual pressure within the injection conduits and the dynamic pressures. A larger internal area of the injection conduits will therefore allow more pressurized fuel to be available to maintain pressure on the nozzle as the needle closes the nozzle at the end of a fuel delivery cycle. Larger injection conduits also reduce the frictional losses associated with the system.
[0047] FIG. 6 illustrates a controlled hydraulic nozzle injection apparatus 200 according to another embodiment of the present invention. As illustrated in FIG. 6 , a fuel injection pump 212 is provided to intermittently supply the injection apparatus 200 with a pressurized stream of fuel, typically a hydrocarbon fuel comprising gasoline, diesel fuel or the like. The pump 212 operates to send streams of pressurized fuel through, in succession, a plurality of dual valve assemblies 226 , a plurality of fuel injection conduits 218 and, finally, to a plurality of fuel injector nozzles 220 which exhaust the fuel streams into an unillustrated combustion chamber of a vehicle.
[0048] Each of the nozzles 220 typically include a known arrangement of needle valves or the like which, when subjected to a threshold pressure, will permit passage of the pressurized fuel into the combustion chamber. Moreover, although there are a discreet number of conduits and fuel injector nozzles shown in FIG. 6 , it will be readily appreciated that the present invention contemplates the incorporation of any number of conduits or nozzles without departing from the broader aspects of the present invention.
[0049] Returning to FIG. 6 , a high pressure manifold 216 is provided and is connected to each of the leak-off conduits 222 of the nozzles 220 in order to assist in boot-strapping residual pressurized fuel, as will be described in more detail later. The high pressure manifold 216 is further connected to the fuel pump 212 via an electrically actuated valve, typically a solenoid or the like, and serves to vacate pressurized fuel from the high pressure manifold 216 , back to the fuel pump 212 , when necessary.
[0050] As more clearly illustrated in FIG. 7 , the dual valve assembly 226 includes a check valve assembly 228 and a pressure relief valve assembly 230 which bootstraps residual pressure left in the injection apparatus 200 at the conclusion of each fuel cycle back into the injection apparatus 200 . By doing so, the present invention seeks to maintain high fuel injection pressures at the end of the fuel delivery cycle, similar to the high injection pressures present at the beginning of the fuel delivery cycle.
[0051] Operation of the injection apparatus 200 will now be described in conjunction with FIGS. 6 and 7 . At the beginning of an initial fuel delivery cycle, the fuel pump 212 pressurizes a predetermined amount of fuel from an unillustrated fuel supply. As best seen in FIG. 7 , once the pressurized fuel overcomes the biasing force of a check spring 232 , a check ball valve 234 will be displaced, thereby allowing the pressurized stream of fuel to pass through the injection conduits 218 on the way to the nozzles 220 where a needle valve, or the like, opens and releases an atomized fuel stream into the combustion chamber of a motorized vehicle.
[0052] At the end of the initial fuel delivery cycle, the check ball valve 234 will reassume its blocking position leaving a measured amount of residual fuel, and therefore pressure, trapped in the injection conduits 218 . While known systems remove this residual pressure, typically by the retraction volume in the delivery valves, the present invention arrests the remaining pressurized fuel by virtue of the pressure relief valve assembly 230 . Owing to this trapped, residual pressurized fuel in the injection conduits 218 , a small amount of the pressurized fuel will be shunted through the leak-off conduits 222 and into the high pressure manifold 216 for later use. The leakage of pressurized fuel into the high pressure manifold 216 affects subsequent movement of the needle valve in the nozzles 220 , and so the opening and closing pressures of the nozzles 220 will be somewhat higher for subsequent fuel deliver cycles.
[0053] As subsequent fuel delivery cycles are performed, the residual pressurized fuel will continue to be ‘boot-strapped’ into the high pressure manifold 216 , as described above, until the injection conduits 218 and the high pressure manifold 216 have reached and stabilized at a predetermined elevated pressure. In one particular design embodiment, the pressure of the injection lines 218 and the high pressure manifold 216 stabilize at approximately 4000 psi, whereby detrimentally higher pressures are guarded against through the action of the pressure relief valve assembly 230 which shunts excessive pressure back to the fuel pump 212 for later use via a fuel return path 223 .
[0054] As will now be appreciated, once a state has been reached in which the injection conduits 218 and the fuel manifold 216 have stabilized at a predetermined elevated pressure (approximately 4000 psi, in the example above), each subsequent fuel delivery cycle will begin and end at a scaled pressure which is substantially higher than normal and higher than the predetermined elevated pressure. A graph illustrating the forgoing pressure architecture during operation of the injection apparatus 200 can be seen in previously discussed FIG. 5 . As can be seen from FIG. 5 , although the pressure curve 150 has similar characteristics to the pressure curve 50 of known fuel delivery systems as illustrated previously in FIGS. 1 and 2 , the pressure of the injected fuel remains high even during the later stages of each fuel delivery cycle, owing to the elevated pressure maintained in the high pressure manifold 216 and the injection conduits 218 as a result of the bootstrapping of pressurized fuel.
[0055] Similar to the operation of the injection apparatus 100 of FIGS. 3 and 4 , the injection apparatus 200 ensures that the fuel streams provided to the combustion chamber of a motorized vehicle are maintained at an elevated pressure, especially at the nozzles 220 , thereby ensuring a more complete combustion of these fuel streams and an associated reduction in exhausted polluting contaminants.
[0056] Moreover, the injection apparatus 200 illustrated in FIGS. 6 and 7 may be incorporated onto existing motorized vehicles without incurring significant expenses. In order to accommodate the injection apparatus 200 into existing fuel delivery systems, an electrically actuated valve 240 , typically a solenoid or the like, is provided between the high pressure manifold 216 and the fuel pump 212 . The solenoid valve 240 is actuated to vacate pressure within the high pressure manifold 216 during the initial cranking of the motorized vehicle's engine, to be in conformance with the motorized vehicle's original pressure design parameters. Once the vehicle has started, the solenoid valve 240 would again be actuated to enable the fuel delivery routine as described above. While the primary function of the solenoid valve 240 is to reduce the build-up of pressure during a starting operation, the present invention also contemplates actuating the solenoid valve 240 in order to lower the opening and closing pressures of the nozzles 220 during low idle to reduce idling noise and the like.
[0057] As best seen in FIG. 6 , the injection apparatus 200 utilizes the leak-off conduits 222 , which are typically present in standard fuel delivery systems, to assist in the bootstrapping of pressurized fuel. The present invention may therefore be easily adapted to existing systems, as well as being more efficient. In certain circumstances, it may be necessary to adjust the tubing or conduit sizes, as well as the size of the nozzles 220 themselves, in order to make the injection apparatus 200 work as designed at all engine operating speeds and for all fuel delivery demands, and the present invention contemplates such modifications without departing from the broader aspects of the present invention, as discussed previously.
[0058] As can be seen from the foregoing disclosure and figures in combination, a controlled nozzle injection apparatus according to the present invention is advantageously provided with a plurality of beneficial operating attributes, including, but not limited to: enabling high starting pressure at the beginning of a fuel delivery cycle, maintaining higher end pressures at the conclusion of a fuel delivery cycle, reducing the exhaust of polluting contaminants and recycling excess pressurized fuel for later use. All of these attributes contribute to the efficient operation of an internal combustion engine and are especially beneficial in those situations where the retro-fitting of existing internal combustion engines are necessary in order to address ever increasingly stringent environmental concerns and regulations.
[0059] FIG. 8 illustrates a controlled hydraulic nozzle injection apparatus 300 according to yet another embodiment of the present invention. As shown therein, the injection apparatus 300 is similar to the apparatus 200 of FIG. 6 in many respects. As with the injection apparatus of FIG. 6 , a fuel injection pump 312 is provided to intermittently supply the injection apparatus 300 with a pressurized stream of fuel, typically a hydrocarbon fuel comprising gasoline, diesel fuel or the like. The pump 312 operates to send streams of pressurized fuel through, in succession, a plurality of dual valve assemblies 326 , a plurality of fuel injection conduits 318 and, finally, to a plurality of fuel injector nozzles 320 which exhaust the fuel streams into an unillustrated combustion chamber of a vehicle.
[0060] Each of the nozzles 320 typically include a known arrangement of needle valves or the like which, when subjected to a threshold pressure, will permit passage of the pressurized fuel into the combustion chamber. Moreover, as with the apparatus 200 of FIG. 6 , although there are a discreet number of conduits 318 and fuel injector nozzles 320 shown in FIG. 8 , it will be readily appreciated that the present invention contemplates the incorporation of any number of conduits or nozzles without departing from the broader aspects of the present invention.
[0061] A manifold 316 is provided and is connected to each of the leak-off conduits 322 of the nozzles 320 in order to assist in boot-strapping the residual pressurized fuel. The high pressure manifold 216 is further connected to the fuel pump 312 and serves to vacate pressurized fuel from the manifold 316 , back to the fuel pump 312 .
[0062] As will be readily appreciated, however, the apparatus 200 of FIG. 6 may not necessarily be pressure balanced, i.e., the pressures in each of the nozzles 220 and injection conduits 218 may not necessarily be uniform. As shown in FIG. 8 , in order to address any non-uniform pressures that may be present, each nozzle 320 is further configured with an electronic control valve and pressure sensor 323 upstream of the manifold 316 . In particular, the electronic control valves and pressure sensors 223 are located along the leak-off conduits 322 , between the nozzles 320 and manifold 316 . As discussed in detail below, the presence of the electronic control valve and pressure sensor 323 allows the pressure in each line 318 to be dynamically and selectively controlled and set for any desired stabilization pressure values, including values in excess or different than 4000 psi. In particular, it allows the pressure at each nozzle 320 to be controlled independently with respect to the pressures at the other nozzles 320 .
[0063] The control valve and pressure sensor assembly 323 is best shown in FIG. 10 . The control valve may be any type of control valve or pressure relief valve known in the art, such as a solenoid and the like, and serves to vacate pressurized fuel from each nozzle 320 to the manifold 316 , when necessary. As shown therein, each control valve assembly 323 is in electrical communication with an engine control unit 325 , which is, in turn, in electrical communication with the engine and receives input from the engine. As will be readily appreciated, the engine control unit determines the amount of fuel, ignition timing and other parameters of the internal combustion engine needed to keep the engine running smoothly. It does this by reading and interpreting input values from the engine, e.g., engine speed, calculated from signals coming from sensor devices monitoring the engine. These input values from the sensor devices in the engine are fed to the engine control unit 325 , which then analyzes this information. The pressure sensors of the control valve assemblies 323 also feed information, in the form of the pressure detected at each nozzle 320 , to the engine control unit 325 for reading and processing.
[0064] In operation, the engine control unit 325 sends a signal to one or more of the control valve assemblies 323 to open or close the control valves in dependence upon the particular operating parameters of the engine, as detected by the sensor devices, and in dependence upon the pressure readings obtained by the pressure sensors of the control valve assemblies 323 . In this respect, the control valve assemblies 323 , in combination with the engine control unit 225 , are capable of dynamically and selectively controlling the pressures within each of the nozzles 320 .
[0065] As will be readily appreciated, the control valve assemblies 323 allow for the reduction of build-up of pressure in each nozzle 320 , e.g., during a starting operation, and can also be selectively actuated in order to lower the opening and closing pressure of each nozzle during low idle to reduce idling noise and the like, or at other times as necessary and in dependence upon readings from the sensor devices. In addition, the control valve assemblies 323 also allow for the build-up of pressure in each nozzle, by maintaining the control valve assemblies 323 in a closed condition, if necessary.
[0066] Importantly, the addition of a control valve assembly 323 to each nozzle 320 along each leak-off conduit 322 allows the pressure at each nozzle 320 and injection conduit 318 to be more precisely controlled, further reducing emissions. In particular, the injection apparatus 300 ensures that each individual fuel stream provided to the combustion chamber is maintained at a precise elevated pressure, especially at the nozzles 320 , thereby ensuring a more complete combustion of these fuel streams and an associated reduction in exhausted polluting contaminants. In addition, the pressure range and duration at each nozzle 320 may also be controlled with the addition of the control valve assembly/pressure sensor device 323 .
[0067] While FIG. 8 illustrates a control valve and pressure sensor 323 for each leak-off conduit 322 , it is contemplated that any number, for example less than all, of the leak-off conduits 322 can be configured with a control valve and pressure sensor, without departing from the broader aspects of the present invention. Indeed, the controlled hydraulic nozzle injection apparatus 300 includes as many as one control valve 323 for each leak-off conduit 322 , and the exact number of such devices may be determined by the starting requirements of a particular engine.
[0068] In operation of the injection apparatus 300 , the fuel pump pressurizes a predetermined amount of fuel from an unillustrated fuel supply. As best shown in FIG. 9 , once the pressurized fuel overcomes the biasing force of a check spring 232 , a check ball valve will be displaced, thereby allowing the pressurized stream of fuel to pass through the injection conduits 318 on the way to the nozzles 320 where a needle valve, or the like, opens and releases an atomized fuel stream into the combustion chamber of a motorized vehicle.
[0069] At the end of the initial fuel delivery cycle, the check ball valve 234 will resume its blocking position leaving a measured amount of residual fuel, and therefore pressure, trapped in the injection conduits 318 . As with the apparatus 200 of FIG. 6 , while known systems remove this residual pressure, the present invention arrests the remaining pressurized fuel by virtue of the pressure relief valve assembly 230 . Further operation of the apparatus 300 , in some embodiments, follows the operation of the apparatus 200 described above in connection with FIG. 6 . In any event, however, the addition of a pressure control valve 323 for each fuel injection nozzle 322 and each injection conduit 318 allows the pressure of fuel within each conduit 318 and at each nozzle 322 to be precisely controlled at almost any point in the fuel delivery process. In particular, the pressure within each conduit and at each nozzle 322 can be dynamically and selectively controlled, and can be controlled independent of the other nozzles 322 and conduits 318 , in dependence upon readings from the associated pressure sensor and input information from the engine regarding engine operating parameters and conditions. As will be readily appreciated, this added level of control further reduces undesirable emissions and provides for more complete combustion of atomized fuel.
[0070] As discussed above, FIG. 3 shows the injection lines of a conventional fuel injection pump 112 connected to a manifold having a plurality of valve sets 125 which are utilized to control the flow and pressure of the fuel streams provided by the fuel pump 112 . FIG. 4 is an enlarged, partial cross-sectional view of the valve sets 125 utilized to control the flow and pressure of the fuel streams in accordance with the present invention. Referring now to FIG. 11 , a controlled nozzle injection apparatus 400 according to another embodiment of the present invention is shown, in which piston and ball valves are utilized to control the flow of fuel, as discussed hereinafter.
[0071] As shown in FIG. 11 , a fuel injection pump 402 having a pumping plunger 404 is provided to intermittently supply the injection apparatus 400 with a pressurized stream of fuel. As discussed above, the fuel is typically a hydrocarbon fuel comprising gasoline, diesel fuel or the like. The pump 402 operations to send streams of pressurized fuel through, in succession, a valve assembly 406 , a fuel injection conduit 408 or conduits and, finally, to a fuel injector nozzle 410 , or a plurality thereof, which exhaust the fuel streams into an unillustrated combustion chamber of a vehicle. A fuel return conduit 412 is also provided for depressurizing the high pressure injection conduit 406 .
[0072] As with the embodiments discussed above, each of the nozzles 410 typically include a known arrangement of needle valves or the like which, when subjected to a threshold pressure, will permit passage of the pressurized fuel into the combustion chamber. The nozzles 410 do not, however, include leak off valves, conduits or the like which are typically provided to known nozzle assemblies to evacuate residual fuel therefrom (as discussed previously). The present embodiment utilizes such leakless nozzles in order to trap residual, pressurized fuel within an unillustrated spring chamber of the needle valves for subsequent use. Moreover, although there are a discreet number of conduits and fuel injector nozzles shown in FIG. 11 , it will be readily appreciated that the present invention contemplates the incorporation of any number of conduits or nozzles without departing from the broader aspects of the present invention.
[0073] As further shown in FIG. 11 , the valve assembly 406 is provided with a plurality of differing valve sets which are utilized to control the flow and pressure of the fuel streams provided by the fuel pump 402 . FIG. 11 is an enlarged, partial cross-sectional view of the valve assembly utilized to control the flow and pressure of the fuel streams in accordance with the present invention.
[0074] As shown in FIG. 11 , a spring-biased ball 414 works in concert with a piston 416 and ball 418 to bootstrap residual pressure left in the injection apparatus 400 at the conclusion of each fuel cycle. By doing so, the present invention maintains high fuel injection pressures at the end of the fuel delivery cycle, similar to the high injection pressures present at the beginning of the fuel delivery cycle.
[0075] Operation of the injection apparatus 400 will now be described in conjunction with FIG. 11 . By way of example, if a 3000 psi residual pressure is desired, then fuel is supplied by the pump 402 and the residual pressure control valve 401 would be set for 3000 psi. If operation is picked up during injection, the pressure in the injection line 408 is approximately 12,000-15,000 psi and the nozzle is open and flowing fuel. Some fuel may leak past the nozzle valve of the nozzle 410 and into the nozzle spring chamber. The spring chamber of the nozzle(s) 410 is sealed (leakless nozzle) so that leakage will increase the spring chamber pressure. In between injections, the residual line pressure is 3000 psi and some fuel will leak out of the spring chamber into the nozzle end of the injection line 408 . As a result, the spring chamber pressure will be equal to the average line pressure, typically 90% of the residual pressure plus 10% of the peak line pressure, in this example 3500 psi. In an embodiment, for starting, the residual pressure control valve 401 may be set for zero pressure in which case the nozzle opening pressure will be static nozzle opening pressure produced by the nozzle valve spring.
[0076] In between injections, spring biased ball 414 is pressed against its seat 420 by its spring 422 and by the 3000 residual pressure in the line. Similarly, piston 416 is pressed against its minimum travel stop 424 . At the start of the next pumping event, piston 416 will be forced upward, holding ball 418 tightly against its seat 426 and preventing any backflow into the residual pressure circuit, i.e., return conduit 412 . Ball 414 will be lifted off its seat 420 , against the spring bias, and fuel will flow towards the nozzle 410 . Pressure will build up in the nozzle 410 until it gets high enough to lift the nozzle valve. The nozzle valve is held closed by the spring force and by the spring chamber pressure acting on the nozzle valve. The pressure required to overcome the spring force is the static nozzle opening pressure (in this case somewhere around 2500 psi). The pressure required to overcome the spring chamber pressure depends on the nozzle geometry, however, it is typically 1.5 times the spring chamber pressure (in this case, approximately 5250 psi). This makes the net nozzle opening pressure 7750 psi, which cannot be easily obtained by spring force alone.
[0077] As will be readily appreciated, this high operating pressure is particularly advantageous when the nozzle valve is to be closed. In a conventional nozzle, it takes approximately 2500 psi acting on the net area (A 1 -A 2 ) to develop enough force to overcome the spring force and begin to open the valve. As soon as the nozzle lifts off its seat, fuel flows into the nozzle sac (area A 2 ). With pressure acting over the full area A 1 (as opposed to the net area (A 1 -A 2 ), the nozzle valve snaps open. At closing, the pressure must drop well below the static opening pressure before the net force (i.e. the pressure acting over the full area A 1 ) drops below the spring force. Dynamically, in a conventional nozzle, the nozzle pressure must drop much further, perhaps below 1500 psi, before there is enough force imbalance to accelerate the nozzle valve in the closing direction. At such time, the engine cylinder pressure is high and the net pressure drop across the nozzle orifices will be small. As a result, fuel may dribble out of the nozzle at the end of injection, and there is even a danger that combustion gases could be forced through the nozzle holes into the nozzle.
[0078] With the apparatus 400 of the present invention, however, the spring chamber pressure plus the spring force combine to force the nozzle valve closed. The nozzle valve acts as a pump and forces the last bit of fuel out of the nozzle 410 and maintaining good atomization right until the very end of injection.
[0079] With further reference to FIG. 11 , to complete the cycle, the pumping plunger spill ports (not shown) are opened, thus dropping the pumping chamber pressure. Ball 414 is forced against its seat 420 by its spring 422 and by the pressure in the injection line 408 . Importantly, ball 414 acts very much like a zero retraction delivery valve, trapping excess fuel in the line 408 . Low pressure in the pumping chamber also allows piston 416 to move downward into contact with its minimum travel stop 424 such that ball 418 is no longer forced against it seat 426 . A passageway is thereby created such that excess pressure in the line 408 can then flow past ball 418 , bringing the line pressure down to the level of the residual pressure gallery 428 . During every injection, a small quantity of fuel enters the residual pressure gallery 418 , so a simple control valve may be utilized to bleed off the excess to maintain the desired residual gallery pressure (in this case approximately 3000 psi).
[0080] For example, as shown in FIG. 4 , a simple spring loaded ball to control the residual pressure and a solenoid operated shuttle valve to turn the residual pressure control on and off may be utilized. Moreover, any number of mechanical and/or electrical systems can be utilized to control the residual pressure with whatever degree of sophistication is required.
[0081] In the embodiment shown in FIG. 11 , valves 414 and 418 are shown as balls acting on a conical seat, however, conical valves acting against conical seats may be utilized without departing from the broader aspects of the present invention to achieve even more reliable operation (i.e., conical valves may be more durable and reliable).
[0082] As discussed above, the controlled hydraulic nozzle injection system 400 of the present invention allows a user to change nozzle opening and closing pressure while the engine is running. As also discussed above, there are two main parts to the system 400 . The first part are control valves which may be installed in the injection lines between the pump and the nozzles, as shown in FIG. 12 , or they may be built into the fuel injection pump, as discussed above in connection with FIG. 11 . The second part of the system is a set of leakless nozzles. In an embodiment, the leakless nozzles may be conventional nozzles with the leakoff line sealed.
[0083] As shown in FIG. 12 , in an embodiment where the control valves are installed in the injection lines, the assembly shown in box A may be grafted to the top of the pumping chamber. As shown therein, the components shown therein are substantially similar in arrangement to the valve assembly 406 shown in FIG. 11 . In particular, the assembly in box A includes an injection line fitting 450 from the pumping chamber and an injection line fitting 452 to the nozzle inlet. The assembly includes a residual pressure valve 454 for controlling the pressure from a control pressure manifold via conduit 456 and a forward check valve 458 similar to ball valve 414 .
[0084] While the invention had been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various obvious changes may be made, and equivalents may be substituted for elements thereof, without departing from the essential scope of the present invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention includes all embodiments falling within the scope of the appended claims. | A nozzle injection apparatus for use in internal combustion engines includes a fuel pump for intermittently pressurizing fuel, an injection conduit in fluid communication with the fuel pump, the injection conduit permitting the pressurized fuel to be communicated to a fuel injection nozzle a control valve in fluid communication with the nozzle, wherein the control valve dynamically and selectively controls a pressure of said pressurized fuel within the injection conduit. | 5 |
[0001] The entire disclosure of Japanese Patent Application No. 2002-265138 filed on Sep. 11, 2002, including specification, claims, drawings and summary, is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a gas compressor control device and a gas turbine plant control mechanism, which are designed to be capable of suppressing a rise in the pressure of a fuel gas supplied to a gas turbine, even if load rejection or load loss occurs.
[0004] 2. Description of the Related Art
[0005] In a gas turbine plant, as shown in FIG. 4, a gas turbine 2 for rotationally driving a generator 1 is supplied with a fuel gas from a gas compressor 4 via fuel gas piping 3 . That is, the fuel gas for use in the gas turbine 2 is pressurized by the gas compressor 4 to a pressure suitable for the gas turbine 2 .
[0006] The amount of fuel consumed by the gas turbine 2 varies with a generator load required of the gas turbine 2 . In detail, when a gas turbine generator output increases, a fuel gas pressure P 2 at the inlet of the gas turbine lowers, so that the gas compressor 4 is further required to raise the pressure of the fuel gas. When the gas turbine generator output decreases, on the other hand, the fuel gas pressure P 2 at the gas turbine inlet increases, so that the gas compressor 4 is required to lower the pressure of the fuel gas.
[0007] A conventional concrete control method for controlling the gas turbine 2 and the gas compressor 4 will be described hereinafter.
[0008] As shown in FIG. 4, a pressure control valve 5 and a flow control valve 6 are interposed in the fuel gas piping 3 . The pressure control valve 5 is disposed upstream (closer to the gas compressor 4 ), while the flow control valve 6 is disposed downstream (closer to the gas turbine 2 ).
[0009] A gas turbine control device 10 controls the valve opening of the flow control valve 6 (i.e. PID control) such that a deviation between an actual generator output W 1 and a preset target generator load set value W 0 is zero. The gas turbine control device 10 also controls the valve opening of the pressure control valve 5 (i.e. PID control) such that a deviation between a flow control valve differential pressure ΔP 1 , which is the difference between the fuel gas pressure upstream from the flow control valve 6 and the fuel gas pressure downstream from the flow control valve 6 , and a preset flow control valve differential pressure set value ΔP 0 is zero.
[0010] The gas compressor 4 , on the other hand, is provided with a recycle pipe 7 for returning the fuel gas from the gas compressor outlet to the gas compressor inlet, a recycle valve 8 interposed in the recycle pipe 7 , and an IGV (inlet guide vane) 9 for controlling the amount of air taken into the gas compressor 4 .
[0011] A gas compressor control device 20 finds P 0 -P 1 , which is a deviation between a fuel gas pressure P 1 at the gas compressor outlet and a preset fuel gas supply pressure set value P 0 . Using a control function FX 1 for the recycle valve 8 , the gas compressor control device 20 controls (PID control) the valve opening of the recycle valve 8 according to the deviation P 0 -P 1 . Using a control function FX 2 for the IGV 9 , moreover, the gas compressor control device 20 controls (PID control) the valve opening of the IGV 9 according to the deviation P 0 -P 1 .
[0012] Namely, the gas compressor control device 20 exercises control to operate the IGV 9 and the recycle valve 8 of the gas compressor 4 so that the fuel gas pressure P 1 at the gas compressor outlet is constant. Concretely, the gas compressor control device 20 controls the openings in such a manner as to decrease the opening of the recycle valve 8 and increase the opening of the IGV 9 when exercising control for raising the fuel gas pressure P 1 , and to increase the opening of the recycle valve 8 and decrease the opening of the IGV 9 when exercising control for lowering the fuel gas pressure P 1 .
[0013] Generally, the gas turbine 2 and the gas compressor 4 are produced by different manufacturers, and it has been common practice that the gas turbine 2 and the gas compressor 4 are not cooperatively controlled.
[0014] In gas turbine power generation equipment having a gas turbine and a generator connected together, there has been a technique for exercising preceding control in order to prevent misfire or back fire of a combustor due to combustion instability (see, for example, Japanese Unexamined Patent Publication No. 1994-241062).
[0015] If the load on the gas turbine 2 falls abruptly, namely, if load rejection (main shut-off device open) occurs or load loss of the gas turbine occurs, the fuel gas pressure P 2 (P 1 ) at the gas turbine inlet (the gas compressor outlet) sharply increases. In this case, conventional simple one-loop feedback control over the pressure on the gas compressor 4 , as shown in FIG. 4, is not enough to deal with this sharp increase. Thus, the fuel gas pressure P 2 (P 1 ) markedly rises, and then lowers to the desired pressure.
[0016] As a result, differential pressure control of the gas turbine may fail to accommodate such pressure changes, so that an excessive amount of fuel is charged into the gas turbine 2 , causing breakage to the combustor or fuel oscillations.
[0017] Conventionally, therefore, a great distance has been provided between the gas turbine 2 and the gas compressor 4 to lengthen the fuel gas piping 3 and ensure a sufficiently large piping volume, thereby absorbing the elevation of the fuel gas pressure due to a sudden load fall (load rejection, load loss) of the gas turbine.
[0018] Recently, however, it has been required to construct a power plant in a small premises area in pursuit of economy. With this restricted premises area, the conventional method of securing long piping between the gas turbine and the gas compressor is nearing its limits.
SUMMARY OF THE INVENTION
[0019] The present invention has been accomplished in the light of the earlier technologies. Its object is to provide a gas compressor control device and a gas turbine plant control mechanism which are capable of preventing an excessive increase in a fuel gas pressure within fuel gas piping during occurrence of a sudden load fall (load rejection or load loss), even when the fuel gas piping connecting a gas turbine and a gas compressor together is short.
[0020] According to an aspect of the present invention for attaining the above object, there is provided a gas compressor control device for exercising opening control of a recycle valve interposed in a recycle pipe which returns a fuel gas from an outlet of a gas compressor to an inlet of the gas compressor, and opening control of an inlet guide vane provided in the gas compressor,
[0021] the gas compressor control device comprising:
[0022] a computing capability unit for computing a recycle valve normal opening command (r 1 ) and an inlet guide vane normal opening command (i 1 ) based on a deviation between a fuel gas pressure (P 1 ) at the gas compressor outlet and a preset fuel gas supply pressure set value (P 0 ); and
[0023] a computing capability unit for computing a recycle valve preceding opening command (r 2 ) and an inlet guide vane preceding opening command (i 2 ) based on a deviation between an actual generator output (W 1 ), which is an actual output of a generator rotationally driven by a gas turbine supplied with the fuel gas from the gas compressor, and a first order lag actual generator output (W 1 ′), which has been obtained by first order lag computation of the actual generator output (W 1 ), and
[0024] the gas compressor control device exercising;
[0025] during a normal operation, opening control of the recycle valve based on a value of the recycle valve normal opening command (r 1 ), and opening control of the inlet guide vane based on a value of the inlet guide vane normal opening command (i 1 ); and
[0026] in an event of a sudden load fall, opening control of the recycle valve based on a value obtained by adding the recycle valve preceding opening command (r 2 ) to the recycle valve normal opening command (r 1 ), and opening control of the inlet guide vane based on a value obtained by adding the inlet guide vane preceding opening command (i 2 ) to the inlet guide vane normal opening command (i 1 ).
[0027] Because of the above-described features, in the event of load loss or load rejection, the recycle valve can be opened in a preceding manner, and the inlet guide vane (IGV) can be closed in a preceding manner. As a result, the fuel gas pressure at the gas compressor outlet can be lowered to suppress the elevation of the fuel gas pressure at the gas turbine inlet. Thus, stable operation can be performed.
[0028] According to another aspect of the present invention, there is provided a gas turbine plant control mechanism comprising:
[0029] a gas compressor control device for exercising opening control of a recycle valve interposed in a recycle pipe which returns a fuel gas from an outlet of a gas compressor to an inlet of the gas compressor, and opening control of an inlet guide vane provided in the gas compressor; and
[0030] a gas turbine control device for exercising opening control of a pressure control valve and a flow control valve interposed in gas piping which feeds the fuel gas from the gas compressor to a gas turbine, and wherein:
[0031] the gas turbine control device comprises a capability unit for feeding an actual generator output (W 1 ), which is an actual output of a generator rotationally driven by the gas turbine, to the gas compressor control device, and for feeding a load sudden fall signal to the gas compressor control device for a preset period of time when load loss or load rejection occurs; and
[0032] the gas compressor control device comprises:
[0033] a computing capability unit for computing a recycle valve normal opening command (r 1 ) and an inlet guide vane normal opening command (i 1 ) based on a deviation between a fuel gas pressure (P 1 ) at the gas compressor outlet and a preset fuel gas supply pressure set value (P 0 ); and
[0034] a computing capability unit for computing a recycle valve preceding opening command (r 2 ) and an inlet guide vane preceding opening command (i 2 ) based on a deviation between the actual generator output (W 1 ), which is the actual output of the generator, and a first order lag actual generator output (W 1 ′), which has been obtained by first order lag computation of the actual generator output (W 1 ), and
[0035] the gas compressor control device exercises;
[0036] when the load sudden fall signal has not been entered, opening control of the recycle valve based on a value of the recycle valve normal opening command (r 1 ), and opening control of the inlet guide vane based on a value of the inlet guide vane normal opening command (i 1 ); and
[0037] when the load sudden fall signal has been entered, opening control of the recycle valve based on a value obtained by adding the recycle valve preceding opening command (r 2 ) to the recycle valve normal opening command (r 1 ), and opening control of the inlet guide vane based on a value obtained by adding the inlet guide vane preceding opening command (i 2 ) to the inlet guide vane normal opening command (i 1 ).
[0038] Because of the above-described cooperative control by the gas turbine control device and the gas compressor control device, in the event of load loss or load rejection, the recycle valve can be opened in a preceding manner, and the inlet guide vane (IGV) can be closed in a preceding manner. As a result, the fuel gas pressure at the gas compressor outlet can be lowered to suppress the elevation of the fuel gas pressure at the gas turbine inlet. Thus, stable operation can be performed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
[0040] [0040]FIG. 1 is a block configurational drawing showing a gas turbine plant incorporating control devices and a control mechanism according to the present invention;
[0041] [0041]FIG. 2 is a block diagram showing the dynamic characteristics of the gas turbine plant in the event of load rejection or load loss;
[0042] [0042]FIG. 3 is a simplified block diagram showing the dynamic characteristics of the gas turbine plant in the event of load rejection or load loss; and
[0043] [0043]FIG. 4 is a block configurational drawing showing a gas turbine plant incorporating a conventional control device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] Preferred embodiments and actions of the present invention will now be described with reference to the accompanying drawings, which in no way limit the invention.
[0045] In the present invention, signals of actual generator output, parallel-off and sudden load fall (sudden fall in generator output) are fed from a gas turbine control device to a gas compressor control device. If load rejection or load loss occurs in a gas turbine, the gas compressor control device actuates an IGV and a recycle valve of a gas compressor in a preceding manner to prevent a rise in the fuel gas pressure at the inlet of the gas turbine.
[0046] The following Bernoulli's equation (1) holds between a fuel gas flow velocity V 1 and a fuel gas pressure P 1 at the outlet of the gas compressor and a fuel gas flow velocity V 2 and a fuel gas pressure P 2 at the inlet of the gas turbine. From this Bernoulli's equation (1), equation (2) is derived.
V 1 2 2 g + P 1 γ = V 2 2 2 g + P 2 γ ( 1 )
[0047] where
[0048] V 1 : fuel gas flow velocity (m/s) at gas compressor outlet,
[0049] V 2 : fuel gas flow velocity (m/s) at gas turbine inlet,
[0050] P 1 : fuel gas pressure (kg/m 2 ) at gas compressor outlet,
[0051] P 2 : fuel gas pressure (kg/m 2 ) at gas turbine inlet, and
[0052] γ: gas turbine fuel specific gravity (kg/m 3 )
P 1 = P 2 - ( V 1 2 - V 2 2 ) × γ 2 g ( 2 )
[0053] Furthermore, the following relation (3) statically holds between the flow velocity V of the fuel gas consumed by the gas turbine and a generator output MW.
V=f ( MW )/ A (3)
[0054] where
[0055] MW: gas turbine generator output (actual generator load) (MW), and
[0056] A: sectional area of piping
[0057] That is, if load rejection or load loss occurs, the fuel gas flow velocity (fuel consumption) V 2 at the gas turbine inlet lowers. If the fuel gas pressure P 1 and the fuel gas flow velocity (discharge) V 1 at the gas compressor outlet do not vary at this time, the fuel gas pressure P 2 at the gas turbine inlet increases.
[0058] After the fuel gas pressure P 2 at the gas turbine inlet increases, the fuel gas flow velocity (fuel gas flow rate) V 1 at the gas compressor outlet follows the fuel gas flow velocity (fuel consumption) V 2 at the gas turbine inlet, so that V 1 =V 2 , whereupon the fuel gas pressure P 1 at the gas compressor outlet also increases.
[0059] Finally, the fuel gas pressure is controlled to a prescribed value by fuel gas pressure control at the gas turbine inlet and fuel gas pressure control at the gas compressor outlet. Thus, both of the fuel gas pressures P 1 and P 2 return to their prescribed values and settle. By then, the fuel gas pressure P 2 at the gas turbine inlet fluctuates, causing abnormality to combustion in the gas turbine, generating combustion oscillations.
[0060] If the fuel gas piping between the gas turbine and the gas compressor is long, it takes time until V 1 =V 2 . The fuel gas pressure at the gas compressor outlet minimally fluctuates. Thus, the fuel gas pressure P 2 at the gas turbine inlet returns to the prescribed value early, and can minimize influence on gas turbine combustion. Hence, the fuel gas piping has hither to been made long.
[0061] However, the aforementioned phenomenon—the elevation of the fuel gas pressure P 2 at the gas turbine inlet in the event of load rejection or load loss—can be suppressed, even if the fuel gas piping between the gas turbine and the gas compressor is short, by exercising control such as to lower the fuel gas pressure P 1 at the gas compressor outlet in a preceding manner.
[0062] The dynamic characteristics in the event of load rejection or load loss are expressed as shown in FIG. 2 by use of a block diagram. In FIG. 2, T 1 represents a delay time from the supply of fuel to the gas turbine until the reflection of the fuel supply in the output of the gas turbine, and T 2 represents the time from a change in the fuel flow velocity at the gas turbine inlet until the fuel flow velocity change is reflected in the fuel flow velocity at the gas compressor outlet.
[0063] In the block diagram of FIG. 2, if the fuel gas piping between the gas turbine and the gas compressor is long, the delay time T 2 increases. As a result, the result of calculation of V 1 2 —V 2 2 in the event of load rejection or load loss takes a large negative value. Thus, even when the fuel gas pressure P 2 at the gas turbine inlet takes a large value, the fuel gas pressure P 1 at the gas compressor outlet is not very high.
[0064] Finally, V 1 =V 2 , and the fuel gas pressure P 1 at the gas compressor outlet equals the fuel gas pressure P 2 at the gas turbine inlet.
[0065] The block diagram shown in FIG. 2 can be simplified as shown in the block diagram of FIG. 3.
[0066] Before load rejection or load loss occurs, the fuel gas pressure P 1 at the gas compressor outlet equals the fuel gas pressure P 2 at the gas turbine inlet. Thus, in case of load rejection or load loss, it is found that the elevation of the fuel gas pressure at the gas compressor outlet depends on the value of the actual generator output before the occurrence of load rejection or load loss, or depends on how fast the actual generator output fell.
EXAMPLE
[0067] Next, an example for embodying the present invention will be described with reference to FIG. 1. Portions exhibiting the same capabilities as in the earlier technology shown in FIG. 4 are assigned the same numerals, and descriptions of these portions will be offered briefly.
[0068] As shown in FIG. 1, a gas compressor 4 is provided with a recycle pipe 7 , a recycle valve 8 , and an IGV (inlet guide vane) 9 . A pressure control valve 5 and a flow control valve 6 are interposed in fuel gas piping 3 A. A fuel gas, increased in pressure by the gas compressor 4 , is passed through the fuel gas piping 3 A and supplied to a gas turbine 2 . The gas turbine 2 supplied with the fuel gas rotationally drives a generator 1 to generate electric power.
[0069] The fuel gas piping 3 A is shorter than the conventional fuel gas piping 3 . Except that the fuel gas piping 3 A is shorter, the above-mentioned mechanical layout and configuration are the same as in the earlier technology (see FIG. 4).
[0070] A gas turbine control device 100 controls the valve opening of the flow control valve 6 (i.e. PID control) such that a deviation between an actual generator output W 1 and a preset target generator load set value W 0 is zero. The gas turbine control device 100 also controls the valve opening of the pressure control valve 5 (i.e. PID control) such that a deviation between a flow control valve differential pressure ΔP 1 , which is the difference between the fuel gas pressure upstream from the flow control valve 6 and the fuel gas pressure downstream from the flow control valve 6 , and a preset flow control valve differential pressure set value ΔP 0 is zero. These control capabilities are the same as those of the conventional gas turbine control device 10 (see FIG. 4).
[0071] In the present embodiment, moreover, the gas turbine control device 100 has the following new capabilities (1) and (2) which the earlier technology lacks:
[0072] (1) The capability of sending a load sudden fall signal SW, a one shot pulse, to a gas compressor control device 200 over a preset period, when a sudden fall in load, i.e. at least one of load loss and load rejection, occurs. In this case, the period for which the load sudden fall signal SW is outputted (the period for which the one shot pulse is at a high level) is the period between the occurrence of load loss or load rejection and the settlement of fuel gas pressures P 1 , P 2 at prescribed values. This period is set for each plant.
[0073] (2) The capability of sending the actual generator output W 1 to the gas compressor control device 200 .
[0074] The gas compressor control device 200 has the capability of controlling the valve openings of the recycle valve 8 and the IGV 9 , and exercises control in manners which are different between normal operation (an operation in the absence of load loss or load rejection) and the occurrence of load loss or load rejection.
[0075] First, the respective computing capabilities of the gas compressor control device 200 will be described. Then, the manners of control during normal operation and in the event of a sudden load fall (load loss or load rejection) will be explained.
[0076] The deviation computing capability 201 of the gas compressor control device 200 finds a fuel gas pressure deviation P 1 -P 0 , which is a deviation between the fuel gas pressure P 1 at the gas compressor outlet and a preset fuel gas supply pressure set value P 0 .
[0077] A PID control capability 202 finds a recycle valve normal opening command r 1 based on the fuel gas pressure deviation P 1 -P 0 , while a PID control capability 203 finds an IGV normal opening command i 1 based on the fuel gas pressure deviation P 1 -P 0 .
[0078] An adding capability 204 adds the recycle valve normal opening command r 1 and a recycle valve preceding opening command r 2 (to be described later) to find a recycle valve command r 3 . Whereas an adding capability 205 adds the IGV normal opening command i 1 and an IGV preceding opening command i 2 (to be described later) to find an IGV command i 3 .
[0079] A recycle valve control function capability (Fx 1 ) 206 finds a recycle valve opening control signal R of a value corresponding to the recycle valve command r 3 , and opening control of the recycle valve 8 is effected responsive to the value of the recycle valve opening control signal R. Whereas an IGV control function capability (Fx 2 ) 207 finds an IGV opening control signal I of a value corresponding to the IGV command i 3 , and opening control of the IGV 9 is effected responsive to the value of the IGV opening control signal I.
[0080] A first order lag function capability 208 outputs the actual generator output W 1 , unchanged, during the period of time that the load sudden fall signal SW has not been entered, and outputs a first order lag actual generator output W 1 ′, which has been obtained by first order lag computation of the actual generator output W 1 , during the period of time that the load sudden fall signal SW has been entered.
[0081] A deviation computing capability 209 finds an actual generator output deviation W 1 ′-W 1 , which is a deviation between the first order lag actual generator output W 1 ′ and the actual generator output W 1 .
[0082] A recycle valve preceding control function capability (Fx 4 ) 210 finds the recycle valve preceding opening command r 2 based on the actual generator output deviation W 1 ′-W 1 . An IGV preceding control function capability (Fx 3 ) 211 finds an IGV preceding opening command i 2 based on the actual generator output deviation W 1 ′-W 1 .
[0083] When the load sudden fall signal SW has not been entered, the output of the deviation computing capability 209 is zero, so that the recycle valve preceding opening command r 2 and the IGV preceding opening command i 2 are also zero. When the load sudden fall signal SW has been entered, the deviation between the first order lag actual generator output W 1 ′ and the actual generator output W 1 increases. As a result, the recycle valve preceding opening command r 2 and the IGV preceding opening command i 2 are outputted which take command values corresponding to the value of the actual generator output deviation W 1 ′-W 1 outputted by the deviation computing capability 209 .
[0084] With the gas compressor control device 200 having the above capabilities, the recycle valve preceding opening command r 2 is zero in normal times. Thus, the recycle valve command r 3 =the recycle valve normal opening command r 1 . Consequently, the recycle valve control function capability 206 finds the recycle valve opening control signal R of a value corresponding to the recycle valve command r 3 (=r 1 ). Responsive to the value of the recycle valve opening control signal R, opening control of the recycle valve 8 is exercised.
[0085] In normal times, the IGV preceding opening command i 2 is zero. Thus, the IGV command i 3 =the IGV normal opening command i 1 . Consequently, the IGV control function capability 207 finds the IGV opening control signal I of a value corresponding to the IGV command i 3 (=i 1 ). Responsive to the value of the IGV opening control signal I, opening control of the IGV 9 is exercised.
[0086] As a result, when the fuel gas pressure P 1 is high, the valve opening of the recycle valve 8 is great, while the opening of the IGV is small. When the fuel gas pressure P 1 is low, the valve opening of the recycle valve 8 is small, while the opening of the IGV is great.
[0087] With the gas compressor control device 200 having the above capabilities, the recycle valve preceding opening command r 2 takes some value in the event of load loss or load rejection. Thus, the recycle valve command r 3 =the recycle valve normal opening command r 1 +the recycle valve preceding opening command r 2 . Consequently, the recycle valve control function capability 206 finds the recycle valve opening control signal R of a value corresponding to the recycle valve command r 3 (=r 1 +r 2 ). Responsive to the value of the recycle valve opening control signal R, opening control of the recycle valve 8 is exercised.
[0088] In the event of load loss or load rejection, the IGV preceding opening command i 2 takes some value. Thus, the IGV command i 3 =the IGV normal opening command i 1 +the IGV preceding opening command i 2 . Consequently, the IGV control function capability 207 finds the IGV opening control signal I of a value corresponding to the IGV command i 3 (=i 1 +i 2 ). Responsive to the value of the IGV opening control signal I, opening control of the IGV 9 is exercised.
[0089] As a result, in the event of load loss or load rejection, the recycle valve 8 can be opened in a preceding manner, while the IGV can be closed in a preceding manner. By so doing, the fuel gas pressure P 1 at the gas compressor outlet can be lowered, and the increase in the fuel gas pressure P 2 at the gas turbine inlet can be suppressed.
[0090] Because of the above-described control, even with the short fuel gas piping 3 A, the fuel gas pressures P 1 , P 2 can be prevented from increasing excessively, and breakage of the combustor or the occurrence of combustion oscillations can be prevented, in the event of load loss or load rejection. Thus, stable operation can be ensured.
[0091] Actually, when load rejection or load loss occurs, it suffices to suppress a rise in the fuel gas pressure P 2 at the gas turbine inlet. Hence, the functions Fx 3 , Fx 4 used by the preceding control function capabilities 210 , 211 shown in FIG. 1 are not fed the values obtained strictly by the calculations shown in the block diagrams of FIGS. 2 and 3, but are initially supplied with values sufficiently smaller than the values given by the calculations. Then, the values supplied are adjusted in accordance with changes in the fuel gas pressure P 2 at the gas turbine inlet during load fluctuations.
[0092] The time constant T 2 , used in the first order lag function capability 208 , is also determined by actually operating the plant, and observing a delay in changes in the fuel gas pressure P 1 at the gas compressor outlet in response to changes in the fuel gas pressure P 2 at the gas turbine inlet.
[0093] While the present invention has been described in the foregoing fashion, it is to be understood that the invention is not limited thereby, but may be varied in many other ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the appended claims. | A gas compressor control device and a gas turbine plant control mechanism are disclosed. A fuel gas pressurized by a gas compressor is supplied to a gas turbine via fuel gas piping. A gas turbine control device adjusts the flow rate of the fuel gas into the gas turbine by exercising opening and closing control of a pressure control valve and a flow control valve. The gas compressor control device controls a fuel gas pressure at the outlet of the gas compressor by effecting opening and closing control of a recycle valve and an IGV. If load rejection or load loss occurs, the gas compressor control device opens the recycle valve in a preceding manner and closes the IGV in a preceding manner. Thus, elevation of the fuel gas pressure at the gas compressor outlet can be prevented, and elevation of a fuel gas pressure at an inlet of the gas turbine can be suppressed, thereby ensuring stable operation. | 5 |
BACKGROUND
[0001] Viral hemorrhagic fever (VHF) refers to a clinical illness associated with fever and a bleeding diathesis caused by a virus that belongs to one of four distinct families of enveloped, negative-sense, single-stranded RNA viruses: Filoviridae, Bunyaviridae, Flaviviridae, and Arenaviridae. A number of viruses in these four families are on the Category A biothreat list because they may cause high morbidity and mortality and are highly infectious by aerosol dissemination [1]. These viruses cause a similar spectrum of illness with similar underlying pathophysiology [2, 3]. Following an incubation period of 4-10 days, patients with VHF abruptly develop fever accompanied by prominent constitutional symptoms such as prostration, dehydration, myalgia and general malaise. As disease progresses, patients develop clinical signs of bleeding, such as petechial hemorrhage, maculopapular rash, accompanied by disturbance of coagulation. During terminal phase of the disease, fatal cases develop disseminated intravascular coagulation (DIC), gross hemorrhage, hypotension, multi-organ failure, and shock.
[0002] Patients with severe VHF usually die from a terminal clinical course that is generally indistinguishable from systemic inflammatory response syndrome (SIRS), also referred to as sepsis, which is the common sequela of severe bacterial and viral infections. Some VHF viruses are particularly prone to cause SIRS; they include Ebola virus (EBOV) and Marburg Virus (MARV) in Filoviridae, Rift Valley Fever virus (RVFV) and Hantaviruses in Bunyaviridae, and Dengue virus in Flaviviridae [4, 5].
SUMMARY
[0003] Described herein are methods for treating systemic inflammatory response syndrome or viral hemorrahagic fever by administering an ecotin polypeptide.
[0004] Described herein is a polypeptide comprising the amino acid sequence of any of SEQ ID NOs: 2-9 and 11-18. Also described: is a polypeptide comprising the amino acid sequence of any of SEQ ID NO:11-18 preceded by a methionine; a polypeptide comprising the amino acid sequence of any of SEQ ID NO:11-18 with up to 5 single amino acid changes or deletions provided that the polypeptide does not comprise the amino acid sequence of SEQ ID NO:10; a polypeptide having up to 3 single amino acid changes provided that the polypeptide does not comprise the amino acid sequence of SEQ ID NO:10; a polypeptide having up to 3 single amino acid changes provided that the polypeptide does not comprise the amino acid sequence of SEQ ID NO:10; a polypeptide having up to 2 single amino acid changes provided that the polypeptide does not comprise the amino acid sequence of SEQ ID NO:10; a polypeptide no more that one amino acid change provided that the polypeptide does not comprise the amino acid sequence of SEQ ID NO:10; a polypeptide comprising the amino acid sequence of any of SEQ ID NO:2-9 and 11-18 with up to 5 single amino acid changes or deletions provided that the polypeptide does not comprise the amino acid sequence of SEQ ID NO:1 or 10; a polypeptide having up to 3 single amino acid changes provided that the polypeptide does not comprise the amino acid sequence of SEQ ID NO:1 or 10; a polypeptide having up to 3 single amino acid changes provided that the polypeptide does not comprise the amino acid sequence of SEQ ID NO:1 or 10; a polypeptide having up to 2 single amino acid changes provided that the polypeptide does not comprise the amino acid sequence of SEQ ID NO:1 or 10; a polypeptide having no more that one amino acid change provided that the polypeptide does not comprise the amino acid sequence of SEQ ID NO:1 or 10; and any such polypeptide preceded by a methionine.
[0005] Further described is a pharmaceutical composition comprising a polypeptide described herein and a pharmaceutically acceptable carrier or excipient. Also discloses is method for treating a patient infected with a microorganism that causes viral hemorrhagic fever, the method comprising administering the pharmaceutical composition or polypeptide described herein. In various embodiments: the patient is infected with a virus from a family selected from the group consisting of: Filoviridae, Bunyaviridae, Flaviviridae, and Arenaviridae; and the patient is infected with a virus selected from Ebola virus (EBOV), Marburg Virus (MARV), Rift Valley Fever virus (RVFV), Hantaviruses, and Dengue virus.
[0006] Also described is a nucleic acid molecule comprising a sequence encoding the polypeptide described herein as well as such a nucleic acid molecule further comprising an expression control sequence operably linked to the sequence encoding the polypeptide. Also describe is a recombinant cell comprising a nucleic acid molecule described herein and a method of producing a polypeptide comprising culturing a recombinant cell of described herein under conditions suitable for expressing the encoded polypeptide and isolating the encoded polypeptide from the recombinant cells.
[0007] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DRAWINGS
[0008] FIG. 1A-B . Effect of NB109 and NB101 on human blood coagulation in vitro. Increasing concentrations of NB109 and NB101 were preincubated with the human plasma samples for 15 min at 37° C. (A) PT and (B) APTT assays were performed using an ACL100 automated coagulometer using standard reagents. Prolongation of clotting time was calculated as (value in candidate treated sample)/(value in control sample) and was plotted against drug concentrations. 1.2-fold and 1.5-fold over the control in clotting times for PT and for APTT respectively are indicated with dashed lines. Error bars represent SEM, n=3 plasmas from three different donors.
[0009] FIG. 2 . Effect of NB101 and NB109 in mice endotoxemia model. BALB/c female mice (N=5) were subjected to two injections of lipopolysaccharide (LPS) as a model for DIC. A 5 μg/mouse priming dose of LPS was injected into the footpad at t=0 hr, followed 24 hours later by an intraperitoneal elicitation dose of 400 μg/mouse. NB101, NB109 or PBS was administered 1 hr prior to the elicitation. Mice were monitored for survival on an hourly basis for up to 70 hours post-elicitation. Graphpad Prism 4.2 was used to assess statistical differences in survival curves by the Kaplan-Meier Log Rank test. Asterisks indicate significant difference between NB101 and PBS as well as NB142 and PBS *p<0.05, ***p<0.0001.
[0010] FIG. 3 . Effect of NB109 on animal survival in the CLP model. CLP surgery was performed on mice. NB109 treatment was given subcutaneously 18hr before CLP (pre-loading), and twice daily follow-up. Group 2 received 60 mg/kg NB109 for pre-loading, and 40 mg/kg for follow-up. Group 3 received 30 mg/kg NB109 for pre-loading, and 20 mg/kg for follow-up. Fluid resuscitation was performed lml daily for 5 days by subcutaneous injection. Survival was observed every l2hr.
[0011] FIG. 4A-B . Effect of NB101 and NB109 in EBOV infection in guinea pigs. On day 0, strain 13 Guinea pigs (N=2) were infected by subcutaneous injection with 1000 pfu of EBOV. Compound leads were administered by i.p. injection, once a day for 7 days initiated 24 hours post-infection. Survival and body weights were monitored daily. Graphpad Prism 4.2 was used to assess statistical differences in survival curves by the Kaplan-Meier Log Rank test (*p<0.05).
[0012] FIG. 5 . Coagulation parameters in mice treated with NB109. BALB/c mice given single i.p. dose of NB109. At 4, 8 and 24 hrs post dosing, PT and aPTT were analyzed. Average and standard deviation from 3-4 mice per group is presented at each time point. *: single data point. **: >180 second.
[0013] FIG. 6 . Plasma concentrations of NB-109 in mice via different delivery routes. NB109 was administered to mice (n=3) at 72 mg/kg. by intravenous injection (i.v.), intraperitoneal injection (i.p.), and subcutaneous injection (s.c.). Blood samples were taken at different time points. Data shown at Mean±SD.
[0014] FIG. 7 . Plasma concentrations of NB109 and coagulation parameters in guinea pigs following single dose administration. Mean±SD, n=3
[0015] FIG. 8 . Plasma Concentrations of NB109 and Coagulation Parameters in Guinea Pigs Following Single Dose Administration Blood samples collected 24 hr after each dose, and 96 hr after the last dose. Mean±SD, n=3.
[0016] FIG. 9 . Effect in mice LPS model. BALB/c mice (N=10) received a 40 μg priming dose of LPS injected into the foot pad at t=0 hr, followed 24 hours later by an intraperitoneal (i.p.) elicitation dose of 400 μg of LPS. One hour prior to the elicitation dose, mice were treated with 45 mg/kg of NB101, NB109 or NB142 delivered i.p. At 2, 4 and 6 hours post-elicitation animals were bled for plasma cytokine levels. Graphpad Prism 4.2 was used to assess statistical differences in survival curves by the Kaplan-Meier Log Rank test. Asterisks indicate significant difference between NB101 and PBS as well as NB142 and PBS *p<0.05, ***p<0.0001.
[0017] FIG. 10A-C . Effect of NB109 and NB142 on animal survival in poly(I:C) challenged mice. 10 week old female BALB/c mice were randomized into vehicle and drug treatment groups (n=6). 200 ug of Poly (I:C) (polyinosinic: polycytidylic acid) was administrated i.p. twice a day, from day 0 to day 3. NB109 or NB142 treatment was given once a day, i.p., at 45 mg/kg/day, initiated on day 0, day 1, or day 2 as indicated in the figures.
[0018] FIG. 11 . Effect of NB101, NB109, and NB142 on cytokines and D-dimer in poly(I:C) challenged mice. BALB/c were injected i.p. of 45 mg/kg NB101, NB109, NB142, or vehicle at 1 hr prior to poly(I:C) challenge. At time zero (t=0hr), 200 ug of Poly (I:C) or PBS per mouse was injected.
[0019] FIG. 12 . Effect of NB142 and NB109 in EBOV infection in guinea pigs. On day 0 strain 13 Guinea pigs (N=3) were infected by subcutaneous injection with 1000 pfu of EBOV. Lead compounds were administered by i.p. injection, once a day for 7 days initiated 24 hours post-infection. Survival and body weights were monitored daily. Graphpad Prism 4.2 was used to assess statistical differences in survival curves by the Kaplan-Meier Log Rank test (*p<0.05)
[0020] FIG. 13 . Pharmacodynamics of candidates.
[0021] BALB/c female mice (N=15) were subjected to two injections of LPS. A 5 μg/mouse priming dose of LPS was injected into the footpad at t=0 hr, followed 24 hours later by an intraperitoneal elicitation dose of 400 μg/mouse. A single dose of NB101, NB109, or NB142 at 45 mg/kg or PBS was administered 1 hr prior to the elicitation. aPTT & PT measurements were taken at indicated time points post treatment.
[0022] FIG. 14 . NB109 production process flow diagram.
DETAILED DESCRIPTION
[0023] Described below are studies on wild type Ecotin (NB101; SEQ ID NO:1) and an Ecotin variant (NB109; SEQ ID NO:2). NB109 differs from Ecotin in one amino acid residue, M84R, at the P1 position of the so-called reactive center loop (“RCL”; amino acids 82-88; amino acid number of mutations refers to the mature ectotin sequence, i.e., SEQ ID NO:1 lacking the first 20 amino acids (MKTILPAVLFAAFATTSAWA; SEQ ID NO:19) as shown in SEQ ID NO:10).
[0024] NB101 is a broad-spectrum protease inhibitor targeting serine elasase (also called neutrophil elastase (NE) or granulocyte elastase (GE)) coagulation factors (Xa, XIIa, VIIa), and kallikrein (Table 1). In addition to its potential anti-inflammatory function via NE inhibition, NB101 directly targets two components of the “SIRS triangle”; coagulation and kallikrein. However, NB101 does not inhibit fibrinolysis. Thus, all potential point mutations at the P1 position of the RCL were screened resulting in NB109. Distinct from NB101, NB109 inhibits plasmin and thrombin. As a result, it directly targets all three components of the “SIRS triangle”.
[0000]
TABLE 1
Inhibition Constant Ki (nM)* of NB101 and NB109
Ki (nM)
Lead
Mutation
Plasmid
Kallikrein
XIIa
Thrombin
Xa
IXa
XIa
VIIa
NB101
wt
DNI
0.07/-
0.09/-
DNI
<0.02/0.2
27/1.9
0.4/-
0.4/-
NB109
M84R
0.3/0.2
0.1/0.2
0.2/-
0.6/0.8
0.02/0.07
1.2/0.4
0.1/-
1.1/-
*Ki against the human and mice proteases are shown as “human/mice”.
DNI: do not inhibit.
“-”: data unavailable.
[0025] NB109 shares the chemical and physical properties with Ecotin. NB109 has an equivalent number of negatively charged residues (Asp+Glu) and positively charged residues (Arg +Lys), and the calculated pI is 6.85 [61]. One unit of compound activity is defined as the amount of compound required to inhibit 50% trypsin under the standard assay conditions. Based on this definition, NB109 has a specific activity of 1×10 5 unit/mg, which is equivalent to NB101.
[0026] Anti-Coagulation Activity in Human Plasma
[0027] NB101 and NB109 were tested to determine their ability to inhibit blood coagulation, in particular the intrinsic pathway of blood coagulation via inhibition of inflammation and kallikrein-kinin system. The agents were test on human blood coagulation in vitro by performing PT (prothrombin time; extrinsic coagulation pathway) and aPTT (activated partial thromboplastin time; intrinsic coagulation pathway) assays. Both molecules exhibited a potent dose-dependant anti-coagulation effect, and NB109 was approximately 2 times more potent than NB101 ( FIG. 1 ), probably due to its activity against thrombin. In addition, both NB109 and NB101 exhibited stronger inhibition (roughly two fold) towards the intrinsic coagulation pathway (as measured by aPTT) than the extrinsic pathway (measured by PT) ( FIG. 1 ).
[0028] It is important to note that PT and aPTT elevations are expected pharmacological effects of the candidates. PT or APTT elevation per se does not signify spontaneous bleeding as an adverse effect. Spontaneous bleeding tendency is associated with uninhibited fibrinolysis and increased vascular permeability [62]. NB101 and NB109 may have a reduced risk of spontaneous bleeding because they inhibit either vascular hyper-permeability or both vascular hyper-permeability and fibrinolysis.
[0029] In Vivo Efficacy Against SIRS
[0030] NB101 and NB109 were tested in the murine endotoxemia model, which is a lethal shock model induced by two consecutive systemic exposures of endotoxin (LPS) administered 24 hr apart. Pathophysiologically, this model is characterized by inflammation, hemorrhage, tissue necrosis, and DIC [63].
[0031] The vehicle-treated mice all suffered a rapid death within one day of LPS challenge, but treatment with NB101 and NB109 had significant survival benefit ( FIG. 2 ). In this study, NB101 and NB109 all increased animal survival in a similar manner, and they both compared very favorably against the current standard anti-DIC treatment, low molecular weight heparin (LMWH). LMWH given twice before the LPS elicitation only improved 30-hr survival of the treated mice by 25% (50% survival in the treated group and 25% survival in the control group) [64].
[0032] Cecal ligation and puncture (CLP) is another commonly used animal model of SIRS. In the CLP model, SIRS is produced by peritonitis following intestinal injury and infection by multiple bacteria that normally reside in the intestines. It is considered to better mimic the natural cause of sepsis [65]. In a preliminary study, NB109 achieved significant (p<0.005) survival advantage in the CLP model ( FIG. 3 ).
[0033] In Vivo Efficacy Against VHF
[0034] NB101 and NB109 were evaluated in guinea pigs infected with Zaire strain of EBOV. The vehicle-treated animals invariably died by Day 9. NB101 and NB109 treatment was initiated at 24 hr post infection, and was given by intraperitoneal injections once a day for 7 days. While NB101 did not affect animal survival or body weight loss, NB109 achieved 50% survival and rescued the surviving animal from fatal body weight loss ( FIG. 4 ). This result provides proof-of-concept. Together, the in vitro and in vivo findings indicate that NB109 and NB101 are potentially potent candidates as anti-SIRS and anti-VHF compounds and pharmaceutical formulations.
[0035] Safety & PK Studies—Effect on Primary Cells
[0036] NB109 was incubated with a collection of human primary cells, including primary human renal proximal tubule cells, renal cortical epithelial cells, lung vascular endothelial cells, or hepatocytes, as well as cells lines, A549 and BEAS-2B, at up to 250 μM. Over 4-day incubation, cytotoxicity was evaluated using the MTS assay. NB109 did not cause cytotoxicity and had no effect on viability of the cells.
[0037] Effect on Hemolysis
[0038] NB109 was examined for indirect hemolysis via activation of complements, or direct hemolysis. As a positive control for the complement-mediated hemolysis, species specific antibodies against red blood cells (RBC) were used to activate the classical complement pathway and initiate the signaling cascade leading to the lysis of the RBC. For evaluating direct hemolytic activity of NB109, the RBC were washed to remove any complement proteins, and then resuspended with heat-inactivated plasma or serum containing NB109. In the human blood, NB109 did not elicit hemolytic reactions, neither direct nor complement mediated, at concentrations up to 1 mg/ml.
[0039] Systemic Safety of NB109 Treatment in Mice Safety and tolerability of NB109 systemic treatment in mice was evaluated in 5 groups of 16 BALB/c mice. Each of the four groups received one intraperitoneal injection of NB109 at 5, 15, 45, and 90 mg/kg, respectively; the fifth received PBS. Mice were sacrificed at 4 hr and 24 hr post dosing and subjected to necropsy, coagulation analysis, and clinical chemistry.
[0040] Upon necropsy, all animals appeared to be normal without signs of hemorrhage. As expected, coagulation parameters were affected in a dose-dependent manner; the effects peaked at 4 hr post treatment and returned to the baseline by 24 hr post treatment (FIG. 5 ), which indicates that NB109 was cleared from the blood within 24 hours. Consistent with what was observed in the human blood, aPTT was more sensitive to NB109 and the effect was observed at 5 mg/kg whereas PT was not affected until 15 mg/kg. PT returned to the baseline level before aPTT did. It should be noted that elevations in PT and aPTT are pharmacological effects and are not considered adverse effects.
[0041] Repeated Dose Toxicity Study in Guinea Pigs
[0042] NB109 was given to Hartley guinea pigs by intraperitoneal administration at doses of 0.1, 0.5, 1.5, and 5 mg/kg/day for 7 days. Safety parameters included clinical signs, serum chemistry, coagulation times, and necropsy.
[0043] All animals survived NB109 treatment, and all clinical observations for NB109-treated animals were normal throughout the course of the study. There was no significant difference in body weight change between the groups, and all groups showed significant weight gain (19-23% by the end of the study). Necropsy of all NB109-treated animals was unremarkable.
[0044] There was a trend of mild and transient elevation of Creatine phosphokinase (CPK) at ≧1.5 mg/kg on Day 2, but the values returned to the normal range by Day 7. A mild elevation of AST was seen on Day 14 at ≧1.5 mg/kg, but other liver enzymes and bilirubin were normal. All other clinical laboratory parameters were within the normal range. No changes in coagulation parameters were observed at doses 1.5 mg/kg and below (Note that the guinea pig has reduced FVII levels, thus a longer PT than other species). At 5.0 mg/kg, elevated PT and aPTT values were observed starting at eight hours after the first dose and continuing on through eight hours after the last dose on Day 7. All PT and aPTT values returned to normal by Day 14.
[0045] Preliminary Pharmacokinetic Analysis
[0046] A preliminary pharmacokinetic (PK) study was conducted in mice in which NB109 was administered by different routes. The data are illustrated in FIG. 6 . Initial plasma concentrations were much higher with IV administration relative to IP or SC injection. Intraperitoneal injection resulted in considerably higher concentrations than did the same dose by SC injection, meaning that the bioavailability of NB109 by the SC route would be less than ideal. Given the variability of the plasma concentration data with IV administration, it was not possible to provide any estimates of PK exposure. However, the plasma concentration for the IP route was amenable to pharmacokinetic modeling (WinNonlin software, Cary, N.C.). The half-life of elimination (t½) of NB109 by the IP route was 7.6 hr.
[0047] A study of NB109 was conducted in guinea pigs to evaluate the relationship between plasma concentrations of drug and blood coagulation parameters following single and repeated dose administration. NB109 was administered IV to Hartley guinea pigs (n=3) at a dose of 5 mg/kg. There was an excellent correlation between plasma levels of NB109 and prolonged aPTT following a single IV dose ( FIG. 7 ). While the aPTT closely mirrored the plasma levels of drug which had almost returned to background levels by 8 hr post-injection, the PT remained prolonged at that time-point.
[0048] Repeated dosing was conducted again with a dose of 5 mg/kg daily for 5 days. The plasma drug levels appeared to increase slightly following the third dose, however the variability in data make any conclusions on drug accumulation difficult to determine ( FIG. 8 ). There was a very good correlation between blood coagulation parameters with plasma NB109. By day 7 (96 hr post-dosing) all parameters had returned to baseline.
[0049] Additional Ecotin Variants
[0050] The constructs shown in Tables 2 and 2A were developed and tested and described further below. The amino acid sequence for the constructs are shown in Table 3 as SEQ ID Nos. 1-9.
[0000]
TABLE 2
Inhibition Constant Ki (nM)* of Peptides
Ki (nM)
Lead
Mutation
Plasmin
Kallikrein
XIIa
Thrombin
Xa
IXa
XIa
VIIa
Preliminary Candidates
NB101
wt
DNI
0.07/-
0.09/-
DNI
<0.02/0.2
27/1.9
0.4/-
0.4/-
NB109
M84R
0.3/0.2
0.1/0.2
0.2/-
0.6/0.8
0.02/0.07
1.2/0.4
0.1/-
1.1/-
Potentially Optimized Candidates
NB142
M84R/
3.4/0.3
0.07/0.1
DNI/-
DNI
0.04/0.09
58/0.8
0.2/-
0.2/-
V81R
NB137
M84R/
2.9/0.3
0.04/0.3
DNI/-
1.8/7.5
0.4/0.1
0.8/0.5
0.07/-
0.4/-
K76I
NB147
M84R/
4.8/2.3
0.2/0.30
9.5/-
DNI/DNI
<0.02/4.07
DNI/DNI
0.9/-
0.7/-
R54D
NB175
M84R/
0.04/0.08
0.09/0.04
<0.01/-
DNI
0.2/0.04
18/0.2
0.5/-
-/-
V81R/
K112M
NB141
M84R/
18.7/1.2
0.07/0.2
DNI/-
1.6/11.6
0.2/0.2
DNI/0.6
DNI/-
0.2/-
S82H
NB145
M84R/
0.01/0.02
0.1/0.09
DNI/-
>1/0.7
0.2/0.02
DNI/0.26
2.3/-
0.5/-
K112M
NB178
M84R/
0.03/0.07
0.07/0.3
0.004/-
3.1/3.5
0.04/0.09
6.9/0.5
0.2/-
-/-
V81G/
K112M
*Ki against the human and mice proteases are shown as “human/mice”.
DNI: do not inhibit.
“-”: data unavailable.
[0000]
TABLE 3
Amino Acid Sequences of Preliminary and
Optimized Lead Candidates with Leader Sequence
SEQ ID
Peptide
Mutation
Amino Acid Sequence
1
NB101
wt
MKTILPAVLFAAFATTSAWAA
ESVQPLEKIAPYPQAEKGMKR
QVIQLTPQEDESTLKVELLIG
QTLEVDCNLHRLGGKLENKTL
EGWGYDYYVFDKVSSPVSTMM
ACPDGKKEKKFVTAYLGDAGM
LRYNSKLPIVVYTPDNVDVKY
RVWKAEEKIDNAVVR
2
NB109
M84R
MKTILPAVLFAAFATTSAWAA
ESVQPLEKIAPYPQAEKGMKR
QVIQLTPQEDESTLKVELLIG
QTLEVDCNLHRLGGKLENKTL
EGWGYDYYVFDKVSSPVST R M
ACPDGKKEKKFVTAYLGDAGM
LRYNSKLPIVVYTPDNVDVKY
RVWKAEEKIDNAVVR
3
NB142
M84R/
MKTILPAVLFAAFATTSAWAA
V81R
ESVQPLEKIAPYPQAEKGMKR
QVIQLTPQEDESTLKVELLIG
QTLEVDCNLHRLGGKLENKTL
EGWGYDYYVFDKVSSP R ST R M
ACPDGKKEKKFVTAYLGDAGM
LRYNSKLPIVVYTPDNVDVKY
RVWKAEEKIDNAVVR
4
NB137
M84R/
MKTILPAVLFAAFATTSAWAA
K76I
ESVQPLEKIAPYPQAEKGMKR
QVIQLTPQEDESTLKVELLIG
QTLEVDCNLHRLGGKLENKTL
EGWGYDYYVFD I VSSPVST R M
ACPDGKKEKKFVTAYLGDAGM
LRYNSKLPIVVYTPDNVDVKY
RVWKAEEKIDNAVVR
5
NB147
M84R/
MKTILPAVLFAAFATTSAWAA
R54D
ESVQPLEKIAPYPQAEKGMKR
QVIQLTPQEDESTLKVELLIG
QTLEVDCNLH D LGGKLENKTL
EGWGYDYYVFDKVSSPVST R M
ACPDGKKEKKFVTAYLGDAGM
LRYNSKLPIVVYTPDNVDVKY
RVWKAEEKIDNAVVR
6
NB175
M84R/
MKTILPAVLFAAFATTSAWAA
V81R/
ESVQPLEKIAPYPQAEKGMKR
K112M
QVIQLTPQEDESTLKVELLIG
QTLEVDCNLHRLGGKLENKTL
EGWGYDYYVFDKVSSP R ST R M
ACPDGKKEKKFVTAYLGDAGM
LRYNS M LPIVVYTPDNVDVKY
RVWKAEEKIDNAVVR
7
NB141
M84R/
MKTILPAVLFAAFATTSAWAA
S821I
ESVQPLEKIAPYPQAEKGMKR
QVIQLTPQEDESTLKVELLIG
QTLEVDCNLHRLGGKLENKTL
EGWGYDYYVFDKVSSPV H T R M
ACPDGKKEKKFVTAYLGDAGM
LRYNSKLPIVVYTPDNVDVKY
RVWKAEEKIDNAVVR
8
NB145
M84R/
MKTILPAVLFAAFATTSAWAA
K112M
ESVQPLEKIAPYPQAEKGMKR
QVIQLTPQEDESTLKVELLIG
QTLEVDCNLHRLGGKLENKTL
EGWGYDYYVFDKVSSPVST R M
ACPDGKKEKKFVTAYLGDAGM
LRYNS M LPIVVYTPDNVDVKY
RVWKAEEKIDNAVVR
9
NB178
M84R/
MKTILPAVLFAAFATTSAWAA
V81G/
ESVQPLEKIAPYPQAEKGMKR
K112M
QVIQLTPQEDESTLKVELLIG
QTLEVDCNLHRLGGKLENKTL
EGWGYDYYVFDKVSSP G ST R M
ACPDGKKEKKFVTAYLGDAGM
LRYNS M LPIVVYTPDNVDVKY
RVWKAEEKIDNAVVR
[0000]
TABLE 4
Amino Acid Sequences of Preliminary and
Optimized Lead Candidates without Leader Sequence
SEQ ID
Peptide
Mutation
Amino Acid Sequence
10
NB101
wt
AESVQPLEKIAPYPQAEKGMK
RQVIQLTPQEDESTLKVELLI
GQTLEVDCNLHRLGGKLENKT
LEGWGYDYYVFDKVSSPVSTM
MACPDGKKEKKFVTAYLGDAG
MLRYNSKLPIVVYTPDNVDVK
YRVWKAEEKIDNAVVR
11
NB109
M84R
AESVQPLEKIAPYPQAEKGMK
RQVIQLTPQEDESTLKVELLI
GQTLEVDCNLHRLGGKLENKT
LEGWGYDYYVFDKVSSPVST R
MACPDGKKEKKFVTAYLGDAG
MLRYNSKLPIVVYTPDNVDVK
YRVWKAEEKIDNAVVR
12
NB142
M84R/
AESVQPLEKIAPYPQAEKGMK
V81R
RQVIQLTPQEDESTLKVELLI
GQTLEVDCNLHRLGGKLENKT
LEGWGYDYYVFDKVSSP R ST R
MACPDGKKEKKFVTAYLGDAG
MLRYNSKLPIVVYTPDNVDVK
YRVWKAEEKIDNAVVR
13
NB137
M84R/
AESVQPLEKIAPYPQAEKGMK
K76I
RQVIQLTPQEDESTLKVELLI
GQTLEVDCNLHRLGGKLENKT
LEGWGYDYYVFD I VSSPVST R
MACPDGKKEKKFVTAYLGDAG
MLRYNSKLPIVVYTPDNVDVK
YRVWKAEEKIDNAVVR
14
NB147
M84R/
AESVQPLEKIAPYPQAEKGMK
R54D
RQVIQLTPQEDESTLKVELLI
GQTLEVDCNLH D LGGKLENKT
LEGWGYDYYVFDKVSSPVST R
MACPDGKKEKKFVTAYLGDAG
MLRYNSKLPIVVYTPDNVDVK
YRVWKAEEKIDNAVVR
15
NB175
M84R/
AESVQPLEKIAPYPQAEKGMK
V81R/
RQVIQLTPQEDESTLKVELLI
K112M
GQTLEVDCNLHRLGGKLENKT
LEGWGYDYYVFDKVSSP R ST R
MACPDGKKEKKFVTAYLGDAG
MLRYNS M LPIVVYTPDNVDVK
YRVWKAEEKIDNAVVR
16
NB141
M84R/
AESVQPLEKIAPYPQAEKGMK
S821I
RQVIQLTPQEDESTLKVELLI
GQTLEVDCNLHRLGGKLENKT
LEGWGYDYYVFDKVSSPV H T R
MACPDGKKEKKFVTAYLGDAG
MLRYNSKLPIVVYTPDNVDVK
YRVWKAEEKIDNAVVR
17
NB145
M84R/
AESVQPLEKIAPYPQAEKGMK
K112M
RQVIQLTPQEDESTLKVELLI
GQTLEVDCNLHRLGGKLENKT
LEGWGYDYYVFDKVSSPVST R
MACPDGKKEKKFVTAYLGDAG
MLRYNS M LPIVVYTPDNVDVK
YRVWKAEEKIDNAVVR
18
NB178
M84R/
AESVQPLEKIAPYPQAEKGMK
V81G/
RQVIQLTPQEDESTLKVELLI
K112M
GQTLEVDCNLHRLGGKLENKT
LEGWGYDYYVFDKVSSP G ST R
MACPDGKKEKKFVTAYLGDAG
MLRYNS M LPIVVYTPDNVDVK
YRVWKAEEKIDNAVVR
[0051] Efficacy in Endotoxemia Model
[0052] Murine endotoxemia model was used as the first-line screening model due to its simplicity. All of the potentially optimized lead candidates protected animals in this model; NB142, NB137, NB147, and NB178 appeared to be the most effective ones. Interestingly, NB142 is significantly superior to NB101 or NB109 in this model (Error! Reference source not found.9). In addition to having the highest rate of animal survival, NB142 also was most effective at inhibiting inflammatory cytokines IL-6 and TNF-α ( FIG. 9 )
[0053] Preliminary Efficacy in VHF Models
[0054] Several of the peptides shown in Table 3 in mice challenged with injections of poly(I:C), an inosine polymer resembling foreign RNA molecules. Since VHF viruses are all RNA viruses, this model is designed to replicate host responses to viral RNA molecules. Similar to VHF viruses, poly(I:C) injection triggers signs of SIRS, including release of inflammatory cytokines, elevated D-dimers (a product of fibrinolysis indicative of DIC), and abundant micro-thrombi in the liver, lung, and kidneys.
[0055] Untreated animals invariably died in five days after the first poly(I:C) injection. When treatment was initiated prior to poly(I:C) injection, NB109, NB142, NB137, and NB147 all significantly prevented animal death. When NB109 treatment was initiated after poly(I:C) injection, it was effective when it was first given at one day after challenge ( FIG. 1 ). NB104 prolonged animal survival even when initiated at 48 hrs after poly(I:C) challenge with only two treatments ( FIG. 10 ). This result suggests that both NB142 and NB109 can prevent SIRS at the time of induction, but NB142 may be more effective at treating established SIRS associated with VHF.
[0056] In the same model, when given prior to poly(I:C) challenge, NB101, NB109, and NB142 all significantly inhibited inflammatory cytokines and D-dimer triggered by poly(I:C). However, among the three candidates, NB142 was the most effective at inhibiting inflammatory cytokines IL-6 and TNF-α (Error! Reference source not found.).
[0057] Next, NB109 and NB142 were compared in a study of guinea pigs infected with Zaire strain of EBOV. While vehicle-treated animals invariably died by Day 9, NB142 at 1 mg/kg/day and NB109 at 5 mg/kg/day achieved significant, 67% survival. Again, NB142 showed superior efficacy, with better survival at a lower dose and remarkable body weight gains ( FIG. 12 ). The strength of this study result also lies in the fact that NB109 and NB142 treatment was with an unoptimized treatment dose and regime initiated at 24 hr post infection.
[0058] Preliminary Pharmacodynamics of NB142, NB101 and NB109 NB142 has distinct pharmacodynamics (PD) from NB101 and NB109 in vivo. While NB101 and NB109 both cause PT elevations, NB142 does not affect PT ( FIG. 13 ). All three candidates cause elevation in aPTT with various potencies. The PD result indicates that NB101 and NB109 inhibit both extrinsic and intrinsic coagulation pathways, whereas NB142 appears to specifically affect the intrinsic coagulation pathway.
[0059] Hematological monitoring of EBOV infected rhesus monkeys reveals that consumptive coagulopathy in EBOV HF is due to activation of the intrinsic coagulative pathway, rather than extrinsic coagulative pathway [66]. Intrinsic coagulative pathway is directly activated by inflammatory cytokines and kallikrein, and is potentiated by plasmin activation. NB142 has anti-inflammatory effects. It also potently inhibits kallikrein and plasmin while sparing thrombin. Thus it may inhibit the upstream events that trigger intrinsic coagulation without exacerbating consumptive coagulopathy. Therefore, NB142 may have a preferred PD profile for VHF treatment.
[0060] Drug Substance
[0061] Peptide can be produced using a high-density, fed-batch E. coli fermentation process followed by periplasmic extraction, an ion-exchange chromatography, and a filtration step to remove endotoxin.
[0062] Fermentation Process
[0063] Two microbial expression systems can be evaluated for lead compound production: E. coli and yeast. NB109 is produced using a time dependent fed-batch E. coli fermentation process using glucose as the carbon source that yields ˜0.2 gm purified NB109 per liter of fermentation. The lead compounds can also be produced with a dissolved oxygen-dependent feed control system that uses glycerol as a carbon source. This fermentation process has resulted >9 grams per liter expression of a different protein drug candidate. This latter process can be easily scaled up. It uses a semi-defined medium composed of USP-grade reagents that are certified animal-free.
[0064] As an alternative to the bacterial expression system, yeast strains such as P. pastoris and H. polymorpha can also be evaluated as a system for production lead compounds. These have the advantages of higher eukaryotic expression systems such as better protein processing, folding and secretion when compared to microbial systems, and still have rapid growth and tightly regulated promoters. Peptides can be expressed by secretion into yeast media to greatly simplify the purification process. As part of the present invention, strains of P. pastoris have been generated to secrete lead compounds into yeast media. These strains are methanol-inducible and amenable to fermentation.
[0065] Further optimization of the P. pastoris system is possible by investigating multiple secretion leader sequences such as a-mating factor, a-amylase, glucoamylase, inulinase, and invertase yeast signal sequences, and transforming multiple wild type and protease deficient yeast strains. Screening of colonies can be performed from supernatants of small scale cultures grown in 96- and 24-well formats. Selected clones can be grown in shaker flask culture before transfer to fermentation. The fermentation process can be established using available BioFlo 3000 and BioFlo IV fermenters with volumes of 4 to 20 liters. Methanol feed for induction of expression can be quantified by an available YSI 2700 Select Biochemistry Analyzer with methanol probe. Fermentation optimization can vary media and feed composition, pH, temperature, feed time course, and time of induction to achieve desired levels of protein expression.
[0066] Purification Process
[0067] The purification process from E. coli fermentation involves a periplasmic extraction followed by an ion-exchange chromatography step for purification and an ion-exchange filtration step for endotoxin reduction. This purification has worked for peptides described herein. The details of this process are presented in FIG. 14 .
[0068] Additional downstream steps can include, but are not limited to, affinity chromatography, hydrophobic interaction chromatography, size-exclusion chromatography, and additional ion-exchange steps. Initial screening can be performed in 96-well filter plates for high throughput without using robotics. Binding conditions to be evaluated can include chromatography resins, salts, ionic strength, and pH. Micro-eluates can be analyzed for overall concentration by UV absorbance using an available 96-well UV spectrophotometer and purity by 48-sample SDS-PAGE (Invitrogen, Carlsbad, Calif.) with Coomassie staining. Select conditions can be scaled up to chromatography using standard 1-10 ml columns on available FPLCs. Yield and purity of the process intermediates can be monitored using a subset of the release tests described below, including SDS-PAGE, HPLC and activity.
[0069] Development can also focus on adapting the purification process to the yeast expression system and adding additional purification steps to enhance purity. Additional steps may include, but are not limited to, hydrophobic interaction chromatography, reversed-phase chromatography, and additional ion-exchange steps.
[0070] Pre-Formulation and Formulation Development
[0071] The lead compounds can be developed into a sterile, non-preserved, unit-dose parenteral product. Current data indicate that the lead compounds can be very robust and stable over a broad range of pH and temperature.
[0072] Estimated Dosage
[0073] Based on the 1 mg/kg/day effective dose of NB142 in the guinea pig EBOV model, the human treatment dose could be approximately 0.2 mg/kg/day. For a maximum of 7-day course, the estimated total drug consumption would be 84 mg (for 60 kg individual) to 280 mg (for 200 kg individual).
[0074] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention.
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[0133] Thromb Haemost 98:97-104
59. Gettins P G (2002) Serpin structure, mechanism, and function. Chem Rev 102:4751-4804 60. Horn J K (2003) Bacterial agents used for bioterrorism. Surg Infect (Larchmt) 4:281-287 61. Gasteiger E, Gattiker A, Hoogland C, Ivanyi I, Appel R D, Bairoch A (2003) ExPASy: The proteomics server for in-depth protein knowledge and analysis. Nucleic Acids Res 31:3784-3788 62. Colman R W, Clowes A W, George J N, Goldhaber S Z, Marder V J (2006) Overview of Hemostasis. In: Colman R W, Marder V J, Clowes A W, George J N, Goldhaber S Z (eds) Hemostasis and Thrombosis Basic Principles and Clinical Practice. Lippincott Williams & Wilkins, Philadelphia, pp 3-16 63. Brozna J P (1990) Shwartzman reaction. Semin Thromb Hemost 16:326-332 64. Slofstra S H, van', V, Buurman W A, Reitsma P H, ten C H, Spek C A (2005) Low molecular weight heparin attenuates multiple organ failure in a murine model of disseminated intravascular coagulation. Crit Care Med 33:1365-1370 65. Hubbard W J, Choudhry M, Schwacha M G, Kerby J D, Rue L W, III, Bland K I, Chaudry I H (2005) Cecal ligation and puncture. Shock 24 Suppl 1:52-57 66. Fisher-Hoch S P, Platt G S, LLoyd G, Simpson D I H (1983) Haematological and biochemical monitoring of Ebola infection in rhesus monkeys: implications for patient management. The Lancet1055-1058 67. Sidwell R W, Smee D F (2003) Viruses of the Bunya- and Togaviridae families: potential as bioterrorism agents and means of control. Antiviral Res 57:101-111 68. Nooteboom A, van der Linden C J, Hendriks T (2004) Modulation of adhesion molecule expression on endothelial cells after induction by lipopolysaccharide-stimulated whole blood. Scand J Immunol 59:440-448 69. Nooteboom A, van der Linden C J, Hendriks T (2004) Modulation of adhesion molecule expression on endothelial cells after induction by lipopolysaccharide-stimulated whole blood. Scand J Immunol 59:440-448 70. Schildberger A, Rossmanith E, Weber V, Falkenhagen D (2009) Monitoring of endothelial cell activation in experimental sepsis with a two-step cell culture model. Innate Immun | Ecotin variants and their use in treating viral hemorrhagic fever are described. Described herein are methods for treating systemic inflammatory response syndrome or viral hemorrahagic fever by administering an ecotin polypeptide. Described herein is a polypeptide comprising the amino acid sequence of any of SEQ ID NOs: 2-9 and 11-18. Also described: is a polypeptide comprising the amino acid sequence of any of SEQ ID NO: 11-18 preceded by a methionine; a polypeptide comprising the amino acid sequence of any of SEQ ID NO: 11 -18 with up to 5 single amino acid changes or deletions provided that the polypeptide does not comprise the amino acid sequence of SEQ ID NO: 10. | 2 |
BACKGROUND
Scanners are generally handheld, sheet-fed or flatbed. Handheld scanners are held by a user and passed over a document or photograph to digitally scan its image. The image quality of a scan performed with a handheld scanner is largely dependent on the steadiness and alignment of the scan pass. Sheet-fed scanners are generally integrated into another device, such as a fax machine; scanning for output to a personal computer or similar device is a secondary function. The quality of images associated with a sheet-fed scanner is largely dependent on the ability of the feed mechanism to handle the article being scanned.
As relatively high resolution flatbed scanners have grown in popularity, handheld scanners have become largely obsolete, while sheet-fed scanners are relegated to the aforementioned secondary role. Flatbed scanners are configured similar to a copier. A document cover lid is opened, the item or media to be scanned is placed face down on a platen or document glass, and a mechanism disposed beneath the glass is activated to scan a digital image of the media. Typically the document cover is closed over the document or photo to hold the media in place and to shut out ambient light. Use of a flatbed scanner is generally not intuitive. Alignment and proper positioning of a photograph, document or other media to be scanned may be problematic to the computer neophile.
Necessarily, a flatbed scanner has a large “footprint” as it must accommodate a document or similar media laid flat. Although smaller flatbed scanners have been introduced, these scanners are generally sized to accept four inch by six inch, or smaller, photographs or similar media. This smaller type of scanner is particularly well suited for sending or sharing photographs with friends and family, via email. Therefore, these small format scanners are generally intended for non-computer users and are often adapted to facilitate attachment of a scanned image to an email using a television set top box such as a WebTV® device. These small format scanners generally use contact image sensor (CIS) technology.
Computer software, email and Internet traffic have become image intensive. Therefore, the use of scanners has become more prevalent. As broader use of scanner technology has developed, several barriers have arisen.
SUMMARY OF THE INVENTION
A scanner has a platen supported by a housing. The platen is adapted to abut an item, or media, to be scanned. A document cover is adapted to sandwich the media against the platen. The document cover is hinged to the housing by at least one first hinge. The document cover has a base portion having a closed position and at lest one open position, and a flap portion independently hinged to the base portion by at least one second hinge. The flap portion is adapted to open to enable insertion of the media onto the platen while the base portion is in the closed position.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of a preferred embodiment of a scanner according to the present invention;
FIG. 2 is a perspective view of the scanner of FIG. 1 with the envelope flap open;
FIG. 3 is a top plan view of the scanner of FIG. 1 ;
FIG. 4 is a top plan view of the scanner of FIG. 1 with the envelope flap open;
FIG. 5 is an end view of the scanner of FIG. 1 with the envelope flap open; and
FIG. 6 is a top plan view of the scanner of FIG. 1 with the document cover open, and the envelope flap open for purposes of illustration.
DETAILED DESCRIPTION
Turning now to the FIGURES, the present invention is directed to flatbed envelope scanner 100 particularly well adapted for sharing photographs with family and friends by nontechnical, casual users. Scanner 100 provides a comfortable, intuitive interface familiar from everyday experience, namely an envelope. To communicate the functionality of sharing photographs or other type of media by electronically mailing them to someone else, present scanner 100 (hereafter referred to as “envelope scanner 100 ”) takes the form of the back of an envelope. Envelope scanner 100 eases use and alignment issues present with existing scanners by providing intuitive guidance for its functional use, which is easily recognizable by the casual, nontechnical user. Hence, one opens flap 101 of envelope scanner 100 and inserts a letter, a photograph or similar planar media into slot 501 of envelope scanner 100 , and closes flap 101 of envelope scanner 100 . The user then presses send button 102 to send an electronic image of the media as an attachment to email to another party or parties.
As will be appreciated by one skilled in the art, the improvements for a scanner disclosed herein may be advantageously incorporated into an oversized scanner or a conventional size scanner, as well as the aforementioned smaller footprint scanner useful for scanning photographs or similar smaller media. The present invention provides a convenient way to insert media for scanning, without limiting versatility of a scanner embodying the present invention. A scanner embodying the present invention may still scan in a conventional manner employing document cover 105 or with document cover 105 removed. A conventional size scanner embodying the present invention may receive conventional size media, such as letter, legal or A4 size documents, into slot 501 as well as smaller media such as photographs. A smaller photo oriented scanner embodying the present invention may receive photos or smaller media through slot 501 for scanning.
As shown in FIGS. 1 through 4 , envelope scanner 100 preferably takes an envelope form in size and appearance. Envelope scanner 100 is preferably a small, thin flatbed scanner having a generally parallelepiped housing 103 . The housing is adapted to rest on a supporting surface such as a tabletop, desktop, other furniture, cabinet, countertop, floor, etcetera. The housing is further adapted to support a document glass or platen 201 . Platen 201 is supported by the generally planar upper side 202 of housing 103 . Platen 201 is adapted to abut, face down, a photograph or similar media such as, but not limited to a sheet of paper, document, letter, other writing, clipping, drawing, planar artwork, or the like. Preferably the user employs send button 102 to initiate operation of a contact image sensor (CIS) or other scanning mechanism, operatively disposed within the housing. The CIS moves under the glass and digitally scans an electronic image of the media placed on the platen. A preferred embodiment of the envelope scanner has a generally low profile facilitated by the use of CIS technology.
With attention directed to FIGS. 2 and 4 through 6 , preferably, document cover 105 is hinged to housing 103 to cover platen 201 during scanning operations and provide a minimum footprint when not in use. Preferred document cover 105 comprises two portions, a generally rectangular cover base 106 hinged, via one or more hinges 602 , to scanner housing 103 and a triangular envelope flap 101 . Preferably, envelope flap 101 is hinged to cover base 106 via one or more hinges 110 . As detailed below, flap 101 is useful for scanning photographs or other planar media. For other types of media such as magazines, books, oversized documents or oversize photographs, entire document cover 105 hinges and lays flat relative to platen 201 . Alternatively, entire document cover 105 may be removed to facilitate scanning of large and/or irregularly shaped items.
As best seen in FIG. 5 , when triangular envelope flap portion 101 of document cover 105 is flipped open, media receptive slot 501 is revealed between cover base 106 and platen 201 . Thus open, the flap also reveals generally triangular opening 206 , best seen in FIGS. 2 , 4 and 6 , defined by flap 101 and cover base 106 . Guides 502 , best seen in FIGS. 5 and 6 , under document cover 105 facilitate more precise, automatic locating of the photograph or other planar media to be scanned allowing the user to insert the media through slot 501 and slide it into position more easily. The edges of the media slide along one or both guides 502 and the media comes to rest against stop 601 , similar to sliding a document into an envelope. Guides 502 and stop 601 automatically locate the media in the correct position on platen 201 for scanning. Preferably, flap 101 and document cover base 106 employ snap closure projection 204 and snap enclosure indent 205 to snap fittingly secure flap 101 to document cover base 106 to facilitate use of the document cover 105 as a unit.
As seen in FIGS. 2 and 4 , face down icon 203 reminds a user to insert media into slot 501 face down for scanning. Preferably, icon 203 , or alternatively a second icon, indicates top and bottom of the media. As illustrated in FIG. 6 , directional icons 603 and 604 disposed about the periphery of platen 201 on upper side 202 of housing 103 facilitate proper orientation of the media to be scanned when document cover 105 is opened to scan oversized items.
Returning to FIG. 1 , an input/output port 108 , such as a universal serial bus (USB) connector is preferably disposed on a side of the housing 101 for connecting envelope scanner 100 to a PC, set top box or similar processing device. Preferably, port 108 offers both I/O capability and power to envelope scanner 100 . Alternatively, power input port 109 receives a power supply cord from a transformer or similar power source.
To use the envelope scanner, the user preferably opens flap 101 and slips the media to be scanned inside envelope scanner 100 , through slot 501 , face down, snaps flap 101 closed and presses send button 102 . As will be appreciated by one skilled in the art, flap 101 need not necessarily be snapped closed, but may rather rest closed in place during scanning. Depending on the software employed by the attached computer, set top box or other processing device and its set-up, a digital image of the media is immediately sent to a predetermined recipient, or a software program is called up on the PC or similar device where the user enters the destination and adds any desired text.
Preferably, the envelope scanner also offers a rotate button 107 . If the orientation of the media or photograph is portrait rather than landscape, the rotate button preferably allows a user to rotate the scanned image ninety degrees, so that the image will appear on the receiver's computer screen or television in the proper orientation. If the image is not in the correct orientation following use of the rotate button, then the user can continue to click the rotate control button, multiple times, until the image is in the correct orientation. | A scanner has a platen supported by a housing. The platen is adapted to abut a media to be scanned. A document cover is adapted to sandwich the media against the platen. The document cover is hinged to the housing by at least one first hinge. The document cover has a base portion having a closed position and at lest one open position, and a flap portion independently hinged to the base portion by at least one second hinge. The flap portion is adapted to open to enable insertion of the media onto the platen while the base portion is in the closed position. | 7 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an apparatus capable of controlling with high precision the recording and reproduction of signals by plural heads, and more particularly to a recording/reproducing apparatus in which a recording/regenerative integrated circuit with plural magneto resistive heads (hereinafter abbreviated to MR heads) connected thereto can be controlled with high precision. The invention further relates to an apparatus for reproducing digital information signals or the like with MR heads, and more particularly to a rotary magnetic head type apparatus in which bias currents to MR heads mounted on a rotary drum can be appropriately controlled.
[0002] An MR head, as it can detect magnetic information signals entered from a recording medium, such as a magnetic tape or a magnetic disk, by variations in resistance, requires the supply of a detecting current (sense current). Furthermore, as such variations in resistance have a nonlinear characteristic with respect to the input magnetic field, an MR head also needs a bias current for keeping the operating point in a more linear region. Recently developed MR heads are designed to these currents (hereinafter to be together referred to as bias currents) use in combination.
[0003] Where MR heads are to be used in a rotary head type magnetic recording/reproducing apparatus, a bias current circuit and a preamplifier circuit are mounted on the rotary drum. Therefore, power to drive these circuits needs to be supplied to the rotary drum side, and it is usually transmitted via a rotary transformer or a slip ring (contact). Also, MR head bias current control signals are transmitted to the rotary drum side via the rotary transformer after being converted into A.C. signals, and further rectified on the rotary drum side to be converted into D.C. voltage signals for controlling the MR heads.
[0004] A technique to mount MR heads on a rotary drum and control bias currents to determine the operating points of the MR heads is described, e.g. in J-P-A No. 177924/1998. Further, J-P-A No. 105909/1998 discloses a bias current regulating apparatus capable of flowing optimal bias currents to individual MR heads. J-P-A No. 201005/1995 reveals a method by which optimal bias currents are applied to active MR heads at the time of executing each head switching command.
SUMMARY OF THE INVENTION
[0005] For high density recording/reproducing apparatuses using a magnetic tape, the prevailing trend is to increase the number of magnetic heads (MR heads) mounted on the rotary drum in order to expand the capacity and enhance the transfer rate. Since each MR head differs in sensitivity and optimal operating point according to its element length from the sliding surface of the tape (MR height), it is preferable to individually optimize the bias current where plural MR heads are to be used. However, if it is necessary to provide the rotary transformer for controlling the MR bias currents with as many channels as the MR heads, it will become difficult to increase the number of MR heads to be mounted on the rotary drum. Furthermore, where control information is to be transmitted in analog signals, there will be another problem of difficulty to achieve high enough precision.
[0006] An object of the present invention, therefore, is to provide a rotary magnetic head type apparatus permitting independent and precise regulation of bias currents supplied to plural MR heads mounted on a rotary drum in a simple structure.
[0007] In order to achieve the object, a rotary magnetic head type apparatus according to the invention is provided on a stationary drum side with a control signal generator for generating control signals for controlling the operating amperages of magneto resistive heads and on the rotary drum side with a decoder circuit for discriminating data of the control signals and a current supply circuit for supplying operating currents to the magneto resistive heads in response to the output signals of the decoder circuit. The control signals are transmitted over a single channel of a rotary transformer and set the operating currents of the magneto resistive heads. Further, the control signals may include control information regarding a regenerative amplifier for reproduced outputs of the magneto resistive heads and recording current setting for recording heads.
[0008] Otherwise, a regenerative integrated circuit comprising of a current supply circuit and a regenerative amplifier is mounted on the rotary drum to switch over among the plurality of MR heads for operation in turn. Usually a regenerative integrated circuit for MR heads is controlled with digital data on three lines including Data, Clock and Chip Select (CS) lines. For this reason, a control signal generator for generating control signals for controlling the regenerative integrated circuit is provided on the stationary drum side, a decoder circuit for discriminating data of the control signals is provided on the rotary drum side, and the three-line signals for controlling the regenerative integrated circuit are supplied from the decoder circuit. This structure requires only one control line for transmission from the stationary side to the rotary side even if the number of MR heads is increased. Moreover, since the transmitted signals are digital signals, highly precise transmission is made possible.
[0009] However, since additional functions in such a regenerative integrated circuit would entail a substantial increase in the quantity of data bits required for their control, if data required for all the controls are transmitted on every occasion of head switching, it will take too long a time. In the worst case, head switching may fail to be done at the desired timing, inviting a loss of some head-reproduced signals. If the number of MR heads is increased and the number of regenerative integrated circuits mounted on the rotary drum also increases, a similar problem will arise because the data for the increased integrated circuits that are used are transmitted by time-division multiplexing. This is also true of controlling the plurality of recording heads in each recording integrated circuit. It is essential to perform head switching at the desired timing in a recording/reproducing apparatus provided with plural heads not only of the MR type but also of any type.
[0010] Another object of the present invention is to provide a recording/reproducing apparatus permitting switching over among plural heads with high precision, in particular a rotary magnetic head type apparatus permitting switching over plural MR heads and recording heads mounted on a rotary drum at high speed.
[0011] In order to achieve the object, a recording/reproducing apparatus according to the present invention is provided with a recording/reproducing unit for recording/reproducing signals onto/from a recording medium with plural heads, a generating unit for generating control data for controlling the recording/reproducing unit, and a transmitting unit for transmitting control data generated by the generating unit to the recording/reproducing unit, wherein data for controlling the switching over among the plurality of heads are transmitted with priority over other control data.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
[0013] [0013]FIG. 1 is a block diagram illustrating a rotary magnetic head type apparatus, which is a preferred embodiment of the present invention.
[0014] [0014]FIG. 2 illustrates bias current supply circuits in the rotary magnetic head type apparatus shown in FIG. 1.
[0015] [0015]FIG. 3 is a block diagram illustrating a rotary magnetic head type apparatus, which is another preferred embodiment of the present invention.
[0016] [0016]FIG. 4 illustrates the control timing in a regenerative integrated circuit in the rotary magnetic head type apparatus shown in FIG. 3.
[0017] [0017]FIG. 5 is a block diagram illustrating a rotary magnetic head type apparatus, which is still another preferred embodiment of the present invention.
[0018] [0018]FIG. 6 is a block diagram illustrating a rotary magnetic head type apparatus, which is yet another preferred embodiment of the present invention.
[0019] [0019]FIG. 7 illustrates rotary transformers in the rotary magnetic head type apparatus shown in FIG. 6.
[0020] [0020]FIG. 8 illustrates rotary transformers embodied in another way in the rotary magnetic head type apparatus shown in FIG. 6.
[0021] [0021]FIG. 9 illustrates in detail the control timing in the regenerative integrated circuit in the rotary magnetic head type apparatus shown in FIG. 3.
[0022] [0022]FIG. 10 illustrates in detail the control timing in another way in the regenerative integrated circuit in the rotary magnetic head type apparatus shown in FIG. 3.
[0023] [0023]FIG. 11 illustrates in detail the control timing in the regenerative integrated circuit in the regenerative integrated circuit and the recording integrated circuit in the rotary magnetic head type apparatus shown in FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] Preferred embodiments of the present invention will be described in detail below.
[0025] [0025]FIG. 1 is a block diagram illustrating a rotary magnetic head type apparatus, which is a preferred embodiment of the present invention. A pair of MR heads 201 and 203 are fitted on a rotary drum 1 in opposite positions 180° apart to read signals recorded on a magnetic tape (not shown) wound approximately 180° in the rotating direction of the drum. Current circuits 401 and 403 are circuits for flowing bias currents to take out signals from the MR heads 201 and 203 . A regenerative amplifier 5 is provided with a two-channel amplifier for the MR heads 201 and 203 . A rotary transformer 28 for transmitting data between the stationary side and the rotary side is provided with a rotary transformer for power 7 , a rotary transformer for reproduced signals 8 and a rotary transformer for control signals 9 . Information signals on MR head bias current data generated by a control signal generator 12 are transmitted to the rotary side via the rotary transformer for control signals 9 . A decoder 6 discriminates data of these signals, and controls the bias currents for the MR heads 201 and 203 by outputting control signals to the current circuits 401 and 403 . Information signals reproduced by the MR heads 201 and 203 from the magnetic tape, after being amplified by the regenerative amplifier 5 , are delivered to the rotary transformer for reproduced signals 8 and a buffer amplifier 11 to undergo signal processing.
[0026] Although the output signals of the control signal generator 12 are transmitted by the rotary transformer for control signals 9 to the rotary side in the above-described embodiment, a slip ring, for instance, may be fitted to the shaft of the rotary drum to transmit the signals directly from the stationary side via a contact. However, considering the risk of error occurrence due to the insufficient reliability of the contact or noise during the long period of high-speed rotation, the above-described transmission of the control signals by the rotary transformer is more preferable. The decoder 6 can be configured of an ordinary digital integrated circuit or, if adaptable in operating speed, a general-purpose microcomputer may be used instead. The buffer amplifier 11 can be configured of a low input impedance circuit, such as a common-base circuit.
[0027] Since such circuit components as the current circuits 401 and 403 , regenerative amplifier 5 and decoder 6 are mounted on the rotary side in the foregoing structure, a power supply circuit 3 is provided on the rotary drum 1 . The power supply circuit 3 , comprises of a rectifier circuit and a voltage regulator, and operates to obtain a desired D.C. voltage from the output A.C. signal of a power signal generator 10 transmitted via the rotary transformer for power 7 . For instance, if a final D.C. voltage of 5 V is desired, a switching signal of about 20 Vp-p, 100 kHz is generated from the stationary side D.C. source voltage of 12 V by the power signal generator 10 . Then, the rotary transformer for power 7 having a turns ratio of 1:1 and a half-wave rectifier circuit as the rectifier circuit are used to obtain a D.C. voltage of around 7 V. Further a 5 V D.C. voltage regulator can be operated.
[0028] Another applicable method for power supply is to fit a slip ring or the like to the shaft of the rotary drum to transmit a voltage directly from the stationary side via a contact. In this case, as the high-speed rotation of the rotary drum 1 continues for a long period, insufficient reliability of the contact or noise might pose a problem. Therefore, the aforementioned power transmission using the rotary transformer is more preferable.
[0029] In this embodiment of the invention, it is possible to switch the output signals of the decoder 6 at every 180° turn of the rotary drum 1 . Thus, one out of the MR heads 201 and 203 , what is on the operating side (what is in contact with the magnetic tape and reproducing signals), is individually controlled to position it on the optimal operating bias point. The control enables the two MR heads 201 and 203 to be controlled with outputs from the one-channel rotary transformer for control signals 9 and the single decoder 6 . In this case, the bias current to the non-operating MR head (not in contact with the magnetic tape) takes on the same amperage as that for the operating MR head.
[0030] It is also possible to output at the same time a signal from the control signal generator 12 to switch over the regenerative amplifier 5 at every 180° turn. The decoder 6 discriminates data, switches over the regenerative amplifier 5 consisting of a two-channel amplifier, and chooses between the output signals of the MR heads 201 and 203 . The selected output signal is transmitted to the stationary side buffer amplifier 11 via the rotary transformer for reproduced signals 8 . This structure enables the output signals of the MR heads 201 and 203 to be transmitted by the single channel rotary transformer for reproduced signals 8 .
[0031] As described above, according to the present invention, it is possible to independently control each of the bias currents for plural MR heads mounted on the rotary drum with a one-channel control signal sent from the stationary drum side, and let them operate at their respective optimal points.
[0032] [0032]FIG. 2 illustrates bias current supply circuits 401 and 403 shown in FIG. 1. A current Miller circuit is configured of transistors 13 and 14 , resistors 17 and 18 , a diode 15 and a resistor 16 . It so operates that currents proportional to currents flowing to a transistor 19 and a resistor 20 flow to the MR heads 201 and 203 . The diode 15 is connected for temperature compensation for the transistors 13 and 14 . The decoder 6 discriminates information on bias currents for the MR heads 201 and 203 transmitted via the rotary transformer for control signals 9 , and transmits the discriminated data to a digital-to-analog (D/A) converter 21 . The D/A converter 21 converts the digital data into analog D.C. voltage signals, which are further converted by the transistor 19 and the resistor 20 into D.C. currents. Thus, the bias currents for the MR heads 201 and 203 can be controlled with the D.C. output voltage of the D/A converter 21 . Where the number of MR heads used in this embodiment is to be increased, as many circuits each configured of the transistor 13 and the resistor shown in FIG. 2 as the total number of heads are provided. Half as many D/A converters 21 as the total number of heads would suffice where two each out of plural MR heads are arranged opposite to each other at 180°. Where they are not arranged opposite at 180°, as many D/A converters 21 as the total number of heads can be provided.
[0033] The embodiment illustrated in FIG. 3 is a version of what is shown in FIG. 1, the difference being that the regenerative amplifier 5 is integrated with the current circuits 401 and 403 to be together used as a regenerative integrated circuit 501 and an oscillator 22 is connected to the decoder 6 . The same components as in FIG. 1 are denoted by respectively the same reference numerals. The regenerative integrated circuit 501 is provided with a two-channel amplifier for the MR heads 201 and 203 , and its operating mode is controlled with data on three control lines including Data, Clock and CS lines. The control functions include, for instance, head (amplifier) switching, MR head bias current setting, regenerative amplifier gain setting, detection of thermal asperity (TA) noise peculiar to MR heads and correction. A register matching each function is selected in advance, and control data are written into it to determine its operating state and value.
[0034] Information signals on the magnetic tape reproduced by the MR heads 201 and 203 are amplified by the regenerative integrated circuit 501 . After that, they are sent to the rotary transformer for reproduced signals 8 and the buffer amplifier 11 to undergo the following signal processing. The buffer amplifier 11 is configured of a low input impedance circuit, such as a common-base circuit. Information signals for the regenerative integrated circuit 501 generated by the control signal generator 12 are transmitted to the rotary side via the rotary transformer for control signals 9 , and subjected to data discrimination by the decoder 6 , which thereby controls the operation of the regenerative integrated circuit 501 .
[0035] As the three different control signals of the regenerative integrated circuit 501 here are digital signal strings, the decoder 6 is also provided with the oscillator 22 for generating digital signals, and discriminates control data transmitted from the control signal generator 12 . Then, the decoder 6 operates to convert these data into digital control data for the regenerative integrated circuit 501 and output them in that form. This structure enables the three control lines to be used as they are even if the number of MR heads 201 and 203 further increases and additional regenerative integrated circuits 501 are provided. It has to be noted, though, that as many CS lines as the number of regenerative integrated circuits 501 that are used would be required. The oscillation frequency of the oscillator 22 is selected from a range of 20 to 30 MHz, though it depends on the type and number of regenerative integrated circuits 501 used.
[0036] By controlling the operating mode in this way, each of the MR heads 201 and 203 can be controlled fully independently of each other. For instance, bias currents for two MR heads differing in MR height can be controlled to keep their respective optimal amperages. Also, the service life of an MR head as an element, as it is dependent on the product of the bias current amperage and the duration of current supply, can be extended by control to minimize the bias current for the MR head during the non-operating 180° period. Further, by switching the gain of the regenerative amplifier in 180° periods, the amplitude of the output signals of the regenerative integrated circuit 501 can be kept constant.
[0037] [0037]FIG. 4 illustrates the control timing in the regenerative integrated circuit 501 . As illustrated, data signals are delivered to the three control lines including Data, Clock and CS immediately before the timing of head switching (signal varying point) to control the regenerative integrated circuit 501 . For instance, by changing head (amplifier) switching information data and MR bias current data on the Data line at every 180°, the bias currents for the MR heads 201 and 203 in contact with the magnetic tape and reproducing signals can be set to their respective optimal amperages. Further a desired one of the output signals of the MR heads 201 and 203 is selected by switching the regenerative integrated circuit 501 consisting of a two-channel amplifier, and it can be transmitted to the stationary side buffer amplifier 11 via the one-channel rotary transformer for reproduced signals 8 .
[0038] Since the control data here for the regenerative integrated circuit 501 should include the address of the control register when they are transmitted, about 20 bytes or more of data are transmitted at every time of head switching. Therefore, transmission of all the data would take 10 μs of time or more, though it partly depends on the clock frequency of the decoder 6 . This period of time will lengthen with an increase in control data as the function of the regenerative integrated circuit 501 is enhanced and with an increase in the number of regenerative integrated circuits 501 .
[0039] In such a state, as head switching fails to take place when it should, there will arise problems that some signals are dropped and signals are reproduced in a state where MR heads are not kept at their respective optimal operating points. In this embodiment of the invention, in order to prevent loss or wrong setting of data at the time of head switching, top priority in the transmission of digital data at the time of head switching is given to head switching signal data and MR current control signal data.
[0040] The control timing in the regenerative integrated circuit 501 will now be explained in detail with reference to FIG. 9. In accordance with the operational timing shown in FIG. 4, head switching signal data and the address of their storage, e.g. the address of register A, are first transmitted. In the regenerative integrated circuit 501 , control varies immediately after the reception of data, and the operating regenerative amplifier is switched to that on the MR head 201 side. Then, operating current data for the MR head 201 and the address of register B in which they are to be stored are transmitted to place the MR head 201 in a state in which it can be operated by a normal current. Finally, the addresses of plural registers and corresponding data for controlling the amplifier gain, high-pass filter cut-off frequency and correction data for thermal asperity noise are transmitted. Thus, head switching signal data and operating current data are transmitted prior to all other data. At the next timing of 180° switching, the regenerative amplifier is controlled to be switched over to the MR head 203 side by a similar operation. Such data as the amplifier gain need not be transmitted at every time of head switching, but may be transmitted at the time of starting up the apparatus or when control becomes necessary.
[0041] The control method describe above can prevent any reproduced signal loss due to an increase in head switching time and ensure stable data reproduction because the head switching operation performed at every 180° and the setting of the MR head operating current are finalized early.
[0042] [0042]FIG. 10 illustrates in detail the control timing in another way in the regenerative integrated circuit 501 in this embodiment.
[0043] This way of timing is the same as that in the embodiment shown in FIG. 9 in that head switching signal data and the address of register A into which they are stored are transmitted first, and operating current data for the MR head and the address of register B in which they are to be stored are transmitted second. In the embodiment of FIG. 10, the next data is allocated for reading the operating state of the regenerative integrated circuit 501 . Register C shown here stores, for instance, information on the result of detection of opening or short-circuiting of MR heads connected to the regenerative integrated circuit 501 and any abnormality in source voltage. The decoder 6 , contrary to the usual way, reads data from the regenerative integrated circuit 501 and re-encodes them, and transmits the data to the control signal generator 12 on the stationary side via the rotary transformer for control signals 9 . By this bidirectional communication, the states of the MR heads 201 and 203 on the rotary drum 1 can be detected from the stationary side.
[0044] However, the above-described operation requires the addition of a bidirectional signal processing circuit to the decoder 6 and the control signal generator 12 . Or where these items of information are outputted from dedicated output terminals of the regenerative integrated circuits 501 and 502 instead of being supplied to the Data line, connection can be made directly to the decoder 6 .
[0045] This embodiment permits transmission of the operating state of the regenerative integrated circuit 501 to the stationary drum side at every timing of head switching, and any faulty operation of the MR head 201 or 203 or occurrence of thermal asperity noise can be coped with in a short period of time.
[0046] [0046]FIG. 5 is a block diagram illustrating a rotary magnetic head type apparatus, which is still another preferred embodiment of the present invention. In FIG. 5, the same components as in FIG. 1 and FIG. 3 are denoted by respectively the same reference numerals. In this embodiment, a pair of recording heads 231 and 233 in opposite positions 180° apart and a recording amplifier 24 with a two-channel output are mounted on the rotary drum 1 to perform recording and reproduction. The recording heads 231 and 233 are arranged in positions respectively 90° off the MR heads 201 and 203 . The heights between the heads are so determined that data tracks recorded on the magnetic tape by the recording heads 231 and 233 can be reproduced as they are by the MR heads 201 and 203 . The rotary transformer 28 is provided with a rotary transformer for recorded data 25 . Recorded data encoded by a recorded data generator 26 are transmitted to the rotary side via the rotary transformer for recorded data 25 . The recording amplifier 24 converts voltage information signals from the rotary transformer for recorded data 25 into currents, and supplies prescribed recording currents to the recording heads 231 and 233 . In this process, the amperages of the recording currents from the recording amplifier 24 are controlled by the decoder 6 . This operation is the same as the control method for the bias currents for the MR heads 201 and 203 described with reference to FIG. 1, and the current gain of the recording amplifier 14 can be varied with the D.C. output voltage of the decoder 6 . Further by selecting the channel output of the recording amplifier 24 at 180° intervals and keeping the recording amplifier 24 on the non-operating side in a non-recording state, the heat generation by the recording amplifier 24 mounted on the rotary drum can be reduced.
[0047] This structure enables the recording heads 231 and 233 to record data and at the same time the MR heads 201 and 203 to reproduce data. For this reason, in the regulation to optimize the bias currents for the MR heads 201 and 203 relative to the recording characteristics of the recording heads 231 and 233 , there is no need to rewind the magnetic tape, making it possible to complete the regulation in a correspondingly shorter period of time.
[0048] Although the recording amplifier 24 is mounted on the rotary side in this embodiment, it may as well be provided on the stationary side. However, its arrangement on the rotary side serves to halve the number of channels required for the rotary transformer for recorded data 25 and in this way smaller amplitude data signals would suffice for transmission to the rotary transformer for recorded data 25 , with the result that cross talk to the rotary transformer for reproduced signals 8 can be minimized. Although the mounting positions of the recording heads 231 and 233 are supposed to be at 90° with respect to the MR heads 201 and 203 in this embodiment, they may as well be at or around 0°. Their positions are not necessarily limited.
[0049] [0049]FIG. 6 is a block diagram illustrating a rotary magnetic head type apparatus, which is yet another preferred embodiment of the present invention. The same components as in FIG. 1, FIG. 3 and FIG. 5 are denoted by respectively the same reference numerals. In this embodiment, there are provided four each of recording heads and MR heads, and two each of recording or reproducing heads are paired and constitute a double azimuth (DA) structure, in which they differ in azimuth angle from each other. This structure results in double as fast a data transfer speed as the rotary magnetic head type apparatus shown in FIG. 5. Pair combinations are recording heads 231 and 232 , 233 and 234 , MR heads 201 and 202 , and 203 and 204 . Further, the recording heads 231 , 232 , 233 and 234 and the MR heads 201 , 202 , 203 and 204 are arranged at 90° intervals, and the recording heads 231 and 233 , the recording heads 232 and 234 , the MR heads 201 and 203 and the MR heads 202 and 204 are mounted opposite to each other at 180°.
[0050] Two sequences of data signals outputted at the same time from the recorded data generators 261 and 262 are recorded onto the magnetic tape via the pairs of rotary transformers for recorded data 251 and 252 , recording integrated circuits 241 and 242 , and recording heads 231 and 232 or 233 and 234 . At the time of reproduction, signals reproduced from the pairs of MR heads 201 and 202 or 203 and 204 are transmitted to buffer amplifiers 111 and 112 on the stationary side via regenerative integrated circuits 501 and 502 and rotary transformers for reproduced signals 801 and 802 .
[0051] The recording integrated circuits 241 and 242 and the regenerative integrated circuits 501 and 502 , like their respective counterparts in the embodiment illustrated in FIG. 3, are controlled with three kinds of digital signals including Data, Clock and CS signals. In this embodiment, provided with two each of recording integrated circuits 241 and 242 and regenerative integrated circuits 501 and 502 , there are four CS lines of output signals from the decoder 6 . The regenerative integrated circuits 501 and 502 are provided with bias current supply circuits for the MR heads, and control the head switch and the amperages of bias currents for MR heads. In the recording integrated circuits 241 and 242 , the head switch and recording current amperages are controlled with three kinds of digital signals.
[0052] These control data are generated by the control signal generator 12 , and transmitted to the decoder 6 via the one-channel rotary transformer for control signals 9 . The decoder 6 generates control data for the recording integrated circuits 241 and 242 and the regenerative integrated circuits 501 and 502 to handle these information data, and controls them via the six control lines. These output data signals are generated in accordance with oscillation clocks from the oscillator 22 connected to the decoder 6 .
[0053] In this embodiment, the bias currents for MR heads 201 , 202 , 203 and 204 mounted on the rotary drum 1 can be regulated independently of one another. Further, as the recording integrated circuits 231 and 232 are controlled from the stationary side, setpoints of the recording currents for the recording heads 231 , 232 , 233 and 234 can also be regulated independently of one another.
[0054] Here, if the Data line connected to the recording integrated circuits 241 and 242 and the regenerative integrated circuits 501 and 502 is a two-way path, for instance the terminal voltages of the MR heads, data on the occurrence of thermal asperity (TA) noise on the MR heads, the result of detection of opening or short-circuiting of heads can be delivered to the decoder 6 , and these items of information can be transmitted to the stationary side. This requires the addition of a bidirectional signal processing circuit to the decoder 6 and the control signal generator 12 , though. Or where these items of information are not outputted to the Data line, they can be inputted directly to the decoder 6 .
[0055] Although the recording integrated circuits 241 and 242 and the regenerative integrated circuit 501 and 502 were described separately, they can be configured of a combined recording/reproducing integrated circuit, and the recording and reproducing functions can be switched over between each other using the aforementioned three control lines.
[0056] [0056]FIG. 7 illustrates embodiments of rotary transformers in the rotary magnetic head type apparatus shown in FIG. 6. The rotary transformer 28 is provided with a rotary transformer for power 7 , a rotary transformer for control signals 9 , rotary transformers for recorded data 251 and 252 , and rotary transformers for reproduced signals 801 and 802 . In the slots of the rotary transformers, short rings 273 , 272 and 271 are inserted to reduce signal cross talk between the transformers. For this purpose, altogether nine such slots are provided. Although the rotary transformer 28 in the embodiment shown in FIG. 7 has a planar shape, it may as well be a coaxial cylinder instead.
[0057] [0057]FIG. 8 illustrates rotary transformers embodied in another way in the rotary magnetic head type apparatus shown in FIG. 6. This is an instance in which, unlike the embodiment shown in FIG. 7, the rotary transformer 28 is separated into a first rotary transformer 281 having the rotary transformer for power 7 and the rotary transformer for control signals 9 and a second rotary transformer 282 having the rotary transformers for recorded data 251 and 252 and the rotary transformers for reproduced signals 801 and 802 . Compared with embodiment of FIG. 7, this embodiment permits a reduction in the number of slots per rotary transformer and the use of a rotary drum smaller in diameter. For this embodiment, too, a coaxial cylindrical rotary transformer may be divided into two parts. Alternatively, the first rotary transformer 281 may be planar and the second rotary transformer 282 may be cylindrical, or vice versa.
[0058] [0058]FIG. 11 illustrates in detail the control timing in the embodiment shown in FIG. 6.
[0059] As the recording system and the reproducing system are arranged 90° apart from each other, the control timing of the recording integrated circuits 241 and 242 and the control timing of the regenerative integrated circuits 501 and 502 are off each other by 90°. For both recording and reproducing, data are transmitted in the order of head switching signal data and amperage data.
[0060] First at the timing of MR head switching, a CS 501 signal for the regenerative integrated circuit 501 is outputted at the pertinent timing shown in FIG. 11 to transmit the address of register A, in which head switching data for the regenerative integrated circuit 501 are stored, and data. At the next time slot, a CS 502 signal for the regenerative integrated circuit 502 is outputted at the pertinent timing shown in FIG. 11 to transmit the address of register D, in which head switching data for the regenerative integrated circuit 502 are stored, and data. At the further next time slots are allocated again for the MR head current data of the regenerative integrated circuit 501 and for the MR head current data of the regenerative integrated circuit 502 to output CS 501 and CS 502 signals at the respective timings.
[0061] Similarly at recording head switching timings differing by 90° in phase, first a CS 241 signal for the recording integrated circuit 241 is outputted at the pertinent timing shown in FIG. 11 to transmit the address of register E, in which head switching data for the recording integrated circuit 241 are stored, and data. At the next time slot, a CS 242 signal for the recording integrated circuit 242 is outputted at the pertinent timing shown in FIG. 11 to transmit the address of register F, in which head switching data for the recording integrated circuit 242 are stored, and data. At the further next time slots are again allocated for the recording head current data of the recording integrated circuit 241 and for the recording head current data of the recording integrated circuit 242 to output CS 241 and CS 242 signals at the respective timings.
[0062] Data which need not be transmitted at every time of head switching including, for instance, the amplifier gain, high-pass filter cut-off frequency and switching data for a thermal asperity noise compensating circuit are allocated collectively to an area for transmission. As stated above, by outputting the signals in this area only at the time of starting up the apparatus or as required, the occurrence of data errors due to the infiltration of communication noise can be prevented.
[0063] In this embodiment, as head switching is given priority in every recording or regenerative integrated circuit, erroneous recording of signals and failure to reproduce signals can be prevented. Incidentally, in the foregoing description of this embodiment, the recording integrated circuits 241 and 242 and the regenerative integrated circuits 501 and 502 were supposed to be separated, they can as well be configured in combined recording/regenerative integrated circuits, and the recording and reproducing functions can be switched over between each other using the aforementioned three control lines. Further, though the mounting positions of the recording heads 231 and 233 are supposed to be at 90° with respect to the MR heads 201 and 203 in this embodiment, they may as well be at or around 0°. Their positions are not necessarily limited.
[0064] As hitherto described, the present invention makes possible early finalization of head switching and operating current setting. This helps prevent failure to reproduce signals and erroneous recording due to a delay in head switching, resulting in stable data recording and reproduction. Further according to the invention, it is possible to control the decoder and the regenerative integrated circuit via a single control line (having a rotary transformer or transformers and the like). Since it is difficult to increase the number of rotary transformers in a rotary magnetic head type apparatus, the invention can be applied with particular effectiveness. This does not mean, however, that the invention can be applied only to rotary magnetic head type apparatuses, but it can also be effectively applied to disk apparatuses.
[0065] Further, although the foregoing description supposed the use of digital signals as recorded/reproduced information signals, the applicability of the invention is not limited to digital signals, but the invention can also be applied to the transmission of frequency-modulated analog signals.
[0066] Also, where MR heads are used, not only head switching data but also data for controlling bias currents have to be transmitted at the time of head switching, the invention embodied as described is particularly useful. However, the application of the invention is not confined to apparatuses provided with MR heads, but can also cover other types of apparatuses in which plural heads are controlled by a recording/ regenerative integrated circuit or circuits.
[0067] Where integrated circuits are used as in the embodiments described above, the increased numbers of functions and of integrated circuits result in a substantial increase in the quantity of necessary data, the invention can be applied with particular effectiveness. However, even where no integrated circuit is used, the application of the invention can help prevent erroneous operation due to a delay in data transmission at the time of switching over between plural heads.
[0068] The present invention is not limited to the above embodiments and various changes and modifications can be made within the spirit and scope of the present invention. Therefore, to appraise the public of the scope of the present invention, the following claims are made. | A recording/reproducing apparatus capable of switching over among a plurality of heads with high precision, wherein the apparatus is provided with: a recording/reproducing unit for recording/ reproducing signals onto/from a recording medium with a plurality of heads; a generating unit for generating control data for controlling the recording/reproducing unit; and a transmitting unit for transmitting control data generated by the generating unit to the recording/reproducing unit, wherein priority is given in transmission to data for controlling the switching of the plurality of heads over other data. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to a melt spinning apparatus for extruding and spinning thermoplastic filaments, and of the type generally disclosed in DE 33 43 714 A1.
Extrusion spinning devices for spinning manmade fibers which have the spinning heads arranged in spinning beams are known in various designs from prior art--see, for example, U.S. Pat. No. 3,891,379, DE 33 43 714 A1, DE-GM 84 07 945 or EP-B 0 163 248. All, or at least most of the known spinning devices are of a technically elaborate design so as to achieve at least approximately identical operating conditions at the spinning units operated, in each case, by the same program. Such efforts are necessary and also customary for manufacturing high-quality multi-filament yarns. As a result, the necessary outlay for maintenance is also high.
From the initially cited DE 33 43 714 A1, an installation for double-sided, continuous spinning of manmade fibers is known, which has a double-sided spinning block. The spinning block comprises a closed, heated structural part, inserted in a penetrating manner into which are pipes, which are aligned vertically and in a row and accommodate spinning units each comprising a filter and a spinneret body. Housed in the spinning block are melt metering pumps (metering gear pumps), to which spinning melt is supplied through distribution lines from a melting extruder and which in turn feed the spinning melt to the spinning units. Of the melt metering pumps, however, it is, in each case, only the part containing the connections for the spinning melt which projects into the heated structural part or container.
Heating of the closed container is effected by an oil, described as diathermic in DE 33 43 714 A1, which is heated by electrical resistance heating elements and contained in a sump provided under the spinneret units. It is, however, only the parts situated in the closed interior of the spinning block which are heated.
The construction known from DE 33 43 714 A1 also has considerable drawbacks. The structural part comparable to a spinning beam is of a very fissured design which is very costly to manufacture. Also, as already mentioned, the melt metering pumps lie in the heat insulation and only partially inside the closed container. They are therefore only partially heated.
It is accordingly an object of the present invention to reduce the outlay required to manufacture as well as to operate and maintain the spinning units and achieve identical production conditions for all spinning units of the spinning apparatus.
SUMMARY OF THE INVENTION
The above and other objects and advantages of the invention are achieved by the provision of a melt spinning apparatus which comprises a gas tight container defining a top wall and a bottom wall, with the top and bottom walls having vertically aligned top and bottom openings therein respectively. A melt spinning unit is disposed in the container and extends between the top and bottom openings, and the melt spinning unit comprises a first pipe secured in said top opening and extending downwardly therefrom, and a second pipe secured in said bottom opening and extending upwardly therefrom. The melt spinning unit also includes a supporting plate secured to each of the first and second pipes so as to interconnect the same, with the supporting plate filling the internal cross section of each of said first and second pipes. A melt metering pump is secured to said supporting plate, and a spinneret assembly is secured below said supporting plate. Also, a melt distribution line extends into the supporting plate and leads to the melt metering pump and from the melt metering pump to the spinneret assembly.
The advantages of the spinning apparatus according to the present invention are uniform heating of all melt-carrying structural parts for all spinning units and good accessibility of the subassemblies comprising the melt metering pump, pump drive and spinneret assembly which are to be maintained. Advantageous solutions also arise for the assembly and installation of prefabricated subassemblies into the container enclosing the spinning units.
The central structural part of the spinning unit is, in each case, the supporting plate fitted in a fixed manner into each pipe, with its melt channel and connection to the melt distribution line. The supporting plate completely fills the cross section of each pipe and prevents heat losses caused by a stack effect in the vertical pipes. The melt metering pump is, in each case, a small individual pump having an external contour adapted to the internal cross section of the pipe. It may be fastened--viewed in spinning direction--below the supporting plate or alternatively, on the supporting plate. In the first case, the spinneret assembly may be connected by a screw connection to a circular-cylindrical projection on the bottom pump plate; in the second case, the projection for fastening the spinneret assembly is on the underside of the supporting plate. Alternatively, it is provided that the spinneret assembly, which then carries the fastening means on its outer periphery, is fastened to the inner periphery of the vertical pipe which accommodates the melt-carrying structural parts.
The pump drive shaft is, in each case, mounted from above. In the first case, it is passed axially through the supporting plate, in the second case it is shorter and extends only as far as the pump gear wheels.
The melt supply is a tubular supply line which is sealingly connected, in particular by welding, to the base of the heating kettle or container which it penetrates. Inside the container, the supply line extends without a gradient and runs equidistantly alongside the row of spinning units. In a preferred construction, the connection between the supply line and the melt distribution line which is provided in the supporting plate and leads to the spinning pump, is established by a branch line which runs, in each case, from the supply line to the melt distribution line in the supporting plate and which in particular emanates from the underside of the melt supply line. The latter is preferably positioned higher than the inlets of the melt distribution lines in the supporting plates.
The melt supply may, however, alternatively be so designed that the supply line in the spinning beam divides into a plurality of branch lines of equal length and preferably identical pressure difference, which are each connected to the melt distribution line in the supporting plate of a spinning unit.
The individual spinning pump comprises three plates with two side walls and the collar plate which receives the gear wheels. The spinning pump may, by being lifted out in an upward direction or alternatively after unscrewing of the spinneret assembly, be removed, e.g., for cleaning or parts exchange and then reinserted.
According to the invention the spinneret assembly, which includes a tubular casing, an apertured spin plate, a filter insert, a distribution plate and a pressure piston loading the sealing diaphragm, is suspended from the spinning pump fastened to the supporting plate or from the supporting plate itself. To said end, the downward pointing wall of the bottom spinning pump plate may have on its underside a projection provided with a thread. The top edge of the spinneret casing is provided with an opposing thread so that the spinneret assembly may be screw connected to the spinning pump. The projection may be annular and have an internal thread or it may have a circular-cylindrical enveloping surface with an external thread. For mixing once more the melt exiting from the spinning pump, a statically acting mixing insert may preferably be inserted into a central bore of the pressure piston. Further preferred forms of fastening are a bayonet catch or a threaded connection to the lower pipe which accommodates the spinneret assembly.
The ideal shape for the container according to the invention for receiving the heating medium is one which is smooth and has as few fissures as possible. In such case, the basic shape of the cross section may be substantially rectangular or circular, a deciding factor possibly being that a large selection of pipes of various diameters, wall thicknesses etc. are available as a starting material for a circular-cylindrical housing, while a rectangular cross section may offer advantages in terms of design. In any case, the necessary gas and pressure tight connection between the container wall and the spinning units or the pipe portions forming the ends of the spinning units may be established directly or indirectly by welding.
The procedure for manufacturing the spinning apparatus according to the invention may be such that--optionally using a suitable assembly device which guarantees the precise position and dimensional accuracy during arrangement of the individual parts of the spinning units and the melt supply system--first the spinning units are assembled and spatially connected to the melt supply line in such a way that they may be inserted as a structural unit into the open-ended container previously provided with the penetration holes, which receive the vertical pipes or mark their location.
Here, care has to be taken that, for such purpose, the length of the assembled spinning units has to be smaller than the height of the rectangular container or the chords of the container with a circular pipe cross section which lie in the planes touching the spinning units.
In either case, after reaching the mounting position, the entire built-in part with the bottom ends of the lower pipes (also referred to herein as the assembly pipes) may be lowered in such a way that the ends may be introduced into the provided openings of the container and connected to the housing. Then, using suitable means, the top ends of the upper pipes (connecting pipes) may be connected in a gas and pressure tight manner to the openings in the top container wall.
Thus, in a preferred embodiment of the invention, the connection may be established by first welding the bottom edge of the assembly pipe, after insertion, directly to the container wall. Then the connecting pipe is connected to the spinning beam housing, e.g. a mounting ring may be provided which has a pipe socket and an inside diameter corresponding to the outside diameter of the connecting pipe with a slight assembly clearance. The mounting ring is first loosely inserted into the top housing opening and slipped over the connecting pipe. Then, for example, to fix the pipe socket of the mounting ring in position, it may be welded first to the housing and then to the top edge of the connecting pipe.
To maintain as uniform a temperature as possible in the entire spinneret assembly, the necessary gap between assembly pipe and spinneret assembly should be as narrow as possible. Thus, so that a narrow and uniform gap is not jeopardized by welding the assembly pipe to the wall of the container, a further possibility of establishing a gas and pressure tight connection between the assembly pipe and the container wall is provided for example, optionally prior to insertion of the mounting part, by welding a mounting ring into each bottom opening. Each mounting ring is sized for receiving the assembly pipe, and at their ends extending into the housing, the rings have sealing collars directed radially inwards. On the free ends of the assembly pipes, it is possible to provide externally threaded rings, which prior to assembly are slipped onto and connected in a gas-tight manner to the pipe and which likewise at their ends have a radial sealing collar, which cooperates with the sealing collar of the mounting ring. By means of threaded nuts, which are threadedly connected to the threaded rings, the radial collars of the mounting ring and threaded ring may be pressed together, and a sealing ring may be disposed between the collars.
Heating of the spinning beam may be effected in a known manner by a heating medium such as, for example, diphenyl which at spinning temperature is present in the form of saturated steam. For such purpose it is equally possible to use known heating devices situated outside of the spinning beam, such as independent individual heating systems integrated into the spinning beams, e.g., immersion heaters situated in the condensate sump.
BRIEF DESCRIPTION OF THE DRAWINGS
Some of the objects and advantages of the present invention having been stated, others will appear as the description proceeds, and when considered in conjunction with the accompanying drawings, in which
FIG. 1 is a cross sectional view of a melt spinning apparatus which embodies the present invention;
FIG. 2 is a fragmentary view similar to FIG. 1, but illustrating a modified structure for fastening the spinneret assembly to the spinning unit;
FIG. 3 is a view similar to FIG. 1 and illustrating a further embodiment of the invention;
FIG. 4 is a view similar to FIG. 2 and illustrating a further embodiment of the invention;
FIG. 5 is a view similar to FIG. 1 and which includes an internal heating system;
FIG. 6 is a view similar to FIG. 1 and illustrating still another embodiment of the invention;
FIG. 7 is a fragmentary view similar to FIG. 6, and illustrating a unilateral heating arrangement;
FIG. 8 is a fragmentary view similar to FIG. 6, and illustrating a heating system within the container;
FIG. 9 is a side elevation view, partly broken away, of one embodiment of the melt spinning apparatus of the invention;
FIG. 10 is a fragmentary view illustrating a gas tight connection between the lower assembly pipe of a spinning unit and the container lower wall;
FIG. 11 illustrates a melt spinning apparatus composed of two rectangular containers which house two parallel rows of spinning units;
FIG. 12 illustrates an embodiment composed of two circular containers, each housing a row of spinning units; and
FIG. 13 illustrates an embodiment similar to that shown in FIG. 11, and further illustrating the ventilation shafts and winders.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows, as a first embodiment, the cross section of a melt spinning apparatus 1 having a rectangular cross section with the melt supply line 7, spinning unit 9 and heating system.
The central part of the spinning unit 9 is a circular-cylindrical supporting plate 4, from the bottom edge of which a pipe portion 3 (assembly pipe) is slipped on and fastened in a gas and pressure tight manner, e.g., by welding. Inside the assembly pipe 3, a melt metering pump (spinning pump), which comprises a top lateral plate 10, a housing plate 11 (collar plate) receiving the gear wheels 13, 14, a bottom lateral plate 12 and the drive shaft 15 extending from above through a hole in the supporting plate 4 to the gear wheel 13, is fastened (not shown) preferably detachably to the underside of the supporting plate 4. For supplying melt to the spinning pump 10-15, a melt distribution line 8A is provided in the supporting plate 4, which leads from the periphery of the supporting plate to the spinning pump inlet. The line 8A also is connected by a branch line 8 to the melt supply line 7.
Here, it should be pointed out that, in the case of the selected design of the spinning pump, its inlet lies outside of the supporting plate axis and the selected representation reveals the path of the melt and not the actual associations. The representation therefore differs from the real situation.
The bottom lateral plate 12 of the spinning pump 10-15 has a central projection 121 provided with an external thread 17, to which a spinneret assembly 16 is screw-connected. The assembly 16 includes a tubular casing, a bottom spin plate 24 having a plurality of apertures therethrough, a melt chamber 23 above the plate 24, a distribution plate 22 above the chamber 23, and a filter insert 21 above the distribution plate 22. A sealing diaphragm 20 and a pressure piston 18 which loads said sealing diaphragm, are located above the filter insert, and a mixer, e.g., a static mixing element 19, is located in a central bore of the pressure piston 18.
From the top edge of the supporting plate 4 a pipe portion 5 (connecting pipe) likewise connected in a gas and pressure tight manner to the supporting plate extends upwards and substantially as far as an opening 50 in the top of the container wall 2, which opening is coaxial with the bottom opening 48 and has a slightly larger diameter than the bottom opening 48.
When designing and assembling the structural unit 49 according to FIG. 9, which comprises a plurality of spinning units 9 and their connection to the melt supply line 7, it should be ensured that there is room for the cross section of an envelope of the structural unit 49 in the free cross section of the container 2 (boiler, kettle). The required length of the assembly pipe 3 arises from the spatial requirement of spinning pump 10-15 and spinneret assembly 16, for which reason the length of the connecting pipe 5 is restricted to enable insertion of the structural unit 49 into the container 2. After insertion and alignment of the structural unit 49, the unit as a whole may be lowered far enough for a sufficient length of the assembly pipes 3 to project out from the edges of the bottom openings 48 to produce a weld joint, with the result that the welds may be produced at the periphery of the pipes 3. For this reason, however, the connecting pipes 5 terminate some distance below the top housing openings 50 which are coaxial with the bottom openings, so that a simple welding process is not possible.
FIG. 1 illustrates one possibility of establishing a connection between the individual connecting pipe 5 and the edge of the top housing opening 50. For such purpose, a mounting ring 6 which includes a radial flange, fits into the top opening 50 and is provided with a pipe socket 6A and has an inside diameter corresponding to the outside diameter of the connecting pipe 5 with a slight assembly clearance. The ring 6 is first inserted into the opening 50 and slipped over the connecting pipe 5 in such a way that the top edge of the latter projects into the pipe socket 6A. The pipe socket 6A is then welded at the periphery first to the container wall 2 and then to the top edge of the connecting pipe 5.
The spinning beam 1 according to FIG. 1 is heated indirectly, i.e. from a heat source (not shown) situated outside of the spinning beam 1, using diphenyl, for example, as a heating medium. For such purpose, supply lines 34 for the vaporous heating medium are provided in the container wall 2 and condensate outlets 35 are provided in the bottom of the spinning beam 1.
FIG. 2 illustrates a spinning beam 1 which is similar to that shown in FIG. 1, but which includes a modified fastening of the spinneret assembly 16. Here, the assembly pipe 3 is relieved in an axial direction to a slightly larger inside diameter and the top portion, which extends as far as the bottom lateral plate 12 of the spinning pump, is provided with an internal thread 51 or a bayonet joint. The spinneret assembly 16, which has an external thread or the counterpart of the bayonet joint, is screw-connected to the thread 51 or bayonet, and a sealing ring 52 being inserted between. The melt seal is guaranteed by the axial mobility of the pressure piston 18 which loads the sealing diaphragm 20.
FIG. 3 shows an alternative construction of the spinning unit 9. Here, the supporting plate 4 at its underside has a projection 41 with an external thread 17 for fastening the spinneret pot 16. The spinning pump is mounted on top of the supporting plate 4 and is removable in an upward direction through the connecting pipe 5. The melt distribution line 8A and the outlet channel are located in the supporting plate 4 in accordance with this construction. Otherwise the construction and assembly of the spinning beam 1 are as described above with reference to FIG. 1.
FIG. 4 is a sectional view of the spinning apparatus according to FIG. 3 with a fastening of the spinneret assembly 16 according to FIG. 2 to the assembly pipe 3.
FIG. 5 shows the bottom part of the cross section of a construction of the spinning apparatus according to the invention which differs from that shown in FIG. 1. Here, a spinning pump 11, 12A, and 13-15 is installed, in which the top lateral plate 10 is replaced by the side of the supporting plate 4 which is directed towards the spinning pump. Also, the projection 17B on the bottom housing plate 12A is annular and provided with an internal thread 17A, while the spinneret assembly 16A has an external thread for its fastening to the projection 17B.
In order to prevent the assembly pipe 3 from becoming warped as a result of being welded to the container wall 2, the connection between the assembly pipe 3 and the bottom housing opening 48 shown in FIG. 5 is established by means of a screw-type connection 28-31 which is described in detail below with reference to FIG. 10.
In a further departure, the construction according to FIG. 5 has its own integrated heating system comprising a condensate collector 36 for the liquid heating medium 25 and an immersion heater 26, which is provided in the condensate collector and dips into the liquid heating medium. The condensate collector extends parallel to the row of spinning units 9.
The spinning unit 9 of the construction of the invention shown in FIGS. 6 and 7, including its connection to the wall of the container 2, is substantially identical to the construction described with reference to FIG. 1. It differs from the previously described embodiment mainly in that the container 2A has a substantially circular cross section. Heating is effected, in this case, by a condensate collector 36 integrated into the container 2A and having immersion heaters 26. In order to prevent condensate from accumulating between the spinning units 9, the condensate collectors, which are shown on both sides and connected to the container 2 substantially by individual openings for the saturated steam, are connected to one another and by smaller openings also to the interior of the container. The modification according to FIG. 7 dispenses with one of the lateral condensate collectors 36.
In the construction of the invention according to FIG. 8, which likewise has a container wall 2A with a circular cross section, the construction of the spinning pump and the connection between the assembly pipe 3 and the container wall 2A are identical to those of FIG. 5. The heating with the heating medium 25 by means of immersion heaters 26 has, however, been shifted into the bottom part of the container.
FIG. 9 shows a side view of two spinning units 9 and a portion of the melt supply line 7 with the branch lines 8, the half of the container wall 2 closest to the viewer having been omitted. The view corresponds substantially to a construction according to FIG. 6 and shows in particular the connections of the condensate collector 36 provided between the spinning units 9. The spinning units 9 are preferably a fixed distance 32 apart. The base 33 of the container 2 may, however, in the case of higher heating steam pressure, preferably take the form of a commercially available dished boiler end.
In FIG. 10 the screw connection between the assembly pipe 3 and the bottom housing opening 48, which is selected in the constructions according to FIGS. 5 and 8 so as to avoid troublesome distortions caused by welded joints, is shown to an enlarged scale while retaining the described connection between the connecting pipe 5 and the top housing opening 50 (not shown). Here, the bottom edge of the assembly pipe 3 has a collar 3A, and a threaded ring 27 with mounting thread 30 is connected in a gas and pressure tight manner to the assembly pipe 3. The threaded ring 27, at its upper end, has a projecting annular collar and has to be fitted prior to connection of the assembly pipe 3 to the supporting plate 4 or, in the absence of the collar 3A, prior to mounting of the structural unit 49. Welded into the housing opening 48 is a mounting ring 28 which, at its end directed into the container 2, has an internal collar. Both collars are dimensioned in such a way that they overlap one another.
For the sealing connection of the assembly pipe 3 to the container wall 2, a ring nut 29 is used which, when screwed in, is supported by a collar on the outer edge of the mounting ring 28 and presses the annular collar of the threaded ring 27, after insertion of a sealing ring 31 between, against the internal collar of the mounting ring 28. Such a solution is particularly suitable for lower heating steam pressures.
FIGS. 11 to 13 show special developments of the invention, in which, in each case, two spinning apparatuses 1 are combined with one another to form an assembly comprising a double row of spinning units 9.
In FIG. 11, two rectangular containers 2 corresponding substantially to the construction according to FIG. 1 with two rows of spinning units 9 and two melt supply lines 7 are combined. The opposing walls between the two containers are omitted. In the bottom region between the rows of spinning units 9 there is, however, a possibility of a quenching channel 39 supplying both rows of spinning units. The melt supply lines 7 may also be replaced by a common line, to which the branch lines 8 are connected. With separate lines it is, however, possible to extrude separate melt flows, e.g., differently colored or treated melt flows. External heating of the heating chamber 38 defined by the two containers is provided, the heating system supply 34 and the condensate removal 35 corresponding to the construction according to FIG. 1.
A similarly constructed combination of two containers, but of circular cross section is shown in FIG. 12. Here, both containers are connected to a heating steam connection 46 and to a connection 47 for the condensate. Supply may be effected in any desired manner, e.g., by connecting a heating steam supply to the heating steam connection 46 and connecting a condensate outlet to the condensate line 47.
Finally, FIG. 13 shows in cross section a two-row spinning installation, the spinning units 9 of which are, for example, at a distance 32 (FIG. 9) apart which corresponds to the length of a bobbin tube 44. The spinning units 9 and the container 2 correspond to the representation of FIG. 11. Here too, heating of the container is effected by external heating. Provided below the common container are two blowing or ventilating boxes 41, which are each supplied with quench air from a quenching chamber 40A, 40B, and two spinning chambers 42, while the groups of filaments 43 are wound into yarn packages 45 on bobbin tubes 44. If, for example, ten spinning units are disposed in each row, it is then possible to use winding spindles 52 onto which ten bobbin tubes 44 may be mounted in succession so that the resulting yarn may be jointly wound. The contact rollers for driving the packages 45 at the package periphery are diagrammatically illustrated and denoted by 53.
What is diagrammatically illustrated in FIG. 13 is a spinning installation for a godet free comb spinning mill. If, however, draw-off devices such as godets for manufacturing finished stretched yarns (FOY) are to be provided, then in such case all of the godet axes are preferably provided parallel to the axes of the winding spindles 52 and to the spinning units 9 of the spinning beam 1, which are disposed in a longitudinal direction parallel and behind one another.
In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation. | A melt spinning apparatus for extruding and spinning thermoplastic filaments as part of the fabrication of a multi-filament yarn. The apparatus includes a plurality of spinning units arranged in a row in a gas tight heated container, and each spinning unit comprises upper and lower coaxial pipes which are interconnected by means of a common supporting plate. The melt metering pump and the spinneret assembly are mounted within the pipes. A method of fabricating the apparatus is also disclosed. | 3 |
TECHNICAL FIELD
[0001] This disclosure relates generally to asphalt shingle manufacturing and more particularly to systems and methods of applying granules to a rapidly moving web of substrate material coated with asphalt.
BACKGROUND
[0002] Asphalt-based roofing materials, such as roofing shingles, roll roofing, and commercial roofing, have long been installed on the roofs of buildings to provide protection from the elements and to give the roof an aesthetically pleasing look. Typically, asphalt-based roofing material is constructed of a substrate such as a glass fiber mat or an organic felt mat, an asphalt coating on the substrate to provide a water barrier, and a surface layer of granules embedded in the asphalt coating. The granules protect the asphalt from deterioration due to exposure to UV and IR radiation from the sun and direct exposure to the elements.
[0003] A common method of manufacturing asphalt-based shingles is to advance a sheet or web of the substrate material through a coater, which coats the web with liquid asphalt forming a hot tacky asphalt coated strip. The asphalt coated strip is typically then passed beneath one or more granule dispensers, which discharge or dispense protective and decorative surface granules onto at least selected portions of the moving asphalt coated strip. A granule dispenser may be as simple as a direct feed nozzle fed by an open hopper that is filled with granules or as complex as a granule blender. The result is a strip of shingle stock, which can later be cut to size to form individual shingles, cut and rolled to form a rolled shingle, or otherwise processed into final products.
[0004] In some shingle manufacturing processes, there is a need to deliver granules at intermittently timed intervals such that granules are deposited on the asphalt coated strip in spaced patterns. In such cases, several mechanisms have been used in the past to start and stop the delivery of granules in a controlled manner. For example, a fluted roll has been inserted at the bottom of a granule dispenser nozzle such that rotation of the fluted roll pulls a charge of granules from a granule hopper and throws the granules a set distance (generally over 12 inches) onto the asphalt coated strip below. In some cases, the charge of granules slides down a polished curved surface toward the substrate material. The curved surface in conjunction with gravity accelerates the charge of granules to approximately the speed of the moving asphalt coated strip below and deposits the charge of granules gently onto the asphalt.
[0005] Prior systems and methods of depositing granules onto an asphalt coated strip in shingle manufacturing have exhibited a variety of inherent problems. Chief among these is that as the speed of production increases, meaning that the speed of the moving asphalt coated strip increases, the edges and patterns of dispensed charges of granules on the asphalt become less and less defined. Eventually, the deposited patterns of granules are so indistinct and distorted as to be unacceptable in appearance, coverage, and protection. Trailing edges in particular of a deposited charge of granules become more and more smeared out as the speed of production is increased and dispensed charges of granules exhibit unacceptable trailing patterns. As a result, granule delivery systems and methods in the past have been practically limited to production speeds below about 800 feet per minute (FPM) of asphalt coated strip travel, even though other areas of production are capable of moving much faster.
[0006] There is a need for a granule delivery system and method for use in shingle manufacturing that is capable of delivering a charge of granules at intermittently timed intervals onto a moving asphalt coated strip with precision, definition, and controllability at manufacturing speeds of over 800 FPM and even over 1000 FPM. It is to the provision of such an apparatus and method that the present invention is primarily directed.
SUMMARY
[0007] Briefly described, a granule delivery system and method are disclosed for dispensing charges of granules intermittently onto a moving asphalt coated strip as the strip is moved in a downstream direction beneath the system. The delivery system includes a hopper for containing a supply or store of granules. A generally cylindrical pocket wheel is mounted at the bottom portion of the hopper with the upper portion of the wheel exposed to granules in the hopper and the lower portion of the wheel exposed to the moving asphalt coated strip below. The outer surface of the rotor is formed with a series of pockets separated by upstanding or raised lands. In one embodiment, a total of six pockets are formed around the periphery of the pocket wheel, although more or fewer than six pockets are possible. A brush seal is located at the bottom of the hopper and includes brushes or other sealing members positioned to ride on the lands of the pocket wheel as the lands are rotated past the brush seal. The brush seal also rides across the open pockets as the pockets rotate out of the hopper to level a charge of granules collected by the pockets and thereby insure that a substantially consistent volume of granules is contained by each pocket.
[0008] The pocket wheel is driven through a gear train by a servo motor that is controlled by a computer controller or an indexer to index the pocket wheel at a controlled speed and through a prescribed rotational angle. More specifically, the pocket wheel is rotated from one position where the brush seal seals against one land to a successive position where the brush seal seals against the next successive land. In the process, the pocket defined between the two lands rotates downwardly and is progressively exposed in an inverted orientation above the moving asphalt coated strip below.
[0009] In operation, the hopper is filled with granules, an asphalt coated strip is moved below the dispenser at a production speed, and the pocket wheel is repeatedly indexed as described. As the pocket wheel rotates in indexed increments, the pockets around the circumference of the wheel move through the granules in the hopper as the pockets traverse the upper portion of the wheel. The pockets are filled with granules as they drive through the store of granules. As each pocket is indexed past the brush seal, the seal rides across the open pocket to level the granules within the pocket, which immediately begin to drop out of the now inverted pocket toward the moving asphalt coated strip below. The granules thus are deposited on the asphalt in a pattern that substantially corresponds with the shape of the pocket.
[0010] The surface speed at which the pocket wheel is indexed is coordinated with the production speed of the asphalt coated strip below. In one embodiment, the surface speed can be approximately the same as the production speed. In such an embodiment, the charge of granules is moving in the production direction at about the same speed as the asphalt coated strip when the granules fall onto the strip. In another embodiment, the surface speed at which the pocket wheel is indexed can be different from the production speed. For example, the surface speed might be coordinated to be one-third the production speed. As a result, a pattern approximately three times the circumferential length of each pocket is deposited on the asphalt coated strip below. Other ratios are possible. In any event, a well defined pattern of granules is deposited and subsequent operation of the system forms a sequential pattern of deposited granules along the length of the asphalt coated strip. The system and method of this invention is capable of depositing a charge of granules that is characterized by very good uniformity, well defined edges, and little distortion. Furthermore, these characteristics are expected to be preserved at production speeds substantially higher than those obtainable with prior art granule blenders and other granule dispensing devices, particularly when ratioed indexing is employed.
[0011] Accordingly, a system and method of delivering charges of granules onto a moving asphalt coated strip in shingle production is disclosed that addresses successfully the problems and shortcomings of existing granule dispensing technology and deposits highly defined patterns of granules at production speeds exceeding the capability of existing equipment. These and other aspects, features, and advantages of the invention will be better appreciated upon review of the detailed description set forth below, taken in conjunction with the accompanying drawing figures, which are briefly described as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 shows granule patterns on strips of material resulting from a traditional prior art granule delivery system run at various increasing production speeds.
[0013] FIG. 2 is a perspective view of a prototype apparatus that embodies principles of the system.
[0014] FIG. 3 is a partially sectioned perspective view of a system that embodies principles of the present invention showing operation of the system to deliver granules to a asphalt coated strip.
[0015] FIG. 4 shows granule patterns on a strip of material resulting from use of the system of this invention to deliver granules on the strip.
DETAILED DESCRIPTION
[0016] Reference will now be made in more detail to the drawing figures, wherein like reference numerals, where appropriate, indicate like parts throughout the several views. FIG. 1 illustrates the production speed limitations of a traditional prior art “granule blender” type granule delivery system. Five webs of material 11 , 12 , 13 , 14 , and 16 were advanced along a shingle production line at five different production rates. As illustrated, web 11 was advanced at 450 FPM, web 12 at 600 FPM, web 13 at 700 FPM, web 14 at 720 FPM, and web 16 was advanced at 750 FPM. As each web moved beneath the granule blender, the blender dropped granules onto the moving web in the traditional prior art manner. In FIG. 1 , the machine direction in which the strips of material moved is indicated by arrow M. In each case, a pattern of granules 17 , 18 , 19 , 21 , and 22 was deposited onto the respective strip of material by the granule blender. The leading edges of each granule pattern are at the top of FIG. 1 and indicated by numeral 23 . Trailing edges are near the bottom of FIG. 1 and are indicated by numeral 24 .
[0017] As can be seen from FIG. 1 , at a production or web speed of 450 FPM, which is a common production speed in the industry, a reasonably tight and well defined pattern of granules is deposited onto the strip 11 . There is some trailing edge patterning, but within acceptable limits. This pattern is acceptable and common for commercial shingle production. As the production speed is increased, the pattern of granules deposited by the prior art granule blender delivery system becomes more and more degraded. At 600 FPM, for instance, the pattern appears a bit more indistinct, the trailing edge 24 is thinned and spread more in the non-machine direction, and the leading edge 23 is less distinct. The same phenomenon continues with increasing production speeds until at 750 FPM production speed, the deposited granules are unacceptably patterned throughout, and the leading and trailing edges of the pattern are unacceptably indistinct. It will thus be seen that traditional prior art granule delivery systems limit the practical production speed of a shingle manufacturing operation to somewhat less than 750 FPM.
[0018] FIG. 2 shows a prototype apparatus that was built to test the methodology of the present invention. The prototype apparatus comprises a housing at least partially defined by side walls 25 . A hopper wall 30 is mounted between the side walls 25 and extends downwardly at an angle toward the bottom rear portion of the housing. A rear wall 35 closes the back side of the housing and together with the angled hopper wall 30 defines an open top hopper 29 for receiving and holding a store of granules to be dispensed by the apparatus. A pocket wheel 36 is mounted in the bottom portion of the housing via a shaft 38 journaled in bearings 39 such that the pocket wheel is rotatable in the direction of arrow 41 . The shaft 38 is coupled through coupler 40 to an indexing drive mechanism including indexer 26 , which, in turn, is driven by a servo motor through a gear box 27 .
[0019] The pocket wheel 36 in this embodiment is generally cylindrical in shape and its peripheral surface is formed with a series of depressed pockets 42 separated by raised lands 43 . In the prototype shown in FIG. 2 , a total of six pockets 42 are formed around the periphery of the pocket wheel 36 ; however, more or fewer than six pockets are possible within the scope of the invention. Further, the pockets of the prototype are generally rectangular, but they may have other configurations for depositing granule charges in different patters as described in more detail below. In operation, the drive mechanism is controlled by the indexer in this case to cause the pocket wheel 36 to rotate in direction 41 in incremental steps of one-sixth of a circle, or 60 degrees. In other words, the pocket wheel is incremented through 60 degrees and then stops for a predetermined time before being incremented again through 60 degrees and so on. The time between incremental rotations as well as the speed of rotation during incremental rotations can be controlled to correspond to a given production rate.
[0020] FIG. 3 illustrates in more detail the high speed granule delivery system 28 for depositing a charge of granules onto a moving asphalt coated strip 32 . The system 28 comprises a granule hopper 29 (only the lower portion of which is visible in FIG. 2 ) having a nozzle or mouth 34 . The mouth 34 of the hopper is generally defined by the wall 35 on the right and the angled hopper wall 30 on the left so that granules 31 in the hopper are constrained to flow downwardly to the relatively narrow mouth 34 of the hopper 29 under the influence of gravity.
[0021] The pocket wheel 36 is rotatably mounted at the bottom of the hopper adjacent the mouth 34 . The pocket wheel 36 in the illustrated embodiment is formed with a hub 37 that is mounted on an axle 38 , which, in turn, is journaled for rotation within a bearing assembly 39 . The bearing assembly 39 is mounted a side wall 25 ( FIG. 2 ) of the system, which is not visible in the partial cross sectional view of FIG. 2 . In operation, as described in more detailed below, the pocket wheel 36 is rotated in direction 41 in indexed increments by the drive mechanism.
[0022] The pocket wheel 36 is generally cylindrical in shape except that its peripheral portion is formed or otherwise configured in this embodiment to define a series of pockets 42 separated by raised lands 43 . There are a total of six pockets in the embodiment of FIG. 3 , but it will be understood by the skilled artisan that this is not a limitation of the invention and that more or fewer than six pockets may be provided. In any event, the pockets are sized such that they define a volume between opposing lands and the sides of the pockets that is substantially equal to the desired volume of a charge of granules to be deposited onto the moving asphalt coated strip 32 below.
[0023] A baffle 44 extends downwardly from the wall 35 of the hopper to a lower end and a seal mount fixture 46 is attached to the lower end of the wall 35 and extends downwardly therefrom. Secured within the seal mount fixture 46 is an elongated seal 48 that is held by the seal mount fixture at a position such that the seal 48 engages against the raised lands 43 of the pocket wheel 36 as the lands move past the seal 48 . Similarly, the seal 48 moves across the open pockets of the pocket when as the pockets rotate past the seal. In the illustrated embodiment, the seal 48 comprises a set of brushes 49 fixed within the seal mount fixture 46 and extending to engage the passing lands, thereby forming a brush seal. It is not necessary that the seal between the seal 48 and the raised lands be water tight. It is only necessary that the seal 48 seal substantially against migration of granules past the seal as the pocket wheel rotates. The brush seal created by the set of brushes 49 has proven adequate to meet this need. Further, the brush seal shown in this embodiment have proven to function well for leveling a charge of granules in the pockets as the pockets rotate past the seal.
[0024] Although brush seals are shown and described above, seals other than brush seals, such as, for instance, rubber fins, a solid gate, a movable gate, a rotary gate, or any other mechanism that prevents unwanted granules from migrating past the periphery of the pocket wheel may be substituted for the illustrated brush seals. Any and all sealing mechanisms should be construed to be equivalent to the illustrated brush seals in FIG. 2 . Further, the location or position of the seal around the periphery of the pocket wheel also may be adjusted by an adjustment slot 47 or other appropriate mechanism to change the angle of attack and other characteristics of granules dispensed during operation of the system, as described in more detail below.
[0025] Operation of the system 28 to perform the method of the invention will now be described in more detail with continuing reference to FIG. 3 . The system 28 is mounted along a shingle fabrication line just above a conveyor, along which a strip 32 of substrate material coated with hot liquid asphalt is conveyed in a downstream or machine direction 33 at a production speed of S feet per minute. The hopper 29 of the system is filled with granules 31 to be dispensed intermittently onto the surface of the strip 32 in substantially rectangular patterns as the strip 32 moves past and below the granule delivery system 28 . As the sticky asphalt coated strip 32 moves past the granule delivery system, the drive mechanism rotates the pocket wheel through an increment of rotation and then stops before rotating the wheel through a next successive increment of rotation.
[0026] In the illustrated embodiment of FIG. 3 , the increment of rotation, indicated by arrow 51 , is one-sixth of a full circle since the pocket wheel 36 of this particular embodiment has six pockets. Further an increment begins with the seal 48 engaging and sealing against the top of one of the lands that separate the pockets and ends with the seal 48 engaging and sealing against the top of the next successive land. Preferably, any acceleration or deceleration of the pocket wheel occurs while the seal is still riding on the land such that the pockets are moving at their full linear speed when they begin to be exposed beyond the seal. In the process, the pocket 42 between the two lands progressively rotates beyond the seal 48 and is exposed to the moving asphalt coated strip below.
[0027] With continued reference to FIG. 3 , and with the forgoing description in mind, it will be seen that when the pocket wheel is rotated, each pocket drives through the store of granules 31 within the lower portion of the hopper below the mouth 34 just before encountering and moving beyond the seal 48 . This fills the volume of the pocket with granules. As the pocket begins to rotate beyond the seal 48 , the seal moves across the open pocket to level off the granule charge in the pocket at about the location of the tops of the lands so that the volume of the granule charge is about the same as the volume of the pocket.
[0028] As soon as the pocket begins to move past the seal 48 , the granules in the pocket begin to fall toward the moving strip below under the influence of gravity, as indicated generally by arrow 48 . At the same time, the granules leave the pocket with a forward speed imparted to them by the rotational momentum of the pocket wheel in direction 51 . The downward and forward motion causes the charge of granules to approach the moving asphalt coated strip 32 at an angle 13 , which is referred to herein as the angle of attack or angular discharge. The angular discharge of the granule charge can be varied according to need through adjustment of the circumferential location where the seal 48 engages the lands 43 of the pocket wheel. The stop position of the pocket wheel between intermittent rotations also can be adjusted to affect the angular discharge of the charge of granules as needed.
[0029] In one embodiment it may be desired that the forward speed of the granules as the charge of granules leaves the pocket be approximately the same as the production speed S of the asphalt coated strip below to deposit a highly defined crisp pattern of granules. This forward speed is established by the rate at which the pocket wheel is rotated by the drive mechanism and can be varied to match a particular production speed by varying this rate of rotation. In this way, the granules fall in this embodiment straight down into the sticky asphalt from the perspective of the moving strip so that they are less likely to bounce or otherwise be scattered when they hit the surface of the strip. Such scattering is further reduced since the granules can be released with the present invention, unlike prior art devices, very close to the surface of the strip. The granules therefore have less momentum to dissipate when they strike the asphalt and are less likely to bounce and otherwise scatter. The ultimate result is that the charge of granules are deposited on the asphalt in a sharply defined grouping with crisp edges and very little if any patterning across the grouping.
[0030] In another embodiment, it may be desired that the forward speed of the granules as they leave the pocket, and thus the rotational speed of the pocket wheel, be greater than or less than the production speed S. As one example, the rotational rate of the pocket wheel may be controlled so that it is, say, one-third of the production speed S such that the speed of the asphalt coated strip below is three times the forward speed of the granules when the granules fall onto the sheet. The result is a deposit of granules onto the asphalt coated sheet that is approximately three times the circumferential length of a pocket of the pocket wheel. Although some granule scattering may occur under these conditions, it is expected to be well within acceptable limits so that a well defined deposit of granules is maintained.
[0031] Using such a ratioed indexing methodology, higher production speeds can be accommodated easily with the present invention. For instance, a production speed of 1500 FPM, far higher than the current norm, should be able to be accommodated with acceptable results with the linear speed of the pocket wheel set to 500 FPM. Of course, the depth of the pockets are predetermined or adjusted with an insert or the like such that the appropriate volume of granules for the desired pattern and thickness of the deposit is delivered with each indexed rotation of the pocket wheel, accounting for the fact that the granules are deposited in a more spread out pattern on the moving sheet. It will be appreciated by the skilled artisan that ratios other than three to one are possible according to production specific requirements.
Example
[0032] A prototype of the present invention, shown in FIG. 2 , was constructed for testing the methodology of the invention to deposit granules at high speeds. A strip of cardboard was obtained to mimic an asphalt coated strip and the strip was placed beneath the prototype system, which was filled with granules. The pocket wheel was then indexed as described above to deposit a charge of granules onto the cardboard. In this example, the linear speed of rotation at the pockets of the pocket wheel was about 50 FPM and for this test, the cardboard strip was stationary. The test was repeated three times at different locations on the cardboard strip and results are illustrated in the photograph of FIG. 4 . In this photograph, the three deposits of granules 62 , 63 , and 64 are shown with respective leading edges 66 , 67 , and 68 ; respective trailing edges 69 , 71 , and 72 ; and side edges 74 . It can be seen that the trailing edges 69 , 71 , and 72 are sharp and well defined and also that the side edges (less important in reality) also are well defined.
[0033] In this example, the forward throw of granules at the leading edges 66 , 67 , and 68 is clearly visible, but it is believed that this is due to the fact that the cardboard strip of the experiment was stationary and not moving. Thus, the forward momentum of the granules relative to the stationary strip of cardboard tended to throw them forward on the strip. When operating on a production line, the linear speed of the production line likely will be approximately the same as or faster by a selected ratio than the linear speed of rotation of the pocket wheel. Thus, the granules will fall either straight down onto the asphalt coating from the perspective of the moving strip or will tend to be scattered backward into the deposited pattern rather than forward on the asphalt coated strip. This should result in a clear well defined pattern (rectangular in this example) without tailings due to acceleration and deceleration profiles. The desired placement of the granules onto the asphalt of the moving sheet can be accomplished largely by appropriate programming of the drive mechanism. As a result, it is believed that crisply patterned deposits of granules can be placed onto a moving asphalt coated strip at production speeds heretofore not achievable.
[0034] The invention has been described herein in terms of preferred embodiments and methodologies considered by the inventor to represent the best mode of carrying out the invention. It will be understood by the skilled artisan; however, that a wide range of additions, deletions, and modifications, both subtle and gross, may be made to the illustrated and exemplary embodiments without departing from the spirit and scope of the invention set forth in the claims. For example, while the pockets of the illustrated embodiment are generally rectangular for depositing rectangular patterns of granules onto an asphalt coated strip, this is not a limitation of the invention. The pockets can, in fact, be formed with any shape that results in a corresponding desired pattern of granules on the strip. Such custom shaped patterns of deposited granules have heretofore not been feasible with prior art techniques. The pockets may be trapezoidal in shape, for instance, to deposit wedge-shaped patterns of granules.
[0035] The edges of the pockets formed by the lands need not be straight but may instead be irregularly shaped to affect the deposited patterns of granules in a desired way. The number of pockets shown in the illustrated embodiment is not a limitation and more or fewer can be provided within the scope of the invention. The pockets in the illustrated embodiment are fixed in size and equal in size. However, it is contemplated that the pockets may be adjustable in size or shape by, for example, implementation of inserts and/or they may be of different sizes and/or shapes to obtain new and previously unobtainable granule patterns on shingle products.
[0036] While the linear speed of rotation in the disclosed embodiment is fixed at some ratio of the production speed, it is within the scope of the invention that the linear speed of rotation may be varied during a granule deposit. This raises the possibility of creating unique patterns such as fading strips along the length of the asphalt coated strip.
[0037] While the apparatus has been described as being driven by a servo motor, a gear reducer or gear train, and an indexer, the system also can be driven by other drive mechanisms such as a servo motor and gear reducer alone and other appropriate drive mechanisms. When using a servo motor and gear reducer alone, the servo motor would be relied upon for very fast acceleration and deceleration profiles. The disclosed configuration, however, provides for improved adjustability and control. Also, in a production setting, several units as disclosed herein are used in unison to deposit patterns of granules at different locations across a web at different triggering times to generate the patterns desired for a particular shingle design. These and other modifications might well be made by one of skill in this art within the scope of the invention, which is delineated only by the claims. | A high speed granule delivery system and method is disclosed for dispensing granules in intermittent patterns onto a moving asphalt coated strip in the manufacture of roofing shingles. The system includes a granule hopper and a rotationally indexable pocket wheel in the bottom of the hopper. A series of pockets are formed in the circumference of the wheel and the pockets are separated by raised lands. A seal on the bottom of the hopper seals against the raised lands as the wheel is indexed. In use, the pockets of the pocket wheel drive through and are filled with granules in the bottom of the hopper. As each pocket is indexed beyond the seal, it is exposed to the moving asphalt coated strip below and its granules fall onto the strip to be embedded in the hot tacky asphalt. The speed at which the wheel is indexed is coordinated with the speed of the asphalt coated strip so that granules and strip are moving at about the same forward speed or at a preselected ratio of speeds when the granules fall onto the strip. Well defined patterns of granules are possible at high production rates. | 1 |
TECHNICAL FIELD
[0001] This invention relates to a cooling air circuit for a gas turbine bucket tip shroud.
BACKGROUND OF THE INVENTION
[0002] Gas turbine buckets have airfoil shaped body portions connected at radially inner ends to root portions and at radially outer ends to tip portions. Some buckets incorporate shrouds at the radially outermost tip, and which cooperate with like shrouds on adjacent buckets to prevent hot gas leakage past the tips and to reduce vibration. The tip shrouds are subject to creep damage, however, due to the combination of high temperature and centrifugally induced bending stresses. In U.S. Pat. No. 5,482,435, there is described a concept for cooling the shroud of a gas turbine bucket, but the cooling design relies on air dedicated to cooling the shroud. Other cooling arrangements for bucket airfoils or fixed nozzle vanes are disclosed in U.S. Pat. Nos. 5,480,281; 5,391,052 and 5,350,277.
BRIEF SUMMARY OF THE INVENTION
[0003] This invention utilizes spent cooling air exhausted from the airfoil itself for cooling the associated tip shroud of the bucket. Specifically, the invention seeks to reduce the likelihood of gas turbine tip shroud creep damage while minimizing the cooling flow required for the bucket airfoil and shroud. Thus, the invention proposes the use of air already used for cooling the bucket airfoil, but still at a lower temperature than the gas in the turbine flowpath, for cooing the tip shroud.
[0004] In one exemplary embodiment of the invention, leading and trailing groups of cooling holes extend radially outwardly within the airfoil generally along respective leading and trailing edges of the airfoil. Each group of holes communicates with a respective cavity or plenum in the radially outermost portion of the airfoil. Spent cooling air from the radial cooling passages flows into the pair of plenums and then through holes in the tip shroud and exhausted into the hot gas path. These latter holes can extend within the plane of the tip shroud and open along the peripheral edges of the shroud, or at an angle so as to open through the top surface of the shroud.
[0005] In a second exemplary embodiment, relatively small film cooling holes are drilled through the radial plenum walls on both the pressure and suction side of the airfoil. These holes open on the underside of the shroud, in the area of the shroud fillets. In a variation of this arrangement, the leading and trailing plenums as described above are connected by an internal connector cavity. Preferably, the majority of the cooling holes open along the pressure and suction side in the leading edge area of the blade, with fewer holes opening in the trailing edge area. Covers are joined to the shroud to close the plenums and one or more metering holes are drilled in the respective covers in order to control the cooling air exhaust.
[0006] In a third exemplary embodiment, the individual radial cooling holes within the airfoil are drilled slightly oversize at the tip shroud end. In other words, each cooling hole may be considered to have its own plenum or chamber. Plugs or inserts are joined to the holes to seal the ends of the latter, while shroud cooling holes are drilled directly into the individual plenums and exit either at the top of the shroud or along the underside of the shroud. A metering hole may be required in the various radial cooling hole plugs to insure proper flow distribution.
[0007] In its broader aspects, the invention relates to an open cooling circuit for a gas turbine bucket wherein the bucket has an airfoil portion, and a tip shroud, the cooling circuit comprising a plurality of radial cooling holes extending through the airfoil portion and communicating with an enlarged internal area within the tip shroud before exiting the tip shroud such that a cooling medium used to cool the airfoil portion is subsequently used to cool the tip shroud.
[0008] In another aspect, the invention relates to an open cooling circuit for a gas turbine airfoil and associated tip shroud comprising a plurality of cooling holes internal to the airfoil and extending in a radially outward direction; a first plenum chamber in an outer radial portion of the airfoil, each of the plurality of holes communicating with the plenum; additional cooling holes in the tip shroud, communicating with the plenum, and exiting through the tip shroud.
[0009] In still another aspect, the invention relates to a method of cooling a gas turbine airfoil and associated tip shroud comprising a) providing radial holes in the airfoil and supplying cooling air to the radial holes; b) channeling the cooling air to a plenum in the airfoil; and c) passing the cooling air from the plenum and through the tip shroud.
[0010] Additional objects and advantages of the invention will become apparent from the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 is a partial side section illustrating the turbine section of a land based gas turbine;
[0012] [0012]FIG. 2 is a partial side elevation, in generally schematic form, illustrating groups of radial cooling passages in a turbine blade and tip shroud in accordance with a first exemplary embodiment of the invention;
[0013] [0013]FIG. 3 is a top plan view of a tip shroud in accordance with the first embodiment of the invention;
[0014] [0014]FIG. 4 is a top plan view showing an alternative to the arrangement shown in FIG. 3;
[0015] [0015]FIG. 5 is a top plan view of a turbine airfoil and tip shroud in accordance with a second exemplary embodiment of the invention;
[0016] [0016]FIG. 6 is a section taken along the line A-A of FIG. 5;
[0017] [0017]FIG. 7 is a top plan of an airfoil and tip shroud similar to FIG. 5, but illustrating a connector cavity between the interior plenums;
[0018] [0018]FIG. 8 is a top plan view of a tip shroud in accordance with a third exemplary embodiment of the invention, illustrating shroud cooling holes opening on the top surface of the tip shroud;
[0019] [0019]FIG. 9 is a top plan view of the tip shroud shown in FIG. 8, but illustrating the shroud cooling holes which open along the bottom surface of the tip shroud;
[0020] [0020]FIG. 10 is a section taken along the line 10 - 10 of FIG. 8; and
[0021] [0021]FIG. 11 is a section taken along the line 11 - 11 of FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
[0022] With reference to FIG. 1, the turbine section 10 of a gas turbine is partially illustrated. The turbine section 10 of the gas turbine is downstream of the turbine combustor 11 and includes a rotor, generally designated R, with four successive stages comprising turbine wheels 12 , 14 , 16 and 18 mounted to and forming part of the rotor shaft assembly for rotation therewith. Each wheel carries a row of buckets B 1 , B 2 , B 3 and B 4 , the blades of which project radially outwardly into the hot combustion gas path of the turbine. The buckets are arranged alternately between fixed nozzles N 1 , N 2 , N 3 and N 4 . Alternatively, between the turbine wheels from forward to aft are spacers 20 , 22 and 24 , each located radially inwardly of a respective nozzle. It will be appreciated that the wheels and spacers are secured to one another by a plurality of circumferentially spaced axially extending bolts 26 (one shown), as in conventional gas turbine construction.
[0023] Turning now to FIGS. 2 and 3, a turbine bucket includes a blade or airfoil portion 30 and an associated radially outer tip shroud 32 . The airfoil 30 has a first set of internal radially extending cooling holes generally designated 34 , and a second set of five radially extending cooling holes 36 . The first set of cooling holes 34 is located in the forward half of the airfoil, closer to the leading edge 38 , whereas the second set of holes 36 is located toward the rearward or trailing edge 40 of the airfoil. The first set of leading edge cooling holes 34 open to a first cavity or plenum 42 at the radially outermost portion of the airfoil, while trailing edge cooling holes 36 open into a second plenum 44 closer to the trailing edge 40 of the airfoil. The plenums 42 and 44 are shaped to conform generally with the shape of the airfoil, and extend radially into the tip shroud 32 . The plenums are sealed by recessed covers such as those shown at 46 , 48 , respectively, in FIG. 4. The covers may have metering holes 50 , 52 for controlling the exhaust rate of the cooling air into the hot gas path.
[0024] In addition, the plenums 42 and 44 can exhaust directly through cooling passages internal to the tip shroud. For example, as shown in FIG. 3, spent cooling air from chamber 42 can exhaust through the edges of the tip shroud via passages 54 , 56 and 58 which lie in the plane of the shroud 32 and which distribute cooling air within the shroud itself, thus film cooling and convection cooling the shroud. Similarly, plenum 44 communicates with a similar passage 60 in the trailing edge portion of the shroud 32 .
[0025] It will be appreciated that the number and diameter of radial holes in the airfoil will depend on the design requirements and manufacturing process capability. Thus, FIG. 2 shows groups 34 , 36 of four and three radial holes respectively, whereas FIG. 3 shows both groups to have five radial holes each.
[0026] In FIG. 4, a variation of this embodiment has cooling holes 62 , 64 , 66 , 68 , 70 and 72 in the tip shroud, in communication with the leading plenum 42 , but angled relative to the plane of the tip shroud so that they exhaust through the top surface 74 of the tip shroud, rather than at the shroud edge. Similarly, cooling holes 76 , 78 and 80 in communication with the trailing plenum 44 also exhaust through the top surface 74 of the shroud.
[0027] [0027]FIGS. 5 and 6 illustrate a second embodiment of the invention, and, for convenience, reference numerals similar to those used in FIGS. 2 and 3 are used in FIG. 4 where applicable to designate corresponding components, but with the prefix “1” added. Thus, a first set of radially extending internal cooling holes 134 extends radially outwardly through the airfoil, closer to the leading edge 138 of the airfoil, opening at plenum 142 . A similar second set of cooling holes 136 extends radially outwardly within the airfoil, closer to the trailing edge 140 of the airfoil, opening into plenum 144 . A first group of shroud cooling holes 162 , 164 , 166 and 168 , 170 , 172 and 174 extend from both the pressure and suction sides, respectively, of the plenum 142 to provide film and convection cooling of the underside of the tip shroud 132 , with the cooling holes exiting the airfoil in the area of the tip shroud fillet 82 . A second group of shroud cooling holes 176 , 178 extend from plenum 144 and open on pressure and suction sides, respectively of the airfoil, again on the underside of the tip shroud. As in the previous embodiment, flow may also be metered out of the plenum covers 146 , 148 by means of one or more metering holes 150 (FIG. 7). The number of shroud cooling holes exiting on the pressure and suction sides of the shroud may vary as required.
[0028] [0028]FIG. 7 is similar to FIG. 5 but includes a connector cavity 84 extending internally between the leading and trailing plenums 142 , 144 , respectively. Cooling holes from the plenums exhaust about the tip shroud undersurface as described above. The connector cavity 84 results in most cooling air flowing to the leading edge plenum 142 to exit via cooling holes 162 , 164 , 166 and 168 , 170 , 172 and 174 arranged primarily along the pressure and suction sides, respectively, of the airfoil in the leading edge region thereof. As in FIG. 6, only two of the cooling holes 176 , 178 exit in the trailing edge area of the airfoil. This arrangement desirably channels most of the cooling air to the leading edge region of the airfoil, to be washed back across the trailing edge region by the hot combustion gas, thereby providing desirable cooling of the shroud. The metering hole 150 in the cover 146 exhausts all of the spent cooling air which is not otherwise used for direct tip shroud cooling along the undersurface thereof, and dilutes the hot gas flowing over the top of the shroud.
[0029] FIGS. 8 - 11 illustrate a third embodiment of the invention, and, for convenience, reference numerals similar to those used to describe the earlier embodiments are used in FIGS. 8 - 11 where applicable to designate corresponding components, but with the prefix “2” added. A first set of radially extending internal cooling holes 234 extends radially outwardly through the airfoil, closer to the leading edge 238 of the airfoil. A second set of internal cooling holes extends radially outwardly within the airfoil, closer to the trailing edge 240 of the airfoil. Each individual radial cooling hole 234 is drilled or counterbored at its radially outer end to define an individual plenum 242 , while each radial cooling hole 236 is similarly drilled or counterbored to form a similar but smaller plenum 244 . Each enlarged chamber or plenum 242 , 244 is sealed by a plug or cover 246 (in FIGS. 8 and 9, the plugs or covers 246 are omitted for purposes of clarity). Each plug or cover may be provided with a metering hole 250 to insure proper flow distribution.
[0030] A first group of shroud film cooling holes 262 , 264 , 266 , 268 , 270 , and 272 extend from the various plenums 242 through the tip shroud and open along the top surface of the tip shroud. Similarly, a second group of film cooling holes 274 , 276 , and 278 extend from the plenums 244 and also open along the top surface of the tip shroud. Note that film cooling holes 264 and 262 extend from the same plenum, while film cooling holes 270 and 272 extend from the next adjacent plenum. The arrangement may vary, however, depending on particular applications.
[0031] [0031]FIG. 9 illustrates film cooling holes extending from the plenums 242 and 244 , but which open along the underside of the tip shroud, generally along the tip shroud fillet 282 . Thus, film cooling holes 284 , 286 , 288 , and 290 extend from two of the plenums 242 and open on the underside of the tip shroud, on both pressure and suction sides of the airfoil. Note that film cooling holes 284 and 290 extend from the same plenum, while a similar arrangement exists with respect to shroud film cooling holes 286 and 288 which extend from the adjacent plenum.
[0032] Shroud film cooling holes 294 and 296 extend from a pair of adjacent plenums 244 associated with radial cooling holes 236 on the opposite side of the tip shroud seal, also along the underside of the tip shroud.
[0033] These arrangements are intended to reduce the likelihood of gas turbine shroud creep damage while minimizing the cooling flow required for the bucket, while more efficiently utilizing spent airfoil cooling air to also cool the tip shroud.
[0034] While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | An open cooling circuit for a gas turbine bucket wherein the bucket has an airfoil portion, and a tip shroud, the cooling circuit including a plurality of radial cooling holes extending through the airfoil portion and communicating with an enlarged internal area within the tip shroud before exiting the tip shroud such that a cooling medium used to cool the airfoil portion is subsequently used to cool the tip shroud. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to fluid delivery systems. In one particular aspect, it relates to enteral fluid delivery systems utilizing closure devices for connection between an enteral fluid container and a patient feed line.
SUMMARY OF THE INVENTION
Broadly, the present invention provides a closure device for connection to a fluid container which has an opening for receiving the device. The closure device has a base section which may sealably cover the container opening. The base section has a spike receiving opening passing there through with at least one aperture, e.g., an air vent on the base section which is spaced from the spike receiving opening. An air filter e.g., hydrophobic air filter, is associated with the air vent. Adjoining the base section is an internal cover, which lies over the aperture, covering it and the base section. The internal cover has a pierceable portion e.g., a weakened section, which is in alignment with the spike receiving opening of the base section.
In a preferred embodiment of the invention, the closure device has a threaded wall portion projecting from the base section which wall portion is adapted to threadly receive a threaded connection of the fluid container. The fluid container may also have a pierceable seal covering the opening.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of a closure device of this invention.
FIG. 2 is a perspective view of the closure device of FIG. 1, showing the device in connection with a fluid container.
FIG. 3a, b, c and d are perspective views showing additional positions of the hydropholic air filter.
FIG. 4 is a perspective view showing a gasket assembly of the closure device of this invention.
FIG. 5 is a perspective view showing the internal operation of a spike.
FIG. 6 is a perspective view showing the spike of FIG. 4 fully inserted in the device.
FIG. 7 is a Top View along the line 7--7 of FIG. 6 showing the rupture of seal 27.
FIG. 8 is a perspective view showing a snap-fit assembly of the closure device on a container.
FIG. 9 is a perspective view showing the closure device sealed across a container opening.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, the closure device 10 generally comprises a base section 11 and a threaded wall portion 12. The base section 11 has a spike receiving opening 13, and an air inlet aperture 14. There may be one or more air inlet apertures 14.
A hydrophobic air filter is associated with the air inlet apertures 14. The position and configuration of the filter may be varied depending upon the number of apertures 14. When multiple apertures are used, the filter may consist of a disk-like filter 16 as shown in FIG. 1. This filter 16 is preferably positioned on the inside of the closure device 10 (as shown in FIG. 1). It may also be positioned over the apertures on the outside of the closure device 10 (not shown).
One or more apertures 14 may also be covered by individual filters which may cover the apertures on the outside of the closure device 10, the inside of the closure device, or may lie within the apertures. These filter positions 16a, 16b, 16c and 16d are shown in FIG. 3a, b, c and d. Filter position 16d differs from position 16b, in that it is raised from the base section 11. The preferred filter position is on the inside of the closure device (16b). The individual filter may be secured to the closure device by any suitable means e.g., sonic welding, so that it will remain in position in relation to the aperture. Suitable hydrophobic air filters may be obtained from Pallflex Products Corp. (Pallflex EMFAB E01008E).
A spike receiving cylindrical member 17, aligned with the spike receiving opening 13, extends outwardly from the base section 11. The opening 13 and the cylindrical member 17 are adapted to receive a piercing spike 18.
An internal cover 19 lies over the filter 16 and the base section 11. The cover 19 may have a plurality of rib members 20, to support and maintain the integrity of the cover. The cover may have a raised edge section 21 which may be adhered to the base section 11; and may have a center portion 22 which is in alignment with the spike receiving opening 13, and the cylindrical member 17, of the base section 11. Preferably, the internal cover 19 is concave in hape on its external surface, e.g., the surface facing away from the base section (see FIG. 2).
As shown in FIG. 2, the wall portion 12 of the closure device is threaded 23, to threadably receive the threaded neck 24 of a fluid container 26, e.g., an enteral fluid container. The container 26 has a seal 27, e.g., a foil seal, across the container opening. When the closure device 10 is attached to the container 26 (as shown in FIG. 2), the foil seal 27 contacts the cover 19.
In a preferred embodiment, the foil seal 27 may be adhesively sealed 25 to the cover 19. Preferably, the foil 27 is adhesively hot sealed (aseptically sealed) to the cover 19, by flowing a heated foodgrade hot melt adhesive between the foil seal 27 and the cover 19. The concave shape of the internal cover 19 insures that a thin layer of adhesive is placed between the cover and the foil seal. The cover 19 protects the apertures 14, and filters 16 from the adhesive, and also insures an open passage through the spike receiving opening 13. Suitable food contact adhesives which may be used are ethylene vinyl acetate based adhesive, (H. B. Fuller HL 7434); and polyethylene based adhesive, (H. B. Fuller HM 1002)
In an additional embodiment of the invention, a gasket 36 may be used in place of the hot melt adhesive (see FIG. 4). The gasket 36 may be formed in situ, or may be preformed, and is aseptically installed in the closure device 10.
The center portion 22 of the cover 19 is surrounded by a weakened area 28. It is preferred that the diameter of the weakened area 28 be larger than the piercing spike 18. The weakened area 28 breaks when the spike 18 is urged against it. As the spike 18 moves against the weakened area 28, the part closest to the tip 29 of the spike 18 breaks first (see FIG. 5). The weakened area 28 continues to break as the spike moves in the spike receiving opening 13.
As shown in FIG. 6, the weakened area 28 does not sever completely from the cover 19, but forms a hinge 31 on the side opposite the tip 29 of the spike 18. The hinge 31 and the center 22, thus form a flap 32 in the cover 19. As the flap 32 is raised by the spike 18, the seal 27 is ruptured, and the spike 18 enters the container 26. The flap 32 keeps the ruptured seal 27 away from the spike 18, insuring that air from the filter has access to the container 26. The spike 18 should penetrate sufficiently far into the container 26 so as not to draw air into the conventional central enteral fluid pathway of the spike. In a preferred embodiment of the flap 32, the innersurface of the center portion 22 e.g., the side facing the base section 11, is convex in shape 33. Thus, only the convex portion of the flap 32 rests on the spike 18, insuring that a sufficient air opening is maintained into the container, see FIG. 7. Though the cover 19 has been preferably described as having a center portion 22, with a circular weakened area 28, other spike penetrating weakened areas may be employed. For example, a weakened area in the form of a cross, triangle and the like, may be used. These alternate weakened areas sections are also pierceable by a spike, and provide air access to the container.
A cap 34 may be placed over the external end of the cylindrical member 17, to prevent contamination of the closure device 10 prior to use. The cap may be teathered to the cylindrical member (not shown).
It is also within the scope of this invention, to use a snap-fit assembly of the closure device 10 and the container 26, thus, eliminating the threaded assembly. As shown in FIG. 8, a circumferential tab section 37 projecting from the base section 11, engages a rim 38 on the container 26, securing the closure device 10 to the container 26. After engagement, the closure device 10 may be further adhered to the container 26 by e.g., sonic welding.
The closure device 10 may also be sealed across a container opening without a threaded assembly, or snap-fit assembly by sealing e.g., sonic welding the base section 11 across the container opening, as shown in FIG. 9.
The closure device 10 of this invention when connected to an enteral fluid container, may be sterilized as a unit with the container. Alternately, the structure of the closure device 10 allows for it to be sterilized separate from an enteral fluid container. The internal cover 19 and cap 34, protects the internal portions of the device from contamination after sterilization.
To administer enteral fluid to a patient using the closure device of this invention, the cap 35 is removed, and a spike 18 (attached to an enteral delivery set) is plunged into the cylindrical member 17 and spike receiving opening 13 breaking the weakened area 28, and the container foil seal 27 as described above, thus releasing the enteral fluid to the patient, and allowing the fluid container to properly vent to the atmosphere. | A closure device for connection to a fluid container which has an opening for receiving the device. The closure device has a base section which may sealably cover the container opening. The base section has a spike receiving opening passing there through with at least one air vent on the base section which is spaced from the spike receiving opening. A hydrophobic air filter, is associated with the air vent. Adjoining the base section is an internal cover, which lies over the aperture, covering it and the base section. The internal cover has a pierceable portion which is in alignment with the spike receiving opening of the base section. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates to the field of ocean wave energy converters (WECs). More particularly the present invention is an apparatus that can be fitted to a new WEC or retrofitted to an existing WEC which provides improved variable buoyancy and enhanced capture width to the flexible pipe or plurality thereof for use with wave energy converters for extracting wave energy, thereby improving efficiency and energy conversion capacity of such WECs.
BACKGROUND OF THE INVENTION
[0002] Certain freely floating wave energy types of wave energy converters have been disclosed by the present applicant's previous patent applications and granted patents, namely the “Free Floating A Wave Energy Converter” under Indian Patent Number 239882, “Free Floating Wave Energy Converter” (FFWEC)/(US Patent # US20080229745), etc., “An Improved Free Floating Wave Energy Converter” (IFFWEC)/[Indian Application 2511/CHE/3458], WO 2013014682 A2), PCT/1N2012/000510, EP20120753590, CA2844023A1, CN103814211A, US20140157767], and as well the US application titled, “Free Floating Wave Energy Converter With Control Devices”.
[0003] The above quoted inventions essentially consist of Inlet and flexible pipe, floating on a body of water, i.e. ocean surface and adapting to wave form. The mouth of the flexible pipe is in fluid communication with an inlet and its outlet in further fluid communication with power takeoff and other devices. The inlet doses air-water slugs into the flexible pipe, which get pushed forward by transverse waves, progressively building up pressure in it—which could be used to drive conventional Hydro-generators or pump water for any other purpose.
[0004] The present invention discloses certain improvements for enhancing and controlling buoyancy of WECs employing flexible pipes to extract wave energy.
[0005] In the prior art, an Indian Application No. 2511/CHE/2011, describes the use of inflatable tubes 1300 , 1302 , wherein FIG. 13B shows an embodiment having certain means and methods for preventing the flexible pipe from sagging or sinking in a body of water.
[0006] The arrangement was also meant to let a segment of the flexible pipe 204 to go below a wave trough, up to a controlled depth, thereby increasing the amplitude or the effective wave height of the flexible pipe 204 , as compared with the wave height of the body of water. Consequently, the wave energy absorption capacity of the flexible pipe 204 would increase, proportional with the effective wave height. To expose the flexible pipe to a larger wave front, the flexible pipe could be oriented at an angle to the oncoming waves.
[0007] Reference is also made to FIG. 1 of the India Patent Application 2511/CHE/2011 and the corresponding explanation therein, in which the pressure head created by the flexible pipe 204 is shown as the sum total of the effective wave heights, less frictional and other losses.
[0008] However, it would be apparent to one skilled in the art that, to create a pressure head in actual conditions, several other factors would also be involved, such as the force required for pushing the water slugs forward, at certain velocity, friction and rate of discharge against a pressure head. In addition to these forces there will also be certain frictional losses, when the flexible pipe goes below water surface, due to water friction on the exterior surface of the flexible pipe.
[0009] As such, the effective width or capture width of the air segment of flexible pipe 204 and inflatable tube 1300 1302 might not be sufficient to prevent the arrangement from sagging or sinking below wave crests, particularly when the pressure differential (effective wave height) is increased.
[0010] Furthermore, details of attaching the inflatable tubes 1300 1302 to the flexible pipe 204 and the added advantages that would accrue from the arrangement were not discussed in the previous invention application.
[0011] The present invention discloses details of an embodiment having certain improvements, additional features and advantages.
SUMMARY OF THE INVENTION
[0012] The objectives of the invention are, to enhance energy extraction capacity of freely floating wave energy converters employing flexible pipe for extracting wave energy, by increasing the capture width, effective wave height or pressure differential of water segments and restrain sagging of the flexible pipe.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The above and other advantages of the present invention would become readily apparent from the following detailed description of preferred embodiments when considered in the light of the accompanying drawings in which:
[0014] FIG. 1 ( a ) depicts flexible pipe with air and water slugs, with no pressure head and 1 ( b ) depicts a pressure head, causing “Phase Shift” and loss in wave height.
[0015] FIGS. 2 ( a ) , 2 ( b ) and 2 ( c ) depict side, front and plan views of the preferred embodiment, respectively.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The description and appended drawing describe and illustrate various exemplary embodiments of the invention to make and use the invention, and are not intended to limit the scope of the invention in any manner. In respect of the methods disclosed, the steps presented are exemplary in nature, and thus, the order of the steps is not necessary or critical. Certain design principles to achieve the desired results are discussed in the succeeding paragraphs.
[0017] FIG. 1( a ) depicts waves “Wd” moving from the left to the right hand side of the page. A flexible pipe 204 floating in phase with waves 1100 . An inlet doses slugs of air 1012 and water 1011 are into the mouth of the flexible pipe 204 or plurality thereof, (not shown in the figure), wherein no energy is being extracted, shown as an empty overhead tank 1120 , with no water in it or “zero” pressure head (PH 0 ) and frictional loss has not been considered.
[0018] In this case, the flexible pipe 204 follows the waves 1100 , while the Center of Buoyancy “B” and Center of Gravity “G” and the air and water slug 1102 / 1101 remain at the center of the respective crests and troughs. The buoyant force (F b ) and the weight (W), act through Center of Buoyancy (B) and C of G (G) of each wave. However, the trough portions of the flexible pipe go slightly below the wave troughs, due to the weight of water in them. The amplitude a p of the flexible pipe 204 and the wave height “H” are nearly the same.
[0019] FIG. 1 ( b ) , on the other hand, shows a flexible pipe floating on water surface and an inlet doses slugs of air 1011 and water 1012 are fed into the mouth of the flexible pipe 204 (not shown in the figure) The flexible pipe is extracting wave energy and thereby creating a pressure head “PH x ”, represented by an overhead tank 1120 having some water in it.
[0020] Slugs of air and water from the flexible pipe 204 are pumped, under pressure through outlet of the flexible pipe, into the tank 1120 , creating pressure head PH x . Pumping water, against a pressure head PH x , at a certain rate and mass flow, together with fluid friction, creates a backpressure H p(x) which acts through G of each trough pushing the flexible pipe 204 back against wave motion. The forces could be resolved into horizontal H p(x) and vertically downwards H p(y) components. In addition to this, the weight of a water slug “W” also acts downwards in the vertical plane.
[0021] Furthermore, the portion of the flexible pipe 204 , which goes under water, creates drag/friction “f w ” from the body of water outside, as the waves move forward, following along the flexible pipe 204 .
[0022] The total horizontal and vertical components at G can be resolved as a resultant “R”.
[0023] Besides these, a buoyant force “F b ” acts vertically upwards, through the Center of Buoyancy “B”. A horizontal component F y opposes forward motion of the flexible pipe 204 , while the vertical component provides lifting force F x .
[0024] To balance the aforementioned forces, water slugs 1011 get pushed backwards and tend to ride up the crests of the advancing waves, while the air segments 1012 shift behind and goes below the wave crests. The Center of Gravity “G” and buoyancy “B” too lag.
[0025] This causes the flexible pipe to 204 to exert horizontal H p(x) +F w and vertical H p(y) pressures on the surface of advancing waves 1100 in the direction a resultant vector “R”, causing a phase shift “φ s ” and reduction in the amplitude a px , of the flexible pipe 204 , as compared with the wave height H, by certain wave height loss H L . Consequently, the Pressure Differential “P d ” of the water slugs also reduces and the water slugs start sinking/sagging. Advancing waves could overrun the crests of flexible pipe, causing it to sag or sink.
[0026] Therefore, the more the pressure head, the more the phase shift, the lesser the Pressure Differential and the lesser the extractable wave energy.
[0027] This would also let water slugs flow down from one trough segment to another, causing the flexible pipe to sag, despite the additional buoyancy provided by the inflatable tube 1300 embodiments disclosed in the previous invention.
[0028] An embodiment 1330 of the present invention offers solutions for overcoming the aforementioned shortcomings.
[0029] FIGS. 2( a ), 2( b ) and 2( c ) show flexible pipe 204 , or plurality thereof, suitably moored, oriented facing at an angle to the waves, floating on a body of water, i.e. ocean surface, and adapting to the wave form.
[0030] Wherein, the mouth of the flexible pipe 204 is in fluid communication with an inlet and its outlet being in further fluid communication with power takeoff and other devices, which are not shown in the present figures.
[0031] Wherein, the inlet doses air-water slugs 1012 - 1011 into the flexible pipe, which get pushed forward by transverse waves, progressively building up pressure in it, which could be used to drive conventional Hydro-generators or pump water for any other purpose.
[0032] Wherein, on an exterior of the flexible pipe 204 or plurality thereof, a plurality of horizontal supports 1315 are attached all along the length of the flexible pipe 204 .
[0033] Wherein, the horizontal supports 1315 extend equally outwards on either side and are spaced evenly all along the length of a flexible pipe 204 .
[0034] Wherein, the horizontal supports 1315 are of suitable span.
[0035] Wherein, the horizontal supports 1315 are evenly and suitably spaced.
[0036] The horizontal supports 1315 could be beams, ribs, and the like, preferably made of non-corrosive and light weight materials, such as composites, having enough tensile strength to withstand continuous load fluctuations, such as latticed constructions, of the desired lengths and profile.
[0037] Wherein, onto the horizontal supports 1315 at least two inflatable tubes 1300 attached along the length of flexible pipe 204 or plurality thereof.
[0038] Wherein, the inflatable tubes 1300 are generally arranged substantially parallel to the flexible pipe 204 .
[0039] Wherein, inflatable tubes 1300 could be attached on an upper, lower or both sides of the horizontal supports 1315 .
[0040] Wherein, inflatable tubes 1300 are preferably made of polymeric material or elastic rubber and the like is selectively inflated and deflated for varying its buoyancy.
[0041] Wherein, inflatable tubes 1300 are selectively inflated and deflated for varying their buoyancy.
[0042] Wherein, inflatable tubes 1300 can be of smaller lengths and suitably interconnected in fluid communication with each other in series.
[0043] Wherein, the openings at the fore and aft ends of the inflatable tubes 1300 are in fluid communication with the pressure source, through pneumatic hoses 1317 , such a blower pump or the pressure chamber 208 , compressor, with pressure regulators, controls, micro-processor, etc., which are not shown in the present figures.
[0044] By increasing the number and/or diameter of the inflatable tubes 1300 and span of the horizontal supports 1315 , the buoyancy and the capture width of the flexible pipe could be proportionately increased.
[0045] When the inflatable tubes 1300 are fully pressurized, the buoyancy along its entire length would be high enough to keep flexible pipe 204 always floating above water, even if it is filled completely with water.
[0046] When the inflatable tubes 1300 are depleted, and the flexible pipe or plurality thereof are mostly filled with water, there would be no buoyancy enhancement. Consequently, the flexible pipe and the attached device 1330 could be made to submerge, particularly during storms. By pumping air back into the inflatable tubes 1300 , the device could be resurfaced and resume normal operations.
[0047] As the pressure in the inflatable tube 1300 is reduced to an extent, the trough segments 1300 B would start sinking due to the combined weight of water slugs, flexible pipe and the attached device 1330 . Consequently air from the trough segments 1300 B would be squeezed out and get pushed into the crest segments of the inflatable tubes 1300 A, further increasing the buoyancy thereat.
[0048] It can be seen that, the crest of the inflatable tube can be made to remain always above wave crests, while its trough segment below troughs.
[0049] By regulating the volume of air in the inflatable tube 1300 , the amplitude a p of the inflatable tubes and flexible pipe 204 or plurality thereof arrangement 1330 , as well as the pressure differential p d can be varied to a substantial extent, as compared with the corresponding wave height H of a wave.
[0050] Further, as a trough segment 1300 B of an inflatable tube sinks, the water pressure acting on its exterior surface rises with depth, thereby progressively constricting/sealing the passage within 1300 B, which would impede/prevent air from flowing freely between its crests segments.
[0051] Consequently, the crest segments of the inflatable tubes 1300 A would always remain above the crests of the waves, i.e. a phase lock would be formed, thereby preventing the flexible pipe from going below the wave crests; which would otherwise lead to sagging.
[0052] The air inside the inflatable/deflatable tubes 1300 A/ 1300 B gets pushed forward along with the waves, as they progress from front to rear end of the tubes and is looped through the pneumatic hoses 1317 , as discussed above.
[0053] Since there will be variation in wave parameters, wave heights and lengths will vary, warranting exchange of air and water slugs between segments. When this happens, difference of air pressure between the effected segments of inflatable pipe 1300 would exceed the sealing limits of the squeezed portions of the inflatable tube 1300 B, thereby permitting air to get transferred between segments.
[0054] Thus, the objectives of the present invention could be achieved by adopting the means and methods disclosed in the preceding paragraphs.
[0055] Various other permutations and combinations of the same principle of operation and arrangements are also possible, but not mentioned herein.
[0056] Numerous characteristics and advantages of the invention covered by this document will be set forth in the foregoing description. It will be understood, however, that this disclosure is, in many respects, only illustrative.
[0057] Changes may be made in details, particularly in matters of shape, size, and arrangement of parts without exceeding the scope of the invention.
[0058] In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope. | A free floating wave energy converter includes at least one flexible pipe, adapted to float at a surface of a body of water, having an inlet end for receiving alternating slugs of water and air when the pipe is moored facing at an angle to a wave direction in the body of water and having an outlet end in fluid communication with a power takeoff and other devices, a plurality of supports attached to the pipe at spaced apart locations, each of the supports extending traverse to a longitudinal axis of the pipe and outwardly in opposite directions and at least two inflatable tubes attached to the supports on opposite sides of the pipe extending longitudinally substantially parallel to the longitudinal axis of the pipe, wherein the pipe is raised and lowered relative to the surface of the water by respectively inflating and deflating the tubes with a gas. | 5 |
REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional Application Ser. No. 61/489748, filed May 25, 2011, entitled “Systems and Methods for Constructing Temporary, Re-locatable Structures,” which is hereby specifically and entirely incorporated by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The invention is directed to systems and methods of constructing temporary or re-locatable structures and, in particular, systems and methods of constructing temporary structures to be energy efficient using insulated panels.
[0004] 2. Background of the Invention
[0005] Global warming, high energy costs, lack of reusable sources of energy, and diminishing resources of fossil fuels are all reasons, among others, to improve the energy efficiency of structures. Traditional temporary structures, such as tents, collapsible fabric or metal structures, or plastic structures, are usually energy inefficient, losing hot and/or cool air though the various surfaces, walls, roofs, windows, doors, gaps, and other components.
[0006] In order to improve the energy efficiency of these temporary buildings it is often necessary to retrofit the building with energy efficient materials, for example with spray-on insulation. Such upgrading is costly, time consuming, and can ruin the structure or re-locatable. Furthermore, existing temporary structures often are difficult to assemble, having multiple parts that must be sorted, organized and installed.
[0007] Therefore, it is desirable to have systems and methods of constructing a temporary structure that is cost effective, easy to install, and provides energy efficiency.
SUMMARY OF THE INVENTION
[0008] The present invention overcomes the problems and disadvantages associated with current strategies and designs and provides new systems and methods of constructing temporary or re-locatable structures.
[0009] A system and method for constructing a temporary or re-locatable structure is disclosed. The system comprises a plurality of side panels and a plurality of roof and floor panels and a plurality of a first track and a plurality of a second track, the first track having an indentation and the second track having a hemmed tab that is adapted to mate with the indentation of the first track. Each side panel has a first edge coupled to a first track and a second, parallel edge coupled to a second track, while each roof and floor panel has two edges coupled to two first tracks and two edges coupled to two second tracks.
[0010] Other embodiments and advantages of the invention are set forth in part in the description, which follows, and in part, may be obvious from this description, or may be learned from the practice of the invention.
DESCRIPTION OF THE DRAWINGS
[0011] The invention is described in greater detail by way of example only and with reference to the attached drawings, in which:
[0012] FIG. 1 depicts an embodiment of a wall of side panels.
[0013] FIG. 2 depicts an embodiment of interlocking tracks.
[0014] FIG. 3 depicts an embodiment of top and bottom tracks.
[0015] FIG. 4 depicts another embodiment of a wall of side panels.
[0016] FIG. 5 depicts a plan for an embodiment of a temporary structure.
[0017] FIG. 6 depicts an embodiment of coupling perpendicular side panels.
[0018] FIG. 7 depicts an embodiment of roof and floor panels.
[0019] FIG. 8 depicts an embodiment of an exterior wall.
[0020] FIGS. 9 a - b depict an embodiment of coupling a wall panel to a floor panel.
[0021] FIGS. 10 a - b depict an embodiment of coupling a wall panel to a roof panel.
[0022] FIGS. 11 a - b depict an embodiment of coupling a wall panel to a roof panel.
[0023] FIGS. 12 a - b depict an embodiment of coupling two roof panels and a roof beam.
[0024] FIGS. 13 a - b depict an embodiment of coupling a wall panel to a floor panel.
[0025] FIGS. 14 a - b depict an embodiment of coupling a wall panel to a floor panel.
[0026] FIGS. 15 a -b depict an embodiment of the elements of an exemplary structure contained within a standard shipping container.
DESCRIPTION OF THE INVENTION
[0027] As embodied and broadly described herein, the disclosures herein provide detailed embodiments of the invention. However, the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. Therefore, there is no intent that specific structural and functional details should be limiting, but rather the intention is that they provide a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention.
[0028] A problem in the art capable of being solved by the embodiments of the present invention is constructing a temporary, re-locatable structure that is energy efficiency. It has been surprisingly discovered that by using interlocking brackets and insulating panels an energy efficient temporary structure can be constructed more easily and quickly than a traditional temporary structure.
[0029] FIG. 1 depicts an exemplary exterior wall 100 . In the preferred embodiment, wall 100 is comprised of a plurality of panels 105 . As shown in FIG. 1 , panels 105 are 8 feet wide by 8.5 feet tall; however other size panels can be used. Preferably each panel 105 is comprised of a polystyrene core; however, other insulating materials such as, but not limited to, fiberglass, urea-formaldehyde, cellulous, and polyethylene can be used. Additionally, panels 105 may be coated with FRP (fiberglass reinforced plastic) boards, film coverings (e.g. graphical image film coverings or heat dissipating film coverings), spray coatings (e.g. insulating spray coatings or fire retardant spray coatings), Strongwell's Safe Plates, or other materials. Panels 105 are preferably also made of a fire retardant material. Preferably, panels 105 have a thickness of either 3.5 inches, 5.5 inches, or 7.5 inches; however other thicknesses are possible. In the preferred embodiment, panels 105 weigh no more than 1.625 pounds per square foot; however other weights are possible.
[0030] FIG. 2 depicts exemplary interlocking tracks 210 a (labeled A in the figures) and 210 b (labeled B in the figures). In the preferred embodiment, each panel 105 has one track 210 a coupled to a first edge and one track 210 b coupled to a second, parallel edge. In the preferred embodiment, tracks 210 a and 210 b are coupled to the long sides of panels 105 , however, depending on the structure, the short sides of panels 105 can be coupled to tracks 210 a and 210 b. Furthermore, in certain embodiments each panel can have two tracks 210 a and two tracks 210 b. Preferably in embodiments with tracks on each edge of the panel 105 , the two tracks 210 a are adjacent to each other and the two tracks 210 b are adjacent to each other such that opposing edges have different tracks. Track 210 a has indented or recessed portion 215 along its outer edge, into which angled hemmed tab 220 of track 210 b mates. On the opposite edge of track 210 b from angled hemmed tab 220 is straight hemmed tab 225 . As can be seen from FIG. 2 , both angled and straight hemmed tabs 220 and 225 extend from the outer edge of track 210 b . In a preferred embodiment a foam seal or other insulation is placed between track 210 a and track 210 b as they coupled. Furthermore, in a preferred embodiment, a fastener 230 (for example, a turn polycarbonate fastener, a rivet, a bolt, a screw, a brad, glue, adhesive, double-stick tape, or another fastener) is used to secure track 210 a to track 210 b once the two tracks are coupled together. Both tracks 210 a and 210 b are preferably made of 20 or 24 gage steel, however other materials can be used. FIG. 3 depicts an embodiment of bottom tracks 335 and top tracks 340 . In a preferred embodiment, bottom track 340 is coupled to the bottom edge of each panel 105 and top track 340 is coupled to the top edge of each panel 105 . Preferably, both bottom track 335 and top track 340 are “C” shaped double tracks. Bottom track 335 and top track 340 preferably couple to panel 105 with fasteners 345 (for example, a turn polycarbonate fastener, a rivet, a bolt, a screw, a brad, glue, adhesive, double-stick tape, or another fastener). Bottom track 335 and top track 340 preferably also couple to the floor and roof with fasteners.
[0031] FIG. 4 depicts another embodiment of an exterior wall 450 . Exterior wall for example may be comprised of two panels 105 and entrance 455 . Another number of panels 105 and entrances 455 can be used in any order. Entrance 455 is preferably made of the same material as panels 105 , however, entrance 455 also includes a door or other entranceway. In FIG. 4 , entrance 455 is shown as 4 feet wide by 8.5 feet tall, however another size panel can be used. Preferably, entrance 455 has the same height as panels 105 .
[0032] FIG. 5 depicts an example of a temporary structure floor plan. As can be seen in the figure, the floor plan is a rectangular structure having two parallel long walls made up of four panels 105 each and two parallel short walls made up of two panels 105 and one entrance 455 each. The configuration shown in FIG. 5 is merely exemplary and another number of panels 105 and entrances 455 can be used to define the structure. Additionally, structures can be assembled in multiples or stacked as needed. Furthermore, structures need not be rectangular, but can have another shape.
[0033] FIG. 6 depicts the self-locking corner 660 used to couple perpendicular sections of wall. Self-locking corner 660 is preferably used to couple a track 210 b of a first panel 105 to a track 210 a of a second, perpendicular panel 105 . Self-locking corner 660 is preferably coupled to tracks 210 a and 210 b with a fastener (for example, a turn polycarbonate fastener, a rivet, a bolt, a screw, a brad, glue, adhesive, double-stick tape, or another fastener). A foam seal or other insulation can be used between tracks 210 a and 210 b to improve the insulation of the structure.
[0034] FIG. 7 depicts roof and floor panels 765 . Preferably roof and floor panels 765 are made of the same materials as panels 105 . As shown in FIG. 7 , roof and floor panels 765 are preferably 8 feet by 10 feet, however other dimensions can be used. In the preferred embodiment, each roof and floor panel 765 is coupled on two sides with track 210 a and on two sides with track 210 b, however other configurations can be utilized. Preferably, the roof is supported by beams. The beams preferably span the 20 foot section of the structure and are placed at 4 foot or 8 foot intervals, however other distributions and sizes of the beams can be used.
[0035] FIG. 8 depicts exterior wall sections 870 with cross beam roof supports at intervals. Exterior wall sections 870 are the same as panels 105 , except exterior wall section 870 are able to be coupled to roof beams 875 . In the preferred embodiment, wall sections 870 are installed down both sides of the temporary structure. Numerous configurations can be implemented to divide the structure into rooms by using panels such as section 870 . Additional temporary structures can be coupled to the first temporary structure to create longer, wider, or stacked (e.g. two story) structures. The additional temporary structures can be coupled to the first temporary structure either side by side, end to end, or one on top of another.
[0036] FIGS. 9 a - b depict an embodiment of a coupling device 909 for coupling a wall panel coupled to track 210 a to a floor panel coupled to track 210 b. Coupling device 909 is substantially “C” shaped. As can be seen in FIG. 9 b , the upper portion of coupling device 909 mates with track 210 a and there is a flange that couples to straight hemmed tab 225 of track 210 b. Coupling device 909 is preferably made of 20 or 24 gage steel, however other materials can be used. In the preferred embodiment a fastener 908 engages coupling device 909 and track 210 a securely coupling the wall panel to the floor panel. Fastener 908 can be a turn polycarbonate fastener, a rivet, a bolt, a screw, a brad, glue, adhesive, double-stick tape, or another fastener.
[0037] FIGS. 10 a - b depict an embodiment of a coupling device 1011 for coupling a wall panel coupled to track 210 b to a roof panel coupled to track 210 b. Coupling device 1011 is substantially “C” shaped. As can be seen in FIG. 10 b , the upper portion of coupling device 1011 has a flange that mates with the angled hemmed tab of the track 210 b of the roof panel while the lower portion of coupling device 1011 mates with track 210 b of the wall panel. Coupling device 1011 is preferably made of 20 or 24 gage steel, however other materials can be used. In the preferred embodiment a fastener 1012 engages coupling device 1011 and track 210 b of the wall panel securely coupling the wall panel to the roof panel. Fastener 1012 can be a turn polycarbonate fastener, a rivet, a bolt, a screw, a brad, glue, adhesive, double-stick tape, or another fastener.
[0038] FIGS. 11 a - b depict an embodiment of a coupling device 1116 for coupling a wall panel coupled to track 210 b to a roof panel coupled to track 210 a. Coupling device 1116 is substantially “C” shaped. As can be seen in FIG. 11 b , the upper portion of coupling device 1116 surrounds track 210 a of the roof panel, while the lower portion of coupling device 1116 abuts with track 210 b of the wall panel. Coupling device 1116 is preferably made of 20 or 24 gage steel, however other materials can be used. In the preferred embodiment fasteners 1117 engage coupling device 1116 and both track 210 b of the wall panel and track 210 a of the roof panel, securely coupling the wall panel to the roof panel. Fasteners 1117 can be a turn polycarbonate fastener, a rivet, a bolt, a screw, a brad, glue, adhesive, double-stick tape, or another fastener.
[0039] FIGS. 12 a - b depict an embodiment of a coupling device 1221 for coupling two roof panels to a beam 1223 . Coupling device 1221 is substantially “A” shaped. As can be seen in FIG. 11 b , the upper portion of coupling device 1221 fits within the indented portion 215 of track 210 a and over angled hemmed tab 220 of track 210 b, while the lower portion abuts beam 1223 . Coupling device 1221 is preferably made of 20 or 24 gage steel, however other materials can be used. In the preferred embodiment a fastener 1222 engages coupling device 1221 and beam 1223 , securely coupling the roof panels to the beam 1223 . Fastener 1222 can be a turn polycarbonate fastener, a rivet, a bolt, a screw, a brad, glue, adhesive, double-stick tape, or another fastener.
[0040] FIGS. 13 a - b depict an embodiment of a coupling device 1333 for coupling two perpendicular wall panels at a corner. Coupling device 1333 is substantially “C” shaped. As can be seen in FIG. 13 b , the left portion of coupling device 1333 mates with track 210 a of a first wall panel, while the right portion of coupling device 1333 abuts track 210 b of the second wall panel. Coupling device 1333 is preferably made of 20 or 24 gage steel, however other materials can be used. In the preferred embodiment fasteners 1334 engage coupling device 1333 and both track 210 a of the first wall panel and track 210 b of the second wall panel, securely coupling the wall panels. Fasteners 1334 can be a turn polycarbonate fastener, a rivet, a bolt, a screw, a brad, glue, adhesive, double-stick tape, or another fastener.
[0041] FIGS. 14 a -b depict an embodiment of a coupling device 1442 for coupling two perpendicular wall panels at a corner. Coupling device 1442 is substantially “C” shaped. As can be seen in FIG. 14 b , the upper portion of coupling device 1442 mates with track 210 a of a first wall panel, while the lower portion of coupling device 1442 abuts track 210 b of the second wall panel. Coupling device 1442 is preferably made of 20 or 24 gage steel, however other materials can be used. In the preferred embodiment fasteners 1443 engage coupling device 1442 and both track 210 a of the first wall panel and track 210 b of the second wall panel, securely coupling the wall panels. Fasteners 1442 can be a turn polycarbonate fastener, a rivet, a bolt, a screw, a brad, glue, adhesive, double-stick tape, or another fastener.
[0042] In the preferred embodiment, each of the components of the temporary structure is manufactured off-site, and then the components are delivered to the site of the temporary structure where they are assembled. Preferably, the temporary structure can be assembled and disassembled with minimum effort and tools. Furthermore, the components can be reused so that the structure is re-locatable. Preferably, during assembly, each fastener is installed either from the inside of the structure or from the roof of the structure.
[0043] FIGS. 15 a - b depict all of the components for an approximately 20′×40′ temporary structure fit within a standard 20 foot shipping container for transportation. In locations where wind is an issue, traditional anchors and tie downs can be used to secure the temporary structure. In the preferred embodiment, the roof can support at least a 40 lb load, however in other embodiment the roof can support greater loads.
[0044] 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 references cited herein, including all publications, U.S. and foreign patents and patent applications, are specifically and entirely incorporated by reference. It is intended that the specification and examples be considered exemplary only with the true scope and spirit of the invention indicated by the following claims. Furthermore, the term “comprising” includes the terms “consisting of” and “consisting essentially of,” and the terms comprising, including, and containing are not intended to be limiting. | A system and method for constructing a temporary structure is disclosed. The system comprises a plurality of wall panels, a plurality of roof panels, a plurality of floor panels, at least one door panel, and each wall panel, roof panel, floor panel, and door panel comprising at least one edge coupled to a first track and at least one edge coupled to a second track. The first track has a first surface with an indentation and a flat second surface. The second track has an angled hemmed tab extending therefrom that is adapted to mate with the indentation of the first track and a straight hemmed tab extending therefrom that is adapted to abut the flat second surface of the first track. | 4 |
This is a continuation of application Ser. No. 154,053 filed Feb. 9, 1988, abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to automotive lubrication system and more specifically to an oil pump which is suitable for use therein.
2. Description of the Prior Art
FIG. 1 shows a prior art trochoid type oil pump of the nature disclosed in Utility Model Publication JUM-A-59-88288. In this arrangement a pump casing 1 is formed with crescent shaped induction and discharge openings 2 and 3 respectively. An inner rotor 5 is mounted on an eccentric drive shaft 4 for synchronous rotation therewith and disposed within a ring shaped outer rotor 6.
In this arrangement the inner rotor is formed with 4 "external" teeth 7 while the outer rotor is formed with 5 "internal" teeth 8. With this arrangement when the drive shaft 4 is rotated by a non-illustrated connection with a prime mover such as an internal combustion engine, the inner and outer rotors rotate in unison. The inner rotor 4 moves within the outer rotor 6 in a manner to define spaces 9 into which oil from the induction opening 2 can enter and be retained in as they pass of the same. As the rotation of the rotors continues the spaces 9 are sequentially moved toward the discharge opening 3 and the oil which is inducted is subsequently compressed and squeezed out therethrough.
However, this arrangement has suffered from the drawback that during the rotation of the teeth of the inner and outer rotors come into mutual contact with one another and especially in the region of the discharge opening 3. Further, as each of the spaces 9 are isolated from one another some of the oil enclosed therein tends to get trapped and as the pulsation of the pump is extremely large, resonance noise tends to be generated.
In a second prior art arrangement of the nature disclosed in JP-A-57-79290 the oil pump has been constructed so that the teeth on the inner and outer rotors have asymmetrical profiles and wherein the contact ratio is less than 1. However, with this arrangement the curvature of the profile, that is to say, the radius of curvature of the faces and the top land portions of the teeth are extremely limited and machining of the the same requires a large number of intricate operations and precision machining. Even then the contact ratio of the internal and external teeth is less than one and in response to minor changes in rotation of the outer rotor the generation of relatively loud chattering noise is induced.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a gear pump for use in automotive lubrication systems or the like which exhibits smooth low vibration operation and which is readily fabricated.
In brief, the above object is achieved by a trochoid type gear pump arrangement which features an outer rotor formed with internal teeth and an inner rotor formed with external teeth which can be receivable in the external ones. The profiles of one or both of the internal and external teeth are rendered asymmetric and arranged to engage only in the region of an intake opening formed in the casing in which the two rotors are housed.
More specifically, the present invention takes the form of a pump which features a casing, the casing having an inlet opening and a discharge opening; an outer rotor rotatably disposed in a recess formed in the casing, the inner rotor being formed with a plurality of internal teeth, the inner teeth being each defined by a shaped convex recess formed in the inner periphery of the outer rotor, the internal teeth having a leading edge and trailing edge, the leading edge preceeding the trailing edge in the direction of rotation; an inner rotor disposed within the outer rotor, the inner rotor being formed with a plurality of external teeth, the external teeth being defined by shaped convex projections which extend from the outer periphery of the inner rotor, the external teeth having a leading edge and a trailing edge, the external teeth being receivable in the internal teeth so that the leading edge of the external teeth are engageable with the leading edge of the internal teeth in the region of the inlet opening; and means defining an asymmetry in at least one of the trailing edges of the internal and external teeth.
According to another aspect of the invention, a fluid pump comprises a casing, the casing having an inlet opening and a discharge opening, an outer rotor rotatably disposed in a recess formed in the casing, the outer rotor being formed with a plurality of internal teeth having a leading edge and trailing edge, the leading edge preceeding the trailing edge in the direction of rotation, the outer rotor being rotatable about a first axis, an inner rotor disposed within the outer rotor, the inner rotor being formed with a plurality of external teeth having a leading edge and a trailing edge, the external teeth being receivable in the internal teeth so that the leading edge of the external teeth are engageable with the leading edge of the internal teeth in the region of the inlet opening, the inner rotor being rotatable about a second axis which is offset from the first axis, and means defining an asymmetry in at least one of the trailing edges of the internal and external teeth.
According to a further aspect of the invention, a fluid pump comprises a casing, the casing having an inlet opening and a discharge opening, an outer rotor rotatably disposed in a recess formed in the casing, the outer rotor being formed with a plurality of internal teeth having a leading edge and trailing edge, the leading edge preceeding the trailing edge in the direction of rotation, the outer rotor being rotatable about a first axis, an inner rotor disposed within the outer rotor, the inner rotor being formed with a plurality of external teeth having a leading edge and a trailing edge, the inner rotor being rotable about a second axis which is so oriented that the external teeth being receivable in the internal teeth so that the leading edge of the external teeth are engageable with the leading edge of the internal teeth in the region of the inlet opening, and means defining an asymmetry in at least one of the trailing edges of the internal and external teeth.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be understood more fully from the detailed description given herebelow and from the accompanying drawings of the preferred embodiment of the invention, which, however, should not be taken to limit the invention to the specific embodiment but are for explanation and understanding only.
In the drawings:
FIG. 1 is a front sectional elevation of the first prior art arrangement discussed in the opening paragraphs of the instant disclosure;
FIG. 2 is a diagram showing details of the tooth profile which characterizes the present invention;
FIG. 3 is a side sectional elevation of a first embodiment of the present invention;
FIG. 4 is a front elevation as seen along along line IV--IV of FIG. 3;
FIG. 5 is a front elevation similar to that shown in FIG. 4 which shows a second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 3 and 4 of the drawings show a first embodiment of the present invention. In this arrangement a pump casing 12 is formed with a circular chamber 11a which is closed by a cover 12. An eccentric drive shaft 13 is disposed through a bore formed in the casing 12 and arranged to extend into the circular chamber 11a.
The casing 12 is further formed with essentially diametrically located induction and discharge openings 14 and 15. These openings respectively communicate with induction and discharge ports 16 and 17 via cavities 14a and 15a.
Inner and outer rotors 18 and 19 are operatively disposed in the circular chamber 11a so as to be rotatable therein. The inner rotor 18 is fixed to the drive shaft 13 for synchronous rotation therewith.
The outer rotor 19 is arranged to rotate about an axis P1 and the inner rotor 19 is arranged to rotate about an axis P2 which is offset from P1 by an amount "e" (see FIG. 4). The inner rotor 18 is formed with nine "external" teeth 20 in its outer periphery, while outer rotor 19 is formed with 10 "internal" teeth 21 about its inner periphery.
The inner and outer rotors 18 and 19 are arranged to mesh with one another to define 10 individual working spaces or chambers 25 therebetween.
The so called "internal" teeth 21 of the outer rotor 19 are defined by shaped recesses formed in the inner periphery of the outer rotor 19, and as shown in FIG. 2, are each arranged so that a tooth profile center line X divides each tooth into what shall be referred to as a trailing edge 22 and a top land portion 21a and a leading edge 23 portion. In this instance the leading edge 23 is defined from the center line in the direction of rotation while the trailing edge is defined from the center line in the direction opposite that of rotation.
Lines Y1 and Y2 are drawn so as to have their origins coincident with the axis P1 and pass through points which lie on the central portions of convex portions 24 which are located on either side of a tooth. Lines Y1 and Y2 define an included angle "θ" therebetween.
The curvature "a" of the trailing edge 22 is such that the first portion 22a thereof has a radius of curvature R1 the origin of which lies on line Y1, while the second portion 22b has a radius of curvature R2 the origin of which lies on the center line X.
The top land section 21a of the tooth follows from the center line X and blends with a convex portion having a curvature "b". In this instance curvature "b" has a radius of curvature R3 the origin of which lies on line Y2. surface 23 having the radius R3 acts as a contact surface and engages the corresponding leading surface 20b of the external teeth 20 and that, at any one time, only a limited number of surfaces are in actual engagement.
In operation, the above described arrangement is such that when the drive shaft 13 is rotated in the clockwise direction, the inner rotor 18 is forced to rotate in unison. In the region of the intake opening 14, the leading surfaces 20b of the external teeth 20 contact the corresponding leading edges 23 of the internal teeth 21 and induces the outer rotor 19 to rotate in the same direction. Under these conditions smooth collision free engagement between the teeth on the inner and outer rotors 18, 19 occurs in the region of the intake opening 14 and a contact ratio of more than 1 is developed. Accordingly, chattering noise and the like is not generated when the outer rotor 19 undergoes slight changes in rotational speed.
Simultaneously, in the induction opening zone, lubricant enters into the chambers 25 defined between the inner and outer rotors and carried around to the exhaust opening side. As shown in FIG. 4, as each working chamber 25 approaches the wide upstream end 15b of the discharge opening 15, the top land sections 20c engage the tops of the convex sections 24. Following this, as the chambers 25 approach the narrow downstream end 15a of the discharge opening the external teeth begin to deeply enter the internal ones and reduce the volume of the chambers 25. At this time the leading edges 20b of the external teeth begin to engage the leading edges of the internal teeth and the volume of the chambers 25 reduces toward zero.
This operation allows the oil in the chambers to be smoothly displaced and prevents any undesirable retention of oil therein from occuring. Further, as the number of surfaces in actual engagement at any one moment are limited and no collisions between teeth occur with this arrangement, the pump casing vibration which leads to the generation of resonance noise is adequately reduced.
Moreover, as the curvature of the leading and trailing edges of the teeth can be selected relatively freely the production of the above described arrangement is readily produced.
FIG. 5 shows a second embodiment of the present invention. In this arrangement the inner and outer teeth profiles are formed so that the leading and trailing edges thereof are basically symmetrical in shape similar to the prior art. However, in this embodiment the external teeth are modified by removing part of the trailing surface. In this instance a flat 20d is ground or otherwise formed on the trailing edge of each tooth. Alternatively, as a variant of the second embodiment it is possible to form flats on the corresponding surfaces of the internal teeth in lieu of, or in addition to, the external ones if so desired.
The operation and effect of this embodiment is essentially similar to the first one.
While the present invention has been disclosed in terms of the preferred embodiment in order to facilitate better understanding of the invention, it should be appreciated that the invention can be embodied in various ways without departing from the principle of the invention. Therefore, the invention should be understood to include all possible embodiments and modifications to the shown embodiments which can be embodied without departing from the principle of the invention set out in the appended claims. | A trochoid type gear pump features an outer rotor formed with internal teeth and an inner rotor formed with external teeth which can be receivable in the external ones. The profiles of one or both of the internal and external teeth are rendered asymmetric and arranged to engage only in the region of an intake opening formed in the casing in which the two rotors are housed. | 5 |
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to dispensers for sheet products.
[0002] Sheet products may be formed into cylindrical rolls having an inner core. The inner core may be removed, and the sheet product may be dispensed in segments. The segments may be drawn by the user from the center of the sheet product roll.
[0003] Drawing segments from the center of a sheet product roll allows a user to easily remove sheet products from a roll while the roll remains stationary.
BRIEF DESCRIPTION OF THE INVENTION
[0004] According to one aspect of the invention, a dispenser plate includes a plate member having an orifice centrally arranged in the plate member, the orifice including a central portion, a first channel portion having a first channel length extending radially from the central portion, and a second channel having a second channel length extending radially from the central portion, wherein the first channel length is greater than the second channel length.
[0005] According to another aspect of the invention, a dispenser includes a containment portion configured to house a cylindrical roll of sheet product, and a dispenser plate retained by the containment portion, the dispenser plate comprising a plate member having an orifice centrally arranged in the plate member, the orifice including a central portion, a first channel portion having a first channel length extending radially from the central portion, and a second channel having a second channel length extending radially from the central portion, wherein the first channel length is greater than the second channel length.
[0006] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0008] FIG. 1 illustrates a perspective view of an exemplary embodiment of a sheet product dispenser.
[0009] FIG. 2 illustrates another perspective view of the roll and the dispenser plate of FIG. 1 .
[0010] FIGS. 3 and 4 illustrate a top view of the roll and the dispenser plate of FIG. 1 .
[0011] FIG. 5 illustrates another top view of the dispenser plate of FIG. 1 .
[0012] FIGS. 6-13 illustrate top views of alternate exemplary embodiments of dispenser plates.
[0013] The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The term “sheet products” as used herein is inclusive of natural and/or synthetic cloth or paper sheets. Sheet products may include both woven and non-woven articles. There are a wide variety of nonwoven processes and they can be either wetlaid or drylaid. Some examples include hydroentagled (sometimes called spunlace), DRC (double re-creped), airlaid, spunbond, carded, paper towel, and meltblown sheet products. Further, sheet products may contain fibrous cellulosic materials that may be derived from natural sources, such as wood pulp fibers, as well as other fibrous material characterized by having hydroxyl groups attached to the polymer backbone. These include glass fibers and synthetic fibers modified with hydroxyl groups. Examples of sheet products include, but are not limited to, wipers, napkins, tissues, rolls, towels or other fibrous, film, polymer, or filamentary products.
[0015] In general sheet products are thin in comparison to their length and breadth and exhibit a relatively flat planar configuration and are flexible to permit folding, rolling, stacking, and the like. The sheet product may have perforations extending in lines across its width to separate individual sheets and facilitate separation or tearing of individual sheets from a roll or folded arrangement at discrete intervals. Individual sheets may be sized as desired to accommodate the many uses of the sheet products. For example, perforation lines may be formed every 10 inches, or other defined interval, to define a universally sized sheet. Multiple perforation lines may be provided to allow the user to select the size of sheet depending on the particular need.
[0016] FIG. 1 illustrates a perspective view of an exemplary embodiment of a dispenser 10 . In the illustrated embodiment, a roll 102 is cylindrically shaped and has a diameter (d r ). The roll 102 is formed around a core 104 that may include, for example, a rigid or semi-rigid tubular segment formed from a paper, plastic, or metallic material. The core 104 has a diameter (d c ).
[0017] The dispenser plate 100 is disposed on an end surface of the roll 102 , and may be attached to the roll 102 using any suitable means including, for example, a wrapper film 200 (illustrated as partially cut-away) such as a plastic or polymer film that envelopes the roll 102 and the dispenser plate 100 and exerts a compressive force on the disperser plate 100 and the roll; securing the disperser plate 100 in the illustrated position. In an embodiment, the dispenser plate 100 , roll 102 , and wrapper film 200 forms a complete dispenser 10 . While a wrapper film 200 is disclosed herein forming the containment portion of the dispenser 10 , it will be appreciated that the wrapper film 200 may be replaced with a more rigid structure without departing from the scope of the invention disclosed herein.
[0018] The dispenser plate 100 may be formed from any suitable material such as a rigid or semi-rigid cardboard material, a plastic, nylon, corrugated, or metallic material. The dispenser plate 100 includes an orifice 106 having a circular portion 108 and a plurality of channels 110 extending radially from the circular portion 108 . In the illustrated embodiment, the channels 110 have dissimilar channel lengths such that each channel 110 extends radially from the circular portion 108 exposing portions of the roll 102 . Though the illustrated embodiment of FIG. 1 includes three channels 110 , alternate embodiments may include any number of channels 110 .
[0019] FIG. 2 illustrates a perspective view of the roll 102 and the dispenser plate 100 . In the illustrated embodiment, the core 104 may be removed by a user by exerting a force in the direction of the line 201 . The core 104 has an inner diameter that is smaller than the inner diameter of the circular portion 108 of the dispenser plate 100 . Once the core 104 is removed, the inner wraps of the roll 102 are exposed.
[0020] FIGS. 3 and 4 illustrate a top view of the roll 102 and the dispenser plate 100 following the removal of the core 104 (of FIG. 2 ). Referring to FIG. 3 , a user may dispense the sheet product of the roll 102 by pulling a leading edge 302 of the exposed inner wrap and drawing the sheet product through the circular portion 108 of the orifice 106 . The user may exert a force radially outward from the circular portion 108 such that a segment of the sheet product contacts an edge of the orifice 106 . The contact between the sheet product and the edge of the orifice 106 frictionally facilitates the tearing of the sheet product segment to separate the sheet product segment from the roll 102 .
[0021] Referring to FIG. 4 , as the roll 102 is depleted by subsequent removal of sheet product segments, the remaining portions of the roll 102 remain exposed by the channels 110 . The dissimilar lengths of the channels 110 allow portions of the roll 102 to remain exposed as the roll 102 is depleted. For example, in the illustrated embodiment, the channel 110 a has the shortest length (extending radially from the circular portion 108 ) relative to the channels 110 b and 110 c , while the channel 110 c has the longest length. As the user removes sheet product from the roll 102 , the remaining inner sheets are exposed by the channels 110 a , 110 b , and 110 c . As the user continues to remove sheets from the roll 102 the wraps of the roll 102 define a gradually increasing void 402 in the center of the roll 102 . When the void 302 expands beyond the length of the channel 110 a , a user may still access the roll 102 through the channels 110 b and 110 c . In the illustrated embodiment, the void 302 has expanded such that the leading edge 302 ′ of the roll 102 is exposed in the longest channel, channel 110 c . The use of channels 110 having dissimilar lengths allows a user to access the sheet product of the roll 102 while maintaining rigidity of the dispenser plate 100 since the area of the orifice 106 effects the rigidity of the dispenser plate 100 , where a greater orifice 106 area reduces the rigidity of the dispenser plate 100 .
[0022] FIG. 5 illustrates a top view of the dispenser plate 100 . The dispenser plate has a diameter (d p ). The circular portion 108 of the orifice 106 has a diameter (y). The channels 110 a , 110 b , and 110 c have a similar channel width (x), and dissimilar channel lengths (L a , L b , and L c ) respectively; extending radially from a center point 501 of the circular portion 108 , where L a <L b <L c .
[0023] FIGS. 6-13 illustrate top views of alternate exemplary embodiments of dispenser plates that operate in a similar manner as the dispenser plate 100 (of FIG. 1 ) described above.
[0024] Referring to FIG. 6 , a dispenser plate 600 includes an orifice 606 having a circular portion 608 and channels 610 . The channels 610 have an arcuate shaped profile and extend radially from the circular portion with dissimilar lengths in a similar manner as described above.
[0025] Referring to FIG. 7 , a dispenser plate 700 includes an orifice 706 having a circular portion 708 and channels 710 . In the illustrated embodiment, the channels 710 include serrated or toothed edges 701 that may facilitate the tearing of a sheet product segment from the roll 102 (of FIG. 1 ). The channels 710 have dissimilar lengths that extend radially from the circular portion 708 .
[0026] Referring to FIG. 8 , a dispenser plate 800 includes an orifice 806 having a circular portion 808 and channels 810 . In the illustrated embodiment, the circular portion 810 includes a serrated or toothed edge 801 that may facilitate the tearing of a sheet product segment from the roll 102 (of FIG. 1 ). The channels 910 have dissimilar lengths that extend radially from the circular portion 808 .
[0027] FIG. 9 illustrates a dispenser plate 900 that includes an orifice 906 having a circular portion 908 and channels 910 . In the illustrated embodiment, the channels 910 are T-shaped and include terminal portions 903 arranged on the distal end of the channels 910 along an axis transverse to the linear axis of the channels 910 . The channels 910 may have dissimilar lengths extending radially from the circular portion 908 .
[0028] FIG. 10 includes a dispenser plate 1000 having an orifice 1006 with a circular portion 1008 and channels 1010 . The channels 1010 are L-Shaped and include a bend forming distal end 1003 that is aligned at an oblique or right angle to the longitudinal axis (extending radially from the circular portion 1008 ) of the channels 1010 .
[0029] FIG. 11 illustrates a dispenser plate 1100 with an orifice 1106 having a circular portion 1108 and channels 1110 . The channels 1110 extend radially from the circular portion 1101 and have similar lengths.
[0030] FIG. 12 illustrates a dispenser plate 1200 having an orifice 1206 including a circular portion 1208 and channels 1210 . The channels 1210 extend radially from the circular portion 1208 and have a gradually decreasing or tapered width. The channels 1210 include circular terminal portion 1203 arranged at the distal ends of the channels 1210 .
[0031] FIG. 13 includes a dispenser plate 1300 including an orifice 1306 having a circular portion 1308 and channels 1310 . The channels 1310 include undulating or scalloped edges 1303 . The channels 1310 extend radially from the circular portion 1308 and may include dissimilar lengths.
[0032] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. | A dispenser plate includes a plate member having an orifice centrally arranged in the plate member, the orifice including a central portion, a first channel portion having a first channel length extending radially from the central portion, and a second channel having a second channel length extending radially from the central portion, wherein the first channel length is greater than the second channel length. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 12/614,769. filed Nov. 9, 2009, which is a continuation-in-part of U.S. application Ser. No. 10/860,199 now U.S. Pat. No. 8,167,285, filed Jun. 2, 2004; which is a regular application of Provisional No. 60/476,105, filed Jun. 4, 2003, the contents of all of which are expressly incorporated herein by reference for all purposes.
FIELD OF ART
[0002] The present invention generally relates to connectors and is more directly related to the use of canted coil springs in connecting a piston and a housing for mechanical and electrical connection purposes.
BACKGROUND
[0003] The connection may used to hold or latch and disconnect or unlatch. Various types of canted coil springs, such as radial, axial, or turn angle springs may be used depending on the characteristics desired for a particular application.
[0004] Axial springs may be RF with coils canting clockwise or F with coils canting counterclockwise, and installed or mounted with a front angle in front or in back relative to a direction of piston travel in an insertion movement. The springs can be mounted in various manners in a groove in either the piston or the housing. While the spring is generally mounted in a round piston or a round housing, the canted coil spring is capable of being utilized in non-circular applications such as elliptical, square, rectangular, or lengthwise grooves.
[0005] Various applications require differing force and force ratios for the initial insertion force. the running force, and the force required to latch and disconnect mating parts. The force, the degree of constraint of the spring, the spring design, the materials used, and the ability of the spring and housing combination to apply a scraping motion to remove oxides that may form on mating parts have been found in accordance with the present invention to determine the electrical performance of the connector. Electrical performance means the resistivity and the resistivity variability of the mated parts.
SUMMARY
[0006] It has been found that the force to connect and the force to disconnect as well as the ratio between the two is determined by the position of the point of contact relative to the end point of the major axis of the spring when the disconnect or unlatch force is applied and the characteristics of the spring and the spring installation or mounting. The maximum force for a given spring occurs when the point of contact is close to the end point of the major axis of the spring. The minimum force for a given spring occurs when the contact point is at the maximum distance from the end point of the major axis, which is the end point of the minor axis of the spring. This invention deals in part with the manner in which the end point is positioned. The material, spring design, and method of installing the spring determine the spring influenced performance characteristics of the invention.
[0007] Accordingly, a spring latching connector in accordance with the present invention generally includes a housing having a bore therethrough along with a piston slidably received in the bore. In one embodiment, the housing bore and piston abut one another in order to eliminate axial play.
[0008] A circular groove is formed in one of the bore and the piston and a circular coil spring is disposed in the groove for latching the piston in a housing together.
[0009] Specifically, in accordance with the present invention a groove is sized and shaped for controlling, in combination with a spring configuration, the disconnect and connect forces of the spring latching connector.
[0010] The circular coil spring preferably includes coils having a major axis and a minor axis and the circular groove includes a cavity for positioning a point of contact in relation to an end of the coil major axis in order to determine the disconnect and the connect forces. More specifically, the groove cavity positions the point of contact proximate the coil major axis in order to maximize the disconnect forces. Alternatively, the groove cavity may be positioned in order that the point of contact is proximate an end of the minor axis in order to minimize the disconnect force.
[0011] In addition, the coil height and groove width may be adjusted in accordance with the present invention to control the disconnect and connect forces.
[0012] Further, a major axis of the coil spring is disposed above an inside diameter of a housing groove for a housing mounted coil spring and below an outer diameter of a piston groove for a piston-mounted coil spring.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention may be more clearly understood with reference to the following detailed description in conjunction with the appended drawings of which:
[0014] FIG. 1 a —shows a front view of a canted coil spring with the coils canting counterclockwise as indicated by the arrow;
[0015] FIG. 1 b shows and enlarged view of the coils;
[0016] FIG. 1 c shows the position of the front and back angle;
[0017] FIG. 1 d shows the difference between the lengths of the front angle and the back angle;
[0018] FIG. 1 e shows the position of the front and back angles;
[0019] FIG. 1 f shows a cross sectional view of a radial spring.
[0020] FIG. 2 a shows a radial spring in a flat bottom-housing groove;
[0021] FIG. 2 b shows a left side view of the spring;
[0022] FIG. 2 c shows a front view of a counterclockwise radial spring with a front angle in the front;
[0023] FIG. 2 d shows a cross sectional view of the spring;
[0024] FIG. 2 e shows a cross sectional view of the spring mounted in a housing, a reference dot point indicating a position of a front angle of a coil, “the end point of a major axis of the coil” being used to explain the relationship between a point of contact and the end point of the major axis of the coil when determining the unlatching or disconnect force, the dot point showing a position of the front angle of the coil;
[0025] FIGS. 3 a - 3 e show a radial spring mounted clockwise in a flat bottom housing groove with the front angle in the back, the spring having coils canting clockwise;
[0026] FIGS. 4 a - 4 e show a latching radial spring in a standard latching groove, housing mounted (shown in FIGS. 4 a and 4 e );
[0027] FIGS. 5 a - 5 e show a radial spring axially loaded with the grooves offset in a latched position with a housing bore and piston abutting one another for eliminating axial play, see FIG. 5 a . This enhances conductivity and reduces resistivity variation;
[0028] FIGS. 6 a - 6 e and 7 a - 7 e show the same type of design but piston mounted. FIGS. 6 a - 6 e show a latching radial spring in a latching groove, piston mounted, while FIGS. 7 a - 7 e shows a latching radial spring with offset axial grooves for minimal axial play piston mounted. The features are the same as indicated in FIGS. 4 a - 4 e and 5 a - 5 e except piston mounted.
[0029] FIG. 7 a shows an abutting relationship between a housing bore and piston similar to FIG. 5 a;
[0030] FIGS. 8 a - 8 d show a series of circular holding multiple radial spring mounted one in each groove. Each spring is separate from the others, FIG. 8 b showing one spring being compressed radially by the shaft as it moves in the direction of the arrow, FIG. 8 a showing two springs deflected radially in the direction of the arrow. FIG. 8 d showing a cross section of the spring. Springs in a multiple manner could also be axial;
[0031] FIGS. 9 a - 9 e show a holding multiple radial springs mounted in multiple grooves, this design being similar to the one indicated in FIGS. 8 a - 8 d but the grooves are physically separated from each other, springs in a multiple manner may also be axial;
[0032] FIGS. 10 a - 10 e show a holding length spring mounted axially in a threaded groove. FIG. 10 b showing the piston partially engaging the housing by deflecting the spring coils, FIG. 10 a showing the shaft moving in the direction of the arrow with further compression of the spring coils, FIG. 10 d showing a length of the spring and FIG. 10 e showing an axial spring mounted in the groove with two spring coils deflected and one not deflected as yet;
[0033] FIGS. 11 a - 11 e shows a face compression axial spring retained by inside angular sidewall;
[0034] FIGS. 12 a - 12 e show a latching radial spring in a radial groove designed for high disconnect to insertion ratio shown radially loaded and causing the coils to turn to provide axial load to reduce axial movement. GW>CH;
[0035] FIGS. 13 a - 13 d show a latching axial spring in an axial groove designed for high disconnect to insertion ratio with the spring shown in an axially loaded position to limit axial play, the spring coils assuming a turn angle position that increases force and provides higher conductivity with reduced variability;
[0036] FIGS. 14 a - 14 k show a spring with ends threaded to form a continuous spring-ring without welding joining, which is different than the design indicated in FIG. 1 ;
[0037] FIGS. 15 a - 15 k show a spring with end joined by a male hook and step-down circular female end to form a continuous circular spring-ring without welding;
[0038] FIGS. 16 a - 16 l show a spring with the coil ends connected by interlacing the end coils to form a continuous spring-ring without welding or joining;
[0039] FIGS. 17 a - 17 l show a spring with coils ends butted inside the groove forming a spring-ring without welding; and
[0040] FIGS. 18 a - 18 f show an unwelded spring ring and to be housed in a flat bottom housing groove, front angle in the front, showing the various different designs that could be used to retain the spring in a groove that can be a housing groove or a piston groove.
DETAILED DESCRIPTION
[0041] Connectors using latching applications have been described extensively, as for example, U.S. Pat. Nos. 4,974,821, 5,139,276, 5,082,390, 5,545,842, 5,411,348 and others.
[0042] Groove configurations have been divided in two types: one type with a spring retained in a housing described in Tables 1 a-1 g and another with the spring retained in a shaft described in Tables 2 a-2 g.
Definitions
[0043] A definition of terms utilized in the present application is appropriate.
[0044] Definition of a radial canted coil spring. A radial canted coil spring has its compression force perpendicular or radial to the centerline of the arc or ring.
[0045] Definition of axial canted coil spring. An axial canted coil spring has its compression force parallel or axial to the centerline of the arc or ring.
[0046] The spring can also assume various angular geometries, varying from 0 to 90 degrees and can assume a concave or a convex position in relation to the centerline of the spring.
[0047] Definition of concave and convex. For the purpose of this patent application, concave and convex are defined as follows:
[0048] The position that a canted coil spring assumes when a radial or axial spring is assembled into a housing and positioned by—passing a piston through the ID so that the ID is forward of the centerline is in a convex position.
[0049] When the spring is assembled into the piston, upon passing the piston through a housing, the spring is positioned by the housing so that the OD of the spring is behind the centerline of the spring is in a convex position.
[0050] The spring-rings can also be extended for insertion into the groove or compressed into the groove. Extension of the spring consists of making the spring ID larger by stretching or gartering the ID of the spring to assume a new position when assembled into a groove or the spring can also be made larger than the groove cavity diameter and then compressed the groove.
[0051] Canted coil springs are available in radial and axial applications. Generally, a radial spring is assembled so that it is loaded radially. An axial spring is generally assembled into a cavity so that the radial force is applied along the major axis of the coil, while the coils are compressed axially and deflect axially along the minor axis of the coil.
[0052] Radial springs. Radial springs can have the coils canting counterclockwise (Table 1 a, row 2, column 13) or clockwise (Table 1 a, row 3, column 13). When the coils cant counterclockwise, the front angle is in the front (row 2, column 13). When the coils cant clockwise (Table 1 a, row 3, column 13), the back angle is in the front. Upon inserting a pin or shaft through the inside diameter of the spring with the spring mounted in the housing in a counterclockwise position (Table 1 a, row 2, columns 2, 3, 5), the shaft will come in contact with the front angle of the coil and the force developed during insertion will be less than when compressing the back angle from a spring in a clockwise position. The degree of insertion force will vary depending on various factors. The running force will be about the same (Table 1 a, row 2, columns 6, 8).
[0053] RUNNING FORCE. Running force is the frictional force that is produced when a constant diameter portion of the pin is passed through the spring.
[0054] Axial springs may also be assembled into a cavity whose groove width is smaller than the coil height (Table 1 a, row 5, columns 2, 3, 5, 6, 7 and 8). Assembly can be done by inserting spring (Table 1 a, row 5, column 13) into the cavity or by taking the radial spring (Table 1 a, row 7, column 13) and turning the spring coils clockwise 90.degree. into a clockwise axial spring (Table 1 a, row 7, column 15) and inserting into the cavity. Under such conditions, the spring will assume an axial position, provided the groove width is smaller than the coil height. Under such conditions, the insertion and running force will be slightly higher than when an axial spring is assembled into the same cavity. The reason is that upon turning the radial spring at assembly, a higher radial force is created, requiring a higher insertion and running force.
[0055] Axial springs RF and F definition. Axial springs can be RF (Table 1 a, row 5, column 13) with the coils canting clockwise or they can be F (Table 1 a, row 6, column 13) with the coils canting counterclockwise. An RF spring is defined as one in which the spring ring has the back angle at the ID of the coils (Table 1 a, row 5, column 12) with the front angle on the OD of the coils. An F spring (Table 1 a, row 6, column 13) has the back angle on the OD and the front angle at the ID of the coils.
[0056] Turn angle springs are shown in Table 1 e, row 10, column 13, Table 1 f, rows 2-5, column 13. The springs can be made with turn angles between 0 and 90 degrees. This spring can have a concave direction (Table 1 a, row 5, column 6) or a convex direction (Table 1 a, row 5, column 8) when assembled into the cavity, depending on the direction in which the pin is inserted. This will affect the insertion and running force.
[0057] F type axial springs always develop higher insertion and running forces than RF springs. The reason is that in an F spring the back angle is always located at the OD of the spring, which produces higher forces.
[0058] Definition of Point of Contact. The point of load where the force is applied on the coil during unlatching or disconnecting of the two mating parts. (Table 1 a, row 2, column 11, row 5, column 11).
[0059] Definition of “end of the major axis of the coil.” The point at the end of the major axis of the coil. (Table 1 a, row 2, column 2 and row 5, column 2).
[0060] Types of grooves that may be used.
[0061] Flat groove. (Table 1 a, row 2, column 4) The simplest type of groove is one that has a flat groove with the groove width larger than the coil width of the spring. In such case, the force is applied radially.
[0062] ‘V’ bottom groove. (Table 1 a, row 4, column 4) This type of groove retains the spring better in the cavity by reducing axial movement and increasing the points of contact. This enhances electrical conductivity and reduces the variability of the conductivity. The groove width is larger than the coil width. The spring force is applied radially.
[0063] Grooves for axial springs. (Table 1 a, row 5, column 2) Grooves for axial springs are designed to better retain the spring at assembly. In such cases, the groove width is smaller than the coil height. At assembly, the spring is compressed along the minor axis axially and upon the insertion of a pin or shaft through the ID of the spring the spring, the coils deflect along the minor axis axially.
[0064] There are variations of these grooves from a flat bottom groove to a tapered bottom groove.
[0065] Axial springs using flat bottom groove. In such cases, the degree of deflection available on the spring is reduced compared to a radial spring, depending on the interference that occurs between the coil height and the groove width.
[0066] The greater the interference between the spring coil height and the groove, the higher the force to deflect the coils and the higher the insertion and running forces.
[0067] In such cases, the spring is loaded radially upon passing a pin through the ID. The deflection occurs by turning the spring angularly in the direction of movement of the pin. An excessive amount of radial force may cause permanent damage to the spring because the spring coils have “no place to go” and butts.
[0068] Axial springs with grooves with a tapered bottom. (Table 1 b, rows 7-9, column 2 through Table 1 c, rows 2-7, column 2) A tapered bottom groove has the advantage that the spring deflects gradually compared to a flat bottom groove. When a pin is passed through the ID of the spring, it will deflect in the direction of motion. The running force depends on the direction of the pin and the type of spring. Lower forces will occur when the pin moves in a concave spring direction (Table 1 b, row 5, column 6) and higher force when the pin moves in a convex spring direction (Table 1 b, row 5, column 8).
[0069] Tapered bottom grooves have the advantage that the spring has a substantial degree of deflection, which occurs by compressing the spring radially, thus allowing for a greater degree of tolerance variation while remaining functional as compared to flat bottom grooves.
[0070] Mounting of groove. Grooves can be mounted in the piston or in the housing, depending on the application. Piston mounted grooves are described in Tables 2 a-2 g.
[0071] Expansion and contracting of springs. A radial spring ring can be expanded from a small inside diameter to a larger inside diameter and can also be compressed from a larger OD to a smaller OD by crowding the OD of the spring into the same cavity. When expanding a spring the back angle and front angles of the spring coils decrease, thus increasing the connecting and running forces. When compressing a radial spring OD into a cavity, which is smaller than the OD of the spring, the coils are deflected radially, causing the back and front angles to increase. The increase of these angles reduces the insertion and running forces when passing a pin through the ID of the spring.
[0072] The following patents and patent application are to be incorporated in this patent application as follows: [0073] 1) U.S. Pat. No. 4,893,795 sheet 2 FIGS. 4, 5A, 5B. 5C, 5D, 5E, 6A and 6B; [0074] 2) U.S. Pat. No. 4,876,781 sheet 2 and sheet 3 FIGS. 5A, 5B, and FIG. 6. [0075] 3) U.S. Pat. No. 4,974,821 page 3 FIGS. 8 and 9 [0076] 4) U.S. Pat. No. 5,108,078 sheet 1 FIGS. 1 through 6 [0077] 5) U.S. Pat. No. 5,139,243 page 1 and 2 FIGS. 1A, 1B, 2A, 2B and also FIGS. 4A, 4B, 5A, and 5E [0078] 6) U.S. Pat. No. 5,139,276 sheet 3 FIGS. 10A, 10B, 10C, 11A, 11B, 12A, 12B, 12C, 13A, 13B, and 14 [0079] 7) U.S. Pat. No. 5,082,390 sheet 2 and 3, FIGS. 4A, 4B, 5A, 5B, 6A, 6B, 7A, 7C, 8A, 8B [0080] 8) U.S. Pat. No. 5,091,606 sheets 11, 12, and 14. FIGS. 42, 43, 44, 45, 46, 47, 48, 48A, 48B, 49, 50A, 50B, 50C, 51A, 51B, 51C, 58A. 58B, 58C, 58D. [0081] 9) U.S. Pat. No. 5,545,842 sheets 1, 2, 3, and 5. FIGS. 1, 4, 6, 9, 13, 14, 19, 26A, 26B, 27A, 27B, 28A, 28B. [0082] 10) U.S. Pat. No. 5,411,348 sheets 2, 3, 4, 5, and 6. FIGS. 5A, 5C, 6A, 6C, 7A, 7C, 7D, 8A, 8B, 8C, 9A, 9C, 10C, 11, 12 and 17. [0083] 11) U.S. Pat. No. 5,615,870 Sheets 1-15, Sheets 17-23 with FIGS. 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 92, 93, 94, 95, 96, 97, 98, 99, 100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119, 120, 121, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135. [0084] 12) U.S. Pat. No. 5,791,638 Sheets 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23. FIGS. 1-61 and 66-88 and 92-135. [0085] 13) U.S. Pat. No. 5,709,371, page 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20, 21, 22, 23. FIGS. 1-61 and 66-88 and 92-135. [0086] 14) Application for patent by Balsells entitled “Spring Holding Connectors” Customer Ser. No. 10/777,974 filed Feb. 12, 2004.
[0073] In general, Tables 1 a-1 g illustrate housing mounted designs for holding and other applications. These tables show 53 different types of grooves and spring geometries in which the spring is mounted in the housing, using different spring configurations and different groove variations, which result in different insertion and running forces.
[0074] Table 1 a, row 2, columns 2-12 show a flat bottom groove with a radial spring.
[0075] Table 1 a, row 2, column 2 shows an assembly with a spring mounted in a housing with a shaft moving forward axially.
[0076] Table 1 a, row 2, column 3 shows the assembly in a latched position.
[0077] Table 1 a, row 2, column 4 shows schematic of a flat bottom groove.
[0078] Table 1 a, row 2, column 5 shows and enlarged portion of Table 1A, row 2, column 2.
[0079] Table 1 a, row 2, column 6 shows the assembly in a hold running connect direction
[0080] Table 1 a, row 2, column 7 shows an enlarged portion of Table 1 a, row 2, column 3 in a latch position.
[0081] Table 1 a, row 2, column 8 shows the assembly in a hold running disconnect direction.
[0082] Table 1 a, row 2, column 9 shows the assembly returning to the inserting position.
[0083] Table 1 a, row 2, column 10 shows an enlarged view of the point of contact between the coils and the shaft.
[0084] Table 1 a, row 2, column 11 shows an enlarged view of Table 1 a, row 2, column 3.
[0085] Table 1 a, row 2, column 12 shows a cross section of the radial spring with the dot indicating the front angle.
[0086] Table 1 a, row 2, column 13 shows the spring in a free position and shows a front view of the canted coil counterclockwise radial spring with the front angle in front.
[0087] Table 1 a, row 3, columns 2-12 show a spring mounted 180.degree. from that shows in Table 1 a, row 2 in a clockwise position.
[0088] Table 1 a, row 4, columns 1-12 show a V-bottom groove with a counterclockwise radial spring.
[0089] Table 1 a, row 5, columns 1-12 show a flat bottom axial groove with an RF axial spring. The groove width is smaller than the coil height and the point of contact is closer to the centerline of the major axis of the spring coil. The closer the point of contact is to the point at the end of the major axis of the coil, the higher the force required to disconnect in a convex direction. (Table 1 a, row 5, columns 7-8).
[0090] Table 1 a, row 6, columns 2-12 show a flat bottom groove with an F axial spring. The groove width is smaller than the coil height.
[0091] Table 1 a, rows 7-8 and Table 1 b, row 9 show a radial spring turned into an axial spring by assembling this spring into a cavity in an axial position.
[0092] More specifically, Table 1 a, row 6 shows a flat bottom axial groove with counterclockwise radial spring mounted in an RF axial position. The groove width is smaller than the coil height.
[0093] Table 1 a, row 8 is a flat bottom groove with a counterclockwise radial spring mounted in an F axial position.
[0094] Table 1 a, row 9 is a flat bottom groove with a clockwise radial spring mounted in an RF axial position. The groove width smaller than the coil height, and
[0095] Table 1 b, row 2 shows a flat bottom axial groove with clockwise radial spring mounted in F axial position. Groove width smaller than the coil height.
[0096] Table 1 b, row 3 shows a V bottom groove with an RF axial spring. The groove width is smaller than the coil height.
[0097] Table 1 b, row 4 shows a flat bottom groove with an RF axial spring with a groove width larger than the coil height. Making the groove width larger than the coil heights allows the point of contact to move further away from the point at the end of the major axis of the coil at disconnect thus decreasing the force.
[0098] Table 1 b, row 5 shows a V bottom flat groove with RF axial spring. The groove width is larger than the coil height. (GW>CH)
[0099] Table 1 b, row 6 shows a design like Table 1 b, row 5, except that the RF axial spring has offset coils that fit into the groove. The offset coils allow partial contact holding within the groove at different intervals along the groove diameter walls, and the coils are deflected axially at different points of the groove on both sides sufficiently to retain the spring in place. The offset coils increase the total axial coil height, which helps retain the spring inside the groove. The insertion and running forces are also reduced compared to Table 1 b, row 5 where the groove width is smaller than the coil height. The difference in force is illustrated in Table 1 b, row 6, column 12, where force versus shaft travel distance is shown illustrating the force developed.
[0100] Table 1 b, row 6, column 13 and 14 shows the offset coils in a free position.
[0101] Table 1 b, row 6, column 11 shows the point of contact in relation to the point at the end of the major axis of the coils with the point of contact further away from the major axis of the coil thus decreasing the force required to disconnect. This can be compared with Table 1 b, row 8, column 11 whereby the point of contact is closer to the point at the end of the major axis of the coil, thus requiring a substantially higher force to disconnect.
[0102] Table 1 b, row 7 shows an axial RF spring with a tapered bottom groove that positions the point of contact (Table 1 b, row 7, column 11) closer to the end point at the end of the major axis of the coil than in Table 1 b, row 6, column 11, thus requiring a greater force to disconnect.
[0103] Table 1 b, row 8 shows a tapered bottom groove of a different configuration but similar to Table 1 b, row 7 with an RF axial spring with a groove width smaller than the coil height. The groove configuration positions the point of contact closer to the end point at the end of the major axis of the coil. An axial RF spring is used in this design.
[0104] Table 1 b, row 9 shows a tapered bottom groove with RF axial spring with a groove width smaller than the coil height. The point of contact is positioned at the end point of the major axis of the coil and disconnect is not possible as the force is applied along the major axis since the spring will not compress along that axis.
[0105] Table 1 c, row 2 shows a tapered bottom groove with an axial spring mounted in the groove. The position of the spring is such that the centerline along the minor axis is slightly above the bore, which results in less deflection of the spring, thus positioning the point of contact further away from the end point of the major axis of the coil, resulting in a lower disconnect force.
[0106] Table 1 c, row 3 shows a tapered bottom groove with an axial spring mounted in the groove. The groove is shown with a 25-degree angle. By increasing the angle, the distance from the end of the major axis of the coil to the point of contact increases (Table 1 c, row 3, column 11 compared to Table 1 b, row 8, column 11), resulting in lower connect and disconnect forces. On the other hand, decreasing the taper angle will bring the point of contact closer to the end of the major axis of the coil, resulting in higher connect and disconnect forces. Increasing the groove angle will increase the spring deflection which will increase the running force.
[0107] Table 1 c, row 4 shows a tapered bottom groove with an RF axial spring with the shaft inserted in the opposite direction. The groove width is smaller than the coil height. In this case. again, the point of contact at the point at the end of the major axis of the coil and no deflection exists and a disconnect is not possible.
[0108] Insertion force in this direction will cause the spring coil to turn counter clockwise thus applying a force along the major axis of the coil and the spring will not deflect along the major axis causing damage to the spring.
[0109] Table 1 c, row 5 shows a tapered bottom groove with 45.degree. turn angle spring with the shaft inserted in the convex direction. The groove width is smaller than the coil width. The angular spring deflects axially.
[0110] Table 1 c, row 6 shows a tapered bottom groove with an RF axial spring filled with an elastomer with a hollow center. The groove width is smaller than the coil height (GW<CH).
[0111] Table 1 c, row 7 Shows a tapered bottom groove with an RF axial spring filled with an elastomer solid, as in Table 1 c, row 6 with the groove width smaller than the coil height (GW<CH).
[0112] Table 1 c, row 8 shows a step round flat bottom groove with an RF axial spring groove with the width smaller than the coil height. This design has a groove with a point of contact that scrapes the wire as the coil moves, removing oxides that may be formed on the surface of the wire. The groove has been designed to provide a lower force at disconnect by increasing the distance between the point of contact and the point at the end of the major axis of the coil.
[0113] Table 1 c, row 9 shows an inverted V bottom groove with RF axial spring. The groove width is smaller than the coil height.
[0114] Table 1 d, row 2 shows a tapered bottom groove with a counterclockwise radial spring mounted in a RF position. The groove width is smaller than the coil height. Notice the position of the point of contact with respect to the end point at the end of the major axis of the coil. The closer the point of contact to the end point at the end of the major axis of the coil the higher the force required to disconnect.
[0115] Table 1 d, row 3 shows a tapered bottom groove with a counterclockwise radial spring mounted in an F axial position. The groove width is smaller than the coil height.
[0116] Table 1 d, row 4 shows a tapered bottom groove with a clockwise radial spring mounted in an RF axial position. The groove width is smaller than the coil height.
[0117] Table 1 d, row 5 shows a tapered bottom groove with a clockwise radial spring mounted in an F axial position. The groove width is smaller than the coil height.
[0118] Table 1 d, row 6 shows a dovetail groove with a counterclockwise radial spring.
[0119] Table 1 d, row 7 shows a special groove with a counterclockwise radial spring.
[0120] Table 1 d, row 8 shows an angle of zero to 22½ degrees flat and tapered bottom groove with a counterclockwise radial spring. The groove width is greater than the coil width. The spring in latching will turn clockwise positioning the coil to reduce the force required to disconnect by positioning the point of contact further away from the end of the end point at the end of the major axis of the coil.
[0121] Table 1 d, row 9 shows an angle of 0 to 22½ degrees. The piston groove has a flat and a tapered bottom with a clockwise spring. The spring has an ID to coil height ratio smaller than 4. Under load, this spring has a higher torsional force that requires a higher force to connect or disconnect the shaft. Upon latching, the spring turns clockwise, moving the point of contact closer to the end of the major axis of the coil (Table 1 d, row 9, column 7 and Table 1 d, row 9, column 11) thus increasing the force to disconnect.
[0122] Table 1 e, row 2 is like Table 1 d, row 9 except that in this case, the spring groove has an ID to coil height ratio greater than 4, thus the radial force applied to the spring at connect or disconnect is substantially lower. As the ratio of the ID of the spring to the coil height increases, the force required to connect or disconnect decreases due to a lower radial force.
[0123] Table 1 e, row 3 has an angle groove with a 0.degree. to 22.5.degree. piston groove angle similar to FIG. 3 except that the piston groove has a ‘V’ bottom groove instead of a ‘V’ bottom groove with a flat. The housing has a ‘V’ bottom groove with a flat at the bottom of the groove. This design permits for specific load points at connect-latched position.
[0124] Table 1 e, row 4 shows a groove angle 30.degree./22½.degree. bottom groove with a counterclockwise radial spring. The groove width is greater than the coil width. By changing the groove angle, the distance between the point of contact and the point at the end of the major axis of the coil is increased, reducing the force at disconnect.
[0125] Table 1 e, row 5 shows an angle 60.degree./22½.degree. bottom groove with a counterclockwise radial spring. The groove width is greater than the coil width.
[0126] Table 1 e, row 6 shows a special V type bottom with a 23.degree. and 60.degree. angle with a counterclockwise radial spring. The groove width greater than the coil width.
[0127] Table 1 e, row 7 shows a V type bottom groove with 23.degree. and 60.degree. angles like Table 1 e, row 6 with a counterclockwise radial spring. The groove width is greater than the coil width. By moving the shaft forward and then back it causes the spring to turn so the point of contact is closer to the point at the end of the major axis of the coil, increasing the force required to disconnect. When the direction of latching is reversed, the piston is traveling in the direction of the back angle in Table 1 e, row 8, column 1 as opposed to traveling in the direction of the front angle in Table 1 e, row 7, column 2. The increased force increases the turning of the spring, thus increasing the distance between the point of contact and the end point of the major axis, decreasing the force required to disconnect or unlatch. Compare Table 1 e, row 7, column 8 showing the piston moving forward and the position of the point of contact ‘A’ with the position of the point of contact Table 1 e, row 7, column 7.
[0128] Table 1 e, row 9 shows a special V bottom type groove with 22.degree. and 60.degree. angles with a radial spring. The contact point is close to the point at the end of the major axis of the coil for a high disconnect force.
[0129] Table 1 e, row 10 through Table 1 f, row 5 show turn angle springs, assembled in different groove designs. Notice the point of contact position in relation to the POINT AT THE END OF THE major axis of the coil.
[0130] More specifically, Table 1 e, row 10 shows a special V-bottom with 23.degree. and 60.degree. angles with a 20.degree. turn angle spring.
[0131] Table 1 f, row 2 shows a special V-bottom with 30.degree. and 60.degree. angles with a 20.degree. turn angle spring.
[0132] Table 1 f, row 3 shows a special V-bottom with 60.degree. and 49.degree. angles with a 20.degree. turn angle spring.
[0133] Table 1 f, row 4 shows a special groove with a 45.degree. turn angle spring. In this case, the point of contact is closer to the point at the end of the minor axis of the coil. Upon insertion, the pin will cause the spring to expand radially and causing the coil to deflect along the minor axis and causing the spring coils to turn counterclockwise to connect. At disconnect the spring coils will deflect along the minor axis and the coils will continue to turn counterclockwise to disconnect. The spring coils will turn clockwise to its original position when the force acting on the spring is released.
[0134] Table 1 f, row 5 shows a special tapered groove with a 30.degree. angle with a 45.degree. angle at the piston groove. Notice the point of contact in relation to the point at the end of the major axis of the coil.
[0135] Table 1 f, rows 6-8 show an axial spring mounted in a tapered bottom groove.
[0136] More specifically, Table 1 f, row 6 shows an angular groove with an RF axial spring with a groove depth greater than the coil width. Notice the position of the point of contact at disconnect with the coil diameter expands radially permitting disconnect.
[0137] Table 1 f, row 7 shows a groove similar to FIG. 38, but with a tapered angle on one side of the groove.
[0138] Table 1 f, row 8 shows a symmetrical angle groove with an RF axial spring. The groove depth is greater than the coil width.
[0139] Table 1 f, row 9 shows a flat bottom-housing groove with a counterclockwise radial spring. The groove width is greater than the coil height. In this case, the piston has a step groove.
[0140] Table 1 g, rows 2-6 show various methods of mounting a panel on a housing, using a length of spring whose groove can be mounted on the housing or on the panel and such groove has a groove width smaller than the coil height so that the spring can be retained in such groove.
[0141] Table 1 g, row 2 shows a panel-mounted design with length of spring with axial loading and holding.
[0142] Table 1 g, row 2, column 2 shows the panel in an inserting position. Table 1 g, row 2, column 3 shows the panel in a connected position. Table 1 g, row 2, column 4 shows a schematic of the groove design. Table 1 g, row 2, column 5 shows the spring being inserted into the cavity. Table 1 g, row 2, column 7 shows the spring in a holding position. Table 1 g, row 2, column 11 shows an enlarged view of Table 1 g, row 2, column 7.
[0143] Table 1 g, row 3 shows a panel mounting design with length of spring with some axial loading and latching, using a flat tapered groove. The groove width is smaller than the coil height. This particular design will permit axial movement of the panel. Table 1 g, row 2, column 3 shows the design in a latch position, which can permit axial movement. Table 1 g, row 3, column 8 shows an enlarged view of the latch position. Table 1 g, row 3, column 5 shows the point in contact in relation to the end major axis of the coil.
[0144] Table 1 g, row 4 shows a panel mounting design with length of spring with latching, which will permit axial movement of the panel and locking, using a rectangular groove on the panel with the groove width smaller than the coil height.
[0145] Table 1 g, row 4, column 3 shows the design in a latch axial position, permitting some axial movement. Table 1 g, row 4, column 5 shows an enlarged view of the latch position. Table 1 g, row 4, column 9 shows a latch locked position to disconnect. Table 1 g, row 4, column 11 shows an enlarged view of the point of contact with end of major axis of the coil at locking.
[0146] Table 1 g, row 5 shows a panel mounting with length of spring with axial loading and latching. Groove width smaller than the coil height.
[0147] Table 1 g, row 5, column 2 shows the panel in an inserting position and Table 1 g, row 5, column 3 in a latched position with the spring retained in the groove mounted in the housing with the grooves offset from each other. The grooves are offset to provide axial loading in the latched position. In this case, the panel has a V-groove design. Notice the axially loaded position of the spring to prevent axial movement when in a connected-latched position.
[0148] Table 1 g, row 6 shows a panel assembly similar to Table 1 g, row 5 except that the panel has a step flat bottom groove instead of a V-bottom type groove and the housing has a flat tapered bottom groove and it is axially loaded in the connect position. Disconnect in the axial position will not be possible because as the panel is pulled it causes the spring to turn, applying the disconnect component force at the end of the major axis of the coil where no deflection occurs.
[0149] The descriptions illustrated in Tables 1 g, rows 2-6 show the holding, latching, and locking in the axial position. Separation of the panel from the housing can be done by sliding the panel longitudinally.
[0150] These designs indicated in Table 1 g, rows 2-6 show a panel-mounted design; however, the design could also be applicable to other designs, such as cylindrical, rectangular, elliptical or other types of surfaces. All designs are shown with GW<CH; however the groove could be made wider to be GW<CH with lower connect-disconnect force.
[0151] Table 1 g, rows 7-9 are similar to Table 1 e, row 3, show different methods of retaining the spring in the cavity.
[0152] Table 1 g, row 7 shows a rectangular washer retaining the spring in position.
[0153] Table 1 g, row 8 shows a snap ring retaining the spring in position.
[0154] Table 1 g, row 9 shows a washer retained in position by rolling over a portion of the housing on to the washer housing to form the retaining groove.
[0155] The designs are shown with specific dimensions, angles and groove configurations. These values can be changed to other angles and groove configurations while achieving the results indicated.
[0156] Piston Mounted Designs for Latching Applications.
[0157] Table 2 a-2 show various designs with the spring mounted in the piston in latching applications. In essence, these applications are similar to the ones that are described in Tables 1 a-1 g except that the spring is mounted in the piston and it encompasses 48 variations of groove designs.
[0158] Table 2 a, row 2 shows a flat bottom groove with counterclockwise radial spring with a groove width greater than the coil width. Table 2 a, columns 2-9, show different assemblies of the spring and grooves and the spring in various positions.
[0159] Table 2 a, row 2, column 2 shows the assembly in an insert position.
[0160] Table 2 a, row 2, column 3 shows the assembly in a latch position.
[0161] Table 2 a, row 2, column 4 shows the cross section of the flat bottom groove.
[0162] Table 2 a, row 2, column 5 shows an enlarged view of Table 2 a, row 2, column 2.
[0163] Table 2 a, row 2, column 6 shows the position of the spring in a hold-RUNNING position with the spring deflected along the minor axis.
[0164] Table 2 a, row 2, column 7 shows an enlarged position of Table 2 a, row 2, column 3 in a latched-connect position moving in a disconnect direction relative to the end point of the major axis.
[0165] Table 2 a, row 2, column 8 shows the assembly in hold-disconnect direction.
[0166] Table 2 a, row 2, column 9 shows the assembly returning to the inserting position.
[0167] Table 2 a, row 2, column 10 shows the spring in a free position.
[0168] Table 2 a, row 2, column 11 shows a partial enlarged view of Table 2 a, row 2, column 7.
[0169] Table 2 a, row 2, column 12 shows a cross sectional view of the spring showing the position of the front angle.
[0170] Table 2 a, row 2, column 13 shows a front view of the spring in a counterclockwise with the radial spring front angle in the front.
[0171] Table 2 a, row 3, is the same position as Table 2 a, row 2 except that the spring has been turned around 180.degree.
[0172] Table 2 a, row 4 shows a V-bottom groove with a counterclockwise radial spring with a groove width greater than the coil width.
[0173] Table 2 a, row 5 shows a flat bottom axial groove with an RF axial spring. The groove width is smaller than the coil height. The point of contact is close to the end point of the major axis of the coil, requiring a high force to disconnect.
[0174] Table 2 a, row 6 shows a design as in Table 2 a, row 5 except it uses an F spring.
[0175] Table 2 a, rows 7-9 and Table 2 b, row 2 shows a radial spring turned into an axial spring. using a flat bottom groove.
[0176] Table 2 b, row 3 shows a V-bottom groove with an RF axial spring. The groove width is smaller than the coil height.
[0177] Table 2 b, row 4 shows a flat bottom groove with an RF axial spring. The groove width is greater than the coil height, thus resulting in lower disconnect force.
[0178] Table 2 b, row 5 shows a V-bottom tapered groove with an RF axial spring. The groove width is greater than the coil height.
[0179] Table 2 b, row 6 shows a design like Table 2 b, row 8, except that the RF axial spring has offset coils that fit into the groove. The offset coils allow partial contact holding within the groove at different intervals along the groove diameter walls, and the coils are deflected axially at different points of the groove on both sides sufficiently to retain the spring in place. The offset coils increase the total axial coil height, which helps retain the spring inside the groove. The insertion and running forces are also reduced compared to Table 2 b, row 8 where the groove width is smaller than the coil height. The difference in force is illustrated in Table 2 b, row 5, column 12, where we show force versus shaft travel distance, illustrating the force developed in Table 2 b, row 7 and in Table 2 b, row 6.
[0180] Table 2 b, row 6, column 12 shows a diagram Force vs. Shaft Travel Distance that compares the force developed by Table 2 b, row 7 vs. Table 2 b, row 6.
[0181] Table 2 b, row 6, columns 14-15 shows the offset coils in a free position.
[0182] Table 2 b, row 6, column 11 shows the point of contact in relation to the point at the end of the major axis of the coils with the point of contact further away from the end point of the major axis of the coil thus decreasing the force required to disconnect. This can be compared with Table 2 b, row 7, column 11 whereby the point of contact is closer to the end point of the major axis of the coil, thus requiring a substantially higher force to disconnect.
[0183] Table 2 b, row 7 shows an axial RF spring with a tapered bottom groove that positions the point of contact (Table 2 b, row 7, column 11) closer to the end point of the major axis of the coil than in Table 2 b, row 6, column 11, thus requiring a greater force to disconnect.
[0184] Table 2 b, row 8 shows a tapered bottom groove of a different configuration but similar to Table 2 b, row 7 with an RF axial spring with a groove width smaller than the coil height. The groove configuration positions the point of contact closer to the end point at the end of the major axis of the coil. An axial RF spring is used in this design.
[0185] Table 2 b, row 9 shows a tapered bottom groove with RF axial spring with a groove width smaller than the coil height. The end point of contact is positioned at the point of contact at the end point of the major axis of the coil and disconnect is not possible as the force is applied along the major axis since the spring will not compress along that axis.
[0186] Table 2 c, row 2 shows a tapered bottom groove with an axial spring mounted in the groove. The position of the spring is such that the centerline along the minor axis is slightly above the bore, thus positioning the point of contact further away from the end point of the major axis of the coil, resulting in a lower disconnect force.
[0187] Table 2 c, row 3 shows a tapered bottom groove with an axial spring mounted in the groove. The groove is shown with a 25-degree angle. By increasing the angle, the distance from the end point of the major axis of the coil to the point of contact increases (Table 2 c, row 3, column 11 compared to Table 2 b, row 9, column 11), resulting in lower connect and disconnect forces. On the other hand, decreasing the taper angle will bring the point of contact closer to the end point of the major axis of the coil, resulting in higher connect and disconnect forces. Increasing the groove angle will increase the spring deflection which will increase the running force (Table 1 c, row 2, column 6, Table 1 c, row 3, column 8).
[0188] Table 2 c, row 4 shows a tapered bottom groove with an RF axial spring with the shaft inserted in the opposite direction. The groove width is smaller than the coil height. In this case, again, the point of contact is at the end point of the major axis of the coil and no deflection exists and a disconnect is not possible.
[0189] Table 2 c, row 5 shows a tapered bottom groove with 45.degree. turn angle spring with the shaft inserted in the convex direction. The groove width is smaller than the coil width. The angular spring deflects axially.
[0190] Table 2 c, row 6 shows a tapered bottom groove with an RF axial spring filled with an elastomer with a hollow center. The groove width is smaller than the coil height (GW<CH).
[0191] Table 2 c, row 7 shows a tapered bottom groove with an RF axial spring filled with an elastomer solid, as in Table 2 c, row 6 with the groove width smaller than the coil height (GW<CH).
[0192] Table 2 c, row 8 shows a step round flat bottom groove with an RF axial spring groove with the width smaller than the coil height. This design has a groove with a point of contact that scrapes the wire as the coil moves, removing oxides that may be formed on the surface of the wire. The groove has been designed to provide a lower force at disconnect by increasing the distance between the point of contact and the end point of the major axis of the coil.
[0193] Table 2 c, row 9 shows an inverted V bottom groove with an RF axial spring. The groove width is smaller than the coil height.
[0194] Table 2 d, row 2 shows a tapered bottom groove with a counterclockwise radial spring mounted in an RF position. The groove width is smaller than the coil height. Notice the position of the point of contact with respect to the end point at the end of the major axis of the coil. The closer the point of contact to the end point of the major axis of the coil, the higher the force required to disconnect.
[0195] Table 2 d, row 3 shows a tapered bottom groove with a counterclockwise radial spring mounted in an F axial position. The groove width is smaller than the coil height.
[0196] Table 2 d, row 4 shows a tapered bottom groove with a clockwise radial spring mounted in an RF axial position. The groove width is smaller than the coil height.
[0197] Table 2 d, row 5 shows a tapered bottom groove with a clockwise radial spring mounted in an F axial position. The groove width is smaller than the coil height.
[0198] Table 2 d, row 6 shows a dovetail groove with a counterclockwise radial spring.
[0199] Table 2 d, row 7 shows a special groove with a counterclockwise radial spring.
[0200] Table 2 d, row 8 shows an angle of zero to 22½ degrees flat and tapered bottom groove with a counterclockwise radial spring. The groove width is greater than the coil width. The spring in latching will turn clockwise positioning the coil to reduce the force required to disconnect by positioning the point of contact further away from the end of the end point at the end of the major axis of the coil.
[0201] Table 2 d, row 9 shows an angle of 0 to 22½ degrees. The piston groove has a flat and a tapered bottom with a clockwise spring. The spring has an ID to coil height ratio smaller than 4. Under load, this spring has a higher torsional force that requires a higher force to connect or disconnect the shaft. Upon latching, the spring turns clockwise, moving the point of contact closer to the end point of the major axis of the coil (Table 2 d, row 9 column 7, column 11) thus increasing the force to disconnect.
[0202] Table 2 e, row 2 is like Table 2 d, row 9 except that in this case, the spring groove has an ID to coil height ratio greater than 4, thus the torsional force applied to the spring at connect or disconnect is substantially lower. As the ratio of the ID of the spring to the coil height increases. the force required to connect or disconnect decreases due to a lower torsional force.
[0203] Table 2 e, row 3 has an angle groove with a 0.degree. to 22.5.degree. piston groove angle similar to Table 2 a, row 4 except that the piston groove in Table 2 e, row 3 has a ‘V’ bottom groove instead of a ‘V’ bottom groove with a flat. The housing in Table 2 e, row 3 has a bottom groove with a flat at the bottom of the groove. This design permits for specific load points at connect-latched position.
[0204] Table 2 e, row 4 shows a groove angle 30.degree./22½.degree. bottom groove with a counterclockwise radial spring. The groove width is greater than the coil width. By changing the groove angle, the distance between the point of contact and the end point of the major axis of the coil is increased, reducing the force at disconnect.
[0205] Table 2 e, row 5 shows an angle 60.degree./22½.degree. bottom groove with a counterclockwise radial spring. The groove width is greater than the coil width.
[0206] Table 2 e, row 6 shows a special V type bottom with a 23.degree. and 60.degree. angle with a counterclockwise radial spring. The groove width is greater than the coil width.
[0207] Table 2 e, rows 7-8 show a V type bottom groove with 23.degree. and 60.degree. angles like Table 2 e, row 6 with a counterclockwise radial spring. The groove width is greater than the coil width. By moving the shaft forward and then back we cause the spring to turn so the point of contact is closer to the end point at the end of the major axis of the coil, increasing the force required to disconnect. When the direction of latching is reversed, the piston is traveling in the direction of the back angle in Table 1 e, row 7, as opposed to traveling in the direction of the front angle in Table 1 e, row 6. The increased force increases the turning of the spring, thus increasing the distance between the point of contact and the end point of the major axis, increasing the force required to disconnect or unlatch. Compare Table 2 e, row 7, column 8 showing the piston moving forward and the position of the point of contact “A” with the position of the point of contact Table 2 e, row 8, column 7.
[0208] Table 2 e, row 9 shows a special V bottom type groove with 22.degree. and 60.degree. angles with a radial spring. The contact point is close to the end point at the end of the major axis of the coil for a higher disconnect force.
[0209] Table 1 f, rows 2-6 show turn angle springs, assembled in different groove designs. Notice the point of contact position in relation to the end point of the major axis of the coil.
[0210] Table 2 f, row 2 shows a special V-bottom with 23.degree. and 60.degree. angles with a 20.degree. turn angle spring.
[0211] Table 2 f, row 3 shows a special V-bottom with 30.degree. and 60.degree. angles with a 20.degree. turn angle spring.
[0212] Table 2 f, row 4 shows a special V-bottom with 30.degree. and 49.degree. angles with a 20.degree. turn angle spring.
[0213] Table 2 f, row 5 shows a special groove with a 45.degree. turn angle spring. In this case. the point of contact is closer to the end point at the end of the minor axis of the coil. Upon insertion, the pin will cause the spring to contract radially (Table 2 f, row 5, column 2) and causing the coil to deflect along the minor axis (Table 2 f, row 5, column 6) and causing the spring coils to turn counterclockwise to connect (Table 2 f, row 5, column 7). At disconnect the spring coils will deflect along the minor axis and the coils will continue to turn counterclockwise to disconnect (Table 2 f, row 5, column 8). The spring coils will turn clockwise to its original position (Table 2 f, row 5, column 9) when the force acting on the spring is released.
[0214] Table 2 f, row 6 shows a special tapered groove with a 30.degree. angle with a 45.degree. angle at the piston groove. Notice the point of contact in relation to the end point at the end of the major axis of the coil.
[0215] Table 2 f, row 7 shows a flat bottom-housing groove with a counterclockwise radial spring. The groove width is greater than the coil height. In this case, the piston has a step groove.
[0216] Table 2 f, row 8 shows a panel mounted design with length of spring with axial loading and holding.
[0217] Table 2 f, row 8, column 2 shows the panel in an insert position. Table 2 f, row 8, column 3 shows the panel in a connected position. Table 2 f, row 8, column 4 shows a schematic of the groove design. Table 2 f, row 8, column 5 shows the spring being inserted into the cavity. Table 2 f, row 5, column 7 shows the spring in a holding position. Table 2 f, row 8, column 11 shows an enlarged view of Table 2 f, row 5, column 7 with the panel bottoming.
[0218] Table 2 f, row 9 shows a panel mounting design with length of spring with some axial loading and latching, using a flat tapered groove. The groove width is smaller than the coil height. This particular design will permit axial movement of the panel. Table 2 f, row 9, column 3 shows the design in a latch position, which will permit axial movement. Table 2 f, row 9, column 7 shows an enlarged view of the latch position. Table 2 f, row 9, column 11 shows the point in contact in relation to the end point of the major axis of the coil.
[0219] Table 2 g, row 2 shows a panel mounting design with length of spring that will permit axial movement of the panel and locking, using a rectangular groove on the housing with the groove width smaller than the coil height.
[0220] Table 2 g, row 2, column 3 shows the design in a latch axial position, permitting some axial movement. Table 2 g, row 2, column 7 shows an enlarged view of the latch locking means and Table 2 g, row 5, column 10 shows an enlarged view of the point of contact with end of major axis of the coil.
[0221] Table 2 g, row 3 shows a panel mounted design using a length of spring. The groove width is smaller than the coil height. Table 2 g, row 3, column 2 shows the panel in an inserting position and Table 2 g, row 3, column 3 in a latched position with the spring retained in the groove mounted in the housing with the grooves offset from each other. The grooves are offset to provide axial loading in the latched position. In this case, the panel has a V-groove design. Notice the axially loaded position of the spring to prevent axial movement when in a connected-latched position.
[0222] Table 2 g, row 4 shows a panel assembly similar to Table 2 g, row 3 except that the panel has a step flat bottom groove instead of a V-bottom type groove and the panel has a flat tapered bottom groove and it is axially loaded in the connect position. Disconnect in the axial position will not be possible because as the panel is pulled it causes the spring to turn, applying the disconnect component force at the end point of the major axis of the coil where no deflection occurs. The descriptions illustrated in Table 2 f, row 8 through Table 2 g, row 4 show the holding, latching, and locking in the axial position. Separation of the panel from the housing can be done by sliding the panel longitudinally.
[0223] The designs indicated in Table 2 f, row 8 through Table 2 g, row 4 show a panel mounted design; however the design could also be applicable to other designs, such as cylindrical, rectangular, elliptical or other types of surfaces. All designs are shown with GW<CH; however the groove could be made wider to be GW<CH with lower connect-disconnect force.
[0224] The designs are shown with specific dimensions, angles and groove configurations. These values can be changed to other angles and groove configurations while achieving the results indicated.
[0225] Spring Characteristics that Affect Performance
[0226] Spring Design and Installation Factors
[0227] Using an axial spring to enhance retention of the spring in the groove or using a radial spring turned into an axial spring at installation.
[0228] Using an axial spring or a radial spring turned into an axial spring at installation to increase initial insertion, running and disconnect forces
[0229] Changing the Coil Width to Coil Height Ratio
[0230] When the coil width to height ratio is close to one, the spring will turn easier reducing forces since the spring is round.
[0231] The smaller the coil width to coil height ratio, the smaller the back angle. The smaller the back angle, the higher the insertion force required when the piston is inserted in the spring into the back angle first. The opposite is true when the coil width to coil height ratio is reversed, i.e., the back angle is larger and the insertion forces are lower.
[0232] Using an F axial spring to increase the insertion running and disconnect forces compared to an RF spring.
[0233] Using an RF axial spring to reduce the insertion, running, and disconnect forces.
[0234] Using an offset axial spring to reduce the initial insertion running force, and disconnect forces.
[0235] Using a length of spring mounted in an axial type groove for panel applications
[0236] Using a spring with a ratio of ID to coil height to vary insertion, connect and the disconnect forces. As the ratio increases, the forces will decrease or vice versa as the ratio decreases the forces increase.
[0237] Using springs with varying turn angles to vary forces.
[0238] Using an axial spring with offset coils where the groove width is smaller than the coil height and addition of the coil height of the various coils to reduce insertion, running, connect, and disconnect forces and the ratio of connect to disconnect force.
[0239] The connect/disconnect forces decrease as the ratio of ID to coil height increases.
[0240] Using variable means to form the ring, ranging from threading the ends, latching the ends, interfacing the ends and butting as opposed to welding.
[0241] Varying the Device Geometry to Control the Forces
[0242] Designing the groove geometry to position the point of contact at disconnect relative to the end point of the major axis of the coil.
[0243] Positioning the end point of the spring major axis. The shorter the distance to the contact point, the higher the force required to disconnect.
[0244] Positioning the end point of the spring minor axis. The shorter the distance to the contact point, the lower the force required to disconnect.
[0245] Varying the groove design and insertion direction to vary the force.
[0246] Varying the groove geometry so that the spring torsional force in the latched position is in an axial direction thus increasing the force required to disconnect and minimizing axial play.
[0247] Position the latching grooves so that they are offset, causing the axial or radial spring coils to turn, introducing an axial force that reduces axial play and increases the force required to connect-disconnect. Table 1 g, row 5, column 12; row 2, Table 2 a, row 6, column 6 and row 8, column 6.
[0248] Position the geometry of the latching grooves that will cause the axial and radial spring coils to turn, increasing the force required to connect-disconnect. FIGS. 12 e and 13 e.
[0249] The use of multiple springs and grooves to increase the forces and the current carrying capacity.
[0250] The forces vary according to the direction of the piston insertion.
[0251] Using threaded grooves with a spring length retained in the groove with a groove width smaller than the coil height.
[0252] In accordance with the present invention to attain the maximum disconnect force, the point of contact should be as close as possible to the end of the major axis of the coil. Table 1 and Table 2 a (rows 5, columns 7 and 11).
[0253] To attain the minimum disconnect force, the contact point, should be as close as possible to the end of the minor axis of the coil. Table 1 a and Table 2 a (row 1, column 7 and 11).
[0254] An axial spring with offset coils mounted in a housing with the groove width smaller than the addition of the coil height of the various coils, providing the following features:
[0255] Lower spring retention force.
[0256] Lower insertion force
[0257] Lower ratio of disconnect to connect
[0258] Lower ratio of disconnect to running force.
[0259] Reference Table 1 b and Table 2 b, row 6 vs. row 8.
[0260] Modification of the groove cavity that affects the position of the point of contact in relation to the end point of the major axis of the coil that affects the force required to disconnect, connect. Reference Table 1 b and Table 2 b, row 8 vs. row 9 and row 8, column 4 vs. row 9, column 4.
[0261] Modification of the groove cavity that affects the position of the point of contact in relation to the end of the major axis of the coil that affects the force required to disconnect-connect. Reference Table 1 b and Table 2 b, row 9 vs. Table 1 c, 2c, row 2 and Table 1 a, 2a, row 9, column 4 vs. Table 2 a, 2c, row 2, column 4.
[0262] The greater the interference between the coil height and the groove width, the higher the force required to disconnect. Table 1 a and Table 2 a (row 5, column 5 versus Table 1 b, 2b, row 4, column 5) Table 1 a, 2a, row 5, column 5 has interference between the coil height and the groove width while row 6 shows a clearance between the coil height and the groove width.
[0263] The higher the position of the coil centerline along the minor axis in relation to the groove depth. (Reference Table 1 b and Table 2 b, row 8, column 4 versus Table 1 c, 2c, row 2, column 4) the higher the force required to disconnect.
[0264] The type of axial spring mounted in a housing or piston RF vs. F with RF having substantially more deflection but lower force compared to F. Reference Table 1 a and Table 2 a, row 5, column 2, column 5, and column 6 versus row 6, column 2, column 5 and column 6.
[0265] Manner and type of spring used affects the force required to connect/disconnect, using an axial RF or an F spring assembled into a groove whose groove width is smaller than the coil height versus a radial spring turned into an axial spring RF or F spring with coils canting clockwise or counterclockwise. Reference Table 1 a and Table 2 a, rows 5 and 6 versus rows 7, 8, 9 and Table 1 b, 2b row 2 and also row 8 vs. Table 1 d, 2d, rows 2-5.
[0266] Direction of movement of the piston or housing a radial spring that affects the force required to connect and disconnect. Reference Tables 1 d, 2 d, row 8, columns 2, 5, 7 and 11 vs. row 9, column 2, 5, 7, and 11 due to variation that exists between row 8 and row 9 between the point of contact and the point at the end of the major axis of the coil that results in substantial variation in forces.
[0267] The greater the insertion force of an axial spring into a groove whose GW<CH, the higher the force required to disconnect (Reference Table 1 b, 2b, row 8, column 5 vs. row 9, column 5).
[0268] Radial springs with different ratios of spring ID to coil height mounted in a housing or piston. Reference Table 1 d, 2d, row 9 vs. Table 1 e, 2e, row 2. The greater the ratio the lower the forces.
[0269] Variations of groove configuration affecting the connect-disconnect force by varying the groove angle. Reference Table 1 e, row 3, column 5, column 7, column 11 vs. row 4, column 5, column 7, column 11. Such angle variation affects the distance between the point of contact and the point at the end of the major axis of the coil. The closer these two points the higher the force required to disconnect.
[0270] The effect of axially loading in the latched position or disconnect and the effect on initial disconnect force and travel.
[0271] A radial spring axially loaded in the latched position will require a higher initial disconnect force than a non-axially loaded spring. ( FIGS. 4 a and 4 e vs. FIGS. 5 a and 5 e and FIGS. 4-5 f vs. 4 - 5 g. Also FIGS. 6 a and 6 e vs. FIGS. 7 a and 7 e and FIG. 6-7 g ). As shown in FIGS. 5 a and 7 a , an abutting relationship between a housing bore and piston eliminating axial play upon connection.
[0272] In that regard, a housing bore, groove, and piston are oriented for enabling the production of an audible sound indicating a connection between the housing and piston upon abutting of the housing bore and piston.
[0273] With reference to FIGS. 5 a - 5 d, a major axis of the coil spring is positioned so that it is above an inside diameter of the housing groove.
[0274] With reference to FIGS. 7 a - 7 d, a major axis of the coil spring is positioned so that it is below an outer diameter of the piston groove.
[0275] An axially loaded axial spring will develop a higher initial force as shown in Table 1 g, row 2, column 3, column 7, column 11 at disconnect than a non-axially loaded, and also Table 2 f, row 8, column 3, column 7 and column 11.
[0276] Direction of the spring upon insertion as pointed out by the direction of the arrows. (Canted coil springs always deflect along the minor axis of the coil). The spring turns in the direction of the arrow, as shown in the following:
[0277] FIGS. 1 a , 1 b forward in the direction of the arrow, Table 1 a and Table 2 a, row 2, column 8 and column 11 in the opposite direction.
[0278] An axial spring axially loaded in the latched position will require a higher disconnect force than a non-axially loaded spring.
[0279] Recognizing the direction in which the spring will deflect and may turn, assists in selecting the groove configuration. When the load is applied, the spring always deflects along the minor axis of the coil as it is the easiest way to deflect. The spring turns when the ratio of the coil width to the coil height is equal to 1 or greater. As the ratio increases, the ability of the spring coils to turn decreases, causing the spring to deflect instead of turn. Specifically,
[0280] A spring with different turn angles in conjunction with different grooves to vary the force to connect and disconnect. Turn angles permit the design of the grooves so that the spring does not have to be turned at assembly. Reference Table 1 f and Table 2 f, rows 2, columns 2, 7, 11 and row 6, columns 2, 5, 7 11;
[0281] Disconnect by expanding the ID of the spring and compressing the coils along the minor axis of the coils to affect insertion, connect and disconnect. Table 1 f, rows 6-8;
[0282] Housing mounted grooves using a single groove versus a split groove. Note: all drawings in Table 1 a show a split groove and Table 2 a shows a single groove in row 4, column 2;
[0283] Panel mounted spring with groove width smaller than the coil height using a spring in length. Axial latching and axial loading the spring to prevent axial movement. Table 1 g, rows 2-3, Table 2 g, rows 8-9;
[0284] Axial loading the spring coils by offsetting the position of the grooves axially between the housing and shaft so as to create an axial load on the spring to reduce or eliminate movement between the shaft and housing. This configuration has a higher force as shown in FIGS. 4-5 ;
[0285] Multiple springs mounted in multiple single grooves of any of the designs in Tables 1 a-1 g, Tables 2 a-2 g and in FIGS. 1-18 f with either radial or axial springs that can be mounted radially or axially with springs for variable force retention, play or no play and conductivity. See FIGS. 8 and 9 .
[0286] Threaded grooves using a spring length retained in the groove having a groove width smaller than the coil height. FIGS. 10 a , 10 b and 10 d;
[0287] Threaded grooves using a radial or turn angle spring in length using a groove having a groove width greater than the coil width (GW>CW) Table 1 a, row 1, column 2, row 4, column 2 and Table 1 d, rows 6-9 through Table 1 f, row 5 and Table 2 g, row 2 and Table 2 f, row 7 and FIGS. 5 , 6 , 7 and 8 ;
[0288] Panel mounted in a housing radial or axial spring in length and the spring can be retained in the panel or the housing for axial holding, latching or locking the panel to the housing and when in a latched or locked position the panel may be axially loaded to eliminate axial play:
[0289] Various types of spring-ring groove mounted designs with variable means to form a ring, ranging from threading the ends, latching the ends, interfacing the ends and butting, using non-welded springs to form a ring. FIGS. 15 , 16 , 17 , and 18 ;
[0290] Different groove configurations that affect the force parameters, depending on the position of the point load in reference to the end point of the major axis of the coil that affects the ratio of disconnect to insertion, disconnect to running force, and the disconnect forces with a radial spring;
[0291] A radial or axial spring whose coil width to coil height ratio is one that will require higher force at connect and disconnect due to the smaller back angle of the coil. The closer the ratio to one the higher the force required to disconnect-connect;
[0292] The smaller the groove width to coil height ratio, the higher forces. Reference Table 1, row 8, column 4 vs. Table 1, row 9, column 4;
[0293] Variation of the groove geometry by including a step groove design to control the position of the contact point relative to the end point of the centerline. Table 1 f, row 9, column 2, 7, and 11;
[0294] Variation of the groove geometry to control the position of the point of contact and the end point of the centerline. Table 1 f, rows 6-8;
[0295] Device with high forces created by offsetting the centerlines of the grooves as shown in Table 2 a, rows 6 and 8;
[0296] Reversing the direction of travel in a clockwise or counterclockwise radial spring will switch from the front angle to the back angle or vice versa, thus changing the relative position of the contact point with respect to the end point of the centerline thus varying the forces. See Table 1 e and Table 2 e, rows 7, column 8 and row 8, column 7 comparing the position of the contact point to the end point centerline; and
[0297] Retention of radial spring with a dovetail type groove Table 1 d and 2 d, rows 6-7.
[0298] Although there has been hereinabove described a specific spring latching connectors radially and axially mounted in accordance with the present invention for the purpose of illustrating the manner in which the invention may be used to advantage, it should be appreciated that the invention is not limited thereto. That is, the present invention may suitably comprise, consist of, or consist essentially of the recited elements. Further, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein. Accordingly, any and all modifications, variations or equivalent arrangements which may occur to those skilled in the art, should be considered to be within the scope of the present invention as defined in the appended claims. | A spring latching connector includes a housing having a bore therethrough, a piston slidably received in said bore, a circular groove formed in one of said bore and piston and a circular coil spring disposed in said groove for latching said piston and housing together. The groove is sized and shaped for controlling, in combination with a spring configuration, disconnect and connect forces of the spring latching connection. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to an adjuster mechanism for a brake.
As brake pads or brake disc wear the gap between the pads and brake disc increases. Due to the increase in distance between the brake pads and the brake disc the brake actuator must travel farther to engage the brake. In other words, there is more slack when the brake is applied which causes the brakes to become less effective. In order to compensate for slack, a slack adjustment mechanism moves the brake pads closer to the brake disc prior to brake engagement. Adjusting the length of the load bearing components assures a consistent amount of actuator travel in spite of brake pad wear.
Conventional brake adjuster mechanisms use relatively complex mechanical assemblies to perform this function. Force from the brake actuator is commonly utilized to drive the adjuster mechanism, which may reduce brake effectiveness and efficiency.
In addition, the adjuster mechanism may shift while the brake is not being applied. Shifting may cause undesirable brake pad wear, or further increase slack in the brake system which may reduce the brake performance.
Accordingly, it is desirable to provide an adjuster mechanism which does not increase driver effort, and which is securely restrained when the brake is not being utilized.
SUMMARY OF THE INVENTION
The slack adjustment system according to the present invention provides an adjustment mechanism which utilizes a biasing member to adjust slack in a system. The biasing member operates independently of the pressure applied to a brake actuator. A locking mechanism is utilized to secure the adjustment mechanism in place when adjustment is not necessary. Additionally, the locking mechanism controls the desired amount of slack.
The locking mechanism selectively engages a tappet or any rotational member engaged with said tappet to prevent the tappet from being rotated and unnecessarily adjusting the gap between the brake pad and the brake disc. A latch interfitting with the tappet prevents rotation when engaged with the tappet. The latch disengages from the tappet after a predetermined movement of the tappet. Release of the locking mechanism allows the tappet to rotate. The biasing member is mounted to engage and rotate the tappet when the locking member is not preventing movement. The biasing member is of a type which applies a rotational force to the thrust assembly independent of the amount of pressure applied to the brake actuator. The biasing member may be a spring, electric motor, air powered motor or the like.
The present invention therefore provides a method of automatically adjusting slack independent of the pressure applied to the brake system by the driver. In addition, a locking device prevents unintentional adjustment of slack in the brake system.
BRIEF DESCRIPTION OF THE DRAWINGS
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows:
FIG. 1 is a sectional side-view of a brake assembly with a slack adjustment system according to the present invention;
FIG. 2 is a sectional plan-view of a brake assembly;
FIG. 3 is a sectional plan-view of the slack adjustment system according to the present invention showing the tappet moved forward by a distance equal to the desired amount of slack, with the latch just disengaged from the rotational member;
FIG. 4 is a sectional plan view of the slack adjustment system according to the present invention showing all components in the brake fully applied position;
FIG. 5 is a sectional plan-view of the slack adjustment system according to the present invention shown in the locked position;
FIG. 6 is a sectional end-view of the rotational member and tappet gear-train showing the preferred directions of rotation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a disc brake assembly 10 which utilizes a slack adjustment system 12 of the present invention. The disc brake assembly 10 has a frame 11 , which encloses the internal components and bears the loads generated by them. As a driver operates a brake (not shown) an input load (schematically illustrated by arrow L) is transferred to a lever 14 , through opening 16 in the frame 11 . The lever 14 is rotatably supported by the frame 11 through a bearing 18 . The lever rotates about a lever axis 20 . That is, the lever 14 rotates clockwise about the lever axis 20 , as illustrated in FIG. 1 . The base of the lever 14 is recessed to hold cylindrical roller 22 . The roller 22 is eccentrically centered relative the center of rotation of the lever 14 . That is, the roller axis 24 moves in an arc around the lever axis 20 .
The input load L causes the lever 14 to rotate about the lever axis 20 and the roller 22 to move in an arc around the lever axis 20 (the position illustrated in phantom shows the extreme of travel available to the lever 14 ). The eccentric movement of the roller 22 engages one or more thrust assemblies 26 and applies a load to the thrust assemblies 26 causing the thrust assemblies 26 to move perpendicularly away from the lever 14 , guided by a housing 61 . The preferred embodiment, shown in FIG. 2 , includes two thrust assemblies 26 . This motion defines a thrust axis 27 perpendicular to the lever and roller axes 20 , 24 . The axial movement of the thrust assemblies 26 along the thrust axis 27 engages the brake pad 28 through the thrust plate 62 . The brake pad 28 engages the brake disc 29 . When the driver releases the brake, actuator input load L is reduced and return spring 31 drives the thrust assemblies 26 to the original position. The lever 14 and roller 22 also return to the original position. The return spring 31 restrains the thrust assemblies 26 , roller 22 and lever 14 in the original position when no input load L is being applied.
The thrust assembly 26 is guided by a housing 61 that is attached to frame 11 by fasteners 32 , (only one shown). The thrust assemblies 26 consists of internally threaded tappet nuts 63 and externally threaded tappet screws 64 . The tappet nuts 63 are rotationally constrained by the housing 61 , such that when the tappet screws 64 are rotated, the length of the thrust assemblies 26 along the thrust axis 27 is altered. The length of the two thrust assemblies 26 may be synchronized by a rotational member 48 , which is permanently engaged with the two tappet screws 64 .
Referring to FIG. 2 , the locking mechanism 42 selectively engages the gear on the tappet screw 64 to prevent the tappet screw 64 from being rotated and unnecessarily adjusting the gap between the brake pad 28 and the brake disc 29 . A latch 54 intermitting with the rotational member 48 prevents rotation when the brake is not applied, and when the brake is applied but the thrust assemblies 26 have moved by less than the pre-defined slack. The latch 54 is mounted to a link 56 , which may be a rod or the like, which is mounted to lever 14 .
When the brake is not applied, or during normal braking movement when the thrust assemblies 26 have moved through less than the pre-defined amount of slack and no adjustment is required, the rotational member 48 and tappet screws 64 may be locked from rotation by a locking mechanism 42 . When the locking mechanism 42 is engaged, the rotational member 48 and tappet screws 64 cannot rotate. The force applied to tappet screws 64 by rotation of lever 14 axially drives the thrust assemblies 26 along the thrust axis 27 toward the brake disc 29 . The locking mechanism 42 , consisting of a latch 54 driven by the lever 14 via a link 56 , moves relative to the gear on the outside of the rotational member 48 (shown in FIG. 3 to be moving along an axis parallel to the thrust axis 27 , but alternatively could be moved radially away from the thrust axis 27 by re-arranging the connecting link 56 ). The point at which the latch 54 disengages is determined by the geometry of the link 56 . When the pre-defined slack between the brake pads 28 and disc 29 has been taken up, the latch 54 disengages from the gear on the rotational member 48 . Simultaneously, load starts to be applied to the brake pad 28 via the thrust assemblies 26 . This load produces a friction torque between the tappet nuts 63 and tappet screws 64 , preventing any relative rotation and, hence, adjustment when the brake is applied, shown in FIG. 4 . When the brake is released, all components are returned to their original positions by the return spring 31 with no adjustment of the length of the thrust assemblies 26 having taken place.
As the brake pad 28 wears away, the slack between the brake pad 28 and the thrust assemblies 26 increases, and the thrust assemblies 26 must move a greater distance along the thrust axis 27 in order to engage the brake pad 28 with the brake disc 29 . To compensate for the wear on the brake pad 28 , the tappet screws 64 are adjusted to increase the overall length of the thrust assembly 26 , resulting in a constant slack being maintained between the brake pad 28 and brake disc 29 .
Referring to FIG. 5 , the slack adjustment system 12 of the present invention is utilized to adjust the slack in the disc brake assembly 10 . When the locking mechanism 42 is released the rotational member 48 and tappet screws 64 can rotate. A biasing member 44 is mounted in the housing 61 , and applies a biasing torque to the rotational member 48 . A biasing axis 46 is preferably parallel to and offset from the thrust axis 27 , but could be in any position or angle inside or outside the frame 11 where it can still be engaged directly or indirectly to the tappet screws 64 . The biasing member 44 is preferably a coil spring but may take other forms such as an electric motor, air motor, or the like. The rotational member 48 is mounted about the biasing member 44 and is driven by the biasing member 44 in a first rotational direction 50 about the biasing axis 46 . The rotational member 48 engages with the gears on the tappet screws 64 preferably by gears on the tappet, but other means of engagement may be used. The tappet screws 64 rotate about the thrust axis 27 in a second rotational direction 52 . That is, rotational member 48 rotates in a counter-clockwise direction, which rotates the tappet screws 64 in a clockwise direction, as illustrated in FIG. 5 . The rotational member 48 is preferably a gear.
Rotation of the tappet screws 64 causes the tappet nuts 63 to move toward the brake pad 28 , thereby lengthening the thrust assemblies 26 and decreasing the slack.
When the brake is applied, the latch 54 disengages with the rotational member 48 after the thrust assembly 26 has moved through the pre-defined slack. If there is excess slack, the tappet screw 64 is free to rotate and is driven in the clockwise in the second rotational direction 52 , lengthening the thrust assemblies 26 and reducing the slack. When the thrust assembly 26 , brake pad 28 and brake disc 29 are in contact and load is applied through the thrust assemblies 26 , a friction torque is produced between the tappet nuts 63 and tappet screws 64 , preventing any relative rotation and, hence, adjustment when the brake is applied. The preferred directions of rotation are shown in FIG. 6 .
When the brake is released, if there is still excess slack when all load is released from the thrust assemblies 26 , the rotational member 48 and tappet screws 64 will be rotated further as described in the previous paragraph. It will continue to rotate until the travel of the thrust assembly 26 becomes equal to the predefined slack. The latch 54 then re-engages with the gear on the rotational member 48 , preventing any further rotation and, hence, adjustment of the length of the thrust assemblies 26 .
The foregoing description is only illustrative of the principles of the invention. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, so that one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specially described. For that reason the following claims should be studied to determine the true scope and content of this invention. | A slack adjustment system for a disk brake includes a biasing member to adjust slack in a brake system. The biasing member operates independently of pressure applied to a brake actuator. A locking device secures the adjustment mechanism in place when adjustment is not necessary. Release of the locking member allows the biasing member to adjust the resting position of brake pads independent of driver applied brake pressure. | 5 |
BACKGROUND
In the hydrocarbon exploration and recovery industry, it is often necessary to anchor equipment within a tubular structure such as a casing or tubing string. A common and long used apparatus for such duty is a set of slips with attendant support structure. In some embodiments, slips are utilized with conical structures that impart radially outwardly directed impetus on each slip as the slip is axially moved along the cone, usually under a compressive load. While such configurations have been extensively used, it is also known that this type of configuration can become stuck in the tubular structure in which it has been set, thereby rendering retrieval thereof difficult.
In another embodiment of a slip configuration, the slips are tangentially loaded to avoid the need for the conical portion. Depending upon the configuration of these tangentially loaded systems, there has been difficulty in retrieval or difficulty in creating acceptable holding strength.
As the art to which this disclosure pertains is always interested in improved technology, the disclosure hereof is likely to be well received.
SUMMARY
A slip system includes a set of drive slips having wickers thereon, substantially all of which being truncated in cross-section; a set of gripping slips operatively interengagable with the set of drive slips; a drive slip end ring in operable communication with the set of drive slips; and a gripping slip end ring in operable communication with the set of gripping slips, the end rings capable of transmitting a load applied in an axial direction of the system to the set of gripping slips and the set of drive slips to tangentially load the set-of drive slips and the set of gripping slips against each other thereby increasing a radial dimension of the system and distributing stresses created in a target tubular.
A method for distributing stress in a target tubular imparted by a slip system includes embedding a plurality of sharp wickers of the slip system into the target tubular; and contacting an inside dimension of the target tubular with a plurality of truncated wickers.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings wherein like elements are numbered alike in the several Figures:
FIG. 1 is a perspective view of one embodiment of the slip system disclosed herein in a set position;
FIG. 2 is a perspective view of one embodiment of the slip system disclosed herein in a retracted position;
FIG. 3 is a perspective view of one of the slips from the illustration of FIG. 1 ;
FIG. 4 is a perspective view of another of the slips illustrated in FIG. 1 having a distinct wicker configuration; and
FIG. 5 is an illustration of an alternate slip ring configured to unset the slip system.
DETAILED DESCRIPTION
Referring to FIG. 1 , the slip system 10 is illustrated in perspective view. Apparent in FIG. 1 is the configuration of a set of drive slips 12 and a set of grip slips 14 that together cooperate in a way that promotes tangential loading of the slips against one another to radially expand. Radial expansion is necessary to set the system 10 by driving certain portions of the wicker threads (numerically introduced and discussed hereunder) into a receiving tubular structure (not shown). System 10 further includes a drive slip ring 16 and a grip slip ring 18 . Ring 16 is endowed with interengagement (for example, T-shaped) slots 20 about a perimeter thereof, each of the slots 20 being substantially the same shape and set of dimensions as each other. Ring 18 on the other hand, in one embodiment, includes a plurality of interengagement (for example, T-shaped) slots 22 disposed about a periphery thereof having a first set of dimensions and a plurality of interengagement (for example, T-shaped) slots 24 having another set of dimensions. In the illustrated embodiment of FIG. 1 , slots 22 and 24 alternate (single alternating) around the perimeter of ring 18 . It is to be understood, however, that more of slot 22 or slot 24 could be grouped together in alternate embodiments such as, for example, two slot 22 's next to one another and two slot 24 's next to one another alternating with the 22 's (double alternating). Further, there is no requirement that there be any particular number of a certain type of slot 22 or 24 , for example, there may only be one slot 24 or two slots 24 , etc. or each slot could be unique as desired (random alternating).
In each of the rings 16 and 18 , the position of slots 20 , 22 or 24 are such, relative to each other, that slips 12 and 14 are alternately positioned when engaged with adjacent T-shaped slots in each ring. The alternate positioning of slips 12 and 14 is easily seen in FIGS. 1 and 2 .
Finally, of note in FIGS. 1 and 2 is the trapezoidal shape of each of the slips 12 and 14 . The trapezoidal shape is important because it facilitates radial expansion of the slip system 10 upon axial compression of the system 10 into a shorter axial dimension. Growth in the radial direction is of course important to a slip system because it is such radial growth that allows the system itself to become anchored into the receiving tubular structure. Because of the trapezoidal shape and positioning of that shape, each slip acts as a wedge (perimetrically) against its two neighboring slips. When the axial length of system 10 is increased, the radial dimension of the system 10 will necessarily and naturally decrease.
It is to be noted that the radial expansion of system 10 is affected entirely by tangential application of force through the slips 12 and 14 ; this means that the ID of the slip system can remain completely open and that conical structures previously used to radially displace slips are not necessary.
Referring now to FIG. 3 , one of the drive slips 12 is illustrated in perspective view and enlarged from the FIGS. 1 and 2 views. In the FIG. 3 view there is visible interlocking members provided in each of the slips in order to keep them engaged as a single unit while simultaneously allowing them to slide relative to each other. Each one of the slips includes a keyed flange 26 , which in the embodiment illustrated, is of L-shape but may be of any shape that allows sliding motion while inhibiting disassociation of each slip from its neighboring slip. On an opposite side of slip 12 is a complementary flange keyhole 28 , one end of which is visible. It will be understood that the flange keyhole 28 extends the length of slip 12 as does keyed flange 26 . If one were to obtain an opposing slip (i.e. slip 14 ) one would notice that the keyed flange 26 and the flange keyhole 28 can be engaged as the slips 12 and 14 slid axially relative to one another. Sliding movement is thus enabled while lateral disassociation is prevented or at least inhibited.
It should also be noted in passing that an angle of the mating surfaces 30 , on each slip 12 and 14 , is dictated by a radius extending from the axis of system 10 . This angle ensures smooth and distributed contact along each face 30 to improve overall efficiency and strength of system 10 .
Still referring to FIG. 3 , drive slips 12 of the current disclosure possess a number of wickers 32 , a substantial number of which are truncated. In the illustrated embodiment, all of the wickers 32 are truncated, but it is to be appreciated that merely a substantial number of the wickers must be truncated to achieve the benefit of distribution of stresses in the receiving tubular structure. It is possible to add pointed wickers without departing from the scope of the invention. Truncation 34 removes what would otherwise be a sharper point of a slip gripping wicker. In one embodiment the truncation amount is of a dimension that is about the same as the amount of a sharp wicker that would be embedded in the material of the receiving tubular structure. Slips 12 are so configured to enhance retrieveability of the slip system 10 as well as assist in the distribution of stresses in the receiving tubular structure.
Each one of the wickers 32 that is truncated, is so truncated to an extent about equal to the amount of penetration into the receiving tubular structure that is anticipated for pointed wickers on the gripping slips 14 . The reason for this is so that when the pointed wickers are maximally embedded in the receiving tubular structure, the wickers 32 will be radially loaded against the receiving tubular structure without penetrating it into. This distributes the stresses of the receiving tubular structure more evenly about the tubular structure consistent with contact around the entirety of the slip system 10 . One further benefit of the configuration of slips 12 is realized in the case of paraffin or other debris lining the inside dimension of the receiving tubular structure. Because wickers 32 are still above the surface of slips 12 , those wickers are able to penetrate debris at the inside dimension of the receiving tubular structure and still ensure contact of truncation 34 with the inside dimension surface of the receiving tubular structure forming a frictional engagement therewith.
Each wicker 32 , of course, possesses a pair of flanks 36 , which in one embodiment, are positioned at 45°. It is to be understood that other angles are possible. It is also noted that in the system 10 , it is not necessary to harden wickers 32 , as they are not intended to bite into the receiving tubular structure. This is not to say that it is undesirable to harden wickers 32 but merely that it is not necessary to do so.
Referring to FIG. 4 , one of the gripping slips 14 is illustrated. It will be noted that there are two distinguishing features of gripping slip 14 over driving slip 12 as illustrated in FIG. 3 . These are a length 40 of a T-upright 42 , and a configuration of wickers 44 and 46 . Addressing the wickers first, it will be apparent that in the illustrated embodiment, every other wicker is sharp pointed (wicker 44 ) while the intervening wickers 46 are truncated (single alternating). In this embodiment, the degree of truncation of wickers 46 is roughly equal to the expected penetration of wickers 44 into the receiving tubular structure (not shown). Again the purpose for this construction, like that of the drive slip illustrated in FIG. 3 , is to distribute the load on the receiving tubular structure imparted by radial motion of slip system 10 . More specifically, upon full penetration of wickers 44 into the receiving tubular structure, wickers 46 come into contact with the inside diameter of the receiving tubular structure thereby distributing stress in that structure. It is to be appreciated that only one embodiment of the slip system contemplated is shown in FIG. 4 . It is also possible for numbers of wickers 44 and 46 to be grouped such as two wickers 44 alternating with two wickers 46 (double alternating) or three wickers 44 alternating with three wickers 46 (triple alternating) or even a number of sharp wickers 44 alternating with a different number of truncated wickers 46 (random alternating). The overall point of alternating sharp and truncated wickers is to distribute stress otherwise imparted in an undistributed way to the receiving tubular structure. It is further possible to retain all of the wickers on slips 14 in the 44 configuration in some embodiments of the invention, since the truncated wickers 32 on the drive slips 12 will still substantially balance stresses in the receiving tubular structure. It will also be noted that pointed wickers 44 should be hardened such that they are sufficiently durable to penetrate the inside diameter of the receiving tubular structure.
Addressing now the upright 42 of the key structure 48 , and referring to both FIGS. 3 and 4 , it is apparent that the length 40 of the upright section 22 is longer than that of the comparable portion of slip 12 . The reason for the length of this portion of slip 14 is to delay a tensile force being applied to this slip 14 when retraction of the slip system 10 is desired. Referring back to FIGS. 1 and 2 and reiterating that the T-shaped slots 22 and 24 are distinct, a review of the drawing will make clear that T-shaped slots 24 , upon an axial tensile load on ring 18 , will cause an immediate transfer of the tensile load to the associated slip 14 . This is distinct from the T-shaped slots 22 wherein the same tensile load applied to ring 18 , is not immediately transferred to the associated slip 14 but rather the ring 18 must axially move relative to the associated slip 14 until surface 50 contacts surface 52 . Upon this contact, the tensile load will be transmitted to the associated slip 14 . In such configuration it will be appreciated that every other slip 14 , in the illustrated embodiment, will be pulled in a direct commensurate with retracting the slip system 10 prior to the other slips 14 being so pulled. This reduces the force necessary to retract the slip system 10 . In the illustrated embodiment, the force is roughly halved while in other embodiments with differing numbers of alternating T-shaped slots 22 and 24 , the reduction in tensile force required will be describable as a percentage of the whole proportional to the number of earlier pulled slips relative to the total number of slips associated with the subject ring.
It will be noted by the astute reader that ring 16 contains only T-shaped slot 20 . The reason that the staggered T-shaped slots are not required on ring 16 is that all of the associated slips 12 substantially lack gripping wickers and therefore, the tensile force required to unseat them is substantially less than that of the slips 14 . Therefore, there is no need to stagger the T-shaped slots in ring 16 . This is by no means to say that it is inappropriate to stagger T-shaped slots 20 , as it certainly is not only possible and functional, but rather merely to state that it is unnecessary.
Referring to FIG. 5 , an alternate embodiment of ring 18 is illustrated which allows for the T-shaped structures on each of the slips 14 to be identical. In this embodiment, the T-shaped structure 48 is not required to be long, as it is illustrated in the FIG. 1 and FIG. 2 embodiments. It will be appreciated that the reason that the elongated section 42 is not needed, is that surface 50 of slots 22 is positioned closer to an end 60 of ring 18 than it is in the FIG. 1 embodiment. One will also note that the clearances between the T-shaped structure 48 and the slots 22 has also been increased to account for potential axial movement of the system. This additional clearance alleviates unnecessary load on the structure 48 when the system is set.
While the figures in this application may suggest to one of ordinary skill in the art the existence of a clear uphole end and downhole end of slip system 10 , based upon conventional illustration methods, it is to be understood that slip system 10 is usable with either end uphole. Generally, it will be desirable to impart a compressive setting force against ring 16 and the drive slips 12 while maintaining ring 18 and gripping slips 14 stationary. This is, however, not a requirement and the slip system 10 is to be understood to be actuable and retractable from either end. It is also to be understood that the system is actuable and retractable from a position downhole of the system of a position uphole of the system.
While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation. | A slip system includes a set of drive slips having wickers thereon, substantially all of which being truncated in cross-section; a set of gripping slips operatively interengagable with the set of drive slips; a drive slip end ring in operable communication with the set of drive slips; and a gripping slip end ring in operable communication with the set of gripping slips, the end rings capable of transmitting a load applied in an axial direction of the system to the set of gripping slips and the set of drive slips to tangentially load the set of drive slips and the set of gripping slips against each other thereby increasing a radial dimension of the system and distributing stresses created in a target tubular and method. | 4 |
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to producing electrical power and, in particular, to producing electrical power during peak demand periods by utilizing peaker cycle heat exhaust recovery.
[0002] Baseload (also base load, or baseload demand) is the minimum amount of power that a utility or distribution company must make available to its customers, or the amount of power required to meet minimum demands based on reasonable expectations of customer requirements. Baseload values typically vary from hour to hour in most commercial and industrial areas. The baseload is generated by a so-called “baseload power plant.”
[0003] Peaks or spikes in customer power demand are handled by smaller and more responsive types of power plants called peaker power plants. Of course, a baseload power plant may be co-located with a peaker power plant. The time that a peaker plant operates may be many hours a day or as little as a few hours per year, depending on the condition of the region's electrical grid. It is expensive to build an efficient power plant, so if a peaker plant is only going to be run for a short or highly variable time, it may not make economic sense to make it as efficient as a base load power plant. In addition, the equipment and fuels used in base load plants are often unsuitable for use in peaker plants because the fluctuating conditions would severely strain the equipment. For these reasons, nuclear, geothermal, waste-to-energy, coal, and biomass plants are rarely, if ever, operated as peaker plants.
[0004] Peaker plants are generally gas turbines that burn natural gas. A few burn petroleum-derived liquids, such as diesel oil and jet fuel, but they are usually more expensive than natural gas, so their use is limited.
[0005] For greater efficiency, a Heat Recovery Steam Generator (HRSG) is added at the exhaust. This is known as a combined cycle plant. Cogeneration uses waste exhaust heat for process or other heating uses. Both of these options are used only in plants that are intended to be operated for longer periods than usual.
[0006] Peak load requirements in the past have been met using different techniques depending on the duration and the maximum power requirements. Some are described below.
[0007] One prior solution is the so-called “duct burning” solution. During the peak load operation, additional fuel is burned in the exhaust stack upstream of a heat recovery steam generator (HRSG) to produce additional heat and hence additional steam flow and concomitant power output in the bottoming cycle. The exhaust gas is oxygen depleted and, thus, the combustion is not highly efficient. Further the non-uniform temperature distribution may lead to HRSG tube life reduction. In addition, the turbines operate slightly in “off-design” conditions to account for more flow during the peak load operation, making the normal combined cycle mode operation less efficient and lower yielding.
[0008] Another solution involves utilizing a simple cycle gas turbine. For applications requiring high peak loads over significantly long periods of time, supplementary simple cycle based gas turbines are used. Start-up time for such turbines must be short, ranging from 7-10 minutes, and it is an important design requirement. Such systems may operate with operating efficiency of about 37% and power output of 175 MW, for example. Such systems, however, may have low peak load efficiency due to un-recovered heat in their exhaust. In addition, these systems may require expensive and less reliable high temperature selective catalytic reduction (SCR) catalysts to reduce peaker cycle NO x production. Further, exhaust fans for high temperature SCR are very expensive and themselves impose a high auxilary demand power penalty. In cases where an ammonia injection system is used in a peaker system, the external skids for the ammunia injection system is very high.
BRIEF DESCRIPTION
[0009] According to one aspect of the invention, an electrical power generation system is provided. The system includes a first gas turbine and a heat recovery steam generator coupled to the gas turbine. The heat recovery steam generator includes a high pressure super-heater having a high pressure super-heater output. The system also includes a second gas turbine and an output duct coupled to the second gas turbine. The system also includes a supplemental high pressure super-heater within the output duct and thermally coupled to the high pressure super-heater output and an attemperator coupled between the high pressure super-heater output and the supplemental high pressure super-heater.
[0010] According to one aspect of the invention, an electrical power generation system is provided. The system of this aspect includes a combined cycle and a peaker cycle. The combined cycle includes a gas turbine and a heat recovery steam generator coupled to the gas turbine. The heat recovery steam generator includes an intermediate pressure super-heater having an intermediate pressure super-heater output and a low pressure super-heater having a low pressure super-heater output. The peaker cycle includes a peaker gas turbine and an output duct coupled to the peaker gas turbine. The peaker cycle also includes a supplemental intermediate pressure super-heater within the output duct and thermally coupled to the high pressure super-heater output and a supplemental low pressure super-heater within the output duct and thermally coupled to the low pressure super-heater output.
[0011] According to yet another aspect of the invention, a method for operating a system including a combined cycle and a peaker cycle, the combined cycle including a gas turbine and a heat recovery steam generator coupled to the gas turbine and a peaker cycle including a peaker gas turbine and an output duct. The method includes superheating a high pressure output product in the heat recovery steam generator; superheating the output product in a supplemental high pressure super-heater within the output duct after the output product has be superheated in the heat recovery steam generator and before the output product is provided a another turbine; and mixing the output product with water in an attemperator before the output product is superheated in the supplemental high pressure super-heater.
[0012] These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
[0014] FIG. 1 is system diagram of an electrical power generation system;
[0015] FIG. 2 is system diagram for the system shown in FIG. 1 including an attemperator;
[0016] FIG. 3 is system diagram of an electrical power generation system according to another embodiment of the present invention; and
[0017] FIG. 4 is system diagram of an electrical power generation system according to another embodiment of the present invention.
[0018] The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION
[0019] FIG. 1 shows an example of an electrical power generation system 100 according to one embodiment of the present invention. The system 100 includes combined cycle 102 and a peaker cycle 104 .
[0020] The combined cycle 102 may include a compressor 106 that includes an air intake 107 . The compressor 106 is coupled to a combustor 108 that combusts a gas or fuel oil in a stream of compressed air. The compressor 108 is coupled to a gas turbine 110 . The gas turbine 110 extracts energy from a flow of hot gas produced by combustion of gas or fuel. In one embodiment, the extracted engery is converted to electricity.
[0021] The output 112 of the gas turbine 110 is an exhaust gas that may be used in other cycles of the combined system 100 . The exhaust gas may be used, for example, to heat steam for use in a steam turbine (not shown). The combined cycle, thus, includes an HSRG 114 . The HSRG 114 may include a high pressure super-heater 116 , an intermediate pressure super-heater 118 and a low pressure super-heater 120 . The HSRG 114 may include only the low pressure super-heater 120 or any combination of the low pressure super-heater 120 and another super-heater.
[0022] The exhaust gas may be at a temperature of approximately 1150° F. Ultimately, the exhaust gas is processed in an exhaust duct 120 which includes a low temperature SCR 124 to treat the exhaust gas before it is released through the stack 126 .
[0023] As described above, the system 100 also includes a peaker cycle 104 . In the prior art, such systems, however, had low peak load efficiency. One cause for this low efficiency may be due to un-recovered heat from exhaust gas in the peaker cycle. In addition, these systems required the utilization of less reliable and expensive high temperature SCR catalysts and an additional external high cost cooling fan to cool the exhaust gas to high temperature SCR levels. Further, such systems typically required an external skid for an ammonia injection system to effectively operate a high temperature SCR.
[0024] The peaker cycle 104 includes a peaker gas turbine 130 . The peaker gas turbine 130 is coupled to a peaker compressor 132 by a peaker combustor 134 . The output temperature of the peaker exhaust gas 140 is about 1150° F. and is passed through a peaker exhaust duct 142 . The peaker exhaust duct 142 includes a low pressure supplementary super-heater 136 and a peaker low-temperature SCR 138 . Of course, the peaker HSRG 142 may be coupled to the stack 126 .
[0025] An output of the low pressure super-heater 114 is coupled to an input of the supplementary low presssure super-heater 136 . An input of the low pressure super-heater may be coupled to a low pressure condenser (not shown).
[0026] The temperature of the output product (typically steam) of the low pressure super-heater 114 is typically about 600° F. As the exhaust gas from the peaker gas turbine 130 passes through the peaker exhaust duct 142 it heats the output product to about 1050° F. while the gas itself cools to about 650° F. The cooling of the peaker gas turbine's 130 exhaust gas to this temperature allows for normal, rather than high temperature, SCR to be performed thereon. In addition, because output product has been heated in the supplementary low pressure super-heater 136 , the waste heat from the peaker cycle 104 has been recovered and, thus, the net efficiency of the combined cycle and peaker cycle is improved.
[0027] The output of the supplemental low pressure super-heater 136 is provided to a low pressure turbine inlet nozzle. In one optional embodiment, and as indicated by the dashed arrow labeled 144 , the output of the supplemental low pressure super-heater 136 may be diverted to different stages of the low pressure turbine as taught, for example, in U.S. Pat. No. 6,442,924.
[0028] FIG. 2 shows an example of an electrical power generation system 200 similar to that shown in FIG. 1 with an optional low pressure water flow 202 . The optional low pressure water flow 202 includes a water pump 204 and a low pressure steam attemperator 206 . The optional additional water flow 202 may serve to reduce the temperature of the output product before introduction into a low pressure turbine. For example, the temperature of the output product entering the low pressure steam attemperator 206 may be about 1050° F. and leave at a temperature of about 700-800 ° F.
[0029] It will be understood from the above description describes a system that allows for the recovery of energy from the peaker cycle. In particular, exhaust gas from the peaker turbine is used to superheat low pressure steam for later use by a combined cycle system and, thereby, increases the efficiency of the combined cycle system.
[0030] Typically, intermediate and high pressure steam temperatures for a typical combined cycle plant are about 1050° F. This makes any additional super heating of these steams using peaker exhaust heat impossible. In one embodiment of the present invention, high pressure steam from the combined cycle is attemperated from about 1050° F. down to about 650° F. before allowing it to pass through the supplementary high pressure super-heater section in the peaker cycle exhaust path. This enables the peaker cycle exhaust heat (temperature about 1150° F.) recovery using high-pressure steam that has high heat-work conversion efficiency. In addition to that, optional LP steam circuit from the combined cycle is also used to reduce the exhaust heat to lowest possible temperature. Overall, this embodiment may enable additional power output gain of 50 MW during peaker cycle operation, compared to 35 MW gain from previous designs. Further, the temperature levels upstream of the catalyst can be maintained as low as required for a combined cycle catalyst to ensure efficient operation of the catalyst.
[0031] In addition, because the energy has been recovered from the exhaust gas it is at a reduced temperature and, therefore, may be treated with normal, rather than high temperature, SCR catalyst. The above description has described only superheating the low pressure steam. Of course, and described below, high and intermediate pressure steam may also be superheated according to embodiments of the present invention. Of course, only high pressure steam, intermediate pressure steam or a combination of both may be superheated by the peaker exhaust gas according to different embodiments of the present invention. That is, embodiments of the present invention are directed to superheating one or more of low, intermediate and high pressure steam with peaker exhaust gas.
[0032] FIG. 3 shows a system 300 according to another embodiment of the present invention. The system includes a peaker cycle 302 . The remainder of the system 300 not included in the peaker cycle 302 shall be referred to herein as a combined cycle.
[0033] The peaker cycle 302 includes a compressor 303 , a combustor 304 and a gas turbine 306 . As discussed above, the gas turbine 306 extracts energy from a flow of hot gas produced by combustion of gas or fuel. In one embodiment, the extracted engery is converted to electricity. The peaker cycle 302 , also includes an output duct 308 . The output duct 308 processes exhaust gas from the gas turbine 306 before it is expelled to the environment. The processing of the exhaust may be accomplished by SCR 314 . In one embodiment, the SCR 314 utilizes normal, rather than high, temperature catalysts.
[0034] The output duct 308 also includes a supplemental low pressure super-heater 310 and a supplemental high pressure super-heater 312 . The supplemental super-heaters 310 and 312 are, respectively, connected to the output of a low pressure super-heater 316 and a high pressure super-heater contained in the combined cycle.
[0035] The combined cycle may include a compressor 320 that includes an air intake 321 . The compressor 320 is coupled to a combustor 322 that combusts a gas or fuel oil in a stream of compressed air. The compressor 322 is coupled to a gas turbine 324 . The gas turbine 324 extracts energy from a flow of hot gas produced by combustion of gas or fuel. In one embodiment, the extracted energy is converted to electricity.
[0036] The output of the gas turbine 324 is an exhaust gas that may be used in other cycles of the combined system. The exhaust gas may be used, for example, to heat steam for use in a high pressure steam turbine 326 and a low pressure steam turbine 328 . To that end, the combined cycle includes an HSRG 330 . The HSRG 330 may include a low pressure super-heater 316 and high pressure super-heater 318 .
[0037] Steam passing through the high pressure super-heater 318 exits at temperature of about 1050° F. The steam is mixed with water by the high pressure pre-attemperator 332 . In one embodiment, the steam leaves the high pressure pre-attemperator 332 at a temperature of about 650° F. The high pressure pre-attemperator 332 receives the steam from an output of the high pressure super-heater 318 and water from a first pump 336 .
[0038] Steam passing through the low pressure super-heater 3 16 exits at temperature of about 550° F. The steam is mixed with water by the low pressure pre-attemperator 334 . In one embodiment, the steam leaves the low pressure pre-attemperator 334 at a temperature of about 350° F. The low pressure pre-attemperator 334 receives the steam from an output of the low pressure super-heater 316 and water from a second pump 338 . The super-heaters 316 and 318 receive water from a third pump 339 .
[0039] The output of both the high pressure pre-attemperator 332 and the low pressure pre-attemperator 334 are then superheated in the output duct 308 of the peaker cycle 302 . In particular, the output of the high pressure pre-attemperator 332 is connected to an input of the supplementary high pressure super-heater 3 12 . In one embodiment, the output of the high pressure pre-attemperator 332 is superheated to a temperature of about 1050° F. by the supplementary high pressure super-heater 312 . The output of the supplementary high pressure super-heater 312 is coupled to an input of a high/intermediate pressure steam turbine 340 .
[0040] The output of the low pressure pre-attemperator 334 is connected to an input of the supplementary low pressure super-heater 310 . In one embodiment, the output of the low pressure pre-attemperator 334 is superheated to a temperature of about 600° F. by the supplementary low pressure super-heater 31 0 . The output of the supplementary low pressure super-heater 310 is coupled to an input of a low pressure steam turbine 342 . Remaining steam from the high/intermediate pressure steam turbine 340 and the low pressure steam turbine 342 is condensed in the condenser 344 and the water produced therein is provided to the pumps 336 , 338 and 339 .
[0041] FIG. 4 shows a system 400 according to another embodiment of the present invention. The system includes a peaker cycle 402 . The remainder of the system 400 not included in the peaker cycle 402 shall be referred to herein as a combined cycle.
[0042] The peaker cycle 402 includes a compressor 403 , a combustor 404 and a gas turbine 406 . As discussed above, the gas turbine 406 extracts energy from a flow of hot gas produced by combustion of gas or fuel. In one embodiment, the extracted engery is converted to electricity. The peaker cycle 402 also includes an output duct 408 . The output duct 408 processes exhaust gas from the gas turbine 406 before it is expelled to the environment. The processing of the exhaust may be accomplished by SCR 414 . In one embodiment, the SCR 414 utilizes normal, rather than high, temperature catalysts.
[0043] The output duct 408 also includes a supplemental low pressure super-heater 410 and a supplemental intermediate pressure super-heater 412 . The supplemental super-heaters 410 and 412 are, respectively, connected to the output of a low pressure super-heater 416 and a intermediate pressure super-heater 418 contained in the combined cycle.
[0044] The combined cycle may include a compressor 420 that includes an air intake 421 . The compressor 420 is coupled to a combustor 422 that combusts a gas or fuel oil in a stream of compressed air. The compressor 422 is coupled to a gas turbine 424 . The gas turbine 424 extracts energy from a flow of hot gas produced by combustion of gas or fuel. In one embodiment, the extracted engery is converted to electricity.
[0045] The output of the gas turbine 424 is an exhaust gas that may be used in other cycles of the combined system. The exhaust gas may be used, for example, to heat steam for use in an intermediate pressure steam turbine 426 and a low pressure steam turbine 428 . To that end, the combined cycle includes an HSRG 430 . The HSRG 430 may includes a low pressure super-heater 416 and an intermediate pressure super-heater 418 .
[0046] Steam passing through the intermediate pressure super-heater 418 exits at temperature of about 1050° F. The steam is mixed with water by the intermediate pressure pre-attemperator 432 . In one embodiment, the steam leaves the intermediate pressure pre-attemperator 432 at a temperature of about 550° F. The intermediate pressure pre-attemperator 432 receives the steam from an output of the intermediate pressure super-heater 418 and water from a first pump 436 .
[0047] Steam passing through the low pressure super-heater 416 exits at temperature of about 600° F. The steam is mixed with water by the low pressure pre-attemperator 434 . In one embodiment, the steam leaves the low pressure pre-attemperator 434 at a temperature of about 350° F. The low pressure pre-attemperator 434 receives the steam from an output of the low pressure super-heater 416 and water from a second pump 438 . The super-heaters 416 and 418 receive water from a third pump 439 .
[0048] The output of both the intermediate pressure pre-attemperator 432 and the low pressure pre-attemperator 434 are then superheated in the output duct 408 of the peaker cycle 402 . In particular, the output of the intermediate pressure pre-attemperator 432 is connected to an input of the supplementary intermediate pressure super-heater 412 . In one embodiment, the output of the intermediate pressure pre-attemperator 432 is superheated to a temperature of about 1050° F. by the supplementary intermediate pressure super-heater 412 . The output of the supplementary intermediate pressure super-heater 412 is coupled to an input of a intermediate pressure steam turbine 440 .
[0049] The output of the low pressure pre-attemperator 434 is connected to an input of the supplementary low pressure super-heater 410 . In one embodiment, the output of the low pressure pre-attemperator 434 is superheated to a temperature of about 600 OF by the supplementary low pressure super-heater 410 . The output of the supplementary low pressure super-heater 410 is coupled to an input of a low pressure steam turbine 442 . Remaining steam from the intermediate pressure steam turbine 440 and the low pressure steam turbine 442 is condensed in the condensor 444 and the water produced therein is provided to the pumps 436 , 438 and 439 .
[0050] While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. | An electrical generation system including a first gas turbine and a a heat recovery steam generator coupled to the gas turbine and including a low pressure super-heater having a low pressure super-heater output. The electrical generation system also includes a second gas turbine, an output duct coupled to the second gas turbine and a supplemental low pressure super-heater within the output duct and thermally coupled to the low pressure super-heater output. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to bicycle shifters and more particularly to a bicycle shifter mountable to an end of a handlebar and having a control mechanism that returns to a neutral position after each shift operation.
Bicycle racing is becoming an increasingly popular and competitive sport. One type of bicycle racing is time trials where the cyclist races against the clock for a certain distance. During these time trials, the aerodynamics of both the bicycle and rider are very important. Typically, a time trial bicycle will have hook-type handlebars. This type of handlebar is generally u-shaped with the “u” pointing in the riding direction and the end of each side of the “u” is turned upwardly. A typical shifter is mounted to the end of each side of the “u.” One disadvantage of these shifters is that they increase the aerodynamic drag encountered by the rider because the lever does not return to a neutral position after each shift operation rather the neutral position of the lever changes depending on which gear is selected. Furthermore, this configuration is not ergonomic and has a complicated design. Accordingly, there is a need for a simple shifter that is mountable to an end of a handlebar that returns to an aerodynamic/ergonomic position.
SUMMARY OF THE INVENTION
The present invention provides a bicycle shifter for pulling and releasing a control cable connected to a gear change mechanism. The bicycle shifter includes a housing, a takeup member, a control mechanism, a holding mechanism and a return assembly. An attachment assembly mounts the housing at or near an end of a bicycle handlebar. The takeup member is rotatable about a shift axis for winding and unwinding the control cable thereon in a cable-pull direction and a cable-release direction. Preferably, the shift axis is substantially perpendicular to an axis of the handlebar. The control mechanism is movable in a first direction to rotate the takeup member in the cable-pull direction and in a second direction opposite the first direction to rotate the takeup member in the cable-release direction. The holding mechanism retains the takeup member in a selected position. The return assembly returns the control mechanism to a neutral position after each shift operation to decrease the aerodynamic drag encountered by the rider.
In one embodiment of the present invention, the control mechanism includes a control lever, a driver rotatably coupled to the control lever and a clutch mechanism operatively coupled to the driver for transferring the motion of the control lever to the takeup member. The control lever is rotatable about the shift axis in the first and second directions to pull and release the control cable and sweeps substantially perpendicular to the handlebar axis. The driver and clutch mechanism are configured to matingly engage. The clutch mechanism is biased toward the driver in the neutral position. In response to the actuation of the control lever, the driver axially and rotationally displaces the clutch mechanism toward the takeup member to transfer the motion of the control lever to the takeup member.
In one embodiment, the driver is rotatable about the shift axis and includes at least two teeth engageable with at least two recesses of the clutch mechanism. The driver teeth include angled surfaces corresponding to angled surfaces of the recesses of the clutch mechanism. Alternatively, the clutch mechanism may include teeth that engage recesses of the driver. The clutch mechanism is rotatable about the shift axis and includes a plurality of clutch teeth engageable with a plurality of takeup teeth of the takeup member in response to actuation of the control lever. With this configuration, when the control lever is actuated, the driver rotates, forcing the angled recesses of the clutch mechanism to move along the angled surfaces of the driver teeth causing the clutch mechanism to displace axially away from the driver toward the takeup member until the clutch teeth engage the takeup teeth. Once the takeup member stops the clutch mechanism from displacing axially, the clutch mechanism starts to rotate. Since the clutch teeth are now engaged with the takeup teeth, the takeup member also rotates.
The return assembly includes a rotational biasing member for rotationally biasing the clutch mechanism to a rotational neutral position and an axial biasing member for axially biasing the clutch mechanism to an axial neutral position away from the takeup member and toward the driver. In one embodiment, the rotational biasing member may be a torsion spring and the axial biasing member is a compression spring disposed between the clutch mechanism and the takeup member. After each shift operation, the torsion spring rotates the clutch mechanism back to its rotational neutral position and the compression spring axially displaces the clutch mechanism away from the takeup member and toward the driver to its axial neutral position The holding mechanism includes a ratchet wheel and at least one detent spring. The ratchet wheel is rotatably coupled to the takeup member and includes a plurality of teeth that correspond to gear positions of the gear change mechanism The detent spring engages the plurality of teeth to retain the ratchet wheel and the takeup member in the selected position.
These and other features and advantages of the present invention will be more fully understood from the following description of one embodiment of the invention, taken together with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a side view of a bicycle shifter in accordance with one embodiment of the present invention;
FIG. 2 is a cross-sectional side view of an attachment assembly for attaching the bicycle shifter of FIG. 1 to a handlebar;
FIG. 3 is a cross-sectional view taken along line A-A of the bicycle shifter of FIG. 1 ;
FIG. 3 a is a cross-sectional view taken along line A-A of the bicycle shifter of FIG. 1 in accordance with another embodiment of the present invention;
FIG. 4 is an exploded view of a driver, a clutch mechanism and a takeup member of the shifter of FIG. 1 ;
FIG. 5 is a side view of a control lever of the control mechanism of the shifter of FIG. 1 ;
FIG. 6 is a cross-sectional view of a holding mechanism of the shifter of FIG. 1 ;
FIG. 7 a is a partial cross-sectional view taken along line B-B of the bicycle shifter of FIG. 3 showing the positions of the driver, clutch mechanism and the takeup member when the shifter is in a neutral position;
FIG. 7 b is a partial cross-sectional view taken along line B-B of the bicycle shifter of FIG. 3 showing the positions of the driver, clutch mechanism and the takeup member during a shifting operation;
FIG. 8 a is cross-sectional view of the clutch mechanism and a rotational biasing member of the shifter of FIG. 1 when the shifter is in a rotational neutral position;
FIG. 8 b is a cross-sectional view of the clutch mechanism and the rotational biasing member of the shifter of FIG. 1 during a cable-pull operation; and
FIG. 8 c is a cross-sectional view of the clutch mechanism and the rotational biasing member of the shifter of FIG. 1 during a cable-release operation.
DETAILED DESCRIPTION
FIGS. 1-8 illustrate a bicycle shifter 10 in accordance with one embodiment of the present invention. The bicycle shifter 10 pulls or releases a control cable 12 connected to a gear change mechanism (not shown) to shift between gear positions of the bicycle. The gear change mechanism may be a rear derailleur, a front derailleur or other similar type of mechanism. The bicycle shifter 10 is shown as a time trial shifter for a road bike, however, the shifter 10 may be used on other types of bicycles such as a mountain bike. In this embodiment, the shifter 10 generally includes a housing 14 , a control mechanism 16 , a takeup member 18 , a holding mechanism 20 and a return assembly 22 . Looking to FIG. 2 , the shifter 10 is mounted at or near an end 24 of a handlebar 26 by an attachment assembly 28 inserted into the end 24 of the handlebar 26 . The attachment assembly 28 includes a bolt 30 threadably connected to the shifter housing 14 , three wedges 32 disposed about the bolt 30 and a wedge spring 34 disposed about the three wedges 32 . The wedge spring 34 biases the wedges 32 radially inward towards the bolt. The bolt 30 includes a socket 36 for receiving a tool such as a hex wrench. To secure the shifter 10 at or near the end 24 of the handlebar 26 , the tool is inserted into the socket 36 and rotated, moving the bolt 30 towards the housing 14 . As the bolt 30 moves toward the housing 14 , tapered surfaces 38 , 40 of the bolt 30 and housing 14 , respectively, deflect the wedges 32 radially outward against the inner surface 42 of the handlebar 26 securing the shifter 10 to end 24 of the handlebar 26 . Of course, other assemblies for attaching the shifter 10 to the handlebar 26 may be used.
Looking to FIGS. 1, 3 and 4 , the housing 14 includes a cover 44 screwed to the housing with three screws 46 . The housing cover 44 includes a bore 48 for receiving a bushing 50 . A shaft 52 extends through the housing 14 and is axially fixed relative to the housing 14 by a screw 54 threadably connected to an end 60 of the shaft 52 and a flange 58 also disposed at the end 60 of the shaft 52 . The shaft 52 has a shift axis that is substantially perpendicular to an axis of the handlebar. In one embodiment of the present invention, the control mechanism 16 includes a control lever 62 , a driver 64 and a clutch mechanism 66 . Looking to FIG. 5 , the control lever 62 is rotatable about the shaft 52 and includes first and second legs 72 , 74 clamped to the driver 64 by a screw 76 extending through the first and second legs 72 , 74 . To secure the control lever 62 on the driver 64 , the screw 76 is tightened causing the first leg 72 to move towards the second leg 74 resulting in a clamping force against the surface of the driver 64 . The angular position of the control lever 62 relative to the housing 14 may be adjusted by selecting the position of the lever 62 relative to the driver 64 . This configuration allows the rider to adjust a neutral position of the control lever 62 .
Looking to FIGS. 3 and 4 , the driver 64 extends though the bushing 50 and is rotatably mounted to the shaft 52 . A thrust bushing 68 is disposed about the driver 64 between the control lever 62 and the housing cover 44 . The driver 64 and clutch mechanism 66 are configured to matingly engage. The driver 64 axially and rotationally displaces the clutch mechanism 66 in response to actuation of the control lever 62 . In this embodiment, the driver 64 includes two driver teeth 70 that engage the clutch mechanism 66 . The clutch mechanism 66 is rotatably mounted to the shaft 52 . The clutch mechanism 66 includes two recesses 78 for receiving the two driver teeth 70 and a plurality of clutch teeth 80 for engaging the takeup member 18 . The driver teeth 70 have angled surfaces 77 that are matingly engaged with corresponding angled surfaces 79 of the recesses 78 when the control lever is in the neutral position, see FIG. 7 b . Alternatively, the clutch mechanism may include teeth that are engageable with recesses of the driver. The clutch mechanism 66 further includes a cavity 82 for receiving the return assembly 22 .
The return assembly 22 includes a rotational biasing member 84 for rotationally biasing the clutch mechanism 16 to a rotational neutral position and an axial biasing member 86 for axially biasing the clutch mechanism 16 away from the takeup member 18 to an axial neutral position. In this embodiment, the rotational biasing member 84 is a torsion spring and the axially biasing member 86 is a compression spring. Looking to FIG. 8 a , the torsion spring 84 includes two legs 88 , 90 that are engageable with an extension 92 , in this embodiment a post extending from the clutch mechanism 66 , and a projection 94 extending from the housing 14 to bias the clutch mechanism 66 toward its rotational neutral position. A spring retainer 96 is attached to the clutch mechanism 66 by two screws 98 to prevent the torsion spring 84 from axially moving relative to the clutch mechanism 66 . The compression spring 86 is disposed between the clutch mechanism 66 and the takeup member 18 . Looking to FIG. 7 a , the compression spring biases the clutch mechanism 66 toward the driver 64 and away from the takeup member 18 .
Looking to FIGS. 3 and 4 , the takeup member 18 , in this embodiment a spool, is rotatably mounted to the shaft 52 . The compression spring 86 biases the takeup member 18 away from the clutching mechanism. The takeup member 18 includes a plurality of takeup teeth 100 located around the periphery of the takeup member 18 for engaging the clutch teeth 80 of the clutch mechanism 66 . The takeup member 18 further includes a groove 102 for receiving the control cable 12 . The groove 102 extends along the periphery of the takeup member 18 . The takeup member 18 is held in a selected position by the holding mechanism 20 . The holding mechanism 20 includes a ratchet wheel 104 and two detent springs 106 . The ratchet wheel 104 includes two projections 108 that are received in recesses 110 of the takeup member 18 to rotatably connect the ratchet wheel 104 to the takeup member 18 . The projections 108 are configured such that the ratchet wheel 104 has a small amount, in this embodiment approximately four degrees, of rotational play relative to the takeup member 18 . Alternatively, the takeup member 18 and ratchet wheel 104 may form one-piece, see FIG. 3 a . Looking to FIG. 6 , the ratchet wheel 104 is rotatably mounted to the shaft 52 and includes two sets of teeth 112 disposed about the periphery of the ratchet wheel 102 . The teeth 112 on the ratchet wheel 102 correspond to gear positions of the gear change mechanism. The detent springs 106 include a first leg 114 supported by the housing and a second leg 116 engageable with the teeth 112 of the ratchet wheel 104 to retain the takeup member in the selected position.
At rest the control lever 62 is located in a neutral position as shown in FIG. 1 . When the control lever 62 is in the neutral position, the clutch mechanism 66 is biased away from the takeup member 18 by the compression spring 86 as shown in FIG. 7 a and is biased rotationally to the neutral position by the torsion spring 84 as shown in FIG. 8 a . To shift the gear change mechanism, the control lever 62 is rotated in a first direction A to pull the control cable and in a second direction B to release the control cable. When the control lever 62 is rotated in the cable-pull direction, the driver 64 rotates with the control lever 62 and as the driver teeth 70 of the driver 64 rotate, the recesses 78 of the clutch mechanism 66 move along angled surfaces 77 of the driver teeth 70 , axially displacing the clutch mechanism 66 toward the takeup member 18 until the clutch teeth 80 of clutch mechanism 66 engage the takeup teeth 100 of the takeup member 18 as shown in FIG. 7 b . Once the clutch mechanism 66 is prevented from displacing any further in the axial direction by the takeup member 18 , the extension 92 of the clutch mechanism 66 exerts a force against the leg 90 of the torsion spring 84 overcoming the biasing force of the torsion spring 84 and rotating the clutch mechanism 66 in the cable-pull direction, see FIG. 8 b . Since the clutch teeth 80 are now engaged with the takeup teeth 100 , the takeup member 18 and ratchet wheel 104 also rotate in the cable-pull direction resulting in the detent springs 106 to engage a next tooth on the ratchet wheel 104 corresponding to the next gear position of the gear change mechanism. If the rider wanted to shift more than one gear at a time in the cable-pull direction, the rider would continue to rotate the control lever until the desired gear position was reached. With this configuration, the rider may shift multiple gears in the cable-pull direction with a single stroke of the control lever 62 .
After the control lever 62 is released, the driver 64 no longer exerts a force against the clutch mechanism 66 and the biasing force of the compression spring 86 causes the clutch mechanism 66 to displace away from the takeup member 18 back to its axial neutral position and the biasing force of the torsion spring 84 causes the clutch mechanism 66 to rotate back to its rotational neutral position as shown in FIG. 8 a . Since the clutch mechanism 66 is coupled with the driver 64 and the driver 64 is coupled with the control lever 62 , the driver 64 and the control lever 62 also return to their neutral positions. The takeup member 18 is retained in its current position by the detent springs 106 engaging the ratchet wheel teeth 112 .
When the control lever 62 is rotated in the cable-release direction, similar to the cable-pull operation, the driver 64 rotates with the control lever 62 and as the driver teeth 70 rotate, the recesses 78 of the clutch mechanism 66 move along the angled surfaces 77 of the drive teeth 70 axially displacing the clutch mechanism 66 toward the takeup member 18 until the clutch teeth 80 of the clutch mechanism 66 engage the takeup teeth 100 of the takeup member 18 . Looking to FIG. 8 c , once the clutch mechanism 66 is prevented from displacing any further in the axial direction by the takeup member 18 , the extension 92 of the clutch mechanism 66 exerts a force against the leg 88 of the torsion spring 84 overcoming the biasing force of the torsion spring 84 and rotating in the cable-release direction. The takeup member 18 and ratchet wheel 104 rotate in the cable-release direction resulting in the detent springs 106 engaging a next tooth in the cable-release direction. If the rider wanted to shift more than one gear at a time in the cable-release direction, the rider would continue to rotate the control lever 62 until the desired gear position was reached. With this configuration, the rider may shift multiple gears in the cable-release direction with a single stroke of the control lever 62 . Similar to the cable-pull operation, after the release of the control lever 62 , the driver 64 , clutch mechanism 66 and the control lever 62 return to their neutral position and the takeup member 18 is retained in its current position.
While this invention has been described in reference to a preferred embodiment, it should be understood that numerous changes could be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the disclosed embodiment, but that it have the full scope permitted by the language of the following claims. | A bicycle shifter for pulling and releasing a control cable connected to a gear change mechanism mountable at or near an end of the handlebar that returns to a neutral position after each shift operation to decrease aerodynamic drag encountered by the rider. The shifter includes a takeup member, a control mechanism, a holding mechanism and a return assembly. The takeup member is rotatable about a shift axis for winding and unwinding the control cable thereon in a cable-pull direction and a cable-release direction. The control mechanism is movable in a first direction to rotate the takeup member in the cable-pull direction and in a second direction to rotate the takeup member in the cable-release direction. The holding mechanism retains the takeup member in a selected position and the return assembly returns the control mechanism to the neutral position after each shift operation. | 8 |
CROSS-REFERENCE TO RELATED APPLICATION
The present application claims priority under 35 U.S.C 119(a) to Korean Application No. 10-2013-0041195, filed on Apr. 15, 2013, in the Korean Intellectual Property Office, which is incorporated herein by reference in its entirety.
BACKGROUND
Simultaneous switching noises (SSN) are typically generated due to inductive components of conductive lines (e.g., interconnection lines) included in electronic circuits when the electronic circuits operate with high frequency signals. These simultaneous switching noises are subject to Faraday's law of induction. According to Faraday's law of induction, a counter electromotive force (e.g., a voltage drop) may be generated between both ends of a conductive line (e.g., a conductive coil) when an alternating current (e.g., an instantaneous current) flows through the conductive line to change a magnetic field around the conductive line. In such a case, the counter electromotive force may increase as the amount of the instantaneous current, the variation rate of the instantaneous current, or the inductance of the conductive line increases. The counter electromotive force generated by the instantaneous current may cause a voltage fluctuation of a power line and/or a ground line of an electronic circuit including the conductive line, and the voltage fluctuation may generate noises which are referred to as the simultaneous switching noises. The counter electromotive force (Vnoise) may be expressed by the following equation.
V noise=− L ( di/dt )
where, “L” denotes an inductance value of the conductive line.
Accordingly, if a number of circuit elements are simultaneously switched on/off, instantaneous changes in current across the power line and the ground line may occur. As a result, inductive voltage drops may occur to increase the simultaneous switching noises in the electronic circuits, for example, semiconductor systems. The simultaneous switching noises may cause signal delays to degrade the reliability of the semiconductor systems.
Each of the semiconductor systems may include various internal circuits, and each of the internal circuits may be configured to include a number of MOS transistors. The MOS transistors may be used as switches to operate the internal circuits. Recently, as the semiconductor systems become more highly integrated, a number of signals and data may be simultaneously transmitted through a number of signal lines or a number of input/output (I/O) lines. If a number of signals and data are simultaneously transmitted, a number of MOS transistors may also be simultaneously switched on/off to cause a number of simultaneous switching noises.
SUMMARY
Various embodiments are directed to I/O line driving circuits.
According to an embodiment, an I/O line driving circuit includes a first I/O line driver and a second I/O line driver. The first I/O line driver receives a first input signal in response to an enable signal to generate a first control signal and drives a first I/O line in response to a second control signal. The second I/O line driver receives a second input signal in response to the enable signal to generate the second control signal and drives a second I/O line in response to the first control signal.
According to an embodiment, an I/O line driving circuit includes a first I/O line driver configured to drive a first I/O line and a second I/O line driver configured to drive a second I/O line adjacent to the first I/O line. The first I/O line driver buffers a first input signal in response to an enable signal to generate a first pull-up signal, uses the first pull-up signal to generates a first control signal, and includes a first pull-up element and a second pull-up element that pull up a level of the first I/O line in response to the first pull-up signal. An operation that the second pull-up element pulls up the level of the first I/O line is controlled by a second control signal generated from a second input signal which is applied to the second I/O line driver to drive the second I/O line.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments concept will become more apparent in view of the attached drawings and accompanying detailed description, in which:
FIG. 1 is a block diagram illustrating a input/output line driving circuit according to an embodiment;
FIG. 2 is a circuit diagram illustrating an example of a first input/output line driver included in the input/output line driving circuit shown in FIG. 1 ;
FIG. 3 is a circuit diagram illustrating an example of a second input/output line driver included in the input/output line driving circuit shown in FIG. 1 ;
FIGS. 4A to 4D are tables illustrating an operation of the first and second input/output line drivers shown in FIGS. 2 and 3 ;
FIG. 5 is a circuit diagram illustrating another example of a first input/output line driver included in the input/output line driving circuit shown in FIG. 1 ;
FIG. 6 is a circuit diagram illustrating another example of a second input/output line driver included in the input/output line driving circuit shown in FIG. 1 ; and
FIGS. 7A to 7D are tables illustrating an operation of the first and second input/output line drivers shown in FIGS. 5 and 6 .
DETAILED DESCRIPTION OF THE EMBODIMENTS
Example embodiments of the inventive concept will be described hereinafter with reference to the accompanying drawings. However, the example embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the inventive concept.
Referring to FIG. 1 , an input/output (hereinafter referred to as “I/O”) line driver circuit according to an embodiment may be configured to include a first I/O line driver GIO_DRV 1 and a second I/O line driver GIO_DRV 2 . The first I/O line driver GIO_DRV 1 may generate a first control signal CNT 1 in response to a first input signal IN 1 and an enable signal EN. In an embodiment, the first I/O line driver GIO_DRV 1 may receive the first input signal IN 1 in response to the enable signal EN to generate the first control signal CNT 1 . The first I/O line driver GIO_DRV 1 may also drive a first I/O line GIO 1 in response to a second control signal CNT 2 . The second I/O line driver GIO_DRV 2 may generate the second control signal CNT 2 in response to a second input signal IN 2 and the enable signal EN. In an embodiment, the second I/O line driver GIO_DRV 2 may receive the second input signal IN 2 in response to the enable signal EN to generate the second control signal CNT 2 . The second I/O line driver GIO_DRV 2 may also drive a second I/O line GIO 2 in response to the first control signal CNT 1 . The first and second control signals CNT 1 and CNT 2 may control pull-up drive operations of the first and second I/O lines GIO 1 and GIO 2 when the levels of the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled up. Further, the first and second control signals CNT 1 and CNT 2 may control pull-down drive operations of the first and second I/O lines GIO 1 and GIO 2 when the levels of the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled down.
Referring to FIG. 2 , the first I/O line driver GIO_DRV 1 may be configured to include a first buffer ND 11 , a first inversion buffer IV 11 , a first buffer unit 11 , a first pull-up element P 11 , a second pull-up element P 12 , a first pull-up drive control element P 13 , a first pull-down element N 11 , a second pull-down element N 12 and a first pull-down drive control element N 13 .
The first buffer ND 11 may generate a first pull-up signal PU 1 in response to the first input signal IN 1 when an enable signal EN applied to the first buffer ND 11 is enabled to have a logic “high” level. For example, the first buffer ND 11 may generate the first pull-up signal PU 1 by inverting the first input signal IN 1 . The first inversion buffer IV 11 may generate the first control signal CNT 1 in response to the first pull-up signal PU 1 . For example, the first inversion buffer IV 11 may generate the first control signal CNT 1 by inverting the first pull-up signal PU 1 . The first buffer unit 11 may generate a first pull-down signal PD 1 in response to a first inverted input signal IN 1 B when the enable signal EN applied to the first buffer unit 11 is enabled to have a logic “high” level. For example, the first buffer unit 11 may generate the first pull-down signal PD 1 by buffering the first inverted input signal IN 1 B. The first inverted input signal IN 1 B may be a complementary signal of the first input signal IN 1 . In an embodiment, the first pull-up element P 11 may be a PMOS transistor. If the first pull-up element P 11 is a PMOS transistor, a source electrode of the first pull-up element P 11 may be electrically connected to a power supply terminal VDD and a drain electrode of the first pull-up element P 11 may be electrically connected to the first I/O line GIO 1 . In such a case, if the first pull-up signal PU 1 enabled to have, for example, a logic “low” level is applied to a gate electrode of the first pull-up element P 11 , the first pull-up element P 11 may be turned on to pull up a level of the first I/O line GIO 1 . In an embodiment, the second pull-up element P 12 may be a PMOS transistor. If the second pull-up element P 12 is a PMOS transistor, a source electrode of the second pull-up element P 12 may be electrically connected to the power supply terminal VDD and a drain electrode of the second pull-up element P 12 may be electrically connected to a node ND 11 . In such a case, if the first pull-up signal PU 1 enabled to have, for example, a logic “low” level is applied to a gate electrode of the second pull-up element P 12 , the second pull-up element P 12 may be turned on to pull up a level of the node ND 11 . In an embodiment, the first pull-up drive control element P 13 may be a PMOS transistor. If the first pull-up drive control element P 13 is a PMOS transistor, a source electrode of the first pull-up drive control element P 13 may be electrically connected to the node ND 11 and a drain electrode of the first pull-up drive control element P 13 may be electrically connected to the first I/O line GIO 1 . In such a case, the first pull-up drive control element P 13 may control a pull-up drive operation of the second pull-up element P 12 in response to the second control signal CNT 2 . For example, when the second control signal CNT 2 , having a logic “low” level, is applied to a gate electrode of the first pull-up drive control element P 13 to turn on the first pull-up drive control element P 13 and the first pull-up signal PU 1 is enabled to have, for example, a logic “low” level, the second pull-up element P 12 may be turned on to pull up a level of the first I/O line GIO 1 .
The first pull-down element N 11 may be an NMOS transistor. In such a case, a drain electrode of the first pull-down element N 11 may be electrically connected to the first I/O line GIO 1 and a source electrode of the first pull-down element N 11 may be electrically connected to a ground terminal VSS. Thus, when the first pull-down signal PD 1 enabled to have, for example, a logic “high” level is applied to a gate electrode of the first pull-down element N 11 , the first pull-down element N 11 may be turned on to pull down a level of the first I/O line GIO 1 . In an embodiment, the second pull-down element N 12 may be an NMOS transistor. If the second pull-down element N 12 is an NMOS transistor, a source electrode of the second pull-down element N 12 may be electrically connected to the ground terminal VSS and a drain electrode of the second pull-down element N 12 may be electrically connected to a node ND 12 . In such a case, if the first pull-down signal PD 1 enabled to have, for example, a logic “high” level is applied to a gate electrode of the second pull-down element N 12 , the second pull-down element N 12 may be turned on to pull down a level of the node ND 12 . In an embodiment, the first pull-down drive control element N 13 may be an NMOS transistor. If the first pull-down drive control element N 13 is an NMOS transistor, a source electrode of the first pull-down drive control element N 13 may be electrically connected to the node ND 12 and a drain electrode of the first pull-down drive control element N 13 may be electrically connected to the first I/O line GIO 1 . In such a case, the first pull-down drive control element N 13 may control a pull-down drive operation of the second pull-down element N 12 in response to the second control signal CNT 2 . For example, when the second control signal CNT 2 , having a logic “high” level, is applied to a gate electrode of the first pull-down drive control element N 13 to turn on the first pull-down drive control element N 13 and the first pull-down signal PD 1 is enabled to have, for example, a logic “high” level, the second pull-down element N 12 may be turned on to pull down a level of the first I/O line GIO 1 .
Referring to FIG. 3 , the second I/O line driver GIO_DRV 2 may be configured to include a second buffer ND 21 , a second inversion buffer IV 21 , a second buffer unit 21 , a third pull-up element P 21 , a fourth pull-up element P 22 , a second pull-up drive control element P 23 , a third pull-down element N 21 , a fourth pull-down element N 22 and a second pull-down drive control element N 23 .
The second buffer ND 21 may generate a second pull-up signal PU 2 in response to the second input signal IN 2 when an enable signal EN applied to the second buffer ND 21 is enabled to have a logic “high” level. For example, the second buffer ND 21 may generate the second pull-up signal PU 2 by inverting the second input signal IN 2 . The second inversion buffer IV 21 may generate the second control signal CNT 2 in response the second pull-up signal PU 2 . For example, the second inversion buffer IV 21 may generate the second control signal CNT 2 by inverting the second pull-up signal PU 2 . The second buffer unit 21 may generate a second pull-down signal PD 2 in response to a second inverted input signal IN 2 B when the enable signal EN applied to the second buffer unit 21 is enabled to have a logic “high” level. For example, the second buffer unit 21 may generate the second pull-down signal PD 2 by buffering the second inverted input signal IN 2 B. The second inverted input signal IN 2 B may be a complementary signal of the second input signal IN 2 . In an embodiment, the third pull-up element P 21 may be a PMOS transistor. If the third pull-up element P 21 is a PMOS transistor, a source electrode of the third pull-up element P 21 may be electrically connected to the power supply terminal VDD and a drain electrode of the third pull-up element P 21 may be electrically connected to the second I/O line GIO 2 . In such a case, if the second pull-up signal PU 2 enabled to have, for example, a logic “low” level is applied to a gate electrode of the third pull-up element P 21 , the third pull-up element P 21 may be turned on to pull up a level of the second I/O line GIO 2 . In an embodiment, the fourth pull-up element P 22 may be a PMOS transistor. If the fourth pull-up element P 22 is a PMOS transistor, a source electrode of the fourth pull-up element P 22 may be electrically connected to the power supply terminal VDD and a drain electrode of the fourth pull-up element P 22 may be electrically connected to a node ND 21 . In such a case, if the second pull-up signal PU 2 enabled to have, for example, a logic “low” level is applied to a gate electrode of the fourth pull-up element P 22 , the fourth pull-up element P 22 may be turned on to pull up a level of the node ND 21 . In an embodiment, the second pull-up drive control element P 23 may be a PMOS transistor. If the second pull-up drive control element P 23 is a PMOS transistor, a source electrode of the second pull-up drive control element P 23 may be electrically connected to the node ND 21 and a drain electrode of the second pull-up drive control element P 23 may be electrically connected to the second I/O line GIO 2 . In such a case, the second pull-up drive control element P 23 may control a pull-up drive operation of the fourth pull-up element P 22 in response to the first control signal CNT 1 . For example, when the first control signal CNT 1 , having a logic “low” level, is applied to a gate electrode of the second pull-up drive control element P 23 to turn on the second pull-up drive control element P 23 and the second pull-up signal PU 2 is enabled to have, for example, a logic “low” level, the fourth pull-up element P 22 may be turned on to pull up a level of the second I/O line GIO 2 .
In an embodiment, the third pull-down element N 21 may be an NMOS transistor. In such a case, a drain electrode of the third pull-down element N 21 may be electrically connected to the second I/O line GIO 2 and a source electrode of the third pull-down element N 21 may be electrically connected to the ground terminal VSS. Thus, when the second pull-down signal PD 2 enabled to have, for example, a logic “high” level is applied to a gate electrode of the third pull-down element N 21 , the third pull-down element N 21 may be turned on to pull down a level of the second I/O line GIO 2 . In an embodiment, the fourth pull-down element N 22 may be an NMOS transistor. If the fourth pull-down element N 22 is an NMOS transistor, a source electrode of the fourth pull-down element N 22 may be electrically connected to the ground terminal VSS and a drain electrode of the fourth pull-down element N 22 may be electrically connected to a node ND 22 . In such a case, if the second pull-down signal PD 2 enabled to have, for example, a logic “high” level is applied to a gate electrode of the fourth pull-down element N 22 , the fourth pull-down element N 22 may be turned on to pull down a level of the node ND 22 . In an embodiment, the second pull-down drive control element N 23 may be an NMOS transistor. If the second pull-down drive control element N 23 is an NMOS transistor, a source electrode of the second pull-down drive control element N 23 may be electrically connected to the node ND 22 and a drain electrode of the second pull-down drive control element N 23 may be electrically connected to the second I/O line GIO 2 . In such a case, the second pull-down drive control element N 23 may control a pull-down drive operation of the fourth pull-down element N 22 in response to the first control signal CNT 1 . For example, when the first control signal CNT 1 , having a logic “high” level, is applied to a gate electrode of the second pull-down drive control element N 23 to turn on the second pull-down drive control element N 23 and the second pull-down signal PD 2 is enabled to have, for example, a logic “high” level, the fourth pull-down element N 22 may be turned on to pull down a level of the second I/O line GIO 2 .
Hereinafter, operations of the first and second I/O line drivers GIO_DRV 1 and GIO_DRV 2 shown in FIGS. 2 and 3 will be described with reference to the tables of FIGS. 4A to 4D .
Referring to FIG. 4A , if the first input signal IN 1 has a logic “high” level, the first inverted input signal IN 1 B has a logic “low” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the first pull-up signal PU 1 may be enabled to have a logic “low” level and the first pull-down signal PD 1 may be disabled to have a logic “low” level. In such a case, the first control signal CNT 1 may be generated to have a logic “high” level since the first pull-up signal PU 1 is enabled to have a logic “low” level. If the second input signal IN 2 has a logic “high” level, the second inverted input signal IN 2 B has a logic “low” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the second pull-up signal PU 2 may be enabled to have a logic “low” level and the second pull-down signal PD 2 may be disabled to have a logic “low” level. In such a case, the second control signal CNT 2 may be generated to have a logic “high” level since the second pull-up signal PU 2 is enabled to have a logic “low” level. Although both the first and second pull-up elements P 11 and P 12 are turned on by the first pull-up signal PU 1 enabled to have a logic “low” level, the first pull-up drive control element P 13 may be turned off by the second control signal CNT 2 having a logic “high” level. Thus, the second pull-up element P 12 cannot pull up a level of the first I/O line GIO 1 of the first I/O line driver GIO_DRV 1 . Further, although both the third and fourth pull-up elements P 21 and P 22 are turned on by the second pull-up signal PU 2 enabled to have a logic “low” level, the second pull-up drive control element P 23 may be turned off by the first control signal CNT 1 having a logic “high” level. Thus, the fourth pull-up element P 22 cannot pull up a level of the second I/O line GIO 2 of the second I/O line driver GIO_DRV 2 . That is, when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled up, the first I/O line GIO 1 can be pulled up only by the first pull-up element P 11 and the second I/O line GIO 2 can be pulled up only by the third pull-up element P 21 .
Referring to FIG. 4B , if the first input signal IN 1 has a logic “high” level, the first inverted input signal IN 1 B has a logic “low” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the first pull-up signal PU 1 may be enabled to have a logic “low” level and the first pull-down signal PD 1 may be disabled to have a logic “low” level. In such a case, the first control signal CNT 1 may be generated to have a logic “high” level since the first pull-up signal PU 1 is enabled to have a logic “low” level. If the second input signal IN 2 has a logic “low” level, the second inverted input signal IN 2 B has a logic “high” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the second pull-up signal PU 2 may be disabled to have a logic “high” level and the second pull-down signal PD 2 may be enabled to have a logic “high” level. In such a case, the second control signal CNT 2 may be generated to have a logic “low” level since the second pull-up signal PU 2 is disabled to have a logic “high” level. Thus, since both the first and second pull-up elements P 11 and P 12 are turned on by the first pull-up signal PU 1 enabled to have a logic “low” level and the first pull-up drive control element P 13 is also turned on by the second control signal CNT 2 having a logic “low” level, a level of the first I/O line GIO 1 of the first I/O line driver GIO_DRV 1 may be pulled up by the first and second pull-up elements P 11 and P 12 . Further, since both the third and fourth pull-down elements N 21 and N 22 are turned on by the second pull-down signal PD 2 enabled to have a logic “high” level and the second pull-down drive control element N 23 is also turned on by the first control signal CNT 1 having a logic “high” level, a level of the second I/O line GIO 2 of the second I/O line driver GIO_DRV 2 may be pulled down by the third and fourth pull-down elements N 21 and N 22 .
Referring to FIG. 4C , if the first input signal IN 1 has a logic “low” level, the first inverted input signal IN 1 B has a logic “high” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the first pull-up signal PU 1 may be disabled to have a logic “high” level and the first pull-down signal PD 1 may be enabled to have a logic “high” level. In such a case, the first control signal CNT 1 may be generated to have a logic “low” level since the first pull-up signal PU 1 is disabled to have a logic “high” level. If the second input signal IN 2 has a logic “high” level, the second inverted input signal IN 2 B has a logic “low” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the second pull-up signal PU 2 may be enabled to have a logic “low” level and the second pull-down signal PD 2 may be disabled to have a logic “low” level. In such a case, the second control signal CNT 2 may be generated to have a logic “high” level since the second pull-up signal PU 2 is enabled to have a logic “low” level. Thus, since both the first and second pull-down elements N 11 and N 12 are turned on by the first pull-down signal PD 1 enabled to have a logic “high” level and the first pull-down drive control element N 13 is also turned on by the second control signal CNT 2 having a logic “high” level, a level of the first I/O line GIO 1 of the first I/O line driver GIO_DRV 1 may be pulled down by the first and second pull-down elements N 11 and N 12 . Further, since both the third and fourth pull-up elements P 21 and P 22 are turned on by the second pull-up signal PU 2 enabled to have a logic “low” level and the second pull-up drive control element P 23 is also turned on by the first control signal CNT 1 having a logic “low” level, a level of the second I/O line GIO 2 of the second I/O line driver GIO_DRV 2 may be pulled up by the third and fourth pull-up elements P 21 and P 22 .
Referring to FIG. 4D , if the first input signal IN 1 has a logic “low” level, the first inverted input signal IN 1 B has a logic “high” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the first pull-up signal PU 1 may be disabled to have a logic “high” level and the first pull-down signal PD 1 may be enabled to have a logic “high” level. In such a case, the first control signal CNT 1 may be generated to have a logic “low” level since the first pull-up signal PU 1 is disabled to have a logic “high” level. If the second input signal IN 2 has a logic “low” level, the second inverted input signal IN 2 B has a logic “high” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the second pull-up signal PU 2 may be disabled to have a logic “high” level and the second pull-down signal PD 2 may be enabled to have a logic “high” level. In such a case, the second control signal CNT 2 may be generated to have a logic “low” level since the second pull-up signal PU 2 is disabled to have a logic “high” level. Although both the first and second pull-down elements N 11 and N 12 are turned on by the first pull-down signal PD 1 enabled to have a logic “high” level, the first pull-down drive control element N 13 may be turned off by the second control signal CNT 2 having a logic “low” level. Thus, the second pull-down element N 12 cannot pull down a level of the first I/O line GIO 1 of the first I/O line driver GIO_DRV 1 . Further, although both the third and fourth pull-down elements N 21 and N 22 are turned on by the second pull-down signal PD 2 enabled to have a logic “high” level, the second pull-down drive control element N 23 may be turned off by the first control signal CNT 1 having a logic “low” level. Thus, the fourth pull-down element N 22 cannot pull down a level of the second I/O line GIO 2 of the second I/O line driver GIO_DRV 2 . That is, when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled down, the first I/O line GIO 1 can be pulled down only by the first pull-down element N 11 and the second I/O line GIO 2 can be pulled down only by the third pull-down element N 21 .
As a result, a drivability of the circuit for driving the first and second I/O lines GIO 1 and GIO 2 shown in FIGS. 2 and 3 may be reduced when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled up or pulled down. That is, when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled up, the first I/O line GIO 1 can be pulled up only by the first pull-up element P 11 and the second I/O line GIO 2 can be pulled up only by the third pull-up element P 21 . Further, when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled down, the first I/O line GIO 1 can be pulled down only by the first pull-down element N 11 and the second I/O line GIO 2 can be pulled down only by the third pull-down element N 21 . Accordingly, when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously driven to the same level, the number of elements which are simultaneously turned on can be reduced to decrease the simultaneous switching noises. Hence, the reliability of semiconductor systems including the I/O line driving circuit according to an embodiment may be improved.
Referring to FIG. 5 , another example of the first I/O line driver GIO_DRV 1 may be configured to include a third buffer ND 12 , a fourth buffer ND 13 , a third inversion buffer IV 12 , a fifth pull-up element P 14 , a sixth pull-up element P 15 , a third pull-up drive control element P 16 , a fifth pull-down element N 14 , a sixth pull-down element N 15 and a third pull-down drive control element N 16 .
The third buffer ND 12 may generate a third pull-up signal PU 3 in response to a first input signal IN 1 when an enable signal EN applied to the third buffer ND 12 is enabled to have a logic “high” level. For example, the third buffer ND 12 may generate the third pull-up signal PU 3 by inverting the first input signal IN 1 . The fourth buffer ND 13 may generate a third control signal CNT 3 in response to a first inverted input signal IN 1 B when the enable signal EN applied to the fourth buffer ND 13 is enabled to have a logic “high” level. For example, the fourth buffer ND 13 may generate the third control signal CNT 3 by inverting the first inverted input signal IN 1 B. The third inversion buffer IV 12 may generate a third pull-down signal PD 3 in response to the third control signal CNT 3 . For example, the third inversion buffer IV 12 may generate the third pull-down signal PD 3 by buffering the third control signal CNT 3 . The fifth pull-up element P 14 may be a PMOS transistor. If the fifth pull-up element P 14 is a PMOS transistor, a source electrode of the fifth pull-up element P 14 may be electrically connected to the power supply terminal VDD and a drain electrode of the fifth pull-up element P 14 may be electrically connected to the first I/O line GIO 1 . In such a case, if the third pull-up signal PU 3 enabled to have, for example, a logic “low” level is applied to a gate electrode of the fifth pull-up element P 14 , the fifth pull-up element P 14 may be turned on to pull up a level of the first I/O line GIO 1 . In an embodiment, the sixth pull-up element P 15 and the third pull-up drive control element P 16 may be PMOS transistors. If the sixth pull-up element P 15 and the third pull-up drive control element P 16 are PMOS transistors, the sixth pull-up element P 15 and the third pull-up drive control element P 16 may be connected in series. Further, a source electrode of the sixth pull-up element P 15 may be electrically connected to the power supply terminal VDD and a drain electrode of the third pull-up drive control element P 16 may be electrically connected to the first I/O line GIO 1 . In such a case, if the third pull-up signal PU 3 enabled to have, for example, a logic “low” level is applied to a gate electrode of the sixth pull-up element P 15 , the sixth pull-up element P 15 may be turned on to pull up a level of a source electrode of the third pull-up drive control element P 16 . In addition, the third pull-up drive control element P 16 may control a pull-up drive operation of the sixth pull-up element P 15 in response to a fourth control signal CNT 4 . For example, when the fourth control signal CNT 4 having a logic “low” level is applied to a gate electrode of the third pull-up drive control element P 16 to turn on the third pull-up drive control element P 16 and the third pull-up signal PU 3 is enabled to have a logic “low” level, the sixth pull-up element P 15 may be turned on to pull up a level of the first I/O line GIO 1 .
The fifth pull-down element N 14 may be an NMOS transistor. In such a case, a drain electrode of the fifth pull-down element N 14 may be electrically connected to the first I/O line GIO 1 and a source electrode of the fifth pull-down element N 14 may be electrically connected to the ground terminal VSS. Thus, when the third pull-down signal PD 3 enabled to have, for example, a logic “high” level is applied to a gate electrode of the fifth pull-down element N 14 , the fifth pull-down element N 14 may be turned on to pull down a level of the first I/O line GIO 1 . In an embodiment, the sixth pull-down element N 15 and the third pull-down drive control element N 16 may be NMOS transistors. If the sixth pull-down element N 15 and the third pull-down drive control element N 16 are NMOS transistors, the sixth pull-down element N 15 and the third pull-down drive control element N 16 may be connected in series. Further, a source electrode of the sixth pull-down element N 15 may be electrically connected to the ground terminal VSS and a drain electrode of the sixth pull-down drive control element N 16 may be electrically connected to the first I/O line GIO 1 . In such a case, if the third pull-down signal PD 3 enabled to have, for example, a logic “high” level is applied to a gate electrode of the sixth pull-down element N 15 , the sixth pull-down element N 15 may be turned on to pull down a level of a source electrode of the third pull-down drive control element N 16 . In addition, the third pull-down drive control element N 16 may control a pull-down drive operation of the sixth pull-down element N 15 in response to the fourth control signal CNT 4 . For example, when the fourth control signal CNT 4 having a logic “high” level is applied to a gate electrode of the third pull-down drive control element N 16 to turn on the third pull-down drive control element N 16 and the third pull-down signal PD 3 is enabled to have a logic “high” level, the sixth pull-down element N 15 may be turned on to pull down a level of the first I/O line GIO 1 .
Referring to FIG. 6 , another example of the second I/O line driver GIO_DRV 2 may be configured to include a fifth buffer ND 22 , a sixth buffer ND 23 , a fourth inversion buffer IV 22 , a seventh pull-up element P 24 , an eighth pull-up element P 25 , a fourth pull-up drive control element P 26 , a seventh pull-down element N 24 , an eighth pull-down element N 25 and a fourth pull-down drive control element N 26 .
The fifth buffer ND 22 may generate a fourth pull-up signal PU 4 in response to a second input signal IN 2 when an enable signal EN is enabled to have a logic “high” level. For example, the fifth buffer ND 22 may generate the fourth pull-up signal PU 4 by inverting the second input signal IN 2 . The sixth buffer ND 23 may generate the fourth control signal CNT 4 in response to the second inverted input signal IN 2 B when the enable signal EN applied to the sixth buffer ND 23 is enabled to have a logic “high” level. For example, the sixth buffer ND 23 may generate the fourth control signal CNT 4 by inverting the second inverted input signal IN 2 B. The fourth inversion buffer IV 22 may generate a fourth pull-down signal PD 4 in response to the fourth control signal CNT 4 . For example, the fourth inversion buffer IV 22 may generate the fourth pull-down signal PD 4 by inverting the fourth control signal CNT 4 . In an embodiment, the seventh pull-up element P 24 may be a PMOS transistor. If the seventh pull-up element P 24 is a PMOS transistor, a source electrode of the seventh pull-up element P 24 may be electrically connected to the power supply terminal VDD and a drain electrode of the seventh pull-up element P 24 may be electrically connected to the second I/O line GIO 2 . In such a case, if the fourth pull-up signal PU 4 enabled to have, for example, a logic “low” level is applied to a gate electrode of the seventh pull-up element P 24 , the seventh pull-up element P 24 may be turned on to pull up a level of the second I/O line GIO 2 . In an embodiment, the eighth pull-up element P 25 and the fourth pull-up drive control element P 26 may be PMOS transistors. If the eighth pull-up element P 25 and the fourth pull-up drive control element P 26 are PMOS transistors, the eighth pull-up element P 25 and the fourth pull-up drive control element P 26 may be connected in series. Further, a source electrode of the eighth pull-up element P 25 may be electrically connected to the power supply terminal VDD and a drain electrode of the fourth pull-up drive control element P 26 may be electrically connected to the second I/O line GIO 2 . In such a case, if the fourth pull-up signal PU 4 enabled to have, for example, a logic “low” level is applied to a gate electrode of the eighth pull-up element P 25 , the eighth pull-up element P 25 may be turned on to pull up a level of a source electrode of the fourth pull-up drive control element P 26 . In addition, the fourth pull-up drive control element P 26 may control a pull-up drive operation of the eighth pull-up element P 25 in response to the third control signal CNT 3 . For example, when the third control signal CNT 3 having a logic “low” level is applied to a gate electrode of the fourth pull-up drive control element P 26 to turn on the fourth pull-up drive control element P 26 and the fourth pull-up signal PU 4 is enabled to have a logic “low” level, the eighth pull-up element P 25 may be turned on to pull up a level of the second I/O line GIO 2 .
In an embodiment, the seventh pull-down element N 24 may be an NMOS transistor. In such a case, a drain electrode of the seventh pull-down element N 24 may be electrically connected to the second I/O line GIO 2 and a source electrode of the seventh pull-down element N 24 may be electrically connected to the ground terminal VSS. Thus, when the fourth pull-down signal PD 4 enabled to have, for example, a logic “high” level is applied to a gate electrode of the seventh pull-down element N 24 , the seventh pull-down element N 24 may be turned on to pull down a level of the second I/O line GIO 2 . In an embodiment, the eighth pull-down element N 25 and the fourth pull-down drive control element N 26 may be NMOS transistors. If the eighth pull-down element N 25 and the fourth pull-down drive control element N 26 are NMOS transistors, the eighth pull-down element N 25 and the fourth pull-down drive control element N 26 may be connected in series. Further, a source electrode of the eighth pull-down element N 25 may be electrically connected to the ground terminal VSS and a drain electrode of the fourth pull-down drive control element N 26 may be electrically connected to the second I/O line GIO 2 . In such a case, if the fourth pull-down signal PD 4 enabled to have, for example, a logic “high” level is applied to a gate electrode of the eighth pull-down element N 25 , the eighth pull-down element N 25 may be turned on to pull down a level of a source electrode of the fourth pull-down drive control element N 26 . In addition, the fourth pull-down drive control element N 26 may control a pull-down drive operation of the eighth pull-down element N 25 in response to the third control signal CNT 3 . For example, when the third control signal CNT 3 having a logic “high” level is applied to a gate electrode of the fourth pull-down drive control element N 26 to turn on the fourth pull-down drive control element N 26 and the fourth pull-down signal PD 4 is enabled to have a logic “high” level, the eighth pull-down element N 25 may be turned on to pull down a level of the second I/O line GIO 2 .
Hereinafter, operations of the first and second I/O line drivers GIO_DRV 1 and GIO_DRV 2 shown in FIGS. 5 and 6 will be described with reference to the tables of FIGS. 7A to 7D .
Referring to FIG. 7A , if the first input signal IN 1 has a logic “high” level, the first inverted input signal IN 1 B has a logic “low” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the third pull-up signal PU 3 may be enabled to have a logic “low” level and the third control signal CNT 3 may be generated to have a logic “high” level since the first inverted input signal IN 1 B has a logic “low” level. The third pull-down signal PD 3 may be disabled to have a logic “low” level since the third control signal CNT 3 has a logic “high” level. If the second input signal IN 2 has a logic “high” level, the second inverted input signal IN 2 B has a logic “low” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the fourth pull-up signal PU 4 may be enabled to have a logic “low” level and the fourth control signal CNT 4 may be generated to have a logic “high” level in response to the second inverted input signal IN 2 B having a logic “low” level. The fourth pull-down signal PD 4 may be disabled to have a logic “low” level since the fourth control signal CNT 4 has a logic “high” level. Although both the fifth and sixth pull-up elements P 14 and P 15 are turned on by the third pull-up signal PU 3 enabled to have a logic “low” level, the third pull-up drive control element P 16 may be turned off by the fourth control signal CNT 4 having a logic “high” level. Thus, the sixth pull-up element P 15 cannot pull up a level of the first I/O line GIO 1 of the first I/O line driver GIO_DRV 1 . Further, although both the seventh and eighth pull-up elements P 24 and P 25 are turned on by the fourth pull-up signal PU 4 enabled to have a logic “low” level, the fourth pull-up drive control element P 26 may be turned off by the third control signal CNT 3 having a logic “high” level. Thus, the eighth pull-up element P 25 cannot pull up a level of the second I/O line GIO 2 of the second I/O line driver GIO_DRV 2 . That is, when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled up, the first I/O line GIO 1 can be pulled up only by the fifth pull-up element P 14 and the second I/O line GIO 2 can be pulled up only by the seventh pull-up element P 24 .
Referring to FIG. 7B , if the first input signal IN 1 has a logic “high” level, the first inverted input signal IN 1 B has a logic “low” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the third pull-up signal PU 3 may be enabled to have a logic “low” level and the third control signal CNT 3 may be generated to have a logic “high” level since the first inverted input signal IN 1 B has a logic “low” level. The third pull-down signal PD 3 may be disabled to have a logic “low” level since the third control signal CNT 3 has a logic “high” level. If the second input signal IN 2 has a logic “low” level, the second inverted input signal IN 2 B has a logic “high” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the fourth pull-up signal PU 4 may be disabled to have a logic “high” level and the fourth control signal CNT 4 may be generated to have a logic “low” level since the second inverted input signal IN 2 B has a logic “high” level. The fourth pull-down signal PD 4 may be enabled to have a logic “high” level since the fourth control signal CNT 4 has a logic “low” level. Thus, because both the fifth and sixth pull-up elements P 14 and P 15 are turned on by the third pull-up signal PU 3 enabled to have a logic “low” level and the third pull-up drive control element P 16 is also turned on by the fourth control signal CNT 4 having a logic “low” level, a level of the first I/O line GIO 1 of the first I/O line driver GIO_DRV 1 may be pulled up by the fifth and sixth pull-up elements P 14 and P 15 . Further, since both the seventh and eighth pull-down elements N 24 and N 25 are turned on by the fourth pull-down signal PD 4 enabled to have a logic “high” level and the fourth pull-down drive control element N 26 is also turned on by the third control signal CNT 3 having a logic “high” level, a level of the second I/O line GIO 2 of the second I/O line driver GIO_DRV 2 may be pulled down by the seventh and eighth pull-down elements N 24 and N 25 .
Referring to FIG. 7C , if the first input signal IN 1 has a logic “low” level, the first inverted input signal IN 1 B has a logic “high” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the third pull-up signal PU 3 may be disabled to have a logic “high” level and the third control signal CNT 3 may be generated to have a logic “low” level since the first inverted input signal IN 1 B has a logic “high” level. The third pull-down signal PD 3 may be enabled to have a logic “high” level since the third control signal CNT 3 has a logic “low” level. If the second input signal IN 2 has a logic “high” level, the second inverted input signal IN 2 B has a logic “low” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the fourth pull-up signal PU 4 may be enabled to have a logic “low” level and the fourth control signal CNT 4 may be generated to have a logic “high” level since the second inverted input signal IN 2 B has a logic “low” level. The fourth pull-down signal PD 4 may be enabled to have a logic “low” level since the fourth control signal CNT 4 has a logic “high” level. Thus, because both the fifth and sixth pull-down elements N 14 and N 15 are turned on by the third pull-down signal PD 3 enabled to have a logic “high” level and the third pull-down drive control element N 16 is also turned on by the fourth control signal CNT 4 having a logic “high” level, a level of the first I/O line GIO 1 of the first I/O line driver GIO_DRV 1 may be pulled down by the fifth and sixth pull-down elements N 14 and N 15 . Further, since both the seventh and eighth pull-up elements P 24 and P 25 are turned on by the fourth pull-up signal PU 4 enabled to have a logic “low” level and the fourth pull-up drive control element P 26 is also turned on by the third control signal CNT 3 having a logic “low” level, a level of the second I/O line GIO 2 of the second I/O line driver GIO_DRV 2 may be pulled up by the seventh and eighth pull-up elements P 24 and P 25 .
Referring to FIG. 7D , if the first input signal IN 1 has a logic “low” level, the first inverted input signal IN 1 B has a logic “high” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the third pull-up signal PU 3 may be disabled to have a logic “high” level and the third control signal CNT 3 may be generated to have a logic “low” level since the first inverted input signal IN 1 B has a logic “high” level. The third pull-down signal PD 3 may be enabled to have a logic “high” level since the third control signal CNT 3 has a logic “low” level. If the second input signal IN 2 has a logic “low” level, the second inverted input signal IN 2 B has a logic “high” level. Accordingly, when the enable signal EN is enabled to have a logic “high” level, the fourth pull-up signal PU 4 may be disabled to have a logic “high” level and the fourth control signal CNT 4 may be generated to have a logic “low” level since the second inverted input signal IN 2 B having a logic “high” level. The fourth pull-down signal PD 4 may be enabled to have a logic “high” level since the fourth control signal CNT 4 has a logic “low” level. Although both the fifth and sixth pull-down elements N 14 and N 15 are turned on by the third pull-down signal PD 3 enabled to have a logic “high” level, the third pull-down drive control element N 16 may be turned off by the fourth control signal CNT 4 having a logic “low” level. Thus, the sixth pull-down element N 15 cannot pull down a level of the first I/O line GIO 1 of the first I/O line driver GIO_DRV 1 . Further, although both the seventh and eighth pull-down elements N 24 and N 25 are turned on by the fourth pull-down signal PD 4 enabled to have a logic “high” level, the fourth pull-down drive control element N 26 may be turned off by the third control signal CNT 3 having a logic “low” level. Thus, the eighth pull-down element N 25 cannot pull down a level of the second I/O line GIO 2 of the second I/O line driver GIO_DRV 2 . That is, when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled down, the first I/O line GIO 1 can be pulled down only by the fifth pull-down element N 14 and the second I/O line GIO 2 can be pulled down only by the seventh pull-down element N 24 .
As a result, a drivability of the circuit for driving the first and second I/O lines GIO 1 and GIO 2 shown in FIGS. 5 and 6 may be reduced when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled up or pulled down. That is, when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled up, the first I/O line GIO 1 can be pulled up only by the fifth pull-up element P 14 and the second I/O line GIO 2 can be pulled up only by the seventh pull-up element P 24 . Further, when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously pulled down, the first I/O line GIO 1 can be pulled down only by the fifth pull-down element N 14 and the second I/O line GIO 2 can be pulled down only by the seventh pull-down element N 24 . Accordingly, when both the first and second I/O lines GIO 1 and GIO 2 are simultaneously driven to the same level, the number of elements which are simultaneously turned on can be reduced to decrease the simultaneous switching noises. Hence, the reliability of semiconductor systems including the I/O line driving circuit according to an embodiment may be improved.
The example embodiments of the inventive concept have been disclosed above for illustrative purposes. Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the inventive concept as disclosed in the accompanying claims. | Input/output (I/O) line driving circuits are provided. The circuit includes a first I/O line driver and a second I/O line driver. The first I/O line driver receives a first input signal in response to an enable signal to generate a first control signal and drives a first I/O line in response to a second control signal. The second I/O line driver receives a second input signal in response to the enable signal to generate the second control signal and drives a second I/O line in response to the first control signal. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to an outboard engine that is steerably attached to the hull of a boat.
BACKGROUND OF THE INVENTION
[0002] Japanese Patent Laid-Open Publication No. 7-149289 (JP-A-7-149289) discloses an outboard engine wherein the outer surface of a drive shaft housing (extension case) in the vertical middle of the outboard engine is covered by a cover.
[0003] In this outboard engine, the outer surface of the drive shaft housing is covered with a cover made of a synthetic resin to reduce the finishing costs needed to improve the outward appearance of the drive shaft housing, and also to simplify the design of the drive shaft housing.
[0004] The cover that covers the outer surface of the drive shaft housing is configured from a two-piece dividable cover having a port cover and a starboard cover.
[0005] Thus, in this outboard engine, covering the outer surface of the drive shaft housing with a cover made of a synthetic resin makes it possible to improve the outward appearance of the drive shaft housing and to simplify the external structure of the housing, and also allows for a greater degree of freedom in the design.
[0006] However, since this cover is configured from two members, which are the port cover and the starboard cover, a large number of attachment bosses is needed to attach and support these two members on the outer surface of the drive shaft housing, the attachment structure of the cover and the drive shaft housing is complicated, and the number of steps for attachment is increased. Particularly, since the cover is configured from two members, pressure must be applied to both the left and right components when the left and right components are assembled, making operability inferior.
[0007] In view of this, the outward appearance of the cover must be simplified, as must the structure for attaching the cover to the drive shaft housing.
SUMMARY OF THE INVENTION
[0008] According to the present invention, there is provided an outboard engine designed to be steerably attached to a hull of a boat by an attachment device, which outboard engine comprises an engine part, a propeller driven by the engine part, a transmission device that includes a longitudinal shaft and a propeller shaft for transmitting an output of the engine part, and a main body for housing at least the engine part and the transmission device, wherein the main body is composed of a leg case that extends in a longitudinal direction and that houses at least part of the longitudinal shaft of the transmission device, and a cover that covers an outer side of the leg case; and the cover is formed integrally by forming a starboard outer surface and a port outer surface continuously in a rear portion of the outboard engine, and is provided with an anti-splash plate formed integrally on a front surface.
[0009] Thus, in the outboard engine, since the cover is formed integrally by forming a starboard outer surface and a port outer surface continuously at the rear of the outboard engine, there are no dividing lines or joining lines in the rear surface of the cover of the outboard engine, for which a favorable outward appearance is vital, and the outward appearance is significantly improved in the outboard engine in which the outer surface of the leg case is covered with a cover.
[0010] Furthermore, since the cover is configured from a single member, the number of components is reduced, and there are fewer attachment portions on the cover, and fewer attachment parts on the leg case. Furthermore, since a single member is set on the side of the leg case, there is no need for multiple setting devices or positioning means, which are needed to set a cover composed of two members, and the operation of the attachment can be simplified.
[0011] Furthermore, the number of components can be reduced since the starboard outer surface and the port outer surface constituting the cover are formed integrally and the anti-splash plate is provided integrally to the front surface.
[0012] It is preferable that the cover have a frontally disposed interlocking part that interlocks with the leg case. Therefore, positioning alignment is simplified during assembly with the leg case side of the outboard engine.
[0013] It is preferable that the cover have fastening parts, and that the fastening parts be provided so as to be in contact with the anti-splash plate and the cover. Therefore, providing the fastening parts that span both the anti-splash plate and the cover is effective for reinforcing the periphery of the fastening parts, and makes it possible to ensure sufficient rigidity when the anti-splash plate is subjected to external forces.
[0014] It is preferable that the cover be provided separately from the attachment device. The anti-splash plate is not limited to the height of the attachment device, and the height of the anti-splash plate can be designed at an arbitrary position. Furthermore, the height of the anti-splash plate is close to the water surface as long as the height is set lower than the height of the attachment device, and the required width of the anti-splash plate can therefore be prevented from being needlessly increased.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] A preferred embodiment of the present invention will be described in detail below, by way of example only, with reference to the accompanying drawings, in which:
[0016] FIG. 1 is a side view of the outboard engine of the present invention on which a leg cover is mounted;
[0017] FIG. 2 is a perspective view of the leg cover shown in FIG. 1 as viewed from above on the starboard side;
[0018] FIG. 3 is a perspective view of the leg cover shown in FIG. 1 as viewed from above on the port side;
[0019] FIG. 4 is a front view of the leg cover shown in FIG. 2 ;
[0020] FIG. 5 is a rear view of the leg cover shown in FIG. 2 ;
[0021] FIG. 6 is a plan view of the leg cover shown in FIG. 2 ;
[0022] FIG. 7 is a longitudinal cross-sectional view of the leg cover shown in FIG. 2 ; and
[0023] FIG. 8 is an exploded perspective view of the leg cover being assembled on the leg case.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0024] Referring to FIG. 1 , an outboard engine 1 comprises an engine cover 2 that houses an engine part 5 ; an undercover 3 that is positioned below the engine cover 2 ; a leg cover 50 that is positioned below the undercover 3 and that covers a leg case (extension case) 8 , which is a drive shaft housing; and a gear case 4 at the lowest position.
[0025] The engine part 5 is composed of a multi-cylinder four-stroke engine having a longitudinally oriented crankshaft 5 a , a transversely oriented cylinder block 5 b , a cylinder head 5 c , a cylinder head cover 5 d , a crankcase 5 e , and a camshaft (not shown).
[0026] The engine cover 2 covers the top half of the engine part 5 , and the top of the undercover 3 covers the bottom of the engine part 5 . The bottom end of the engine part 5 is supported by a mounting case 6 . An oil case 7 is disposed below the mounting case 6 . The oil case 7 and the gear case 4 are connected by the leg case 8 .
[0027] A drive shaft 9 is connected to the crankshaft 5 a , and passes vertically through the mounting case 6 , the oil case 7 , and the leg case 8 and extends into the gear case 4 . The drive shaft 9 transmits the drive force outputted from the engine part 5 to a propeller shaft 11 a via a gear mechanism 10 installed in the gear case 4 , thereby driving a propeller 11 . The drive shaft 9 and the propeller 11 constitute a transmission device.
[0028] An anti-cavitation plate 12 is provided on the gear case 4 at a position above the propeller 11 . An anti-splash plate 13 is provided on the gear case 4 at a position above the anti-cavitation plate 12 .
[0029] A concavity 14 in which a stern bracket 15 and a swivel case 16 are installed is formed in the front of the undercover 3 and the leg cover 50 . The outboard engine 1 is attached to the stern S 1 of a hull S by means of the stern bracket 15 . This stern bracket 15 is an attachment device for attaching the outboard engine 1 to the stern S 1 . The outboard engine 1 swings vertically about a tilt shaft 15 a provided to the stern bracket 15 , and also swings horizontally about a swivel shaft 17 inside the swivel case 16 . The swivel shaft 17 enables the outboard engine 1 to be steered.
[0030] The outboard engine main body is configured from the engine part, the mounting case, the oil case, the leg case, and the engine cover and undercover that house these components.
[0031] Next, the configuration of the leg cover 50 will be described with reference to FIGS. 2 through 7 .
[0032] Compared to the portion of the leg cover 50 that extends from a top part 50 a to a middle part 50 b , a bottom half 50 c is longer in the longitudinal direction of the outboard engine 1 , i.e., is formed to protrude farther forward. Thus, the leg cover 50 is in the shape of a long boot and comprises a port side wall 51 , a starboard side wall 52 , and a rear side wall 53 in which the rear ends of the port side wall 51 and the starboard side wall 52 are formed integrally.
[0033] The front ends of the port side wall (port outer surface) 51 and the starboard side wall (starboard outer surface) 52 that extend from the top parts to the middle parts have left and right front side walls 55 , 56 that are bent inward so as to face each other. The left and right front side walls 55 , 56 are connected in a joining part 54 , and protrude so as to form a V shape in plan view. Left and right protruding parts 51 a , 52 a that protrude outward are formed in portions that extend from the bottoms of the left and right front side walls 55 , 56 to the front halves of the port and starboard side walls 51 , 52 .
[0034] A protruding frame 58 that protrudes farther forward than the left and right front side walls 55 , 56 is formed on the protruding parts 51 a , 52 a . The protruding frame 58 is composed of left and right portions 58 a , 58 b that are both in the shape of a U when viewed from the front, wherein a window 57 having a horizontal rectangular shape is formed in the front surface. The left and right portions 58 a , 58 b face each other. The top surface 58 c of the protruding frame 58 forms a shelf and protrudes laterally forward.
[0035] The port and starboard side walls 51 , 52 have extending parts 51 b , 52 b that extend forward in the bottom. The extending parts 51 b , 52 b have roof parts 51 c , 52 c in the top surfaces.
[0036] A gap 59 is formed between the end edges 51 d , 52 d of the portions that protrude from the left and right extending parts 51 b , 52 b , as shown in FIG. 4 . Anti-splash plate halves 60 a , 60 a that form a substantial half circle when joined together are formed integrally in the tops of the left and right extending parts 51 b , 52 b . The anti-splash plate halves 60 a , 60 a extend forward from the left and right extending parts 51 b , 52 b , and the distal ends thereof have arcuate shapes. An anti-splash plate 60 is configured form the anti-splash plate halves 60 a , 60 a.
[0037] Notches 61 , 61 are formed in the front ends of the anti-splash plate 60 . A narrow gap 62 that extends in the longitudinal direction is formed behind these notches 61 , 61 . A space is formed in the area behind the gap 62 . A roof piece 63 that protrudes from the front ends of the left and right roof parts 51 c , 52 c is formed at a position above this space. An interlocking part 64 is formed by the roof piece 63 and the gap 62 .
[0038] The leg cover 50 has an attachment piece 65 provided in the top edge at the rear so as to protrude upward, and multiple interlocking pieces 66 provided in the top edge at the front so as to protrude upward. Fastening holes 67 , 67 are formed in the bottom rear parts of the port and starboard side walls 51 , 52 . Fastening holes 68 , 68 are also formed in the front side walls 55 , 56 . The reference number 69 in FIG. 2 denotes a drain hole.
[0039] A gap 62 is formed between the left and right portions 60 a , 60 a of the anti-splash plate 60 , as shown in FIG. 4 . Reinforcing ribs 70 , 70 are provided at the top halves of the opposing end edges 51 d , 52 d of the port and starboard side walls 51 , 52 . These reinforcing ribs 70 are connected to the extending parts 51 b , 52 b and to the anti-splash plate 60 , and constitute a fastening unit for fastening the port and starboard side walls 51 , 52 . The reinforcing ribs 70 fasten the port and starboard side walls 51 , 52 together when a bolt is inserted through fastening holes 71 , as shown in FIG. 7 .
[0040] The leg cover 50 is integrally molded from a synthetic resin.
[0041] The leg case 8 has at the top end a flange 8 a that bonds with a bottom end flange 7 a of the oil case 7 , as shown in FIG. 8 . A protrusion 8 b that protrudes forward is formed in the bottom front surface of the leg case 8 . Both sides of the protrusion 8 b are provided with mounting housings 8 , 18 that buffer and support a center housing 17 a provided at the bottom end of the swivel shaft 17 .
[0042] Next, the procedure of assembling the leg cover 50 on the leg case 8 will be described with reference to FIGS. 2 and 8 .
[0043] First, the port and starboard side walls 51 , 52 of the leg cover 50 are separated to the left and right as shown by the arrows a and b, and a space is opened between the left and right front side walls 55 , 56 that are opened to the left and right. In this state, the leg cover 50 is oriented forward and is fitted over the rear of the leg case 8 of the outboard engine 1 , as shown by the arrow c.
[0044] At this time, the bottom end of the leg cover 50 is moved along the top surface of the anti-splash plate 13 provided at the bottom of the outboard engine 1 to move the leg cover 50 forward and to encase the leg case 8 from the sides. The leg cover 50 is made of a flexible synthetic resin, and the rear side wall 53 of the port and starboard side walls 51 , 52 easily bends and expands.
[0045] When the leg cover 50 is moved forward in the direction of the arrow c, the left and right protruding parts 51 a , 52 a enclose the mounting housings 18 , 18 from the sides, thereby hiding the mounting housings 18 , 18 . The protrusion 8 b is encircled by the protruding frame 58 , and the front end surface of the protrusion 8 b faces the window 57 .
[0046] A tongue-like interlocking piece 81 shown in FIGS. 1, 4 , and 6 is provided at the bottom front end of the leg case 8 . The interlocking piece 81 protrudes forward from the interlocking part 64 between the roof piece 63 and the front top surface of the anti-splash plate 60 shown in FIG. 2 , and allows the leg case 8 and the leg cover 50 to be easily positioned during assembly.
[0047] The attachment piece 65 at the rear of the leg cover 50 is screwed onto the undercover 3 , and the interlocking pieces 66 at the front are interlocked with the undercover 3 . The leg cover 50 is bolted onto the leg case 8 by using the fastening holes (fastening parts) 67 , 67 shown in FIG. 2 . The left and right front side walls 55 , 56 of the leg cover 50 are connected using bolts via the fastening holes (fastening parts) 68 , 68 . The anti-splash plate 60 is fastened by inserting a bolt through the fastening holes 71 , 71 in the reinforcing ribs (fastening parts) 70 , 70 . Thus, the leg cover 50 is attached so as to cover the outer surface of the leg case 8 .
[0048] The leg cover 50 , rather than being a two-piece dividable member, is formed from a single integrated plate member, wherein the front portion is opened to encase and cover the leg case 8 of the outboard engine 1 , and then the cover is easily attached to the leg case 8 by being fastened using bolts.
[0049] Obviously, various minor changes and modifications of the present invention are possible in light of the above teaching. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described. | An outboard engine with a cover for allowing for an improved outward appearance is disclosed. The engine includes a leg case that houses a drive shaft for transmitting the output from the engine to a propeller. The cover covers the leg case. The cover is formed integrally, and a front part is designed to be opened. The front part is opened and is made to encase and cover a periphery of the leg case. | 1 |
This application is a continuation-in-part of application Ser. No. 07/821,975, filed Jan. 16, 1992 now U.S. Pat. No. 5,153,969.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention pertains to apparatus for holding and containing gathered cord and more specifically to apparatus suitable for tidying otherwise unsightly appliance cords.
2. Description of the Prior Art
It is not uncommon for numerous electrical appliances to be left in the open on countertops in such rooms as kitchens and bathrooms and in such work areas as home shop work benches. Electrical cords can be snugged up to outlets in some cases and become somewhat tidy. In other instances, cords can be tacked neatly to the floor or wall when the appliance base is located some distance from the plug, provided the base is left permanently located in a single place of use.
However, there are many times when neither of the above conditions exist. For example, a hair dryer does not remain on the counter in one location, but is most conveniently picked up for use and placed down when not in use. In order to be put in a condition that is somewhat sightly when not in use, hair dryers are often unplugged all together and put away in a drawer. However, a hair dryer or similar appliance that is put away must be set up again before it can be used in spite of the fact that it is intended to be left plugged in ready for use and merely turned off by its on/off switch.
U.S. Pat. No. 4,742,429, commonly owned, describes a bathroom electrical appliance caddy that accommodates electrical appliances in a cabinet-mounted housing that can be readily slid out of the cabinet when one or more appliances carried therein is ready for use and put away when not in use. However, appliances with long and/or ungainly cords located on one or both shelves of such a caddy are often left in an unsightly condition. The cords are just tossed back onto the housing shelves of the housing before the housing is slid back into the cabinet. Loose cords can subsequently tangle or knock off items from their shelves when subsequently pulled out.
In some installations, cords are purposely curled or retracted. For example, it is common for the handset of a telephone to be connected to its base by a curled cord that tightly winds up when the handset is returned to its cradle. However, most appliances do not come with such curled cords and it is not convenient to replace cords that come with most appliances with such self-policing cords.
Cords have been tidied in the past in many ways by persons not pleased with either the unsightly appearance of such cords or perhaps because unsightly cords can become tangled and therefore potentially hazardous. Tangled cords, for example, that are assumed not to be tangled when tugged can drag undesired items with them. To keep this from happening, long cords have been tied in knots by their users or twist ties have been used to join gathered loops of cords together. Some appliances come with cylindrical clamps that encircle a gathered cord mass to semi-permanently clamp a predetermined number of loops together to foreshorten the cord. None of these methods are particularly useful for gathering and holding cords together in a temporary gather that can be quickly and conveniently subsequently released to allow gathering again in a different manner, for instance with more or less cord loops.
Therefore, it is a feature of the present invention to provide an improved apparatus that can be employed with loosely gathered appliance cords or the like to make them more tidy than they otherwise would be.
It is another feature of the present invention to provide an improved cord clasp that is of little trouble to manipulate and readjust and can be used with almost any appliance cord in common use.
SUMMARY OF THE INVENTION
The apparatus in a preferred embodiment of the present invention includes two substantially identical jaw members pivoted together along a ridge between their respective cord surrounding portions and their handle portions. A spring or other bias means urges the two cord surrounding portions together. The cord surrounding portions are preferably curvilinear and the tips of their front edges curve more than the remainder of their surfaces. The tips are gently rounded and are located at one side of their respective front edges. In another preferred embodiment, the jaw members are pivoted together by two hinges having a spring between the hinges for urging the cord surrounding portions together. The jaw members have handle portions having a plurality of ridges for gripping the handles. Alternatively, the jaw members may have outwardly curved handle portions. The handle portions are farther apart than are the cord surrounding portions when the clasp is closed. The jaw members taper from a wider profile at the handle portions to a narrower profile at the tips of the cord surrounding portions. The two cord surrounding portions come together in complementary fashion and at least loosely retain the gathered cord with which they are employed within their grasp even when the thickness of the cords do not allow the surrounding portions to close completely. Squeezing the handle portions together opens the cord surrounding portions to allow the cord to be released or repositioned.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above-recited features, advantages and objects of the invention, as well as others which will become apparent, are attained and can be understood in detail, more particular description of the invention briefly summarized above may be had by reference to the exemplary embodiments thereof which are illustrated in the drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate only typical preferred embodiments of the invention and are therefore not to be considered limiting of its scope as the invention may admit to other equally effective embodiments.
In the drawings:
FIG. 1 is a pictorial view of a typical appliance having a cord tidied by a cord clasp in accordance with a preferred embodiment of the present invention.
FIG. 2 is an oblique side view of a first preferred embodiment of the cord clasp in accordance with the present invention wherein the jaw members thereof have a long, low profile.
FIG. 3 is a bottom view of the embodiment shown in FIG. 2 showing the dimensional relationships of the jaw members.
FIG. 4 is an end view of the embodiment shown in FIG. 2.
FIG. 5 is an oblique side view of a second preferred embodiment of the present invention wherein the jaw members thereof have a more circular profile than the first embodiment for rolling the cord loops together as the clasp is closed.
FIG. 6 is a side view of a third preferred embodiment of the present invention wherein the bias means urging closure is from a portion of one of the jaw members.
FIG. 7 is a side view of a fourth preferred embodiment of the present invention wherein the handle portions have a plurality of ridges for gripping the handles.
FIG. 8 is a top view of the preferred embodiment of FIG. 7 from the view of line 8--8.
FIG. 9 is a side view of a fifth preferred embodiment of the present invention, wherein the handle portions are outwardly curved.
FIG. 10 is a rear view of a bias means for urging closure of the jaw members of a preferred embodiment.
FIG. 11 is an end view of a sixth preferred embodiment.
FIG. 12 is an end view of a seventh preferred embodiment.
FIG. 13 is an end view of an eighth preferred embodiment.
FIG. 14 is an end view of a ninth preferred embodiment.
FIG. 15 is an end view of a tenth preferred embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now referring to the drawings, and first to FIG. 1, an appliance 10, such as a hand-held hair dryer, is shown having an elongated flexible electrical cord 12 attached thereto for plugging into a suitable electrical outlet (not shown). When the appliance is not in use, the cord is looped, folded or otherwise gathered in multiple thicknesses. Because such thicknesses, even when tidy to begin with, tend to separate and spread apart and become untidy because of their resiliency when tightly gathered, a clasp 14 in accordance with the present invention is enclosed about them to retain them in their tidy condition.
A first preferred embodiment of a clasp 14 is shown in FIG. 2. The clasp generally comprises two main parts, namely, first elongated jaw member 16 and second elongated jaw member 18. Typically, jaw members 16 and 18 are configured in plastic, moldable hard rubber or the like in suitable complementary molds in a manner well known in the art. Jaw member 16 is in one piece, but can be considered as comprising cord surrounding portion 20 and handle portion 22. Similarly, jaw member 18 comprises cord surrounding portion 24 and handle portion 26. As shown in FIG. 2, this embodiment has a long, low profile.
Cord surrounding portion 20 and handle portion 22 converge together at internal pivot ridge 28 and cord surrounding portion 24 and handle portion 26 converge together at cooperatively contacting facing pivot ridge 30. A biasing means in the form of a coil spring 32 with suitable lap-over ends in the external surface valleys opposite the internal surface ridges hold the jaw members together. A suitable dog 31 attached to ridge 30 and operating through a hole in ridge 28 can be provided as further security in holding together members 16 and 18. When handles 22 and 26 are squeezed together, cord surrounding portions 20 and 24 separate so that the gathered cord to be clasped or held can be inserted.
Cord surrounding portions 20 and 24 have complementary curvilinear surfaces. However, as noted, the front edge of portion 20 includes a gently pointed tip 34 to one side, which tip can curve more or be more rounded than the remainder of its shape. In like fashion, the front edge of portion 24 includes a gently pointed tip 36 to its side opposite that of tip 34. Also in similar fashion, the surface of portion 24 in the vicinity of tip 36 can be more rounded or curved than the remainder of its surface. It should be noted that since the tips are on a greater arc portion of their respective curves than the remainders of their front edges, it is the tips that provide the initial in-gathering of the cord thicknesses. The tips also ensure that the cord loops are held within the grasp of the clasp more efficiently than if the front edges of portions 20 and 24 had been straight across and with no exaggerated curves, as may be seen from FIG. 4.
As noted above, the shapes of portions 20 and 24 are complementary to provide clasping of cord 12 within its grasp. Most conveniently, portions 20 and 24 can be identically shaped and can even be made from the same mold, if desired. To make the parts identically as shown in FIG. 2, top member 16 is subsequently stamped to form a hole and to remove the dog 31 that was molded in place.
Now referring to FIG. 5, an oblique view of a cord clasp 46 is shown that is similar to cord clasp 16; however, clasp 46 is generally shorter and rounder in profile. This is because cord surrounding portions 50 and 54 of the respective jaw members have a more circular profile that encourages the loops of cord being gathered to roll into the grasp of the jaw members as the handles of the clasp are operated. Again, the two parts are complementary and include tips 64 and 66 (hidden in the side view shown), tip 64 being on one side of jaw member 50 and tip 66 being on the other side of jaw member 54. The two jaw members can be held and biased closed together by a spring such as spring 32 or other equivalent means such as spring 33 that has only one end that extends to overlap member 50. It should be noted that the forward edges do not have to completely shut to encompass the cord loops, although if there are only a few loops, the two edges will come together, at least at one point. Note further that the clasp can conveniently be made from a resilient plastic or metal structure, such as by stamping, if preferred. In such case a dog 35 is made from stamping out a portion of the material in the lower ridge. A hole to accommodate dog 35 is stamped in the upper ridge.
Referring to FIGS. 2 and 5, it will be seen that both clasps are quite broad so as to embrace or enclose a significant portion of each loop. Preferably the width of a clasp is a minimum of 1 inch wide and can be 2 inches wide or greater. For the FIG. 5 embodiment, the width of the cord surrounding portion is substantially as wide as this portion is long.
FIG. 6 shows yet a third embodiment of a suitable clasp in accordance with this invention. In this case the shape is similar to the clasp shown in FIG. 5; however, the clasp is made of resilient metal, such as aluminum or steel. The two jaw members in this case are held together at the ridges by dog 70 in the same or similar manner to that described for FIG. 5 so as to permit pivoting action to occur. A segment 80 is formed by a cutting or stamping action to form a leaf spring depending from handle 84 of the upper jaw member. End 81 of segment 80 is bent over and passed through hole 83 in the lower cord surrounding or jaw member of the clasp to bias the clasp shut when the handles are released. Alternatively, a separate leaf spring can be attached to one handle and bent to contact the other in similar fashion.
FIG. 7 shows a fourth preferred embodiment of the present invention. The embodiment shown has a first elongated jaw member 90 and a second elongated jaw member 92. Jaw member 90 can be considered as comprising cord surrounding portion 94 and handle portion 96. Jaw member 92 can be considered as comprising cord surrounding portion 98 and handle portion 100. Handle portions 96 and 100 have one or more ridges 102 for gripping the handles with fingers or knuckles when opening the clasp. The ridges will be approximately 1/8 inch wide and approximately 1/32 inch in height. The ridges will be spaced approximately 1/4 inch to 3/8 inch apart.
The cord clasp is shown in the open position in FIG. 7, wherein the jaw members are parallel to one another. When the clasp is closed, it will have a tapered profile such that handle portions 96 and 100 are farther apart than are cord surrounding portions 94 and 98. As shown in FIG. 8, the jaw members fan out slightly in width from the handle portions to the front edges.
Referring to FIG. 9, a fifth preferred embodiment of the present invention is shown. The clasp shown has a first elongated jaw member 120 and a second elongated jaw member 122. Jaw member 120 is in one piece, but it can be considered as comprising cord surrounding portion 124 and handle portion 126. Similarly, jaw member 122 comprises cord surrounding portion 128 and handle portion 130. As discussed with respect to FIG. 7, the clasp has a tapered profile wherein the clasp is narrowest where cord surrounding portions 124 and 128 converge. The clasp is widest in profile at handle portions 126 and 130.
Handle portions 96 and 100 curve out at approximately 45° at the end. The curved area of the handle portions accommodate finger tips or knuckles for squeezing the handle portions 126 and 130 together to open the clasp. When the handle portions are squeezed together, cord surrounding portions 124 and 128 separate so that the gathered cord to be clasped or held can be inserted. The handle portions will be parallel to each other when the cord clasp is in the open position.
The clasp is narrower in profile where the surrounding portions converge to enable snugly securing a small number of loops of cord. The wider profiled area of the cord surrounding portions enable snugly securing a larger bundle of cord loops. The narrower end of the clasp may range from a height of 1/4 inch to 11/2 inch. When the clasp is closed, the narrow end of the clasp will be 1/4 inch in height. As handle ends 126 and 130 are squeezed, cord surrounding portions 124 and 128 will separate up to approximately 11/2 inch, or approximately the height of the pivot point. When a small number of cord loops need to be secured, the clasp is opened, the cord loops inserted and positioned at the narrow end of the clasp. When the clasp is closed, the small number of cord loops are held securely in place at the narrow end of the clasp. If a large number of cord loops need to be secured, the wider end of the clasp may be utilized to accommodate the cord.
As shown in FIG. 10, a biasing means in the form of a first hinge 103a and a second hinge 103b hold the jaw members together. Hinge 103a comprises a first arm 104a and a second arm 106a. Hinge 103b comprises a first arm 104b and a second arm 106b. Shaft 108 is pressed fit through both hinges and holds spring 110 in place between the hinges. Spring 110 has a first leg 112 and a second leg 114, which contact jaw members 90 and 92, respectively. The legs of the spring urge the clasp closed. The hinges will be located approximately 3/4 inch from the end of the handle portions to permit pivoting action to occur. The pivot point will be approximately 11/2 inch in height.
Cord surrounding portions shown in FIGS. 7 and 9 have complementary shaped surfaces. Additional alternative shaped surfaces are shown in FIGS. 11 through 15. The front edges of the cord surrounding portions are complementary shaped such that the front edge of the lower cord surrounding portion and the front edge of the upper cord surrounding portion may be closedly engaged. The front edge of an upper cord surrounding portion may be shaped to resemble one or more shark's teeth. FIG. 11 shows the front ends having a single shark tooth 200 shape. FIG. 12 shows the front edges having a plurality of shark's teeth 202, 204, and 206. The forward edges of the jaw members may be angled at opposite sides to respective first pointed tip 208 and second pointed tip 210, as shown in FIG. 13. FIG. 14 shows a preferred embodiment of the present invention having a first jagged edge 212 and a second jagged edge 214. FIG. 15 shows the front edges of a preferred embodiment having a plurality of complementary-shaped rounded tips 216 and 218, however, a singular complementary-shaped rounded tip may be used. All the shaped surfaces shown in FIGS. 11 through 15 enable the clasp to continue to hold the cord in place even when the cord surrounding portions are not closedly engaged. Although the described embodiments have complementary-shaped surfaces, not all embodiments comprise surfaces which are mirror images of one another.
The clasp shown in FIG. 7 can be made by fabricating individual handle-and-jaw-member segments. A separate mold is created for a segment of the elongated jaw member having two segments of predetermined size for surrounding the gathered cord. A second mold is created for a segment of a two segment handle portion having a plurality of transverse ridges. One of the transverse ridges is located at the forward end of the segment of the handle portion that adjoins the segment of the jaw member. The elongated jaw member mold and the handle portion mold are joined to form a common mold. The handle-and-jaw-member segment is molded in the joined molds in one fill with solidifying plastic material. The line on the molded segment where the jaw member mold and the handle portion mold are joined is hidden at the trough of the transverse ridge on the forward end of the segment of the handle portion. Clasps having various segment lengths for surrounding the gathered cord can be made by joining the mold for the handle portion described with jaw member segment molds of varying lengths. It is unnecessary to have molds of handles of different dimensions since the gripping requirements of the handle do not change with the length of the jaw member segments.
The clasps shown are quite broad so as to embrace or enclose a significant portion of each cord loop. Preferably the clasp will be at least 1 inch wide, and can be up to 4 inches wide or greater. The clasps of FIGS. 7, 9, and 11 through 15, may be made of any of the materials discussed previously herein.
While several preferred embodiments of the invention have been described and illustrated, it will be understood that the invention is not limited thereto, since many modifications may be made and will become apparent to those skilled in the art. For example, other suitable pivots or hinges can be used for connecting together the jaw members. Moreover, other bias means for urging the jaw members together can also be employed, if desired. | A cord clasp is disclosed for holding together several loops or folds of an appliance cord in order to keep the cord tidy. The clasp includes two complementary facing jaw members, each having a cord surrounding portion and a handle portion separated by a pivoting ridge. A bias means keeps the jaws or cord surrounding portions together. The jaw members are farther apart at the handle portions than at the closure point of the cord surrounding portions. The jaw members are quite wide and have complementary shaped front edges. The shape of the clasp enables the cords to be grasped or held securely when only a small number of cord loops are gathered or when a large number of cord loops are gathered. The cords will also be held even if the cord surrounding portions do not come completely together. Also disclosed is a molding process for a preferred embodiment wherein a mold for a handle segment can be employed with a selected mold for a jaw-member segment to permit the handle mold to be adapted for use with jaw-member segment molds of varying lengths. | 5 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to an operating surface for home appliances having an operating panel with at least one operating element and/or indicator element arranged thereon, wherein the operating panel and/or the at least one operating element and/or the at least one indicator element can be illuminated, at least in part, by at least one electrically operated light source.
[0003] 2. Discussion of Related Art
[0004] It is known to employ transparent operating surfaces in electrical household appliances, elevators or similar electrical devices. Transparent plastic materials or glass are used as the panel material. The components essential to the operation of the electrical device are arranged at or on the operating surfaces. These are input elements, such as switches, control and regulating units, which are for example embodied as rotary, sliding and toggle switches, as well as proximity switches. Visual indicator elements, such as seven-segment indicators, light-emitting diodes, graphics-capable displays, glow lamps, for example, as well as backlit structured elements printed on the panel, are also employed. Acoustic indicator elements can also be integrated.
[0005] The indicator elements are primarily used for acknowledging a performed input to the user, or to provide information regarding the operational status, for example when running a program. It is also possible to visually show error reports, as well as warning signals.
[0006] The customary design of the operating panels is determined by the shape of the panel, the arrangement and the type of the input and output elements, as well as by printed material. Also, light sources arranged behind the operating panel can take over design functions.
[0007] The indicators with graphic displays used are elaborate in their implementation and expensive to produce, but allow the representation of various types of information in different ways.
[0008] The light-emitting diodes, glow lamps, incandescent lamps or similar standard light sources customarily employed for illuminating structured elements applied to the operating panel have one disadvantage, that they are not flat and thus do not offer a uniform illumination of larger surfaces in particular. The light propagation of standard light-emitting diodes, for example, is directed, so that the brightness of such a light source is largely a function of the observation angle. Also, the standard light sources have a relatively large structural height, which greatly restricts the design possibilities of the operating surface.
SUMMARY OF THE INVENTION
[0009] It is one object of this invention to provide an operating surface, in particular for home appliances, which can be uniformly lit, while having a low structural height. Also, the operating surface in accordance with this invention is intended to be inexpensive, and its illuminating device should save energy and provide a large design range.
[0010] The object is achieved with an operating surface, particularly for home appliances, with the characteristics described in this specification and in the claims.
[0011] Accordingly, the light source contains at least one organic electroluminescent component. Such components have a particularly low current consumption at low voltage and can be produced flat in almost any arbitrary shape.
[0012] In one embodiment, the organic electroluminescent component comprises an organic light-emitting diode (OLED). Along with a particularly good adaptability, the OLED can be advantageously produced. It offers novel design options, for example for a night design, with a flat illumination of the operating panel, wherein the total structure of the operating panel and the OLED can be made very flat. This offers advantages with respect to the structural height, in particular in combination with the use of flat proximity switches. Uniform, flat and bright back-lighting of the operating panel is assured by use of the OLEDs. Furthermore, the brightness of flat OLEDs is independent of the observation angle. Large structured elements can be uniformly backlit, and a multitude of colors can be represented.
[0013] In an advantageous manner, the operating panel and/or the operating element and/or the indicator element are constructed, at least partially, of glass, plastic or similar transparent materials. During this, the at least one organic electroluminescent component shines through the respective transparent elements. For this purpose, the at least one organic electroluminescent component can be arranged on the side of the operating panel and/or the operating element and/or the indicator element facing away from the observer and facing toward the device.
[0014] For example, in order to achieve the flat backlighting of partial areas of the operating panel or, for example, a homogeneous representation of indications by the organic electroluminescent component, in the same color and with the same brightness, at least one structured element embodied as a positive or negative representation can be applied to the side facing the user and/or to the side facing away from the user and facing toward the operating panel and/or the operating element and/or the indicator element. In this case the structured elements can include letters, numbers, any arbitrary two-dimensional shapes or similar symbols. The embodiment of frame shapes or flat borders, for example on the operating panel, can be realized as desired with the structured elements. Special design applications, and moreover comfortable user guidance, can be easily realized with the backlit structured elements.
[0015] For this purpose at least one structured element, which is backlit by at least one organic electroluminescent component, can be imprinted on the side of the operating panel and/or the operating element and/or the indicator element facing toward or away from the user.
[0016] To produce an operating surface which is as smooth as possible and insensitive to soiling, at least one structured element in the form of a mask arrangement, which is backlit by at least one organic electroluminescent component, can be applied between the at least one organic electroluminescent component and the side facing away from the operating panel and/or the operating element and/or the indicator element.
[0017] To achieve a visual emphasis of defined symbolic elements, a plurality of structured elements and organic electroluminescent components can be provided. In this case at least one organic electroluminescent component is assigned to each structured element and backlights the associated structured elements and/or a surrounding area defined at the structured element.
[0018] So that the visually emphasized symbolic elements can also display individual information contents, it is possible to provide a plurality of organic electroluminescent components, of which at least individual organic electroluminescent components can be separately controlled. For realizing this individual control, the individual organic electroluminescent components can be connected with each other via a bus.
[0019] Additional information can be displayed if the organic electroluminescent components radiate light in preset colors. However, alternatively the transparent material of the operating panel and/or of the operating element and/or of the indicator element can be colored in a predetermined color, at least near or in the area of the attached structured elements.
[0020] In a particularly advantageous manner, the organic electroluminescent components can be designed flat, angled or curved in accordance with the shape of at least a portion of the operating panel and/or the operating element and/or the indicator element. The organic electroluminescent components can have round, square or similar predetermined arbitrary shapes. Thus it is possible to realize completely individual design applications.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] This invention is explained in greater detail in view of preferred embodiments and making reference to the drawings, wherein:
[0022] FIG. 1 shows a schematic view from above on an embodiment of an operating surface of a household washing machine with backlit operating panel areas and backlit operating and indicator elements;
[0023] FIG. 2 shows a schematic lateral and sectional view of an operating surface of a household washing machine in accordance with one embodiment; and
[0024] FIG. 3 shows a schematic lateral and sectional view of an operating surface of a household washing machine in accordance with another embodiment.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0025] One embodiment of an operating surface of a household washing machine with an operating panel 10 , which has a backlit operating panel area 11 and operating elements 12 and 14 and a two-digit seven-segment indicator 16 , is shown in a schematic view from above in FIG. 1 .
[0026] The operating surface is arranged in the front area of the washing machine and has an operating panel 10 made of glass, plastic or similar transparent material, which is backed by an opaque mask. A frame-shaped area 11 is cut out of the mask, on which a flat organic light-emitting diode (OLED) is arranged on the side facing the washing machine. The light radiated by the OLED passes through the transparent operating panel 10 in the frame-shaped area 11 , so that an illuminated frame is formed. The OLED radiates colored light, so that the frame area 11 has a special design meaning by the “night design” here represented. The frame area 11 is uniformly illuminated and can be viewed at the same brightness from any arbitrary visual angle, because the OLED does not radiate the light in a directed way.
[0027] A rotatory input knob 12 for selecting the washing program is arranged on the operating panel 10 in the left area of the operating surface next to the frame 11 . The rotatory input knob 12 has different rotatory positions, which are identified by the letter sequence “A, B, C, D, E, F, G, H” in accordance with the selectable washing programs. Defined segments are assigned to the individual letters on the rotatory input knob 12 . The areas of the segments of the rotatory input knob 12 are of a transparent plastic material, on whose side facing the operating panel 10 the letters “A, B, C, D, E, F. G. H” are applied in the form of a positive mask made of an opaque material, or are printed. In addition, the segments assigned to the individual letters each have an OLED on the side facing the operating panel 10 . Depending on the switch position of the rotatory input knob 12 , an OLED is triggered, or provided with a voltage, so that it radiates and simultaneously indicates the segment provided with the defined letter. In this way the set washing program can be easily read off by the user with the radiating letter segments “A, B, C, D, E, F, G, or H”. In FIG. 1 , the segment with the letter “B” is represented to be illuminated, by which it is indicated that the B washing program is activated.
[0028] Six keys 14 are arranged in the center area of the operating panel 10 , which are used for selecting additional washing programs, such as “easy care washing cycle”, “rpm reduction” or the like. In the represented embodiment, the six keys are provided in a simplified way by the numbers “1, 2, 3, 4, 5, and 6”. The individual keys 14 are made of a transparent plastic material facing the user, and an OLED is placed behind each one. If one of the keys 14 is pressed, the associated OLED is activated. In FIG. 1 the key with the number “3” is depressed, so that the corresponding OLED radiates.
[0029] A two-digit seven-segment indicator 16 is arranged to the right of the keys 14 on the operating panel 10 , which have seven individually controllable OLEDs. All numbers between 0 and 99 can be represented by such a display. The indicator 16 shown in the drawing represents the remaining running time of the washing program, in the represented case the number “19”, which indicates that the washing program will be finished in nineteen minutes. Only the radiating OLEDs of the indicator are visible. For this purpose, at least the area of the indicator 16 is made transparent on the operating panel 10 so that, although the radiating OLEDs are visible, the unilluminated OLEDs remain hidden. In this case the OLEDs of the rotatory knob, of the keys, of the “night light” and of the seven-segment indicator can have different colors, or can be white. It is possible to realize a uniform appearance if the OLEDs are laid out in one color.
[0030] FIG. 2 shows in a schematic lateral view and in section an operating surface of a household washing machine. The operating surface has an operating panel 10 . The user views the lateral face 22 of the operating panel 10 , while the illuminating arrangement, for one, and also the front of the washing machine are arranged on the opposite side 20 of the operating panel 10 . A structured mask layer 24 , for example made of a self-adhesive opaque foil, is applied to the side 20 of the operating panel 10 . In place of the mask layer 24 , a structured layer, or the symbols themselves, can be imprinted in a positive or negative representation.
[0031] In its left portion, the mask layer 24 forms a symbol 24 . 1 , for example a letter or a number. In the center and right portions, however, the mask layer 24 is embodied so that flat areas 24 . 2 and 24 . 3 , for example a frame structure, such as the frame structure 11 represented in FIG. 1 , is left free. An active layer of OLEDs adjoins the mask layer 24 . An OLED 18 . 1 is arranged at the symbol 24 . 1 and radiates through the symbol 24 . 1 and thereafter through the transparent operating panel 10 . Further OLEDs 18 . 2 and 18 . 3 , which are wired together via a bus system and can be individually controlled, are arranged in the flat areas 24 . 2 and 24 . 3 and radiate through them.
[0032] A similar operating surface of a household washing machine is shown in a schematic lateral view and in section in FIG. 3 . In contrast to the embodiment explained in view of FIG. 2 , a structured layer 26 is imprinted on the side 22 of the operating panel facing the user. In its left area the structured layer 26 forms a symbol 26 . 1 , for example a letter or a number. In the center and right areas, however, the structured layer 26 is embodied so that flat areas 26 . 2 and 26 . 3 , for example a frame structure, such as the frame structure 11 shown in FIG. 1 , is left free. The structured layer 26 is imprinted on the transparent operating panel 10 . A passivating, or protective layer made of a transparent lacquer can be applied to the structured layer 26 .
[0033] An active layer of OLEDs adjoins the side of the operating panel 10 facing the device. An OLED 18 . 1 is arranged below the symbol 26 . 1 , which radiates through the transparent operating panel 10 and thereafter through the symbol 26 . 1 . Further OLEDs 18 . 2 and 18 . 3 , which are wired together via a bus system and can be individually controlled, are arranged underneath the flat areas 26 . 2 and 26 . 3 and radiate through them.
[0034] The OLEDs 18 . 1 , 18 . 2 , 18 . 3 radiate light of different colors. For example, the symbol 24 . 1 or 26 . 1 is illuminated in yellow by the OLED 18 . 1 , while the flat area 24 . 2 or 26 . 2 is illuminated in green by the OLED 18 . 2 , and the flat area 24 . 3 or 26 . 3 is illuminated in blue by the OLED 18 . 3 . The operating panel 10 can be colorless and transparent.
[0035] It is possible to embody the operating panel 10 to be colored and transparent, and the OLEDs 18 . 1 , 18 . 2 , 18 . 3 can radiate neutral light through the operating panel 10 .
[0036] In accordance with the embodiments shown in FIGS. 2 and 3 , the operating panel 10 , the mask layer 24 , or the structured layer 26 , as well as the associated OLEDs 18 . 1 , 18 . 2 , and 18 . 3 are flat. However, the operating panel 10 can also be curved, corrugated or angled. The mask layer 24 , or the structured layer 26 , as well as the associated OLEDs 18 . 1 , 18 . 2 , and 18 . 3 , can follow this shape. The OLEDs can also be embodied in a large range of arbitrary shapes.
[0037] German Patent Reference 103 36 354.8, the priority document corresponding to this invention, and its teachings are incorporated, by reference, into this specification. | An operating surface for home appliances having an operating panel with at least one operating element and/or indicator element thereon arranged. The operating panel, at least one operating element and/or the at least one indicator element can be illuminated, at least in part, by at least one electrically operated light source. The light source includes at least one organic electroluminescent component, for example an organic light-emitting diode (OLED). | 3 |
This is a continuation of application Ser. No. 405,904, filed Aug. 6, 1982, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a precision system for machining symmetrical surfaces generated from conic sections to a mirror finish.
2. Description of the Prior Art
In the field of modern precision machinery, it has been desired to develop a machine tool having a machining precision of smaller than 0.1 micron as required for laser technology and super-LSI technology. With conventional machining tools, however, machining precision of smaller than 0.1 micron could be achieved chiefly by grinding, and objects which could be ground have been limited to flat surfaces and circumferential surfaces such as the periphery of cylinders. With conventional machine tools, therefore, it was not possible to machine surfaces generated from conic sections, such as parabolic surfaces and hyperboloids, to a mirror finish.
The reasons for this inability with conventional machine tools could be attributed to both, errors produced by the changing temperature of machine parts of the machine tool and to problems with the system for driving the tool, particularly insufficient precision of the guide surface, poor resolution of the motor, insufficient precision of the feed screw, insufficient precision of the detector for position feedback, and inadequate response characteristics of the drive system. Plane surfaces and circumferential surfaces are machined fundamentally by controlling the relative movement between a grinder that moves only along a single axis and the workpiece. In machining surfaces generated from conic sections, however, control must be effected along the directions of two axes simultaneously.
In conventional feed drive systems, if precision is not critical, the two axes (X,Y) have been controlled simultaneously by a numerical control (NC) machine tool. With NC machine tools, however, the detection of table movement or the like is precise to 1 micron on the average, and is precise to only about ±0.5 micron even in particularly carefully designed machines. Furthermore, if a minimum resolution instruction value is set to 0.01 (micron/pulse) and a maximum feed rate for cutting to 600 mm/minute, pulses must be distributed at high speeds, on the order of 1 MHz, so that translating commands into control pulses (interpretation) for NC machine tools becomes difficult.
With regard to the position detector for controlling the feedback, although the amount of movement can be measured fairly accurately, only a measuring device employing a laser can now offer the precision of about 0.01 micron. Even when the laser-type measuring device is employed, however, the drive system is not capable of responding to error signals that are produced.
SUMMARY OF THE INVENTION
The object of the present invention is to provide a precision machining system which is capable of machining surfaces generated from conic sections while maintaining a precision of smaller than 0.1 micron. For this purpose, a tool-holding unit of the present invention is positioned along a Y axis by a fine displacing drive unit which operates at high speeds and with high precision. Also, an X-axis drive system and a Y-axis drive system are provided for driving the tool-holding unit in the XY plane. The position of the tool-holding unit is measured by an optical length measuring device, and the difference between the measured value and a desired value is compensated by the fine displacing drive unit. When the amount of compensation in the fine displacing drive unit exceeds a predetermined value, the Y-axis drive system is actuated so that the amount of compensation by the fine displacing drive unit lies within a predetermined range.
BRIEF DESCRIPTON OF THE DRAWINGS
FIG. 1 is a block diagram illustrating an embodiment of the present invention;
FIG. 2 is a top plan view showing a tool support of the above-mentioned embodiment;
FIG. 3 is a side elevational view of FIG. 2;
FIG. 4 is a sectional view taken along the line 4--4 in FIG. 2;
FIG. 5 is a side elevational, partially schematic view showing a piezo-electric fine displacing element employed in the above embodiment;
FIG. 6 is a diagram showing the relation between the voltage applied to the piezo-electric crystal in FIG. 5 and the amount of expansion;
FIG. 7 is a block diagram illustrating the main section of the NC control unit;
FIG. 8 is a graph showing the operation of the controller in FIG. 1;
FIG. 9 is a block diagram illustrating another embodiment of the present invention;
FIG. 10 is a circuit diagram showing an integration circuit according to an embodiment of the present invention; and
FIG. 11 is a circuit diagram illustrating an example of the fine displacing element drive circuit of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An embodiment of the invention will be described below in detail with reference to a block diagram of FIG. 1, in which a cutting tool 100 comes into contact with a workpiece 102 that is held by a chuck 104 mounted on a rotary shaft 106. Cutting tool 100 is moved relative to workpiece 102 to machine the surface thereof into any desired shape. In the following description, cutting tool 100 is actuated along Cartesian coordinates consisting of a Y axis parallel with rotary shaft 106 and an X axis normal to rotary shaft 106. Cutting tool 100 is held by a tool-holding unit 108 which, in turn, is connected to a tool support 110 by means of a fine displacing element 112.
FIGS. 2 to 4 are various views illustrating tool support 110. Tool-holding unit 108 is held by tool support 110 via static hydraulic bearings 114 so as to slide in the Y direction. Cutting tool 100 is attached to the front end of tool-holding unit 108, and the ends of fine displacing element 112 are firmly attached to the rear end of tool-holding unit 108 and to an end wall 116 protruding from the end of tool support 110.
FIG. 5 is a side view showing an example of fine displacing element 112 which includes, three piezo-electric elements 118 that are stacked in the form of layers with electrodes 120,122,124 and 126 made of a silver foil or the like being interposed between them. Coupling members 128 are attached to the outer sides of electrodes 120 and 126 via insulating members 130. Electrodes 122 and 126 are grounded, and several hundred volts are applied to electrodes 120 and 124, so that piezo-electric elements 118 expand and contract in the direction in which they are stacked.
FIG. 6 is a diagram showing the relation between the voltage K applied to fine displacing element 112 and the amount of expansion. When a voltage K of 500 volts is applied to a single piezo-electric element 118 having a thickness of 1 mm, an expansion of 0.25 micron can be obtained. If the applied voltage is controlled over a range of 500±300 volts so that each piezo-electric element 118 produces the displacement of ±0.15 micron, the thickness of the stack of three piezo-electric elements 118 can be controlled over a range of 0.3 micron to 1.2 microns. When the voltage is controlled within a suitable range, thickness varies nearly linearly with respect to the applied voltage, and the response characteristics are also quite good. Therefore, by controlling the voltage applied to fine displacing element 112, tool-holding unit 108 can be driven relative to tool support 110 along the Y axis to control the position of cutting tool 100.
In FIG. 1, reference numeral 132 denotes an X-axis drive mechanism which drives tool support 110 along the X axis. Y-axis drive mechanism 133 drives tool support 110 along the Y axis. Drive mechanisms 132 and 133 each include a drive motor 134 and a feed screw 136 that is rotated by drive motors 134. Length measuring unit 138 produces pulses related to the movement of tool-holding unit 108 along the X axis and X-axis position counter 140 counts the pulses to produce an indication of the position of the end portion of cutting tool 100 in the X direction. The value counted by X-axis position counter 140 is fed to function generator 142 which determines the corresponding desired position of the end portion of cutting tool 100 along the Y axis depending upon the desired curved surface that is to be machined. The Y-axis desired position is fed to a data register 144, and the contents of data register 144 are fed both to a first comparator 146 and to a second comparator 148.
The pulses produced by Y-axis length measuring unit 150 are counted by Y-axis position counter 152, and the counted value corresponding to actual position along the Y-axis of the end portion of cutting tool 100 is fed both to second comparator 148 via a holding circuit 154 and to first comparator 146. The output of first comparator 146 is converted into a voltage at a predetermined ratio by fine displacing drive circuit 156, and is applied to fine displacing element 112. Second comparator 148 feeds a drive signal to NC control unit 158 to drive tool support 110 by means of drive system 133 by a predetermined distance in the Y direction every time the difference between the measured position Y and the desired position exceeds a predetermined value. In response to the drive signal from second comparator 148, NC control unit 158 drives tool support 110 by a predetermined amount in a stepped manner. Therefore, by suitably setting the predetermined amount, the control voltage applied to fine displacing element 112 can be maintained within a suitable range, so that linearity is not lost by the application of an excessive voltage.
FIG. 7 is a block diagram illustrating the main section of NC control unit 158, in which position commands for the X direction and the Y direction are received from input unit 159. Conventionally in the art of NC control units the position commands are stored on tape so that input unit 159 is conventionally a tape drive. Obviously other types of input devices could also be used. Conventional interpolation operation units 164 and 166 receive the position commands from input unit 159 and generate position pulses related to the desired movement of tool support 110. These pulses are counted by counters 160 and 162, and are converted into analog signals through D/A converters 168 and 170 and are then fed to servo amplifiers 172 and 174. The drive signal produced by second comparator 148 is fed to Y command counter 162. Thus the output of second comparator 148 may be a pulse which is "OR-ed" with the pulses from interpolation operation unit 166 at an input stage of counter 162.
Being constructed as mentioned above, prior to initiating the machining operation, NC control unit 158 drives cutting tool 100 to an origin (X 0 , Y 0 ) from where workpiece 102 is to be machined, and further resets all of the counters and registers. When the machining operation is initiated, cutting tool 100 is driven at a speed from the outer circumference of workpiece 102 toward the center by X-axis drive mechanism 132 that is powered by X-axis servo amplifier 172 responsive to the data which is fed from a paper tape or the like in input unit 159. X-axis length measuring unit 138 produces a pulse for every 0.01 micron, for example, depending upon the position in the X-axis direction of tool-holding unit 108 which holds cutting tool 100. The number of pulses is counted by X-axis position counter 140 to obtain a measured X direction position of cutting tool 100 relative to the origin X 0 from where the machining operation is started. The measured value X position is fed to function generator 142, and a corresponding desired Y direction position is supplied to data register 144. In this case, the position is given by X-axis position counter 140 in the form of a digital value. Therefore, the Y position determination is repeated every predetermined amount of movement in the X direction, for example, after every 5 microns, depending upon the precision and response characteristics of the drive system.
Pulses produced by Y-axis length measuring unit 150 related to the actual position of cutting tool 100 in the Y direction, are counted by Y-axis position counter 152, and the measured Y position is fed to holding circuit 154 which holds the measured Y position in synchronism with the changes of the output of function generator 142.
The measured Y position in holding circuit 154 and the desired Y position stored in data register 144 are fed to second comparator 148 and are compared. Whenever the difference thereof exceeds a predetermined value, second comparator 148 feeds an output to NC control unit 158 which drives Y-axis drive mechanism 133 via Y-axis servo amplifier 174, such that the position of cutting tool 100 in the Y direction is moved in a stepped manner. At the same time, the difference between the measured Y position and the desired Y position is found by first comparator 146. This difference is converted into a corresponding voltage through fine displacing drive circuit 156 to control the voltage that is applied to fine displacing element 112, in order to control the position of tool-holding unit 108.
FIG. 8 illustrates the operation of the controller of FIG. 1. In FIG. 8, function F represents the ideal shape of the surface to be machined, f(x) represents the desired position generated by function generator 142 and Y represents the actual position of cutting tool 100. Curve C represents the amount of expansion or contraction of fine displacing element 112 from its central position. As long as curve C stays within the range of linearity, fine displacing element 112 provides all adjustment in the Y direction (such as for f(X 0 ) through f(X 2 )). However, when the difference between the desired position and the actual position becomes so great that fine displacement element 112 would have to leave the linear range to respond (such as at f(X 3 )), the output of second comparator 148 causes NC controller 158 to drive Y-axis servo-amplifier 174 and Y-axis drive mechanism 133 so as to relieve fine displacing element 112. Accordingly, the drive signal applied to fine displacing element 112 can be controlled to lie within a predetermined range such that good linearity is maintained.
With this embodiment of the present invention, errors in the position of cutting tool 100 produced by the mechanical driving mechanism are corrected by fine displacing element 112 which works based upon the piezo-electric effect. Furthermore, if the voltage applied to fine displacing element 112 exceeds a proper range, cutting tool 100 is so driven by the drive mechanism that the correction quantity decreases. Consequently, fine displacing element 112 operates within a proper range at all times.
FIG. 9 shows a circuit block diagram of a second embodiment of the present invention. In this block diagram, instead of NC controller 158 as shown in FIG. 1, setting device 200 for producing a signal representing the feed rate along the X axis and adder 202 are provided. Elements numbered the same as in FIG. 1 have functions identical to the same elements of FIG. 1.
Setting device 200 produces a feed rate signal by which tool support 110 is driven at a constant speed in the X direction. Setting device 200 may produce a plurality of feed rate signals each indicating a different rate for different intervals in the X direction.
For example, if workpiece 102 has a steep slope portion and a gentle slope portion, the feed rate for the steep slope is set to be small, and the feed rate for the gentle slope is set to be large so that the value of f(x) may change continuously.
Adder 202 adds the value of data register 144 and the output value from the second comparator 148 and the resultant value is supplied to servo amplifier 174 after D/A conversion. The system shown in FIG. 10 may be constructed at lower cost than that of FIG. 1.
The present invention should not be limited to the above-mentioned embodiments only. For example, good control is provided even if second comparator 148 and hold 154 are eliminated. First comparator 146 and fine displacing element 112 still guarantee a fast, accurate response. Since the output of function generator 142 is applied through adder 202 to Y-axis servo amplifier 174, Y-axis drive system 133 is still able to maintain fine displacing element 112 in a relatively linear range. Obviously, control will not be quite as good as the embodiment in FIG. 9.
Also, function generator 142 need not be limited to the one which calculates, at high speed, the desired Y position based upon the measured X position. Instead, function generator 142 may be provided with a memory which stores the Y positions that have been calculated beforehand, so that the stored contents are read out successively.
When fine displacing element 112 responds too sharply to the drive signals, an integration circuit 204 may advantageously be inserted between the output of first comparator 146 and fine displacing element drive circuit 156 as indicated by a broken line in FIGS. 1 and 9. FIG. 10 is a circuit diagram illustrating an example of integration circuit 204. A digital signal consisting of a plurality of bits from first comparator 146 is converted into an analog signal through a digital-to-analog converter 206, and is fed to an operational amplifier 208 via a resistor 210 and a first switch 212. Operational amplifier 208 has a capacitor 214 connected across its input and output terminals and a series circuit, having a discharge resistor 216 and a second switch 218, is connected in parallel with capacitor 214.
In operation initially, first switch 212 is connected to resistor 210, and second switch 218 is opened so that the ananlog signals are integrated. After the integration is finished, first switch 212 is connected to ground potential, and second switch 218 is closed so that the electric charge stored in capacitor 214 is discharged.
FIG. 11 is a circuit diagram illustrating an example of a fine displacing element drive circuit 156, in which the collectors and emitters of three transistors 220, 222 and 224 are connected in cascade to control the voltage of several hundreds of volts applied to fine displacing element 112. An analog signal from first comparator 146 is applied to input terminal 226. This signal is fed to the base of transistor 220 via a buffer amplifier 228. Emitters and collectors of transistors 220, 222 and 224 are connected in cascade, a resistor 230 is inserted between the collector and the base of transistor 224, a resistor 232 is inserted between the base of transistor 224 and the base of transistor 222, and a resistor 234 is inserted between the base of transistor 222 and the emitter of transistor 220. A series circuit consisting of a power supply 236 of hundreds of volts and fine displacing element 112 is connected between the emitter of the transistor 222 and the collector of transistor 224. Owing to the above connection, the voltage applied across the emitter and the collector of transistors 220, 222 and 224 is reduced to about one-third the voltage of the power supply; i.e., required breakdown voltage of transistors 220, 222 and 224 can be loosened.
In the above-mentioned embodiments, furthermore, function generator 142 produces a desired position relative to the origin Y 0 of machining. Alternatively, function generator 142 may be so constructed as to produce the difference Y n -Y n-1 between the desired position Y n-1 corresponding to the position X n-1 in the X-axis direction and the desired position Y n corresponding to the position X n in the X-axis direction at that moment.
According to the present invention as illustrated in detail in the foregoing, the positional error of the cutting tool in the cutting direction caused by the mechanical driving mechanism is corrected by a fine displacing element, and the cutting tool is also driven by a drive mechanism so that the quantity of correction is reduced when the fine displacing element must operate outside of a proper range.
It is therefore possible to provide a precision machining system which is capable of machining surfaces generated from conic sections very precisely, while driving a fine displacing element within a proper range at all times.
Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. | A precision machining system for machining a workpiece into a desired surface with two tool driving units. A first drive unit moves the tool along at least two axes to shape the workpiece similar to a desired surface. A second drive unit moves the tool along one of the axes in a very finely controlled manner. A measuring unit measures the tool position with an accuracy higher than that to which the first drive unit can respond. A signal producing unit is responsive to the measuring unit for producing a control signal for controlling the operation of the second drive unit while the first drive unit is operating. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to a fastener that can be used in a variety of structural applications, including the attachment of overlapping membranes, for use as an embedded anchor, or to affix objects to a hollow wall.
DESCRIPTION OF THE RELATED ART
Two of the most troublesome fastener applications are to a hollow wall section and to a solid substrate. In both cases the material in which the fastener is often set often cannot adequately grip the fastener to resist pull out forces. Examples of these materials include drywall, concrete, and sheet metal. Fasteners that merely rely on material grip strength on the fastener cannot attain satisfactory pull out loads. This problem is approached in one of two ways. Either a mechanical interference fit is created or an adhesive is used to affix the fastener in both these applications.
Lack of grip strength is often found in conjunction with weak membrane shear strength. As a result, even if the gripping strength of the fastener were sufficient, concentrated forces at the fastener membrane interface may allow the fastener to pull the membrane out.
Another commonly encountered problem occurs when attaching objects to hollow walls membranes with inaccessible interior surfaces. Either the fastener is attached directly to the substrate or the fastener is mounted to the hollow wall's interior surface. The fastener's direct attachment is typically accomplished solely through the use of an adhesive that secures the fastener to the substrate. The drawback to this approach is that the fastener's holding strength is limited by either the adhesive bond strength or the substrate's surface shear strength. Direct attachment to the substrate produces a physically weaker structure because the wall provides no shear strength support as it would for a fastener that extends through the wall surface. An additional drawback is that once in place, the installation is permanent and cannot be removed without damaging the wall.
Alternately, the fastener can be mounted to the interior surface of the membrane using expandable fasteners. The fastener is placed into a bore hole made into the membrane. The fastener is then caused to expand. This creates an interference fit behind the membrane surface that prevents fastener disengagement.
U.S. Pat. No. 4,659,269 to Stromiedel (1987) discloses a fastener with radially expansible portions made from relatively flexible deformable materials. This flexibility reduces the rigidity of the fastener reducing its holding strength. Forces exerted on these fasteners may cause relative movement between the fastener and wall surface. This prevents the fastener from accomplishing the critical functional requirement of providing rigid support.
U.S. Pat. No. 4,425,065 to Sweeney (1984) discloses a fastener design that utilizes an interference fit with the interior membrane surface that is adhesively fixed in place. The drawback of this design is that the fastener's expansion creates a minimal interference area with the surface membrane. Fastener pull out forces are transferred to this relatively small area. This creates highly localized stresses in these fastener components and at the wall where these fastener components abut. The fastener design forces these load-bearing elements to be extremely small in proportion to the fastener's overall size. As a result the fastener's inefficient design causes its rated load-bearing strength to be severely derated in relation to the fastener's size.
The close tolerances required to achieve an interference fit between the wall surface and the expanded portions of the fastener also limits the usefulness of this design. If the deployed fastener does not contact the wall surface, the fastener will be free to slide relative to the wall for the nonengagement distance. This free movement distance is sufficient to render the fastener nonfunctional in many applications.
Embedded fasteners for use as anchors in solid surfaces present a somewhat different problem. The prior art teaches that a purely adhesive means can be used to affix a fastener in a solid substrate. The ability of the adhesive means to resist pull out forces is determined by the weakest bond produced by either the adhesive to the fastener, the adhesive to the substrate, or the adhesive shear strength. The prior art also teaches that a mechanical interference can be established to anchor a fastener in a solid substrate. The drawback with this method is that these anchors are often embedded in concrete that may have loose aggregate around the peripheral edges of the bore hole. As a result the mechanical interference fit may slip due to the loose aggregate.
SUMMARY OF THE INVENTION
The present invention overcomes the disadvantages and shortcomings of the prior art described above. The operating principal of the present invention is the creation of an interference fit between the fastener and a substrate in which it is embedded or attached. This objective is accomplished by the fastener's radial expansion after it is set in its bore hole. The fastener's transformed geometry is permanently fixed with an adhesive or fusing material released from within the fastener.
The chief design advantage of this fastener is that it employs both an interference fit and adhesive means to secure the fastener in position. The interference fit that results mechanically prevents the fastener's disengagement from the substrate to which it is affixed. The fastener's new structure is engineered to uniformly distribute stresses that the fastener is expected to incur, thus improving the fastener's rated load capacity. The inter-bracing of fastener components uniformly distributes stresses throughout the fastener. Load capacity is enhanced not only from the geometrical transformation, but also from the lamination of multiple layers of materials that create a composite with increased material strength.
Load-bearing strength is difficult to attain because the membrane sections are often thin and weak. This makes it difficult for any fastener to hold a significant load. This fastener however can evenly distribute imposed forces over a large membrane area to prevent fastener pull out. Thus, this design is an advancement over U.S. Pat. No. 4,425,065 to Sweeney (1984) because of this much larger effective interference area.
Besides the objects and advantages of the present invention described above, several additional objects and advantages of the present invention are:
1. This fastener, unlike many other designs, has a number of multi functional applications. The fastener may be mounted inside a hollow surface which is otherwise inaccessible, it may be completely embedded in a solid substrate, or used to attach overlapping panels. This allows one fastener to be used in many applications reducing inventory requirements.
2. The self fusing fastener may be made entirely from plastic thus eliminating corrosion and the possibility of creating a ground when the device is used in electrical applications.
3. Mechanical fasteners, particulary the threaded type, are prone to failure because of high ambient vibration. Vibration can result in the loss of preload, and even the disengagement of the fastener. The present invention precludes this possibility because the fastener adhesively permanently locks the screw threads. As a result, the design of the present invention eliminates one of the primary fastener failure modes.
4. In an application where the fastener projects thru a membrane and attaches to the membrane's inside surface, the prior art teaches a combination of mechanical and adhesive means to affix the fastener. Because the adhesive distribution to the substrate surface is not controlled, the bond strength will vary from installation to installation. Thus, the fastener's load rating is indeterminate. The present invention's holding strength is dictated solely by the fastener's mechanical elements. Because the fasteners' dimensions, geometry, and materials of construction are known, the fastener's rated strength can be determined on a consistent and reliable basis. This allows the fastener to be use in critical engineered applications.
5. In an application where the fastener is embedded in a solid substrate, the fastener uses a combination of mechanical and adhesive means to resist pull out forces. This combination results in a rated pull out strength greater then could be achieved by either means alone. The mechanical interference fit creates a wedge against pull out forces that the adhesive maintains.
6. The installation of the present invention is easier than other available fasteners on the market. The present invention may be installed in a single step. Other fastener designs on the market require multiple steps to complete installation.
7. The present invention is held in place by purely mechanical means which does not require precise adhesive distribution to obtain maximum installation strength.
Still, further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
This self fusing fastener provides a convenient, strong, and reliable method to affix objects to a variety of difficult applications. These applications include affixing objects to hollow walls and providing anchorage in solid substrates. This fastener can service a number of different applications without sacrificing strength because it combines both an adhesive and mechanical means to affix the fastener. The fastener's design allows it to attain maximum load bearing strength, reliability, and simplicity of installation.
Although the discussion above contains many specifics, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some presently preferred embodiments of this invention. Although a specific embodiment of this invention has been described, it is apparent that some minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.
For example, the number of folding and flaring elements and the specific geometry of the fastener can be altered dependent on the specific application to which the fastener will be applied. Thus, the appended claims and their legal equivalents should determine the scope of the invention, rather than by the examples provided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a complete self fusing fastener, with both types of expandable elements, and adhesive material, before installation.
FIG. 2 is a side sectional view of a complete self fusing fastener, with both types of expandable elements, and adhesive material, before installation.
FIG. 3 is a side sectional view of a complete self fusing fastener of FIG. 1 in its installed configuration in a hollow wall.
FIG. 4 is a side sectional view of a complete self fusing fastener of FIG. 1 in its installed configuration in a completely collapsed position in a hollow wall.
FIG. 5 side sectional view of a complete self fusing fastener of FIG. 1 in its installed configuration in an embedded application.
FIG. 6 is a perspective view of an alternative embodiment of the present invention with only the flaring elements.
FIG. 7 is a perspective view of a second embodiment of the present invention with only the collapsing elements.
FIG. 8 is a side elevation view of a third embodiment of the present invention with a pull chord, before installation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention advances the fastener state of the art by providing a stronger, easier to install fastener, that can produce consistent reliable load ratings. A preferred embodiment of the present invention is illustrated in FIG. 1 (perspective view) and FIG. 2 (cross section view). The present invention consists of a fastener tube 1 with a concentric bore. The fastener tube 1 is comprised of three cylindrical sections. The middle tube section has flexible folding elements 6. The second tube section has flaring elements 7 at the far end of fastener tube 1. Shoulder 3 extends radially inward and contains a bore concentrically aligned with the tube bore. The first tube section terminates in a flange 2. The flange may also have projecting spikes 13 to prevent the flange from rotating during installation. The flange may also be prevented form rotating by using a tool inserted into the flange holding holes 14 to maintain the fastener's position. Holding fins 16 may also be placed around the first tube section to prevent rotation. Finally, an adhesive on the underside of the flange and in contact with the wall may also be used to prevent rotation. An adhesive packet 5 is located in the tube bore.
The fastener tube may be most easily formed from a single cylindrical tube with a bore. The folding elements 6 can be created by cutting a series of parallel axial slits along the fastener tube 1. These slits do not extend to either end of the tube 1. Each pair of slits forms a pair of folding elements 6. The collapse of these folding elements 6 can be controlled through the appropriate interior or exterior circumferential scoring 17 of the fastener tube. The flaring elements are most easily created by cutting a series of parallel slots from the end of the tube 1 opposite the flange 2. Contained within and captured by the tube 1 at the opposite end of the flange 2 is a plug 4. The plug 4 also has a hollow bore concentric with the fastener tube bore to receive a screw 8. The plug 4 may be threaded to receive the screw 8. The fastener plug 4 may be designed with a boss 12 designed to fit within the internal diameter of the first tube section. Extending from the boss 12 may be a barb 10 designed to puncture the adhesive packet 5 to release adhesive to the tube's interior.
Integral or attached to the plug 4 is a serrated member 11 that prevents rotational movement of the plug 4. The serrated outer circumference engages the tube's interior wall or shoulder interior wall to prevent plug rotation when the screw 8 engages the plug. The serrated member may be disc shaped with serrations along the outer circumference and a central bore to accommodate the screw. The serrated member may be metallic and internally threaded to engage the fastener screw. This increases the strength of the fastener by providing a metallic mating surface for the screw threads that will resistant pull out forces more effectively then could be attained with the plastic plug alone.
The preferred embodiment of this invention uses plastic materials for the fastener tube and the plug. This fastener however, is not limited to polymer materials. Other materials such as metals may also be employed. The plastic selected should belong to a class of plastic that provides a high level of elasticity such as polyamide polymers. Other potential plastics include polyvinyl chloride (PVC) and acrylo-nitrile-butadiene-styrene (ABS). A myriad of other plastic materials may be utilized and specifically selected on the basis of engineering design features that vary with the particulars of any specific application. These polymers may be reinforced with fillers, such as glass fibers to attain higher strengths or other desired properties.
The fastening screw may be metallic or plastic. A plastic screw offers the significant advantage of electrical non-conductivity where a metallic screw may cause a ground. The all plastic fastener is also corrosion free.
The adhesive material may be selected from a myriad of available adhesives. The specific type selected is dependent on the fastener materials of construction, the substrate material, the bond strength desired, etc. A quick setting adhesive is the most practical for use with the present invention. These adhesive classes include, but are not limited, to cyanoacrylates, anaerobics, and epoxies. Furthermore, adhesives that are not normally quick setting at normal ambient conditions may be accelerated through the appropriate accelerator to cure the adhesive. Although a quick setting adhesive is the preferred embodiment, a slower setting adhesive may be utilized in certain embodiments of the present invention. Embodiments that use a screw can maintain the fastener position until the adhesive has sufficient time to set.
Obviously a number of different adhesive materials and associated packaging systems could be employed within the fastener. Any adhesive may be appropriate provided it can permanently affix the fastener in its transformed geometry. The adhesive may be packaged in any manner provided it meets the one functional requirement that it contain the adhesive until such time that the fastener is expanded. These adhesives may be packaged in breakable plastic packets. These packets release their contents either when the fastener screw is inserted into the fastener tube or when the fastener collapses. Multiple packets may be supplied within the fastener. This allows the use of multi component adhesives. For example, epoxies that require a curing or cross linking component may be used in this fastener. Alternately the adhesive may be micro encapsulated for later release.
Finally, the adhesive material may be a fusing agent that chemically welds the plastics together. The fusing material causes two pieces of plastic to essentially melt together and reharden. PVC and ABS for example, may be chemically fused to form a single piece with the application of the appropriate solvents.
In addition to the preferred embodiment shown in FIG. 1, alternate embodiments can be created by selecting to have either the flaring elements or the folding elements based on the fastener's intended application. FIG. 6 shows the fastener with only the flaring elements whereas FIG. 7 only utilizes the folding elements.
Another embodiment of the present invention eliminates the fastener screw 8. A pull chord 9 attaches to the second end and extends through the tube bore and exits through the fastener flange 2. The pull chord terminates in a pull tab 15. The pull chord itself has a series of burrs 18 along the length of the chord that creates a unidirectional interference between the chord and the flange. This prevents the pull chord from being retracted, thus losing compression on the fastener's folding elements, once it is pulled into place. The pull chord may be cut off and a decorative button pushed into the fastener tube to hide the fastener flange and remnants of the pull chord. Alternately a fastener may be screwed into the tube or attached to the flange's outer surface.
The following operational description is for an application where the fastener projects thru a membrane and attaches to the membrane's inside surface. FIG. 1 shows the uninstalled fastener before insertion into the bore hole. The present invention is placed in a bore hole sized to fit the fastener tube 1 diameter. The fastener's flange 2 prevents the fastener from sliding through the bore hole. The flange may also have projecting spikes 13 that are driven into the membrane to prevent fastener rotation during installation. A screw 8 is placed through the flange end of the fastener and made to engage the fastener plug 4. The insertion of the screw 8 may be used to rupture the adhesive packet 5 and releases the adhesive along the interior of the tube. Because the tube 1 is not in its expanded position, the adhesive is contained within the tube and uniformly distributed along the tube's inner surface area.
Screw 8 is turned causing the fastener plug 4 to be urged toward the fastener flange 2. Holding holes in the flange may be used to prevent fastener rotation. Because of the fastener tube's interior-tapered surface, the plug's movement forces the fastener's flaring elements 7 to radially expand outward. Further movement of the flaring elements is stopped as the plug 4 is captured in the tapered tube section. As the screw action continues, plug travel causes the folding elements 6 to radially expand and separate. A barb 10 protruding from the plug 4 may be used to puncture the adhesive packet 5 as the fastener collapses. The collapse of the folding elements 6 allows the plug to continue to move toward the flange 2. Further movement of the plug 4 causes each of the folding elements 6 to fold in half.
The tube's collapse may be controlled by selectively reducing the folding element strength at the locations where it is desired that the fastener collapse. For example, circumferentially scoring of either the fastener tube's interior or exterior surfaces will control the tube's direction and points of collapse. In this manner the structural transformation of the tube may be closely controlled. This selective scoring also allows the fastener elements to completely fold together, allowing the adhesive to more effectively bond these elements.
When the plug approaches the interior wall surface resistance to movement increases until forward movement is halted. The boss 12 seats into the bore of first tube section 13. The adhesive material fuses the plastic folding elements, the plug, and the tube together into one interbraced fastening unit. In addition, the fastener's folding elements are now completely folded, and adhered together by the released adhesive. The released adhesive will also contact the interior wall. This causes the folding elements to adhere to the interior wall surface.
It should be noted that the above description is the preferred embodiment of the fastener. This fastener embodiment accommodates multiple fastening applications. This embodiment will also work in hollow walls, and for the connection of thin membrane sections as shown in FIG. 3 and FIG. 4. FIG. 3 shows the installed and semi-expanded fastener. FIG. 4 shows the installed fastener in the completely expanded position. It should be noted that alternative fastener designs may be made to contain either the folding elements or the flaring elements alone, thus specializing the fastener for a particular application.
FIG. 8 shows an alternative embodiment of the present invention. In this embodiment a pull chord 9 is used to collapse the fastener, rather than a screw as shown in FIG. 1. The fastener embodiment shown in FIG. 8 can be used in the types of applications as shown in FIG. 3 and FIG. 4. When the chord is pulled, the plug 4 is drawn toward the fastener flange 2. This radially expands the flaring elements 7 and collapses the folding elements 6. It also punctures the adhesive packet 5 releasing the adhesive to lock the fastener in place. Forward motion of the plug is halted when the plug boss 12 engages and mates with the bore of the first tube section 13. Burrs 18 on the pull chord allow only unidirectional movement through the flange thus maintaining the position of the fastener as it collapses. | I claim a self fusing fastener device with radially expansible wings that permanently lock into place through an adhesive means which causes the fastener to act as a single rigid attaching element that resists pull out as a result of the interference fit produced by the radially expansible folding and flaring elements. | 5 |
BACKGROUND OF THE INVENTION
This invention has to do with improvements in apparatus for durable press treating of fabric, particularly fabric made up into garments, with vapor phase treating agents. The invention is further concerned with techniques for durable press treating of garments in the vapor phase whereby effective treatments are effected in a rapid, environmentally acceptable and materials consumption efficient manner. In a particular sense, the invention provides improvements in apparatus of a type useful for on-site treating of garments e.g. by small manufacturers, cleaners of fabrics, and others having a specific need to treat garments with durable press agents without cumbersome and costly full-scale production equipment, such as is used in the commercial production of treated fabric, either by the wet process or the vapor phase process.
PRIOR ART
It is known to treat fabrics and fabrics made up into garments with durable press agents, the agents being known per se, for the purpose of imparting wrinkle-resistance and pleat or crease retention. Ofttimes fabrics are treated by a wet process prior to being made up into garments. In other instances, garments having been made up are treated to impart the desirable characteristics of durable press. In my earlier patent, U.S. Pat. No. 3,513,669 I disclosed apparatus for vapor phase treatment of articles, including garments, wherein the durable press treating agents were introduced into a treating chamber of substantial construction driven by a blower through and around the chamber wherein garments to be treated were disposed, and thereafter withdrawn. The apparatus disclosed relied upon gas flow to carry the treating agents to the garments and the gas flow movement to impregnate the garments with the vapor phase treating agents. Overpressures within the treating chamber were avoided through the use of pressure responsive vents. While this apparatus is effective for its intended purpose, there exists a need for a self-contained and portable system not designed for factory production levels particularly, and one which is accordingly lower in cost, easily installed and moved from an installation site, and one which is efficient in terms of materials consumption.
SUMMARY OF THE INVENTION
Accordingly, the present invention provides an improvement on known apparatus for vapor-phase treating of garments with durable press treating agents. Specifically, the invention provides a self-contained, portable, collapsible and low-cost, easily installed and readily moved apparatus suitable for treating garments on a scale that might be employed at a small manufacturer of garments or at a cleaning establishment wherein it is desired to originally impart or to renew durable press characteristics to already formed garments.
It is a signal feature of the invention that pressurization of the treating chamber is employed, rather than simple gas flow to increase treating contact of the vapor phase reagents with the garments to be treated, effecting economies in operating time and materials consumption, as well as simplifying and reducing the cost of the equipment needed, in accordance with the objectives of the invention.
Accordingly, the invention provides a self-contained apparatus for vapor-phase treatment of garments with durable press treating agents, which comprises a vaporized treating agent supply, a pressurizable treating chamber for enclosing garments to be agent treated, and an unused treating agent recovery means, adapted to cyclically depressurize and repressurize the chamber interior in timed relation to the presence of treating agent in the chamber, to relatively pressure-impregnate the garments with the treating agent.
The treating agent supply may comprise a tank of treating agent liquid, a valved inlet communicating the tank and the treating chamber interior, and a means of volatilizing the liquid for passage into the chamber interior. The volatilizing means typically including a normally gaseous propellant within the tank in treating agent delivering relation to the chamber interior. Additionally, the volatilizing means may include a heater for flash vaporizing the treating agent liquid exteriorly of the chamber.
The agent recovery means typically includes a scrubbing tank containing treating agent neutralizing liquid, and means contacting unused treating agent vapor with the neutralizing liquid within the tank and exteriorly of the chamber. The treating agent scrubbing tank may further include an outlet tube sparging unused treating agent from the chamber interior into the neutralizing liquid. More particularly, the agent recovery tank may comprise first and second compartments, the first compartment having a head space closed to the atmosphere and the second compartment having a head space open to the atmosphere, the neutralizing agent being present in both compartments, the outlet tube sparging unused treating agent into the first compartment for neutralization in both first and second compartments and in sequence. There may further be provided in accordance herewith means communicating the first tank compartment head space with the neutralizing liquid in the tank second compartment.
The apparatus further includes wall means defining the chamber, and a garment passing opening into the chamber, the opening having a gast tight closure. The wall means may be coated and internally heated against treating agent deposit thereon, and be sufficiently flexible to be folded upon themselves and supported by a rigid frame to define the chamber. Accordingly, in a specific embodiment, the wall means comprise a flexible sheet having a chamber surface of treating agent deposit resistant synthetic organic plastic, resistance heating elements embedded within the wall means in chamber surface heating relation, and heat insulative material limiting heating of the non-chamber surface of the wall means.
In particularly preferred embodiments, the apparatus includes pump means adapted to evacuate the chamber, the treating agent supply being pressurized relative to the evacuated chamber interior to deliver treating agents into the chamber in repressurizing relation to pressure treat the garments with the treating agents. The pump means may be connected to evacuate the chamber into the recovery means, depressurizing the chamber for further repressurization with treating agent and cyclically in timed relation to the presence of garments in the chamber through the wall means opening. In this embodiment, the treating agent recovery means may include a scrubbing tank containing treating agent neutralizing liquid, and the chamber outlet tube may be in sparging communication with the neutralizing liquid in the tank, the pump then delivering the treating agent into the tank through the outlet tube in chamber evacuating and depressurizing relation. And with reference to the treating agent supply in this embodiment, such supply may comprise a tank beyond the wall of the chamber and containing treating agent liquid under pressure above that of the evacuated chamber from a normally gaseous propellant, a valved inlet communicating the tank and the chamber interior through the wall means, and a heater at the tank flash volatilizing the treating agent for passage through the inlet into the chamber under propellant pressure.
Additional features of the preferred embodiments include the agent recovery tank comprising first and second compartments, the first compartment having a head spaced closed to the atmosphere and the second compartment having a head space open to the atmosphere; the neutralizing liquid being present in both compartments, the outlet tube sparging unused treating agent into the first compartment for neutralization in the first and second compartments, in sequence; and further, means communicating the tank first compartment head space with the neutralizing liquid in the tank second compartment; and wall means defining the chamber and a garment-passing opening; into the chamber, the opening having a gas tight closure; said wall means being coated and internally heated against treating agent deposit thereon, e.g. the wall means comprising a flexible sheet having a chamber surface of treating agent deposit resistant synthetic organic plastic, resistance heating elements embedded within the wall means in chamber surface heating relation, and heat insulative material limiting heating of the non-chamber surface of the wall means, the sheet being supported by a rigid frame in chamber defining relation.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be further described as to an illustrative embodiment in conjunction with the attached drawings, in which:
FIG. 1 is a view in vertical section of apparatus according to the invention;
FIG. 2 is a view in side elevation of the apparatus taken on line 2--2 in FIG. 1;
FIG. 3 is a detail view in transverse section and greatly enlarged of the closure means taken on line 3--3 in FIG. 1;
FIG. 4 is a view like FIG. 3 of an alternate form of wall means closure; and
FIG. 5 is a view taken on line 5--5 of FIG. 2, and enlarged.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference now to the drawings in detail, the apparatus 10 is shown in FIGS. 1 and 2 to comprise sheet material panels generally indicated by numeral 12 and specifically arranged to define a top wall 14, a bottom wall 16 resting on floor 17, a rear wall 18, a front wall 20 having sealing closure 22 thereon and left side wall 24 and right side wall 26. These panels are sewn or heat or solvent sealed together to define a vapor tight and pressurizable chamber 27 sized as indicated to provide an enclosure interior 28 for garments 30 to be treated, supported within the enclosure interior 28 on rack 32.
As best seen in FIG. 3, the sheet material wall panels 12 are laminates of a high temperature resistant, generally nonpolar inner surface layer 34 e.g. of Teflon, silicone and the like, optionally reinforced with an additional layer of tough flexible plastic, also high temperature resistant, e.g. polycarbonate, silicone, rubber or the like (not shown) and an outer layer 38 of heat insulative material, e.g. fiberglass 38, suitably covered with a cloth or plastic fabric covering 40.
Embedded within the wall panel surface layer 34 are multiple wires 42 defining an electrical resistance heater distributed throughout the wall panels 12 for purposes to appear.
The wall panels 12 are supported in their assembled relation by circumferential support frame 44 formed of pipe or the like and secured to the side walls 24, 26 by hook fasteners 46. Rack 32 is supported by reinforcements 47 on side walls 24, 26, its weight being transferred thereby to the frame 44. A typical chamber may be 5 feet in height, 4 feet wide and 2 feet deep.
The treating agent supply comprises one or more tanks 48 communicating with the interior 28 of chamber 12. The tanks 48 are pressure resistant vessels containing generally liquid, but vaporizable garment durable press treating agents, e.g. those referred to my earlier patent mentioned above, and more particularly a solution of a formaldehyde donor, a fiber swelling agent, an activator or catalyst, and water. This treating solution, known per se, or a like durable press imparting agent is pressurized within the tank by a propellant. The term "propellant" herein refers to normally gaseous but liquifiable (or subliming) material which can be placed in a container to pressurize the contents, such as are used in aerosol "bombs." Among such materials there may be mentioned carbon dioxide, nitrogen, halohydrocarbons such as fluorocarbons and chlorofluorocarbons. The particular propellant is not critical, provided the material is inert with respect to the durable press agents and provides sufficient pressure within the tank 48 to deliver the agent into the chamber interior 28.
The treating agent tanks 48 may be two in number as shown, or more. A typical tank might contain about 1 quart to 1.5 quarts of the treating agent plus propellant sufficient to deliver the agent into the chamber interior 28, or enough for one treatment in a chamber 27 of the size indicated above. Additional tanks will enable additional treatments. One aspect of the apparatus self-containment is thus apparent. The treating agent tanks can be readily replaced on a one-tank, one-use basis; the tank being provided from a central supply to particular users much as industrial gases are supplied to welding shops.
The treating agent is passed from the tank 48 by opening valve 50 and letting the agent under propellant pressure enter conduit 52 which enters the chamber 27 through fitting 54 in left side wall 24 in sealed relation.
A longitudinal portion of conduit 52 is defined by a flash heater 56 best shown in FIG. 5 and comprising a circular series of heater tubes 58 having a central core of electrically heatable wire 60, tubes being surrounded by conduit 52, to define a passage 61 for the contents of tank 48 in which heat is applied (up to 325°-350° F) to the tank contents, heating them to vaporization, the produced vapors then passing into the chamber interior 28 as the vapor supply to the chamber.
Prior to activating delivery of the treating agent vapor, the chamber interior 28 into which garments 30 have been placed on rack 32 and through opening 22 (subsequently reclosed pressure-tightly) is depressurized, i.e. the interior pressure is reduced below ambient or atmospheric pressure, creating within the chamber 12 and the garments 30 a negative pressure condition, e.g. of 2 to 5 inches of water below atmosphere.
The depressurization of the chamber interior 28 is accomplished by pump 64 communicating on its suction side with the chamber interior, through conduit 66 which enters right side wall 26 of the chamber 27 through fitting 68, and on the pump pressure side, conduit 70 communicates the pump with scrubbing 72 to be described.
After the pump 64 has depressurized the chamber interior 28, the valve 50 on treating agent tank 48 is opened, the treating agent released under propellant pressure passes through conduit 52, is vaporized by heater 56 and, as a vapor, enters chamber interior 28. Because of the negative pressure condition within the chamber 27 and garments 30 therein, substantive contact of the vapor with the garments is effected rapidly and effectively. The treating agent appears to pressure-impregnate and polymerize within and on the fabric fiber interstices and an overall high level of durable press treatment is realized. Treatment times of 5 minutes to 1 hour or more may be used, and preferably 15 to 20 minutes, depending on the quantity of garments 30 being treated, the pressure differential between tank 48 and chamber interior 28, the treating agent used, the extent of treatment desired and like variable factors.
To prevent deposition of the treating agent on the chamber interior walls, these walls are internally heated and anti-deposition coated. With reference to FIG. 3, front wall 20, which is typical in this respect, is shown, Wall 20 comprises an inner layer 34 (faces the chamber interior 28) of Teflon, silicone or like nonadherent, inert polymer having suitable temperature resistance. The inner layer has embedded within it a distributed series of electrical resistance wires or screen 42 which are capable of heating the exposed surface of inner layer 34 to a temperature at which the vapor introduced into the chamber interior 28 will not polymerizingly deposit, e.g. 225°-300° F.
The quantity of vapor introduced into chamber interior 28 is such as replaces from 25% to 150% or more or less of the quantity of air or like gas evacuated from the chamber by blower-pump 64. This is, typically, the chamber interior 28 pressure will be not less than 110% and preferably will be 125% to 250% of the atmospheric pressure when vapor pressurized. The chamber 27 being flexibly walled may assume concave or convex shapes during the treatment cycle, reflecting the depressurization and repressurization.
The invention further provides for recovery of unused treating agent. The purpose of this recovery is not reuse of these agents, but the satisfaction of most stringent environmental considerations, including minimum release of displeasing olefactory vapors. Accordingly, following garment treatment, and prior to opening the chamber 27 by disengaging the tongue-in-groove closure 78 shown in FIG. 3 or the alternate double tongue, double groove closure 78a shown in FIG. 4, the pump 64 is again activated and the gases and unused vapor within chamber interior 28 exhausted. These removed gases and unused vapors are passed through conduit 70 which, as shown (FIG. 1), terminates beneath the surface of neutralizing liquid 80 in a manner to sparge the gases and vapors into the liquid.
Suitable liquids for neutralization include materials which will precipitate, complex, polymerize or absorb the unused vapors, i.e. render them less volatile, to preclude their release from the surface of liquid 80. Typical materials known for this purpose include sodium carbonate, sodium bicarbonate, sodium bisulfate, various dicyandiamides, ammonium hydroxide, sodium hydroxide and potassium hydroxide and like scrubbers for amine type materials, and formaldehyde vapors.
The mixed vapors and gases are released by conduit 70 into liquid 80. Vapors are scrubbed from the gases, as the gases pass upwardly through the liquid 80. The gases released from the surface of neutralizing liquid 80 in the first compartment 82 of scrubbing tank 84 of recovery unit 72 enter the head space 82a thereof and are conveyed, by pressure differential, through tube 86 to tank second compartment 88 having head space 88a which is in open communication with the atmosphere at 90 through vent pipe 92. The gases passing into compartment 88 are further scrubbed in this compartment liquid 94, pass into head space 88a, and are released to the atmosphere at 90 only after they rise through neutralizing liquid 94, scrubbed clean of offensive vapors, by the compartments indicated, or multiplied banks of such compartments, as necessary. | Self-contained apparatus for vapor phase treating of garments with durable press treating agents. The apparatus comprises a vaporized treating agent supply tank, a pressurizable treating chamber for enclosing garments to be agent treated, and an unused treating agent recovery means, the assembly being adapted to cyclically depressurize and repressurize the chamber interior in timed relation to the presence of treating agent in the chamber to relatively pressure impregnate the garments with the treating agent. | 3 |
FIELD OF THE DISCLOSURE
The disclosure relates to pillboxes used to store pills or similar solid mendicants or other small objects in individual compartments, and in particular, to devices for loading such pillboxes.
BACKGROUND OF THE DISCLOSURE
Pillboxes are multi-compartment containers having lids or tops that individually open and close the compartments. Pills are placed in the open compartments and the compartments are then closed. When it is time to take a pill, a compartment is opened and the pill is removed for use.
Pillboxes are normally designed to hold pills sufficient for some specific dosage regimen. The pillbox compartments are typically arranged to extend side-by-side along the length of the pillbox, with the number of compartments based on the frequency the pills are to be taken. One common pillbox, for example, has seven transparent compartments labeled to identify each day of the week and are intended to store a week's worth of pills separated by day of the week. Another common pillbox has four transparent compartments labeled to identify different parts of the day—for example, morning, noon, evening, bedtime—and are intended to store a day's worth of pills that are taken at different times of the day.
A user knows whether or not he or she has taken a pill for that day of the week or time of day by simply looking to see whether or not that day's compartment contains pills.
Some pillbox users have physical limitations that makes it difficult for them to place pills into the open compartments of a pillbox. There is a need for a pillbox loading device that allows for easier loading of pillboxes.
SUMMARY OF THE DISCLOSURE
Disclosed is a pillbox loading device that includes a box-like member having spaced apart first and second side walls, spaced apart first and second end walls interconnecting the first and second side walls, the first and second end walls spaced apart from one another in a horizontal direction, and a top closing an upper end of the box-like member, each of the end walls and side walls extending in a vertical direction downwardly away from the top.
The second wall includes a slot extending through the second side wall. The top defines an opening that extends through the top and includes a number of channels and channel walls separating adjacent pairs of channels, the slot being spaced from one or both of the side edges and spaced vertically from an upper end of the first side wall. The channels are side-by-side to one another and extend from the first end wall to the second end wall. Each channel includes a floor extending away from the top opening and sloping upwardly from the top opening towards the top end of the box-like member.
In use, the pillbox is received within the side wall slot to place the open containers of the pillbox in the interior of the box-like member and to align the top opening with the containers. The channels in effect define funnels that direct pills placed on the channel floors towards the opening and to fall into respective compartments of the pillbox.
Because the boxlike member is wider than the pillbox, the widths of the channels away from the top opening is greater than the width of the pillbox compartments, making it easier for a user to place pills on the device and having the device funnel the pills to the pillbox compartments.
In possible embodiments of the disclosed loading device, channel ledges are provided that enable a user to place pills on the channel ledges temporarily before loading the pillbox.
Other objects and features of the disclosure will become apparent as the description proceeds, especially when taken in conjunction with the accompanying drawing sheets illustrating one or more illustrative embodiments.
BRIEF SUMMARY OF THE DRAWINGS
FIGS. 1 and 2 are top and front views respectively of a first embodiment pillbox loading device.
FIG. 3 is a sectional view of the pillbox loading device shown in FIG. 1 taken along line 3 - 3 of FIG. 2 .
FIG. 4 is similar to FIG. 3 but includes a pillbox in position for loading by the pillbox loading device.
FIG. 5 is a sectional view similar to FIG. 3 of a second embodiment pillbox loading device.
FIG. 6 is a top view of a third embodiment pillbox loading device.
FIG. 7 is a top view of a fourth embodiment pillbox loading device.
FIG. 8 is a top view of a fifth embodiment pillbox loading device.
FIG. 9 is a top view of a sixth embodiment pillbox loading device.
FIG. 10 is a sectional view of the pillbox loading device shown in FIG. 9 taken along lines 10 - 10 of FIG. 9 .
FIG. 11 is a sectional view similar to FIG. 10 of a seventh embodiment pillbox loading device.
FIG. 12 is a top view of an eighth embodiment pillbox loading device.
FIG. 13 is a sectional view of the pillbox loading device shown in FIG. 12 taken along line 13 - 13 of FIG. 12 .
DETAILED DESCRIPTION
FIGS. 1-3 illustrate a first embodiment pillbox loading device 10 . The illustrated pillbox loading device is intended for loading the pillbox compartments of a pillbox P having seven side-by-side storage compartments, the pillbox compartments being shown in phantom lines in FIG. 1 .
The pillbox loading device 10 is a unitary one-piece box or box-like member 11 having a pair of spaced-apart first and second side walls 12 , 14 respectively and a pair of spaced-apart first and second end walls 16 , 18 respectively. The side walls and end walls surround and define a generally prismatic interior 20 of the box 11 .
The side walls and end walls define an upper end 22 and an open lower end 24 of the box 11 . A top 26 closes the upper portion of the box, with the side walls and end walls extending in a vertical direction downwardly away from the top 26 . The side walls and end walls extend to the lower end 24 of the box, the bottom ends of the side walls and end walls being co-planar to allow the bottom of the loading device 10 to be supported evenly on a flat surface.
The second side wall 14 includes a through-opening or slot 30 that is defined by a pair of spaced-apart vertical side walls 32 , 34 and a horizontal wall 36 joining the upper ends of the side walls 32 , 34 ( FIG. 3 exaggerates the thickness of the side wall 14 to more clearly show the slot side wall 32 ). The slot 30 extends vertically from the horizontal wall 36 to the bottom end of the side wall 12 , and is horizontally centered between the end walls 16 , 18 . The slot 30 is sized to closely receive the compartment body of a pillbox as will be described in greater detail below.
The top 26 is spaced vertically below the upper end of the box 11 and extends from the first end wall 16 to the second end wall 18 . The top 26 extends from the first side wall 12 towards the second side wall 14 . The top 26 stops short of the second end wall 14 along an edge 38 spaced away from the first side wall 14 . The edge 38 , the end walls, and the first side wall 12 cooperatively define a mouth or top opening 40 that communicates with the interior 20 . The top opening 40 extends along the second side wall 14 from the first end wall 16 to the second end wall 18 .
The top 26 includes or defines seven channels 42 (the channels are labeled in FIG. 1 as channels 42 a , 42 b , 42 c , 42 d , 42 e , 42 f , 42 g respectively), each channel 42 associated with a respective compartment of the pillbox P. The channels 42 are located on an upper surface 44 of the top 26 and are side-by side one another. Elongate channel walls 46 extend along the length of the channels 42 on opposite sides of the channels and also separate adjacent pairs of channels. The top surface 44 forms floors of the respective channels 42 a - 42 g . The channel walls 46 are proud of the top surface 44 .
Through slots 48 are formed between adjacent channels 42 and are sized to receive compartment walls of the pillbox P during use as will be explained in greater detail below. The channel walls 46 bifurcate at the slots 48 and run the length of the slots 48 on both sides of the slots.
Each channel floor 44 extends upwardly away from the opening 40 and extends to an adjacent end wall 16 , 18 or the first side wall 12 . Channel 42 a extends to the end wall 16 . The channels 42 b , 42 c , 42 d , 42 e , 42 f each extends to the first side wall 12 . The channel 42 g extends to the end wall 18 .
Each channel floor includes an upwardly sloping floor portion 44 a that extends away from the opening 40 and a level floor portion or ledge 44 b that extends to the side or end wall. The lower end of each floor portion 44 a is intended to be received within a respective compartment of the pillbox P.
As shown in FIG. 1 , the width dimension of the side wall 12 extending between the end walls is substantially greater than the total length of the compartments of the pillbox P. The width dimension of each of the end walls 16 , 18 extending between the side walls is greater than the width of the compartments of the pillbox P. As each channel floor extends away from the opening 40 , the width of the floor increases. Away from the opening 40 the width of each of the floors is substantially greater than the width of each individual pillbox compartment.
FIG. 4 illustrates use of the pillbox loading device 10 to load the pillbox P resting on a flat surface (not shown) and with the pillbox compartments open. The box 11 is placed over the pillbox P so that the pillbox compartments are received in the box interior 20 through the open bottom end of the box. The pillbox P is received in the wall slot 30 to locate the channels 42 over the pillbox compartments. As the box 11 is placed over the pillbox P, the slots 48 receive the compartment walls that separate the pillbox compartments. Interference of the compartment walls with the sides of the slots 48 assist in limiting relative movement of the pillbox relative to the device 10 during use of the device 10 . The lower end of the box 11 is placed against the flat surface with the lower ends of the channels 42 received in and extending into respective compartments of the pillbox P as shown in FIG. 4 .
The upper channel ledges 44 b are level and enable a user to rest pills on the channel ledges 44 b before loading the pills into the pillbox. Because the width of each of the channel ledges 44 b are substantially greater than the pillbox compartment width, placing pills on the channel ledges 44 b is easier than placing the pills directly into the pillbox compartments. Pills resting on the channel ledges 44 b are simply slid down the channel portions 44 a to slide the pills down the channels and into the pillbox compartments. The channels 42 form respective funnels that direct the pills to the opening 30 and to then fall through the opening 30 into the pill compartments. The pairs of channel walls 46 lining the channels 42 resist pills in the channels 42 from moving out of their channels and aid in funneling the pills to the pillbox compartments.
After loading the pillbox, the box 11 is lifted away from the pillbox P and the pillbox compartments are then closed.
FIG. 5 illustrates a second embodiment pillbox loading device 110 that is similar to the loading device 10 . In this embodiment the inclined floor portions 44 a are less steep as compared to the device 10 so that the top opening 40 is spaced vertically above the horizontal slot wall 36 . The pillbox P can slide through the slot 30 without obstruction from the top 26 to place the pillbox containers within the box interior 20 . The slots 38 of the device 10 are eliminated because the channels 42 do not extend into the pillbox containers during use. To assist in positioning the device 110 relative to the pillbox, interior side walls 47 and 47 ′ are sized to closely receive the body of the pillbox as the pillbox slides into the box member 11 .
The slope of the inclined floor portions 44 a in other embodiments of the device 110 can be increased by increasing the height of the box 11 .
FIG. 6 illustrates a third embodiment pillbox loading device 210 that is similar to the loading device 110 . The loading device 210 differs from the loading device 10 in that the top 26 adjacent the respective end walls 16 , 18 extends entirely to the second side wall 14 . The side wall 14 bounds one side of the channel 42 a and the channel 42 g and allows the width of the channel ledges of the channels 42 a , 42 g to be increased.
FIG. 7 illustrates a fourth embodiment pillbox loading device 310 that is similar to the loading device 210 . The loading device 310 differs from the loading device 210 only in the width of the channels 42 . The channels 42 a , 42 g in addition to extending towards respective end walls 16 , 18 also extend towards the side wall 12 . The width of the channel ledges of the other channels 42 b - 42 f is reduced from those of the device 210 .
FIG. 8 illustrates a fifth embodiment pillbox loading device 410 that is intended for loading a pillbox P′. In this embodiment the top opening 40 is centered between the side walls 12 , 14 and the end walls 16 , 18 . The channels 42 each extend away from both sides of the opening 40 to the adjacent side and end walls. This embodiment enables channel ledges to be formed along both side walls 12 , 14 .
FIGS. 9 and 10 illustrate a sixth embodiment pillbox loading device 510 . The pillbox loading device 510 is similar to the device 310 but the channel walls 46 are located on only the upwardly sloping channel portions 44 a and stop at the ledge channel portions 44 b . The ledge portions 44 b form a single obstruction-free ledge 49 that extends the width of the first side wall 12 . The ledge channel portions 44 b also slope downwardly from the ledge channel portions 44 a to the adjacent side or end walls. When the device 510 is placed on a horizontal surface, pills placed on the ledge 49 are urged by gravity towards the side wall 12 . After all the pills intended to be loaded are placed on the ledge 49 , a user slides the pills off the ledge and into the channels to load the pillbox.
FIG. 11 illustrates a seventh embodiment pillbox loading device 610 . The pillbox loading device 610 is similar to the device 510 but includes an elongate rotatable shaft 50 journaled in the end walls 16 , 18 . The shaft 50 is located just above the side of the ledge 49 closely spaced from the upper ends of the channels 46 . The shaft 50 is rotated by a handle 52 located outside of the box member 11 . Attached to the shaft 50 for rotation with the shaft 50 is a flat plate 54 that normally sits just above and essentially covers all the ledge 49 . As shown in FIG. 11 , the plate 54 in its normal position slopes downwardly with the ledge 49 towards the side wall 12 and rests against the ledge 49 . Pills are loaded on top of the plate 54 , and the shaft 50 is rotated counterclockwise by the user as viewed in FIG. 11 . This rotates the plate 54 away from the ledge 44 and tilts the plate 55 upwardly so that gravity urges the pills to move off the plate 55 and onto the channels 42 .
FIGS. 12 and 13 illustrate an eighth embodiment pillbox loading device 710 . The pillbox loading device 710 is similar to the device 610 but the plate 54 is replaced with individual plates 54 a - 54 g . Each plate 54 a - 54 g is rotatable about a fixed shaft 50 and includes a tab 56 that extends through a slot in the side wall 12 . The channel walls 46 include wall segments located on opposite sides of a plate 54 . A user loads the plates with pills, and then uses the tabs 56 to individually rotate a plate for loading an individual pill compartments. In other possible embodiments the plates 54 a - 54 g are designed to either individually rotate or to rotate together as a unit at the user's option. Each plate 54 would be designed in an embodiment to selectively snap or otherwise connect to adjacent plates for conjoint rotation with the adjacent plates. In yet other embodiments an additional actuator such as a rod that goes beneath the tabs 56 and revolves around on an axis similar to the shaft axis 50 could drive the plates simultaneously for loading the pill compartments.
Although the illustrated embodiments have been described being used to load pills into the pillbox compartments, it should be understood that this is exemplary only and that the described loading device can be used to load other small items—buttons, jewelry, coins, or the like—into a pillbox.
While one or more embodiments have been disclosed and described in detail, it is understood that this is capable of modification and that the scope of the disclosure is not limited to the precise details set forth but includes modifications obvious to a person of ordinary skill in possession of this disclosure and also such changes and alterations as fall within the purview of the following claims. | A pillbox loading device receives a pillbox and has a top opening alignable with the pillbox compartments. Channels extend from the top opening and define funnels that guide the pills into the pillbox. | 1 |
This application is a continuation of application Ser. No. 08/401,237 filed Mar. 9, 1995, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for producing a semiconductor substrate. More specifically, the present invention relates to a process for producing a monocrystalline semiconductor on a dielectric-isolated or insulative material, or a monocrystalline compound semiconductor on a semiconductor substrate. Further the present invention relates to a process for producing an electronic device or an integrated circuit formed on a single crystalline semiconductor layer.
2. Related Background Art
The technique of formation of monocrystalline Si (silicon) semiconductor on an insulative material is well known as silicon-on-insulator (SOI) technique. A device prepared by the SOI technique has various advantages which are not achievable by a bulk Si substrate in usual Si integrated circuits, as noted below:
1. Ease of dielectric isolation, and possibility of high degree of integration'
2. High resistance against radioactive ray;
3. Low floating capacity, and the possibility of high speed operation;
4. The welling process is unnecessary;
5. Preventability of latch-up; and
6. Possibility of producing a complete depletion type field-effect transistor to name a few.
The process of forming the SOI structure has been actively studied for several decades. The results of the studies are summarized, for example, in the paper: Special Issue; "Single-crystal silicon on non-single-crystal insulators"; edited by G. W. Cullen, Journal of Crystal Growth; Vol.63, No.3, pp.429-590 (1983).
SOS (silicon on sapphire) is known and is produced by heteroepitaxial growth of silicon on monocrystalline sapphire by CVD (chemical vapor deposition). The SOS technique, which is successful as one of SOI techniques, is limited in its application, because of many crystal defects caused by mismatch of the lattice at the interface between the Si layer and the underlying sapphire, contamination of the Si layer with aluminum from the sapphire substrate, expense of the substrate, and the difficulty of large-area substrate formation.
Recently, studies are being made to produce the SOI structure without using a sapphire substrate. The studies are classified roughly into the two processes below:
1. A first process which includes surface oxidation of a monocrystalline Si substrate, local exposure of the Si substrate by opening a window, and epitaxial growth of Si laterally from the exposed portion as the seed to form an Si layer on SiO 2 . (Si layer deposition on SiO 2 ).
2. A second process including SiO 2 formation beneath a monocrystalline SiO 2 substrate, utilizing the SiO 2 substrate as the active layer. (No Si layer deposition).
The device formed on a compound semiconductor exhibits performances, such as high speed, and luminescence, which are not achievable by Si. Such types of devices are formed by epitaxial growth on a compound semiconductor substrate such as GaAs. The compound semiconductor substrate, however, has disadvantages of high cost, low mechanical strength, and difficulty in the formation of a large-area wafer. Accordingly, heteroepitaxial growth of a compound semiconductor on an Si wafer is being studied to attain low cost, high mechanical strength, and ease of production of a large-area wafer.
The above-known process 1 (Si layer deposition on SiO 2 ) includes methods of direct lateral epitaxial growth of monocrystalline Si layer by CVD; deposition of amorphous Si and subsequent heat treatment to cause solid-phase lateral epitaxial growth; melting recrystallization to grow monocrystalline layer on an SiO 2 by irradiation of amorphous or polycrystalline Si layer with a focused energy beam such as an electron beam and laser beam; and a zone melting recrystallization in which a bar-shaped heater is moved to scan with a belt-like melt zone. These methods respectively have advantages and disadvantages, involving problems in process controllability, productivity, product uniformity, and product quality, and are not industrialized yet. For example, the CVD method requires sacrificial oxidation, giving low crystallinity in the solid-phase growth. The beam annealing method involves problems in processing time of focused beam scanning and in controllability of beam superposition and focusing. Of the above methods, the zone melting recrystallization is the most advanced method, and is employed in relatively large scale integrated circuits. This method, however, still causes crystal defects in subgrain boundaries, and is not successful in the production of a minority carrier device.
The above known process 2 in which the Si substrate is not utilized as the seed for epitaxial growth includes the four methods below:
1. An oxidation film is formed on a monocrystalline Si substrate which has V-shaped grooves on the surface formed by anisotropical etching; a polycrystalline Si layer is deposited in a thickness approximate to that of the Si substrate on the oxidation film; and the back face of the Si substrate is ground to form a monocrystalline Si region isolated dielectrically by surrounding with the V-shaped grooves. This method involves problems in controllability and productivity in deposition of polycrystalline Si in a thickness of as large as several hundred microns, and in removal of the monocrystalline Si substrate by grinding at the back face to leave an isolated active Si layer only.
2. An SiO 2 layer is formed by ion implantation into a monocrystalline Si substrate (SIMOX: Separation by ion implanted oxygen). This is the most highly advanced method in view of the matching with the Si process. This method, however, requires implantation of oxygen ions in an amount of as much as 10 18 ions/cm 2 , which takes a long time, resulting in low productivity and high wafer cost. Further, the product has many remaining crystal defects, and does not have satisfactory properties for the industrial production of a minority carrier device.
3. An SOI structure is formed by oxidation of porous Si for dielectric isolation. In this method, an N-type Si layer is formed in an island-like pattern on a P-type monocrystalline Si substrate surface by proton ion implantation (Imai, et al.: J. Crystal Growth, Vol. 63, p. 547 (1983)) or by epitaxial growth and patterning, and subsequently only the P-type Si substrate is made porous by anodic oxidation in an HF solution to surround the island-patterned N-type Si, and the N-type Si island is dielectrically isolated by accelerated oxidation. In this method, the isolated Si regions are fixed prior to the device process, which may limit the freedom of device design disadvantageously.
4. Different from the above conventional SOI formation, a method has recently come to be noticed in which a monocrystalline Si substrate is bonded to another thermally oxidized monocrystalline Si substrate by heat treatment or use of an adhesive to form an SOI structure. This method requires uniform thinness of the active layer for the device: namely, formation of a film of a micron thick or thinner from a monocrystalline substrate of several hundred microns thick. This thin film may be formed by either of the two methods below.
1. Thin film formation by grinding; and
2. Thin film formation by selective etching.
The grinding method does not readily give a uniform thin film. In particular, formation of a film of submicron thickness results in thickness variation of tens of percent. This irregularity is a serious problem. With a larger diameter of the wafer, the uniformity of the thickness is much more difficult to attain.
The etching method is regarded to be effective for uniform thin film formation. This method, however, involves the problems of insufficient selectivity of about 10 2 at the highest, inferior surface properties after etching, and low crystallinity of the SOI layer because of the employed ion implantation, epitaxial or heteroepitaxial growth on a high-concentration B-doped Si layer. (C. Harendt, et al.: J. Elect. Mater., Vol. 20, p. 267 (1991); H. Baumgart, et al.: Extended Abstract of ECS 1st International Symposium of Wafer Bonding, pp. 733 (1991); and C. E. Hunt: Extended Abstract of ECS 1st International Symposium of Wafer Bonding, pp. 696 (1991))
The semiconductor substrate which is prepared by lamination requires two wafers essentially, and a major part of one of the wafers is discarded by grinding or etching, thereby wasting the resource. Therefore, the SOI prepared by lamination involves many problems in controllability, uniformity, production cost, and so forth in conventional processes.
A thin Si layer deposited on a light-transmissive substrate typified by a glass plate becomes amorphous or polycrystalline owing to disorder of crystallinity of the substrate, not giving high performance of the device. Simple deposition of Si does not give desired quality of single crystal layer owing to the amorphous crystal structure of the substrate.
The light-transmissive substrate is essential for construction of a light-receiving element such as a contact sensor, and projection type of liquid crystal image-displaying apparatus. Additionally, a driving element of high performance is necessary for higher density, higher resolution, and higher precision of the sensor and of the image elements of the display. Consequently, the element provided on a light transmissive substrate is also required to have a monocrystalline layer of high crystallinity.
Amorphous Si or polycrystalline Si will not give a driving element having the required sufficient performance because of the many defects in the crystal structure.
As mentioned above, a compound semiconductor device requires essentially a compound semiconductor substrate. The compound semiconductor substrate, however, is expensive, and is not readily formed in a larger size.
Epitaxial growth of a compound semiconductor such as GaAs on an Si substrate gives a grown film of poor crystallinity owing to the difference in the lattice constants and the thermal expansion coefficients, thereby the resulting grown film being unsuitable for use for a device.
Epitaxial growth of a compound semiconductor on porous Si is intended for mitigation of mismatch of the lattices. However, the substrate does not have sufficient stability and reliability owing to the low thermal stability and long-term deterioration of the porous Si.
In view of the above-mentioned problems, Takao Yonehara, one of the inventors of the present invention, disclosed formerly a novel process for preparing a semiconductor member in European Patent Publication No. 0469630A2. This process comprises the steps of forming a member having a nonporous monocrystalline semiconductor region on a porous monocrystalline semiconductor region; bonding the surface of a member of which the surface is constituted of an insulating substance onto the surface of the nonporous monocrystalline semiconductor region; and then removing the porous monocrystalline semiconductor region by etching. This process is satisfactory for solving the above-mentioned problems. Further improvement of the disclosed process for higher productivity and lower production cost will contribute greatly to the industries concerned.
SUMMARY OF THE INVENTION
The present invention intends to improve further the process disclosed in the above European Patent for producing a semiconductor member.
The present invention further intends to provide a process for producing economically a semiconductor substrate having a monocrystalline layer or a compound semiconductor monocrystalline layer having excellent crystallinity, large-area and a uniform flat surface on a surface of a monocrystalline substrate, in which the substrate is removed to leave the active semiconductor layer to obtain a monocrystalline layer or a compound semiconductor monocrystalline layer formed on the surface and having few defects.
The present invention still further intends to provide a process for producing a semiconductor substrate on a transparent substrate (light-transmissive substrate) for obtaining a monocrystalline Si semiconductor layer or a monocrystalline compound semiconductor layer having crystallinity as high as that of a monocrystalline wafer with high productivity, high uniformity, high controllability, and low production cost.
The present invention still further intends to provide a process for producing a semiconductor substrate useful in place of expensive SOS or SIMOX in the production of a large scale integrated circuit of SOI structure.
A first embodiment of the process for producing a semiconductor substrate of the present invention comprises the steps of: forming a nonporous monocrystalline semiconductor layer on a porous layer of the first substrate having the porous layer; bonding the nonporous monocrystalline layer onto a second substrate; separating the bonded substrates at the porous layer; removing the porous layer on the second substrate; and removing the porous layer constituting the first substrate.
A second embodiment of the process for producing a semiconductor substrate of the present invention comprises the steps of: forming a nonporous monocrystalline semiconductor layer on a porous layer of a first substrate having the porous layer; bonding the nonporous monocrystalline layer onto a second substrate with interposition of an insulative layer; separating the bonded substrates at the porous layer; removing the porous layer on the second substrate; and removing the porous layer constituting the first substrate.
In the present invention, the lamination-bonded substrates are separated at the porous layer, and the porous layer is removed from the second substrate having a nonporous monocrystalline semiconductor layer. Thereby, a semiconductor substrate is prepared which has nonporous monocrystalline semiconductor layer of high quality. Furthermore, the first substrate can be repeatedly used for producing the semiconductor substrate in the next production cycle by removing the remaining porous layer on the first substrate after the separation of the two substrates. Thereby, the semiconductor substrate can be produced with higher productivity and lower cost.
The present invention enables preparation of a monocrystalline layer of Si or the like, or a monocrystalline compound semiconductor layer having excellent crystallinity similar to monocrystalline wafers on a substrate including a light-transmissive substrate with advantages in productivity, uniformity, controllability, and production cost.
The present invention further enables production of a semiconductor substrate which can be a substitute for expensive SOS and SIMOX in the production of large scale integrated circuits of an SOI structure.
According to the present invention, the combined substrates are separated at the porous layer or layers into two or more substrates, and the one or more separated substrates may be used as a semiconductor substrate after removal of the remaining porous layer, and the other substrate may be used repeatedly in the next production cycle of a semiconductor substrate.
Further, according to the present invention, two semiconductor substrates can be produced simultaneously by forming porous layers and nonporous layers on the e layers on the both faces of a substrate, bonding thereto two other substrates, and separating the substrates at the porous layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A to 1E are schematic drawings for explaining an example of the process of the present invention.
FIGS. 2A to 2E are schematic drawings for explaining another example of the process of the present invention.
FIGS. 3A to 3E are schematic drawings for explaining a still another example of the process of the present invention.
FIGS. 4A to 4E are schematic drawings for explaining a further example of the process of the present invention.
FIGS. 5A to 5E are schematic drawings for explaining a still further example of the process of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The process for producing a semiconductor substrate of the present invention is described by employing a silicon substrate as an example.
The mechanical strength of porous silicon is much lower than that of bulk silicon depending on the porosity thereof. For instance, porous silicon having a porosity of 50% is considered to have half the mechanical strength of bulk silicon. Therefore, on application of a tensile force, a compressive force, or a shearing force to a laminated wafer, the porous layer will be broken first. The larger the porosity of the porous layer, the less force is needed for the breakdown of the layer.
A silicon substrate can be made porous by anodization in an HF solution. The resulting porous Si layer has a density ranging from 1.1 to 0.6 g/cm 3 depending on the HF solution concentration of from 50 to 20% in comparison with the density of 2.33 g/cm 3 of monocrystalline Si. The porous layer is formed only on a P-type Si substrate, but is not formed on an N-type Si layer for the reasons described later. The porous Si layer has pores of about 600 Å in average diameter according to transmissive electron microscopy.
The porous Si was found by Uhlir, et al. in the year 1956 during the study of electropolishing of semiconductors (A. Uhlir: Bell Syst. Tech. J., vol. 35, p. 333 (1956)).
Unagami, et al. found that positive holes are required for anodization of Si in an HF solution, and the reactions proceed as shown in their report on dissolution of Si in anodization (T. Unagami, et al.: J. Electrochem. Soc., vol. 127, p. 476 (1980)) as below: ##EQU1## where e + and e - represent respectively a positive hole and an electron; n and λ represent respectively the number of positive holes required for dissolving one Si atom. Unagami reported that porous Si is formed under the condition of n>2, or λ>4.
According to the above consideration, P-type Si which has positive holes can be made porous, whereas N-type Si cannot be made porous. This selectivity for porosity was evidenced by Nagano, et al., and Imai (Nagano, Nakajima, Yasuno, Oonaka, and Kajihara: Denshi Tsushin Gakkai Gijutsu Kenkyu Hokoku (Technical Research Report of Electronic Communication Society) vol. 79, SSD79-9549 (1979); and K. Imai: Solid-State Electronics, vol. 24, p. 159 (1981)).
On the other hand, a report is found that high concentration N-type Si can be made porous (R. P. Holmstrom and J. Y. Chi: Appl. Phys. Lett., vol. 42, p. 386 (1983)). Therefore, selection of the substrate is important for producing porous Si regardless of P-type or N-type.
The porous Si layer has pores of about 600 Å in average diameter by observation by transmission electron microscopy, and the density is less than half that of monocrystalline Si. Nevertheless, the single crystallinity is maintained, and thereon a monocrystalline Si can be made to grow epitaxially in a layer. However, in the epitaxial growth at a temperature of 1000° C. or higher, the internal pores will come to be rearranged, which impairs the accelerated etching characteristics. Therefore, low temperature growth processes are preferred for epitaxial growth of the Si layer, such as molecular beam epitaxial growth, plasma CVD, reduced pressure CVD, photo-assisted CVD, bias sputtering, and liquid-phase epitaxial growth.
The porous layer has a large volume of voids therein, having a half or lower density of the material, and having a surface area remarkably large for the volume. Accordingly, the chemical etching is greatly accelerated in comparison with that of the normal monocrystalline layer.
Embodiment 1
A first monocrystalline Si substrate 11 is made porous at the surface to form a porous layer 12 as shown in FIG. 1A. Then, nonporous monocrystalline Si layer 13 is formed on the porous Si layer 12 as shown in FIG. 1B.
Another Si supporting substrate 14 is brought into contact with the nonporous monocrystalline Si layer 13 with interposition of an insulative layer 15 at room temperature as shown in FIG. 1C, and then the contacted matter was subjected to anode coupling, compression, heat treatment, or combination thereof to bond tightly the Si supporting substrate 14 and the monocrystalline layer 13 with interposition of the insulative layer 15. The insulative layer 15 may be formed preliminarily on either one of the monocrystalline Si layer 13 or the Si supporting substrate 14, or the three sheets may be bonded with an insulative thin film interposed.
Subsequently, the substrates are separated at the porous Si layer 12 as shown in FIG. 1D. On the Si supporting substrate 14, the layers have the structure of porous Si 12/monocrystalline Si layer 13/insulative layer 15/Si supporting substrate 14.
The porous Si 12 is removed selectively by non-electrolytic wet chemical etching by use of at least one of a usual Si etching solution, hydrofluoric acid or a mixture of hydrofluoric acid with alcohol and/or hydrogen peroxide as the porous Si-selective etching solution, and buffered hydrofluoric acid or a mixture of hydrofluoric acid with alcohol and/or hydrogen peroxide to leave the thin-layered monocrystalline Si layer 13 on the insulative substrate 15 and 14. As described above in detail, the porous Si can be etched selectively by a usual Si etching solution owing to the extremely large surface area of the porous surface area.
Otherwise, the porous Si 12 is selectively removed by grinding by utilizing the monocrystalline Si layer 13 as the grinding stopper.
FIG. 1E illustrates a semiconductor substrate of the present invention. The monocrystalline Si layer 13 is formed flat and uniformly in a thin layer on the insulative substrate 15 and 14 over the entire large area of the wafer. The resulting semiconductor substrate is useful for production of insulation-isolated electronic elements.
The first monocrystalline Si substrate 11 may be repeatedly used for the same use after removal of the remaining Si and surface flattening treatment if the surface has become roughened unacceptably in the next production cycle.
The method of separation of the two substrates at the porous Si layer in the present invention includes crushing of the porous layer by compression on both faces of the bonded substrates; pulling of the respective substrates in opposite directions; insertion of a jig or the like into the porous layer; application of force in opposite directions parallel to the bonded face of the substrates; application of supersonic vibration to the porous layer; and so forth.
The porosity of the porous Si layer suitable for the separation ranges generally from 10 to 80%, preferably from 20 to 60%.
Embodiment 2
A first monocrystalline Si substrate 21 is made porous at the surface to form a porous layer 22 as shown in FIG. 2A. Then a nonporous monocrystalline Si layer 23 is formed on the porous Si layer 22 as shown in FIG. 2B.
A light-transmissive supporting substrate 24 is brought into contact with the monocrystalline Si layer 23 with interposition of an insulative layer 25 at room temperature as shown in FIG. 2C, and then the contacted matter was subjected to anode coupling, compression, heat treatment, or combination of the treatment to bond tightly the light-transmissive supporting substrate 24 and the monocrystalline layer 23 with interposition of the insulative layer 25. The insulative layer 25 may be formed preliminarily on either one of the monocrystalline Si layer or the light-transmissive supporting substrate 24, or the three sheets may be bonded with interposition of an insulative thin film.
Subsequently, the substrates are separated at the porous Si layer 22 as shown in FIG. 2D. On the light-transmissive supporting substrate, the layers have the structure of porous Si 22/monocrystalline Si layer 23/insulative layer 25/light-transmissive supporting substrate 24.
The porous Si 22 is removed selectively by non-electrolytic wet chemical etching by use of at least one of a usual Si etching solution, hydrofluoric acid or a mixture of hydrofluoric acid with alcohol and/or hydrogen peroxide as the porous Si-selective etching solution, and buffered hydrofluoric acid or a mixture of hydrofluoric acid with alcohol and/or hydrogen peroxide to leave a thin-layered monocrystalline Si layer 23 on the insulative substrate 25 and 24. As described above in detail, the porous Si can be etched selectively by a usual Si etching solution because of the extremely large surface area of the porous surface area.
Otherwise, the porous Si 23 is selectively removed by grinding by utilizing the monocrystalline Si layer 22 as the grinding stopper.
FIG. 2E illustrates a semiconductor substrate of the present invention. The monocrystalline Si layer 23 is formed flat and uniformly in a thin layer on the insulative substrate 25 and 24 over the entire large area of the wafer. The obtained semiconductor substrate is useful for production of insulation-isolated electronic elements.
The presence of the interposed insulative layer 25 is not essential.
The first monocrystalline Si substrate 21 may be repeatedly used for the same use after removal of the remaining Si and surface flattening treatment if the surface has become roughened unacceptably in the next production cycle.
Embodiment 3
A first monocrystalline Si substrate 31 is made porous at the surface to form a porous layer 32 as shown in FIG. 3A. Then a nonporous monocrystalline compound semiconductor layer 33 is formed on the porous Si layer 32 as shown in FIG. 3B.
Another Si supporting substrate 34 is brought into close contact with the monocrystalline compound semiconductor layer 33 with interposition of an insulative layer 35 at room temperature as shown in FIG. 3C, and then the contacted matter was subjected to anode coupling, compression, or heat treatment, or combination of the treatments to bond tightly the Si supporting substrate 34 and the monocrystalline layer 33 with interposition of the insulative layer 35. The insulative layer 35 may be formed preliminarily on either one of the monocrystalline compound semiconductor layer or the Si supporting substrate 34, or the three sheets may be bonded with interposition of an insulative thin film.
Subsequently, the substrates are separated at the porous Si layer 32 as shown in FIG. 3D. On the Si supporting substrate, the layers have the structure of porous Si 32/monocrystalline compound semiconductor layer 33/insulative layer 35/Si supporting substrate 34.
The porous Si 32 is removed selectively by chemical etching by use of an etching solution which is capable of etching Si at a higher etching rate than the compound semiconductor to leave the thin-layered monocrystalline compound semiconductor layer 33 on the insulative substrate 35 and 34.
Otherwise, the porous Si 32 is selectively removed by grinding by utilizing the monocrystalline compound semiconductor layer 33 as the grinding stopper.
FIG. 3E illustrates a semiconductor substrate of the present invention. The monocrystalline compound semiconductor layer 33 is formed flat and uniformly in a thin layer on the insulative substrate 35 and 34 over the entire large area of the wafer. The resulting semiconductor substrate is useful as a compound semiconductor substrate and for production of insulation-isolated electronic elements.
When the substrate is used as a compound semiconductor substrate, the insulative layer 35 is not essential.
The first monocrystalline Si substrate 31 may be repeatedly used for the same use after removal of the remaining Si and surface flattening treatment if the surface has become roughened unacceptably in the next production cycle.
Embodiment 4
A first monocrystalline Si substrate 41 is made porous at the surface to form a porous layer 42 as shown in FIG. 4A. Then a nonporous monocrystalline compound semiconductor layer 43 is formed on the porous Si layer 42 as shown in FIG. 4B.
A light-transmissive supporting substrate 44 is brought into close contact with the monocrystalline compound semiconductor layer 43 with interposition of an insulative layer 45 at room temperature as shown in FIG. 4C, and then the contacted matter was subjected to anode coupling, compression, heat treatment, or combination of the treatments to bond tightly the light-transmissive supporting substrate 44 with the monocrystalline layer 43 with interposition of the insulative layer 45. The insulative layer 45 may be formed preliminarily on either one of the monocrystalline compound semiconductor layer or the light-transmissive supporting substrate 44, or the three sheets may be bonded with interposition of an insulative thin film.
Subsequently, the substrates are separated at the porous Si layer 42 as shown in FIG. 4D. On the light-transmissive supporting substrate, the layers have the structure of porous Si 42/monocrystalline compound semiconductor layer 43/insulative layer 45/light-transmissive supporting substrate 44.
The porous Si 42 is removed selectively by chemical etching by use of an etching solution which is capable of etching Si at a higher etching rate than the compound semiconductor to leave a thin-layered monocrystalline compound semiconductor layer 43 on the insulative substrate 45 and 44.
Otherwise, the porous Si 42 is selectively removed by grinding by utilizing the monocrystalline compound semiconductor layer 43 as the grinding stopper.
FIG. 4E illustrates a semiconductor substrate of the present invention. The monocrystalline compound semiconductor layer 43 is formed flat and uniformly in a thin layer on the insulative substrate 45 and 44 over the entire large area of the wafer. The resulting semiconductor substrate is useful for production of insulation-isolated electronic elements.
The insulative layer 45 is not essential in this embodiment.
The first monocrystalline Si substrate 41 may be repeatedly used for the same use after removal of the remaining Si and surface flattening treatment if the surface has become roughened unacceptably in the next production cycle.
Embodiment 5
A first monocrystalline Si substrate 51 is made porous at the both faces to form porous layers 52, 53 as shown in FIG. 5A. Then, nonporous monocrystalline compound semiconductor layers 54, 55 are formed on the porous Si layers 52, 53 as shown in FIG. 5B.
Two supporting substrates 56, 57 are brought into close contact with the monocrystalline semiconductor layers 54, 55 with interposition of insulative layers 58, 59 respectively at room temperature as shown in FIG. 5C, and then the contacted matter is subjected to anode coupling, compression, heat treatment, or combination of the treatments to bond tightly the supporting substrates 56, 57 and the monocrystalline layers 54, 55 with interposition of the insulative layers 58, 59. In the bonding, the respective insulative layers 58, 59 may be formed preliminarily on either one of the monocrystalline semiconductor layer 54, 55 or the supporting substrate 56, or the five sheets may be bonded with interposition of insulative thin films.
Subsequently, the substrates are separated into three at the both porous Si layers 52, 53 as shown in FIG. 5D. The two supporting substrates come to have a structure of porous Si/monocrystalline semiconductor layer/insulative layer/supporting substrate (52/54/58/56, and 53/55/59/57).
The porous Si layers 52, 53 are removed selectively by chemical etching to leave thin-layered monocrystalline semiconductor layers 54, 55 on the supporting substrates 58/56 and 59/57.
Otherwise, the porous Si 52, 53 is selectively removed by grinding by utilizing the monocrystalline semiconductor layers 54, 55 as the grinding stopper.
FIG. 5E illustrates semiconductor substrates prepared according to the present invention. The monocrystalline compound semiconductor layers are formed flat and uniformly in a thin layer on the supporting substrates over the entire large area of the two wafers at a time with a large area. The resulting semiconductor substrate is useful for production of insulation-isolated electronic elements.
The insulative intervening layers 58, 59 are not essential.
The supporting substrates 56, 57 need not be the same.
The first monocrystalline Si substrate 51 may be repeatedly used for the same use after removal of the remaining Si and surface flattening treatment if the surface has become roughened unacceptably in the next production cycle.
EXAMPLE 1
A first monocrystalline (100) Si substrate of P-type having a diameter of 6 inches, a thickness of 625 μm, and a specific resistance of 0.01 Ω·cm was anodized in an HF solution under the anodization conditions as below:
______________________________________Current density: 5 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:1:1Time: 12 minutesThickness of porous Si: 10 μmPorosity: 15%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for one hour. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si, monocrystalline Si was allowed to grow epitaxially in a thickness of 1 μm by CVD (chemical vapor deposition) under the growth conditions below:
______________________________________Source gas: SiH.sub.2 Cl.sub.2 /H.sub.2Gas flow rate: 0.5/180 l/minGas pressure: 80 TorrTemperature: 950° C.Growth rate: 0.3 μm/min______________________________________
The face of the epitaxially grown Si layer was thermally oxidized to form an SiO 2 layer of 100 nm thick.
On the face of this Si substrate, a separately prepared second Si substrate having an SiO 2 layer of 500 nm thick was superposed with the SiO 2 layer inside, and the superposed matter was heat-treated at 900° C. for 2 hours to bond the substrates tightly.
A pulling force was applied to the resulting bonded wafer in the direction perpendicular to the wafer face in such a manner that a plate was bonded respectively to each of the both faces of the wafer with an adhesive and the plates were pulled to opposite directions with a jig. Consequently, the porous Si layer was broken to cause separation of the wafer into two sheets with the porous Si layers exposed.
The porous Si layer on the second substrate was etched selectively in a mixture of 49% hydrofluoric acid and 30% hydrogen peroxide (1:5) with agitation. The porous Si was etched and removed completely with the monocrystalline Si remaining unetched as an etching stopper. The etching rate of the nonporous monocrystalline Si was extremely low, the selection ratio of the etching rate of the porous Si being 105 or higher. Therefore, the decrease in thickness of the nonporous layer by etching was practicably negligible (several tens of Å).
Consequently, a monocrystalline Si layer was formed in a thickness of 1 μm on an Si oxide film. The monocrystalline Si layer did not change at all by the selective etching of the porous Si layer.
The cross-section of the Si layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the Si layer and the excellent crystallinity was retained.
Thus an SOI substrate was obtained which has a semiconductor layer of high quality.
The other Si substrate having been separated at the porous Si layer portion was etched in the same manner as above to remove the remaining porous layer, and its surface was polished. The obtained Si substrate was used repeatedly for the same use in the next production cycle. Thereby a plurality of SOI substrates having a semiconductor layer of high quality were obtained.
EXAMPLE 2
A first monocrystalline (100) Si substrate of P-type having a diameter of 4 inches, a thickness of 525 μm, and a specific resistance of 0.01 Ω·cm was anodized in an HF solution under the anodization conditions as below:
______________________________________Current density: 7 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:1:1Time: 12 minutesThickness of porous Si: 10 μmPorosity: 15%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for 2 hours. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si, monocrystalline Si was allowed to grow epitaxially in a thickness of 0.5 μm by MBE (molecular beam epitaxy) under the growth conditions below:
______________________________________Temperature: 700° C.Pressure: 1 × 10.sup.-9 TorrGrowth rate: 0.1 μm/secTemperature: 950° C.Growth rate: 0.3 μm/min______________________________________
The face of the epitaxially grown Si layer was thermally oxidized to form an SiO 2 layer of 100 nm thick.
On the face of the SiO 2 layer, was superposed a separately prepared fused quartz substrate, and the superposed matter was heat-treated at 400° C. for 2 hours to bond the substrates.
A sufficient compression force was applied uniformly to the resulting bonded wafer in the direction perpendicular to the wafer face such that plates were bonded to each of the both faces of the wafer with an adhesive and the compression force was applied with the same jig as in Example 1.
Consequently, the porous Si layer was broken to cause separation of the wafer into two sheets with the porous Si layers exposed.
The porous Si layers were etched selectively in a mixture of buffered hydrofluoric acid and 30% hydrogen peroxide (1:5) with agitation. Thereby the porous Si was etched and removed completely with the monocrystalline Si remaining unetched as an etch-stop material. The etching rate of the nonporous monocrystalline Si was extremely low, the selection ratio of the etching rate of the porous Si being, 105 or higher. Therefore, the decrease in thickness of the nonporous layer by etching was practicably negligible (several tens of Å).
Consequently, a monocrystalline Si layer was formed in a thickness of 0.5 μm on a fused quartz substrate. The monocrystalline Si layer did not change at all by the selective etching of the porous Si layer.
The cross-section of the Si layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the Si layer and the excellent crystallinity was retained.
A plurality of SOI substrates having a semiconductor layer of high quality were prepared by repeating the above process in the same manner as in Example 1.
EXAMPLE 3
A first monocrystalline (100) Si substrate of P-type or N-type having a diameter of 6 inches, a thickness of 625 μm, and a specific resistance of 0.01 Q·cm was anodized in an HF solution under the anodization conditions as below:
______________________________________Current density: 7 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:1:1Time: 12 minutesThickness of porous Si: 10 μmPorosity: 15%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for one hour. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si, monocrystalline GaAs was allowed to grow epitaxially in a thickness of 1 μm by MOCVD (metal organic chemical vapor deposition) under the growth conditions below:
______________________________________Source gas: TMG/AsH.sub.3 /H.sub.2Gas pressure: 80 TorrTemperature: 700° C.______________________________________
On the face of the formed GaAs layer, was superposed a separately prepared second Si substrate, and the superposed matter was heat-treated at 900° C. for one hour to bond the substrates tightly.
A sufficient compression force was applied to the resulting bonded wafer in the same manner as in Example 2. Thereby, the porous Si layer was broken to allow the wafer to separate into two sheets with the porous Si layers exposed.
Then, the oxide film on the inner wall of the porous Si layer was removed by hydrofluoric acid, and the porous
Si was etched with a mixture of ethylene diamine, pyrocathecol, and water (17 ml: 3 g: 8 ml) at 110° C. Thereby the porous Si was etched selectively and removed completely with the monocrystalline GaAs remaining unetched as an etch-stopping material. The etching rate of the nonporous monocrystalline GaAs was extremely low and practicably negligible.
Consequently, a monocrystalline GaAs layer was formed in a thickness of 1 μm on a Si substrate. The monocrystalline GaAs layer did not change at all by the selective etching of the porous Si layer.
The cross-section of the GaAs layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the GaAs layer and the excellent crystallinity was retained.
A plurality of semiconductor substrates having a GaAs layer of high quality were prepared by repeating the above process in the same manner as in Example 2.
GaAs on an insulative film was also prepared by employing an Si substrate having an oxide film as the supporting substrate.
EXAMPLE 4
A first monocrystalline (100) Si substrate of P-type or N-type having a diameter of 5 inches, a thickness of 625μm, and a specific resistance of 0.01 n·cm was anodized in an HF solution under the anodization conditions as below:
______________________________________Current density: 10 mA·cm.sub.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:1:1Time: 24 minutesThickness of porous Si: 20 μmPorosity: 17%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for 2 hours. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si, monocrystalline AlGaAs was allowed to grow epitaxially in a thickness of 0.5 μm by MBE (molecular beam epitaxy).
On the face of the formed AlGaAs layer, was superposed a face of a separately prepared low-melting glass substrate. The superposed matter was heat-treated at 500° C. for 2 hours to bond the substrates tightly.
A sufficient compression force was applied to the resulting bonded wafer in the same manner as in Example 2. Thereby, the porous Si layer was broken to allow the wafer to separate into two sheets with the porous Si layers exposed.
The porous Si was etched with hydrofluoric acid solution. Thereby the porous Si was etched selectively and removed off completely with the monocrystalline AlGaAs remaining unetched as an etch-stopping material. The etching rate of the nonporous monocrystalline AlGaAs was extremely low and practicably negligible.
Consequently, a monocrystalline AlGaAs layer was formed in a thickness of 0.5 ˜m on a glass substrate. The monocrystalline AlGaAs layer did not change at all by the selective etching of the porous Si layer.
The cross-section of the AlGaAs layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the AlGaAs layer and the excellent crystallinity was retained.
A plurality of semiconductor substrates having a GaAs layer of high quality were prepared by repeating the above process in the same manner as in Example 2.
EXAMPLE 5
A first monocrystalline (100) Si substrate of P-type or N-type having been polished on the both faces and having a diameter of 6 inches, a thickness of 625 μm, and a specific resistance of 0.01 Ω·cm was anodized on the both faces in an HF solution under the anodization conditions below:
______________________________________Current density: 5 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:1:1Time: 12 × 2 minutesThickness of porous Si: 10 μm eachPorosity: 15%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for one hour. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si formed on the both faces of the substrate, monocrystalline Si was allowed to grow epitaxially in a thickness of 1 μm respectively by CVD (chemical vapor deposition) under the growth conditions below:
______________________________________Source gas: SiH.sub.2 Cl.sub.2 /H.sub.2Gas flow rate: 0.5/180 l/minGas pressure: 80 TorrTemperature: 950° C.Growth rate: 0.3 μm/min______________________________________
The faces of the formed epitaxial Si layers were thermally oxidized to form SiO 2 layers in a thickness of 100 nm.
On each of the faces of the SiO 2 layers, a separately prepared Si substrate having a 500-nm thick SiO 2 layer was superposed respectively with the SiO 2 layers inside, and the superposed matter was heat-treated at 600° C. for 2 hours to bond the substrates tightly.
A sufficient pulling force was applied to the resulting bonded wafer in the direction perpendicular to the bonded wafer face in the same manner as in Example 1. Thereby, the two porous Si layers were broken to allow the wafer to separate into three sheets with the porous Si layers exposed.
The porous Si layers were etched selectively with a mixture of 49% hydrofluoric acid with 30% hydrogen peroxide (1:5) with agitation. Thereby the porous Si was etched selectively and removed completely with the monocrystalline Si remaining unetched as an etch-stopping material. The etching rate of the nonporous monocrystalline Si was extremely low, the selection ratio of the etching rate of the porous Si being 105 or higher. Therefore, the decrease in thickness of the nonporous layer by etching was practicably negligible (several tens of Å).
Consequently, a monocrystalline Si layer was formed in a thickness of 1 μm respectively on the two Si oxide films simultaneously. The monocrystalline Si layers did not change at all by the selective etching of the porous Si layer.
The cross-section of the Si layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the Si layer and the excellent crystallinity was retained.
A plurality of semiconductor substrates having a semiconductor layer of high quality were prepared by repeating the above process in the same manner as in Example 1.
EXAMPLE 6
A first monocrystalline (100) Si substrate of P-type or N-type having a diameter of 5 inches, a thickness of 625 ˜m, and a specific resistance of 0.01 Ω·cm was anodized in an HF solution under the anodization conditions below:
______________________________________Current density: 7 mA·cm.sub.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:1:1Time: 4 minutesThickness of porous Si: 3 μmPorosity: 15%______________________________________
The anodization was conducted further under the conditions below:
______________________________________Current density: 30 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:3:2Time: 3 minutesThickness of porous Si: 10 μmPorosity: 45%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for one hour. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si formed on the substrate, monocrystalline Si was allowed to grow epitaxially in a thickness of 0.3 μm by CVD under the conditions below:
______________________________________Source gas: SiH.sub.4Carrier gas: H.sub.2Temperature: 850° C.Pressure: 1 × 10.sup.-2 TorrGrowth rate: 3.3 nm/sec______________________________________
The surface of the formed epitaxial Si layer was thermally oxidized to form SiO 2 layer in a thickness of 100 nm. On the face of the SiO 2 layer, a separately prepared second Si substrate having a 500-nm thick SiO 2 layer was superposed with the SiO 2 layer inside, and the superposed matter was heat-treated at 700° C. for 2 hours to bond the substrates tightly.
A sufficient pulling force was applied to the resulting bonded wafer in the direction perpendicular to the bonded wafer face in the same manner as in Example 1. Thereby, the porous Si layer was broken to allow the wafer to separate into two sheets with the porous Si layers exposed.
The porous Si on the second Si substrate was etched selectively with an etching solution of HF/HNO 2 /CH 3 COOH type. Thereby the porous Si was etched selectively and removed completely. The etching rate of the nonporous monocrystalline Si was extremely low, so that the thickness decrease of the nonporous layer by etching was practicably negligible.
Consequently, a monocrystalline Si layer was formed in a thickness of 1 μm on the Si oxide film. The monocrystalline Si layers did not change at all by the selective etching of the porous Si layer.
The cross-section of the Si layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the Si layer and the excellent crystallinity was retained. A plurality of semiconductor substrates having a semiconductor layer of high quality were prepared by repeating the above process in the same manner as in Example 1.
EXAMPLE 7
A first monocrystalline (100) Si substrate of P-type or N-type having a diameter of 6 inches, a thickness of 625 μ, and a specific resistance of 0.01 Q·cm was anodized in an HF solution under the anodization conditions below:
______________________________________Current density: 5 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.5 H.sub.5 OH = 1:1:1Time: 12 minutesThickness of porous Si: 10 μmPorosity: 15%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for one hour. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si formed on the substrate, monocrystalline Si was allowed to grow epitaxially in a thickness of 1 gm by CVD under the growth conditions below:
______________________________________Source gas: SiH.sub.2 Cl.sub.2 /H.sub.2Gas flow rate: 0.5/180 l/minGas pressure: 80 TorrTemperature: 950° C.Growth rate: 0.3 μm/min______________________________________
The surface of the formed epitaxial Si layer was thermally oxidized to form SiO 2 layer in a thickness of 100 nm.
On the face of the SiO 2 layer, a separately prepared second Si substrate having a 500-nm thick SiO 2 layer was superposed with the SiO 2 layer inside, and the superposed matter was heat-treated at 900° C. for 2 hours to bond the substrates tightly.
A sufficient pulling force was applied to the resulting bonded wafer in the direction perpendicular to the bonded wafer face in the same manner as in Example 1. Thereby, the porous Si layer was broken to allow the wafer to separate into two sheets with the porous Si layers exposed.
The porous Si layer on the second substrate was ground selectively by utilizing the monocrystalline layer as the stopper. Thereby the porous Si was removed selectively.
Consequently, a monocrystalline Si layer was formed in a thickness of 1 μm on the Si oxide film. The monocrystalline Si layers did not change at all by the selective grinding of the porous Si layer.
The cross-section of the Si layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the Si layer and the excellent crystallinity was retained.
A plurality of semiconductor substrates having a semiconductor layer of high quality were prepared by repeating the above process in the same manner as in Example 1.
EXAMPLE 8
A first monocrystalline (100) Si substrate of P-type or N-type having a diameter of 6 inches, a thickness of 625 μm and a specific resistance of 0.01 Ω·cm was anodized in an HF solution under the anodization conditions below:
______________________________________Current density: 5 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:1:1Time: 12 minutesThickness of porous Si: 10 μmPorosity: 15%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for one hour. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si formed on the substrate, monocrystalline Si was allowed to grow epitaxially in a thickness of 1 μm by CVD under the conditions below:
______________________________________Source gas: SiH.sub.2 Cl.sub.2 /H.sub.2Gas flow rate: 0.5/180 l/minGas pressure: 80 TorrTemperature: 950° C.Growth rate: 0.3 μm/min______________________________________
The surface of the formed epitaxial Si layer was thermally oxidized to form SiO 2 layer in a thickness of 100 nm.
On the face of the SiO 2 layer, a separately prepared second Si substrate having a 500-nm thick SiO 2 layer was superposed with the SiO 2 layer inside, and the superposed matter was heat-treated at 900° C. for 2 hours to bond the substrates tightly.
A supersonic energy was applied to the resulting bonded wafer in a vessel provided with a supersonic oscillator. Thereby, the porous Si layer was broken to allow the wafer to separate into two sheets with the porous Si layers exposed.
The porous Si layer on the second Si substrate was etched selectively with a mixture of 49% hydrofluoric acid with 30% hydrogen peroxide (1:5) with agitation. Thereby the porous Si was etched selectively and removed completely with the monocrystalline Si remaining unetched as an etch-stopping material. The etching rate of the nonporous monocrystalline Si was extremely low, the selection ratio of the etching rate of the porous Si being 105 or higher. Therefore, the decrease in thickness of the nonporous layer by etching was practicably negligible (several tens of Å).
Consequently, a monocrystalline Si layer was formed in a thickness of 1 μm on the Si oxide film. The monocrystalline Si layers did not change at all by the selective etching of the porous Si layer.
The cross-section of the Si layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the Si layer and the excellent crystallinity was retained.
The first monocrystalline Si substrate was used repeatedly for the same use after removal of the porous Si remaining thereon.
EXAMPLE 9
A first monocrystalline (100) Si substrate of P-type or N-type having a diameter of 4 inches, a thickness of 525 μm, and a specific resistance of 0.01 Ω·cm was anodized in an HF solution under the anodization conditions as below:
______________________________________Current density: 7 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:1:1Time: 12 minutesThickness of porous Si: 10 μmPorosity: 15%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for 2 hours. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si, monocrystalline Si was allowed to grow epitaxially in a thickness of 0.5 μm by MBE (molecular beam epitaxy) under the growth conditions below:
______________________________________Temperature: 700° C.Pressure: 1 × 10.sup.-9 TorrGrowth rate: O.1 nm/secTemperature: 950° C.Growth rate: 0.3 μm/min______________________________________
The surface of the epitaxially grown Si layer was thermally oxidized to form an SiO 2 layer of 100 nm thick.
On the face of the SiO 2 layer, was superposed a separately prepared fused quartz substrate, and the superposed matter was heat-treated at 400° C. for 2 hours to bond the substrates.
The end of the porous layer was bared to the edge face of the wafer, and the porous Si is slightly etched. Thereto, a sharp blade like a shaver blade was inserted. Thereby, the porous layer was broken, and the wafer was separated into two sheets with the porous Si layers exposed.
The porous Si layer on the fused quartz substrate was etched selectively in a mixture of buffered hydrofluoric acid and 30% hydrogen peroxide (1:5) with agitation. Thereby the porous Si was etched and removed completely with the monocrystalline Si remaining unetched as an etch-stopping material. The etching rate of the nonporous monocrystalline Si was extremely low, the selection ratio of the etching rate of the porous Si being, 105 or higher. Therefore, the decrease in thickness of the nonporous layer by etching was practicably negligible (several tens of Å).
Consequently, a monocrystalline Si layer was formed in a thickness of 0.5 μm on a fused quartz substrate. The monocrystalline Si layer did not change at all by the selective etching of the porous Si layer.
The cross-section of the Si layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the Si layer and the excellent crystallinity was retained.
The same results were obtained without forming the oxide film of the surface of the epitaxial Si surface. The first monocrystalline Si substrate was used repeatedly for the same use after removal of the remaining porous Si and mirror-polishing of the surface.
EXAMPLE 10
A first monocrystalline (100) Si substrate of P-type or N-type having a polished face on each side and having a diameter of 6 inches, a thickness of 625 μm, and a specific resistance of 0.01 Ω·cm was anodized on both sides in an HF solution under the anodization conditions below:
______________________________________Current density: 5 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:1:1Time: 12 × 2 minutesThickness of porous Si: 10 μum eachPorosity: 15%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for one hour. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si formed on both faces of the substrate, monocrystalline Si was allowed to grow epitaxially in a thickness of 1 μm by CVD (chemical vapor deposition) under the conditions below:
______________________________________Source gas: SiH.sub.2 Cl.sub.2 /H.sub.2Gas flow rate: 0.5/180 l/minGas pressure: 80 TorrTemperature: 950° C.Growth rate: 0.3 μm/min______________________________________
The surfaces of the formed epitaxial Si layers were thermally oxidized to form SiO 2 layers in a thickness of 100 nm.
On each of the faces of the SiO 2 layers, a separately prepared second Si substrate having a 500-nm thick SiO 2 layer was superposed with the SiO 2 layer inside, and the superposed matter was heat-treated at 600° C. for 2 hours to bond the substrates tightly.
The porous layers were bared at the edge face of the wafer, and a liquid such as water was allowed to penetrate into the porous Si. The entire bonded wafer was heated or cooled, whereby the porous Si layers were broken owing to expansion or other causes to allow the wafer to separate into three sheets with the porous Si layers exposed.
The porous Si layers were etched selectively with a mixture of 49% hydrofluoric acid with 30% hydrogen peroxide (1:5) with agitation. Thereby the porous Si was etched selectively and removed completely with the monocrystalline Si remaining unetched as an etch-stopping material. The etching rate of the nonporous monocrystalline Si was extremely low, the selection ratio of the etching rate of the porous Si being 105 or higher. Therefore, the decrease in thickness of the nonporous layer by etching was practicably negligible (several tens of Å).
Consequently, a monocrystalline Si layer was formed in a thickness of 1 μm respectively on the two Si oxide films simultaneously. The monocrystalline Si layers did not change at all by the selective etching of the porous Si layer.
The cross-section of the Si layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the Si layer and the excellent crystallinity was retained.
The same results were obtained without formation of the oxide film on the surface of the epitaxial Si layer.
The first monocrystalline Si substrate was used repeatedly for the same use after removal of the remaining porous Si and flattening of the surface by hydrogen treatment.
EXAMPLE 11
A first monocrystalline (100) Si substrate of P-type or N-type having a diameter of 5 inches, a thickness of 625 μm, and a specific resistance of 0.01 Q·cm was anodized in an HF solution under the anodization conditions below:
______________________________________Current density: 7 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:1:1Time: 4 minutesThickness of porous Si: 3 μmPorosity: 15%______________________________________
The anodization was conducted further under the conditions below:
______________________________________Current density: 30 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:3:2Time: 3 minutesThickness of porous Si: 10 μmPorosity: 45%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for one hour. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si formed on the substrate, monocrystalline Si was allowed to grow epitaxially in a thickness of 0.3 μm by CVD under the conditions below:
______________________________________Source gas: SiH.sub.4Carrier gas: H.sub.2Temperature: 850° C.Pressure: 1 × 10.sup.-2 TorrGrowth rate: 3.3 nm/sec______________________________________
The surface of the formed epitaxial Si layer was thermally oxidized to form a SiO 2 layer in a thickness of 100 nm.
On the face of the SiO 2 layer, a separately prepared second Si substrate having a 500-nm thick SiO 2 layer was superposed with the SiO 2 layer inside, and the superposed matter was heat-treated at 700° C. for 2 hours to bond the substrates tightly.
A force was applied to the first (or second) substrate in a direction parallel to the second (or first) substrate, whereby the porous Si layer was broken by the shear stress to allow the wafer to separate into two sheets with the porous Si layers exposed.
The porous Si layer was etched selectively with an HF/HNO 3 /CH 3 COOH type etching solution. Thereby the porous Si was etched selectively and removed completely. The etching rate of the nonporous monocrystalline Si was extremely low, so that the decrease in thickness of the nonporous layer by etching was practicably negligible.
Consequently, a monocrystalline Si layer was formed in a thickness of 1 μm on the Si oxide layer. The monocrystalline Si layer did not change at all by the selective etching of the porous Si layer.
The cross-section of the Si layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the Si layer and the excellent crystallinity was retained.
The same results were obtained without forming the oxide film on the surface of the epitaxial Si layer surface.
The first monocrystalline Si substrate was used repeatedly for the same use after removal of the remaining porous Si.
EXAMPLE 12
A first monocrystalline (100) Si substrate of P-type or N-type having a diameter of 5 inches, a thickness of 625 μm, and a specific resistance of 0.01 Q·cm was anodized in an HF solution under the anodization conditions below:
______________________________________Current density: 7 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:1:1Time: 4 minutesThickness of porous Si: 3 μmPorosity: 15%______________________________________
The anodization was conducted further under the conditions below:
______________________________________Current density: 30 mA·cm.sup.-2Anodization solution: HF:H.sub.2 O:C.sub.2 H.sub.5 OH = 1:3:2Time: 3 minutesThickness of porous Si: 10 μmPorosity: 45%______________________________________
This substrate was oxidized at 400° C. in an oxygen atmosphere for one hour. Thereby the inner wall of the pores of the porous Si was covered with a thermal oxidation film. On the porous Si formed on the substrate, monocrystalline Si was allowed to grow epitaxially in a thickness of 0.3 μm by CVD under the conditions below:
______________________________________Source gas: SiH.sub.4Carrier gas: H.sub.2Temperature: 850° C.Pressure: 1 × 10.sup.-2 TorrGrowth rate: 3.3 nm/sec______________________________________
The surface of the formed epitaxial Si layer was thermally oxidized to form a SiO 2 layer in a thickness of 100 nm.
On the face of the SiO 2 layer, a separately prepared second Si substrate having a 500-nm thick SiO 2 layer was superposed with the SiO 2 layer inside, and the superposed matter was heat-treated at 700° C. for 2 hours to bond the substrates tightly.
The porous layers were bared at the edge face of the wafer, and the porous Si was etched from the edge face with a selective etching solution, whereby the wafer came to be separated into two sheets.
Further, the porous Si layer on the second Si substrate was etched selectively with an HF/HNO 3 /CH 3 COOH type etching solution. Thereby the porous Si was etched selectively and removed completely. The etching rate of the nonporous monocrystalline Si was extremely low, so that the thickness decrease of the nonporous layer by etching was practicably negligible.
Consequently, a monocrystalline Si layer was formed in a thickness of 1 μm on the Si oxide film. The monocrystalline Si layers did not change at all by the selective etching of the porous Si layer.
The cross-section of the Si layer was observed by transmission electron microscopy, and it was confirmed that no additional crystal defect was formed in the Si layer and the excellent crystallinity was retained.
The same results were obtained without forming the oxide film on the surface of the epitaxial Si layer surface.
The first monocrystalline Si substrate was used repeatedly for the same use after removal of the remaining porous Si. | A process for producing a semiconductor substrate is provided which comprises steps of forming a porous layer on a first substrate, forming a nonporous monocrystalline semiconductor layer on the porous layer of the first substrate, bonding the nonporous monocrystalline layer onto a second substrate, separating the bonded substrates at the porous layer, removing the porous layer on the second substrate, and removing the porous layer constituting the first substrate. | 8 |
BACKGROUND OF THE INVENTION
This invention relates to valves for the control of fluid flow, and in particular, to a new and improved valve especially suited for post-mix dispensing of beverages where a concentrate is mixed with a diluent, typically a syrup with water or soda. A typical post-mix valve of this type is shown in U.S. Pat. No. 3,863,810.
In post-mix dispensing, a "finished" beverage is produced by the mixing of a concentrate and a diluent at the time and point of dispensing. Typically, concentrate and diluent are brought to a valve controlling two flow paths, which valve when activated provides for flow of both concentrate and diluent to a mixing nozzle, with these two streams coming together over the container into which the drink is being dispensed.
Today's post-mix dispensers, such as that shown in the aforementioned patent, provide one or two diluent sources and a plurality of concentrate sources. Carbonated water or soda is provided as a diluent for drink syrups such as Coca-Cola, 7-Up and root beer. Also, plain water may be provided as a diluent for juice concentrates for producing noncarbonated beverages. Both carbonated and non-carbonated drinks can be provided from a dispenser of the conventional type, with one or more of the valves being dedicated to a non-carbonated diluent source and one or more dedicated to a soda source. This arrangement requires a predetermined fixed configuration for the flow paths within the housing of the dispenser and requires specific configuration orders from the customer, more complicated inventories and production control, and often longer lead times in responding to orders.
One of the objects of the present invention is to provide a solution to this problem. More specifically, it is an object to provide a new and improved valve having two inlet ports for flow control to an outlet port, with the valve being readily changed to permit flow only from the first inlet port or only from the second inlet port.
Valves used for flow control, such as that shown in the aforementioned patent, incorporate a number of sealing elements between the valve spindle and housing to avoid leakage and cross-contamination between adjacent flow streams. Common forms for such sealing elements are O-rings, packings, and V-seals, which typically are positioned in counterbores, seats and ring-grooves. Providing the locations for the sealing elements often requires additional machining steps during manufacture and additional steps in positioning the sealing elements during assembly. Also, replacement of individual sealing elements in an assembled unit requires disassembly at the sealing element and/or special tooling for accessing the sealing element.
It is an object of the present invention to provide a solution to this troublesome problem and more specifically, it is an object to provide a valve with a removeable seal cartridge slidingly insertable into the valve bore, with the valve spindle carried in the seal cartridge. It is another object of the invention to provide such a seal cartridge which can be integrally molded or otherwise produced with a plurality of seal rings so that the cartridge with the rings can be inserted into and removed from a bore without requiring disassembly of the valve.
Other objects, advantages, features and results will more fully appear in the course of the following description.
SUMMARY OF THE INVENTION
A valve for control of fluid flow with a valve bore in a housing, a seal cartridge slidingly inserted into the bore and having integrally formed seal rings in sealing engagement with the bore, and a valve spindle carried in the seal cartridge for sealing engagement with the seal rings and moveable between a valve closed position and a valve open position for controlling flow of fluid between inlet and outlet ports of the housing. A seal cartridge formed as a unit with spaced seal rings for ready insertion into and removal from the valve bore as a single unit. A valve with a valve bore having two inlet ports and an outlet port, with the seal cartridge including an inlet port blocking member with the seal cartridge positionable in the bore to selectively locate the blocking member at each of the inlet ports.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an overall view illustrating a beverage dispenser incorporating the presently preferred embodiment of the invention;
FIG. 2 is an enlarged sectional view taken along the line 2--2 of FIG. 1;
FIG. 3 is an enlarged partial sectional view taken along the line 3--3 of FIG. 1;
FIG. 4 is an exploded perspective view illustrating the assembly of the valve of FIG. 3;
FIG. 5 is an enlarged partial sectional view taken along the line 5--5 of FIG. 3;
FIG. 6 is an enlarged partial sectional view taken along the line 6--6 of FIG. 3;
FIG. 7 is a perspective view of an alternative embodiment of seal cartridge;
FIG. 8 is a sectional view through a valve incorporating the seal cartridge of FIG. 7;
FIG. 9 is a perspective view of another alternative embodiment for the seal cartridge; and
FIG. 10 is a sectional view through a valve incorporating the seal cartridge of FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The dispenser as shown in FIG. 1 may be conventional in design and construction, with the exceptions to be discussed below. Dispensers of this type are presently on the market, and one such dispenser is shown in U.S. Pat. No. 3,863,810.
The dispenser includes a housing 10 with a top plate 11 attached by screws 12, a nozzle 13 which may be a push fit onto the housing, and a shroud 14 which may be held in place by the top plate 11. A plurality of fluid sources is connected to the housing by a connector 17 with fluid lines 18 in a flexible hose 19. The valves are positioned within the housing 10 and are operated by push buttons 20, with seven valves incorporated in the specific embodiment illustrated. With this particular unit, five concentrate lines and two diluent lines are provided at the connector 17 and are controlled by seven of the push buttons 20. Of course, one of the valves of the invention may be used alone, and any number of the valves may be used in a dispenser.
In the preferred embodiment illustrated, the housing is a laminated structure of a plurality of plates 21-27 with the lateral or horizontal fluid flow paths formed in the plates by milling, and with the vertical flow paths including the valve bores, formed by drilling. This is a conventional method for production of such housings. In the conventional design, grooves and/or shoulders are provided in the various plates at the valve bores for receiving O-rings as seals. Also in the conventional design, each concentrate source is connected to a different valve bore, and one diluent source is connected to certain bores while the other diluent source is connected to other valve bores. Usually one bore is used for water only and one bore for soda only.
The valve of the present invention differs from the conventional design in two respects; a single valve seal cartridge is utilized for each valve rather than a plurality of separate sealing elements, and two diluent sources are connected to the same valve rather than having only a single diluent source per valve. Having two sources to a single valve provides for ease of switching from one diluent to the other. Flow paths for the diluents are shown in FIG. 2, and the valve construction is shown in FIGS. 3-6.
A cylindrical valve bore 31 is provided in the housing 10 through the plates 21-27. A concentrate flow path is provided by an inlet port 32 and an outlet port 33. A diluent flow path is provided by an inlet port 34 for water and another inlet port 35 for soda, and an outlet port 36. Preferably, an index slot 37 is provided in the plate 21 at the top of the housing adjacent the bore 31.
A seal cartridge 41 is positioned in the bore 31. The seal cartridge is formed as a single unit, typically an elastomer molding, and in the preferred embodiment illustrated, the bore 31 is cylindrical and the seal cartridge 41 slides into and is rotatable in the bore.
As best seen in FIG. 4, the seal cartridge has seal rings 42-46, a bottom 47, and preferably, an index tab 48 at the top. The seal rings 42-45 are joined by spacers 49. The seal rings 45, 46 are joined by a port blocking web 50 with seal ribs 51.
A valve spindle 55 is positioned in the seal cartridge 41. The valve spindle has lands 56, 57, 58, and in the preferred design, a spring 59 is positioned between the bottom 47 of the seal cartridge and the valve land 58, for urging the valve upward to the valve closed position as shown in FIG. 3.
The diluent flow paths in the housing are shown in FIG. 2. The soda line is connected at the path 65 and flows to inlet ports at a number of the bores, including the bore 31 and the bore 66. The water line is connected to the path 67 and flows to a number of bores including the bore 31 and the bore 68. With this arrangement, soda can be provided to any of the bores except 68 and water can be provided to any of the bores except 66. Typically there is no provision for a concentrate at the bores 66, 68.
The selection of soda or water for the bore 31 and other four bores served by both diluent lines is made by positioning the seal cartridge in the bore. As illustrated in FIG. 3, the seal cartridge is inserted with the port blocking web 50, seal rings 45, 46 and seal ribs 51 closing off the soda inlet port 35. This is best accomplished by positioning the index tab 48 in the slot 37 as illustrated. If it is desired to have water as the diluent for this valve, the seal cartridge is raised slightly to move the index tab out of the slot, the cartridge is rotated 180 degrees and pushed down to the operating position. Now the water inlet port 34 is sealed off and the soda inlet port 35 is open.
This repositioning of the seal cartridge does not affect the concentrate flow path. The concentrate inlet and outlet flow paths and the diluent outlet flow paths are conventional in design, with the fluids leaving the housing through the conventional flow paths. The five concentrate outlets from the housing to the nozzle are seen in FIG. 2 at 70, and the diluent outlet at 71.
In operation, a specific beverage is dispensed by pushing the appropriate button 20, thereby moving the corresponding valve spindle 55 downward and compressing the spring 59. When in the normal or valve closed position, the seal ring 43 about the land 57 blocks fluid flow between the inlet port 32 and outlet port 33, and the seal ring 45 and land 58 block fluid flow between inlet port 34 and the outlet port 36, with the seal ring 44 and land 57 preventing mixing of the two fluids and the seal ring 42 preventing leakage outward. Moving the spindle downward and compressing the spring, moves the land 57 out of the seal ring 43 and provides a flow path between the inlet port 32 and the outlet port 33. Also, the land 58 is moved out of the seal ring 45 providing a flow path between the inlet port 34 and the outlet port 36. If the seal cartridge is rotated 180 degrees to the position opposite that shown in FIG. 3, then inlet port 34 is sealed off and the flow path is established between the inlet port 35 and the outlet port 36.
An alternative embodiment of the valve is shown in FIGS. 7 and 8, with a seal cartridge 81 having seal rings 82, 83, 84 joined by spacers 85. The seal cartridge 81 is positioned in a bore in a housing 82, with the bore being a stepped configuration with cylindrical sections 83, 84, 85. A valve spindle 86 is inserted in the seal cartridge, with a spring 87 between the bottom of the spindle and the bottom of the seal cartridge. The spindle has a valve seat 89 which engages the seal ring 83 for closing a flow path between port 91 and port 92. The bore in the housing is closed at the upper end by the seal ring 82 and at the lower end by the seal ring 84 and bottom plate 94.
Another alternative embodiment is shown in FIGS. 9 and 10, with a seal cartridge 101 having seal rings 102, 103, 104, with the seal rings 102, 103 joined by a sleeve 105 and with the seal rings 103, 104 joined by spacers 106.
The seal cartridge 101 is positioned in a two-step bore 109, 110 of a housing 111, with ports 112 and 113. A rotatable spindle 114 with a ball 115 is positioned in the seal cartridge and the bottom of the housing is closed by a plate 116. The valve is shown in the closed position in FIG. 10, and is moved to the open position by rotating the spindle 90 degrees to align the passage 118 in the ball with the ports 112, 113. In this embodiment, the seal ring 102 provides sealing against leakage, with the seal rings 103 and 104 providing the sealing at the ball, and with the seal ring 104 also sealing against leakage between the bottom plate and the housing.
Thus it is seen that the unitary seal cartridge with integral seal rings provides the desired valve sealing operation and also permits insertion and removal of seal rings as a unit, without requiring separate grooves and the like for retaining individual sealing elements. Also, the seal cartridge provides use with a valve having a pair of inlet ports for a single flow path to an outlet port and selection of one of the inlet ports. Of course, the reverse operation can also be used, with the flow in the opposite direction from a single inlet port to a selected one of two outlet ports. While the specification and claims refer to two inlet ports and a single outlet port in a flow path, it will be understood that the reverse operation with a single inlet port and two outlet ports is covered as a part of the invention.
Currently, non-carbonated beverages of juice variety have become more in demand. This demand has created new markets as well as modified traditional markets (corner bars, restaurants, sporting events) and varies widely with popular attitude and geographic location.
The ability to provide a carbonated/non-carbonated option on most dispensing equipment of the hydraulic type, shown in FIG. 1, has been limited. Customers must specify to their distributors who in turn specify to the manufacturer the configuration of carbonated and non-carbonated flavors that are intended to be served. For example: of 8 possible flavors, 5 are to be carbonated and 3 are not. This results in the manufacture of a specific dispenser that has carbonated water rounted to 5 of the flavor valves and non-carbonated water routed to 3 of the flavor valves. Once this is done, the configuration is permanent. There is no practical way to change the configuration to 4 carbonated flavors plus 4 non-carbonated flavors, for example.
This system produces complicated inventories and often requires long lead times to manufacture customer's specific configurations.
The convertible post-mix dispenser was developed to solve the problems of permanent configurations and specialty inventories. The unit provides both carbonated and non-carbonated water to each flavor valve. These two sources are oriented 180° apart from each other in the same plane of delivery. Refer to FIG. 2. A multiple element valve seal cartridge is used which, when installed in one orientation, allows the flow of one diluent while sealing out the other diluent. To switch to the other diluent, the cartridge simply is removed, turned 180°, and reinserted. An indexing tab provides indication of correct orientation.
It should be noted that changing from carbonated to non-carbonated flavors is usually done at the time of installation. However, reconfiguring and servicing the unit is now possible in the field without call for a factory configured head. | A valve for control of fluid flow, the valve including a housing having a valve bore with inlet and outlet ports, a seal cartridge slidingly inserted into the bore and having integrally formed seal rings, in sealing engagement with the bore, and a valve spindle carried in the seal cartridge in sealing engagement with the seal rings with the spindle moveable between valve closed and open positions. A valve having two inlet ports and an outlet port with the seal cartridge being selectively positionable in the housing for controlling flow from a selected one of the inlet ports to the outlet port. | 8 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to an optical communication system in which an optical beam is modulated in accordance with data in a transmitter, and the modulated optical beam is then transmitted to a remote receiver which recovers the data. The invention has particular, but not exclusive, application to a so-called 40G optical communication network at which data is communicated along a data pipe at a rate of 40 Gigabits per second (Gbps) or more.
[0003] 2. The Background Art
[0004] In recent years, the need to increase data rates in optical communication to the benchmark figures of 40 Gbps and 100 Gbps has prompted much research. One problem with increasing data rates is the consequent increase in frequency bandwidth, which is problematic due to increased dispersion in optical fibers and also because an increase in frequency bandwidth requires a greater frequency spacing of data channels in a wavelength division multiplexing (WDM) system.
[0005] The use of optical duobinary modulation, in which a data signal is added to a one-bit delayed version of itself to generate a three level signal, has attracted attention due to its narrow bandwidth in comparison with a binary non-return-to-zero (NRZ) modulated signal. In practice, optical duobinary modulation typically employs a precoder to perform differential encoding in order to prevent error propagation. In order to maintain the bandwidth advantage when using such a precoder, one binary logic level output by the precoder is converted to a low amplitude state of the optical signal while the other binary logic level output by the precoder is converted to high amplitude states of the optical signal having opposite phases. At the receiver, conveniently the low amplitude state is converted to one binary logic value while both the high amplitude states are converted to the other binary logic value to recover the original data signal.
[0006] Other modulation techniques deployed include phase-shift keying (DPSK) and quadrature phase shift keying (QPSK), particularly in differential format. In addition, polarization division multiplexing has been used to further increase the data rates by employing two optical signals at the same frequency but with orthogonal polarizations. Polarization division multiplexing typically requires, however, a complex receiver due to the difficulty in separating the two optical signals at the receiver with acceptable levels of crosstalk.
SUMMARY OF THE INVENTION
[0007] One aspect of the present invention provides for a transmitter in which a pair of optical signals having different frequencies are modulated using a duobinary encoding scheme, and then multiplexed using polarization division multiplexing. Advantageously, the frequency difference between the two signals can be less than the data rate conveyed by each signal, resulting in a narrow spectral bandwidth, while still allowing demultiplexing at a receiver using simple bandpass filters and without the need of any form of polarization tracking.
[0008] Another aspect of the invention provides for a receiver having a wavelength-dependent beam splitter arrangement for splitting a received optical signal into two portions which are each directed to respective detectors. A first spectral component at a first frequency is preferentially split into the first portion, and a second spectral component at a second frequency is preferentially split into the second portion. Advantageously, the frequency difference between the first and second frequencies can be less than the data rate of a detected signal. The receiver does not require any polarization tracking or balancing, and accordingly is straightforward to implement.
[0009] A further aspect of the invention provides a Dense Wavelength Division Multiplexing (DWDM) optical communication system in which a plurality of transmitters generate a modulated optical signal by using polarization division modulation to combine two optical signals at slightly different frequencies, modulated in accordance with a duobinary encoding scheme, to generate respective optical data signals. The optical data signals are combined using wavelength division multiplexing, and transmitted over an optical fibre to a demultiplexer which demultiplexes the optical data signals. Each optical data signal is then split into two portions, and each portion is directed via a respective bandpass filter to a respective detector.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a block diagram showing the main components of an optical communication system forming a preferred embodiment of the invention;
[0011] FIG. 2 is a graph showing the variation of electric field for an optical signal output by a Mach-Zehnder modulator with variation of an applied electrical potential;
[0012] FIG. 3 is a graph showing an exemplary waveform input into a low pass filter forming part of a transmitter of the optical communication system of FIG. 1 ;
[0013] FIG. 4 is a graph showing the waveform output by the low-pass filter in response to the exemplary input waveform illustrated in FIG. 3 ;
[0014] FIG. 5 is a graph showing an exemplary frequency spectrum of the output of a transmitter of the optical communication system illustrated in FIG. 1 ;
[0015] FIG. 6 is a graph showing transmissivity against frequency for a bandpass filter in a receiver forming part of the optical communication system illustrated in FIG. 1 ;
[0016] FIG. 7 is a block diagram showing the main components of a first alternative receiver for the optical communication system illustrated in FIG. 1 ;
[0017] FIG. 8 is a block diagram showing the main components of a second alternative receiver for the optical communication system illustrated in FIG. 1 ; and
[0018] FIG. 9 is a block diagram of a DWDM optical communication system including optical communication in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] Details of the present invention will now be described, including exemplary aspects and embodiments thereof. Referring to the drawings and the following description, like reference numbers are used to identify like or functionally similar elements, and are intended to illustrate major features of exemplary embodiments in a highly simplified diagrammatic manner. Moreover, the drawings are not intended to depict every feature of actual embodiments nor the relative dimensions of the depicted elements, and are not drawn to scale.
[0020] As shown in FIG. 1 , in an optical communication system according to the present invention a transmitter 1 transmits a modulated optical signal through an optical fiber 3 to a receiver 5 . The optical signal is modulated in accordance with first and second data signals which are input to respective precoders 7 a , 7 b of the transmitter 1 . In this embodiment, each data signal conveys data serially at a data rate of 22 Gigabits per second (Gbps). The pair of data signals may be formed from a single data signal at 44 Gbps.
[0021] Each of the precoders 7 performs differential encoding. In particular, in each precoder the input data signal is inverted and then input into one input of an exclusive-OR gate, and the output of the exclusive-OR gate for each clock cycle is input into the other input of the exclusive-OR gate for the following clock cycle. The output of the exclusive-OR gate also forms the output of the precoder 7 .
[0022] The output of each precoder 7 a , 7 b is input to a respective 2V π drive circuit 9 a , 9 b , with each 2V π drive circuit 9 applying control voltages to a corresponding Mach-Zehnder modulator 13 . As those skilled in the art will appreciate, a Mach-Zehnder modulator splits a received coherent optical signal into two light beams which are directed through respective arms of the Mach-Zehnder modulator and then recombined. A variable optical path difference is introduced into one or both of the light paths in order to vary the amplitude of the recombined optical signal.
[0023] In this embodiment, each 2V π , drive circuit 9 has a pair of V π drive circuits, with the output of each V π drive circuit being input, via a respective low-pass filter 11 , to an electrode associated with a respective arm of corresponding Mach-Zehnder modulator (MZM) 13 . One of the V π drive circuits is driven by the output of the corresponding precoder 7 while the other of the V π drive circuits is driven by the inverse of the output of the corresponding precoder 7 so that differential driving is performed. Each Mach-Zehnder modulator 13 is biased at a level where the optical path difference between the two paths is 180°, resulting in a null output as the light travelling down one path destructively interferes with the light travelling down the other path. The 2V π drive circuits 9 are configured such that a potential difference of amplitude V is applied across the electrodes associated with the arms of the MZM 13 , with the polarity of the applied voltage dependent on the binary logic level output by the corresponding precoder 7 . The application of the potential difference V with one polarity results in a maximum amplitude of the recombined optical signal output by the MZM 13 with a first phase while the application of the potential difference V with the other polarity results in a maximum amplitude of the recombined optical signal output by the MZM 13 at a second phase which is 180° out of phase with the first phase. In other words, as illustrated in FIG. 2 , the electric field strengths E of the recombined optical signal output by the MZM 13 when the potential difference V is applied with opposite polarities are of equal amplitude but opposite sign.
[0024] The low-pass filters 11 are configured such that the output of each low-pass filter 11 substantially corresponds to the average of the voltage levels output by the corresponding 2V π drive circuit 9 for the last two data bits. Accordingly, if the output of a V π drive circuit 9 corresponds to a sequence of two different bits, then the voltage output by the low-pass filter is effectively zero, whereas if the two bits are the same then the voltage output by the low pass filter corresponds to the input voltage. This is a conventional way of implementing a duobinary encoding scheme.
[0025] In this embodiment, the low-pass filters 11 are 5 th order Bessel filters which provide a substantially flat group delay up to 13.4 GHz. FIGS. 3 and 4 respectively show an exemplary input to a low-pass filter 11 and the corresponding output of the low-pass filter 11 .
[0026] First and second lasers 15 a , 15 b output coherent light beams which are input to respective ones of the modulators 13 a , 13 b . In this embodiment, the first laser 15 a outputs a coherent optical beam at a first wavelength λ 1 and the second laser 15 b outputs a coherent light beam at a second wavelength λ 2 , with the frequency difference between the two laser equal to 16 GHz. This frequency difference is therefore less than the data rate of one of the data signals. Further, the outputs of the first and second lasers 15 a , 15 b have linear polarizations which are mutually orthogonal to each other. A polarization beam combiner 17 combines the two outputs of the MZMs to form the output signal of the transmitter 1 , and this output signal is coupled into the optical fibre 3 . The different polarization states of the outputs of the MZMs reduces interference between the data of the first and second data signals. FIG. 5 shows the frequency spectrum of an exemplary output of the transmitter 1 . It will be seen that there are two local maxima, which correspond to the wavelengths of the first and second lasers 9 .
[0027] Table 1 illustrates states of the transmitter 1 for an exemplary data string.
[0000]
TABLE 1
States of components of the transmitter
1 for an exemplary data string.
Clock Cycle
−1
0
1
2
3
4
5
Data
0
1
0
1
1
1
Precoder Output
0
1
1
0
0
0
0
Drive Circuit Output
−V
V
V
−V
−V
−V
−V
Low-pass Filter Output
0
V
0
−V
−V
−V
MZM Output
0
E
0
−E
−E
−E
[0028] In table 1 it will be seem that the output of the MZM 13 corresponds to a duobinary encoded version of the data signal in which the binary logic state “1” is represented by an electric field amplitude E at two phases which are 180° out of phase with each other. Accordingly, a spectral component at wavelength λ 1 is modulated in accordance with the first data signal and a spectral component at wavelength λ 2 is modulated in accordance with the second data signal. At the receiver, a data signal can be recovered simply by detecting the amplitude of the electric field strength at the corresponding wavelength.
[0029] Returning to FIG. 1 , after passing through the optical fiber 3 , the signal output by the transmitter 1 is input to the receiver 5 where it is split into two equal portions by a beam splitter 19 . In this embodiment, the beam splitter 19 is wavelength insensitive so that the spectral distributions of each of the split portions are the same. One split portion is input to a first bandpass filter 21 a and the other split portion is input to a second bandpass filter 21 b . The first bandpass filter 21 a is centred at λ 1 while the second bandpass filter 21 b is centred at λ 2 . The first and second bandpass filters 21 a , 21 b both have a 3 dB bandwidth of 16 GHz, so that light transmitted by the first bandpass filter 21 a generally originates from the first laser 15 a and light transmitted by the second bandpass filter 21 b generally originates from the second laser 15 b . FIG. 6 illustrated how the transmissivity of a bandpass filter 21 varies with frequency.
[0030] The light transmitted by the first bandpass filter 21 a is detected by a first detector 23 a to recover the first data signal and the light transmitted by the second bandpass filter 21 b is detected by a second detector 23 b to recover the second data signal.
[0031] It will be appreciated that the light output from each bandpass filter 21 could be amplified using an optical amplifier prior to detection.
[0032] In an embodiment, the components of the transmitter 1 are formed in an integrated optical circuit, and similarly the components of the detector 5 are formed in an integrated optical circuit.
[0033] In the receiver 5 discussed above, the beam splitter 19 and the first and second bandpass filters 21 a , 21 b form a wavelength-dependent beam splitting arrangement. Other forms of wavelength-dependent beam splitting arrangements are possible. For example, as shown in FIG. 7 , in an alternative embodiment a receiver 5 ′ has a wavelength-dependent beam splitter arrangement in the form of an optical de-interleaves 27 which directs a first optical signal predominantly comprising a first spectral component to a first detector 23 a and a second optical signal predominantly comprising a second spectral component to a second detector 23 b . More generally, as shown in FIG. 8 , in an embodiment a receiver 5 ″ has a wavelength-dependent beam splitter arrangement in the form of a wavelength demultiplexer 29 .
[0034] Due to the narrow bandwidths of the transmitted optical signals, transmitters and receivers according to the present invention are well suited to a DWDM optical communication system. In a DWDM, multiple channels at different wavelength are multiplexed into a single fiber communications window, usually the window around 1550 nm to take advantage of the devices available at that wavelength. As shown in FIG. 9 , a plurality of transmitters as described above each output an optical signal having two components centred at slightly different frequencies, with the frequencies used in one transmitter 1 being spaced from the frequencies used in all the other transmitters 1 . The output signals are input to a wavelength multiplexer 31 which combines the output signals, and the combined output signal is transmitted through the optical fiber 3 . Following transmission through the optical fiber 3 , the transmitted signal is demultiplexed by the wavelength demultiplexer 33 to recover the optical signals having two components at slightly different frequencies, and these optical signals are input into respective receivers 5 as described above.
[0035] In the embodiment illustrated in FIG. 1 , two lasers 9 a , 9 b are used having orthogonal linear polarizations. It will be appreciated that differences in the polarization state could be used, for example orthogonal circular polarizations. Alternatively, two lasers emitting light beams having identical polarizations could be used, with the polarization state of one light beam being altered prior to combining with the other light beam in the polarization beam combiner. It will be further appreciated that a single laser can be used to generate two light beams at slightly different frequencies. | An optical communication system having a transmitter in which a pair of optical signals having different frequencies are modulated using a duobinary encoding scheme, and then multiplexed using polarization division multiplexing. Advantageously, the frequency difference between the two signals can be less than the data rate conveyed by each signal, resulting in a narrow spectral bandwidth, while still allowing demultiplexing at a receiver using simple bandpass filters and without the need of any form of polarization tracking. A receiver has a beam splitter for splitting the received optical signal into two portions which are each directed, via respective bandpass filters centred at slightly different frequencies, to respective detectors. Advantageously, the frequency difference between the frequencies at which the bandpass filters are centred can be less than the data rate of a detected signal. The receiver does not require any polarization tracking or balancing, and accordingly is straightforward to implement | 7 |
RELATED APPLICATION INFORMATION
This application is a 371 of International Application PCT/IN2011/000655 filed 22 Sep. 2011 entitled “Integrated Process For The Production Of Oil Bearing Chlorella Variabilis For Lipid Extraction Utilizing By Products Of Jatropha Methyl Ester (JME) Production”, which was published in the English language on 29 Mar. 2012, with International Publication Number WO 2012/038978 A1, and which claims priority from Indian Patent Application 684/DEL/2010 filed 22 Sep. 2010, the content of which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to integrated process for the production of oil bearing Chlorella variabilis for lipid extraction utilizing by-products of Jatropha methyl ester (JME) production from whole seeds of Jatropha.
The present invention further relates to an integrated process for the preparation of chlorella methyl ester (CME) from Jatropha methyl ester (JME) byproducts in a cost effective manner.
The present invention further relates to an alternative method of mixotrophic growth of microalgae (a photoautotroph) on the nutrient (C/N/P) rich waste products of JME.
BACKGROUND OF THE INVENTION
Reference may be made to Journal “Journal of Applied Phycology, 2009, 21: pp 493-507” wherein information available in the literature on Microalgal growth rates, lipid content and lipid productivities for 55 species of microalgae, including 17 Chlorophyta, 11 Bacillariophyta and five Cyanobacteria as well as other taxa is described.
Reference may be made to the Report prepared by Tom Bruton for Sustainable Energy Ireland; 2009 (www.sei.ie/algaereport), There are at least 30,000 known species of microalgae which is a very heterogeneous group and not fully explored. From the vast number of known marine and freshwater species, only handfuls are currently of commercial significance. These include Chlorella, Spirulina and Haematococcus . Of these only Dunaliella is predominantly a marine species. Hence, the need is to explore and exploit the Microalgae from marine ecosystem.
Reference may be made to the Journal by Ito et al. “J. Bioscience & Bioengineering, 2005, 100, pp 260-265” wherein the biochemical production of hydrogen and ethanol from the glycerol-containing wastes discharged after biodiesel manufacturing process is described. It is reported that the biochemical activity is much lower than with pure glycerol due to the presence of high salt content in the wastes.
Reference may be made to the patent WO/2008/083352 entitled “Production of biofuels using algae” describing two stage process for production of biofuels from algae including cultivation of an oil-producing algae by promoting sequential photoautotrophic and heterotrophic growth. They co-cultivate nitrogen fixing cyanobacteria to provide nitrogen as nutrient in first stage and subsequently adding sugar obtained from hydrolysis of starch and cellulose. No specific mention is made of the subject matter of the present application.
Reference may be made to the Journal by A. H. Scragg et at “Enzyme and Microbial Technology 2003, 33, pp 884-889” wherein microalgae such as the Chlorella spp. with a cell size in the range of 3-10 μm ideal for combustion in a diesel engine; the liquid fuel consists of an emulsion of biodiesel (transesterified rapeseed oil), a surfactant and cells of Chlorella vulgaris (biomass slurry) used as an unmodified stationary diesel engine for the supply of electricity is described.
Reference may be made to the review paper by Chen (Trends Biotechnology 1996, 14, 421-426) which describes algal oil production and possibility of microalgae to be cultured in heterotrophic conditions where organic carbons, such as sugars and organic acids, serve as carbon sources.
Reference may be made to the paper by Xiaoling Miao et al (Bioresource Technology 2006, 97, pp 841-846) which describes heterotrophically cultivated Chlorella protothecoides (using 10 g/l glucose and 0.1 g/l glycine) to accumulate as much as 55% of its dry weight as oil, compared to only 14% in cells grown photoautotrophically. This patent utilizes costly as well as edible sugars and amino acids like glucose and glycine respectively.
Reference may be made to the patent US0086937A1 by Hazelbeck et al entitled ‘Photosynthetic oil production in a two-stage reactor’ describing two stage reactor for growth and oil production in algae mixing nutrients which contains phosphorous, sulfur, nitrogen, carbonates, numerous trace element with dissolved CO 2 and constant agitation involving lot of energy inputs.
Reference may be made to the paper by Han Xu et al (Journal of Biotechnology 2006; 126, pp 499-507) which describes heterotrophic growth of C. protothecoides using corn powder hydrolysate having the crude lipid content of 55.2% in 3L medium in 5L biofermenters. A high density heterotrophic culture of C. protothecoides with CPH feeding was established in the 5 L stirred tank biofermenter. Lipid content in the algal cells cultivated in the biofermenter was 46.1%, which was a little lower than that in the Erlenmeyer flasks (55.3%). The cell growth reached maximum value (3.92 g L−1) after 144 h culture with the substrate of CPH, while the maximum value was 3.74 g L−1 with the substrate of glucose in Erlenmeyer flasks containing 300 mL medium at 28±1° C. under continuous shaking (180 rpm) and air flowing in the dark. It indicated that, it was feasible to use CPH as organic carbon to cultivate Chlorella.
Reference may be made to the paper by Fu-Ying Feng et al “Process Biochemistry 2005; 40; 1315-1318” wherein effects of glucose, sodium thiosulphate and a combination of these two compounds in culture medium on growth kinetics and fatty acid production of Chlorella sp. Has been described. Two different concentrations (2.5 mmol and 5.0 mmol) of both components in culture medium were used. They suggest that an appropriate concentration of glucose in combination with sodium thiosulphate can enhance the accumulation of lipids of Chlorella sp. cells.
Reference may be made to the paper by Liang, Yanna et al “Biotechnology Letters 2009; 7; 1043-1049”, which describes autotrophic growth with cellular lipid content (38%), and the lipid productivity was much lower compared with those from heterotrophic growth with acetate, glucose, or glycerol. Optimal cell growth (2 g l−1) and lipid productivity (54 mg/1/day) was attained using glucose at 1% (w/v) whereas higher concentrations of glucose and glycerol were inhibitory.
Reference may be made to the paper by Chih-Hung Hsieh et al “Bioresource Technology 2009, 100(17), pp 3921-3926” which describes Chlorella sp cultivated in various culture modes to assess biomass and lipid productivity. In the batch mode, the biomass concentrations and lipid content of Chlorella sp. cultivated in a medium containing 0.025-0.200 g L −1 urea were 0.464-2.027 g L −1 and 0.661-0.326 g g −1 , respectively. The maximum lipid productivity of 0.124 g L −1 occurred in a medium containing 0.100 g L −1 urea. In the fed-batch cultivation, the highest lipid content was obtained by feeding 0.025 g L −1 of urea during the stationary phase, but the lipid productivity was not significantly increased. However, a semi-continuous process was carried out by harvesting the culture and renewing urea at 0.025 g L −1 each time when the cultivation achieved the early stationary phase. The maximum lipid productivity of 0.139 g d −1 L −1 in the semi-continuous culture was highest in comparison with those in the batch and fed-batch cultivations. Reference may be made to the paper by Mandal et al (Applied Microbiology Biotechnology 2009, 84: 281-291) which describes microalgae such as Scenedesmus obliquus accumulating lipid inside the cell under nitrogen and phosphorous deficient condition. The lipid content increase significantly up to 43% of dry cell weight under N-deficiency.
Reference may be made to the paper by Demirbas “Energy Sources, Part A, 31:163-168, 2009”, which describes comparative lipid profiling of Chlorella protothecoides and Cladophora fracta which contains 29.4% cell dry weight and 14.2% cell dry weight respectively.
Reference may be made to the paper by Cheng et al “Journal of chemical technology & Biotechnology 2009; 84,5; pp 777-781” which describes Chlorella protothecoides utilizing hydrolysate of Jerusalem artichoke tuber ( Helianthus tuberosus L) as carbon source and accumulated lipid in vivo, with lipid content as high as 44% cdw, and a carbon source to lipid conversion ratio of about 25% in a 4-day scale cultivation. The lipids were extracted and then converted into biodiesel by transesterification. Cetane acid methyl ester, linoleic acid methyl ester and oleic acid methyl ester were the dominating components of the biodiesel produced. Unsaturated fatty acids methyl ester constituted over 82% of the total biodiesel content.
Reference may be made to the paper by Bertoldi et al “Grasas Y Aceites 2006; 57 (3) pp 270-274” wherein Lipids, fatty acids composition and carotenoids of Chlorella vulgaris cultivated in industrial and agriculture waste waters, the results “showed that lipid contents did not present” significant difference .The use of hydroponic wastewater as an alternative culture medium for the cultivation of Chlorella vulgaris generates good perspectives for lipid, fatty acid and carotenoid production.
Reference may be made to the paper by Xiufeng Li et al “Biotechnology and Bioengineering 2007, 98(4) pp 764-771”, which describes heterotrophic Chlorella protothecoides focused on scaling up fermentation in bioreactors. through substrate feeding and fermentation process controls, the cell density of C. protothecoides achieved 15.5 gL −1 in 5 L, 12.8 gL −1 in 750 L, and 14.2 gL −1 in 11,000 L bioreactors, respectively. Resulted from heterotrophic metabolism, the lipid content reached 46.1%, 48.7%, and 44.3% of cell dry weight in samples from 5 L, 750 L, and 11,000 L bioreactors, respectively.
Reference may be made to the paper by Wei et al “Journal of Industrial Microbiology Biotechnology DOI 10.1007/s10295-009-0624-x”, which describes heterotrophic growth of Chlorella protothecoides using cassava starch hydrolysate i.e. CSH made by two step enzymatic process evolving amylase and gluco-amylase as the organic carbon source, the highest biomass and the maximum total lipid yield obtained were 15.8 and 4.19 g/L, representing increases of 42.3 and 27.7%, respectively, compared to using glucose as the organic carbon source.
It will be evident from the prior art that no cost-effective process has been disclosed for production of Microalgal biomass from biodiesel co-product streams and even with the use of costly co-nutrients and cumbersome 2-step process. The present invention seeks to overcome all the basic limitations and to evolve a novel, simplified and cost-effective process of producing lipids from the microalgal biomass generated from glycerol co-product stream of methyl ester process starting from Jatropha whole seed capsule. Several associated improvements in the process e.g. best utilization of problematic waste, particularly oil sludge generated during mechanical expelling of oil and still bottom of glycerol distillation process, also form part of the present invention, besides involving fed batch process for initially increasing the biomass productivity and then improving the lipid content i.e. lipid IC productivity.
OBJECTIVE OF THE INVENTION
Main objective of the present invention is to provide integrated process for the production of oil bearing Chlorella variabilis for lipid extraction utilizing by-products of Jatropha methyl ester (JME) production from whole seeds.
Another objective of the present invention is to provide an integrated process for the cost effective preparation of nutrient media for the Mixotrophic growth of Chlorella variabilis from Jatropha methyl ester (JME) by-products obtained from the whole dried fruits of Jatropha.
Another objective of the present invention is to provide an integrated process for the enhancement of lipid productivity through Mixotrophic growth of the microalgae ( Chlorella sp.) in Jatropha methyl ester byproducts for making fatty acid methyl ester.
Another objective of the present invention is to produce Microalgal biodiesel with least energy inputs and almost zero effluent discharge.
Still another object of the present invention is to utilize the crude glycerol after mopping up of methanol as a carbon and nutrient source in growth and production media for microalgal growth and production of oil/lipid in cost-effective manner.
Another object of the present invention is to protect the Chlorella variabilis by adding a UV-specific dye (UV-absorbent) during outdoor mass culture from UV-damages especially in summer of India (40° C.-50° C.) maintaining the viability of the culture.
Another object of the present invention is to utilize the cake obtained after expelling oil from Jatropha seeds as a source of amino acids and other nutrients in the growth medium and thereby to dispense with complex media such as Zarrouk's medium, M4N medium, ASNIII medium and another sugar containing growth medium.
Another object of the present invention is to show that toxic impurities such as phorbol esters and curcin which are indicated to be present in the oil cake do not hamper oil production in the processes of the present invention.
Another object of the present invention is to demonstrate production of lipids with desired quality of fatty acids.
Another object of the present invention is to show that a marine Chlorella variabilis isolate from the Indian coast gives a yield of 20-35% with respect to cell dry weight by inoculating the culture directly into a medium containing the alkaline crude glycerol layer and the hydrolysate derived from deoiled Jatropha cake and without use of any other nutrient/micronutrients and without any other intervention such as sparging, pH adjustment, temperature control, agitation, aeration, etc.
Another object of the present invention is to achieve such lipid production in the simplest and cheapest manner and in the shortest possible time.
SUMMARY OF THE INVENTION
Accordingly, present invention provides an integrated process for the production of oil bearing Chlorella variabilis for lipid extraction utilizing by-products of Jatropha methyl ester (JME) production from whole dried fruits of Jatropha and the said process comprising the steps of:
i. providing deoiled cake having 4-6% (w/w) nitrogen of Jatropha seeds by known method; ii. hydrolysating the deoiled cake as provided in step (i) with hot acidic aqueous solution followed by adjusting pH in the range of 5.5 to 8.5 with alkaline materials to obtain a nitrogen-rich Jatropha oil cake hydrolysate (JOCH); iii. providing 1-5% (w/v) of the crude glycerol containing methanol-depleted glycerol layer (GL7 and GL8) as a growth-cum production medium for marine Chlorella variabilis by known method; iv. inoculating 1-10% (v/v) of the marine Chlorella variabilis seed culture into growth-cum-production medium as provided in step (iii) and 1-10% (v/v) of Jatropha oil cake hydrolysate as prepared in step (ii) and incubating for a period in the range of 7 to 15 days at a pH in the range of 7.0-8.0 at a temperature in the range of 25-40° C. to obtain lipid containing biomass; v. optionally inoculating 1-10% (v/v) of the marine Chlorella variabilis seed culture on the 1 st day of seed culture inoculation with tap water, for initial 4 to 10 days incubation with only seawater or 1:2 diluted seawater in tap water and after 4 th to 10 th day subsequently adding GL7 to obtain lipid containing biomass; vi. optionally inoculating 1-10% (v/v) of the marine Chlorella variabilis seed culture on the 1 st day of seed culture inoculation with tap water, for initial 4 to 10 days incubation with only seawater or 1:2 diluted seawater in tap water and after 4 th to 10 th day subsequently adding GL8 to obtain lipid containing biomass; vii. drying the biomass as obtained in step (iv to vi) in sun or directly using the wet biomass for lipid extraction; viii. extracting the lipid from biomass as obtained in step (vii) by known method.
In an embodiment of the present invention, acid used is selected from H 3 PO 4 /H 2 SO 4 .
In yet another embodiment of the present invention, alkaline material is selected from crude glycerol layer, potassium hydroxide and magnesium hydroxide.
In yet another embodiment of the present invention, 2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole) UV-specific dye is added during outdoor mass to protect from UV damage especially in summer of India (40° C. to 50° C.) maintaining the viability of the culture.
In yet another embodiment of the present invention, methanol-depleted glycerol layer is obtained by mopped up of the ethanol from the glycerol layer by known method.
In yet another embodiment of the present invention, yield of the lipid with respect to cell dry weight were in the range of 20 to 35%.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 represent effect of pH on settling of the Chlorella variabilis and scale up processing of Chlorella . The integrated scheme of the present invention is also shown in FIG. 1 .
FIG. 2 shows GCMS of chlorella fatty acid methyl ester.
DETAILED DESCRIPTION OF THE INVENTION
The biochemical process of photosynthesis provides algae with the ability to convert solar energy into chemical energy through chlorophyll as antenna for trapping the radiation required for building its food. During cell growth, this chemical energy is used to drive synthetic reaction, such as the formation of sugars or the fixation of nitrogen into amino acids for protein synthesis. Excess chemical energy is stored in the form of fats and oils as triglycerides. Therefore, it can be seen that cell growth and triglycerides production compete for the same chemical energy. As a result, the simultaneous rates of growth and oil production are inversely related.
Present invention provides an integrated process for the cost effective preparation of nutrient media for the Mixotrophic growth of Chlorella variabilis from Jatropha methyl ester (biodiesel) by-products obtained from the whole dried fruits of Jatropha and the said process comprising the following steps:
a. mechanically deshelling the sun-dried fruits and collecting separately the shells and the seeds; b. mechanically expelling the oil from the seeds by known technique; Deoiled cake is obtained in the prior art [(Ghosh et al US pre-grant publication No is 2006/0080891 A1) (1838/DEL/2009 dated 7 Sep. 2009)]; c. utilizing the small amounts of waste oil generated in (b) above as a binder for briquetting of the seed shells; d. treating a part of the deoiled cake obtained in (b) above with acid to hydrolyse the cake and to obtain a nitrogen-rich hydrolysate; e. utilising the larger part of the methanol-depleted glycerol layer as a lipid production medium for marine Chlorella variabilis and the remaining residues for the production of biodegradable polymer i.e. polyhydroxyalkanoates (PHAs) through marine bacteria MTCC 5345 (as in patent filed 1838/DEL/2009 dated 7 Sep. 2009); f. inoculating 1-10% (v/v) of the marine Chlorella variabilis seed culture into growth-cum-production medium containing 1-5% (w/v) of the crude glycerol of step (1) and 1-10% (v/v) of Jatropha oil cake hydrolysate as prepared in step (d) and incubating for a period in the range of (7-15 days) at a pH of 7.0-8.0 at a temperature in the range of 25-40° C.; g. inoculating 1-10% (v/v) of the marine Chlorella sp. in Jatropha oil cake hydrolysate as above on the 1 st day of seed culture inoculation with tap water, only seawater and 1:2 diluted seawater in tap water for initial (4-10days) incubation and subsequently adding GL7 after 4 th to 10 th day for lipid production. h. inoculating 1-10% (v/v) of the marine Chlorella sp. in Jatropha oil cake hydrolysate as above on the 1 st day of seed culture inoculation with tap water, only seawater and 1:2 diluted seawater in tap water for initial (4-10 days) incubation and subsequently adding GL8 after 4 th to 10 th day for lipid production. i. drying the biomass in sun or directly using the wet biomass for lipid extraction and making biodiesel.
The hydrolysate obtained in step (d) was extracted by treating Jatropha oil cake having 4-6% (w/w) nitrogen, with hot acidic aqueous solution of H 3 PO 4 /H 2 SO 4 and thereafter adjusting pH to 5.5-8.5 with alkaline materials such as crude glycerol layer, potassium hydroxide and magnesium hydroxide to yield salts which have buffering action and contributing to the nutrient value of the hydrolysate instead of as problematic electrolytes which retard the bioconversion process of the prior art.
The methanol has been mopped up from the glycerol layer in the process as described in the Ghosh et al US-patent entitled “An improved process for the preparation of fatty acid methyl ester (Biodiesel) from triglycerides oil through transesterification” pre-grant publication No is 2006/0080891 A1 dated 20 Apr. 2006; and the residues left after a successful cycle, consisting mainly of solids and free liquids that have no value in terms of further distillable solvent/product are considered as a good source of nutrients. production by Microalgal conversion processes of steps (d to i) were carried out with a marine Chlorella variabilis isolate and the lipid yields with respect to cell dry weight were in the range of (20 to 35%).
The above steps may equally apply to a variety of Microalgal spp.
The microalgae was grown in Zarrouk's medium and thereafter, it was inoculated into the production medium containing 1-5% of glycerol still bottom and other essential nutrients and the contents left to incubate under static ambient condition for 7-15 days.
The microalgae was grown in seawater, tap water, seawater and tap water in 1:2 ratio, 1-5% (w/v) of GL8 and other essential nutrients and the contents left to incubate under static and agitated condition (100-300 rpm) for 7-15 days.
The microalgae was grown in only seawater, only tap water, and combination of sea water:tap water 1:2, 1-5% (w/v) of glycerol still bottom (GL7 and GL8 separately) and other essential nutrients and the contents left to incubate under static ambient condition for 7-15 days.
The microalgae were grown in seawater, Tap water and seawater:tap water 1:2, 1-10% (w/v) JOCH with other micronutrients for 7-15 days under static condition.
The microalgae were grown in seawater, tap water, and seawater:tap water 1:2, 1-5% (w/v) GL7 with other micronutrients for 7-15 days under static condition.
The microalgae were grown in seawater, tap water and seawater:tap water 1:2, 1-5% (w/v) GL8 with other micronutrients for 7-15 days under static condition.
The microalgae was grown in seawater, tap water, and seawater:tap water 1:2 with mixture of Jatropha deoiled cake hydrolysate (JOCH) 1-10% and glycerol still bottom 1-5% w/v in seawater, tap water and 1:2 ratio mixer of sea water and tap water with other essential nutrients and the contents left to incubate under static ambient condition for 7-15 days.
The microalgae were grown in sea water, tap water and sea water:tap water 1:2 initially with 1-10% (v/v) of Jatropha oil cake Hydrolysate (JOCH) subsequently adding GL7 after 4 th and 10th day under static condition for 15 days.
The lipid was extracted by known method. (ref Bligh, E. G. and Dyer, W. J. 1959. A rapid method for total lipid extraction and purification. Can. J. Biochem. Physiol. 37:911-917.) The fatty acid profile shows the applicability of the lipid in making biodiesel.
The aim of the present invention is to develop an integrated process for the production of Microalgal biomass utilizing Jatropha methyl ester co-products. With regards to the deoiled Jatropha cake and crude glycerol layer, the question arises as to what is the highest level of simplification possible in its effective use. As disclosed in the present invention, if the excess methanol in the glycerol layer can be removed by simple means, then the rest of the mass can be utilized directly for preparation of lipids in microalgae by simple and cost effective means. Once the methanol is mopped up as in the prior art (Ghosh et al, US pre-grant publication No is 2006/0080891 A1) (1838/DEL/2009 dated 7 Sep. 2009) the glycerol layer is demonstrated to be an excellent source of nutrient for efficient and cost-effective production of lipids by a marine Chlorella culture isolated in the course of the invention. The hydrolysate produced from Jatropha deoiled cake obtained through reactive extraction with hot phosphoric acid/sulphuric acid is shown to be an ideal complementary partner to the crude glycerol, the two in tandem providing the nutrients required for the lipid production by the marine Chlorella culture under ambient conditions. The two together also help to neutralize (acid-base) each other to some extent thereby driving down the cost of neutralization. There are several additional inventions such as merging the normal 2-stages operation process into a single step, dispensing altogether with all nutrients/micronutrients by deriving the essential phosphate buffers and essential elements from the hydrolysate and glycerol layer besides carbon and nitrogen. In a decentralized operation, where such a plant will be set up in the vicinity of agricultural fields, the supernatant after recovery of harvestable biomass can be discharged directly into the field for soil fertigation or can even be used as a foliar spray, besides recycling in the Microalgal mass cultivation (outdoors).
It is further demonstrated that the still bottom remaining after glycerol recovery is an equally effective nutrient and promoter for the lipid production by a marine Microalgal culture, the efficiency of production being nearly twofold higher than with pure glycerol. Thus, the problematic waste is found to be an ideal source of nutrients.
All of these inventions taken together lead to an improved integrated process of production of methyl ester from sun dried whole seed capsules of Jatropha curcas with gainful utilization of co-product streams.
The strain used in this invention was isolated from west coast of India (located between N 20° 41.341′ latitude and E 70° 53.734′ longitude).
The deposit of the biological material used in the invention that is CHLORELLA VARIABILIS has been made at ATCC, USA in accordance with the provisions of the Budapest treaty.
However, till date the applicants were unable to obtain the deposit number in respect thereof. The deposit number of the strain will be furnished as soon as we obtain it from the ATCC, USA.
The Chlorella species used for the purposes of the present invention bears. 98% similarity with the already reported Chlorella strains. It was observed that the strain Chlorella variabilis used in the present invention can be interchangeably used with the Chlorella variabilis strain already available at ATCC vide No. 50258 (NC64A).
Inventive Features of the Invention
(i) Isolating robust marine microalgae which enables lipid to be produced from the still bottom in a mixotrophic manner that is more advantageous than under photoautotrophic growth of the microalgae thereby converting a problematic waste into lipid which is a useful raw material for making fatty acid methyl ester (biodiesel).
(ii) Identifying through the process of screening of microalgae a potent isolate which efficiently utilizes the larger volume of crude glycerol layer directly, together with the hydrolysate of Jatropha deoiled cake, as the only nutrients in the process leading to production of lipid (20-40%) with respect to cell dry weight. Further, combining the steps of growth and production undertaken separately in the conventional processes of lipid production into a single operation and thereby simplifying the process. Also dispensing with the need for temperature control after demonstrating tolerance of the process to temperature variations over 30-45° C.
(iii) recognizing that in preparing the hydrolysate of deoiled cake used in the microalgal process, it is advantageous to use phosphoric acid and thereafter to neutralize the acid extract with the alkaline glycerol layer itself—and additional KOH/Mg(OH) 2 as may be required—so that the resultant salts support the lipid productivity instead of thwarting it.
(iv) The microalgae could be grown in sea water, tap water and sea water:tap water 1:2 initially with 1-10% (v/v) of Jatropha oil cake Hydrolysate (JOCH) subsequently adding GL7 after 4 th and 10th day under static condition for 15 days.
(v) Utilizing the small amount of residual biomass of microalgae, which is inevitably generated during the process of mechanical expelling and causes problems of disposal in either aqua feed/poultry feed/cattle feed—, or to produce denser and stronger briquettes from the empty shells as in the prior art (Ghosh et al, US pre-grant publication No is 2006/ 0080891 A1) (1838/DEL/2009 dated 7 Sep. 2009).
Lipids from Jatropha Biodiesel Waste Residues Through Microalgae
Table Inductively coupled Plasma (ICP) results showing
Elemental analysis of GL7 and GL8
Analyte (mg/L)
GL7
GL8
Calcium
3.263
8.189
Cadmium
0.002
0.002
Cobalt
0.000
0.002
Chromium
0.005
0.023
Copper
0.075
0.046
Iron
0.360
0.554
Potassium
48.90
21.63
Magnesium
2.183
3.552
Manganese
0.022
0.040
Molybdenum
0.004
0.004
Sodium
17.21
38.24
Nickel
0.006
0.022
Lead
0.015
0.152
Zinc
0.814
0.131
Biodesel waste residue (BWR3)
content
Base
Biomass
lipid
of lipid
medium
BWR3
BWR6
JOCH
Light
A/S
(gram)
(gram)
(%)
Example 1
200 ml
L
S
0.801
0.13
16.22
ZM
Example 2
200 ml
L
S
0.347
0.0506
14.58
SW
Example 3
200 ml
D
S
0.217
0.0312
14.37
SW
Example 4
200 ml
1%
L
A
0.367
0.054
14.71
SW
Example 5
200 ml
2%
L
A
0.42
0.077
18.33
SW
Example 6
200 ml
1%
L
A
0.387
0.087
22.48
(SW:TW:
1:2)
Example 7
200 ml
2%
L
A
0.453
0.097
21.41
(SW:TW:
1:2)
Example 8
200 ml
1%
L
S
0.447
0.085
19.01
SW
Example 9
200 ml
2%
L
S
0.407
0.074
18.18
SW
Example 10
200 ml
1%
L
S
0.463
0.125
26.99
(SW:TW:
1:2)
Example 11
200 ml
2%
L
S
0.487
0.163
33.47
(SW:TW:
1:2)
Example 12
200 ml
1%
D
S
0.398
0.0863
21.68
(SW:TW:
1:2)
Example 13
200 ml
2%
D
S
0.378
0.0839
22.19
(SW:TW:
1:2)
Example 15a
1000 ml
1%
L
S
3.34
0.18
5.38
TW
Example 15b
1000 ml
2%
L
S
1.9
0.1
5.26
TW
Example 15 c
1000 ml
5%
L
S
1.75
0.09
5.14
TW
Example 15 d
1000 ml
10%
L
S
0.67
0.15
22.38
TW
Example 16a
1000 ml
1%
L
S
2.36
0.24
10.16
TW
Example 16b
1000 ml
2%
L
S
7.15
0.04
0.55
TW
Example 16c
1000 ml
5%
L
S
6.84
0.03
0.43
TW
Example 17a
1000 ml
2%
2%
L
S
2.8
0.2
7.14
TW
Example 17b
1000 ml
2%
5%
L
S
1.75
0.34
19.42
TW
Example 17c
1000 ml
2%
10%
L
S
3.1
0.7
22.58
TW
Example 18a
200 ml
1% (After
1%
L
S
0.62
0.132
21.29
SW
10 Days)
Example 18b
200 ml
1% (after
1%
L
S
0.47
0.103
21.91
(SW:TW:
10 days)
1:2)
Example 18C
200 ml
1%
1%
L
S
0.51
0.101
19.80
SW
Example 18d
200 ml
1%
1%
L
S
0.25
0.0401
16.04
(SW:TW:
1:2)
Example 21a
200 ml
2% BWR-6
1%
L
S
0.441
0.0455
10.31
SW
(after 10
days)
Example 21b
200 ml
2% BWR-6
1%
L
S
0.437
0.048
10.98
(SW:TW:
(after 10
1:2)
days)
Example 21c
200 ml
5% BWR-6
1%
L
S
0.558
0.0785
14.06
SW
(after 10
days)
Example 21d
200 ml
5% BWR-6
1%
L
S
0.454
0.1505
33.14
(SW:TW:
(after 10
1:2)
days)
Example 22a
200 ml
2% BWR-6
1%
L
S
0.344
0.014
4.06
SW
(After 4
Days)
Example 22 b
200 ml
2% BWR-6
1%
L
S
0.302
0.019
6.29
(SW:TW:
(After 4
1:2)
Days)
Example 22c
200 ml
5% BWR-6
1%
L
S
0.3785
0.0524
13.84
SW
(After 4
Days)
example 22d
200 ml
5% BWR-6
1%
L
S
0.2635
0.0217
8.23
(SW:TW:
(After 4
1:2)
Days)
Example 23
100 L
L
S
401.21
97.29
24.24
Zarrouk's
medium
(1:2 in tap
water)
Example 24
100 L TW
2%
L
S
380.12
90.53
23.81
Example 25
100
2%
L
S
440.01
150.61
34.22
L(Sw:TW:
1:2
EXAMPLES
The following examples are given by way of illustration and therefore should not be construed to limit the scope of the present invention.
Example 1
Chlorella sp was found to be one of the most efficient algae and has been used in the present invention. 200 ml of Zarrouk's medium was prepared comprising 16.8 gram Sodium bicarbonate, 0.5 g di-Potassium hydrogen phosphate, 2.5 gram Sodium nitrate, 0.2 g Magnesium sulphate, 1.0 gram Sodium chloride, 0.01 gram Ferrous sulphate, 1.0 g potassium sulphate, 0.04 gram Calcium Chloride and 0.08 g EDTA dissolved in one liter of distilled water. The medium was then autoclaved at 121° C. for 20 minutes. The medium is inoculated With 20% of Chlorella culture (OD 1.4-1.6 at 540 nm) Flask was kept in static condition at 30° C. Optical density of culture was monitored at regular interval of 3 days. After 21 days, the cells were harvested by centrifuging and the pellet obtained was oven dried at 60° C. to get cell dry weight of 0.801 g having lipid content of 0.13 g and 16.22% cell dry weight.
Example 2
Chlorella variabilis was grown in 200 ml of sea water in static condition under light incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C. and cell pellet was washed twice with distilled water and dried in oven (60° C.) for 16 hr. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. Biomass obtained was 0.347 g having lipid content of 0.0506 gram, and 14.58% cell dry weight.
Example 3
Chlorella variabilis was grown in sea water in static condition under dark. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 28° C. and cell pellet was washed twice with distilled water and dried in oven at 60° C. for 16 h. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total Lipid was obtained. Biomass obtained was 0.217 g having lipid content of 0.0312 g, and 14.37% cell dry weight.
Example 4
Chlorella variabilis was grown in sea water with 1% of Jatropha biodiesel waste residues (GL8/BWR3) in agitated condition incubated under light intensity of 60 μE m −2 s −1 provided by cool-white fluorescent tubes with a dark:light cycle of 12:12 h. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice by distilled water and dried in oven at 60° C. for 16 h. Lipid was extracted from dried mass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. From the dried biomass 0.367 g of Chlorella sp., 0.054 g of lipid content i.e. 14.71% cell dry weight.
Example 5
Chlorella variabilis was grown in sea water with 2% of Jatropha biodiesel waste residues (GL8/BWR3) in agitated condition incubated under light intensity of 60 μE m −2 s −1 provided by cool-white fluorescent tubes with a dark:light cycle of 12:12 h. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 27° C. and cell pellet was washed twice by distilled water and dried in oven at 60° C. for 16 h. Lipid was extracted from dried mass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. From the dried biomass 0.420 g of Chlorella sp., 0.077 g of lipid content i.e. 18.33% cell dry weight.
Example 6
Chlorella variabilis was grown in diluted sea water (1:2 in tap water) with 1% of Jatropha biodiesel waste residues (GL8/BWR3) in agitated condition under light incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 26° C. and cell pellet was washed twice with distilled water and dried in oven at 60° C. for 16 hr. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1); and after evaporation of solvent the total lipid was obtained. Biomass obtained was 0.387 g having lipid content of 0.087 mg, and 22.48% cell dry weight.
Example 7
Chlorella variabilis was grown in diluted sea water (1:2 in tap water) with 2% of Jatropha biodiesel waste residues (GL8/BWR3) in agitated condition under light incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice with distilled water and dried in oven at 60° C. for 16 hr. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total Lipid was obtained. Biomass obtained was 0.453 g having lipid content of 0.097 g, and 21.41% cell dry weight.
Example 8
Chlorella variabilis was grown in sea water with 1% of Jatropha biodiesel waste residues (GL8/BWR3) in static condition under light incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice with distilled water and dried in oven at 60° C. for 16 hr. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. Biomass obtained was 0.447 g having lipid content of 0.085 g, and 19.01% cell dry weight.
Example 9
Chlorella variabilis was grown in sea water with 2% of Jatropha biodiesel waste residues (GL8/BWR3) in static condition under light incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice with distilled water and dried in oven at 60° C. for 16 hr. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. Biomass obtained was 0.407 g having lipid content of 0.074 g, and 18.18% cell dry weight.
Example 10
Chlorella variabilis was grown in diluted sea water (1:2 in tap water) with 1% of Jatropha biodiesel waste residues (GL8/BWR3) in static condition under light incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice with distilled water and dried in oven at 60° C. for 16 hr. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. Biomass obtained was 0.463 g having lipid content of 0.125 g, and 26.99% cell dry weight.
Example 11
Chlorella variabilis was grown in diluted sea water (1:2 in tap water) with 2% of Jatropha biodiesel waste residues (GL8/BWR3) in static condition under light incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice with distilled water and dried in oven at 60° C. for 16 hr. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. Biomass obtained was 0.487 g having lipid content of 0.163 g, and 33.47% cell dry weight.
Example 12
Chlorella variabilis was grown in diluted sea water (1:2 in tap water) with 1% of Jatropha biodiesel waste residues (GL8/BWR3) in static condition under dark incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice with distilled water and dried in oven at 60° C. for 16 hr. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. Biomass obtained was 0.398 g having lipid content of 0.0863 g, and 21.68% cell dry weight.
Example 13
Chlorella variabilis was grown in diluted sea water (1:2 in tap water) with 2% of Jatropha biodiesel waste residues (GL8/BWR3) in static condition under dark incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice with distilled water and dried in oven at 60° C. over night. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. Biomass obtained was 0.378 mg having lipid content of 0.0839 g, and 22.19% cell dry weight.
Example 14
The spent glycerol layer, GL 7, was utilized as nutrient source for Microalgal production of lipid. GL7 was utilized directly for accumulation of lipid in Microalgae Chlorella. Jatropha oil cake hydrolysate (JOCH) was extracted by treating Jatropha oil cake, having 4-6% (w/w) N, with hot acidic aqueous solution of H 3 PO 4 /H 2 SO 4 and thereafter adjusting pH suitably with alkaline materials such as crude glycerol layer, potassium hydroxide and magnesium hydroxide to yield salts which have buffering action and also contribute to the nutrient value of the hydrolysate. Isolated microalgae Chlorella variabilis was used for accumulation of lipid inside the cell using the GL-7 and JOCH for growth and production.
Example 15
Chlorella variabilis was grown with 1% JOCH, 2% JOCH, 5% JOCH and 10% JOCH, with tap water to grow up the cells of Chlorella variabilis under static condition with light. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 21 days. After 21 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed two times by distilled water and dried in oven (60° C.) for 16 hr. Lipid was extracted from weighed dried mass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. In the 1% JOCH highest biomass was obtained but % of lipid content is less.
This example teaches us that, for biomass production 1% of JOCH is useful, which can be used for biomass production but not lipid. For lipid accumulation after enhancement of biomass, lipid accumulation can be achieved.
TABLE 1
1% JOCH
2% JOCH
5% JOCH
10% JOCH
Day
Example 15a
Example 15b
Example 15c
Example 15d
Dry biomass
3.34
1.9
1.75
0.67
(gram)
Lipid (gram)
0.18
0.1
0.09
0.15
Yield %
5.38
5.26
5.14
22.38
Example 16
Chlorella variabilis was grown with 1% GL7, 2% GL7, 5% GL7 with tap water to grow the cells of Chlorella variabilis in static condition with light. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 21 days. After 21 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice by distilled water and dried in oven (60° C.) for 16 hr. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. In the 2% GL7 highest biomass was obtained but % of lipid content is less.
TABLE 2
1% GL-7
2% GL-7
5% GL-7
Day
Example 16a
Example 16b
Example 16c
Dry biomass (gram)
2.36
7.15
6.84
Lipid (gram)
0.24
0.04
0.03
Yield %
10.16
0.55
0.43
Example 17
Chlorella variabilis was grown with combination of 2%, 5%, 10% JOCH with 2% GL7 in tap water to grow the cells of Chlorella variabilis in static condition with light. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 21 days. After 21 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice with distilled water and dried in oven (60° C.) for 16 hr. Lipid was extracted from weighed dried mass using Chloroform:Methanol (2:1), and after evaporation of solvent the total Lipid was obtained. In the 2% GL7 and 10% JOCH highest biomass 3.1 gram was obtained with of 22.58% (0.7 gram) lipid content.
TABLE 3
2% GL-7 + 2%
2% GL-7 + 5%
2% GL-7 + 10%
JOCH
JOCH
JOCH
Day
Example 17a
Example 17b
Example 17c
Dry biomass (gram)
2.8
1.75
3.1
Lipid (gram)
0.2
0.34
0.7
Yield %
7.14
19.42
22.58
Example 18
Chlorella variabilis was grown in sea water with different concentration of GL7 & JOCH in 200 ml culture medium at static condition in light incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 2 days. In one set JOCH is added initially (0 day) & GL-7 is added after 10 days of growth and biomass & lipid composition change is observed. After 21 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice by distilled water and dried in oven for 16 hr. Lipid was extracted from weighed dried mass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. Biomass of Chlorella & lipid content was found maximum in media containing 1% JOCH (0 day) and GL7 is added at 10th day in sea water.
TABLE 4
1% JOCH +
1% JOCH +
GL-7 (After
1% GL-7 + 1%
1% GL-7 +
GL-7 (After
10 Days) in
JOCH in
1% JOCH
10 Days)
1:2 diluted sea
sea water
in 1:2 diluted
in sea water
water
Example
sea water
Parameter
Example 18a
Example 18b
18c
Example 18d
Biomass
0.62 gm
0.47 gm
0.51 gm
0.25 gm
(gm)
Lipid (gm)
0.132 gm
0.103 gm
0.101 gm
0.0401 gm
Yield (%)
21.29
21.9
19.80
16.04
Example 19
Protection of Chlorella variabilis from UV-damage through the dye of 2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole) class used in concentration of 0.33% was studied under lab conditions by exposing 50 ml of culture under UV-lamp (30 W) of Laminar air flow for 12 hours kept at a distance of 10 cm and 50 cm from the source of UV-light. The cell damage was quantitatively determined through UV-visible spectrophotometer (OD at 540nm) and UV-fluorescence studies (excitation at 540 nm); UV effect on dry cell mass and lipid content of Chlorella was studied that revealed the following results.
TABLE 5
Dry weight of
Chlorella
lipid
Culture
biomass
content
lipid
Chlorella (UV unexposed)
62
16.4
26.45
Chlorella + dye (UV unexposed)
73.3
16.0
21.82
Chlorella + dye (10 cm UV exposed)
56.8
8.0
14.08
Chlorella (10 cm UV exposed)
51.5
5.1
9.9
Chlorella + dye (50 cm UV exposed)
74.7
15.4
20.6
Chlorella (50 cm UV exposed)
53.8
8.6
15.98
Example 20
Protection of Chlorella variabilis from UV-damage through the dye of 2,5-thiophenediylbis(5-tert-butyl-1,3-benzoxazole) class used in concentration of 0.33% was studied under outdoor cultivation on terrace during peak period of Indian summer conditions especially in Gujarat with following radiation data (table xy an) 100 ml of culture was exposed under the direct sunlight for two days. The total UV radiation was measured in wm-throughout the day using Eppley TUVR (as shown in Figure.) The cell damage was quantitatively determined through UV-visible spectrophotometer (OD at 540 nm) and UV-fluorescence studies (excitation at 540 nm).
TABLE 6
Dry weight of
Chlorella
Lipid
Culture
biomass (mg)
content (mg)
Lipid %
UV untreated Chlorella
135.6
11.1
8.185
UV untreated Chlorella with dye
129.1
13.7
10.611
Chlorella outdoor
163
12.99
7.969
Chlorella + dye outdoor
140
17.4
12.428
Outdoor expriment depicting effect of UV radiations on Chlorella biomass and lipid.
Outdoor experiment depicting effect of UV radiations on Chlorella biomass and lipid.
Example 21
Chlorella variabilis was grown in sea water with different concentration of biodiesel byproduct (BWR 6 & JOCH) with 200 ml culture medium at static condition in light incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 18 days. JOCH is added initially (0 day) & BWR-6 is added after 10 days of growth and biomass & lipid composition change is observed. After 18 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice by distilled water and dried in oven for 16 hr. Lipid was extracted from weighed dried mass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained.
TABLE 7
1% JOCH +
1% JOCH +
1% JOCH +
1% JOCH +
2% BWR-6
2% BWR-6
5% BWR-6
5% BWR-6
(after
(after 10 days)
(after
(after 10 days)
10 days) in
in 1:2 dil.
10 days)
in 1:2 dil.
sea water
sea water
in sea water
sea water
Parameter
Example 21a
Example 21b
Example 21c
Example 21d
Biomass
0.4410 gm
0.4370 gm
0.5580 gm
0.4540 gm
(gm)
Lipid (gm)
0.0455 gm
0.048 gm
0.0785 gm
0.1505 gm
Yield %
10.31
10.98
14.06
33.14
Example 22
Chlorella variabilis was grown in sea water with different concentration of biodiesel byproduct (BWR 6 & JOCH) with 200 ml culture medium at static condition in light incubation. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 10 days. JOCH is added initially (0 day) & BWR-6 is added after 4 days of growth and biomass & lipid composition change is observed. After 10 days; the cell mass was harvested by centrifugation at 11,000 rpm for 10 min at 30° C., and cell pellet was washed twice by distilled water and dried in oven for 16 hr. Lipid was extracted from weighed dried mass using Chloroform:Methanol (2:1), and after evaporation of solvent the total Lipid was obtained.
TABLE 8
1% JOCH +
1% JOCH +
1% JOCH +
1% JOCH +
2% BWR-6
2% BWR-6
5% BWR-6
5% BWR-6
(After
(After 4 Days)
(After 4
(After 4 Days)
4 Days) in
in 1:2 diluted
Days) in
in 1:2 diluted
sea water
sea water
sea water
sea water
Parameter
Example 22a
Example 22b
Example 22c
Example 22d
Biomass
0.3440 gm
0.3020 gm
0.3785 gm
0.2635 gm
(gm)
Lipid (gm)
0.014 gm
0.019 gm
0.0524 gm
0.0217 gm
Yield %
4.2
6.29
13.8
8.26
Example 23
Chlorella variabilis was grown in diluted Zarrouk's medium (1:2 in tap water) in 100 liter culture medium in open plastic tank (l×b×h 1.47 m×0.74 m·0.22 m) with 10% inoculum of 0.6 OD at 540 nm. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was settled by pH adjustment pH 4.5 using H 3 PO 4 after which the dewatered cells were sundried. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. Biomass obtained was 401.21 gram in 100 liter, having lipid content of 97.29 gram i.e. 24.25% cell dry weight.
Example 24
Chlorella variabilis was grown in 2% BWR-3 in tap water in 100 liter culture medium in open plastic tank (l×b×h 1.47 m×0.74 m·0.22 m) with 10% inoculum of 0.6 OD at 540 nm. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was settled by pH adjustment pH 4.5 using H 3 PO 4 after which the dewatered cells were sundried. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. Biomass obtained was 380:12 gram in 100 liter, having lipid content of 90.53 gram i.e. 23.81% cell dry weight.
Example 25
Chlorella variabilis was grown in 2% BWR-3 in sea water:tap water (1:2) in 100 liter culture medium in open plastic tank (l×b×h 1.47 m×0.74 m·0.22 m) with 10% inoculum of 0.6 OD at 540 nm. Growth rate was measured spectrophotometrically (OD at 540 nm) up to 16 days. After 16 days; the cell mass was settled by pH adjustment pH 4.5 using H 3 PO 4 after which the dewatered cells were sundried. Lipid was extracted from dried biomass using Chloroform:Methanol (2:1), and after evaporation of solvent the total lipid was obtained. Biomass obtained was 440.01 gram in 100 liter, having lipid content of 150.61 gram i.e. 34.23% cell dry weight.
TABLE 9 Percentage of fatty acid in algal oil Sr. No Fatty acid Percentage % 1 Caprylic acid 0.047 2 Myristic acid 0.413 3 Pentadecanoic acid 0.207 4 Palmitoleic acid 13.82 5 Palmitic acid 34.46 6 Heptadecanoic acid 1.38 7 Oleic acid 25.46 8 Steric acid 23.28 9 11-Eicosenoic acid 0.67 10 Behenic acid 0.24
Advantages of the Invention
1. Utilization of co-streams of Jatropha methyl ester for Mixotrophic growth of Microalgae and conversion into lipids in an efficient and cost-effective manner. 2. Protection of the mass culture of Chlorella variabilis from UV-damages by adding a dye and maintaining the biomass productivity. 3. Improvement in the yield and overall lipid productivity by having fed batch system of growing Microalgal culture initially with JOCH in sea water+tap water (1:2) and after few days crude glycerol, both obtained as byproducts during the process of Jatropha biodiesel. | An energy efficient process for the preparation of marine microalgae Chlorella fatty acid methyl ester (CME) from hydrolysate of deoiled cake of Jatropha (JOCH) and crude glycerol co-product stream (GL7 and GL8) along with seawater diluted with tap water (1:2). A small part of the crude glycerol layer in case of JME is processed to recover glycerol for glycerol washing and the otherwise problematic still bottom is utilized for microbial synthesis of PHAs and the rest is utilized for Microalgal conversion of JME byproducts into CME. The remaining part of the methanol-depleted glycerol layer is utilized, along with hydrolysate of the Jatropha deoiled cake (JOCH), for single-stage Microalgal production of lipids by a marine Microalgal isolate ( Chlorella sp.) without the need for any other nutrients. Waste streams from the microalgal processes can be discharged directly into agricultural fields as biofertilizer or recycled back in the mass cultivation. | 8 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a process for making substituted thiazolyl-amino pyridines, which inhibit, regulate and/or modulate tyrosine kinase signal transduction, and may be used to treat tyrosine kinase-dependent diseases and conditions, such as angiogenesis, cancer, tumor growth, atherosclerosis, age related macular degeneration, diabetic retinopathy, inflammatory diseases, and the like in mammals.
[0002] Tyrosine kinases are a class of enzymes that catalyze the transfer of the terminal phosphate of adenosine triphosphate to tyrosine residues in protein substrates. Tyrosine kinases play critical roles in signal transduction for a number of cell functions via substrate phosphorylation. Though the exact mechanisms of signal transduction is still unclear, tyrosine kinases have been shown to be important contributing factors in cell proliferation, carcinogenesis and cell differentiation.
[0003] Tyrosine kinases can be categorized as receptor type or non-receptor type. Receptor type tyrosine kinases have an extracellular, a transmembrane, and an intracellular portion, while non-receptor type tyrosine kinases are wholly intracellular.
[0004] The receptor-type tyrosine kinases are comprised of a large number of transmembrane receptors with diverse biological activity. In fact, about twenty different subfamilies of receptor-type tyrosine kinases have been identified. One tyrosine kinase subfamily, designated the HER subfamily, is comprised of EGFR, HER2, HER3, and HER4. Ligands of this subfamily of receptors include epithileal growth factor, TGF-α, amphiregulin, HB-EGF, betacellulin and heregulin. Another subfamily of these receptor-type tyrosine kinases is the insulin subfamily, which includes INS-R, IGF-IR, and IR-R. The PDGF subfamily includes the PDGF-α and β receptors, CSFIR, c-kit and FLK-II. Then there is the FLK family which is comprised of the kinase insert domain receptor (KDR), fetal liver kinase-1 (FLK-1), fetal liver kinase-4 (FLK-4) and the fms-like tyrosine kinase-1 (flt-1). The PDGF and FLK families are usually considered together due to the similarities of the two groups. For a detailed discussion of the receptor-type tyrosine kinases, see Plowman et al., DN & P 7(6):334-339, 1994, which is hereby incorporated by reference.
[0005] The non-receptor type of tyrosine kinases is also comprised of numerous subfamilies, including Src, Frk, Btk, Csk, Abl, Zap70, Fes/Fps, Fak, Jak, Ack, and LIMK. Each of these subfamilies is further sub-divided into varying receptors. For example, the Src subfamily is one of the largest and includes Src, Yes, Fyn, Lyn, Lck, Blk, Hck, Fgr, and Yrk. The Src subfamily of enzymes has been linked to oncogenesis. For a more detailed discussion of the non-receptor type of tyrosine kinases, see Bolen Oncogene, 8:2025-2031 (1993), which is hereby incorporated by reference.
[0006] Both receptor-type and non-receptor type tyrosine kinases are implicated in cellular signaling pathways leading to numerous pathogenic conditions, including cancer, psoriasis and hyperimmune responses.
[0007] Several receptor-type tyrosine kinases, and the growth factors that bind thereto, have been suggested to play a role in angiogenesis, although some may promote angiogenesis indirectly (Mustonen and Alitalo, J. Cell Biol. 129:895-898, 1995). One such receptor-type tyrosine kinase is fetal liver kinase 1 or FLK-1. The human analog of FLK-1 is the kinase insert domain-containing receptor KDR, which is also known as vascular endothelial cell growth factor receptor 2 or VEGFR-2, since it binds VEGF with high affinity. Finally, the murine version of this receptor has also been called NYK (Oelrichs et al., Oncogene 8(1):11-15, 1993). VEGF and KDR are a ligand-receptor pair that play an important role in the proliferation of vascular endothelial cells, and the formation and sprouting of blood vessels, termed vasculogenesis and angiogenesis, respectively.
[0008] Angiogenesis is characterized by excessive activity of vascular endothelial growth factor (VEGF). VEGF is actually comprised of a family of ligands (Klagsburn and D'Amore, Cytokine & Growth Factor Reviews 7:259-270, 1996). VEGF binds the high affinity membrane-spanning tyrosine kinase receptor KDR and the related fms-like tyrosine kinase-1, also known as Flt-1 or vascular endothelial cell growth factor receptor 1 (VEGFR-1). Cell culture and gene knockout experiments indicate that each receptor contributes to different aspects of angiogenesis. KDR mediates the mitogenic function of VEGF whereas Flt-1 appears to modulate non-mitogenic functions such as those associated with cellular adhesion. Inhibiting KDR thus modulates the level of mitogenic VEGF activity. In fact, tumor growth has been shown to be susceptible to the antiangiogenic effects of VEGF receptor antagonists. (Kim et al., Nature 362, pp. 841-844, 1993).
[0009] Solid tumors can therefore be treated by tyrosine kinase inhibitors since these tumors depend on angiogenesis for the formation of the blood vessels necessary to support their growth. These solid tumors include histiocytic lymphoma, cancers of the brain, genitourinary tract, lymphatic system, stomach, larynx and lung, including lung adenocarcinoma and small cell lung cancer. Additional examples include cancers in which overexpression or activation of Raf-activating oncogenes (e.g., K-ras, erb-B) is observed. Such cancers include pancreatic and breast carcinoma. Accordingly, inhibitors of these tyrosine kinases are useful for the prevention and treatment of proliferative diseases dependent on these enzymes.
[0010] The angiogenic activity of VEGF is not limited to tumors. VEGF accounts for most of the angiogenic activity produced in or near the retina in diabetic retinopathy. This vascular growth in the retina leads to visual degeneration culminating in blindness. Ocular VEGF mRNA and protein are elevated by conditions such as retinal vein occlusion in primates and decreased pO 2 levels in mice that lead to neovascularization. Intraocular injections of anti-VEGF monoclonal antibodies or VEGF receptor immunofusions inhibit ocular neovascularization in both primate and rodent models. Regardless of the cause of induction of VEGF in human diabetic retinopathy, inhibition of ocular VEGF is useful in treating the disease.
[0011] Expression of VEGF is also significantly increased in hypoxic regions of animal and human tumors adjacent to areas of necrosis. VEGF is also upregulated by the expression of the oncogenes ras, raf, src and mutant p53 (all of which are relevant to targeting cancer). Monoclonal anti-VEGF antibodies inhibit the growth of human tumors in nude mice. Although these same tumor cells continue to express VEGF in culture, the antibodies do not diminish their mitotic rate. Thus tumor-derived VEGF does not function as an autocrine mitogenic factor. Therefore, VEGF contributes to tumor growth in vivo by promoting angiogenesis through its paracrine vascular endothelial cell chemotactic and mitogenic activities. These monoclonal antibodies also inhibit the growth of typically less well vascularized human colon cancers in athymic mice and decrease the number of tumors arising from inoculated cells.
[0012] Viral expression of a VEGF-binding construct of Flk-1, Flt-1, the mouse KDR receptor homologue, truncated to eliminate the cytoplasmic tyrosine kinase domains but retaining a membrane anchor, virtually abolishes the growth of a transplantable glioblastoma in mice presumably by the dominant negative mechanism of heterodimer formation with membrane spanning endothelial cell VEGF receptors. Embryonic stem cells, which normally grow as solid tumors in nude mice, do not produce detectable tumors if both VEGF alleles are knocked out. Taken together, these data indicate the role of VEGF in the growth of solid tumors. Inhibition of KDR or Flt-1 is implicated in pathological angiogenesis, and these receptors are useful in the treatment of diseases in which angiogenesis is part of the overall pathology, e.g., inflammation, diabetic retinal vascularization, as well as various forms of cancer since tumor growth is known to be dependent on angiogenesis. (Weidner et al., N. Engl. J. Med., 324, pp. 1-8, 1991).
[0013] A number of compounds have been identified as inhibiting tyrosine kinase signal transduction, in particular as inhibitors of KDR. Several of these KDR inhibitors are characterized by a substituted thiazolyl-amino pyridinyl moiety, such as those illustrated in PCT Publication WO 01/17995.
[0014] Accordingly, a practical, efficient synthesis of substituted thiazolyl-amino pyridines is desirable and is an object of this invention.
SUMMARY OF THE INVENTION
[0015] The present invention relates to a process for preparing substituted substituted thiazolyl-amino pyridines, such as those illustrated in Formula I
[0016] which are capable of inhibiting, modulating and/or regulating signal transduction of both receptor-type and non-receptor type tyrosine kinases.
DETAILED DESCRIPTION OF THE INVENTION
[0017] A first embodiment of the instant invention is a process for preparing substituted thiazolyl-amino pyridines, such as those illustrated by Formula I:
[0018] or a pharmaceutically acceptable salt or stereoisomer thereof, wherein
[0019] R is H, unsubstituted or substituted C 1 -C 10 alkyl or unsubstituted or substituted aryl;
[0020] R 1 is —C(═O)NR 3 H;
[0021] R 2 is
[0022] 1) H,
[0023] 2) OH,
[0024] 3) OC 1 -C 6 alkyl,
[0025] 4) C 1 -C 6 alkyl, or
[0026] 5) halo; and
[0027] R 3 is C 1 -C 6 alkyl;
[0028] which comprises the steps of:
[0029] a) preparing a slurry of a compound of Formula II
[0030] (where R is defined above), a compound of Formula III
[0031] (where X is a halo and R 2 is defined above) and a base in a solvent;
[0032] b) adding a palladium catalyst and a bisphosphine ligand to the slurry to produce a coupling product of Formula IV
[0033] c) adding a piperazine-urea of Formula V
[0034] to the coupling product of Formula IV; and
[0035] d) completing a reductive amination to produce the compound of Formula I.
[0036] A further embodiment of the first embodiment is a process comprising the steps of:
[0037] a) preparing a slurry of a compound of Formula II
[0038] (where R is defined above), a compound of Formula III
[0039] (where X is a halo and R 2 is defined above) and a phosphate in a solvent;
[0040] b) adding Pd 2 (dba) 3 and Xantphos to the slurry to produce a coupling product of Formula IV
[0041] c) adding a piperazine-urea of Formula V
[0042] to the coupling product of Formula IV; and
[0043] d) completing a reductive amination to produce the compound of Formula I.
[0044] Another embodiment of the first embodiment for preparing a compound of Formula I comprises the steps of:
[0045] a) preparing a slurry of a compound of Formula II
[0046] (where R is defined above), a compound of Formula III
[0047] (where X is a halo and R 2 is defined above) and a carbonate in a solvent;
[0048] b) adding Pd 2 (dba) 3 and Xantphos to the slurry to produce a coupling product of Formula IV
[0049] c) adding a piperazine-urea of Formula V
[0050] to the coupling product of Formula IV; and
[0051] d) completing a reductive amination to produce the compound of Formula I.
[0052] A second embodiment of the instant invention is a process for preparing 4-[2-(5-cyano-thiazol-2-ylamino)-pyridin-4-ylmethyl]-piperazine-1-carboxylic acid methylamide which comprises the steps of:
[0053] a) preparing a slurry of 2-chloro-4-formylpyridine, 2-aminothiazole and K 3 PO 4 in toluene;
[0054] b) adding Pd 2 (dba) 3 and Xantphos to the slurry to produce a coupling product;
[0055] c) adding N-methylaminocarbonylpiperazine in DMAc to the coupling product; and
[0056] d) completing a reductive amination by adding Et 3 N, acetic acid and NaBH(OAc) 3 to produce 4-[2-(5-cyano-thiazol-2-ylamino)-pyridin-4-ylmethyl]-piperazine-1-carboxylic acid methylamide.
[0057] In a further embodiment of the second embodiment described above is the process which further comprises the step of adding Pd 2 (dba) 3 and Xantphos to the slurry and heating to a temperature of about 60° C. to about 100° C. to produce a coupling product.
[0058] A third embodiment of the instant invention is the process for preparing a compound of Formula I which comprises the steps of:
[0059] a) preparing a slurry of a compound of Formula II
[0060] (where R is defined above), a compound of Formula III
[0061] (where Z is CN or CO 2 H; X is a halo and R 2 is defined above) and a base in a solvent;
[0062] b) adding a palladium catalyst and a bisphosphine ligand to the slurry to produce a coupling product of Formula IV
[0063] c) reducing the coupling product of Formula IV;
[0064] d) adding a piperazine-urea of Formula V
[0065] to the coupling product of Formula IV; and
[0066] e) completing a reductive amination to produce the compound of Formula I.
[0067] A fourth embodiment of the instant invention is the process for preparing a compound of Formula I which comprises the steps of:
[0068] a) preparing a slurry of a compound of Formula II
[0069] (where R is defined above), a compound of Formula III
[0070] (where X is a halo and R 2 is defined above) and a base in a solvent;
[0071] b) adding a palladium catalyst and a bisphosphine ligand to the slurry to produce a coupling product of Formula IV
[0072] c) halogenating the coupling product of Formula IV;
[0073] d) adding a piperazine-urea of Formula V
[0074] to the coupling product of Formula IV; and
[0075] e) completing a reductive amination to produce the compound of Formula I.
[0076] A fifth embodiment of the instant invention is the process for preparing a compound of Formula I which comprises the steps of:
[0077] a) preparing a slurry of a compound of Formula II
[0078] (where R is defined above), a compound of Formula III
[0079] (where X is a halo and, R and R 2 are defined above) and a base in a solvent;
[0080] b) adding a palladium catalyst and a bisphosphine ligand to the slurry to produce a coupling product of Formula IV
[0081] c) adding a piperazine-urea of Formula V
[0082] to the coupling product of Formula IV; and
[0083] d) completing a reductive amination to produce the compound of Formula I.
[0084] A sixth embodiment of the instant invention is the process for preparing Xantphos comprising the steps of:
[0085] a) adding MTBE, 9,9-dimethylxanthene and TMEDA to produce a solution;
[0086] b) adding s-BuLi to the solution to produce a mixture;
[0087] c) slowly adding Ph 2 PCl to produce a resulting mixture;
[0088] d) aging the resulting mixture and adding more Ph 2 PCl; and
[0089] e) filtering to isolate Xantphos.
[0090] These and other aspects of the invention will be apparent from the teachings contained herein.
[0091] “Tyrosine kinase-dependent diseases or conditions” refers to pathologic conditions that depend on the activity of one or more tyrosine kinases. Tyrosine kinases either directly or indirectly participate in the signal transduction pathways of a variety of cellular activities including proliferation, adhesion and migration, and differentiation. Diseases associated with tyrosine kinase activities include the proliferation of tumor cells, the pathologic neovascularization that supports solid tumor growth, ocular neovascularization (diabetic retinopathy, age-related macular degeneration, and the like) and inflammation (psoriasis, rheumatoid arthritis, and the like).
[0092] The compounds of the present invention may have asymmetric centers, chiral axes, and chiral planes (as described in: E. L. Eliel and S. H. Wilen, Stereochemistry of Carbon Compounds , John Wiley & Sons, New York, 1994, pages 1119-1190), and occur as racemates, racemic mixtures, and as individual diastereomers, with all possible isomers and mixtures thereof, including optical isomers, being included in the present invention. In addition, the compounds disclosed herein may exist as tautomers and both tautomeric forms are intended to be encompassed by the scope of the invention, even though only one tautomeric structure is depicted.
[0093] When any substituent and/or variable occurs more than one time in any constituent, its definition on each occurrence is independent at every other occurrence. Also, combinations of substituents and variables are permissible only if such combinations result in stable compounds. Lines drawn into the ring systems from substituents indicate that the indicated bond may be attached to any of the substitutable ring atoms. If the ring system is polycyclic, it is intended that the bond be attached to any of the suitable carbon atoms on the proximal ring only.
[0094] It is understood that substituents and substitution patterns on the compounds of the instant invention can be selected by one of ordinary skill in the art to provide compounds that are chemically stable and that can be readily synthesized by techniques known in the art, as well as those methods set forth below, from readily available starting materials. If a substituent is itself substituted with more than one group, it is understood that these multiple groups may be on the same carbon or on different carbons, so long as a stable structure results. The phrase “optionally substituted with one or more substituents” should be taken to be equivalent to the phrase “optionally substituted with at least one substituent” and in such cases the preferred embodiment will have from zero to three substituents.
[0095] As used herein, “alkyl” and “alkylene” are intended to include both branched and unbranched, cyclic and acyclic saturated aliphatic hydrocarbon groups having the specified number of carbon atoms. For example, C 1 -C 10 , as in “C 1 -C 10 alkyl” is defined to include groups having 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbons in a linear or branched arrangement and may be cyclic or acyclic. For example, “C 1 -C 10 alkyl” specifically includes methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, i-butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, cyclopropyl, methyl-cyclopropyl, 2,2-dimethyl-cyclobutyl, 2-ethyl-cyclopentyl, cyclohexyl, and so on. In some instances, definitions may appear for the same variable reciting both alkyl and cycloalkyl when a different number of carbons is intended for the respective substituents. The use of both terms in one definition should not be interpreted to mean in another definition that “alkyl” does not encompass “cycloalkyl” when only “alkyl” is used.
[0096] “Alkoxy” represents an alkyl group of indicated number of carbon atoms as defined above attached through an oxygen bridge.
[0097] If no number of carbon atoms is specified, the term “alkenyl” refers to a non-aromatic hydrocarbon radical, which may be branched or unbranched and cyclic or acyclic, containing from 2 to 10 carbon atoms and at least one carbon to carbon double bond. Preferably one carbon to carbon double bond is present, and up to four non-aromatic carbon-carbon double bonds may be present. Thus, “C 2 -C 6 alkenyl” means an alkenyl radical having from 2 to 6 carbon atoms. Alkenyl groups include ethenyl, propenyl, butenyl, 2-methylbutenyl, cyclohexenyl, methylenylcyclohexenyl, and so on.
[0098] The term “alkynyl” refers to a hydrocarbon radical, which may be branched or unbranched and cyclic or acyclic, containing from 2 to 10 carbon atoms and at least one carbon to carbon triple bond. Up to three carbon-carbon triple bonds may be present. Thus, “C 2 -C 6 alkynyl” means an alkynyl radical having from 2 to 6 carbon atoms. Alkynyl groups include ethynyl, propynyl, butynyl, 3-methylbutynyl and so on.
[0099] In certain instances, substituents may be defined with a range of carbons that includes zero, such as (C 0 -C 6 )alkylene-aryl. If aryl is taken to be phenyl, this definition would include phenyl itself as well as —CH 2 Ph, —CH 2 CH 2 Ph, CH(CH 3 ) CH 2 CH(CH 3 )Ph, and so on.
[0100] As used herein, “aryl” is intended to mean phenyl and substituted phenyl, including moieties with a fused benzo group. Examples of such aryl elements include phenyl, naphthyl, tetrahydronaphthyl, indanyl, biphenyl, phenanthryl, anthryl or acenaphthyl. In cases where the aryl substituent is bicyclic, it is understood that attachment is via the phenyl ring. Unless otherwise indicated, “aryl” includes phenyls substituted with one or more substituents.
[0101] The term heteroaryl, as used herein, represents a stable monocyclic or bicyclic ring of up to 7 atoms in each ring, wherein at least one ring is aromatic and contains from 1 to 4 heteroatoms selected from the group consisting of O, N and S. Heteroaryl groups within the scope of this definition include but are not limited to: acridinyl, carbazolyl, cinnolinyl, quinoxalinyl, pyrrazolyl, indolyl, benzotriazolyl, furanyl, thienyl, benzothienyl, benzofuranyl, quinolinyl, isoquinolinyl, oxazolyl, isoxazolyl, indolyl, pyrazinyl, pyridazinyl, pyridinyl, pyrimidinyl, pyrrolyl, tetrahydroquinoline. As with the definition of heterocycle below, “heteroaryl” is also understood to include the N-oxide derivative of any nitrogen-containing heteroaryl. In cases where the heteroaryl substituent is bicyclic and one ring is non-aromatic or contains no heteroatoms, it is understood that attachment is via the aromatic ring or via the heteroatom containing ring, respectively.
[0102] As appreciated by those of skill in the art, “halo” or “halogen” as used herein is intended to include chloro, fluoro, bromo and iodo.
[0103] The term “heterocycle” or “heterocyclyl” as used herein is intended to mean a 5- to 10-membered aromatic or nonaromatic heterocycle containing from 1 to 4 heteroatoms selected from the group consisting of O, N and S, and includes bicyclic groups. “Heterocyclyl” therefore includes the above mentioned heteroaryls, as well as dihydro and tetrathydro analogs thereof. Further examples of “heterocyclyl” include, but are not limited to the following: benzoimidazolyl, benzofuranyl, benzofurazanyl, benzopyrazolyl, benzotriazolyl, benzothiophenyl, benzoxazolyl, carbazolyl, carbolinyl, cinnolinyl, furanyl, imidazolyl, indolinyl, indolyl, indolazinyl, indazolyl, isobenzofuranyl, isoindolyl, isoquinolyl, isothiazolyl, isoxazolyl, naphthpyridinyl, oxadiazolyl, oxazolyl, oxazoline, isoxazoline, oxetanyl, pyranyl, pyrazinyl, pyrazolyl, pyridazinyl, pyridopyridinyl, pyridazinyl, pyridyl, pyrimidyl, pyrrolyl, quinazolinyl, quinolyl, quinoxalinyl, tetrahydropyranyl, tetrazolyl, tetrazolopyridyl, thiadiazolyl, thiazolyl, thienyl, triazolyl, azetidinyl, aziridinyl, 1,4-dioxanyl, hexahydroazepinyl, piperazinyl, piperidinyl, pyrrolidinyl, morpholinyl, thiomorpholinyl, dihydrobenzoimidazolyl, dihydrobenzofuranyl, dihydrobenzothiophenyl, dihydrobenzoxazolyl, dihydrofuranyl, dihydroimidazolyl, dihydroindolyl, dihydroisooxazolyl, dihydroisothiazolyl, dihydrooxadiazolyl, dihydrooxazolyl, dihydropyrazinyl, dihydropyrazolyl, dihydropyridinyl, dihydropyrimidinyl, dihydropyrrolyl, dihydroquinolinyl, dihydrotetrazolyl, dihydrothiadiazolyl, dihydrothiazolyl, dihydrothienyl, dihydrotriazolyl, dihydroazetidinyl, methylenedioxybenzoyl, tetrahydrofuranyl, and tetrahydrothienyl, and N-oxides thereof. Attachment of a heterocyclyl substituent can occur via a carbon atom or via a heteroatom.
[0104] The alkyl, alkylene, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl and heterocyclyl substituents may be unsubstituted or unsubstituted, unless specifically defined otherwise. For example, a (C 1 -C 6 )alkyl may be substituted with one, two or three substituents selected from F, Cl, Br, CF 3 , N 3 , NO 2 , NH 2 , oxo, —OH, —O(C 1 -C 6 alkyl), S(O) 0-2 , (C 1 -C 6 alkyl) S(O) 0-2 -, (C 1 -C 6 alkyl)S(O) 0-2 (C 1 -C 6 alkyl)-, C 3 -C 10 cycloalkyl, C 2 -C 6 alkenyl, C 2 -C 6 alkynyl, —C(O)NH, (C 1 -C 6 alkyl) C(O)NH—, H 2 NC(NH)—, (C 1 -C 6 alkyl)C(O)—, —O(C 1 -C 6 alkyl)CF 3 , (C 1 -C 6 alkyl)OC(O)—, (C 1 -C 6 alkyl)O(C 1 -C 6 alkyl)-, (C 1 -C 6 alkyl)C(O) 2 (C 1 -C 6 alkyl)-, (C 1 -C 6 alkyl)OC(O)NH—, aryl, benzyl, heterocycle, aralkyl, heterocyclylalkyl, halo-aryl, halo-benzyl, halo-heterocycle, cyano-aryl, cyano-benzyl and cyano-heterocycle. In this case, if one substituent is oxo and the other is OH, the following are included in the definition: —(C═O)CH 2 CH(OH)CH 3 , —(C═O)OH, —CH 2 (OH)CH 2 CH(O), and so on.
[0105] In an embodiment of the instant process, compounds of Formulae II and III are added, with a base to a solvent. Preferably, the base is a carbonate or phosphate. A palladium catalyst and a bisphosphine ligand are added to the slurry to produce a coupling product of Formula IV. In a preferred embodiment of the instant invention, the process comprises adding Pd 2 (dba) 3 and Xantphos to the slurry. In a more preferred embodiment, the process further comprises adding Pd 2 (dba) 3 and Xantphos to the slurry and heating to a temperature of about 60° C. to about 100° C. to produce a coupling product. A piperazine-urea of Formula V is added to the coupling product. Then reductive amination is done to produce a compound of Formula I.
[0106] The base compound utilized in the instant invention includes, but is not limited to, phosphates, bicarbonates, carbonates, alkoxides or hydroxides. Preferably, the base is a phosphate or carbonate. Examples of phosphates that may be used in the instant process may include, but are not limited to, cesium phosphate, lithium phosphate, potassium phosphate, sodium phosphate, and the like. Examples of carbonates that be may utilized may include, but are not limited to, cesium carbonate, lithium carbonate, potassium carbonate, sodium carbonate, and the like.
[0107] As used herein, a “solvent” may include, but is not limited to, water, alcohols, unchlorinated or chlorinated hydrocarbons, nitriles, ketones, ethers, polar aprotic solvents or mixtures thereof. Types of alcohols that may be used include, but are not limited to, methanol, ethanol, n-propanol, i-propanol, butanol or an alkoxyethanol. Types of unchlorinated hydrocarbons include, but are not limited to, toluene or xylene. Types of chlorinated hydrocarbons include, but are not limited to, dichloro-methane, chloroform, chlorobenzene or ODCB. Types of nitriles include, but are limited to, acetonitrile, propionitrile, benzonitrile or tolunitrile. Types of ketones include, but are not limited to, acetone, MEK, MIBK and cyclohexanone. Types of ethers include, but are not limited to, diethyl ether, MTBE, THF, DME and DEM. Types of polar aprotic solvents include, but are not limited to, formamide, DMF, DMA, NMP, DMPU, DMSO, and sulfolane. Preferably, the solvent is DMF, DMAc, Toluene, Acetonitirile, or an ether. Most preferably, the solvent is DMF or DMAc.
[0108] Examples of palladium catalysts that may be used in the instant invention include, but are not limited to, Pd 2 (dba) 3 , Pd(dba) 2 , Pd(OAc) 2 ; Pd(PPh 3 ) 4 , PdCl 2 , PdBr 2 , PdF 2 , PdI 2 and the like. More preferably, the palladium catalyst is Pd 2 (dba) 3 or Pd(dba) 2 .
[0109] Types of bisphosphine ligands that may be utilized in the instant invention include, but are not limited to, Xantphos, BINAP, DPPF, DPPP, DPEPhos, and the like. Most preferably, Xantphos is used.
[0110] In embodiments of the instant invention, the process comprises the step of reducing the coupling product of Formula IV. This reduction may be performed using standard techniques, such as those described in Smith, M. B., March, J.; Advanced Organic Chemistry ; Reactions, Mechanisms, and Structures., 5th ed., John Wiley & Sons, New York, 2001.
[0111] In the fourth embodiment of the instant invention, the process comprises the step of halogenating the coupling product of Formula IV. As used herein, “halogenating” may be done by the addition of a halogenating agent in order to attach a halo or halogen to a compound. Halogenating agents may include, but are not limited to Br 2 , NBS, 1,3-dibromo-5,5-dimethylhydantoin, pyr.HBr 3 , NCS, Cl 2 , 1,3-dichloro-5,5-dimethylhydantoin, pyr.HCl 3 , F 2 , 1,3-difluro-5,5-dimethylhydantoin and the like, to a solution or mixture. Most preferably, the instant process comprises the step of brominating the coupling product of Formula IV by adding a “brominating agent”, such as Br 2 , NBS, 1,3-dibromo-5,5-dimethylhydantoin, pyr.HBr 3 , and the like.
[0112] The salts of the compounds prepared by the instant processes include the conventional salts of the compounds, e.g., inorganic or organic acids. For example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, palmoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxybenzoic, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isethionic, trifluoroacetic and the like.
[0113] With respect to compounds which contain an acid moiety, a salt may take the form, for example, —COOM, where M is a negative charge, which is balanced by a counterion, e.g., an alkali metal cation such as sodium or potassium. Other pharmaceutically acceptable counterions may be calcium, magnesium, zinc, ammonium, or alkylammonium cations such as tetramethylammonium, tetrabutylammonium, choline, triethylhydroammonium, meglumine, triethanolhydroammonium and the like.
[0114] Some of the abbreviations that may be used in the description of the chemistry and in the Examples include:
ACN Acetonitrile; Ac 2 O Acetic anhydride; AcOH Acetic acid; AIBN 2,2′-Azobisisobutyronitrile; BINAP 2,2′-Bis(diphenylphosphino)-1,1′ binaphthyl; Bn Benzyl; BOC/Boc tert-Butoxycarbonyl; BSA Bovine Serum Albumin; CAN Ceric Ammonia Nitrate; CBz Carbobenzyloxy; CI Chemical Ionization; DBA dibenzanthracene; DBAD Di-tert-butyl azodicarboxylate; DBU 1,8-Diazabicyclo[5.4.0]undec-7-ene; DCE 1,2-Dichloroethane; DEAD diethylazodicarboxylate; DEM diethoxymethane; DIAD diisopropylazodicarboxylate; DIEA N,N-Diisopropylethylamine; DMAC N,N-dimethylacetamide; DMAP 4-Dimethylaminopyridine; DME 1,2-Dimethoxyethane; DMF N,N-Dimethylformamide; DMPU 1,3-Dimethyl-3,4,5,6-tetrahydro-2-(1H)-pyrimidinone; DMSO Methyl sulfoxide; DPAD dipiperidineazodicarbonyl; DPEPhos 1,1′-(Bisdiphenylphosphino)diphenylether; DPPA Diphenyiphosphoryl azide; DPPF 1,1′-(Bisdiphenylphosphino)ferrocene; DPPP 1,3-(Bisdiphenylphosphino)propane; DTT Dithiothreitol; EDC 1-(3-Dimethylaminopropyl)-3-ethyl- carbodiimide-hydrochloride; EDTA Ethylenediaminetetraacetic acid; ES Electrospray; ESI Electrospray ionization; Et 2 O Diethyl ether; Et 3 N Triethylamine; EtOAc Ethyl acetate; EtOH Ethanol; FAB Fast atom bombardment; HEPES 4-(2-Hydroxyethyl)-1-piperazineethanesulfonic acid; HOAc Acetic acid; HMTA Hexamethylenetetramine; HOBT 1-Hydroxybenzotriazole hydrate; HOOBT 3-Hydroxy-1,2,2-benzotriazin-4(3H)-one; HPLC High-performance liquid chromatography; HRMS High Resolution Mass Spectroscopy; KOtBu Potassium tert-butoxide; LAH Lithium aluminum hydride; LCMS Liquid Chromatography Mass Spectroscopy; MCPBA m-Chloroperoxybenzoic acid; Me Methyl; MEK Methyl ethyl ketone; MeOH Methanol; MIBK Methyl isobutyl ketone; Ms Methanesulfonyl; MS Mass Spectroscopy; MsCl Methanesulfonyl chloride; MsOH methanesulfonic acid; MTBE tert-butyl methyl ether; n-Bu n-butyl; n-Bu 3 P Tri-n-butylphosphine; NaHMDS Sodium bis(trimethylsilyl)amide; NBS N-Bromosuccinimide; NMP N-Methyl pyrrolidinone; ODCB Ortho Dichlorobenzene, or 1,2-dichlorobenzene; Pd(PPh 3 ) 4 Palladium tetrakis(triphenylphosphine); Pd 2 (dba) 2 Tris(dibenzylideneacetone)dipalladium (0) Ph phenyl; PMSF α-Toluenesulfonyl fluoride; Py or pyr Pyridine; PYBOP Benzotnazol-1-yloxytripyrrolidinophosphonium (or PyBOP) hexafluorophosphate; RPLC Reverse Phase Liquid Chromatography; rt (or RT) Room Temperature; t-Bu tert-Butyl; TBAF Tetrabutylammonium fluoride; TBSCl tert-Butyldimethylsilyl chloride; TFA Trifluoroacetic acid; THF Tetrahydrofuran; TIPS Triisopropylsilyl; TMEDA N,N,N′,N′-Tetramethylethylenediamine; TMS Tetramethylsilane; Tr Trityl; TsOH P-Toluenesulfonic acid; Xantphos 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene.
[0115] The use of the process of the instant invention to prepare KDR inhibitors (such as those described in PCT Publ. WO 01/17995) is illustrated in the following schemes, in addition to other standard manipulations that are known in the literature or exemplified in the experimental procedures. These schemes and examples, therefore, are not limited by the compounds listed or by any particular substituents employed for illustrative purposes.
EXAMPLES
[0116] Examples provided are intended to assist in a further understanding of the invention. Particular materials employed, species and conditions are intended to be further illustrative of the invention and not limiting of the reasonable scope thereof.
Example 1
[0117] [0117]
[0118] Bromine (2.88 Kg, 18.0 mole) is added to a solution of 3-methoxyacrylonitrile (1.50 Kg, 18.0 mole, mixture of cis-/trans-isomers) in acetonitrile (3.00 L) at 5-10° C. The mixture is aged for 20 minutes, then pre-cooled water (˜5° C., 12.0 L) is added and vigorous stirred for 1 hour.
[0119] NaOAc.3H 2 O, (2.21 Kg, 16.2 mole, 0.90 equiv.) is added and stirred for 15 minutes and then thiourea (1.51 Kg, 19.80 mole, 1.10 equiv.) is added (endothermic dissolution followed by ˜10-15° C. exotherm in ˜0.5 h). The mixture is aged at 15° C. for 1.5 hour, then more NaOAc.3H 2 O (1.47 Kg, 0.60 equiv.) is added. It is slowly heated to 60° C. in 1 hour and aged for 3 hours at 60° C. then cooled to 10° C.
[0120] NaOH (10 N, 1.13 L, 0.625 equiv.) is added to adjust the pH to 3.8-4.0. After aging for 1 hour, the product is filtered and washed with water (11.5 L). Drying give 1.86 Kg of the crude aminothiazole as a brown solid, (97A %), 80.7% yield.
[0121] The crude product is dissolved into acetone (35 L) at 50° C. and treated with Darco KB-B (380 g) for 2 hours. It is filtered through a Solka-Floc pad and then rinsed with acetone (5 L). The filtrate is concentrated in vacuo to ˜7 L (˜5 L residue acetone). Heptane (10 L) is added in 0.5 hour and the slurry is aged for 1 hour. The product is filtered and the filter cake is washed with 2/1 heptane/acetone (6 L). Drying at rt affords 1.72 Kg of the aminothiazole as a pinkish solid, 75% yield. HPLC conditions: Ace-C8 4.6×250 mm column; linear gradient: 5-80% MeCN in 12 minutes, 0.1% H 3 PO 4 in the aqueous mobile phase; Flow rate: 1.50 ml/min; UV detection at 220 nm.
Example 2
Preparation of 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene, Xantphos
[0122] [0122]
[0123] To a 1L round bottom flask (RBF) are added MTBE (500 mL), 9,9-dimethylxanthene (26.65 g) and TMEDA (30.6 g). After degassing the solution, s-BuLi (155 g, 1.3 M in cyclohexane) is cannulated into a dropping funnel and then slowly added over 30 min while maintaining the batch temperature at 10-20° C. The mixture is then aged for 16 h at room temperature. Ph 2 PCl is added slowly via a dropping funnel while maintain the mildly exothermic reaction at 10-20° C.
[0124] ˜60% of the Ph 2 PCl (30 mL) is added in 0.5 hour. The mixture is aged for 15 minutes before addition of the remaining Ph 2 PCl. After aged for 5.5 h at room temperature, the reaction is quenched with MeOH (2.0 mL). The product is filtered and the slightly yellow solid is washed consecutively with MeOH (200 mL), water (200 mL), MeOH (200 mL) and MTBE (200 mL) and dried to give an off-white solid as product (54.8 g, 77% yield).
Example 2A
Preparation of 9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene, Xantphos
[0125] [0125]
[0126] To a 5L round bottom flask (RBF) are added MTBE (2.5 L), 9,9-dimethylxanthene (131.4 g, 0.60 mole) and TMEDA (155 g, 1.32 mole). After degassing the solution, s-BuLi (1.11 L, 1.3 M in cyclohexane, 1.44 mole) is cannulated into a dropping funnel and then slowly added over 60 min while maintaining the batch temperature at 6-10° C. The mixture is then aged for 14 h at room temperature. Ph 2 PCl is added slowly via a dropping funnel while maintain the mildly exothermic reaction at 10-20° C.
[0127] ˜60% of the Ph 2 PCl (175 mL, 0.93 mole) is added in 0.5 hour. The mixture is aged for 10 minutes before addition of the remaining Ph 2 PCl (120 mL, 0.63 mole). After aged for 5 h at room temperature, the reaction is quenched with MeOH (9.9 mL, 0.24 mole). The product is filtered and the slightly yellow solid is washed consecutively with MTBE (250 mL), MeOH (2×250 mL), water (2×300 mL), MeOH (2×250 mL) and MTBE (250 mL) and dried to give an off-white solid as product (304.2 g, 88% yield).
Example 3
[0128] [0128]
[0129] A slurry of 2-chloro-4-formylpyridine (1.49 Kg, 10.5 mole, 1.05 equiv), 2-aminothiazole (1.27 Kg, 10.0 mole, 1.0 equiv), K 3 PO 4 (2.34 Kg, 11.0 mole, 1.1 equiv) in toluene (20 L) is degassed by two vacuum/nitrogen cycles. Pd 2 (dba) 3 (114.5 g, 0.125 mmol, 2.5 mol % Pd) and Xantphos (159 g, 0.275 mole, 2.75 mol %) are then added and the mixture is degassed by one vacuum/nitrogen cycle followed by bubbling nitrogen through the slurry for 10 minutes. The mixture is heated to 60° C. and degassed water (90 mL, 5.0 mole, 0.5 equiv) was added over 5 minutes. The mixture is then heated to 90° C. and aged for 8 h.
[0130] It is cooled to room temperature and filtered. The filter cake is washed with toluene (20 L) until very little DBA is observed in the wash. DMAc (24 L) is added to the filter cake to dissolve the product. The insoluble is filtered off and washed with more DMAc (6 L). The filtrate is acidified with concentrate HCl (110 mL) to pH 2.7. Water (3 L) is added and the mixture is concentrated at 40-50° C. under vacuum to remove most of the residual toluene by azeotropic distillation. More water (3×1L) is added as the distillation progress.
[0131] The mixture is seeded and then water (13 L) is added at a rate of ˜1.3 L/h. The product is filtered and washed with 5/4 DMAc/water (4.0 L×2), water (4.0 L), acetone (4 L×2), and then oven dried at 40C. under vacuum (100 mmHg) with nitrogen sweep to give 1.92 Kg product (94.5 wt %, 97A %).
Example 4
Preparation of N-benzyl-N′-methylaminocarbonylpiperazine Dihydrate
[0132] [0132]
[0133] To a 50-L 3-neck RBF is added H 2 O (6.0 L) followed by K 2 CO 3 (4.56 Kg) with stirring. It is cooled to 10° C. Acetonitrile (12 L) and methylamine (40 wt % in water, 1.40 Kg) are added and the mixture is cooled to 0-5° C. Phenyl chloroformate (2.59 Kg) is then added as quickly as possible while maintaining the exothermic reaction at <15° C. 1-Benzylpiperazine is added 15 min after addition of phenyl chloroformate and the biphasic mixture is heated to 70° C. After aging for 1 h at 70° C., the reaction mixture was concentrated under vacuum to remove most of the MeCN.
[0134] NaOH (7.5L 5 N NaOH) is added and the mixture is seeded. The suspension is then cooled to rt and aged for 1 hour. The product is filtered and the filter cake is washed with cold NaOH (0.5 N aq, 4 L×2) and then ice-cold water (4 L×2). It is purified by recrystallization from toluene (15 L) to remove any dibenzylpiperazine impurity. NaOH is used to remove phenol. The solubility of the product in water is somewhat high (7 mg/mL) at rt, so iced water is used for the wash.
Example 5
Preparation of N-methylaminocarbonylpiperazine Hydrochloride (2)
[0135] [0135]
[0136] HCl (74 mL 12 N, 0.10 eq) is added to MeOH (7 L) and then piperazine urea 1 (2.69 Kg, 10.0 mol) is added. The mixture is hydrogenated using 5% Pd/C (180 g) under 40 psi of hydrogen pressure at 40° C. for 18 h. Pd/C is slurried in MeOH (1 L) and transferred by vacuum.
[0137] After confirming the completion of the reaction, the mixture is filtered through a pad of Solka-Floc and washed with MeOH (2 L) then IPA (4 L). The colorless solution is concentrated to ˜5-6 L at ca 40° C. under vacuum. IPA (5 L) is added followed by HCl (12 N aq, 0.767 L, 0.92 eq) until the pH of the solution becomes ˜3. The mixture is then concentrated under vacuum and flushed with more IPA (5+5 L) to a final volume of 6 L. KF of the supernatant should be <1 w % water. It is then aged at 15° C. for 5 h.
[0138] The resulting white crystals are filtered and washed with IPA (4 L). It is then dried in a vacuum oven at 40° C. with slow nitrogen sweep to give 1.53 Kg of 2 (99 w %, 95% corrected yield).
Example 6
[0139] [0139]
[0140] To a slurry of the pyridine aldehyde (2.19 Kg, 94.5 w %, 9.00 mole) and the piperazine urea HCl salt (1.79 Kg, 9.90 mmol) in DMAc (13.5 L) is added Et 3 N (1.00 Kg, 9.90 mole) followed by acetic acid (2.16 Kg, 36.0 mole) with cooling (15° C.). After aging for 0.5 h, NaBH(OAc) 3 (2.29 Kg, 10.8 mole) is added in 8 portions (25 minutes/portion).
[0141] The mixture is stirred for 1 hour and the completion of the reaction confirmed by HPLC. Water (6.8 L) is added slowly (14 h) to complete the crystallization. Seed with monohydrate of the free base after ˜1-2 L of water has been added.
[0142] The product is filtered after aging for 3 hours and the filter cake washed with 3/2 DMAc/water (6.7 L), then 1/1 acetone/water (6 L) then acetone (2×4 L). Oven drying at 40 C. with slow nitrogen sweep afforded 2.71 Kg of the crude product. HPLC assay, 95.4 w %, 98.9A %, 80.4% correct yield. KF=2.5 w %.
Assays
[0143] The compounds prepared utilizing the instant invention described in the Examples were tested by the assays described below and were found to have kinase inhibitory activity. Other assays are known in the literature and could be readily performed by those of skill in the art (see, for example, Dhanabal et al., Cancer Res. 59:189-197; Xin et al., J. Biol. Chem. 274:9116-9121; Sheu et al., Anticancer Res. 18:4435-4441; Ausprunk et al., Dev. Biol. 38:237-248; Gimbrone et al., J. Natl. Cancer Inst. 52:413-427; Nicosia et al., In Vitro 18:538-549).
[0144] I. VEGF Receptor Kinase Assay
[0145] VEGF receptor kinase activity is measured by incorporation of radio-labeled phosphate into polyglutamic acid, tyrosine, 4:1 (pEY) substrate. The phosphorylated pEY product is trapped onto a filter membrane and the incorporation of radio-labeled phosphate quantified by scintillation counting.
[0146] Materials
[0147] VEGF Receptor Kinase
[0148] The intracellular tyrosine kinase domains of human KDR (Terman, B. I. et al. Oncogene (1991) vol. 6, pp. 1677-1683.) and Flt-1 (Shibuya, M. et al. Oncogene (1990) vol. 5, pp. 519-524) were cloned as glutathione S-transferase (GST) gene fusion proteins. This was accomplished by cloning the cytoplasmic domain of the KDR kinase as an in frame fusion at the carboxy terminus of the GST gene. Soluble recombinant GST-kinase domain fusion proteins were expressed in Spodoptera frugiperda (Sf21) insect cells (Invitrogen) using a baculovirus expression vector (pAcG2T, Pharmingen).
[0149] The other materials used and their compositions were as follows:
[0150] Lysis buffer: 50 mM Tris pH 7.4, 0.5 M NaCl, 5 mM DTT, 1 mM EDTA, 0.5% triton X-100, 10% glycerol, 10 mg/mL of each leupeptin, pepstatin and aprotinin and 1 mM phenylmethylsulfonyl fluoride (all Sigma).
[0151] Wash buffer: 50 mM Tris pH 7.4, 0.5 M NaCl, 5 mM DTT, 1 mM EDTA, 0.05% triton X-100, 10% glycerol, 10 mg/mL of each leupeptin, pepstatin and aprotinin and 1 mM phenylmethylsulfonyl fluoride.
[0152] Dialysis buffer: 50 mM Tris pH 7.4, 0.5 M NaCl, 5 mM DTT, 1 mM EDTA, 0.05% triton X-100, 50% glycerol, 10 mg/mL of each leupeptin, pepstatin and aprotinin and 1 mM phenylmethylsuflonyl fluoride.
[0153] 10× reaction buffer: 200 mM Tris, pH 7.4, 1.0 M NaCl, 50 mM MnCl 2 , 10 mM DTT and 5 mg/mL bovine serum albumin (Sigma).
[0154] Enzyme dilution buffer: 50 mM Tris, pH 7.4, 0.1 M NaCl, 1 mM DTT, 10% glycerol, 100 mg/mL BSA.
[0155] 10× Substrate: 750 μg/mL poly (glutamic acid, tyrosine; 4:1) (Sigma).
[0156] Stop solution: 30% trichloroacetic acid, 0.2 M sodium pyrophosphate (both Fisher).
[0157] Wash solution: 15% trichloroacetic acid, 0.2 M sodium pyrophosphate.
[0158] Filter plates: Millipore #MAFC NOB, GF/C glass fiber 96 well plate.
[0159] Method
[0160] A. Protein Purification
[0161] 1. Sf21 cells were infected with recombinant virus at a multiplicity of infection of 5 virus particles/cell and grown at 27° C. for 48 hours.
[0162] 2. All steps were performed at 4° C. Infected cells were harvested by centrifugation at 1000× g and lysed at 4° C. for 30 minutes with 1/10 volume of lysis buffer followed by centrifugation at 100,000×g for 1 hour. The supernatant was then passed over a glutathione Sepharose column (Pharmacia) equilibrated in lysis buffer and washed with 5 volumes of the same buffer followed by 5 volumes of wash buffer. Recombinant GST-KDR protein was eluted with wash buffer/10 mM reduced glutathione (Sigma) and dialyzed against dialysis buffer.
[0163] B. VEGF Receptor Kinase Assay
[0164] 1) Add 5 μl of inhibitor or control to the assay in 50% DMSO.
[0165] 2) Add 35 μl of reaction mix containing 5 μl of 10× reaction buffer, 5 μl 25 mM ATP/10 μCi [ 33 P]ATP (Amersham), and 5 μl 10× substrate.
[0166] 3) Start the reaction by the addition of 10 μl of KDR (25 nM) in enzyme dilution buffer.
[0167] 4) Mix and incubate at room temperature for 15 minutes.
[0168] 5) Stop by the addition of 50 μl stop solution.
[0169] 6) Incubate for 15 minutes at 4° C.
[0170] 7) Transfer a 90 μl aliquot to filter plate.
[0171] 8) Aspirate and wash 3 times with wash solution.
[0172] 9) Add 30 μl of scintillation cocktail, seal plate and count in a Wallac Microbeta scintillation counter.
[0173] II. Human Umbilical Vein Endothelial Cell Mitogenesis Assay
[0174] Human umbilical vein endothelial cells (HUVECs) in culture proliferate in response to VEGF treatment and can be used as an assay system to quantify the effects of KDR kinase inhibitors on VEGF stimulation. In the assay described, quiescent HUVEC monolayers are treated with vehicle or test compound 2 hours prior to addition of VEGF or basic fibroblast growth factor (bFGF). The mitogenic response to VEGF or bFGF is determined by measuring the incorporation of [ 3 H] thymidine into cellular DNA.
[0175] Materials
[0176] HUVECs: HUVECs frozen as primary culture isolates are obtained from Clonetics Corp. Cells are maintained in Endothelial Growth Medium (EGM; Clonetics) and are used for mitogenic assays described in passages 3-7 below.
[0177] Culture Plates: NUNCLON 96-well polystyrene tissue culture plates (NUNC #167008).
[0178] Assay Medium: Dulbecco's modification of Eagle's medium containing 1 g/mL glucose (low-glucose DMEM; Mediatech) plus 10% (v/v) fetal bovine serum (Clonetics).
[0179] Test Compounds: Working stocks of test compounds are diluted serially in 100% dimethylsulfoxide (DMSO) to 400-fold greater than their desired final concentrations. Final dilutions to 1× concentration are made directly into Assay Medium immediately prior to addition to cells.
[0180] 10× Growth Factors: Solutions of human VEGF 165 (500 ng/mL; R&D Systems) and bFGF (10 ng/mL; R&D Systems) are prepared in Assay Medium.
[0181] 10× [ 3 H]Thymidine: [Methyl- 3 H]thymidine (20 Ci/mmol; Dupont-NEN) is diluted to 80 μCi/mL in low-glucose DMEM.
[0182] Cell Wash Medium: Hank's balanced salt solution (Mediatech) containing 1 mg/mL bovine serum albumin (Boehringer-Mannheim).
[0183] Cell Lysis Solution: 1 N NaOH, 2% (w/v) Na 2 CO 3 .
[0184] Method
[0185] 1. HUVEC monolayers maintained in EGM are harvested by trypsinization and plated at a density of 4000 cells per 100 μL Assay Medium per well in 96-well plates. Cells are growth-arrested for 24 hours at 37° C. in a humidified atmosphere containing 5% CO 2 .
[0186] [0186] 2 . Growth-arrest medium is replaced by 100 μL Assay Medium containing either vehicle (0.25% [v/v] DMSO) or the desired final concentration of test compound. All determinations are performed in triplicate. Cells are then incubated at 37° C. with 5% CO 2 for 2 hours to allow test compounds to enter cells.
[0187] 3. After the 2-hour pretreatment period, cells are stimulated by addition of 10 μL/well of either Assay Medium, 10× VEGF solution or 10× bFGF solution. Cells are then incubated at 37° C. and 5% CO 2 .
[0188] 4. After 24 hours in the presence of growth factors, 10× [ 3 H]thymidine (10 μL/well) is added.
[0189] 5. Three days after addition of [ 3 H]thymidine, medium is removed by aspiration, and cells are washed twice with Cell Wash Medium (400 μL/well followed by 200 μL/well). The washed, adherent cells are then solubilized by addition of Cell Lysis Solution (100 μL/well) and warming to 37° C. for 30 minutes. Cell lysates are transferred to 7-mL glass scintillation vials containing 150 μL of water. Scintillation cocktail (5 mL/vial) is added, and cell-associated radioactivity is determined by liquid scintillation spectroscopy.
[0190] Based upon the foregoing assays the comopunds of Formula I are inhibitors of VEGF and thus are useful for the inhibition of angiogenesis, such as in the treatment of ocular disease, e.g., diabetic retinopathy and in the treatment of cancers, e.g., solid tumors. The instant compounds inhibit VEGF-stimulated mitogenesis of human vascular endothelial cells in culture with IC 50 values between 0.01-5.0 μM. These compounds may also show selectivity over related tyrosine kinases (e.g., FGFR1 and the Src family; for relationship between Src kinases and VEGFR kinases, see Eliceiri et al., Molecular Cell, Vol. 4, pp. 915-924, December 1999).
[0191] III. FLT-1 Kinase Assay
[0192] Flt-1 was expressed as a GST fusion to the Flt-1 kinase domain and was expressed in baculovirus/insect cells. The following protocol was employed to assay compounds for Flt-1 kinase inhibitory activity:
[0193] 1) Inhibitors were diluted to account for the final dilution in the assay, 1:20.
[0194] 2) The appropriate amount of reaction mix was prepared at room temperature:
[0195] 10× Buffer (20 mM Tris pH 7.4/0.1 M NaCl/1 mM DTT final)
[0196] 0.1M MnCl 2 (5 mM final)
[0197] pEY substrate (75 μg/mL)
[0198] ATP/[ 33 P]ATP (2.5 μM/1 μCi final)
[0199] BSA (500 μg/mL final).
[0200] 3) 5 μL of the diluted inhibitor was added to the reaction mix. (Final volume of 5 μL in 50% DMSO). To the positive control wells, blank DMSO (50%) was added.
[0201] 4) 35 μL of the reaction mix was added to each well of a 96 well plate.
[0202] 5) Enzyme was diluted into enzyme dilution buffer (kept at 4° C.).
[0203] 6) 10 μL of the diluted enzyme was added to each well and mix (5 nM final). To the negative control wells, 10 μL 0.5 M EDTA was added per well instead (final 100 mM).
[0204] 7) Incubation was then carried out at room temperature for 30 minutes.
[0205] 8) Stopped by the addition of an equal volume (50 μL) of 30% TCA/0.1M Na pyrophosphate.
[0206] 9) Incubation was then carried out for 15 minutes to allow precipitation.
[0207] 10) Transfered to Millipore filter plate.
[0208] 11) Washed 3× with 15% TCA/0.1M Na pyrophosphate (125 μL per wash).
[0209] 12) Allowed to dry under vacuum for 2-3 minutes.
[0210] 13) Dryed in hood for ˜20 minutes.
[0211] 14) Assembled Wallac Millipore adapter and added 50 μL of scintillant to each well and counted.
[0212] IV. FLT-3 Kinase Assay
[0213] Flt-3 was expressed as a GST fusion to the Flt-3 kinase domain, and was expressed in baculovirus/insect cells. The following protocol was employed to assay compounds for Flt-3 kinase inhibitory activity:
[0214] 1) Dilute inhibitors (account for the final dilution into the assay, 1:20)
[0215] 2) Prepare the appropriate amount of reaction mix at room temperature.
[0216] 10× Buffer (20 mM Tris pH 7.4/0.1 M NaCl/1 mM DTT final)
[0217] 0.1M MnCl 2 (5 mM final)
[0218] pEY substrate (75 μg/mL)
[0219] ATP/[ 33 P]ATP (0.5 μM/L μCi final)
[0220] BSA (500 μg/mL final)
[0221] 3) Add 5 μL of the diluted inhibitor to the reaction mix. (Final volume of 5 μL in 50% DMSO). Positive control wells—add blank DMSO (50%).
[0222] 4) Add 35 μL of the reaction mix to each well of a 96 well plate.
[0223] 5) Dilute enzyme into enzyme dilution buffer (keep at 4° C.).
[0224] 6) Add 10 μL of the diluted enzyme to each well and mix (5-10 nM final). Negative control wells—add 10 μL 0.5 M EDTA per well instead (final 100 mM)
[0225] 7) Incubate at room temperature for 60 minutes.
[0226] 8) Stop by the addition of an equal volume (50 μL) of 30% TCA/0.1M Na pyrophosphate.
[0227] 9) Incubate for 15 minutes to allow precipitation.
[0228] 10) Transfer to Millipore filter plate.
[0229] 11) Wash 3× with 15% TCA/0.1M Na pyrophosphate (125 μL per wash).
[0230] 12) Allow to dry under vacuum for 2-3 minutes.
[0231] 13) Dry in hood for ˜20 minutes.
[0232] 14) Assemble Wallac Millipore adapter and add 50 μL of scintillant to each well and count. | The present invention relates to a process for preparing substituted thiazolyl-amino pyridines, which are capable of inhibiting, modulating and/or regulating signal transduction of both receptor-type and non-receptor type tyrosine kinases. | 2 |
RELATED APPLICATIONS
[0001] This application is a divisional application of U.S. patent application Ser. No. 13/339,811, filed Dec. 29, 2011, which claims priority to U.S. Provisional Patent Application Ser. No. 61/428,613, filed Dec. 30, 2010.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The present invention relates generally to the production of renewable fuels. More specifically, the invention concerns the integration of a biomass conversion facility with a conventional refinery to efficiently produce commercial quantities of renewable fuels.
[0004] 2. Description of the Related Art
[0005] With the rising costs and environmental concerns associated with fossil fuels, renewable energy sources have become increasingly important. The development of renewable fuel sources provides a means for reducing the dependence on fossil fuels. Accordingly, many different areas of renewable fuel research are currently being explored and developed.
[0006] With its low cost and wide availability, biomass has increasingly been emphasized as an ideal feedstock in renewable fuel research. Consequently, many different conversion processes have been developed that use biomass as a feedstock to produce useful biofuels and/or specialty chemicals. Existing biomass conversion processes include, for example, combustion, gasification, slow pyrolysis, fast pyrolysis, liquefaction, and enzymatic conversion. One of the useful products that may be derived from the aforementioned biomass conversion processes is a liquid product commonly referred to as “bio-oil.” Bio-oil may be processed into transportation fuels, hydrocarbon chemicals, and/or specialty chemicals.
[0007] Despite recent advancements in biomass conversion processes, many of the existing biomass conversion processes produce low-quality bio-oils that are highly unstable and often contain high amounts of oxygen. These bio-oils require extensive secondary upgrading in order to be utilized as transportation fuels and/or as fuel additives due their instability. Furthermore, the transportation fuels and/or fuel additives derived from bio-oil vary in quality depending on factors affecting the stability of the bio-oil, such as the original oxygen content of the bio-oil.
[0008] Bio-oils can be subjected to various upgrading processes in order to process the bio-oil into renewable fuels and/or fuel additives. However, prior upgrading processes have been relatively inefficient and produce renewable fuels and/or fuel additives that have limited use in today's market. Furthermore, only limited amounts of these bio-oil derived transportation fuels and/or fuel additives may be combinable with petroleum-derived gasoline or diesel.
[0009] Accordingly, there is a need for an improved process and system for using bio-oil to produce renewable fuels.
SUMMARY OF THE INVENTION
[0010] In one embodiment, the present invention is directed to a process for producing a renewable fuel, where the process comprises the steps of (a) providing one or more bio-oils selected from the group consisting of a high-stability bio-oil, an intermediate-stability bio-oil, and a low-stability bio-oil, wherein the high-stability bio-oil has a stability parameter of less than 30 centipoise per hour (cp/h), the intermediate-stability bio-oil has a stability parameter in the range of 30 to 75 cp/h, and the low-stability bio-oil has a stability parameter greater than 75 cp/h; and (b) processing at least one of the bio-oils in a petroleum refinery according to one or more of the following methods: (i) combining at least a portion of the high-stability bio-oil with a first petroleum-derived stream of the petroleum refinery to thereby form a first combined stream, hydrotreating the first combined stream to thereby produce a first hydrotreated stream, and fractionating the first hydrotreated stream; (ii) combining at least a portion of the high-stability bio-oil with a second petroleum-derived stream of the petroleum refinery to thereby form a second combined stream, catalytically cracking the second combined stream to thereby produce a second cracked stream, and fractionating the second cracked stream; (iii) combining at least a portion of the intermediate-stability bio-oil with a third petroleum-derived stream of the petroleum refinery to thereby form a third combined stream, hydrotreating the third combined stream to thereby produce a third hydrotreated stream, catalytically cracking at least a portion of the third hydrotreated stream to thereby produce a third cracked stream, and fractionating the third cracked stream; (iv) combining at least a portion of the intermediate-stability bio-oil with a fourth petroleum-derived stream of the petroleum refinery to thereby form a fourth combined stream, hydrotreating the fourth combined stream to thereby produce a fourth hydrotreated stream, thermally cracking at least a portion of the fourth hydrotreated stream to thereby produce a fourth cracked stream, and fractionating the fourth cracked stream; (v) combining at least a portion of the low-stability bio-oil with a fifth petroleum-derived stream of the petroleum refinery to thereby form a fifth combined stream, thermally cracking at least a portion of the fifth combined stream to thereby produce a fifth cracked stream, and fractionating the fifth cracked stream; and/or (vi) combining at least a portion the low-stability bio-oil with a sixth petroleum-derived stream of the petroleum refinery to thereby form a sixth combined stream, fractionating at least a portion of the sixth combined stream into at least a sixth heavy bio-fraction and a sixth light bio-fraction, hydrotreating at least a portion of the sixth light bio-fraction to thereby produce a sixth hydrotreated bio-fraction, and thermally cracking at least a portion of the sixth heavy bio-fraction to thereby produce a sixth thermally cracked bio-fraction.
[0011] In another embodiment, the present invention is directed to a system for producing renewable fuels, where the system comprises (a) a bio-oil production facility comprising a biomass conversion reactor for converting biomass into bio-oil; (b) a petroleum refinery for refining petroleum products; and (c) an integration system for optionally combining at least a portion of the bio-oil from the bio-oil production facility with one or more petroleum-derived streams in the petroleum refinery for co-processing therewith. In another embodiment, the bio-oil can be co-processed with one or more petroleum-derived streams without first combining the two streams (i.e. charging each stream to the conversion unit as a separate feed). The integration system comprises at least one of a first, second, third, fourth, fifth, and/or sixth integration mechanism for combining at least a portion of the bio-oil with at least one of the petroleum-derived streams. The refinery comprises one or more of the following refining systems: (i) a first hydrotreating unit and a first fractionator, wherein the first hydrotreating unit is located downstream of the first integration mechanism and the first fractionator is located downstream of the first hydrotreating unit; (ii) a second catalytic cracking unit and a second fractionator, wherein the second catalytic cracking unit is located downstream of the second integration mechanism and the second fractionator is located downstream of the second catalytic cracking unit; (iii) a third hydrotreating unit, a third catalytic cracking unit, and a third fractionator, wherein the third hydrotreating unit is located downstream of the third integration mechanism, wherein the third catalytic cracking unit is located downstream of the third hydrotreating unit, wherein the third fractionator is located downstream of the third catalytic cracking unit; (iv) a fourth hydrotreating unit, a fourth hydrocracking unit, and a fourth fractionator, wherein the fourth hydrotreating unit is located downstream of the fourth integration mechanism, wherein the fourth hydrocracking unit is located downstream of the fourth hydrotreating unit, wherein the fourth fractionator is located downstream of the fourth hydrocracking unit; (v) a fifth thermal cracking unit and a fifth fractionator, wherein the fifth thermal cracking unit is located downstream of the fifth integration mechanism and the fifth fractionator is located downstream of the fifth thermal cracking unit; and/or (vi) a sixth fractionator, a sixth thermal cracking unit, and a sixth hydrotreating unit, wherein the sixth fractionator is located downstream of the sixth integration mechanism, wherein the sixth thermal cracking unit is located downstream of the sixth fractionator, and the sixth hydrotreating unit is located downstream of the sixth fractionator.
BRIEF DESCRIPTION OF THE FIGURES
[0012] FIG. 1 is a schematic diagram of an integrated biomass conversion and petroleum refining system according to one embodiment of the present invention.
[0013] FIG. 2 is an exemplary stability parameter plot showing the change in bio-oil viscosity as a function of time for a high-stability bio-oil having a stability parameter (slope of the straight line fit) of 0.1325 centipoise per hour.
DETAILED DESCRIPTION
[0014] FIG. 1 depicts an integrated system for producing renewable fuels from biomass and traditional petroleum-derived streams. In particular, FIG. 1 illustrates a biomass conversion system 10 that is integrated with a petroleum refinery 12 via an integration system 14 . As discussed in further detail below, the manner in which the biomass conversion system 10 is integrated into the petroleum refinery 12 can vary based on various properties, such as stability and/or oxygen content, of the produced bio-oil and the desired product slate from the petroleum refinery 12 . As shown in FIG. 1 , integration of the biomass conversion system 10 and the petroleum refinery 12 can allow for the commercial scale production of renewable fuels such as, for example, bio-gasoline, bio-jet fuel, bio-diesel, bio-fuel oil, and/or bio-coke.
[0015] The biomass conversion system 10 of FIG. 1 includes a biomass source 16 for supplying a biomass feedstock to be converted to bio-oil. The biomass source 16 can be, for example, a hopper, storage bin, railcar, over-the-road trailer, or any other device that may hold or store biomass. The biomass supplied by the biomass source 16 can be in the form of solid particles. The biomass particles can be fibrous biomass materials comprising cellulose. Examples of suitable cellulose-containing materials include algae, paper waste, and/or cotton linters. In one embodiment, the biomass particles can comprise a lignocellulosic material. Examples of suitable lignocellulosic materials include forestry waste such as wood chips, saw dust, pulping waste, and tree branches; agricultural waste such as corn stover, wheat straw, and bagasse; and/or energy crops such as eucalyptus, switch grass, and coppice.
[0016] As depicted in FIG. 1 , the solid biomass particles from the biomass source 16 can be supplied to a biomass feed system 18 . The biomass feed system 18 can be any system capable of feeding solid particulate biomass to a biomass conversion reactor 20 . While in the biomass feed system 18 , the biomass material may undergo a number of pretreatments to facilitate the subsequent conversion reactions. Such pretreatments may include drying, roasting, torrefaction, demineralization, steam explosion, mechanical agitation, and/or any combination thereof.
[0017] In one embodiment, it may be desirable to combine the biomass with a catalyst in the biomass feed system 18 prior to introducing the biomass into the biomass conversion reactor 20 . Alternatively, the catalyst may be introduced directly into the biomass conversion reactor 20 . The catalyst may be fresh and/or regenerated catalyst. The catalyst can, for example, comprise a solid acid, such as a zeolite. Examples of suitable zeolites include ZSM-5, mordenite, beta, ferrierite, and zeolite-Y. Additionally, the catalyst may comprise a super acid. Examples of suitable super acids include sulfonated, phosphated, or fluorinated forms of zirconia, titania, alumina, silica-alumina, and/or clays. In another embodiment, the catalyst may comprise a solid base. Examples of suitable solid bases include metal oxides, metal hydroxides, and/or metal carbonates. In particular, the oxides, hydroxides, and carbonates of alkali metals, alkaline earth metals, transition metals, and/or rare earth metals are suitable. Other suitable solid bases are layered double hydroxides, mixed metal oxides, hydrotalcite, clays, and/or combinations thereof. In yet another embodiment, the catalyst can also comprise an alumina, such as alpha-alumina.
[0018] It should be noted that solid biomass materials generally contain minerals. It is recognized that some of these minerals, such as potassium carbonate, can have catalytic activity in the conversion of the biomass material. Even though these minerals are typically present during the chemical conversion taking place in the biomass conversion reactor 20 , they are not considered catalysts.
[0019] The biomass feed system 18 introduces the biomass feedstock into a biomass conversion reactor 20 . In the biomass conversion reactor 20 , biomass is subjected to a conversion reaction that produces bio-oil. The biomass conversion reactor 20 can facilitate different chemical conversion reactions such as fast pyrolysis, slow pyrolysis, liquefaction, gasification, or enzymatic conversion. The biomass conversion reactor 20 can be, for example, a fluidized bed reactor, a cyclone reactor, an ablative reactor, or a riser reactor.
[0020] In one embodiment, the biomass conversion reactor 20 can be a riser reactor and the conversion reaction can be fast pyrolysis. More specifically, fast pyrolysis may include catalytic cracking As used herein, “pyrolysis” refers to the chemical conversion of biomass caused by heating the feedstock in an atmosphere that is substantially free of oxygen. In one embodiment, pyrolysis is carried out in the presence of an inert gas, such as nitrogen, carbon dioxide, and/or steam. Alternatively, pyrolysis can be carried out in the presence of a reducing gas, such as hydrogen, carbon monoxide, noncondensable gases recycled from the biomass conversion process, and/or any combination thereof.
[0021] Fast pyrolysis is characterized by short residence times and rapid heating of the biomass feedstock. The residence times of the fast pyrolysis reaction can be, for example, less than 10 seconds, less than 5 seconds, or less than 2 seconds. Fast pyrolysis may occur at temperatures between 200 and 1,000° C., between 250 and 800° C., or between 300 and 600° C.
[0022] Referring again to FIG. 1 , the conversion effluent 21 exiting the biomass conversion reactor 20 generally comprises gas, vapors, and solids. As used herein, the vapors produced during the conversion reaction may interchangeably be referred to as “bio-oil,” which is the common name for the vapors when condensed into their liquid state.
[0023] In one embodiment of the present invention, the conversion reaction carried out in the biomass conversion reactor 20 produces a bio-oil of high-stability. Such high-stability bio-oil has a stability parameter of less than 30 centipoise per hour (cp/h). In certain embodiments, the high-stability bio-oil can have an oxygen content of less than 15 percent by weight. In another embodiment of the present invention, the conversion reaction carried out in the biomass conversion reactor 20 produces a bio-oil of intermediate-stability. Such intermediate-stability bio-oil has a stability parameter in the range of 30 to 75 cp/h. In certain embodiments, the intermediate-stability bio-oil can have an oxygen content in the range of 15 to 18 percent by weight. In still another embodiment of the present invention, the conversion reaction carried out in the biomass conversion reactor 20 produces a bio-oil of low-stability. Such low-stability bio-oil has a stability parameter greater than 75 cp/h. In certain embodiments, the low-stability bio-oil can have an oxygen content greater than 18 percent by weight.
[0024] As used herein, the “stability parameter” of a bio-oil is defined as the slope of a best-fit straight line for a plot of bio-oil viscosity (centipoises) over time (hours), where the plotted viscosity values are determined while the bio-oil is aged at 90° C. on samples taken at the onset of aging (time=0 hours), 8 hours from the onset of aging, 24 hours from the onset of aging, and 48 hours from the onset of aging. Only data points exhibiting a correlation coefficient greater than 0.9 (R 2 >0.9) are used to determine the stability parameter.
[0025] FIG. 2 provides an exemplary stability parameter plot where the slope of the best-fit straight line (i.e., the stability parameter) is 0.135 cp/h and the correlation coefficient (R 2 ) for all four data points (times=0, 8, 24, and 48 hours) is 0.9519. Since the stability parameter for the bio-oil tested in FIG. 2 is less than 30 cp/h, the bio-oil would be considered a “high-stability bio-oil.”
[0026] Although FIG. 1 depicts only one biomass conversion system 10 with a single biomass conversion reactor 20 , certain embodiments of the present invention may employ multiple biomass conversion systems or multiple biomass conversion reactors to convert the same or different biomass feedstocks into a plurality of individual bio-oil streams having different stability properties. Two or more of these bio-oil streams of varying stability can be simultaneously integrated into the petroleum refinery 12 in accordance with the integration techniques discussed in detail below.
[0027] When fast pyrolysis is carried out in the biomass conversion reactor 20 , the conversion effluent 21 generally comprises solid particles of char, ash, and/or spent catalyst. The conversion effluent 21 can be introduced into a solids separator 22 . The solids separator 22 can be any conventional device capable of separating solids from gas and vapors such as, for example, a cyclone separator or a gas filter. The solids separator 22 removes a substantial portion of the solids (e.g., spent catalysts, char, and/or heat carrier solids) from the conversion effluent 21 . The solid particles 23 recovered in the solids separator 22 can be introduced into a regenerator 24 for regeneration, typically by combustion. After regeneration, at least a portion of the hot regenerated solids can be introduced directly into the biomass conversion reactor 20 via line 26 . Alternatively or additionally, the hot regenerated solids can be directed via line 28 to the biomass feed system 18 for combination with the biomass feedstock prior to introduction into the biomass conversion reactor 20 .
[0028] The substantially solids-free fluid stream 30 exiting the solids separator 22 can then be introduced into an optional fluids separator 32 . In one embodiment, it is preferred that the bio-oil entering the fluids separator 32 has not previously been subjected to a deoxygenation process such as, for example, hydrotreating. The fluids separator 32 can be any system capable of separating unwanted fluid components 33 from the solids-free fluid stream 30 to provide the desired bio-oil 34 . The identity of the unwanted fluid components 33 may vary depending on many factors; however, common unwanted components may include noncondensable gases and/or water. The unwanted fluid components 33 may also include components, such as certain olefins, that are more valuable as individual products rather than as renewable feeds to the petroleum refinery.
[0029] As discussed previously, the separated bio-oil 34 is integrated into the petroleum refinery 12 based on the stability of the bio-oil 34 and the desired product slate of the refinery 12 . In one embodiment, an optional analyzer 35 is provided to determine the stability parameter and/or the oxygen content of the bio-oil 34 so that the optimal method of integration can be chosen based on the stability parameter and/or the oxygen content of the bio-oil 34 as measured by the analyzer 35 .
[0030] When the bio-oil 34 exhibits a stability parameter of less than 30 cp/h and/or has an oxygen content of less than 15 weight percent, such high-stability bio-oil is routed through line 36 of the integration system 14 . When the bio-oil 34 exhibits a stability parameter in the range of 30 to 75 cp/h and/or has an oxygen content of 15 to 18 weight percent, such intermediate-stability bio-oil is routed through line 38 of the integration system 14 . When the bio-oil 34 exhibits a stability parameter greater than 75 cp/h and/or has an oxygen content greater than 18 weight percent, such low-stability bio-oil is routed through line 40 of the integration system 14 . The integration system 14 can introduce the bio-oil 34 into the conventional petroleum refinery 12 at one or more appropriate locations, in the appropriate amount, and under the appropriate conditions so the bio-oil is co-processed with a petroleum-derived stream of the refinery. The petroleum-derived stream with which the bio-oil 34 is co-processed can be, for example, virgin gasoil/diesel, light cycle oil (LCO), light catalytic-cycle oil (LCCO), atmospheric residue (AR), deasphalted oil (DAO), heavy crude oil (HCO), heavy catalytic-cycle oil (HCCO), vacuum gas oil (VGO), and/or vacuum residue (VR).
[0031] When the biomass conversion system 10 produces a high-stability bio-oil, the integration system 14 can direct the high-stability bio-oil to a first treatment process via lines 36 and 36 a and/or to a second treatment process via lines 36 and 36 b.
[0032] In the first treatment process, the high-stability bio-oil in line 36 a can be combined with a first conventional petroleum-derived stream “A” of the refinery 12 . As used herein, “conventional” is understood to encompass any facility, apparatus, or plant whose purpose and function is in conjunction with the accepted standards and/or well known practices in the relevant art concerning petroleum refining or petrochemicals production. The amount of the high-stability bio-oil combined with the first petroleum-derived stream A can be at least 0.01, 0.1, 1, or 2 percent and/or not more than 50, 25, 10, or 5 percent by weight of the combined streams. The first petroleum-derived stream A can be, for example, virgin gasoils/diesel, light cycle oil (LCO), and/or light conversion-cycle oil (LCCO). The combining of the high-stability bio-oil and the first petroleum-derived stream A can take place upstream of a conventional hydrotreater 42 of the refinery 12 . Alternatively, the combining of the high-stability bio-oil and the first petroleum-derived stream A can take place within the conventional hydrotreater 42 . In one embodiment, the hydrotreater 42 is a conventional diesel hydrotreating unit of the petroleum refinery 12 . In the hydrotreater 42 , the combined stream is subjected to hydrotreatment to thereby produce a hydrotreated stream that can then be subjected to fractionation in a first fractionator 44 . Such fractionation can produce one or more of the following renewable fuel products: bio-gasoline, bio-jet fuel, bio-diesel, bio-fuel oil, and/or bio-coke.
[0033] In the second treatment process, the high-stability bio-oil in line 36 b can be combined with a second conventional petroleum-derived stream “B” of the refinery 12 . The amount of the high-stability bio-oil combined with the second petroleum-derived stream B can be at least 0.01, 0.1, 1, or 2 percent and/or not more than 50, 25, 10, or 5 percent by weight of the combined streams. The second petroleum-derived stream B can be, for example, atmospheric residue (AR), deasphalted oil (DAO), vacuum gas oil (VGO), heavy catalytic-cycle oil (HCCO), and/or vacuum residue (VR). The combining of the high-stability bio-oil and the second petroleum-derived stream B can take place upstream of a conventional catalytic cracker 46 of the refinery 12 . Alternatively, the combining of the high-stability bio-oil and the second petroleum-derived stream B can take place within the conventional catalytic cracker 46 . In one embodiment, the catalytic cracker 46 is a conventional fluid catalytic cracking (FCC) unit or a conventional resid fluid catalytic cracking (RFCC) unit of the petroleum refinery 12 . In the catalytic cracker 46 , the combined stream is subjected to catalytic cracking to thereby produce a catalytically cracked stream that can then be subjected to fractionation in a second fractionator 48 . Such fractionation can produce one or more of the following renewable fuel products: bio-gasoline, bio-jet fuel, bio-diesel, bio-fuel oil, and/or bio-coke.
[0034] When the biomass conversion system 10 produces an intermediate-stability bio-oil, the integration system 14 can direct the intermediate-stability bio-oil to a third treatment process via lines 38 and 38 a and/or to a fourth treatment process via lines 38 and 38 b.
[0035] In the third treatment process, the intermediate-stability bio-oil in line 38 a can be combined with a third conventional petroleum-derived stream “C” of the refinery 12 . The amount of the intermediate-stability bio-oil combined with the third petroleum-derived stream C can be at least 0.01, 0.1, 1, or 2 percent and/or not more than 50, 25, 10, or 5 percent by weight of the combined streams. The third petroleum-derived stream C can be, for example, light cycle oil (LCO), and/or light conversion-cycle oil (LCCO), deasphalted oil (DAO), vacuum gas oil (VGO), and/or heavy catalytic-cycle oil (HCCO). The combining of the intermediate-stability bio-oil and the third petroleum-derived stream C can take place upstream of a conventional hydrotreater 50 of the refinery 12 . Alternatively, the combining of the intermediate-stability bio-oil and the third petroleum-derived stream C can take place within the conventional hydrotreater 50 . In the hydrotreater 50 , the combined stream is subjected to hydrotreatment to thereby produce a hydrotreated stream that can then be subjected to catalytic cracking in a conventional catalytic cracker 52 of the refinery 12 . In one embodiment, the catalytic cracker 52 is a conventional fluid catalytic cracking (FCC) unit and the hydrotreater 50 located upstream of the catalytic cracker 52 is a conventional FCC-feed pre-treater. The cracked stream exiting the catalytic cracker 52 can then be subjected to fractionation in a third fractionator 54 . Such fractionation can produce one or more of the following renewable fuel products: bio-gasoline, bio jet fuel, bio-diesel, bio-fuel oil, and/or bio-coke.
[0036] In the fourth treatment process, the intermediate-stability bio-oil in line 38 b can be combined with a fourth conventional petroleum-derived stream “D” of the refinery 12 . The amount of the intermediate-stability bio-oil combined with the fourth petroleum-derived stream D can be at least 0.01, 0.1, 1, or 2 percent and/or not more than 50, 25, 10, or 5 percent by weight of the combined streams. The fourth petroleum-derived stream D can be, for example, light cycle oil (LCO), and/or light conversion-cycle oil (LCCO), deasphalted oil (DAO), vacuum gas oil (VGO), and/or heavy catalytic-cycle oil (HCCO). The combining of the intermediate-stability bio-oil and the fourth petroleum-derived stream D can take place upstream of a conventional hydrotreater 56 of the refinery 12 . Alternatively, the combining of the intermediate-stability bio-oil and the fourth petroleum-derived stream D can take place within the conventional hydrotreater 56 . In the hydrotreater 56 , the combined stream is subjected to hydrotreatment to thereby produce a hydrotreated stream that can then be subjected to hydrocracking in a conventional hydrocracker 58 of the refinery 12 . In one embodiment, the hydrocracker 58 is a conventional hydrocracking unit. The cracked stream exiting the hydrocracker 58 can then be subjected to fractionation in a fourth fractionator 60 . Such fractionation can produce one or more of the following renewable fuel products: bio-gasoline, bio jet fuel, bio-diesel, bio-fuel oil, and/or bio-coke.
[0037] When the biomass conversion system 10 produces a low-stability bio-oil, the integration system 14 can direct the low-stability bio-oil to a fifth treatment process via lines 40 and 40 a and/or to a sixth treatment process via lines 40 and 40 b.
[0038] In the fifth treatment process, the low-stability bio-oil in line 40 a can be combined with a fifth conventional petroleum-derived stream “E” of the refinery 12 . The amount of the low-stability bio-oil combined with the fifth petroleum-derived stream E can be at least 0.01, 0.1, 1, or 2 percent and/or not more than 50, 25, 10, or 5 percent by weight of the combined streams. The fifth petroleum-derived stream E can be, for example, light cycle oil (LCO), and/or light conversion-cycle oil (LCCO), vacuum residue (VR). The combining of the low-stability bio-oil and the fifth petroleum-derived stream E can take place upstream of a conventional thermal cracker 62 of the refinery 12 . Alternatively, the combining of the low-stability bio-oil and the fifth petroleum-derived stream E can take place within the conventional thermal cracker 62 . In the thermal cracker 62 , the combined stream is subjected to thermal cracking to thereby produce a cracked stream 64 that is then removed from the thermal cracker 62 . The cracked stream 64 can then be divided into a stabilized cracked stream 64 a and a bio-coke stream 64 b. The stabilized cracked stream 64 a can then be subjected to fractionation in a fifth fractionator 66 , while the bio-coke stream 64 b is removed from the system. In one embodiment, the thermal cracker 62 is a conventional coker unit. Such fractionation can produce one or more of the following renewable fuel products: bio-gasoline, bio jet fuel, bio-diesel, bio-fuel oil, and/or bio-coke.
[0039] In the sixth treatment process, the low-stability bio-oil in line 40 b can be combined with a sixth conventional petroleum-derived stream “F” of the refinery 12 . The amount of the low-stability bio-oil combined with the sixth petroleum-derived stream F can be at least 0.01, 0.1, 1, or 2 percent and/or not more than 50, 25, 10, or 5 percent by weight of the combined streams. The sixth petroleum-derived stream F can be a heavy residual stream such as, for example, light cycle oil (LCO), and/or light conversion-cycle oil (LCCO), atmospheric residuum (AR), and/or deasphalted oil (DAO). The combining of the low-stability bio-oil and the sixth petroleum-derived stream F can take place upstream of a sixth fractionator 68 of the refinery 12 . Alternatively, the combining of the low-stability bio-oil and the sixth petroleum-derived stream F can take place within the fractionator 68 . In one embodiment, the sixth fractionator 68 is a conventional coker fractionator. In the fractionator 68 , the combined stream can be subjected to fractionation to thereby produce at least two fractionated streams. One of the fractionated streams (e.g., a bio-distillate fraction) exiting the fractionator 68 can then be subjected to hydrotreatment in a sixth hydrotreater 70 of the refinery 12 . Another of the fractionated streams exiting the fractionator 68 (e.g., a bio-residual fraction) can then be subjected to thermal cracking in a sixth thermal cracker 72 of the refinery 12 . In one embodiment, the thermal cracker 72 is a conventional coker unit. The hydrotreated stream exiting the hydrotreater 70 can be bio-gasoline, bio jet fuel, bio-diesel, bio-fuel oil, and/or bio-coke, while the cracked stream exiting the thermal cracker 72 can be referred to as bio-coke.
[0040] The bio-gasoline, bio jet fuel, bio-diesel, and bio-fuel oil produced by the method described herein can have boiling ranges that are typical for conventional gasoline, jet fuel, diesel, and fuel oil, respectively. Accordingly, at least 75, 85, or 95 weight percent of the bio-gasoline produced by the process described herein has a boiling point in the range of 40 to 215° C.; at least 75, 85, or 95 weight percent of the bio jet fuel produced by the process described herein has a boiling point in the range of 175 to 325° C.; at least 75, 85, or 95 weight percent of the bio-diesel produced by the process described herein has a boiling point in the range of 250 to 350° C.; and at least 75, 85, or 95 weight percent of the bio-fuel oil produced by the process described herein has a boiling point in the range of 325 to 600° C.
EXAMPLES
Example 1
[0041] A 65 g sample of a bio-oil, derived from the thermo-catalytic conversion of biomass and containing 11 wt % oxygen and a stability parameter of 0.1 cp/h, was combined with a 35 g quantity of a petroleum-derived LCO stream. Results of the mixing are shown in the Table 1 below. The boiling point ranges were determined using simulated distillation.
[0000]
TABLE 1
Petroleum-
Bio-oil
Derived LCO
Mixture
Mid-boiling point (° C.)
220
276
253
Boiling Point Range (° C.)
70-520
114-420
70-510
Oxygen Content (wt %)
10
<0.5
6.5
TAN (mg KOH/g)
7
0.2
4
Wt % boiling below 215 C.
53
13
33
Wt % boiling above 325 C.
24
23
24
[0042] The data in Table 1 above demonstrates that high stability bio-oil can be blended with a high proportion of LCO to render a feedstock that can be processed in conventional diesel HDT, since the high boiling point fraction is substantially the same as conventional feeds.
Example 2
[0043] An 80 g sample of a bio-oil, derived from the thermo-catalytic conversion of biomass and containing 16 wt % oxygen, and a stability parameter of 32 cp/h, was combined with a 20 g quantity of a petroleum-derived LCO stream. Results of the mixing are shown in the Table 2 below. The boiling point ranges were determined using simulated distillation.
[0000]
TABLE 2
Petroleum-
Bio-oil
Derived LCO
Mixture
Mid-boiling point (° C.)
226
276
253
Boiling Point Range (° C.)
100-540
114-420
110-515
Oxygen Content (wt %)
16
<0.5
12
TAN (mg KOH/g)
23
0.2
15
Wt % boiling below 215 C.
44
13
36
Wt % boiling above 325 C.
54
23
54
[0044] The data in Table 2 above demonstrates that moderate stability bio-oil can be blended with a lower proportion of LCO to render a feedstock that can be processed in conventional VGO HDT and or FCC units, since the high boiling point fraction is substantially the same as that of typical streams processed in such units.
[0045] The preferred forms of the invention described above are to be used as illustration only, and should not be used in a limiting sense to interpret the scope of the present invention. Modifications to the exemplary embodiments, set forth above, could be readily made by those skilled in the art without departing from the spirit of the present invention.
[0046] It is the inventors' intent to rely on the Doctrine of Equivalents to determine and assess the reasonably fair scope of the present invention as it pertains to any processes and systems not materially departing from but outside the literal scope of the invention as set forth in the following claims. | Renewable fuels are produced in commercial quantities and with enhanced efficiency by integrating a bio-oil production system with a conventional petroleum refinery so that the bio-oil is co-processed with a petroleum-derived stream in the refinery. The techniques used to integrate the bio-oil production system and conventional petroleum refineries are selected based on the quality of the bio-oil and the desired product slate from the refinery. | 2 |
BACKGROUND OF THE INVENTION
Paper is made on a Fourdrinier machine in which a slurry, or stock, comprising paper fibers, water, and optional additives for the paper is fed from a head box to a moving wire. The fibers are caught on the surface of the wire and become a paper web and the water drains through the wire and is discharged from the machine. When the paper web is dry enough to be self-supporting it is removed from the wire and carried through further processing stages in the machine and finally is dried and rolled up. One of the controlling factors governing the speed at which the machine is run is the length of time required to cause the paper to become sufficiently dry so as to be self-supporting. Paper is sold in a highly competitive market and the savings in manufacturing costs resulting from a small increase in machine speed can be a substantial competitive advantage. Accordingly, it is of great importance to speed up the removal of water from the paper web.
At the point where the stock is deposited on the wire from the head box, the wire is supported by a series of blades or foils which extend across the machine, with spaces between the blades to permit the water to pass therethrough. The wire subsequently passes across a suction box where additional water is removed by suction. The blades which are positioned underneath the moving wire close to the head box are generally of a type shown in Wrist U.S. Pat. No. 2,928,465. These blades are characterized by having a horizontal upper surface at the leading edge of the blade, this leading surface sometimes being called the land portion, followed by a trailing portion, sometimes called the foiling surface, which diverges from the horizontal an an angle up to about 5°. It was found that this configuration for a foil caused water to be drawn through the wire more rapidly as a consequence of suction generated between the wire and the foiling portion. Such a blade removes water portion. the web or wire in two ways: The nose, or leading edge of the foil, bears against the wire and scrapes water from the lower surface of the wire; and the trailing portion causes a partial vacuum to pull water from the slurry side of paper fibers on the upper sides of the wire to the lower surface of the wire.
Since the first use of blades of the type shown by Wrist there have been many efforts to improve them. Foils have been produced with adjustable angles between the land and the trailing portion in an effort to improve performance. Because these blades are subject to wear they have been made easily removable and easily replaceable. Extra hard or wear-resistant materials have been employed in the manufacture of blades and wear-resistant coatings have been placed on the blade surfaces. Adjustable supports for such blades are shown, for example, in Dunlap U.S. Pat. No. 3,027,940. A wear-resistant coating or plate for the land portion of a blade is shown for example in Duncan U.S. Pat. No. 3,351,524. A wear-resistant insert fitted into a groove in the upper surface of the land and coplanar with the land surface is shown for example in Buchanan U.S. Pat. No. 3,446,702, and in Beacom U.S. Pat. No. 3,732,142. A wear-resistant insert in the trailing portion of the blade adjacent its intersection with the land is shown for example in Kienzl U.S. Pat. No. 3,738,911, and a wear-resistant tip is shown in Charbonneau U.S. Pat. No. 3,778,342. In addition, a wide variety of mounting means have been employed for quick change of blades. Thus, dovetails, as shown in Roecker U.S. Pat. Nos. 3,377,236, T-bars as shown in White 3,337,394, and other mounting means are employed.
In spite of all these changes in blade structure, there has not yet been much successful change in the contour of the upper surface of blades, and most or all blades heretofore in use have retained the contour of a horizontal land surface followed by a trailing foiling surface at a downward angle of 5° or less. For example, the blade of Buchanan U.S. Pat. Nos. 3,446,702 employs the same contour as that of Wrist 2,928,465 with the apparent exception that the angle between the plane of the land portion and the foiling portion is accentuated, particularly as the blade is worn by use.
GENERAL NATURE OF THE INVENTION
According to the present invention a new and improved blade for a Fourdrinier machine is provided with a new upper surface contour. Where prior blades generally have an angular intersection between a horizontal front or land surface and a trailing or foiling surface, the blades of the present invention have a raised curved bearing surface and the front edge or nose of the blade is pointed upwardly at an angle of about 1/2° to about 1° or so. The nose of the blade thus maintains a skimming contact with the under surface of the wire, removing all except a thin film of water from the bottom of the wire which then curves smoothly around the curved intersection and extends in substantially a catenary curve to the next blade. Immediately back of the curved bearing surface of the blade the foiling angle of up to about 5° is accentuated with resultant improvement in water removal.
The curved bearing surface of the blade supports and receives most of the weight and abrasion of the moving wire and a hard, wear resistant surface is provided at this point. To achieve this purpose a rounded wear resistant insert is employed, this insert preferably being cylindricalin shape and optionally made up of a plurality of cylindrical in segments positioned end-to-end in a groove positioned at and overlapping the line of junction between the land portion and the foil portion of the blade.
The radius of curvature of this insert preferably is in the order of 1/8 to 1/4 inch, such as the curvature of a 1/4 to 1/2 inch diameter cylindrical member. Such a curved surface positioned at and overlapping the intersection of land and foiling surfaces is raised above said surfaces by about 0.005 inch. If it is excessively high above the adjacent land surface, fines and other solid particles may collect in front of the insert or curve. If it is too near the plane of the land portion it decreases the water removing performance of the blade. For a blade with 1/8 inch radius of curvature of the raised portion, such blade to be used for a variety of papers including fine paper, a surface raised to 0.003 to 0.008 inch is now preferred.
The front or land portion of the blade points upwardly from the base of the raised bearing surface toward a raised nose, assuring a skimming or scraping contact between nose and machine wire, thus producing optimum water removal as the blade first meets the moving wire. The upward angle in the land surface of a new blade is about 1/2 to 1 degree. As the blade is used on a machine this upward tilt can be worn to its desired angle and contour provided the angle when new is sufficient to achieve the proper original skimming contact. If the upward tilt is significantly less than about 1/2 degree the wire and blade do not meet to remove water sufficiently; if the upward tilt is excessive, i.e., greater than about 1 degree, longer break-in wear is required but the blade ultimately breaks in to the desired configuration.
When a Fourdrinier machine is in use and operation, the wire moves from each bearing surface of a blade to the next such surface in a sequence of catenaries. Although the wire touches the blade surface at other points, most of the weight and and accordingly most of the abrasion is at these bearing surfaces. The bearing surfaces are, accordingly, smoothly rounded to minimize wear and damage to the wire. They are also highly abrasion resistant so as to last many months between replacements. According to the best mode of construction and operation of the invention as now understood, a cylindrical abrasion resistant insert properly positioned to overlap the juncture between land and foiling portion is mounted within a recess in the blade.
With the preferred embodiment of the invention, i.e. a cylindrical abrasion resistant insert, it is not necessary to replace the entire blade nor even replace the insert when the curved bearing surface becomes worn. Instead, the insert is rotated to bring to the top a fresh, unworn bearing surface. In this way, the expense of replacement is reduced and, perhaps even more importantly, rotation is much faster than replacement and machine down time is reduced.
The invention is illustrated in the drawings, in which:
FIG. 1 is an end cross-section of a blade according to one embodiment of the invention;
FIG. 2 is an end cross-section of a blade according to another embodiment of the invention, wherein different mounting means is employed;
FIG. 3 is a perspective view of one embodiment of the invention employing still a different mounting means;
FIG. 4 is a segmented view of the articles in any of FIGS. 1, 2, and 3.
FIG. 5 is a diagrammatic view of blades according to this invention supporting a paper machine wire.
DETAILED DESCRIPTION OF THE INVENTION
In FIG. 1 is shown a foil blade generally designated 10 which usually is a body of extruded plastic or the like. The upper surface of the blade includes a front or land portion 11 and a rear or foiling portion 12, inclined downwardly. Overlapping the joint between the land 11 and the rear portion 12 is a smoothly rounded bearing surface 13 formed by a cylindrical insert 14 mounted in a groove 15. At the upper surface of the groove 15 are two lips 16 one located in the forward or land surface 11 and one located in the foiling portion 12 and adapted to grip the insert 14. At the base of the blade 10 is mounting means such as a T-bar comprising a flat groove 18 extending the length of the blade and having lips 19 on either side thereof. A T-bar mounting of this type is one conventional mounting means employed for mounting a blade removably on a fixed support member and is disclosed, for example, in U.S. Pat. No. 3,732,142.
In FIG. 2 is shown a similar blade generally designated 10 having a forward or land portion 11, a foiling portion 12, a bearing surface 13 formed by an insert 14 in groove 15 as in the blade of FIG. 1. In the blade of FIG. 2 there is a dovetail groove 20 extending the length of the blade. A dovetail groove of this type is another conventional mounting means used for easy removal of the blade from a fixed mounting support on a Fourdrinier machine, as is disclosed for example in U.S. Pat. No. 3,377,236.
The forward or land portion 11 of the blades shown in FIGS. 1 and 2 meets a front wall 21 of the blade at an angle which generally is somewhat sharper than a 90° angle. The leading edge 22 or nose 22 of blade 10 is adapted to skim the lower surface of the moving wire of a Fourdrinier machine to skim water off the undersurface thereof. The land 11 drops away from the nose at a very slight angle such as an angle of about 1/2° to 1° from the horizontal, with the result that the portion of the land 11 adjacent bearing surface 13 is slightly lower than the leading edge of the land.
The nose 22 of the blade is raised at least enough to assure contact between the nose 22 and the machine wire. When contact between the nose of a new blade and the wire is insufficient, the blade does not properly skim water off the wire. When the contact is mildly excessive, the moving wire rapidly wears the blade to a skimming condition, automatically adjusting for factors relating to machine speed, type of paper being made, moisture content of the paper as it reaches the blade location, etc. Accordingly, the tolerance is fairly rigid for a minimum angle of at least about 1/2° slope of the land portion and is significantly less rigid for a maximum angle of about 1° or so.
In FIG. 3 is shown a view of a modified blade 10 having a land portion 11, a foiling portion 12, a front wall 21, and a dovetail 23 for mounting the blade on a paper making machine. In this blade a plurality of cylindrical segments 14a are positioned in the groove 15 (not identified in this Figure) in end-to-end position to extend from one end of the blade to the other. As shown in FIG. 4 these segments 14a positioned in the groove between land portion 11 and foiling portion 12 are held in place by an end plate 25 and a spring 26 which bears against the end of the adjacent segment 14a of the insert 14. When the insert 14 becomes worn so that its top level begins to approach the level of land 11 and foiling portion 12, the insert can be rotated to bring a fresh bearing surface into position. The insert 14 is most easily rotated by removing end plate 25 to loosen spring 26 whereupon the insert segments 14a are relatively easily rotatable.
In FIG. 5 is shown diagrammatically a series of blades 10 positioned on a fourdrinier machine with a plurality of bearing surfaces 13. The wire 28 is supported by each bearing surface 13 and the nose 22 or leading edge of each blade 10 skims against the under surface of wire 28. The wire 28 is moving in the direction indicated by arrow 29 when the machine is in operation.
The contact between wire 28 and the bearing surfaces 13 is a supporting contact and is in fact the principle supporrting contact for wire 28 at this area of the machine. The wire extends between adjacent support points or bearing surfaces in essentially a catenary curve the shape of which depends on the machine speed, the type of paper being produced and other similar factors. The contact between wire 28 and nose 22 of each blade unlike the contact at the bearing surfaces is essentially a skimming contact which supports little if any weight of the wire and which serves to skim water off the under surface of the blade. It has been found that optimum removal of water from the paper on wire 28 is achieved when any contact between the wire and land portion 11 of the blade and contact between the wire and foiling portion 12 of the blade is essentially a non-supporting contact. In fact, wire 28 appears to ride an extremely small distance above foiling portion 12 and it is believed that vacuum forms therebetween and that this vacuum is helpful in drawing extra quantities of water to the bottom surface of the wire 28 so that this water can be skimmed from such surface by the next succeeding nose 22.
In the presently preferred embodiment of the invention the bearing surface 13 is formed by a cylindrical insert 14 in the upper portion of the blade. Blades used in paper making machines are generally quite long, usually being between about 10 or 12 feet for fairly short blades up to lengths of 20 or more feet for longer blades. Ceramic blades or other blades formed of wear resistant or abrasion resistant material are very expensive and extremely difficult to manufacture, and in particular, are difficult to manufacture to tolerances required for paper making equipment. It has become the custom, accordingly, to employ inserts such as, for example, the inserts of the Buchanan patent and the Beacom patent identified above. It is the preferred form of the present invention to achieve the elevated, curved bearing surface 13 by means of an added member or element such as insert 14. In this manner, bearing surface 13 receives most of the wear when the machine is in operation, and bearing surface 13 is made of a wear resistant material such as aluminum oxide, although other materials such as carbide, silicon carbide and other ceramic materials may be used, or rods or like members having a coating of a wear resistant material may be employed. Such coated rods may have the advantage of being less brittle and of being manufactured in longer lengths or longer segments. The smooth, cylindrical surface of insert 14 permits it to be rotated after a number of months' wear so as to bring a fresh bearing surface into supporting position to support the machine wire.
The blade of the present invention is easily installed either on machines already having replaceable blades or on machines with permanently mounted blades. Many machines now in use have familiar T-bar mountings such as for blades as shown in FIG. 1, or have dovetail mountings as for blades of the type shown in FIGS. 2 or 3. With such blade mounting the old blade is removed and the new blade of the present invention is inserted in its place. Care should be taken to be sure the mounting is truly horizontal so as to achieve maximum benefit from the new blade contour. With permanent mounting, the new blade with a base shaped like the existing base is permanently mounted in the same manner as the old: often upon changing to the blade of the present invention a quick-replacement mounting should be installed as part of the change of blade. In most cases it is to be expected that the new blade of the present invention with a rotatable insert will last for several years of heavy duty operation. | A drainage blade for a paper making machine has an upper surface contour including a front land portion, a rear foiling portion inclined downwardly at an angle up to about 5° and bridging the two portions, a smoothly curved, elevated bearing surface which extends above both the land portion and the foiling portion of the blade. Between the bearing surface and the leading edge of the blade, the land portion slopes upwardly at a small angle which may be about 1/2° to about 1°. The bearing surface is formed by a cylindrical insert which is rotated when the insert wears close to the level of the blade surface. | 3 |
FIELD OF THE INVENTION
The present invention relates to method and apparatus for producing intermetallic castings, such as, for example, titanium aluminide castings, in high volumes at reduced cost without harmful contamination resulting from reactions between the intermetallic melt and melt containment materials.
BACKGROUND OF THE INVENTION
Many alloys with high weight percentages of a reactive metal, such as titanium, react with air and most common crucible refractories to the degree that the alloy is contaminated to an unacceptable extent. As a result, it is common to melt such alloys in water cooled, metal (e.g. copper) crucibles using electric arc or induction to generate heat in the alloy charge.
U.S. Pat. No. 4 738 713 is representative of one such melting technique. The patented melting method is very inefficient in the use of electrical power. Moreover, experience with such a method indicates that the amount of melt superheat achievable is limited and sensitive to crucible life. However, the method is in use since the method can use lower cost melt stock than consumable arc melting techniques which require specially prepared melting electrodes of the alloy desired.
Arc melting techniques using water cooled copper crucibles (e.g. see U.S. Pat. No. 2 564 337) can provide higher superheats in melting the reactive alloys. However, arc melting techniques, as well as induction melting techniques, are dangerous due to the potential for explosion in the event of crucible failure wherein cooling water comes into contact with the molten reactive alloy to form hydrogen gas. Both arc melting and induction melting techniques are practiced in remote manner, such as from behind explosion proof walls in specially constructed buildings with blow-out walls. As a result, operation of such cold-wall metal crucibles or furnaces has been costly with good process control difficult to achieve.
Some prior art workers have melted and cast reactive alloys, such as titanium alloys, using calcium oxide crucibles. However, contamination of the alloy melt with oxygen is rapid and, with some alloys containing aluminum, extensive aluminum oxide vapor is evolved in such amounts as to preclude practical operation of traditional casting units by contaminating vacuum systems and chambers associated with the casting unit.
Other prior art workers, see U.S. Pat. No. 3 484 840, have rapidly melted titanium alloys in graphite lined crucibles in order to avoid harmful contamination of the melt. The patented process does not permit accurate control of the melt temperature and excessive melt contamination can occur if the heating cycle is too long. In addition, control of the melt flow out of the bottom of the crucible is difficult since melting of the center portion of a metal disc at the crucible bottom is employed to this end. With this arrangement, the melt flow orifice will vary with the melting rate, charge diameter, and disc size, making control of melt flow difficult.
Intermetallic alloys, such as especially TiAl, have received considerable attention in recent years for use in the aerospace and automobile industries in service applications where their high strength at elevated temperature and relatively light weight are highly desirable. However, these intermetallic alloys contain a majority of titanium (e.g. so-called gamma TiAl includes 66 weight % Ti with the balance essentially Al) which makes melting and casting without contamination difficult and very costly. In order to be adapted for use in such components as automobile exhaust valves, the intermetallic alloys must be melted and cast without harmful contamination in a high production, low cost manner.
It is an object of the present invention to provide a method and apparatus useful for, although not limited to, making intermetallic castings without harmful contamination in a high production, low cost manner especially suited to the requirements of the automobile, aerospace and other industries.
It is another object of the present invention to provide a method and apparatus for making intermetallic castings using a refractory melting vessel and a combination of molten and solid melting stock in a manner to avoid harmful contamination of the melt by reaction with the vessel.
It is another object of the invention to provide a method and apparatus for making intermetallic castings in a low cost manner by virtue of using relatively low cost melting stock which requires reduced energy requirement in order to yield a melt ready for casting into a mold.
SUMMARY OF THE INVENTION
The present invention involves a method and apparatus for making an intermetallic casting (e.g. a titanium, nickel, iron, etc. aluminide casting) wherein a charge comprising a solid first metal is disposed in a vessel, and a charge comprising a second metal that reacts exothermically with the first metal is melted in another vessel. The molten charge comprising the second metal is introduced to the vessel containing the charge of the first metal so as to contact the first metal. Alternately, a charge of the second metal in solid form is placed in the melting vessel to contact the other charge. The charges comprising the first and second metals are rapidly heated (e.g. by induction) in the vessel to exothermically react them and form a melt heated to a castable temperature for gravity or counter-gravity casting (e.g. as shown in U.S. Pat. No. 5 042 561) into a mold. The exothermic reaction between the first and second metals releases substantial heat (i.e. the intermetallic has a high heat of formation) that reduces the time needed to obtain a melt ready for casting into a mold. In particular, the exothermic reaction between the first and second metals, in effect, reduces the residence time of the intermetallic melt in the vessel. This reduced residence time, in turn, reduces potential contamination of the melt by reaction with the vessel material. Means, such as a vacuum, inert gas or substantially non-reactive atmosphere, preferably is used during the method as required to preclude the melt and casting from harmful reaction with air.
Moreover, the energy requirements needed to heat and melt the metals in the vessel are considerably reduced. Low cost forms of the first and second metals can be used in practicing the invention. As a result, overall casting costs are reduced. The method and apparatus of the invention can be used to produce large numbers of low cost, contamination-free intermetallic castings as needed by the automobile, aerospace, and other industries.
In one embodiment of the invention, the charge of the first metal is selected from one of titanium, nickel, iron, or other desired metal. The molten or solid charge of the second metal is aluminum, silicon, or other desired metal. The charge of the first metal preferably is preheated prior to introduction of the molten second metal in the vessel.
In another embodiment of the invention, the melt is gravity cast into a mold disposed below the vessel by breaking or fracturing a frangible closure member at a bottom of the vessel so as to communicate the mold and the vessel. The melt temperature (e.g. melt superheat) can be accurately controlled by appropriate timing of the breakage of the closure member to release the melt into the underlying mold. The closure member can be broken by striking it with a movable tapping rod in the vessel or, alternately, by establishing a suitable fluid pressure differential across the closure member, such as by raising the gas pressure on the melt inside the vessel relative to gas pressure outside the vessel.
In still another embodiment of the invention, the melt is countergravity cast into a mold disposed above the vessel through a fill pipe located between the melt and the mold (e.g. see U.S. Pat. No. 5 042 561). After countergravity casting, the vessel can be drained of unused melt remaining therein by breaking a frangible closure member at a bottom of the vessel. Upon breakage of the closure member, the vessel is communicated to an underlying chill mold for receiving and solidifying the unused melt in the chill mold. This arrangement reduces the time required to remove unused, drained melt and assemble a new crucible and mold for further casting.
In still another embodiment of the invention, the mold comprises a thin-walled investment mold disposed in a mass of refractory (e.g. ceramic) particulates during gravity or countergravity casting of the melt therein. The melting vessel may be also surrounded by a mass of similar refractory particulates. The particulate masses (or other non-reactive confining means) confine any melt that might escape from the vessel or mold.
In a particular embodiment of the invention, a plurality of titanium aluminide castings are made by disposing a charge of solid titanium in a refractory (e.g. graphite) lined vessel, preheating the charge to an elevated temperature below the liquidus temperature of titanium, melting aluminum in another vessel, and introducing the molten aluminum to the lined vessel so as to contact the charge of titanium. The aluminum and titanium are heated in the vessel to exothermically react and form an intermetallic melt for gravity or countergavity casting into an investment mold having a plurality of molding cavities. The exothermic reaction between the aluminum and titanium reduces the residence time of the melt in the vessel to reduce contamination of the melt by reaction with the vessel and also reduces energy requirements for producing the melt ready for casting. The titanium metal and aluminum can comprise relatively low cost scrap metal.
Other objects and advantages of the present invention will become apparent from the following detailed description and the drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic, sectioned side view of an apparatus in accordance with one embodiment of the invention for practicing a gravity casting method embodiment of the invention.
FIG. 2 is similar to FIG. 1 with the funnel replaced by the tapping rod.
FIG. 3 is a view of apparatus similar to that of FIG. 1 illustrating an alternative means (gas pressure differential means) for breaking the bottom closure member of the melting vessel. In FIG. 2, like features of FIG. 1 are represented by like reference numerals.
FIG. 4 is a schematic, sectioned side view of an apparatus in accordance with a second embodiment of the invention for practicing a countergravity casting method embodiment of the invention.
FIG. 5 is similar to FIG. 4 with the fill pipe immersed in the melt.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, apparatus in accordance with an embodiment of the invention for making intermetallic castings is shown as including a mold section 10 and a stationary melting section 12 with the mold section disposed beneath the melting section for gravity casting of an intermetallic melt. Although the apparatus will be described with respect to casting a TiAl melt for purposes of illustration, the invention is not so limited and can be practiced to make castings of other intermetallic alloys such as including, but not limited to, Ti 3 Al, TiAl 3 , NiAl, and other desired aluminides and silicides wherein the intermetallicalloy comprises first and second metals that react exothermically in the manner described herebelow. The intermetallic alloy can include alloyants in addition to the first and second metals. For example, a TiAl alloyed with Mn, Nb, and/or other alloyant can be cast.
The mold section 10 includes a steel mold container 20 having a chamber 20ain which an investment mold 22 having a plurality of mold cavities 24 is disposed in a mass 26 of low reactivity particulates. The chamber 20 includes a lower cylindrical region and an upper conical region as shown. The mold 22 includes a down feed or sprue 28 connected to the mold cavities 24 via lateral ingates 31.
An upper extension or region 29 is formed integrally with the mold 22 to provide a cylindrical, melting vessel support collar 30 and a central, cylindrical melt-receiving chamber 32 that communicates the mold sprue 28 to the melting vessel 54.
The investment mold 22 and the integral extension 29 are formed by the wellknown lost wax process wherein a wax or other removable pattern is investedwith refractory particulate slurry and stucco in repeated fashion to build up a desired mold wall thickness about the pattern. The pattern is then removed by melting or other techniques to leave the mold which is typically fired thereafter at elevated temperature to develop desired strength for casting.
For casting the TiAl intermetallic alloy mentioned hereabove, the investment mold 22 includes an inner zirconia or yttria facecoat and zironia or alumina outer back-up layers forming the body of the mold (e.g.see U.S. Pat. No. 4 740 246). The total mold wall thickness employed can befrom 0.1 to 0.3 inch. The inner face coat is selected to exhibit, at most, only minor reaction with the TiAl melt cast therein so as to minimize contamination of the melt during solidification in the mold 22. A preferred inner mold-facecoat for casting TiAl is applied as a slurry comprising zirconium acetate liquid and zirconia flour, dried, and stuccoed with fused alumina (mesh size 80). One facecoat layer is applied.Preferred backup layers for use with this facecoat are applied as a slurry comprising ethyl silicate liquid and tabular alumina, dried, and stuccoed with fused alumina (mesh size 36). Suitable mold face coats for melts other than TiAl can be readily determined.
The particulates of mass 26 are selected to exhibit low reactivity relativeto the particular melt being melted and cast into the mold 22 so that in the event of any melt leakage from the mold 22, the melt will be confined in a harmless manner without reaction in the mass 26. For a TiAl melt, theparticulates of mass 26 comprise zirconia grain of -100 +200 mesh size.
The mold container 20 includes a port 36 communicated via a conventional on/off valve 38 to a source 40 of argon or other inert gas. The port 36 isscreened by a perforated screen 41 selected to be impermeable to the particulates of mass 26 so as to confine them within the container 20. As will be described herebelow, the valve 38 is actuated during the casting operation to admit argon gas to the container 20 about the mold.
The mold container 20 is movable relative to the melting section 12 by an elevator 21 (shown schematically) beneath the container 20. The mold container 20 includes proximate its upper end a radially extending, peripheral shoulder or flange 42 which is adapted to engage the melting section 12 during the casting operation.
In particular, the melting section 12 includes a metal (e.g. steel) meltingenclosure 50 forming a melting chamber 52 about a refractory melting vessel54. The melting enclosure 50 includes a side wall 56 and a removable top 58sealed to the side wall via a sealing gasket 60.
The side wall 56 includes a radially extending, peripheral shoulder or flange 62 against which the mold container shoulder or flange 42 is sealingly engaged by actuation of the lift 21 during the casting operation. A gas sealing gasket 63 is disposed between the shoulders 42, 62.
The side wall 56 also includes a sealed entry port 66 for passage of electrical power supply couplings 68a, 68b from an electrical power source(not shown) to an induction coil 68 disposed in the chamber 52 about the melting vessel 54. The side wall 56 also includes a port 70 communicated via a conduit 72 and valve 74 to a source 76 of argon or other inert gas and, alternately, to a vacuum source (e.g. vacuum pump) 78.
The removable top 58 includes a sealable port 80 through which a molten metal component of the intermetallic melt is introduced into the melting vessel 54 via a refractory (e.g. clay bonded mullite) funnel 81 temporarily inserted in port 80. An optional tapping rod 82 can also be sealingly received in the port 80 as shown in FIG. 2 for use in a manner to be described to release melt from the melting vessel 54.
The side wall 56 includes an outer, annular shoulder or flange 84a fastenedto an inner, annular shoulder 84b on which coil supports 86, typically 4, are circumferentially disposed to support the induction coil 68. The flanges 84a, 84b are fastened by nut/bolt fasteners 84c so as to permit different flanges 84b to be used to accommodate different size melting vessels/induction coils.
The mass 26 of particulates extends upwardly between the coil 68 and the melting vessel 54 so as to confine any melt that might leak or otherwise escape from the vessel 54 within the low reactivity particulates.
As shown in FIG. 1, a cylindrical, tubular ceramic shell 90 is supported and fastened (e.g. by potassium silicate ceramic adhesive) atop the collar30. The collar 30 is shown including a frangible, refractory closure member92 held in position by gravity so as to be located proximate the bottom of the melting vessel 54. The closure member 92 includes annular notch 92a that renders the closure member readily breakable to release the melt fromthe melting vessel 54 to the mold 22.
The ceramic shell 90 is also formed by the lost wax process described hereabove from like ceramic materials to like wall thickness as used for the mold 22. The closure member 92 is also of like material and thickness as the mold 22 and shell 90.
The melting vessel 54 thus is formed by the collar 30, shell 90, and closure member 92. After the collar 30, shell 90, and closure member 92 are assembled together to form the melting vessel 54, the vessel 54 is lined with GRAFOIL graphite sheet or graphite cloth material liner 94 available from Polycarbon Corporation. The liner thickness is typically 0.010 inch. The liner 94 is adequately non-reactive with the melt over theshort time period that the melt resides in the melting vessel 54. The linermay be coated with yttria to reduce carbon pickup by the melt. Other liner materials that can be used for containing the TiAl melt include, but are not limited to, yttria and thoria. Liner materials suitable for melts other th-an TrAl melt can be selected as desired so as to be generally non-reactive with the melt during the melt residence time in the vessel 54.
The open upper end of the melting vessel 54 is partially closed by a closure plate 100 made of fibrous alumina. The plate 100 includes a central opening 102 through which the molten metal component of the intermetallic melt can be introduced to the vessel. The opening also receives the aforementioned tapping rod 82, if used.
In use in accordance with a method embodiment of the invention, the mold 22is invested in the particulate mass 26 (e.g. zirconia grain) in the container 20. The GRAFOIL lined shell 90 with the closure member 92 thereon then is placed against the collar 30.
A charge C1 of solid unalloyed titanium (first metal of the intermetallic alloy) pieces is positioned in the melting vessel 54 and the plate 100 is placed on the shell 90. The charge C1 of titanium can comprise titanium scrap sheet, briquettes, or other shapes. Alloyant(s) to be included in the melt may be dispersed as alloyant particulates with the titanium charge C1 so as to provide fast solutioning of the alloyant in the melt.
The Ti scrap sheet pieces are typically 1 inch×1 inch×1/16 inchmaximum in size and obtained from Chemalloy Co. The briquettes are made from titanium sponge to sizes approximately 1 inch×1 inch×3 inches. The titanium charge C1 is added in an amount to provide the desired Ti weight % in the intermetallic casting. The charge C1 typically is introduced manually.
The charged assembly is raised upward by the elevator 21, such as a hydraulic lifting mechanism, located beneath the container 20. The chargedassembly is raised to position the melting vessel 54 within the induction coil 68 in the stationary melting enclosure 50. The top 58 of the melting enclosure 50 is absent or remotely positioned at this point.
The annular space between the melting vessel 54 and the coil 68 then is filled through the open enclosure 50 with the particulates (zirconia grain) to extend the mass 26 to the level shown in FIG. 1 about the vessel54. The top 58 then is sealingly positioned on the sealing gasket 60 of side wall 56 in preparation for initiation of the melting/casting operation.
At the beginning of the casting cycle, the melting chamber 52 is first evacuated to less than 0.1 torr (100 microns) and then backfilled with argon to slightly above atmospheric pressure (>5 torr, usually 5-80 torr) via the port 70. The charge (melting stock) C1 of induction coil 68 to 300-1500° F. (i.e. below the liquidus temperature of titanium).
Concurrently, a charge (melting stock) C2 of aluminum is melted in a melting vessel 110 outside the casting apparatus to provide the second metal component of the intermetallic alloy. In particular, a charge of aluminum scrap or other unalloyed (or alloyed with a small % of alloyant) aluminum is air melted by a conventional gas-fired melter in the vessel 110 which is composed of a clay/graphite refractory. The molten aluminum charge C2 is heated in vessel 110 to about 1300° F., providing 80° F. of superheat. The molten aluminum is poured into the meltingvessel 54 through the refractory funnel 81 temporarily positioned in the port 80 which is open to this end. The amount of molten aluminum added to the vessel 54 corresponds to the weight % of aluminum desired in the intermetallic alloy. The funnel is removed, and the tapping rod 82 then issealingly inserted in the port 80 and held in a position above and aligned with the vessel plate opening 102. The funnel 81 is removed, and the tapping rod 82 is then sealingly disposed in the port 80 as shown in FIG. 2.
The melting chamber 52 is then evacuated to about 100 microns or less via the port 70. Evacuation of the chamber 52 also results in evacuation of the mold container 20 and its contents to the same level. The tapping rod 82 is retained or held in the position of FIG. 2 by a wing bolt clamp 131 engaged about the rod 82 and engaging the top seal member 83 of the top 58
Upon reaching the desired vacuum level in the chamber 52 (e.g. 60 seconds),the induction coil 68 is energized to a power level to heat/melt the solid titanium charge C1 and the molten aluminum charge C2 and react them in themelting vessel 54. The titanium and aluminum charges react exothermically in the vessel 54 to generate substantial heat that accelerates the meltingprocess to reduce the time needed to obtain an intermetallic melt M ready for casting into the mold 22 and that also replaces electrical power that otherwise would be required from the induction coil 68. Generally, a powerlevel in the range of 200 to 240KW applied for 1.25 to 2.00 minutes can be used to produce TiAl melts in the range of 40 to 50 pounds. The power level and time can be varied and controlled to achieve the desired superheat in short times. Other power levels and times can be used producemelts of other intermetallic alloys.
The time required to produce a TiAl melt in the vessel 54 ready for castingin the mold 22 is quite short, not exceeding a power-on time of about 2 minutes typically. As a result, the residence time of the melt in the vessel 54 is short enough that no harmful reaction of the melt and the vessel refractory liner is experienced. This results in a melt that is useful for structural castings. Specifically, carbon contents less than 0.04 weight % and oxygen contents less than 0.18 weight % have been obtained in the melt.
As soon as the melt reaches the desired casting (superheat) temperature (e.g. after only 1.25 minutes), the melt is cast into the mold 22 by movement of the tapping rod 82 downwardly in a manner to strike and break the frangible closure member 92 and the liner 94. This releases the melt for gravity flow into the central chamber 32 and down the sprue 28 into the mold cavities 24 via the lateral ingates 31. Casting of the melt into the mold 22 is thus precisely controlled by controlling the time at which the closure member 92 is broken to release the melt for flow to the mold 22. The broken closure member 92 is caught by three (only two shown) circumferentially spaced zirconia rods 120 in the central chamber 32 so asto maintain melt flow passages open.
The tapping rod 82 is released by manually releasing the wing bolt clamp 131 to allow atmospheric pressure on the outer rod end 82a to move the rod82 toward the vessel through the melt to allow the inner rod end 82b to break the closure member 92 and liner 94.
In lieu of using the tapping rod 82 to break the closure member 92, a pressure differential can be established across the closure member to thissame end. For example, the interior of the melting vessel 54 can be pressurized via a suitable argon gas pressure supply conduit 121 and cap 122 (FIG. 3) positionable over the open upper end of the vessel 54 to introduce argon gas thereinto, for example, from a conventional argon source 129 via a valve 133. The interior of the vessel 54 thereby can be pressurized relative to the container 20 to establish a sufficient gas pressure differential across the closure member 92 to break it when the melt is at the desired casting temperature, thereby releasing the melt to flow from the vessel 54 to the mold 22.
In FIG. 3, the Al melt is introduced from the vessel 110 through a valve 141 which is opened to this end. The melt is poured through a funnel (not shown) communicated to the open valve 141. The melt flows through conduit 121 into the vessel 54.
As mentioned hereabove, the mold material is selected to minimize melt/moldreactions while the melt solidifies in the mold 22. This also aids in production of TiAl castings free of harmful contamination.
After the melt is cast into the mold 22 in the manner described, the container 20 and chamber 52 are backfilled with argon to atmospheric pressure. In effect, the mold 22 containing the melt is flooded in an argon atmosphere while the melt cools and solidifies in the mold 22 to prevent oxidation of the casting. Once the container 20 and chamber 52 arefilled with argon, the mold section 10 (flooded with argon through passage 36) can be removed from engagement with the melting section 12 by loweringthe elevator 21. The container 20, melt-filled mold 22, and melting vessel 54 are thereby removed from the melting section 12 (i.e. from melting chamber 52) so that a new mold container 20, mold 22, and melting vessel 54 filled with a new titanium charge can be positioned in the melting chamber 52 as described hereabove to repeat the cycle described hereabove.Similarly, a new molten aluminum charge C2 is formed in the vessel 110.
Referring to FIG. 4, apparatus in accordance with another embodiment of theinvention for making intermetallic castings by countergravity casting is shown. In particular, the apparatus includes a mold section 210 and a melting section 212 with the mold section disposed above the melting section for countergravity casting the intermetallic melt. The mold container 220 is movable relative to the melting section 12 by a hydraulically actuated arm (not shown) as illustrated shown in aforementioned U.S. Pat. No. 5 042 561.
The mold section 210 includes a steel mold container 220 having a cylindrical chamber 220a in which an investment mold 222 having a plurality of mold cavities 224 is disposed in a mass 226 of low reactivityparticulates. The mold 222 rests on an elongated, refractory (e.g. carbon) fill pipe 223 depending therefrom outside the container 220. The fill pipe223 is joined to the bottom of the mold 222 and extends sealingly through abottom opening in the container 220 as shown, for example, in U.S. Pat. No.5 042 561. A mold sprue 228 is communicated to the fill pipe 223 and to themold cavities 224 via lateral ingates 231. The investment mold 222 is formed by the aforementioned lost wax process.
The mold container 220 includes a openable/closeable lid 225 connected to the container via a hinge 225a. The lid 225 carries a sheet rubber gasket 229 communicated to ambient atmosphere by vent opening 221.
The mold 222 is embedded in particulates mass 226 selected to exhibit low reactivity to the particular melt being melted and cast into the mold 222 so that in the event of any melt leakage from the mold 222, the melt will be confined in a manner without harmful reaction in the mass 226. Suitableparticulates for a TiAl melt are described hereabove. The rubber gasket 229compacts the particulate mass 226 about the mold 222 when a relative vacuumis drawn in the container 220 to support the mold during casting.
The mold container 220 includes a peripherally extending chamber 236 communicated via a conventional on/off valve 238 to a source 240 of vacuum, such as a vacuum pump. The chamber 236 is screened by a perforatedscreen 241 selected to be impermeable to the particulates of mass 226 so asto confine them within the container 220. The mold container 220 also includes an inlet conduit 237 for admitting argon from a suitably screeneddistribution conduit 243 to the container 220 from a suitable source 247.
The melting section 212 includes a metal (e.g. steel) melting enclosure 250forming a melting chamber 252 about a refractory melting vessel 254. The melting enclosure 250 includes a side wall 256 and a removable top 258 sealed to the side wall via a sealing gasket 260. A sliding cover 261 of the type set forth in aforementioned U.S. Pat. No. 5 042 561 is disposed on a fixed cover 259 of the top 258 and is slidable to receive fill pipe 223 for the purposes set forth in that patent. The fixed cover 259 includes an opening 259a for the mold fill pipe 223 as shown in FIG. 3. The sliding cover 261 includes an opening 261a for receiving the fill pipe223 when openings 259a, 261a are aligned to cast the melt from the vessel 254 into the mold 222.
The side wall 256 includes a sealed entry port 266 for passage of electrical power supply couplings 268a, 268b from an electrical power source (not shown) to an induction coil 268 disposed in the chamber 252 about the melting vessel 254. The side wall 256 also includes a port 270 communicated via a conduit 272 and valve 274 to a source 276 of argon or other inert gas and, alternately, to a vacuum source (e.g. vacuum pump) 278.
The side wall 256 includes an inner shoulder or flange 284 on which coil supports 286 sit to support the induction coil 268. A mass 219 of low reactivity particulates (like mass 226) extends upwardly between the coil 268 and the melting vessel 254 so as to confine any melt that might leak or otherwise escape from the vessel 254 within the low reactivity particulates.
The melting vessel 254 comprises a cylindrical, tubular ceramic shell 290 supported and fastened (e.g. by potassium silicate ceramic adhesive) atop a ceramic collar 291. The collar 291 is shown including a frangible, refractory closure member 292 held in place by gravity so as to be locatedproximate the bottom of the melting vessel 254 defined by shell 290, collar291, and closure member 292. The closure member 292 includes annular notch 292a that renders the closure member readily breakable following the casting operation in a manner to be described.
The ceramic shell 290 and collar 291 are also formed by the lost wax process described hereabove. For casting TiAl, shell 290, collar 291 and closure member 292 comprise the materials described hereabove in connection with the embodiment of FIG. 1. After the shell 290, collar 291,and closure member 292 are assembled together to form the melting vessel 254, the vessel 254 is lined with GRAFOIL graphite sheet or graphite clothmaterial liner 294 also of the type described hereabove.
The open upper end of the melting vessel 254 is partially closed by a closure plate 300 made of fibrous alumina. The plate 300 includes a central opening 302 through which the molten metal component of the intermetallic melt and the mold fill pipe 223 can be introduced to the vessel.
The lower closed end of the melting vessel 254 includes an outer shoulder or flange 310 that sealingly engages a similar shoulder or flange 320 on alowermost chill mold container 322. The container 322 includes a metal (e.g. copper) chill mold 324 positioned therein below the bottom of the melting vessel 254 such that the collar 291 rests sealingly on the chill mold 324. The particulates mass 219 is disposed about the collar 291 down to the chill mold as shown and confined by a sleeve 323. The container 322is supported on an elevator 221.
In use in accordance with a countergravity casting embodiment of the invention, the mold 222 is invested in the particulate mass 226 (e.g. zirconia grain) in the container 220 with the fill pipe 223 extending out of the container 220, FIG. 4.
The melting vessel 254 is assembled and positioned on the chill mold 324 disposed in the container 322. The container 322 is raised by the elevator221 to position the charged vessel 254 in the meltinq chamber 252 within the induction coil 268 as shown in FIG. 4. Particulates 219 are then introduced about the melting vessel through opening 302. The charge C2 of solid unalloyed titanium (first metal of the intermetallic alloy) pieces is placed in the melting vessel 254 and the plate 300 is placed thereon. The charge of titanium can comprise low cost titanium scrap sheet, briquettes, and other suitable shapes as described hereabove. Alloyant particulates may be dispersed in the titanium charge C1 as described above.
To begin the casting cycle, the melting chamber 252 is first evacuated to about 100 microns and then backfilled with argon to slightly above atmospheric pressure (>5 torr) via the port 270. The charge (melting stock) of titanium solid pieces is then preheated, if desired, by induction coil 268 to 350-1500° F. (i.e. below the liquidus temperature of titanium).
Concurrently, a charge (melting stock) of aluminum is melted in a melting vessel (not shown but similar to vessel 110 of FIG. 1) outside the castingapparatus to provide the second metal component of the intermetallic alloy.In particular, a charge of aluminum scrap or other unalloyed (or alloyed) aluminum is air melted in the vessel which includes a clay/graphite refractory lining in the manner described hereabove. The molten aluminum is heated to a superheat of about 80° F. and then poured into the melting vessel 254 through the ports 259a, 261a and 302. The amount of molten aluminum added to the vessel 254 corresponds to the weight % of aluminum desired in the intermetallic alloy.
With argon gas pressure slightly above atmospheric pressure, the induction coil 268 is energized to a power level to heat the solid titanium charge and the molten aluminum charge to melt and react them in the melting vessel 254. The titanium and aluminum charges react exothermically in the vessel 254 to generate substantial heat that accelerates the melting process to reduce the time needed to obtain an intermetallic melt M ready for casting into the mold 222 and that also replaces electrical power thatotherwise would be required from the induction coil 268. A power level of 240 KW has been used to produce a TiAl melt (42 pounds) ready for casting after only 1.25 minutes following energization of the induction coil 268. Generally, a power level in the range of 200 to 240 KW applied for 1.25 to2.0 minutes can be used to produce TiAl melts in the weight range of 40 to 50 pounds. The power level and time can be varied and controlled to achieve the desired superheat in short times.
The time required to produce a TiAl melt M in the vessel 254 ready for casting in the mold 222 is quite short, not exceeding a power-on time of about 2 minutes typically. As a result, the residence time of the melt in the vessel 254 is short enough that no harmful reaction of the melt and the vessel refractory liner is experienced. This results in a melt that isuseful for structural castings.
As soon as the melt reaches the desired casting (superheat) temperature (e.g. after only 1.25 minutes), the container 220 is lowered to insert thefill pipe 223 through the port 259a and also port 302 into in the melt M inthe vessel 254, FIG. 5. The container 220 is moved by the aforementioned hydraulically actuated arm (not shown). Before or upon immersion of the fill pipe in the melt, a vacuum is drawn in the container via chamber 236.A vacuum is thereby applied to the mold 222 compared to the atmospheric argon gas pressure in the melting chamber 252 so as to establish a negative pressure differential pressure between the mold cavities 224 and the melt in the vessel 254 sufficient to draw the melt upwardly through the fill pipe 223 into the mold 222.
After the mold 222 is filled with the melt and the castings are solidified in mold cavities 224, the container 220 is lowered to cause the fill pipe 223 to strike and break the closure member 292 and liner 294. The container 220 is then raised to withdraw the fill pipe 223 from the melt chamber 252. Some of the melt in the fill pipe drains back into the vesselduring this movement. The drained melt and any unused melt remaining in thevessel 254 flow into the chill mold 324 where the melt rapidly solidifies. After the melt in the chill mold cools sufficiently (e.g. to 1100° F.), the melt-filled chill mold 324 and the vessel 254 then can be removedfrom the melting chamber 252 by lowering the elevator 221.
Use of the chill mold 324 to rapidly solidify the drained/unused melt reduces the time otherwise required to establish a new container 322, chill mold 324, and vessel 254 charged with titanium for further casting of parts. Without the chill mold 234, the drained/unused melt must remain in the vessel 254 and slowly cool to a low enough temperature to permit removal from the melting chamber.
After the new container 322, chill mold 324 and charged vessel 254 are in place in the melting chamber 252 as described before, the aluminum melt can be prepared in the other melting vessel (see vessel 110 of FIG. 1) andthe casting cycle described hereabove repeated to cast a new mold 222 in a container 220. As a result, casting cycle time is reduced.
The melt-filled mold 222 (just removed from the melting chamber 252) is left in its container 220 with argon flow through inlet 237 so that the melt can solidify and/or cool to ambient under argon. As mentioned hereabove, the mold material is selected to minimize melt/mold reactions while the melt solidifies in the mold 222. This also aids in production ofTiAl castings free of harmful contamination.
The apparatus of FIGS. 4-5 is characterized by a short casting cycle time. For example, in the production of automobile exhaust valves made of TiAl, three molds 222 each containing 270 mold cavities can be countergravity cast per hour using the apparatus of FIG. 3. The charge of TiAl in the vessel would be 54 pounds with 11 pounds drained from the fill pipe 223 when it is withdrawn from the melt after the mold 222 is filled. A total of 4 million exhaust valves can be cast per apparatus (FIG. 4-5) per year as a result. The valves will be cast at low cost relative to other available techniques and will be free of harmful contamination resulting from melt/vessel and melt/mold reactions.
Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention. | The present invention involves a method and apparatus for making an intermetallic casting (e.g. a titanium, nickel, iron, etc. aluminide casting) wherein a charge of a solid first metal protected from air as required is disposed in a vessel, and a charge of a second metal that reacts exothermically with the first metal is melted in another vessel. The molten second metal is introduced to the vessel containing the charge of the first metal so as to contact the first metal. The first and second metals are heated in the vessel to exothermically react them and form a melt for gravity or countergravity casting into a mold. The exothermic reaction between the first and second metals releases substantial heat that reduces the time needed to obtain a melt ready for casting into a mold. In particular, the exothermic reaction between the first and second metals, in effect, reduces the residence time of the intermetallic melt in the vessel. This reduced residence time, in turn, reduces potential contamination of the melt by reaction with the vessel material. Moreover, the energy requirements needed to heat and melt the metals in the vessel are considerably reduced. Low cost forms of the first and second metals can be used in practicing the invention. As a result, overall casting costs are reduced. The method and apparatus of the invention can be used to produce large numbers of low cost, low contamination intermetallic castings as needed by the automobile, aerospace, and other industries. | 1 |
This is a continuation of application Ser. No. 945,951, filed Dec. 24, 1986, which was abandoned upon the filing hereof.
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The present invention relates to an illumination optical system for an endoscope.
(b) Description of the Prior Art
Known illumination optical systems for endoscopes are generally composed as shown in FIG. 1. That is, an illumination lens 3 having a concave surface with strong curvature on the light guide side and having a strong diverging function is arranged in front of, i.e., on the object side of, the light exiting surface of a light guide 1 so that the light coming out from the light guide diverges to a wide area. However, the above-mentioned kind of illumination optical systems have a problem described below. That is, as the diverging angles of rays become larger toward the marginal portion of the illumination lens, the density of illumination rays becomes considerably low in the marginal portion of the illumination field and, consequently, the intensity of light in the marginal portion of thereof becomes considerably low. Besides, the rays that come out from the light exiting surface of the light guide at large angles in respect to the optical axis are scattered and lost by causing diffused reflection at the inner peripheral surface of the illumination lens or return to the light guide side without going out from the illumination lens by causing total reflection at the marginal portion of the front surface of the illumination lens. As a result, the brightness of illumination in the marginal portion of the illumination field becomes largely different from the brightness in the central portion thereof, and it is immpossible to obtain uniform illumination over the whole illumination field.
To solve the above-mentioned problem, it is proposed to adopt an aspherical surface for an illumination lens. For example, Japanese published unexamined utility model application No. 17071/82 discloses an illumination optical system for an endoscope provided with an illumination lens which is arranged that the surface on the light guide side is formed as a complex surface, which has a central portion formed as a spherical surface and a marginal portion formed as a conical surface, and the surface on the object side is formed as a planar surface. However, in case of said known illumination optical system the above-mentioned problem is not solved satisfactorily, and the problem of lack of uniformity of illumination still remains.
Now, for known illumination optical systems for endoscopes, detailed description is given below regarding the problem of lack of uniformity of illumination, especially, regarding the problem that the intensity of light in the marginal portion of the illumination field becomes considerably different from the intensity of light in the central portion thereof.
The conventional illumination optical systems shown in FIG. 1 comprise illumination lenses having the numerical data shown below.
Conventional lens 1
______________________________________r.sub.1 = ∞d.sub.1 = 0.4545 n.sub.1 = 1.883 ν.sub.1 = 40.78r.sub.2 = 1.1818______________________________________
Conventional lens 2
______________________________________r.sub.1 = ∞d.sub.1 = 0.4545 n.sub.1 = 1.883 ν.sub.1 = 40.78r.sub.2 = 1.045______________________________________
In the numerical data shown in the above, reference symbols r 1 and r 2 respectively represent radii of curvature of the first and second surfaces of the illumination lens, reference symbol d 1 represents the thickness of the illumination lens, reference symbol n 1 represents the refractive index of the illumination lens, and reference symbol ν 1 represents Abbe's number of the illumination lens.
Here, a ray which goes out from the light guide 1 in the direction parallel with the axis of the light guide is considered (said ray is hereinafter referred to as the principal ray) and, when the height of the principal ray is represented by reference symbol h, the angle formed by the principal ray after going out from the illumination lens in respect to the optical axis is represented by reference symbol A(h).
In case of the known illumination system shown in the above, A(h) sharply becomes large according to increase of h as shown in FIG. 2. This means that the density of principal rays becomes low in the marginal portion of the illumination field of the endoscope and, therefore, the brightness of illumination becomes low in the marginal portion. Here, the rays which go out from an optical fiber in the light guide is represented by the principal ray because, out of those rays, a ray which is closer to the state that the ray is parallel with the axis of the light guide has higher intensity of light.
Besides, when A(h) becomes considerably larger as the height of ray becomes higher (i.e., as h becomes larger), rays are largely refracted by the marginal portion of the illumination lens. This causes such phenomenon that rays partially come to the inner peripheral surface of the illumination lens and are thereby diffused and such phenomenon that incident angles of rays on the marginal portion of the front surface of the illumination lens become large and those rays partially return to the light source side by causing total reflection. As a result, the decrease of the intensity of light in the marginal portion is further promoted.
SUMMARY OF THE INVENTION
It is, therefore, a primary object of the present invention to provide an illumination optical system for an endoscope which is applicable to a wide angle endoscope and, at the same time, which is arranged that bright illumination is obtained up to the marginal portion of the field and the loss in the intensity of light is small.
To attain the above-mentioned object, the illumination optical system for an endoscope according to the present invention is arranged that the illumination lens thereof comprises at least one aspherical lens element having at least one aspherical surface expressed by the formula (1) shown below and that the shape of said aspherical surface is selected so as to fulfill the conditions (2), (3) and (4) shown below: ##EQU1## where, C=1/R (where, reference symbol R represents the raidus of curvature of the vertex portion of the aspherical surface), reference symbol y represents the radius measured from the optical axis (x axis), reference symbol P represents the constant of cone, reference symbols B, E, . . . respectively represent coefficients of aspherical surface, reference symbol h represents the height of ray, reference symbol A(h) represents the angle between the principal ray and optical axis (x axis) formed after the principal ray passes through the aspherical surface, reference symbol r represents the the radius of an illuminating surface illuminated by a light source (where, in the case of the embodiment shown in FIG. 3, the light exiting surface of the light guide fiber bundle 1 operates as an illuminating surface to illuminate an object, and r represents the radius of the illuminating surface. In a case where a frosted glass is placed in front of a lamp so as to form an illuminating surface, r represents the radius of the said frosted glass plate, or in a case where a plurality of small light emitting diodes are placed side by side so as to form an illuminating surface, r represents the radius of the aggregate of the light emitting diodes.), reference symbol x 1 represents the difference between the x coordinate of the foremost point (point on the object side) and x coordinate of the rear most point (point on the light source side) on the first surface (surface on the object side) of the aspherical lens, and reference symbol x 2 represents the difference between the x coordinate of the foremost point (point on the object side) and x coordinate of the rearmost point (point on the light source side) on the second surface (surface on the light source side) of the aspherical lens. Besides, the origin of the coordinate system for the formula (1) is the intersecting point between the vertex portion of the aspherical surface and the optical axis as shown in FIG. 4. Respective parameters explained in the above are shown in FIGS. 3 and 9 which respectively illustrate preferred embodiments of the present invention.
Now, meanings of respective conditions shown in the above are described below.
The meaning of the condition (2) is as follows. As described before, in cases of the known illumination lenses, the lack of uniformity of the brightness of the illumination field is caused by the face that the value of A(h) becomes larger in the monotone increasing pattern as the value of h becomes larger. Therefore, when the increasing tendency of A(h) is suppressed, it is possible to increase the uniformity of illumination. Here, in case that the object has a spherical surface and the distal end of the endoscope is located at the center of curvature of the spherical surface, the value of dA/dh, i.e., the rate of increase of A in relation to increase of h, becomes constant when it is arranged that the formula d 2 A/dh 2 =0 is fulfilled and, consequently, the illumination becomes perfectly uniform. An endoscope is to be inserted to a narrow space such as a stomach and to be used for observation of the inside thereof. In most cases, the inner surface of such object to be observed is concave toward the distal end of the endoscope as shown in FIG. 5, and it is possible to apply the above-mentioned idea regarding the case that the object has a spherical surface. Therefore, when it is arranged that the formula d 2 A/dh 2 ≈0 is fulfilled, it is possible to improve the uniformity of illumination. Furthermore, an endoscope objectives have strong negative distortion, images of objects in the marginal portion become small and, therefore, it is permissible even when the marginal portion of the field is somewhat dark. In other words, it is all right when the value of d sinA/dh is approximately constant, i.e., when d 2 /dh 2 (sin A(h))=0. On the other hand, when d.sup. 2 /dh 2 (sin A(h))<0, the marginal portion of the field will become brighter. However, even in case of a substantially spherical inner surface such as an inner surface of a stomach, the object surface may be regarded as a substantially flat surface when the distal end of the endoscope is brought to a position very near the wall of the stomach. Besides, even when the marginal portion of the field becomes brighter, anything inconvenient will not be caused. Therefore, it is all right as far as the afore-mentioned condition (2), i.e., d 2 /dh 2 (sin A(h))≦0, is fulfilled.
Here, h is supposed to be 0≦h≦r. However, it is not required that the condition (2) is fulfilled for all values of h but it is sufficient for practical use as far as the range of values of h where it becomes d 2 sin A/dh 2 ≦0 as shown in FIG. 8 exists in the range of 0≦h≦r. Besides, the practical light distribution characteristic will be also improved as far as such values of h that fulfill the formula d 2 sin A/dh 2 ≦0 exist in the state that they correspond to about 20% or more of the area of the light exiting surface of the light guide (or the light projecting surface of the light source). Furthermore, to make the light distribution to the marginal portion of the field favourable, it is preferable to arrange that the range of h where the condition (2) is fulfilled exists in the range of h≧0.4r. This is because, out of rays which come out from the light exiting surface of the light guide, rays more distant from the optical axis serve to illuminate the portion of the field more distant from the optical axis and, therefore, it is preferable, for improvement of the light distribution to the marginal portion of the field, to arrange that the condition (2) is fulfilled in the zone which is comparatively distant from the optical axis. Besides, it is preferable to further arrange that the condition (2) is fulfilled at least over the area of 0.15r in the range of h≧0.4r. This is because the light distribution characteristic might not be improved if the condition (2) is fulfilled in a very small area only. That is, as far as the condition (2) is fulfilled at least over the area of 0.15r in the range of h≧0.4r, the influence thereof is given to a considerable part of rays which come out from the light guide and are directed toward the marginal portion of the field and, therefore, the light distribution characteristic is improved more favourably.
Now, the meaning of the condition (3) is described below. In recent years, the field angle of endoscopes is becoming wider, and many of endoscopes have field angles about 90° to 130°. On the other hand, the light distribution angle of the light guide itself is about 60°. Therefore, it is necessary to widen the light distribution angle by 30° or more by using a lens. For this purpose, it is all right when the lens serves to refract the principal rays by refraction angles of 15° or more. Here, the marginal portion of the field is illuminated by rays in the range where h is large, i.e., rays in the range where the height of ray is about h≧0.8r. Therefore, it is all right when the relation A(0.8r)≧15° is fulfilled. In other words, it is all right when the condition (5) shown below is fulfilled.
sin A (0.8r)≧0.2588 (5)
This means that, when the mean value of sin A in the marginal portion of the light guide is regarded as ##EQU2## it is all right when the relation
sin A≧0.2588
is fulfilled. That is, it is all right when the condition (3) is fulfilled.
Now, the meaning of the condition (4) is explained below. The condition (4) defines the relation between x 1 and x 2 where, as shown in FIG. 9, reference symbol x 1 represents the difference between the x coordinate of the foremost point O 1 (point on the object side) and x coordinate of the rearmost point G 1 (point on the light source side) on the first surface of the aspherical lens, and reference symbol x 2 represents the difference between the x coordinate of the foremost point O 2 (point on the object side) and x coordinate of the rearmost point (point on the light source side) on the second surface of the aspherical lens. Here, when the light exiting surface of the light guide comes to a position closer to the object side compared with the rearmost point on the second surface of the lens as shown in FIG. 9, reference symbol x 2 represents the difference between the x coordinate of the point O 2 and x coordinate of the light exiting surface G 2 of the light guide.
As it will be understood from FIG. 9, x 1 and X 2 respectively correspond to approximate values of refractive powers of the first and second surfaces and, therefore, the condition (4) means that the refractive power of the second surface is stronger than that of the first surface.
In case that the relation between x 1 and x 2 becomes x 1 >x 2 , the refractive power of the first surface becomes stronger than that of the second surface. As a result, total reflection of rays l' with large NA tends to be caused, and the loss in the intensity of light beocmes large.
FIG. 10 shows an example of a lens which fulfills the condition (4).
As described so far, the aspherical lens in the illumination optical system for an endoscope according to the present invention is arranged that at least one of the first and second surfaces thereof is formed as an aspherical surface with a shape expressed, for example, by the formula (1) and said aspherical surface may be formed either as a concave surface or as a convex surface and, moreover, may be formed as a surface whose sectional profile has a plural number of concave and convex portions. Besides, said aspherical lens is arranged to fulfill the conditions (2), (3) and (4). The illumination optical system for an endoscope according to the present invention comprising the above-mentioned aspherical lens makes it possible to attain the object of the present invention as described already.
It is difficult to analytically obtain a solution for the shape of an aspherical surface which fulfills said conditions (2), (3) and (4). However, it is possible to obtain the shape when the ray tracing method by a computer is adopted in the same way as the case that it is applied to imaging lenses in general.
The shape of the aspherical surface of the aspherical lens to be adopted in the illumination optical system according to the present invention is not limited to a surface which is rotationally symmetrical round x axis (optical axis). To eliminate the parallax in relation to the objective 4, at least one surface may be made eccentric by δ or tilted as shown in FIG. 12. In that case, when the illumination lens comprises a plural number of lens elements, it is possible to obtain the same effect as above when the illumination lens as a whole or at least one lens element thereof is made eccentric or tilted.
In case that a curved surface of a lens is arranged to have a shape which is not rotationally symmetrical round x axis as described in the above, it is all right as far as said curved surface is arranged to have an aspherical shape expressed by the formula (1) in the state that the lens is sectioned by a plane containing the axis which approximately passes the center of at least one optical fiber in the light guide. When the aspherical surface, which is determined as above and expressed by the formula (1), is arranged to fulfill the conditions (2), (3) and (4), it is possible to obtain an illumination lens which produces favourable light distribution and serves to attain the object of the present invention.
The cross-sectional shape of the light guide is not limited to a circular shape. For example, there exists a light guide with a square cross-sectional shape as shown in FIG. 13. In case of such light guide, the illumination lens according to the present invention may be arranged to have a curved surface having a shape with four-fold rotation symmetry as shown in said figure. FIG. 14 shows the shape of said curved surface in y and u directions. When the cross-sectional shape of the light guide is not circular as mentioned in the above, r in the condition (3) may be determined by converting the cross section of that light guide into a circle with the equal area.
Furthermore, instead of a curved surface expressed by the formula (1), it is also possible to adopt a surface whose sectional profile is obtained when a curved line is approximated by combining short straight line segments as shown in FIG. 15. Besides, it is also possible to adopt a surface whose sectional profile is obtained when a curved line is approximated by combining short straight line segments and short curved line segments as shown in FIG. 16. When adopting a surface whose sectional profile is obtained by approximating a curved line by combining short straight line segments or by combining short straight line segments and short curved line segments as mentioned in the above, portions corresponding to joint portions between line segments will become somewhat pointed. In case that such surface is adopted as the surface on the object side of the lens, the object might be injured. Therefore, it is preferable to adopt such surface as a surface on the image side.
Furthermore, it is possible to apply the idea according to the present invention also to a lens having a curved surface with a shape as shown in FIG. 17, i.e., a curved surface formed by combining two different aspherical surfaces. In that case, it is all right as far as said curved surface is formed that an arbitrary portion of the two aspherical surfaces fulfills the formula d 2 sin A/dh 2 ≦0. Besides, in the same way as the case of a single aspherical surface described already, it is more preferable when such values of h that fulfill the above-mentioned formula exist in the state that they correspond to about 20% or more of the area of the light exiting surface of the light guide, the range of h where the condition (2) is fulfilled exists in the range of h≧0.4r and, moreover, it is further arranged that the condition (2) is fulfilled at least over the area of 0.15r in the range of h≧0.4r.
Furthermore, the illumination optical system according to the present invention may be composed that an illumination lens comprising two or more aspherical lens elements is arranged in front of a light guide as shown in FIG. 18. In that case, it is sufficient when the conditions (2) and (3) are applied to the rays which already passed the two (the plural number of) aspherical lens elements, and the condition (4) is applied to at least one of the aspherical lens elements.
In the present invention, the term "aspherical surface" is used in the meaning that it includes such surface whose sectional profile is obtained by approximating a curved line by combining short straight line segments or combining short straight line segments and short curved line segments as described before.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a sectional view illustrating the composition of known illumination optical systems;
FIG. 2 shows a graph illustrating the relation between values of A and values of h of known illumination lenses of known illumination optical systems;
FIG. 3 shows a sectional view illustrating the composition of the illumination optical system for an endoscope according to the present invention;
FIG. 4 shows a coordinate system representing the formula which expresses an aspherical surface adopted in the present invention;
FIG. 5 shows a sectional view illustrating the light distribution of an illumination optical system comprising an aspherical lens;
FIG. 6 shows a graph illustrating the relation between values of sin A and values of h of known illumination lenses;
FIG. 7 shows a graph illustrating the relation between values of sin A and values of h of illumination lenses in Embodiments 1 through 5 of the present invention;
FIG. 8 shows a graph illustrating an example of the relation between values of sin A and values of h of the illumination optical system according to the present invention;
FIGS. 9 through 11 respectively show sectional views of illumination optical systems shown for the purpose of explanation of the condition (4) given in the present invention;
FIG. 12 shows a sectional view illustrating the composition of the illumination optical system according to the present invention in the state that the parallax is eliminated;
FIG. 13 shows a perspective view of the illumination optical system according to the present invention which is to be used in combination with a light guide having a square cross-sectional shape;
FIG. 14 shows the sectional shape of the curved surface of the aspherical lens shown in FIG. 13;
FIGS. 15 through 17 respectively show sectional profiles of other examples of aspherical surfaces to be adopted for aspherical lenses to be used in the present invention;
FIG. 18 shows a sectional view of another example of the illumination optical system according to the present invention wherein a plural number of aspherical lens elements are adopted;
FIGS. 19 through 27 respectively show sectional views of Embodiments 1 through 9 of the present invention;
FIG. 28 shows a sectional view illustrating the state of refraction of a principal ray by an aspherical lens whose aspherical surface is formed as a paraboloid; and
FIG. 29 shows a graph illustrating the relation between values of sin A and values of h of Embodiments 6 through 9 of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now, preferred embodiments of the illumination lens for the illumination optical system for an endoscope according to the present invention are shown below.
Embodiment 1
r 1 =∞ (aspherical surface)
d 1 =0.4545 n 1 =1.883 ν 1 =40.78
r 2 =1.1364
P 1 =1
x 1 =0.059, x 2 =0.8182, y max =1.30
B 1 =-0.55×10 -1 , E 1 =0.6442×10 -2
Embodiment 2
r 1 =∞ (aspherical surface)
d 1 =0.4545 n 1 =1.883 ν 1 =40.78
r 2 =1.2627
P 1 =1
x 1 =0.092, x 2 =0.6278, y max =1.368
B 1 =-0.715×10 -1 , E 1 =0.6442×10 -2
Embodiment 3
r 1 =∞ (aspherical surface)
d 1 =0.4545 n 1 =1.883 ν 1 =40.78
r 2 =1.1364 (aspherical surface)
P 1 =1 P 2 =1
x 1 =0.046, x 2 =0.8181, y max =1.18
B 1 =-0.55×10 -1 , F 1 =0.6442×10 -2
F 2 =0.6442×10 -2
Embodiment 4
r 1 =∞ (aspherical surface)
d 1 =0.4545 n 1 =1.883 ν 1 =40.78
r 2 =1.2627
P 1 =1
x 1 =0.1, x 2 =0.6273, y max =1.53
B 1 =-0.88×10 -1 , E 1 =0.29282×10 -1
Embodiment 5
r 1 =∞ (aspherical surface)
d 1 =0.4545 n 1 =1.883 ν 1 =40.78
r 2 =1.2627
P 1 =1, x 1 =0, x 2 =0.6273
F 1 =0.19197×10 -1
Embodiment 6
r 1 =∞
d 1 =0.4545 n 1 =1.883 ν 1 =40.78
r 2 =∞ (aspherical surface)
P 2 =1, B 2 =0.44
Embodiment 7
r 1 =∞
d 1 =0.4545 n 1 =1.883 ν 1 =40.78
r 2 =∞ (aspherical surface)
P 2 =1, B 2 =0.55
Embodiment 8
r 1 =∞
d 1 =0.4545 n 1 =1.883 ν 1 =40.78
r 2 =∞ (aspherical surface)
P 2 =1, B 2 =0.66
Embodiment 9
r 1 =∞
d 1 =0.4545 n 1 =1.883 ν 1 =40.78
r 2 =∞ (aspherical surface)
P 2 =1, B 2 =0.55, E 2 =-0.6442×10 -2
In respective embodiments shown in the above, reference symbols r 1 and r 2 respectively represent radii of curvature of the first and second surfaces of the illumination lens, reference symbol d 1 represents the thickness of the illumination lens, reference symbol n 1 represents the refractive index of the illumination lens, and reference symbol ν 1 represents Abbe's number of the illumination lens. The numerical data of respective embodiments shown in the above are normallized to the state of r=1 where reference symbol r represents the radius of the illuminated surface illuminated by the light source such as the light source L schematically illustrated in FIG. 1.
FIG. 7 shows a graph illustrating the curves of sin A in relation to h obtained from the illumination lenses in some of preferred embodiments of the present invention, and FIG. 6 shows a graph illustrating the curves of sin A in relation to h obtained from known illumination lenses.
As it will be understood from said figures, in case of FIG. 7 (present invention) the curves are convex toward the top of the graph, i.e., d 2 sin A/dh 2 <0. On the other hand, in case of FIG. 6 (know illumination lenses), the curves shown in the graph are convex toward the bottom of the graph, i.e., d 2 sin A/dh 2 >0. In other words, in cases of the embodiments of the present invention, the density of rays is approximately uniform also in the marginal portion of the field or becomes somewhat higher toward the marginal portion. On the other hand, in cases of the known illumination lenses, the density of rays becomes lower toward the marginal portion of the field.
The illumination lenses in Embodiments 1 and 2 are respectively shown in FIGS. 19 and 20 and are arranged that the first surface thereof is formed as an aspherical surface. The curves of sin A of the illumination lenses in said embodiments are as shown by the curves a and b in FIG. 7.
The illumination lens in Embodiment 3 is shown in FIG. 21 and is arranged that both of the first and second surface thereof are formed as aspherical surfaces. In case of the illumination lens in Embodiment 3, the second surface is formed that the curvature of the marginal portion is weak. Therefore, rays which come to the inner peripheral surface of the lens are not many and, consequently, it is possible to obtain bright illumination. The curve of sin A of the illumination lens in Embodiment 3 is as shown by the curve c in FIG. 7.
The illumination lens in Embodiment 4 is shown in FIG. 22 and is arranged that the first surface thereof is formed as an aspherical surface. In case of the aspherical surface of the illumination lens in Embodiment 4, the coefficients of aspherical surface of the second and fourth orders are not zero unlike those of Embodiments 1 and 2. The curve of sin A of the illumination lens in Embodiment 4 is as shown by the curve d in FIG. 7.
The illumination lenses in Embodiment 1 through 4 described so far are respectively arranged that the first surface thereof has a concave central portion and a convex marginal portion. This has such effect to prevent the rays other than the principal rays, i.e., the rays with large NA, from causing total reflection at the marginal portion of the first surface of the lens and to thereby make the light distribution favourable. When the distance from the foremost point on the above-mentioned convex marginal portion to the optical axis is represented by reference symbol y (max), it is preferable to arrange that y max ≧1/2r. If y (max) is made smaller than 1/2r, the positive refractive action of the marginal portion of the lens becomes too strong, and the light distribution angle becomes small.
The illumination lens in Embodiment 5 is shown in FIG. 23 and is arranged that the first surface thereof is formed as an aspherical surface. However, the central portion of said first surface is not concave. In case of the illumination lens in Embodiment 5, it is possible to obtain a uniform light distribution though the light distribution angle is small. The curve of sin A of the illumination lens in Embodiment 5 is as shown by the curve e in FIG. 7.
The illumination lenses in Embodiments 6, 7 and 8 are respectively shown in FIGS. 24, 25 and 26 and are respectively arranged that the second surface thereof is formed as a paraboloid. Out of them, the paraboloid of the illumination lens in Embodiment 6 has the weakest curvature while the paraboloid of the illumination lens in Embodiment 8 has the strongest curvature. Therefore, the light distribution angle becomes larger in the order of Embodiments 6, 7 and 8.
In cases of Embodiments 6, 7 and 8, the second surface is formed that the curvature of the marginal portion is weak. Therefore, rays which come to the inner peripheral surface of the lens are not many and, consequently, the loss in the intensity of light is small. Besides, as the curved surface does not have an inflection point, it is convenient for the manufacture. Furthermore, in cases of these embodiments, it is preferable to arrange that the coefficient B of aspherical surface of the second order becomes B≧0.2. If it becomes B<0.2, the curvature of the paraboloid becomes too weak. As a result, the intensity of light in the marginal portion of the illumination field becomes insufficient, and the performance becomes unsatisfactory.
The curves of sin A of Embodiments 6, 7 and 8 are respectively shown by the curves f, g and h in FIG. 29.
In cases of Embodiments 6, 7 and 8, when the first surface is formed as a planar surface and the second surface is formed as a paraboloid, sin A is analytically expressed as a function of h, B (coefficient of aspherical surface of the second order) and n (refractive index of the lens). Here, i 2 , γ 2 and i 1 shown in FIG. 28 are respectively defined as follows.
i.sub.2 =tan.sup.-1 2By
sin γ.sub.2 =1/n sin (tan.sup.-1 2By)
i.sub.i =i.sub.2 -γ.sub.2
Hence, sin A becomes as follows:
sin A=n sin i.sub.i =n sin [(tan.sup.-1 2By)-sin.sup.-1 {1/n sin (tan.sup.-1 2By)}] (6)
Therefore, when the formula (6) is solved by defining as y=0.8r, A=15° and n=1.5˜1.9, it is possible to determine the lowest limit value of B which fulfills the condition (5). Besides, for the condition (3), it is also possible to obtain the lowest limit value of B in the same way as above.
Furthermore, in cases of Embodiments 6, 7 and 8, when the first surface is formed as a planar surface and the second surface is formed as an aspherical surface expressed by the formula (1) (where P≠0), sin A becomes as follows. That is, when the equation of the second surface is expressed as x=f(S), tan i 2 becomes as follows:
tan i.sub.2 =df/ds
Hence, sin A becomes as follows:
sin A=n sin [tan.sup.-1 (df/ds)-sin.sup.-1 {1/n sin (tan.sup.-1 df/ds)}](7)
Therefore, when the formula (7) is solved by defining as y=0.8r, A=15° and n=1.5˜1.9 it is possible to obtain the values of C and coefficients of aspherical surface which fulfill the condition (5).
Therefore, when a lens which fulfills the condition (3) is formed by using the formula (6) or (7), it is possible to obtain an illumination optical system whose light distribution characteristic is favourable.
The illumination lens in Embodiment 9 is shown in FIG. 27 and is arranged that the second surface thereof is formed as a surface of the sixth order. In case of the illumination lens in Embodiment 9, the loss in the intensity of light is smaller compared with those in Embodiments 6, 7 and 8. The curve of sin A of the illumination lens in Embodiment 9 is as shown by the curve i in FIG. 29.
All the aspherical surfaces adopted in the preferred embodiments described so far are arranged as paraboloids, i.e., P=1. However, it is possible to obtain the same effect also when an ellipsoid (0<P<1) or hyperboloid (P<0) is adopted as an aspherical surface.
Besides, a light projecting element such as a light emitting diode, semiconductor laser, lamp or the like may be used instead of the light guide. In those case, the term "radius r of the light source" shown in the description so far is to be taken as follows. That is, in case of a lamp, r represents the distance from the optical axis to the end of the filament of the lamp and, in case of a light emitting diode or semiconductor laser, r represents the distance from the optical axis to the periphery of the light emitting surface thereof (in case that a plurality of light emitting diodes are placed side by side so as to form a light source, r represents the distance from the optical axis to the periphery of the light emitting surface of the light emitting diode located at the position most distant from the optical axis).
Furthermore, when the aspherical surface is formed by pressing of a glass material or by plastic molding, it is possible to reduce the cost of production. | An illumination optical system for an endoscope comprising an illumination lens, which is provided on the object side of the light exiting end of a light projecting element and comprises at least one aspherical lens element, the illumination optical system for an endoscope being arranged to be applicable to a wide angle endoscope and, at the same time, being arranged to have a favorable light distribution characteristic, which ensures bright illumination up to the marginal portion of the field, and arranged that the loss in the intensity of light is small. | 6 |
RELATED APPLICATIONS
This application is a continuation of U.S. application Ser. No. 11/375,907, filed Mar. 15, 2006 now U.S. Pat. No. 7,268,469, which is a continuation of U.S. application Ser. No. 10/726,774, filed Dec. 3, 2003, now U.S. Pat. No. 7,117,876, issued Oct. 10, 2006, which is a divisional of U.S. application Ser. No. 10/243,463, filed Sep. 12, 2002, now U.S. Pat. No. 6,681,782, issued Jan. 27, 2004, which is a continuation of U.S. application Ser. No. 09/953,504, filed Sep. 13, 2001, now U.S. Pat. No. 6,463,938, issued Oct. 15, 2002, which is a continuation of U.S. application Ser. No. 09/643,328, filed Aug. 22, 2000, now U.S. Pat. No. 6,295,999, issued Oct. 2, 2001, which is a continuation of U.S. application Ser. No. 09/057,182, filed Apr. 8, 1998, now U.S. Pat. No. 6,140,744, issued Oct. 31, 2000, which is a continuation-in-part of U.S. application Ser. No. 08/724,518, filed Sep. 30, 1996, now U.S. Pat. No. 6,039,059, issued Mar. 21, 2000.
FIELD OF THE INVENTION
This invention relates to a system for megasonic processing of an article requiring high levels of cleanliness.
BACKGROUND OF THE INVENTION
Semiconductor wafers are frequently cleaned in cleaning solution into which megasonic energy is propagated. Megasonic cleaning systems, which operate at a frequency over twenty times higher than ultrasonic, safely and effectively remove particles from materials without the negative side effects associated with ultrasonic cleaning.
Megasonic energy cleaning apparatuses typically comprise a piezoelectric transducer coupled to a transmitter. Tile transducer is electrically excited such that it vibrates, and the transmitter transmits high frequency energy into liquid in a processing tank. The agitation of the cleaning fluid produced by tile megasonic energy loosens particles on the, semiconductor wafers. Contaminants are thus vibrated away from the surfaces of the wafer. In one arrangement, fluid enters the wet processing container from the bottom of the tank and overflows the container at the top. Contaminants may thus be removed from the tank through the overflow of the fluid and by quickly dumping the fluid.
A gas impingement and suction cleaning process for electrostatographic reproducing apparatuses which utilizes ultrasonic energy and air under pressure is disclosed in U.S. Pat. No. 4,111,546, issued to Maret.
A process for cleaning by cavitation in liquefied gas is disclosed in U.S. Pat. No. 5,316,591, issued to Chao et al. Undesired material is removed from a substrate by introducing a liquefied gas into a cleaning chamber and exposing the liquefied gas to cavitation-producing means. The shape of the horn to provide the cavitation is not disclosed in detail and does not concentrate the sonic agitation to a particular location within the cleaning vessel.
In U.S. Pat. No. 4,537,511, issued to Frei, an elongated metal tube in a tank of cleaning fluid is energized in the longitudinal wave mode by a transducer that extends through a wall of the tank and is attached to the end of the tube. In order to compensate for relatively high internal losses, the radiating arrangement uses a relatively thin-walled tubular member.
A need exists for an improved apparatus and method which can be used to clean semiconductor wafers.
SUMMARY OF THE INVENTION
The above-referenced parent patent applications claim various forms of the invention. The present application is directed to additional embodiments of the invention.
It is therefore an object of the present invention to provide a system for megasonic processing.
It is therefore another object of the present invention to provide a system for megasonic processing of an article requiring extremely high levels of cleanliness.
These and other objects are met by the present invention, which in one aspect is a system for megasonic processing of an article comprising: a rotary support for supporting an article; a dispenser for applying a fluid to a surface of an article positioned on the support; and a transducer assembly comprising (i) a transmitter positioned adjacent to the article on the rotary support so that when the fluid is applied to the surface of the article via the dispenser, a meniscus of the fluid is formed between a portion of the transmitter and the surface of the article and (ii) not more than one transducer coupled to the transmitter, the transducer adapted to oscillate at a frequency for propagating megasonic energy through the transmitter and into the meniscus of the fluid.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view of one embodiment of the megasonic energy cleaning system of the present invention.
FIG. 2 is a side cross-sectional view of the system shown in FIG. 1 .
FIG. 3 is an exploded perspective view of the probe assembly shown in FIG. 1 .
FIG. 4 is a side view of an alternative probe in accordance with the present invention.
FIGS. 5 a - 5 c are alternative probe tips which may be used in connection with the present invention.
FIG. 6 is a schematic view of the probe of the present invention used with cleaning fluid being sprayed onto the upper surface of a wafer.
FIG. 7 is a cross-sectional view on line 7 - 7 of FIG. 6 .
FIG. 8 is a schematic view of the probe cleaning both surfaces of a wafer.
FIG. 9 is a schematic view of the probe of FIG. 1 extending through discs to be cleaned.
FIG. 9 a is a fragmentary, cross sectional view of a cap for a probe tip.
FIG. 9 b is a fragmentary, cross sectional view of another probe tip cap.
FIG. 10 is a schematic view of a probe vertically oriented with respect to a wafer.
FIG. 11 a side elevational, partially sectionalized view of another embodiment of the invention having an alternate means of coupling the probe to a support.
FIG. 12 is a side elevational, partially sectionalized view of another embodiment of the invention having an alternate means of mounting the probe to the housing.
FIG. 13 is a side elevational, partially sectionalized view of another embodiment of the invention having an alternate arrangement for mounting the probe and an alternate probe construction.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1-3 illustrate a megasonic energy cleaning apparatus made in accordance with the present invention with an elongated probe 104 inserted through the wall 100 of a processing tank 101 . As seen, the probe is supported in cantilever fashion on one end exterior of the container. A suitable O-ring 102 , sandwiched between the probe 104 and the tank wall, provides a proper seal for the processing tank 101 . A heat transfer member 134 , contained within a housing 120 , is acoustically and mechanically coupled to the probe 104 . Also contained within the housing 120 is a piezoelectric transducer 140 acoustically coupled to the heat transfer member 134 . Electrical connectors 142 , 154 , and 126 are connected between the transducer 140 and a source of acoustic energy (not shown).
The housing supports an inlet conduit 124 and an outlet conduit 122 for coolant and has an opening 152 for electrical connectors. The housing is closed by an annular plate 118 with an opening 132 for the probe. The plate in turn is attached to the tank.
Within the processing tank 101 , a support or susceptor 108 is positioned parallel to and in close proximity to the probe 104 . The susceptor 108 may take various forms, the arrangement illustrated including an outer rim 108 a supported by a plurality of spokes 108 b connected to a hub 108 c supported on a shaft 110 , which extends through a bottom wall of the processing tank 101 . Outside the tank 101 , the shaft 110 is connected to a motor 112 .
The elongated probe 104 is preferably made of a relatively inert, non-contaminating material, such as quartz, which efficiently transmits acoustic energy. While utilizing a quartz probe is satisfactory for most cleaning solutions, solutions containing hydrofluoric acid can etch quartz. Thus, a probe made of sapphire silicon carbide, boron nitride, vitreous carbon, glassy carbon coated graphite, or other suitable materials may be employed instead of quartz. Also, quartz may be coated by a material that can withstand HF such as silicon carbide or vitreous carbon.
The probe 104 comprises a solid, elongated, constant cross-section spindle-like or rod-like cleaning portion 104 a, and a base or rear portion 104 b. The cross-section of the probe is preferably round and advantageously, the diameter of the cleaning portion 104 a of the probe 104 is smaller in diameter than the rear portion 104 b of the probe 104 . The tip of cleaning portion 104 a terminates in a tip face/surface 104 c. In a prototype arrangement the area of the rear face of the rear portion 104 b is 25 times that of the tip face 104 c of portion 104 a. Of course, cross-sectional shapes other than circular may be employed.
A cylindrically-shaped rod portion 104 a having a small diameter is desirable to concentrate the megasonic energy along the length of the rod 104 a . The diameter of the probe, however, should be sufficient to withstand mechanical vibration produced by the megasonic energy transmitted by the probe. Preferably, the radius of the rod portion 104 b should be equal to or smaller than the wavelength of the frequency of the energy applied to it. This structure produces a desired standing surface wave action which directs energy radially into liquid contacting the rod. In a prototype, the radius of the cylindrical portion of the probe contained within the tank was approximately 0.2 of an inch and operated at a wave length of about 0.28 of an inch. This produced 3 to 4 wave lengths per inch along the rod length and has provided good results.
The probe cleaning portion 104 a should be long enough so that the entire surface area of the wafer is exposed to the probe during wafer cleaning. In a preferred embodiment, because the wafer is rotated beneath the probe, the length of the cleaning portion 104 b should be long enough to reach at least the center of the wafer. Therefore, as the wafer is rotated beneath the probe, the entire surface area of the wafer is close to the probe. Actually, the probe could probably function satisfactorily even if it does not reach the center of the wafer since megasonic vibration from the probe tip would provide some agitation towards the wafer center.
The length of the probe is also determined by a predetermined number of wavelengths usually in increments of half wavelengths of the energy applied to the probe. In one embodiment, the length of the probe cleaning portion 104 a equals nineteen wavelengths of the applied energy. Due to variations in transducers, it is necessary to tune the transducer to obtain the desired wavelength, so that it works at its most efficient point.
The rear probe portion 104 b, which is positioned exterior the tank, flares to a diameter larger than the diameter of the cleaning portion 104 a. In a first embodiment of the present invention, shown in FIGS. 1-3 , the diameter of the cross-section of the rear portion of the probe gradually increases to a cylindrical section 104 d. The large surface area at the end of the rear portion 104 d is advantageous for transmitting a large amount of megasonic energy which is then concentrated in the smaller diameter section 104 a.
As illustrated in FIG. 4 , in an alternative embodiment of the present invention, the diameter of the cross-section of the rear portion of the probe increases in stepped increments, rather than gradually. The stepped increments occur at wavelength multiples to efficiently transmit the megasonic energy. For example, in one embodiment, the thinnest portion 158 of the probe has a length of approximately nineteen wavelengths, the next larger diameter portion 160 is about three wavelengths in axial length and the largest diameter portion 162 is about four wavelengths in axial length. The goal is to simulate the results obtained with the tapered arrangement of FIG. 1 .
FIGS. 5 a - 5 c depict further embodiments for the tip of the probe. The different probe tips may help cover a portion of the wafer surface that otherwise would not be covered by a flat probe end 157 . The probe may have a conical tip 164 , an inverted conical tip 166 , or a rounded tip 168 .
The probe base 104 d is acoustically coupled to a heat transfer member 134 and is physically supported by that member. The probe end face is preferably bonded or glued to the support by a suitable adhesive material. In addition to the bonding material, a thin metal screen 141 , shown in FIG. 3 , is sandwiched between the probe end and the member 134 . The screen with its small holes filled with adhesive provides a more permanent vibration connection than that obtained with the adhesive by itself. The screen utilized in a prototype arrangement was of the expanded metal type, only about 0.002 inch thick with flattened strands defining pockets between strands capturing the adhesive. The adhesive employed was purchased from E.V. Roberts in Los Angeles and formed by a resin identified as number 5000, and a hardener identified as number 61 . The screen material is sold by a U.S. company, Delkar. The probe can possibly be clamped or otherwise coupled to the heat transfer member so long as the probe is adequately physically supported and megasonic energy is efficiently transmitted to the probe.
As another alternative, the screen 141 may be made of a berylium copper, only about 0.001 inch thick, made by various companies using chemical milling-processes. One available screen holes for confining the resin that are larger than that of the Delkar.
The heat transfer member 134 is made of aluminum, or some other good conductor of heat and megasonic energy. In the arrangement illustrated, the heat transfer member is cylindrical and has an annular groove 136 , which serves as a coolant duct large enough to provide an adequate amount of coolant to suitably cool the apparatus. Smaller annular grooves 138 , 139 on both sides of the coolant groove 136 are fitted with suitable seals, such as O-rings 135 , 137 to isolate the coolant and prevent it from interfering with the electrical connections to the transducer 140 .
The transducer 140 is bonded, glued, or otherwise acoustically coupled to the rear flat surface of the heat transfer member 134 . A suitable bonding material is that identified as ECF 550 , available from Ablestick of Gardena, Calif. The transducer 140 is preferably disc shaped and has a diameter larger than the diameter of the rear end of the probe section 104 d to maximize transfer of acoustic energy from the transducer to the probe. The heat transfer member is preferably gold-plated to prevent oxidizing of the aluminum and, hence, provide better bonding to the transducer and the probe. The member 134 should have an axial thickness that is approximately equal to an even number of wave lengths or half wave lengths of the energy to be applied to the probe.
The transducer 140 and the heat transfer member 134 are both contained within the housing 120 that is preferably cylindrical in shape. The heat transfer member is captured within an annular recess 133 in an inner wall of the housing 120 .
The housing is preferably made of aluminum to facilitate heat transfer to the coolant. The housing has openings 144 and 146 for the outlet 122 and the inlet conduit 124 for the liquid coolant. On its closed end, the housing 134 has an opening 152 for the electrical connections 126 and 154 . Openings 148 , 150 allow a gaseous purge to enter and exit the housing 120 .
An open end of the housing 120 is attached to the annular plate 118 having the central opening 132 through which extends the probe rear section 104 d. The annular plate has an outer diameter extending) beyond the housing 120 and has a plurality of holes organized in two rings through an inner ring of holes 131 , a plurality of connectors 128 , such as screws, extend to attach the plate 118 to the housing 120 . The annular plate 118 is mounted to the tank wall 100 by a plurality of threaded fasteners 117 that extend through the outer ring of plate holes 130 and thread into the tank wall 100 . The fasteners also extend through sleeves or spacers 116 that space the plate 118 from the tank wall. The spacers position the transducer and flared rear portion 104 b of the probe outside the tank so that only the cleaning portion of the probe and the probe tip extend into the tank. Also, the spacers isolate the plate 118 and the housing from the tank somewhat, so that vibration from the heat transfer member, the housing and the plate to the wall is minimized.
The processing tank 101 is made of material that does not contaminate the wafer. The tank should have an inlet (not shown) for introducing fluid into the tank and an outlet (not shown) to carry away particles removed from the article.
As the size of semiconductor wafers increases, rather than cleaning a cassette of wafers at once, it is more practical and less expensive to use a cleaning apparatus and method that cleans a single wafer at a time. Advantageously the size of the probe of the present invention may vary in length depending on the size of the wafer to be cleaned.
A semiconductor wafer 106 or other article to be cleaned is placed on the support 108 within the tank 101 . The wafer is positioned sufficiently close to the probe so that the agitation of the fluid between the probe and the wafer loosens particles on the surface of the wafer. Preferably, the distance between the probe and surface of the wafer is no greater than about 0.1 of an inch.
The motor 112 rotates the support 108 beneath the probe 104 so that the entire upper surface of the article is sufficiently close to the vibrating probe 104 to remove particles from the surface of the article. To obtain the necessary relative movement between the probe and the wafer 106 , an arrangement could be provided wherein the wafer is moved transversely beneath the probe. Also, an arrangement could be provided wherein the support 108 remains in place while a probe moves above the surface of the wafer 106 .
When the piezoelectric transducer 140 is electrically excited, it vibrates at a high frequency. Preferably the transducer is energized at megasonic frequencies with the desired wattage consistent with the probe size length and work to be performed. The vibration is transmitted through the heat transfer member. 134 and to the elongated probe 104 . The probe 104 then transmits the high frequency energy into cleaning fluid between the probe and the wafer. One of the significant advantages of the arrangement is that the large rear portion of the probe can accommodate a large transducer, and the smaller forward probe portion concentrates the megasonic vibration into a small area so as to maximize particle loosening capability. Sufficient fluid substance between the probe and the wafer will effectively transmit the energy across the small gap between the probe and the wafer to produce the desired cleaning. As the surface area of the wafer 106 comes within close proximity to the probe 104 , the agitation of the fluid between the probe 104 and the wafer 106 loosens particles on the semiconductor wafer 106 . Contaminants are thus vibrated away from the surfaces of the wafer 106 . The loosened particles may be carried away by a continued flow of fluid.
Applying significant wattage to the transducer 140 generates considerable heat, which could present damage to tie transducer 140 . Therefore, coolant is pumped through the housing 120 to cool the member 134 and, hence, the transducer.
A first coolant, preferably a liquid such as water, is introduced into one side of the housing 120 , circulates around the heat transfer member 134 and exits the opposite end of the housing 120 . Because the heat transfer member 134 is made of a good thermal conductor, significant quantities of heat may be easily conducted away by tile liquid coolant. The rate of cooling can, of course, be readily monitored by changing the flow rate and/or temperature of the coolant.
A second, optional coolant circulates over the transducer by entering and exiting the housing 120 through openings 148 , 150 on the closed end of the housing. Due to the presence of the transducer 140 and the electrical wiring 142 , 154 , an inert gas such as nitrogen is used as a coolant or as a purging gas in this portion of the housing.
An alternative arrangement for coupling the probe end 104 b to the member 134 is illustrated in FIG. 11 . Instead of having the probe bonded to the member 134 , a so-called vacuum grease is applied to the screen 141 , and the probe is pressed against the member 134 by a coil spring 143 . Vacuum grease is a viscous grease which can withstand pressures on opposite sides of a joint without leaking or being readily displaced. In a prototype arrangement, the combination of the grease and the metal spring provided a reliable acoustic coupling. As may be seen in FIG. 11 , the housing 120 instead of being mounted directly to the plate 118 , is mounted to the plate 118 by standoffs, which comprise the sleeves 116 and the fasteners 117 . The sleeves 116 and the fasteners 117 are shorter than that shown in FIG. 2 , such that the plate 118 surrounds the tapered portion of the probe. This leaves a gap between the housing 120 and the plate 118 . The coil spring 143 is positioned in this gap and compressed between the plate 118 and the tapered portion of the probe. Thus, the spring presses the probe toward the member 134 . This arrangement acoustically couples the probe to the heat transfer member 134 . A Teflon sleeve 149 is preferably positioned over the first coil of the spring 143 adjacent the probe so that the metal spring does not damage the quartz probe.
An arrangement is illustrated in FIG. 6 , wherein the probe assembly of FIG. 1 is shown in conjunction with a tank 200 which is open on its upper end and has a drain line 202 in its lower end. The probe 104 is shown extending through a slot 203 into the tank above a wafer 106 mounted on a suitable support 208 including an annular rim 208 a, a plurality of spokes 208 b, joined to a hub 208 c positioned on the upper end of a shaft 210 rotated by a motor 212 .
In use, deionized water or other cleaning solution is sprayed onto the upper surface of the wafer from a nozzle 214 while the probe 104 is being acoustically energized. The liquid creates a meniscus 115 between the lower portion of the probe and the adjacent upper surface of the rotating wafer. This is schematically illustrated in FIG. 7 . The liquid provides a medium through which the megasonic energy is transmitted to the surface of the wafer to loosen particles. These loosened particles are flushed away by the continuously flowing spray and the rotating wafer. When the liquid flow is interrupted, a certain amount of drying action is obtained through centrifical force of the liquid off of the water.
The probe assembly may be conveniently mounted on a suitable support, schematically illustrated at 216 . The support is capable of pivoting the assembly upwardly, as indicated by the arrow in FIG. 6 , to facilitate the installation and removal of wafers. Alternatively, the slot 203 may instead be formed as a hole, closed at the top, and the probe may be moved radially in and out.
FIG. 8 illustrates an alternative or addition to the arrangement of FIG. 6 wherein both the lower and upper sides of a wafer are cleaned. A spray nozzle 254 extends through a side wall of a tank 200 and is angled upwardly slightly so that cleaning fluid may be sprayed between the spokes 208 b and onto the lower surface of a wafer 106 and is directed radially inwardly so that as the wafer rotates, the entire lower surface is sprayed with the fluid. The wafer is subjected to megasonic energy by the probe 104 in the same manner as described above in connection with FIG. 6 . This agitation vibrates the wafer as well as the fluid on the lower surface of the wafer which is radially aligned with the probe as the wafer rotates. This agitation loosens particles on the lower surface of the wafer, and the particles are flushed away with the fluid which falls or drips from the lower surface of the wafer.
Various fluids may be employed as the spray applied to the wafer in FIGS. 6 and 8 . In addition to liquid or high pressure gas, so-called dry ice snow may be applied. Va-Tran Systems, Inc. of Chula Vista, Calif. markets a product under the trademark SNO GUN for producing and applying such material. A major advantage of that approach is that there is no disposal problem after cleaning. Contamination is carried away from the clean surface in a stream of inert, harmless vapor. Disposal costs of cleaning media are eliminated. Advertising literature regarding the SNO GUN product states that cleaning with dry ice snow removes particles more thoroughly than blowing with dry nitrogen. It is said that the device removes even sub-micron particles as tiny as 0.2 microns, which are difficult or impossible to remove with a nitrogen jet. Such technology is further described in U.S. Pat. No. 5,364,474, which is incorporated herein by reference.
Referring to FIG. 9 , the probe assembly of FIG. 1 is shown mounted to a wall of a tank 300 . The probe 104 extends generally horizontally through central openings in a plurality of vertically orientated substrates such as “compact discs” 302 . The discs may be mounted in a cassette immersed in the tank with the holes in the discs aligned with the probe. The cassette carrying the discs can then be moved laterally so that the probe extends through the holes in the discs, without actually contacting the discs. The tank is filled with liquid, such as deionized water to completely cover the discs. The probe is then vibrated by megasonic energy in the manner described above in connection with FIG. 1 . The agitation produced by the probe is transmitted into the cleaning liquid between the discs to loosen particles on the surfaces of the discs. The energy propagates radially outward from the probe such that both sides of each disc are exposed to such energy. Cleaning liquid may be introduced into the container in continuous flow and allowed to overflow the upper end of the container to carry away loosened particles.
Because some megasonic energy will be transmitted through the end of the probe with the probe tip immersed in the liquid, a small cap 306 is positioned on the tip of the probe with the cap containing an air space 308 between two glass walls 306 a and 306 b , as shown in FIG. 9 a . Since megasonic energy does not travel through ambient air to any significant degree, the cap prevents the loss of energy through the end of the probe. An alternative cap 310 shown in FIG. 9 b employs a short section of glass tubing 312 attached to the end of the probe. As seen, the outer diameter of the tube is equal to the outer diameter of the probe, and the outer end of the tube spaced from the probe is closed by a disc 314 .
FIG. 10 illustrates another embodiment of the probe of the invention. A probe assembly 400 is shown which is similar to the assembly of FIG. 1 except that the probe 404 is much shorter than the probe 104 in FIG. 1 . In addition, the assembly 400 is oriented with the probe extending generally vertically, generally perpendicular to the surface of the horizontal wafer 106 . Cleaning fluid is applied to the upper surface of the wafer, and the lower tip of the probe is in contact with this fluid. Consequently, megasonic energy is transmitted through this medium onto the surface of the wafer causing loosening of particles. Since the sides of the probe are not exposed to this medium, there is no appreciable megasonic energy transmitted from the vertical sides of the probe. Instead, such megasonic energy is concentrated into the tip. The tip can be moved radially with respect to the wafer as the wafer rotates so as to apply megasonic energy to the entire surface of the wafer. Alternatively, the probe may traverse the entire upper surface. Any suitable support 410 containing a mechanism to provide the desired movement may be employed.
As mentioned above, the preferred form of the probe assembly includes a probe made of inert material such as quartz and a heat transfer member coupled to the rear of the probe made of a good heat conducting material such as aluminum. Since it is the cylindrical portion of the probe which is in contact with the cleaning fluid and is positioned adjacent the wafer, an alternative arrangement could be devised wherein a forward portion, such as section 104 a in FIG. 1 could be made of the inert material and the rear portion 104 b could be made of aluminum and hence could be made as one piece with the heat transfer member 134 . This of course means that the joint between the two components would be at the rear of the cylindrical portion 104 a . While such a bonding area would not be as strong as the arrangement illustrated in FIG. 1 , it may be useful in certain situations.
In the other direction, there may be some applications in which it is not necessary to employ quartz or other such inert material for the probe. Instead, the entire probe could be made of aluminum or other such material. In that situation, the heat transfer member could then be made as a one-piece unit with the probe. Also, with a metal probe it may be practical to spray the cleaning fluid through the probe itself. For example in the arrangement of FIG. 10 , fluid inlet could be located in the side of the large diameter end of the probe and an outlet can be located in the end face of the small diameter probe end. The fluid would also serve as a coolant to cool the transducer, particularly if dry ice snow were employed.
The embodiment of FIG. 12 has a number of similarities to the other embodiments, but has some important distinctions. That arrangement includes a cup-shaped housing 520 similar to the housing 120 in FIG. 2 , but inverted with respect to the housing 120 . The housing 520 includes a closed end wall 520 a having a surface 520 b facing the interior of the housing 520 and having an exterior surface 520 c facing away from the housing. Coupled to the interior end wall surface 520 b is a disc-shaped transducer 540 analogous to the transducer 140 referred to above in connection with FIGS. 2 and 3 . The transducer 540 is preferably bonded to the wall surface 520 b in the same manner mentioned above in connection with FIGS. 2 and 3 . The probe 504 comprises a solid elongated, constant cross-section spindle-like or rod-like cleaning portion 504 a. The large end 504 b of a probe 504 is acoustically coupled to the housing end wall exterior surface 520 c. The acoustic coupling is accomplished by the use of a coil spring 543 surrounding the probe 504 and reacting against the spring retainer plate 518 to press the large end 504 b of the probe towards the housing end wall 520 a. As discussed in connection with FIG. 3 , a screen 141 , together with an appropriate viscous material, is sandwiched between the large end of the probe and the end wall 520 a. The coil spring adjacent the large end of the probe has a sleeve or sleeve portions 544 made of a material which will not damage the probe. The O-ring 521 is held in place and compressed against the end wall 520 a and the probe by a retainer ring 519 having a surface 519 a which presses against the O-ring 521 . The O-ring 521 thus prevents the escape of the viscous material from between the probe and the housing end wall, and centers the probe. The retainer ring is attached to the housing by a plurality of bolts 525 which extend through the retainer ring and thread into the housing. The spring 543 is captured and compressed by a reaction plate 518 which surrounds the probe and is attached to the housing by a plurality of fasteners 528 which thread into the retainer ring 519 and are spaced from it by sleeves 516 surrounding the fasteners 528 . For convenience of illustration, the fasteners 525 and 528 are all shown in the same plane in FIG. 12 . In actual practice, the fasteners 528 would preferably be on the same bolt hole diameter as the fasteners 525 , and they of course would be spaced with respect to the fasteners 525 . Also, the fasteners would not necessarily be spaced 180 E apart as illustrated, but would be spaced in whatever manner is practical.
Positioned within the cup-shaped housing 520 is an annular heat transfer member 534 which has an external diameter sized to fit snugly within the housing 520 . An annular groove 536 in the exterior of the heat transfer member 534 , creates a liquid cooling channel in combination with the inner surface of the housing 520 . A pair of O-rings 537 that fit within annular grooves in the heat transfer member seal the coolant channel 536 so that the remainder of the interior of the housing is sealed from the liquid. This prevents interference with the electrical energy being supplied to the transducer. Further, transducer vibration energy is not dissipated into the interior of the housing, but instead is transmitted into the housing end wall 520 a and into the probe 504 . The heat transfer member 534 is axially captured within the housing by means of an annular shoulder 520 d and by a housing end plate 560 . A plurality of fasteners 528 connect the plate 560 to the housing. A liquid coolant inlet 562 a is mounted in an opening in the end plate 560 and threads into a passage 519 in the heat transfer member that extends axially and then radially into the annular channel 536 . A similar outlet fitting 562 b mounts in the end plate 560 diametrically opposed from the 562 a fitting, and threads into another passage 519 that extends axially and radially into the channel 536 .
A plurality of axially extending bores 563 are also formed in the heat transfer member 534 , aligned with gas inlets 561 a, b formed in the plate 560 . The inlets 561 a, b and bores 563 are shown in the same plane with the passages 519 for convenience. In actual practice, the bores 563 would preferably not be in the same plane as the passages 519 , and instead would be circumferentially offset, and could also be formed in the same circle around the center of the heat transfer member 534 . The inlets 561 a, b through the end plate 560 for the fittings 562 a and 562 b would likewise be moved to be aligned with the passages 563 .
The electrical connection for the transducer 540 is illustrated by the wire 554 , although the more complete connection would be as shown in FIG. 3 . That wire extends through a fining 568 which in turn is connected to an electrical cord 526 .
In operation, there are a number of advantages to the embodiment illustrated in FIG. 12 . By coupling the transducer and the probe to the housing end wall, more energy may be transmitted to the probe than with the corresponding amount of power applied to the transducer in the arrangement of FIG. 2 , inasmuch as the housing end wall has less mass than the mass of the heat transfer member 140 shown in. FIG. 3 . While some energy is lost into the other portions of the housing, there is a net increase in efficiency. The relatively thin end wall has fewer internal energy reflections than a thicker wall simply because of the reduced mass. However, in addition the housing end wall does not have the discontinuities caused by the grooves in the heat transfer member of FIG. 2 , or by the O-ring in the grooves.
By making the housing 520 of aluminum or other material which is a relatively good thermal energy conductor, the heat generated by the transducer can be readily dissipated with the arrangement of FIG. 12 . The heat transfer member 534 can be made of the desired axial length without concern for its mass because it is not to be vibrated as in the arrangement of FIG. 2 . The cooling liquid enters through the fitting 562 a, flows axially and then radially into the channel 536 , where it splits into two branch flows in opposite directions, that meet on the other side of the heat transfer member and flow out the fitting 562 b.
Similarly, cooling gas such as nitrogen can be connected to one or more of the bores 563 in the heat transfer member and into the central area of the housing. The gas is exhausted through one of the bores 563 leading to a second outlet 561 b. Two passages 563 are illustrated in FIG. 12 . Three are preferable, but more or less may be utilized if desired. To perform an additional function, bolts may be threaded into the bores 563 to assist in withdrawing the heat transfer member from the housing.
The assembly illustrated in FIG. 12 may be used in connection with a wall mounted arrangement such as that shown in. FIG. 1 , or may be used with a system such as that as illustrated in FIG. 8 , wherein the probe assembly is moved into or out of position with respect to a wafer to facilitate insertion and removal of wafers. As mentioned above, such a probe may be moved out of the way by mounting it on a bracket that will pivot it in the direction of the arrow 218 shown in FIG. 8 , or it may be on a track arrangement (not shown) which will move it radially inwardly and outwardly with respect to the wafer and its supporting member. The assembly of FIG. 12 may be mounted to these other structures in any suitable fashion, such as by making connections to the end plate 560 .
The arrangement of FIG. 13 includes a generally tubular or cylindrical housing 620 . Positioned within the housing is a heat transfer member 634 having an outer annular wall 634 a which fits snugly within a surrounding annular wall of the housing 620 . The heat transfer member 634 has an annular channel 636 formed in its outer surface that faces the surrounding housing wall to form a coolant passage. A coolant inlet 644 in the housing wall leads into the passage and an outlet 646 on the opposite side of the housing leads out of the passage.
As seen in FIG. 13 , the heat transfer member 634 has somewhat of an H-shaped cross section created by a central disc-shaped wall 634 b integrally formed with the surrounding annular wall 634 a. As seen, the central wall 634 b is relatively thin and it is radially aligned with the surrounding coolant passage 636 . The heat transfer member is axially captured within the housing by an internal shoulder on one end of the housing and by an end plate 660 on the other end.
A piezoelectric transducer 640 is acoustically coupled to one side of the central wall 634 b, such as in the same manner discussed above in connection with the other embodiments. A probe 604 is acoustically coupled to the other side of the central wall 634 b. Again, this may be done in various ways, such as the screen and grease technique discussed above. An O-ring 621 surrounds the base of the probe and is compressed against the probe and the central wall 634 b by a cylindrical portion of an end member 619 having a flange attached to the end of the housing 620 . The O-ring confines the coupling grease and helps center the probe 604 . The probe is pressed against the central wall 634 b by a spring 643 compressed between an annular spring retainer plate 618 and the probe 604 .
The housing and heat transfer member illustrated in FIG. 13 may be used with the probes illustrated in the above-mentioned embodiments, but it is illustrated in FIG. 13 with an alternate probe construction. Instead of having the probe made of one piece, it is formed in separate portions including a base 605 adjacent the central wall 634 b of the heat transfer member, and an elongated cleaning rod 606 . The base 605 has a cylindrical exterior with a reduced diameter portion 605 a on the end spaced from the central wall 634 b. One end of the spring 643 surrounds the base portion 605 a and engages the shoulder on the base 605 adjacent the portion 605 a. The rod 606 of the probe fits within a central socket formed in the base 605 . It is bonded to the base by a suitable adhesive which will not interfere with the transmission of the megasonic energy provided by the transducer 640 and propagated through the central wall 634 b and the base 605 of the probe.
The base 605 call have a frusto-conical configuration just as the rear portion of the probe in FIG. 12 , and the spring 643 could then engage the sloping side wall of such shape rather than having the step configuration shown in FIG. 13 . Also, in theory, the rod 606 could have a tapered end and the spring could engage it as suggested by FIG. 12 .
A primary purpose of having a probe made of two different portions is that one portion can be made of a different material from the other. For example, the base 605 can be utilized in any cleaning operation since it does not contact the cleaning solution; however, the rod 606 must be compatible with the cleaning solution. Thus, if the cleaning solution is compatible with quartz, a one-piece arrangement such as that illustrated in FIG. 1 or FIG. 12 could be conveniently utilized. If, however, the cleaning solution is not compatible with quartz, such as a solution containing hydrofluoric acid, a material for the rod is needed that is compatible, such as vitreous carbon, while the base can be quartz. It is currently difficult to obtain vitreous carbon in a shape such as that illustrated in FIG. 12 . However, a straight cylindrical rod is more readily available. Hence, it is practical to utilize it in the arrangement illustrated in FIG. 13 . Of course any other desirable combination of suitable materials for the rod and the base may be employed.
As mentioned above, the arrangement of FIG. 13 is particularly desirable from the standpoint that the transmission of megasonic energy is efficient through the thin wall portion of the heat exchange member, but yet the heat exchange process is very efficient. This is because the transducer, which is the heat generator, is in direct contact with the heat transfer member, which is in direct contact with the coolant passage 636 . It should be recognized that other heat transfer arrangements may be employed. For example, if the heat transfer member has sufficient surface area, it might be possible to have it air-cooled rather than liquid-cooled. It should also be recognized that various other modifications of that type may be made to the embodiments illustrated without departing from the scope of the invention, and all such changes are intended to fall within the scope of the invention, as defined by the appended claims. | A system for megasonic processing of an article. In one aspect, the system for megasonic processing comprises a rotary support for supporting an article, a dispenser for applying a fluid to a surface of an article positioned on the rotary support; and a transducer assembly. The transducer assembly comprises (i) a transmitter positioned adjacent to the article on the rotary support so that when the fluid is applied to the surface of the article via the dispenser, a meniscus of the fluid is formed between a portion of the transmitter and the surface of the article and (ii) not more than one transducer coupled to the transmitter, the transducer adapted to oscillate at a frequency for propagating megasonic energy through the transmitter and into the meniscus of the fluid. | 8 |
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