description stringlengths 2.98k 3.35M | abstract stringlengths 94 10.6k | cpc int64 0 8 |
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to portable toilets of the type including a bowl unit and a waste holding tank adapted to be detachably secured together with the bowl unit supported on the holding tank.
Typically, the bowl unit has a bowl with an outlet which communicates with an inlet at the top of the holding tank. The holding tank is provided with a valve mechanism which normally closes the inlet but which can be opened to allow waste to enter the holding tank from the bowl. The holding tank also has an outlet which is normally closed, for example by a screw cap, and through which waste can be emptied from the holding tank after the tank has been detached from the bowl unit. The holding tank is designed to be readily portable for this purpose.
A practical problem sometimes encountered in emptying the holding tank is that the waste material may not flow smoothly from the holding tank outlet because the flow of waste material tends to fill or largely obstruct the outlet at least periodically during the emptying cycle. As a result, partial vacuums are intermittently created above the liquid in the holding tank and tend to cause surging or other irregularies in the flow from the tank. This can result in objectionable splashing of the liquid being poured from the tank.
2. Description of the Prior Art
European Patent Application No. 83303054.7 of Thetford Corporation published Dec. 7, 1983 under publication No. 0 095 903 A2 discloses a portable toilet having a manually operable vent valve in the top wall of the holding tank for venting the "head space" of the holding tank during emptying. The valve disclosed in the patent application is spring-biassed to a normally closed position and has an actuator button that must be depressed to hold the valve open against the effect of its spring biassing. In order to be effective, the valve must be held open throughout the operation of emptying the holding tank. A full tank can be quite heavy and the action required to hold the valve open while manipulating the tank to empty its contents is awkward to perform.
An object of the present invention is to provide a portable toilet having an improved vent means.
SUMMARY OF THE INVENTION
The invention provides a portable toilet including a bowl unit and a waste holding tank which are adapted to be detachably secured together with the bowl unit supported on the tank. The holding tank has a closable outlet through which waste can be emptied from the tank after it has be detached from the bowl unit and vent means operable to permit entry of air into the holding tank during emptying. The vent means is provided on portions of the bowl unit and holding tank which are opposed to one another when the unit and tank are secured together. The vent means takes the form of a valve element on the holding tank defining a vent passageway between the interior of the holding tank and ambient air, and means adapted to automatically close the vent passageway when the bowl unit and holding tank are secured together.
In a simple form of the invention the passageway in the valve element could be an opening that is closed when the bowl unit and holding tank are secured together, and opened simply by separation of the bowl unit and holding tank. However, the valve element preferably includes a valve member which is manually displaceable between a first position in which the passageway is closed by the valve member, and a second position in which the passageway is open, permitting air flow therealong. In this event, the valve member is preferably arranged to project from the valve element in its second (open) position and to be depressed to its first (closed) position upon interengagement of the bowl unit and holding tank. In a preferred embodiment, the valve element will project from the holding tank into a recess on the bowl unit and the valve member will be depressed towards its closed position by contact with the bottom of the recess.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be more clearly understood, reference will now be made to the accompanying drawings which illustrate preferred embodiments of the invention by way of example, and in which:
FIG. 1 is a perspective view of a portable toilet in accordance with the invention with the bowl unit shown in an exploded position above the holding tank;
FIG. 2 is a vertical sectional view through the vent means of the toilet of FIG. 1 according to one embodiment of the invention;
FIG. 3 is a perspective view of part of the vent means shown in FIG. 2;
FIG. 4 is a vertical sectional view through vent means according to a further embodiment of the invention; and,
FIGS. 5 and 6 are side elevational and plan views respectively of part of the vent means of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1, a portable toilet 20 is shown to comprise a bowl unit 22 and a holding tank 24 and may be generally of the form disclosed in Canadian Pat. No. 1,157,207 issued Nov. 22, 1983 to Sanitation Equipment Limited. Reference may be made to that patent for a detail description of the bowl unit and holding tank. For present purposes, it is sufficient to note that the bowl unit and holding tank are adapted to be detachably secured together with the bowl unit supported on the holding tank; for purposes of illustration, the bowl unit is shown in an exploded position above the holding tank. The bowl unit includes a toilet bowl, part of which is visible at 26 in FIG. 1. The bowl has an outlet shown in dotted outline at 28 in a bottom wall 30 of the bowl unit, and the outlet co-operates with an inlet 32 of the holding tank when the bowl unit is seated on the holding tank so that waste can be flushed into the holding tank at appropriate times.
Entry of waste into the holding tank is controlled by a valve assembly generally indicated by reference numeral 34. The valve assembly is controlled by a handle 36 at the front of the holding tank which can be pulled outwardly as indicated in ghost outline to open a valve member 38 below inlet 32. Details of the valve mechanism are not given here because they form no part of the present invention. Reference may be had to Canadian Pat. No. 1,046,705 issued Feb. 20, 1979 to Sanitation Equipment Limited for details of the valve assembly. The bowl unit also includes a reservoir (not shown) for flushing liquid and is provided with a manually operable pump 40 for delivering flushing liquid from the reservoir into the bowl. A cap covering an inlet through which the reservoir can be replenished is indicated by reference numeral 42. The bowl unit is also provided with a lift up seat 44 surrounding the bowl and a lid 46. Again, reference may be had to the Canadian patents identified above for a detail description of these parts.
Holding tank 24 is also provided with a closable outlet generally indicated at 48 through which waste can be emptied from the holding tank after the tank has been detached from the bowl unit. The outlet takes the form of an externally screw-threaded cylindrical neck, part of which is visible at 50 shown in FIG. 1, fitted with a screw cap 52. Both the holding tank and the bowl unit are assembled from a number of plastic mouldings. The holding tank itself is made up of upper and lower mouldings denoted respectively 54 and 56 sealed together at a joint line 58. The upper moulding 54 includes the neck for outlet 48 and a raised portion 60 forming a housing for the valve mechanism. Surrounding that portion is a generally flat area 62 on which the bowl unit seats when the bowl unit and holding tank are assembled. The bottom wall 30 of the bowl unit is contoured to be generally complimentary to the contour of the top wall of the holding tank so that the bowl unit will sit firmly on the holding tank, all generally as described in the Canadian patents referred to above.
Four generally cylindrical projections extend upwardly from the flat area 62 at the top of the holding tank and are received in complimentary recesses in the bottom wall 30 of the bowl unit. These projections and recesses assure proper alignment of the bowl unit on the holding tank when the toilet is assembled. In FIG. 1, three of the projections are denoted by reference numeral 64 and take the form of plain hollow formations in the plastic moulding 54 forming the top of the holding tank. Part of moulding 54 has been broken away to show one of these projections. Each projection 64 has a generally hemispherical top.
The fourth projection, at the front left side of the holding tank as seen in FIG. 1 is denoted by reference numeral 66 and has essentially the same profile as the other projections 64; however, this projection takes the form of a hollow sleeve fitted with a valve member (as will be described) and is designed to provide vent means operable to permit entry of air into the holding tank during emptying thereof. Details of the vent means will be given later particularly with reference to FIGS. 2 to 6; FIGS. 2 and 3 illustrate a form of vent means according to one embodiment of the invention, while FIGS. 4 to 6 show an alternative form, according to a further embodiment.
The bottom wall 30 of bowl unit 22 incorporates four recesses 68 positioned to receive the projections 64 and 66. The four recesses are essentially identical and a portion of the bowl unit has been broken away to show one of these recesses as typical of all four. Thus, each recess is defined by an inwardly directed formation in the bottom wall 30 of the bowl unit and is of cylindrical shape with a domed portion at the bottom of the recess. Each recess is dimensioned to closely receive the corresponding projection 64 or 66 so that there is only sufficient clearance to permit the projection to enter the recess without allowing significant lateral movement between the bowl unit and holding tank. In this way, the projections and recesses assure correct alignment of the bowl unit on the holding tank. The projections also penetrate to the full depths of the respective recesses.
A pair of latches at opposite sides of the bowl unit, one of which is shown at 70, engage corresponding keepers 72 on the holding tank for detachably securing the bowl unit and holding tank together. Each latch 70 is pivotally coupled to the bowl unit and has a nose 74 for engagement below a bar formation 76 of keeper 72 when the bowl unit is on the holding tank. The top portion of latch 70 is then pressed inwardly and the latch snaps over-center to lock the bowl unit and holding tank together. Obviously, the latches can be released in reverse fashion simply by prising the tops of the latches outwardly until the latch again goes over-center and the latch is released.
Reference will now be made to FIGS. 2 and 3 in describing a first embodiment of the invention.
In FIG. 2, the projection 66 of FIG. 1 is shown in vertical section while FIG. 3 shows that projection in perspective. FIG. 2 also shows part of the bottom wall 30 of the bowl unit including the recess 68 intended to receive projection 66. Part of the moulding forming the top of the holding tank is also shown at 54.
Projection 66 includes a hollow generally cylindrical formation or sleeve 78 in the top wall of moulding 54. Sleeve 78 is hollow and has a circular opening 78a at its top, thereby providing a vent passageway 80 between the interior of the waste holding tank and ambient air. A poppet valve member 82 and a co-operating seal 84 are provided within sleeve 78 for the purpose of closing vent passageway 80 at appropriate times. Seal 84 takes the form of a plug disposed generally centrally of passageway 80 and connected to moulding 54 by three spaced webs (see FIG. 3). Valve member 82 is designed to be movable vertically in sleeve 78 between the raised position in which it is shown in FIG. 2 and in which passageway 80 is open, and a depressed position in which the passageway is closed. This is achieved by providing a central longitudinal passageway 88 through valve member 82 and arranging for the lower end of the passageway to be plugged by seal 84 when the valve member is in its depressed position.
As can perhaps best be seen in FIG. 3, valve member 82 is of hollow cylindrical form with the passageway 88 extending from end to end thereof, and has an enlarged annular head 90 at its upper end. This head is of the same external diameter as the formation 66 and is profiled to generally follow the domed profile of the other projections 64 (FIG. 1) at the top of the holding tank. In addition, a thin and relatively flexible ring or rib 92 encircles valve member 82 at a spacing below head 90 and frictionally engages the wall of passageway 80 so that the valve member tends to be frictionally retained in a position to which it is moved. Rib 92 also acts as a stop for limiting movement of the valve member upwardly away from the holding tank. As can best be seen in FIG. 2, rib 92 co-operates with an inturned annular lip 94 at the top of formation 66, surrounding opening 78a. Valve member 82 is shown substantially at the limit of its upward movement with rib 92 almost in contact with lip 94. It will be understood that, if the valve member 82 is depressed from the position shown in FIG. 2, seal 84 will enter the lower end of the passageway 88 through the valve member so that the valve member and seal will effectively close the vent passageway 80. Abutment of head 90 with the top of sleeve 78 limits downward movement of the valve member.
Valve member 82 is a one-piece moulding in a plastic material (for example polyethylene). Similarly, the mouldings 54 and 56 from which the holding tank is made are also plastic (for example polypropylene). The inherent flexibility of these mouldings permits valve member 82 to be assembled into sleeve 78 by pressing the valve member downwardly so that the rib 92 snaps through opening 78 as a result of temporary resilient deformation of the rib 92 and/or lip 94. Once installed, co-operation between the rib 92 and the lip 94 will prevent removal of the valve member under normal operating conditions of the toilet.
As discussed previously, the recesses 68 in the bottom wall of the bowl unit 22 (FIG. 1) are each dimensioned to closely receive the relevant projection 64, 66. In the case of projection 66, the overall height of the top of the valve member 82 above the flat surface area of the holding tank when the valve member is in the open position shown in FIG. 2 is greater than the depth of the corresponding recess 68 and the depth of that recess is selected to correspond substantially exactly to the height of the valve member in its closed position. Accordingly, if the valve member is left open and the bowl unit is fitted onto the holding tank, the top of the valve member 82 will seat fully within the associated recess 68 as indicated in FIG. 2 and as soon as the bowl unit is depressed and locked to the holding tank, the valve member will automatically be closed by virtue of its contact with the bottom of the recess 68. This ensures that the vent can never accidentally be left open, which could lead to spillage of liquid from the holding tank and/or escape of undesirable odours from the tank.
When the toilet is in use, and the holding tank requires emptying, the bowl unit is first detached from the holding tank by operating latch 70 and the corresponding latch at the opposite side of the tank and the bowl unit is lifted off the tank. The user then carries the holding tank to a disposal site for emptying. A handle which is partly visible at the rear of the holding tank in FIG. 1 and is designated by reference numeral 96 is integrally moulded into the holding tank to assist in carrying. At the disposal site, the waste outlet cap 52 is removed and the vent is opened by pulling up on the head 90 of the poppet valve member 82, bringing the valve member to the position in which it is shown in FIG. 2. Vent passageway 80 is then open. The holding tank is then tipped by raising the front end of the tank (the end at which the flush handle 36 appears) and waste will flow out of the outlet 50 while air flows in through passageway 80. This venting of the tank assures smooth outflow of liquid therefrom. When the tank has been emptied and cleaned if necessary, the cap 52 is replaced. Valve member 82 can then be manually depressed to close the vent passageway 80 or the valve member can be left open until the bowl unit is again seated on the holding tank when the valve member will automatically be closed by seating in the associated recess 68 in the bottom wall of the holding tank, as described above.
Reference will now be made to FIGS. 4, 5 and 6 in describing vent means according to a further embodiment of the invention. Primed reference numerals will be used in those views to denote parts corresponding to parts shown in the previous views.
The vent means shown in FIGS. 4, 5 and 6 differs from the vent means of FIGS. 2 and 3 primarily in that the internal valve member 82 in FIGS. 2 and 3 has been replaced by a valve member in the form of an external cap denoted by reference numeral 98 in FIG. 4. The cap fits over a generally cylindrical sleeve 78' which projects upwardly from the flat area 62 at the top of the holding tank 24. As can be seen from FIGS. 5 and 6, sleeve 78' is generally of cylindrical shape overall. Cap 98 is also generally cylindrical but has a domed top shaped to fit within one of the recesses 68 at the underside of the bowl unit 22 of the toilet and formed with a circular vent opening 100. The cap also has a skirt 102 which surrounds and frictionally grips sleeve 78' as well as forming a liquid seal therewith as will be described.
Sleeve 78 defines an internal vent passageway 80' which communicates with the interior of the waste holding tank. At the upper end of the sleeve a plug member 104 extends transversely of passageway 80' and is supported about sleeve 78' by four equally spaced legs 106 extending between the sleeve and the plug member, as best seen in FIGS. 5 and 6.
Plug member 104 is generally disc-shaped with a chamfered edge 104a around its top surface and is dimensioned to fit within and seal the opening 100 in cap 98. As shown in FIG. 4, cap 98 is in a raised position in which the passageway 80' in sleeve 78' provides communication between the interior of the waste holding tank and ambient air. Cap 98 can also be depressed from the position in which it is shown in FIG. 4 to a position in which plug member 104 fits within and seals the opening 100 in the cap. This position of the cap member is indicated in ghost outline in FIG. 4 and it will be seen that the top surface of plug member 104 lies generally flush with the top of cap 98 at this time.
The portion of the external surface of sleeve 78' which is surrounded by the skirt 102 of cap 98 includes a "waist" area 108 extending between upper and lower shoulders 110 and 112 respectively. It will be seen that the lower shoulder 112 is defined by a straight chamfer while the upper shoulder 110 is radiussed at 110a (FIG. 5) to define a protuberant rib which frictionally engages the internal surface of the skirt 102. As best seen in FIG. 4, a similar but oppositely directed rib 114 extends around the interior surface of skirt 102 and engages below the rib 110 on the sleeve 78' when cap 98 is in its raised (open) position. When the cap is depressed, rib 114 engages shoulder 112 and defines the "vent-closed" position of the cap. In other words, the co-operating ribs 110, 114 and shoulder 112 serve to define the extent to which cap 98 can be moved up and down between the vent-open and vent-closed positions. Frictional engagement between the respective ribs 110, 114 also serves to hold the cap 98 in a position to which it is moved with respect to sleeve 78'.
The two ribs 110, 114 additionally provide two annular seal areas between sleeve 78' and cap 98 in the depressed (closed) position of cap 98. As discussed previously, in the depressed position of cap 98, plug member 104 seals within the opening 100 in the cap preventing accidental leakage of liquid or gas from passageway 80' to ambient air through opening 100. In addition, the ribs 110, 114 provide respective seals between the skirt 102 of cap 98 and sleeve 78' to guard against a possibility of leakage downwardly through skirt 102.
As in the previous embodiment, sleeve 78' is moulded integrally with the moulding 54 that forms the top of the waste holding tank 24. Cap 98 is also a one-piece plastic moulding.
The vent means of FIGS. 4, 5 and 6 operates in essentially similar fashion to the vent means described previously. When the bowl unit and holding tank have been separated, the valve member of the vent means (cap 98) is manually raised to the position shown in FIG. 4 and remains in that position during emptying of the tank. Air can then enter through cap opening 100, flow between the legs 106 below plug member 104, and from there into the waste holding tank via passageway 80'. At the end of the emptying operation, cap 98 is depressed to cause plug member 104 to seal within opening 100 and close vent passageway 80'.
Cap 98 will be automatically depressed to close passageway 80' when the bowl unit 22 and waste holding tank 24 of the toilet are fitted together, by virtue of the engagement of cap 98 within the association recess 68' at the underside of the bowl unit, generally as described previously. In other words, cap 98 is fully seated within the associated recess 68' and in its depressed position when the bowl unit and holding tank are coupled together.
In summary, the vent means of the respective embodiments operate in essentially similar fashion except in the embodiments of FIGS. 2 and 3, the valve member of the vent means slides internally within the vent passageway while in the embodiment of FIGS. 4 to 6, the valve member takes the form of an external cap. It is believed that the two forms of vent means will be functionally similar although the form shown in FIGS. 4 to 6 may be preferred in terms of ease of manufacture.
It will of course be appreciated that the preceding description relates to particular preferred embodiments of the invention only and that many modifications are possible within the broad scope of the invention. For example, the vent means provided by the invention need not be incorporated in an alignment formation on the holding tank but could be provided separately. In a simple embodiment, the valve element on the holding tank need not incorporate a valve member but the vent passageway could simply be closed by a portion of the bowl unit (for example a portion defining a plug fitting into the passageway) when the bowl unit is seated on the holding tank. However, this arrangement would not be preferred because the vent means would then be open at all times when the bowl unit is not seated on the holding tank. Another possibility would be to in effect reverse the arrangement illustrated and provide a male element on the bowl unit that would engage in an opening or a female recess in the holding tank. The recess or opening could be closed directly by the male element on the bowl unit or that element could actuate a valve member, similar to valve member 82.
Where a movable valve member is provided, the member is preferably manually movable between a first position in which the vent passageway is closed and a second position in which the passageway is open, and is positively retained in each position. This avoids the problem of the prior art discussed above where the valve member must be held open durig the entire holding tank emptying operation. However, the valve member need not be of the exact form shown. For example, the valve member could be arranged to open and close vent openings in the side of sleeve 78 or 78' to open and close the vent passageway. | A portable toilet of the type having a waste holding tank which is separable from a bowl unit of the toilet. The tank includes a vent for permitting entry of air to the holding tank during emptying thereof. This avoids surging of the contents of the tank during emptying, assuring a smooth flow of the liquid and minimizing splashing. In a preferred embodiment, the vent takes the form of a sleeve projecting upwardly from the holding tank and defining a vent passageway, and a cap on the sleeve which can be manually raised to open the vent passageway but which is automatically depressed to close the vent when the bowl unit is secured to the holding tank. | 4 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a vertically telescopic robot and, more particularly to a robot suitable for operation in a clean room.
[0003] 2. Description of the Related Art
[0004] Conventionally, in manufacturing equipment installed in a clean room, such as semiconductor wafer manufacturing equipment, when a large stroke of vertical movement is required, a cylindrical coordinates robot a shown in FIGS. 1, 2 is used for handling a work w such as a semiconductor wafer.
[0005] As shown in FIG. 1, to rotate and convey the work w in a horizontal plane in θ direction around Z-axis, the cylindrical coordinates robot a is structured such that a column-shaped Z-axis member e is provided upwardly from an upper face d of a rotating member c pivotally mounted on a base unit b, and a horizontal member f having a wafer handling unit g is mounted on the Z-axis member e such that it is vertically movable. The wafer handling unit g is mounted such that it can reciprocate in X-axis direction (horizontal direction) in FIG. 1. According to the configuration of the cylindrical coordinates robot a, the horizontal member f moves up/down between a lower end position shown in FIG. 1 and an upper end position shown in FIG. 2, and the Z-axis member e, together with the rotating member c, rotates in the θ direction around the Z-axis. Thereby, the wafer handling unit g conveys the work w such as the semiconductor wafer to a predetermined position.
[0006] In some cases, in the manufacturing equipment, instead of the cylindrical coordinates robot a shown in FIGS. 1, 2, an articulated robot h shown in FIGS. 3, 4, as a general industrial robot is used. The articulated robot h is configured such that a wafer handling unit k is attached to a tip end of an arm j having a base end attached to a rotatable base unit i. The arm j has a plurality of joints m 1 , m 2 , m 3 and is bendable. According to the configuration of the articulated robot h, the wafer handling unit k is displacable in Z-axis direction between an upper position shown in FIG. 3 and a lower position shown in FIG. 4 and is movable in a horizontal plane. Also, the arm j is displacable in θ direction around the Z-axis.
[0007] However, in the articulated robot h, if the arm j is bent by a large angle to reduce a length thereof in the Z-axis direction as shown in FIG. 4, that is, to lower the wafer handling unit k, a portion such as the joint m 2 , is greatly protruded from the base unit i in horizontal direction X and tends to interfere with its vicinity. For this reason, it is difficult to make the entire device using the articulated robot h compact.
[0008] In a clean room or a clean booth of which extremely high level cleanliness is demanded, air purifying equipment costs a great deal, and it is therefore necessary to minimize a foot print (foot area) of the manufacturing equipment in order to reduce a cost per unit area. Accordingly, most of respective devices in the manufacturing equipment are vertically provided, and the operation in the Z-axis direction of the robot for use in the manufacturing equipment is necessarily increased. Under the circumstance, the cylindrical coordinates robot a shown in FIGS. 1, 2, which does not significantly interfere with its vicinity and has a long stroke in the vertical direction, has been mainly used.
[0009] However, in the cylindrical coordinates robot a shown in FIGS. 1, 2, because a space for the Z-axis member e is required beside a space for the wafer handling unit g for conveying the work w in the Z-axis direction, an interferential space n is formed, as shown in a plan view of FIG. 5. This interferential space n impedes the device using the cylindrical coordinates robot a from being made compact, although it is smaller than an interferential space of the articulated robot h shown in FIGS. 3, 4.
[0010] When horizontally handling a disc-shaped work w such as the semiconductor wafer or a glass electrode for liquid crystal, there is a possibility that dust is generated from an upper portion of the Z-axis member e that is situated above the work w and falls on a surface of the work w and the work w is contaminated. For this reason, it is sometimes difficult to keep the demanded cleanliness of the work w.
[0011] Since the Z-axis member e have a length greater than that of a displacement stroke in the Z-axis direction of the wafer handling unit g of the horizontal member f, the member e is difficult to handle in installation or maintenance. For example, when carried into/out of the clean room, the long Z-axis member e must be handled as it is, which makes operation difficult. Also, when transferred from a manufacturing factory to a place where the member e is used, the Z-axis member e tends to be damaged and is bulky during transfer is reduced, because the long Z-axis member must be handled as it is.
[0012] By the way, as a horizontal movement mechanism of the wafer handling unit g, prior arts using a multistage slide mechanism, with higher space efficiency, are disclosed in Japanese Laid-Open Patent Publication No. Sho. 58-84435 (1983), Japanese Laid-Open Patent Publication No. Sho. 62-297085 (1987), Japanese Laid-Open Patent Publication No. Hei. 9-36200 (1997), and the like.
[0013] In these prior arts, up-down axes are moved in a horizontal direction. As a matter of course, these axes can be applied to vertical movement. However, since sliders in the respective stages are driven by combination of a rope and pulleys, it is not easy for the multistage slide mechanism to withstand excess weight including its own weight. When a highly rigid metal wire is used as the rope as a solution to the above problem, another problem that a holding force of the sliders is reduced because friction generated between the wire and the pulleys is small, will arise. Consequently, the configuration disclosed in each of the Publications, without being altered, cannot be applied to the cylindrical coordinates robot a.
[0014] Japanese Laid-Open Patent Publication No. Hei. 11-87461 (1999) discloses a substrate conveying device that holds a substrate and conveys the substrate to a predetermined position, comprising: a sweepable conveying arm that holds the substrate and conveys the substrate in the horizontal direction; a telescopic up-down mechanism that extends/retracts in the vertical direction to move the conveying arm up/down; and a cover provided such that it covers the telescopic up-down mechanism, extending/retracting in association with extension/retraction of the telescopic up-down mechanism, and having an opening in an upper face thereof.
[0015] However, in the device disclosed in the Japanese Laid-Open Patent Publication No. Hei. 11-87461 (1999), since the cover of the telescopic up-down mechanism is separated from the telescopic up-down mechanism, a foot print cannot be made sufficiently small. In addition, since this large cover, together with the telescopic up-down mechanism, extends/retracts during the extension/retraction of the telescopic up-down mechanism, air flow is greatly disordered, which tends to cause powder dust to swirl.
SUMMARY OF THE INVENTION
[0016] The present invention has been developed for obviating the above-described problems and an object of the present invention is to provide a robot comprising a telescopic-drive mechanism which does not contaminate works in a purified environment such as a clean room, is easy to handle, and requires no cover for covering the telescopic-drive mechanism.
[0017] According to an embodiment of the present invention, there is provided a robot comprising: an up-down axis in which a plurality of hollow axis sectional elements telescopically continue; and a telescopic-drive mechanism for driving the up-down axis to be vertically extended or retracted between an extended state in which a tip end of the up-down axis extends with respect to a base end thereof and a retracted state in which the tip end is moved close to the base end, wherein the telescopic-drive mechanism is integrated on one side of the up-down axis without being exposed from the up-down axis.
[0018] According to another embodiment of the present invention, there is provided a robot comprising: an up-down axis in which a plurality of hollow axis sectional elements telescopically continue; a telescopic-drive mechanism for driving the up-down axis to be vertically extended or retracted between an extended state in which a tip end of the up-down axis extends with respect to a base end thereof and a retracted state in which the tip end is moved close to the base end; and an operation axis unit having a rotatable base provided at a top portion of the up-down axis, wherein the telescopic-drive mechanism is integrated on one side of the up-down axis without being exposed from the up-down axis.
[0019] It is preferable that the robot comprises an exhaust means provided at a lower end portion of the up-down axis, for exhausting a gas inside of the up-down axis, or an exhaust duct provided at the lower end portion of the up-down axis such that the exhaust duct communicates with the interior of the up-down axis, thereby making an interior of the up-down axis have a negative pressure.
[0020] In the robot of the present invention, the telescopic-drive mechanism is structured such that the up-down axis comprises: a main up-down means for moving a second axis sectional element up or down with respect to a first axis sectional element situated at the base end, the second axis sectional element being situated above the first axis sectional element; and a subordinate up-down means for moving remaining axis sectional elements other than the second axis sectional element up or down, following up movement or down movement of the second axis sectional element. In this case, it is preferable that the up-down axis has a substantially rectangular cross section and the main up-down means and the subordinate up-down means are provided on a side face of a long side of the rectangular cross section of the up-down axis.
[0021] It is preferable that the main up-down means comprises a ball screwing mechanism. The subordinate up-down means comprises: a band-shaped or line-shaped drive member having flexibility; and a rotating member, and the rotating member is rotatably mounted to an upper end portion of a storage portion of an intermediate axis sectional element, the drive member is installed around the rotating member, and the drive member has a lower end portion attached to a lower axis sectional element and an upper end portion attached to an upper axis sectional element. In this case, it is preferable that a plurality of drive members are installed in parallel around the rotating member.
[0022] Also, it is preferable that the robot of the present invention comprises: a guide portion for guiding up movement or down movement of the plurality of axis sectional elements driven by the main up-down means and the subordinate up-down means and is more preferable that the guide portion is provided adjacently to the subordinate up-down means.
[0023] In the robot of the present invention, the telescopic-drive mechanism for extending/retracting the axis sectional elements is integrated on one side of the up-down axis without being exposed therefrom, the powder dust generated as a result of operation of the telescopic-drive mechanism is prevented from flying to all directions in the clean room, and simultaneously, the configuration of the robot can be simplified.
[0024] In addition, since transfer and installation can be carried out with the robot retracted, space efficiency in transfer is improved and complexity of installation operation is avoided. Correspondingly, a transfer cost and an installation cost are reduced.
[0025] Further, according to still another preferred embodiment of the present invention, since the operation axis unit is rotatably provided at the top portion of the up-down axis, the foot area in equipment which the robot occupies becomes substantially as small as a bottom area of the first axis sectional element at the base end, and therefore, the equipment can be easily made compact. Moreover, since the operation axis unit is positioned at the highest position, the work such as the wafer is prevented from being contaminated by the power dust caused by the operation of the operation axis unit.
[0026] The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] [0027]FIG. 1 is a perspective view showing the conventional cylindrical coordinates robot and showing a state in which a wafer handling unit is positioned at a lower end position;
[0028] [0028]FIG. 2 is a perspective view showing the conventional cylindrical coordinates robot and showing a state in which the wafer handling unit is positioned at an upper end position;
[0029] [0029]FIG. 3 is a perspective view showing the conventional articulated robot and showing a sate in which a wafer handling unit is positioned at an upper end position;
[0030] [0030]FIG. 4 is a perspective view showing the conventional articulated robot and showing a sate in which the wafer handling unit is positioned at a lower end position;
[0031] [0031]FIG. 5 is a plan view showing an interferential space of the conventional cylindrical coordinates robot;
[0032] [0032]FIG. 6 is a perspective view schematically showing a subordinate up-down mechanism employed in a robot of the present invention;
[0033] [0033]FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6;
[0034] [0034]FIG. 8A is an enlarged sectional plan view showing main portions of the subordinate up-down mechanism shown in FIGS. 6, 7;
[0035] [0035]FIG. 8B is an enlarged sectional side view showing main portions of the subordinate up-down mechanism shown in FIGS. 6, 7;
[0036] [0036]FIG. 9 is a schematic view showing a state in which drive belts are installed in parallel around an up-down roller in the subordinate up-down mechanism shown in FIGS. 6, 7;
[0037] [0037]FIG. 10 is a schematic view showing a first guide portion of the subordinate up-down mechanism shown in FIGS. 6, 7;
[0038] [0038]FIG. 11 is a schematic view showing a main up-down mechanism employed in the robot of the present invention;
[0039] [0039]FIG. 12 is a perspective view schematically showing an up-down axis of the robot of the present invention;
[0040] [0040]FIG. 13 is a cross-sectional view taken along line XIII-XIII in FIG. 12;
[0041] [0041]FIG. 14 is a perspective view schematically showing an operation axis unit of the robot of the present invention; and
[0042] [0042]FIG. 15 is a schematic view showing the robot of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] Hereinafter, preferred embodiments will be described with reference to accompanying drawings, although the present invention is not limited to the embodiment.
[0044] [0044]FIG. 6 is a perspective view schematically showing main portions of a subordinate up-down mechanism (subordinate up-down means) S which is employed in a telescopic robot (hereinafter referred to as a robot) according to an embodiment of the present invention and FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. In the example shown in these Figures, the subordinate up-down mechanism S is adapted to move a first axis sectional element SM 1 , a second axis sectional element SM 2 , a third axis sectional element SM 3 , and a fourth axis sectional element SM 4 , up/down in association with a main up-down mechanism (main up-down means). The first to fourth axis sectional elements SM 1 -SM 4 are telescopically placed in a vertical direction. The elements SM 1 -SM 4 respectively have substantially channel shaped cross sections. The elements SM 1 -SM 4 are arranged in the same direction such that these elements respectively surround their adjacent elements in this order, that is, these elements respectively overlap with their adjacent elements in this order as having a predetermined clearance. The fourth axis sectional element SM 4 has a lower end portion fixed to a base (not shown). The third axis sectional element SM 3 , the second axis sectional element SM 2 , and the first axis sectional element SM 1 are upwardly extended in this order from the fourth axis sectional element SM 4 .
[0045] Specifically, the subordinate up-down mechanism S comprises a first subordinate up-down portion K 1 for moving the third axis sectional element SM 3 up/down, following the up/down movement of the second axis sectional element SM 2 driven by a main up-down mechanism mentioned in detail later, a second subordinate up-down portion K 2 for moving the fourth axis sectional element SM 4 up/down, following the up/down movement of the third axis sectional element SM 3 driven by the first subordinate up-down portion K 1 , and a guide portion G for guiding the up/down movement by the first and second subordinate up-down portions K 1 , K 2 . The first subordinate up-down portion K 1 and the second subordinate up-down portion K 2 are provided on the same side of the axis sectional elements SM, for example, on a front face side (on a front and right side of FIG. 6). In other words, the first subordinate up-down portion K 1 and the second subordinate up-down portion K 2 are integrated on one side of the axis sectional elements SM.
[0046] The first subordinate up-down portion K 1 comprises an up-down roller 1 , a drive belt 2 installed around the up-down roller 1 , and a separating plate 3 , and its main portion is stored in a storage portion 10 of the second axis sectional element SM 2 . To store the storage portion 10 , the first axis sectional element SM 1 is provided with a storage concave portion 12 formed in a corresponding inner face of a front wall Wf.
[0047] More specifically, the up-down roller 1 has a rotating shaft 1 a rotatably attached to a side wall of the storage portion 10 , in an upper end portion 10 a of the storage portion 10 formed by protruding a central portion of the front wall Wf of the second axis sectional element SM 2 from an upper end thereof to a lower end thereof in a direction toward a front face (see FIG. 8A). In this case, the vertical position at which the up-down roller 1 is provided is adjusted so that the drive belt 2 installed on a top portion thereof is not protruded from an upper end of the second axis sectional element SM 2 (see FIG. 8B). An end portion of the rotational shaft 1 a of the roller 1 is not exposed, that is, the end portion of the rotational shaft 1 a is stored in a side wall of the storage portion 10 (see FIG. 8A). In FIG. 8A, for the sake of convenience, a clearance between the rotational shaft 1 a and the side wall is enlarged.
[0048] The drive belt 2 installed around the up-down roller 1 is, for example, made of a stainless band steel or a wire having predetermined strength and flexibility. One end portion lower end portion) 2 a of the drive belt 2 is downwardly extended along the inner face of the front wall Wf of the second axis sectional element SM 2 and fixed to a lower end portion of the inner face of the front wall Wf of the first axis sectional element SM 1 by means of a mounting member 5 a . The other end portion (upper end portion) 2 b of the drive belt 2 is fixed to a predetermined portion of an outer face of the front wall Wf of the third axis sectional element SM 3 by means of a mounting member 5 b . The position of the predetermined portion is adjusted to allow the third axis sectional element SM 3 be moved up/down by a predetermined distance when the second axis sectional element SM 2 is moved up/down by the main up-down mechanism. While the number of the drive belt 2 is one in the illustrated example, it is preferable that a plurality of belts are provided as shown in FIG. 9. This is because, when the plurality of belts 2 are provided, maintenance of the drive belts 2 can be alternately performed and a jig for keeping the position of the axis sectional element SM in maintenance of the drive belt 2 can be dispensed with.
[0049] The separating plate 3 has a width substantially equal to an inner dimension of the storage portion 10 and a length from below of the up-down roller 1 to a lower end of the second axis sectional element SM 2 . The separating plate 3 is provided between two portions of the drive belt 2 installed around the up-down roller 1 . More specifically, the separating plate 3 is provided immediately below the up-down roller 1 so that moment due to load (vertically and downwardly) applied on the up-down roller 1 is not applied on the separating plate 3 . The separating plate 3 is a rigid member that is sufficiently rigid not to be elastically deformed by the moment and rigid enough to withstand a force applied to an end portion of the drive belt 2 of the second subordinate up-down portion K 2 mentioned later.
[0050] As should be appreciated from the foregoing description, the up-down roller 1 , the drive belt 2 , and the separating plate 3 constituting the first subordinate up-down portion K 1 are not exposed.
[0051] The front wall Wf of the axis sectional element SM may be a removably attachable cover, for easy maintenance.
[0052] Like the first subordinate up-down portion K 1 , the second subordinate up-down portion K 2 comprises an up-down roller 1 , a drive belt 2 installed around the up-down roller 1 , and a separating plate 3 , and its main portion is stored in a storage portion 10 of the third axis sectional element SM 3 .
[0053] More specifically, the up-down roller 1 has a rotating shaft 1 a rotatably attached to a side wall of the storage portion 10 , in an upper end portion 1 O a of the storage portion 10 formed by protruding a central portion of the front wall Wf of the third axis sectional element SM 3 from an upper end thereof to a lower end thereof in a direction toward a front face (see FIG. 8A). In this case, the vertical position at which the up-down roller 1 is provided is adjusted so that the drive belt 2 installed on a top portion thereof is not protruded from an upper end of the third axis sectional element SM 3 (see FIG. 8B). An end portion of the rotational shaft 1 a of the roller 1 is not exposed, that is, the end portion of the rotational shaft 1 a is stored in a side wall of the storage portion 10 (see FIG. 8A).
[0054] One end portion (lower end portion) 2 a of the drive belt 2 installed around the up-down roller 1 is downwardly extended along an inner face of the front wall Wf of the third axis sectional element SM 3 and fixed to a predetermined portion of a lower portion of an inner face of the separating plate 3 provided in the second axis sectional element SM 2 by means of the mounting member 5 a , and the other end portion (upper end portion) 2 b thereof is fixed to a predetermined portion of an outer face of the front wall Wf of the fourth axis sectional element SM 4 by means of the mounting member 5 b . The positions of these predetermined portions are adjusted so that the fourth axis sectional element SM 4 can be moved up/down by a predetermined distance when the third axis sectional element SM 3 is moved up/down by the first subordinate up-down portion K 1 .
[0055] The separating plate 3 has a width substantially equal to a inner dimension of the storage portion 10 and a length from below of the up-down roller 1 to a lower end of the third axis sectional element SM 3 . The separating plate 3 is provided between two portions of the drive belt 2 installed around the up-down roller 1 .
[0056] As should be appreciated from the foregoing description, the up-down roller 1 , the drive belt 2 , and the separating plate 3 constituting the second subordinate up-down portion K 2 are not exposed.
[0057] As shown in FIG. 6, the guide portion G comprises a first guide portion G 1 for guiding up-down movement of the second axis sectional element SM 2 , a second guide portion G 2 for guiding up-down movement of the third axis sectional element SM 3 , and a third guide portion G 3 for guiding up-down movement of the four axis sectional element SM 4 . Since the first guide portion G 1 , the second guide portion G 2 , and the third guide portion G 3 have the same structure, hereinbelow, a structure of the first guide portion G 1 will be described with reference to FIG. 10.
[0058] As shown in FIG. 10, the first guide portion G 1 is constituted by a pair of guide mechanisms 6 (a right guide mechanism 6 R and a left guide mechanism 6 L), which are provided such that the storage portion 10 is interposed between them, adjacently to the storage portion 10 , and symmetrically with respect to the storage portion 10 in a width direction thereof. The right guide mechanism 6 R and the left guide mechanism 6 L are each constituted by a guide member 7 vertically provided along an outer face of the second axis sectional element SM 2 and having a guide groove 7 a formed in a front face thereof, and a slide member 8 vertically provided at a portion of the inner face of the first axis sectional element SM 1 , which is associated with the guide member 7 , for being slidably fitted into the guide groove 7 a.
[0059] Although the pair of the guide mechanisms 6 of the guide portion G are placed symmetrically in the illustrated example, the configuration of the guide portion G is not limited to this.
[0060] As shown in FIG. 11, the main up-down mechanism E comprises a screw shaft 21 for up-down movement, a drive motor 22 , a gear mechanism 23 for transmitting a driving force of the drive motor 22 to the screw shaft 21 , and an up-down block 24 screwed on the screw shaft 21 for being moved up/down. The mechanism for transmitting the driving force is not limited to the gear mechanism 23 , and may be one of various types of power transmission mechanisms. For example, a belt mechanism may be employed.
[0061] The screw shaft 21 may be, for example, a ball screw shaft. The screw shaft 21 is vertically and rotatably provided such that it is spaced a predetermined distance apart from the front wall Wf of the first axis sectional element SM 1 , for example, it is situated at a position associated with the storage portion 10 of the second axis sectional element SM 2 . An output gear 23 a of the gear mechanism 23 is attached to an upper end of the screw shaft 21 .
[0062] The drive motor 22 is provided closer to the upper end of the screw shaft 21 and in parallel with the screw shaft 21 such that the up-down shaft 22 a is directed downwardly. An input gear 23 b of the gear mechanism 23 is attached to a tip end portion of the up-down shaft 22 a.
[0063] The up-down block 24 has a base end portion 24 a penetrating through a window 25 for up-down movement provided at a portion of the first axis sectional element SM 1 , which corresponds to a vertical length of the screw shaft 21 , is provided and joined to a predetermined portion of a lower end portion of the front wall Wf forming the storage portion 10 of the second axis sectional element SM 2 .
[0064] The main up-down mechanism E is configured as described above. In this configuration, when the drive motor 22 is driven, the resulting driving force is transmitted to the screw shaft 21 via the gear mechanism 23 and causes the screw shaft 21 to be rotated, thereby moving the up-down block 24 up/down along the screw shaft 21 . Since the base end portion 24 a of the up-down block 24 is joined to the second axis sectional element SM 2 , the second axis sectional element SM 2 is moved up/down, along with the up/down movement of the up-down block 24 .
[0065] As shown in FIG. 11, the main up-down mechanism E so configured is covered by a casing 26 for storing the main up-down mechanism E.
[0066] Subsequently, the up-down movement of the subordinate up-down mechanism S having the above configuration will be described.
[0067] When the second axis sectional element SM 2 is moved up by the main up-down mechanism E, the upper end 2 b of the drive belt 2 is pulled up by the up movement of the second axis sectional element SM 2 because the lower end 2 a of the drive belt 2 is fixed to the inner face of the lower end portion of the first axis sectional element SM 1 . Also, since the upper end 2 b of the drive belt 2 is fixed to the outer face of the third axis sectional element SM 3 , the upper end 2 b pulls up the third axis sectional element SM 3 . In other words, the second axis sectional element SM 2 , the first axis sectional element SM 1 , and the third axis sectional element SM 3 , respectively correspond to an intermediate axis sectional element, a lower axis sectional element, and an upper axis sectional element, and relative to the intermediate axis sectional element, the upper axis sectional element is moved up and the lower axis sectional element is moved down.
[0068] When the third axis sectional element SM 3 is pulled up, the upper end 2 b of the drive belt 2 is correspondingly pulled up. Also, since the upper end 2 b of the drive belt 2 is fixed to the fourth axis sectional element SM 4 , the upper end 2 b pulls up the fourth axis sectional element SM 4 . In other words, the third axis sectional element SM 3 , the second axis sectional element SM 2 , and the fourth axis sectional element SM 4 , respectively correspond to an intermediate axis sectional element, a lower axis sectional element, and an upper axis sectional element, and relative to the intermediate axis sectional element, the upper axis sectional element is moved up and the lower axis sectional element is moved down.
[0069] Thus, the second axis sectional element SM 2 to the fourth axis sectional element SM 4 are telescopically advanced. Since this advancement is guided by the guide portion G, i.e., the first guide portion G 1 , the second guide portion G 2 , and the third guide portion G 3 , the axis sectional elements SM 2 , SM 3 , SM 4 do not waggle rightward or leftward while they are advanced.
[0070] On the other hand, when the second axis sectional element SM 2 is moved down by the main up-down mechanism E, the upper end 2 b of the drive belt 2 is pulled down by the down movement of the second axis sectional element SM 2 since the lower end 2 a of the drive belt 2 is fixed to the inner face of the lower end portion of the first axis driving element SM 1 . Also, since the upper end 2 b of the drive belt 2 is fixed to the outer face of the third axis sectional element SM 3 , the upper end 2 b pulls down the third axis sectional element SM 3 . When the third axis sectional element SM 3 is pulled down, the upper end 2 b of the drive belt 2 is correspondingly pulled down. Since the upper end 2 b of the drive belt 2 is fixed to the fourth axis sectional element SM 4 , the upper end 2 b pulls down the fourth axis sectional element SM 4 . Thus, the second axis sectional element SM 2 to the fourth axis sectional element SM 4 are telescopically retracted. Since this retraction is guided by the guide portion G 1 , i.e., the first guide portion G 1 , the second guide portion G 2 , and the third guide portion G 3 , the axis sectional elements SM 2 , SM 3 , SM 4 do not waggle rightward or leftward during retraction.
[0071] Subsequently, a robot comprising the telescopic-drive mechanism constituted by the main up-down mechanism E and the subordinate up-down mechanism S so configured, will be described.
[0072] [0072]FIG. 12 is a perspective view schematically showing an up-down axis J of the robot with constituents except the subordinate up-down mechanism S omitted and FIG. 13 is a cross-sectional view taken along line XIII-XII in FIG. 12.
[0073] As shown in FIGS. 12, 13, the up-down axis J is structured such that a channel-shaped member U is placed opposite to the substantially channel-shaped axis sectional element SM and a tip end portion of the channel-shaped axis sectional element SM and a tip end portion of the channel-shaped member U are joined and united to form an axis sectional element JM having a substantially rectangular cross section. Each axis sectional element JM is telescopically movable up/down. More specifically, the first axis sectional element SM 1 and a channel-shaped member U 1 are joined and united to form a hollow-column shaped first axis sectional element JM 1 having a substantially rectangular cross section. Provided inside of the first axis sectional element JM 1 is a hollow-column shaped second axis sectional element JM 2 having a substantially cross section which is formed by joining and uniting the second axis sectional element SM 2 and a channel-shaped member U 2 . Provided inside of the second axis sectional element JM 2 is a hollow-column shaped third axis sectional element JM 3 having a substantially cross section which is formed by joining and uniting the third axis sectional element SM 3 and a channel-shaped member U 3 . Provided inside of the third axis sectional element JM 3 is a hollow-column shaped fourth axis sectional element JM 4 having a substantially cross section which is formed by joining and uniting the fourth axis sectional element SM 4 and a channel-shaped member U 4 . Thus, the entire up-down axis J is telescopically extensible/retractable. In this case, the main up-down mechanism E and the subordinate up-down mechanism S constituting the telescopic-drive mechanism are integrated on a long side of a rectangle of the rectangular cross section.
[0074] As shown in FIG. 14, an operation axis unit 30 is provided at a top portion of the up-down axis J, i.e., at a tip end of the fourth axis sectional element JM 4 .
[0075] The operation axis unit 30 comprises a circular disc shaped unit base 31 attached to the tip end portion of the fourth axis sectional element JM 4 , a turn table 32 rotatably placed on the unit base 31 , an arm 33 attached to the turn table 32 at a suitable position, and a wafer handling unit 34 attached to an upper face of a tip end portion of the arm 33 . The conventionally known rotating mechanism may be suitably used as a rotating mechanism of the turn table 32 and the conventionally known handling unit may be also used as the wafer handling unit 34 . The arm 33 is constituted by a first arm 33 a having a base end portion rotatably attached to the turn table 32 at a suitable position and a second arm 33 b rotatably attached to the upper face of the first arm 33 a . In FIG. 14, reference numeral W denotes a work such as a wafer.
[0076] As shown in FIG. 15, inside of a lower end portion of the up-down axis J, i.e., inside of a lower end portion of the first axis sectional element JM 1 , exhaust fans 40 are provided to cause an interior of the up-down axis J to have a negative pressure. For this reason, powder dust is prevented from being ejected from slide portions of the axis sectional elements JM 1 , JM 2 , JM 3 , JM 4 into the clean room. As shown in FIG. 16, the exhaust fans 40 may be replaced by exhaust ducts 41 connected to the lower end portion of the first axis sectional element JM 1 to cause the interior of the up-down axis J to have a negative pressure. In FIGS. 15, 16, reference R denotes a robot.
[0077] Thus, in the robot R of this embodiment, the up-down axis is structured such that the axis sectional elements SM including constituents of the subordinate up-down mechanisms S are integrated on one side of the up-down axis, moment applied on the guide mechanism G and the axis sectional element JM can be significantly reduced as compared to a case where the subordinate up-down mechanism elements S are alternately placed. Consequently, distortion of each of the axis sectional elements JM 1 , JM 2 , JM 3 , JM 4 can be significantly reduced while they are moved up/down and the up-down axis J can be smoothly moved up/down. Also, since the subordinate up-down mechanisms S are integrated on one side of the up-down axis J, the guide mechanisms G can be also integrated on one side where the subordinate up-down mechanisms S are provided. Therefore, configuration can be easily simplified. Further, since the main up-down mechanism E is also integrated on one side of the up-down axis J where the subordinate up-down mechanisms S are provided, maintenance for them can be efficiently made.
[0078] While the description has been given to the embodiment of the present invention, the present invention is not limited to this, and can be modified in various ways. For example, while in this embodiment, the up-down axis has a size reducable in a direction from the base end thereof toward the tip end thereof, this may have a size reducable in a direction from the tip end toward the base end.
[0079] As described in detail, according to the present invention, the telescopic-drive mechanism is integrated on one side of the up-down axis without being exposed therefrom. Therefore, the powder dust generated as a result of operation of the telescopic-drive mechanism is prevented from flying to all directions in the clean room, and simultaneously, the configuration of the robot can be simplified.
[0080] In addition, since transfer and installation can be carried out with the robot retracted, space efficiency in transfer is improved and complexity of installation operation is avoided. Correspondingly, a transfer cost and an installation cost are reduced.
[0081] Further, according to the preferred embodiment of the present invention, since the operation axis unit is rotatably provided on the top portion of the up-down axis, the foot area in equipment which the robot occupies becomes substantially as small as a bottom area of the first axis sectional element at the base end, and therefore, the equipment can be easily made compact. Moreover, since the operation axis unit is positioned at the highest position, the work such as the wafer is prevented from being contaminated by the power dust caused by the operation of the operation axis unit.
[0082] As this invention may be embodied in several forms without departing from the sprit of essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within metes and bounds of the claims, or equivalence of such metes and bounds thereof are therefore intended to be embraced by the claims. | Provided is a robot comprising a telescopic-drive mechanism which does not contaminate works in a purified environment such as a clean room, is easy to handle, and requires no cover for covering the telescopic-drive mechanism. A robot comprises: an up-down axis in which a plurality of hollow axis sectional elements telescopically continue; and a telescopic-drive mechanism for driving the up-down axis to be vertically extended or retracted between an extended state in which a tip end of the up-down axis extends with respect to a base end thereof and a retracted state in which the tip end is moved close to the base end, wherein the telescopic-drive mechanism is integrated on one side of the up-down axis without being exposed from the up-down axis. | 8 |
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of Ser. No. 08/278,246 filed Jul. 21, 1994 (now U.S. Pat. No. 5,440,658); which is a continuation-in-part of Ser. No. 08/142,938 filed Oct. 29, 1993 (now U.S. Pat. No. 5,466,174); which is a continuation-in-part of Ser. No. 08/082,963 filed Jun. 29, 1993, now U.S. Pat. No. 5,368,503 issued Nov. 29, 1994.
This invention relates generally to optical coupling of light sources and fiber optics cables, and more particularly, to optical coupling of light-emitting diodes (LEDs) to the light entrance ends of such cables.
Light refracting lenses have been proposed for such optical coupling purposes; however, efficient coupling is substantially reduced if the light emitters of LEDs are not axially centered relative to LED lenses.
There is need for improved apparatus and method to overcome such inefficiencies.
SUMMARY OF THE INVENTION
It is a major object to provide such improved apparatus and method. Basically, the invention comprises, in combination:
a) a mounting means having a longitudinal axis,
b) an LED having a light emitter and a light-passing lens oriented along the axis,
c) a cable having optical fibers defining a light entrance end in a location facing longitudinally toward the LED and spaced therefrom, and
d) a light-reflecting light pipe located longitudinally between the LED lens and the cable entrance end.
Accordingly, even though the LED should be produced to have its emitter off axis, slightly, the efficiency of light coupling from the LED to the fiber optics cable entrance end will not be materially reduced.
Further objects include the provision of the light-refracting light pipe to taper toward the cable end, for efficient light coupling, the provision of such a light pipe to have a generally conical surface oriented to reflect light rays from the LED lens toward the cable entrance end; the provision and location of the light pipe to have a relatively large entrance end and a relatively small exit end, the entrance end proximate the LED lens, and the exit end proximate the cable entrance end.
Yet another object includes the provision of mounting means to include a tubular housing in which the light pipe is received, and a cable connector having barbs connecting to the cable, and/or the reception of the end of the tubular housing into the connector, with barb retention.
A further object includes the provision of a hollow connector connected to the mounting means and having a first portion to receive the cable and to position the cable entrance end relative to the light pipe, the connector having grip means thereon to grip the cable and to resist endwise withdrawal of the cable relative to the connector and mounting means. As will be seen, the grip means advantageously comprises barbs on the connector.
Yet another object includes provision of a mounting panel to which the hollow connector is connected, the hollow connector and mounting means typically having telescopic interconnection.
An additional object includes provision of a projection on the mounting means to connect the mounting means sidewardly to a circuit board.
Further objects include the provision of spring fingers on the mounting means to connect to the LED, and a flange on the mounting means to connect to a mounting panel.
These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which:
DRAWING DESCRIPTION
FIG. 1 is a cross section taken through an assembly incorporating the invention;
FIG. 2 is an axial section taken through the mounting structure for the LED and light pipe;
FIG. 3 is an elevation showing the light pipe;
FIG. 4 is an elevation, partly in axial section, showing an LED and its end support;
FIG. 5 is a side view showing a fiber optics cable;
FIG. 6 is an axial section taken through a connector that telescopically connects to the mounting structure and positions the cable;
FIG. 7 is an axial section like FIG. 2 but enlarged to show detail, and is taken on lines 7--7 of FIG. 10;
FIG. 8 is an end view taken on lines 8--8 of FIG. 7;
FIG. 9 is an axial section taken through the mounting means but rotated 90° relative to FIG. 7, and is taken on lines 9--9 of FIG. 10;
FIG. 10 is an end view taken on lines 10--10 of FIG. 9;
FIG. 11 is an enlarged side elevation showing the LED support that is also seen in FIG. 4, and in as molded condition;
FIG. 12 is an end view taken on lines 12--12 of FIG. 11;
FIG. 13 is an end view taken on lines 13--13 of FIG. 11;
FIG. 14 is a top view taken on lines 14--14 of FIG. 13;
FIG. 15 is a view like FIG. 11 but showing the lens support with an end closure swung downwardly to installed condition;
FIG. 16 is an end view taken on lines 16--16 of FIG. 15;
FIG. 17 is an end view taken on lines 17--17 of FIG. 15;
FIG. 18 is a top plan view taken on lines 18--18 of FIG. 16;
FIG. 19 is a top plan view taken on lines 19--19 of FIG. 17;
FIG. 19a is a section taken on lines 20--20 of FIG. 19;
FIG. 20 is a view like FIG. 1 showing another form of the invention;
FIGS. 21-25 are views of the FIG. 20 embodiment, in elevation and corresponding to FIGS. 2-6;
FIG. 26 is an end view of the FIG. 21 housing, and taken on lines 26--26 of FIG. 21;
FIG. 26a is a view like FIG. 26 showing attachment to a panel;
FIGS. 27-29 are views of the FIGS. 20-26 mounting means, and include, respectively, an axial section, in elevation, and end views taken on lines 28--28 and 29--29 of FIG. 22;
FIG. 30 is a view like FIG. 27 but showing an installed light pipe;
FIG. 31 is a ray trace diagram;
FIG. 32 is another ray trace diagram; and
FIG. 33 is a view showing cable transmitted signal detection.
DETAILED DESCRIPTION
In the drawings, FIGS. 1-19a, the basic elements include a mounting means, or housing means, indicated generally at 10, an LED 11 received by the tubular mounting means, a fiber optics cable 12 also received by the mounting means in axially spaced relation to the LED, as seen in FIG. 1; and a light pipe 13 located between the curved lens 11a of the LED, and the light entrance end 12a of the cable. The latter includes a single strand or a bundle of optical fibers terminating at end 12a.
The hollow mounting means 10 may be generally rectangular, as shown in FIG. 10, and has a short bore 10a, elongated walls 10b and 10bb forming a rectangle in cross section, angled, circularly spaced shoulders 10c connecting 10a and 10b, internal flange 10d, smaller short bore at 10e, counterbore 10f at the axially opposite side of the step, and annular flare at 10g. The axis is seen at 15. A projection 16 at the outer side of the housing body has a bayonet connection thereon at 17, to connect into an opening 18 in a circuit board 19, as seen in FIG. 1, to firmly attach the housing to the board.
A shoulder 20 in the housing is adapted to seat the base flange 11b of the LED; and a plug-shaped support 21 is received in the enlarged bore 23 of the housing to retain the LED in position. Grip means, such as barbs, may be located on the periphery of the support 21 to grip the bore 23 and hold the support in position, as shown. Note end 21a of the support engaging the base flange 11b.
Cable connector 30, which is tubular, has an enlarged end 30a, internally barbed at 31, to provide barb rings that press or push connect to the housing at 32. Connector 30 has internal barbs at 33 on its reduced diameter end 30b, to engage and retain the fiber optics cable 12 in predetermined axial position, with outermost annular extent of its end 12a engaging the flange 10d. Therefore, the light-passing optical fibers in the cable terminate at a plane defined by the flange 10d, optically facing toward the LED. The cable may be simply pushed axially into the connector and thereby into position in the housing 10.
The light-reflecting light pipe 13 is conically tapered toward the cable end 12a and has a small end in a plane adjacent flange 10d, and a large end in a plane normal to axis 15, proximate the leftwardmost tip of the LED lens 11a. Planes extending axially longitudinally, in the direction of arrow 35, and containing axis 15, intersect the conical surface 13c of the light pipe along lines concave toward axis 15, as is clear from FIGS. 3 and 7.
FIG. 7 shows the positioning of the fully inserted light pipe 13, as by engagement of its nose portion with four of the shoulders 10c spaced about axis 15 (see such shoulders in FIG. 10). Two diametrically opposed, axially extending ridges 36, which are resiliently yieldable, serve to engage the light pipe as it is being endwise inserted. See FIG. 9 with ridge ramps 36a slidably engaging the light pipe at diametrically opposite locations, the ramps having substantially flat surfaces to engage and position the light pipe. The ridges 36 also provide a centering function for the rear portion of the light pipe in fully inserted position. See FIG. 9 showing ridge ramps 36b engaging the light pipe shown in broken lines 13' in fully inserted position.
The inner walls 10bb of the hollow housing 10, i.e., mounting means, support edges 13h of the light pipe in the plane of FIG. 7. The light pipe may consist of molded, transparent plastic material, and may have a reflective (silvered) outer coating facing inwardly to reflect light, as described herein, toward the entrance end of the fiber optics cable. Thus, the light pipe is frictionally held in position, axially, between the cable and LED.
The light pipe is characterized in that light from the LED is always reflected toward the small end of the light pipe, even though the emitter of the LED is off-axis 15. See FIG. 31 schematically showing ray traces toward the small end 40 of the light pipe with the emitter 41 on-axis, and FIG. 32 showing ray traces reflected off the inner side 13f of the light pipe at eccentrically located region 13gg, extending toward the small end 40 of the light pipe with the emitter 41 off-axis, all ray traces arriving at the small end 40 facing the end of the fiber optic cable. Therefore, installation inaccuracies of the LED into the mounting means 60 do not appreciably diminish the light intensity delivered to the end 12a of the fiber optics cable.
Turning to FIGS. 11-14, the LED end support 21 is shown to have a retention means 42 connected to it, as by web 43. Openings 60 in support 21 pass the LED terminals 44. After the LED terminals 44 are bent downwardly to project toward and through the circuit board, as seen in FIG. 1, the retention means 42, such as a panel, as shown, is then deflected downwardly to cover the exposed terminals. See FIGS. 15-19a. Snap connections may be provided between 42 and 21, as at elements 45 and 46. The LED terminals fit in slots 47 provided on panel 42, as seen in FIG. 14. A part or projection 48, integral with 21, is received in a hole 49 in the circuit board, to position the support 21 and the LED terminals relative to the board.
Dovetailed tongue and groove connections 50 and 51 on 21 may be provided for connection to adjacent supports 21, associated with adjacent units, as seen in FIG. 1. Dovetail tongue and groove connections 50' and 51' seen in FIG. 16 interfit connections 150' and 151' seen in FIG. 10.
FIGS. 20-25 are views similar to FIGS. 1-6, with corresponding elements bearing the same numerals. In this modification, an integral flange 80 is provided on the mounting means 10, to endwise engage a mounting panel 81. The enlarged end 30a of the connector 30 is assembled to 10 to fit closely within an opening 82 through that panel. As shown in FIGS. 26 and 26a, fasteners 83 and 84 project through slots 85 and 86 in flange 80, and through the panel, to attach the flange to panel 80.
The mounting means in this instance has integral spring fingers 90 that project rightwardly to connect to the LED flange 11b, and position the LED in predetermined relation to the light pipe 13. Note slots 94 separating the spring fingers. See FIGS. 27-30 and my prior U.S. Pat. No. 5,068,771.
Bumps 99 on the tubular bore 100 of 10 position the larger end of the light pipe. See FIG. 30.
Referring back to FIGS. 11-19, the through holes 60 are shown to include five holes, 60a-60e, in a row. Holes 60a, 60c, and 60e are spaced apart to receive three leads of a tri-lead LED; whereas, intermediate holes 60b and 60d are spaced apart to receive the two leads of a bi-lead LED. Protrusions 210 are adapted to support the apparatus in stand-off relation on a circuit board.
FIG. 33 shows detection of light signals transmitted via cable 12, in response to signal application to that cable, as described above. Elements corresponding to those described possibly bear the same numbers, but which are primed. The LED-type device 11' has a light detector 11e' (instead of an emitter) therein, and the LED-curved envelope or lens 11a' is positioned very close to the end 12a' of the cable. Light rays from the cable end 12a' to the detector element are indicated at 200. Electrical signals are transmitted at 201 from 11e' to the circuitry 202, as on a circuit board.
Spring fingers 90' on the mounting means retain and position the LED device 11' relative to the end of the cable. | In combination, a mounting structure having a longitudinal axis; an LED having a light emitter and a light-passing lens oriented along the axis; a cable having optical fibers defining a light entrance end in a location facing longitudinally toward the LED and spaced therefrom; and a light-reflecting light pipe located longitudinally between the LED lens and the cable entrance end. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. application Ser. No. 11/770,455 filed on Jun. 28, 2007, the contents of which are incorporated herein by reference
FIELD OF THE INVENTION
[0002] The present invention relates to reconfigurable circuits, and more particularly, to programmable via devices and methods for fabrication thereof.
BACKGROUND OF THE INVENTION
[0003] Reconfigurable circuits have been widely used in the semiconductor industry for field programmable gate arrays (FPGAs) and for repair of a defective memory element. The FPGA consists of a set of simple, configurable logic blocks in an array with interspersed switches that can rearrange interconnections between the logic blocks.
[0004] Reconfigurable circuits are also expected to play a significant role in three-dimensional integration technology that is being currently developed. Three-dimensional integration fabricates multilayer structures that can form a single chip combination with different functionalities. In these multilayer (and multifunctional) systems, reconfigurable circuit connection is typically needed to provide controllable logic functionality, memory repair, data encryption, as well as other functions.
[0005] A programmable via is an enabling technology for high-performance reconfigurable logic applications without the trade offs in low logic gate density and power. Phase change materials are an attractive option for this application, but to date, have drawn the most attention from semiconductor memory developers as a possible replacement to flash memory.
[0006] Programmable vias implementing phase change materials have been developed. One notable challenge that exists, however, with regard to the practical implementation of programmable vias in logic devices, is being able to scale the programmable via process technology to integrate with the current technology node. To date, programmable via process technology is not readily scalable.
[0007] Therefore, scalable programmable via technology would be desirable.
SUMMARY OF THE INVENTION
[0008] The present invention provides programmable via devices and methods for the fabrication thereof. In one aspect of the invention, a programmable via device is provided. The programmable via device comprises a substrate; a dielectric layer on the substrate; a heater on at least a portion of a side of the dielectric layer opposite the substrate; a first oxide layer over the side of the dielectric layer opposite the substrate and surrounding at least a portion of the heater; a first capping layer over a side of the first oxide layer opposite the dielectric layer; at least one programmable via extending through the first capping layer and the first oxide layer and in contact with the heater, the programmable via comprising at least one phase change material; a second capping layer over the programmable via; a second oxide layer over a side of the first capping layer opposite the first oxide layer; a pair of first conductive vias, each extending through the first and second oxide layers and the first capping layer, and in contact with the heater; and a second conductive via, located between the pair of first conductive vias, extending through the second oxide layer and in contact with the second capping layer.
[0009] In another aspect of the invention, a method of fabricating a programmable via device is provided. The method comprises the following steps. A substrate is provided. A dielectric layer is formed on the substrate. A heater is formed over at least a portion of a side of the dielectric layer opposite the substrate. A first oxide layer is deposited over the side of the dielectric layer opposite the substrate, so as to surround at least a portion of the heater. A pair of first conductive vias is formed, wherein each of the first conductive vias extends through the first oxide layer and is in contact with the heater. A first capping layer is deposited over a side of the first oxide layer opposite the dielectric layer. At least one programmable via is formed extending through the first capping layer and the first oxide layer, between the pair of first conductive vias, and in contact with the heater, the programmable via comprising at least one phase change material. A second capping layer is formed over the programmable via. A second oxide layer is deposited over a side of the first capping layer opposite the first oxide layer. The pair of first conductive vias is extended through the first capping layer and the second oxide layer. A second conductive via is formed through the second oxide layer and in contact with the second capping layer.
[0010] In yet another aspect of the invention, a method of performing a logic function is provided. The method comprises the following steps. A programmable via device is provided. The programmable via device comprises a substrate; a dielectric layer on the substrate; a heater on at least a portion of a side of the dielectric layer opposite the substrate; a first oxide layer over the side of the dielectric layer opposite the substrate and surrounding at least a portion of the heater; a first capping layer over a side of the first oxide layer opposite the dielectric layer; at least one programmable via extending through the first capping layer and the first oxide layer and in contact with the heater, the programmable via comprising at least one phase change material; a second capping layer over the programmable via; a second oxide layer over a side of the first capping layer opposite the first oxide layer; a pair of first conductive vias, each extending through the first and second oxide layers and the first capping layer, and in contact with the heater; and a second conductive via, located between the pair of first conductive vias, extending through the second oxide layer and in contact with the second capping layer. An OFF switching pulse is passed through the heater, when the programmable via is in a conductive state, the OFF switching pulse being configured to amorphize at least a portion of the phase change material in the programmable via to switch the programmable via to a resistive state and/or an ON switching pulse is passed through the heater, when the programmable via is in a resistive state, the ON switching pulse being configured to anneal at least a portion of the phase change material in the programmable via to switch the programmable via to a conductive state.
[0011] A more complete understanding of the present invention, as well as further features and advantages of the present invention, will be obtained by reference to the following detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a diagram illustrating an exemplary programmable via device according to an embodiment of the present invention;
[0013] FIGS. 2A-E are diagrams illustrating an exemplary methodology for fabricating a programmable via device according to an embodiment of the present invention;
[0014] FIGS. 3A-C are graphs illustrating operation of a phase change material according to an embodiment of the present invention;
[0015] FIG. 4 is a diagram illustrating an exemplary methodology for performing a logic function with the programmable via device of FIG. 1 according to an embodiment of the present invention;
[0016] FIG. 5 is a graph illustrating resistance-current (R-I) characteristics for switching the programmable via device of FIG. 1 to an OFF state according to an embodiment of the present invention;
[0017] FIG. 6 is a graph illustrating R-I characteristics for switching the programmable via device of FIG. 1 to an ON state according to an embodiment of the present invention; and
[0018] FIG. 7 is a graph illustrating cycling data from an endurance test of the programmable via device of FIG. 1 performed at room temperature according to an embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0019] FIG. 1 is a diagram illustrating exemplary programmable via device 100 . Programmable via device 100 comprises a substrate 102 , a dielectric layer 104 , a heater 106 , oxide layers 108 and 110 , capping layers 112 and 114 , conductive vias 116 , 118 and 120 and programmable via 122 .
[0020] Specifically, programmable via device 100 comprises dielectric layer 104 over substrate 102 . Substrate 102 can comprise any suitable semiconductor material, including, but not limited to, silicon (Si). Dielectric layer 104 , an insulating layer, can comprise any suitable dielectric material, including, but not limited to, oxides such as silicon dioxide (SiO 2 ).
[0021] Heater 106 is present on a side of dielectric layer 104 opposite substrate 102 . As shown in FIG. 1 , heater 106 extends laterally over a portion of dielectric layer 104 . To achieve the best efficiency of electrical-thermal transformation (i.e., from heater to programmable via), according to an exemplary embodiment heater 106 comprises a thin layer of a refractory metal having a thickness of between about five nanometers (nm) and about 100 nm with a relatively high resistivity of between about 100 ohm centimeter (Ωcm) and about 10,000 Ωcm, e.g., of between about 500 Ωcm and about 3,000 Ωcm. Suitable refractory metals include, but are not limited to, tantalum nitride (TaN) and metals having the formula Ta x Si y N z , wherein x, y and z are each between zero and about one.
[0022] Oxide layer 108 is present over dielectric layer 104 and surrounds heater 106 . As will be described in detail below, oxide layer 108 has conductive vias 116 and 120 and programmable via 122 extending therethrough. According to an exemplary embodiment, oxide layer 108 comprises SiO 2 .
[0023] Capping layer 112 is present over a side of oxide layer 108 opposite dielectric layer 104 . According to an exemplary embodiment, capping layer 112 comprises silicon nitride (SiN). SiN is a preferred capping material because of its dielectric properties and effectiveness as an etch stop during fabrication (see description below).
[0024] Programmable via 122 extends through capping layer 112 and oxide layer 108 , e.g., and is in contact with heater 106 . Programmable via 122 comprises a phase change material. Suitable phase change materials include, but are not limited to, one or more of ternary alloys of germanium (Ge), antimony (Sb) and tellurium (Te) (GST), such as Ge 2 Sb 2 Te 5 , GeSb, GeSb 4 and doped derivatives thereof with substitution/addition of other elements, such as nitrogen (N) and Si.
[0025] Capping layer 114 is present over programmable via 122 . Capping layer 114 extends laterally a distance beyond programmable via 122 to provide adequate coverage over programmable via 122 , but not so far as to make contact with either of conductive vias 116 or 120 . According to an exemplary embodiment, capping layer 114 comprises a titanium nitride—titanium alloy (TiN/Ti). TiN/Ti provides both a good diffusion barrier between conductive via 118 and the phase change material in programmable via 122 and good adhesion between conductive via 118 and the phase change material in programmable via 122 .
[0026] Oxide layer 110 is present over a side of capping layer 112 /capping layer 114 opposite oxide layer 108 /capping layer 112 , respectively. According to an exemplary embodiment, oxide layer 110 comprises SiO 2 .
[0027] Conductive vias 116 and 120 extend through oxide layers 108 and 110 and capping layer 112 , and make contact with heater 106 . Conductive vias 116 and 120 can each comprise any suitable standard complementary metal-oxide-semiconductor (CMOS) process metal(s), including, but not limited to, one or more of tungsten (W) and copper (Cu). Conductive via 118 is present between conductive vias 116 and 120 , and extends through oxide layer 110 making contact with capping layer 114 . Like conductive vias 116 and 120 , conductive via 118 can also comprise any suitable standard CMOS process metal(s), including, but not limited to, one or more of W and Cu.
[0028] Having points of contact present between conductive vias 116 / 120 and heater 106 , and between conductive via 118 and capping layer 114 , i.e., contact points 103 / 105 and 107 , respectively, can introduce an amount of resistance within the device (referred to hereinafter as “internal contact resistance”). Internal contact resistance affects the operating voltage of the device. Namely, the larger the internal contact resistance, the larger a starting voltage to programmable function of the device, i.e., operating voltage required to switch logic states of the device.
[0029] Depending on the structure of the device/method used to form the device, the effect of internal contact resistance on operating voltage can be significant. For example, U.S. patent application Ser. No. 11/612,631, filed on Dec. 19, 2006 by Chen et al., entitled “Programmable Via Structure and Method of Fabricating Same,” the disclosure of which is incorporated by reference herein, describes a programmable via structure formed using a lift-off process. The lift-off process can permit oxidation of/between contact surfaces to occur that can increase the internal contact resistance of the device raising the operating voltage, e.g., to ten volts or greater.
[0030] As will be described in detail below, programmable via device 100 is fabricated so as to have little, if any, internal contact resistance, i.e., less than about 10 −4 ohm square centimeter (Ωcm 2 ). As a result, programmable via device 100 has an operating voltage of less than about five volts, e.g., between about two volts and about three volts.
[0031] FIGS. 2A-E are diagrams illustrating exemplary methodology 200 for fabricating a programmable via device, such as programmable via device 100 described in conjunction with the description of FIG. 1 , above. The fabrication techniques described herein are CMOS compatible and thus readily scalable to meet various technology node feature size requirements.
[0032] In step 202 , substrate 102 is provided. Dielectric layer 104 is formed on substrate 102 . According to an exemplary embodiment, substrate 102 comprises Si and dielectric layer 104 comprises an oxide layer (as described above) grown on substrate 102 using a thermal oxidation process. Alternatively, dielectric layer 104 can comprise an oxide layer deposited on substrate 102 using a conventional deposition process, such as chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD) and chemical solution deposition and evaporation. With either technique, dielectric layer 104 is formed having a thickness of between about five nm and about 2,000 nm, e.g., between about 100 nm and about 500 nm.
[0033] Heater material layer 230 is then deposited on dielectric layer 104 . According to an exemplary embodiment, heater material layer 230 comprises a refractory metal (as described above) and is deposited on dielectric layer 104 using a CVD technique, such as low pressure chemical vapor deposition (LPCVD).
[0034] In step 204 , heater material layer 230 is patterned to form heater 106 . According to an exemplary embodiment, photolithography is used to pattern heater material layer 230 , wherein a photoresist is deposited on heater material layer 230 , masked and patterned with the footprint of heater 106 . A conventional dry etch, such as reactive ion etching (RIE) is then used to form heater 106 .
[0035] In step 206 , oxide layer 108 is deposited over dielectric layer 104 so as to surround heater 106 . According to an exemplary embodiment, oxide layer 108 is deposited using CVD. As shown in step 206 , oxide layer 108 takes on the topography of heater 106 on dielectric layer 104 .
[0036] In step 208 , vias 234 and 236 are formed through oxide layer 108 . According to an exemplary embodiment, vias 234 and 236 are formed using photolithography, wherein a photoresist is deposited on oxide layer 108 , masked and patterned with the vias. A deep RIE is then be used to form vias 234 and 236 through oxide layer 108 , with heater 106 acting as an etch stop.
[0037] In step 210 , each of vias 234 and 236 , formed in step 208 , above, are filled with a metal such as one or more of W and Cu (as described above) to form conductive vias. The metal will establish a direct contact point between each of the vias and the heater. This process insures that little, if any, internal contact resistance will be generated by the device structure. Chemical mechanical planarization (CMP) is then used to planarize vias 234 / 236 and oxide layer 108 .
[0038] In step 212 , capping layer 112 is deposited over a side of oxide layer 108 opposite dielectric layer 104 . According to an exemplary embodiment, capping layer 112 is deposited on oxide layer 108 using CVD.
[0039] In step 214 , via 238 is formed through oxide layer 108 and capping layer 112 between vias 234 and 236 . According to an exemplary embodiment, via 238 is formed using photolithography, wherein a photoresist is deposited on capping layer 112 , masked and patterned with the via. A deep RIE is then used to form via 238 through oxide layer 108 and capping layer 112 , with heater 106 acting as an etch stop.
[0040] In step 216 , via 238 formed in step 214 , above, is filled with a phase change material (as described above). CMP is then used to planarize the phase change material with capping layer 112 as an etch stop. As a result, programmable via 122 is formed.
[0041] In step 218 , capping layer 240 is deposited over a side of capping layer 112 opposite oxide layer 108 . According to an exemplary embodiment, capping layer 240 is deposited over capping layer 112 using CVD. In step 220 , capping layer 240 is patterned to form capping layer 114 , covering and extending laterally a distance beyond programmable via 122 , so as to provide adequate coverage over programmable via 122 (as described above). According to an exemplary embodiment, capping layer 114 is formed using photolithography, wherein a photoresist is deposited on capping layer 240 , masked and patterned with the footprint and location of capping layer 114 . A RIE is then used to form capping layer 114 , with capping layer 112 as an etch stop.
[0042] In step 222 , oxide layer 110 is deposited over a side of capping layer 112 opposite oxide layer 108 , and covering capping layer 114 . According to an exemplary embodiment, oxide layer 110 is deposited over capping layer 112 using CVD.
[0043] In step 224 , via 242 is formed through oxide layer 110 , and vias 244 and 246 are formed through oxide layer 110 and capping layer 112 . According to an exemplary embodiment, a two-step etching process is used to form vias 242 , 244 and 246 . Namely, a photoresist is deposited on oxide layer 110 , masked and patterned with each of the vias. An oxide-selective RIE is then used to etch vias 242 and 244 / 246 through oxide layer 110 , with capping layers 114 and 112 , respectively, as etch stops. A second, nitride-selective RIE is then used to etch vias 244 / 246 through capping layer 112 .
[0044] In step 226 , each of vias 244 and 246 , formed in step 224 , above, are filled with a metal such as one or more of W and Cu (as described above) to form conductive vias. Since vias 244 and 246 in conjunction with vias 234 and 236 (formed in steps 208 and 210 ), respectively, will comprise conductive vias of the device, it is preferable that the same metal be used to fill vias 234 / 244 and vias 236 / 246 . Via 242 , formed in step 224 , above, is also filled with a metal such as one or more of W and Cu (as described above), forming conductive via 118 .
[0045] CMP is then used to planarize the metal with oxide layer 110 as an etch stop. As a result, via 244 extends via 234 to form conductive via 116 and via 246 extends via 236 to from conductive via 120 .
[0046] Programmable via device 100 is thus formed. Advantageously, the device is planar which permits easy integration into logic circuits.
[0047] FIGS. 3A-C are graphs illustrating operation of the phase change material used in the programmable via of programmable via device 100 , described, for example, in conjunction with the description of FIG. 1 , above. FIG. 3A is a graph illustrating two theta (deg) (x-ray diffraction) evolution of the crystal structure of Ge 2 Sb 2 Te 5 from amorphous (no line), to face-centered cubic (fcc) to hexagonal close-packed (hcp) on heating (with temperature measured in degrees Celsius (° C.)). In FIG. 3A , at room temperature (e.g., about 27° C.), and up to moderately elevated temperatures (e.g., up to between about 400° C. and about 500° C.), the material is stable in two phases, a crystalline phase which is a moderately good conductor of electricity (i.e., about 200 microohms centimeter (μΩcm), and an amorphous phase which is insulating. FIG. 3B is a graph illustrating resistivity (measured in μΩcm) versus temperature (measured in ° C.) for two phase change material samples, i.e., Ge 2 Sb 2 Te 5 and doped SbTe, showing different resistivities of different phases. The phases are interconverted by thermal cycling.
[0048] FIG. 3C is a graph illustrating thermal cycling for SET and RESET processes of the phase change material, as a function of temperature and time. Namely, the thermal cycling comprises a “RESET” (or OFF) pulse and a “SET” (or ON) pulse. The “RESET” (or OFF) pulse involves a conversion from crystalline to amorphous form. In this step, the temperature is raised above melting, followed by a rapid quench in a time t 1 as a result of which a disordered arrangement of atoms in the melt is retained. The “SET” (or ON) pulse involves an anneal at a lower temperature, for a longer time t 2 , which enables the amorphous form to crystallize.
[0049] FIG. 4 is a diagram illustrating exemplary methodology 400 for performing a logic function with programmable via device 100 , described, for example, in conjunction with the description of FIG. 1 , above. The phase change material used in programmable via 122 can be switched between resistive (OFF-amorphous) and conductive (ON-crystalline) states by passing a current pulse through heater 106 which is in contact with programmable via 122 .
[0050] Specifically, in step 402 programmable via device 100 is in an ON state. In step 404 , an abrupt, e.g., a 10 nanosecond (ns) ramp up, a 50 ns plateau and a two ns ramp down, high-current, e.g., greater than one milliamp (mA), pulse is passed through heater 106 to melt and quench/amorphize a thin region of the phase change material adjacent to the heater. OFF switching pulses are described in detail in conjunction with the description of FIG. 5 , below. Another exemplary OFF switching pulse can comprise a 19 ns ramp up, a 20 ns plateau and a two ns ramp down, at a current of greater than one mA.
[0051] In step 406 , programmable via device 100 is now in a resistive (OFF-amorphous) state, and can remain in the OFF state until switched again. In step 408 , an ON switching operation is accomplished by applying a relatively low current, e.g., less than or equal to about 0.5 mA, longer pulse, e.g., a 200 ns ramp up, a 1,000 ns plateau and a 200 ns ramp down, through heater 106 to anneal the amorphous phase change material to a crystalline state. ON switching pulses are described in detail in conjunction with the description of FIG. 6 , below. Programmable via device 100 is now back in the conductive (ON-crystalline) state. The state of programmable via device 100 , resistive or conductive, can be read through conductive vias 118 and 120 .
[0052] FIG. 5 is a graph 500 illustrating resistance-current (R-I) characteristics for switching programmable via device 100 , described, for example, in conjunction with the description of FIG. 1 , above, to an OFF state. According to an exemplary embodiment, 50 ns pulses with gradually increased power were applied to heater 106 from the ON state. Specifically, a ten ns ramp up, a 50 ns plateau and a two ns ramp down were employed. After each pulse, programmable via device 100 was switched back to the ON state. When the pulse current reached about two milliamps (mA), the programmable via resistance started to increase and finally reached the OFF state.
[0053] FIG. 6 is a graph 600 illustrating R-I characteristics for switching programmable via device 100 , described, for example, in conjunction with the description of FIG. 1 , above, to an ON state. Starting from an OFF state, one microsecond (μs) pulses with gradually increased power were applied to heater 106 , finally implementing switching of the device to the ON state. Specifically, a 200 ns ramp up, a 1,000 ns plateau and then a 200 ns ramp down were employed.
[0054] FIG. 7 is a graph 700 illustrating cycling data from an endurance test performed on programmable via device 100 , described, for example, in conjunction with the description of FIG. 1 , above, at room temperature. The endurance test results show a stable sense margin without obvious degradation within the ON/OFF cycles.
[0055] Although illustrative embodiments of the present invention have been described herein, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be made by one skilled in the art without departing from the scope of the invention. | Programmable via devices and methods for the fabrication thereof are provided. In one aspect, a programmable via device is provided comprising a substrate; a dielectric layer on the substrate; a heater on at least a portion of a side of the dielectric layer opposite the substrate; a first oxide layer over the side of the dielectric layer opposite the substrate and surrounding at least a portion of the heater; a first capping layer over a side of the first oxide layer opposite the dielectric layer; at least one programmable via extending through the first capping layer and the first oxide layer and in contact with the heater, the programmable via comprising at least one phase change material; a second capping layer over the programmable via; a second oxide layer over a side of the first capping layer opposite the first oxide layer; a pair of first conductive vias, each extending through the first and second oxide layers and the first capping layer, and in contact with the heater; and a second conductive via, located between the pair of first conductive vias, extending through the second oxide layer and in contact with the second capping layer. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a rotary heat exchanger and more specifically to a rotary heat exchanger which exhibits good heat exchange characteristics and has an improved seal and bearing structure.
2. Description of the Prior Art
Japanese Published Unexamined Patent Application Nos. -59-41111 and -60-23277 disclose rotary heat exchangers like the one shown in FIGS. 1 and 2. This type of device includes an inlet port 1 through which fluid F is supplied to a supply chamber 2. A seal arrangement 3 supports a supply conduit 4 in a manner wherein the upstream end of the conduit 4 is placed in fluid communication with the supply chamber 2. The downstream end of the supply conduit 4 communicates with an essentially annular rotatable supply header 5. A plurality of hollow blower blades are arranged to establish fluid communication between the outer peripheral portion of the supply header 5 and the corresponding portion of a rotatable exhaust header 7. An exhaust conduit 8 is arranged to communicate at its upstream end with the exhaust header 7 and to be rotatably supported by seal arrangements 9 and 10 in an exhaust chamber 11. The portion of the exhaust conduit 8 defined between the two seal arangements 9 and 10 is apertured so that the fluid which is supplied into the exhaust header 7 can be discharged into the exhaust chamber 11 and subsequently drained therefrom via an outlet conduit 12.
The hollow blower blades 6 are provided with a plurality fins 13 which improve the heat exhange efficiency of the arrangement. A motor 14 is operatively connected to an end portion of the exhaust conduit 8. When this motor 14 is energized the rotary headers 5 and 7 and interconnecting hollow blower blades 6 are induced to rotate and define a rotary blower arrangement.
However, this arrangement has the drawbacks that both the fins 13 which are either in the form of circular or annular plates and the hollow blower blades 6 must be precisely formed and assembled in order to achieve a good fit and balance of the rotating parts. This of course makes their production and assembly time-consuming, which, in combination with the high precision requirements, increases the cost of the device undesirably.
In addition, as air has a finite viscosity, a boundary layer tends to be formed over the surface of the fins 13 and reduces the amount of heat exchange with the air passing through the device. However, if the number of fins 13 are increased to improve this situation, the surface area of the blower blades 6 actually available for inducing the necessary flow of air through the device tends to be reduced and therefore reduces the amount of air which is blown through. This therefore limits the number of additional fins which can be added and therefore causes a number of design limitations.
Further, the seal arrangements 3, 9 and 10 which are provided in order to prevent leakage of the fluid being cooled, are subject to vibration and radially acting forces due to the inevitable slight imbalance in the rotating parts of the device, and tend to readily deteriorate to the point of permitting leakage to occur.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a heat exchanger of the above-mentioned rotating blower type which has a structure which permits ready fabrication and assembly and which features good heat exchange efficiency.
In brief, the above object is achieved by an arrangement which features a plurality of arcuate hollow blow blades with extend between first and second rotating bodies and which conduct liquid from one to the other. Each of the blades is provided with its own set of fins which are arranged to interleave between and overlap those on the adjacent blades. The rotating bodies are constructed to define inlet and outlet chambers therein and have bearings disposed between stationary inlet and outlet pipes and the first and second rotating bodies which protect seals from damaging forces when the device is rotating.
A rotary heat exchanger according to a first aspect of the present invention comprises first and second rotatable bodies, the defining therein inlet and outlet chambers respectively, the first and second rotatable bodies being arranged to be rotatable about a common axis and spaced from one another along the axis. A plurality of conduits lead from the first rotatable body to second rotatable body, the and fluidly interconnect the inlet and outlet chambers; and a plurality of fins provided on each of the conduits. The fins being arranged so that the fins on one conduit interleave with and overlap the fins formed on the conduits located on either side of the one conduit.
A heat exchanger according to the present invention may further include: a stationary inlet pipe which fluidly communicate with the inlet chamber, a first bearing operatively disposed between the inlet pipe and the first rotatable body; a stationary outlet pipe which fluidly communicates with the outlet chamber, a second bearing operatively disposed between the outlet pipe and the second rotatable body; a first seal disposed on the inlet pipe to prevent fluid in the; and a second seal disposed on the outlet pipe to prevent fluid in the outlet chamber from leaking out therefrom second bearing protecting the second seal from forces the first and second bearings protect the seals from forces produced during rotation of the heat exchanger.
An engine cooling arrangement according to the present invention comprises an engine compartment; an engine disposed in the engine compartment; a rotary heat exchanger disposed in the engine compartment, and; a duct disposed about the rotary heat exchanger. The duct guides the air which passes through the rotary heat exchanger out of the engine compartment without contacting the engine.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a prior art rotary heat exchanger;
FIG. 2 is a schematic elevational view showing the basic construction of the device shown in FIG. 1;
FIG. 3 is a front sectional elevation of an embodiment of a rotary heat exchanger according to the present invention;
FIG. 4 is a side sectional view taken along line A--A of FIG. 3;
FIG. 5 is a perspective view of the embodiment of FIG. 3; and
FIG. 6 is a schematic view showing the embodiment of FIG. 3 as applied to the cooling system of an automotive vehicle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 3 to 5 show an embodiment of the present invention. This arrangement comprises a plurality of hollow arcuate blower blades 21 (see FIG. 4) on which a plurality of radially extending fins are disposed. The blower blades 21 are arranged in an annular pattern and extend between and fluidly communicate between first and second end plate members 23 and 29.
Both of the end plates 23, 29 are dish-shaped and cooperate with covers 24, 30 to define an enclosed space. Circular closure plates 25, 31 are sealingly connected to the inner faces of the covers 24, 30 respectively, in a manner to define inlet and outlet chambers. Each of the circular closure plates 25, 31 has at is center an inwardly projecting boss in which concentric bore is formed.
Stationary inlet and outlet pipes 27, 33 support the above-mentioned structure by roller bearings 26, 32. Each of the inlet and outlet pipes includes a portion which is received in the bore of the boss of the corresponding closure plate. These portions have small diameter radial bores 27a and 33a while the corresponding bosses have corresponding radial bores 25a and 31a formed therein. The two sets of bores are offset with respect to one and other and allow the liquid which is flowing through the heat exchanger to form a liquid layer between the stationary inlet and outlet pipes and the rotating bosses in a maner which provides a kind of lubricating action.
Seal members generally denoted by numerals 28 and 34 are disposed about each of the inlet and outlet pipes 27, 33. These seal members are located in an annular chamber defined between the outboard faces of the circular plates 25, 31 and radially extending flange members which support the roller bearings 26, 32. Both of the seals are of identical construction and for simplicity only the seal arrangement provided at the inlet end of the device will be described.
The above-mentioned seal 34 comprises a floating seal member 28a, a carbon seal 28b, a spring 28c and a shaft seal 28d. The annular floating seal member 28a is disposed in an annular recess formed in the outboard face of the plate 25. The carbon seal 28b abuts the outboard edge of the floating seal member and is biased against it by the spring 28c which engages the shaft seal 28d at the other end.
The provision of the roller bearings 26 about the seals prevents the seal arrangements from being exposed to loads such as radial acting forces and vibrations produced by the rotation of the heat exchanger and thus ensures the longevity and effectiveness of the seals.
In order to provide a drive connection between a source of rotational energy such as the crankshaft of an internal engine or electric motor, a V-shaped recess 30a is formed in the cover 30. This recess enables a V-belt to be operatively connected to the cover 30 and to enable the heat exchange unit which is defined between the inlet and outlet pipes 27 and 33 to be rotated at a selected rotational speed.
It is course possible to provide the drive connection at the inlet pipe end if so desired. Alternative drive arrangements are also possible.
The above described arrangement can be utilized as a radiator for an automotive engine as shown in FIG. 6. In this figure, element number 41 an engine bonnet or hood, 42 is an engine compartment, 43 is a duct structure in which the rotary heat exchanger R.R according to the present invention is disposed, 44 is an automotive engine which is fluidly communicated with the heat exchanger in a manner which allows engine coolant to be circulated therethrough, 45 is a radiator grill or the like through which air can flow into the engine room 42, and 46 is a bumper.
As indicated by the large arrows, the air which flows through the grill 45 is split into two main flows, one of which actually enters the engine compartment 42 and the other of which flows through the duct 43 in which the rotary heat exchanger R.R is disposed. This flow division serves to direct the air which contains the heat extracted from the engine coolant by the heat exchanger R.R directly out of the engine compartment thus prevents the engine 44 from being exposed to the flow of hot air, which would tend to reheat the engine 44 and defeat the operation of the heat exchanger.
The air which does pass over the engine is essentially at ambient temperature and is able to more effectively remove heat from the engine and various devices are mounted on the engine and are equipped with heat susceptible elements such as fan belts, and fuel injection lines thereon.
In operation, the heated coolant is pumped from the engine by a coolant pump (not shown) and passed through the inlet pipe 27 into the inlet chamber. A drive connection (e.g. a v-belt) rotates the rotatable portions of the heat exchangers. The hot liquid introduced into the inlet chamber flows radially outwardly and enters the hollow blower blades 21. As the fluid flows through these blades, 21 the heat in the liquid is transferred to the cooler metal sheeting from which the blades 21 are formed and into the cooling fins 22 and thereafter is conducted to the cooling fins 22. As indicated by the arrows, the fluid which flows through the hollow blower blades 21 enters the outlet chamber and thereafter passes out through the outlet pipe 33 and returns to the engine coolant jacket.
Due to the arcuate shape of the hollow blower blades 21 (see FIG. 4) air is induced to both blow through the device and pass over the surface of the blades 21 and the cooling fins 22. Further, as the cooling fins 22 are each relatively small, the layer of air which tends to form on the fins 22 is prevented from being excessively thick. Therefore, the fins 22 can perform the expected amount of fanning action. In addition, as the fins 22 are staggered and overlap one another (see FIG. 5 for example) it is possible to increase the surface area of the fins 22 which is available for heat exchange as compared with the prior art arrangement shown in FIG. 1. It is also possible additionally increase the amount of air which flows through and over the rotating blower blades 21. This improves the efficiency with which heat can be exchanged between the engine coolant and the ambient atmosphere.
The above-described arrangement also renders it possible to more readily manufacture and assemble the device. Namely each of the blower blades 21 can be produced and provided with the cooling fins 22 prior to connection with the end plates 23, 29. Connection with the end plates is also rendered easier in that it is not necessary to precisely locate the blower blades 21 with respect to circular perforate plates as in the prior art.
The bearing/seal arrangement, as mentioned above, provides a strong and durable arrangement which is resistant to wear and subsequent leakage and which ensures smooth rotation of the device.
Another benefit of the present invention is that it is possible to arrange the heat exchanger across a front of the vehicle and readily connect the heat exchanger to a source of rotational energy (particularly in the case of transversely arranged engines). Further, due to the essentially cylindrical elongated configuration of the device (see FIG. 5) it is possible to dispose the heat exchanger at a low level, such as near the vehicle bumper, and thus it is possible to lower the profile of the front portion of the engine compartment in a manner not possible when conventional stationary upright type radiators are used. This enables the front of the vehicle to be lowered and reduces the air resistance and drag characteristics of the vehicle. | A rotary heat exchanger has a plurality of arcuate hollow blow blades with extend between first and second rotating bodies and which conduct liquid from one to the other. Each of the blades is provided with its own set of fins which are arranged to interleave between and overlap those on the adjacent blades. The rotating bodies are constructed to define inlet and outlet chambers therein. Bearings which are disposed between stationary inlet and outlet pipes and the first and second rotating bodies protect seals from damaging forces when the device is rotating. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
The present invention is a continuation of U.S. patent application Ser. No. 10/694,111, filed Oct. 27, 2003 now U.S. Pat. No. 6,963,003, entitled Oxygen-Containing Heterocyclic Fused Naphthopyrans, which claims benefit of U.S. Provisional Application Ser. No. 60/422,147 filed on Oct. 28, 2002.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to novel naphthopyran-type compounds that have, in particular, photochromic properties. The invention also relates to the use of these photochromic compounds in ophthalmic articles (goggles, lenses and eye-shields, for example). The invention particularly relates to naphthopyrans having an oxygen-containing saturated heterocyclic group fused to the naphthalene ring. These naphthopyrans have two intense absorption bands in the visible light range, and are particularly suitable for use in photochromic articles, such as eyeglass lenses, which have a brown or driver activated color.
2. Background of the Art
Photochromism generally concerns the ability of a compound to reversibly change color under different light conditions. One particular type of photochromic phenomenon concerns the reversible change in color of a compound from an original color to a different color when the compound is exposed to a source of ultraviolet radiation, such as solar radiation or light radiated from a mercury or xenon lamp. The photochromic compound fades to the original color within a period of time after the photochromic compound is isolated from the ultraviolet radiation, such as by placing the compound in a dark room.
Photochromic compounds find applications in various fields, such as for the manufacture of ophthalmic lenses, contact lenses, solar protection glasses, goggles, sun screens, filters, camera optics, photographic apparatus optics or other optical devices and observation devices, glazing, decorative objects, currency elements and even for information storage by optical inscription (coding). For example, photochromic compounds, such as naphthopyrans, are incorporated into plastic ophthalmic lenses to effect color changes in the lenses when the lenses are exposed to particular lighting conditions. Additionally, different photochromic compounds may be blended together to create a color effect that is different from respective color effects of the individual photochromic compounds. As an example, a first photochromic compound that turns orange or red when activated by light and a second photochromic compound that turns blue when activated by light may be blended together to form a photochromic mixture that produces a shade of gray when activated by light.
Amongst the numerous photochromic compounds described in the prior art, naphthopyrans and larger ring systems derived from them received the most intensive investigations due to their suitable properties (fatigue, fading rate, color, temperature dependence) for use in eyeglass lenses. The simplest naphthopyran photochromic compounds are represented by the formula below:
Attempts were made to achieve improvements by using different substituents at various positions, especially on the naphthalene core. The improvements include proper fading rate, desired color, better fatigue, etc. One of the important improvements is for a naphthopyran to provide a blended color hue. As aforementioned, to give eyeglass lenses a neutral gray or brown color, it may necessitate the use of at least two photochromic compounds of different colors, i.e., two separate compounds having distinct maximal absorption wavelengths in the visible region of the electromagnetic spectrum. However, the use of combinations of photochromic compounds imposes other requirements on both the individual photochromic compounds and the groups of photochromic compounds. In particular, the coloration and discoloration kinetics of the (two or more) combined active photochromic compounds must be essentially identical. The same applies for their stability with time, and also for their compatibility with a single plastic or inorganic support.
It is thus highly desirable to obtain photochromic compounds that have a blended color hue provided by two or more distinct absorption bands in the visible region. With such photochromic compounds it is possible to use only one compound for the desired color (e.g., gray or brown), or at least to require minimum amount of complementary color compound.
U.S. Pat. No. 5,645,767 discloses photochromic indeno[2,1-f]naphtho[1,2-b]pyrans having a blue/gray activated color. A blue/gray color will be perceived when there is a major absorption of visible light in the 580–620 nm range (Band B thereafter referring to the longer wavelengths) coupled with a minor absorption in the 420–500 nm range (Band A thereafter referring to the shorter wavelengths).
U.S. Pat. No. 6,096,246 (incorporated by reference) describes naphtho[1,2-b]pyrans having alkoxy groups as substituents at the 7- and 9-positions of the naphthopyran ring. The activated forms of these compounds exhibit two intense absorption bands in the visible light range. It is reported that the optical density of Band A in some cases is higher than the optical density of Band B, but in the majority of cases Band A is of lower optical density than Band B.
U.S. Pat. No. 6,146,554 (incorporated by reference) discloses photochromic indeno[2,1-f]naphtho[1,2-b]pyrans having a green activated color. A greenish color will be perceived when there is a major absorption of visible light in the 580–620 nm range coupled with a major absorption of roughly equal intensity in the 400–480 nm range. U.S. Pat. No. 6,248,264 (incorporated by reference) describes naphtho[1,2-b]pyrans having amino functional groups as substituents at the 7- or 9-positions of the naphthopyran ring. These compounds are disclosed as exhibiting a brown or red/brown activated color. A red/brown color will be perceived when there is a major absorption of visible light in the 420–500 nm range coupled with a minor absorption in the 520–560 nm range.
U.S. Pat. Nos. 6,296,785 and 6,348,6043 (incorporated by reference) disclose indeno[2,1-f]naphtho[1,2-b]pyrans and naphtho[1,2-b]pyrans, respectively, having two adjacent moderate to strong electron donor substituents at the 6 and 7 positions of indeno[2,1-f]naphtho[1,2-b]pyrans and the 8 and 9 positions of naphtho[1,2-b]pyrans. The activated forms of these compounds exhibit two intense absorption bands in the visible light range. In the majority of cases Band A (420–500 nm) is of stronger optical density than Band B (480–620 nm) making them suitable for use in photochromic articles having a brown activated color.
U.S. Pat. No. 6,353,102 (incorporated by reference) describes naphtho[1,2-b]pyrans having carbonyl functional groups as substituents at the 6-position of the naphthopyran ring. These compounds are disclosed as also exhibiting two absorption bands in the visible light range. The relative intensity of the two bands depends on other substituents on the ring.
From the above description, it is apparent that photochromic compounds having two absorption bands can be obtained by selecting certain substituents at the naphthopyran ring, especially at the 6 to 9 positions of the naphtho portion. Although some prior art references teach how to select substituents, it seems that such prior art references are incomplete and do not achieve the formulative results of the present invention.
Therefore, it is an object of this invention to provide novel series of photochromic compounds that exhibit two intense absorption bands in the visible range wherein the relative intensity between Band A and Band B is greater than unity. These photochromic compounds will be especially useful in making brown or driver (red-brown) photochromic articles such as eyeglass lenses with a single compound or minimum use of a complementary color compound.
All publications and patents referred to in this application are hereby incorporated by reference.
DESCRIPTION OF THE INVENTION
An objective of this invention is achieved by preparing a novel family of naphthopyran compounds having a central nucleus of the formula:
wherein F is a 5- to 7-member saturated heterocyclic ring group fused to the i or j side of the naphthopyran ring containing one oxygen that is atom directly connected to the 7-, 8- or 9-position;
R 6 represents
i. a C1–C6 alkyl, alkoxy, ii. a —C(O)R group, wherein R is selected from hydrogen, hydroxy, alkyl, alkoxy, iii. an aryl or heteroaryl group which comprises in its basic structure (that is, in its ring atoms, the rings comprising 5, 6 or 7 atoms) 6 to 24 carbon atoms or 4 to 24 carbon atoms respectively and at least one heteroatom selected from sulfur, oxygen and nitrogen; the basic structure being optionally substituted with at least one substituent selected from: iv. a halogen atom (e.g., fluorine, chlorine and bromine), v. a hydroxy group, vi. a linear or branched alkyl group comprising 1 to 12 carbon atoms, vii. a linear or branched alkoxy group comprising 1 to 12 carbon atoms, viii. a haloalkyl or haloalkoxy group corresponding to the (C1–C12) alkyl or alkoxy groups above respectively which are substituted with at least one halogen atom, and notably a fluoroalkyl group of this type, ix. a linear or branched alkenyl group comprising 2 to 12 carbon atoms, and notably a vinyl group or an allyl group, x. an —NH2 group, xi. an —NHR8 group, R8 representing a linear or branched alkyl group comprising 1 to 6 carbon atoms, xii. a
group, in which R 9 and R 10 , which are the same or different, independently representing a linear or branched alkyl group comprising 1 to 6 carbon atoms, or representing (together with the nitrogen atom to which they are bound) a 5- to 7-membered ring which can comprise at least one other heteroatom selected from oxygen, sulfur and nitrogen, said nitrogen being optionally substituted with a group that is a linear or branched alkyl group comprising 1 to 6 carbon atoms,
xiii. a methacryloyl group or an acryloyl group,
xiv. a polyether, polyamide, polycarbonate, polycarbamate, polyurea or polyester residue;
R 5 represents:
i. a hydroxy, ii. a halogen, and notably fluorine, chlorine or bromine, iii. a linear or branched alkyl group which comprises 1 to 12 carbon atoms (advantageously 1 to 6 carbon atoms), iv. a cycloalkyl group comprising 3 to 12 carbon atoms, v. a linear or branched alkoxy group comprising 1 to 12 carbon atoms (most advantageously 1 to 6 carbon atoms), vi. a haloalkyl, halocycloalkyl, or haloalkoxy group corresponding to the alkyl, cycloalkyl, alkoxy groups above respectively, which are substituted with at least one halogen atom, notably selected from fluorine, chlorine and bromine, vii. a linear or branched alkenyl or alkynyl group comprising 1–12 carbon atoms, preferably a vinyl or allyl group, viii. a linear or branched alkenyloxy or alkynyloxy group comprising 1–12 carbon atoms, preferably an allyloxy group, ix. an aryl or heteroaryl group having the same definition as R 6 given supra, x. an aralkyl or heteroaralkyl group, the alkyl group, which is linear or branched, comprising 1 to 4 carbon atoms, and the aryl and heteroaryl groups having the same definitions as R6 given supra, xi. an amine or amide group: —NH 2 , —NHR 8 , —CONH 2 , —CONHR 8 ,
R 8 , R 9 , and R 10 having their respective definitions given above for the amine substituents of the values R 6 ,
xii. a —C(R 11 ) 2 X group, wherein X is —CN, halogen, hydroxy, alkoxy, benzoyloxy, C1–C6 acyloxy, amino, C1–C6 mono-alklamino, C1–C6 dialkyl amino, morpholino, piperidino, 1-indolinyl, pyrrolidyl, or trimethylsilyloxy, R 16 is hydrogen, C1–C6 alkyl, phenyl or naphthyl with C1–C6 alkyl or C1–C6 alkoxy substituents,
xiii. an —OCOR 12 or —COOR 12 group, R 12 representing a straight or branched alkyl group comprising 1 to 6 carbon atoms, or a cycloalkyl group comprising 3 to 7 carbon atoms, or a phenyl group, optionally substituted with at least one of the substituents listed above within the values in the definitions of R 6 ,
xiv. a methacryloyl group or an acryloyl group, an epoxy group having the formula,
in which k=1, 2 or 3,
xv. a polyether, polyamide, polycarbonate, polycarbamate, polyurea or polyester residue;
R 1 and R 2 , which are identical or different, independently represent:
i. a hydrogen, ii. a linear or branched alkyl group which comprises 1 to 12 carbon atoms (with or without substitution), iii. a cycloalkyl group which comprises 3 to 12 carbon atoms, iv. an aryl or heteroaryl group as R 6 defined supra, v. an aralkyl or heteroaralkyl group, the alkyl group, which is linear or branched, comprising 1 to 4 carbon atoms and the aryl and heteroaryl groups having the definitions given above, or vi. the two substituents R1 and R2 together forming ring group such as those represented by an adamantyl, norbornyl, fluorenylidene, 5,5- or 10,10-di(C1–C6)alkylanthracenylidene, 5 (or 10)-(C1–C6)alkyl-5 (or 10)-OH (or OR 15 )anthracenylidene or spiro(C5–C6)cycloalkylanthracenylidene ring group; said ring group being optionally substituted with at least one of the substituents listed above in the definitions for R 1 , R 2 ; said ring group being optionally substituted with two adjacent groups that form a 5- to 6-member aromatic or non-aromatic ring which can comprise at least one heteroatom selected from oxygen, sulfur, and nitrogen;
each R 7 group can be the same or different, independently representing
i. a hydrogen, ii. a linear, branched, or cyclic alkyl group, iii. a linear, branched, or cyclic alkoxy group, iv. a linear or branched alkenyl or alkynyl group, v. a linear or branched alkenyloxy or alkynyloxy group, vi. an aryl or heteroaryl group having the same definition as that given supra for R 6 , vii. two of the R 7 groups, which are adjacent or bonded to the same carbon atom in the group F, form a 5- to 7-membered non-aromatic ring which may comprise at least one hetroatom selected from the group consisting of oxygen, sulfur, and nitrogen, and viii. m is an integer of 0 to 6.
The term “group” has established meanings according to the practice of the present invention. Where the term “group” is used, the chemical unit described is intended to include and allow for substituents consistent with the primary chemical unit. For example, where the term alkyl group is used, that term is intended to include classic alkyl materials such as methyl, ethyl, propyl, butyl, hexyl, octyl, iso-octyl, dodecyl, cyclohexyl and the like, and is also intended to include alkyl units with substitution thereon consistent with the underlying nature of an alkyl unit, such as hydroxymethyl, bromoethyl, dichloropropyl, 1,2,3,4-tetrachlotobutyl, omega-cyanohexyl and the like. Where the term “alkyl moiety” is used, no substitution is allowed.
Where the term ‘group’ is used in the practice of the present invention, those terms refer to the capability of the structure to have substitution, or no substitution on the chemical unit. The term ‘group’ refers to any chemical structure, while the term ‘central nucleus’ refers specifically to a ring structure as the core chemical moiety. For example, an ‘alkyl group’ includes unsubstituted n-alkyl, iso-alkyl, methyl ethyl, octyly, iso-octyl, docecyl, and the like, and substituted alkyl such as hydroxymethyl, 1-chloroethyl, 2-cyano-butyl, 3-ethyl-4-hexyl, omega-carboxy-pentyl, and the like. Where the term ‘moiety’ is used, as in the term alkyl moiety, for example, that term refers to only unsubstituted chemical units. Similarly, where the term ‘central nucleus’ is used, such as in the central nucleus of a naphthyl, any substituent may be present on the central nucleus of the naphthyl group, such as 1-methyl-, 2-chloro-, 2,4-dimethoxy-, 2,2′-dimethoxy- and the like. Where the term having a structure of the specific formula is used, no substitution is allowed beyond that of the described formula.
Among the substituents that can be considered for the compounds of formula (I) according to the invention, groups should be considered that comprise and/or form at least one function which can be polymerized and/or crosslinked, which groups are preferably selected from the following list including but not limited to: alkenyl, advantageously vinyl, methacryloyl, acryloyl, acryloxyalkyl, methacryloxyalkyl or epoxy.
Thus, the photochromic compounds according to the invention can be monomers, of different types or not, that can react with each other or with other comonomers to form homopolymers and/or copolymers that bear a photochromic functionality and possess mechanical properties of macromolecules. It follows that one of the objects of the present invention consists of these homopolymers or copolymers comprising (co)monomers and/or of crosslinked compounds, that, at least in part, consist of photochromic compounds (I) according to the invention.
In the same general concept, the above-mentioned compounds (I) can be crosslinking agents that have one or more reactive functions capable of allowing the formation of bridges between chains of polymers of photochromic nature or not. The crosslinked compounds that can be obtained in this manner also are a part of the present invention.
Amongst such compounds according to formula (I), preferred photochromic are those which have the formula below: in which:
m and n are integers of 1 or 2,
R′ 1 , and R′ 2 , same or different, represent
i. a hydrogen, ii. a linear, branched, or cyclic alkyl, iii. an alkyoxy with the alkyl portion being linear, branched, or cyclic, iv. an unsubstituted, mono- or di-substituted aryl, v. an aryloxy with the aryl being unsubstituted, mono- or di-substituted;
R 5 represents
i. a linear, branched, or cyclic alkyl group, ii. a linear or branched alkenyl or alkynyl group, iii. a —C(R 11 ) 2 X group, wherein X is hydroxy, alkoxy, benzoyloxy, C1–C6 acyloxy, iv. an optionally substituted phenyl or benzyl group, v. a —COR 12 , or —COOR 12 group, R 12 representing a linear, branched, or cyclic alkyl group comprising 1 to 6 carbon atoms;
R 6 represents an unsubstituted, mono-, di- or tri-substituted aromatic or hetero-aromatic group selected from phenyl, naphthyl, pyridyl, furanyl, benzofuranyl, thenyl, benzothienyl;
R 7 represents
i. a hydrogen, ii. a linear, branched, or cyclic alkyl group, iii. a linear, branched, or cyclic alkoxy group, iv. a linear or branched alkenyl or alkynyl group, v. a linear or branched alkenyloxy or alkynyloxy group, vi. an aryl or heteroaryl group having the same definition as that given supra for R 6 , vii. two of the R 7 groups, which are adjacent or bonded to the same carbon atom in the group F, form a 5- to 7-membered non-aromatic ring which may comprise at least one hetroatom selected from the group consisting of oxygen, sulfur, and nitrogen, and viii. m is an integer of 0 to 2.
The person skilled in the art will obviously have understood that the branched alkyl, alkoxy, alkenyl, alkenyloxy groups, and cyclic alkyl as defined above, comprise a sufficient number of carbon in order to be branched or cyclic.
These compounds of the invention present particularly advantageous photochromic properties, such as, having strong coloration ability with two intense absorption bands in the visible range. They are particularly useful in making brown or driver colored eyeglass lenses. These compounds are also preferably stable and compatible with matrices made of at least one organic polymer or mineral material (e.g., inert inorganic binder), both in the form included in the matrix and in the form of a coating.
General Synthetic Procedure for Preparation of the Compounds
The compounds of the invention can be obtained by the condensation of a derivative of 1-naphthol that is suitably substituted and a derivative of propargyl alcohol. The condensation can be carried out in organic solvents, particularly non-polar solvents such as toluene, xylene or tetrahydrofuran and, optionally, in the presence of a catalyst, acid catalysts, and especially acid catalysts such as fluorinated organic acid catalysts, p-toluenesulfonic acid, chloroacetic acid or acid aluminic acid):
These synthetic routes are classical and have been described in the above-mentioned references of the prior art as well as in U.S. Pat. No. 4,818,096. The propargyl alcohols are either commercially available or easily synthesized by the reaction of lithium acetylide or ethynyl (magnesium bromide) with the corresponding ketones (R 1 )CO(R 2 ). The ketones are also either commercially available or easily synthesized by the classical methods, for example, the Friedel-Crafts reaction from an acid chloride.
The derivatives of 1-naphthol are obtained by various methods adapted from the literature. Below we give some references on methods that allow the synthesis of the compounds of the invention.
Method 1: Johnson et al. Org. React. 1951, Vol. 6, p. 1.
Method 2: U.S. Pat. No. 5,200,116 (Example 2) or U.S. Pat. No. 6,207,084
The starting benzophenone in Method 1 can be prepared by the well-known Friedel-Crafts acylation of dihydrobenzofuran with benzoyl chloride, and the starting ketone in Method 2 can be prepared according to the procedure in U.S. Pat. No. 6,210,608.
To those skilled in the art, the alkoxycarbonyl group in the naphthol (III) can be transformed into a variety of different groups including methyl, hydroxymethyl, benzoyl, alkenyl, etc. For example,
In the reactions, DIBAL-H: diisobutoxyaluminum hydride, pTsOH:p-toluenesulphonic acid, MeOH:methanol.
Regarding the commercial application of compounds according to the present invention, it should be noted that they can be used as a photochromic material dispersed in the composition of a polymer matrix. They can also be used in solution.
A photochromic solution can be obtained by dissolving the compound in an organic solvent, such as toluene, dichloromethane, tetrahydrofuran or ethanol. The solutions obtained are generally colorless and transparent. When exposed to sunlight, they develop a strong coloration and they recover the color of this state when placed in an environment with lesser exposure to solar radiation or, in other words, when they are no longer exposed to UV radiation. In general, a very low concentration of products (on the order of 0.01–5% by weight or volume) is sufficient to obtain an intense coloration.
The most interesting applications are those in which the photochrome is dispersed uniformly within or on the surface of a polymer, copolymer or mixture of polymers. The implementation methods that can be considered are of a great variety. Among those known to a person skilled in the art, one can cite, for example, diffusion in the (co)polymer, from a suspension or solution of the photochrome, in a silicone oil, in an aliphatic or aromatic hydrocarbon, in a glycol, or from another polymer matrix. Currently the diffusion is carried out at a temperature of 50–200° C. for a duration of 15 minutes to several hours, depending on the nature of the polymer matrix. Another implementation technique consists in mixing the photochrome in a formulation of polymerizable materials, in depositing this mixture on a surface or in a mold and in then carrying out the polymerization. These implementation techniques and others are described in the article by CRANO et al. “Spiroxazines and their use in photochromic lenses,” published in Applied Photochromic Polymer Systems, Publishers Blackie and Son Ltd., 1992. According to a variant of the invention, it is also possible to consider grafting the photochromes onto (co)polymers. Thus, another aspect of the invention consists of the (co)polymers grafted with at least one of the photochromes described above.
As examples of preferred polymer materials for optical applications of the photochromic compound according to the invention, one can mention the following products including, but not limited to: alkyl, cycloalkyl, aryl or arylalkyl poly(mono-, di-, tri-, tetra)acrylate or poly(mono-, di-, tri-, tetra) methacrylate, optionally halogenated or comprising at least ether and/or ester and/or carbonate and/or carbamate and/or thiocarbamate and/or urea and/or amide group; polystyrene, polycarbonate (e.g., bisphenol A polycarbonate, poly(carbonate of diallyl diethylene glycol), polyepoxy, polyurethane, polythiourethane, polysiloxane, polyacrylonitrile, polyamide, aliphatic or aromatic polyester, vinyl polymers, cellulose acetate, cellulose triacetate, cellulose acetate-propionate or polyvinylbutyral, copolymers of two or more types of monomers or mixtures of the above-mentioned polymers, preferably polycarbonate-polyurethane, poly(meth)acrylate-polyurethane, polystyrene-poly(meth)acrylate or polystyrene-polyacrylonitrile, advantageously a mixture of polyester and/or polycarbonate or poly(meth)acrylate.
In a particularly preferred manner, the photochromic naphthopyrans of the invention are used in polyester or polyether type thermoplastic polyurethanes, two-part polyurethane adhesives.
The quantity of photochrome used in various articles depends on the desired degree of darkening. In particular, it is used in a quantity of 0.01–10 wt % of the total weight of the layer in which the photochrome is included. The photochromic compounds according to the invention can be used alone or in a mixture with other products to form a composition that can be in solid or liquid form, for example, in a solution or in a dispersion, as has already been mentioned above. These compositions, which constitute another object of the invention, can comprise one or more compounds (I) according to the invention and other complementary photochromic compounds which allow the attaining of dark colorations, for example, gray or brown, which the public desires in applications such as ophthalmic or sun-protection eyewear. These additional photochromic compounds can be those known to a person skilled in the art and described in the literature, for example, other naphthopyrans, benzopyrans, chromenes (U.S. Pat. Nos. 3,567,605, 5,238,981, World Patent No. 9,422,850, European Patent No. 562,915), spiropyrans or naphthospiropyrans (U.S. Pat. No. 5,238,981) and spiroxazines (CRANO et al., “Applied Photochromic Polyrmer Systems,” Publishers Blackie & Son Ltd., 1992, Chapter 2).
These compositions according to the invention can also comprise:
Non-photochromic dyes allowing the adjustment of the tint, and/or one or more stabilizers, such as, for example, an antioxidant, and/or one or more anti-UV screens, and/or one or more anti[free]radical agents, and/or deactivators that deactivate the states of photochemical excitation.
These additives can enable further improvements in the durability of said compositions.
According to another one of its aspects pertaining to the application of the photochromic compounds (I), the present invention also relates to ophthalmic articles, such as articles of ophthalmic or sun protection eyewear articles, or eye shields comprising at least one compound according to the invention and/or at least one (co)polymer formed, at least in part, of repeating units derived from compounds having formula (I) and/or at least one composition comprising compounds (I) according to the invention, as defined above, and/or at least one matrix, as defined above, made of an organic polymer material or a mineral material or a mineral-organic hybrid material incorporating at least one compound of the invention.
In practice, the articles to which the present invention applies more particularly are photochromic ophthalmic or sun-protection lenses, glass paneling (glasses for buildings, for locomotion devices, automobiles), optical devices, decorative articles, sun-protection articles, information storage, etc.
The present invention will be better understood in the light of the following examples of synthesis and photochromic validation of compounds having the general formula (I). These examples are not intended to be interpreted as limiting the invention, but rather, show specific aspects of the invention within the broad generic scope disclosed.
EXAMPLES
Example 1
Step 1: To a reaction flask containing 2,3-dihydrobenzofuran (13.5 grams) and benzoyl chloride (16.6 grams) in 170 milliliters (mL) of methylene chloride were added anhydrous aluminum chloride (18.0 grams) under nitrogen blanket over 40 minutes. The reaction temperature was controlled at around 25° C. with an ice/water bath. The reaction mixture was stirred at room temperature overnight. The resulting mixture was poured into 150 mL of ice/water and stirred vigorously for 30 minutes. The organic layer was separated, washed with water, dried over magnesium sulfate. The methylene chloride solvent was removed by rotary evaporation to give 25 grams of thick pink oil. It is used ‘as is’ in the next step.
Step 2: The product from Step 1 (25 g), dimethyl succinate (21.0 g), and potassium t-butoxide (16.5 g) were mixed in 250 ml of toluene. The mixture was refluxed for 2 hours under nitrogen blanket. After it was cooled to room temperature, 200 ml of water was added and mixed well. The aqueous phase was separated, acidified with 5N HCl, and extracted with 3×100 ml of ethyl acetate. The combined extracts were washed once with water, dried over magnesium sulfate. The solvent was removed under reduced pressure to give 40.5 g of honey-like crude half-ester product. It was known that the crude product contains some aliphatic oil contaminants from the ethyl acetate solvent. It is used without purification.
Step 3: The crude half-ester from Step 2 (40 g) was added to reaction flask containing 180 ml of acetic anhydride and 23 g of anhydrous potassium acetate. The mixture was refluxed for 1.5 hours, cooled, filtered. The solid in the filtration funnel was washed thoroughly with ethyl acetate. The combined filtrate was concentrated to just dry under vacuum. The dark solid was re-dissolved in ethyl acetate and washed with water, dried over magnesium sulfate. The organic solution was concentrated under reduced pressure. The residual was subjected to a silica column with ethyl acetate/hexane 1:4 as elutant. Two main portions were obtained: 8.7 g of light yellow solid, and 36 g of light brown thick oil. An NMR spectrum showed the light yellow solid to have a structure of Compound 1-3-p1: (2,3-dihydro-5-phenyl-6-methoxycarbonyl-8-acetoxy-naphtho[2,3-b]furan). The oil portion contains uncertain amount of Compound 1-3-p1 and its two isomers Compound 1-3-p2 and Compound 1-3-p3, in ethyoxyethanol and methy isoamyl ketone Icontaminates from ethyl acetate solvent.
Step 4: The oil mixture from Step 3 (12 grams) was dissolved in 70 ml of toluene and 10 g of p-toluenesulfonic acid was added. The reaction solution is refluxed for 2 hours, cooled, washed with water, and concentrated to 21 grams of thick oil mixture.
Step 5: The mixture from Step 4 (14.5 grams) was reacted with 2.0 g of 1,1-di(4-methoxyphenyl)-2-propyn-1-ol in 20 ml of toluene in presence of catalytic amount of p-toluenesulfonic acid under reflux for 3 hours. The reaction solution was cooled, concentrated. A silica column with ethyl acetate/hexane 1:4 as eluent provided three photochromic compounds: 450 mg of 1-5-p1, 5 mg of 1-5-p2, and 500 mg of 1-5-p3. Proton NMR confirmed that Compound 1-5-p2 has the molecular structure of this example.
Comparative Example 1
Proton NMR confirmed that Compound 1-5-p1 has the molecular structure of this example.
Comparative Example 2
Proton NMR confirmed that Compound 1-5-p3 has the molecular structure of this example.
Example 2
Step 1: Compound 1-3-p1 from Step 3 of Example 1 (1.85 g) was mixed with 50 ml of methanol and 1 ml of concentrated HCl. The mixture was refluxed for 7 hours before it was cooled down to room temperature. 100 ml of water was then added. The product was extracted with 200 ml ether and followed by separation, drying over magnesium sulfate, filtering, and vacuum drying to yield 1.55 g of very light yellow powder.
Step 2: The product of Step 1 (0.5 g) was dissolved in 10 ml of THF, and 4 ml of cyclopentylmagnesium bromide (2M in ether) was dropped in at room temperature. After stirring for 2 days, few mililiters of 1N HCl was added in. The mixture was extracted with toluene, dried over magnesium sulfate, filtered, and concentrated to a solid paste. The paste was then washed with hexane to provide 0.64 g of off-white powder.
Step 3: The product from Step 2 (0.56 g) was mixed with 10 wt. % p-toluenesulfonic acid and 50 ml of toluene. The mixture was refluxed for one and half hour, concentrated, and chromatographied with silica column and 1:5 of EtOAc/Hexane as eluent. 0.08 g waxy solid was obtained.
Step 4: The waxy solid was then reacted with 1-phenyl-1-biphenyl-2-propyn-1-ol (0.1 g) in 15 ml of toluene and catalytic amount of p-toluenesulfonic acid for 30 minutes at 50 to 80° C. After concentrated and purified by a silica column with 1:15 ethyl acetate/hexane as eluent, the photochromic portion was re-crystallized in petroleum ether to yield 60 mg of light brown powder. Its structure was confirmed by NMR.
Example 3
Step 1: Steps 2 and 3 of Example 2 were followed except that cyclopentylmagesium bromide was replace by n-butylmagnesium chloride (3M in ether). In this case, two products were obtained as Compound 3-1-a (0.08 g) and 3-1-b (0.15 g). They are light yellow waxy solid.
Step 2: Compound 3-1-b (0.12 g) was reacted with 1,1-di(4-methoxyphenyl)-2-propyn-1-ol (0.24 g) in 20 ml of toluene and catalytic amount of p-toluenesulfonic acid for 50 minutes at 50 to 80° C. After concentrated and purified by a silica column with 1:20 ethyl acetate/hexane as eluent, 140 mg of white powder was obtained. Its structure was confirmed by NMR.
Example 4
Compound 3-1-a (0.08 g) was reacted with 1,1-di(4-methoxyphenyl)-2-propyn-1-ol (0.1 g) in 10 ml of toluene and catalytic amount of p-toluenesulfonic acid for 50 minutes at 30 to 80° C. After concentrated and purified by a silica column with 1:15 ethyl acetate/hexane as eluent, 80 mg of light yellow powder was obtained. Its structure was confirmed by NMR.
Photochromic Property Measurement:
Each of the compounds was dissolved in a solution of a thermoplastic polyurethane (20%) in THF to make a casting solution containing 1 wt. % of the photochromic compound with respect to the polyurethane. Photochromic polyurethane films of about 0.1 mm thick were then prepared with the casting solutions on flat borosilicate glass pieces. After complete evaporation of solvent, the UV-visible absorptions are then measured before and after exposure the photochromic polyurethane films to a 365 nm UV source. The photochromic properties: the wavelengths □ A and □ B of the two principle absorption bands and relative induced optical density (RIOD, defined as the ratio of induced optical density between band A and band B) of these compounds are given in the Table 1 below.
TABLE 1
Compound
□ A (nm)
□ B (nm)
RIOD
Example 1
440
530
0.91
Example 2
420
530
1.85
Example 3
440
540
1.54
Example 4
440
540
1.39
Comparative
430
538
0.76
Example 1
Comparative
420
520
0.46
Example 2
The data presented in Table 1 show that each tested compound of the present invention has two absorption peaks in the visible spectrum and a relative induced optical density of greater than 0.80. The data demonstrates that a single compound of the present invention exhibits a blended activated hue. By employing a compound of the present invention having two activated visible absorption maxima, fewer distinct compounds are required to achieve a blend of activated visible absorption maxima to produce the desired activated hue, e.g. neutral color. In addition, the blended activated hue of a compound of the present invention is particularly suitable for use in photochromic articles having a brown or driver activated color due to the greater optical density of Band A (420–500 nm) than the optical density of Band B (500–600 nm).
The present invention has been described with reference to specific details of particular embodiments thereof. It is not intended that such details be regarded as limitations upon the scope of the invention except insofar as to the extent that they are included in the accompanying claims. All publications and patents referred to in this application are hereby incorporated by reference. | This invention relates to novel naphthopyrans having an oxygen-containing heterocyclic group F annelated on the i, j, or k side of the naphthopyran ring, having certain substituents at the 2, 5, and 6 positions of the naphthopyran ring. These naphthopyrans may have the formula (I) presented below:
These compounds (I) have interesting photochromic properties. Also related to this invention are host materials that contain such naphthopyran compounds, and articles such as ophthalmic lenses or other plastic transparencies that incorporate the naphthopyran compounds. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a sealed rolling bearing such as a ball bearing or a roller bearing sealed by one or a pair of metallic seal rings, which comprise not only those made entirely of metal plate but those rings the marginal portion of which are to be fitted to the sealing groove which are made of metal plate, for example, a sealing ring having a sealing lip at the portion opposite to its retaining side. More particularly, this invention relates to an improved sealing ring and a sealed rolling bearing utilizing this type of sealing ring which enables maintainance of a minimum extent of deformation and dimensional change, particularly, deformation of the circularity of the outer race or inner race due to an assembly operation.
2. Prior Art
Means for retaining seal rings in sealed bearing, are known in the art. For example, U.S. Pat. No. 3,206,262 teaches each sealing ring being fixed or fitted to a sealing groove by means of a resilient seal retaining snap ring. Other prior art, such as, U.S. Pat. Nos. 2,355,805; 2,850,792 and 3,203,740, teach sealing rings being inserted directly into a sealing groove by force fitting or with further wedging. However, these prior art references have several drawbacks which it is desired to eliminate.
For example, retaining snap rings may cause only a relatively small extent of deformation and dimensional change of the bearing race due to inserting and fitting of the sealing ring, and, thus, may be more advantageous than the force fitting method with respect to dimensional accuracy. However, snap rings require a complicated configurations of the sealing groove along with preparation of extra retaining snap rings, as well as requiring improving machining and assembling efficiency, productivity, as well as in expensive production costs.
Also, there are encountered other problems with respect to the sealing performance due to variations in the sealing clearance formed, for instance, between the inner peripheral edge of the seal ring and the outer surface of the stepped portion of the inner ring. This is brought about by such inherent features of this type of fixing means that there remains only a minimum clearance necessary for assembly operation between the peripheral edge of the free side of the seal ring and the stepped surface of the inner race, and accordingly, there may arise variations in the clearance. This is liable to cause an undesirable metal to metal contact between a sealing ring and an inner race when the clearance is excessively small. Therefore, this type of fixing or fitting of the sealing ring has been found to be too difficult for application to small size bearings or miniature bearings.
On the other hand, in the latter type of fixing or fitting, both the sealing ring and the sealing groove formed in the outer or inner bearing race are of simple confirurations and their assembly can be performed by a mere force fitting or with further wedging, and therefore, is somewhat more advantageous with respect to productivity, assembling work and production costs.
However, the peripheral portion of the sealing ring is press formed and has the same thickness throughout the entire ring body. Consequently, there inevitably arises considerable deformation and dimensional change in the bearing race due to the wedging operation as well as uneven locking of the sealing ring to the sealing groove due to the deformation and/or dimensional variation. In other words, the larger the applied wedging force for preventing the uneven locking the larger is the deformation of the outer race. On the contrary, if the wedging is carried out with such a lower force that no substantial deformation is caused, there, arises another problem that the loosely wedged sealing rings may rotate during their service.
As explained above, it has been proved to be excessively difficult up to the present, to maintain deformations and dimensional change of the bearing race to be as small as possible and to firmly retain the sealing ring such that it may not rotate.
Particularly, a fatal drawback of the force type of fixing was the fact that it has been applied to almost none of the bearings having bearing races of small wall thickness, extra small bearings or miniature bearings.
OBJECTS OF THE INVENTION
In view of the above mentioned drawbacks of the conventional sealed rolling bearings, it is therefore, an object of this invention to provide sealed rolling bearings free from such drawbacks, and particularly, to provide a sealing ring retaining construction and a sealed rolling bearing utilizing this sealing ring which can be applied to extra small bearings and miniature bearings using bearing races of small wall thickness.
In this regard, this invention is directed to assembling and securing a sealing ring or sealing rings of a sealed rolling bearing to a bearing race thereof without causing any substantial deformation thereof.
It is a further object of this invention to provide a sealing ring which can be assembled easily and in a secured manner.
It is a further object of this invention is to provide a sealing ring suitable for extra small bearings and miniature bearings.
A still further object of this invention is to provide a sealed rolling bearing capable of easy assembly and which satisfies all the requirements of high durability, secure sealing performance and low production costs.
SUMMARY OF THE INVENTION
According to the present invention, a peripheral edge of the retaining side of a sealing ring is bent in a direction almost parallel to the central axis of the bearing race to form a peripheral wall raised along the axis of the bearing, and the top portion of the peripheral wall is chamfered at its retaining side. A bearing ring to which the sealing ring is secured is formed or machined with a sealing groove defined in part by a wall extending obliquely to the central axis.
The bearing of this invention is assembled in such a manner that the peripheral wall of the sealing ring is deformed and retained by the sealing groove after having been pressed in.
In an alternate embodiment of the invention, a top portion of the peripheral wall of the sealing ring formed by bending is further chamfered either to have a sharp knife edge or to have a truncated profile.
The sealing ring of the present invention can be assembled to the sealing groove of the bearing race with limited face-to-face contact. Alternatively, the surface of the retaining wall of the sealing groove can be placed in contact either with the truncated tip end of the peripheral wall defined by the chamfered surface and the top surface remains without being punched off or with a sharp knife edge.
When the sealing ring is in an assembled position, the peripheral wall of the sealing ring is widened to expand obliquely or substantially parallel to the central axis and is retained by a tight contact with the remaining wall of the sealing groove of the bearing race.
In a further embodiment of this invention, a part of the peripheral wall of the sealing ring is further wedged or caulked for more secure retention.
Engagement between the peripheral wall of the sealing ring with the retaining wall may be made resiliently or rigidly.
As explained above, the sealing ring of the present invention may change its shape at the peripheral wall when it is inserted in the bearing ring without resulting in any appreciable amount of distortion of the bearing race. Furthermore, the two components can be assembled with greater security of retention by only being pressed in or with some slight wedging.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention, reference is made to the following detailed description and accompanying drawing. In the drawing like reference characters refer to like parts throughout the several views in which:
FIG. 1 is a sectional view of a first embodiment of the present invention;
FIG. 2 is a fragmentary, enlarged sectional view of the present invention showing the relation of contact between the sealing ring and the sealing groove as shown in FIG. 1;
FIG. 3 is a sectional view showing another embodiment of this invention;
FIG. 4 is an enlarged fragmentary sectional view showing a different manner of contact between the sealing ring and the sealing groove of this invention;
FIG. 5 is an enlarged, fragmentary sectional view showing a different manner of contact from that shown in FIG. 4, in which a sealing ring having sharp edge is placed in contact with the sealing groove; and
FIGS. 6, 7 and 8 are graphs showing the extent of the deformation in comparison with the bearing rings after the sealing rings have been assembled and rightened.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and, in particular, FIGS. 1, 2 and 3, there is depicted a rolling bearing comprising: an outer race 1, an inner race 2, a ball 3, a cage 4 and a sealing ring 5. For purposes of brevity, the following explanation will be made with reference to only one side of bearing.
The outer race 1 is provided with an annular sealing groove 11 having a substantially V-shaped cross section at its bottom corner. This is defined by an annular positioning wall 12 extending substantially perpendicular to the central axis of the bearing and by an annular retaining wall 13 which extends obliquely to and away from the central axis towards the inside of the race. The annular surfact of the wall 13 may take a straight conical shape or curved shape, as desired.
As clearly shown in the enlarged view of FIG. 2, the sealing ring 5 is press formed from a metal sheet, and the configuration of the retaining side of the annular peripheral wall of the press formed sealing ring prior to assembly, shown in phantom, is similar to a trough shape in section and comprises an annular peripheral wall 51 extending toward the retaining wall 13 of the sealing groove 11; an annular bottom wall 52 formed contiguous to and tightly contactable with the positioning wall of the bearing, and an annular raised portion 53 which extends obliquely in both the radial and axial directions of the bearing.
The peripheral wall 51 has an annular chamfered portion having an annular peripheral surface 512. The wall thickness of the chamfered portion decreases gradually towards the tip end of the peripheral wall.
Chamfering can be performed either by punching and drawing subsequent to press forming or by a so-called punching and drawing operation carried out concurrent with press forming.
In the embodiment shown in FIG. 2, the tip portion of the peripheral wall is chamfered such that a small marginal edge 511 remains between the chamfered surface 512 and the annular opposite surface of the peripheral wall.
The sealing ring 5, thus, formed can be retained by the sealing groove with almost the entire peripheral surface 512 of the chamfered portion being tightly contacted with the retaining surface 13 of the annular sealing groove. Thus, there remains only a very small labyrinth clearance t(FIG. 1) between the inner periphery of the sealing ring and the stepped outer periphery of the inner race thereby ensuring a very tight seal which is necessary for this type of sealed bearing.
Assembly and retention of the sealing ring 5 in the sealing groove 11 of the bearing is performed by inserting, from the outside, the sealing ring 5 into the sealing groove 11 for tentative retention, and, then, further slightly wedging the chamfered portion 512 against the retaining wall 13 for greater security of retention.
In FIG. 2 there is depicted in phantom another type of sealing ring having only an annular peripheral wall and a flat annular inner base not having a trough shaped cross section with raised central flange.
Referring, now, to FIG. 3 there is shown another type of peripheral wall of the sealing ring and defining another embodiment of this invention. According to this embodiment the tip edge of the chamfered portion forms a sharp annular edge defining an angle formed by the chamfered surface 512 and an annular inner surface 514 of the sealing ring. In this construction, retention of the sealing ring 5 by the sealing groove 11 is performed in such a manner that the tip portion of the chamfered portion including the sharp peripheral edge is kept in tight contact with the retaining wall 13 of the outer bearing race 1. In this embodiment, the sealing ring 5 is retained by a face-to-face contact of the two components by a mere pressing-in of the sealing ring 5 into the sealing groove 11, without any subsequent wedging being applied.
FIG. 4 depicts an embodiment wherein an annular edge 513 defined by the chamfered surface 512 and the remaining top edge surface 511 is resiliently biased to the retaining wall 13 to ensure tight so-called "linear" contact therebetween.
FIG. 5 depicts a further embodiment, wherein an annular sharp peripheral edge 513 is defined by the chamfered annular surface 512 of the sealing ring and the inner annular surface 514 of the sealing ring 5 is placed in line contact with the retaining wall 13 of the sealing groove.
In order to test the efficiency of the present invention, comparison tests were conducted to determine the difference in the extent of the deformation or distortion after assembly with respect to the non-circularity of the outer races between bearings using sealing rings of this invention and bearings using conventional type retaining means.
In the comparison tests, fifty pieces each of miniature stainless steel bearings having the same dimensions were used, namely, outer diameter: 8 mm, inner diameter: 5 mm, breadth of bearing ring: 2.5 mm, wall thickness of inner race: 0.4 mm, number of balls: 13 ea. sealing ring made of stainless steel sheet of 0.1 mm thick.
The results obtained are shown in FIGS. 6 through FIG. 8.
FIG. 6 shows the results obtained by the test bearings using the conventional method of inserting with further wedging; FIG. 7 shows the results of the test bearings using a conventional retaining snap ring and FIG. 8 shows the results obtained by the test bearings of this invention.
As can be clearly seen from FIG. 8, deviation from circularity of most of the test bearings have been subjected to assembly lies within 3 microns, and were proved to be far superior to those of the conventional type seals mentioned.
As explained above, a sealed rolling bearing of this invention having the novel sealing ring 5 which is provided with a chamfered portion 512 has, for example, an annular peripheral surface 512 the wall thickness of which gradually decreases toward its outer edge and is accompanied by a gradual decrease in rigidity. By this construction, at least a part of the chamfered periphery 512, having the reduced rigidity, firmly rests on the retaining wall 13 of the sealing groove 11 and is securedly retained thereby. Therefore, the chamfered portion of the sealing ring lightly contacts the retaining wall but with a secure retaining force. In other words, a smaller extent of compressive force applied to the sealing ring will result in relatively greater retaining force, consequently, there exists neither any fear of undesirable rotation of the sealing ring during the service, nor any possible deformation of the bearing race during its assembly. This is because the peripheral wall, particularly the chamfered portion thereof, will easily deform when it passes through the sealing groove without being accompanied by any appreciable deformation of the mating bearing race.
Owing to the above mentioned manner of inserting and retaining the sealing ring, sealing clearance t, can be maintained uniform and as small as possible.
As heretofore noted, assembly of the sealing ring can be performed merely by pushing it in from the end face of the bearing races or with further wedging. Only very small amounts of deformation of the mating bearing race occurs, thus, assuring easy assembly, high productivity, reduction in necessary control operations and lowering of assembling cost.
It should be noted that the preceding explanation has been made relative to bearings wherein the sealing rings are retained by outer races. However, it is to be understood that the present invention can be performed in any other alternative manner, for example, sealing rings may be retained by an inner race or only a single sealing ring may be used in one side of the bearing as a single sealed bearing.
Also, when chamfering of the peripheral wall, e.g. by punching, the diametral dimension can be kept accurate with minimal variation. As a result, variation in the required fitting force and in the deformation of the mating bearing race can also be maintained at a minimum.
Because of this dimensional accuracy assembly of of the sealing with constant force together with uniform and smaller sealing clearance is achieved. This, in turn, improves sealing performance of the product bearing.
Slight annular ridges or indentations may be formed when forming sealing rings by punching. However, they are effective in improving clinching of the seal rings to their mating retaining wall of the bearing race.
It is also apparent that chamfering of the peripheral wall of the sealing rings may be made in many other means such as machining, swaging or the like.
In the embodiments of the present invention, the chamfered surface of the sealing wall, i.e., surface 512, is shown to take an acute angle to the surface of sealing groove, but it is also apparent that many other modifications can be selected depending on the shape of the retaining wall to be used; requirements on retaining forces, and production means. Thus, the chamfered surface may be acute, perpendicular or obtuse retaining wall.
Sealing rings used for the test bearings for the comparison test, as previously explained, were prepared to form an inclination to the peripheral wall by taking advantage of spring back of the used material because the size of the sealing rings were too small to apply any additional forming tool.
According to the present invention, any appreciable amount of deformation or "out of circularity" in either race during assembly can be avoided. Consequently, rolling bearings of this invention satisfy both good bearing performance, such as rotation performance and low noise performance, as well as superior sealing performance.
As explained above, sealed rolling bearings of the present invention are particularly advantageous for such bearings using bearing races having small wall thicknesses which are susceptible to deformation during assembly of sealing rings and extra small bearings or miniature bearings which are obliged to use bearing races of small wall thickness.
Many additional changes in construction and widely different embodiments of this invention can be made without departing from the spirit and scope of this invention. | The marginal periphery of a locking side of an annular sealing ring is bent along an axial direction of the sealing ring to form a peripheral wall being chamfered at its peripheral edge. An annular sealing groove or grooves for receiving and retaining the annular sealing ring is formed either on an outer race or inner race of a rolling bearing. A retaining surface of the annular sealing groove is formed with a straight or curved profile and extends obliquely away from the central axis of the sealing ring toward the interior of the sealing ring body. Due to this construction, a chamfered portion of the sealing ring easily and resiliently deforms when it is merely pushed into the sealing groove or is tightened further by wedging or caulking, thus, enabling easy and firm assembly of the sealing ring without any appreciable deformation of the outer race or inner race which receives and retains the sealing ring. | 5 |
RELATED APPLICATION DATA
This application claims the priority benefit of U.S. Provisional Application Ser. No. 61/724,804, filed Nov. 9, 2012, which is hereby incorporated in its entirety herein by reference.
FIELD OF THE INVENTION
The present invention relates to polymeric laminate materials, containers made from same and methods for the storage of agricultural products and the like. The present invention further relates to barrier films, in particular, barrier films exhibiting functional properties for the management of adverse conditions, pertaining particularly, but not limited to, food storage.
BACKGROUND OF THE INVENTION
Polymeric laminates may be used for the storage of agricultural products and the like, such as harvested grain, silage.
In agricultural production, it is beneficial to prevent post-harvest loss through the use of on-farm storage techniques and containers.
There are several concomitant problems attendant to on-farm storage of dry foodstuffs (e.g., grain and feedstock), such as the prevention of water ingress and the subsequent moisture accumulation in the surface layer of the grain adjacent the innermost layer of the container.
Free-standing storage containers for bagged agricultural commodities are prone to insect infestation and infestation development and growth of molds and resulting toxins. In addition, long term storage of dry foodstuffs typically is threatened by rodents and insects, as well as by bacteria fungus, such as aflatoxin. Accordingly, it is beneficial to provide on-farm storage containers that prevent or reduce the infestation and fungal growth. To reduce fungal growth, the containers should maintain some degree of oxygen permeability.
The container must also have sufficient strength and resiliency to withstand the forces associated with grain storage and transport.
In the preparation of polymeric materials of this type for these purposes, there has been a deficiency in the prior art in that, while the prevention of water ingress and associated moisture accumulation, as well as the use of rodent repellants, insecticides and fungicides are known, prior structural materials have not been able to achieve effective oxygen transmission (i.e., reduce oxygen flow toward the foodstuff and allow oxygen to flow away from the foodstuff), water vapor transmission and moisture management (i.e., water absorbancy) so as to be able to effectively reduce the risks associated with fungal growth, aflatoxin and mycotoxins; all while providing the other benefits of the active ingredients above.
Post-harvest losses due to poor handling, poor storage, insect infestations and mold or rot significantly hinder income generation for small-scale farmers. “In Tanzania, maize losses of up to 35% may occur due to Prostephanus truncatus (Larger Grain Borer) within 5 to 6 months if improperly stored (Mallya, 1992) and up to 60% losses may occur after 9 months of storage (Keil, 1988), a situation which may result in serious famine” according to the FAO's Paper on Insect Damage, Post Harvest Compendium. In Kenyan highlands, total losses due to pests in maize were estimated at 57% with insects being more important than disease (Grisley, 1997). In Zimbabwe, grain damage of 92% in stored maize was reported due to insect pests, treatment with malthion reduced damage by only 10% (Matrio, et al. 1992). Infestations of stored cowpeas can be as high as 90% in markets and in village stores (Alabeek, 1996). A wide variety of food stuffs are affected by insects, mold and fungi infestation is not limited to maize grains and pulses. Insect pests, in addition to fungal diseases, are responsible for 50% damage in cassava (Maninek, 1994). Losses of up to 70% in dried cassava roots after 4 months of storage were reportedly due to P. truncatus . (Hodges, et al., 1985).
Insect pests inflict their damage on stored products mainly by direct feeding. Some species feed on the endosperm, causing loss of weight and quality, while other species feed on the germ, resulting in poor seed germination and less viability (Malek & Parveen, 1989; Santus, et al. 1990). In addition to direct consumption of the product, insect pests contaminate their feeding media through excretion, molting, dead bodies and their own existence in the product which is not commercially desirable. Damage done by insect pests encourages infection with bacteria and fungal disease through transmission of their spores (Cravedi & Quaroni, 1982; E. Kundayo, 1988; Dunkel, 1980). The presence of insects also raises the stored product temperature, due to their feeding activity, resulting in hot spots (Appert, 1987; Mills, 1989). These “hot spots” can lead to condensation and excessive moisture, resulting in the growth of mold or fungi. Insects activity can have a profound effect on the spread of fungal diseases through transmitting the spores and increasing the surface area susceptible to fungal infection, which eventually increases production of mycotoxins (Dunkel, 1988).
Despite the physical damage of insect pests, infestations resulting from poor post-harvest storage can have economically devastating effects on farmers, communities, and the economies of several countries depending on exportation of maize, wheat and other food stuffs. For example, P. truncatus cost Tanzania roughly US $91 million annually in lost maize intended for consumption or export (Bionet International & Global Invasion Species Program). Farmers in sub-Sharan Africa are frequently forced to sell stored produce prematurely because of the deterioration due to insect damage that occurs if storage periods are extended (Global, et al. 1996, Brice et al. 1996, Marsland & Golob 1996, Donaldson, et al., 1996). Inability to store and protect post-harvest leads to significant income loss as farmers do not have the flexibility to wait for the higher price as the market fluctuates. The difficulties of on-farm food storage and the economic burden of post-harvest loss are devastating for farmers in developing countries, particularly due to the lack of available resources for building of storage units, the lack of information regarding insecticide/pesticide use, as well as lack of affordability.
On-farm storage difficulties and post-harvest losses occur mainly as a result of temperature, moisture, respiration of stored contents, infestation of insects, infestation of rodents and fumonisins, mycotxins and aflatoxins resulting from mold and fungi growth, due to lack of oxygen transmission and water vapor transmission of storage containers presently employed. Whether intended for human consumption, or used as animal food stock, stored product contamination poses serious health risks. Aflatoxin consumed by dairy cattle, though altered in their body, still remains toxic and shows up in the milk (Christensen & Meronuck, 1986, Gwinner, et al., 1996). A. fumagatis is report to result in high levels of abortion in cattle feeding on contaminated food; also infects human lungs (Darwish, et al., 1991; Pandey & Prasad 1993; Abud, et al., 1995).
The use of plastic sacks, bag storage, prefabricated iron halls and flexible plastic silos are increasingly gaining ground among farmers for short term storage (Peterson & Simila, 1990; Compton, et al., 1993; Bartali, 1994). However, none of the current storage mechanisms effectively manage the comprehensive set of factors including insect and pest repellency, barrier to oxygen, etc.
Accordingly, there remains a need for improved polymeric and woven laminates for dry on-farm storage of dry foodstuffs.
SUMMARY OF THE INVENTION
The present invention includes laminates and containers comprising same for the storage of agricultural products and the like, such as harvested grain and silage, as well as methods of storing grain for a period of time to permit on-farm storage and the subsequent economies of timely market approach. Films of the present invention may also find beneficial use in building applications, such as in grain storage facilities, such as in grain warehouse floor applications.
The laminates of the present invention may be produced using coextrusion, profile extrusion, thermoforming, film lamination, weaving, knitting and bonding machinery and processes, such as blow molding, film blowing and thermal point bonding and sheet bonding, stenter coating, known and used in the art.
Polymeric Laminate—Coextruded Version
In general terms, the invention includes a polymeric laminate comprising: (a) an outermost layer comprising a thermoplastic polymeric material containing at least one rodent repellent material, at least one pesticide and/or insecticide and an ultraviolet blocking material; (b) an innermost layer comprising a food grade polymer and an adhesive; and, interposed without respect to order between the outermost layer and innermost layers, the following layers: (c) an oxygen barrier intermediate layer comprising a thermoplastic polymeric material containing at least one additive that functions as a desiccant, a free radical scavenger or an oxygen barrier; and (d) a bio-composite absorbent/compatibilizer layer comprising a thermoplastic polymeric material containing at least one super-absorbent polymer and activated carbon, such as activated bamboo carbon charcoal or another antifungal additive (such as Triclosan). Examples are shown in FIGS. 1-1 e.
It is preferred that the outermost layer comprises a first layer comprising a polyolefin, a rodent repellent and an ultraviolet blocking material; and a second layer comprising a thermoplastic polymeric material and at least one insecticide or pesticide material. It is further preferred that the bio-composite absorbent/compatibilizer layer comprises a first layer comprising at least one super-absorbent polymer; and a second layer comprising activated bamboo carbon.
The outermost layer may comprise a polyolefin selected from the group consisting of polypropylene, HDPE, LDPE, LLDPE, VLDPE and copolymers and homoploymers thereof.
The insecticide may be selected from the group consisting of synthetic pyrethroids, such as permethrin and deltamethrin and/or organophosphorous compounds, pirimiphos methyl, chlorpiriphos methyl, fenitrothion, malathion and/or composition or mixtures thereof and/or ethnobotanical mixtures, including without limitation neem plant or oil, sweet flag worm seed and peppers, geranium oil and menthol, and/or other plant-based materials.
In another related variation of the present invention, the polymeric laminate comprises: (a) an outermost layer comprising a polyolefin, a rodent repellent and an ultraviolet blocking material; (b) an innermost layer comprising a food grade polymer and an adhesive; and, interposed without respect to order between the outermost layer and innermost layers, the following layers: (c) an insecticide/pesticide intermediate layer comprising a thermoplastic polymeric material and either an insecticide or a pesticide material; (d) an oxygen barrier intermediate layer comprising ethylene vinyl alcohol and preferably EMMA with inorganic/organic additives; (e) a bio-composite absorbent layer comprising super-absorbent polymers; and (f) a bio-composite compatibilizer layer comprising activated bamboo carbon and a compatibilizer.
The compatibilizer(s) used in accordance with the present invention may include any compatibilizer effective to render the additive compatible with the surrounding polymer, such as those selected from the group consisting of chitin and citric acid.
In still another variant of the present invention, the invention includes a polymeric laminate comprising: (a) an outermost layer comprising a polyolefin, an insecticide/pesticide material, a cuticle desiccant and an ultraviolet blocking material; (b) an innermost layer comprising a food grade polymer and an adhesive; and, interposed without respect to order between the outermost layer and innermost layers, the following layers: (c) an rodent repellent intermediate layer comprising a thermoplastic polymeric material, a rodent repellent material and ethyl vinyl acetate; (d) an oxygen barrier intermediate layer comprising ethylene vinyl alcohol and/or EMMA and at least one inorganic/organic additives, (e) a bio-composite absorbent layer comprising at least one super-absorbent polymer(s); and (f) a bio-composite compatibilizer layer comprising activated bamboo carbon charcoal or another antifungal additive, and a compatibilizer.
Polymeric Laminate—Mesh Version
In still another variation of the present invention, the invention includes a polymeric laminate comprising, as shown for example in FIG. 2 : (a) an outermost layer comprising a woven thermoplastic polymeric material containing at least one rodent repellent material and an ultraviolet blocking material, and a layer comprising at least one pesticide; (b) an innermost layer comprising a food grade polymer and an adhesive; and, interposed without respect to order between the outermost layer and innermost layers, the following layers: and (c) a bio-composite layer comprising a thermoplastic yarn mesh containing at least one super-absorbent polymer and activated carbon, such as an activated bamboo carbon charcoal or another antifungal additive.
It is preferred that the bio-composite layer be of an HDPE mesh containing at least one super-absorbent polymer, and a second layer comprising an HDPE mesh containing a biocomposite material and activated bamboo carbon.
Another variation of the present invention is a polymeric laminate comprising (a) an outermost layer comprising a thermoplastic polymeric material containing at least one rodent repellent material; (b) an innermost layer comprising a food grade polymer and an adhesive; and, interposed without respect to order between the outermost layer and innermost layers, the following layers: (c) a woven thermoplastic polymeric material; (d) a thermoplastic polymer layer containing at least one pesticide; (e) a bio-composite layer comprising a thermoplastic yarn mesh containing at least one super-absorbent polymer and activated carbon.
In one variation, the bio-composite layer comprises a thermoplastic mesh, such as HDPE or polypropylene mesh containing at least one super-absorbent polymer, and a second layer comprising an HDPE or polypropylene mesh containing a biocomposite material and activated bamboo carbon.
Still another variation of the invention is a polymeric laminate comprising (as exemplified in FIGS. 2 b and 2 c ): (a) an outermost layer comprising a woven thermoplastic polymeric material containing at least one rodent repellent material and an ultraviolet blocking material, and a layer comprising at least one pesticide; (b) an innermost layer comprising a food grade polymer and an adhesive; and, interposed without respect to order between the outermost layer and innermost layers, the following layers: (c) a bio-composite layer comprising a thermoplastic yarn mesh containing at least one super-absorbent polymer and activated carbon such as activated bamboo carbon charcoal or another antifungal additive.
A further variation is a polymeric laminate comprising (see FIG. 3 ): (a) an outermost layer comprising a woven thermoplastic polymeric material containing at least one ultraviolet blocking material as well as, optionally, the rodent repellent and the at least one pesticide; (b) an innermost layer comprising a food grade polymer and an adhesive; and, interposed without respect to order between the outermost layer and innermost layers, the following layers: (c) a first bubble plastic thermoplastic polymeric material layer comprising bubbles containing at least one rodent repellent material; (d) a second bubble plastic thermoplastic polymeric material layer comprising bubbles containing at least one pesticide; (e) a non-woven or other equivalent layer, such as a filter membrane, that encapsulates cellulosic or other naturally absorbent materials and/or superabsorbent polymers, and (f) an optional bio-composite layer comprising a thermoplastic yarn mesh containing at least one super-absorbent polymer and activated carbon.
A variant of this embodiment additionally comprises a layer of a thermoplastic polymeric material containing calcium carbonate or equivalent material as a filler/blocking agent, and disposed between the second bubble plastic thermoplastic polymeric material layer and the a non-woven or other equivalent layer.
Preferably, the first bubble plastic layer comprises a polymer selected from the group consisting of LDPE, VLDPE, polypropylene or other suitable polymeric material, adhered to the outermost layer by an adhesive such as EVOH, and wherein second bubble plastic layer bubbles are provided with an insecticide in powder form, such as diatomaceous earth or other cuticle desiccant.
Yet another embodiment of the present invention includes a polymeric laminate comprising: (a) an outermost layer comprising a thermoplastic polymeric material containing at least one ultraviolet blocking material as well as, optionally, the rodent repellent and at least one pesticide; (b) an innermost layer comprising a food grade polymer and an adhesive; and, interposed without respect to order between the outermost layer and innermost layers, the following layers: (c) a first bubble plastic thermoplastic polymeric material layer comprising bubbles containing at least one rodent repellent material; (d) a second bubble plastic thermoplastic polymeric material layer comprising bubbles containing at least one pesticide; (e) a bio-composite absorbent layer comprising at least one super-absorbent polymer(s); and (f) a bio-composite compatibilizer layer comprising activated carbon such as bamboo carbon, and a compatibilizer.
With respect to all of the embodiments of the present invention, it will be recognized that the layered substrates, or mixtures thereof may include recycled material in place of or in addition to biobased material in an amount of up to 100% of the biobased material. As used herein, “recycled” materials encompass post-consumer recycled (PCR) materials, post-industrial recycled (PIR) materials, and a mixture thereof.
A Polymeric Storage Container for Harvested Agricultural Products
The present invention also includes a polymeric storage container for harvested agricultural products, the container comprising a polymeric laminate according to any of embodiments of the invention. These may be produced by any methods and through the use of machinery known and used in the art for creating polymeric bags and other containers made from or incorporating polymeric sheet or woven sheet material, into or supported by a framed structure.
System for Storage of Harvested Agricultural Products
A system for storage of harvested agricultural products, the system involving the use of such laminates or containers made therefrom and/or bags for on-farm storage at a farm.
Laminates of the present invention may be used in a system and method for free-standing hermetic storage of bulk, boxed or bagged commodities, such as that described for instance in U.S. Pat. No. 8,141,328, which is hereby incorporated herein by reference.
The present invention may also be considered an improvement upon the materials and methods described in Korean Patent Application No. KR10109267, which is hereby incorporated herein by reference.
The foregoing and other objects, features, and advantages of this invention will become more readily apparent from the following detailed description of a preferred embodiment which proceeds with reference to the accompanying drawings, wherein the preferred embodiment of the invention is shown and described, simply by way of illustration of the best mode contemplated of carrying out the invention.
As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive. It will also be appreciated that the detailed description represents the preferred embodiment of the invention, and that individual steps of the process of the invention may be practiced independently so as to achieve similar results; and likewise that variations of the described laminates and containers may be made by modifications in the design or manufacturing process to achieve similar results.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of a polymeric laminate in accordance with one embodiment of the present invention.
FIG. 1 a is a schematic of a polymeric laminate in accordance with an alternative embodiment of the present invention.
FIG. 1 b is a schematic of a polymeric laminate in accordance with yet another alternative embodiment of the present invention.
FIG. 1 c is a schematic of a polymeric laminate in accordance with yet another alternative embodiment of the present invention.
FIG. 1 d is a schematic of a polymeric laminate in accordance with yet another alternative embodiment of the present invention.
FIG. 1 e is a schematic of a polymeric laminate in accordance with yet another alternative embodiment of the present invention.
FIG. 2 is a schematic of a woven material laminate in accordance with one embodiment of the present invention.
FIG. 2 a is a schematic of a woven material laminate in accordance with an alternative embodiment of the present invention.
FIG. 2 b is a schematic of a woven material laminate in accordance with yet another alternative embodiment of the present invention.
FIG. 2 c is a schematic of a woven material laminate in accordance with yet another alternative embodiment of the present invention.
FIG. 3 is a schematic representation of the production of a polymeric laminate in accordance with one embodiment of the present invention.
FIG. 3 a is a schematic representation of the production of a polymeric laminate in accordance with one embodiment of the present invention.
FIG. 4 is a schematic of a grain storage bag containing grain, in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In accordance with the foregoing summary, the following provides a detailed description of the preferred embodiment, which is presently considered to be the best mode thereof.
As used throughout this application, the term “polymer” refers to a material which is the product of a polymerization or copolymerization reaction of natural, synthetic or combined natural and synthetic monomers and/or co-monomers and is inclusive of homopolymers, copolymers, terpolymers, etc. In general, the layers of the multilayer film described in the present application may comprise a single polymer, a mixture of a single polymer and non-polymeric material, a combination of two or more polymers blended together, or a mixture of a blend of two or more polymers and non-polymeric material. It will be noted that many polymers may be synthesized by the mutual reaction of complementary monomers. It will also be noted that some polymers are obtained by the chemical modification of other polymers such that the structure of the macromolecules that constitute the resulting polymer may be thought of as having been formed by the homopolymerization of a hypothetical monomer.
As used throughout this application, the term “thermoplastic” refers to a polymer or polymer mixture that softens when exposed to heat and then returns to its original condition when cooled to room temperature. In general, thermoplastic materials may include natural or synthetic polymers.
FIG. 1 is a schematic of a polymeric laminate in accordance with one embodiment of the present invention which may be produced by co-extrusion and film-blowing, such as by using centurion equipment commercially available from Kung Hsing of Taiwan. This may be made as a multi-layer coextrusion wherein the substrate is not limited to the number or order of the layers.
The typical thickness range of the laminates of the present invention made from coextrusion is from about 100 microns to 600 microns, although other thicknesses may be produced. The thicknesses of the individual layers may be determined to obtain overall laminate dimensions, but typically will be in the general range of 80 to 150 microns.
The outermost layer 1 may be produced of a thermoplastic material, such as a polyolefin selected from the group consisting of polypropylene, HDPE, LDPE, LLDPE, VLDPE and copolymers and homoploymers thereof. An example of the LLDPE is PLEXAR 800 commercially available from Lyondell Basel.
The rodent repellent(s) that may be used in accordance with the present invention may include without limitation any synthetic or natural rodent repellent miscible with the polyolefin and/or thermoplastic base layer, such as denatonium benzoate, denatonium benzoate, trinitrobenezene-aryl amine complexes, and tributyl tin chloride. Natural rodent repellents may include, without limitation, salicylic ester, menthol, corn mint oil, eucalyptus, camphor, terpene, peppermint oil, citronella oil, rosemary oil, clove oil, geranium oil, cayenne pepper, methyl nonyl ketone, or combinations thereof.
The ultraviolet blocking material(s) may be any material effectively miscible with the base polymer, and in an effective amount known in the art such as, for instance, from about 2% to about 5% percent by weight. An example of such a material is Optiblock 10 commercially available from Specialty Minerals, Inc.
The pesticide intermediate layer 2 may comprise a thermoplastic polymeric material or polyolefin, and at least one insecticide or pesticide material that may include any synthetic or natural insecticide or pesticide compatible with the polymeric material, provided in an effective amount to reduce or eliminate infestation. Examples include those selected from the group consisting of synthetic pyrethroids, such as permethrin. Most preferably, the insecticide is a combination of pirimiphos-methyl (sold commercially under the name Actellic Superdust), with permethrin at a concentration of 3% by weight and pirimiphos-methyl at 14% by weight, or other silicone dioxide plus synthetic pyrethroids or mixtures thereof.
The insecticide may also include a cuticle desiccant material, or materials that sterilize insects, inhibit their growth or retard their reproduction.
The thermoplastic polymeric material may be selected from among any material that may be amenable to co-extrusion while being able to contain the active ingredients at an effective level. Examples may include ethyl vinyl acetate or a thermoplastic polymer mixed with natural starches so as to form a biocomposite. An example of such a starch-blended polyester is Ecoflex from BASF.
The oxygen barrier intermediate layer 3 preferably may comprise any thermoplastic material, though it is preferred to use ethyl vinyl alcohol (EVOH), ethylene methyl acrylic co-polymer (EMMA) or ethylene-methacrylic acid (EMAA) owing to their increased adhesion with the other layers. An example of such an EMMA material is PXL 164 commercially available from Lyondell Basel as PLEXAR. This layer includes at least one oxygen barrier material, such as inorganic or organic additives that function as desiccants, free radical scavengers or oxygen barriers, and provided in effective amount to penetrating from the outside layer. This amount will vary with the foodstuff volume to laminate surface area ratio of the specific application, but generally will be in the range of from about 2% to 75% by weight. Such inorganic additives may include iron, ascorbic acid, calcium hydroxide, activated carbon, sodium chloride, potassium chloride, magnesium oxide, titanium oxide, aluminum oxides, chromium oxide, calcium oxide, silica, bentonite, zeolites, montmorillonite, mullites, wollastonites and agalmatolite clay.
Organic additives may include such substances as are known in the field, such as compatibilizers metal alcoholates and alkoxysilanes. Typical content of these materials will be in the range of from about 3% to about 25% percent by weight, or otherwise, depending upon the nature of the material to be incorporated into the polymeric structural layer.
The bio-composite absorbent layer 4 comprises one or more super-absorbent polymers, such as sodium polyacrylates commercially available from Shanghai Dinghan Chemical Co., Shanghai, PRC, or from Teijin Limited of Taiwan, and provided in an effective amount to absorb water issuing from the dry foodstuff to be contained. This amount may be determined by reference to local climatic conditions and the amount of moisture to be generated through transpiration of the stored product, such as in the context of contained corn or maize.
The bio-composite absorbent layer 4 may preferably be provided with micro perforations of a valve type to manage oxygen transmission and moisture vapor transmission, in accordance with methods known in the art. Such valve perforations, when preferably placed at approximately a 45 degree angle to the laminate surface, are effective to allow water to migrate from this layer to reach the outside of the laminate, yet prohibitive of in-flow.
The bio-composite compatibilizer layer 5 comprises a thermoplastic polymer material as the base material, with addition of activated carbon, preferably activated bamboo carbon, and a compatibilizer, in an amount effective to such as chitin, citric acid, such as Ciroflex A4, commercially available from Vertellus. Typical content of these materials will be in the range of from about 1% to about 25% percent by weight.
Any of the foregoing layers 3 , 4 or 5 may contain a blocking ingredient, such as calcium carbonate, silica or talc, that restrict the mobility of the pesticide or rodent repellent ingredient to prevent them reaching the contained dry foodstuff.
The innermost layer 6 comprises preferably a food grade polymer and an adhesive adapted to affix this layer to the immediately adjacent intermediate layer, such as layer 5 . Examples of food grade polymers may include Sabic 6135 NE.
It will be understood that each of the individual layers shown and described may be combined and/or amalgamated along with the active ingredients contained within or affixed to each such layer so as to produce a functional laminate not inconsistent with the integration of the constituent layers and the function of the active ingredients. Examples of such variation are described herein.
FIG. 1 a is a schematic of a polymeric laminate in accordance with an alternative embodiment of the present invention. This embodiment is similar to that of FIG. 1 except that the outermost layer contains the pesticide and the UV blocker ingredient, while the first intermediate layer contains the rodent repellency ingredient(s).
FIG. 1 b is a schematic of a polymeric laminate in accordance with yet another alternative embodiment of the present invention. This embodiment is similar to that of FIG. 1 except that layers 1 and 2 have been effectively combined by being coextruded as a single layer.
FIG. 1 c is a schematic of a polymeric laminate in accordance with yet another alternative embodiment of the present invention. This embodiment is similar to that of FIG. 1 except that arrangement of layers 4 and 5 has been reversed.
FIG. 1 d is a schematic of a polymeric laminate in accordance with yet another alternative embodiment of the present invention. This embodiment is similar to that of FIG. 1 except that layers 4 and 5 have been effectively combined by being coextruded as a single layer.
FIG. 1 e is a schematic of a polymeric laminate in accordance with yet another alternative embodiment of the present invention. This embodiment is similar to that of FIGS. 1-1 d except that layer 6 is produced as a single layer and inserted as liner when the film is converted to a bag through the use of such techniques as horizontal or vertical form, fill and seal, or manually.
FIG. 2 is a schematic of a woven material laminate in accordance with one embodiment of the present invention. This Figure shows outermost layer 1 which is a tape-woven layer 7 of an HDPE (or polypropylene) flat yarn containing the pesticide and rodent repellent ingredients which is thermally laminated with a EMMA thermoplastic layer 8 also containing a pesticide. It is preferred that the pesticide in the warp or weft of layer 7 be different from that of layer 8 . Additionally, the warp (or weft) of layer 7 may contain the pesticide while the weft (or warp) of layer 7 contains the rodent repellent. The HDPE (or polypropylene) flat yarn may come from post-industrial or post-consumer recycled material.
FIG. 2 also shows the HDPE monofilament yarn mesh layer 9 which has the superabsorbent polymer chemically incorporated into the yarn. Layer 10 is a biocomposite mesh prepared from a monofilament yarn of HDPE with activated carbon contained in the polymer. Layer 11 is a sheet of food grade polymer with an adhesive to bind it to the mesh layer 10 . The laminate of FIG. 2 is prepared by first assembling sub-laminates of layers 7 and 8 and 9 - 11 , respectively, followed by thermal point bonding the two sub-laminates together, as indicated by the series of X's in FIG. 2 .
FIG. 2 a is a schematic of a woven material laminate in accordance with an alternative embodiment of the present invention. This embodiment is similar to that of FIG. 2 except that layers 1 and 2 have been effectively combined by being coextruded as a single layer.
FIG. 2 a is a schematic of a woven material laminate in accordance with an alternative embodiment of the present invention. This embodiment is similar to that of FIG. 2 except that the woven layer 13 contains no active ingredients while additional layer 12 laminated on the outside of the woven layer 13 contains a rodent repellent and layer 14 contains an insecticide. This embodiment also shows layers 15 and 16 that are similar to layers 9 and 10 of FIG. 2 , and layer 17 that may be produced as a single layer and inserted as liner when the film is converted to a bag through the use of such techniques as horizontal or vertical form, fill and seal, or manually.
FIG. 2 b is a schematic of a woven material laminate in accordance with yet another alternative embodiment of the present invention. This embodiment is similar to that of FIG. 2 with layers 18 and 19 similar to layers 7 and 8 , and with the exception that layers 9 and 10 have been combined as a single layer 20 , and layer 21 being produced as a single layer and inserted as liner when the film is converted to a bag through the use of such techniques as horizontal or vertical form, fill and seal, or manually.
FIG. 2 c is a schematic of a woven material laminate in accordance with yet another alternative embodiment of the present invention. This embodiment is similar to that of FIG. 2 b with layers 24 and 25 being coextruded as a single sub-laminate prior to thermal point bonding.
FIG. 3 is a schematic representation of the production of a polymeric laminate formed in accordance with yet another alternative embodiment of the present invention. FIG. 3 shows outermost layer 30 which would be the same construction as layers 7 and 8 of FIG. 2 . Layer 31 is a bubble plastic layer of LDPE, VLDPE, polypropylene or other suitable polymeric material, adhered to layer 30 by an adhesive such as EVOH, and wherein the bubbles are provided with an insecticide in powder form, such as diatomaceous earth (such as is sold under the trade name Protect-It from Headley Technologies) or other cuticle desiccant and may or may not include one or more of the synthetic pyrethroids or synthetic organophosphate insecticides or insect growth regulator. Layer 32 is an opposing layer of bubble plastic (such as may be produced by thermoforming in combination with layer 31 ) wherein the bubbles are provided with a rodent repellent such as those described herein. Layer 33 is a separate layer of a thermoplastic material containing a filler/blocking agent (such as calcium carbonate) provided so as to prevent any liberated rodent repellent and/or insecticide/pesticide from migrating toward the food grade layer.
Layer 34 is a non-woven or other equivalent layer, such as a filter membrane, that encapsulates cellulosic or other naturally absorbent materials (such as coconut husks, apricot pits, and the like) and/or superabsorbent polymers, to provide a moisture barrier to retain and absorb moisture issuing from the contained foodstuff, such as that of transpiration of grain and the like.
Layer 35 is an adhesive layer, such as EVOH or other equivalent materials, such as those described herein. Layer 36 is a food grade polymer that is attached to layer 34 by adhesive layer 35 . Layers 34 / 35 / 36 may then thermal point bonded to layers 30 - 33 .
FIG. 3 a is a schematic representation of the production of a polymeric laminate formed in accordance with yet another alternative embodiment of the present invention. This embodiment is similar to that of FIG. 3 with layers 37 , 38 and 39 being equivalent to layers 30 , 31 and 32 ; and wherein layers 34 and 35 have been replaced with layers 40 and 41 which are the same as layers 4 and 5 of FIG. 1 , and wherein layer 43 is the same as layer 6 of FIG. 1 with optional adhesive layer 42 where the food grade layer is separately produced.
FIG. 4 is a schematic representation of the production of a polymeric laminate of the construction shown in FIG. 3 a , and wherein like reference numerals indicate the respective layers, and formed into a bag and containing grain 44 , in accordance with one embodiment of the present invention. This schematic shows the detailed construction of the cooperative layers 38 and 39 which provide an insecticide in powder form, and a rodent repellent, respectively.
It will be appreciated that the logical order of the steps are used for purposes of illustration only, and that the constituent layers, their measurements and active ingredient determinations may be varied where not otherwise inconsistent with the purpose and result obtained in the practice of the invention.
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting on the invention described herein. The scope of the invention is thus indicated by the appended claims rather than by the foregoing description, and all changes that come within the meaning and range of equivalency of the claims are intended to be embraced therein. | The present invention includes polymeric laminate materials, containers made from same and methods for the storage of agricultural products and the like. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This invention is most closely related to Mr. Kao's invention U.S. Pat. No. 5,678,458 Oct. 21, 1997. Especially in relation to the sport of flatland bicycling, the present invention claims the benefit of Mr. Kao's stem, as well as any other modern day stem.
STATEMENT REGARDING FED SPONSORED R & D
[0002] Not Applicable.
REFFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING APPENDIX
[0003] Not Applicable.
BACKGROUND OF THE INVENTION
[0004] This invention relates to bicycles, specifically to an improved way of attaching the handlebars to the steer-tube of a bicycle.
DESCRIPTION OF PRIOR ART
[0005] A class of bicycle riding known as BMX (bicycle motor cross) is generally divided into four categories: racing, dirt, street, and flatland. This invention pertains mostly to flatland riding and an improvement in building a flatland bicycle. Flatland differs from other BMX categories mainly in that no jumps or obstacles are used. In flatland the rider performs a number of stunts such as changing direction while rolling on one wheel, flipping the bike around, flipping the handlebars around and so on while riding on flat pavement. Ending the trick by getting back on the bike and rolling away on both wheels without ever touching the ground with his feet.
[0006] A flatland bicycle differs from other BMX bicycles mainly in the use of a smaller, shorter frame for easier maneuvering while rolling of one wheel. And a shorter stem is used, so that when the handlebars are rotated 180 degrees from their original position they remain as close as possible to that original position in relation to the pedals, the seat and the rest of the bicycle. This is done so that when the rider flips the handlebars around 180 degrees, in order to keep balanced, he does not have to adjust as much with his body weight to compensate for the changed distance between the handlebars and the rest of the bicycle.
[0007] A specific way of routing the brake cables is employed when building a flatland bicycle. This is done in such a way that the brake cables, attached to the brake levers on the handlebars and routed to the brakes on the fork or frame of the bicycle, do not get tangled when the handlebars are rotated around their axis numerous times, as is frequently done as part of certain tricks.
[0008] The problem for Flatland riders has been that while manufacturers have made very short stems, they have not been able to make a stem that features a way for the handlebars to be attached in the center of the axis on which the steer-tube of the bicycle rotates. The problem for manufacturers has been that a stem is comprised of a vertical clamp (securing the stem to the steer-tube and keeping the steering bearings in place), and a horizontal clamp (securing the handlebars to the stem, and thus to the bicycle). Manufacturers have made stems to have a front end, featuring a horizontal clamp and a rear end, featuring a vertical clamp. As a result of this when the handlebars are attached they are off center in relation to the rotational axis of the steer-tube. A new design is needed to fix this problem.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention solves the problem of the handlebars being attached off center of the rotational axis of the steer-tube. The way the present invention tackles this problem is by featuring the horizontal clamp, for clamping down the handlebars, directly on top of the vertical clamp, which is used to clamp the steer-tube. This places the handlebars directly in the center of the rotational axis of the steer-tube. Now, when, as part of a trick, a rider rotates the handlebars 180 degrees, the handlebars are still in the same position in relation to the rest of the bicycle.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] The drawings depict the several views of the components of the preferred embodiment of the invention.
[0011] FIG. 1 shows a top view of the cap of the stem.
[0012] FIG. 2 shows a side view of the cap of the stem.
[0013] FIG. 3 shows a side view of the cap of the stem, same as FIG. 2 , only turned 90 degrees.
[0014] FIG. 4 shows a side view of the cap of the stem, same as FIG. 3 , with the hidden lines shown, to assist in the understanding of the physical properties of the cap of the stem.
[0015] FIG. 5 shows a top view of the base of the stem.
[0016] FIG. 6 shows a side view of the base of the stem.
[0017] FIG. 7 shows a side view of the base of the stem, same as FIG. 6 , only turned 90 degrees.
[0018] FIG. 8 shows a side view of the base of the stem, same as FIG. 7 , with the hidden lines shown, to assist in the understanding of the physical properties of the base of the stem.
[0019] FIG. 9 shows an exploded view of the stem, including all the components of the stem, as well as the top portion of the steer tube and the bolts, to assist in the understanding of the assembly of the stem.
[0020] FIG. 10 shows a complete, assembled view of the stem, as well as the handlebars, the frame of the bicycle, the front fork of the bicycle, and the brake-cable-housing, in order to assist in the understanding of the assembly of the stem.
DETAILED DESCRIPTION OF INVENTION
[0021] The preferred embodiment of this invention has two main components: a base 3 , which features a steer-tube clamp and part of the clamping surface for the handlebar clamp, and a cap 1 that completes the handlebar clamp. Both of these components are used to separately fasten the stem 2 vertically, and the handlebar 29 horizontally.
[0022] The base 3 of the stem is in the form of a block. The main feature of the base 3 of the stem is a C-clamp, which is used to attach the stem 2 to the steer-tube 27 . The base 3 features a through vertical inner cavity 5 , in other words a hole, which defines the clamping surface of the steer tube clamp. There is, through one of the walls of the base 3 , along the axis of the vertical inner cavity 5 ; a longitudinal slot 11 . The wall 4 of the base 3 , on one side of the longitudinal slot 11 has, at a 90 degree angle to the longitudinal slot 11 , a number of horizontal through holes 21 , for passing through them; bolts A. 25 . The wall 6 of the base 3 on the opposite side of the longitudinal slot 11 has, at a 90 degree angle to the slot 11 , a number of matching horizontal threaded holes 23 as means of accepting bolts A. 25 . Upon tightening of bolts A. 25 the two sides of the wall, 4 and 6 , are pulled towards each other. The longitudinal slot 11 provides means for the two sides of the wall, 4 and 6 , of the C-clamp to compress relative to each other, thus changing the diameter of the through vertical inner cavity 5 .
[0023] Toward the top of the base 3 of the stem, there is a widened section of the longitudinal slot 13 , made to be sufficiently wide for the brake-cable-housing 35 to be passed through it, and then down through the steer-tube 27 .
[0024] On the top surface of the base 3 of the stem, at a 90 degree angle to the longitudinal slot 11 , and at the same angle to the vertical inner cavity 5 , there is a horizontal semi cylindrical groove 7 for accepting the handlebar 29 . Because the horizontal semi cylindrical groove 7 passes at a 90 degree angle directly through the vertical inner cavity 5 ; only the two opposing walls, 4 and 6 , of the C-clamp bear the semi cylindrical groove 7 . The center axis of the horizontal semi cylindrical groove 7 is coincident to the center axis of the vertical inner cavity 5 in the base 3 of the stem. In other words, there is no offset between the horizontal handlebar clamp and the vertical steer-tube clamp. Due to the fact that, when assembled, the vertical steer tube clamp clamps the steer tube 27 and the horizontal handlebar clamp clamps the handlebar 29 ; there is no offset between the rotational axis of the steer-tube 27 and the handlebar 29 .
[0025] On the top surface of the base 3 of the stem there is on every corner of the base 3 ; a vertical threaded hole 19 . The function of the vertical threaded holes 19 is to accept bolts B. 26 that attach the cap 1 of the stem to the base 3 , and thus secure the handlebar 29 in place.
[0026] The cap 1 of the stem has, through its corners, a number of vertical through holes 17 , matching the vertical threaded holes 19 in the corners of the base 3 . Bolts B. 26 are passed through the vertical through holes 17 in the cap 1 of the stem, and into the vertical threaded holes 19 in the base 3 . The bottom surface of the cap 1 has a horizontal semi cylindrical groove 9 matching the horizontal semi cylindrical groove 7 on the top surface of the stem base 3 . When bolts B. 26 , attaching the top cap 1 to the base 3 of the stem, are tightened, the distance between the cap 1 and the base 3 is decreased, thus sandwiching the handlebar 29 between the two semi cylindrical grooves, 7 and 9 , and securing it in place. Due to the fact that the distance between the vertical threaded holes 19 in the base 3 of the stem changes when the steer-tube clamp is tightened or loosened; at least one of the vertical through holes 17 in the cap 1 is in the form of a slot. This gives bolts B. 26 , attaching the cap 1 to the base 3 , sufficient space to move about, perpendicular to their axes, when the steer-tube clamp is tightened or loosened.
[0027] The cap 1 features a vertical hole for passing through it, brake-cable-housing 35 . The brake-cable-housing hole 15 in the cap 1 is positioned in such a way as to align with the widened section of the longitudinal slot 13 in the base 3 of the stem when assembled. This allows the brake-cable-housing 35 to be passed from the brake lever on the handlebar 29 through the top portion of the stem 2 through the steer tube 27 , and to the front brake which is attached to the front fork 31 of the bicycle.
[0028] It is realized that upon assembly and the tightening of bolts A. 25 the horizontal semi-cylindrical groove 7 will become distorted due to the resulting compression of wall 4 towards wall 6 . However, this distortion will not be sufficient to, upon further assembly, cause the handlebar 29 to become misaligned.
[0029] While the foregoing describes and illustrates particular embodiments of the invention, it is to be understood that many modifications may be made without departing from the spirit of the invention. I intend the following claims to cover any such modifications as fall within the true spirit and scope of the invention. | A bicycle handlebar stem specifically characterized, and distinct from other such stems in making it possible to attach the clamping surface of the handlebar in the center of the rotational axis of the steer tube. This stem, in union with a zero-degree-offset fork (already manufactured and popularly used) creates a front wheel/fork/stem/handlebar assembly; which is symmetrical in every respect. Such a symmetrical assembly being particularly dsirable in performing certain functions or tricks on stunt bicycles. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates in general to devices for maintaining materials at a desired temperature above ambient, and particularly for such devices as are used in the transportation and delivery of prepared pre-cooked food products.
[0003] 2. The Prior Art
[0004] Many methods and devices exist for the transportation of already-prepared “hot” food products. Some of these methods and devices rely simply on attempting to contain and prevent heat loss from the prepared food, through the use of insulated containers (e.g., Styrofoam “coolers”, insulated bags having metalized surfaces, vacuum bottles and containers using air gaps as insulation). Such unpowered systems eventually lose heat to their ambient surroundings, leading to loss of temperature in the prepared food products.
[0005] Other food product transportation systems may employ pre-heated elements installed in the walls of a container, such as pre-heated ceramic discs. However, these systems also will eventually lose heat, leading to heat loss in the food products.
[0006] Powered containers and systems exist for maintaining food at an elevated temperature; however, such powered systems tend to be too large in scale to be readily portable.
[0007] It would be desirable to provide an apparatus and system for transporting prepared “hot” food products, which does not suffer from continual heat loss, and which is readily portable.
SUMMARY OF THE INVENTION
[0008] The present invention comprises in part a food warmer. In an embodiment of the invention, the food warmer comprises a box having an internal cavity, an opening defined in a face thereof, and a movable cover cooperating with the opening, to enable access to the internal cavity. The box may include an outer shell; an innermost facing layer; an insulation layer disposed between at least portions of the outer shell and at least portions of the innermost facing layer; and a powered heating system disposed at least in part, along inwardly-facing surfaces of at least portions of the insulation layer.
[0009] The present invention also comprises a method for fabricating a food warmer, comprising the steps of:
[0010] providing a box, having an internal cavity, an opening defined in a face thereof, and a movable cover cooperating with the opening, to enable access to the internal cavity, the step of providing a box further including the steps of
[0011] forming an outer shell;
[0012] placing an insulation layer within the outer shell;
[0013] providing a powered heating system disposed at least in part, along inwardly-facing surfaces of at least portions of the insulation layer;
[0014] placing an innermost facing layer within the outer shell, so that the insulation layer is disposed between at least portions of the outer shell and at least portions of the inner facing layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a perspective view of a food warmer according to an embodiment of the invention.
[0016] FIG. 2 is a top view of the food warmer of FIG. 1 .
[0017] FIG. 3 is a front view of the food warmer of FIG. 1 .
[0018] FIG. 4 is a side elevation of the food warmer of FIG. 1 .
[0019] FIG. 5 is a top view of a heating element assembly, according to an embodiment of the invention.
[0020] FIG. 6 is a perspective exploded view thereof.
[0021] FIG. 7 is a front exploded view thereof.
[0022] FIG. 8 is an enlarged fragmentary sectional view, taken along line 8 - 8 of FIG. 4 .
[0023] FIG. 9 is a schematic illustration of the electrical circuitry for a food warmer according to an embodiment of the invention.
DETAILED DESCRIPTION
[0024] While this invention is susceptible of embodiment in many different forms, there is shown in the drawings, and described in detail herein, one embodiment, with the understanding that the present disclosure is to be considered an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated.
[0025] The following description and drawings are illustrative and are not to be construed as limiting. Numerous specific details are described to provide a thorough understanding of the disclosure. However, in certain instances, well-known or conventional details are not described in order to avoid obscuring the description. References to one or an embodiment in the present disclosure can be, but not necessarily are, references to the same embodiment; and, such references mean at least one of the embodiments.
[0026] FIGS. 1-4 illustrate a food warmer according to the principles of the present invention. Food warmer 20 includes a parallelepiped box 22 (or other three dimensional shape), having a hinged front wall 24 , and top wall 26 , bottom wall 28 , back wall 30 , and side walls 32 , 34 . Referring, by way of example, to FIG. 8 , which is an enlarged fragmentary sectional view of side wall 32 , taken along line 8 - 8 of FIG. 4 , each of the walls is preferably fabricated from a plastic or fabric (e.g., corrugated polypropylene, molded thermoplastic, canvas, nylon, etc) shell layer 40 for strength and light weight, with an innermost facing layer 42 being, in embodiments of the invention, a laminate of aluminum foil 44 and polyester film 46 . An insulation layer 48 of, e.g., polystyrene foam, preferably having a relatively high R value (e.g., R>4), is disposed between the outer shell layer 42 and the inner wall layer 44 , along all of the top, bottom, side and rear walls of box 22 , and may be disposed between the outer shell layer 42 and inner wall layer of the front wall of box 22 , to maximize containment of heat within food warmer 20 .
[0027] Hinged front wall 24 may be held in place in a closed position by any suitable method, such as by simple friction, small projections on the door mating with recesses in structure surrounding and defining front opening 23 of box 22 or by any suitable latching method, such as by magnetic catches, snaps and straps, mechanical latches (generally shown at 25 in FIG. 1 ), etc.
[0028] To provide the heating effect, a heating element 50 is placed between the insulation sheet 48 and the inner wall layer 44 . Heating element 50 , in embodiments of the invention, includes flattened carbon fiber strip 52 , and is wound around the interior of the warmer 20 , as suggested by the broken lines in FIG. 4 . Heating element 50 is provided, for most of its length with a protective and insulative cover for carbon fiber strip 52 , in the form of thermoplastic sleeve 53 . In an embodiment, the heating element may be as shown and described in U.S. Pat. No. 7,247,822 that is incorporated herein by reference. Power for heating element 50 is provided via car power outlet adapter 54 , connected to cord 56 . Cord 56 is electrically connected to heating element 50 by connection 58 , which is illustrated in detail in FIGS. 5-7 .
[0029] In an embodiment of the invention, suitably mounted, preferably vertical/linear carrying handles 36 may be mounted to the wire rack to bear the forces of the contents and protrude through the outer shell layer of top 26 . In an alternate embodiment, handles may be mounted to the outer shell with appropriate strain relief. Feet 38 (preferably rubber) may be provided in embodiments of the invention, to elevate food warmer 20 above any flat surfaces upon which food warmer 20 may be placed, to prevent marring thereof.
[0030] A metal rack 39 , having a plurality of shelves 41 , is provided. Preferably, rack 39 will be configured to support a substantial weight, e.g., on the order of 90 pounds.
[0031] Connection 58 , which interconnects cord 56 to heating element 50 , includes first connection element 60 and second connection element 62 . First connection element 60 includes one or more locator pins 64 (four in the illustrated embodiment of FIG. 6 ), as well as an array of fixation elements 66 or energy directors. Second connection element 62 includes one or more locator apertures 68 corresponding to the one or more locator pins 64 of first connection element 62 , as well as an array of fixation elements 70 , which correspond to and align with fixation elements 66 of first connection element 62 . Connection 50 is formed by placing an end of heating element 50 , in which carbon fiber strip 52 is exposed, between first and second connection elements 62 , 64 , respectively. An end of cord 56 , in which the insulation 72 has been removed to expose the conductor 74 , is positioned adjacent the exposed portion of carbon fiber strip 52 . Locator pin(s) 64 is/are aligned with locator aperture(s) 68 , and first and second connection elements 62 , 64 are pressed together, and exposed to sonic/ultrasonic waves of sufficient force, frequency and duration, to cause a number of fixation elements 66 and/or 70 to pass through carbon fiber strip 52 , and abut and fuse to one another, effectively welding first and second connection elements 62 , 64 together, and holding the exposed end of conductor 74 in tight electrical contact with the exposed portion of carbon fiber strip 52 .
[0032] FIG. 9 is a schematic illustration of the electrical circuitry 90 for warmer 20 . In an embodiment of the invention, V in =13.8 VDC (typical rated voltage for a motor vehicle interior power outlet), F 1 = 10 A (fuse typically located in a motor vehicle adapter 54 ) and R (representing a typical load for the heating element)=1.9 ohms. Thermostat 76 will be positioned in warmer 20 at a suitable location (which may be on the inner surface of innermost facing layer 42 , or between insulation layer 48 and innermost facing layer 42 ), and operably inserted electrically between adapter 54 and heating element 50 , so as to provide automatic control of the temperature within warmer 22 , to maintain warmer temperature 22 within a desired, predetermined temperature range. The numerical values provided in FIG. 9 are provided merely by way of example, and the invention is not intended to be limited thereof.
[0033] The walls of box 22 may be fabricated using suitable known fabrication methods, in order to ensure that no heat leakage spots are created, especially along the edges and corners where two or three walls meet. Fabrication of warmer 20 may be accomplished by first forming the outer shell 40 of box 22 . Heating element 50 is first attached to the insulation layer 48 . Then innermost facing layer is applied over this assembly. Next, this assembly is formed and placed within the outer shell 40 . Rack 39 (which in embodiments of the invention may be removable, e.g., for cleaning) will then be positioned in the inner cavity of box 22 .
[0034] As an alternative to hinged front wall 24 , a completely removable cover (not shown) may be provided, which can be inserted into (or placed over) front opening 23 , to enable controlled access to the interior of box 22 . Such a removable cover may still be fabricated in a manner similar to that of the rest of box 22 , having an outer shell layer, an inner facing layer, and an insulation layer therebetween. In more complex embodiments of the invention, heating elements may be provided in either hinged front wall 24 or in a removable cover, though additional power transmission cords would be required to connect such heating elements to the electrical circuitry in the rest of box 22 .
[0035] It is to be understood that the foregoing numerical values are provided simply by way of example, and that other embodiments of the invention may be provided with components having other numerical values, without departing from the scope of the invention.
[0036] Reference in this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but not other embodiments.
[0037] The terms used in this specification generally have their ordinary meanings in the art, within the context of the disclosure, and in the specific context where each term is used. Certain terms that are used to describe the disclosure are discussed above, or elsewhere in the specification, to provide additional guidance to the practitioner regarding the description of the disclosure. For convenience, certain terms may be highlighted, for example using italics and/or quotation marks. The use of highlighting has no influence on the scope and meaning of a term; the scope and meaning of a term is the same, in the same context, whether or not it is highlighted. It will be appreciated that same thing can be said in more than one way.
[0038] Consequently, alternative language and synonyms may be used for any one or more of the terms discussed herein, nor is any special significance to be placed upon whether or not a term is elaborated or discussed herein. Synonyms for certain terms are provided. A recital of one or more synonyms does not exclude the use of other synonyms. The use of examples anywhere in this specification including examples of any terms discussed herein is illustrative only, and in no way limits the scope and meaning of the disclosure or of any exemplified term. Likewise, the disclosure is not limited to various embodiments given in this specification.
[0039] Without intent to limit the scope of the disclosure, exemplary instruments, apparatus, methods and their related results according to the embodiments of the present disclosure are given below. Note that titles or subtitles may be used in the examples for convenience of a reader, which in no way should limit the scope of the invention. Moreover, certain theories may be proposed and disclosed herein; however, in no way, whether they are right or wrong, should they limit the scope of the disclosure so long as the disclosure is practiced according to the disclosure without regard for any particular theory or scheme of action
[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. In the case of conflict, the present document, including definitions will control.
[0041] The term “proximate” shall mean at or near the object being modified by the term “proximate”. Any numerical values provided herein are given by way of example and the scope of the claimed invention is not intended to be limited in any way thereby.
[0042] The foregoing description and drawings merely explain and illustrate the invention, and the invention is not limited thereto, except as those skilled in the art who have the present disclosure before them will be able to make modifications and variations therein without departing from the scope of the invention. | A portable food warmer is provided with a powered heating element, includes an enclosure, formed from an outer shell and an inner layer, with the powered heating element positioned between the outer shell and the inner layer. A steel rack is provided to support food items contained therein. The powered heating element preferably is in the form of a carbon fiber ribbon, wrapped around the enclosure, between the outer shell and inner layer. | 8 |
RELATED PATENTS AND PATENT APPLICATIONS
[0001] The present application is a continuation of U.S. patent application Ser. No. 14/696,449, now U.S. Pat. No. 9,410,530, which is a continuation of U.S. patent application Ser. No. 14/107,951, which is pending, which is a continuation of U.S. patent application Ser. No. 13/607,270, now U.S. Pat. No. 8,608,426, which is a continuation of U.S. patent application Ser. No. 12/215,232, abandoned; and is co-pending with U.S. patent application Ser. No. 15/224,721, which is pending, which is a continuation of U.S. patent application Ser. No. 14/691,695, now U.S. Pat. No. 9,404,475, which is a continuation of U.S. patent application Ser. No. 14/107,922, now U.S. Pat. No. 9,133,821, which is a continuation of U.S. patent application Ser. No. 13/607,167, which is a continuation of U.S. patent application Ser. No. 12/215,232, abandoned, the disclosures of which are incorporated herein by reference.
FIELD OF INVENTION
[0002] The field of invention relates to a system for channeling wind to one or more wind turbines in order to increase the productivity of the wind turbines.
BACKGROUND OF THE INVENTION
[0003] Wind turbines harness the kinetic energy of the wind and convert it into mechanical or electric power. Traditional wind turbines have a horizontal spinning axis that allowed blades of the wind turbine to rotate around the axis. As wind engages the blades, the blades move around the horizontal spinning axis of the wind turbine. The relative rotation of the blades to the horizontal axis may then be converted into energy.
[0004] Wind turbines only capture wind that engages the blades. Thus, only the wind directly passing in line with the wind turbine is converted into energy.
SUMMARY OF THE INVENTION
[0005] In the method of this invention, the force of wind acting on a wind turbine is increased thereby increasing the resulting energy output of the wind turbine. This method is achieved by positioning one or more wind compressors proximate a first side of a wind turbine and one or more wind compressors proximate the second side of the wind turbine, where the second side is distal from the first side. The wind compressors comprise an obstruction configured to redirect a wind flow from each of the wind compressors toward the wind turbine. The one or more wind compressors should be arranged proximate to the wind turbine in a configuration that creates a Venturi effect on the wind flow aimed at the wind compressors so that the redirected wind flows converge toward the wind turbine at an increased velocity and force.
[0006] The wind directing system of this invention comprises one or more wind compressors which are proximate to a first side of the wind turbine and one or more wind compressors which are proximate a second side of the wind turbine. The second side is distal from the first side. Each of the wind turbines of this invention comprise an obstruction which is configured to redirect wind flow from each of the wind compressors toward the wind turbines so that the converged wind flow creates a Venturi effect. The redirected wind flow has an increased velocity and force. The system also comprises a plurality of transporters with one or more wind compressors coupled to at least one transporter. The transporters are configured to move at least one wind compressor to a location that maximizes the force of the wind encountered by the wind compressor and directed by the wind compressor to the wind turbine.
[0007] In one embodiment, the wind compressor system for directing wind toward one or more wind turbines of this invention comprises one or more riggings with a sail coupled to each one which is configured to engage and redirect the wind so that the wind converges toward the one or more wind turbines in a Venturi effect. A transporter is also coupled to the riggings and is configured to maintain a first location of the sail while the sail redirects wind toward the one or more wind turbines. The system also comprises a controller which is configured to move the transporter to a second location in response to a change in the wind direction.
[0008] This invention also entails a wind powered generator system for generating electrical power from wind power which comprises a vertical turbine rotor, a vertical turbine support, and one or more blades coupled to the turbine rotor which are configured to move the turbine rotor relative to the turbine support. One or magnet sets are located between the turbine support and the turbine rotor. There is also a space between a portion of the turbine rotor and the turbine support, where the space is created by the magnetic force from the one or more magnet sets. One or more generators are configured to generate electric power from the rotating movement of the turbine rotor. The one or more wind compressors are proximate to a first side of the turbine support and one or more compressors are also proximate to a second side of the turbine support, where the second side is distal from the first side. Each of the wind compressors have an obstruction which is configured to redirect wind flow from each of the wind compressors toward the turbine rotors so that the converged wind flow from the wind compressors creates a Venturi effect. The converged wind flow results in an increased velocity and wind force on the turbine rotors.
[0009] The method of this invention for generating electricity comprises attaching a set of dipolar magnets to a turbine rotor and a turbine support. In one aspect, the magnets are located between the turbine rotor and the turbine support, creating an opposing magnetic force that reduces friction and creates a space between the turbine rotor and the turbine support. As one or more blades engage with wind, the vertical turbine rotor is rotated relative to the turbine support. A generator converts the mechanical energy of the moving vertical turbine into electric power. One or more wind compressors are proximate to a first side of a turbine support and to a second side of the turbine support where the second side is distal from the first side. The wind compressors comprise an obstruction configured to redirect wind flow from each of the wind compressors towards the turbine rotor. The wind compressors proximate to the turbine support create a Venturi effect on the wind flow aimed at the wind compressors so that the redirected wind flow converges toward the turbine rotor at an increased velocity and force. The mechanical energy of the moving turbine rotor is converted into electric power by the use of a generator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] While the specification concludes with claims particularly pointing out and distinctly claiming the subject matter that is regarded as forming the present invention, it is believed that the invention will be better understood from the following description taken in conjunction with the accompanying DRAWINGS, where like reference numerals designate like structural and other elements, in which:
[0011] FIG. 1A is a schematic cross-sectional view of a wind turbine according to one embodiment of the present invention;
[0012] FIG. 1B is a schematic top view of a wind turbine according to one embodiment of the present invention;
[0013] FIG. 2 is a schematic cross-sectional view of a wind turbine according to one embodiment of the present invention;
[0014] FIG. 3 is a schematic side view of a wind turbine according to one embodiment of the present invention;
[0015] FIG. 4 is a schematic top view of a wind turbine with wind compressors according to one embodiment of the present invention;
[0016] FIG. 5 is a schematic top view of wind turbines with wind compressors according to one embodiment of the present invention;
[0017] FIG. 6 is a front view of a wind compressor according to one embodiment of the present invention; and
[0018] FIG. 7 is a side view of a wind compressor according to one embodiment of the present invention.
DETAILED DESCRIPTION
[0019] The following detailed description is presented to enable any person skilled in the art to make and use the invention. For purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the present invention. However, it will be apparent to one skilled in the art that these specific details are not required to practice the invention. Descriptions of specific applications are provided only as representative examples. Various modifications to the preferred embodiments will be readily apparent to one skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the scope of the invention. The present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest possible scope consistent with the principles and features disclosed herein.
[0020] FIG. 1A is a schematic cross sectional view of a wind turbine 100 , according to one embodiment. The wind turbine 100 , as shown, is a vertical axis wind turbine. Therefore, a core axis 102 of the wind turbine 100 is substantially in a vertical plane relative to the Earth. The wind turbine 100 may have a turbine rotor 104 and a turbine support 106 within and concentric to the turbine rotor 104 . The turbine rotor 104 rotates around the core axis 102 of the turbine support 106 in response to wind engaging one or more blades 108 , shown schematically. The kinetic energy from the wind is captured by the blades 108 thereby rotating the turbine rotor 104 . The turbine core support 106 may remain stationary as the turbine rotor 104 rotates around the axis 102 . In order to reduce the effects of friction between the rotating turbine rotor 104 and the turbine support 106 , one or more sets of magnets 110 are used to reduce the weight force of the turbine rotor 104 acting on the turbine support 106 . A generator 112 may be located proximate the wind turbine 100 in order to convert the mechanical energy of the rotating turbine rotor 104 into electric power.
[0021] The turbine rotor 104 , as shown in FIG. 1A , comprises a central axis 113 that is substantially centered around the axis 102 . The turbine rotor 104 , may include a top 114 and a bottom 116 extending out from the central axis 113 . As shown, the central axis 113 supports the top 114 and the bottom 116 . The top 114 and/or the bottom 116 , as shown, extends radially away from the central axis 113 . In FIG. 1B a top view of the wind turbine 100 is shown. The top view shows the top 114 extending a first radius R 1 away from the axis 102 . The bottom 116 may extend the same distance as the top 114 from the axis 102 ; however, it should be appreciated that the distance the top 114 and bottom 116 extend from the axis 102 may vary depending on design conditions. The top 114 , as shown in FIGS. 1A and 1B , extends over the top of a support shaft 118 of the turbine support 106 ; however, it should be appreciated that other suitable configurations for the top 114 may be used.
[0022] The turbine rotor 104 may have alternative designs to the one shown in FIG. 1 . For example, the turbine rotor 104 may not cover the top of the support shaft 118 , as shown in FIG. 2 . Further, the turbine rotor 104 may simply include the top 114 and the bottom 116 and be held together by the blades 108 . Further still, the top 114 and/or the bottom 116 may not be shaped in a circular pattern, but instead may extend as supports over each of the blades 108 in an effort to save money on materials and reduce the weight of the turbine rotor 104 . The turbine rotor 104 may have any suitable design capable of supporting the blades 108 and rotating around the axis 102 .
[0023] The bottom 116 of the turbine rotor 104 may include one or more of the magnets 110 . The one or more magnets 110 located in the bottom 116 of the turbine rotor 104 provide an opposing force against one or more magnets 110 located on the turbine support 106 . The opposing force created by the one or more magnets 110 reduces the weight load of the turbine rotor 104 on the turbine support 106 , as will be discussed in more detail below.
[0024] The turbine support 106 may be any suitable shape capable of supporting the weight of the turbine rotor 104 and stabilizing the turbine rotor 104 as it rotates about the axis 102 . The turbine support 106 , as shown in FIG. 1A , includes a base 120 and the support shaft 118 . The base 120 may rest under the bottom 116 of the turbine rotor 104 . The base 120 typically acts as a support between a surface 124 , such as the ground or bed rock, and the turbine rotor 104 . The base 120 may include a platform 122 adjacent the turbine rotor 104 and a bottom member 123 adjacent the surface 124 . The base 120 may be any suitable shape so long as the base is capable of supporting the weight of the turbine rotor 104 .
[0025] The surface 124 , as shown in FIG. 1A , is the ground; however, it should be appreciated that the surface 124 may be any suitable surface for supporting the base 120 including, but not limited to, a trailer, a boat, a rail car as illustrated in FIG. 3 , a top of a building, a top of a parking garage, a top of a stadium, and the like.
[0026] The platform 122 typically provides the support for the wright of the turbine rotor 104 . The platform 122 may include one or more magnets 110 B which provide an opposing force against the one or more magnets 110 A located on the bottom 116 of the turbine rotor 104 , as will be described in more detail below. The base 120 and/or the platform 122 may extend the same radial distance from the axis 102 as the turbine rotor 104 . Alternatively, the base 120 may extend a shorter radial distance from the axis 102 than the turbine rotor 104 , or, in another alternative embodiment, may extend a longer radial distance from the axis 102 than the turbine rotor 104 . It should be appreciated that the platform 122 may be any suitable shape capable of providing a vertical support surface for the turbine rotor 104 .
[0027] The support shaft 118 of the turbine support 106 may provide for stabilization of the turbine rotor 104 . The support shaft 118 , as shown in FIGS. 1A and 1B is located radially inside the central axis 113 of the turbine rotor 104 . FIG. 1A shows the support shaft 118 as a substantially solid shaft which is slightly smaller than the interior of the central axis 113 of the turbine rotor 104 . Alternatively, as shown in FIG. 2 , the support shaft 118 may define an opening that allows for an interior access way 202 . The support shaft 118 allows the turbine rotor 104 to rotate in response to the wind while preventing the turbine rotor 104 from moving substantially in the direction perpendicular to the core axis 102 . The support shaft 118 may include one or more magnets 110 C which provide an opposing force against one or more magnets 110 D located on the central axis 113 of the turbine rotor 104 . The magnet 110 C located on the support shaft 118 may act to stabilize the turbine rotor as will be discussed in more detail below.
[0028] The wind turbine 100 may include a connector 126 , shown schematically in FIGS. 1A and 3 . The connector 126 may secure the turbine rotor 104 to the turbine support 106 while allowing the turbine rotor 104 to rotate. FIG. 1A shows the connector 126 as a pin type connection which is secured to the support shaft 118 and penetrates an opening in the top 114 of the turbine rotor 104 . A head of the pin may rest on the top 114 of the turbine rotor 104 . The opening may be large enough to not engage the pin as the turbine rotor 104 rotates about the turbine support 106 . The head may simply provide an upward travel limit for the turbine rotor 104 . Thus, typically the turbine rotor 104 may not engage the connector 126 ; however, in the event that the turbine rotor 104 lifts off of the turbine support 106 , the head will stop it from becoming detached from the wind turbine 100 . It should be appreciated that any suitable arrangement for securing the turbine rotor 104 to the turbine support 106 may be used.
[0029] The one or more sets of magnets 110 C, 110 D reduce friction between the turbine support 104 and the turbine rotor 106 by creating a space between the turbine support 104 and the turbine rotor 106 . The magnets replace the role of roller bearings in prior wind turbines. The one or more magnets 110 A, 110 B positioned on the bottom 116 of the turbine rotor 104 and the platform 122 of the turbine support may include one or more levitation magnets and one or more stabilization magnets. The levitation magnets supply an opposing force between the bottom 116 of the turbine rotor 104 and the platform 122 . The opposing force created by the levitation magnets may create a force on the turbine rotor 104 substantially opposite to a gravitational force on the turbine rotor 104 . The levitation magnets can provide a large enough opposing force to lift the turbine rotor 104 off of the platform 122 thereby eliminating friction between the platform 122 and the turbine rotor 104 . Specifically, a space may be created between the platform 122 and the bottom 116 of the turbine rotor 104 as a result of the opposing force. Alternatively, the opposing force created by the levitation magnets may only negate a portion of the gravitational force, so that the friction force between the platform 122 and the turbine rotor 104 is reduced.
[0030] The stabilization magnets 110 D, 110 C, as shown in FIG. 1A , are designed to provide an opposing force between the central axis 113 and the support shaft 118 . The stabilization magnets may be located directly on the interior of the central axis 113 and the exterior of the support shaft 118 . The stabilization magnets may maintain a space between the inner diameter of the central axis 113 and the outer diameter of the support shaft 118 . Therefore, during rotation of the turbine rotor 104 there may be no friction between the central axis 113 of the turbine rotor 104 and the support shaft 118 . It should be appreciated that other means of reducing the friction between central axis 113 and the support shaft 118 may be used including, but not limited to, a bearing.
[0031] Friction may be eliminated between the turbine rotor 104 and the turbine support 106 using both the levitation magnets and stabilization magnets. The one or more sets of magnets 110 may be any magnets suitable for creating an opposing force including but not limited to a permanent magnet, an electromagnet, permanent rare earth magnet, ferromagnetic materials, permanent magnet materials, magnet wires and the like. A permanent rare earth magnet may include samarium cobalt (SmCo) and/or neodymium (NdFEB). Further, the one or more magnets 110 may be arranged in any suitable manner so long as they reduce the friction between the turbine rotor 104 and the turbine support 106 . FIGS. 1A, 2, and 3 show the one or more sets of magnets 110 as a series of permanent magnets spaced apart from one another; however, it should be appreciated that an electromagnet may be used in order to magnetize a portion of the turbine rotor 104 and the turbine support 106 . Further, in an alternative embodiment, a portion of the turbine rotor 104 and the turbine support 106 may be magnetized to provide the opposing force. Thus in an alternative embodiment, the entire platform 122 and/or base 120 may be magnetized to provide an opposing force on the bottom 116 of the turbine rotor 104 which may also be magnetized.
[0032] The blades 108 may be any suitable blade capable of converting the kinetic energy of the wind into mechanical energy. In one embodiment, the blades 108 are made from a thin metal material, however, it should be appreciated that blades may be any suitable material including, but not limited to, a poly-carbon, a fabric, a synthetic material.
[0033] The blades 108 may be fixed to the turbine rotor 104 in a static position. Alternatively, the blades 108 may be moveably attached to the turbine rotor 104 . For example, a connection between the blades 108 and the turbine rotor 104 may allow the angle of the blades 108 to adjust in relation to the turbine rotor 104 . The angle may adjust manually or automatically in response to the wind conditions at the location.
[0034] The turbine rotor 104 provides mechanical energy for the one or more generators 112 as the turbine rotor 104 rotates about the axis 102 . In one embodiment, a generator gear 128 is moved by a portion of the turbine rotor 104 as the turbine rotor 104 rotates. As shown in FIG. 1A , an outer edge 130 of the gear 128 may be proximate an edge of the turbine rotor 104 . In one embodiment, the gear 128 engages the turbine rotor 104 with a traditional gear and/or transmission device capable of transferring rotation to the gear 128 .
[0035] In an additional or alternative embodiment, the gear 128 may be a magnetic gear. The magnetic gear is a gear that moves in response to a magnetic force between the turbine rotor 104 and the magnetic gear. At least one of the gear 128 and/or the proximate portion of the turbine rotor 104 may be magnetized. Thus, as the turbine rotor 104 rotates proximate the gear 128 the magnetic force moves the gear 128 in response to the turbine rotor 104 rotation. The magnetic gear allows the turbine rotor 104 to rotate the gear 128 without any friction between the two components.
[0036] FIG. 3 shows the magnetic gear according to one embodiment. A rotor gear component 300 may protrude from the outer surface of the turbine rotor 104 . The rotor gear component 300 may extend beyond the outer diameter of the turbine rotor 103 and rotate with the turbine rotor 104 . As shown, the rotor gear component 300 is a plate extending around an outer diameter of the turbine rotor 104 ; however, it should be appreciated that any suitable configuration for the rotor gear component 300 may be used. The gear 128 may include one or more gear wheels 302 which extend from the gear to a location proximate the rotor gear component 300 . As shown in FIG. 3 , there are two gear wheels 302 which are located above and below a portion of the rotor gear component 300 . As the turbine rotor 104 rotates, the rotor gear component 300 rotates. A portion of the rotor gear component 300 may pass in between two portions of one or more gear wheels 302 . Any of the rotor gear component 300 , and the one or more gear wheels 302 may be magnetized. The type of magnet used to produce the magnetic force for the magnetic gear may be any magnet described herein. The magnetic force between the components of the magnetic gear move the gear 128 , thereby generating electricity and/or power in the generator 112 .
[0037] The generators 112 may be located at various locations proximate the turbine rotor 104 . FIG. 1B shows three generators 112 located around the perimeter of the turbine rotor 104 . It should be appreciated that any suitable number of generators 112 may be used around the perimeter of the turbine rotor 104 . Further, the generator 112 may be located at other locations proximate the turbine rotor including, but not limited to, proximate the shaft 102 of the turbine rotor, in line with the axis 102 above and/or below the turbine rotor 104 , and the like.
[0038] The generator 112 may be any suitable generator for converting mechanical energy into power including, but not limited to, electric generators, motors, linear generators, and the like.
[0039] In one embodiment, one or more of the generators 112 is a linear synchronous motor (LSM). The LSM motor may advance the turbine support 120 and may double as a braking system.
[0040] The power generated by the generator may be fed directly to a power grid.
[0041] Further, it should be appreciated that the power may alternatively or additionally be used on site or stored. The stored power may be used at a later date when demand for the power is higher. Examples of power storage units include, but are not limited to, batteries and generating stored compressed air, a flywheel system, a magnetically levitated flywheel system, hydraulic accumulators, capacitors, super capacitors, a combination thereof, and the like.
[0042] The one or more magnets 110 reduce and potentially eliminate friction between the turbine rotor 104 and the turbine support 106 . This friction reduction allows the scale of the wind turbine 100 to be much larger than a conventional wind turbine. In a conventional wind turbine the larger the wind turbine, the more friction is created between the moving parts. The amount of friction eventually limits the effective size of a conventional wind turbine. In one example, the wind turbine may have an outer diameter of 1000 ft. In a preferred embodiment, a fixed wind turbine 200 , as shown in FIG. 2 , has an outer diameter of about 600 ft. and is capable of producing more than 1 GWh of power. A smaller portable wind turbine 304 , shown in FIG. 3 , may be adapted to transport to remote locations. The portable version may have a diameter of greater than 15 ft. and a height of greater than 15 ft. In a preferred embodiment, the portable version has an outer diameter of about 30 ft. and a height of about 25 ft. and is capable of producing 50 MWh of power. It should be appreciated that the size and scale of the wind turbine may vary depending on a customers need. Further, it should be appreciated that more than one wind turbine may be located on the same portable transports system, and/or at one fixed location.
[0043] Although, the overall size of the wind turbine 100 may be much larger than a traditional wind turbine, the amount of power one wind turbine 100 produces is much larger than a traditional wind turbine. Therefore, the total land use required for the wind turbine 100 may be reduced over that required for a traditional wind farm.
[0044] The embodiment shown in FIG. 2 shows the fixed wind turbine 200 , according to one embodiment. The fixed wind turbine 200 may have a turbine support 106 which extends over the turbine rotor 104 . The one or more magnets 110 may be on an upper portion 201 of the turbine support 106 in addition to the locations described above.
[0045] The fixed wind turbine 200 may include an interior access way 202 , according to one embodiment. It should be appreciated that any of the wind turbines 100 , 200 and 304 may include an interior access way 202 . The interior access way 202 allows a person to access the interior of the turbine support 106 . The interior access way 202 may extend above and/or below the turbine rotor 104 in order to give the person access to various locations in the fixed wind turbine 200 . The interior access way 202 may allow a person to perform maintenance on the magnets 110 and other components of the wind turbine 100 , 200 , and 304 . Further, the interior access way 202 may have a means for transporting persons up and down the interior access way 202 . The means for transporting persons may be any suitable item including, but not limited to, an elevator, a cable elevator, a hydraulic elevator, a magnetic elevator, a stair, a spiral staircase, an escalator, a ladder, a rope, a fireman pole, a spiral elevator, and the like. The spiral elevator is an elevator that transports one or more persons up and down the interior access way 202 in a spiral fashion around the interior of the interior access way 202 . For example, the spiral elevator may travel in a similar path to a spiral staircase. The elevator and/or spiral elevator may use magnetic levitation to lift the elevator up and down.
[0046] The upper portion 201 of the turbine support 106 may include an observation deck 204 . The observation deck 204 may extend around the perimeter of the wind turbine 100 , 200 and/or 304 , thereby allowing a person to view the surrounding area from the observation deck 204 . The observation deck 204 may also serve as a location for an operator to control various features of the wind turbine, as will be discussed in more detail below.
[0047] The upper portion 201 of the turbine support 106 may further include a helipad 206 . The helipad 202 allows persons to fly to the wind turbine 100 , 200 , and/or 304 and land a helicopter (not shown) directly on the wind turbine. This may be particularly useful in remote locations, or locations with limited access including, but not limited to, the ocean, a lake, a industrial area, a tundra, a desert, and the like.
[0048] The upper portion 201 of the turbine support 106 may further have one or more cranes 208 . The cranes 208 allow an operator to lift heavy equipment. The crane 208 may be a tandem crane capable of rotating around the diameter of the wind turbine. The crane may assist in the construction of the wind turbine 100 .
[0049] FIG. 4 shows a top view of the wind turbine 100 in conjunction with one or more wind compressors 400 . The wind compressors 400 are each an obstruction configured to channel the wind toward the wind turbine 100 . As illustrated in FIG. 5 , a wind compressor 400 is positioned on either side of the wind turbine 500 so as to redirect the flow of wind towards the wind turbine 500 . The wind compressor 400 funnels the wind 506 into the wind turbine 500 . The convergence of the winds towards the wind turbine 500 creates a Venturi effect thereby increasing the speed and force of the winds upon the wind turbine 500 . This Venturi effect on the wind turbines increases the rpms or rotation speed of the rotors which translates into increased electrical energy produced by the generators 112 ( FIG. 1A ). This increase in wind energy and force upon the turbine blades 108 is thus translated from the wind turbine 500 to the generator 112 resulting in an increased output of electricity. This invention 400 increases the efficiency and ultimate output of the wind turbine 100 , 500 up to, beyond 1000-2000 megawatts (MGW) per hour or 1 gigawatt (GW) per hour. Known wind turbines produce between 2-4 MGW/hour.
[0050] The wind compressor 400 may be any suitable obstruction capable of re-channeling the natural flow of wind towards the wind turbines 100 , 400 . Suitable wind compressors include, but are not limited to, a sail, a railroad car, a trailer truck body, a structure, and the like. Structurally the obstructions comprise a shape and size to capture and redirect a body of wind towards the wind turbine. In one embodiment an obstruction such as a sail, which comprises a large area in two dimensions but is basically a flat object, must be anchored to avoid displacement by the force of the wind. Other obstructions, such as the rail road car or trailer truck, should have enough weight to avoid wind displacement.
[0051] Each of the wind compressors 400 may be moveably coupled to a transporter 403 , or transport device to move the compressor 400 to a location or position that captures the wind flow as the direction of wind changes and directs the wind flow towards the wind turbine. The transporter may be any suitable transporter 403 capable of moving the wind compressor 400 including, but not limited to, a locomotive to move a rail car, an automobile, a truck, a trailer, a boat, a Sino trailer, a heavy duty self-propelled modular transporter 403 and the like. Each of the transporters 403 may include an engine or motor capable of propelling the transporter 403 . The location of each of the wind compressors 400 may be adjusted to suit the prevailing wind pattern at a particular location. Further, the location of the wind compressors 400 may be automatically and/or manually changed to suit shifts in the wind direction. To that end, the transporter 403 may include a drive member for moving the transporter 403 . The transporter 403 may be in communication with a controller, for manipulating the location of each of the transporters 403 in response to the wind direction. A separate controller may be located within each of the transporters 403 .
[0052] One or more pathways 402 , shown in FIG. 4 , may guide transporters 403 as they carry the wind compressors 400 to a new location around the wind turbine 100 . The one or more pathways 402 may be any suitable pathway for guiding the transporters including, but not limited to, a railroad, a monorail, a roadway, a waterway, and the like. As shown in FIG. 4 , the one or more pathways 402 are a series of increasingly larger circles which extend around the entire wind turbine 100 . It should be appreciated that any suitable configuration for the pathways 402 may be used. As described above, the size of the wind turbine 100 may be greatly increased due to the minimized friction between the turbine rotor 104 and the turbine support 106 . Thus, the pathways 402 may encompass a large area around the wind turbine 100 . The wind compressors 400 as a group may extend out any distance from the wind turbine 100 , only limited by the land use in the area. Thus, a large area of wind may be channeled directly toward the wind turbine 100 thereby increasing the amount of wind engaging the blades 108 .
[0053] In one aspect of this invention, the controller may be a single controller 404 capable of controlling each of the transporters 403 from an onsite or remote location. The controller(s) 404 may be in wired or wireless communication with the transporters 403 . The controller(s) 404 may initiate an actuator thereby controlling the engine, motor or drive member of the transporter 403 . The controller(s) may comprise a central processing unit (CPU), support circuits and memory. The CPU may comprise a general processing computer, microprocessor, or digital signal processor of a type that is used for signal processing. The support circuits may comprise well known circuits such as cache, clock circuits, power supplies, input/output circuits, and the like. The memory may comprise read only memory, random access memory, disk drive memory, removable storage and other forms of digital memory in various combinations. The memory stores control software and signal processing software. The control software is generally used to provide control of the systems of the wind turbine including the location of the transporters 403 , the blade direction, the amount of power being stored versus sent to the power grid, and the like. The processor may be capable of calculating the optimal location of each of the wind compressors based on data from the sensors.
[0054] One or more sensors 310 , shown in FIGS. 3 and 5 , may be located on the wind turbines 100 , 200 , 304 and/or 500 and/or in the area surrounding the wind turbines. The sensors 310 may detect the current wind direction and/or strength and send the information to a controller 312 . The sensors 310 may also detect the speed of rotation of the turbine rotor 104 . The controller 312 may receive information regarding any of the components and/or sensors associated with the wind turbines. The controller 312 may then send instructions to various components of the wind turbines, the wind compressors and/or the generators in order to optimize the efficiency of the wind turbines. The controller 312 may be located inside the base of the tower, at the concrete foundation, a remote location, or in the control room at the top of the tower.
[0055] It should be appreciated that the wind compressors may be used in conjunction with any number and type of wind turbine, or wind farms. For example, the wind compressors 400 may be used with one or more horizontal wind turbines, traditional vertical wind turbines, the wind turbines described herein and any combination thereof.
[0056] FIG. 5 shows a schematic top view of two wind compressors 400 used in conjunction with multiple wind turbines 500 . The wind compressors 400 are located on two sides of the wind turbines 500 . The wind turbines 500 represent any wind turbine described herein. The wind compressors 400 engage wind 504 which would typically pass and not affect the wind turbines 500 . The wind 504 engages the wind compressors 400 and is redirected as a directed wind 506 . The directed wind 506 leaves the wind compressor 400 at a location that optimally affects at least one or the wind turbines 500 . The wind compressors 400 may shield a portion of the wind turbines 500 from an engaging wind 508 in order to increase the affect of the wind on the wind turbines 500 .
[0057] The engaging wind 508 is the wind that would directly engage the wind turbines 500 . For example, the wind compressors 400 shown in FIG. 5 shield a portion 509 of a vertical wind turbine which would be moving in the opposite direction to the wind 504 . The redirected wind 506 and the engaging wind 506 then engage an upstream side 510 of each of the wind turbines 500 . This arrangement may greatly increase the effectiveness of the wind turbines 500 .
[0058] Although the wind compressors 400 are shown on each side of the wind turbines 500 , it should be appreciated that any arrangement that increases the productivity of the wind turbine 500 may be used.
[0059] FIG. 6 shows a front view of the wind compressor 400 according to one embodiment. The transporter supporting the wind compressor is shown as a trailer 600 . The trailer supports a rigging 602 . The rigging 602 supports a sail 604 . FIG. 7 shows a side view of the wind compressor 400 , according to one embodiment. The sail 604 is full blown and shown in a mode of the wind engaging the sail 604 .
[0060] The rigging 602 , as shown in FIGS. 6 and 7 includes multiple poles extending in a substantially vertical direction from the transporter. The multiple poles are configured to couple to the sail 604 . The poles may couple to the sail 604 proximate two sides of the sail 604 . In one embodiment, two poles may be spaced apart from one another in order to allow the sail to extend a large distance between the poles. As shown, the poles vary in height; however, it should be appreciated that any arrangement of the poles may be used. Further, the rigging may be any suitable structure capable of supporting the sail 604 .
[0061] The sail 604 is any suitable surface intended to deflect wind. As shown, the sail is a flexible material held by the rigging. The flexible material may be any flexible material including, but not limited to, a canvass, a cloth, a polycarbon, a metal, a glued and molded sail, a mylar, and the like. Further, the sail may be a solid non-flexible material which deflects wind that engages the sail. The non-flexible material may not require the rigging.
[0062] Preferred methods and apparatus for practicing the present invention have been described. It will be understood and readily apparent to the skilled artisan that many changes and modifications may be made to the above-described embodiments without departing from the spirit and the scope of the present invention. The foregoing is illustrative only and that other embodiments of the integrated processes and apparatus may be employed without departing from the true scope of the invention defined in the following claims. | A wind compressor system having one or more wind turbines and a plurality of wind compressors located proximate the one or more wind turbines. The wind compressors optimize the energy created by the wind turbines by redirecting and converging the wind from the wind compressor to the wind turbines. Each of the wind compressors comprises an obstruction having a size and shape adapted to converge the wind currents by means of a Venturi effect toward the one or more turbines thereby increasing the velocity and force of the wind hitting the wind turbine. A plurality of transporters coupled to the wind compressors. The transporters configured to move at least one wind compressors to a location that maximizes the force of the wind encountered by the turbine. | 5 |
BACKGROUND OF THE INVENTION
(A) Field of the Invention
The present invention relates to an endoscope arranged to be able to perform a three-dimensional measurement by utilizing Moire topography.
(B) Description of the Prior Art
In case Moire topography is performed, it is in general necessary to provide a lattice for both the illumination optical system and the observation optical system. When it is intended to make an ordinary topographic observation by using these same optical systems, such a lattice hinders the observation. Especially, in case of a small-sized optical instrument such as endoscope, it is practically impossible to detachably mount a lattice within the foremost end portion of the instrument, and thus the prior known endoscope have the drawback that, for performing a Moire topography and an ordinary endoscopic observation, two separate endoscopic instruments (each being designed for a different specific purpose) have to be used. Also, there has been placed on the market an endoscopic instrument in which the lattice for observation optical system is omitted because the image of an object is scanned by using a photomultiplier. In such an instrument, it has been impossible to house a photomultiplier within the small space at the foremost end portion of the instrument because the size thereof is too large.
SUMMARY OF THE INVENTION
It is, therefore, the primary object of the present invention to provide an endoscope which allows measurements including three-dimensional measurement by Moire topography without the use of a special lattice and without affecting ordinary endoscopic observation in any way.
This object is achieved according to the present invention by the arrangement comprising: an illumination light supply consisting of a plurality of fine illuminating members which are disposed regularly; illumination optical system for projecting the beam of light of said light supply onto an object under study; a focusing optical system for forming the image of the object; image pickup means consisting of a plurality of picture elements regularly disposed at the position of the object image formed by the focusing optical system; and controlling means for controlling the illumination of the respective fine illuminating members to insure that the illumination light supply will illuminate in the form of lattice so that, by this lattice-form illumination given by the illumination light supply, there are performed measurements of the object including a three-dimensional measurement thereof.
According to a preferred formation of the present invention, the illumination light supply comprises a light guide which is formed by placing together a large number of optical fibers into a bundle and whose light-incidence end is bifurcated into two portions. It should be noted that those optical fibers in these two light-incidence end portions are arranged, at the single light-emission end of this light guide, in such a pattern that the optical fibers in one of the incidence end portion and those in the other incidence end portion Between the light supply and the light-incidence ends of the light guide, there is provided a rotary filter having a red light transmitting sector, a green light transmitting sector, a blue light transmitting sector and an infrared light transmitting sector. The infrared light transmitting sector is constructed so as to insure that the infrared light beam impinges onto only one of the two light-incidence ends of the light guide whereby allowing the illumination light supply to emit light with a lattice pattern.
According to another preferred formation of the present invention, the illumination light supply is constructed as an array of successively arranged LEDs emitting a red light, a green light, a blue light and an infrared light, respectively.
According to still another preferred formation of the present invention, one of the two light-incedince end portions of the light guide is covered with an infrared light cutting filter, and an incandescent light is used as the light supply. In this case, striped filters for separating colors are provided in the foreground of the image pickup device.
According to the present invention, it will be noted that, at the time of an ordinary endoscopic observation, it is possible to perform a three-dimansional measurement of an object under observation by Moire topography without providing any visually obstructive lattice. It is also possible to indicate on a color display a compound image consisting of the image of the object under examination and a contour image formed by Moire fringes superposed on the image of the object. Thus, it is possible to present, with an improved reality, the concavo-convex, i.e. uneven, pattern of the surface of the object under observation. Moreover, the system as a whole can be constructed in a compact size, so that the resulting endoscopic instrument can be used very conveniently.
These and other objects of the present invention will become more apparent during the course of the following description and appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic general illustration of an embodiment of the endoscope according to the present invention.
FIG. 2 is a diagrammatic detailed illustration of a light guide employed in the embodiment of FIG. 1.
FIG. 3 is a diagrammatic front view of a rotary filter of FIG. 1.
FIGS. 4 and 5 are illustrations for explaining the principle for allowing the observer to know the unevenness of the surface of an object by utilizing Moire fringes.
FIG. 6 is a diagrammatic illustration showing the unevenness of the surface of an object which is to be shown on the display.
FIG. 7 is a diagrammatic illustration showing the signal readout section of a solid-state image sensor.
FIG. 8 is a block diagram showing a signal readout circuit of the solid-state image sensor.
FIG. 9 is a diagrammatic illustration showing the structure of an interline transfer type solid-state image sensor.
FIGS. 10A and 10B are diagrammatic illustrations showing the entirety and a part, respectively, of an illuminating lens moving mechanism.
FIGS. 11A and 11B are diagrammatic illustrations, respectively, for explaining a second embodiment of the present invention.
FIGS. 12A, 12B and 12C are diagrammatic illustrations for explaining a third embodiment of the present invention.
FIG. 13 is a block diagram of the electric circuit portion which is applied to the third embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention will hereunder be described with respect to the embodiments illustrated in the accompanying drawings.
In FIG. 1, reference numeral 1 represents a light supply lamp; 2 a light guide having bifurcated light-incidence ends 2a and 2b and having one light-emission end 2c where respective optical fibers are regularly arranged as shown in FIG. 2 in such a way that the optical fibers in the two light-incidence end portions 2a and 2b are arranged at the light-emission end in alternate rows of fibers relative to each other; 3 a rotary filter disposed between the light supply lamp 1 and the light-incidence ends of the light guide 2, and which is divided into four sectors consisting of a red light transmitting sector 3a, a green light transmitting sector 3b, a blue light transmitting sector 3c and an infrared light transmitting sector 3d as shown in FIG. 3. Furthermore, the infrared light transmitting sector 3d is constructed to have an opaque region 3d' to face the sector 2b of the light incidence end of the light guide 2 when the sector 3d is placed in a light path; 4 an illumination lens for projecting onto the object 5 under observation the light-emission end of the light guide 2 as being the illumination light supply which consists of a plurality of fine light-emitting members; 6 an objective lens of the observation optical system for forming the image of the object 5 under observation; and 7 a solid-state image sensor disposed at the focusing position of the objective lens 6. Numeral 8 represents a synchronizing circuit; 9 a motor driving circuit for driving a motor M which rotates the rotary filter 3 in accordance with a control signal delivered from the synchronous circuit 8; 10 a driving circuit for actuating the solid-state image sensor 7 based on a control signal delivered from the synchronous circuit 8; 11 a preamplifier for amplifying an output signal delivered from the solid-state image sensor 7; 12 a processing circuit; 13 an A/D converter circuit; 14 a multiplexer; 15 to 18 memories for being inputted with signals allotted, respectively, by the multiplexer 14 to correspond to the illuminations of red light, green light, blue light or infrared light emitting in synchronism with the rotation of the rotary filter 3; 20, 21 and 22 D/A converter circuits, respectively; 23 a color encoder; 24 a mixing circuit; 25 a color display; 26 a measuring and processing circuit for processing various data such as determination or identification of the frequency of Moire fringes, removal of unwanted fringes, and so forth, and for performing image processing; 27 a D/A converter circuit; 28 a projection image processing circuit for converting that output of the measuring and processing circuit 26 which has already been converted by the D/A converter circuit 27 to an analog signal into a compound projection image signal; and 29 a color display for indicating a contour image of the object 5 under observation as depicted by Moire fringes in accordance with the signal coming from the projection image processing circuit 28. The forward end portion of the light guide 2, the illuminating lens 4, the objective lens 6 and the solid-state image sensor 7 are housed especially in the foremost end portion of the main body E of the endoscope.
The embodiment of the present invention is construction as described above. Therefore, the beam of light emitting from the light supply lamp 1 is successively converted to a red light, a green light, a blue light and an infrared light along with the rotation of the rotary filter 3 driven by the motor M, to illuminate the object 5 of observation via the light guide 2 and the illuminating lens 4. It should be noted. however, that the beam of infrared light which is transmitted through the rotary filter 3 when the infrared light transmitting sector 3d of the rotary filter 3 is inserted in the path of light will enter into the light guide 2 only through the light-incidence end 2a thereof. Therefore, the infrared light beam will emit at the light-emission end of the light guide 2 through every other row of optical fibers. Thus, the object 5 under survey will be illuminated with stripes or fringes. On the other hand, when either one of the other light-transmitting sectors of the rotary filter 3, i.e. either the red light transmitting sector 3a, the green light transmitting sector 3b or the blue light transmitting sector 3c, is inserted in the path of light beam, it will be noted that the red light, the green light or the blue light which has transmitted through the rotary filter 3 will enter the light guide 2 through both of the light-incidence ends 2a and 2b of the light guide 2, and as a result the light beam will emit through the entire output region of the light-emission end 2c of the light guide 2. Accordingly, the object 5 under observation is illuminated uniformly. The light reflected from the illuminated object 5 under survey is thus focused on the solid-state image sensor 7 by the focusing lens 6. This solid-state image sensor 7 is actuated by the driving circuit 10 in synchronism with the rotation of the rotary filter 3 based on a control signal delivered from the synchronous circuit 8, and output signals of the image of the object produced by the red light, the green light, the blue light and the infrared light, successively. These signals which are outputted are amplified by the preamplifier 11 and are processed by the processing circuit 12, and they are converted to digital signals by the A/D converter 13, and these digital signals are allotted to respective memories 15 to 18, respectively, by the multiplexer 14. That is, the image signal produced by the red light is inputted to the memory 15; the image signal developed by the green light is inputted to the memory 16; the image signal formed by the blue light is inputted to the memory 17; and the image signal caused by the infrared light is inputted to the memory 18, respectively. Those image signals due to the red light, the green light and the blue light which have been stored in the memories 15, 16 and 17, respectively, are read out simultaneously by the timing signal coming from the synchronous circuit 8, and are converted to analog signals by the D/A converter circuits 20, 21 and 22, respectively, and are supplied to the color encoder 23, where video signals are produced. These video signals are supplied further to the mixing circuit 24 where they are added with a synchronous signal delivered from the synchronous circuit 8 to thereby become a compound projection image signal to be displayed on the color display 25. Also, the image signal due to the infrared light, which has been stored in the memory 19, is first processed by the measuring and processing circuit 26, and thereafter it is converted to an analog signal by the D/A converter circuit 27, and is supplied to the projection image processing circuit 28 where the signal is provided with a synchronous signal coming from a synchronous circuit 8. It should be noted here that, in case there is the need to superpose an ordinary image onto the image which may, for example, be of a contour pattern obtained from the measuring and processing circuit 26, said signal is made into a compound projection image signal which is produced by mixing the image signal with a signal coming from the color encoder 23, and this compound projection image signal is displayed by the color display 29 such as CRT.
The method of obtaining a contour image by processing image data stored in the memory 18 has already been put to practice and is known from, for example, Yatagai et al's Opt. Eng. 21 (1982) 901, and 21 (1982) 432 of same and also 23 (1984) 401 of same, and accordingly, its detailed explanation is omitted.
Now a brief description will be provided of the principle that the concavo-convex (i.e. uneven) surface of the object can be ascertained by Moire fringes or stripes. The method employed in the present invention is called the projection method. As shown in FIG. 4, lattice P 1 is projected onto an object O through a lens L 1 to form the image of the object O by a lens L 2 , so that this object image is observed through a lattice P 2 . The image of the lattice P 1 projected onto the object O deforms in accordance with the concavo-convex (uneven) pattern of the surface of the object O, and Moire fringes are formed between the image of this deformed lattice P 1 and the lattice P 2 . To make the explanation simple, let us here suppose that the projection lens L 1 is the same as the focusing lens L 2 , and that the lattice P 1 is same as the lattice P 2 , respectively. Then, as shown in FIG. 5, it is assumed that the distance between the lattice and the principal point of the lens facing the lattice is assumed to be a, the distance between the principal point of the lens and the reference point (to be determined appropriately) at the surface of the object O to be l, the distance between the principal points of the respective lenses to be d, the focal distance of respective lenses to be f, the pitches of the respective lattices to be S, and the frequency of Moire fringes to be N. Then, the depth of the N-th Moire fringe as counted from the reference point will be given by: ##EQU1## In this way, it is possible to know the concavo-convex (uneven) appearance of a given surface by utilizing Moire fringes. The above-mentioned calculation is performed by the measuring and processing circuit 26. Furthermore, by means of the microcomputer which is contained in this measuring and processing circuit, there is performed the processing of the signals necessary for the depiction, on the display 29, of such a diagram pattern as shown in FIG. 6. As will be understood from the above explanation, the light-emitting end face of the light guide 2 in, for example, the embodiment of FIG. 1 corresponds to the lattice P 1 , and the light-receiving face of the solid-state image sensor 7 corresponds to the lattice P 2 . Also, an arrangement may be made so that the signals delivered from the measuring and processing circuit 26 are outputted to various data terminal devices such as a magnetic disc memory, or to an X-Y plotter. It should be noted here that the arrangement is provided such that, at the time of observation utilizing infrared light, there is read out a signal from picture elements of every other row (see FIG. 7) or every other column of the solid-state image sensor 7. Accordingly, there is obtained a contour image formed by Moire fringes in the same way as that obtained when the object 5 under survey is observed via the lattice having a pitch representing the width or distance between the rows of picture elements of the solid-state image sensor 7. For this reason, either by providing a gating circuit 30 at the output portion of the solid-state image sensor 7 as shown in FIG. 8, and by alternately switching this circuit 30 to "on" and "off" in synchronism with the driving pulses of the driving circuit 10 of the solid-state image sensor 7, or by reading out signals from the memory 18 in correspondence to the outputs of the image elements of every other row or column of the solid-state image sensor 7, or by performing image processing by the measuring and processing circuit 26, there are read out signals delivered from the picture elements of every other row or column of the solid-state image sensor 7. Furthermore, in the case of the solid-state image sensor of the interlacing type, it is possible to easily read out signals of every other row or column by deriving signals of only the first field or the second field. Also, from the fact that the picture elements themselves of the solid-state image sensor are arranged in the form of a lattice, it will be understood that especially in the case of an interline transfer type solid-state image sensor (see FIG. 9) wherein vertical transfer registers 32, 32', 32", . . . are arranged between light-sensitive sections 31, 31', 31", . . . forming non-sensitive zones, it is also possible to obtain a contour image due to Moire fringes by the output signals from all the picture elements instead of by the signals from every other row or column.
FIGS. 10A and 10B show a mechanism for moving an illuminating lens 4 in such a way that, only when the infrared light transmitting sector 3d of the rotary filter 3 is inserted in the path of light beam in synchronism with the rotation of the rotary filter 3, the light-emission end of the light guide 2 is focused on the object 5 under observation, and that when the other light-transmitting sectors 3a, 3b or 3c of the rotary filter 3 are inserted in the path of light, the light-emission end of the light guide 2 is projected as a blurred image onto the object 5 under observation. Numeral 33 represents a lens frame for supporting the illuminating lens 4 advanceably and retreatably in the direction of the optical axis; 34 a spring having its one end fixed to the lens frame 33 for pulling the lens frame 33 in the direction of the arrow; 35 a cam plate provided on a shaft 36 which is arranged to be brought, by such means as a worm gear, into engagement with the shaft of the motor M which is assigned to rotate the rotary filter 3 and which makes one revolution during one rotation of the rotary filter 3. One end of a rod 37 having its other end fixed to the lens frame 33 abuts, by means of the spring force of a spring 34, a cam face 35a of the cam plate 35. The cam face 35a is constructed to have a shape such that, when the infrared light transmitting sector 3d of the rotary filter 3 is inserted in the path of light, the rod 37 is brought into contact with the larger-diameter portion 35a' extending through about 90 degrees of the cam face 35a of the cam plate 35, and that when the other light-transmitting sector 3a, 3b or 3c is inserted in the path of light, said rod 37 is in contact with the remainder smaller-diameter portion 35a" of the cam face 35a of the cam plate 35. It should be understood that, when the rod 37 is in contact with the larger-diameter portion 35a' of the cam face 35a, the illuminating lens 4 is at a position of focusing the light-emission end of the light guide 2 on the object 5 under observation. In case, however, the rod 37 is abutting the smaller-diameter portion 35a" of the cam face 35a, the illuminating lens 4 is located at a position closer to the light-emission end of the light guide 2, so that the light-emission end of this light guide 2 is projected, as a blurred image, onto the object 5 under observation. Thus, in case of illumination by red light, green light or blue light, it will be noted that, among the core and clad which constitute the individual optical fibers of the light guide 2, only the core will illuminate, so that the mesh-like illumination which can be produced when the light-emission end of the light guide 2 is focused on the object 5 under survey is eliminated due to blurring. In case of illumination by infrared light, however, the light-emission end of the light guide 2 is clearly focused in a stripe pattern on the object 5 under examination.
FIGS. 11A and 11B show a second embodiment of the present invention. Numeral 40 represents an LED array (see FIG. 11B) consisting of successively arranged rows R, G, B and I of LEDs (which may be semiconductor laser, for example) emitting red light, green light, blue light and infrared light, respectively, at the position of the light-emission end of the light guide 2, in place of the light supply lamp 1, the light guide 2 and the rotary filter 3 which are employed in the embodiment of FIG. 1. The remains arrangement of this second embodiment is similar to that of the embodiment of FIG. 1. According to this arrangement, the rows of LED array are lighted up successively in the order of R, G, B and I by a driving circuit 41 based on a control signal delivered from the synchronizing circuit 8, whereby there can be performed face-after-face type image-pickup operation. In this case also, if an arrangement is provided so as to move the illuminating lens 4 in the same way as in FIG. 10, it will be understood that, in case of illumination by red light, green light or blue light, the object 5 under observation will be illuminated substantially uniformly due to blurring. It should be noted here that an arrangement may be provided so that the signals from the solid-state image sensor are read out for example once every two rows or three rows in accordance with the time intervals of emission of light from the LEDs.
FIGS. 12A, 12B, 12C and 13 show a third embodiment of the present invention. In place of the rotary filter 3 employed in the embodiment of FIG. 1, there is disposed an infrared light cutting filter 50 (FIG. 12A) in the foreground of the light-emission end 2b of the light guide 2. Also, a color-separating stripe filter 51 (FIGS. 12B and 12C) is disposed in the foreground of the solid-state image sensor 7, so that visible light impinges onto the two light-incidence ends 2a and 2b of the light guide 2, whereby the light emits through the entire region of the light-emission end of the light guide 2 to illuminate the object 5 under survey. However, infrared light enters only through the light-incidence end 2a of the light guide 2 due to the function of the infrared light cutting filter 50, so that the light emits through the light-emission end of the light guide 2 at every other row of optical fibers to illuminate the object 5 under survey in a stripe pattern. The image of the object 5 under observation thus illuminated is focused on the solid-state image sensor 7 by the objective lens 6. The output signal of the solid-state image sensor 7 is amplified by the preamplifier 11, and it is converted to a digital signal by the A/D converter circuit 13, and thereafter it is distributed into image signals produced by red light, green light, blue light and infrared light, respectively, as allotted by the multiplexer 14, as shown in FIG. 13. After these respective signals are processed by the processing circuit 12', the image signals produced by red light, green light and blue light are converted to analog signals by the D/A converter circuits 20, 21 and 22, respectively, and they are supplied to the color encoder 23 whereby a video signal is formed. This video signal is supplied to the mixing circuit 24 to become a compound image projection signal. By this image projection signal, a color projection image is presented on the color display 25. Also, the infrared light is processed by the measuring and processing circuit 26, and thereafter it is converted to an analog signal by the D/A converter circuit 27, and then it is converted further to a compound image projection signal by the projection image processing circuit 28 to present a contour image on the color display 29. It should be understood here that the stripe filter 51 requires that the sector I intended to transmit infrared light to be of lattice form. With respect to the sectors R, G and B which transmit red light, green light and blue light, respectively, they may be formed in mosaic pattern instead of lattice form. In such a case, however, the color-separating circuit will need some modification in its arrangement.
In the above-state description, in the first and second embodiments, the observation by utilizing Moire fringes employs infrared light. It should be understood, however, that in place of infrared light, there may be used visible light such as red light, green light and blue light. Also, in the respective embodiments stated above, it is also possible to use invisible light such as ultraviolet light in place of infrared light.
In the above-mentioned description, the principle of the present invention has been stated with respect to endoscope. It should be understood, however, that this principle is not limited thereto, but it can be applied also to optical instruments which perform Moire topography. | A measuring endoscope for making three-dimensional measurements of a object without using a special lattice and without hampering direct observation of the object. The measuring endoscope includes a light supply source for supplying illumination, and an illumination variation device for providing a plurality of particular illuminations, and illumination transmission means including a plurality of fiber optic cables. The fiber optic cables have a first input section separated from a second input section. The second section receives one particular illumination which the first section does not. At the output end of the fiber optic cables, fiber optic cables from the first section are interlaced, row-by-row with the fiber optic cables from the second section. An illumination lens then directs the light from the fiber optic cables onto the object. A lattice-shaped light pattern then appears on the object. Light reflected from the object is received by an objective lens system and is directed to an imaged sensor. The image sensor includes a large number of regularly arranged picture elements. Image processing devices then convert the received image into electrical signals. The image processing means process selected electrical signals from among all electrical signals received. These selected electrical signals are obtained from picture elements from positions where the lattice of the object image is formed on the light receiving surface. These selected electrical signals may then be processed to provide a three-dimensional measurement of the object. A control device controls the supply of light to the fiber optic cables to ensure that the light is emitted from the fiber optic cables in a lattice form. Finally, a display device connected to the image processor provides a display according to the three-dimensional image of the object. | 7 |
This is a continuation of application Ser. No. 07/241,189 filed Sept. 7, 1988, now U.S. Pat. No. 4,968,441.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to propellants and explosives. More particularly, this invention relates to cast cured propellants and explosives containing energetic polymeric binders.
2. Description of the Prior Art
Conventional plastic-bonded explosives (PBXs) contain inert polymers as desensitizing binders. One commonly used inert binder is polyethylene glycol. Pressed PBX compositions can have relatively low levels of polymer or wax. Cast-cured PBXs contain higher levels or rubbery polymers to improve the processing. High levels of polymer make these compositions less hazardous, but also less energetic.
Some studies have suggested that the hazard properties in detonable propellants and explosives become more benign as propellant toughness is increased. Propellant toughness is a combination of tensile strength and elongation properties. These properties are known to be improved by an increase in the percent volume of polymer in the composition.
A reduction in the amount of crystalline explosive filler such as cyclotetramethylene tetranitramine tetranitramine (HMX) and cyclotrimethylenetrinitramine (RDX) will improve the safety properties. Energetic plasticizers have been substituted for a portion of the solid fillers with varied success. Previously, the use of high levels of plasticizers has been associated with the problem of plasticizer exudation.
SUMMARY OF THE INVENTION
The present invention is a cast-cured propellant and explosive composition. The composition comprises glycidyl azide polymer as an energetic binder, a plasticizer selected from the group consisting of bis(2,2-dinitro-2-fluoroethyl) formal, a eutectic mixture of bis(2,2-dinitropropyl) formal/acetal, trimethylolethane trinitrate, triethyleneglycol dinitrate, and HMX. Additionally, aluminum can be added to the composition.
OBJECTS OF THE INVENTION
Accordingly, it is an object of this invention to provide a cast-cured propellant and explosive composition having a high content of polymeric binder and energetic plasticizer with a reduced HMX or RDX content.
Another object of this invention is to provide a cast-cured propellant and explosive using the energetic binder glycidyl azide polymer in place of the inert polymer binder.
Still another object of the invention is to provide a propellant and explosive with improved mechanical properties to give greater safety.
Yet another object of the invention is to provide a propellant and explosive having a high tensile strength and better elongation properties.
These and other objects of the invention will become apparent from the following specification.
DETAILED DESCRIPTION OF THE INVENTION
The energetic azido-polymer glycidyl azide polymer (GAP) is used as a binder in plastic-bonded explosive compositions. Basically, the energetic binder GAP comprises hydroxyterminated aliphatic polyether having pendent alkyl azide groups. The GAP energetic binder is more fully described in U.S. Pat. No. 4,268,450. PBXs with this binder have enhanced properties in the areas of performance and safety. Formulations with the relatively high content of the energetic polymer GAP significantly increase the volumetric fraction of polymers, but do not reduce performance. The level of crystalline explosive HMX or RDX is reduced as the energetic binder content is increased. This transfer of energy releasing groups from the solid phase to the soft polymeric binder phase results in a high performance propellant or explosive with reduced hazard potential.
A further enhancement of the safety properties of a cast-cured PBX is achieved by replacing additional HMX or RDX, the solid crystalline filler, with an energetic plasticizer. Improved safety results from reduced sensitivity to initiation by impact shock and deflagration to detonation transition during processing, transportation, and combat use. High levels of plasticizers previously caused problems having a tendency to suffer plasticizer exudation. Explosives and propellants have stringent requirements which allow no exudation during temperature cycling and the aging of plasticized compositions. The need for more energetic rocket propellants led to the development of various compositions containing high levels of energetic plasticizers which exhibit no exudation.
GAP has been found to retain high levels of plasticizers without exudation (plasticizer/polymer, Pl/Po=6.0). Earlier compositions with the inert binder polyethylene glycol contained up to only 3 parts plasticizer per 1 part polymeric binder. The plasticizers used with the GAP binder in these formulations include bis(2,2-dinitro-2-fluoroethyl) formal (FEFO), a eutectic mixture of bis(2,2-dinitropropyl) formal/acetal (BDNPF/A), trimethylolethane trinitrate (TMETN), and triethyleneglycol dinitrate. FEFO is the most desirable PBX plasticizer because of its high energy contribution and least loss of mechanical properties. BNDPF/A is lower in energy contribution but has favorable effects on PBX mechanical and hazard properties.
A number of 70 g propellant formulations were prepared under vacuum in high shear vertical mixers according to standard procedure known to those in the art. Triphenyl bismuth (0.02 wt percent) and dibutyltin dilaurate (0.005 wt. percent) were used as catalysts, while the biuret trimer of hexamethylene diisocyanate was used as the curative for these compositions. Curatives such as 4,4'-Diisocyanatodicyclohexylmethane or hexamethylene diisocyanate can be used to replace a portion of the biuret trimer. Both the ethylene glycol initiated GAP and the glycerol initiated GAP were used. The mechanical properties were best with the ethylene glycol initiated GAP. The characteristics of the ethylene glycol GAP which was made by Rocketdyne Division of Rockwell International were: Mn-1869, Mw 2139, pd-1.14, eg. wt. 1122, ΔHf cal/g 189, and density 1.3.
The following examples illustrate specific embodiments of the invention: Example I summarizes the formulations of GAP alone and with the various plasticizers.
EXAMPLE I
______________________________________Ingredient, % Wt A B C D______________________________________GAP 16.26 16.26 16.26 30.7FEFO 13.74 -- -- --TMETN -- 13.74 -- --BDNPF/A -- -- 13.74 --HMX (10 μm) 60.0 60.0 60.0 56.25Al (18 μm) 10.0 10.0 10.0 13.04Impact sensitivity (cm 28 31 36 482.5 Kg, 50%)______________________________________
EXAMPLE II
______________________________________Ingredient, % Wt A B C D______________________________________GAP 6 16.26 21.72 11.28BDNPF/A 24 13.74 18.32 19.43Al 13 10 -- 13.04HMX 57 60 60 56.25Sensitivity 29 36 39 22Impact (2.5 Kg, 50%)Friction (ABL, 1000 lb) 9/10 NF -- NF NFElectrostatic (0.25 J) 10/10 NF -- -- 10/10 NFVacuum Thermal -- -- -- 0.22Stability (100° C., 48 hrs,ml/g)Elongation(max. stress, %) -- -- -- 41(rupture, %) -- -- -- 124Stress (max, psi) -- -- -- 40Modulus (PSI/PSI) -- -- -- 265______________________________________
A formulation made similar to composition A in Example II, only with polyethylene glycol (PEG) rather than GAP had plasticizer exudation. The formulation with GAP produced satisfactory results. Detonation pressures of various compositions containing GAP were calculated using the Kamlet method. The compositions contain varied amounts of the GAP binder and FEFO plasticizer to reduce the amount of HMX or RDX. The mechanical properties such as toughness are related to the volume percent of polymer. As toughness increases the hazard sensitivity properties are improved.
EXAMPLE III
______________________________________Prior art comp (1) (2) (3) (4) (5) (6)______________________________________PEG 6.4 -- -- -- -- --GAP -- 25.0 12.6 11.0 7.0 10.0FEFO 18.61 -- 50.4 44.0 28.0 20.0HMX -- 75.0 37.0 -- 65.0 57.0 + 13.0 AlRDX 75.-- -- -- 45.0 -- --Polymer, vol % 8.9 32.8 16.0 13.9 9.2 14.8det. press 266 278 267 267 311 295(Kj, Kbar)______________________________________
Obviously, many modification and variations of the present invention are possible in light of the above teachings. It is therefore to be understood, that within the scope of the appended claims, the invention may be practiced otherwise that specifically described. | A cast cured propellant and explosive with a higher volume percentage of ymer resulting in improved mechanical and safety properties is made from glycidyl azide polymer, an energetic plasticizer and HMX or RDX. Aluminum powder can also be added. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a tool display device, and more particularly a tool display device that holds a tool and provides security and anti-thief features when displaying a tool with a tool head.
2. Description of Related Art
With reference to FIG. 13, a conventional tool display device in accordance with the prior art is composed of a back-plate ( 50 ) and a tool bracket ( 60 ) attached to the back-plate ( 50 ).
The back-plate ( 50 ) is rectangular and has a bottom edge, a top edge and two side edges. Two mortises ( 51 ) are respectively defined near the bottom edge and opposite side edges of the back-plate ( 50 ). A through hole ( 52 ) is defined in the back-plate ( 50 ) between each mortise ( 51 ) and the side edge.
The tool bracket ( 60 ) is substantially U-shaped with a receiving space ( 61 ) to hold a tool (not shown) and has two sides. An ear ( 62 ) is formed at each side of the receiving space ( 61 ). Each ear ( 62 ) has a face (not numbered) to abut the back-plate ( 50 ) and a lipped protrusion ( 64 ) formed on the face to engage the corresponding mortise ( 51 ) to attach the tool bracket ( 60 ) to the back-plate ( 50 ) to suspend a tool between the back-plate ( 50 ) and the tool bracket ( 60 ). A through hole ( 65 ) is defined in each ear ( 62 ) near lipped protrusion ( 64 ) to align with the corresponding through hole ( 52 ) in the back-plate ( 50 ). A plug ( 63 ) with shaft and two ends has a head (not numbered) on one end and a lip (not numbered) on the other end. The shaft is partially split longitudinally so the lip and the shaft can be pressed through the through hole ( 65 ) in the ear ( 62 ) and the through hole in the back-plate ( 52 ) and provide an anti-thief feature.
However, the conventional tool display device still has the following drawbacks caused from its structure:
1. The lipped protrusion ( 64 ) on the tool bracket ( 60 ) detachably engages the mortise ( 51 ) in the back-plate ( 50 ) to hold the tool on the tool display device. However, the lipped protrusion ( 64 ) is easily broken when the tool bracket ( 60 ) detaches from the back-plate ( 50 ) several times or when the tool bracket ( 60 ) holds a heavy tool. Therefore, the conventional display device is not durable.
2. When using the lipped protrusion ( 64 ) and the mortise ( 52 ) to mount the tool, the conventional display device further needs the plug ( 63 ) to achieve the anti-thief effect. Therefore, manufacturers need two attachment processes to complete the conventional tool display device, and that makes the assembly of the conventional tool display device unnecessarily time-consuming and troublesome. Furthermore, production cost of the conventional tool display device is also raised.
To eliminate the foregoing disadvantages of the conventional tool display device, the present invention provides a tool display device conveniently assembled, which stably holds a tool on the tool display device.
SUMMARY OF THE INVENTION
A first objective of the invention is to provide a tool display device that is convenient to assemble or disassemble.
A second objective of the invention is to provide a tool display device that holds a tool stably.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a tool display device in accordance with the present invention;
FIG. 2 is an exploded perspective view of the tool display device in FIG. 1;
FIG. 3 is an enlarged side plan view in partial section of a retaining device of the tool display device along line 3 — 3 in FIG. 1;
FIG. 4 is an operational front plan view of the tool display device in FIG. 1;
FIG. 5 is an operational front plan view of the tool display device, in FIG. 1;
FIG. 6 is an exploded perspective view of the tool display device in FIG. 1, wherein a mounting cushion is mounted on the tool inside the receiving space;
FIG. 7 is a cross-sectional top plan view of the tool display device in FIG. 6;
FIG. 8 is an exploded perspective view of a second embodiment of the tool display device in accordance with the present invention, wherein the mounting cushion is circular;
FIG. 9 is a cross-sectional side plan view of the second embodiment of the tool display device in FIG. 8;
FIG. 10 is a cross-sectional top view of the second embodiment of the tool display device in FIG. 9;
FIG. 11 is a perspective view of a third embodiment of the tool display device in accordance with the present invention, wherein the tool has a connecting head extending through the back-plate and a second mounting cushion is mounted on the connecting head;
FIG. 12 is a perspective view of a fourth embodiment of the tool display device in accordance with the present invention, wherein the second mounting cushion has a rectangular through hole; and
FIG. 13 is an exploded view of a conventional tool display device in accordance with the prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIGS. 1 to 3 , a tool display device is comprises of a back-plate ( 10 ) and a tool bracket ( 20 ). The tool bracket ( 20 ) is detachably mounted on the back-plate ( 10 ) to hold a tool (not shown) between the back-plate ( 10 ) and the tool bracket ( 20 ).
The back-plate ( 10 ) is rectangular and has a bottom, a top, two sides and four corners. A holding plate ( 11 ) with a top, a bottom and two sides is attached to each side of the back-plate ( 10 ) and extends toward the other holding plate ( 11 ). A mounting slot ( 12 ) is defined between each holding plate ( 11 ) and the back plate ( 10 ), and a notch ( 13 ) is defined through the top of each holding plate ( 11 ).
The tool bracket ( 20 ) has a middle portion and two sides. A receiving space ( 21 ) with an opening (not numbered) is defined in a middle portion of the tool bracket ( 20 ). The opening faces to the back-plate ( 10 ). Two ears ( 22 ) are respectively formed at opposite sides of the tool bracket ( 20 ) to correspond to the mounting slots ( 12 ) on the back-plate ( 10 ). Each ear ( 22 ) has a top, a bottom, a nub ( 23 ) and a cutout ( 25 ). The nub ( 23 ) is formed at the top of the ear ( 22 ) to engage the notch ( 13 ) in the holding plate ( 11 ). The cutout ( 25 ) is defined in the bottom of the ear ( 22 ) to form an inside leg (not numbered) and a resilient outside leg ( 26 ) at the bottom of the ear ( 22 ). The resilient outside leg ( 26 ) has a distal end that extends downward beyond the bottom of the tool bracket ( 20 ), the holding plate, and the back-plate ( 10 ). A hook ( 27 ) with a top flat face ( 28 ) is formed on the distal end of the resilient outside leg ( 26 ).
With reference to FIGS. 2 to 4 , when attaching the tool bracket ( 20 ) on the back-plate ( 10 ) the tool bracket ( 20 ) moves downward along the back-plate ( 10 ) so the ears ( 22 ) slide into the corresponding mounting slots ( 12 ). The resilient outside leg ( 26 ) is compressed within the mounting slot ( 12 ) because the hook ( 27 ) is pressed inward. The tool bracket ( 20 ) moves downward until the nub ( 23 ) rests inside the notch ( 13 ) and the hook ( 27 ) on the resilient outside leg ( 26 ) extends beyond the bottom of the holding plate ( 11 ) to prevent the tool bracket ( 20 ) from sliding up to achieve anti-thief feature. Therefore, only one step is needed to assemble the tool display device.
With reference to FIGS. 3 and 5, to remove the tool from the tool display device, scissors ( 30 ) are used to cut the hook ( 27 ) off so the tool bracket ( 20 ) can be slid up to and be detached from the back-plate ( 10 ). Additionally, the top flat face ( 28 ) of the hook ( 27 ) extends beyond the bottom of the holding plate ( 11 ) to form a gap between the hook ( 27 ) and the holding plate ( 11 ) so that the scissors ( 30 ) can cut the hook ( 27 ) off the resilient outside leg ( 26 ) easily. After cutting the hook ( 27 ) off the resilient outside leg ( 26 ), the tool bracket ( 20 ) can be easily detached from or attached to the back-plate ( 10 ) so the tool display device can be used to store tools. Since the nub ( 23 ) and notch ( 13 ) are not easily broken, the tool display device is durable for holding a tool.
With reference to FIGS. 6 and 7, a second embodiment of the tool display device in accordance with the present invention improves the stability a tool suspended on the device. At least one cushion is mounted on the tool between the back-plate ( 10 ) and the tool bracket ( 20 ). A wrench ( 32 ) having a handle is secured inside the receiving space ( 21 ) between the back-plate ( 10 ) and the tool bracket ( 20 ). A first mounting cushion ( 40 ) is essentially rectangular and mounts around the handle of the wrench ( 32 ) abut the bottom face of the tool display device for damping the rock of the tool or to fill space between the handle and the tool display device. Therefore, the wrench ( 32 ) does not tilt or swing in the receiving space ( 21 ) and is kept straight.
With reference to FIGS. 8 to 10 , a third embodiment of the tool display device has a tool head recess ( 15 ) defined in the in the back-plate ( 10 ) to partially receive a tool head inside. A ratchet wrench ( 33 ) having a round handle is held between the back-plate ( 10 ) and the tool bracket ( 20 ). A second mounting cushion ( 41 ) is circular and mounted around the round handle to abut the bottom face of the tool display device for damping the rock of the tool or to fill space between the handle and the tool display device.
With reference to FIGS. 8, 11 and 12 , the back-plate ( 10 ) further has a through hole ( 151 ) defined through the tool head recess ( 15 ), and the wrench ( 33 ) has a connecting rod ( 34 ) that extends through the through hole ( 151 ). A third mounting cushion ( 42 ) with a securing hole is mounted around the connecting rod ( 34 ) and attaches to the back-plate ( 10 ) to secure the wrench ( 33 ) stably on the tool display device. In FIG. 11, the securing hole is circular and in FIG. 12, the securing hole is rectangular.
According to above description, the tool display device in accordance with the present invention has the following advantages.
1. When assembling the tool display device, the tool bracket ( 20 ) attaches to the back-plate ( 10 ) by sliding the ears ( 22 ) into the mounting slot ( 12 ) of the back-plate ( 10 ). The nub ( 23 ) is received in the notch ( 13 ) and the hook ( 27 ) extends out of the mounting slot ( 12 ) to secured the tool bracket ( 20 ) on the back-plate ( 10 ) and to prevent the tool bracket ( 20 ) from sliding up to achieve an anti-thief feature. Therefore, the manufacturer only needs one step to quickly assemble the tool display device.
2. Because the back-plate ( 10 ) and the tool bracket ( 20 ) are formed as individual pieces by injection molding, there is no need to produce an extra element to lock the pieces together. Therefore, production cost is reduced.
3. The mounting cushion mounted on the tool works with the back-plate ( 10 ) and the tool bracket ( 20 ) to prevent the tool from tilting or swinging when the tool is secured on the tool display device.
Even though numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, the disclosure is illustrative only, and changes nay be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed. | A tool display device consists of a back-plate ( 10 ) and a tool bracket ( 20 ) to hang a tool on the tool display device. The back-plate ( 10 ) has two holding plates ( 11 ) respectively formed at two sides of the back-plate ( 10 ). Each holding plate ( 11 ) forms a mounting slot ( 12 ) with the back-plate ( 10 ). The tool bracket ( 20 ) has two ears ( 22 ). Each ear ( 22 ) slides into and is securely held in the corresponding mounting slot ( 12 ) by a hook ( 27 ) on a distal end of a resilient outside leg ( 26 ) formed on the ear ( 22 ). The tool display device further has at least one cushion secured on the tool to keep the tool stable. | 0 |
REFERENCE TO RELATED APPLICATION
The present application is a continuation of U.S. patent application Ser. No. 07/991,074, filed Dec. 9, 1992 now abandoned, which is incorporated herein by reference as if fully set forth.
BACKGROUND OF THE INVENTION
The invention relates to television entertainment systems for providing television programming to consumer homes. More particularly, the invention relates to cable television packaging, delivery and presentation systems which provide consumers with many television programming options.
Advances in television entertainment have been primarily driven by breakthroughs in technology. In 1939, advances on Vladmir Zworykin's picture tube provided the stimulus for NBC to begin its first regular broadcasts. In 1975, advances in satellite technology provided consumers with increased programming to homes.
Many of these technology breakthroughs have produced inconvenient systems for consumers. One example is the ubiquitous three remote control home, having a separate and unique remote control for the TV, cable box and VCR. More recently, technology has provided cable users in certain parts of the country with 100 channels of programming. This increased program capacity is beyond the ability of many consumers to use effectively. No method of managing the program choices has been provided to consumers.
Consumers are demanding that future advances in television entertainment, particularly programs and program choices, be presented to the consumer in a user friendly manner. Consumer preferences, instead of technological breakthroughs, will drive the television entertainment market for at least the next 20 years. As computer vendors have experienced a switch from marketing new technology in computer hardware to marketing better useability, interfaces and service, the television entertainment industry will also experience a switch from new technology driving the market to consumer useability driving the market.
Consumers want products incorporating new technology that are useful, and will no longer purchase new technology for the sake of novelty or status. Technological advances in sophisticated hardware are beginning to surpass the capability of the average consumer to use the new technology. Careful engineering must be done to make entertainment products incorporating new technology useful and desired by consumers.
In order for new television entertainment products to be successful, the products must satisfy consumer demands. TV consumers wish to go from limited viewing choices to a variety of choices, from no control of programming to complete control. Consumers wish to advance from cumbersome and inconvenient television to easy and convenient television and keep costs down. Consumers do not wish to pay for one hundred channels when due to lack of programming information, they seldom, if ever, watch programming on many of these channels.
The concepts of interactive television, high definition television and 300 channel cable systems in consumer homes will not sell if they are not packaged, delivered and presented in a useable fashion to consumers. The problem is that TV programming is not being managed, packaged, delivered, and presented to consumers in a user friendly manner.
Consumers are already being bombarded with programming options, numerous “free” cable channels, subscription cable channels and pay-per-view choices. Any further increase in TV entertainment choices, without a user friendly presentation and approach, will likely bewilder viewers with a mind-numbing array of choices.
The TV industry has traditionally marketed and sold its programs to consumers in bulk, such as continuous feed broadcast and long-term subscriptions to movie channels. The TV industry is unable to sell its programming in large quantities on a unit per unit basis, such as the ordering of one program. Consumers prefer a unit sales approach because it keeps costs down and allows the consumer to be more selective in their viewing.
Additionally, viewership fragmentation, which has already begun, will increase. Programming not presented in a user friendly manner will suffer with a decrease in viewership and revenue.
What is needed is an economical system which can gather television programming in a variety of formats, package the programs, deliver the programs, and present the programs through a user friendly interface which allows the consumer to easily select from among the many program choices. The system must be capable of handling hundreds of programs in different formats, be expandable for future types of programming, include a method for billing consumers, and be inexpensive. The present invention is addressed to fulfill these needs.
SUMMARY OF INVENTION
A set top terminal is disclosed for creating a favorites menu of television programs available for viewing, based on a user's preferences. The terminal receives a television signal from an operations center, extracts individual programs from the signal, and sends one or more of the individual programs to a television for display, based on a selection by the user. The terminal generates an interactive electronic program guide for the selection of programs. The favorites menu of the guide narrows the list of available programs to those most likely of interest to the user. The terminal receives and stores user information, including general demographic information and viewing preference information. The viewing preference information may be received directly from the user, for example by querying the user. Alternatively, it may be learned by tracking the user's viewing habits. The viewing preference information may include, for example, frequently-watched channels, frequently-watched programs, or information related to program content. The user information may be stored in a user profile. Using the user information, the terminal identifies those programs available for viewing that most closely match the user information. A program menu including the identified programs is then generated for display on a television.
The expanded cable television program delivery system dramatically increases programming capacity using compressed transmission of television program signals. Developments in digital bandwidth compression technology now allow much greater throughput of television program signals over existing or slightly modified transmission media. The program delivery system provides subscribers with a user friendly interface to operate and exploit a six-fold or more increase in current program delivery capability.
Subscribers will be able to access the expanded program package and view selected programs through a menu-driven access scheme that allows each subscriber to select individual programs by sequencing a series of menus. The menus are sequenced by the subscriber using simple alpha-numeric and iconic character access, allowing the subscriber to access desired programs by simply pressing a single button rather than subscriber to access desired programs by simply pressing a single button rather than recalling from memory and pressing the actual two or more digit numeric number assigned to a selection. Thus, with the press of single buttons, the subscriber can advance from one menu to the next. In this fashion, the subscriber can sequence the menus and select a program from any given menu. The programs are grouped by category so that similar program offerings are found on the same menu.
System Description
1. Major System Components
In its most basic form, the system uses a program delivery system in conjunction with a conventional cable television system. The program delivery system contemplates (i) at least one operations center, where program packaging and control information are received and then assembled in the fowl of digital data, and (ii) a digital compression system, where the digital data is compressed, combined/multiplexed, encoded, and mapped into digital signals for satellite transmission (i.e., modulated, upconverted and amplified). The program delivery system transports the digital signals to the concatenated cable television system where the signals are received at the cable headend. Within the cable headend, the received signals may be decoded, demultiplexed, managed by a local central distribution and switching mechanism and then transmitted to subscriber homes via the cable system.
The delivery system employs an in-home decompression capability employing a decompressor housed within a set-top terminal in each subscriber's home. The decompressor remains transparent from the subscriber's point of view and allows any of the compressed signals to be demultiplexed and individually extracted from the composite data stream and then individually decompressed upon selection of a corresponding program by the subscriber. Within the set-top terminal, video signals are converted into analog signals. Control signals are extracted, decompressed and either executed immediately or placed in local storage in a ROM. The program control signals correspond to specific television programs with menu program options that each subscriber may access through a subscriber interface. The subscriber interface is a combined alpha, numeric and iconic remote control device which provides direct or menu-driven program access.
An array of menu templates are generated by a either a computer program within the set-top terminal or by the cable headend. The menu templates are generated using the program control information signals received from the Operations Center. A computer program within the set top terminal generates the on-screen menu displays and allocates a specific menu program option for each program signal. A combined alpha and numeric remote control provides the user interface to each program signal, allowing selection of a specific menu option which corresponds to a particular program signal.
2. Operations Center and Digital Compression System
The Operations Center performs two primary services, packaging television programs and generating the program control signal. At the Operations Center television programs are accumulated from various sources in both analog and digital form. The programs are then packaged into groups and categories which allow for easy menu access to programs and provides optimal marketing of programs to subscribers. The packaging process also accounts for any groupings by transponder which are necessary. After a packaging scheme is developed, the program control information which, among other things, describes the packaging, is generated by a computer and delivered with the packaged programs to the head end and/or subscriber. The system also accommodates local cable and television companies with programming time for local advertising and/or programming time availability.
The delivery system employs digital compression techniques to increase existing satellite transponder capacity by at least a 6:1 ratio, resulting in a six-fold increase in program delivery capability. The input signals are compressed, combined and encoded prior to satellite transmission, and subsequently transponded to various receive sites. There are a number of compression algorithms that presently exist which can achieve the resultant increase in capacity and improved signal quality desired for the invention.
3. System Control
Network management, control and monitoring of all compressors and decompressors in the network, is performed by a network controller at the cable headend, where program selection activity, and account and billing information is monitored. In the preferred embodiment, the network controller monitors, among other things, automatic poll-back responses from the set-top terminals remotely located at each subscribers' home. The polling and automatic report-back cycle occurs frequently enough to allow the network controller to maintain accurate account and billing information as well as monitor authorized channel access. In the simplest embodiment, information to be sent to the network controller will be stored in ROM within each subscriber's set-top terminal and retrieved only upon polling by the network controller.
Control information from the set top terminal will be sent to the network controller at the cable headend and not directly to the operations center. The digital compression and delivery system of the preferred embodiment provides a one-way path from the Operations Center to the cable headend. Thus, program monitoring and selection control will take place only at the cable headend by the local cable company and its decentralized network controllers (i.e., decentralized relative to the Operations Center which is central to the program delivery system). The local cable company will in turn be in communication with the operations center or a regional control center which accumulates return data from the set-top terminal for statistical or billing purposes. Alternatively, the operations center, and statistical and billing sites could be collocated.
4. Menu-Driven Program Selection
At a given receive site, any of the compressed signals may be demultiplexed or individually extracted from the data stream and passed from the cable headend over the cable system to the subscriber's set-top terminal. Within the set-top terminal, the individual compressed signals are decompressed and either placed in local storage (from which the menu template may be created), executed immediately, or sent directly to the screen. A combined alpha, numeric and iconic remote control device provides the subscriber interface to the system.
Through this interface, the subscriber may select desired programming through the systems menu-driven scheme or by directly accessing a specific channel by its actual number. The menu-driven scheme provides the subscriber with one-step access to all major menus, ranging from hit movies to specialty programs. From any of the major menus, the subscriber can in turn access submenus and minor menus by alpha character access. By using menu-driven, iconic or alpha-character access, the subscriber can access desired programs by simply pressing a single button rather than recalling from memory and pressing the actual channel number to make a selection. The subscriber can access regular broadcast and basic cable television stations by using either the numeric keys on the remote control and pressing the corresponding channel number, or one of the menu icon selection options.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic of the overall system design.
FIG. 2 is a schematic of the primary components of the invention.
FIG. 3 a is a diagram of the bandwidth allocation for a 750 mHz system.
FIG. 3 b is a diagram/chart of the compressed channel allocation for the system.
FIG. 3 c is a diagram showing how three cable television systems with different bandwidths may use the program delivery system of the present invention simultaneously.
FIG. 3 d is a diagram showing three different cable headend systems, each system receiving the entire satellite signal and stripping those parts of the signal which cannot be handled by the local cable system.
FIG. 3 e is a diagram showing dynamic change in bandwidth allocation from a typical week day prime time signal.
FIG. 4 a is a block diagram of the Operations Center and Master Control Site.
FIG. 4 b is a block diagram of the computer assisted packaging shown in FIG. 4 a.
FIG. 5 is a flow chart of the processing occurring at the Operations Center.
FIG. 6 is a chart of the program control information carried by the program control information signal.
FIG. 7 a is a block diagram of the internals of the set top terminal.
FIG. 7 b is a block diagram of an alternative embodiment of the internals of the set top terminal.
FIG. 8 a is a perspective front view of a set top terminal.
FIG. 8 b is a perspective rear view of a set top terminal.
FIG. 9 a is a schematic of a basic decompression box and upgrade module, with the associated connections.
FIG. 9 b is a schematic of an alternative embodiment of a simple decompression unit and upgrade module, with associated connections.
FIG. 10 a is a drawing of storage for on-screen menu templates stored in graphics memory of the set top terminal.
FIG. 10 b is a drawing showing the hierarchical storage of graphics memory for the set top terminal.
FIG. 10 c is a drawing of a flow chart showing the steps required for the microprocessor to retrieve, combine and display a menu.
FIG. 10 d is a drawing of a flow chart showing the steps required for the microprocessor to sequence program menus.
FIG. 11 a is a schematic showing the two parts of a remote control unit.
FIG. 11 b is a drawing of the complete remote control derived from FIG. 11 a.
FIG. 12 a is a perspective view of the preferred remote control unit of the present invention.
FIG. 12 b is another drawing of the preferred remote control unit shown in FIG. 12 a.
FIG. 13 is a flow chart of the progression of primary menus in the menu driven system of the set top terminal.
FIG. 14 a is a drawing of the basic menus used in the present invention, including the ten major menus represented by icons.
FIG. 14 b is a drawing of the basic menus used in the present invention, in addition to FIG. 14 a.
FIGS. 15 a - 15 b are drawings of introductory menus.
FIGS. 16 a - 16 e are drawings of menus related to program guide services.
FIGS. 17 a - 17 c are drawings of interactive television promotional menus, for Levels A-C.
FIGS. 17 d - 17 j are drawings of submenus for interactive television services, Level A.
FIGS. 18 a - 18 l are drawings of interactive services, Level B, particularly related to on-screen airline reservations.
FIGS. 19 a - 19 e are drawings of menus for digital audio services.
FIGS. 20-28 illustrate many of the menus presented in the preceding Figures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows an overview of the cable television menu driven program delivery system 200 . The Operations Center 202 is shown receiving external programming signals which correspond to particular programming categories that are available for a subscriber's viewing. These external signals may be in analog or digital form and may be received via landline, microwave transmission, or satellite. Some of these external signals may be transmitted from the program source to the Operations Center 202 in compressed digital format or other nonstandard digital formats. These external signals are received and packaged along with programming that is stored at the Operations Center 202 (not shown here).
Examples of external program sources 204 shown in FIG. 1 are: Sporting events, children's programs, documentaries, high definition TV sources, specialty channels, interactive services, weather, news, and other nonfiction or entertainment. Any source that can provide either audio or video or both may be utilized to provide programming to the Operations Center 202 .
After packaging, the packaged television program signal is prepared for satellite transmission 206 and sent from the Operations Center 202 to the cable headend 208 via satellite transmission 206 . Depending on the specific embodiment, the television program signal may need to be compressed, combined/multiplexed, encoded, mapped, modulated, upconverted and amplified. This system, which is intended to be compatible with existing C and Ku Band satellite transmission 206 technologies, accepts video, audio and data signals ranging in signal quality, and input from a number of sources.
Upon receipt of the programming signal at the cable headend 208 , the signal is again treated if necessary and sent into a concatenated cable system to the subscriber's home. The signal reaches the subscribers home in a compressed format and must be decompressed prior to viewing. Included in the delivered program signal is information which enables equipment at the subscriber's home to display menus for choosing particular programs. Depending on the particular embodiment, the television program signal may arrive at the subscriber's home via one or more coaxial cables, fiber cables, twisted pairs, cellular telephone connections, or personal communications network (PCN) hookups.
This connection between the subscriber's home and the cable headend 208 allows for two-way communications. Utilizing this two-way communications, the cable headend 208 receives information about a subscriber's account, billing, and programs viewed. Also, the cable headend 208 is capable of sending computer data or computer software information to the subscriber's home.
As shown in FIG. 1 , an analog cable TV system 210 can continue to exist alongside and within the digitally compressed system of the present invention. The digital transmissions do not effect the analog system. In fact, the analog cable signal may be transmitted simultaneously on the same cable as the digital signal. The cable headends may continue to supply subscribers with local channels in an analog signal format.
FIG. 2 shows a more detailed overview of the operation of the present invention. The Operations Center 202 shown performs program packaging and delivery control. In the preferred embodiment, the packaged program signal will be treated at a master control uplink site 211 prior to being transmitted to the satellite 206 . Various satellite multi-accessing schemes and architectures can be used with the system, including both single channel per transponder time division multiplex (TDM) and multiple channel per transponder single channel per carrier (SCPC). Time division multiplexing is the more desirable scheme. The signal is transmitted from the satellite 206 to the cable headend 208 where a computer system including a digital switch treats the signal and delivers it through cables to a subscriber's home. In alternate embodiments, multiple Operations Center 202 and multiple uplink sites can be simultaneously utilized.
In the embodiment shown in FIG. 2 , two cables 216 are used between the cable headend 208 and the subscriber's home. In this particular embodiment, analog signals, digitally compressed signals, other digital signals and up-stream/interactivity signals are sent and received over the two cables 216 .
The cable headend 208 receives the digitally compressed and multiplexed signal from the satellite 206 and processes the signal for further distribution to the subscriber homes. The cable headend 208 performs two primary functions in the cable delivery system. It will act as a signal processor 212 and distribution center for routing the digitally compressed signals to subscribers and it will act as a network controller 214 receiving information from subscribers and passing the information on to the Operations Center 202 or other remote sites (such as regional, statistical and billing sites not shown). In order to perform these two functions, the cable headend 208 of the preferred embodiment is equipped with two computer processors working in unison. Use of two processors performing different functions increases the speed and capability of the cable headend 208 without a significant increase in cost. One processor, the signal processor 212 , handles the receiving and processing of the satellite 206 signal for distribution to subscribers. The second processor acts as a network controller 214 and monitors activity of the subscriber's set top terminal 220 . The cable headend 208 can be operated by one CPU or a series of CPU's which perform the signal processing and network control functions.
The signal processor 212 will treat the signal as necessary for use by the subscriber's set top terminal 220 . In the simplest embodiment, the amount of processing that is necessary by the signal processor 212 is limited to demultiplexing and frequency allocation. However, in alternative embodiments, the signal processor 212 demultiplexes the signal, allocates frequencies and then re-multiplexes the signal using a different multiplexing scheme prior to the signal's distribution to the subscriber. In addition, for embodiments in which the control of local availability time is desired at the cable headend 208 , the signal processor 212 must be capable of compressing and adding additional signals to the satellite 206 signal. In order to incorporate local programming, the signal processor 212 would demultiplex the satellite 206 signal, compress the local programming, combine the compressed local program with the satellite 206 signal and then multiplex the signal prior to delivery to the subscriber terminals. Most of the activities necessary for incorporating local programming will be automatically performed by the signal processor 212 . In the preferred embodiment, the signal processor 212 incorporates all the necessary digital switching capability to serve numerous subscribers.
Signals received by the cable headend 208 must be decompressed before transmission from headend to subscriber location only when the compression algorithm used for the cable system differs from the one used for satellite transmission 206 . This difference may result from different bandwidth constraints between the cable transmission media and the satellite 206 transponder. Such a difference would necessitate the use of separate compression algorithms to maintain desired signal quality and throughput over both of the transmission mediums.
System control is performed by the network controller 214 . The primary task of the network controller 214 at the cable headend 208 is to manage the configuration of the set top terminals, which includes receiving and processing signals from the set top terminal units. The network controller 214 must also monitor selections at subscribers' homes, maintain accurate account and billing information, authorize subscriber channel access, and authorize particular set top terminals to operate in the system. Information required to operate the network will be stored in memory (either in RAM, ROM, magnetic or optical Read/Write) at the cable headend 208 and also in memory (RAM and/or ROM) within each subscriber's set top terminal 220 . Two-way communications between the network controller 214 and set top terminal 220 will occur over cable lines. Interactive television programming can be accommodated through the network controller 214 . In addition, the network controller 214 will be able to access set top terminals via phone lines for trouble shooting, special features or sophisticated reprogramming.
The network controller 214 regularly polls each set top terminal 220 to acquire needed information to operate the system. The network controller 214 sends signals to set top terminals to authorize their operation and to authorize access to specific channels. If a subscriber has failed to pay a recent bill, the network controller 214 can deauthorize the subscriber's set top terminal 220 . When a subscriber orders a program or channel the network controller 214 checks the subscriber's account for good standing and then authorizes the access by signaling the set top terminal 220 .
To perform its functions, the network controller 214 must work closely with the signal processor 212 . In many instances the program control information signal received from the Operations Center 202 must be modified prior to being sent to the set top terminals. These modifications to the program control information are made by the network controller 214 working in conjunction with the signal processor 212 to send a set top terminal 220 control information stream (STTCIS). From the signal processor 212 , the network controller 214 receives the program control information signal which includes cable franchise specific information added by the Operations Center 202 . The network controller 214 modifies the program control information signal, if necessary, and communicates the new information to the signal processor 212 . The signal processor 212 then forwards the information to the set top terminal 220 in the form of the STTCIS. In most instances the network controller 214 will modify the program control information signal by adding additional information. In a simple embodiment the program control information signal can be passed through the cable headend 208 to the set top terminal 220 without any modifications.
Although the signal processor 212 will handle the addition of simple local availabilities (e.g. local advertisements) into the signal sent to the set top terminal 220 , the network controller 214 will handle any of the more sophisticated local programming needs such as interactive programming and certain data services. The network controller 214 will receive any electronic signals sent by the set top terminal 220 including those in response to interactive service requests and some data service requests. The network controller 214 coordinates the necessary switching and access to allow the subscriber to enjoy these services.
The network controller 214 has the capability of performing “on the fly programming” changes, assisting in masking portions of subscriber's television screens (split screen video), assist in selecting different audio signals for the same video (foreign languages), assist in interactive features, create tiered programming, etc. For last minute changes to programming (such as for a local emergency or important regional events), an operator using the network controller 214 can modify the program control information signal “on the fly” and change menus available to the subscriber. This accommodates short notice changes to program packaging that can not be provided to the Operations Center 202 in advance. In order to accommodate split screen techniques for promo and demo video (which will be described later), those undesired video portions of the screen must be masked. The network controller 214 can send the necessary control information to inform the set top terminal 220 to mask portions of a specific channel's video. For example, a video channel with a split screen showing four separate videos would require a ¾ mask to focus the viewer on the featured video clip.
Tiered programming allows different users to view different video even though they are “tuned” to the same channel. For example, the network controller 214 may know the demographics of its subscriber's through a database, by “learning” from prior subscriber choices, from an interactive selection, or from other means. Using the demographics information, the network controller 214 may target commercials to the correct audience by showing different commercials to subscriber's with different demographics. Even though subscriber's will believe they are “tuned” to one channel, they will be switched to a different channel for the tiered video. Alternatively, the subscriber's may be offered an option of several commercials from which to choose.
To accommodate foreign speaking subscribers, multiple audio channels for television programming may be provided. The subscriber may be shown menus of programs available in his native language. The function of choosing the correct audio to correspond to the selected language may be handled by either the set top terminal 220 or the network controller 214 depending upon the configuration. Local programming in several languages or additional audio channels for a foreign language translation of a popular television program may be provided by the network controller 214 . Using a picture-on-picture feature, sign language may be similarly made available to certain set top terminals for the deaf. Also, a text overlay may be easily produced on the lower part of the screen for the deaf.
In the more sophisticated and expensive embodiments, the network controller 214 can act as a central computer and provide intra-set top terminal interactive games, inter-set top terminal interactive games, computer bulletin board type services, message services (Electronic mail) etc. For example, a subscriber may play war games with six of his (anonymous) fellow subscribers each in their own home each operating a separate tank. The network controller 214 gathers the players via set top terminal communications and acts as the referee. A bulletin board or message system can be set up to discuss a particular program such as “Twin Peaks Whodunit” for enthusiasts. These interactive features are further described below with the interactive services level B menu and the set top terminal hardware upgrade level B interactive unit.
Also shown in FIG. 2 is the set top terminal 220 that receives the signals from the cable headend 208 and manipulates them for the subscriber. The set top terminal 220 is equipped with local computer memory and the capability of interpreting the digitally compressed signal to produce menus for the subscriber. Although the set top terminal 220 is shown on top of the subscriber's television 222 , it may be placed anywhere in the subscriber's home that is accessible by the remote control. The remote control communicates the subscriber's selections to the set top terminal 220 . The subscriber's selections are generally based upon menus or other prompts displayed on the television screen. A typical menu is shown in FIG. 2 on the television screen.
One of the achievements of the present invention is effective utilization of digital compression technology by packaging television programs into categories that allow easy access to television programs by consumers. With current digital compression techniques for video, the typical 50-channel capacity cable satellite receiving system can be increased to 300 channels. Presently, one transponder is used for each satellite delivered channel. The preferred embodiment uses 18 satellite transponders and compression ratios of 4/1 to 8/1 to achieve a capacity of 136 satellite delivered channels. More transponders or higher compression ratios can be used to deliver up to the channel capacity of any existing cable system.
Typical program packaging and delivery first involves the digitizing of the video signals. This is then followed by one of a variety of digital compression techniques that are available. Following compression the channels must be multiplexed and sent to the satellite 206 dish that will provide the uplink. A variety of multiplexing schemes may be used in the system. In some situations, it may be advantageous to use different multiplexing schemes in different parts of the overall system. In other words, one multiplexing scheme may be used for satellite transmission 206 and a second remultiplexing scheme for the land transmission.
Once the signal has arrived at the uplink or master control site, it must be modulated, upconverted, and amplified. Various types of satellites and transponders capable of handling digital signals may be used in this cable television packaging and delivery system. An example of a digital satellite that may be used is the AT&T Telstar 303 .
In order to achieve the required throughput of video and audio information for the system, digital compression techniques for video are employed. A television signal is first digitized. The object of digitization is two-fold: First, in the case of an analog signal, like a television picture, digitization allows the signal to be converted from a wave-form into a digital binary format. Secondly, standard digital formats are designed to have the resulting pictures or video stills take up less space on their respective storage mediums. Essentially, standard digital formats define methods of compression.
A video screen is divided into picture elements known as pixels. Images define one pixel at a time are referred to as “bit-mapped” images. Most compression techniques take the bit-mapped images and convert them into a series of mathematical algorithms both to reduce storage space and to allow for the mathematical manipulation of images that is often not possible with analog formats. This is possible because many images have pixels that repeat themselves. For example, a photograph of a blue, cloudless sky will have a great number of “repeating” picture elements. This redundancy can be represented with great precision by mathematical formulas. Finally, once images have digitized, the standard digitized formats also include techniques required to re-render the images into their final form, either fully bit-mapped or into an analog wave-form. There are three basic digital compression techniques: within-frame (intraframe), frame-to-frame (interframe), and within-carrier. Intraframe compression processes each frame in a television picture to contain fewer visual details and, therefore, the picture contains fewer digital bits. For example, information on blocks of pixels is sent rather than individual digitized pixels themselves. A six by six block of pixels contains thirty-six pixels. Each pixel can be defined by an eight-bit word. Therefore, a six by six block of pixels equals two hundred eighty-eight bits. If the information on the block rather than the individual pixels themselves, is transmitted, this reduces the amount of information transmitted. Blocks of various sizes may be used as is known by those skilled in the art.
Interframe compression transmits only changes between frames, thus omitting elements repeated in successive frames. Motion prediction technology and motion detection technology are necessary to determine what portions of a changing picture may be compressed. Therefore, if a block does not vary between several frames, the block is transmitted once, and repeated at the receive site for successive frames.
Within-carrier compression allows the compression ratio to dynamically vary depending upon the amount of changes between frames. If a large number of changes occur between frames, the compression ratio drops from, for example, sixteen-to-one to eight-to-one. If action is intense, the compression ratio may dip to four to one.
Various compression methods are used for the above techniques. In vector quantization, a block is compared to a library of standard blocks and a best fit comparison is made between the two. Each block in the library has a corresponding sixteen bit code. Only this code is transmitted to represent the block, rather than the actual block of pixels itself. Therefore, a two hundred eighty-eight bit block of pixels is converted into a sixteen bit code resulting in a compression ratio of 288 bits/16 bits ‘18. The converse process is performed at the receive site to convert the sixteen bit codes into two hundred eighty-eight bit blocks for reproduction on a television receiver. Other types of compression are known to those skilled in the art, including, for example, discrete cosine transform (“DCT”).
Several standard digital formats representing both digitizing standards and compression standards have been developed. For example, JPEG (joint photographic experts group) is a standard for single picture digitization. Motion picture digitization may be represented by standards such as MPEG or MPEG2 (motion picture engineering group specification). Other proprietary standards have been developed in addition to these. Although MPEG and MPEG2 for motion pictures are preferred in the present invention, any reliable digital format with compression may be used with the present invention.
Various hybrids of the above compression techniques have been developed by several companies including AT&T, Compression Labs, Inc., General Instrument, Scientific-Atlanta, Philips, and Zenith. As is known by those skilled in the art, any of the compression techniques developed by these companies, and other known techniques, may be used with the present invention.
FIG. 3 a shows effective allocation of 750 mHz of bandwidth for television programming. In FIG. 3 a bandwidth is allocated for both analog and digitally compressed signals. In the preferred embodiment, the bandwidth is divided so that each category of program receives a portion of the bandwidth. These categories correspond with major menus of the user interface software. The representative categories shown in FIG. 3 a include: (1) high definition TV made possible through the use of compression technology, (2) A La Carte Channel category which provides specialty channels for subscription periods such as monthly, and (3) pay-per-view.
FIG. 3 b shows a chart of compressed channel allocation for a variety of programming categories that have been found to be desirable to subscribers. By grouping similar shows or a series of shows into blocks of channels, the system is able to more conveniently display similar programming with on-screen television menus. For example, in the movie category, which has the greatest allocation of channels, the same movie may be shown continuously and simultaneously on different channels. Each channel starts the movie at a different time allowing the subscriber to choose a more suitable movie starting time.
In order to accommodate cable TV systems that have different bandwidths and channel capacities, the television programming and television program control information may be divided into parts such as priority one, two, three. The large bandwidth cable TV systems can accommodate all the parts of the television programming and all parts of the television programming control information. Those cable TV systems with a more limited bandwidth are able to use the program delivery system 200 by only accepting the number of parts that the cable system can handle within its bandwidth.
For instance, as is shown in FIG. 3 c , three cable television systems with different bandwidths may use the program delivery system 200 simultaneously with each system accepting only those parts of the information sent which it is capable of handling. Priority one television programming and menus 230 are accepted by all three systems. Priority two television programming and menus 233 are not accepted by the cable television system whose capacity is the smallest or in this case 330 mHz (40 channels) system. Priority two television programming and menus 233 are accepted and used by the two larger capacity cable television systems shown. Priority three television programming and menus 236 are only used by the largest capacity television system which is capable of handling all three parts—Priority one, two and three programming and menu information.
With this division of television programming and menus, the program delivery system 200 may be utilized simultaneously by a variety of concatenated cable systems with varying system capacities. By placing the heavily watched or more profitable programming and menus in the Priority one division, both users and owners of the cable TV systems will be accommodated as best as possible within the limited bandwidth.
FIG. 3 d shows three different cable headend 208 systems, each system receiving the entire satellite signal from the Operations Center 202 and stripping those parts of the signal which cannot be handled by the local cable system due to bandwidth limitations. In this particular embodiment, the three local cable television systems shown have bandwidth limitations which correspond with the bandwidth limitations depicted in the previous FIG. 3 c . As the bandwidth decreases, the programming options available to the viewer in the exemplary on-screen menu decreases. Using this preferred embodiment, the Operations Center 202 is able to send one identical signal to the satellite 206 that is sent to all the cable headends. Each cable headend 208 accepts the entire signal and customizes the signal for the local cable system by stripping those portions of the Operations Center 202 signal that are unable to be handled by the local cable system. An alternate embodiment requires the Operations Center 202 to send different signals for reception by different capacity cable headends.
There are several ways in which the cable headend 208 may strip the unnecessary signal from the Operations Center 202 . A person skilled in the art will derive many methods from the three examples discussed below. One simple method is for the cable headend 208 receiver to receive the entire signal and then manipulate the signal to strip away those unnecessary portions. A second method is for the signal to be sent in three portions with each portion having a separate header. The cable headend 208 would then recognize the headers and only receive those signals in which the proper header is identified. For the second method, the Operations Center 202 must divide the signal into three parts and send a separate header lead before each signal for each part.
The third and preferred method is for a set of transponders to be assigned to one priority level and each cable headend 208 to receive signals from the transponders corresponding to the proper priority level. For example, if there are three priority levels and 18 transponders, transponders one through nine may be assigned to priority level one, transponders ten through fourteen priority level two, and transponders fifteen through eighteen assigned to priority level three. Thus, a cable headend 208 capable of operating at priority level two only would only receive signals from transponders one through nine, and ten through fourteen.
In addition to dividing the television programming and menus into parts, the Operations Center 202 of the preferred embodiment is also capable of dynamically changing the bandwidth allocation for a particular category of programming. FIG. 3 e depicts this dynamic change in bandwidth allocation from a typical week day prime time 238 signal to a Saturday afternoon in October 240 (during the college football season). FIG. 3 e highlights the fact that the bandwidth allocated to sports is limited to eight selections during week day prime time 238 but is increased to sixteen selections during a Saturday afternoon in October 240 . This dynamic increase in bandwidth allocation allows the system to accommodate changes in programming occurring on an hourly, daily, weekly, monthly, seasonal and annual basis.
In addition to dynamically allocating bandwidth for programming categories, the Operations Center 202 can also dynamically change the menu capacities in order to accommodate the change in programming and bandwidth. For example, on a Saturday afternoon in October 240 , the major menu for sports may include a separate subcategory for college football. This subcategory would, in turn, have a separate submenu with a listing of four, six, eight, or more college football games available for viewing. In order to accommodate this dynamic menu change, the Operations Center 202 must add a submenu listing to the major sports menu, create a new or temporary submenu for college football, and allocate the necessary menu space on the college football submenu.
Once the television programs have been packaged and a program control information signal is generated to describe the various categories and programs available, the packaged programs are then digitized, compressed, and combined with the program control information signal. Upon the signal's departure from the Operations Center 202 the breakdown into categories is insignificant and the signal is treated like any other digitally compressed signal.
FIG. 4 a shows the basic operations that must occur in order for the packaged signal to be sent to the satellite 206 . External digital and analog signals must be received from television programming sources and converted to a standard digital format 242 , defined above for the computer assisted packaging equipment (CAP) 246 . Also within the Operations Center 202 , stored programs 244 must be accessed using banks of looping tape machines or other video storage/retrieval devices, either analog or digital, and converted to a standard digital format 242 prior to use by the CAP 246 .
The programmer/packager utilizing the CAP 246 must input a variety of information in order to allow the CAP 246 to perform its function of generating program control information and packaging programs. Some of the information required by the CAP 246 are the date, time slots and program categories desired by the television programmer.
The CAP 246 system includes one or more CPUs and one or more programmer/packager consoles. In the preferred embodiment, each packager console includes one or more CRT screens, a keyboard, a mouse (or cursor movement), and standard video editing equipment. In large Operations Centers 202 s multiple packager consoles may be needed for the CAP 246 .
As shown in FIG. 4 b , the first step in the operation of the CAP 246 is selecting the type of programming 248 which will be packaged. Basically there are 6 broad categories in which most television programming can be classified: static programming 250 , interactive services 252 , pay per view 254 , live sports specials 256 , mini pays 258 , and data services. Static programs are programs which will show repetitively over a period of time such as a day or week. Static programs include movies showing repetitively on movie channels, children's programs, documentaries, news, entertainment.
Interactive services includes interactive programs using the Vertical Blanking Interval (VBI) or other data streams synchronized with the programming to communicate interactive features (such as those used in education), and games. Pay per view are programs which are individually ordered by the subscriber. After ordering, the subscriber is authorized to access the program for a limited time, (e.g. three hours, two days, etc.). Live sports specials are live events usually related to sports which subscribers are unlikely to watch on taped delay.
Mini pays are channels to which each set top box may subscribe. The subscriptions for mini pays 258 may be daily, weekly, or monthly. An example would be the Science Fiction channel. Data services are services in which information is interactively presented to the subscriber using a modem or other high rate of speed data transfer. Some examples are Prodigy, services for airline reservations, and TV guide services (e.g. TV Guide X*PRESSJ, InSightJ, etc.). Data could also include classified or other forms of advertising.
After selecting the type of programming, the packager must identify a pool of programs (within the category) to be packaged. The next CAP 246 step varies for different program categories. For the category of live sports, additional program interstitial elements 262 may be added such as promos and other sports news before further processing. For the live sports, static, interactive services 252 and pay per view 254 categories the following CAP 246 step is for one television program to be selected 264 . This is followed by each program individually being assigned dates to be played or a start date (for continuous play) and start times 266 . Many dates and start times may be assigned to any given program. The program information for these categories may then be processed for allocation of transponder space and setting of prices.
Mini pays and data services require less processing by the CAP 246 . After identifying the mini pays 258 , the CAP 246 may proceed to allocation of transponder space and pricing for the mini pays 258 . Data services in the preferred embodiment generally do not require allocation of transponder space and generally do not require price setting. The information for data services 260 may be directly processed for menu configuration. In alternate embodiments the data services 260 may be processed through these portions of the CAP 246 program.
The CAP 246 then uses an interactive algorithm to allocate transponder space 268 and set prices 270 . The factors weighed by the algorithm are: 1. buy rates of the program, 2. margin of profit on the program, 3. length of the program, 4. any contractual requirement which overrides other factors (such as requirement to run a specific football game live in its entirety). The information on buy rates of the program may be obtained from the Central Statistical and Billing Site or a Regional Statistical and Billing Site as will be described later. The CAP 246 must consider the priority levels of programming when allocating transponder space. Particularly, as in the preferred embodiment, transponders are assigned to three specific priority levels.
Following transponder allocation and price setting, the CAP 246 proceeds to menu configuration 272 . The positioning of programs within the menu configuration 272 can have an effect on subscriber buy rates for the program. Therefore, an algorithm accounting for either a manually assigned program importance, or a calculated weight of the program importance, is used to determine each programs position within the menu scheme. For instance, a popular program with a high profit margin may be assigned a high weight of importance and shown in a prominent place in the menu scheme. Alternatively, a high profit program with sagging sales may be manually assigned a prominent place in the program schedule to increase sales.
After a series of entries by the programmer/packager at the Operations Center 202 , the CAP 246 displays draft menus or schedules (including priority levels) for programming. The packager may now manipulate the menus and schedules and make changes as he feels necessary. After each change, the packager may again display the menus or schedules and determine if any more changes are necessary. When the packager is satisfied with the menu configuration 272 and scheduling of television programs, he may then instruct the CAP 246 to complete the process.
After menu configuration 272 , the CAP 246 may begin the process of generating a program control information signal 274 . In order to generate program control information signals which are specific to a particular cable headend 208 system, the CAP 246 incorporates cable franchise configuration information 276 . In the preferred embodiment, basic cable franchise configuration information 276 is stored at the Operations Center 202 . The cable franchises upload changes to their specific franchise information from time to time to the Operations Center 202 for storage. Preferably a separate CPU handles the management of the cable franchise information. From the stored cable franchise information, the CAP 246 generates a cable franchise control information signal which is unique to each franchise.
Using the unique cable franchise control information signals 278 and the menu configuration 272 information, the CAP 246 generates the program control information signal 274 . The program control information that is unique to a particular cable franchise may be identified in various ways such as with a header. With the header identification, the cable headend 208 may extract the portions of the program control information signal which it needs. Now, the CAP 246 may complete its process by electronically packaging the programs into groupings 280 for the signal transmission and adding the program control information to the packaged programs 282 to form a single signal for transmission. Through manual entries by the packager or by comparing against a list of programs, the CAP 246 will determine whether the programs are arriving from external sources 204 or sources internal to the Operations Center 202 .
Upon completion of the CAP's functions, the Operations Center 202 or the uplink site compresses 284 , multiplexes 286 , amplifies 288 and modulates 290 the signal for satellite transmission 292 . In a basic embodiment, the CAP 246 will also allow entry of time slots for local avails where no national programming will occur.
FIG. 5 is a more detailed flow chart of some of the functions performed by the CAP 246 after an initial program schedule has been entered and menu configurations generated. The flow chart 300 shows six basic functions that are performed by the CAP 246 : (1) editing program schedule for local availability 304 (only for non-standard services, i.e. those services that are not national cable services); (2) generating program control information signals 307 ; (3) processing external programs 310 ; (4) processing internal programs 320 ; (5) processing live feeds 330 ; and, (6) packaging of program information 340 . In an alternate embodiment, the CAP 246 is capable of incorporating local programs and accommodating local availability for local television stations.
Following completion of the programming scheduling (accounting for local availability if necessary) and menu generation 304 , the CAP 246 may perform three tasks simultaneously, generating program information signals 307 , processing external programs 310 and processing internal programs 320 .
The CAP 246 automatically identifies external programs needed 312 and identifies which external feed to request the external program 314 . The CAP 246 gathers and receives the external programming information and converts it to a standard digital format 316 for use. The CAP 246 also identifies internal programs 322 , accesses the internal programs 324 , and converts them to a standard digital format if necessary 326 . In addition, the CAP 246 identifies live signal feeds 333 that will be necessary to complete the packaged programming signal 336 . In its final task, the CAP 246 completes the packaging of the programs, combines the packaged program signal with the program control information signal, amplifies the signal and sends it out for further processing prior to uplink.
In the preferred embodiment, the Operations Center 202 and uplink or master control site are collocated. However, the Operations Center 202 and uplink site may be located in different geographical places. Also, functions and equipment within the Operations Center 202 may be remotely located. For instance, the program storage may be at a different site and the programs may be sent to the CAP 246 via landline.
In alternate embodiments using multiple Operations Centers, it is preferred that one Operation Center be designated the Master Operations Center and all other Operations Centers be Slave Operations Centers. The Master Operations Center performs the functions of managing and coordinating the Slave Operations Centers. Depending on the method in which the Slave Operations Centers share functions, the Master Operations Center coordination function may involve synchronization of simultaneous transmissions from multiple Slave Operations Centers. To perform its functions, the Master Operations Center may include a system clock for synchronization.
An efficient method of dividing tasks among Operations Centers is to assign specific satellite transponders to each Operations Center 202 and to assign external program sources 204 to the nearest Operations Center. Of course this division of resources may not always be possible. Since programming will be grouped into priority levels with each priority level likely to be assigned specific satellite transponders, it is also possible to assign each Operations Center to a priority level. For example, in a three priority level system with two Slave Operations Centers and 18 transponders, the Master Operations Center may be assigned priority level 1 and assigned 9 transponders. Slave Operations Center A may be assigned priority level 2 and 5 transponders, while Slave Operations Center B is assigned priority level 3 and 4 transponders. In a multiple Operations Center configuration dynamic bandwidth allocation and dynamic menu capacity allocation become more complex and must be coordinated by the Master Operations Center.
Similar to multiple Operations Centers, a delivery system may have multiple satellite uplinks. Preferably each Operations Center has one or more uplink sites. Each Operations Center controls the functions of its assigned uplink sites and may assign one site as a master uplink site.
The program control information signal generated by the Operations Center provides data on the scheduling and description of programs to the network controller 214 or in an alternate configuration directly to the set top terminal 220 for display to the subscriber. In the preferred embodiment, the program control information signal is stored and modified by the network controller 214 and sent to the set top terminal 220 in the form of a set top terminal control information stream (STTCIS). This configuration is required to accommodate differences in individual cable systems and possible differences in set top terminal devices. The set top terminal 220 integrates either the program control signal or the set top terminal control information stream together with data stored in the memory of the set top terminal 220 , to generate on-screen displays for assisting the subscriber in choosing the programs he wishes to view. (Throughout the description the term “program control information” is being used to indicate control information coming from the cable headend 208 to the set top terminal 220 , whether it is sent directly from the Operations Center, processed by the Network controller 214 and then forwarded to the set top box (STTCIS), or transmitted over telephone lines.)
The types of information that can be sent via the program control signal include: number of program categories, names of program categories, what channels are assigned to a specific category (such as specialty channels), names of channels, names of programs on each channel, program start times, length of programs, description of programs, menu assignment for each program, pricing, whether there is a sample video clip for advertisement for the program, and any other program, menu or product information.
The goal of the menu driven program selection system is to allow the subscriber to choose a program by touring through a series of menus utilizing a remote control for cursor movement. The final choice in the series of menus will identify one particular channel and one time for activation of that channel. Armed with a channel and activation time the set top terminal 220 can display the selected program on the television for the viewer. To achieve this goal a simple embodiment assigns an intelligent alpha-numeric code to each program. This alpha-numeric code identifies the category of the program, the menu in which the program should be displayed, its transmission time(s), and the position on the menu that the program should be displayed.
In this simple embodiment, the program control information, including these menu codes, is sent continuously from the Operations Center to the network controller 214 , and ultimately to the set top terminal 220 . For example, four hours worth of programming information can be sent via the program control information signal continuously in the format shown in FIG. 6 .
FIG. 6 shows the basic information that is needed by the set top terminal 220 . The program descriptions shown are coded abbreviations. For example, C for comedy, N for news, S for sports, A for cartoons, and TX for text. If there is a textual description for a program, such as a movie, the description may be given following that program's coded description or may be communicated following the four hours' worth of programming information. As is shown in the coded listing, program descriptions for programs greater than a half hour in length need not be repeated (each half hour). The video description code informs the set top terminal 220 of whether there is still or live video available to advertise the program.
For example, a sporting program may be assigned a code of B35-010194-1600-3.25-Michigan St. vs. USC. The letter B would assign the program to category B, sports. The second alpha-numeric character number 3 would assign the program to the third menu of the sports category. The third character of the code, number 5, assigns the program to the fifth program slot on the third menu. The next six characters, Jan. 1, 1994, represent the date. The following four characters, 1600 represent the start time which is followed by the length of the program and the program name. This entry represents a sports show, a college football game, which will be aired at 4:00 PM on New Years day 1994.
In the 12:30 Channel 1 entry of FIG. 6 , two menu codes are shown. By allowing two menu codes, programs that may fit under two different category descriptions may be shown in both menus to the subscriber. With this minimal amount of information being communicated to the set top terminal 220 on a regular basis, the terminal is able to determine the proper menu location for each program and the proper time and channel to activate for the subscriber after his menu selection.
The program control information signal and STTCIS can be formatted in a variety of ways and the on-screen menus can be produced in many different ways. For instance, if the program control information signal carries no menu format information, the menu format for creating the menus can be fixed in ROM at the set-top terminal. This method allows the program control signal to carry less information but has the least flexibility since the menu formats can not be changed without physically swapping the ROM holding the menu format information. In the preferred embodiment, the menu format information is stored at the set top terminal 220 in temporary memory either in a RAM or EPROM. This configuration provides the desired flexibility in the menu format while still limiting the amount of information needed to be communicated via the program control information signal. New menu format information would be sent via the program control information signal or the STTCIS to the set top terminals each time there was a change to a menu.
In the simplest embodiment, the menus remain fixed and only the text changes. Thus, the program control information signal can be limited to primarily text and a text generator can be employed in the set top terminal 220 . This simple embodiment keeps the cost of the set top terminal 220 low and limits the bandwidth necessary for the program control information. Another simple embodiment uses a separate channel full-time (large bandwidth) just for the menu information.
As will be described later, live video signals may be used in windows of certain menus. These video signals can be sent via the program control information signal, STTCIS, or can be taken off channels being transmitted simultaneously with the menu display. If the video signal is taken off a channel, less information needs to be sent via the program control information signal. However, this technique requires that separate decompression hardware be used for the program control information and the channel carrying the video. Separate decompressors for the video signals and program information signal allows for the greatest flexibility in the system and is therefore the preferred embodiment. A separate decompressor also assists in assuring that the switch from menus to television programming is smooth and without any significant time delay.
Live video for menus, promos or demos may be sent to the set top terminal 220 in several ways: a) on a dedicated channel, b) on a regular program channel and scaled to size, c) sent along with the program control information signal, etc. However, in the preferred embodiment, a great deal of short promos or demo video are sent using a split screen technique on a dedicated channel.
Using a split screen technique, any number of different video clips may be sent (e.g. 2, 4, 6, 8). To show the video clip on a menu, the video must either be scaled and redirected to a video window on a menu screen or a masking methodology can be used. Masking involves playing the entire channel of video (all 2, 4, 6, or 8 split screens) in background and masking the unwanted video clip portions of the split screen by playing the menu in foreground and overlaying the unwanted background video. Masking is the least expensive method because it does not require any special hardware and it increases video throughput to the set top terminal 220 . However, using the masking technique without any video redirecting causes each video clip to be located in a different position on the screen. It also requires the masking to be different for each video clip and makes consistent format difficult. Scaling and redirecting video is generally difficult, expensive and requires additional hardware.
In order to limit the amount of bandwidth needed to transmit the program control information signal, various compression techniques employed for non-video may be used such as block coding, contour coding, blob encoding, and run-length encoding. Further, the program control information signal may be divided into text and graphics, or video, text and graphics and then recombined at the set top terminal 220 using a text generator, graphics decompression, and video decompression as necessary.
FIG. 7 a shows a basic block diagram of a digital compression set top terminal 220 . In some respects, the set top terminal 220 is similar to other converter boxes currently available and can include a variety of error detection, decryption 600 and coding techniques such as anti-taping encoding. The set-top terminal must also have a tuner 603 , digital demodulator 606 , and demultiplexers 609 , 616 as well as audio equipment 612 , 614 . Also shown in FIG. 7 a is a remote control interface 626 for receiving and processing signals from remote control unit 900 . A modem 627 is provided for allowing communication between a microprocessor 602 and the cable head end. NTSC encoder 625 provides an NTSC video output to be output as a standard television signal.
The microprocessor 602 is capable of executing program instructions stored in memory. These instructions allow a user to access various menus by making selections on the remote control 900 . The various program instructions for accessing menus and performing other functions are described below.
The manner in which the video is decompressed and the menus are generated from the program control signal or STTCIS varies depending on the specific embodiment of the invention. However, at a minimum, one video decompressor capable of decompressing one video signal must be used. Basic menu format information may be stored in a graphics memory comprising ROM, non-volatile RAM, EPROM, and/or EEPROM 620 . Video decompressors 618 and 622 may be used if the video is compressed, and additional equipment to generate menus may be included. In one embodiment, a separate decompressor 622 is used to process the program control information signal and a video combiner 624 incorporates video and menu graphic information. In the preferred embodiment, the program signal is sent with three primary parts, compressed video (or video location information), compressed graphics, and text. After the program signal is demultiplexed into its component parts, a video decompressor, a graphic decompressor, a text generator and a combiner are used to assist in creating the menus.
FIG. 7 b shows a basic block diagram of an alternative digital compression set top terminal 220 . The same components shown in FIG. 7 a are repeated in FIG. 7 b , and given the same reference number (e.g., tuner 603 , modem 617 , NTSC encoder 625 , etc.). FIG. 7 b also shows the addition of a smart card interface 617 to allow additional features to be included on a smart card insertable into the smart card interface 617 . Error correction circuitry 607 is also shown receiving the demodulated signal, prior to demultiplexing the signal. Memory associated with the microprocessor 602 , the demultiplexer 609 , the decryptor 600 , and the video decompressor 618 is shown in FIG. 7 b.
Box 700 in FIG. 7 b shows the elements of an upgrade module which is described below with respect to FIGS. 9 a and 9 b . The remaining circuitry in FIG. 7 b shows a basic decompression box 720 , also described below.
The circuitry in box 700 includes a video, graphics and text demultiplexer 616 , a text and graphics video plane combiner 624 , a graphic decompressor 622 and a graphics memory 620 . Graphics in memory 620 is preferably run-length compressed, however other methods of compressing graphics may be used as is known by those skilled in the art.
The generated menus and video are combined in the combiner 624 and output to an anti-taping encoder 619 . Any method of anti-tapping encoding known by those skilled in the art may be used with the present invention.
FIGS. 8 a and 8 b show front and back views respectively for the preferred embodiment of the set top terminal 220 . The front panel of the set top terminal 220 as shown in FIG. 8 a includes an infrared sensor 630 and a series of LED displays 640 . These LED displays 640 preferably indicate with an icon or a letter (e.g. A-K) the major menu currently selected by the set top terminal 220 . This visual display will remain lit while the subscriber is watching (or listening to) programming within a major menu. The LEDs 640 of the preferred embodiment also show the channels selected directly by a user, or menu channel selections which range from 1 to 50.
LEDs 640 are preferably provided to indicate a decompression error, a processing error, or other error. Text messages may alternatively be provided to more clearly indicate particular errors to servicemen or subscribers. These error indications aid in repairing or correcting any such errors in the set top terminal 220 or assist in programming the set top terminal 220 . Further displays may include current channel, time, volume level, sleep time, parental lock (security), account balance, use of a hardware upgrade, second channel being recorded by VCR, use of the Level D music hardware upgrade in a separate room, and any other displays useful to a subscriber to indicate the current status of the set top terminal 220 .
The LED's 640 may also provide an indication of the digital audio channel currently tuned. With this display feature, subscribers may use the digital audio feature without activating the television screen. The source of a signal and output selected (e.g., a subscriber's separate audio system, a VCR, etc.) may be displayed. Although LED's are preferred, the set top terminal 220 may also use a CRT, LCD's, or other display technology.
On the right front half of the set top terminal 220 there is a flapped opening 635 into a cavity that allows the insertion of a magnetic cartridge (or similar portable storage device, including optical disk, ROM, EPROM, etc.). This cartridge opening 635 allows the set top terminal 220 to be upgraded or reprogrammed locally with the use of a magnetic tape cartridge. Game cartridges may also be accepted through a similar flapped opening allowing the subscriber to play video games using the set top terminal 220 .
On the top or cover of the set top terminal 220 are located pushbutton controls 645 . In the preferred embodiment these pushbutton controls 645 duplicate the two-part alpha-iconic remote control that will be described later. Any function that can be performed on the remote may also be performed at the set top terminal 220 using the duplicative pushbutton controls 645 .
FIG. 8 b provides a rear view of one embodiment of the set top terminal 220 including the input/output equipment of the terminal. Moving from left to right there are a pair of output terminals 650 , a pair of input terminals 652 , a pair of stereo/audio output terminals 654 , a satellite dish input port 656 , a telephone jack 658 and an RS422 port 660 . Further to the right there is an upgrade port 662 and a cover plate 664 held in place by a series of sheet metal screws.
The set top terminal 220 has two outputs 650 , one for a television and one for a VCR. Control signals may be transmitted through the VCR output to allow the VCR to be automatically controlled by the set top terminal 220 . Certain program may be selected by a subscriber from menus, and the VCR will be automatically activated to record the selected program.
The set top terminal 220 is equipped to handle one or two cable inputs by way of inputs 652 for incoming signals. In addition, a phone jack 658 and RS242 or 422 port 660 are provided for maintenance, trouble shooting, reprogramming and additional customer features. In alternate embodiments, the telephone jack 658 may be used as the primary mode of communication between the cable headend 208 and the set top terminal 220 . This connection is possible through the local telephone companies, cellular telephone companies or personal communications networks (PCN).
In an alternative configuration, in areas without cable services where subscribers use backyard satellite systems (TV RO) to receive packaged television services, the set top terminal 220 will include the appropriate hardware to allow connection to the satellite 206 reception equipment through port 656 . In this configuration, the menu system within the set top terminal 220 will be programmed directly from the operations center. Additionally, an upstream communication mechanism must be in place at the subscriber's home (i.e. modem) to communicate information to the operations center.
In order to provide the greatest flexibility possible and prevent the set top terminal 220 from becoming outdated during the terminal's useful life, an additional electronic card slot or expansion slot has been built into the preferred embodiment. This expansion slot is covered by the metal plate cover 664 shown in FIG. 8 b . It is anticipated that additional memory or capabilities may be needed for certain customer features and also to update the system as the cable delivery system's capabilities increase. The expansion slot provides an easy method to upgrade the terminal hardware.
In the preferred embodiment, the set top terminal 220 includes a hardware upgrade port 662 as shown in FIG. 8 b , in addition to the expansion slots behind plate 664 . The hardware upgrade port 662 should accommodate at least a four-wire connection for: (1) error corrected, decrypted data output of the set top terminal 220 , (2) control interface, (3) decompressed video output of set top terminal 220 , and (4) video input port. In the preferred embodiment multiple wires are used to perform each of the four functions. The four sets of wires are combined in a single cable with a single multipin connector. Port 662 may also be used to attach various hardware upgrades below to a set top terminal 220 .
In the preferred embodiment, multipin connections may be used for the multiwire cable. The multipin connection 662 may range from DB9 to DB25. A SCSI, or small computer systems interface, port may also be provided. Alternatively, four or more ports may be provided instead of the single port depicted.
The preferred embodiment has four hardware upgrades available for a set top terminal 220 : a Level B interactive unit, a Level C interactive unit with compact disc capability, a Level D digital radio tuner for separate room use, and a Level E information download unit. Each of these upgrades is connected to the set top terminal 220 unit via the same upgrade port 662 described earlier. The same four wires in a single cable described earlier may be used.
The Level B interactive unit will allow the user access to online data base services for applications such as home shopping, airline reservations, news, financial services, classified advertising, home banking, and interactive teletext services. For example, with this upgrade, a user will be able to reserve plane tickets or buy consumer electronics. The primary feature of this upgrade unit is that it allows actual transactions to occur requiring two way communications via modem with outside services. This added two way communications capability may be with the cable headend 208 . Additionally, this two way communications may occur over cellular or PCN.
The Level C interactive unit will employ a high volume local storage capacity, including compact disc or other random access digital data formats. This unit will allow use of interactive multi-media applications. For example, computer games, multi-media educational software, encyclopedias, other reference volumes (e.g. Shakespeare library), etc. In the preferred embodiment, many of these applications will interact with live programming providing additional information and interactivity to the basic program feed. For example, a viewer watching a show set in a foreign country may be able to retrieve additional information, maps, economic data, etc. about that country that are stored on the compact disc. In the level C applications, the upgrade hardware may closely monitor the television broadcast via additional data channels (e.g. vertical blanking interval, or other digital data encoded within live video) providing context sensitive interactivity.
The Level D hardware upgrade, digital radio tuner, will allow the subscriber separate access to the digital radio channels while other programming (not necessarily radio) is being viewed on the television. Typically this upgrade would be used for digital radio usage in a separate room from that of the television. The upgrade has a separate tuner, decompressor, and visual display. In the preferred embodiment a second remote control (scaled down version) is provided to access the audio system.
The Level E hardware upgrade allows the subscriber to download large volumes of information from the operations center or cable headend 208 . The Level E hardware upgrade will enable subscribers to download data such as books to local storage. Primarily the Level E hardware upgrade is additional local storage via hard disk, floppy, optical disk, magnetic cartridge etc. Preferably a small portable reader called “everyBookJ” is also provided with the upgrade to enable downloaded text to be read without the use of a TV.
The downloadable information may be text or video supplied by the operations center or cable headend 208 . With this upgrade, books may be downloaded and read anywhere with the portable reader. Using this upgrade video may be downloaded and stored in compressed form for later decompression. The video would be decompressed only at the time of viewing. Important text that the public desires immediate access may made available through this system. Text such as the President's speech, a new law, or a recent abortion decision rendered by the Supreme Court may be made immediately available.
Using a more sophisticated port, especially the SCSI port, multiple hardware upgrade units may be connected, or “daisy-chained” together, to operate simultaneously.
FIG. 9 a shows sets of wires in a single cable connecting an upgrade module 700 and the simple decompression box 720 through a port similar to the hardware upgrade port 662 . The simple decompression box 720 preferably is an industry standard decompression box capable of communicating with an upgrade module to enhance functionality. For example, a microprocessor in the simple decompression box 720 will be able to communicate with a microprocessor in an upgrade module 700 .
Thus, as shown in FIG. 9 a , if this type of connection is built into a simple decompression box that does not have the full functionality of the set top terminal 220 , an upgrade module unit 700 may be connected providing the simple decompression box 720 with the full functionality of a set top terminal 220 . Subscribers who have purchased simple decompression boxes 720 may be given all the functions of a set top terminal 220 inexpensively.
In the preferred embodiment, multipin connections may be used for a multiwire cable connecting decompression box 720 with the upgrade module 700 . The multipin connection may range from DB9 to DB25. A SCSI, or small computer systems interface, port may also be provided. Alternatively, four or more ports may be provided instead of the single port depicted.
The digital data set of output wires of the simple decompression box 720 will preferably output error corrected and decrypted data to the upgrade set top terminal 700 . The second set of wires, the interface connection, allows the microprocessor in the upgrade module 700 to communicate to the microprocessor of the simple decompression box 720 . In this manner, the video circuitry of the upgrade module 700 and the simple decompression box 720 may be synchronized. The third set of wires, the decompressed video output, can provide the upgrade module 700 with a decompressed video signal to manipulate. The fourth set of wires, video input set, allows the simple decompression box 720 to accept a video signal that is a combined text, graphics, and video signal.
Upgrade module 700 preferably includes at least the following circuitry: a video, graphics and text demultiplexer; a text and graphics video plane combiner; a run-length graphics decompressor; and, a run-length compressed graphics memory (non-volatile RAM, ROM, EPROM, or EEPROM). By means of communications through the multi wire connection between upgrade modules 700 and simple decompression box 720 , compressed video and control signals may be demultiplexed by the demultiplexer within upgrade module 700 . The run-length graphics decompressor, by communicating with the run-length compressed graphics RAM, permits decompression of the input compressed video signal. The text and graphics video plane combiner in upgrade module 700 allows the demultiplexed and decompressed signal to be output, through simple decompression box 720 , to a subscriber's television with both video and overlay menus with text.
FIG. 9 a shows the CATV input 722 , the video input 724 , and the video and audio outputs 726 , 728 , as part of simple decompression box 720 . This is the preferred embodiment because this will reduce the component cost of upgrade module 700 . Upgrade module 700 could simply be a cartridge insertable into simple decompression box 720 . Alternatively, as shown in FIG. 9 b , the CATV input 722 , the video input 724 and the video and audio outputs 726 , 728 may be included as part of upgrade module 700 .
The electronics of the set top terminal 220 must receive signals from the Cable headend 208 or Operations Center and separate the program control information from the packaged programs. After separation of the program control information, this signal may be used to generate program menus allowing the user to select specific television programs from within the packaged programs. After selection of a particular program, the set top terminal 220 will demultiplex and extract a single channel signal then decompress the appropriate channel signal to allow the user to watch his selected program. Although the set top terminal 220 can be equipped to decompress all the program signals, this adds unnecessary cost since the subscriber will view one channel at a time. Upon the occurrence of an error in this selection and decompression procedure, the set top terminal 220 LED display will warn the subscriber of an error.
During the normal functioning of the set top terminal 220 the LED display can be customized by the user to display the time, the program channel, VCR activation or other pertinent information. Although the set top terminals may be operated using the keyboards located on top of the set top terminal 220 box, it is expected that most subscribers will use the remote control.
Although the preferred embodiment decompresses one channel at a time for the viewer, users who desire to use the picture-on-picture capability of their televisions can be provided with an upgrade to the set top terminal 220 allowing two channels to be tuned and decompressed at any given time. Once two signals are available to the television the picture-on-picture capability may be utilized to its fullest potential. With the picture-on-picture capability available in the set top terminal 220 , a special television is not required for picture-on-picture functionality.
In the preferred embodiment all of the customer features available on the set top terminal 220 will be controllable via on-screen menu displays. In this manner, the subscriber using a cursor may easily customize the programming of his set top terminal 220 . The basic programming of each set top terminal 220 will be located on ROM within the set top terminal 220 . Random access memory, the magnetic cartridge capability, and the extension card slot will each allow upgrades and changes to be easily made to the set top terminal 220 .
In the preferred embodiment, the set top terminal 220 will include features that are now being adopted in the industry such as parental controls and locks, electronic diagnostics and error detection, mute, on-screen volume control, sleep timer, recall of last selection, etc. Each of these features has a corresponding menu that allows on-screen customizing and activation of the feature. The set top terminal 220 also includes a sophisticated favorite channel list and favorite program list.
In addition to all the features that the set top terminals supports with its current internal programming, additional features may be added or existing features upgraded through remote reprogramming of the set top terminal 220 . Utilizing the resident operating system on the ROM, the cable head end is able to reprogram the random access memory of the set top terminal 220 . With this capability the cable head end can remotely upgrade software on the set top terminals.
In the preferred embodiment, the cable head end will reprogram the menu format from time to time based upon special events or programming needs, such as Olympic telecasts, presidential elections, etc. This reprogramming will occur by using the program control information channel and sending the appropriate signals over this channel. In an alternative embodiment, one channel is dedicated for the special programming needs. When reprogramming is to occur, the cable head end will send an interruption sequence on the program control information channel that informs the set top terminal 220 that reprogramming information is to follow. Significant reprogramming of the set top terminals will occur infrequently. However, the changing of color or formats on menus occur more often. In alternative embodiments, color changes to menus may be accomplished via the program control information itself and does not require reprogramming from the cable head end.
In the preferred embodiment, the basic building blocks or templates of the on-screen menu displays will be stored on graphics memory consisting of no-volatile RAM, ROM, EPROM, or preferably, EEPROM, as shown as 620 in FIG. 10 . With the information from this graphics memory 620 , the microprocessor 602 , graphics decompressor 622 , text generator 621 (if necessary), and video combiner 624 will build a menu screen. The memory files of the graphics memory or EEPROM 620 are preferably categorized into three categories, background graphics 800 , logo graphics 820 , and menu and display graphics 850 .
A background graphics file 800 will store menu backgrounds such as: universal main menu backgrounds 804 , universal submenu backgrounds 808 , promo backgrounds 812 and custom menu formats 816 . A logo graphics file 820 will store any necessary logos such as: Your Choice TV logos 824 , Network logo files 828 , cable system logo files 832 , studio logo files 836 , and graphic elements file 840 . A menu display and cursor graphics file 850 will store menu display blocks 854 and cursor highlight overlays 858 as well as any other miscellaneous files needed to build the menus.
Using this method of storing menus, the menus can be changed by reprogramming the graphics memory 620 of the set top terminal 220 . To revise the entire design of displayed menus, the network controller 214 or operations center instructs the EEPROM 620 to be erased and reprogrammed with new menu templates. To change one menu format or logo, the network controller 214 or operations center instructs just the one location in memory to be erased and rewritten. Obviously, this menu reprogramming can be done locally (at the set top terminal 220 ) by a servicemen.
As shown in FIG. 10 a , each memory subfile is further divided into various memory blocks. For example, the background graphics file 800 contains the universal main menu backgrounds 804 . The universal main menu backgrounds memory 804 includes memory units UM 1 , UM 2 and UM 3 , as shown in FIG. 10 a . Similarly, the logo graphics file 820 and menu display and curser graphics file 850 further contain within those subfile individual memory blocks (for example, studio logo file 836 has memory block SL 1 ; menu display blocks 854 has memory menu display block MD 1 ).
FIG. 10 b shows the hierarchical storage of text transmitted from the cable head end as STTSCIS. Although text may be continuously transmitted with the video signals to set top terminals 220 , text may also be transmitted intermittently. In such a case, the text is stored in the set top terminal. Preferably, the text is transmitted and stored in a compressed format using known techniques. Additionally, the text is preferably stored in graphic memory 620 within set top terminal 220 .
Depending upon the use of the text, it will be stored in one of three portions of memory. Information sent with the text will either direct the text to a particular portion of memory, or include information as to the priority of text. The microprocessor 602 may then direct the text to the appropriate memory location for storage.
If the text is to be used frequently and over a long period of time, a long term storage 875 will be used. If the text will be used for a shorter period of time (for example, a month), the text will be directed to an intermediate storage area 877 . If the text is to be used almost immediately, or for a short period of time (for example, within a few days) the text is directed to a short term storage area 879 . Microprocessor 602 locates the appropriate text required for a particular menu and retrieves it from the appropriate portion of memory 620 . The text is output from the graphics memory 620 to the text generator 621 . Text generated from the text generator 621 is thereafter directed to text/graphics combiner 624 .
FIG. 10 c shows the steps performed by the microprocessor 602 for creating a menu based upon a series of overlay screens. These instructions are stored in memory within the set top terminal 220 . Alternatively, these instructions or routines are transmitted from the operations center 202 to be stored in memory within the individual set top terminals 220 .
Initially, microprocessor 602 instructs tuner 603 to select a channel. The channel is decompressed, and error corrected and decrypted, if necessary. If the video is to be reduced in size, so as to be placed within a video window 1556 , or is a split screen video window which must be enlarged, the video is scaled to the appropriate size. Additionally, the video may be required to be redirected to a portion of the television screen. This is done by creating a series of offsets for each pixel location of the video.
Graphics must also be used to create a menu in most instances. As is shown in block 882 , the microprocessor 602 must fetch a background file, fetch a logo file and fetch a menu display and cursor file in most instances. Each of these files must be decompressed. Following decompression, the file is sent to video combiner 886 .
Similarly, microprocessor 602 must fetch text, as shown in block 884 . Depending upon the memory location of the text, microprocessor 602 will fetch the text for long-term, intermediate-term, or short-term storage, as described above. Based upon this memory retrieval, the text is generated and sent to video combiner 886 . Video combiner 886 combines the video (if any) with as many screens of a decompressed graphics as are necessary, and any text. The image or portions of the image are stored in combiner 886 until all overlays are received by combiner 886 . Thereafter, the entire image is sent, under direction of another routine, to be displayed on the television screen, as represented by display block 888 .
FIG. 10 d is a full chart of programming instructions performed by microprocessor 602 for sequencing menus. Upon powerup of the set top terminal 220 , start up routine 890 is performed. Any error checking is thereafter performed ( 891 ), and introductory menu subroutine 892 is performed. This subroutine displays the introductory menu and the microprocessor thereafter awaits for an input 893 .
If the subscriber inputs a channel selection 894 , video for the particular channel is decompressed 895 . Otherwise, the microprocessor performs another routine 896 to display the home menu 897 .
At the home menu portion of the sequence of routines, a subscriber may select one of the major menus, thus starting the sequence of displays represented by routine block 898 . Alternatively, a subscriber may go directly to a major menu by depressing a menu select button on remote 900 and the microprocessor will execute another the go to submenu subroutine 896 .
Once a subscriber has selected a major menu, the appropriate subroutines are executed by the microprocessor using a series of instructions shown in block 898 . After each display, microprocessor 602 awaits for a selection by the subscriber, shown as block 899 . These blocks could be also represented as decision blocks.
After displaying the major menu, and receiving a selection by the user, a particular submenu for a subcategory is displayed, if such a menu exists. Again, microprocessor 602 waits for an input from the subscriber after executing a routine to display a program listing submenu. Thereafter, after receiving an input, microprocessor 602 performs the next routine for displaying a program description submenu. Thereafter, if a particular selection requires a confirmation menu, that subroutine is executed and the appropriate menu displayed. Thereafter, the selected video is decompressed, and displayed on the television screen. If there are any display overlay menus or hidden menus, the proper subroutine is executed by microprocessor 602 and these menus are displayed.
At any time during the selection of menus in major menu block 898 , the subscriber may also depress another major menu button to move into a second column of process instructions (represented by major menu 2 , major menu 3 , etc. columns). Thus, a subscriber may move from major menu to major menu. Additionally, a subscriber may depress a home menu button on remote 900 to return to the home menu at any time.
The various subroutines executed by microprocessor 602 allow a subscriber to navigate through the various menus of the present invention. A subscriber may sequence back through menus or return to the home menu with a one-touch return of the home menu button on remote 900 . All of these functions help to add to the system's user friendliness.
As shown in FIGS. 11 a and 11 b , a two-section remote control is shown. To reduce costs and make the set top terminal 220 as user friendly as possible, a standard television remote control 860 is augmented by adding a new section 862 that provides the additional digital menu access and ordering functions. FIG. 11 a depicts the addition of menu access and cursor movement control to a Gerald RC 650 Remote Control. The cursor movement and function buttons required for the set top terminal's operation may be added to any standard remote control format allowing the user to feel more at home with the new remote control. FIG. 11 b shows the two section remote control combined in a single unit 864 .
The remote control 864 has an ordering button 866 , four-way cursor movement, and a “go” button 868 , and menu access buttons 870 . The remote operates using infrared with the signals being received by the infrared sensor on the front of the set top terminal 220 .
In the simplest embodiment the remote may be built with only cursor movement and a go button. In more sophisticated embodiments the remote control may be provided with buttons that are programmable to perform specific functions for a series of entries. An intelligent or smart remote would increase both the cost and capability of the set top terminal 220 system. Using this augmented remote control the subscriber can navigate the program menu system of the set top terminal 220 .
FIGS. 12 a and 12 b show an alternative and preferred embodiment of the remote control for use in the present invention. The standard television receiver remote control switches or buttons 920 are again separated from the menu accessing ordering function buttons 950 . The standard television receiver remote control buttons 920 include volume control, channel select, power and signal source buttons. The menu buttons 950 include cursor movement and select, menu select, and pay television buttons. However, the standard buttons 920 are separated from the menu access and ordering buttons 950 in the longitudinal direction of the remote, as opposed to the width-wise separation, shown in FIG. 11 a . Additionally, the color of the buttons or the surrounding background may differ between the standard television remote control buttons 920 and the menu buttons 950 to visually differentiate between these two groups of buttons.
The width and depth of the remote control unit 900 are considerably less than the length to allow the remote control unit 900 to fit easily within a user's palm. The remote control unit 900 in preferably has the center of mass balanced substantially near the longitudinal middle. This allows a user's thumb to naturally be placed in substantially the middle portion of the remote control unit 900 , when it is picked up by a user.
Since the center of mass of the remote control unit 900 is placed substantially near the longitudinal middle of the remote 900 , thereby having a user's thumb naturally fall in this same center region, the standard remote 920 and menu access 950 switches or buttons most frequently accessed and depressed by a user are placed within easy reach of the user's thumb. Channel and volume increment and decrement buttons 910 are placed near this center of mass and longitudinal center line. The channel buttons 910 are preferably beveled in opposing directions to allow a user to feel for and press a desired button without looking down at remote 900 . Similarly, the volume buttons 910 are preferably beveled in opposing directions for the same reason.
Additionally, the channel buttons 910 could have a surface texture different from those of the volume buttons 910 to allow even easier differentiation between channel and volume buttons 910 . For example, the volume buttons could have a rough surface texture, while the channel buttons could have a smooth surface texture.
Also placed in the longitudinal center, within easy reach of a user's thumb, are cursor movement buttons 970 and “go” button 975 . The “go” button 975 selects an option corresponding to the placement of the cursor. As opposed to buttons, a joystick may be used with a selection on the stick, or a trackball, depressible for selecting a desired choice. The cursor buttons 970 are placed ninety degrees apart, with the “go” button 975 placed within the center of the cursor movement buttons 970 , as shown in FIG. 12 b . The cursor movement buttons 970 are preferably beveled inwardly toward the “go” button 975 . The “go” button 975 is recessed below the level of the cursor movement buttons 970 so that it is not accidentally pressed while depressing the cursor movement buttons 970 . In addition to the beveling on the cursor movement buttons 970 , they may also have a surface texture to allow a user to feel for and select the appropriate button without looking down at the remote 900 . Directional arrows could be raised or recessed on the surface of the cursor movement buttons 970 for this purpose.
Menu select buttons 960 are placed near buttons 970 as shown in FIG. 12 b . Menu select buttons 960 are preferably the largest buttons on remote 900 . Menu select buttons 960 preferably have icons or other graphics imprinted on their top surface or adjacent to the corresponding button. For example, a button for the sports major menu may contain a baseball icon. The icons represent the programming available on the particular major menu selected by the menu select buttons 960 . The icons may also be raised above the level of the menu select buttons to provide a textured surface. This would allow a user to select an appropriate menu button 960 by feel, without looking at the remote control unit 900 . The icons would require substantial differences in texture, while still providing a meaningful graphic related to the associated menu.
As shown in FIGS. 12 a and 12 b , labels and icons are provided for the following major menus: movies, sports, children's programming, documentary/news, entertainment, magazines, programming guide, HDTV (high definition television), interactive TV, music, and an additional button for further programming. Menu select buttons 960 may also be labeled A through J for the above programs, with the last button for all additional major menus labeled K-Z.
The layout of the user select buttons for the remote 900 have been designed to allow a user to select an appropriate button without viewing the remote by using the layout of buttons shown in FIGS. 12 a and 12 b , in conjunction with textured or beveled buttons. With this “eye-off-of-the-remote” construction, most of the frequently used buttons may be located by the sense of touch alone. However, to aid selection of an appropriate button visually, certain buttons may have different colors. For example, the menu select buttons 960 may all be of a color different from the rest of the buttons on the remote 900 . Additionally, the colors should be selected to provide for easy location and identification by a user. For example, if the icons are printed in black ink, yellow menu select buttons 960 are preferred, because yellow would provide the greatest visual contrast with the black ink.
Although remote 900 is described with a variety of channel selection buttons, nearly all buttons from a standard remote control (section 920 buttons) could be eliminated. The present invention would allow a subscriber to use a remote control containing only menu select buttons and/or cursor movement and select buttons.
The power button 924 and “go” button 975 preferably have a separate color from the other buttons on the remote 900 . The power button 924 is preferably a separate color because this button is used infrequently. The power button is placed out of a user's thumb's reach so it is not accidentally depressed. The power button 924 should be distinguished from the other buttons because a television viewer must locate this button first before viewing any programming. Similarly, the “go” button 975 is used often because it provides the means for a user to select options, and thus should be easily distinguished from the other buttons.
Pay television buttons 980 may also be assigned a color different from the other buttons on the remote 900 . By making the pay television buttons 980 a different color, it would help a user to avoid selecting an undesired pay television program.
As used herein, “button” is contemplated to include all manner of switches or touch sensitive circuitry to activate a particular function in the remote control unit 900 . Additionally, although the remote control unit 900 communicates with the set-top box by means of infrared transmission, other forms of communication are contemplated, including ultrasound, radio frequency and other electromagnetic frequency communication.
FIG. 13 shows the basic structure of the program menu system. Although the term “menus” has been used above, the menus could also be seen as defining zones or categories of programming. The first series of menus, Introductory menu 1000 , Home menu 1010 , Major Menus 1020 , and Submenus 1050 execute subscriber program selection inputs. The During program menus 1200 provide a subscriber with additional features or options after a program has been selected and shown. There are two primary types of During program menus 1200 , Hidden Menus 1380 and Program Overlay Menus. Both are described in the following text and figures. The menu sequence and each menu structure has been particularly program designed using the “eye-off-the-remote” design concept. A subscriber can easily navigate through the menu system with the cursor movement and “go” buttons 970 , 975 . Since the subscriber never needs to take his eye off the television screen, the cable operator is likely to have the subscriber's complete attention.
The introductory menu screen 1000 automatically appears upon power-up and initialization of the set top terminal 220 . The introductory menu screen 1000 welcomes the user to the cable system and provides important announcements or messages. In addition, the introductory menu 1000 can be used to inform the subscriber if he has a personal or group message that has been sent to his set top terminal 220 by the cable headend. The subscriber may then access the personal or group message with an appropriate key entry while viewing the introductory menu 1000 . Since the introductory menu 1000 must be viewed by each subscriber, it also provides an opportunity for the cable provider to run advertisements.
Following the introductory menu screen 1000 the subscriber will normally be advanced to the home menu screen 1010 . The home menu 1010 is the basic menu that the subscriber will return to make his first level of viewing decisions. From the home menu 1010 , the subscriber is able to access all television programming options. Some programming options may be accessed through cursor movement on the screen, others directly by a button selection on the remote control 900 , or both, on-screen selection and remote control 900 direct access.
In the normal progression through the menu screens, the subscriber will be forwarded to a major menu screen 1020 that correlates to his direct remote control 900 selection or selection from the home menu screen 1010 . The selections on the home menu 1010 are for large categories of programming options and therefore the major menu 1020 allows the subscriber to further refine his search for the television program of his choice.
Following the major menu 1020 the subscriber will navigate through one or more submenu screens 1050 from which he will choose one particular program for viewing. For most programming selections the user will proceed from the home menu 1010 to a major menu 1020 and then to one or more submenus 1050 . However, for certain programming options or functions of the set top terminal 220 the user may skip one or more menus in the sequence. For example, in the preferred embodiment the subscriber may directly access a major menu 1020 by pressing a single icon button. In an alternative embodiment, the introductory menu 1000 will provide the user with the capability of directly accessing information on his cable television account without proceeding through a series of menus.
The series of menus shown in FIG. 13 is the normal or standard format for a variety of alternative embodiments to the present invention. An introductory screen upon power up that contains important messages, followed by a home menu 1010 with major programming categories is the basis upon which many alternative embodiments of the menu driven selection process can be built.
Skipping a sequence or level of the menu structure is possible and perhaps desired in certain instances. In simple alternate embodiments it is possible to combine the home menu 1010 and introductory menu 1000 into one menu that performs both functions. It will be obvious to one skilled in the art that the specific functions of the Home menu 1010 and Introductory menu 1000 may be exchanged or shared in a number of ways. It is also possible to allow a user to skip directly from the introductory menu 1000 to a submenu 1050 . This can be accomplished most easily with a separate direct access remote control 900 button. Generally, a subscriber will access a television program through execution of a submenu 1050 .
The During program menus 1200 are enacted by the set top terminal 220 only after the subscriber has selected a television program. These menus provide the subscriber with additional functionality and/or additional information while he is viewing a selected program. The During program menus 1200 sequence can be further subdivided into at least two types of menus, Hidden Menus 1380 and Program Overlay Menus 1390 .
To avoid disturbing a subscriber during viewing of a program, the Hidden Menus 1380 are not shown to the subscriber but instead “reside” at the set top terminal 220 microprocessor. The Hidden Menus 1380 do not effect the selected program audio. The microprocessor awaits a button entry either from the remote 900 or set top terminal 220 buttons before executing or displaying any Hidden Menu options. The Hidden Menus 1380 provide the subscriber with additional functions such as entering an interactive mode or escaping from a selected program.
Program Overlay Menus 1390 are similar to Hidden Menus 1380 in that they occur during a program. However, the Program Overlay Menus 1390 are overlayed onto portions of the television screen and not hidden. The Program Overlay Menus 1390 allow the subscriber to continue to watch the selected television program with audio but place additional information on portions of the television screen. Most overlays cover small portions of the screen allowing the subscriber to continue to comfortably view his program selection. Other Overlays which are by their nature more important than the program being viewed will overlay onto greater portions of the screen. In the preferred embodiment, some Program Overlay Menus 1390 reduce or scale down the entire programs video screen and redirect the video to a portion of the screen.
All menu entries may be made either from buttons available on the top cover of the set top terminal 220 or from the remote 900 .
FIG. 14 a shows the preferred embodiment for subscriber selection of television programming. FIG. 14 b shows additional major menu 1020 categories, 1042 , 1044 , 1046 , 1048 , which may be used with the invention. Again, the introductory menu 1000 followed by the home menu 1010 is the preferred sequence of on-screen displays. In the preferred embodiment shown in 14 a , the home menu 1010 provides a choice of ten major menus 1022 , 1024 , 1026 , 1028 , 1030 , 1032 , 1034 , 1036 , 1038 , 1040 . Upon selection of a major menu 1020 category from the home menu 1010 , the program proceeds to a major menu 1020 offering further viewer selections. Each major menu 1020 is customized to target the expected viewership. Depending on the number of available program choices the major menus 1020 either breakdown the major category into sub-categories or provide the subscriber with access to further information on a particular program.
For example, the major menu 1020 for children's programming provides a list of subcategories 1052 from which the subscriber selects. Upon selection of a subcategory a submenu 1054 , 1056 listing program choices within that sub-category is shown to the subscriber. Upon selection of a particular programming choice within the first submenu 1050 , the subscriber is then provided with a second submenu 1058 describing the program that the subscriber has selected. From this menu, the subscriber may now confirm his program choice and receive a confirmation submenu 1060 from the set top terminal 220 software.
Since the system utilizes digital signals in compressed format, High Definition Television programming can also be accommodated through the menu system. In addition, since the set top terminal 220 has two way communication with the cable headend, interactive television programming is possible, with return signals generated by the set top terminal 220 . Similarly, the system can support “movies on demand” where a subscriber communicates through the set top terminal 220 with an automated facility to order movies stored at the facility.
Using this on-screen menu approach to program selection, there is nearly an unlimited number of menus that can be shown to the subscriber. The memory capability of the set top terminal 220 and the quantity of information that is sent via the program control information signal are the only limits on the number of menus and amount of information that can be displayed to the subscriber. The approach of using a series of menus in a simple tree sequence is both easy for the subscriber to use and simply implemented by the set top terminal 220 and remote control device 900 with cursor movement. A user interface software programmer will find many obvious variations from the preferred embodiment shown.
FIGS. 15 a and 15 b show examples of introductory menu screens that are displayed on the subscriber's television. FIG. 15 a , the preferred embodiment, welcomes the subscriber to the cable system and offers the subscriber three options. The subscriber may choose regular cable television (channels 2 through 39 ), programs on demand (e.g., movies), or instructions on the use of the remote control 900 . Other basic program options are possible on the introductory menu screen 1000 . For example, instead of, or in addition to, the remote control 900 instructions, a system “help” feature can be offered on the introductory menu 1000 .
FIG. 15 b shows an alternate embodiment for the introductory menu screen 1000 . In the upper left-hand corner of the menu, there is a small window 1002 that may be customized to the subscriber. A subscriber will be given the option of showing the current time in this window. In the upper right-hand corner a second customized window 1004 is available in which a subscriber may show the day and date. These windows may be easily customized for subscribers to show military time, European date, phase of the moon, quote of the day, or other informational messages. These windows may be customized by subscribers using on-screen menu displays following the introductory menu 1000 .
In the preferred embodiment, the subscriber is given the capability of accessing base channels such as regular broadcast TV and standard cable channels directly from the introductory menu 1000 by entering the channel number. The subscriber is also given the capability of directly accessing his account with the cable company. Further, in the preferred embodiment, the subscriber may directly access a major menu 1020 and bypass the home menu screen 1010 . If the subscriber is familiar with the programming choices available on the major menus 1020 , he may select an icon button 960 , or a lettered key (alpha key) from his remote control 900 and directly access the desired major menu 1020 . If any key entry other than those expected by the set top terminal 220 software program is made, the home menu 1010 is placed on the television screen. In addition, after a period of time if no selections are made from the introductory menu 1000 , the program may default to the home menu screen 1010 .
In the preferred embodiment, TV guide services, listing programs available on network schedules, will be available on a major menu, as shown in FIG. 16 a . In the preferred embodiment, the major TV guide menu 1036 would offer submenus, such as network schedules for the next seven days, today's network schedules for the next six hours, and TV guide picks for the next seven days. If the particular set top terminal 220 has been subscribed to the TV guide service, the subscriber may proceed to a submenu showing schedules of programs. If the subscriber chooses the network schedule submenu 1236 , he is offered a list of network schedules to choose from as shown in FIG. 16 b . If a subscriber were to choose, for instance, HBO, the submenu 1238 shown in FIG. 16 c would appear. This submenu allows a subscriber to choose the program date that interests him. Following selection of a date, the subscriber is shown a more specific submenu 1242 listing programs available on the particular date as shown in 16 d.
Following a program choice, a program description submenu 1244 is placed on the television screen as shown in FIG. 16 e . In addition, from this program description submenu, the viewer may choose to record the selected program on his VCR using the guide record feature.
FIGS. 17 a, 17 b , and 17 c demonstrate the use of promotional menus to sell subscriptions to services in the system. In particular, FIG. 17 a is a promotional menu 1304 for Level A interactive services. Level A interactive services offers subscribers additional information about programs such as quizzes, geographical facts, etc. This information may be received by the set top terminal 220 in several data formats including VBI and in the program control information signal. FIG. 17 b is a promotional menu 1306 for Level B interactive services which include a variety of on-line type services such as Prodigy, Yellow Pages, Airline Reservations, etc.
FIG. 17 c is a promotion menu 1308 for the Level C interactive services. The Level C interactive services utilize local storage such as CD technology to offer an enormous range of multi-media experiences. The Level C interactive services require a hardware upgrade as described earlier. Specially adopted CD-I and CD-ROM units are needed for this service.
FIGS. 17 d through 17 j show menus that are available using the interactive Level A services. When interactive Levels A services are available in a television program, the system will display the interactive logo consisting of the letter “I” and two arrows with semicircular tails. In the preferred embodiment the set top terminal 220 will place the interactive logo on the television screen as an overlay menu 1310 . In the preferred embodiment, the set top terminal 220 will detect that there is data or information available about a television program which can be displayed to a subscriber using the interactive service. When the set top terminal 220 senses that there is interactive information available, it will generate the interactive logo overlay menu and place it on the television screen. For example, the set top terminal 220 will detect that information on a television program is being sent in the vertical blanking interval (VBI) and generate an interactive logo overlay menu which will appear on the subscriber's television screen for approximately fifteen seconds during each ten minute interval of programming.
When the subscriber sees the interactive logo on his television screen, he is made aware of the fact that interactive services are available in conjunction with his television program. If the subscriber presses his interactive remote control button, an additional overlay menu will be generated by the set top terminal 220 and placed on the screen. This menu 1310 is shown in FIG. 17 d being overlayed on an interactive television program. From this menu the subscriber may select interactive features or return to the television program without interactive features.
If the subscriber selects interactive features he will be presented with the interactive Level A submenu 1312 in FIG. 17 e . From this submenu the subscriber may choose a variety of different types of textual interactivity with the current television program. Some examples are quizzes, fast facts, more info, where in the world, products, etc. At any time during the interactive submenus the user may return to the television program without interactive features.
This interactive submenu has an example of taking a complete television program video, scaling it down to a smaller size and directing the video into a video window of a submenu.
FIG. 17 f shows an interactive fast facts submenu 1314 . In this submenu textual information is given to the subscriber in the lower half of his screen. This textual information will change as additional data is received by the set top terminal 220 relating to this television program.
FIG. 17 g shows the use of the subcategory “more information” in the interactive service. This submenu 1316 gives additional information related to the television program to the viewer in textual form in the lower half of the screen. FIG. 17 h is an interactive submenu 1318 for the subcategory “quiz.” In this interactive subcategory, the user is presented with questions and a series of possible answers. If the subscriber desires, he selects one of the answers to the quiz question. After his selection, the set top terminal 220 sequences to another menu. The set top terminal 220 sequences to the interactive quiz answers submenu which informs the subscriber whether he has chosen the correct answer or not. FIG. 17 i shows a correctly answered quiz question 1320 and FIG. 17 j shows an incorrectly answered quiz question 1324 . In the preferred embodiment, the menu graphics for both of these menus 17 i and 17 j is the same. The only difference is in the text which can be generated by the text generator of the set top terminal 220 .
FIG. 18 a is an example of a submenu for Level B interactive services. From this menu screen 1330 , any of a number of on-line data services could be accessed. In FIG. 18 a , the airline reservations selection has been selected by the subscriber.
FIGS. 18 a through 18 l provide an example of a sequence of menus that a subscriber may encounter with an on-line data service. In particular, this example relates to airline information and reservations and the subscriber in this sequence is reserving and purchasing airline tickets. FIG. 18 b is an example of the first submenu 1332 for a data service offering various options. In this case, the subscriber has the option of checking current reservations or making new reservations. In each of these submenus related to a data service, the subscriber is able to return to the home menu 1010 or regular cable TV and exit the data service. FIG. 18 c requires the subscriber to enter information related to his airline reservation in this submenu 1334 , such as: domestic or international flight, year of flight reservation, month of flight reservation.
FIG. 18 d is another submenu in the airline information and reservation data service. FIG. 18 d provides an example of how the subscriber may choose among many options on a single screen 1336 . In this manner, the preferred embodiment of the system can avoid the use of a separate keyboard for textual entry. Although a separate keyboard may be provided as an upgrade, it is an added expense which some subscribers may wish to avoid. FIG. 18 d shows an “eye off the remote” approach to entering information. FIG. 18 d allows the user to chose the State in which he will depart and the state in which he will arrive. The airline information reservation submenu 1338 shown in FIG. 18 e allows a subscriber to choose the airports from which he will depart and arrive and also the approximate time period of his departure and his arrival. FIG. 18 f , an airline information and reservation submenu 1340 , allows a subscriber to view six available flights. A subscriber may select one of the flights to check on its availability.
FIG. 18 g , an airline information and reservation submenu 1342 , allows a subscriber to enter the month, day and year for the availability date he desires. In this submenu, the subscriber is offered the option of correcting any errors in the entered information. This particular submenu is for a particular flight, including flight number.
FIG. 18 h , an airline information and reservation submenu 1344 , allows a subscriber to view remaining seats available on a flight. From the menu, the subscriber may select his seat assignments. This submenu is an example of how information may be graphically shown to a subscriber using a portion of the menu and different coloring schemes. In this menu, the lower half of the screen shows the passenger compartment of an airplane with all the seat locations graphically represented by square blocks. By coloring the available seat locations in blue and the unavailable seat locations in a different color, the menu can present a great deal of information in a limited amount of space. This graphic presentation of information for the interactive on-line data services is an important method of visually displaying large amounts of information to the subscriber.
FIG. 18 i , an airline information and reservation submenu 1346 , allows the subscriber to choose a one-way or round-trip ticket and to confirm his reservations. If the subscriber desires to proceed, he may charge his airline ticket to his credit card by choosing the appropriate strip menu on the lower part of the screen.
FIG. 18 j , an airline information and reservation submenu 1348 , is an example of how credit card purchases may be made using the interactive on-line data services. In this particular menu, the subscriber is charging a round-trip plane ticket on his credit card. The subscriber simply needs to enter his credit card number, expiration date, and credit card type to charge his airline ticket.
FIG. 18 k , an airline information and reservation submenu 1350 , is an example of a menu which may be shown whenever an on-line data service is processing a request sent by the subscriber. In this particular menu, the on-line data service is processing the subscriber's credit card charge for his airline ticket.
FIG. 18 l , an airline information and reservation submenu 1352 , confirms a subscriber's airline ticket purchase and passes on information on where the ticket may be picked up.
FIG. 19 a is a major menu 1038 displaying the digital/audio program choices which are available for subscribers who have paid the monthly fee. In a chart format, the major menu shows the top five, top ten, and top forty songs available in six different categories of music. Below the chart, the system is able to provide a text message describing the particulars of the audio program selected.
The digital/audio feature of the invention allows a subscriber to listen to CD quality audio selections through his stereo. This can be accomplished by running cables directly from the set top terminal 220 to the subscriber's amplifier/stereo system. Alternatively, the user may listen to audio selections through his television system.
FIGS. 19 d and 19 e are the same major menu 1038 as FIG. 19 a but shows a different selection and a different program description in the lower text 1408 , 1412 . From any of the menu screens for the digital/audio feature, the subscriber may return to regular cable TV with the press of a single button.
FIGS. 19 b and 19 c are promotional menus 1400 , 1404 for the digital/audio feature. Using the same logos and menu format, the system can provide a text description enticing the subscriber to pay the monthly fee and join the service. In FIG. 19 b , the menu allows the user to test the system with a free demonstration. The menu in FIG. 19 c allows the subscriber to request additional promotional information about the system. Both FIGS. 19 b and 19 c are representative of promotional menus that may be used throughout the menued system.
FIGS. 20 through 28 demonstrate the generation of menu screens. | A set top terminal is disclosed for creating a favorites menu of television programs available for viewing, based on a user's preferences. The terminal receives a television signal from an operations center, extracts individual programs from the signal, and sends one or more of the individual programs to a television for display, based on a selection by the user. The terminal generates an interactive electronic program guide for the selection of programs. The favorites menu of the guide narrows the list of available programs to those most likely of interest to the user. The terminal receives and stores user information, including general demographic information and viewing preference information. The viewing preference information may be received directly from the user, for example by querying the user. Alternatively, it may be learned by tracking the user's viewing habits. The viewing preference information may include, for example, frequently-watched channels, frequently-watched programs, or information related to program content. The user information may be stored in a user profile. Using the user information, the terminal identifies those programs available for viewing that most closely match the user information. A program menu including the identified programs is then generated for display on a television. | 7 |
TECHNICAL FIELD
This invention relates in general to automated instruction and testing methods, and more particularly to a method for certifying a worker, at any of a plurality of test sites, to work at one or more of a plurality of work sites.
BACKGROUND OF THE INVENTION
There has been an increased focus on training workers to do their jobs effectively and safely preliminary to doing the work for which they were hired. This kind of vocational education and certification is now required in many instances by the Occupational Health and Safety Administration (OHSA) to ensure safe work practices. There are basic safety practices which will be pertinent for a large variety of workplaces, particularly those of a single industry or a related group of industries, and then there are practices which will be peculiar to a particular plant or worksite and which relate to the exact work conditions, apparatus and processes obtaining at that site. The general, basic safety practices are conventionally given in a traditional classroom setting and are taught by human instructors. Specific, customized safety practices have conventionally been the job of safety personnel assigned to a particular plant or worksite.
Another recent trend is an increasing dependency by industry on independent contractors rather than employees. These contractors are retained for relatively short periods by any one plant or workplace, and often work at several sites owned by different proprietors within a single year. At the start of each work period at a work site, the contractor has had to be recertified; this had resulted in repetitious, unnecessary and expensive recertification procedures undertaken by each different plant proprietor of a single contractor during a year. Also, the plant proprietors are reluctant to routinely provide such safety instruction to persons who are not long-term employees.
Recently, in an attempt to address this problem, in the State of Texas a local group of petrochemical plants has federated into a Safety Council. This Safety Council is a nonprofit organization that provides a central facility for the instruction of contract workers who tend to circulate among the plants. A basic, instructor-led safety course is given, and then the workers are put through a computer-generated, plant specific course for the facility at which they would like to work. The computer instruction concludes with a test which, if the worker passes, will certify the worker on safety requirements for a particular plant for a given, usually long period of time, such as a year or more. Each worker's test results (typically simplified to whether the worker passed or has not yet passed a safety test for a particular facility) is stored in a database at the Safety Council. These test outcomes are accessible by each plant proprietor/member of the Safety Council, for the purpose of determining whether that contract worker is qualified to work at the plant in question. This arrangement obviates repetitive and unnecessary instruction and testing while still maintaining acceptable levels of worker safety knowledge.
While this Safety Council has been effective in providing a pooled safety program for a local group of plants, improvements could still be made with respect to geographic availability.
SUMMARY OF INVENTION
According to the present invention, a relational database is maintained that provides, for each of a plurality of plants or work sites, a set of specific questions relating to the safety of the plant. Each work site is owned or managed by a proprietor (typically a company or division), which determines minimum acceptable passing criteria for the test for that facility, and which communicates these passing criteria to the database. It is preferred that this database be located at a central database facility.
A plurality of testing sites, such as community colleges, are each linked to the database by means such as a wide area network. In a preferred embodiment, this network is the Internet. At each testing site there is a secure testing terminal at which prospective workers receive instruction and, at the conclusion thereof, take a test relating to a specific worksite. A test administrator associated with the test site verifies the identity of the prospective worker wishing to receive the instruction and take the test, and further ensures that that prospective worker is correctly identified to the database, for example by setting up the instruction course in advance. The database (which has an executable computer program associated with it) provides the electronic instruction on the terminal, and at the conclusion thereof administers the test. Preferably, the database generates, in real time, a test from a random selection of prestored questions. The database prompts the worker for answers to each of the test questions, compares them to the model answers, and determines if the responses are sufficiently matched to the model answers that, according to the standards predetermined by the work site management, the worker has passed the test. If this is the case, a “pass” indication is recorded in the database for that work site and that worker. This “pass” indication will typically be valid for a relatively long predetermined period of time, such as a year, before further instruction is required.
In this way, remoteness of the prospective worker from the work site need not be an insurmountable problem. The worker can receive instruction in respect of a work site on the other side of the country or world near his or her present residence, receive certification and be ready to work upon arrival. This is also an aid to the plant or work site operator, as the available pool of certified labor is greatly expanded, reducing labor shortages and costs.
Preferably, the site-specific test and course is offered together with a separate, basic course which applies to all or many of the worksites. This basic course is preferably instructor-led and may be taken before the site-specific course. It is further preferred that the basic course test results be transmitted to and stored at the central repository.
BRIEF DESCRIPTION OF THE DRAWINGS
Further aspects of the invention may be discerned in the following detailed description when taken in conjunction with the drawings, in which like characters denote like parts and in which:
FIG. 1 is a high level schematic system block diagram of an instruction and testing network according to the invention;
FIGS. 2-5 are a high level flow charts showing the procedure by which basic and site-specific instruction and testing are given according to the invention;
FIG. 6 is a diagram of a WORKER table in the relational database maintained according to the invention;
FIG. 7 is a diagram of a WORKSITE table in the relational database maintained according to the invention; and
FIG. 8 is a diagram of a TEST ADMINISTRATOR table in the relational database maintained according to the invention.
DETAILED DESCRIPTION
FIG. 1 is a high-level schematic diagram of an instruction and testing system according to the invention. An education and testing service provider has at least one site or repository 10 . The site 10 preferably includes a database server 11 and a web server 12 . The servers 11 and 12 are connected together as by a local network connection 13 .
The database server 11 has sufficient random access memory, such as 2 Meg, to operate a bootable operating system, the relational database developed according to the invention and the related executable computer program which runs it. The database server 11 also possesses one or more processors which are powerful enough to assemble tests, administer courses and tests over the network and store the results in the database. The servers 11 and 12 will typically have an administrator terminal 14 to permit access to the relational database and executable program(s).
The web server 12 also has a network interface to permit it to communicate to a wide-area network 16 , and a firewall application 18 to prohibit unauthorized access. The network 16 is preferably the Internet.
Each of a plurality of test sites 20 - 24 are connected to the web server 12 over the network 16 . The network connection can be a 28.8 k or 56 k baud conventional telephone line, an ISDN line, or a more expensive and faster connection method such as DSL or a T1 line. The Internet 16 would include the internet service provider (ISP) of each of the test sites 20 - 24 , to the extent that these sites are not self-hosting. While three such sites 20 - 24 are shown, there will typically be dozens or even hundreds of such sites. Most or all of the test sites may be instantiated by facilities at community colleges, which often specialize in vocational education.
Preferably, communication over the network 16 is done by some secure method such as PPTP (point to point tunneling protocol), which creates what appears to be a virtual private network. This communications protocol is represented by the pipes 26 surrounding the internet connections, to show the degree of privacy.
In FIG. 1, exemplary test site 20 has been illustrated in detail. Sites 22 and 24 will in general be similar. Each site 20 - 24 has at least one, and typically more than one, terminal 28 (two terminals 28 a and 28 b are shown by way of example) at which a worker can receive course instruction over the network 12 and a test at the end of such instruction. Each site 20 - 24 also has means to verify the identity of the worker, so as to prevent “ringers” from taking tests for others. Human-specific and hard-to-defeat automatic identification measures include fingerprint scanning and retinal scanning. At the time of writing, however, these automated identification techniques tend to be expensive, and therefore a more preferable method is to staff the test site with a human administrator who will ask for e.g. photo identification to verify that the worker is who he says he is. This same or a different administrator will also ensure that the worker is correctly identified to the server, as by entering identifying data on an administrator terminal 30 , so that the test results will be correctly attributed to that worker and no one else.
Each terminal at the test site has a display and a graphical user interface, such as a mouse, or some other method of recording the worker's responses. The worker terminals 28 a-b and the administrator terminal 30 are connected to a local area network server 32 , which in turn manages the connection to the Internet 16 . In other, simpler embodiments, only one worker test station 28 may be present, and no LAN server 32 or administrator terminal 30 ; in these simpler embodiments, the administrator would set up the test on the worker terminal 28 before permitting the worker to continue.
Each of the plants or worksites 40 - 44 (only three are shown, although there will be dozens and perhaps hundreds) each have peculiar working environments and may employ processes and equipment not found at the other plants. That is why a site-specific course and test are necessary. The work sites will typically be permanent manufacturing facilities or subsections of the same, but may also be less permanent sites such as construction sites. The management of each plant 40 - 44 furnishes a site-specific course to the repository 10 , a set of questions to be asked on the material, and a criterion, such as a number of the questions answered correctly, to determined whether the worker has passed the test to the plant management's satisfaction. The pass/fail criterion may be more complex than a simple number of questions answered correctly. For example, the management of plant 40 a may desire that each of a predetermined subset of questions be always asked, and that each of them be answered correctly before the worker is deemed to pass the test.
Because all of the testing sites and work sites are connected through a wide area network 16 such as the Internet, geographical proximity of the worker to the plant or work site is no longer necessary. The worker only need be close to one of the test sites, which as mentioned above ideally will be sited at the numerous community colleges across the country.
While the invention is particularly useful for the administration of safety-related courses and tests, it is not limited to this. The present invention has application to any situation in which a worker or other student is required to master material pertinent to a remote site. This Internet-based electronic coursework may be used, for example, to train a new employee or contractor on office procedures before the worker starts work at that site. This method reduces downtime of the worker associated with getting acclimated to the new work environment, and this preparation can be more at the convenience of the new worker.
FIGS. 2-5 are flow diagrams of the illustrated embodiment of the invention.
FIG. 2 is a flowchart segment setting up the instruction and test and identifying the worker, both to the test site and to the database. At step 200 , the contracting company (the proprietor of one of the worksites) calls, faxes or emails a request for one or more of its contracting workers or employees to take either a basic course relevant to many worksites, and/or one or more site-specific courses. The communication is made to one or more participating test sites. At step 202 , the central repository approves registration and enters the fact that the worker will be taking this instruction into the system.
At step 204 , any of various methods can be used to confirm back to the company that the course instruction will be given, giving date, time and the place of instruction. At step 205 , the contractor worker or employee will show up at the appropriate testing facility at the proper time.
The contract worker next identifies him or herself to a test site adrninistrator, producing a photo ID such as a license, passport, social security card or the like. At step 208 , it is preferred that the worker sign an attendance sheet confirming attendance on the specific date. It is also preferred, at step 210 , that the contract employee sign a release waiver allowing the plants to access training records on the database. This concludes the introductory segment of the procedure. The procedure then branches to either the basic instruction and test as step 214 , or a site-specific test at step 216 .
FIG. 3 is a flowchart concerning the basis test 214 . At step 218 , the worker is seating in a classroom for, e.g., a 4-hour basic OSHA training class, which is instructor led. At step 220 , a written test is administered at the end of that course. At step 222 , the test is graded before the students leave and, at step 224 , the test results are given to each student, indicating whether they have passed or have failed the course. At step 226 , the student is asked to initial the grade to confirm the score.
At step 228 , these results are entered into the database either manually, electronically or otherwise, to preferably make up a portion of the relational database that later may be accessed by the contracting company. The entirety of the instruction may then end at step 232 , or instead the worker may proceed to a site-specific segment of the instruction at step 216 .
FIG. 4 is a high level flow chart concerning the site-specific procedure according to the invention. At step 234 , the contract employee or worker is lead to a multi-media computer lab and is seated at a station. At step 236 , the lab room administrator logs the employee onto the system using the name and social security number as the password and ID.
At step 238 , an appropriate computer based site-specific module is accessed from the relational database (or, alternatively, from a local memory) and is started for the worker by the administrator. Then, at step 240 , the student takes the site-specific computer based training module on the worker computer station.
At some time during, before or immediately following this course, the database will retrieve a set of questions based on the selection of the worksite which is made by the administrator. The database will randomly select a series of questions from a site-specific table of such questions to assemble the test. The database will return to the test site those questions, together with their model answers and a site-specific pass/fail criterion.
At step 242 , the student takes this test immediately upon completion of the course. At step 244 , the computer compares the worker's responses to the model answers, the pass/fail criterion is applied, and the test is automatically graded. The score is given to the worker. At step 246 , the worker is asked to initial the score on the sign-in sheet. At step 248 , this score is automatically populated back to the relational database. At step 250 , the worker may return to do the basic course at step 214 if this had not been done before, or instruction may be completed.
FIG. 5 is a terminating portion of the procedure. In one embodiment, at step 252 , the contract employee picture is taken; this picture may be populated back to the relational database. At step 254 , a course card (such as a safety card) is issued to the worker containing the name, picture ID, social security number, list of courses that the worker has passed, and possibly other information. The entire procedure terminates at step 256 .
The system randomly selects a number of questions (and their respective model answers) from a WORKSITE table in order to assemble the test. This can be done in any of several ways. For example, the management of the selected work site may have furnished to the system the total number of questions to be asked in any test. The questions stored in the WORKSITE database table could be keyed by a number or other identifier. The system could, lottery-like, generate a series of random numbers within the range of the total number of questions formulated for the selected work site. These numbers would identify the questions to be asked on that particular test.
Preliminary to administering the course, the system retrieves an e.g. multimedia instruction file from the WORKSITE database table or an associated space, and gives a course on the material. Preferably, the course is interactive and prompts the worker to answer questions along the way.
Alternatively, the system may download both the course material and the test to the terminal 28 in one step, with test results then transmitted back to the repository 10 at the conclusion of the process. In this embodiment, the server 32 will have programming sufficient to administer the coursework and test locally, and to automatically report back the results over the Internet 16 to the database server 11 at its conclusion. The degree to which the executable portions of the system are centralized or distributed may be changed according to the predilection of the system designer. For example, in one alternative embodiment the multimedia course file is transmitted in advance to each test site, and the file for the selected work site is accessed at the time that the course and test are taken.
In the illustrated embodiment, the system will issue a card to the worker, using for example printing apparatus 124 (FIG. 1) that is preferably installed at each test site at the purpose. Alternatively, the card may be printed at the central repository 10 and mailed to the worker. The system uses data which are the same as that present in a WORKER table of the database at step 122 . Alternatively, some or all of these worker-identifying indicia may be retrieved from a test site local memory such as server 32 .
FIGS. 6-8 are diagrams of three different tables which could be constructed in an exemplary database according to the invention. It is to be understood that numerous other tables, fields and interrelationships can be stored in the database than the ones illustrated and described, such as tables relating to basic test information and drug testing information. The WORKER table preferably includes various fields uniquely identifying the worker, such as the worker's name, address and worker number (such as social security number). The WORKER table also identifies an image file that stores a photograph of the worker, for use in generating an ID card. Finally, each member of the WORKER table will have an array of worksite data, where for each of M work sites there will be a field to record whether the worker has passed a specific test for that work site, and when.
FIG. 7 illustrates a representative WORKSITE table in the database. Each member of this table will have a worksite identifier that uniquely identifies the work site to the system. For each such work site, there is also stored the number of questions to be asked (this could vary, and is supplied by work site management), the number of and text for each possible question relating to that worksite, the total number N of questions to be presented to the worker, an identifier for the multimedia course file to be downloaded to the test site, and the pass criterion established by work site management (which typically will be a function of the number of questions presented). WORKSITE will also contain the frequency with which instruction should be given to each worker, which in turn will permit an expiration date on the worker's certification to be calculated. WORKSITE will also contain a manager ID and password to restrict access to the content of that WORKSITE member to personnel authorized by the management of that work site.
FIG. 8 is a diagram of an exemplary database table which identifies each test site and the administrator authorized to initiate testing at that test site. There may be more than one such administrator at each such site.
While certain embodiments have been described in the foregoing detailed description and illustrated in the appended drawings, the present invention is not limited thereto but only by the scope and spirit of the appended claims. | A testing system, particularly directed at contract workers, permits computer-aided instruction and testing at each of a plurality of testing sites. Different tests are created and administered for each of a plurality of work sites, which can be selected by the prospective contract worker. Whether the worker passed a particular site-specific test is stored in a database, which is turn is accessible by the work site management. The system has particular application to safety instruction and testing as mandated by the Occupational Health and Safety Administration. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to metallic material for flutes, and more particularly relates to improvement in tonal quality of sounds generated by flutes made of Ag alloys.
In the field of conventional flutes, nickel silver is used for popular class flutes, Ag alloys are used for middle and high class flutes and Au alloys are used for high class flutes. In particular, coin silver (90% Ag-Cu alloy) and sterling silver (92.5% Ag-Cu alloy) have enjoyed general poularity in use for middle and high class flutes.
In the production of Ag alloy type flutes, the alloy material is subjected to repeated annealing each at a temperature in a range from 600° to 750° C. Treatment of the alloy material at such a high temperature softens the material and coarsens the crystal grain size of the alloy. With recent advances in scientific investigation of acoustic mechanisms of sounds generated by flutes, it is said that the hardness of the material and the grain size and orientation of the crystal may pose some influence on the acoustic characteristics of the sounds. From this point of view, softening of the material and coarsening the crystal grain size are believed to adversely affect the tone quality of flutes. In particular the tone colour of sounds generated by flutes.
In attempt to overcome this possible disadvantage, it is proposed that a microscopic surface waving be applied to the inner surface of a flute or that the inner surface be plated so as to control the pneumatic flow generated by blowing the flute. Despite various efforts in the field, no sufficient improvement in actual tone colour has ever been attained, particularly in the case of the popular class flutes.
SUMMARY OF THE INVENTION
It is the object of the present invention to improve tone colour of sounds generated by flutes made of Ag alloys.
In accordance with one aspect of the present invention, a metallic material for flutes contain 5 to 25% by weight of Cu, 0.05 to 1% by weight of one or more of Ni, Fe, Co and Cr, and Ag in balance.
In accordance with another aspect of the present invention, a metallic material for flutes contains 5 to 28 by weight of Cu, 0.05 to 1% by weight of one or more of Mn, Ti, Zr and Si, and Ag in balance.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
According to the present invention, the metallic material contains 5 to 28% by weight of Cu. Any content below 5% by weight would make the material too soft to be used for flutes. The content of 28% by weight is the eutectic limit beyond which the workability of the material is much longer and the corrosion resistance of Ag is seriously degraded.
According to one aspect of the present invention, the material contains 0.05 to 1% by weight of one or more of Ni, Fe, Co and Cr. Any content of these elements below the lower limit would not effectively suppress the undesirable softening of the material and the coarsening of the crystal grain size during annealing. Any content above the upper limit would impair workability of the material.
According to another aspect of the present invention, the material contains 0.05 to 1% by weight of one or more of Mn, Ti Zr and Si. Any content of these elements below the lower limit would not effectively suppress the undesirable softening of the material and the coarsening of the crystal grain size during annealing. Any content above the upper limit would impair workability of the material.
EXAMPLES
EXAMPLE 1
A mixture of 1,890 g. of Ag, 100 g. of Cu, 1 g. of Fe, 6 g. of Ni, 1 g. of Co and 2 g. of Cr. was melted in a tanman furnace for casting to form a test piece, identified as Sample No. 1. After hot forging and cutting, the test piece was subjected to repeated annealing and rolling down to a thickness of 1.2 mm. Next, the test piece was heated at 750° C. for 30 minutes for measurement of crystal grain size. The test piece was further rolled down to a thickness of 1.0 mm. for measurement of hardness.
A mixture of 1,850 g. of Ag, 130 g. of Cu, 4 g. of Fe, and 16 g. of Ni was melted in a tanman furnace for casting to a form a test piece, identified as Sample No. 2. As in the case of Sample No. 1, the test piece was worked down to a thickness of 1.2 mm. for measurement of crystal grain size. The test piece was further rolled down to a thickness of 1.0 mm. for measurement of hardness.
The test piece was further worked to a pipe having a 24 mm. outer diameter, 21.6 mm. inner diameter and 1.2 mm. thickness. This pipe was further subjected to repeated annealing and extension to form a pipe of 20.5 mm. outer diameter, 19.5 mm. inner diameter and 0.5 mm. thickness. The pipe thus obtained was heated in an N 2 gas environment at 750° C. for 30 minutes. After skinpass treatment, the pipe was again heated in an N 2 gas environment at 300° C. for 2 hours for stabilization purpose. The pipe was then formed into a flute for comparison of tone colour with a flute made of the conventional material.
Further Samples Nos. 3 to 11 were prepared in the same manner as that of Sample No. 1. Samples Nos. 5 and 7 were formed into flutes like Sample No. 2.
For comparsion, Samples Nos. 12 to 14 were prepared from conventional materials in the same manner as Sample No. 1. Samples Nos. 12 and 13 were formed into flutes. The results are shown in Table 1.
TABLE 1______________________________________Composition (% by weight) PropertySample Ag Cu Fe Ni Co Cr I II III______________________________________1 94.5 5.0 0.05 0.3 0.05 0.1 45 1202 92.5 6.5 0.2 0.8 40 121 ⊚3 92.0 7.0 1.0 40 1204 92.0 7.4 0.3 0.3 40 1185 90.0 9.0 1.0 35 1246 90.0 9.0 0.8 0.05 0.15 30 1257 90.0 9.2 0.5 0.1 0.2 30 130 ⊚8 80.0 19.0 1.0 25 1329 75.0 24.0 0.2 0.8 25 14510 75.0 24.0 0.8 0.2 25 14511 71.5 28.0 0.1 0.2 0.2 20 15012 92.5 7.5 65 110 ○13 90.0 10.0 55 116 ○14 75.0 25.0 50 128______________________________________
It is clear from this experimental data that, in comparison with Samples 12-14 formed from conventional materials, the samples prepared in accordance with the present invention suppress grain size enlargement and thereby maintain their hardness. By adding small produce amounts of the indicated elements to the conventional Ag-Cu alloy, grain growth is suppressed so that a grain size in the range of from about 20 um to about 45 um results. Thus, flutes generating brilliant sounds in the mid to high notes can be obtained.
EXAMPLE 2
Sample Nos. 21 to 31 in accordance with the present invention were prepared in the same manner as those in Example 1, but using the compositions shown in Table 2. For comparison purposes, Samples 32 to 34, consisting of conventional materials, were also prepared.
TABLE 2______________________________________Composition (% by weight) propertySample Ag Cu Mn Ti Zr Si I II III______________________________________21 94.7 5.0 0.05 0.05 0.2 40 11822 92.5 6.9 0.5 0.1 35 12523 92.5 6.5 1.0 40 12824 91.0 8.4 0.5 0.1 35 12525 90.0 9.4 0.3 0.3 35 125 ⊚26 90.0 9.5 0.2 0.2 0.05 0.05 30 13027 90.0 9.6 0.3 0.1 30 128 ⊚28 81.2 18.0 0.8 25 13529 80.0 19.6 0.3 0.1 25 13530 74.5 25.0 0.5 25 14031 74.5 25.0 0.5 25 14532 92.5 7.5 65 110 ○33 90.0 10.0 55 116 ○34 75.0 25.0 50 128______________________________________ *I; Crystal diameter in μm II; Hardness in Hv III; Tone colour excellent ⊚ good ○ no bad
These data also will indicate the merits of the present invention. | In the composition of a Ag alloy type material used for production of flutes, a specified amount of at least one of Ni, Fe, Co and Cr or at least one of Mn, Ti, Zi and Si is added to suppress softening and crystal grain size coarsening caused by annealing in production. Thus, flutes which generate brilliant sounds in mid to high notes can be obtained by using the above material. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to a tape cassette storage and carrying case, and more particularly to such a tape cassette case wherein the cassettes are securely held for storage, and wherein the cassettes are easily removed for use.
The object of the invention is to provide such a tape cassette storage and carrying case which is easy to manufacture, easy to handle, easy to open and in which the cassettes are easily removed therefrom.
SUMMARY OF THE INVENTION
According to the present invention, a tape cassette storage and carrying case comprises first and second substantially hollow shell members each having an open end and a bottom opposite the open end, the shell members being pivotally connected together and being relatively movable between a closed position wherein the open ends face each other, and an open position wherein sides of the shells are adjacent each other; support means mounted at the inner, bottom ends of the shell members and defining a plurality of stepped support levels for cassettes inserted in the shells from the open ends of the shells, the support levels for each adjacent cassette being different and being stepwise graduated relative to the adjacent support levels, the stepped support levels of the shell members being graduated in opposite directions; and means for maintaining the shells in the closed position to enclose cassettes stored therein.
Preferably the support levels of each shell are stepwise graduated in ascending or descending manner from the front toward the back of the shell members. Further, the shell members preferably each have a cut-out wall portion and a protruding wall portion at the open ends thereof, the protruding wall portion of one shell being in mating registration with the cut-out wall portion of the other shell.
In a further preferred arrangement, a friction lock is provided for maintaining the shell members in an open position adjacent each other, and the shell members have highly rounded bottom corners at the corners adjacent the pivoting means to facilitate opening of the carrying case.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front perspective view of a tape cassette storage and carrying case according to the present invention;
FIG. 2 is a front elevational view thereof, the rear elevational view being identical;
FIG. 3 is a left side elevational view thereof, the right side elevational view being identical;
FIG. 4 is a front elevational view in the open state;
FIG. 5 is a bottom view in the open state;
FIG. 6 is a top view in the open state;
FIGS. 7-9 are sectional views taken at various positions in FIG. 6;
FIG. 10 is a sectional view of a modified embodiment;
FIGS. 11 and 12 are enlarged fractional views of the hinge portion of the present invention; and
FIG. 13 illustrates a modified embodiment, and also showing the construction of the closure catch in greater detail.
DETAILED DESCRIPTION
Referring to FIGS. 1-6, the cassette storage and carrying case, hereinafter referred to as "case", comprises two shell portions 1, 2, each shell 1, 2 having a portion of a handle 3 formed on the upper surface thereof. The handle 3 incorporates a locking catch to maintain the case in the closed position, as will be discussed in greater detail hereinbelow.
The shell portions 1, 2 are pivotally connected by means of pivot pins 4, 5 which may, for example, take the form of rivets or other rigid members. The case has legs or feet 6, 7 which serve to raise the case and which also serve as locking members to maintain the two shells 1, 2 in their open position. More particularly, the leg 6 comprises pivotally connected portions 6a, 6b and the leg 7 comprises pivotally connected portions 7a, 7b. When the shells 1, 2 are pivotally moved to their opened condition as shown in FIGS. 4-6, the leg members 6a and 6b have an interference fit relative to each other to provide a frictional sliding lock to maintain the shells in their open state. A similar frictional sliding locking arrangement can be provided with respect to leg portions 7a, 7b. The interference fit is better seen in FIGS. 11 and 12, FIG. 11 illustrating the shells 1, 2 in a partially open state, and FIG. 12 illustrating the shells 1 and 2 in the fully opened state. As shown in FIGS. 11 and 12, the leg portions 7a, 7b are angled relative to each other such that when pivoted to the fully opened condition, they frictionally engage each other along at least a portion of the length thereof to effectively lock the shells 1, 2 in the open position in a simple and expedient manner. This frictional, sliding locking arrangement is achieved without complex mechanisms which could complicate molding and increase costs.
FIG. 6 is a top view of the interior of the shells 1, 2. Only one of the shells 1, 2 will be described in detail hereinbelow since both shells are substantially identical in general construction. The left side of shell 1 is provided with horizontally extending partitions 10, 12 and 14, and the right side is provided with respective partitions 11, 13 and 15 which are in alignment with respective partitions 10, 12, 14. Thus, four tape cassette compartments are provided for receiving four cassette tape boxes 16-19 shown in dashed lines in the right shell 2 in FIG. 6. Spacer ribs 20 are provided to space the cassette cases from the side edges of the shells 1, 2.
As best seen in FIGS. 7-9, the shells 1, 2 are also provided with cassette support members 21, 22 which are stepped to provide different levels of support at the respective storage compartments of the tape cassette carrying case. The cassettes inserted into the carrying case respectively rest on the steps 23-26 (FIG. 7) so that the upper edges of the stored cassettes are in a corresponding stepped arrangement to provide for easier removal of the individual stored cassettes from the carrying case.
As seen from FIG. 8, the stepped arrangement in the right hand shell 2 is opposite from that of left hand shell 1. By virtue of this arrangement, the cassette carrying case can be closed and the highest level cassette (on step 23) in one shell will be in registration with the lowest level cassette (on step 26) in the mating shell. This maintains the oppositely mounted cassettes securely in position and reduces rattling when the case is closed.
It is pointed out that the abutting surfaces 28, 29 of shells 1, 2 are generally "S" shaped in the embodiment of FIGS. 1-12. When the shells 1, 2 are closed, the S-shaped adjacent portions are in registration to provide a substantially fully closed structure to prevent intrusion of dust and other contaminating particles. When opened, the recesses 30, 31 (see FIG. 4) provide a finger gripping open area for sliding the lowermost mounted tape cassette (resting on lowermost step of ribs 21, 22) out of the case. The lowermost tape cassette extends above the lowermost portion of the recesses 30, 31 so that it may be gripped by the fingers of a user and slid upwardly out of the storage case. This is an important feature of the invention.
FIG. 10 illustrates a modified arrangement having a resilient wedge of foamed plastic, foam rubber, or the like, 35 mounted in the lower portion of the shells 1, 2 between stepped support members 21, 22. The wedge 35 extends just above the stepped support members 21, 22. When the cassettes are mounted in the shells 1, 2 of the storage case and the case is closed, the cassettes in one shell with have their upper surfaces bearing against respective upper surfaces of the cassettes in the other shell to slightly push them downwardly against the resilient wedge 35 toward the respective steps. The slight biasing pressure exerted by the wedge 35 further prevents rattling of the cassettes in the case when the case is closed. A further advantage is that when the shells are opened, the resiliency of the wedge 35 will push or spring the cassettes slightly upwardly to facilitate removing them from the storage case.
FIG. 13 illustrates a modified arrangement wherein the generally S-shaped abutting surfaces 28,29 of the embodiment of FIGS. 1-12 are replaced by generally trapezoidal surfaces 38,39. The trapezoidal surfaces 38,39, which generally form a "S-shape" perform substantially the same functions as the surfaces 28,29 shown in the embodiment of FIGS. 1-12. The sloped portions 40,41 and 42 provide relief areas to permit the shells 1, 2 to be pivoted relative to each other from the closed to the open position. The internal construction of the embodiment of FIG. 13 is identical to that of FIGS. 1-12, as well as the construction of the legs and pivoting mechanism.
In the FIG. 13 embodiment, the handle 43 extends the full width of the case, the dimension of the handle in the side view being substantially identical to that shown in FIG. 3.
The locking catches on the handle 3 of the embodiment of FIGS. 1-12 is substantially identical to that in the embodiment of FIG. 13. The description below will be given with respect to the locking catch in the embodiment of FIGS. 1-12. The locking catch in FIG. 13 will not be described separately, but identical numerals, but primed, will be used to designate corresponding parts in FIG. 13, the detailed description thereof being omitted. The handle 3 comprises a left side portion 45 with a resilient projection 44 and a right side portion 46 which has a projection 47 which is releasably and lockingly engageable with the projection or resilient extension 44. The resilient extension or projection 44 is wider in the direction of dimension "x" than the remaining portions of the handle, and particularly the portion of the handle 46. This is to provide a gripping area for the users fingers in order to lift the resilient projection or extension 44 relative to the remaining portions of the handle to disengage the projection 47 from the slot 48 formed in the extension 44. The arrangement of the locking device shown in FIGS. 1-13 is of particular advantage since it permits the shells, with the integral handle and locking device, to be manufactured without using a cam-action mold. The material of the handle is preferably a resilient plastic material with "memory", such as ABS or impact styrene. The projection 47 preferably has a tapered leading edge 49 to facilitate engagement of the extension 44 over the projection 47 when closing the cassette carrying case.
An important feature of the present invention is the provision of the rounded bottom edges 50 of the shells 1, 2. By virtue of the rounded bottom edges, the carrying case of the present invention can be easily opened with only one hand. This is of particular advantage when the carrying case is used in an automobile and the driver opens the carrying case. This enables the driver to easily open the carrying case with one hand, while still maintaining control of the vehicle with the other hand. This is accomplished by lifting the projection or extension 44 to release the lock and then rolling either one of the shells over the rounded edges 50 to automatically cause the shells to pivot with respect to each other about pivot point 4, thereby easily opening the case. For example, assuming the user opens the case by gripping and rolling shell 2 in the clockwise direction after releasing the closing latch, the pivot point 4 will also rotate in a clockwise direction and be raised upwardly. This automatically causes the left-hand shell 1 to rotate in the counterclockwise direction. The rotation of one of the shells is continued until the legs 6a, 6b reach the positions shown in FIG. 4, at which position they frictionally engage and lock with each other to maintain the carrying case in the open position, thereby permitting the user to easily remove the desired cassette, without excessive fumbling. Since the carrying case remains frictionally locked in its open position, removing cassettes therefrom is facilitated, especially when the user is operating an automobile.
While the invention has been described above with respect to specific embodiments, it should be clear that various modifications and alterations can be made within the scope of the invention as defined in the appended claims. For example, the form and shape of the closure lock may be varied, as desired, as may the shape of the abutting surfaces 28, 29. The overall outer shape of the carrying case may also be varied, as desired. The complete case is preferably molded in two pieces, to wit: two shells each having integral handle portions, of ABS or impact styrene. | A tape cassette storage and the carrying case comprising hollow shell members pivotally connected together and being relatively movable between a closed position and an open position. The shells have a support arrangement mounted at the inner bottom ends thereof which defines a plurality of stepped support levels for cassettes which are inserted into the shells from the open ends of the shells. The support levels for each cassette are different and are stepwise graduated in an ascending manner from the front toward the back of the shell members, the step support level of the two shell members ascending in opposite directions. A lock is provided to lock the shells in the closed position, and a friction lock is provided to lock the shells in their open position. | 6 |
BACKGROUND OF THE INVENTION
This invention relates to an improved removable closure plate construction that is adapted for easy removal and provides a liquid-tight seal in an elongated floatable offshore hollow tubular column structure.
Closure plates are typically utilized in conjunction with offshore platforms having a subsurface structure referred to as a jacket. The jacket structure contains a plurality of tubular columns through which piles are driven during installation. Jackets which are too large to be lifted must be launched after transportation to an offshore installation site. Jackets are usually constructed on shore with temporary closure plates installed in the jacket legs or columns to render the structure buoyant. The closure plates are selectively located within the jacket columns so that the jacket floats in a predictable, stable position. To achieve a predictable, stable, flotation position, the closure plates must be placed in the columns to form flotation chambers which can be selectively flooded with water at the installation site to rotate the jacket to the proper upright position. When the jacket is in its proper upright position, the column closure plates are removed to provide substantially unobstructed access through which piles are driven to anchor the jacket to the ocean bed.
The object of the present invention is to provide an improved removable closure plate of the type disclosed in U.S. Pat. No. 3,613,381. In the prior art, the lower closure plate assembly is basically a truncated plate cone whose circumference is welded to the inside wall of a jacket column and when used in conjunction with an upper closure plate forms a flotation chamber. A chain is welded to the underside of the cone about its perimeter and the chain is attached to an eccentrically located pulling arm which extends through the cone. The closure plate is torn away from the column in segments by the application of a force to the pulling arm.
The present invention eliminates the eccentrically located pull arm and the chain welded to the underside of the closure plate as disclosed in the prior art. The improved removable closure plate, herein disclosed, centrally locates the pulling arm, is capable of resisting pressure from both sides and can be constructed of relatively thin metal for use in large diameter columns. Additionally, the improved removable closure plate is capable of resisting greater pressures for a comparable material thickness, is broken away from the column as a unit and develops a very large mechanical advantage for ease in removal.
SUMMARY OF THE INVENTION
The present invention relates to improvement in the construction of a removable closure plate of the type used in an elongated hollow tubular column structure which is adapted for flotation to an offshore site where it is immersed by flooding for installation in an upright position. The closure plate, adapted for easy removal, provides a liquid-tight seal in the columnar structure. The improved closure plate centrally locates a tearing pull arm device that is removably connected to the upper central portion of the closure plate and further rigidly secures the pull arm to the hub section of the lower component portion of the closure plate. The closure plate is further removably connected, about its periphery, to the inside surface of the column. The lower component part of the closure plate is fixedly connected, circumferentially, to the upper portion of the closure plate. The closure plate connections both about the pull arm and about the column form liquid-tight seals.
The closure plate is removed by exerting a force through a wire rope, cable, or the like which is connected to the pull arm. As the force exerted through the connection and transmitted to the pull arm is sufficiently increased, the seal about the upper portion of the closure plate and pull arm is ruptured. The applied force is maintained until it is sufficient to then rupture the seal between the closure plate and the column. The closure plate is thus broken away from and pulled upthrough and out of the column as a unit.
The invention will be described in relation to a single closure plate used to provide a liquid-tight seal in a hollow column. However, it should be understood that the invention applies equally to a plurality of closure plates used to form liquid-tight compartments in a single hollow tubular structure.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific results obtained by its use, reference should be made to the accompanying drawings and descriptive matter in which there is illustrated and described a typical embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial sectional side elevation view of a hollow tubular column structure depicting an improved removable closure plate.
FIG. 2 is a plan view of the closure plate taken along line 2--2 of FIG. 1.
FIG. 3 is an enlarged detailed sectional elevation view depicting the upper central portion of the closure plate shown in FIG. 1.
FIG. 4 is an enlarged fragmentary view depicting the lower portion of the closure plate connected to the column wall as shown in FIG. 1.
FIG. 5 is an enlarged detailed sectional elevation view depicting the lower central portion of the closure plate shown in FIG. 1.
FIG. 6 is a bottom plan view of the closure plate taken along line 6--6 of FIG. 1.
FIG. 7 and FIG. 8 illustrate alternate embodiments of the structure depicted in FIG. 6.
FIG. 9 is a sectional elevation view depicting the closure plate after it has broken away from the column.
FIG. 10 illustrates an alternate embodiment of the closure plate depicted in FIG. 1.
FIG. 11 is a bottom plan view of the closure plate taken along line 11--11 of FIG. 10.
FIG. 12 illustrates another embodiment of the closure plate depicted in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1-6, there is illustrated a portion of a jacket column 10 of an offshore platform, not shown, depicting an installed improved removable closure plate 14. The closure plate 14 has a substantially hemispherical upper component portion 16, a lower component portion 18 and a centrally located tearing pull arm or pull member 22. Pull arm 22 extends through a central opening in upper portion 16 and is removably connected about its circumference to upper portion 16 by seal weld 24 and is further rigidly connected circumferentially about its base to hub 20 of lower portion 18 by weld 28. Closure plate 14 is removably connected about its periphery to the inside surface of column 10 by means of seal weld 26. The closure plate with welds about pull arm 22 and column wall 12 is designed to resist hydrostatic pressure from either side, as required. Lower portion 18 is fixedly connected about its circumference to upper portion 16 and fixedly connected radially about hub 20 by means of welds 32, depicted in FIGS. 4, and 30 respectively. Aperture 23 is located in pull arm 22 to receive a wire rope, cable, chain, or the like, not shown, that will be utilized to exert an external tearing or breakaway force on pull arm 22 to remove closure plate 14 from the inside surface of wall 12 of column 10. The seal welds between pull arm 22 and upper closure plate portion 16 and between the closure plate and the inside surface of column wall 12 are liquid tight. Lower portion 18 has a disc shaped configuration having a plurality of openings 34 as illustrated in FIG. 6.
It should be noted that, for discussion purposes, the welds herein described are referred to as welds or seal welds whereas the concept disclosed applies equally to other types of connections wherein surfaces between metal parts are sealed.
FIGS. 7-8 depict different embodiments of the bottom plan view of the lower portion 18A, 18B of closure plate 14. Lower portion 18A, 18B has a plurality of apertures such as the elongated slots 36 of FIG. 7 or the spaces 40 between radial spokes 38 of FIG. 8. Radial spokes 38 are strengthened by reinforcing ribs 39.
The openings in lower portion 18, 18A, 18B allow water to enter the space between the upper and lower closure plate portions 16 and 18 and allows the passage of water therethrough to prevent the application of net hydrostatic force to lower portion 18, 18A, 18B.
Closure plate 14 is disengaged from the inside surface of column wall 12 by exerting a force on pull arm 22 through a connection, not shown, affixed to pull arm 22 at its aperture 23. Sufficient force is applied to pull arm 22 to first rupture seal weld 24 between upper portion 16 and pull arm 22. The force is sufficiently maintained to then pull hub 20 out of the plane of lower portion or disc 18 with the resulting development of very high radial tension in disc 18 that ruptures seal weld 26 between the closure plate and the inside surface of column wall 12. Closure plate 14 is thus broken away from and pulled up through and out of column 10 as a unit as depicted in FIG. 9.
FIGS. 10-11 depict an alternate embodiment of closure plate 14 wherein a circumferential metal reinforcing ring 42 is disposed adjacent to pull arm 22 and is fixedly connected about its periphery to upper closure plate portion 16 by the placement of welds 44. Additionally, a continuous metal shim 46 is rigidly connected to the inside surface of wall 12 of column 10 through connecting seal welds 48 placed along the upper and lower surfaces of shim 46. The closure plate is removably connected about its periphery in a liquid-tight manner to shim 46 by seal weld 50.
FIG. 12 illustrates another embodiment of the invention wherein the closure plate upper portion 16 is substantially of a torispherical configuration, all other depicted elements being alike to those described with respect to FIGS. 1 and 8. It will be understood that the torispherical upper portion 16 is usually applicable with the embodiments shown in FIGS. 6, 7 and 10.
It will be further understood that the closure plate upper portion configuration also encompasses such shapes as ellipsoidal, conical or other surface of revolution. All other elements being alike those herein described in the specification. | An improved removable closure plate arrangement providing a liquid-tight seal in an elongated floatable offshore hollow tubular column structure. The closure plate being adapted for easy removal and including a centrally located pull member removably connected to the upper and fixedly connected to the lower portion of the closure plate with the closure plate being removably connected about its periphery to the inside surface of the column. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent application Ser. No. 14/468,002, filed Aug. 25, 2014, which is a continuation of U.S. patent application Ser. No. 13/365,970, filed Feb. 3, 2012, which claims priority to U.S. Provisional Patent Application No. 61/439,695, titled Positive Drive for Sliding Gate Operation, filed Feb. 4, 2011, each of which is incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] The invention relates generally to gate control devices, and more particularly, it relates to sliding gate systems and/or gate driving mechanisms for use with linear sliding types of gates (i.e. horizontal and vertical) and associated methods.
BACKGROUND
[0003] The prior art includes numerous types of actuators and linkages for swinging type gates, and numerous devices for actuating pivoting gates as well as security barriers. One type of gate utilized in security perimeter protection is the sliding gate that can be operated open or closed by longitudinal sliding motion. These types of gates have been acted upon for their motive force by several means.
[0004] The most ubiquitous means of driving a sliding gate is with the use of a chain and sprocket arrangement wherein the ends of the chain are attached to the gate ends and wrapped around a sprocket on a gate driving motor. The chain drive has the disadvantage of requiring oiling to extend its service life and the inherent mess this makes when exposed to dirt. Further, the chains are limited in length due to sag, and stretch and wear only compound this drawback.
[0005] Another means of driving a sliding gate is rack and pinion drive, which utilizes an involute gear tooth pinion on the gate driving motor and a corresponding gear rack attached to the gate. These types of drives have the inherent disadvantage of requiring precise alignment between rack and pinion so as to not bind when the distance between rack and pinion vary, or require some means to hold the rack and pinion in intimate contact, which encourages wear in an involute gear. Further, again, these drives require lubrication to maintain their life. U.S. Pat. No. 5,261,187 to Prenger describes a spring loaded rack apparatus to attempt to get around the alignment problem, but does not address the contact issue. U.S. Pat. No. 5,515,650 to Machill describes a means of assembling a plastic rack into a channel and attaching it to the gate but does not address concerns over controlling the mesh between rack and pinion.
[0006] Yet another means of driving a sliding gate includes wheels clamped together onto a flat, relatively thin longitudinal drive member, and the arrangement utilizes frictional force generated by the clamping force and the coefficient of friction between wheel surfaces and the drive member. This means is illustrated in FIG. 2 which shows the wheels clamped upon a drive member. This means of driving a sliding gate works well with the exception of when said wheel and drive member get wet or encrusted in ice, slippage may occur when driving a heavy gate.
SUMMARY
[0007] The present invention provides a gate driving assembly and related methods that overcome drawbacks experienced in the prior art and that provide other benefits. At least one embodiment provides a gate drive mechanism that requires no maintenance or lubrication, can be used on any length of gate, is unaffected by inconsistencies in alignment, and provides a positive drive so as to ensure high forces are transmitted to the gate in any weather conditions. The gate drive mechanism of the embodiment comprises a rolling tooth profile on a linear drive member and a corresponding rolling tooth profile on the drive wheel. In this manner, the concern for wear is gone due to the rolling nature of this tooth engagement, as opposed to the sliding nature of a typical involute gear tooth in a normal rack and pinion drive.
[0008] In an embodiment the gate drive mechanism can have the drive wheel mounted on a motor which is free to translate up and down while still transmitting the linear component of force needed to move the gate. The drive wheel and the linear drive member can be made of materials or a combination of materials that minimize wear and are inherently self lubricating and non-corroding.
[0009] In accordance with one aspect, the linear drive member comprises a molded plastic rolling tooth profile with means to slide this in sections into a correspondingly shaped aluminum extrusion in order to assemble the required length of drive to accommodate a given gate length. The drive wheel can be molded from a plastic such as polyurethane (PUR), thermoplastic vulcanite (TPV), or any other such tough, resilient plastic material. This material may be combined with some other material to form the hub of the drive wheel, such that a high strength hub is provided for structural purposes.
[0010] In at least one embodiment an idler wheel can be placed opposite the drive wheel on the other side of the linear drive member for the purpose of applying a consistent and predetermined normal force to the drive wheel. The idler wheel may be plain, or it may be a second toothed drive wheel.
[0011] One embodiment provides a linear gate drive assembly for use with a gate panel. The assembly can comprise a drive rail connectable to the gate panel, wherein the drive rail has a longitudinal axis and a first drive surface. A linear drive portion has a first plurality of teeth thereon with a first rolling tooth profile, wherein the linear drive portion is coupled to the first drive surface and defines a toothed second drive surface opposite the first drive surface. A support structure is adjacent to the drive rail, and the drive rail is moveable axially relative to the support structure. One or more drive motors is coupled to the support structure. A first drive wheel is attached to the one or more drive motors and is rotatable upon activation of the one or more drive motors. The first drive wheel engages the first drive surface and imparts a first drive force on the drive rail upon rotation of the first drive wheel to move the drive rail axially. A second drive wheel is attached to the one or more drive motors and engages the second drive surface. The second drive wheel has a plurality of second teeth disposed about a circumference, and the second teeth define a second rolling tooth profile that substantially corresponds to the first rolling tooth profile, wherein the second plurality of teeth mate with the first plurality of teeth. Rotation of the second drive wheel imparts axial and normal forces via a rolling teeth interface between the first and second teeth for driving the drive rail axially and moving the gate panel.
[0012] Another embodiment provides a security gate assembly. The security gate assembly can include a gate panel laterally movable between open and closed positions. A drive rail is fixed to the gate panel and is movable with the gate panel laterally between the open and closed positions. A linear drive portion can be attached to the drive rail and has a first plurality of teeth thereon that define a toothed second drive surface opposite the first drive surface. The first plurality of teeth define a first rolling tooth profile. One or more drive motors is coupled to a support structure, and a first drive wheel is rotatably attached to the one or more drive motors. The first drive wheel engages the first drive surface and imparts a first drive force on the drive rail upon rotation of the first drive wheel to move the drive rail and gate panel laterally. A second drive wheel is attached to the one or more drive motors and engages the second drive surface. The second drive wheel can have a plurality of second teeth disposed about a circumference and that define a second rolling tooth profile substantially corresponding to the first rolling tooth profile, wherein the second plurality of teeth mate with the first plurality of teeth, and wherein rotation of the second drive wheel imparts axial and normal forces via a rolling teeth interface between the first and second teeth for driving the drive rail axially and moving the gate panel between the open and closed positions.
[0013] Another embodiment provides a method of forming a security gate assembly. The method can include attaching a drive rail to a gate panel, wherein the drive rail has a longitudinal axis and a first drive surface. The method can include attaching a linear drive portion to the drive rail, wherein the linear drive portion has a first plurality of teeth thereon with a first rolling tooth profile. The linear drive portion defines a toothed second drive surface opposite the first drive surface. The method can include attaching first and second drive assemblies to a support structure adjacent to the drive rail, wherein the drive rail and gate panel are moveable as a unit laterally relative to the support structure. The first drive assembly can have a first drive motor and first drive wheel pivotally coupled to the support structure. The second drive assembly can have a second drive motor and second drive wheel pivotally coupled to the support structure. The first drive wheel engages the first drive surface and imparts a first drive force on the drive rail upon rotation of the first drive wheel to move the drive rail axially. The second drive wheel engages the second drive surface. The second drive wheel has a plurality of second teeth disposed about a circumference and that have a second rolling tooth profile substantially corresponding to the first rolling tooth profile. The second plurality of teeth mates with the first plurality of teeth. Rotation of the second drive wheel imparts axial and normal forces via a rolling teeth interface between the first and second teeth for driving the drive rail axially and moving the gate panel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a view of a sliding gate system in accordance with an embodiment of the present invention.
[0015] FIG. 2 is a view of a prior art drive system.
[0016] FIG. 3 is an isometric view of a drive system of the sliding gate system of FIG. 1 .
[0017] FIG. 4 is an enlarged side elevation view of a portion of the drive system of FIG. 3 .
[0018] FIG. 5 is a sectional view taken substantially along line 5 - 5 of FIG. 3 .
[0019] FIG. 6 is an enlarged schematic side elevation view of a rolling tooth profile drive of an embodiment.
[0020] FIG. 7 is an enlarged schematic side elevation view of a tooth profile arrangement of another embodiment.
[0021] FIG. 8 is a sectional view of an extruded gate drive rail with a linear drive member inserted in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0022] Sliding gate systems, associated drive systems, and related methods are described in detail herein in accordance with embodiments of the present disclosure. The systems and associated assemblies and/or features overcome drawbacks experienced in the prior art and provide other benefits. Certain details are set forth in the following description and in FIGS. 1-8 to provide a thorough and enabling description of various embodiments of the disclosure. Other details describing well-known structures and components often associated with gate assemblies and associated with forming such assemblies, however, are not set forth below to avoid unnecessarily obscuring the description of various embodiments of the disclosure. Many of the details, dimensions, angles, relative sizes of components, and/or other features shown in the Figures are merely illustrative of particular embodiments of the disclosure. Accordingly, other embodiments can have other details, dimensions, angles, sizes, and/or features without departing from the spirit and scope of the present disclosure. In addition, further embodiments of the disclosure may be practiced without several of the details described below, while still other embodiments of the disclosure may be practiced with additional details and/or features. In the Figures, identical reference numbers identify identical, or at least generally similar, elements. Moreover, one of ordinary skill in the art will appreciate that any relative positional terms such as above, below, over, under, etc. do not necessarily require a specific orientation of the footwear assemblies as described herein. Rather, these or similar terms are intended to describe the relative position of various features of the disclosure described herein.
[0023] The terminology used in the description presented below is intended to be interpreted in its broadest reasonable manner, even though it is being used in conjunction with a detailed description of certain specific embodiments of the invention. Certain terms may even be emphasized below; however, any terminology intended to be interpreted in any restricted manner will be overtly and specifically defined as such in this Detailed Description section.
[0024] References throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment and included in at least one embodiment of the present invention. Thus, the appearances of the phrase “in one embodiment” or “in an embodiment” in various places throughout the specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0025] As seen in FIG. 1 , a sliding gate system 10 consists of a gate panel 1 which contains a drive rail 3 securely fastened to the gate, and a gate operating device 2 that may be attached to a concrete pad or to a secondary structure for support.
[0026] Referring to FIG. 3 , FIG. 4 and FIG. 5 , in the illustrated embodiment, a linear drive member 4 having drive teeth 13 thereon is fixed to the drive rail 3 . An upper drive wheel 6 is attached to a drive motor 9 . This combination of wheel and motor is then mounted in upper drive arm 7 . It should be noted here that this method of drive is equally effective where the motor 9 is replaced with any of a variety of geared speed reducers or other power transmission means which support a rotary application of torque to the drive wheel.
[0027] A toothed drive wheel 5 having drive teeth 15 thereon is attached to a second drive motor 9 . This combination of the toothed drive wheel 5 and lower drive motor 9 is mounted in a lower drive arm 8 . The teeth 15 of the toothed drive wheel 5 are engaged with the teeth 13 of the linear drive member 4 .
[0028] The upper drive arm 7 and the lower drive arm 8 are rotatably connected to the gate operating device 2 , such as to a support frame, in a configuration so the upper and lower drive arms 7 and 8 can rotate relative to the support frame, thereby allowing the upper and lower drive wheels 6 and 5 to translate in a roughly vertical curvilinear path. This arrangement allows for any inconsistency in the straightness and level of the horizontal drive rail 3 as the gate panel 1 ( FIG. 1 ) translates horizontally along its path. It should be noted that any number of substantially equivalent means of allowing the combination of drive wheels and motors to translate essentially vertically while still providing reaction to the horizontal force of moving the gate could be used.
[0029] The upper drive arm 7 and the lower drive arm 8 are held together with toggle clamp 17 and spring 18 . This arrangement of the toggle clamp 17 and spring 18 provide a constant and predictable force that squeezes the upper drive wheel 6 and the toothed drive wheel 5 together thus supplying a normal force N between the upper drive wheel 6 and the horizontal drive rail 3 and between the toothed drive wheel 5 and the linear drive member 4 . The toggle claim 17 and the spring 18 are coupled to the upper and lower drive arms 7 and 8 , so as to effectively tie the upper drive wheel 6 to the lower toothed drive wheel 5 . Accordingly, the drive wheels 6 and 5 will translate in unison in the event of vertical motion of the wheels relative to the support frame. This means that the drive wheels 6 and 5 will always remain in firm engagement with the drive rail 3 and linear drive member 4 , respectively, while the toggle clamp is in the engaged position.
[0030] Referring to FIG. 6 is a close up view of the engagement of a section of the linear drive member 4 engaged with the portion of a toothed drive wheel 5 . On the linear drive member 4 , the root of the tooth 13 is formed as a substantially circular shape. The crest of the tooth 15 on the toothed drive wheel 5 is formed as a substantially corresponding circular shape, and engaged such that the crest of the tooth 15 may roll freely on the root of the tooth 13 of the linear drive member 4 . In a linear fashion, at a distance of half the pitch p along the linear drive member 4 , a crest of the tooth 14 is formed in a substantially circular shape. While the example described above refers to a substantially circular shape, other arcuate shapes, such as truly circular, ellipsoid, or any generally curvilinear shape, could be used as long as it facilitates rolling between the crest of the teeth on the drive wheel and the root of the teeth of the linear drive member.
[0031] A pressure angle θ is defined by the angle of the tangent point where the curvilinear portion of the tooth meets the curvilinear portion of the root. Hence there is a portion of torque which is transferred along the direction of the linear drive member and a portion which is imparted normal to the direction of the linear drive member. The horizontal portion is given by Fh=F Sin θ and the normal portion is given by Fn=F Cos θ.
[0032] In addition to the motive force provided by the pressure angle of the tooth, significant force is imparted from the upper drive wheel 6 to the horizontal drive rail 3 through pure friction. In this case, the frictional force is given by F=μN, where μ is the coefficient of friction between the material of the upper drive wheel 6 and the horizontal drive rail 3 .
[0033] A likewise effect is had from the frictional interface between the toothed drive wheel 5 and the linear drive member 4 . For this reason it is desirable to make the mating surface of both the upper drive wheel and the toothed drive wheel from a material that exhibits high friction versus the materials they bear against.
[0034] In operation, the toothed drive wheel 5 rolls on a tooth 15 of the wheel, then transfers to rolling on a tooth 13 of the linear drive member 4 , then back to rolling on the wheel 5 , etc.
[0035] As shown in FIG. 6 , the distance d 1 from the center of the toothed drive wheel, c to the crest of the tooth 15 is larger than the distance d 2 from the center to the root of the next tooth 16 . This difference in distance causes a variation in the speed that the linear drive member 4 travels given a fixed rotational speed of the toothed drive wheel 5 . Thus the average speed is based on the average radius from the center of the toothed drive wheel c. One way of minimizing this variation is to utilize a lower pressure angle. This approach is shown in FIG. 7 , where the pressure angle θ is relatively small. This leads to a relatively smaller difference between d 1 and d 2 although as noted above, the horizontal component of drive is smaller and the normal component of drive is larger, which may be undesirable.
[0036] The material for the toothed drive wheel 5 as well as the upper drive wheel 6 of an embodiment can have high coefficients of friction, low wear, wide temperature range, compliance to debris, and require no lubrication. These properties are available in a range of polymer compounds, for example polymers that are commonly injection molded such as acrylinitrile butadiene styrene (ABS), polycarbonate (PC), polyester (PES), polyethylene (PE), polystyrene (PS), acetal, polyamides (PA), polypropylene (PP), Polyvinyl chloride (PVC). These properties could also be achieved using molded rubbers, polyurethane (PU), thermoplastic vulcanate (TPV), or thermoplastic urethane (TPU). Other embodiments could use other suitable materials.
[0037] The material for the linear drive member 4 likewise can include the properties of high coefficient of friction, low wear, wide temperature range, compliance to debris, and require no lubrication. These properties are available in a range of polymer compounds, for example polymers that are commonly injection molded such as acrylinitrile butadiene styrene (ABS), polycarbonate (PC), polyester (PES), polyethylene (PE), polystyrene (PS), acetal, polyamides (PA), polypropylene (PP), Polyvinyl chloride (PVC). These properties could also be achieved using molded rubbers, polyurethane (PU), thermoplastic vulcanate (TPV), or thermoplastic urethane (TPU). Other embodiments could use other suitable materials.
[0038] Another embodiment utilizes instead of a motor driving the upper drive roller, one or more unpowered idler rollers on the opposite side of the linear drive member 4 supported by bearing means with the sole purpose to apply a normal clamping force to the toothed drive wheel 5 . In yet another embodiment, the gate drive assembly 10 uses a toothed drive wheel with the rolling tooth profile as described above that engages the teeth on the linear drive, with out using the other drive motor and drive wheel. In this alternate embodiment, the linear drive portion can be attached directly to a rigid portion of the gate panel. The toothed drive wheel can be attached to motor assembly carried by a drive arm spring loaded against the toothed drive surface. Alternatively, the toothed drive wheel can be held rigidly in a relationship to the portion of the gate with the toothed drive surface.
[0039] In another aspect of the invention, as shown in FIG. 8 , the linear drive member 4 and the drive rail 3 can be equipped with an interlocking feature 17 (of which this is just one example of) whose purpose is to hold the linear drive member from moving in all but the drive direction.
[0040] A particular embodiment of the gate assembly comprises a sliding gate, a gate operating device containing a motor, and a gate drive mechanism. The gate drive mechanism of this embodiment comprises a linear drive member with a rolling tooth profile and a drive wheel attached to the output shaft of the motor. Additionally, the drive wheel includes a rolling tooth profile that corresponds to the tooth profile on the linear drive member to which it is rotatably in contact with.
[0041] In one embodiment the motor may be constrained in the longitudinal direction and not in the vertical direction. Additionally, the motor may be mounted on an arm rotatably attached to the gate operating device.
[0042] A second motor and drive wheel may be included to drive the opposite side of the longitudinal drive member. This drive wheel may include a rolling tooth profile corresponding to a rolling tooth profile on the linear drive member with which it is rotatably in contact. Alternatively, the drive wheel on the second motor may be a conventional round drive wheel. Furthermore, one or more unpowered idler rollers may be included on the opposite side of the linear drive member.
[0043] The linear drive member or the drive wheel, or both, may be constructed from a polymeric material, such as polyurethane. Additionally, the linear drive member may be of a certain length such that when placed end to end, the pitch of the rolling tooth profile is maintained. Finally, linear drive members may be of such length that when inserted into a correspondingly shaped gate drive rail extrusion, the lengths are restrained from movement in any but the longitudinal direction.
[0044] Those skilled in the art will recognize that this drive method can apply to other barriers requiring linear motion to open and close them, and the orientation is not important.
[0045] From the foregoing, it will be appreciated that specific embodiments of the invention have been described herein for purposes of illustration, but that various modifications may be made without deviating from the spirit and scope of the invention. Additionally, aspects of the invention described in the context of particular embodiments or examples may be combined or eliminated in other embodiments. Although advantages associated with certain embodiments of the invention have been described in the context of those embodiments, other embodiments may also exhibit such advantages. Additionally not all embodiments need necessarily exhibit such advantages to fall within the scope of the invention. | A linear gate drive assembly with a drive rail connectable to a gate panel. The drive rail has a first drive surface. A linear drive portion is coupled to the first drive surface and has teeth thereon with a first rolling tooth profile. The linear drive portion defines a toothed second drive surface. Dive motors are pivotally coupled to a support structure. A first drive wheel is attached to one drive motor and engages the first drive surface to impart an axial drive force on the drive rail. A second drive wheel is attached to another drive motor and engages the second drive surface. The second drive wheel has second teeth that mate with the first teeth and that define a second rolling tooth profile that substantially corresponds to the first rolling tooth profile. Rotation of the second drive wheel imparts axial and normal forces via a rolling teeth interface the mating teeth for moving the drive rail and the gate panel. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2016-001878, filed on Jan. 7, 2016. Each of the above application(s) is hereby expressly incorporated by reference, in its entirety, into the present application.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an imaging lens that is appropriate for an on-board camera and an imaging apparatus that has the imaging lens.
2. Description of the Related Art
Recently, cameras are mounted on a vehicle, and are used to assist a driver to check blind areas such as sides lateral to the driver and/or a rear side or are used to recognize images such as vehicles around own vehicle, pedestrians, and/or obstacles. Among these cameras, a front sensing camera for vehicle collision prevention and/or automatic brake application is used to mostly capture an image of a traffic light far from the front of a vehicle and/or an image of a brake lamp of a vehicle running forward, and detect the traffic light, the brake lamp, and/or the like through image identification software. As an imaging lens usable in such an on-board camera, for example, an imaging lens described in JP2014-85559A to be described later is known. JP2014-85559A discloses a lens system having six elements.
SUMMARY OF THE INVENTION
The above-mentioned front sensing camera is mostly provided in the vicinity of a front glass in a vehicle. However, in a state where a vehicle is stopped particularly in summer, a temperature of an inside of the vehicle tends to be extremely increased by the greenhouse effect as compared with a temperature of the outside of the vehicle. Thus, there is a concern that focus shift caused by temperature fluctuation becomes larger than that in a case where a camera is provided outside the vehicle.
In the related art, in an imaging lens for an on-board camera, generally, a lens (first lens) closest to an object side is made of glass in order to cope with yellowing and/or scratch, and second and following lenses are made of resin in order to reduce costs. Further, since it is necessary for the imaging lens for the on-board camera to have a certain degree of wide-angle performance, it is necessary for the first lens or the first and second lenses from the object side to have certain degrees of negative powers. In order to cope with the focus shift caused by temperature fluctuation, generally, a power of the first lens made of glass, which less causes deformation due to temperature fluctuation, is increased, and a power of the second lens made of resin, which more causes the deformation due to temperature fluctuation, is decreased.
However, the front sensing camera is provided in a vehicle which is a closed room, and the first lens is directly exposed to sun light. Thus, even in a case where the first lens is made of glass, a power thereof is large, and thus there is a concern that an amount of focus shift caused by temperature fluctuation becomes large.
The present invention has been made in consideration of the above-mentioned situation, and its object is to provide an imaging lens that has a small amount of focus shift caused by temperature fluctuation and an imaging apparatus that comprises this imaging lens.
The imaging lens of the present invention consists of, in order from an object side: a first lens that is convex toward the object side and has a negative refractive power; a second lens that has a negative refractive power; a third lens that has a positive refractive power; a fourth lens that has a positive refractive power; a fifth lens that has a positive refractive power; and a sixth lens that has a negative refractive power. The imaging lens satisfies the following conditional expressions (1) to (4).
−0.89< f/f 12<−0.53 (1)
−0.19< f/f 1<−0.1 (2)
−0.70< f/f 2<−0.45 (3)
2.4< f 1/ f 2<5.7 (4)
Here, f is a focal length of a whole system,
f12 is a composite focal length of the first lens and the second lens,
f1 is a focal length of the first lens, and
f2 is a focal length of the second lens.
It is preferable that the imaging lens of the present invention satisfies the above-mentioned conditional expressions (1) to (4), and satisfies any one or a plurality of combinations of the following conditional expressions (1-1) to (4-1).
−0.81< f/f 12<−0.61 (1-1)
−0.17< f/f 1<−0.11 (2-1)
−0.64< f/f 2<−0.47 (3-1)
2.7< f 1/ f 2<5.2 (4-1)
An imaging apparatus of the present invention comprises the above-mentioned imaging lens of the present invention.
It should be noted that a term “includes, substantially ˜” means that the imaging lens may include not only the above-mentioned elements but also lenses substantially having no powers, optical elements, which are not lenses, such as a diaphragm, a mask, a cover glass, and a filter, and mechanism parts such as a lens flange, a lens barrel, an imaging element, and/or a hand shaking correction mechanism.
Further, reference signs of surface shapes, radii of curvature, and/or refractive powers of the lenses are assumed as those in paraxial regions in a case where some lenses have aspheric surfaces.
The imaging lens of the present invention consists of, in order from an object side: the first lens that is convex toward the object side and has a negative refractive power; the second lens that has a negative refractive power; the third lens that has a positive refractive power; the fourth lens that has a positive refractive power; the fifth lens that has a positive refractive power; and the sixth lens that has a negative refractive power. The imaging lens satisfies the following conditional expressions (1) to (4). Therefore, it is possible to form an imaging lens that has a small amount of focus shift caused by temperature fluctuation.
−0.89< f/f 12<−0.53 (1)
−0.19< f/f 1<−0.1 (2)
−0.70< f/f 2<−0.45 (3)
2.4< f 1/ f 2<5.7 (4)
Further, the imaging apparatus of the present invention comprises the imaging lens of the present invention. Thus, it is possible to appropriately perform imaging in a wide temperature range.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view illustrating a lens configuration of an imaging lens (common to Example 1) according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view illustrating a lens configuration of an imaging lens of Example 2 of the present invention.
FIG. 3 is a cross-sectional view illustrating a lens configuration of an imaging lens of Example 3 of the present invention.
FIG. 4 is a diagram of aberrations of the imaging lens of Example 1 of the present invention.
FIG. 5 is a diagram of aberrations of the imaging lens of Example 2 of the present invention.
FIG. 6 is a diagram of aberrations of the imaging lens of Example 3 of the present invention.
FIG. 7 is a schematic configuration diagram of an imaging apparatus according to an embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, embodiments of the present invention will be described with reference to drawings. FIG. 1 is a cross-sectional view illustrating a lens configuration of an imaging lens according to an embodiment of the present invention. The exemplary configuration shown in FIG. 1 is the same as the configuration of the imaging lens of Example 1 to be described later. In FIG. 1 , a left side thereof is an object side, and a right side thereof is an image side. In addition, an aperture diaphragm St shown in the drawing does not necessarily indicate its sizes and/or shapes, but indicates a position of the diaphragm on the optical axis Z. Further, on-axis rays wa and rays with a maximum angle of view wb are also shown together.
As shown in FIG. 1 , the imaging lens includes, substantially in order from the object side: a first lens L 1 that is convex toward the object side and has a negative refractive power; a second lens L 2 that has a negative refractive power; a third lens L 3 that has a positive refractive power; a fourth lens L 4 that has a positive refractive power; a fifth lens L 5 that has a positive refractive power; and a sixth lens L 6 that has a negative refractive power.
As described above, an object side surface of the first lens L 1 is formed as a convex surface, and thereby it becomes easy to correct distortion of peripheral portion even in a wide-angle lens.
Both of the first lens L 1 and the second lens L 2 , which are two lenses disposed in order from the most object side, are formed as negative lenses, and thereby it becomes easy to increase an angle of view of the whole lens system.
The third lens L 3 , which is disposed after the first lens L 1 and second lens L 2 , is formed as a positive lens, and thereby it is possible to favorably correct a curvature of field.
The imaging lens is configured to satisfy the following conditional expressions (1) to (4).
First, the conditional expression (1) will be described. By not allowing the result of the conditional expression (1) to be equal to or greater than the upper limit, it is possible to prevent a negative composite refractive power of the first lens L 1 and the second lens L 2 from extremely decreasing. Thus, this contributes to wide-angle. By not allowing the result of the conditional expression (1) to be equal to or less than the lower limit, it is possible to prevent the negative composite refractive power of the first lens L 1 and the second lens L 2 from extremely increasing. As a result, it is possible to prevent an absolute value of radius of curvature of each surface of the lenses from extremely decreasing. Thus, it is possible to prevent high-order aberrations from occurring.
Next, the conditional expressions (2) to (4) will be described. By allowing the first lens L 1 and the second lens L 2 to have negative powers necessary for wide-angle such that the conditional expressions (2) to (4) are satisfied, a power of the first lens L 1 having a largest amount of temperature fluctuation is set to be relatively small, and a power of the second lens L 2 having an amount of temperature fluctuation smaller than that of the first lens L 1 is set to be relatively large. Thereby, it is possible to reduce an amount of focus shift caused by temperature fluctuation of the whole lens system.
Particularly, by not allowing the result of the conditional expression (2) to be equal to or greater than the upper limit, it becomes easy to increase an angle of view thereof. By not allowing the result of the conditional expression (2) to be equal to or less than the lower limit, rays are gently deflected by the first lens L 1 , and thus it becomes easy to correct distortion.
By not allowing the result of the conditional expression (3) to be equal to or greater than the upper limit, it becomes easy to increase an angle of view thereof. By not allowing the result of the conditional expression (3) to be equal to or less than the lower limit, rays are gently deflected by the second lens L 2 , and thus it becomes easy to correct distortion.
By not allowing the result of the conditional expression (4) to be equal to or greater than the upper limit, rays, which are incident from a wide angle of view, are deflected stepwise. Thus, it is possible to prevent high-order aberrations from occurring. By not allowing the result of the conditional expression (4) to be equal to or less than the lower limit, it becomes easy to correct lateral chromatic aberration.
−0.89< f/f 12<−0.53 (1)
−0.19< f/f 1<−0.1 (2)
−0.70< f/f 2<−0.45 (3)
2.4< f 1/ f 2<5.7 (4)
Here, f is a focal length of a whole system,
f12 is a composite focal length of the first lens and the second lens,
f1 is a focal length of the first lens, and
f2 is a focal length of the second lens.
If the imaging lens of the present invention satisfies the above-mentioned conditional expressions (1) to (4) and satisfies any one or a plurality of combinations of the following conditional expressions (1-1) to (4-1), more favorable characteristics can be obtained.
−0.81< f/f 12<−0.61 (1-1)
−0.17< f/f 1<−0.11 (2-1)
−0.64< f/f 2<−0.47 (3-1)
2.7< f 1/ f 2<5.2 (4-1)
In a case of using the imaging lens under severe environment, it is possible to perform protective multilayer film coating. Not only the protective coating but also antireflective coating for reducing ghost light in use may be performed.
If the imaging lens is intended to be applied to imaging apparatus, a cover glass, a prism, and/or various filters such as an infrared cut filter and a lowpass filter may be disposed between the lens system and an image plane Sim in accordance with a configuration of a camera on which the lens is mounted. In addition, instead of positioning such various filters between the lens system and the image plane Sim, such various filters may be disposed between lenses, and coating for applying the same effects as the various filters may be performed on a lens surface of any one lens thereof.
Next, numerical examples of the imaging lens of the present invention will be described.
First, the imaging lens of Example 1 will be described. FIG. 1 is a cross-sectional view illustrating a lens configuration of the imaging lens of Example 1. In FIG. 1 and FIGS. 2 to 3 corresponding to Examples 2 to 3 to be described later, left sides thereof are the object side, and right sides thereof are the image side. In addition, the aperture diaphragm St shown in the drawings does not necessarily indicate its sizes and/or shapes, and indicates a position of the diaphragm on the optical axis Z.
Table 1 shows basic lens data of the imaging lens of Example 1, Table 2 shows data about specification thereof, and Table 3 shows data about aspheric coefficients thereof. Hereinafter, meanings of the reference signs in the tables are, for example, as described in Example 1, and are basically the same as those in Examples 2 to 3.
In the lens data of Table 1, the column of the surface number shows surface numbers. The surface of the elements closest to the object side is the first surface, and the surface numbers sequentially increase toward the image side. The column of the radius of curvature shows radii of curvature of the respective surfaces. The column of the surface distance shows distances on the optical axis Z between the respective surfaces and the subsequent surfaces. The column of n shows refractive indexes of the respective optical elements at the d-line (a wavelength of 587.6 nm, where nm represents nanometer). The column of v shows Abbe numbers of the respective optical elements at the d-line (a wavelength of 587.6 nm).
Here, the sign of the radius of curvature is positive in a case where a surface has a shape convex toward the object side, and is negative in a case where a surface has a shape convex toward the image side. The basic lens data also includes and indicates the aperture diaphragm St. In a place of a surface number of a surface corresponding to the aperture diaphragm St, the surface number and a term of (diaphragm) are noted.
The data about specification of Table 2 shows values of a focal length f′ of the whole system, a back focal length Bf′, an F number FNo., and a total angle of view 2ω.
In the basic lens data and the data about specification, degree ([°]) is used as a unit of an angle, and millimeter (mm) is used as a unit of a length, but appropriate different units may be used since the optical system can be used even in a case where the system is enlarged or reduced in proportion.
In the lens data of Table 1, the reference sign * is attached to surface numbers of aspheric surfaces, and radii of curvature of the aspheric surfaces are represented by numerical values of paraxial radii of curvature. The data about aspheric coefficients of Table 3 shows the surface numbers of the aspheric surfaces and aspheric coefficients of the aspheric surfaces. The aspheric coefficients are values of the coefficients KA and Am (m=3, . . . , 20) in aspheric surface expression represented as the following expression.
Zd=C·h 2 /{1+(1 −KA·C 2 ·h 2 ) 1/2 }+ΣAm·h m
Here, Zd is an aspheric surface depth (a length of a perpendicular from a point on an aspheric surface at height h to a plane that is perpendicular to the optical axis and contacts with the vertex of the aspheric surface),
h is a height (a distance from the optical axis to the lens surface),
C is an inverse of a paraxial radius of curvature, and
KA and Am are aspheric coefficients (m=3, . . . , 20).
TABLE 1
Example 1 Lens Data (n and ν are at d-line)
Surface number
Radius of curvature
Surface distance
n
ν
1
8.1637
1.5072
1.72916
54.68
2
4.3357
1.9262
*3
−22.0674
1.5028
1.53112
55.30
*4
3.1542
2.0548
5
79.1625
3.0315
1.83400
37.34
6
−8.1095
1.5685
7 (Diaphragm)
∞
0.8554
*8
73.7537
1.9088
1.53112
55.30
*9
−8.8845
0.1076
*10
4.1251
1.8600
1.53112
55.30
*11
−3.0110
0.1013
12
−4.5243
1.5000
1.95906
17.47
13
−22.9887
3.4699
TABLE 2
Example 1 Specification
f′
2.40
Bf′
3.47
FNo.
2.30
2ω[°]
112.6
TABLE 3
Example 1 Aspheric Coefficients
Surface number
3
4
8
9
KA
−6.3780907E+02
9.0454896E−01
−2.6856241E+03
8.4981204E+00
A3
−2.0669099E−18
−5.8223475E−18
−4.4487105E−17
−1.4938872E−19
A4
1.4380625E−02
3.3027545E−02
−5.9278717E−05
−2.0425054E−02
A5
2.8980451E−04
−4.2906902E−04
6.0880794E−04
−1.7779162E−03
A6
−1.8035031E−03
−2.2251616E−03
8.0122730E−04
1.2469331E−02
A7
−4.0483864E−04
−3.0782956E−03
−9.6855187E−04
−4.5974803E−04
A8
3.0404371E−04
1.4045470E−03
−5.4422072E−04
−3.6362959E−03
A9
5.9951858E−05
5.1032704E−04
8.0391016E−05
2.1385286E−05
A10
−3.4519061E−05
−1.1641892E−04
1.4965159E−04
6.4087785E−04
A11
−5.4051637E−06
−3.8655989E−05
−1.7324213E−05
−2.5451216E−06
A12
2.5613476E−06
−4.8313075E−05
−1.9729840E−05
−6.8693765E−05
A13
3.0706269E−07
1.1246354E−06
1.9602881E−06
3.7196794E−07
A14
−1.2148328E−07
1.4323344E−05
1.4481259E−06
4.5900158E−06
A15
−1.0506269E−08
4.2820777E−08
−1.1062737E−07
−2.6524069E−08
A16
3.4595272E−09
−1.8150488E−06
−6.1396583E−08
−1.8749492E−07
A17
1.9856391E−10
−1.9536580E−09
3.1157271E−09
9.1471149E−10
A18
−5.2666556E−11
1.1513508E−07
1.4100682E−09
4.2807384E−09
A19
−1.5921881E−12
−3.5292782E−11
−3.4967751E−11
−1.2341116E−11
A20
3.1858511E−13
−2.9165384E−09
−1.3620941E−11
−4.1845315E−11
Surface number
10
11
KA
6.4378590E−01
8.7390392E−01
A3
2.0116759E−18
−6.9002226E−18
A4
−2.3485358E−02
4.4979777E−03
A5
1.4560556E−03
1.1550579E−02
A6
1.2956495E−02
−4.8564808E−03
A7
−1.7517988E−03
−5.5819804E−03
A8
−4.3139127E−03
3.8230974E−03
A9
6.5617634E−04
2.3421670E−03
A10
9.5946722E−04
−1.8433968E−03
A11
−1.4363346E−04
−5.9272795E−04
A12
−1.4259928E−04
5.3523446E−04
A13
1.9100862E−05
9.2574531E−05
A14
1.3443779E−05
−9.6011554E−05
A15
−1.5188692E−06
−8.8097932E−06
A16
−7.4642904E−07
1.0367141E−05
A17
6.6647968E−08
4.6749657E−07
A18
2.1520824E−08
−6.1338478E−07
A19
−1.2440238E−09
−1.0616900E−08
A20
−2.3651365E−10
1.5221997E−08
FIG. 4 shows aberration diagrams of the imaging lens of Example 1. In addition, in order from the left side of FIG. 4 , spherical aberration, astigmatism, distortion, and lateral chromatic aberration are shown. Such aberration diagrams show aberrations in a state where the object distance is set as an infinite distance. The aberration diagrams illustrating spherical aberration, astigmatism, and distortion indicates aberrations that occur when the d-line (a wavelength of 587.6 nm) is set as a reference wavelength. In the spherical aberration diagram, aberrations at the d-line (a wavelength of 587.6 nm), the C-line (a wavelength of 656.3 nm), and the F-line (a wavelength of 486.1 nm) are respectively indicated by the solid line, the long dashed line, and the short dashed line. In the astigmatism diagram, aberrations in sagittal and tangential directions are respectively indicated by the solid line and the short dashed line. In the lateral chromatic aberration diagram, aberrations at the C-line (a wavelength of 656.3 nm) and the F-line (a wavelength of 486.1 nm) are respectively indicated by the long dashed line and the short dashed line. In the spherical aberration diagram, FNo. indicates an F number. In the other aberration diagrams, ω indicates a half angle of view.
In the description of Example 1, reference signs, meanings, and description methods of the respective data pieces are the same as those in the following examples unless otherwise noted. Therefore, in the following description, repeated description will be omitted.
Next, an imaging lens of Example 2 will be described. FIG. 2 is a cross-sectional view illustrating a lens configuration of the imaging lens of Example 2. Further, Table 4 shows basic lens data of the imaging lens of Example 2, Table 5 shows data about specification thereof, and Table 6 shows data about aspheric coefficients thereof. FIG. 5 shows aberration diagrams thereof.
TABLE 4
Example 2 Lens Data (n and ν are at d-line)
Surface number
Radius of curvature
Surface distance
n
ν
1
8.2863
1.6384
1.75500
52.32
2
4.3990
1.6406
*3
−331.8913
1.5000
1.53112
55.30
*4
2.7460
1.8021
*5
−1651.5669
2.5850
1.63360
23.61
*6
−8.4101
1.6657
7 (Diaphragm)
∞
0.1009
*8
34.6154
2.5421
1.53112
55.30
*9
−8.3410
0.1590
*10
4.1669
1.9868
1.53112
55.30
*11
−2.8021
0.1000
12
−4.3720
1.6164
1.95906
17.47
13
−17.2422
3.8098
TABLE 5
Example 2 Specification
f′
2.42
Bf′
3.81
FNo.
2.30
2ω[°]
112.2
TABLE 6
Example 2 Aspheric Coefficients
Surface number
3
4
5
6
KA
−4.4015836E+04
1.0791805E+00
−2.8023936E+10
2.0205630E+00
A3
1.6563170E−18
1.0651118E−18
9.2042922E−19
−2.7032971E−19
A4
1.6759009E−02
2.6450853E−02
−3.5714504E−04
5.8869937E−03
A5
−9.5142714E−04
2.1218993E−04
2.2856927E−03
−1.4767692E−05
A6
−2.4611974E−03
−4.4730736E−03
−1.1604011E−03
−5.5676126E−03
A7
−1.3572837E−04
−3.2259348E−03
−7.4233129E−04
2.2132624E−03
A8
4.7624384E−04
2.6472498E−03
5.0568242E−04
3.2874915E−03
A9
2.0367712E−05
8.9156055E−04
1.4329202E−04
−1.6050610E−03
A10
−6.4511035E−05
−8.8451840E−04
−1.0680638E−04
−1.0674795E−03
A11
−1.8168646E−06
−1.5014762E−04
−1.6794796E−05
5.6583172E−04
A12
5.9611708E−06
1.7027590E−04
1.3544781E−05
1.8153934E−04
A13
1.0981882E−07
1.6044654E−05
1.2136167E−06
−1.1542707E−04
A14
−3.6386762E−07
−1.9418936E−05
−1.0684994E−06
−8.7717326E−06
A15
−3.9673562E−09
−1.0377080E−06
−5.2944979E−08
1.3690073E−05
A16
1.3863436E−08
1.2889440E−06
5.1030611E−08
−2.0883691E−06
A17
7.8458218E−11
3.7169318E−08
1.2806224E−09
−8.7303629E−07
A18
−2.9729900E−10
−4.6066858E−08
−1.3447222E−09
3.5102782E−07
A19
−6.5325283E−13
−5.6531992E−10
−1.3206877E−11
2.3079285E−08
A20
2.7275617E−12
6.8655317E−10
1.4955960E−11
−1.6127385E−08
Surface number
8
9
10
11
KA
−1.8432747E+02
8.3796861E+00
1.1992384E+00
7.4728880E−01
A3
4.9239968E−17
−4.1578423E−18
1.5563044E−18
−2.6679346E−19
A4
2.9409076E−03
−2.2820046E−05
−3.1141677E−03
6.0398333E−03
A5
2.9949945E−03
−3.6419773E−03
−3.6390079E−03
9.8285858E−03
A6
−2.1765012E−03
1.7406001E−03
2.0821282E−03
−2.6872199E−03
A7
−5.7369858E−04
6.9078916E−04
1.4561386E−03
−4.2133807E−03
A8
4.6733861E−04
−4.4514242E−04
−9.5090266E−04
1.6565516E−03
A9
−1.3254321E−05
−1.0474607E−04
−3.6393980E−04
1.9637149E−03
A10
−5.8557475E−05
5.4381309E−05
2.5879305E−04
−9.0939186E−04
A11
2.1177374E−06
8.4129646E−06
5.5537823E−05
−5.4318223E−04
A12
4.6736205E−06
−3.6836599E−06
−4.1763882E−05
2.8726806E−04
A13
−7.0170902E−08
−3.9740999E−07
−5.3188425E−06
9.2268116E−05
A14
−2.3734464E−07
1.4923178E−07
4.0199082E−06
−5.3219691E−05
A15
1.8378890E−10
1.1059341E−08
3.1069208E−07
−9.5196956E−06
A16
7.3109610E−09
−3.6204847E−09
−2.2700520E−07
5.7679663E−06
A17
3.6280326E−11
−1.6724023E−10
−1.0061467E−08
5.4483335E−07
A18
−1.2398661E−10
4.8595427E−11
6.9520046E−09
−3.3666151E−07
A19
−5.5703321E−13
1.0593147E−12
1.3795439E−10
−1.3267904E−08
A20
8.8528471E−13
−2.7809168E−13
−8.9256444E−11
8.1410215E−09
Next, an imaging lens of Example 3 will be described. FIG. 3 is a cross-sectional view illustrating a lens configuration of the imaging lens of Example 3. Further, Table 7 shows basic lens data of the imaging lens of Example 3, Table 8 shows data about specification thereof, and Table 9 shows data about aspheric coefficients thereof. FIG. 6 shows aberration diagrams thereof.
TABLE 7
Example 3 Lens Data (n and ν are at d-line)
Surface number
Radius of curvature
Surface distance
n
ν
1
7.9721
1.5001
1.88300
40.76
2
4.9809
2.3216
*3
−8.3528
1.5677
1.53112
55.30
*4
3.1719
1.4122
*5
6.4821
5.4888
1.63360
23.61
*6
6.9333
0.1098
7 (Diaphragm)
∞
0.1001
*8
5.0780
1.5110
1.53112
55.30
*9
−6.2224
1.1511
*10
3.6424
1.9288
1.53112
55.30
*11
−2.8503
0.1000
*12
−2.7293
1.5005
1.63360
23.61
*13
−10.5282
3.1695
TABLE 8
Example 3 Specification
F′
2.40
Bf′
3.17
FNo.
2.30
2ω[°]
112.2
TABLE 9
Example 3 Aspheric Coefficients
Surface number
3
4
5
6
KA
−8.5116921E+01
9.9658851E−01
−3.3792087E+01
−2.2814797E+01
A3
1.3322112E−18
−1.0924182E−17
4.4235494E−18
−1.8404365E−17
A4
1.3357766E−02
5.6489543E−02
2.2329570E−02
−8.3002686E−03
A5
−1.0731703E−03
−2.4181984E−02
−3.4821878E−03
2.0170028E−02
A6
−1.5305369E−03
3.6247847E−03
−5.6847549E−03
−6.7411470E−03
A7
3.5087370E−05
7.1009980E−03
2.7347942E−03
−6.1809546E−03
A8
1.5659994E−04
−6.7580978E−03
4.4009461E−04
9.2054843E−03
A9
−2.9108418E−06
−1.0248062E−03
−6.8399012E−04
2.2016228E−03
A10
−1.1082682E−05
2.8137340E−03
5.6208386E−05
−4.1337655E−03
A11
1.8433774E−07
−1.1650447E−04
9.9253953E−05
−5.5097774E−04
A12
5.8027429E−07
−6.8872304E−04
−1.2271391E−05
1.0176678E−03
A13
−6.7841804E−09
6.2338492E−05
−8.6800338E−06
8.7401981E−05
A14
−2.2377463E−08
1.1186287E−04
7.9110427E−07
−1.5093822E−04
A15
1.5890223E−10
−8.7598307E−06
4.4963419E−07
−8.4614742E−06
A16
5.8061144E−10
−1.1540917E−05
−1.5690146E−08
1.3464213E−05
A17
−2.0937734E−12
5.5393104E−07
−1.2694775E−08
4.5754651E−07
A18
−8.7922497E−12
6.6218964E−07
−3.1657912E−10
−6.6622330E−07
A19
1.1574843E−14
−1.3493504E−08
1.5043901E−10
−1.0572673E−08
A20
5.7685159E−14
−1.5808646E−08
1.2111293E−11
1.4057360E−08
Surface number
8
9
10
11
KA
−3.9609134E+01
7.2098366E+00
8.5557948E−01
5.0350473E−01
A3
6.3458905E−17
7.0175815E−18
1.6527920E−18
−1.2229102E−18
A4
1.1007151E−02
−1.8898190E−02
−1.3551371E−02
−1.3306730E−02
A5
−5.2976432E−03
−2.1237439E−03
−7.5113044E−04
3.0860264E−03
A6
−5.7210835E−03
3.4154270E−03
3.3457544E−03
2.2186632E−02
A7
4.0425567E−03
1.4978201E−05
−1.0763533E−03
−1.4194293E−03
A8
2.0949237E−03
−7.4942780E−04
−4.9793329E−04
−1.5257188E−02
A9
−1.0028326E−03
6.7415393E−06
3.7577963E−04
1.0503861E−03
A10
−3.9688157E−04
9.2642665E−05
5.0615140E−05
6.3840268E−03
A11
1.1112913E−04
−1.1197744E−06
−6.5217525E−05
−3.6946827E−04
A12
4.2280014E−05
−6.6775513E−06
−5.7358282E−06
−1.6901899E−03
A13
−6.9706318E−06
7.2252441E−08
6.5972737E−06
7.1417715E−05
A14
−2.6650991E−06
2.9153049E−07
6.9252161E−07
2.7752623E−04
A15
2.5410352E−07
−2.3917424E−09
−3.9156144E−07
−7.9068506E−06
A16
9.8565663E−08
−7.6142306E−09
−5.4970325E−08
−2.7295578E−05
A17
−5.0120698E−09
4.0927449E−11
1.2643686E−08
4.6979728E−07
A18
−1.9780973E−09
1.0946075E−10
2.2706699E−09
1.4741525E−06
A19
4.1408048E−11
−2.8730911E−13
−1.7160560E−10
−1.1643013E−08
A20
1.6628884E−11
−6.6641617E−13
−3.7275101E−11
−3.3651276E−08
Surface number
12
13
KA
7.7266793E−01
−4.7835701E+01
A3
1.6322517E−18
5.6155528E−19
A4
−1.3688378E−02
−1.0708391E−02
A5
2.9798597E−03
7.7966683E−03
A6
2.2150948E−02
2.6353089E−03
A7
2.4725521E−04
−4.2298541E−03
A8
−1.5704059E−02
2.9861431E−04
A9
−4.5929854E−05
1.2728603E−03
A10
6.9885785E−03
−3.2659808E−04
A11
−5.5457083E−05
−2.3158331E−04
A12
−1.9558817E−03
8.3586840E−05
A13
2.2129457E−05
2.5921333E−05
A14
3.3788028E−04
−1.1024931E−05
A15
−3.5351556E−06
−1.7478165E−06
A16
−3.4893514E−05
8.0863931E−07
A17
2.6960355E−07
6.5142548E−08
A18
1.9769549E−06
−3.1185380E−08
A19
−8.1187627E−09
−1.0308395E−09
A20
−4.7345139E−08
4.9258287E−10
Table 10 shows values corresponding to the conditional expressions (1) to (4) of the imaging lenses of Examples 1 to 3. It should be noted that, in the above-mentioned examples, the d-line is set as the reference wavelength, and the values shown in the following Table 10 are values at the reference wavelength.
TABLE 10
Expression
Conditional
number
expression
Example 1
Example 2
Example 3
(1)
f/f12
−0.678
−0.673
−0.741
(2)
f/f1
−0.158
−0.160
−0.122
(3)
f/f2
−0.471
−0.473
−0.581
(4)
f1/f2
2.987
2.963
4.756
As can be seen from the above-mentioned data, all the imaging lenses of Example 1 to 3 satisfy the conditional expressions (1) to (4), and are imaging lenses each of which has a small amount of focus shift caused by temperature fluctuation.
Further, the lens system disclosed in JP2014-85559A is a wide-angle lens system of which an angle of view ranges from 130° to 190°. Thus, in combination between the lens system and an imaging element of the recent general full HD (1920×1080 pixels) class, the number of pixels, which can be allocated in a region far from the front, among pixels of the imaging element becomes small, that is, a resolution of the region far from the front becomes low. As a result, there is a problem in that it is difficult to detect a traffic light and/or a brake lamp operated by image identification software. However, the angles of view of all the imaging lenses of Examples 1 to 3 are about 110°, and the number of pixels, which can be allocated in the region far from the front, can be set to be large. As a result, it is possible to solve such a problem.
Next, an imaging apparatus according to an embodiment of the present invention will be described. Here, as an embodiment of the imaging apparatus of the present invention, an example in a case of applying the invention to an on-board camera will be described. FIG. 7 shows a situation where the on-board camera is mounted on a vehicle.
In FIG. 7 , a vehicle 100 comprises an in-vehicle camera 101 (imaging apparatus) which is mounted on the rear of the rearview mirror in order to capture an image in a range of field of view which is the same as that of a driver. The in-vehicle camera 101 comprises: the imaging lens according to the embodiment of the present invention; and an imaging element that converts an optical image, which is formed through an imaging lens, into an electrical signal. Since the on-board camera (in-vehicle camera 101 ) of the present embodiment comprises the imaging lens of the present invention, it is possible to appropriately perform imaging in a wide temperature range.
The present invention has been hitherto described through embodiments and examples, but the present invention is not limited to the above-mentioned embodiments and examples, and may be modified into various forms. For example, values such as the radius of curvature, the surface distance, the refractive index, and the Abbe number of each lens component are not limited to the values shown in the numerical examples, and different values may be used therefor.
The imaging apparatus according to the embodiment of the present invention may also be provided as not only an in-vehicle camera but also an outside-vehicle camera. Further, in addition to the on-board camera, the imaging apparatus may include various embodiments such as a mobile terminal camera, a surveillance camera, and a digital camera.
EXPLANATION OF REFERENCES
100 : vehicle
101 : in-vehicle camera
L 1 to L 6 : lens
Sim: image plane
St: aperture diaphragm
wa: on-axis rays
wb: rays with maximum angle of view
Z: optical axis | Provided are an imaging lens that has a small amount of focus shift caused by temperature fluctuation and an imaging apparatus that has this imaging lens. The imaging lens consists of, in order from an object side: a first lens that is convex toward the object side and has a negative refractive power; a second lens that has a negative refractive power; a third lens that has a positive refractive power; a fourth lens that has a positive refractive power; a fifth lens that has a positive refractive power; and a sixth lens that has a negative refractive power. The imaging lens satisfies the following conditional expressions (1) to (4).
−0.89< f/f 12<−0.53 (1)
−0.19< f/f 1<−0.1 (2)
−0.70< f/f 2<−0.45 (3)
2.4< f 1/ f 2<5.7 (4) | 6 |
BACKGROUND
[0001] Well operators in the hydrocarbon recovery industry often seal tubulars to downhole wellbores such as casings and liners. Several systems exist for sealing the tubulars to the downhole wellbores and many function adequately. Most of these systems, however, include complex actuation devices. For example, many systems axially compress an elastomeric sleeve causing it to expand radially into sealing engagement with the downhole wellbore. This axial compression includes valves, pistons and actuators each having multiple moving parts and sliding seals that have potential failure modes associated therewith. Such systems are complex, costly and difficult to effectively deploy. Accordingly, the industry is receptive to simple, cost effective systems for plugging a downhole wellbore.
BRIEF DESCRIPTION
[0002] Disclosed herein is a method for plugging a downhole wellbore. The method includes, running an anchor and swellable seal disposed at a mandrel within the downhole wellbore, setting the anchor within the downhole wellbore, releasing the anchor and the swellable seal, and swelling the swellable seal into contact with another downhole structure.
[0003] Further disclosed herein is a downhole wellbore plugging system. The system includes, a mandrel that is runnable within a downhole wellbore and releasable therewithin, an anchor disposed at the mandrel being anchorable to the downhole wellbore, and a swellable seal disposed at the mandrel being sealable with the downhole wellbore and the mandrel.
[0004] Further disclosed herein is a method for plugging a downhole wellbore. The method includes, running a tool having an anchor and a swellable seal into the downhole wellbore with a wireline, anchoring the tool within the downhole wellbore, retrieving the wireline, and swelling the swellable seal into contact with another downhole structure subsequent to retrieval of the wireline.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
[0006] FIG. 1 depicts a schematic view of a wellbore plugging system according to an embodiment disclosed herein.
DETAILED DESCRIPTION
[0007] A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figure.
[0008] Referring to FIG. 1 , an embodiment of a wellbore plugging system disclosed herein is illustrated generally at 10 . The system 10 , among other things includes a downhole tool 12 having, a mandrel 14 with a swellable seal 18 and an anchor 22 mounted thereat. The tool 12 is positionable downhole within a wellbore 26 by a wireline 28 that is disconnectable from the mandrel 14 by a disconnectable connector 30 . The swellable seal 18 can be made of a variety of materials that swell when exposed to certain well fluids, such as hydrocarbons and water, for example. Additionally, the swellable seal 18 can swell in response to exposure to certain conditions that are commonly encountered in downhole environments, such as, high temperatures and high pressures as well as exposure to certain chemicals. The swellable seal 18 , can forcibly contact structures it comes in contact with in response to the increase in volume that occurs during swelling. Such contactable structures include walls 32 of the wellbore 26 , which may be a casing, liner or other tubular member, or open hole, or an outer surface 34 of the mandrel 14 , for example. These contact forces are sufficient to create a seal between the swellable seal 18 and the outer surface 34 as well as between the swellable seal 18 and the walls 32 . The swellable seal 18 can also be sealed to the mandrel 14 based on the original construction such that swelling of the swellable seal 18 is not needed to form the seal with the outer surface 34 . A duration of time needed from initiation of swelling to formation of a seal is dependent upon various factors, some of which will be reviewed below.
[0009] The swell rate, or the rate of increase in volume, of the swellable seal 18 , can vary depending upon a variety of parameters. For example, the chemical make up of both the swellable seal 18 itself and the well fluid into which the swellable seal 18 is submerged, can greatly affect the swell rate. Additionally, clearance dimensions between the swellable seal 18 and the surfaces 32 , 34 as well as the dimensions of the swellable seal 18 itself will also affect the time required to form a seal. Typically, the greater the clearance the longer the duration before a seal is formed. A designer can, therefore, use these parameters to set a desired time duration from initiation of swelling to initiation of sealing. Delay in swelling to the point of sealing may be desirable to allow time for an operator to run the tool 12 into the desired position downhole prior to forming a seal with the walls 32 , for example. Such delays may be set from just a few hours to several days or more.
[0010] In embodiments of the invention, an operator will set the anchor 22 prior to forming the seal. The anchor 22 has slips 44 that are deployable and engagable with the walls 32 of the wellbore 26 to fixedly attach the system 10 to the wellbore 26 . Although the system disclosed herein has the anchor 22 positioned above the swellable seal 18 , along the mandrel 14 , alternate embodiments could just as well have the anchor 22 positioned below the swellable seal 18 . Regardless of the relative positions of the anchor 22 with the swellable seal 18 , initiation to actuate the setting of the anchor 22 can be carried out in various ways.
[0011] For example, setting of the anchor 22 can be initiated, and optionally actuated, from surface via the wireline 28 . The wireline 28 can be used to initiate a trigger 36 that actuates an actuator 40 , or the wireline 28 can be used to actuate the actuator 40 directly. For example, in embodiments wherein the wireline 28 is an electric wireline 28 an electrical signal could be transmitted along the wireline 28 and used to open a valve (the trigger 36 ) that permits downhole fluid under hydrostatic pressure access to a chamber containing a piston and a compressible gas at atmospheric pressure, to thereby move the piston (the actuator 40 ) to set the anchor 22 . In an alternate embodiment, the electrical transmission can be used to energize a motor (the trigger 36 ) that drives a pump (the actuator 40 ) to hydraulically set the anchor 22 . Still other embodiments, of the system 10 , could employ timing devices (the trigger 36 ), or other means, that initiate actuation in response to exposure to a specific downhole parameter, such as, elevated pressure, elevated temperature and chemical exposure, for example.
[0012] Regardless of the trigger 36 and the actuator 40 employed to set the anchor 22 , the anchor 22 should be set prior to setting of the swellable seal 18 . In embodiments wherein the swellable seal 18 begins swelling as soon as it is exposed to certain downhole conditions, the duration to set the swellable seal 18 needs to be longer than the time it will take to run the tool 12 to the desired depth. This will prevent rubbing damage due to excess friction between the swellable seal 18 and the walls 32 while the tool 12 is being run. Once the tool 12 is in position the swelling of the swellable seal 18 can continue until a seal is formed.
[0013] Optionally, an operator is free to disconnect the wireline 28 from the tool 12 , at the disconnectable connector 30 , once the anchor 22 is set, even if the swellable seal 18 has not yet sealingly engaged the walls 32 . As such, a swellable seal 18 that takes several days to fully swell and seal with the walls 32 may be a desirable condition to assure that the operator has adequate time to fully run the tool 12 to the desired depth. It may be advantageous to position the disconnectable connector 30 between the actuator 40 and the anchor 22 to thereby allow an operator to remove the trigger 36 and the actuator 40 with the wireline 28 thereby minimizing a portion of the tool 12 that remains downhole.
[0014] The foregoing embodiments allow a well operator to quickly and inexpensively run the tool 12 with the wireline 28 to a position within the wellbore 26 , set the anchor 22 and then retrieve the wireline 28 and then wait for the swellable seal 18 to permanently plug off the wellbore 26 . Since it is not uncommon for wells to water out from the bottom up, several of the tools 12 could be used in a single well to sequentially plug off zones from the bottom up as they begin producing water.
[0015] While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. | A method for plugging a downhole wellbore including, running an anchor and swellable seal disposed at a mandrel within the downhole wellbore, setting the anchor within the downhole wellbore, releasing the anchor and the swellable seal, and swelling the swellable seal into contact with another downhole structure | 4 |
GOVERNMENT RIGHTS
[0001] This invention was made with U.S. Government support under Contract No. #N00178-11-C-1025 awarded by Naval Surface Warfare Center. The Government may have certain rights in aspects of the invention.
FIELD OF THE INVENTION
[0002] The subject invention relates to robot controllers.
BACKGROUND OF THE INVENTION
[0003] There are a variety of remotely controlled mobile robots available and each typically include their own specific “Operator Control Unit” (OCU) used by an operator to wirelessly drive and steer the robot, operate its arm, maneuver its cameras, and the like. That is, the OCU for the well-known QinetiQ-NA, Inc. “Talon” robot cannot be used as an OCU to control the iRobot Corp. “PackBot” robot and vise-versa. The same is sometimes true with respect to different model robots of even the same company or vendor and also true with respect to unmanned aerial and watercraft vehicles, different remote sensors, weapons, and the like. For example, the OCU of the “Raven” drone cannot be used to control the “Talon” robot.
[0004] The result is an incentive for a so-called “common controller”. The U.S. Army program is called the “AN/PSW-2 Common Controller”.
[0005] U.S. Pat. No. 8,119,109 of iRobot Corp., incorporated herein by this reference, discloses a “twin grip design” input device connected to a rugged laptop computer for controlling teleoperative remote controllable vehicles. The software of the computer is stated to be proprietary but also includes “common OCU software”. How the signals output by the switches of the device are processed by the computer is not disclosed but different button function modes are possible.
[0006] Others are developing tactical control units with scalable war fighter-machine interfaces. Still others are attempting to adapt game type controllers for controlling unmanned aerial and ground vehicles.
[0007] Those skilled in the art have also studied controlling multiple robots or payloads. One example is a soldier controlling a flying drone and, at the same time, controlling a ground robot using one controller. The handheld controller could have one switch set for the ground robot and another switch set for the drone but then the handheld controller would be large and complex.
[0008] U.S. Pat. No. 5,394,168, incorporated herein by this reference, discloses a game controller with buttons for controlling movement of one object and an optical subsystem for controlling movement of a different object. U.S. Pat. No. 8,199,109 states that the controller has “mode changing software” which is not disclosed. The “109 patent also states the controller can be used to control two or more payloads.
SUMMARY OF THE INVENTION
[0009] A problem occurs when a “common” OCU includes proprietary hardware and/or software and the different teleoperatable remotely controlled vehicles each include proprietary hardware and software. Arriving in a true common OCU which is able to remotely control vehicles of different types and from different vendors is challenging.
[0010] In one example of this invention, vendors of different remote control vehicles can keep their controlling hardware (e.g., radios and the like) and their controlling software proprietary. The different radios can even transmit at different frequencies, use different protocols, and the like. Source code of proprietary software is not required. The common controller system of one example of the invention can be used to control any remotely controlled vehicle because the common controller system accepts any remote control vehicle's radio pack and proprietary software for controlling the radio pack.
[0011] The invention features, in one example, the ability to use a commercially available handheld controller without the need for mode changing software. The radios and radio software applications for different unmanned system are accommodated. When the controller system will be used to control a drone, robot, or the like, its radio and software applications are incorporated.
[0012] Featured is an unmanned systems operator control system comprising a set of switches and control enumeration software configured to report a superset of virtual switches. A first unmanned system control application subscribes to a first switch subset of the superset and outputs commands controlling a first unmanned system based on activation of the set of switches. A second unmanned system control application subscribes to a second switch subset of the superset and outputs commands controlling a second unmanned system based on activation of the set of switches. A mode switching subsystem is configured, in a first state, to map the set of switches to the first switch subset and, in a second state, to map the set of switches to the second switch subset.
[0013] In one example, the set of switches are associated with a handheld controller and include at least one joystick and a plurality of X buttons and the superset includes at least two joysticks and 2X buttons. The mode switching subsystem is also typically associated with the handheld controller. One handheld controller further includes a first screen for the first unmanned system and a second screen for the second unmanned system. In one version, the first unmanned system control application and the second unmanned system control application are associated with a core module. A first radio is for transmitting control commands to the first unmanned system. A second radio is for transmitting control commands to the second unmanned system.
[0014] The system may also include a video server and transmitter for wirelessly transmitting video displayed on the video screen(s).
[0015] Also featured is a method of controlling a plurality of unmanned systems with one handheld controller having a set of switches. The set of switches are mapped to a first switch subset of a superset of virtual switches. The method includes subscribing to the first switch subset when controlling a first unmanned system using the set of switches. The set of switches are mapped to a second switch subset of a superset of virtual switches and the second switch subset is subscribed to when controlling the second unmanned system using the set of switches. Preferably, video associated with the first unmanned system is displayed on a first screen and video associated with the second unmanned system is displayed on a second video screen.
[0016] Also featured is a tactical robot controller for first and second robots comprising a first unmanned system control application is configured to output commands controlling a first unmanned system via a first radio. At least a second unmanned system control application system is configured to output commands controlling a second unmanned system via a second radio. A handheld controller includes a set of switches for controlling the first and second unmanned systems and also software delivering switch data to the first unmanned system control application and to the second unmanned system control application. A mode selection is switchable between the first and second unmanned systems. In one preferred embodiment, the handheld controller includes software configured to report a superset of virtual switches, the first unmanned system control application subscribes to a first switch subset of the superset, the second unmanned system control application subscribes to a second switch subset of the superset, and the handheld controller software is configured to map the set of handheld controller switches to the first switch subset when the mode selection is switched to the first unmanned system and to map the set of handheld controller switches to the second switch subset when the mode selection is switched to the second unmanned system.
[0017] Also featured is a tactical robot control method for first and second robots comprising controlling a first unmanned system by delivering switch data to a first unmanned system control application issuing commands to the first unmanned system via a first radio, controlling a second unmanned system by delivering switch data to a second unmanned system control application issuing commands to the second unmanned system via a second radio, and switching between control of the first unmanned system and the second unmanned system.
[0018] The method may further include the step of reporting a superset of virtual switches based on a set of physical switches generating the switch data, subscribing the first unmanned system control application to a first switch subset of the virtual superset, subscribing the second unmanned system control application to a second switch subset of the virtual superset, and switching between control of the first unmanned system and the second unmanned system by mapping the set of physical switches to the first switch subset when controlling the first unmanned system and mapping the set of physical switches to the second switch subset when controlling the second unmanned system.
[0019] The subject invention, however, in other embodiments, need not achieve all these objectives and the claims hereof should not be limited to structures or methods capable of achieving these objectives.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0020] Other objects, features and advantages will occur to those skilled in the art from the following description of a preferred embodiment and the accompanying drawings, in which:
[0021] FIG. 1 is a highly schematic view showing an example of a handheld controller in accordance with the invention;
[0022] FIG. 2 is a block diagram showing the primary components associated with a tactical robot controller in accordance with one example of the invention;
[0023] FIG. 3 is a schematic view of the core module shown in block diagram form in FIG. 2 ; and
[0024] FIG. 4 is a flow chart depicting the primary steps associated with a method in accordance with an example of the invention and the programming of the software disclosed herein.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Aside from the preferred embodiment or embodiments disclosed below, this invention is capable of other embodiments and of being practiced or being carried out in various ways. Thus, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. If only one embodiment is described herein, the claims hereof are not to be limited to that embodiment. Moreover, the claims hereof are not to be read restrictively unless there is clear and convincing evidence manifesting a certain exclusion, restriction, or disclaimer.
[0026] FIG. 1 depicts an example of a handheld controller 20 with first screen 22 a , second screen 22 b , and housing 26 for a set of switches including, in this particular example, joysticks 28 a and 28 b and 20 buttons such as button 28 c , 28 d , 28 e and the like. Also featured is mode button 32 .
[0027] In general, the user can control two or more robots such as ground robot 34 depicted on screen 22 a and flying drone 36 as depicted on screen 22 b . Video from cameras on the robots is typically delivered to screen 22 a and 22 b via the robot's radio set. In one example, in a first mode, joystick 28 a may be used to control (e.g., turn) ground robot 34 while, in a second mode, joystick 28 a is used to control (e.g., turn) drone 36 . The different modes are activated by mode button 32 . In other examples, there is only one screen and video from the robot cameras is shown in an alternate fashion on the screen in conjunction with the activation of mode button 32 and/or by splitting the screen.
[0028] One preferred architecture for a tactical robot controller is shown in FIG. 2 where controller 20 includes one or more touch screens 22 , a set of switches 28 , and processor 40 running control enumeration software 42 as well as other software. Processor 40 may be or include one or more microprocessors, application specific integrated circuits, programmable logic devices, controllers and the like. The control enumeration software is configured to deliver switch data to and output a message (via processor 40 and USB cable 44 ) to core 50 concerning the switch set of handheld controller 20 . In this particular example, control enumeration software 42 would normally generate a USB control enumeration message indicating handheld controller 20 has two joysticks and 20 buttons.
[0029] But, in order to control multiple robots, control enumeration software 42 is specifically configured to report a superset of virtual switches. e.g., four joysticks and 40 buttons.
[0030] Core 50 includes central processing unit 52 (configured for a windows environment, for example) running application software modules such as first unmanned system control application 54 a and second unmanned system control application 54 b . These applications, in general, generate control signals for their respective robots based on the activation of switches associated with handheld controller 20 .
[0031] In this invention, application 54 a specially subscribes to a first switch subset of the aforementioned superset of virtual switches. Application 54 b specially subscribes to a second switch subset of the aforementioned superset of virtual switches. In the example above, application 54 a may subscribe to the first and second joysticks and buttons 1 - 20 . Application 54 h then subscribes to the third and fourth joysticks and buttons 21 - 40 .
[0032] When mode selection switch 32 is activated to control the first robot, software 42 maps the actual physical set of controller switches to the first virtual switch subset, here the first and second joysticks and buttons 1 - 20 . When the mode selection 32 is activated to control the second robot, software 42 maps the actual physical set of switches to the second virtual switch subset, here the third and forth joysticks and buttons 21 - 40 .
[0033] In this way, application software 54 a which subscribes only to the first virtual switch subset controls the first robot 34 (via signals transmitted by radio 56 a ) when the mode for the first robot is selected and application software 54 a ignores signals from handheld controller 20 when the mode for the second robot is selected since now the handheld controller has mapped its physical switches to the second virtual switch subset which application 54 a does not subscribe to. Further, application software 54 b which subscribes only to the second virtual switch subset, controls the second robot 36 (via signals transmitted by radio 56 b ) when the mode for the second robot is selected and application software 54 b ignores signals from the handheld controller 20 when the mode for the first robot is selected since now the handheld controller has mapped the physical switches to the first virtual switch subset which application 54 b does not subscribe to.
[0034] If three robots are to be controlled, the superset of virtual switches could be larger and there may be three switch subsets and three control applications each subscribed to a different subset and transmitting signals to three different radios. Note that the subsets need not, when combined, coincide with the superset, there may be overlap between the subsets, and the superset need not coincide with all the physical buttons.
[0035] In one particular example, when the mode for control of robot 34 is selected and joystick 28 a , FIG. 1 is toggled to the right, software 42 has mapped joystick 28 a to joystick No. 1. Software 42 reports to CPU 52 a switch data message that joystick No. 1 has toggled to the right and application 54 a , which subscribes to joystick No. 1, sends a command via radio 56 a to turn robot 34 to the right. When the mode for the control of robot 36 is selected and joystick 28 a , FIG. 1 is toggled to the right, software 42 has mapped joystick 28 a to joystick No. 3. Software 42 reports to CPU 52 a message that joystick No. 3 has toggled to the right and application 54 b , which subscribes to joystick No. 3, sends a command via radio 56 b to turn drone 36 so it banks to the right.
[0036] Note how radios 56 a and control software 54 a may be provided from the vendor of robot 34 and radio 56 b and application software 54 b may be provided from the vendor of robot 36 . By loading a vendor software and carrying out the subscription and mapping steps described above for the physical switches, a true common controller is realized.
[0037] FIG. 3 shows an example of electronic subsystem core module 50 physically and electrically coupled, in one particular example, to power supply module 60 which includes swappable batteries 62 a and 62 b . Weighing less than 5.5 lbs, this combination can be placed in a small molle pack or pouch coupled to a soldier's existing molle pack. Core 50 includes heat sink 64 , a Wi-Fi/Bluetooth antenna, and various ports or connectors. Handheld controller 20 , FIG. 2 is electrically coupled to core module 50 , FIG. 3 via USB cable plugged into connector 66 . Various radio packs such as radio pack 56 a and 56 b , FIG. 2 can be electrically coupled to core 50 , FIG. 3 via a cable plugged into connectors 66 a and 66 b . Other ports are for a headset, other radio packs, and/or a personal computer interface (USB, Ethernet, or the like). Power supply module 60 is shown physically as well as electrically coupled to core module 50 but this is not a necessary limitation of the invention. Power supply module 60 can be coupled to core module 50 via a cable, for example.
[0038] A solider using handheld controller 20 , FIG. 1 may have core module 50 and power supply module 60 located in the bottom half of a molle pouch while the radio packs can be located in the upper half of the molle pouch. The molle pouch can be coupled to an assault pack.
[0039] As discussed above, by changing the radio pack and executing different software programs operable on the core module, the solider can use the handheld controller to control different ground robots, different UAVs, remotely controlled watercraft, various pods of an aircraft, sensors, and the like.
[0040] The vendors of such devices typically provide their own radio packs plugged into and software programs loaded onto core module. In order to make a software program operate correctly, interface control software modules can be included using a USB button map provided to the various vendors. A vendor can keep its software programs, protocols, and the configuration of a radio pack proprietary.
[0041] Core module 50 may also include video server 51 electrically connected to a video out lead of CPU 52 (e.g., a 1-2 GHz dual core processor operating Windows XP OS and employing 4 GB of RAM) for digitizing to an MPEG video stream the analog video signal processed by CPU 52 . This MPEG video signal is transmitted by Wi-Fi transmitter 53 so other personnel can view, on a smart phone, for example, the video feed displayed on screens 22 a and/or 22 b.
[0042] Note that in some embodiments the software 42 , 54 a , 54 b and the like can be combined, distributed in various modules, and/or reside in firmware. Other software is typically associated with the system. In general, there is software configured, as discussed above, to report to the CPU or other processor(s) a superset of virtual switches, step 80 FIG. 4 . One robots control application subscribes to a first switch subset, step 82 and another robots control application subscribes to a second switch subset, step 84 . For a first mode, the set of physical switches are mapped to the first switch subset, step 84 and, for the other mode controlling another robot, the set of physical handheld controller switches are mapped to the second switch subset, step 88 .
[0043] Also note that the functionality of processor 40 and CPU 52 may be combined or reside in circuitry and distributed other than as shown. Microprocessors, controllers, application specific integrated circuits, programmable logic devices and the like may be used. Various signal processing and other electronic and electrical circuitry and printed circuit boards are not shown.
[0044] Therefore, although specific features of the invention are shown in some drawings and not in others, this is for convenience only as each feature may be combined with any or all of the other features in accordance with the invention. The words “including”, “comprising”, “having”, and “with” as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection. Moreover, any embodiments disclosed in the subject application are not to be taken as the only possible embodiments.
[0045] In addition, any amendment presented during the prosecution of the patent application for this patent is not a disclaimer of any claim element presented in the application as filed: those skilled in the art cannot reasonably be expected to draft a claim that would literally encompass all possible equivalents, many equivalents will be unforeseeable at the time of the amendment and are beyond a fair interpretation of what is to be surrendered (if anything), the rationale underlying the amendment may bear no more than a tangential relation to many equivalents, and/or there are many other reasons the applicant can not be expected to describe certain insubstantial substitutes for any claim element amended.
[0046] Other embodiments will occur to those skilled in the art and are within the following claims. | An unmanned systems operator control system includes a hand held controller with a set of switches and control enumeration software specially configured to report a superset of virtual switches based on the physical switches. A core unit includes a first unmanned system control application subscribing to a first switch subset of the superset and outputting commands controlling a first unmanned system based on activation of the set of switches. A second unmanned system control application subscribes to a second switch subset of the superset and outputs commands controlling a second unmanned system based on activation of the set of switches. A mode switching subsystem is configured, in a first state, to map the set of switches to the first switch subset and, in a second state, to map the set of switches to the second switch subset. | 6 |
TECHNICAL FIELD
This invention generally relates to a quick change housing for a strip material. More particularly, the invention relates to a quick change housing that permits the ready replacement of the strip material while the holder remains in an inspection apparatus.
BACKGROUND OF THE INVENTION
In the microelectronics industry, the inspection of parts often requires the use of polarized lights. Inspection apparatuses create polarized light by passing nonpolarized light through a strip of polarization material to the inspection area where the part is placed. The strip material is retained in a holder by a solid cap that covers and is bolted to a proximate end of the holder. The holder is within and bolted to the apparatus.
The strip material degrades and must be replaced. To replace the strip material, the holder bolts are removed, the holder is pulled out of the apparatus, the cap bolts are removed, the cap is removed, the old strip material removed, a new strip material is inserted into the holder, the cap is replaced, the cap bolts are replaced, the holder is replaced in the apparatus and the holder bolts are replaced. As if all of these steps were not time consuming enough, the difficulty in replacing the holder in the apparatus exacerbates the problem because a distal end of the holder must be placed in an orifice or on a shoulder deep within the apparatus with no mechanical or visual aid for guidance. Thus, trial and error must be relied upon. The inordinate amount of downtime resulting from replacing the strip material is lost inspection time which slows production. The downtime results in nonproductive time for the apparatus operator and extra work time for the maintenance person who replaces the strip material.
A holder that permits the rapid and easy replacement of a strip material and which does not exhibit at least some of the aforementioned shortcomings of the existing holders is highly desirable.
SUMMARY OF THE INVENTION
The invention provides a quick change holder whose structure permits the rapid and easy replacement of a strip material retained therein. The holder includes first and second side panels having a proximate end. The side panels define a cavity therebetween capable of receiving a strip material therein. The proximate end has an opening in communication with the cavity that is capable of permitting the strip material to pass therethrough.
Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the preferred embodiments and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a representative inspection apparatus that uses a quick change holder for a strip material.
FIG. 2 illustrates an element of the apparatus of FIG. 1 having the holder therein.
FIG. 3 is an exploded view of the holder.
FIG. 4 is a side perspective view of the holder.
FIG. 5 is a top elevational view of the holder in the apparatus.
FIG. 6 is a side elevational view of the holder in the apparatus taken along line 6--6 of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, an inspection apparatus 10, e.g., an Orbot Inspection Tool Model Nos. MLC 12 and 1031, commercially available from Orbotech, has a chamber 12 in which quick change housings 14 reside. The holders 14 are secured to a wall 16 of the apparatus 10. Lamps 18 provide the nonpolarized light to be polarized.
Referring to FIGS. 3 and 4, the holder 14 includes first and second panels 20 and 22, respectively, that when assembled define a cavity 24 that is capable of receiving a strip material 26 therein. The panels 20 and 22 have grooves 28 and 30, respectively, that retain the strip material 26. A window 32 defined by the panels 20 and 22 permit light to pass through the strip material 26. In an alternative that is not illustrated, the panels are side panels that are juxtaposed to define the cavity and have cooperating lips that retain the strip material.
A proximate end 34 of the holder 14 has an opening 36 that is in communication with the cavity 24 and which permits the strip material 26 to pass therethrough. A proximate end cap 38 is positioned over the proximate end 32. The proximate end cap 38 has an aperture 40 in communication with the opening 36 which permits the strip material 26 to pass therethrough. A distal end 42 of the holder 14 has a distal end cap 44 secured thereto that inhibits passage of the strip material therethrough.
Referring to FIGS. 5 and 6, the holder 14 is within the apparatus and secured to wall 16 and an opposed apparatus wall 46. The end caps 38 and 40 are on the exterior of the walls 16 and 46, respectively. The opening 36 is in communication with an exterior 48 of the apparatus to permit the strip material 26 to be inserted into the holder 14 while the holder 14 remains in the apparatus. The aperture 40 facilitates this communication. The holder 14 is shorter than the strip material 26 which extends into the exterior 48.
Referring back to FIG. 2, springs 52 for reversibly securing the strip material 26 within the holders 14 are affixed to the wall 16 movably about shoulder screws 54. To secure the strip material 26, biased fingers 56 and 58 of the spring 52 are moved in directions against their respective biases as indicated by arrows A and B, respectively. The strip material 26 is placed between the fingers 56 and 58 and the fingers 56 and 58 are released to engage the strip material 26. The strip material 26 prohibits the fingers 56 and 58 from obtaining their original position with the resulting force securing the strip material 26 in position.
To replace the strip material 26, the fingers 56 and 58 are moved in the directions indicated by arrows A and B, respectively, the strip material 26 is pulled out, new strip material (not shown) is slide into the holder 14 and the fingers 56 and 58 are released.
The present quick change holder permits rapid and easy replacement of a strip material in an apparatus without the downtime and problems faced in the past. This is because the holder remains in the apparatus during the change and avoids having to remove bolts and the holder and replace the bolts and the holder, which is especially troublesome when one cannot see where the holder is to be replaces. The strip material is guided during reinsertion by the holder itself to facilitate replacement.
This invention has been described in connection with the inspection of microelectronic parts using polarized light for which it is particularly well suited. In such an application the strip material is a film that polarizes the light. One skilled in the art would recognize that the invention is not limited thereto and can be used in the inspection of other items and with strip material other than one that polarizes light.
This invention has been described in terms of specific embodiments set forth in detail. It should be understood, however, that these embodiments are presented by way of illustration only, and that the invention is not necessarily limited thereto. Modifications and variations within the spirit and scope of the claims that follow will be readily apparent from this disclosure, as those skilled in the art will appreciate. | A quick change holder for an inspection apparatus is maintained within the apparatus when a strip material retained within the holder is changed. The holder includes first and second panels that define a cavity therebetween that receives the strip material. | 6 |
RELATED APPLICATIONS
This application is a division of U.S. Ser. No. 07/21,952, filed Mar. 5, 1987, now U.S. Pat. No. 4,851,533, by Magid A. Abou-Gharbia entitled "1,4-Diazine Derivatives".
DESCRIPTION OF THE INVENTION
In accordance with this invention there is provided a group of antipsychotic-anxiolytic agents of the formula: ##STR3## in which
n is one of the integers 0 or 1;
and
when n is 1, R 1 and R 2 are hydrogen or alkyl of 1 to 3 carbon atoms, and R 6 and R 7 , taken together, are tetramethylene, pentamethylene or hexamethylene;
and
when n is 0, R 1 and R 2 , taken together, are ##STR4## where
the dotted line represents optional unsaturation;
p is one of the integers 2, 3, 4 or 5;
q is one of the integers 1, 2 or 3;
and
R 3 is ##STR5## where
R 4 is hydrogen, alkyl of 1 to 6 carbon atoms; alkoxy of 1 to 6 carbon atoms or halo;
and
R 5 is hydrogen or halo; or a pharmaceutically acceptable salt thereof.
In the preceding description of the compounds of this invention, the term "halogen" is intended to embrace chlorine, bromine and fluorine and the pharmaceutically acceptable salts are those derived from such organic and inorganic acids as: acetic, lactic, citric, tartaric, succinic, maleic, malonic, gluconic, hydrochloric, hydrobromic, phosphoric, nitric, sulfuric, methanesulfonic, and similarly known acceptable acids.
The compounds of this invention are readily prepared by a variety of conventional methods generally involving alkylation of the imide with X-(CH 2 ) p --R 3 where X is chlorine or bromine, p is 2 to 5 and R 3 is the appropriately substituted pyridine or pyrazine moiety. Where R 3 is a substituted heterocyclic-piperidinyl moiety, the compounds are prepared by the alkylation described in the preceding sentence followed by reduction of the aromatic ring, as by hydrogenation (e.g. in CH 3 OH with 2% Rh/Al 2 O 3 catalyst and glacial acetic acid) and N-alkylation in dimethylformamide with ##STR6## in the presence of cesium carbonate, where X is chlorine or bromine and R 5 is defined above. The reactants involved are either commercially available or are prepared by known procedures well within the skill of the chemist.
The antipsychotic properties of the compounds of this invention were established by the standard, pharmacologically accepted procedure involving a conditioned avoidance study in which trained male CD rats (Charles River), 400-450 g. body weight, are exposed to a fifteen second warning tone (conditioned stimulus) conditioned for an additional fifteen seconds accompanied by electric shock. The rat can avoid the electric shock by jumping to an exposed shelf (shelf-jump response). In this test situation, a response during the initial warning tone is considered an avoidance response while a response during shock delivery is considered an escape response. The avoidance response was determined and the compound being tested evaluated as active or inactive at the dose administered.
As a measure of extrapyramidal side effects, the compounds of this invention were studied as antagonists of apomorphine-induced stereotyped behavior wherein CF-1 mice (Charles River) receive the test compound i.p. (six mice per dose level) and thirty minutes later receive 10 mg./kg. apomorphine s.c. Five minutes after injection, the rearing-head-bobbing-licking syndrome induced by apomorphine is evaluated as present or absent for each animal. Readings are repeated every five minutes during a thirty minute test session. An ED 50 value (with 95% confidence intervals) is calculated for inhibition of apomorphine-induced stereotyped behavior by simple linear regression analysis. The compounds of this invention were inactive in this study. Thus, the compounds of this invention demonstrate a low potential for side effects which attends long term treatment with such standard antipsychotic drugs as haloperidol and chlorpromazine.
From these data, the activity profile of the compounds of this invention are seen to be that of antipsychotic agents with much lower potential for extra-pyramidal side effects such as attend the use of major tranquillizers (sedation, pseudoparkinsonism, ataxia, muscle relaxation, etc.). This activity profile resembles that of the anxiolytic compound buspirone.
Hence, the compounds of this invention are antipsychotic agents and anxiolytic agents useful in the treatment of psychoses such as paranoia and schizophrenia and in alleviating anxiety. As such, they may be administered neat or with a pharmaceutical carrier to a patient in need thereof. The pharmaceutical carrier may be solid or liquid.
A solid carrier can include one or more substances which may also act as flavoring agents, lubricants, solubilisers, suspending agents, fillers, glidants, compression aids, binders or tablet-disintegrating agents; it can also be an encapsulating material. In powders the carrier is a finely divided solid which is in admixture with the finely divided active ingredient. In tablets the active ingredient is mixed with a carrier having the necessary compression properties in suitable proportions and compacted in the shape and size desired. The powders and tablets preferably contain up to 99% of the active ingredient. Suitable solid carriers include, for example, calcium phosphate, magnesium stearate, talc, sugars, lactose, dextrin, starch, gelatin, cellulose, methyl cellulose, sodium carboxymethyl cellulose, polyvinylpyrrolidine, low melting waxes and ion exchange resins.
Liquid carriers are used in preparing solutions, suspensions, emulsions, syrups, elixirs and pressurized compositions. The active ingredient can be dissolved or suspended in a pharmaceutically acceptable liquid carrier such as water, an organic solvent, a mixture of both or pharmaceutically acceptable oils or fats. The liquid carrier can contain other suitable pharmaceutical additives such as solubilisers, emulsifiers, buffers, preservatives, sweeteners, flavoring agents, suspending agents, thickening agents, colors, viscosity regulators, stabilisers or osmo-regulators. Suitable examples of liquid carriers for oral and parenteral administration include water (particularly containing additives as above, e.g. cellulose derivatives, preferably sodium carboxymethyl cellulose solution), alcohols (including monohydric alcohols and polyhydric alcohols, e.g. glycols) and their derivatives, and oils (e.g. fractionated coconut oil and arachis oil). For parenteral administration the carrier can also be an oily ester such as ethyl oleate and isopropyl myristate. Sterile liquid carriers are used in sterile liquid form compositions for parenteral administration. The liquid carrier for pressurized compositions can be halogenated hydrocarbon or other pharmaceutically acceptable propellent.
Liquid pharmaceutical compositions which are sterile solutions or suspensions can be utilized by, for example, intamuscular, intraperitoneal or subcutaneous injection. Sterile solutions can also be administered intravenously. When the compound is orally active it can be administered orally either in liquid or solid composition form.
Preferably the pharmaceutical composition is in unit dosage form, e.g. as tablets or capsules. In such form, the composition is sub-divided in unit dose containing appropriate quantities of the active ingredient; the unit dosage forms can be packaged compositions, for example, packeted powders, vials, ampoules, prefilled syringes or sachets containing liquids. The unit dosage form can be, for example, a capsule or tablet itself, or it can be the appropriate number of any such compositions in package form.
The dosage to be used in the treatment of a specific psychosis must be subjectively determined by the attending physician. The variables involved include the specific psychosis or state of anxiety and the size, age and response pattern of the patient.
The following examples illustrate the production of compounds of this invention. After each example the pharmacological evaluation for the compound produced is presented. The conditioned avoidance test is reported as self-jump (S-J) at the intraperitoneal (i.p.) dose administered in mg./kg. As indicated above, all the compounds of this invention were inactive as apomorphine antagonists.
EXAMPLE 1
4,4a,5,5a,6,6a-Hexahydro-2-[4-(4-pyridinyl)butyl]-4,6-ethenocycloprop[f]isoindole-1,3-(2H,3aH)-dione
To a stirred solution of 2.2 g. (0.011 mol) of 1,3-dioxo-2H-4,6-etheno-1,3,3a,6a-tetrahydrocycloprop[f]isoindole in 50 ml. of dimethylformamide is added 3 g. (0.011 mol) of cesium carbonate and 3.2 g. (0.011 mol) of 4-pyridinylbutyl bromide hydrobromide. The reaction mixture is stirred at room temperature for 48 hours, dimethylformamide is evaporated under reduced pressure and the residue is extracted with methylene chloride (3×200 ml.). The methylene chloride extracts are collected, washed with water, dried over anhydrous Na 2 SO 4 and evaporated under reduced pressure. The semisolid residue was subjected to HPLC separated using ethyl acetate as eluent. Evaporation of the solvent from the desired fraction (TLC R f 0.13) affords 1.6 g. (45% yield) of the titled compound which is converted to the hydrochloride salt by dissolving the free base in ethanol and adding ethanol saturated with hydrogen chloride; m.p. 228°-230° C.
Analysis for: C 20 H 22 N 2 O 2 HCl
Calculated: C, 66.94; H, 6.41; N, 7.81
Found: C, 66.61; H, 6.36; N, 7.82
S-J: Active (40 mg./kg.)
EXAMPLE 2
2-[4-[1-(6-chloro-2-pyrazinyl)-4-piperidinyl]butyl]-4,4a,5,5a,6,6a-hexahydro-4,6-ethenocycloprop[f]isoindole-1,3-(2H,3aH)-dione
To an ethanolic solution of the compound of Example 1 (2 g.; 0.006 mol in 50 ml. of ethanol) under nitrogen was added 0.4 g. of rhodium over aluminium oxide and 1 ml. of glacial acetic acid.
The reaction mixture was hydrogenated at room temperature in a Barr shaker with hydrogen (50 psi) for 3 hours; then it was filtered and the solvent was removed under reduced pressure. The remaining oil was dissolved in 50 ml. of dimethylformamide and to that solution was added 0.5 g. of cesium carbonate and 1.1 g. (0.007 mol) of 2,6-dichloropyrazine. The reaction mixture was stirred at room temperature for 48 hours and following the same work up of Example 1, it afforded the title compound which was converted to the hydrochloride salt; m.p. 138°-140° C.
Analysis for: C 24 H 29 ClN 4 O 2 HCl
Calculated: C, 60.37; H, 6.28; N, 11.74; Cl, 14.80
Found: C, 60.54; H, 6.64; N, 11.50; Cl, 14.18
S-J: Active (40 mg./kg.)
EXAMPLE 3
8-[4-(4-pyridinyl)butyl]-8-azaspiro[4.5]decane-7,9-dione
To a stirred solution of 1.8 g. (0.011 mol) of 3,3-tetramethyleneglutarimide in 50 ml. of dimethylformamide is added 3 g. (0.011 mol) of cesium carbonate and 3.2 g. (0.011 mol) of 4-pyridinylbutyl bromide hydrobromide. The reaction mixture is stirred at room temperature for 48 hours, dimethylformamide is evaporated under reduced pressure and the residue is extracted with methylene chloride (3×200 ml.). The methylene chloride extracts are collected, washed with water, dried over anhydrous Na 2 SO 4 and evaporated under reduced pressure. The semisolid residue was subjected to HPLC separated using ethyl acetate as eluent. Evaporation of the solvent from the desired fraction (TLC R f 0.2) affords 1.0 g. (30% yield) of the titled compound which is converted to the hydrochloride salt by dissolving the free base in ethanol and adding ethanol saturated with hydrogen chloride; m.p. 155°-157° C.
Analysis for: C 18 H 24 N 2 O 2 HCl1/2H 2 O
Calculated: C, 62.51; H, 7.52; N, 8.10
Found: C, 62.74; H, 7.22; N, 8.44
S-J: Active (40 mg./kg.)
EXAMPLE 4
4,5,6,7,8,8a-Hexahydro-2-[4-(4-pyridinyl)butyl]-4,8-ethenocyclohepta[c]pyrrole-1,3-(2H;3aH)dione
To a stirred solution of 1.9 g. (0.01 mol) of hexahydro-4,8-ethenocyclohepta[c]pyrrole-1,3-(2H, 3aH)dione in 50 ml. of dimethylformamide is added 3 g. (0.01 mol) of cesium carbonate and 3.2 g. (0.01 mol) of 4-pyridinylbutylbromide hydrobromide.
The reaction mixture is stirred at room temperature overnight and dimethylformamide is evaporated under reduced pressure.
The remaining residue is extracted with 3×200 ml. of CH 2 Cl 2 , washed with water, dried and evaporated under reduced pressure.
The separated solid was converted to the hydrochloride salt; m.p. 190°-192° C.
Analysis for: C 20 H 24 N 2 O 2 HCl1/2H 2 O
Calculated: C, 64.95; H, 7.03; N, 7.57
Found: C, 65.42; H, 7.01; N, 7.69
S-J: Active (40 mg./kg.) | ##STR1## in which the dotted lines represent optional unsaturation;
p is one of the integers 2, 3, 4 or 5;
q is one of the integers 1, 2 or 3;
and ##STR2## where R 4 is hydrogen, alkyl, alkoxy or halo; or a pharmaceutically acceptable salt thereof are antipsychotic and anxiolytic agents. | 2 |
This is a Continuation of U.S. application Ser. No. 08/318,220, filed Oct. 5, 1994, now abandoned.
FIELD AND BACKGROUND OF THE INVENTION
This invention relates generally to a pumping or liquid flow system, and more particularly to such a system including at least one heat generating control component for a motor-pump unit and apparatus for cooling the control component, and to apparatus for sensing the pressure of the liquid.
Pumping systems including electric motor-pump units are well known and in common use. Examples include residential water supply systems and gasoline dispensing systems in service stations. A typical water supply system includes a motor-pump unit in a well, a water pipe connected to the unit and extending out of the well to a pressure tank, and a control that senses the water pressure in the tank and controls the unit to maintain the pressure in a selected pressure range.
Traditionally mechanical pressure gauges are used to monitor the flow pressure through such a system. Normally these pressure gauges are mounted on flow pipes whose pressures are to be monitored, using pipe stands or stubs. One popular method of mounting is to provide a bored hole in the pipe, the hole is then threaded, and then a small pipe stand or stub having male threads at one end and a pressure gauge on the opposite end is screwed into the hole. Flow pressure is transmitted to the pressure gauge through the pipe stub to the pressure gauge.
There are numerous commercially available pressure sensors for use with pipe stubs. Most of these pressure sensors incorporate a chamber having a diaphragm with an inlet on one side of the diaphragm and an outlet on the other side of the diaphragm. The pressure sensing inlet normally has female threads for receiving male threads of the pipe stub and a narrow passage filled with a liquid, such as oil, is on the other side of the diaphragm. Water pressure in the pipe causes movement of the diaphragm which, in turn, moves the liquid in the stub on the other side of the diaphragm. Movement of this liquid in the narrow passage causes movement of an indicator to monitor pressure in the pipe.
In the foregoing arrangement the small measuring passage located above the diaphragm often must be filled with oil. This presents a manufacturing problem because such a narrow passage is very difficult to fill with oil or any other liquid without leaving an air bubble therein. In order to properly fill such a gauge with the liquid needed for its functioning, it is therefore necessary first to apply a vacuum to the passage. It is an advantage of this invention that a pressure sensing mechanism is provided for a motor-pump system which can be easily mounted and filled but yet does not require the use of a filling oil and the need for pulling a vacuum.
Some pressure sensor installations require on-site opening of a pipe wall on which the pressure gauge is installed. For example, some require holes in the walls of the pipes and some require protrusions in the walls of the pipes. Such operations are expensive and difficult to incorporate. Another advantage of this invention is that a pressure sensing mechanism is provided which when installed becomes in-line with the pipe line and is relatively inexpensive to manufacture and install.
One prior art device for pipe pressure sensing comprises a part that defines a hollow chamber which is fastened onto a pipe to clamp a diaphragm between the pipe and a portion of the chamber unit surrounding a pressure inlet opening into the chamber. The diaphragm has a round, sensing protrusion with a sensing tip on an outer end thereof, which extends outwardly from one side of the diaphragm and extends through a round hole in the pipe so as to communicate the pressure in the pipe to the chamber. Although this design presents some improvement over the others, it also utilizes a mechanical interface among liquid, diaphragm, and liquid again to convey the pressure in the pipe to the gauge. It is another advantage of the present invention that it includes a mechanical-electrical transducer which more accurately measures the pressure in a motor-pump system.
Various types of pipe pressure sensors can only be used with specific types of pipe, but it is an advantage of this invention that a pipe pressure sensor is provided which can be used with various types of pipe including both plastic and metal pipes.
Control units for pump-motor units including electronics are typically cooled by air cooling through a metallic radiating panel used as a heat sink or a cooling plate. Various types of stock heat sinks are commercially available. Due to the low convective ability of air cooling, the size of such heat dissipating devices is relatively large compared with the overall size of the control package itself. The broad concept of cooling electrical devices by means of a flowing medium was introduced some time ago. In one particular design a closed recirculation cooling system was developed to cool electrodes at different electrical potentials. An advantage of the present invention is that the size of packaging is reduced by using a liquid cooling medium in lieu of the well known air cooling method.
In another prior art design, a printed circuit board package for high density packaging includes electronic circuit components cooled by a liquid cooled cold plate or heat sink. A circulating coolant is also included. A compliant interface including a heat conductive and electrically insulative paste between the cold plate and the circuit components is provided. The paste, which flows like a highly viscous liquid, is used in conjunction with a deformable thin film to compensate for any variations or irregularities so as to conform with the surfaces of the individual circuit packages. An objective of the present invention is to utilize a flow medium of the motor-pump system as a coolant to remove the heat generated by the electrical components, by incorporating a heat sink in the motor-pump system that is cooled directly by the liquid medium in the system, and to avoid the use of any deformable fill or heat conductive paste for mounting the electrical components.
It is a further general object of the present invention to provide a compact system including a pressure sensor and a heat sink in one integral module, thus making the module easy to install in a motor-pump system using only ordinary plumbing tools.
SUMMARY OF THE INVENTION
Apparatus constructed in accordance with the present invention comprises a flow carrier connectable in a liquid flow system including an electric motor-pump unit and a conduit for conveying a pumped liquid to a liquid utilization apparatus. The flow carrier is connectable in the conduit and includes an opening which exposes the liquid flowing through the carrier. A heat sink or cold plate is located on the carrier over the opening, the heat sink covering the opening and having a wet side exposed to the liquid. The heat sink further includes a dry side, and heat generating control components are secured to the dry side. A sensor is also mounted on the heat sink and responds to a characteristic, such as the pressure, of the liquid. The sensor and the control components are operable to control the motor-pump unit. The invention further comprises a novel pressure sensor including a diaphragm having a seal.
In a domestic water supply system, for example, the liquid utilization apparatus includes the plumbing in a building. In a gasoline supply system, the liquid utilization apparatus comprises a gasoline dispenser.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from the following detailed description taken in conjunction with the accompanying figures of the drawings, wherein:
FIG. 1 is a schematic illustration of a domestic water supply system including apparatus incorporating the invention;
FIG. 2 is an elevational view of a flow carrier of the apparatus;
FIG. 3 is a plan view of the flow carrier;
FIG. 4 is an exploded perspective view of the carrier;
FIG. 5 is a top plan view of the carrier;
FIG. 6 is a bottom plan view of the carrier;
FIG. 7 is a sectional view taken on the line 7--7 of FIG. 5;
FIG. 8 is a sectional view taken on the line 8--8 of FIG. 6;
FIG. 9 is a sectional view taken on the line 9--9 of FIG. 6;
FIG. 10 is an enlarged view of part of the carrier;
FIG. 11 is a further enlarged sectional view taken on the line 11--11 of FIG. 10; and
FIGS. 12 to 15 show an alternative construction of a flow carrier.
DETAILED DESCRIPTION OF THE INVENTION
While FIG. 1 illustrates a domestic water supply system, it will be apparent that the invention may also be useful in other areas. The water supply system includes a unit 10 including a pump 11 driven by an electric motor 12. The unit 10 is located in a well 13 containing water 14. The unit 10 is suspended in the well by a pipe 16 which also conveys the pumped water to the ground surface. A drop cable 17 connects electric power to the motor 12.
At the surface, and normally within a home in a domestic water supply system, is located a control unit 21 that is connected to the pipe 16, as will be described. The pipe 16 is connected to fill a pressure tank 22 and to supply water to a pipe 23 of the plumbing of the residence. The cable 17 is also connected to the control unit 21, and the unit 21 controls the supply of electrical power from a typical AC power supply 24 such as a 220 volt, 60 cycle supply.
With reference to FIGS. 2, 3 and 4, the control unit 21 includes a flow carrier 31 which is connected between the pipes 16 and 23. The carrier 31 includes a conduit 32 (see FIG. 8) including threaded couplings at its ends 33 for connections between the pipe 16 and the pipe 23, and it forms a flow passage 32a between the ends 33. At approximately the center of the carrier 31, the conduit 32 is enlarged to form a generally semi-spherical dome or bulb 36 which is solid on the underside (as seen in FIGS. 2 and 4) and has a flat upper side with an opening therein. Between the bulb 36 and each of the ends 33, the conduit 32 is generally rectangular and has a flat side that is substantially coplanar with the flat upper side of the bulb. The ends 33 are enlarged and threaded for coupling with the pipe 23.
In the example of the invention illustrated in FIGS. 2-4, the carrier 31 includes a plate 41 which is formed integrally with the flat upper sides of the conduit 32 and the bulb 36. The carrier 31 may be formed of a cast or molded metal or suitable plastic such as a polymer, for example. As shown in FIG. 4, the opening in the upper side of the bulb 36 appears as a circle in the plate 41. An upwardly turned flange or rim 42 is formed around the periphery of the plate 41, and a cover 43 fits around the rim 42 and is fastened by bolts 44 to the carrier 31. The cover 43 is enlarged as indicated at 46 in the area above the bulb 36, and the parts 41 and 43 form an enclosure for a control package 47 including heat generating electronics.
In FIGS. 5, 6 and 7, the entire plate 41 is not illustrated; instead, only an annular portion of the plate 41, surrounding the opening of the bulb 36, is shown. The annular portion may be extended to form the entire bottom wall of an enclosure as shown in FIG. 3, or a separate enclosure may be mounted on top of the annular portion as shown in FIGS. 12-15.
A flat thermally conductive plate 51 (preferably made of metal) is positioned over the open upper side of the bulb 36 (see FIGS. 4, 10 and 11) and forms a heat sink or cold plate. Around the open upper side of the bulb 36 is an annular seal groove 52, and a seal 53 (FIGS. 4 and 10) is mounted in the groove 52 and forms a seal between the plate 41 and the underside of the cold plate 51 which in this instance is substantially square as shown in FIGS. 4 and 10. A series of holes 54 are formed in the plate 51 and in the carrier 31 radially outside the seal 53, and screws secure the plate 51 to the plate 41. A hole 56 is formed in plate 51, and a sensor 57 is mounted on the plate 51 above the hole 56.
In the present example, the sensor 57 comprises a liquid pressure sensor best shown in FIG. 11. An annular diaphragm 58 is positioned over the upper side of the hole 56, and an O-ring 59 is formed integrally with the outer periphery of the diaphragm. An annular diaphragm clamp 61 is positioned over the outer periphery of the diaphragm 58 and a groove 62.in the clamp receives the O-ring 59, thereby forming a seal around the hole 56, between the lower surface or side of the plate 51 and the upper surface or side of the plate. As a result, the annular diaphragm 58 has a wet side in contact with the liquid and a dry side not in contact with the liquid. As shown in FIG. 4 and best shown in FIG. 11, the plate 51 includes an area surrounding the hole 56 engaged by the O-ring 59 such that portions of the upper side of the plate 51 not within the area are isolated from the liquid. As further shown in FIGS. 4 and 11, the area may be a recessed area 156.
A sensor cup 66 is positioned over the diaphragm clamp 61 and is secured to the plate 51 by screws 67, the cup 66 serving to hold the clamp 61 and the diaphragm 58 on the plate 51. As shown in FIG. 11, the cup 66 forms a cavity 68 which entirely contains and holds the sensor 57 which has a pressure sensitive side which is positioned against the upper side of the diaphragm 58. As further shown in FIG. 11, the cup 66 holds the sensor 57 in a substantially stationary position.
The sensor 57, in this specific example, is a pressure sensor that produces an analog electric signal which is representative of the liquid pressure. The bottom side 69 of the sensor is flexible and is pressed upwardly by the liquid pressure acting on the diaphragm 58. The sensor may, for example, include a variable resistance strain gauge, or variable resistor connected in a Wheatstone bridge arrangement. Electrical leads 71 are connected to the sensor 57 and extend out of the cup 66 through an opening 72.
The control 47 further includes electronic components 73 and 74 which are secured to the upper dry side of the plate 51 by screws 76. The components 73 and 74 are power components which generate heat during use, and they are part of the control circuit for the motor 12. In the present example, the control circuit comprises a conventional DC link arrangement and the motor 12 is a three-phase synchronous variable speed motor. The component 74 comprises an AC to DC rectifier and the component 73 comprises a DC to variable frequency AC inverter. The power supply 24 (FIG. 1) is connected to the rectifier 74 and the output of the inverter 73 is connected to the drop cable 17 and to the motor 12. The pressure sensor 57 has its output signal connected in the DC link to control the frequency of the inverter output. The DC link preferably also includes ramp circuits, as is well known to those skilled in this art. The specific construction of the motor control circuit does not form part of the present invention; the control circuit may have the construction disclosed in U.S. Pat. No. 5,580,221 titled "Motor Control Circuit" for Pressure Control of a Pumping System, the disclosure of which is incorporated herein by reference.
It is an important feature of the present invention that the components in need of cooling are mounted directly on the upper side (the dry side) of the cold plate 51 and that the bottom side (the wet side) of the plate 51 is directly exposed to the liquid flowing through the conduit 32, and that the components in need of cooling control the motor 12 and the flow of the cooling liquid. Consequently, the cooling liquid flows while the components are generating heat. Further, the invention utilizes as a coolant a liquid which is being circulated for another purpose (i.e., the invention does not require a separate dedicated cooling arrangement). Further, the liquid acts essentially directly on the sensor 57 because only the diaphragm 58 is interposed between them.
The semi-spherical dome or bulb 36 forms a relatively large opening and therefore the plate 51 has a large surface area in contact with the cooling liquid. FIGS. 3, 5, 7 and 9 show that the interior of the bulb includes a plurality of radial ribs 81a to 81f and a center post portion 82 which connects the radially inner ends of the ribs. As shown, for example, in FIG. 3, the radially outer ends of the ribs 81a and 81b connect with the bulb 36 on opposite sides of the inlet flow area of the conduit 32, and the ribs 81d and 81e also connect with the bulb 36 on opposite sides of the outlet flow area of the conduit 32. As shown in FIG. 7, the upper edges of the ribs taper downwardly toward the post 82 and are spaced from the lower side of the plate 51. The liquid enters the bulb 36 between the ribs 81a and 81b, flows through the flow area between the upper edges of the ribs and the plate 51, and flows out of the bulb between the ribs 81d and 81e. The flow area between the plate 51 and the upper edges of the ribs is preferably less than the flow area 32a (see FIG. 8) of the conduit 32, whereby the velocity of the liquid flow is increased underneath the plate 51. Further, the relatively large opening of the upper side of the bulb forms a relatively large area of the plate where the liquid cools (or draws heat away from) the plate 51. For example, the diameter of the opening of the bulb 36 is preferably in the range of from 1.5 to 5.0 times the outer diameter of the conduit 32. In addition to accelerating the liquid flow, the ribs also serve to strengthen the bulb. A plurality of radially extending strengthening ribs 86 (FIGS. 2 and 6) may also be formed on the exterior of the bulb.
Apparatus in accordance with the invention also has the following listed advantages:
1. A single integral package includes a control, heat sink and sensor.
2. It may be installed using ordinary plumbing tools.
3. It is compact in size but is high in cooling efficiency per unit area.
4. There is a direct sensing of liquid pressure by a mechanical-electrical pressure transducer or sensor.
5. It includes a one-piece flow carrier with liquid flow acceleration ability and ease of assembly.
6. A combined heat sink and pressure sensor are mounted in the same unit.
7. The sensor, electronic components and heat sink are concealed inside the module or package.
8. The package may be used with any type of piping system, such as metal or plastic.
FIGS. 12 through 15 show an alternative construction of the flow carrier and the housing for the power or control module and the pressure sensor. Whereas in FIGS. 1 to 11, the bottom part of the housing is formed integrally with the flow carrier, in the embodiment shown in FIGS. 12 to 15 they are separately formed.
The flow carrier 101 of FIGS. 12 to 15 comprises a tubular conduit 102 having threaded coupling portions 103 at its ends and a semi-spherical bulb 104 at its center. The upper side of the bulb 104 forms a round opening 106 and a generally circular flange 107 is formed around the opening 106. Exterior reinforcing ribs 108 (FIGS. 12 and 14) are formed on the underside of the flange, between the flange and the bulb. A ring of mounting holes 108 are formed in the flange 107.
The upper side of the flange 107 and the adjacent portions of the conduit 102 are flat, and the bottom wall of a housing 111 is positioned on the flat surface. An opening 112 having the shape of a cold plate 113 is formed in the bottom wall of the housing, and the plate 113 plus the housing 111 are secured to the carrier by bolts 114. A pressure sensor 116 and heat generating power control components 117 (FIG. 13) are mounted on the control plate 113, as described in connection with FIGS. 2 to 11. While not illustrated, a cover is preferably mounted over the upper side of the housing 111. In other respects, the embodiment of the invention shown in FIGS. 12 to 15 is essentially the same as that shown in FIGS. 2 to 11 and has similar advantages.
It will be apparent from the foregoing that novel and useful apparatus is described and illustrated. The apparatus forms a compact package or module for sensing the pressure of liquid being pumped and for cooling heat generating components of a control system. The control system is operable to control a motor-pump unit which moves the liquid through the apparatus, whereby the liquid being pumped is utilized to cool the control system. The pressure sensor is directly responsive to the liquid pressure and the components to be cooled are directly mounted on a heat sink which also supports the pressure sensor. Further, the flow carrier is shaped to accelerate the liquid flow across the heat sink for liquid cooling of the heat sink and the components. The pressure sensor includes an improved diaphragm having an O-ring integrally molded on its outer periphery, for forming a seal around the diaphragm. | Apparatus comprising a flow carrier connectable in a liquid flow system including an electric motor-pump unit and a conduit for conveying a pumped liquid to a liquid utilization apparatus. The flow carrier is connectable in the conduit and includes an opening which exposes the liquid flowing through the carrier. A heat sink or cold plate is located on the carrier over the opening, the heat sink covering the opening and having a wet side exposed to the liquid. The heat sink further includes a dry side, and heat generating control components are secured to the dry side. A sensor is also mounted on the heat sink and responds to a characteristic, such as the pressure, of the liquid. The sensor and the control components are operable to control the motor-pump unit. In a domestic water supply system, for example, the liquid utilization apparatus includes the plumbing in a building. In a gasoline supply system, the liquid utilization apparatus comprises a gasoline dispenser. | 5 |
RELATED APPLICATION
This application claims the benefit of the filing date of U.S. provisional application No. 60/213,491, filed Jun. 23, 2000.
BACKGROUND
This application relates to refrigerant handling systems and, in particular, to systems for automatically recycling refrigerant from the air conditioning systems of automotive vehicles.
Typically, automotive air conditioning service systems are designed to recover refrigerant from the vehicle air conditioning system, remove impurities therefrom and recycle the conditioned refrigerant back to the vehicle after servicing of the air conditioner is complete, so as to minimize venting of refrigerant to atmosphere. Such service systems commonly include a compressor for withdrawing refrigerant in vapor form from the vehicle and compressing it, a condenser for liquefying the compressed vapor, a storage vessel for storing the recovered refrigerant and a vacuum pump for drawing a vacuum on the automotive air-conditioning system prior to recharging recycled refrigerant thereto.
In some prior refrigerant recycling systems there is no vacuum pump. Rather, the compressor is utilized as both a compressor and as a pump for drawing a vacuum on the automotive refrigeration system. This reduces the cost and complexity of the system, but also reduces the performance somewhat, since the compressor pump is not capable of drawing a vacuum to as low a refrigeration system pressure as could be achieved with a separate vacuum pump. While it is possible in such recycling systems to retrofit the system with a vacuum pump in order to improve performance, this is a relatively complicated procedure and would normally require a technician from the manufacturer to perform the installation at substantial cost to the customer.
SUMMARY
This application discloses a refrigerant handling apparatus which avoids the disadvantages of prior apparatuses while affording additional structural and operating advantages.
An important aspect is the provision of an automatic refrigerant handling apparatus which permits simple installation of an optional device by a user without the need for professional technical assistance.
Another aspect is the provision of an apparatus of the type set forth which includes a processor operating under stored program control and which automatically recognizes the presence of the optional device to alter the operation of the apparatus accordingly.
A still further aspect is the provision of an apparatus of the type set forth, wherein the optional device is a vacuum pump.
Yet another aspect is the provision of a method of utilizing the apparatus of the type set forth.
Certain ones of these and other aspects may be attained by providing an automatic refrigerant handling apparatus comprising: a compressor pump having a suction port adapted to be coupled to an associated refrigeration system to be serviced and a discharge port, a condenser coupled to the discharge port, a refrigerant storage vessel coupled to the condenser, control circuitry including a processor operating under control of a stored program and coupled to the compressor pump for controlling operation thereof in accordance with a predetermined procedure for recycling refrigerant from the refrigeration system, and a connection jack connected to the control circuitry and adapted to mateably receive a connector of an associated optional device, the control circuitry including a sensing circuit for detecting connection of the connector to the jack, the stored program including a routine responsive to the sensing circuit for altering the predetermined procedure to utilize the optional device if connection of the connector to the jack is detected.
BRIEF DESCRIPTION OF THE DRAWINGS
For the purpose of facilitating an understanding of the subject matter sought to be protected, there are illustrated in the accompanying drawings embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated.
FIG. 1 is a partially functional block and partially schematic diagram of a refrigerant handling apparatus;
FIG. 2 is a fluidic schematic diagram of the apparatus of FIG. 1;
FIG. 3 is a flow diagram of the main program loop of a software program for controlling the operation of the processor of the system of FIG. 1; and
FIG. 4 is a flow diagram of a routine of the software program.
DETAILED DESCRIPTION
Referring to FIGS. 1 and 2, there is illustrated a refrigerant recycling system, generally designated by the numeral 10 , which is, for the most part, a type commercially available from Snap-on Diagnostics under the designation “KoolKare.” Accordingly, only so much of the recycling system 10 as is necessary for an understanding of the present invention is described herein. Referring to FIG. 1, the system 10 includes an AC power circuit 11 provided with a three-prong plug 12 for connection to a standard AC supply. The AC power circuit 11 is connected to a power supply circuit 13 , which provides suitable DC voltage to processing and control circuits 15 , which include a processor 16 operating under stored program control. The AC power circuit 11 has a ground line 17 , a neutral line 18 and a “hot” line 19 in standard fashion, respectively connected to corresponding terminals of a five-terminal connection jack 20 , which is mounted at a conveniently accessible location on the system housing. The hot line 19 is connected to the connection jack 20 through a relay 21 , operating under control of the processing and control circuits 15 . The other two terminals of the connection jack 20 are, respectively, connected to one end of sense lines 22 and 23 , the opposite ends of which are respectively connected to terminals of a plug 24 which is mateably engageable with a jack 25 of the processing and control circuits 15 , the jack 25 in turn being connected to the processor 16 . The sense lines 22 and 23 cooperate with the processor to form a sensing circuit.
The recycling system 10 includes an optional vacuum pump 26 having three power lines connected to corresponding terminals of a connector plug 27 which is adapted to be plugged into the connection jack 20 for electrically connecting the vacuum pump to the recycling system 10 and, more specifically, for connecting to lines 17 - 19 . Two terminals of the plug 27 respectively connect to, and are interconnected by, a jumper 28 on the plug 27 . While the plug 27 is shown as a 5-terminal plug, since only 5 terminals are used, it may have a larger number of terminals to permit spacing between primary (line voltage) and secondary (low voltage) terminals.
Referring to FIG. 2, the recycling system 10 is adapted to be connected to the air-conditioning system of an automotive vehicle, as at 30 , the connection 30 being coupled through a suitable filter and a vacuum solenoid valve 31 to an oil separator 32 for removing oil from the refrigerant, the output of the oil separator 32 in turn being connected to a vacuum switch 33 and, through an oil separator solenoid valve 34 , to a master filter/dryer 35 , the output of which is connected through a manifold 36 to the suction port of a compressor/pump 37 . The discharge of the compressor pump 37 is coupled to the input of an oil separator/reservoir 38 . The system 10 is also provided with a low pressure cutoff switch 41 connected to the input of the oil separator solenoid 34 and a high pressure cutoff switch 42 connected to the output of the oil separator reservoir 38 . The output of the oil separator/reservoir 38 is also connected through a vent solenoid valve 43 to a vent line 44 . A process port of the compressor/pump 37 is connected through a solenoid valve 45 to a return port of the oil separator/reservoir 38 . The output of the condenser 40 is connected through a moisture indicator 46 and a liquid solenoid valve 47 to the Input of a refrigerant recovery tank 50 through suitable anti-blowback valves. The input of the tank 50 is also connected through a purge solenoid valve 51 and an air filter 52 in a purge line, and is also connected to a purge transducer 53 .
The refrigerant recovery tank 50 has a liquid outlet coupled through a filter and suitable anti-blowback valves, and then through a charge solenoid valve 55 and a check valve 56 to the automotive connection point 30 . The output of the oil separator 32 is connected through a filter bypass solenoid valve 58 to a vacuum conduit 57 , the other end of which is normally connected to the manifold 36 .
The vacuum pump 26 has a suction port and an exhaust port. In order to install the vacuum pump 26 in the recycling system 10 , a cap or plug 29 is removed from the suction port of the vacuum pump 26 , the lower end of the vacuum conduit 57 is disconnected from the manifold 36 and reconnected to the suction port of the vacuum pump 26 , and the plug 29 is then installed on the port of the manifold 36 from which the vacuum line 57 was just disconnected, resulting in the arrangement illustrated in FIG. 2 . The discharge port of the vacuum pump 26 is vented to atmosphere. The electrical plug 27 of the vacuum pump 26 is then plugged into the socket 20 of the recycling system 10 (see FIG. 1 ). A suitable mount (not shown) is provided on the housing of the recycling system 10 to facilitate supporting of the vacuum pump 26 on the housing in a position where it can be conveniently connected to the pneumatic circuitry of the recycling system 10 and to the electrical circuitry thereof.
It will be appreciated that the recycling system 10 can be operated in a number of different modes, most of which are not germane to the subject matter of this application and, therefore, will not be described herein. In operation, when the vacuum pump 26 is installed on the recycling system 10 , as indicated in FIGS. I and 2 , its presence will be detected by the processor 16 by reason of the fact that the sense lines 22 and 23 are interconnected by the jumper 28 on the vacuum pump plug 27 . The program which controls the operation of the processor 16 includes a routine responsive to the sensing circuit of which the sense lines 22 and 23 form a part, to control the operation of the system 10 .
Referring to FIG. 3, there is illustrated a flow chart for a portion of the main program loop of the program for the processor 16 , this portion being designated 60 . In this portion of the loop, the program checks at 61 to see if a vacuum pump is connected, by monitoring the sensing circuit. If a vacuum pump is connected, the program then sets a vacuum-detect variable at 62 and, if it is not connected, it clears the vacuum detect variable at 63 and proceeds to the remainder of the loop. The program operates in a normal manner until the operator signals that a vacuum is to be pulled on the air-conditioning system of the vehicle being serviced. At this point the program enters a vacuum routine 65 , illustrated in FIG. 4 . The routine first checks at 66 to see if a vacuum is to be pulled. If not, it exists the routine and returns to the main loop. If a vacuum is to be pulled, the program next checks at 67 to see if the vacuum detect variable is set (FIG. 3) signifying that the vacuum pump 26 is installed. If it is not, the routine then moves to 68 to open the oil solenoid valve 45 and then runs the compressor/pump 37 for about five seconds to remove from the oil separator 38 any oil which might be accumulated therein. Next, the program, at 69 , opens the vacuum solenoid valve 31 , the filter bypass solenoid valve 58 and the vent solenoid valve 43 for drawing a vacuum on the refrigeration system using the compressor/pump 37 . Then, at 70 , it turns on the compressor 37 to draw a vacuum.
If, at 67 , the vacuum pump is installed, the routine then, at 71 , opens the vacuum solenoid valve 31 and the filter bypass solenoid valve 58 and closes all other solenoid valves, for drawing a vacuum using the vacuum pump 26 and then, at 72 turns on the vacuum pump for drawing vacuum.
The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants' 0 contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art. | An automatic refrigerant handling apparatus has a compressor pump for withdrawing a refrigerant from an associated refrigeration system to be serviced, a condenser for liquefying the refrigerant and a storage vessel for storing the recovered refrigerant, the compressor pump also being capable of evacuating the refrigeration system to a first refrigeration system pressure. The apparatus has a connection jack for receiving a connector of an associated optional vacuum pump, the connector including a jumper which interconnects two terminals on the jack when the vacuum pump is connected so that the control circuitry of the apparatus can recognize the presence of the vacuum pump, whereupon the program routine of the control processor utilizes the vacuum pump instead of the compressor pump to draw a vacuum on the associated refrigeration system. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of co-pending U.S. patent application Ser. No. 11/405,368, filed Apr. 17, 2006, which claims priority from U.S. Provisional Patent Application No. 60/672,945, filed Apr. 19, 2005, both of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] Unique electronic properties of silicon carbide (SiC) make it a very desirable material for state-of-the-art semiconductor devices that can operate at high frequencies, high voltages and current densities, and in harsh conditions. In many such devices, silicon carbide is utilized as a substrate on which the semiconductor device structure is formed using epitaxy, photolithography and metallization. Depending on the device design, the substrate must possess specified electronic parameters, such as conductivity type and resistivity. While devices operating at high and microwave frequencies (RF devices) require semi-insulating (SI) substrates with very high resistivity, for other devices, such as high power switching devices, low-resistivity n-type and p-type substrates are needed.
[0003] Presently, SiC single crystals are grown on the industrial scale by a sublimation technique called Physical Vapor Transport (PVT). A schematic diagram of a typical prior art PVT arrangement is shown in FIG. 1 . In PVT, polycrystalline grains of silicon carbide (SiC source) 1 are loaded on the bottom of a growth container 2 and a SiC seed crystal 4 is attached to a top of growth container 2 . Desirably, growth container 2 is made of a material, such as graphite, that is not reactive with SiC or any dopant (discussed hereinafter) added thereto. The loaded growth container 2 is evacuated, filled with inert gas to a certain, desired pressure and heated via at least one heating element 3 (e.g., an RF coil) to a growth temperature, e.g., between 1900° C. and 2400° C. Growth container 2 is heated in such a fashion that a vertical temperature gradient is created making the SiC source 1 temperature higher than that of the SiC seed 4 . At high temperatures, silicon carbide of the SiC source 1 sublimes releasing a spectrum of volatile molecular species to the vapor phase. The most abundant of these gaseous species are Si, Si 2 C and SiC 2 . Driven by the temperature gradient, they are transported to the SiC seed 4 and condense on it causing growth of a SiC single crystal 5 on the SiC seed 4 . Prior art patents in this area include, for example, U.S. Pat. Nos. 6,805,745; 5,683,507; 5,611,955; 5,667,587; 5,746,827; and Re. 34,861, which are all incorporated herein by reference.
[0004] Those skilled in the art of semiconductor materials know that production of SiC substrates with desirable electronic properties is impossible without purposeful introduction of certain impurities in a process known as doping. In silicon carbide, the chemical bonds are so exceptionally strong and solid-state diffusion of impurities is so slow that doping in the bulk can be accomplished only at the stage of crystal growth, when the doping element (dopant) incorporates directly into the lattice of the growing SiC crystal 5 .
[0005] As a particular example of SiC doping during growth, n-type SiC crystals are produced by adding small amounts of gaseous nitrogen (N 2 ) to growth container 2 atmosphere. Nitrogen-doped SiC single crystals with very uniform electrical properties can be readily grown by maintaining appropriate partial pressure of N 2 during growth.
[0006] With the exception of the nitrogen-doped crystals, attaining uniform electrical properties in other types of SiC crystals, including semi-insulating, p-type and phosphorus doped n-type crystals, is much more difficult because the doping compounds are not gaseous but solid. Vanadium is one particularly important dopant, which is used to produce a high-resistivity semi-insulating SiC crystal. Aluminum is another important dopant used for the growth of conductive crystals of p-type. Other solid dopants include boron, phosphorus, heavy metals and rare earth elements.
[0007] Prior art doping of SiC crystals using a solid dopant is carried out by admixing small amounts of impurity directly to the SiC source 1 . For instance, vanadium can be introduced in the form of elemental vanadium, vanadium carbide or vanadium silicide. Aluminum can be introduced in the elemental form, aluminum carbide or aluminum silicide. Other suitable solid dopants, such as boron or phosphorus, can be similarly introduced as elements, carbides or silicides. The doping compound can be in the physical form of powder, pieces or chips.
[0008] During SiC crystal 5 sublimation growth, multi-step chemical reactions take place between the SiC source 1 and the dopant admixed directly in the SiC source. These reactions proceed through several stages and lead to the formation of multiple intermediary compounds. In the case of vanadium doping, thermodynamic analysis shows that the product of reaction between SiC and vanadium dopant (whether elemental, carbide or silicide) depends on the stoichiometry of SiC. That is, when the SiC source 1 is Si-rich and its composition corresponds to the two-phase equilibrium between SiC and Si, formation of vanadium silicide (VSi 2 ) is likely. When the SiC source is C-rich and its composition corresponds to the two-phase equilibrium between SiC and C, formation of vanadium carbide (VC x ) is likely.
[0009] It is known that freshly synthesized SiC source 1 is, typically, Si-rich. Due to the incongruent character of SiC sublimation, the initially silicon-rich SiC source 1 gradually becomes carbon-rich. This change in the stoichiometry of the SiC source 1 during sublimation growth causes the following sequence of reactions:
[0010] During initial stages of growth, when the SiC source 1 is Si-rich, reaction between vanadium dopant and SiC yields vanadium silicide VSi 2 .
[0011] As the growth progresses and the SiC source 1 becomes more carbon-rich, vanadium silicide converts to intermediate carbo-silicide VC x Si y .
[0012] During final stages of growth, when the SiC source 1 is carbon-rich, vanadium carbo-silicide converts into vanadium carbide VC x .
[0013] Accordingly, the partial pressure of vanadium-bearing species in the vapor phase decreases from high at the beginning of growth to low at the end. The change in the vanadium partial pressure results in the characteristic concentration profile with too much vanadium in the first-to-grow portions of the SiC crystal 5 boule and too little in the last-to-grow portions. For this reason, electrical properties of SiC crystals grown using the doping technique of prior art are spatially nonuniform and the yield of high electronic quality substrates is low.
[0014] The above case of vanadium doping was given for the purpose of example only. Similar problems exist in the cases when other solid dopants are added to the SiC source 1 directly, including, but not limited to aluminum, boron and phosphorus.
SUMMARY OF THE INVENTION
[0015] The present invention is a system for producing spatially uniform and controlled concentration of a dopant throughout a SiC crystal boule that avoids or eliminates the too high dopant concentration in the first-to-grow boule portions and the too low dopant concentration in the last-to-grow portions. The dopant concentration can be sufficiently high to achieve the desired electronic properties of the SiC material while, at the same time, the dopant concentration can be low enough to avoid generation of crystal defects. Moreover, the dopant concentration does not change appreciably as the crystal grows. Therefore, longer boules with spatially uniform electrical properties can be grown resulting in higher quality of the SiC substrates, higher yields and productivity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a cross section of a prior art physical vapor transport arrangement;
[0017] FIG. 2 is a cross section of a time-release capsule in accordance with the present invention for use in the physical vapor transport arrangement shown in FIG. 1 ;
[0018] FIGS. 3 a - 3 c are cross-sectional views of one or more capsules of FIG. 2 positioned in different locations within the physical vapor transport arrangement shown in FIG. 1 ;
[0019] FIG. 4 is a graph of resistivity versus wafer number for wafers sliced from a boule grown in accordance with the prior art;
[0020] FIG. 5 is a low magnification optical view of the first wafer utilized to form the plot shown in FIG. 4 ;
[0021] FIG. 6 is a plot of the resistivity of each wafer sliced from a boule grown in accordance with the present invention; and
[0022] FIG. 7 is another plot of the resistivity of each wafer sliced from another boule grown in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] With reference to FIG. 2 , the advantages of spatially uniform and controlled doping are realized using a time-release capsule 14 , which is loaded with a stable form of solid dopant, and placed inside growth container 2 . Capsule 14 is desirably made of an inert material, which is reactive with neither SiC nor the dopant. For a majority of applications, dense and low-porosity graphite is a preferred material for capsule 14 . Other possible materials include refractory metals, their carbides and nitrides. However, this is not to be construed as limiting the invention.
[0024] Capsule 14 includes a tight lid 15 having one or more calibrated through-holes or capillaries 16 of predetermined diameter and length. There are no limitations on the dimensions of capsule 14 except that it should fit inside growth container 2 and not restrict the flow of vapor to the SiC seed 4 .
[0025] At a suitable time, capsule 14 is loaded with the proper amount of solid dopant 17 . Dopant 17 must be either in a stable chemical form that is not reactive with the material of capsule 14 or in a form that upon reaction with the material forming capsule 14 produces a stable compound. For the majority of practical applications, the preferred forms of solid dopant are: (i) elemental form, (ii) carbide and (iii) silicide. However, this is not to be construed as limiting the invention.
[0026] During sublimation growth of the SiC crystal 5 , capsule 14 is situated inside growth container 2 . In one embodiment, shown in FIG. 3 a , a single capsule 14 is positioned on the top surface of the SiC source 1 near the axis of growth container 2 . In another embodiment, shown in FIG. 3 b , several capsules 14 are positioned on the top surface of the SiC source 1 near the wall of growth container 2 . In yet another embodiment, shown in FIG. 3 c , capsule 14 is buried within the material forming the SiC source 1 .
[0027] The principle of operation of capsule 14 is based on the well-known phenomenon of effusion, i.e., the slow escape of vapor from a sealed vessel through a small orifice. At high temperatures, the vapor pressure of dopant 17 inside capsule 14 forces it to escape through each capillary 16 . If the cross section of each capillary 16 is sufficiently small, the vapor pressure of dopant 17 in capsule 14 does not differ substantially from the equilibrium value.
[0028] The laws of effusion are well-known and, for given growth conditions (temperature, vapor pressure of the inert gas, volatility of the substance contained in capsule 14 , capillary 16 diameter and capillary 16 length), the flux of the molecules of dopant 17 escaping capsule 14 via each capillary 16 can be readily calculated. Thus, the dimension of each capillary 16 and number of capillaries 16 can be tailored to achieve a steady and well-controlled flux of the impurity dopant 17 atoms from capsule 14 to the growing SiC crystal 5 .
[0029] For relatively small doping levels, a capsule 14 having a single capillary 16 can be used (see embodiment in FIG. 3 a ). For higher doping levels or doping with multiple dopants 17 , multiple capsules 14 can be used (see embodiment in FIG. 3 b ), as well as a capsule 14 with multiple capillaries. For special purposes, such as programmable or delayed doping, one or more time-release capsules 14 buried in the depth of the SiC source 1 can be utilized (see embodiment in FIG. 3 c ).
[0030] According to prior art SiC doping, a small amount of dopant is admixed directly to the SiC source 1 material, leading to chemical reactions between the dopant and SiC source 1 . These reactions, combined with changes in the stoichiometry of the SiC source 1 material, lead to progressive changes in the partial pressure of the dopant. As a result, prior art doping produces initially high concentrations of dopant in the crystal followed by a decrease in the dopant concentration over the SiC crystal 5 length. Crystals grown according to the prior art have too high a degree of dopant in the first-to-grow sections and insufficient dopant in the last-to-grow sections. The dopant level in the first-to-grow boule sections can be so high that second-phase precipitates form in the crystal bulk leading to the generation of crystal defects.
[0031] The present invention eliminates the problems of the prior art by using one or more time-release capsules 14 for the doping of SiC crystals 5 during crystal growth. The invention has two distinct advantages:
[0032] First, the present invention eliminates direct contact between the dopant 17 and the SiC source 1 . This is accomplished by placing the dopant 17 inside of a capsule 14 made of an inert material.
[0033] Second, the present invention offers a means for precise control of the dopant 17 concentration. This is achieved by choosing the number of capsules 14 , the number and dimensions of the capillaries 16 , and the position of each capsule 14 within growth container 2 .
[0034] The present invention offers the following technical advantages over the prior art. First, it eliminates direct contact between the dopant 17 and the SiC source 1 , so the transient processes associated with the chemical reactions between the dopant 17 and SiC source 1 are avoided or eliminated. Secondly, the present invention provides a means to precisely control the flux of the dopant 17 to the SiC seed 4 . These technical advantages lead to the production of precisely and uniformly doped SiC crystals 5 .
[0035] The direct consequence of precise and spatially uniform doping is SiC single crystals 5 with spatially uniform and controllable electrical properties. In addition to the superior electrical properties, the invention avoids or eliminates the formation of impurity precipitates and associated defects and, thus, leads to the improvement in the SiC crystal 5 quality and wafer yield.
[0036] Specifically, for a vanadium doped SiC crystal 5 , the application of the present invention increases the yield of usable prime quality SiC wafers by as much as 50%. This in-turn leads to reduced costs and improved profitability.
[0037] The present invention has been applied to the growth of semi-insulating 6H-SiC single crystals doped during growth with vanadium. However, this is not to be construed as limiting the invention since it is envisioned that the invention can also be applied to the growth of 4H-SiC, 3C-SiC or 15R-SiC single crystals doped during growth with a suitable dopant. In Examples 2 and 3 below, a single time-release capsule 14 made of pure dense graphite was used. All other parameters of the SiC growth process, such as temperature, pressure, temperature gradient, etc., were in accordance with existing growth techniques used for the production of SiC crystals 5 .
Example 1
[0038] In accordance with the prior art SiC crystal growth method, an appropriate amount of elemental vanadium was admixed to the SiC source 1 . The SiC source/vanadium mixture and a SiC seed 4 were loaded into growth container 2 which was then evacuated and filled with an inert gas to a desired pressure. Following this, the temperature of growth container 2 was raised to a temperature sufficient to cause the growth of the SiC crystal 5 .
[0039] Thereafter, the grown SiC crystal 5 boule was sliced into wafers and the impurity content for vanadium and other elements was measured using Secondary Ion Mass Spectroscopy (SIMS) in wafer #2 and wafer #17 (the last wafer in the boule). The results showed that wafer #2 contained vanadium at about 1.4×10 17 cm −3 while wafer #17 contained vanadium at about 2×10 14 cm −3 .
[0040] With reference to FIG. 4 , the resistivity of each wafer obtained from the grown boule was measured and plotted. In the plot, each point represents an average resistivity for the particular wafer. As can be seen, the resistivity of the first-to-grow wafers is very high (on the order of 2×10 17 Ωcm) while the resistivity of the last-to-grow wafers is low, below 10 5 Ωcm. One skilled in the art would immediately recognize that only those wafers that have the resistivity above 10 5 Ωcm are semi-insulating and can be used in the manufacturing of RF devices, while wafers with the resistivity below 10 5 Ωcm would be rejected.
[0041] Investigation under a low-magnification optical microscope of the first-to-grow wafers sliced from this boule showed that at least three of them contained precipitates of V-rich second phase (see FIG. 5 ). The precipitates caused generation of defects such as dislocations and micropipes, which spread from the area populated by precipitates into other parts of the boule.
[0042] Thus, prior art SiC doping causes nonuniform distribution of dopant, spatially nonuniform electrical properties, and formation of crystal defects.
Example 2
[0043] In accordance with a SiC crystal growth method of the present invention, a capsule 14 having a capillary 16 of 1.5 mm in diameter and 6 mm long was loaded with 1 g of pure vanadium carbide (VC 0.88 , 99.999+%). Capsule 14 was positioned atop the SiC source 1 in growth container 2 . All other parameters of this growth run were in accordance with existing standard technological procedures.
[0044] After finishing this growth run and cooling to room temperature, capsule 14 was recovered and its content investigated. A pellet of sintered vanadium carbide was found inside capsule 14 . Chemical analysis of the pellet showed that it consisted of vanadium and carbon in the stoichiometric ratio of VC x (x≈0.8) with traces of silicon accounting for less than 3 weight %. Thus, there was no major chemical transformation in capsule 14 during growth, and vanadium was preserved in its stable form of vanadium carbide. The traces of silicon could be a result of silicon diffusion through the capsule wall or silicon vapor back streaming through the capillary 16 . Both these marginal processes could not change significantly the composition of the dopant 17 in capsule 14 .
[0045] The grown boule was sliced into wafers, two of which, wafer #03 (near the SiC seed 4 ) and wafer #15 (near the boule dome), were analyzed for impurity content using SIMS. The results showed that wafer #03 contained vanadium at a level of 2.90×10 16 cm −3 while wafer #15 contained vanadium at a level of 2.34×10 6 cm −3 . Investigation under a microscope found no precipitates of secondary phases. Moreover, the density of micropipes and other defects in this boule was observed to be low.
[0046] With reference to FIG. 6 , the resistivity of each wafer obtained from the boule grown in accordance with this Example 2 was measured and plotted. In the plot, each point represents an average resistivity for the particular wafer. As can be seen, the resistivity of all 15 wafers sliced from this boule was close to 1.7×10 11 Ωcm, with no visible decrease in the last-to-grow wafers.
Example 3
[0047] In accordance with a SiC crystal growth method of the present invention, a capsule 14 having a capillary 16 of 1.5 mm in diameter and 6 mm long was loaded with 1 g of elemental vanadium of 99.995% purity. Capsule 14 was positioned atop the SiC source 1 in growth container 2 . All other parameters of this growth run were in accordance with existing standard technological procedures.
[0048] After finishing this growth run and cooling to room temperature, the capsule content was investigated. It was found that during heating to the growth temperature, vanadium melted and reacted with carbon of the capsule wall to form stable vanadium carbide, VC x with x≈0.9. No further chemical transformations occurred during growth cycle.
[0049] The grown boule was sliced into wafers, two of which, wafer #03 and wafer #17 (the last wafer of the boule), were analyzed for impurity content using SIMS. The results showed that wafer #03 contained vanadium at a level of 3.4×10 16 cm −3 while wafer #17 contained vanadium at a level of about 2.7×10 6 cm −3 .
[0050] The resistivity in the wafers sliced from this boule was so high that it exceeded the upper sensitivity limit of the measuring instrument. Accordingly, the resistivity data is plotted in FIG. 7 as empty circles at 10 12 Ωcm indicating that the actual resistivity is higher. These values of resistivity exceeded by several orders of magnitude the current requirements for semi-insulating SiC substrates.
[0051] The level of vanadium in this boule was high enough to cause full electrical compensation, but much lower than the solubility limit, so no precipitates of secondary phases were formed. The grown boule was of good crystal quality with low densities of micropipes and other defects.
[0052] The invention has been described with reference to the preferred embodiments. Obvious modifications and alterations will occur to others upon reading and understanding the preceding detailed description. It is intended that the invention be construed as including all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. | A physical vapor transport system includes a growth chamber charged with source material and a seed crystal in spaced relation, and at least one capsule having at least one capillary extending between an interior thereof and an exterior thereof, wherein the interior of the capsule is charged with a dopant. Each capsule is installed in the growth chamber. Through a growth reaction carried out in the growth chamber following installation of each capsule therein, a crystal is formed on the seed crystal using the source material, wherein the formed crystal is doped with the dopant. | 2 |
FIELD OF THE INVENTION
This invention relates to nozzles for free jet dye lasers and in particular a nozzle for providing a jet having a central portion of plane parallel sides.
BACKGROUND OF THE INVENTION
In laser applications which require high power densities in master oscillators or amplifiers such as for use in laser enrichment, burning and other problems can occur at the interface between the actively lasing medium and the containment walls for the laser medium. A possible solution to this difficulty is the use of the free jet laser as, for example, shown in U.S. Pat. No. 3,766,489. The free jet eliminates the boundary layer problem in the region of the lasing medium bordering the containment walls.
For use in the laser enrichment application, the free jet must be carefully dimensioned to insure a high quality laser beam, that is one free from distortion and excessive divergence. This is important because it is required that the laser beam for the enrichment application travel great distances with low beam divergence. Such beam quality requires that the actively lasing region of the free jet have precisely plane parallel surfaces which cannot be achieved with such prior art nozzles.
BRIEF SUMMARY OF THE INVENTION
In the preferred embodiment of the present invention, a nozzle for a free jet dye laser is shown in which the nozzle orifice is adjustable to provide a configuration that yields a precisely plane parallel central region to the free jet. The nozzle orifice which provides this free jet characteristic comprises a constriction that is long and narrow in cross-section transverse to the flow of dye medium. Adjustment screws are provided to further narrow the center portion of the constriction and provide a precise control over the contour of the edges of the orifice defining the constriction.
The observed tendency of the dye jet to bunch and thicken in the center is thus counteracted by the central narrowing of the orifice constriction. The degree of this effect is precisely controllable with the adjustment screws to provide a perfectly plane parallel central portion to the free dye jet. The correct adjustment for a plane parallel jet center may be made in a test system or during actual lasing operation of the dye jet. The degree of correction for best beam quality can be obtained by visual observation of the test system or the resulting beam.
Using the nozzle of the present invention, it is possible to correct for first and higher order deviations in the opposite surfaces of the dye jet from a condition of perfectly plane parallel and to achieve a beam of high quality which is desirable for use in laser enrichment apparatus.
BRIEF DESCRIPTION OF THE DRAWING
These and other features of the present invention are more fully described below in the detailed description of the preferred embodiments and in the accompanying drawing of which:
FIG. 1 is a side elevation view of a first embodiment of the dye jet nozzle according to the present invention;
FIG. 2 is a bottom pictorial view of the nozzle of FIG. 1;
FIG. 3 is an enlarged view of the nozzle orifice and adjusting screws used to obtain a desired constriction cross-section in the nozzle orifice;
FIG. 4 is a side sectional view of an alternative nozzle according to the present invention;
FIG. 5 is a bottom pictorial view of the nozzle of FIG. 4;
FIG. 6 is a representation of a free dye jet as provided by a nozzle of the present invention;
FIG. 7 is a cross-sectional view of the dye jet of FIG. 6;
FIG. 8 is a schematic view of a laser application employing a dye jet according to the present invention;
FIG. 9 is a schematic view of a test system for adjusting the nozzle of the present invention; and
FIGS. 10A and 10B illustrate two images formed in the test system of FIG. 9.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The present invention contemplates a nozzle for a free jet dye laser which provides a precisely plane parallel central region in the dye jet for high beam quality. The nozzle of the invention has a concave cross-section in the region where it forms the laser dye jet and is adjustable for precise control in achieving the desired jet configuration. FIG. 1 illustrates in elevation one embodiment of such a nozzle having an input conduit 12 which receives a flowing dye solution, typically Rhodamine 6G in an ethylene glycol medium. The conduit 12 may typically be a circular metal pipe and approximately 0.3 centimeters to 1.0 centimeters in diameter. One end of the conduit has a tapered portion 14 leading to a flattened orifice 16 which provides the constriction in the conduit having a cross-section which is generally long and narrow. FIG. 2 shows a bottom view of the nozzle indicating more clearly the opening 18 in the orifice 16.
The end of the conduit 12 is secured in a metal block 20 attached just above the tapered portion 14. The block 20 has first and second arm portions 22 and 24 which extend down to a level with the tip of the orifice 16. The extensions 22 and 24 are set parallel to the long dimension of the cross-section of the orifice 16. First and second adjusting screws 26 and 28 are threaded through the extensions 22 and 24 to encounter the sides of the orifice 16 at the center of the opening 18. The screws 26 and 28 are threaded to provide a fine adjustment in the shape of the opening 18 and in particular to permit a narrowing of the opening 18 in the center where the screws force against it as is illustrated more clearly in an expanded and magnified representation, not necessarily to scale, of the orifice in FIG. 3. By maintaining a positive pressure from the adjustment screws 26 and 28, the orifice can be made to gradually narrow from the ends to the points where the screws contact it.
A second alternative form for the invention is illustrated in FIGS. 4 and 5. In FIG. 4 a sectional view of a nozzle is shown and includes right- and left-hand plate members 40 and 42 having a channel 44 defined therebetween to act as a conduit for a dye solution applied from a pipe 46 into a hole 48 in one of the plates 40. The plates 40 and 42 are spaced to define the channel 44 by edge spacers 50 and 52 which are illustrated in FIG. 5 showing a bottom view of the nozzle of FIG. 4. At the top of the channel 44, a plug 54 prevents flowing of the dye solution upwards. A section of each end of each plate 40 and 42 bordering the channel 44 is machined out to leave depressions 56 and 58 and relatively thin portions 60 and 62 of the plates between the depressions 56 and 58 and the channel 44. Adjusting screws 64 and 66 are threaded through from outside edges of the plates 40 and 42 to contact the thin end portions 60 and 62 to permit a slight narrowing of the slit 68 defined between the thin end portions 60 and 62 thereby producing the nozzle orifice in the configuration of the present invention.
In the preferred embodiment of the invention, the orifice is typically 0.25 cm to 5 cm in length and 0.25 mm to a few mm in width of opening.
With respect to FIG. 6, there is a pictorial and diagrammatic view of a free jet 72 as it would be typically provided from a nozzle 70 which may be the nozzle of either FIGS. 1 and 2 or FIGS. 4 and 5. The jet 72 has typically an arrowhead shape with a central portion 74, which is to be activated in an inner region for lasing, and outer portions 76 which tend to show a bunching of the fluid due to surface tension effects. Beyond a point 78 where the jet comes together again after leaving the nozzle 70, it will again separate in a plane orthogonal to the original plane for a similar distance after which it will converge and reseparate again in an orthogonal plane to produce a series of sections 82, etc. as shown in FIG. 6. Ultimately, the jet will deteriorate into a series of drops. In order to prevent the jet from emerging as a series of drops, it should be characterized by a low Reynolds number. The use of ethylene glycol facilitates achieving this result.
A cross-section of the jet 72 is illustrated in FIG. 7, showing the thicker edge portions 76 bordering central portion 74. The central portion 74 is illustrated as having plane parallel surfaces 84 and 86 which can be achieved accurately only by the concave or narrowed center pattern for the orifice slit as described above. An orifice configuration having strictly parallel slits will tend to produce some degree of bowing in the central portion 74 of the jet as illustrated by the dotted lines 88 and 90.
The plane parallel quality to the surface 84 and 86 of the jet 72 is of significance in maintaining beam convergence over substantial distances of many meters encountered in the application as a laser amplifier or master oscillator for uranium or isotope enrichment in general.
FIG. 8 illustrates a configuration where such a jet may be useful as a master oscillator for generating a specific frequency laser beam of high optical quality suitable for amplification and for use throughout a uranium enrichment plant of the type illustrated in U.S. Pat. No. 3,772,519 or U.S. Pat. No. 3,939,354. In FIG. 8, there is illustrated such a master oscillator employing a free jet 92 which is excited to a lasing condition by an input laser beam 94 through a lens 96 from a laser pump source 98 such as a nitrogen laser. The jet 92 lases within a cavity defined by a 100% reflecting mirror 100 placed to one side of the jet 92 to reflect radiation back toward the active portion of the jet 92. A 100% reflecting, converging mirror 102 is positioned on the other side of the jet 92 to reflect radiation through a set of frequency selecting prisms 104, 106 and 108 and sequentially through a frequency limiting filter 110, such as an etalon filter, and partially reflecting output mirror 112 which returns a portion of the radiation to the cavity through the filters 110, 108, 106 and 104, and through the mirror 102 to the dye cell 92. Radiation taken from the mirror 112 may be directed to a series of amplifiers and power amplifiers to generate a final high power beam which is to be utilized throughout the laser enrichment plant.
While some beam divergence is to be expected in any laser, such divergence can be controlled or compensated so long as the beam quality is sufficient to provide uniform and nontime-varying divergence patterns. In order to insure this high degree of beam quality necessary for long beam runs through a laser enrichment plant, it is important to provide a precisely defined and consistent plane parallel central portion for the dye jet 92 by employing nozzles of the invention illustrated above.
More than one pair of opposed adjustment screws as illustrated above in the two views of the invention may be employed, as for example a pair of adjustment screws placed generally in locations 93 parallel and to either side of the screws 26 and 27 or 64 and 66 in FIGS. 1 and 4 respectively, toward the ends of the constriction of each orifice. Such additional pairs of adjustment screws can be employed to provide correction for higher order distortions in the surfaces of the free jet.
In order to determine the proper adjustment of the pair or pairs of adjustment screws illustrated in the present invention, a free jet dye laser of the type illustrated in FIG. 8 may be employed, and the divergence of the laser output beam adjusted for minimum. Preferably, however, a test system of the type illustrated in FIG. 9 is employed. As shown there, a laser 116 which may be any laser adjusted for good collimation in the output beam applies its output radiation 118 through a converging lens 120 to provide a convergence to a point 122 and expansion through a further converging lens 124 to provide a coherent output beam 126 of expanded width, typically corresponding to the cross-sectional area of the free jet region to be employed for active lasing. The beaam 126 is applied to a free jet 128 produced by a nozzle according to the present invention which can be adjusted in the degree to which the surfaces of the central portion are parallel. The beam 126 is directed substantially orthogonal to the surface of the jet 128. The jet 128 is employed in the present invention not for lasing but as a refractive optical element. The beam 126 after passing through the jet 120 is applied to a converging lens 130 which converges the beam to a point. A pinhole plate 132 is placed with its pinhole aperture 134 at the convergence point for the radiation from the lens 130. The radiation passing through the pinhole 134 is applied to a viewing screen 136 to provide an image. As illustrated in FIG. 10A, an image 138 formed on the screen 136 will show a line 140. The adjustment screws in the nozzle of the present invention may then be set to the point where the line is at its widest as for example in line 142 illustrated in FIG. 10B.
Other modifications or variations on the nozzle illustrated above may be implemented within the spirit and scope of the present invention. It is accordingly intended to define the scope of the invention only in accordance with the following claims. | A nozzle for a free jet dye laser wherein the nozzle orifice has an adjustable convex contour to permit realization of precisely plane parallel sides in the central jet region. A jet of this precision is desired to support a high quality laser beam for use in laser enrichment apparatus. The precise planar characteristic of the central portion of the jet is achieved by a narrowing of the central portion of the nozzle orifice. A set of adjustment screws are provided to define the specific contour of the narrowing to insure that the sides of the free jet are precisely plane parallel. A system is shown for detecting the degree to which the sides are plane parallel so that an optimum adjustment in the orifice can be achieved. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to jigs and has specific reference to a tool means of this character for drilling and/or tapping in skis the holes to be subsequently engaged by the screws used for fixing ski bindings thereto. The invention is also directed to a method of drilling and tapping these holes in succession.
2. Description of the Prior Art
The tool means now in general use for fixing ski bindings comprise on the one hand a jig associated with a twist bit and on the other hand as crew-tap.
The jig comprises several bit guiding sockets having a relative spacing or distance between centers corresponding to that of the holes formed in the ski binding for the passage of the fixing screws. The jig is provided with retaining members, generally of the jaw type, for safely fastening the jig to the ski during the drilling and/or tapping operation.
As a rule, the twist bit is of the shouldered type, the body being connected to its tip by a shoulder adapted to engage the top surface of the ski upon completion of the drilling step.
On the other hand, the tap consists in most instances of a handle and of a tap bit secured centrally and at right angles thereto, the assembly being substantially T-shaped.
At the end of the drilling operation the jig is removed from the ski.
When self-tapping screws are used, the binding can be secured directly to the ski, since these screws tap their holes directly during the screwing operation.
If conventional screws are used each hole must be tapped. This step is accomplished manually by using a tap.
The jig and drilling method broadly described hereinabove are objectionable on account of the following drawbacks:
Since the presence of a jig conceals the twist drill tip to the operator, the latter becomes aware that the drilling depth is attained when he feels an increased resistance to the drill penetration, this increased resistance corresponding to the engagement between the drill shoulder and the ski surface.
However, this estimation, based on a feeling, that the desired drilling depth is attained, is rather uncertain and likely to be a source of frequent errors. Therefore, some operators are inclined, in a first step, to drill relatively shallow holes and to subsequently remove the jig and complete the drilling operation in a second step during which they can check the drilling progress visually. Though the risks of errors are thus reduced, the time necessary for completing the operation is increased considerably.
Another source of frequent errors is the tapping operation carried out subsequently. In fact, this operation is performed after removing the jig, so that the tap is not guided and its point is likely to engage the hole askew and thus damage this hole, inasmuch as after about each half-turn of the tap the operator must release it, since this tap is actuated and operated in the fashion of a corkscrew.
From the foregoing it is clear that up to now no tool means nor methods have been proposed for rapidly and accurately drilling and tapping holes for fixing ski-bindings to skis unless the operator's skill and experience constitute a determinant factor.
It is the essential object of the present invention to compensate for this insufficiency.
SUMMARY OF THE INVENTION
For this purpose, the tool means according to this invention comprises a jig and a twist bit and/or tap of the type set forth hereinabove. According to the invention, the jig comprises a frame liable to elastic distortion so that, at least at the end of the drilling and/or tapping stroke, the inner face of the guide socket fitted in the frame can engage the top surface of the ski while the twist bit and/or the tap is or are provided with a shoulder adapted to engage the top or outer end face of the corresponding guide socket, the distance measured between the tip of the bit and/or tap and said shoulder being equal to the sum of the axial length of the guide socket and the depth of the hole to be drilled and/or tapped.
The frame advantageously comprises a pair of flexible rods extending parallel to the ski axis and the guide sockets are guided by a pair of slides movable along said rods.
Preferably, a frustoconical portion is interposed between the tip and the body of the bit, and the shoulder formed on the bit and/or tap may consist of a sleeve-like insert. Also advantageously, the tap actuating member may consist of a crank handle.
The method of drilling and tapping according to this invention consists in holding the drill jig rigid with the ski during the tapping operation, the sockets being used for guiding the tap.
Other features and advantages of this invention will appear as the following description proceeds with reference to the accompanying drawing illustrating by way of example a typical form of embodiment of the tool means of this invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a top view showing a jig according to this invention, fitted to a ski preliminary to the drilling and tapping operations;
FIG. 2 illustrates the position of the tool means of this invention before a drilling operation, the jig being shown in section according to the dot and dash line II--II of FIG. 1;
FIG. 3 is a view similar to FIG. 2 but showing the relative positions of the drill, bit, jig and ski at the end of a drilling operation;
FIG. 4 illustrates on a larger scale the jig in section taken along the line IV--IV of FIG. 2;
FIGS. 5 and 6 illustrate on a larger scale a bit and the corresponding guide socket, respectively, according to the invention;
FIG. 7 shows how the bit and socket of FIGS. 5 and 6 cooperate during a drilling operation;
FIG. 8 is a view similar to FIG. 2 showing tool means consistent with the invention, before starting a tapping operation;
FIG. 9 is a view similar to FIG. 8 but taken at the end of the tapping operation;
FIGS. 10 and 11 illustrate on a larger scale a tap and a corresponding drill socket according to this invention, and
FIG. 12 shows the tap and socket of FIGS. 10 and 11 which are associated for performing a tapping operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The drill jig illustrated in FIGS. 1 to 4 of the drawing comprises essentially a frame 1 consisting of a pair of parallel rods 2 assembled at their ends by a pair of cross members 3. The jig further comprises a pair of clamping jaws 4, 5 and two slides 6, 7 movable along and guided by the rods 2.
The jaws 4, 5 fulcrumed to cross members 3 are used in the known fashion for firmly securing the jig to the ski during the drilling and tapping operations. Spring means shown only diagrammatically at 8 and 9 are provided for constantly urging the jaws 4, 5 against the corresponding side faces of the ski S in order to grip the latter. In this position the rods 2 are parallel to the longitudinal center line of the ski.
Fitted in accurately drilled holes perpendicular to the main faces of slides 6 and 7 are a plurality of guide means 10 in the form of cylindrical sockets. The relative arrangement of these sockets 10 on slides 6 and 7 corresponds of course to the through holes provided for the fastening screws in the front section (toe abutment device) and rear section (heel hold-down device) of the safety ski binding (not shown), assuming that the front end of the ski is on the left side of FIGS. 1 and 2.
The lower portion of cross members 3 are provided with shallow projections 30 engaging the top surface of the ski S. The rods 2 are connected to the cross members 3 with the interposition of rubber or like resilient grommets 31.
The bit 11 illustrated in FIGS. 2, 3, 5 and 7, adapted to be rotated by a conventional drill P, comprises a shank 16, a collar or shoulder 15, a main body 12, a tip 13 of a diameter somewhat smaller than that of said body 12, and a frusto-conical portion 14 interconnecting said portions 12 and 13. The helical grooves 17 are formed mainly in portions 13, 14 and partly in portion 12, as shown.
The guide socket 10 as clearly shown in FIG. 6, has a substantially cylindrical configuration and is secured to the slide 6 so that its end portions project from the top and bottom faces of the slide. Each socket 10 has a flat annular top bearing face 20 and at its lower end a notch 18 for purposes to be explained presently. The inner diameter of socket 10 matches the diameter of the bit body 12.
The tapping means illustrated in FIGS. 8 to 12 of the drawing comprise the jig already described hereinabove and a tap assembly T comprising a tap proper 21 and a manual driver consisting of a crank handle 28 and a knob 29.
The tap 21 is locked against rotation in the crank handle 28 by means of a member 27 embedded in the latter (FIG. 12) and cooperating with the square-sectioned top portion 33 of tap 21. The coupling is releasable in the axial direction of translation and comprises means on said crank handle 28 which are adapted snappily to engage a groove 34 formed on said tap 21.
This tap 21 comprises a body 22 and a thread-cutting end or tip 23. The body 22 has another groove 26 formed therein which is snappily engageable by a plastic sleeve-like insert 24 formed with an annular bead or shoulder 25. The outer diameter of this sleeve 24 is equal to the inner diameter of guide sockets 10.
The above-described drilling and tapping tool means are used as follows:
Firstly, the jig is secured to the ski as shown in FIGS. 1 and 2, and the slides 6, 7 are moved along the guide rods 2 to the proper positions for fixing the safety ski binding to the ski, the relative spacing of slides 6 and 7 depending of course on the skier's boot size. Then, the slides 6, 7 are locked in position through suitable means (not shown). To simplify the drawing, the top surface of the ski is shown as being a flat one (FIGS. 2 and 3). Under these conditions, the jig bears on the ski only through shallow projections 30 formed on the bottom faces of cross members 3, so that the guide sockets 10 are slightly spaced from the ski. However, in actual practice the ski is more or less curved, with a convex top surface, and the guide sockets 10 tend to bear against the ski surface.
Now according to this invention the rods 2 are liable to undergo an elastic deformation in order to accomodate the ski curvature, this deformation being allowed by the provision of resilient grommets or washers 31 between the rods 2 and cross members 3. Thus, as a rule all the guide sockets 10 contact the ski surface when the jig is secured to the ski. If not, this contact takes place at any rate at the end of the drilling stroke, as illustrated in FIG. 3. This advantageous result is due to the provision on bit 11 of a shoulder 15 which, at the end of the downward or drilling stroke of the bit, engages the top annular bearing face 20 of socket 10, thus causing the rods 2 to yield resiliently until the bottom end of socket 10 contacts the ski (FIG. 3). When this contact takes place the proper drilling depth is attained automatically. In fact, according to the invention, the length h1 of the bit body 12 is equal to the height of socket 10; consequently the hole depth is well-defined and equal to the distance h3 measured between the outer end of tip 13 and the bit body 12.
When he is aware that the bit abuts the top of the cooperating socket 10, the operator extracts the bit from the hole and starts drilling the next hole through another socket, the elastic rods 2 resuming their initial, straight configuration.
It will be seen that chips, cuttings and like waste 19 are easily removed through the notch 18 formed in each socket 10.
The purpose of the frustoconical portion 14 is to countersink the holes and thus provide room for the chips to be cut subsequently during the ski binding operation involving the screwing in of fastening screws.
In general, the drilling operation is followed by a tapping operation.
According to this invention the jig 1 is held on the ski during this second operation. The tap assembly T is then guided during its rotational movements by the corresponding socket 10 so that the movements of tap 21 take place accurately in the axial direction of the hole.
As in the case of the drilling step, the shoulder 25 of tap 21 eventually engages the annular bearing face 20 of socket 10, the lower face of latter bearing in turn on the ski.
The crank handle assembly 28, 29 facilitates the tap operation because the operator can keep the tap rotating continuously, in contrast to the present mode of operation requiring that the crank be released after each half-revolution.
From the foregoing it will be clearly apparent to those conversant with the art that with the tool means according to the instant invention even unskilled hands can safely drill and tap holes in skis for fixing ski bindings thereto.
Of course, the invention should not be construed as being strictly limited by the specific form of embodiment shown and illustrated herein by way of example, since many modifications and changes may be brought thereto without departing from the basic principles of the invention as set forth in the appended claims. | A jig for drilling and/or tapping in a ski top the holes necessary for fixing a safety ski binding thereto comprises a frame adapted to be temporarily secured to the ski and consisting of a pair of parallel elastic rods along which a pair of slides are movable and adapted to be locked in the desired positions; each slide carries the necessary number of guide sockets for the bit and/or tap, the socket length and position on the frame being such that in combination with shoulder means provided on the bit and/or tap the depth of penetration of the bit or tap into the ski cannot exceed a predetermined value. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present document is based on and claims priority to U.S. Provisional Application Ser. No. 61/153,671, filed 19 Feb., 2009, the contents of which are herein incorporated by reference.
BACKGROUND
[0002] The following descriptions and examples are not admitted to be prior art by virtue of their inclusion in this section.
[0003] Inline barrier valves are used in downhole well applications. Accidental and inadvertent closing or opening of these valves can cause catastrophic failures. For example, inline lubricator valves are used to balance pressure while running an intervention tool downhole. If a failure occurs that results in an inadvertent opening or closing of the valve, substantial risk arises with respect to damage to equipment and/or injury to personnel.
SUMMARY
[0004] In general, embodiments of the present disclosure provide a technique for enabling failsafe control of actuators used to actuate downhole tools, such as downhole valves. According to one embodiment, a well system may comprise a tool having an adjustable member. An actuation mechanism serves as a fail-as-is mechanism and works in cooperation with the adjustable member. The actuation member is shiftable upon receiving a predetermined input; however the actuation member does not move the adjustable member upon each shift. Once the actuation member has been shifted the requisite number of times to move the adjustable member to another position, at least one subsequent shift of the actuation member is not able to cause movement of the adjustable member. This provides a fail-as-is technique for ensuring the tool, e.g. valve, is not inadvertently actuated to another operational position.
[0005] Other or alternative features will become apparent from the following description, from the drawings, and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements. It should be understood, however, that the accompanying drawings illustrate only the various implementations described herein and are not meant to limit the scope of various technologies described herein. The drawings are as follows:
[0007] FIG. 1 is a schematic illustration of a well with a well system incorporating an actuation/fail-as-is mechanism, according to an embodiment of the present disclosure;
[0008] FIG. 2 is a cross-sectional view of one example of a fail-as-is mechanism coupled with a well tool, according to an embodiment of the present disclosure;
[0009] FIG. 3 is a front elevation view of one example of the fail-as-is mechanism illustrated in FIG. 2 , according to an embodiment of the present disclosure;
[0010] FIG. 4 is a schematic illustration of the fail-as-is mechanism and cooperating tool in an operational position, according to an embodiment of the present disclosure;
[0011] FIG. 5 is a schematic illustration of the fail-as-is mechanism and cooperating tool in another operational position, according to an embodiment of the present disclosure;
[0012] FIG. 6 is a schematic illustration of the fail-as-is mechanism and cooperating tool in another operational position, according to an embodiment of the present disclosure;
[0013] FIG. 7 is a schematic illustration of the fail-as-is mechanism and cooperating tool in another operational position, according to an embodiment of the present disclosure; and
[0014] FIG. 8 is a schematic illustration of the fail-as-is mechanism and cooperating tool in another operational position, according to an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0015] In the following description, numerous details are set forth to provide an understanding of the present disclosure. However, it will be understood by those of ordinary skill in the art that embodiments of the present disclosure may be practiced without these details, and that numerous variations or modifications from the described embodiments may be possible. In the specification and appended claims: the terms “connect”, “connection”, “connected”, “in connection with”, “connecting”, “couple”, “coupled”, “coupled with”, and “coupling” are used to mean “in direct connection with” or “in connection with via another element”; and the term “set” is used to mean “one element” or “more than one element”. As used herein, the terms “up” and “down”, “upper” and “lower”, “upwardly” and downwardly”, “upstream” and “downstream”; “above” and “below”; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments of the invention.
[0016] Embodiments of the present disclosure generally relate to a well system and well devices employing a failsafe control. According to one embodiment, the well system comprises a well tool and an actuation mechanism which cooperates with the well tool to move or shift the well tool between operational positions. The actuation mechanism is designed and serves as a fail-as-is mechanism that reduces or eliminates the risk of inadvertent actuation of the well tool.
[0017] According to one specific example, the well tool comprises a valve coupled in cooperation with the actuation mechanism. The actuation mechanism is designed as a fail-as-is mechanism that allows the valve to remain in a current position if there is a failure in a control mechanism, such as a loss of hydraulic pressure in a control line maintaining the valve in an open position. The fail-as-is mechanism also enables the tool, e.g., valve, to remain in a current position in the case of a related component failure. If the valve is in an open position when the component failure occurs, for example, the valve remains open. Similarly, if the valve is in the closed position when the failure occurs, the valve remains closed.
[0018] The tool and its actuation mechanism may have a variety of forms for use with a variety of overall well systems. In one well system embodiment, the tool comprises a valve deployed in an intervention tool. The valve may comprise a lubricator valve deployed in the intervention tool to balance pressure as the intervention tool is run downhole into a wellbore. The fail-as-is mechanism prevents inadvertent shifting of the valve to another operational position even if a control line or other valve component fails during run-in of the intervention tool.
[0019] Referring generally to FIG. 1 , a well system 20 is illustrated, according to one embodiment of the present disclosure. In the example illustrated, a well 22 comprises a wellbore 24 which may be lined with a casing 26 , although in other situations the wellbore may be either an open, or partially cased wellbore. In this example, the well system 20 comprises a well string 28 having a variety of operational components 30 . The specific types of operational components 30 depend on the well operation to be performed. Well string 28 further comprises a well tool 32 that may be moved/shifted between operational positions via an actuation mechanism 34 . In this example, actuation mechanism 34 comprises a fail-as-is mechanism to help prevent inadvertent actuation of the well tool 32 to another operational position.
[0020] The well string 28 may be deployed downhole by a conveyance 36 which may have a variety of forms, such as production tubing, coiled tubing, cable, or other suitable conveyances.
[0021] The conveyance 36 is used to deliver well string 28 and its well tool 32 downhole to a desired location in a wellbore 24 . Generally, conveyance 34 is delivered downhole beneath surface equipment 38 positioned at a surface location 40 . By way of example, surface equipment 38 may comprise a wellhead and/or rig equipment. In one specific example, the well string 28 comprises an intervention tool system, and well tool 32 is a valve, such as a lubricator valve. It also should be noted that the illustrated wellbore 24 is a generally vertical wellbore, however the system and methodology also may be utilized in deviated, e.g. horizontal, wellbores.
[0022] Referring generally to FIG. 2 , one exemplary embodiment of well tool 32 and the cooperating actuation mechanism 34 is illustrated. In this embodiment, well tool 32 comprises a movable member 42 that may be moved between operational positions. Although well tool 32 may comprise a variety of tools, the illustrated well tool example comprises a valve, and movable member 42 comprises a valve member movable/shiftable between operational flow positions. Well tool 32 may comprise an inline barrier valve, for example, in which movable valve member 42 is movable between a closed position and an open position. The open position allows fluid flow through a primary flow passage 44 extending through well tool 32 and actuation mechanism 34 .
[0023] In the embodiment illustrated in FIG. 2 , movable member 42 is a ball valve member having an interior flow passage 46 . The ball valve member 42 is pivotably mounted in a surrounding valve housing 48 against a ball seal 50 . Ball valve member 42 is pivoted against ball seal 50 between an open position, allowing flow along flow passage 44 and interior flow passage 46 , and a closed position blocking flow along flow passage 44 . In FIG. 2 , the movable member/ball 42 is illustrated in the open flow position.
[0024] The movable member 42 is coupled into cooperation with the actuation mechanism 34 , which serves as a fail-as-is mechanism. As illustrated, actuation mechanism 34 comprises a mandrel 52 translatably mounted in a cylinder 54 defined by an actuation mechanism housing 56 . Although valve housing 48 and actuation mechanism housing 56 may be formed as separate housings, the illustrated embodiment shows the valve housing 48 and actuation mechanism housing 56 as a single integral housing.
[0025] Mandrel 52 is sealed with respect to the surrounding actuation mechanism housing 56 via a plurality of seals 58 . By way of example, seals 58 may comprise circular seals mounted in corresponding grooves 60 formed circumferentially along the interior surface of actuation mechanism housing 56 . The mandrel 52 also comprises a longitudinal passage 62 through which fluid may be conducted as it flows along flow passage 44 . Mandrel 52 is coupled with movable member 42 via a suitable mandrel operator 64 . If movable member 42 comprises a ball valve, as illustrated, mandrel operator 64 comprises a linkage configured to pivot the ball valve between open and closed positions as mandrel 52 translates back and forth in a longitudinal direction along cylinder 54 .
[0026] Shifting of mandrel 52 back and forth within the actuation mechanism housing 56 may be achieved via actuation of a piston 66 cooperatively coupled with mandrel 52 . Piston 66 is slidably mounted within a recessed region 68 that is recessed into an interior wall of actuation mechanism housing 56 at a location surrounding mandrel 52 . A predetermined input may be applied to piston 66 to selectively shift the piston back and forth in recessed region 68 . However, every transition of the piston 66 along recessed region 68 does not impart motion to mandrel 52 , and at least one “dummy” shifting of piston 66 is provided between each actual movement of mandrel 52 . In other words, the interaction of piston 66 and of mandrel 52 enables the actuation mechanism 34 to perform as a fail-as-is mechanism by limiting movement of mandrel 52 (and thus valve member 42 ) to specific shifts within a series of shifts. Effectively, piston 66 is decoupled from mandrel 52 in that movement of piston does not necessarily move mandrel 52 .
[0027] The predetermined input applied to shift piston 66 may be in a variety of forms, such as electrical, electro-hydraulic, hydraulic, or other types of inputs. In the specific example illustrated, the input is a hydraulic input provided by one or more hydraulic lines 70 . If hydraulic inputs are used, single hydraulic lines may be used to move piston 66 against a resilient member; or two or more hydraulic lines 70 may be employed to selectively move the piston 66 back and forth along recessed region 68 . In the embodiment illustrated, for example, the predetermined hydraulic input is provided by a pair of hydraulic lines 70 with an individual hydraulic line positioned on each side of piston 66 to selectively move the piston back and forth.
[0028] The hydraulic lines 70 are located to deliver hydraulic fluid into recessed region 68 on opposite sides of piston 66 via ports 72 extending through housing 56 . The piston 66 may comprise a plurality of seals 74 positioned to form a seal between piston 66 and mandrel 52 on one side of the piston; and between piston 66 and an interior surface defining recessed region 68 on a radially opposite side of the piston. Pressurized hydraulic fluid is selectively applied to each side of piston 66 to drive the piston back and forth in recessed region 68 and to ultimately shift mandrel 52 , thereby moving the movable member 42 to another operational position.
[0029] For each shift of piston 66 that causes movement of mandrel 52 and movable member 42 , at least one subsequent shifting of the piston 66 is not able to cause movement of the mandrel 52 . In many applications, a plurality of subsequent shifts of the piston 66 may not move mandrel 52 . These “dummy” shifts ensure actuation mechanism 34 functions as a fail-as-is mechanism and prevents inadvertent actuation of movable member 42 to another operational position. The selective movement of mandrel 52 under the influence of piston 66 is caused by a selective engagement mechanism 76 , which enables cooperation between actuation mechanism 34 and well tool 32 without directly coupling piston 66 to mandrel 52 .
[0030] According to one embodiment, selective engagement mechanism 76 is an indexer or indexing system in which piston 66 comprises a plurality of slots 78 that move in cooperation with corresponding keys 80 mounted on mandrel 52 . In FIG. 3 , one example of an indexing system 76 is illustrated in greater detail. In this example, piston 66 comprises the plurality of slots 78 formed by a series of short slots 82 and a series of long slots 84 which are longitudinally oriented along piston 66 . By way of specific example, the indexing system may comprise a J-slot indexing system with at least one long J-slot 84 between each sequential pair of short J-slots 82 moving in a circumferential direction around piston 66 . In the specific example, a plurality of long J-slots 84 , e.g. two J-slots, is positioned between each sequential pair of short J-slots 82 . Additionally, the piston 66 may have two sets of the plurality of slots 78 in which each set of slots is positioned at an opposed longitudinal end of piston 66 . The slots 78 are oriented for engagement with corresponding sets of keys 80 mounted to mandrel 52 , on both longitudinal ends of piston 66 .
[0031] When the piston 66 is shifted, sloped surfaces 86 engage corresponding keys 80 and slightly rotate the piston 66 relative to the mandrel 52 so that the keys 80 move along the corresponding slots 78 . If the keys 80 move into a short slot 82 , continued movement of piston 66 forces a corresponding movement of mandrel 52 . By having slots 78 on both longitudinal ends of piston 66 , a similar engagement occurs as the piston 66 is shifted longitudinally in each direction. The engagement of keys 80 at one longitudinal end of the piston 66 effectively rotates the piston slightly for appropriate engagement with keys 80 at an opposite longitudinal end of the piston 66 when the piston 66 is transitioned in the opposite longitudinal direction. However, between each sequential pair of short slots 82 , one or more long slots 84 prevent movement of the mandrel 52 during one or more subsequent shifts. This is accomplished by forming long slots 84 with sufficient length to prevent the “bottoming out” of keys 80 over the full longitudinal transition or stroke of piston 66 .
[0032] As a result, the decoupling between piston 66 and mandrel 52 creates a fail-as-is mechanism that can be used in a variety of downhole tools. A few examples of suitable downhole tools include downhole completion tools, which may be in the form of valves, e.g. barrier valves, ball valves, safety valves, inflow control valves, as well as a variety of other tools. The unintended actuation of the downhole tool is prevented because the motion of piston 66 is decoupled from the mandrel 52 following the transition of mandrel 52 . In the embodiment illustrated, movable member 42 is a ball valve movable via appropriate activation of selective engagement mechanism 76 . The selective engagement mechanism 76 may be an index system comprising J-slots located on opposite longitudinal ends of the piston 66 such that each set of slots 78 is arranged in a pattern with short J-slots 82 separated by two long J-slots 84 , for example.
[0033] In the embodiment illustrated, mandrel 52 has two sets of matching sized lugs or keys 80 . When piston 66 moves through a full stroke along recessed region 68 and the subject mandrel keys 80 move into a long slot 84 , the mandrel 52 does not move. On the other hand, if the mandrel keys 80 move into one of the short slots 82 , the mandrel 52 moves according to the corresponding movement of the piston 66 as it transitions through its piston stroke. In the illustrated example, the movement of mandrel 52 cycles the valve member 42 between open and closed positions. After intentionally actuating the movable member 42 , the subsequent, repeated cycling of piston 66 results in the next two piston strokes moving through two dummy cycles in which the mandrel keys 80 engage long slots 84 . Accordingly, in the case of a failure, e.g. a control line leak, the next two cycles or strokes of piston 66 produce two non-activating movements which fail to move mandrel 52 . This prevents inadvertent actuation of the downhole well tool 32 .
[0034] In the embodiment illustrated in FIG. 2 , the actuation mechanism 34 is a hydraulic actuation mechanism with a displacement based fail-as-is feature for selectively moving a ball type, downhole barrier valve while protecting the valve from inadvertent actuation. However, other embodiments of the fail-as-is feature may comprise other components, actuation techniques, and configurations for moving a variety of tools between operational positions while protecting the tool from inadvertent actuation. Furthermore, the series of actuations of piston 66 between each movement of movable member 42 may be selected according to the requirements of a specific application, well tool, and/or operator considerations. In the example illustrated, two long slots 84 are followed with a short slot 82 , resulting in two “dead” cycles prior to actuating the well tool 32 . The number of “dead” cycles in which the piston 66 does not actuate the mandrel 52 may be as few as one or as many as three or more depending on the specific application. In some cases, the “dead” cycles may only follow one of the operational sequences. For example, two operational cycles may occur sequentially followed by one or more “dead” cycles.
[0035] Referring generally to FIGS. 4-8 , a series of actuation cycles is provided in sequential figures to help illustrate the cooperation of actuation mechanism 34 and well tool 32 . The cooperation results in selective movement of the movable member 42 , e.g. valve member, between operational positions while protecting the well tool from inadvertent actuation. In the illustrated sequence, the piston 66 is initially in a rightmost position and the keys 80 located on the right side of piston 66 are engaged with the short slots 82 , as illustrated in FIG. 4 . The piston 66 is illustrated as actuated through its full stroke to the right, thus transitioning mandrel 52 to the right side which, in turn, moves valve member 42 to an open position. (See FIG. 2 ).
[0036] As described above, when selective engagement mechanism 76 comprises and indexing system, piston 66 and slots 78 may be partially rotated around the mandrel 52 during each engagement to allow progression from one cycle to the next. When the piston 66 is subsequently cycled or stroked to the left, the keys 80 located on the left side of piston 66 are engaged with long slots 84 , as illustrated in FIG. 5 . During this stroke of piston 66 , the mandrel 52 does not move. In the example illustrated, this subsequent stroke is called the “dummy up” cycle. The next sequential cycle or stroke of the piston 66 is again to the right, but this stroke results in engagement of the keys 80 located on the right side of piston 66 with long slots 84 , as illustrated in FIG. 6 . This stroke is also a dummy stroke and may be referred to as a “dummy down” stroke, which again protects valve member 42 from inadvertent actuation to a next operational position, e.g. a closed position.
[0037] During the next actuation of piston 66 , the piston is cycled or stroked to the left and the left keys 80 are engaged by short slots 82 , as illustrated in FIG. 7 . Continued movement of piston 66 through its full stroke, along recessed region 68 , causes movement of the keys 80 and mandrel 52 toward the left, as illustrated in FIG. 8 . This actuation of piston 66 and the resultant movement of mandrel 52 cause movement of valve member 42 to a subsequent operational position. In this particular example, the valve member 42 is transitioned from an open position to a closed position.
[0038] The fail-as-is feature of the actuation mechanism 34 protects the well tool against inadvertent actuation by providing at least one dummy cycle, e.g. two dummy cycles, between actual actuation steps. For example, after the ball valve is cycled open, the piston 66 is in the initial actuation position illustrated in FIG. 4 . If one of the control lines 70 breaks and causes a pressure imbalance across piston 66 , the piston may be actuated through the “dummy up” cycle. Because this cycle is a dummy cycle, the movable member 42 , e.g. ball valve, is not actuated and remains in its current position. This same protection against inadvertent actuation also is provided when the movable member 42 is in a different operational position, e.g. when the ball valve is in a closed position. Again, if a control line 70 or other component breaks and creates a pressure imbalance across piston 66 , the piston is simply moved through a dummy cycle and the movable member 42 remains in its current position. Accordingly, the actuation mechanism 34 serves as a fail-as-is mechanism that enables well tool actuation, while protecting the well tool from inadvertent actuation.
[0039] The overall well system 20 may be designed for use in a variety of well applications and well environments. Accordingly, the number, type and configuration of components and systems within the overall system may be adjusted to accommodate different applications. For example, the well tool and actuation mechanism may be employed in an intervention tool system or in a variety of other types of well systems. The technique for shifting actuation mechanism 34 may rely on a variety of predetermined inputs, such as hydraulic inputs, electrical inputs, electro-hydraulic inputs, and other inputs suitable for imparting motion to the shiftable piston. Furthermore, the piston, mandrel, selective engagement mechanism, and other components of the actuation mechanism may be adjusted to the specifics of a given well application and well tool. Similarly, the well tool may comprise a variety of valves and other types of well tools actuated between operational positions via various linkages between the actuation mechanism and the movable element of the well tool.
[0040] Elements of the embodiments have been introduced with either the articles “a” or “an.” The articles are intended to mean that there are one or more of the elements. The terms “including” and “having” are intended to be inclusive such that there may be additional elements other than the elements listed. The term “or” when used with a list of at least two elements is intended to mean any element or combination of elements.
[0041] Although only a few embodiments of the present disclosure have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this disclosure. Accordingly, such modifications are intended to be included within the scope of this disclosure as defined in the claims. | A technique enables failsafe control over actuators used to actuate downhole tools. The technique may utilize a well system having a tool with an adjustable member. An actuation mechanism serves as a fail-as-is mechanism and works in cooperation with the adjustable member. The actuation member is shiftable upon receiving a predetermined input; however the actuation member does not move the adjustable member upon each shift. Once the actuation member has been shifted the requisite number of times to move the adjustable member to another position, at least one subsequent shift of the actuation member is not able to cause movement of the adjustable member. The result is a fail-as-is technique for ensuring the tool is not inadvertently actuated to another operational position. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to fourdrinier paper machines. More specifically, the present invention relates to deckle structures for confining the papermaking stock pond carried on the fourdrinier screen.
2. Description of the Prior Art
Fourdrinier paper machines are characterized by a closed loop web formation screen driven over an open, flat table surface. Extremely dilute, aqueous papermaking stock is jetted upon the traveling screen from a horizontally elongated nozzle; usually associated with a stock accumulation chamber called a headbox.
As the traveling screen carries the stock flow from the slice jet landing zone, aqueous vehicle, i.e., water, drains through the screen to leave the fiber constituent of the papermaking stock accumulated upon the upper screen surface as a consolidated mat.
Between the stock landing zone and that longitudinally displaced point along the screen belt traveling route whereat the mat consolidates into a paper web, the stock is supported on the screen surface as a liquid pond of diminishing depth. Without lateral containment, lateral liquid stock flow cross-directionally sweeps fiber stock towards the screen sides thereby undesirably tapering the paper web edge thickness.
To prevent such undesirable thickness tapering along the paper web edges, lateral pond confinement structures called "deckle boards" are positioned above and along the screen edges in the machine direction from the slice landing zone. Traditionally, deckle boards are similar to a pair longitudinal dams, each extending along the screen traveling direction respective to each lateral edge of the screen with the screen per se running under the deckle boards.
A more recent innovation to the deckle structure has been to combine the deckle board with a screen edge cupping rail located outboard of the deckle board, as represented by U.S. Pat. No. 4,968,387 to R. L. Beran et al. The curled screen edges, traveling along respective, oppositely cupped rail profiles, hydraulically confine the stock pond. The deckle boards, internally of the cupped rails, are vertically positioned above the screen as to leave a substantial hydraulic channel beneath the lower deckle board edge. Machine white water fills the flow channel between the cupping rail and the outside surface of the deckle board. The inside faces of the deckle boards delineate the outer edge limits of the stock fiber. Standing waves generated in the stock pond are permitted to pass under the deckle board into white water channel and dissipate up the edge cup profile without reflection.
All deckle structure, whether of the traditional design or that using cupped rails, is positioned within close proximity of the energetically traveling stock pond. The structure is located within a virtual mist of fiber particles being continuously splashed from the traveling stock pond. These fiber particles have a high adhesive affinity for any solid surface such as is offered by the deckle structure. Fiber coatings continue to accumulate and soon begin to flake off in agglomerated chunks and fall into the fresh stock pond for web processing. Such web integrated chunks of agglomerated old fiber disrupt the web quality and runnability.
Although the prior art, as represented by U.S. Pat. No. 3,607,624 to W. R. Moody, has partially recognized the value of protecting the deckle structure with a continuously flowing water film, that recognition did not teach a functional structure that would adequately accomplish the objective. Many portions of the Moody structure are not water film flushed and are fiber accumulation surfaces.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a configuration of cupping rail structure wherein virtually all external surfaces are continuously water-flushed.
Another object of the invention is to provide a cupping rail structure having a flushing film distribution fountain for uniformly distributing surface flushing water over the exposed cupping rail surfaces.
These and other objects of the invention are accomplished by cupping rail structures that are crowned by smooth, table flat fluid distribution surfaces. Fluid flow apertures through the distribution surface communicate the distribution surface with a fluid supply conduit. Such fluid flow apertures are located in regularly spaced alignment between the surface weir edge and a flow barrier whereby flow from a fluid pond on the distribution surface is in one direction from the barrier and over the weir edge. Cylindrical axes of the apertures are alternately oriented between vertical alignment to about 15° to 45° from vertical turned toward the weir edge.
Cupping rail structure below the weir edge is substantially smooth and continuously faired with no abrupt or horizontal surfaces.
One side-wall of a square section fluid conduit is provided with a plate bracket which projects beyond both side-wall edges: one projection serving as the fluid flow barrier for the flushing film distribution fountain and the other projection serving as an alignment and mounting bracket for securing the conduit to the top edge of a cupping rail.
DESCRIPTION OF THE DRAWINGS
Relative to the drawings wherein like reference characters designate like or similar elements throughout the several FIGURES of the drawings:
FIG. 1 is an abbreviated pictorial of a paper machine headbox section showing the present invention operatively combined therewith;
FIG. 2 is a sectional view of the present invention in operative combination with directly associated paper machine structure;
FIG. 3 is a detail of the invention in operative combination with a warped, screen edge cupping rail.
FIG. 4 is a sectioned detail of a deckle board embodiment of the present invention flushing film distribution fountain; and
FIG. 5 is a sectional detail of a screen edge cupping rail embodiment of the present invention flushing film distribution fountain.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For environmental setting, FIG. 1 illustrates the relevant elements of a fourdrinier paper machine as comprising a headbox 10 which discharges dilute, aqueous papermaking stock from a slice opening 11 onto a horizontally carried, table segment of an endless belt screen 12. The screen is turned about and drawn from a breast roll 13 under headbox 10. Extensions 14 from the slice end wall, characterized as "pond sides" or "cheeking pieces," confine the fluid stock beyond the plane of discharge from the slice and may include the line of stock landing 15.
Dynamically, the jet of fluid stock lands upon the screen 12 which is moving at approximately the same horizontal velocity as the stock jet. Although drainage of the stock aqueous vehicle begins immediately, the initial drainage process continues for several seconds during which the stock remains as a highly fluidized pond 16. As this pond is carried away from the slice opening 11, water removal diminishes the pond depth until sufficient free water is removed to form a consolidated fibrous mat 18. That point of mat consolidation is observed on the paper machine as a "dry line" zone 17. Thus formed, the mat is further dried by pressure and heat to an integral, continuous paper web.
In transit, the pond 16 is laterally confined by deckle structure 20. Such deckle structure of the present invention is shown by FIGS. 2 through 5 as including a deckle board assembly 21 and a screen edge cupping rail assembly 40.
The deckle board assembly 21 is shown by FIG. 2 to comprise a thin, (1/8 in wide) polycarbonate (Lexan) blade 22 bonded to a polymethymethacrylate (Plexiglas) attachment body 23.
This structure is supported by a position adjustable bracket means not shown such as that disclosed by U.S. Pat. No. 3,607,624 to W. R. Moody et al. The attachment body 23 is shaped with a step 24 to receive the blade 22 thickness thereby providing an uninterrupted inside vertical surface 25. Above the blade 22, the block 23 is formed with a pair of longitudinal rail channels 26 which receive a corresponding pair of bracket rails 27 supported by a square section C-clip 28.
The bight section 29 of the C-clip is secured to a flushing fountain 30 comprising a square section conduit 31 having a substantially flat top surface 32. Longitudinally along the top surface midline is an upstanding blade or fluid barrier 33 secured to the surface as by welding. On both sides of the blade 33, between the respective vertical faces of the blade and the corresponding top surface edge 34, a series of fountain holes 36 and 37 communicate the interior of conduit 31 with the exterior elements of top surface 32.
Bore axes of the holes are alternated between a vertical or 0° orientation for holes 36 to some angle between 10° and 45° for holes 37. The FIGS. 2 and 4 illustrated angle of 30° is merely representative. The axis angle for holes 37 is turned away from the center blade 33 and toward the weir edge 34 respective to both rows of holes.
Representative dimensioning for the fountain holes 36 and 37 may include a ratio of about 25% wherein the hole diameter is 20% of the hole spacing period. For example, a periodic distance of 1/4 inch between holes 36 and 37 would suggest a hole diameter of 1/16 inch.
The screen edge cupping rail assembly 40 comprises the rail element 41 having a concave inside surface 42 for supporting the lateral edges of the traveling screen 12. The "inside" orientation refers to the rail side most proximate of the screen 12 and the stock pond 16.
The top of rail 40 is crowned with a plurality of flushing fountain sections 43, each about 18 to 24 inches long, as illustrated by FIG. 3. Each fountain section comprises a square section fluid conduit 44 and a side plate 45. The fluid conduit provides a flat top surface 46 penetrated by holes 47 and 48 between the upwardly projected inside surface of side plate 45 and the weir edge 49 of top surface 46. Similar to the holes 36 and 37 in the deckle structure flushing fountain, holes 47 and 48 have an alternating bore axis orientation with the axis of holes 47 aligned at substantially 0° with vertical and the axis of holes 48 set at an angle of 15° to 45° from vertical toward the top surface weir edge 49.
The lower projected surface of side plate 45 provides a mounting clamp and alignment fence whereby the fountain section 43 may be secured to the rail element 41.
To obtain minute adjustments of the screen 12 travel profile, the edge cupping rail 41 is often secured to the paper machine forming table in a twisted and warped configuration as suggested by FIG. 3. If continuous along the length of rail 41, the rigidity of the flushing fountain conduit 44 and side plate 45 would prohibit such desired twisting of rail 41 when firmly secured thereto. However, by serving the rail assembly with short sections of flushing fountain 43, such twisting may be accommodated. For this reason, each fountain section 43 is secured by only one cap screw 51 through an oversized aperture 52 in the plate 45. By this means, small angular differences in the attachment angle between each fountain section 43 and a respective increment of the rail 41 may be accommodated. Other, more elaborate, adjustable anchoring mechanisms ma be applied to this structural unit but the single cap screw 51 is adequate, simple and inexpensive.
To supply flushing water to each, independent fountain conduit 1 31 and 44, flexible hose conduits 53 and 54 connect the square section conduits to a supply manifold 55.
Operatively, water rises from the inside of square conduits 31 and 44 to flood the top surfaces 32 and 46. The flow barrier provided by vertical walls 33 and 45 cooperates with the hole bore axis orientation to distribute a substantially even thickness water film flow over the weir edge 34 and 49. Below the weir edges, the deckle and rail structures are smoothly faired into the fourdrinier pond 16 to maintain the film distribution. To the extent that localized surface irregularities and discontinuities exist along the conduit top surfaces, the angular axis holes 37 and 48 push the flow over the wire edges and prevent channeling. To the extent that film distribution is maintained, no dry surface is available for splash fiber accumulation.
Numerous alternative and mechanically equivalent design configurations may be devised for particular invention features. For example, the deckle blade 22 may be inserted into a central slot along the attachment body 23 with both sides tapered fairly into the deckle blade side planes. As my invention, however, | Paper machine cupping rails for curling the lateral edges of a web formation screen are protected from fiber accumulations by a uniformly distributed water film that continuously flows from a flat, horizontal upper surface respective to a plurality of conduit length increments. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2012/075343 filed Dec. 13, 2012, and claims the benefit thereof. The International Application claims the benefit of European Application No. EP12156510 filed Feb. 22, 2012. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to a layer system having a ceramic layer to which an aluminum-rich outer layer is applied, and to a process.
BACKGROUND OF INVENTION
[0003] When carrying out inspections on gas turbines, attacks on thermal barrier layers are observed, particularly in the case of oil-fired turbines. Closer examinations show that—as has also already been observed in aviation turbines—CMAS attacks were the trigger for the damage to the layer. A compound of calcium, magnesium, aluminum and silicon or iron leads to low-melting eutectics on thermal barrier layers in the temperature range around 1200° C.-1250° C. or higher. These compounds release the yttrium oxide needed for stabilization from the thermal barrier layer. This leads to strongly monoclinic phase transitions upon a change in temperature in the ceramic, and these lead to the destruction of the thermal barrier layer.
[0004] To date, this effect has arisen only to a limited extent in stationary turbines, since the surface temperatures of the thermal barrier layer used did not reach the required melting temperatures of CMAS and iron. Protection was therefore not needed. With an increasing gas temperature, however, this attack increases in magnitude.
SUMMARY OF INVENTION
[0005] It is therefore an object of the invention to solve the aforementioned problem.
[0006] The object is achieved by a layer system and a process as claimed.
[0007] The dependent claims list further advantageous measures which can be combined with one another, as desired, in order to achieve further advantages.
[0008] Within the context of investigations with extremely small particles of aluminum, it was possible to show that particles of this type form high-melting compounds in connection with CMAS, for example anorthite. These particles, in the order of magnitude of 100 nm to 50 μm, can be introduced into a binder matrix and readily sprayed using an air gun. This matrix is applied to a thermal barrier layer surface. By virtue of these extremely small particles, on the one hand a large active surface area is available, but on the other hand the system is very ductile owing to the loose compound structure. The chemically very aggressive CMAS compound reacts with the aluminum excess to form anorthite. This is a high-melting compound which prevents or at least reduces the CMAS attack. A particular advantage of this coating is the possibility of repeated application even when the component is installed. The anorthite layer which builds up additionally affords protection against the attack of the CMAS compound.
[0009] The aluminum-containing protective layer can also be applied to rotor blades and guide vanes of a gas turbine when the latter are installed, in which case in particular a housing half of the gas turbine is open.
[0010] The coating can be applied cost-effectively (aluminum particles in a binder matrix) and easily.
[0011] The additional protective layer system makes it possible for the operator of a gas turbine to also operate a cost-effective partially stabilized zirconium oxide system under a CMAS attack.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In the drawing:
[0013] FIG. 1 shows a layer system according to the invention,
[0014] FIG. 2 shows a turbine blade or vane, and
[0015] FIG. 3 shows a list of superalloys.
DETAILED DESCRIPTION OF INVENTION
[0016] The description and the figures represent merely exemplary embodiments of the invention.
[0017] FIG. 1 shows a layer system 1 according to aspects of the invention.
[0018] The layer system 1 comprises a substrate 4 . The substrate 4 comprises, in particular consists of, a nickel-based or cobalt-based superalloy, in particular as shown in FIG. 3 .
[0019] The layer system 1 furthermore comprises a ceramic layer 10 . The ceramic layer 10 can comprise zirconium oxide, partially stabilized zirconium oxide or two-layered ceramic systems made up of zirconium oxide and/or a pyrochlore phase such as gadolinium hafnate or zirconate.
[0020] A metallic bonding layer and/or an aluminum oxide layer (TGO) can be present between the ceramic layer 10 and the substrate 4 . These can be aluminide layers or NiCoCrAlY layers which form the TGO.
[0021] Further ceramic thermal barrier layer systems as are known in the case of high-temperature components, in particular in the case of turbine blades or vanes or components of gas turbines, can be the starting basis.
[0022] A layer of aluminum particles is present as the outermost layer 13 on the ceramic layer 10 , said layer 13 being exposed to a hot gas in a gas turbine in the case of a turbine blade or vane.
[0023] It is preferable for the layer to consist of aluminum or aluminum particles.
[0024] The particle size here is preferably 0 . 1 μm to 50 μm.
[0025] Aluminum always has an oxide layer.
[0026] In particular, the proportion of aluminum (Al) represents the largest proportion.
[0027] It is also possible to use layers 13 containing compounds which comprise aluminum in a superstoichiometric ratio or comprise aluminum in excess, but preferably no aluminides (NiAl, . . . ) or MCrAlY.
[0028] Possible processes for applying the layer 13 made of an emulsion consisting of the Al particles and a binder are spraying, application using a brush, application using a roller or dipping the components into the emulsion.
[0029] Further types of aluminum coating are possible, such as aluminum plating.
[0030] FIG. 2 shows a perspective view of a rotor blade 120 or guide vane 130 of a turbomachine, which extends along a longitudinal axis 121 .
[0031] The turbomachine may be a gas turbine of an aircraft or of a power plant for generating electricity, a steam turbine or a compressor.
[0032] The blade or vane 120 , 130 has, in succession along the longitudinal axis 121 , a securing region 400 , an adjoining blade or vane platform 403 and a main blade or vane part 406 and a blade or vane tip 415 .
[0033] As a guide vane 130 , the vane 130 may have a further platform (not shown) at its vane tip 415 .
[0034] A blade or vane root 183 , which is used to secure the rotor blades 120 , 130 to a shaft or a disk (not shown), is formed in the securing region 400 .
[0035] The blade or vane root 183 is designed, for example, in hammerhead form. Other configurations, such as a fir-tree or dovetail root, are possible.
[0036] The blade or vane 120 , 130 has a leading edge 409 and a trailing edge 412 for a medium which flows past the main blade or vane part 406 .
[0037] In the case of conventional blades or vanes 120 , 130 , by way of example solid metallic materials, in particular superalloys, are used in all regions 400 , 403 , 406 of the blade or vane 120 , 130 .
[0038] Superalloys of this type are known, for example, from EP 1 204 776 B1, EP 1 306 454, EP 1 319 729 A1, WO 99/67435 or WO 00/44949.
[0039] The blade or vane 120 , 130 may in this case be produced by a casting process, by means of directional solidification, by a forging process, by a milling process or combinations thereof.
[0040] Workpieces with a single-crystal structure or structures are used as components for machines which, in operation, are exposed to high mechanical, thermal and/or chemical stresses.
[0041] Single-crystal workpieces of this type are produced, for example, by directional solidification from the melt. This involves casting processes in which the liquid metallic alloy solidifies to form the single-crystal structure, i.e. the single-crystal workpiece, or solidifies directionally.
[0042] In this case, dendritic crystals are oriented along the direction of heat flow and form either a columnar crystalline grain structure (i.e. grains which run over the entire length of the workpiece and are referred to here, in accordance with the language customarily used, as directionally solidified) or a single-crystal structure, i.e. the entire workpiece consists of one single crystal. In these processes, a transition to globular (polycrystalline) solidification needs to be avoided, since non-directional growth inevitably forms transverse and longitudinal grain boundaries, which negate the favorable properties of the directionally solidified or single-crystal component.
[0043] Where the text refers in general terms to directionally solidified microstructures, this is to be understood as meaning both single crystals, which do not have any grain boundaries or at most have small-angle grain boundaries, and columnar crystal structures, which do have grain boundaries running in the longitudinal direction but do not have any transverse grain boundaries. This second form of crystalline structures is also described as directionally solidified microstructures (directionally solidified structures).
[0044] Processes of this type are known from U.S. Pat. No. 6,024,792 and EP 0 892 090 A1.
[0045] The blades or vanes 120 , 130 may likewise have coatings protecting against corrosion or oxidation e.g. (MCrAlX; M is at least one element selected from the group consisting of iron (Fe), cobalt (Co), nickel (Ni), X is an active element and stands for yttrium (Y) and/or silicon and/or at least one rare earth element, or hafnium (Hf)). Alloys of this type are known from EP 0 486 489 B1, EP 0 786 017 B1, EP 0 412 397 B1 or EP 1 306 454 A1.
[0046] The density is preferably 95% of the theoretical density.
[0047] A protective aluminum oxide layer (TGO=thermally grown oxide layer) is formed on the MCrAlX layer (as an intermediate layer or as the outermost layer).
[0048] The layer preferably has a composition Co-30Ni-28Cr-8Al-0.6Y-0.7Si or Co-28Ni-24Cr-10A1-0.6Y. In addition to these cobalt-based protective coatings, it is also preferable to use nickel-based protective layers, such as Ni-10Cr-12Al-0.6Y-3Re or Ni-12Co-21Cr-11Al-0.4Y-2Re or Ni-25Co-17Cr-10Al-0.4Y-1.5Re.
[0049] It is also possible for a thermal barrier layer, which is preferably the outermost layer, to be present on the MCrAlX, consisting for example of ZrO 2 , Y 2 O 3 -ZrO 2 , i.e. unstabilized, partially stabilized or fully stabilized by yttrium oxide and/or calcium oxide and/or magnesium oxide.
[0050] The thermal barrier layer covers the entire MCrAlX layer.
[0051] Columnar grains are produced in the thermal barrier layer by suitable coating processes, such as for example electron beam physical vapor deposition (EB-PVD).
[0052] Other coating processes are possible, e.g. atmospheric plasma spraying (APS), LPPS, VPS or CVD. The thermal barrier layer may include grains that are porous or have micro-cracks or macro-cracks, in order to improve the resistance to thermal shocks.
[0053] The thermal barrier layer is therefore preferably more porous than the MCrAlX layer.
[0054] Refurbishment means that after they have been used, protective layers may have to be removed from components 120 , 130 (e.g. by sand-blasting). Then, the corrosion and/or oxidation layers and products are removed. If appropriate, cracks in the component 120 , 130 are also repaired. This is followed by recoating of the component 120 , 130 , after which the component 120 , 130 can be reused.
[0055] The blade or vane 120 , 130 may be hollow or solid in form. If the blade or vane 120 , 130 is to be cooled, it is hollow and may also have film-cooling holes 418 (indicated by dashed lines). | A layer system is provided that has at least: a substrate, a ceramic layer and an outermost layer, which has an aluminum-rich form, in particular directly on the ceramic layer, and optionally a metallic bonding layer between the substrate and the ceramic layer, and in which the outermost layer has aluminum particles, in particular aluminum particles with a particle size of 100 nm to 50 μm. As a result of applying particles of aluminum to an outermost layer, the ceramic layer is better protected against what is known as CMAS (calcium, magnesium, aluminum and silicon) attacks. | 2 |
BACKGROUND OF THE INVENTION
The present invention concerns a veneer cutter, primarily a guillotine-type cutter applicable for cutting plywood face veneer.
DESCRIPTION OF THE RELATED ART
The face veneer forming the top and bottom layers of plywood must be cut very precisely, as well for the part of cutting the front edge, rear edge as the defective portions thereof. A good cutting result can be provided with a guillotine-type cutter, wherein the cutting blade has a one-sided beveled edge, and the cutting is performed with the blade having its front rake face passing closely the shear edge of a counter blade. One problem with the cutters of prior art has been, that the cutters are able to apply this cutting, providing the best final result, alternatively to perform a front edge cutting or a rear edge cutting only for a veneer sheet progressing through the cutter.
SUMMARY OF THE INVENTION
An improvement of the above described problem has been achieved by means of a plywood veneer cutter according to the present invention, wherein the cutting is performed by means of a blade having a one-sided beveled cutting edge and consequently an essentially planar front rake, by passing the front rake face of the blade closely a shear edge of a stationary counter blade, substantially in the perpendicular direction to the plane of the veneer, whereby there are two of said blades in a common reciprocating cutting movement at a distance from each other in the feeding direction of the veneer. The cutting blades are arranged with their front rake faces facing away from each other and the first blade is positioned to reach a higher elevation during the cutting stroke from the veneer to be cut than the second blade.
BRIEF DESCRIPTION OF THE FIGURES
The construction and way of operation of the cutter according to the invention will be described in the following, with respect to the enclosed drawing, wherein
FIG. 1 is a principle diagram of trimming of a defective veneer sheet,
FIG. 2 illustrates one structural embodiment of a veneer cutter in one operational situation,
FIG. 3 illustrates the veneer cutter of FIG. 2 , when cutting the front edge of a veneer sheet,
FIG. 4 illustrates a veneer cutter of FIG. 2 in an operational situation, where a good veneer sheet is transported through the cutter,
FIG. 5 illustrates the veneer cutter of FIG. 2 , when cutting the rear edge of a veneer sheet, and
FIG. 6 illustrates the veneer cutter, when cutting a defective portion of a veneer sheet.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the situation of FIG. 1 , a cutting diagram is illustrated for a veneer sheet having different types of quality defects. Defective portions are removed, and the good veneer portions are combined in a veneer jointing machine into a veneer sheet acceptable as a face veneer for plywood. Firstly, the front edge or the leading edge of the veneer must be absolutely straight and perpendicular to the side edge lines of the veneer. This is not always the case. This straightening cutting is illustrated in FIG. 1 as cutting off the slice 27 .
After this cutting, the veneer can have a good portion 26 of a random width, ending up to a defective portion 25 (in this text the term “width” means traditionally the direction crossing the grain direction of the veneer). In this portion a device controlling the veneer entering the cutter has noticed a hole in the central area of the veneer. The defective portion is removed and guided to a scrap veneer disposing means. The following good portion 24 , again, is recovered, etc.
The good veneer portions 28 of different widths received from the cutting are combined into a face veneer sheet in a jointing machine, wherein the veneer pieces are bonded with an abutment joint using a suitable gluing technique, like glue spots or glue string to form a face veneer sheet. The basic construction of one embodiment of the cutter used for the above described cutting procedure is illustrated in the enclosed FIG. 2 . The cutter is shown in the figure at the initial position of the cutting procedure.
The figure shows a stationary frame beam 1 of the cutter, supporting a movable blade beam 14 . The blade beam 14 is connected to the frame beam 1 by means of an actuator 9 for providing the cutting operation of the cutter. The actuator is in the described embodiment a cylinder-piston apparatus 9 , being able to move the blade beam back and forth in the vertical direction for the stroke length required by the cutting movement.
Cutting blades 3 and 3 ′ are mounted onto the opposite vertical sides of the blade beam 14 , the blades being immovable with respect to the blade beam. Thus, the cutting blades are located in the feed direction A of the veneer at the distance from each other defined by the width of the blade beam 14 . The first and second cutting blades 3 and 3 ′, respectively, are at their lower edge beveled one-sided, whereby the front rake face is down to the cutting edge substantially straight. The cutting blades are attached to the blade beam so that their front rake faces are facing away from each other, and their sharpening bevels are facing to each other.
Both of the cutting blades 3 and 3 ′ have a counter blade 11 , 11 ′, respectively, located in the apparatus so, that their shear edges are facing to each other. In other words, the front rake faces of the cutting blades 3 and 3 ′ facing away from each other are designed to move closely with respect to the shear edge of their respective counter blade during the cutting movement, at a distance of a cutting tolerance.
With the above described blade arrangement, the cutter can be provided with a function, wherein the edge remaining to the usable portion of the veneer to be cut respectively can be arranged to be an edge which during the cutting was facing against the front rake face of the cutting blade, and supported during the cutting on the shear edge of the counter blade.
Due to the free space B left between the counter blades 11 and 11 ′, the scrap portions resulted from the cutting can be removed from the cutter.
The operations model of the cutter in accordance with the invention is described with reference to the enclosed FIGS. 3 to 6 .
In FIG. 3 , a veneer sheet 12 has been fed in the direction A guided by a preceding feed and control apparatus onto the counter blade 11 of the first cutting blade 3 for a length that has been defined by a control apparatus as a cutaway portion (slice 27 in FIG. 1 ). The blade beam 14 is ordered to perform a cutting stroke, whereby the blade 3 cuts the slice 13 from the front edge of the veneer. If the control apparatus had found the remaining veneer sheet to be good, the feeding apparatus takes the veneer sheet 12 through the cutter ( FIG. 4 ) into a phase shown in FIG. 5 . In this phase the rear edge of the veneer sheet is straightened by removing a slice 16 therefrom.
In case the control apparatus has discovered defective portions (portions 23 ; 25 ) in FIG. 1 ), in the veneer, the operation of the cutter is controlled corresponding to the operation described above, in other words, the cutting before a defective portion is performed with the second blade 3 ′ and the cutting after the defective portion is performed with the first blade 3 . The defective cutaway portion drops down between the counter blades 11 and 11 ′.
FIG. 6 shows a cutting situation illustrating one operational feature of the invention. The defective portion 17 appeared in the veneer 12 , being e.g. a defective point in the central area of the veneer, has been cut off by the second blade 3 ′ from the veneer moved forwards in the direction A. The veneer has been fed on, for a width required by the width of the defective portion 17 , so that the rear edge of the defective portion can be brought under the first blade 3 . In this situation, before the first blade 3 performs the cutting, the second blade 3 ′ is below the edge of its respective counter blade 11 ′ preventing the wide defective portion from moving to the delivery path of the sound veneer, in the direction A. Instead, the defective portion 17 is forced to the space B between the counter blades 11 and 11 ′, and is discharged from the cutter among the scrap slices after the cutting performed by the first blade.
For disclosing an additional structural feature of the invention, reference is still made to the apparatus illustrated in FIG. 2 . Pressing means 2 and 2 ′ are mounted on the front rake face of the both cutting blades 3 and 3 ′, respectively. These pressing means have limited movable in the direction of the cutting movement on the surface of the blades 3 and 3 ′. The pressing means 2 and 2 ′ have an actuator 8 and 8 ′, respectively, for providing a motion of the pressing means on the surface of the blades in the cutting direction with a predetermined force. The meaning of this predetermined force is to push the pressing means 2 , 2 ′ below the cutting edge of the respective blade, when the blades are in their inoperative position, above the respective counter blade.
The force pressing the pressing means must, however, be smaller than the force for pushing the blade beam 14 towards the counter blades 11 and 11 ′ for performing the cutting. Thereby the pressing means yields to the cutting movement, when the pressing means has set against the counter blade or against the veneer resting thereon, and the pressing means slide on the surface of the blade to the opposite direction of the cutting movement. The pressing force must, however, be so strong, that the veneer between the pressing means 2 or 2 ′ and the counter blade 11 or 11 ′, respectively, can be straightened, whereby the precise cutting result can be guaranteed. Waving or bending of the veneer can thereby not affect the exactness of the cutting. | Veneer cutter, wherein the cutting is provided by a blade, the front rake face thereof being movable to pass a stationary counter blade, substantially in a perpendicular direction to the plane of the veneer. The cutter includes two blades in a common cutting movement and arranged at a distance from each other in the feed direction of the veneer. The cutting blades are located with their front rake faces facing away from each other, and the first blade in the feed direction is positioned at a higher elevation from a common plane of the counter blades than the second blade. | 1 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to an improved catheter, and more particularly to an improved catheter which provides an increased viable lifetime and also minimizes potential trauma to the patient and the possibility of accidental needle contact with the medical practitioner.
[0002] Catheters are used for introducing fluids into an anatomical passageway of a patient undergoing treatment. Typically, a catheter is inserted into the anatomical passageway, such as a blood vessel. The catheter is then connected to an administration line from which fluids are introduced into the patient's vascular system through the catheter. Alternatively, catheters may be placed directly into tissue of a patient, such as a muscle or organ so that a fluid medication may be administered directly to a specific site asystemically as is well understood by those of skill in the art.
[0003] There are various methods of inserting a catheter into an anatomical passageway. These methods typically involve the use of a sharpened metal needle in conjunction with the catheter. In one such method the metal needle defines a lumen. The metal needle is inserted into the patient's anatomical passageway. Once the needle is in place, the catheter is introduced through the lumen and into the passageway. This type of catheter system is known as a through-the-needle system. Once the catheter is inserted, the needle is removed. This requires the medical practitioner to pull the needle with its sharp edge out of the patient and guide it over or along the catheter until it is removed.
[0004] Another type of catheter system is the over-the-needle system. In such a system, a catheter is placed over a rigid needle. The needle and catheter are simultaneously inserted into the patient's anatomical passageway. Thereafter, the needle is withdrawn from the interior of the catheter, leaving the catheter disposed within the patient.
[0005] A common problem associated with many over-the-needle catheters is that they tend to travel axially away from the tip of the needle and thus collapse during the insertion procedure. The patient's skin and tissue tend to resist the introduction of a catheter and push the distal tip of the catheter body backward. The catheter body thus wrinkles in an accordion or bellows-like manner over the needle as the distal end of the catheter travels backward toward the proximal end thereof while the needle is urged through the skin and tissue. This tendency of the catheter to wrinkle results from urging the catheter into the patient by applying a force to a separate needle as opposed to the catheter. Currently, virtually all over-the-needle catheters are formed of a single thermoplastic material such as polyvinylchloride (PVC), Teflon® polyurethane or the like, which provides stiff columnar strength during insertion. The catheter also remains relatively stiff when disposed within an anatomical passageway. Such stiffness traumatizes the walls of the anatomical passageway and typically requires removal of the catheter from the passageway or vessel in two days or less.
[0006] An over-the-needle catheter is described in U.S. Pat. No. 5,533,988, issued on Jul. 9, 1996 to Dickerson et al. and entitled “Over-The-Needle Catheter”. The catheter includes a flexible body and a hardened tip at the distal end. The hardened tip forms an abutment at the distal end of the catheter. A rigid needle extends within the catheter during the insertion process. The rigid needle engages the abutment in an attempt to prevent the catheter body from collapsing during the insertion process. The hardened tip may comprise a metal, among other materials. Optionally, the tip may comprise a plastic material which softens upon contact with moisture or upon reaching a temperature approximately equal to the patient's body temperature.
[0007] A significant disadvantage of both the prior art through-the-needle and over-the-needle systems is that a sharpened needle must be removed once the catheter has been inserted into the patient. Removal of the sharpened needle undesirably exposes both the patient and the medical practitioner to accidental contact with the needle, a continuing problem in view of the highly contagious and/or fatal nature of such diseases as AIDS and Hepatitis A. Removal of the sharpened needle with the catheter in place also presents the problem of damage to the catheter itself.
[0008] Certain modifications have been made to minimize the possibility of accidental contact of patients or medical practitioners with the needle. One such modification is described in U.S. Pat. No. 5,683,370, issued Nov. 4, 1997 to Luther et al. entitled “Hard Tip Over-The-Needle Catheter and Method of Manufacturing the Same.” The catheter assembly includes an introducing needle which includes a cylindrical protective guard or sheath which is slidably advanced over the sharp tip of the needle after the catheter is inserted and the needle is removed from the patient.
[0009] However, current devices and methods still require some action by the medical practitioner to remove and dispose of a sharpened needle immediately after inserting the catheter. The timing of this procedure presents drawbacks. Often a catheter is inserted at a moment when time is of the essence. For example, the patient may require emergency medical treatment. The risks associated with the removal of such sharp objects therefore could be minimized by waiting until the patient's treatment is concluded, a time which often involves less haste and less risk to adversely affect a patient's health.
[0010] In addition to the above-described drawbacks associated with present catheters, catheters have also exhibited a limited useful lifetime or viability. For example, present intravenous catheters typically need to be removed approximately every forty-eight hours and then a new catheter is inserted into a different area of the passageway to leave the passageway wall intact. Thus, a catheter must be replaced numerous times in even a short hospital stay by a patient which increases the risks of accidental sticks and contamination. Additional drawbacks are present as well. The removal and reinsertion of catheters increases the trauma to the patient's anatomical passageways, e.g. blood vessels. The frequent replacement of catheters during the course of a patient's treatment also increases medical costs, in terms of both time and materials. Accordingly, a catheter would ideally remain in place until the patient's need for treatment with a catheter is completed. Several factors, however, affect how long a catheter may remain viable.
[0011] The principal reason for the need to frequently remove and replace a catheter relates to the trauma it causes to the patient's anatomical passageways such as blood vessels. The trauma may be caused by movement of the patient and/or the portion of the catheter assembly located outside the patient. For example, with regard to an intravenous catheter such external movement is translated to the portion of the catheter located within the patient's vein and causes the catheter to press against the inside wall of the vein. Such pressure may lead to damage to the inner walls of the patient's vein or even internal bleeding. The flexibility of a catheter affects the degree to which it presses against the inside of the vein. Although catheters are generally flexible, they have not heretofore been flexible enough to alleviate the problem associated with a catheter pressing against the inside of a patient's anatomical passageway.
[0012] Another problem associated with catheters relates to undesirable clotting of blood sometimes associated with certain materials of construction. Depending upon the material of construction of the catheter, blood may form clots when it is drawn up into the catheter. One such material which sometimes causes blood to clot is Teflon®. Although the flow of fluids is typically from the catheter into the patient, the flow sometimes reverses. For example, when an instrument is removed from the fluid communication line connected to the catheter, it may result in a small decrease in pressure within the catheter thereby causing fluid to back up into the catheter from the patient's vascular system. When the fluid within the tip of the catheter includes blood it may sometimes clot within the Teflon® catheter. Once flow is returned to normal, the clotted blood may be introduced back into the patient's vascular system. This can lead to various problems. Because the tip of the catheter remains in contact with the blood when the catheter is disposed within a blood vessel, the material of construction of the inner portion of the catheter tip often plays a significant role in the degree of undesirable clotting.
[0013] The needle tip used in connection with the insertion of catheters, whether it be over-the-needle or through-the-needle systems, is typically formed by an oblique angle cut at the end of a hollow tube or cannula. While a needle formed in such a manner is highly effective for insertion, it can sometimes pass entirely through an anatomical passageway such as a blood vessel or can damage the opposing wall of the passageway during the insertion process. The degree to which such deleterious effects can be avoided depends almost entirely on the skill of the medical practitioner performing the insertion. Moreover, when the needle tip is to remain within the passageway for an extended period during treatment, such conventional needle tips may increase the possibility of trauma to the inside surface of the passageway depending upon the particular application. Therefore, a new catheter with a safety inserter is needed by those skilled in the art to increase safety of patients and healthcare workers alike.
SUMMARY OF THE INVENTION
[0014] The present invention provides a catheter comprising a flexible tube with a sharpened needle tip permanently secured to a distal end of the catheter to facilitate insertion of the catheter into a patient's anatomical passageway. The sharpened needle tip secured to the catheter remains within the patient's blood vessel during treatment. As a result, the invention does not require that a separate sharpened needle be inserted with the catheter and then removed immediately after the catheter is properly positioned.
[0015] Another feature of this invention is that it provides a catheter with increased flexibility to minimize trauma to the interior of an anatomical passageway such as a blood vessel, which increases the time period during which the catheter remains viable within the patient, and also increases the length of catheter which can be maintained within the anatomical passageway. The flexibility of the tube allows the needle tip to be flow directed towards the center of the vessel thereby minimizing trauma to the vessel and increasing the time period during which the catheter remains viable.
[0016] An additional advantage of the preferred embodiment of this invention is that it provides a catheter tip formed of a material which minimizes the clotting of blood which may back up into the catheter.
[0017] The preferred embodiment uses a retaining material adjacent the distal end of the flexible tube and extending around a portion of the circumference of the sharpened needle tip to secure the needle tip to the distal end of the catheter. To provide further support to the needle, one or more cavities are advantageously formed in the outer surface of the needle, which are filled with the material of the flexible tube, the retaining material, or both. Additional securement is provided by the melting and mingling of the two plastic materials comprising the flexible tube and retaining material when the needle tip is affixed to the distal end of the catheter.
[0018] A further feature of the preferred catheter assembly apparatus and method is that insertion of the catheter into a blood vessel or the like does not require a separate sharpened inserter to be used with the catheter. The catheter assembly comprises a catheter and a safety inserter. The safety inserter may be removably engaged within the catheter. Preferably, the inserter comprises a base portion and a distal end portion. The proximal end of the safety inserter is sized to accommodate a hydrophilic filter plug and/or a luer tip of a syringe. The distal end portion is sized to fit within the sharpened needle tip. The base portion is sized to fit within the flexible tube and to abut an annular shoulder formed by the proximate edge of the needle tip. Preferably, this inserter has a blunt distal end since the sharpened needle tip secured to the distal end of a flexible tube enables insertion of the catheter into the patient's anatomical passageway such as a blood vessel.
[0019] In accordance with a further aspect of the present invention, the safety inserter has a closed distal end and corresponds to the shape of the needle tip at the distal end of the catheter. Such a catheter is particularly useful as an epidural catheter or a catheter to access implanted ports wherein no flashback is required.
[0020] In accordance with a further aspect, the invention provides a needle tip and method of forming the same wherein the point of the needle tip is substantially aligned with a central axis of the lumen defined by the needle tip or cannula from which it was derived. The improved needle tip minimizes the risk of injury to walls of an anatomical passageway.
[0021] Further features and advantages of the present invention will become apparent to those of skill in the art in view of the detailed description of preferred embodiments which follow, when considered together with the attached claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 is a perspective view of a catheter assembly of the present invention, comprising a safety inserter and a catheter.
[0023] [0023]FIG. 2 is a perspective view of a catheter of the present invention.
[0024] [0024]FIG. 3 is a cross-sectional view of the catheter.
[0025] [0025]FIG. 4 is a perspective view of an alternative embodiment of the distal end of the catheter.
[0026] [0026]FIG. 5 is an enlarged cross-sectional view of the distal end of a catheter of the present invention showing a preferred mechanism for securing the sharpened needle at the distal end of the catheter.
[0027] [0027]FIG. 6 is a cross-sectional view of a safety inserter of the present invention.
[0028] [0028]FIG. 7 is a perspective and an enlarged cross-sectional view of the distal end of the catheter assembly wherein the safety inserter is inserted into the catheter.
[0029] [0029]FIG. 8 is a perspective view of the improved sharpened needle tip of the present invention.
[0030] [0030]FIG. 9 is an enlarged cross-sectional view of the improved sharpened needle tip of the present invention.
[0031] [0031]FIG. 10 is an enlarged cross-sectional view of the distal end of the catheter assembly wherein the safety inserter has a closed distal end.
[0032] [0032]FIG. 11 is an enlarged cross-sectional view of the distal end of the catheter assembly wherein the safety inserter has a closed distal end corresponding to the internal configuration of an epidural needle tip.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] [0033]FIG. 1 depicts the improved catheter assembly 10 of the present invention. The catheter assembly 10 comprises a safety inserter 12 and a catheter 14 .
[0034] Referring to FIGS. 2 and 3, the catheter 14 comprises a flexible tube 16 defining a lumen 18 therethrough. A sharpened needle tip 20 is secured to a distal end of the flexible tube 16 . A hub 22 is formed at a proximal end of the catheter 14 . The hub 22 facilitates connection of the catheter 14 with an administration line (not shown) to provide for the communication of fluids through the catheter 14 , as will be easily understood by those skilled in the art.
[0035] The flexible tube 16 advantageously is preferably formed of a soft thermoplastic material. Preferably, the flexible tube 16 is formed of a material having a hardness value between 50 and 90 Shor A, more preferably between 65 and 85 Shor A, and most preferably approximately 70 Shor A. In a preferred embodiment, the flexible tube 16 is formed of polyurethane. A suitable polyurethane is sold under the tradename Carbothane™ by Thermedics Corporation of Woburn, Mass. and has a hardness value of approximately 70 Shor A.
[0036] The soft flexible tube 16 minimizes the trauma to the internal surface of the anatomical passageway into which the catheter 14 is placed. Thus, movement of the patient and/or the catheter 14 located outside the patient is not substantially translated to movement of the portion of the flexible tube 16 within the patient's anatomical passageway. When the catheter 14 is disposed within an anatomical passageway such as a blood vessel, the flexibility of the tube 16 allows the catheter 14 to be flow directed to the center of the blood vessel, the area of highest velocity flow which is sometimes referred to as the “hemodynamic center” of the vessel. The minimization of trauma to the internal surface of the blood vessel allows the catheter 14 to remain viable for longer periods than heretofore feasible. When used intravenously, the catheter 14 of the present invention may remain viable for a treatment period in excess of seven days, and preferably in excess of ten days. In some instances the catheter 14 may remain viable for two weeks or more. The increased viability of the catheter 14 has many advantages. For example, it decreases the number of times a patient will need to be “stuck” due to the removal and reinsertion of a catheter 14 during the course of treatment. In addition, it minimizes the number of times medical practitioners are exposed to sharp needles and the potential for accidental sticks. It also decreases the cost, in terms of both time and materials, associated with the use of multiple catheters during the course of treatment. The flexibility of the tube 16 also allows for an increased length of tube to be extended within the patient's anatomical passageway as the application may require.
[0037] Flexible tubes containing flexible interwoven wires in the tubular wall such as manufactured by H.V. Technologies of Trenton, Ga. are available. These tubes have the advantage of high strength, high radiopacity and high flow rates because of decreased wall thickness. Walls of only 0.003 inches are possible.
[0038] The size of the flexible tube 16 varies by application. Generally, the outside diameter of the flexible tube 16 will range from approximately 0.02 to 0.08 inches. A flexible tube 16 of a preferred embodiment for intravenous use has an outside diameter of 0.035 inches, a wall thickness of 0.005 inches, and thereby forms a lumen of 0.025 inches in diameter.
[0039] Referring to FIGS. 3, 4 and 5 a sharpened needle tip 20 is secured to a distal end of the flexible tube 16 . In one aspect of the invention the sharpened needle tip 20 is formed by cutting the end off a conventional sharpened cannula. The cannula comprises an elongated tube defining a lumen and having an oblique angled cut to form its sharp end.
[0040] The needle tip 20 therefore has an inner surface 24 defining a lumen 28 . The proximal end of the needle tip 20 forms a short tube 30 (FIG. 3). The distal end of the needle tip 20 has a piercing point 26 .
[0041] Preferably, the sharpened needle tip 20 is formed of a metal. One suitable metal is a 300 Series stainless steel. The needle tip 20 may be a suitable length for the application at issue. Preferably, it is approximately 0.1 to 0.25 inches in length. The outside diameter of the needle tip 20 corresponds to the inside diameter of the flexible tube 16 of the catheter 14 . Preferably, the diameter of the lumen 28 defined by the inner surface of the needle tip 20 is approximately 60-90% of the outside diameter so as to maintain the structural integrity of the needle tip 20 during use.
[0042] At least a portion of the proximal end of the needle tip 20 extends into the distal end 17 of the flexible tube 16 . In a preferred embodiment wherein the needle tip 20 has length of 0.23 inches, approximately 0.13 inches extend within the flexible tube 16 . Referring to FIG. 5, preferably the outer surface 32 of the needle tip 20 is adjacent the inner surface 34 of the flexible tube 16 . The proximal edge of the needle tip 20 forms an annular shoulder 36 within the flexible tube 16 . The lumen 28 of the sharpened needle tip 20 is in fluid communication with the lumen 18 defined by the flexible tube 16 . Preferably, the lumen 28 of the sharpened needle tip 20 is coaxial with the lumen 18 defined by the flexible tube 16 .
[0043] Referring to FIG. 3, the proximal end of the flexible tube 16 is attached to a hub assembly 22 and is in fluid communication therewith. The hub assembly 22 facilitates connection of the catheter 14 to a communication line from which fluids are administered to a patient. Any suitable hub assembly 22 may be utilized as is understood in the art.
[0044] As shown in FIG. 3, in a preferred embodiment, the catheter 14 further comprises a strain relief 38 disposed around the flexible tube 16 . The strain relief 38 facilitates the attachment of the flexible tube 16 to the hub 22 and also provides additional structural integrity to the flexible tube 16 . This is useful if the catheter 14 needs to clamped. For example, after the catheter 14 is inserted into a patient, a hemostasis clip may be applied to prevent the flow of fluids through the catheter 14 while an administration line is connected. By applying the clip to the outer surface of the strain relief 38 , it will close the lumen 18 of the flexible tube 16 without creating the risk of damaging the flexible tube 16 which is in fluid communication with the patient's anatomical passageway. In a preferred embodiment, the flexible tube 16 and strain relief 38 are fixed within a hub 22 . Alternatively, they can be fixed to an outer surface of a hub 22 or other apparatus so long as fluid communication is maintained through the catheter 14 and hub 22 .
[0045] Referring to FIGS. 1 and 6, the safety inserter 12 of the catheter assembly 10 comprises a base 40 , a body portion 42 and a distal portion 44 . In a preferred embodiment, the base 40 facilitates handling of the catheter assembly 10 during insertion of the catheter 14 and subsequent removal of the inserter 12 . The base 40 therefore preferably includes a surface 43 for gripping during the insertion and removal process. The base 40 further defines a flashback chamber 46 , which can also be configured to accommodate a luer. As shown in FIG. 1, a hydrophilic plug 11 is inserted into the flashback chamber which facilitates venting of air from the flashback chamber 46 while also preventing leakage of blood or fluids therefrom. The base 40 of the inserter is adapted to engage the hub 22 of the catheter 14 . In a preferred embodiment, the base 40 forms a friction fit with the hub 22 .
[0046] Referring to FIGS. 6 and 7, the body portion 42 of the safety inserter 12 is sized to fit within the lumen 18 of flexible tube 16 of the catheter 14 , but not within the lumen 28 formed by the sharpened needle tip 20 . The distal end portion 44 of the safety inserter 12 is sized to fit within the lumen 28 formed by the sharpened needle tip 20 of the catheter 14 . The distal edge 47 of the distal end portion 44 of the inserter 12 need not be sharp, and is preferably blunt to avoid the possibility of damage to the catheter 14 or the risk of needle stick injuries.
[0047] In a preferred embodiment, the body portion 42 of the safety inserter 12 is formed by a cannula 48 having an outside diameter corresponding to the diameter of the lumen 18 defined by the flexible tube 16 of the catheter 14 . A smaller cannula 50 is fixed within the larger cannula 48 . The small cannula 50 extends out from a distal end of the large cannula 48 to form the distal end portion 44 of the safety inserter 12 . The outside diameter of the smaller cannula 50 corresponds to the inside diameter of the sharpened needle tip 20 and the inside diameter of cannula 48 . Alternatively, the safety inserter 12 may be manufactured as a unitary piece. When the safety inserter 12 is engaged within the catheter 14 , the distal edge 53 of the large cannula abuts the annular shoulder 36 formed at the proximal edge of the sharpened needle tip 20 . In a preferred embodiment, the sharpened needle tip 20 is formed by cutting the sharp end off a sharpened cannula 48 . The remaining cannula is then used as the large cannula 48 of the safety inserter 12 . This assures that the needle tip 20 and large cannula 48 are properly sized.
[0048] The lumen 49 defined by the large and small cannulas 48 , 50 may be in communication with the flashback chamber 46 of the base 40 . In one embodiment, the small cannula 50 extends into the flashback chamber 46 ; however, the cannula 50 may terminate distal the flashback chamber 46 as will be easily understood.
[0049] The sharpened needle tip 20 may be secured to the flexible tube 16 in any suitable manner. A particularly effective means of attachment comprises the use of a radio frequency (RF) welder. Application of the RF energy heats the flexible tube 16 material of the catheter 14 and causes it to adhere to the sharpened needle tip 20 . Additionally, it causes the simultaneous melting and some commingling of the two plastic materials forming the flexible tube 16 and retaining material 52 to further promote the securement of the needle tip 20 .
[0050] In a preferred embodiment, the catheter 14 , as shown in FIG. 5, further comprises a retaining material 52 adjacent the distal end of the flexible tube 16 and disposed around at least a portion of the outer surface of the needle tip 20 . Preferably, the retaining material 52 forms an annular ring surrounding the outer circumference of the needle tip 20 . A mandrel (not shown) is preferably placed within the flexible tube 16 and the needle tip 20 during the attachment process. Alternatively, a safety inserter 12 of the present invention can be used for this purpose. The retaining material 52 and a portion of the flexible tube 16 are then heated with the RF welder. Pressure may also be applied to the outer surface of the flexible tube 16 and the retaining material 52 . The retaining material 52 adheres to the needle tip 20 and tube 16 during the welding process. Likewise, the tube 16 adheres to the needle tip 20 during welding.
[0051] The retaining material 52 preferably comprises a plastic having a hardness greater than the material forming the flexible tube 16 . Preferably the retaining material is a polyurethane. In one preferred embodiment the retaining material is a polyurethane having a hardness value of approximately 99 Shor A. The retaining material may, of course, be of any other hardness.
[0052] In another aspect of the invention, a first set of one or more cavities 54 a, b are formed in the outer surface 32 the needle tip 20 . The cavities 54 a, b extend from the outer surface 32 of the needle tip 20 toward the inner surface 24 . Preferably, the cavities extend from the outer surface 32 to the inner surface 24 forming a hole through the outer circumference of the needle tip 20 . During the attachment process, the needle tip 20 is positioned within the distal end of the flexible tube 16 with the first set of one or more cavities 54 a, b located distal the end of the flexible tube 16 . The retaining material 52 is formed in an annular shape around the circumference of a portion of the needle tip 20 extending beyond the flexible tube 16 and covering the holes 54 a,b . A mandrel is placed within the flexible tube 16 and needle tip 20 . The retaining material 52 is heated with the RF welder. In its molten state the retaining material 52 fills the first set of one or more cavities 54 a, b to further secure the needle tip 20 to the flexible tube 16 . In addition, the retaining material 52 adheres to the tube 16 .
[0053] In another aspect of the invention, a second set of one or more cavities are formed in the outer surface 32 of the needle tip 20 . Preferably, the cavities 56 a, b extend from the outer surface 32 to the inner surface 24 forming a hole through the outer circumference of the needle. Alternatively, the cavities may be indentations that do not extend through the needle tip 20 . During the attachment process, the needle tip 20 is positioned within the distal end of the flexible tube 16 with the first set of one or more attachment cavities 54 a, b located beyond the end of the flexible tube 16 , and the second set of one or more attachment cavities 56 a, b located within the lumen 18 defined by flexible tube 16 . The retaining material 52 is formed in an annular ring around the circumference of the needle tip 20 as described above. Another advantage of the invention is the harder (99 Shor A) material can be formed to eliminate any transition shoulder between the point of the needle tip 20 and the flexible tube 16 thereby minimizing trauma during insertion. An RF welder is applied to the retaining material 52 and flexible tube 16 as described above. The first set of one or more cavities 54 a, b is filled with the retaining material 52 . The material of the flexible tube 16 fills the second set of one or more cavities 56 a, b.
[0054] The cavities 54 , 56 can be any suitable size, depending upon the size of the needle tip 20 and the corresponding flexible tube 16 . In a preferred embodiment the cavities 54 , 56 form holes in the needle tip 20 having a diameter of 0.005 inches. A sufficient number of holes may be used, but not so many that would interfere with the structural integrity of the needle tip 20 . In a preferred embodiment of the invention, the first and second sets of cavities 54 , 56 each comprise two holes. It should be understood that the tube 16 retaining material 52 and needle tip 20 may be adhered without the use of holes or indents. Moreover, the tube 16 may be adhered to the needle tip 20 without the use of a retaining material 52 as will be understood by those skilled in the art. For example, the tube 16 may be RF bonded directly to the needle tip 20 and the distal end 17 of the tube may be sloped toward the needle tip 20 in the bonding process to eliminate a shoulder which may harm a vessel wall upon insertion of the catheter 14 in a passageway of a patient.
[0055] Of course, the needle tip 20 may be provided with external projections which communicate with indents or holes in the flexible tube 16 and/or retaining material 52 to add in securing the tip 20 to the tube 16 and/or material 52 as will be easily understood by those of skill in the art.
[0056] [0056]FIGS. 8 and 9 illustrate another embodiment of the invention wherein an improved needle tip 58 has been adapted to minimize trauma to the interior of the anatomical passageway in which it is inserted. The conventional needle tip 20 shown, for example, in FIG. 5 has a piercing point 26 at its most distal end. The piercing point 26 is aligned with the outer surface 32 of the short tube 30 forming the proximal end of the needle. In the embodiment wherein the needle tip 20 is formed by cutting an end off a sharpened cannula, the point 26 is in a place defined by a portion of the wall of the cannula. The improved needle tip 58 of this further aspect of the invention has a piercing point 60 substantially aligned with a central axis 62 of the lumen 64 . Preferably, the improved needle tip 58 is formed by bending a conventional needle tip 20 so that the piercing point 60 of the needle tip 58 is so aligned. Alternatively, the needle can be manufactured in the desired configuration. By providing the needle point 60 substantially along the central axis 62 of the lumen 64 of the needle tip 58 , the risk of the needle tip 58 piercing the opposing wall of a passageway or vessel of a patient is significantly reduced, both during the insertion process and while the catheter 14 is disposed within a patient's anatomical passageway. In practice, a healthcare worker sometimes inserts a standard needle tip 20 too far, so that it enters the vessel and then pierces the opposing wall of the vessel. Upon withdrawal of the needle tip, internal bleeding occurs. By placing the point 60 along the central axis 62 , the risk of piercing the opposite vessel wall is significantly reduced because the catheter is typically inserted into the vessel at an acute angle to the longitudinal axis of the vessel, as will be easily understood by those of skill in the art. Similarly, the point 60 of needle tip 58 will naturally be less likely to contact the inside wall of an anatomical passageway in which it is disposed thereby reducing the risk of trauma to the patient.
[0057] Having thus described the construction of certain preferred embodiments of the apparatus of the present invention and the associated method of making the same, a preferred treatment method utilizing the apparatus of the invention is described. The safety inserter 12 is initially placed within the catheter 14 . The distal end portion 44 of the safety inserter 12 extends within the lumen 28 defined by the needle (FIG. 7). The distal edge 47 of the distal end portion 44 extends sufficiently far into the needle tip 20 to provide support during insertion but not so far that the blunt end 47 of the inserter will interfere with the piercing point 26 of the needle tip 20 . The body portion 42 of the inserter extends within the flexible tube 16 of the catheter 14 . The distal edge 53 of the outer cannula 48 forming the base portion 42 preferably abuts the proximal edge 36 of the needle tip 20 to allow the practitioner to urge the catheter 14 into a patient's anatomical passageway by applying force to the inserter 12 , which is translated to the needle tip 20 . In one preferred application the catheter 14 is urged into a patient's vein to provide intravenous treatment to the patient.
[0058] Once the catheter 14 is properly placed within the patient's anatomical passageway, a homeostasis clip or suitable device is applied to close the flexible tube 16 . Preferably the clip is applied to the strain relief 38 . The catheter 14 is held in place while the inserter 12 is removed. The blunt inserter 12 is eventually discarded. The hub 22 of the catheter 14 may then be connected to a fluid communication line such as a standard administration set. The catheter 14 , including the sharpened needle tip 20 , remains disposed within the patient's anatomical passageway. Fluid communication is established through the catheter 14 wherein fluids are infused into or withdrawn from the patient by removal of the clip. Preferably, the catheter 14 remains in place during the entire period in which the patient is treated with a catheter 14 . Thereafter, the catheter 14 is removed. Because the sharpened needle tip 20 is disposed at the end of a flexible tube 16 as opposed to a rigid cannula as in prior art inserters, the risk of accidental sticks is minimized. Furthermore, because the catheter 14 is often removed at the conclusion of treatment, there is typically a lesser degree of haste involved, thereby allowing the medical practitioner to more easily exercise the proper degree of care in removing and discarding the needle tip 20 .
[0059] [0059]FIGS. 10 and 11 illustrate further aspects of the invention, which are particularly useful for applications which do not require a flashback. These include epidural catheters and catheters used to access implanted ports such as described in U.S. Pat. No. 5,403,283 issued on Apr. 4, 1995 to Luther and entitled “Percutaneous Port Catheter Assembly and Method of Use”. The inserters 61 and 63 do not include a lumen through their length and preferably are closed at their distal end. This aspect of the invention is particularly suitable for epidural catheters since the catheter is ideally formed so as not to introduce tissue into the epidural space. An open lumen at the distal end of the catheter 14 may cause tissue to be carried into the epidural space during the insertion process.
[0060] Referring to FIG. 10, the inserter 61 is sized to fit within the lumen 18 defined by the flexible tube 16 and the lumen 28 formed by the sharpened needle tip 20 . The distal end 62 of the inserter 61 preferably corresponds roughly to the shape of the needle tip 20 . The distal end 62 of the inserter is preferably blunt to prevent the inserter 61 from piercing or penetrating the skin of a person. The end of the inserter may be sand-blasted to provide the dull or blunted distal end 62 .
[0061] [0061]FIG. 11 illustrates an embodiment that is particularly suitable for use in epidural applications. The needle tip 65 has a distal end 69 configured in the Toughy or Hustead configuration of conventional epidural needle points. The insert 63 corresponds roughly to the shape of the needle tip 65 , and is preferably dulled or blunted at its distal end 68 .
[0062] Although the present invention has been described in terms of certain preferred embodiments, other embodiments of the invention will become apparent to those of skill in the art in view of the disclosure herein. Accordingly, the scope of the present invention is not intended to be limited by the foregoing, but rather by reference to the attached claims. | Disclosed is a catheter having a flexible tube and a sharpened needle secured to the catheter at its distal end. The catheter does not require a separate sharpened instrument to enable insertion into an anatomical passageway. The sharpened needle of the catheter remains disposed within an anatomical passageway during treatment. Also disclosed is a catheter assembly comprising the catheter and a safety inserter. The safety inserter has a blunt end and facilitates the insertion of the catheter by providing a mechanism to urge the sharpened needle of the catheter into an anatomical passageway. Also disclosed is an improved needle tip which minimizes trauma to an anatomical passageway. Also disclosed are methods of using and forming the catheter, catheter assembly and needle tip. | 0 |
This is a continuation of U.S. patent application Ser. No. 08/951,352, filed Oct. 16, 1997 now U.S. Pat. No. 5,921,575.
BACKGROUND OF THE INVENTION
The invention relates to an airbag device for a motor vehicle.
A wide variety of designs of airbag devices have been disclosed and they offer effective protection of a vehicle occupant in the event of a traffic accident.
SUMMARY OF THE INVENTION
The invention is based on the object of providing a preassembled, modular, active head protection (airbag) system for motor vehicles.
To achieve this object, the invention proposes an airbag device for a motor vehicle, having an airbag which consists of an inflatable gas cushion, a gas generator for filling the airbag, a gas conduction pipe which extends through a separated region of the airbag, outlet openings in the gas conduction pipe, a profile strip with a shooting channel formed therein, in which the airbag laid in stacked folds is received in addition to the gas conduction pipe, and attachment elements for holding the construction unit comprising the profile strip, airbag and gas conduction pipe.
The profile strip with the airbag and gas conduction pipe can advantageously extend in each case along one side of the vehicle from the A-pillar to the C-pillar and be arranged on the vehicle body, in the transition region from the vehicle roof and one side wall of the vehicle.
The profile strip which receives the gas conduction pipe and the airbag within the shooting channel may be a component which is simple in terms of production and, in particular, is also cost-effective, and it preferably has an essentially U-shaped cross-section with two limbs and a bar which connects them together. In this case, the bar is expediently adapted to the shape of the gas conduction pipe which is supported thereon.
The profile strip may be made as an extruded or injection-molded plastic part, and it preferably consists of a thermoplastic, such as PP, PP-EPDM, TPE or PVC.
A particularly expedient further development of the invention consists in the fact that the profile strip is reinforced by an incorporated structure band consisting of metal, such as steel or aluminum. The airbag device can thus be used throughout the entire temperature range (-40° C.-+120° C.) required by users, since the mechanical properties are essentially determined by the metal structure band.
A further refinement of the invention provides for the limbs of the profile strip to diverge before the airbag and gas conduction pipe are introduced into the profile opening forming the shooting channel, and for the limbs of the profile strip to be aligned approximately parallel to one another after the airbag and gas conduction pipe have been introduced. The initially diverging limbs make assembly easier, that is to say mainly the introduction of the gas conduction pipe and the airbag into the shooting channel, and can be moved without difficulty into the desired alignment, such as a parallel position, by means of simple auxiliary equipment belonging to the prior art.
Particular advantages of the invention can be seen in the fact that the unfolding direction of the airbag is defined by the shooting channel, that there is linear support of the airbag during the unfolding operation and thus uniform unfolding, and that the installation site of the profile strip is freely selectable, since the natural rigidity of the airbag device can be varied within broad limits by the choice of material and the material combination for the profile strip.
Furthermore, the restraint, i.e. the resistance that the airbag has to overcome during unfolding, can be varied within broad limits, specifically by the structure band incorporated in the profile strip, by the angle between the flanks (profile limbs) and furthermore by the fact that the profile strip has means for closing the profile opening or the shooting channel. For this purpose, provision may be made for the profile strip to have a continuous closure lip, on the opening side, which may, in particular, also have a continuous tear-open seam formed, for example, by a perforation. The closure lip is advantageously formed on along an edge at a free end of the limb of the profile strip and, with the other edge, forms a joint with the second limb of the profile strip, in which case the joint may be a clip, welded, bonded or sewn joint.
Restraint of the airbag can also be achieved in that a shrink tube is arranged around the gas conduction pipe and the folded airbag, which tube has a defined tear-open seam which coincides with the orifice of the shooting channel.
A further expedient refinement of the invention provides for the limbs of the profile strip to have beads or the like which can be overcome by the gas conduction pipe during assembly to secure the gas conduction pipe in its position.
The gas conduction pipe and the profile strip should have a configuration which follows the contour of the body, which can be realized by the gas conduction pipe and, if appropriate, also the profile strip being designed in a curve, such as an elongated curve. During the bending of the profile strip, attention must be paid to the fact that its opening cross-section remains unchanged over the total axial extent.
The fastening elements for the airbag device expediently comprise simple clips which can be preassembled on the profile strip or on the body, are arranged adjacently in rows, and should be made of plastic or preferably of metal, such as spring plate.
It is important for the folded airbag to have a band securement which defines the span line for the unfolded airbag.
An exemplary embodiment of the invention is explained in greater detail below with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an exploded perspective view of an airbag device with a vehicle body.
FIG. 2 depicts a cross-sectional view of the air bag device and vehicle body following the line A--A in FIG. 1.
FIG. 3 depicts a cross-sectional view through the airbag device according to a first embodiment.
FIG. 4 depicts a cross-sectional view through the airbag device according to a second embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the Figures, the novel airbag device is a head protection module which is denoted by the reference numeral 1 and is to be arranged in the transition region from the vehicle roof to each side wall of the vehicle in a manner which can be seen in FIGS. 1 and 2. The head protection module comprises a gas generator 2, an adaptor 3 to produce a connection between the gas generator 2 and a gas conduction pipe 4, a folded airbag 5 and a profile strip 13 made with a shooting channel 6. The airbag device extends from the A-pillar 14 (instrument panel region) up to the C-pillar 15 and is adapted to the course of the body. The airbag device is to be attached to the vehicle body by means of clips 7, in which case the clips 7, which may be made of spring plate, can be preassembled on the body or on the airbag device. Holding/spanning bands 8 define a span line 12.
For reasons of completeness, FIG. 1 illustrates a modified pillar cladding 9 for the A-pillar 14, a modified pillar cladding 9 for the C-pillar, a B-pillar cladding 10 and a shaped roof 11.
FIG. 3 shows a cross-section of the airbag device and demonstrates that the shooting channel 6 is made in a profile strip 13 which has a U-shaped cross-section with two limbs and a bar which connects them together. The profile strip expediently consists of a thermoplastic material and is made by injection-molding or extrusion methods. An incorporated structure band 16 gives the profile strip 13 sufficient rigidity to meet the technical requirements. The gas conduction pipe 4 and the airbag 5 stacked in folds are received inside the shooting channel 6. The gas conduction pipe 4 is seated in a separate region of the airbag which may be formed by sewing. Outlet openings (not shown) in the gas conduction pipe 4 are directed towards the folded airbag in order to unfold it or rapidly inflate it when it is required.
Inside the shooting channel 6, the limbs of the profile strip 13 have beads 17 which narrow the shooting channel 6. The beads 17 can easily be overcome by the gas conduction pipe 4 when the latter is introduced, but they then secure its position inside the shooting channel 6.
In the exemplary embodiment according to FIG. 3, the shooting channel 6 is designed to be open. In contrast, the airbag 5 laid in folds is enclosed by a shrink tube 18 which has a tear-open seam 19 in the region of the orifice of the shooting channel. The tear-open seam 19 is designed in such a way that it opens at a specific pressure of the filling gas, and the airbag 5 can unfold into the vehicle interior.
In the exemplary embodiment according to FIG. 4, the difference compared to that of FIG. 3 consists essentially in the fact that the shooting channel 6 is closed by a closure lip 20, and the airbag 5 is not surrounded by a shrink tube 18. In this case, the closure lip 20 thus exerts a restraining effect on the filling gas generated. At a specific pressure of the filling gas, the closure lip 20 can open, for example along a tear-open seam 21 formed therein.
The closure lip 20 may be formed at an edge at a free end 22 of one limb on the profile strip 13, e.g. in the manner of a film hinge, and at an edge at a free end 23 of the other limb form a joint, e.g. a clip joint, with the profile strip 13. This joint may be a clip, welded, bonded or sewn.
FIG. 2 illustrates the arrangement of the novel airbag device in a vehicle and the alignment of the shooting channel 6 which permits the airbag to unfold into a position which provides a head protection for a vehicle occupant. In the intended and illustrated airbag device, the inflated airbag comes into effect between the head of a vehicle occupant and the side window of a vehicle which is adjacent to him/her, so that the head of the vehicle occupant cannot impact either against the side window or against hard regions of the frame of the body.
As shown in FIG. 2, the airbag device can be covered by the shaped roof 11, an intended bending point 24 in the shaped roof 11 ensuring that an edge region 25 instantly exposes the shooting channel 6 when the airbag unfolds.
A sequence of assembly is explained briefly below.
EXAMPLE 1
Produce the airbag by sewing a cushion with a sewn section to provide an insertion tunnel for the gas filling pipe.
Fold the airbag in an extended position.
Secure the folds with shrink tubing, in which case the film is to be provided with a tear-open seam.
Bend the gas conduction pipe according to the contour/body (elongated bending) and punch out outlet openings (preferably) in the bending device.
Insert the bent gas conduction pipe into the airbag/shrink tube unit.
Produce an infinitely extruded profile strip, cut it to the desired length and, if necessary, bend it to the contour of the body (elongated bending).
Introduce the preassembled unit (gas conduction pipe, airbag, shrink tube) into the shooting channel of the profile strip and position undercuts around the gas conduction pipe by a rolling operation, simultaneously aligning the profile limbs as required.
Attach the gas generator to the gas conduction pipe using the adaptor.
Insert the module into clamping clips (on the body).
Fix and secure the module to the gas generator fastening and to the projecting gas conduction pipe on the body using screws.
EXAMPLE 2
Produce the airbag by sewing a cushion with a sewn section to provide an insertion tunnel for the gas filling pipe.
Fold the airbag in an extended position.
Secure the folds at some points using bands.
Bend the gas conduction pipe according to the contour/body (elongated bending) and punch out outlet openings (preferably) in the bending device.
Insert the bent gas conduction pipe into the airbag/band securement.
Produce an infinitely extruded profile strip with a closure lip, cut it to the desired length and, if necessary, bend it to the contour of the body (elongated bending).
Introduce the preassembled unit (gas conduction pipe, airbag) into the shooting channel of the profile strip and position undercuts around the gas conduction pipe by a rolling operation, with simultaneous rolled alignment of the profile limbs.
Clip the closure lip into the undercut.
Attach the gas generator to the gas conduction pipe using the adaptor.
Insert the module into clamping clips (on the body).
Fix and secure the module to the gas generator fastening and to the projecting gas conduction pipe on the body using screws.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims. | An airbag device for a vehicle is described, which has an airbag consisting of an inflatable gas cushion, a gas generator for filling the airbag, a gas conduction pipe which extends through a separated region of the airbag, outlet openings in the gas conduction pipe, a profile strip with a shooting channel formed therein, in which the airbag laid in stacked folds is received in addition to the gas conduction pipe and attachment elements for holding the construction unit comprising the profile strip, airbag and gas conduction pipe. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
Not Applicable.
Statements Regarding Federally Sponsored Research or Development
Not Applicable.
Reference to a Microfiche Appendix
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to fired heaters, also known as process furnaces, and more specifically to fired heaters used in processing hydrocarbons.
2. Description of the Related Art
Typical fired heaters are designed to heat hydrocarbons. Numerous processes on hydrocarbons are carried out in furnaces commonly known as fired heaters, or process furnaces, or fired heater furnaces, pipe stills.
Fired heaters are equipment in which fluid is heated to high temperatures by burning fuel gas or fuel oil in a combustion chamber. The tubes carrying the fluid are located in the center or on sides in the combustion chamber. The combustion chamber is lined with refractory material. The hot flue gases in the vicinity of the burners transmit heat to the fluid feed primarily by radiant heat transfer mechanism. This part of the heater is known as the radiant section or firebox section. The flue gases leaving the radiant section are typically at 1400–1800° F. and more heat can be recovered from these gases. Additional heat is recovered in the convection section where the flue gases are cooled by exchanging the heat with the fluid. In heaters, fluid generally enters the convection section first and then flows through the radiant section to maximize the heat recovery. In some heaters, process fluid enters through the radiant section and leaves through the radiant section. In these heaters, heat in the convection section is recovered by generating steam or preheating other hydrocarbon services. Flue gases are disposed off to the atmosphere through a stack.
Most refineries possess catalytic reforming units. In these catalytic reforming units, a hydrocarbon, for example, light petroleum distillate (naphtha) is contacted with platinum catalyst at elevated temperature and pressure. This process produces high-octane liquid product that is rich in aromatic compounds. The process upgrades low octane number straight run naphtha to high-octane motor fuels. In a typical unit, the feed to the unit is mixed with recycle hydrogen gas and it is heated first in heat exchangers and then in a fired heater. The feed is then sent to a reactor. Most reactions that occur in the reactor are endothermic reactions and occur in stages. The reactors are separated into several stages. Inter stage heaters may be installed between the reaction stages to maintain the desired temperature of the hydrocarbon feed.
Refineries have been de-bottlenecking their units to improve the fired heater capacity and improve thermal efficiency of the system. FIG. 1 illustrates the commonly practiced concept of the technique (prior art) used for heating the feed. A typical existing unit 100 comprises a convection section 120 and a radiant section 150 . The feed is first sent to the convection section 120 through a plurality of fluid passes 122 , 124 , 126 , 128 , and 130 , comprising fluid oath 135 for example. The preheated fluid then enters the radiant section 150 where it is heated further and the fluid exits through a fluid exit path 140 . The fluid exiting the fluid path 140 may then be further passed through a series of concatenated fired heaters similar to the fired heater system 100 .
Alternatively, the fluid may be introduced directly into the radiant section or in the convection section. Typically, when the fluid is directly introduced in the radiant section, a significant a mount of heat energy remains in the flue gases. A portion of this remaining energy may be recovered in the convection section by generating steam, preheating combustion air, or preheating other streams. Often times the refiners do not need the steam and they do not have other attractive choices.
In such fired u nits, the feed consists of hydrocarbon vapors and recycle hydrogen gas. The feed in vapor form has a very large volume and pressure drop across the heater is very important. Low-pressure drop minimizes recycle gas compressor differential pressure and the necessary compressor horsepower. The result is lower utility consumption. Low-pressure drop also permits operation at lowest reactor pressure. As a result, the heaters are designed as all radiant heaters with large manifolds at the inlets and outlets. Convection sections are typically used for steam generation or other waste heat recovery operations. Often times, the byproducts of waste heat recovery are not needed, and the heat is discharged in to the atmosphere.
BRIEF SUMMARY OF THE INVENTION
Exemplary techniques for heating hydrocarbon fluids in fired heaters are illustrated in which the fluid is divided into at least two fluid paths. The fluid in the first path is heated by predominantly one heat transfer mechanism and the fluid in the second path is heated by predominantly a second heat transfer mechanism. Thus, effectively, the technique provides for parallel heat transfer paths.
A fired heater furnace is adapted for processing hydrocarbons fluids such that the fluid path is divided into a plurality of paths. The fluid in each path is heated by predominantly different heat transfer mechanisms. After heating the fluids in different heating paths, the fluids are combined. The combined fluid may again be heated in a furnace coupled to the first furnace. Alternately, the combined fluid may be processed in a reactor and then sent to another furnace for heating.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
A better understanding of the present invention can be obtained when the following detailed description of some embodiments is considered in conjunction with the following drawings in which:
FIG. 1 is a conceptual block diagram of typical heating of hydrocarbon fluids in a furnace (prior art).
FIG. 2 is a conceptual block diagram of heating of hydrocarbon fluids in a furnace according to the invention.
FIG. 3 is a diagram depicting a typical example system of heating of hydrocarbon fluids in a furnace (prior art) of FIG. 1 .
FIG. 4 is a diagram showing an exemplary embodiment according to the invention of FIG. 2 showing division of the fluid flow and heating thereof.
DETAILED DESCRIPTION OF THE INVENTION
As noted above, what the refiners and fired heater owners need is improved recovery of the thermal energy so that the waste energy can be used without being restricted to aforementioned choices. It would be preferable to utilize the waste thermal energy to increase production capacity of the unit rather than heat auxiliary products or discharge that energy to the atmosphere when heating the auxiliary products is not desired. Increasing production by improved utilization of the waste energy also contributes to the quality of environment in that efficient utilization of energy leads to reduced environmental energy discharge. Techniques and apparatus disclosed herein achieve that aim by increasing production capacity with significantly lower increase in capital cost and provide techniques of efficiently utilizing the energy produced in the fired heaters to increase the output.
With reference to FIG. 2 , is a conceptual block diagram of heating of hydrocarbon fluids in a furnace 200 according to the invention. A fluid feed line 235 is divided into a first group of fluid passes 222 , and a second group of fluid passes 224 , 226 , 228 , and 230 , for example. The feed fluid through fluid passes 222 , and 224 is heated in the convection section 210 , and the feed fluid through fluid passes 224 , 226 , 228 , and 230 is heated in the radiation section 250 . The processed fluids are then recombined in the fluid outlet 240 . The feed fluid corning out from the fluid outlet 240 may then again be sent through a next fired furnace similar to the furnace 200 , and so on until desired products are obtained, or yet another process may need to be performed on the hydrocarbon fluid. Division of fluids into a number of flow paths is well within the skill of those practicing the art.
With reference to FIG. 3 is a diagram depicting a typical example system of heating of hydrocarbon fluids in a furnace (prior art) of FIG. 1 . The fired heater 300 as shown has a fired furnace 310 fluidically coupled to a similar fired furnace 310 where output of the furnace 310 is fed as input to the furnace 410 . In this manner, a plurality of furnaces may be cascaded to process the hydrocarbon fluids. There may be further processing of the fluid before it is sent from one furnace to the next furnace. The furnace 310 roughly comprises of two sections from the perspective of thermal energy delivery to the input fluids: a radiant (or radiation) section 315 , a convection section 320 , and a stack section 325 for exhaust of unusable waste energy. The furnace 310 has at least one or more burners 380 . The hydrocarbon fluid enters the furnace 310 through path 338 . The fluid pressure and temperature are monitored at nodes 340 , 350 , 370 and 375 . There may be an optional manifold valve 375 to control the flow of the hydrocarbon fluids. When the fluid enters through the node 340 , it is first heated in the convection section 320 , and then heated in the radiant section 315 . The fluid heated in the radiant section then exits through the nodes 370 and 365 for further processing as desired.
Following TABLE I shows the pressure and temperature at the input node 340 and output node 365 of an example furnace of the conventional design, with a flow rate of 333,890 Lb/Hr. The TABLE I is further discussed below in the context of the invention to demonstrate the effect of implementing the invention.
TABLE I
Process
Node
Node
S.N.
Conditions
Units
340
365
1
Flow rate
Lb/hr
333,890
333,890
2
Opr. Temp.
° F.
785
985
3
Opr. Pres.
Psi
178.2
174.0
Now referring to FIG. 4 , a diagram of an exemplary embodiment of fired heaters 500 according to the invention of FIG. 2 is shown. The fired heater 500 as shown has a fired furnace 510 fluidically coupled to a similar fired furnace 610 where output of the furnace 510 is fed as input to the furnace 610 . In this manner, a plurality of furnaces may be cascaded to process the hydrocarbon fluids. The fluid heated in the furnace 510 may be processed in a reactor 567 to perform chemical reactions or other desired processing and then sent to furnace 610 for further heating. Since furnaces 510 and 610 are substantially alike, it would suffice to illustrate the technique and apparatus of the invention with reference to furnace 510 .
Again, referring to FIG. 4 , the furnace 510 roughly comprises of two sections from the perspective of thermal energy delivery to the input fluids: a radiant (or radiation) section 515 , a convection section 520 , and a stack section 525 for exhaust of unusable waste energy. The furnace 510 has at least one or more burners 580 . An input hydrocarbon fluid path 538 is divided into at least two fluid paths, a first fluid path 530 , and a second fluid path 535 . In general, each of the fluid paths comprises a plurality of fluid passes. The fluid going into the first fluid path 530 is heated predominantly by radiation heat transfer mechanism. Since the fluid in the first fluid path 530 traverses in fluid passes which are in closer proximity of the burners 580 , the heat transfer mechanism is predominantly by radiation and to a secondary extent, the heat transfer mechanism is convection. It is estimated that various fluid passes in the radiation section 515 receive heat energy somewhere between 80–85% through the radiation heat transfer mechanism and remaining energy by the convection heat transfer mechanism. Likewise, it is estimated that various fluid passes in the convection section 520 receive heat energy somewhere between 80–85% through convection heat transfer mechanism and the remaining energy through the radiation heat transfer mechanism. Thus, the nomenclature of naming the sections of the furnaces should be understood to mean as involving the dominant heat transfer mechanism in those sections resulting from the proximity to the burners 580 . The estimated percentages may vary significantly in installation to installation due to their geometry and construction materials employed therein.
Referring to FIG. 4 again, a certain fluid pressure at an input node 540 is maintained. The input fluid is divided by means of a divider 555 such that a reasonable fluid pressure differential between a node 550 and a node 560 is maintained. The fluid flow divider 555 may be a manifold, a fixed size orifice, or a manually controllable valve, or an automatically controllable valve that can maintain or control a pressure differential between the node 550 and the node 560 . Those skilled in the art may employ numerous other alternatives to maintain such pressure differential. As may be noted the fluid passing through the first path 530 is heated in the radiation section 515 , and the fluid passing through the second path 535 is heated in the convection section 520 . The fluids after being heated in the radiation section 515 and the convection section 520 are again combined in a manifold 575 for further heat treating and may be sent to another furnace 610 coupled to the furnace 510 . The process may be carried out in as many stages as required according to the need of the chemical reaction or the desired product. Table II shows the pressure levels at nodes 540 , 545 , 550 (input side nodes) and nodes 560 , 565 , 570 (output side nodes) of an exemplary implementation of the technique utilized in the apparatus illustrated herein.
TABLE II
Process
Node
Node
Node
Node
Node
Node
S.N.
conditions
Units
540
550
570
545
560
565
1
Flow rate
Lb/hr
333,890
258,970
258,970
74,920
74,920
333,890
2
Opr. Temp.
° F.
785
785
985
785
985
985
3
Opr. Pres.
Psi
178.1
178.1
175.7
178.1
175.7
175.7
Note that the pressure differential between the input side nodes ( 540 , 545 , and 550 ) and the output side nodes ( 560 , 565 , and 570 ) in the exemplary system is merely 2.4 psi. This low-pressure differential attained through the illustrated technique reduces power consumption used in the compressors and thus the size of the compressors may be accordingly reduced to maintain the same fluid flow. Lower pressure differential also permits the reactor operation at lower pressure. The advantageous lower pressure operation may also be utilized in designing relative sizes of the radiant section and the convection section to further optimize performance of a fired heater.
Now referring to Table I and Table II, it can be seen that the fluid pressure drop from the input node 340 to the output node 365 for the conventional fired heater system 300 is 4.2 psi. The corresponding pressure drop from the input node 540 to the output node 565 for the fired heater system of the exemplary illustrated system is mere 2.4 psi, i.e., input to output side pressure drop of the conventional system in this example is about 75% higher than the exemplary system.
Note that the higher pressure drop of the conventional design limits the performance of pumps and compressors and consumes substantial amount of energy. The performance of heaters illustrated in both cases is determined by performing simulations using a widely used computer program known as “DIRECT FIRED HEATERS FNRC-5” developed by PFR Engineering Systems, Inc. of Los Angeles, Calif.
Another major advantage of the technique and the apparatus illustrated herein is the reduction in initial cost resulting due to savings in the required external piping. In the conventional design, the full size inlet manifold and piping needs to be relocated to the convection section. In the illustrated technique, the apparatus, and the system, the size of manifold and piping is substantially reduced.
The techniques and the illustrated apparatus may be used to heat any kind of hydrocarbons fluid with proper adjustment of the size of the apparatus whether for production or development in the laboratories. Such adjustments in the size and routine fabrication details are within the skills of those practicing the art.
The foregoing disclosure and description of the preferred embodiments are illustrative and explanatory thereof, and various changes in the components, the fired heater configurations, and configurations of the techniques, as well as in the details of the illustrated apparatus and techniques of operation may be made without departing from the spirit and scope of the invention as claimed in the appended claims. | A fired heater is adapted for increasing the output of a plant where the furnace capacity is considerably improved without corresponding increase in the pressure drop. The described technique utilizes a parallel thermal path in contrast to the conventional series thermal path for heating a hydrocarbon fluid. The fluid is divided into at least two paths where the fluid in the first path is heated primarily by radiation heat transfer mechanism and the fluid in the second path is heated primarily by convection heat transfer mechanism. The at least two fluid streams may then be combined to continue with other desired processing of the fluid. | 5 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/691,314, filed Jun. 15, 2005, which is incorporated herein by reference.
FIELD
This application relates to dental equipment for practicing dentistry, and in particular to dental delivery systems and related components used in the practice of dentistry.
BACKGROUND
Dental delivery systems refer to the systems used to provide water, air, vacuum, electrical power, etc. for use in dental procedures.
Delivery systems typically encompass a stationary portion (e.g., a mount to a wall, floor, cabinet, dental chair, etc.) and a movable portion allowing a working end of the system to be positioned convenient to the care provider(s) (e.g., dentist, dental assistant, surgeon, etc.) administering treatment to a patient, who typically occupies the dental chair. Known delivery systems are mounted to the dental chair, to an adjacent side wall or cabinet, or to a wall or cabinet located to the rear of the patient, i.e., near the head end of the dental chair (also referred to as the “12 o'clock position”). Side or rear mounted delivery systems are referred to as non-chair mounted delivery systems.
Delivery systems are typically used in most every dental procedure, and they must occupy a portion of the space close to the patient. Therefore, designing delivery systems such that the care providers have optimal workspaces within which they can administer treatment and have the implements and equipment close at hand is important.
Delivery systems include the conduits, lines, connections and implements for supplying water, air and vacuum. Today, such systems also include data lines for communicating data and the associated electronic devices, computer systems and peripherals used by care providers.
At the working end, the delivery system typically has an array of tools and instruments used by the care givers and structures for holding these implements when they are not in use. For general dentistry, these implements would typically include one or more of the following: air/water syringes, vacuum devices, hand pieces (including dental drills), oral cameras, controls for the dental chair and other equipment, displays, etc. These implements may be provided for use at separate locations, i.e., where some are configured for use from the dentist's work position and some from the dental assistant's position, or some commonly used implements may be provided at each work position.
SUMMARY
The present disclosure is directed toward all new and non-obvious features and method acts disclosed herein both alone and in novel and non-obvious combinations and sub-combinations with one another. The disclosure is not limited to constructions which exhibit all of the advantages or components disclosed herein. The embodiments set forth herein provide examples of desirable constructions and are not to be construed as limiting the breadth of the disclosure.
Described herein are various embodiments of a dental delivery system that overcomes at least several of the drawbacks of the prior art. For example, in one exemplary embodiment, a rear dental delivery system through which at least one of water, air and vacuum are delivered for use by a care giver in treating a patient occupying a nearby dental chair can include at least one movable arm that is pivotably mounted to a pivot connection and an upright mounted to the at least one movable arm. The pivot connection can be mounted at approximately a floor level and the at least one movable arm can be configured to pivot slightly above the floor level so as to reduce obstruction in a space separating the dental chair from the dental delivery system.
In some implementations, the rear dental delivery system can include a work surface coupled to the upright. In specific implementations, the work surface can be generally circular and pivotably coupled to the upright at a pivot point spaced apart from a central axis of the work surface. In specific implementations, the work surface has a periphery with at least a portion of the periphery being curved. The work surface can be pivotably coupled to the upright at a pivot point positioned near the periphery. In yet certain implementations, an auxiliary tool holder can be selectively positionable along an edge of the work surface.
In certain implementations, the delivery system can include a housing positioned adjacent a junction between the at least one movable arm and the upright.
In specific implementations, an arm can be pivotably coupled to the work surface and comprise a tool holder that is movably coupled to the arm. The tool holder can have at least one movable tool clamp. In at least one implementation, the tool holder includes a control pad that is capable of controlling at least one dental chair function.
In some implementations, the rear dental delivery system can include a second upright that can be positioned closer to the pivot connection than the first mentioned upright. In certain implementations, the second upright can support an extension arm that is movable relative to the second upright. In specific implementations, the first upright supports implements generally used by a dental assistant and the second upright supports implements generally used by a dentist or dental hygienist.
In certain implementations, the second upright is coupled to the first upright at a point spaced above the at least one arm. The delivery system can also include a housing that covers a junction between the at least one movable arm, the first upright and the second upright. The second upright can be coupled to the first upright in a spaced apart relationship via a bracket.
In certain implementations, the pivot connection of the rear dental delivery system is positioned rearwardly and approximately aligned with a head end of a dental chair. In specific implementations, the pivot connection is positioned adjacent a cabinet and does not extend above a level of cabinet access openings, thereby allowing the cabinet access openings to be accessed while rear dental delivery system is installed. In specific implementations, the dental chair is a reclineable dental chair and, when in the reclined position, a distance between the dental chair and the cabinet is between approximately 20 inches and approximately 26 inches.
In some implementations, the distance between the floor level and the at least one movable arm is less than approximately six inches. In some implementations, the pivot connection includes an attachment portion configured for attachment to a horizontal surface.
In certain implementations, the delivery system includes air and vacuum connections extending through the pivot connection, the at least one movable arm and the upright.
According to one exemplary embodiment, a rear dental delivery system through which at least water, air and vacuum are delivered for use by a care giver in treating a patient occupying a nearby dental chair can include at least one movable arm pivotably mounted to a pivot connection positioned substantially at a floor level. The delivery system can also include an upright mounted to the at least one movable arm and a work surface mounted at an off-center location to the upright. The work surface can have a periphery where at least a portion of the periphery is curved. An arm can be pivotably mounted to an approximate center of an underside of the work surface and protruding beyond the curved periphery. The arm can assist in holding implements used by the care giver in convenient storage positions.
One exemplary embodiment of a method of delivering water, air and a vacuum line to a dental operatory having a dental chair and a rear area adjacent a head end of the chair can include pivotably mounting a swing arm to pivot close to a horizontal surface at a step-over height. The method can also include mounting an upright member to the swing arm proximate a distal end of the swing arm. The method can further include mounting a work surface to the upright member to pivot about a location offset from a central axis of the work surface. The work surface can be elevated above the swing arm and a knee space accommodating a seated practitioner can be defined below the work surface and above the swing arm.
The foregoing and other features and advantages will become more apparent from the following detailed description, which proceeds with reference to the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective depiction of one exemplary embodiment of a dental operatory having a side mounted delivery system and a rear mounted delivery system.
FIG. 2 is an enlarged elevational view of the rear mounted delivery system of FIG. 1 shown mounted adjacent a cabinet.
FIG. 3 is a plan view of the rear mounted delivery system of FIG. 1 in various configurations as depicted by dashed lines.
FIG. 4 is a plan view of the rear mounted delivery system of FIG. 1 showing the work surface in various configurations as depicted by dashed lines with certain components of the delivery system not shown for clarity.
FIG. 5 is an elevational view of an exemplary embodiment of a rear mounted delivery system mounted to a cabinet and having a second upright member.
FIG. 6 is a plan view of the rear mounted delivery system of FIG. 5 in various configurations depicted by dashed lines.
FIG. 7 is a perspective view of an auxiliary tool holder removably attached to a work surface of a rear mounted delivery system.
FIG. 8 is a perspective view of an auxiliary tray movably attached to a work surface of a rear mounted delivery system.
FIG. 9 is a partial plan view of an exemplary dental operatory showing a dental assistant and dentist in a variety of positions relative to the dental chair and the rear mounted dental delivery system.
FIG. 10 is an elevational view of an exemplary dental operatory having a rear mounted dental delivery system, dental chair, dentist chair and cabinet.
FIG. 11 is an elevational view of the dental operatory of FIG. 9 showing the dentist in a standing position and the dental chair in an inclined position.
FIG. 12 is a plan view of the dental operatory of FIG. 1 shown with the side mounted dental delivery system extended for use by a dentist.
FIG. 13 is an enlarged elevational view of the rear mounted delivery system of FIG. 5 shown with a cover removed to expose an interior of the system.
FIG. 14 is an elevational view of a monitor mount with an attached monitor suitable for use with a rear mounted delivery system.
FIG. 15 is a perspective view of an in-cabinet mounting for a dental rinse water supply bottle suitable for use with a rear mounted delivery system.
FIG. 16 is a perspective view of a dental line cleaning system integrated in a cabinet and suitable for use with a rear mounted delivery system.
DETAILED DESCRIPTION
Described herein are various embodiments of rear and side mounted dental delivery systems suitable for use in a dental operatory. For example, in FIG. 1 , an exemplary embodiment of a dental operatory 100 having a dental chair 120 , side mounted delivery system 140 and a rear mounted delivery system 160 . The operatory 100 can have an opening 158 between the end of a rear wall 143 and an adjacent side wall 141 . This represents one possible doorway for care providers and patients to access the operatory 100 . Of course, the doorway may be positioned at another location, or there may be multiple doorways.
As shown, the side mounted delivery system 140 can be positioned to one side of the dental chair 120 , which is shown in the reclined position, and the rear mounted delivery system 160 can be positioned to the rear of the dental chair, i.e., adjacent its head end 122 , or approximately at the twelve o'clock position.
The side mounted delivery system 140 , which typically includes the implements used by the dentist, is pivotally attached to a wall 141 , such as via a cabinet 142 , adjacent the chair 120 as shown. In FIG. 1 , the side mounted delivery system 140 is shown in a storage position, which is spaced apart from the dental chair to provide a walkway for care providers and patients. When in use, the side mounted delivery system 140 is typically pivoted to a position closer to the dental chair 120 (see FIG. 12 ).
In relation to the dental chair 120 , the rear mounted delivery system 160 is pivotably attached to an adjacent rear wall 143 or cabinet, such as the cabinet 144 , at a rear centerline, or 12 o'clock position, indicated at 145 in FIG. 3 . Although not specifically shown, the operatory 100 need not have a cabinet attached to the rear wall 143 and the rear mounted delivery system can extend transversely from the rear wall. In some implementations having a cabinet attached to the rear wall 143 , such as cabinet 144 , the cabinet can have separate portions, such as a lower cabinet 154 and an upper cabinet 156 as shown in FIG. 1 , or it may be a single structure such as is shown, for example, in FIG. 14 .
Referring to FIG. 2 , the rear mounted delivery system 160 has a pivot connection 146 , a pivotable arm 148 , an upright 150 attached to the arm 148 , a work surface 152 supported by the upright 150 , and an arm 170 pivotably supported by the work surface.
Preferably, the pivot connection 146 is generally positioned at a low level, e.g. near the level of the floor 147 as shown. In the exemplary implementations, a stationary, or attachment portion, of the pivot connection 146 is mounted to a secure stationary horizontal surface, such as the floor 147 , by fasteners, such as fasteners 149 (see FIG. 3 ). Alternatively, or in addition to mounting the stationary portion of the pivot connection 146 to the floor, the stationary portion can be mounted to a cabinet, such as cabinet 144 , which in turn is securely mounted to a stationary and secure object, such as a wall and/or a floor.
The pivot connection 146 can be mounted to the floor such that a portion of the connection is positioned at least partially underneath the cabinet 154 and a portion extends transversely away from the cabinet. The arm 148 can be pivotably coupled to the portion extending away from the cabinet and be generally horizontal as shown. This configuration of the pivot connection 146 and the arm 148 provides sufficient ease and flexibility in repositioning equipment, but increases the work space available to the care providers by positioning the arm and pivot connection away from the areas of their knees and hips. For example, a leg and knee space 151 defined between the underside of the work surface 152 and the upper surface of the support arm 148 can allow for uninhibited movement of a care provider's legs into various positions required for operation on a patient.
In some implementations, the horizontal extent of the arm 148 can be about as great as one half the width of the cabinet. In other implementations, the arm is longer than one half the width of the cabinet. Of course, the arm could be shorter than one half the width of the cabinet.
The upright 150 pivotably supports at least one member, such as work surface 152 , extending laterally and capable of supporting equipment. In the illustrated implementations, the work surface 152 is pivotably supported by the upright 150 and extends horizontally relative to the ground. As illustrated, a pivot connection 112 defining a pivot point, which can be positioned at the approximate center of the pivot connection, can couple the work surface to the upright and be coupled to an underside of the work surface at a location offset from the center of the work surface. As shown in FIG. 16 , in some embodiments, the pivot connection 112 can include a structural member 153 , which can also act as a cover.
In the illustrated embodiments, the work surface 152 can be raised or lowered as desired. For example, as shown in FIG. 16 , the upright 150 can include an adjustment mechanism 161 for conveniently adjusting the height of the work surface 152 relative to the arm 148 or ground level. The adjustment mechanism 161 can include a cylindrical portion 163 insertable into a top portion 165 of upright 150 . The cylindrical portion 163 can have multiple axially displaced external grooves mateable with a bracket 167 having an annular tooth or protrusion portion and being removably attachable to the cylindrical portion. When attached, the tooth portion of the bracket 167 is matingly received in a respective groove of the cylindrical portion 163 thus preventing the bracket from movement in the axial direction. The cylindrical portion 163 is lowered into the top portion 165 of upright 150 until the bracket 167 contacts the upright to prevent the cylindrical portion from movement in the downward direction. The work surface 152 is adjustable by matingly attaching the bracket 167 to one of the grooves associated with the desired height of the work surface. In other implementations, the adjustment mechanism can be another type of mechanism, such as a ratcheting type mechanism, commonly known in the art.
As shown in the exemplary implementations, the arm 170 is pivotably supported by the work surface 152 via a pivot connection 114 defining a pivot point, which can be at an approximate center of the pivot connection. In the illustrated embodiments, the pivot connection 114 between the arm 170 and the work surface 152 is located on the underside of the work surface at its approximate center. The arm 170 can support a tool holder 172 as shown. In some implementations, the tool holder 172 can be pivotably supported by the arm 170 via a pivot connection 116 defining a pivot point, which can be at an approximate center of the pivot connection. In some embodiments, the pivot connection 116 is coupled to the tool holder 172 at a location midway along the length of the tool holder 172 , while in the illustrated embodiments, the pivot connection is coupled to the tool holder proximate one of the two ends of the tool holder. Moreover, a control, or touch, pad 179 for controlling various characteristics of the system can be mounted to the pivot connection 116 or directly to the tool holder 172 .
The non-chair mounted delivery systems, i.e., the side mounted delivery system 140 and the rear mounted delivery system 160 , are preferred by some care providers for providing space-saving benefits. For example, when a side mounted delivery system is provided, it typically replaces a chair mounted system. Similarly, when a rear mounted delivery system is provided, it also typically replaces a chair mounted system. Of course, it would be possible to use one or both of the delivery systems 140 and 160 in conjunction with a chair mounted delivery system if desired.
Of particular value is the ability of a user to customize the positioning of one or more of the various components of the rear and side mounted dental delivery systems described herein. More specifically, the increased range of motion of the rear mounted delivery system results in better visibility, less stretching and reduced extraneous motion for a user of the delivery system. Further, the multi-tiered or multi-layered approach to positioning the various components of the rear mounted delivery system provides additional customizability, convenience and space-saving benefits over conventional delivery systems. FIGS. 3 and 4 show some of the possibilities for positioning the rear delivery system 160 and its components.
In FIG. 3 , the arm 148 has been pivoted approximately 90-degrees about pivot connection 146 , which defines a pivot point, from the position of the arm shown in FIG. 1 (also indicated in dashed-line in FIG. 3 as extending generally parallel to the cabinet and to the right of the pivot connection 146 ) such that the arm extends generally transversally from the cabinet 144 . The arm 148 can be pivoted from this position to a position in which the arm extends generally parallel to the cabinet and to the left of the pivot connection 146 as indicated in dashed-line in FIG. 3 . As can be recognized, the arm 148 also can be pivoted into any position intermediate the positions shown in FIG. 3 . In other words, the arm 148 can be pivoted, or rotated, about pivot connection 146 into any position within a range of about 180 degrees.
The ability to pivot the arm 148 to either side can be used, among other purposes, to adapt the rear delivery system for use by right-handed or left-handed care providers. Further, the pivot arm 148 can be positioned at an intermediate point between the two extremes as shown in FIG. 3 , which is a position that might be used when the head end of the chair remains elevated (see FIG. 11 ).
As shown in FIG. 3 , arm 170 is pivotable approximately 270-degrees about pivot connection 114 independent of pivot arm 148 . In other implementations, however, the arm 170 can be pivotable more or less than 270-degrees about pivot connection 114 . Likewise, the tool holder 172 is pivotable about pivot connection 116 independent of pivot arm 148 and arm 170 . As shown, in some implementations, the tool holder 172 is pivotable approximately 270-degrees about pivot connection 116 . In some implementations, however, the tool holder 172 is pivotable more or less than 270-degrees about pivot connection 116 . In some embodiments, the arm 170 and the work surface 152 can be sized as shown such that the tool holder 172 remains close to the edge of the work surface and conveniently within grasp.
In some implementations, the tool holder 172 includes multiple tool clamps 173 (e.g., as shown in FIG. 2 ) placed laterally along an axis of the tool holder 172 . Each tool clamp 173 is configured to removably secure a single dental implement as shown, or multiple implements in other implementations. The tool clamps 173 can be individually movable relative to an axis of the tool holder 172 , such as by being rotatable about the axis of the tool holder, and sustainable in one of various positions about the axis by an internal latching mechanism (not shown). In this manner, the tool clamps can be rotated independently of each other to place a respective implement in a desired and convenient orientation for access by a user.
Referring to FIG. 4 , the work surface 152 is pivotable approximately 360-degrees about pivot connection 112 independent of pivot arm 148 , arm 170 and tool holder 172 .
As has been described, the pivot arm 148 , work surface 152 , arm 170 , tool holder 172 and tool clamps 173 can be movable independently of each other. In other words, the rear delivery system 160 shown in FIGS. 1-4 can be described as having five degrees of adjustability or positionability.
While FIG. 1 shows a configuration in which there is a separate side mounted delivery system 140 specifically configured for use by, for example, a dentist (or hygienist), and a rear mounted delivery system 160 specifically configured for use by, for example, a dental assistant (or hygienist), FIG. 5 shows a two-position rear delivery system 162 designed to provide two work positions, i.e., the work position for the hygienist or assistant and the work position for the dentist or hygienist, as well as the required implements used in each position.
In the illustrated embodiments, the rear delivery system 162 includes some features that are similar to the features of rear delivery system 160 . Corresponding similar features have matching reference numerals unless otherwise noted.
The rear delivery system 162 includes a second upright 164 . In some implementations, the second upright 164 is attached to the arm 148 and, in the illustrated implementations, the second upright 164 is coupled to the upright 150 via a bracket 175 (see FIG. 13 ). As perhaps best shown in FIG. 5 , a cover 167 can be positioned as shown to at least partially enclose an interior 181 , which as will be discussed below in greater detail, can include the bracket 175 (see FIG. 13 ). A knee space 159 defined between the underside of the work surface 152 and the upper surface of the cover 167 can allow for uninhibited movement of a care provider's knees into various positions during operation on a patient.
As shown, the second upright 164 pivotably supports an extension arm 166 at an upper end via a pivot connection 118 defining a pivot point, which can be at the approximate center of the pivot connection. Alternatively, in some implementations, the upright 164 and extension arm 166 are integrally formed, i.e., formed of a one-piece monolithic construction, and the upright 164 is pivotably coupled to the upright 150 , such as via bracket 175 (see FIG. 13 ) or support arm 148 .
The extension arm 166 can pivotably support a tool holder 168 via a pivot connection 119 defining a pivot point, which can be at the approximate center of the pivot connection. The pivot connection 119 can be coupled to the tool holder 168 at one of the ends of the tool holder or at a location intermediate its ends. Moreover, a control, or touch, pad 169 for controlling various characteristics of the system can be mounted to the pivot connection 119 or directly to the tool holder 168 .
Similar to the upright 150 , the height of the second upright 164 and thus the extension arm 166 and tool holder 172 can be adjusted. For example, as shown in FIG. 5 , the upright 164 can include an adjustment mechanism 80 for conveniently adjusting the height of the extension arm 166 relative to the arm 148 or ground level 147 . The adjustment mechanism 80 can include a cylindrical portion 82 insertable into an opening 84 in the cover 167 . The cylindrical portion 82 can have multiple axially displaced external grooves mateable with a toothed bracket 86 removably attachable to the cylindrical portion. When attached, the bracket 86 contacts a second upright mounting bracket 175 , as will be described in more detail below, to prevent the cylindrical portion 82 from movement in the downward direction. The extension arm height is adjustable by matingly attaching the bracket 86 to one of the grooves associated with the desired height of the extension arm 166 . In other implementations, the adjustment mechanism can be another type of mechanism, such as a ratcheting type mechanism commonly known in the art.
In addition to the same possibilities for positioning the arm 148 , arm 170 , tool holder 172 and work surface 152 as described above in relation to rear delivery system 160 , the rear delivery system 162 is also capable of other positioning possibilities. For example, as shown in FIG. 6 , the extension arm 166 is pivotable about pivot connection 118 independently of the pivot or support arm 148 , work surface 152 , arm 170 and tool holder 172 . In the illustrated implementation, the extension arm 166 is rotatable approximately 180-degrees about pivot connection 118 with complete rotation being inhibited by first upright 150 .
Referring again to FIG. 6 , in one specific implementation, the tool holder 168 is rotatable about pivot connection 119 independently of arm 148 , work surface 152 , arm 170 , tool holder 172 and extension arm 166 . Further, similar to tool holder 172 , tool holder 168 can have multiple independently movable tool clamps 177 (see FIG. 5 ) for removably securing dental implements.
As has been described, the pivot arm 148 , work surface 152 , arm 166 , tool holder 168 , arm 170 , tool holder 172 and tool clamps 177 can be movable independently of each other. In other words, the rear delivery system 162 shown in FIGS. 5 and 6 can be described as having seven degrees of adjustability or positionability.
As indicated generally at 171 in FIGS. 2 and 5 , various implements and their associated conduits and cables, can be positioned as shown relative to the holder 172 and the holder 168 . Each one of the various implements and associated conduit or cable can provide, for example, a fluid, such as air and water, or a vacuuming line. Desirably, at least a portion of the conduits and cables extend through at least one of the members, e.g., the arm 148 , the upright 150 , the arm 170 , the second upright 164 , the arm 166 . In some implementations, at least some of the conduits and cables extend through at least one of the pivot connections, or arm connectors, 110 , 112 , 114 , 116 , 118 , 119 . In this manner, portions of the cables and conduits can be hidden or contained within the arms and arm connectors to minimize extraneous exposure of cables and conduits to dentists, dental assistants and patients.
Optionally, in some implementations, the rear delivery system as described herein can include an auxiliary tool holder 190 , as shown in FIG. 7 , which is adapted for temporary attachment at any point along the periphery of the work surface 152 .
Referring to FIG. 8 , the rear mounted delivery system, e.g., delivery system 160 , can have additional components, such as auxiliary tray 176 , to provide added flexibility in positioning the rear delivery system. Auxiliary tray 176 is pivotally connected to an edge of the work surface 152 for positioning above the work surface.
FIGS. 9 and 10 show the rear delivery system, which in this example is delivery system 162 , in use during a range of typical dental procedures to illustrate the functionality of the various components. In the figures, FIG. 90 is portraying the dentist's role, and FIG. 92 is portraying the dental assistant's role.
Referring to FIG. 9 , it can be seen that the extension arm 166 (obscured in the figure) has been positioned such that the tool holder 168 is conveniently positioned for the dentist 90 and the tool holder 172 is conveniently positioned for the dental assistant 92 .
As shown in solid lines, the dentist 90 is operating from a 10 o'clock position relative to the patient. The dentist 90 can move to his left from the 10 o'clock position to the 11 o'clock position, indicated in dashed lines, without requiring the assistant to change her position or the position of the work surface 152 . Although not specifically shown, the work surface 152 and tool holder 168 can be moved from the position shown in FIG. 9 such that the dentist 90 can operate from the 12 o'clock position and freely move between the 12 o'clock position and the 10 o'clock position without requiring repositioning of the work surface or tool holder.
In some specific implementations, the operatory 100 of FIG. 1 can be configured such that a distance D between the cabinet 154 and the head end 122 of the chair 120 (see FIG. 9 ) is between approximately 20 and 26 inches. Such a distance D allows the dentist 90 or assistant 92 to easily position him/herself in the 12 o'clock position between the cabinet and the dental chair 120 . Further, as shown, the dentist 90 also can move to his/her right from the 10 o'clock position to about the 8 o'clock position, indicated in dashed lines, relative to the patient. In other words, in some implementations, the dentist 90 can move between various positions relative to the patient without requiring adjustment of any of the various components of the rear dental delivery system.
Since the arm 148 is at a step-over height, i.e., between zero and six inches, the arm does not impede movement of the dentist 90 by blocking the dentist's legs. More specifically, the leg or knee spaces 151 , 159 allow a dentist's or assistant's legs to move freely between the arm 148 and the work surface 152 as the dentist or assistant moves between various positions relative to a patient. For example, as perhaps best shown in FIG. 10 , dentist 90 is sitting on a conventional chair, or stool, 94 in an operating position. When in the operating position and while sitting down, there is sufficient clearance between the arm 148 and the work surface 152 such that the dentist can freely position his legs between the arm and the work surface without undesirable contact with the components of the rear delivery system or requiring adjustment of the delivery system.
Alternatively, if desirable, as the dentist 90 moves from one position to another, such as from the 11 o'clock position to the 8 o'clock position, he can grab and pivot the arm 166 toward him to provide him more convenient access, e.g., to the tool holder 168 . As also shown in FIG. 9 , the assistant 92 has the tool holder 172 , and specifically the control pad 179 , positioned within convenient reach of her right hand.
Now referring to FIG. 11 , the dentist 90 is operating from a standing position instead of a seated position, such as during treatment of a patient who cannot be reclined. As shown, with the dentist chair 120 in the inclined position, the arm 148 has been swung to an intermediate position, e.g., approximately transverse to the cabinet 154 , such that the work surface 152 and the tool holder 168 remain within convenient reach. With the arm 148 in the intermediate position, an assistant (not shown) in the standing position can conveniently reach the tool holder 172 .
FIG. 12 shows an exemplary position of the rear mounted delivery system 160 and side mounted delivery system 140 in use. As shown, the dentist 90 is using the tools held by the side mounted delivery system 140 and the dental assistant 92 is using the tools held in the tool holder 172 of the rear mounted delivery system 160 .
FIG. 13 shows the rear delivery system 162 with a portion of the cover 167 removed to expose the interior 181 . Within the interior 181 , there is a main control unit having various pneumatic and electronic circuits used in controlling the various implements and/or other equipment, such as the chair, a cuspidor, etc. In addition, room is provided for positioning additional components in the event that other circuits are required, such as, e.g., an add-on oral camera. Manual controls 96 for the fluid or electrical systems can be provided on or extend from an outer surface of the cover 167 .
In typical dental delivery systems, the control unit is placed within the cabinets and occupies space that could otherwise be used for storage. Positioning the main control unit of the rear mounted delivery system 162 external to the cabinetry, e.g., in a space between the support arm 148 and the first upright 150 , frees up space within the cabinetry for storage of other systems, objects or supplies, such as an in-cabinet mounting for a dental rinse water supply bottle and a dental line cleaning system as will be described in more detail below.
Also shown in FIG. 13 is an optional method of coupling the second upright 164 to the first upright 150 . A bracket 175 is mounted to the upright 150 . The bracket 175 has a second upright receiving portion 191 extending laterally from the first upright 150 . The second upright 164 can be secured within the second upright receiving portion 191 , for example, by resting the bracket 86 on the receiving portion 191 such that the second upright is offset from and extends generally parallel to the first upright 150 . The upright can be rotatable within and relative to the receiving portion 191 of the bracket 175 .
FIG. 14 shows an optional monitor mount 200 with an attached monitor 98 suited for use with the rear delivery system. The monitor mount 200 can be coupled as shown to an underside of the upper cabinet 156 . The monitor mount 200 provides a functional and aesthetically pleasing solution to laterally positioning the monitor at any position along the width between the ends of the cabinet (as shown in dashed lines), and also allows the monitor to be positioned “around the corners” of the cabinet (as shown in dashed lines). The angle of the monitor relative to a level axis can also be adjusted.
FIG. 15 shows an optional in-cabinet mounting 210 for a dental rinse water supply bottle suited for use with a non-chair mounted delivery system. Use of the in-cabinet mounting 210 allows the water supply bottle to be moved from another location, e.g., attached to the dental chair or the delivery system, to the less obtrusive position within the cabinet 144 .
FIG. 16 shows an optional dental line cleaning system 220 integrated in the cabinet. When activated with an attached line, the line cleaning system 220 dispenses a selected amount of cleaner into the line. In the exemplary implementation, the dental line cleaning system 220 includes three fittings (in three standard sizes) for coupling to cleaning lines 99 and injecting a cleaning fluid.
In view of the many possible embodiments to which the above principles may be applied, it should be recognized that the illustrated embodiments are only preferred examples and should not be taken as limiting the scope of the invention. Rather, the invention is intended to encompass all modifications, alternatives, and equivalents as may be included in the spirit and scope of the invention, as defined by the following claims. | Described herein are various embodiments of a dental delivery system. For example, in one exemplary embodiment, a rear dental delivery system through which at least one of water, air and vacuum are delivered for use by a care giver in treating a patient occupying a nearby dental chair can include at least one movable arm that is pivotably mounted to a pivot connection and an upright mounted to the at least one movable arm. The pivot connection can be mounted at approximately a floor level and the at least one movable arm can be configured to pivot slightly above the floor level so as to reduce obstruction in a space separating the dental chair from the dental delivery system. | 0 |
BACKGROUND
The invention relates to a pedal arrangement, in particular, for vehicles or motor vehicles, with a standing pedal that is provided with a sensor that is connected to a device for generating a desired value signal, in particular, for a drive, and that is supported so that it can pivot on a horizontal pivot axis in the position of use, wherein this pivot axis is arranged at a distance to a pedal face that can be acted upon by a user, wherein the pivot axis for the standing pedal is arranged on or in a housing or housing-like carrier in which is located at least one friction element that can be pressed by one or more restoring springs against a stationary part or against a housing wall, wherein, in the housing, a pivoting activation lever is provided with two lever arms arranged on both sides of its pivot bearing, wherein a first lever arm is acted upon by the pedal—directly or indirectly—or attaches directly or indirectly to the pedal and the restoring spring is active on a second lever arm of the activation lever, and the axis of the pivot bearing of the activation lever extends parallel to the pivot axis of the standing pedal.
Such a pedal arrangement is described in DE 10 2006 035 882 B4 and has proven itself. For the friction element that is important for the function, in this known arrangement, an additional holder arranged on the activation lever is provided with a projection part whose region standing apart from the holder interacts with the stationary part or the housing wall with friction.
The invention is therefore based on the objective of creating a pedal arrangement of the type defined above that allows the holder with a projecting region and the friction element arranged on this region to be eliminated.
SUMMARY
The objective is met in a pedal arrangement as defined above in that the pivoting activation lever itself is constructed as a friction element and forms a friction contact over at least one part of its pivoting path on at least one inner side of the housing or housing-like carrier and that the restoring spring is arranged or mounted between a stop located on the lever arm of the activation lever and a position of the housing set apart from this stop in the extension direction of the spring, wherein the distance between the stop on the lever arm and the position for the pivoting of the pivot lever changes. Thus, the spring can perform its action and is tensioned by the pedal being pressed down for the pivoting of the pivot lever and causes the return when the pedal is relaxed or released.
Through this arrangement, a holder for the friction element and a part that projects from this holder and that carries the actual friction element can be eliminated, because the activation lever itself is used as the friction element. Thus it obtains an additional function.
Here it is useful when the outer side of this pivot lever extending approximately concentric to the pivot bearing of the activation lever forms a friction contact on a housing wall acting upon it at least in some regions and is movable along this wall. In this way, a relatively large friction face can be formed and utilized.
The stop for the compression spring can be the front end of the lever arm of the activation lever interacting with the spring. Thus, it is not necessary to provide a separate stop on this lever arm, which, however, would also be possible.
The front end of the lever arm used as a stop for the compression spring can run at an acute angle to a tangent on the outer side of this lever arm in the region of the front end. Thus, the front end stands at an angle and not radially relative to the arc-shaped housing wall that is used as a counter friction face, so that the compression spring can be mounted at a favorable angle between this front end and a position in the housing, in order to generate the best possible pressure effect for a tensioned spring.
The direction of the spring force of the compression spring on the slanted front end of the lever arm can have a force component that presses the outer side of the activation lever onto the housing wall. Thus, the spring causes not only the return of the pivot lever, but also cooperates for the generation of the friction force.
Here it is useful when the outer side of the activation lever or at least the outer side of the lever arm acted upon by the restoring spring and the housing wall contacted by this lever arm have a circular-arc-shaped profile in the displacement direction. Thus, the friction faces are adapted essentially to the movement of the activation lever and its lever arms for the adjustment relative to the pivot bearing.
Here, in the previously explained cases in which a restoring spring is mentioned, several such restoring springs could also be provided. In addition, the restoring spring could also be constructed as a tension spring, if it were mounted on the housing after the lever arm in the displacement direction of the lever arm.
It is especially favorable, however, when the position of the housing is constructed as a slanted face for supporting the restoring spring constructed as a compression spring, wherein this slanted face rises at an angle inward from the adjacent arc-shaped part of the housing wall such that it is arranged in at least one adjustment position of the activation lever and its slanted front face approximately parallel to this front face. Therefore, for the displacement of the pedal in the direction of a greater load and the associated displacement of the activation lever and its lever arm acting on the restoring spring or compression spring, the situation is produced that the two faces between which the restoring spring is mounted have the most favorable parallel arrangement relative to each other in any pedal position in which the spring can best exert its forces onto the lever arm in the restoring direction.
Here it is advantageous when the slanted end face of the activation lever and the slanted counter-support position provided in the housing for the compression spring when the pedal is pressed down, that is, the full-load position, are arranged approximately parallel to each other and have a small distance to each other, so that the compression spring located in-between has its greatest possible compression. Accordingly, in this position it also exerts the greatest possible force and indeed for the restoring movement of the lever arm and the pedal initially in the most favorable direction.
The lever arm of the activation lever interacting with the compression spring can be arranged so that it can pivot on the activation lever and can be connected via a hinge or a material weakening in the form of a film hinge to the activation lever, wherein the pivot axis for the lever arm is arranged parallel to that for the activation lever. Therefore, the force component originating from the restoring spring can be even more effective for generating a friction force between the activation lever or lever arm and the housing wall, because at least the lever arm acted upon directly by the spring can be better pressed against the housing wall than the counter friction face due to its relative capability for pivoting.
The counter friction surface of the housing with a circular-arc-shaped profile in its longitudinal section can be arranged eccentric to the center axis of the pivot bearing of the activation lever in the sense that the friction increases with increasing pivoting of the pedal. Thus, the impression is given to the user that when the pedal is pressed down, an increase in force proportional to the increase in load appears on the pedal. However, it is also possible to eliminate such a change or increase in the friction force during the activation of the pedal.
For the pressurization of the first lever arm of the activation lever that has a profile opposite the lever arm acted upon by the compression spring, a transmission element can be provided starting from the pedal that extends as a connection between the pedal and the lever arm of the activation lever and attaches to the activation lever and the pedal with a positive-fit or integral connection and, indeed, in the direction in which the activation lever is oriented in the connection region. Pressing down on the pedal thus produces, due to the transmission element, a corresponding extension movement of the lever arm that is therefore transmitted to the enter pivot lever and thus also to the second lever arm.
The positive-fit connection between the transmission element and the lever arm of the activation lever can be formed by a locking part of an insertion part located on the transmission element that can be locked or inserted into a fitting recess. Thus, this connection is active in two activation directions, so that forces can also be received in both directions of the pedal movements. For example, the pedal cannot be raised, even if contaminants block the return, without the activation lever actually being reset. Undesired separation or undesired lifting of the pedal from the activation lever and from the associated activation means is avoided in this way. Thus, it is also possible to provide the neutral stop acting directly on the lever arm on which the transmission element of the pedal is active. The neutral point is precise accordingly.
The positive-fit connection between the transmission element and the lever arm of the activation lever can be detachable. This simplifies repairs.
For good transmission with good movement of the interacting parts, it is advantageous when the transmission element is connected in an articulating fashion with the pedal and with the lever arm. In practice, the transmission element between the pedal and lever arm thus forms a couple whose parts can pivot about their respective pivot axes without this movement being negatively affected by the transmission element.
The engagement position of the transmission element on the one lever arm of the activation lever can be set farther away from the pivot axis of the pedal than the engagement position of the restoring or compression spring on the other lever arm of the activation lever. In other words, the lever arm acted upon by the compression spring and also the compression spring itself are preferably closer to the pivot axis of the pedal than the transmission element between the pedal and activation lever. Indeed, an inverse arrangement would also be possible, but in this way, more favorable lever and movement relationships and the pedal pivoting can allow a more precise dosing and adjustment of the respective partial load due to the longer lever arm with which force is applied on the transmission element.
It should also be mentioned that the transmission element could be constructed so wide in the extension direction of the axes of the pivot bearings that it covers the angular space between itself and the pivot axis of the pedal and at least essentially closes this space at the side. Thus, an additional function is obtained, because it can prevent any coarse parts from reaching under the pedal in its hinge region and from blocking the pedal movement.
Primarily for a combination of individual or several of the features and measures described above, a pedal arrangement is produced with a standing pedal that requires relatively few parts, because the component on which the restoring spring or the restoring springs attach and that transmits the respective pedal position using sensors is simultaneously constructed itself as a friction element.
BRIEF DESCRIPTION OF THE DRAWINGS
Below, one embodiment of the invention will be described in detail with reference to the drawing. Shown in a partial schematic diagram are:
FIG. 1 is a longitudinal section view of a pedal arrangement according to the invention with a standing pedal that is located in its starting or rest position, and
FIG. 2 is a view corresponding to FIG. 1 , wherein the pedal is pivoted into its full-load position and therefore an activation lever belonging to the pedal arrangement is pivoted, and a restoring spring is tensioned.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A pedal arrangement designated overall with 1 that can be provided primarily in vehicles or motor vehicles, but also in other applications so that a user can produce changes in speed with his or her foot has a standing pedal 2 whose pivot axis 3 is arranged deeper than the pedal projecting from it, so that the pedal 2 “stands” over the pivot axis 3 . The inclination or the angle of the pedal 2 relative to a horizontal plane can here be different according to the vehicle type or application.
The pedal 2 is provided with a sensor that is designated overall with 4 and that corresponds approximately to the sensor 4 according to DE 10 2006 035 882 B4 and is connected to a known device that is not shown in detail, indicated at box 26 , for generating a desired value signal, especially for a drive, and reacts to the respective pivoting of the pedal 2 .
The pivot axis 3 for the pedal 2 is arranged at a distance to a pedal face 5 that can be acted upon by the user on or in a housing 6 in which a friction element 9 is provided that can be pressed against the housing wall 8 by a restoring spring 7 that is to be described in more detail below and that is constructed as a compression spring. Instead of a housing 6 , a partially open housing-like carrier could also be provided.
In both figures, one sees that, in the housing 6 , a pivoting activation lever designated overall with 10 is provided with two lever arms 12 and 13 arranged on both sides of its pivot bearing 11 , wherein a first lever arm 12 is acted upon by the pedal 2 in a way still to be described. The restoring spring 7 attaches to a second lever arm 13 of the activation lever 10 , as can be seen clearly in FIGS. 1 and 2 . The axis of the pivot bearing 11 of the activation lever 10 here extends parallel to the pivot axis 3 of the standing pedal 2 .
The pedal position sensor 4 provided on the pedal arrangement 1 is constructed in the embodiment as a rotational-angle sensor that is arranged or integrated on the activation lever 10 and here in a compact way on its pivot bearing 11 , so that, on one hand, an economical rotational-angle sensor is used and this can also be accommodated without requiring significant additional space. Here, a rotating part of a non-contact magnetic sensor 4 can be supported advantageously so that it can rotate on the pivot bearing 11 of the activation lever 10 and the stationary part or stator of the sensor 4 can be connected to the housing 6 , wherein these parts of the sensor can function in a non-contact fashion with each other, so that wear can also not gradually affect the function of the sensor 4 in a negative way.
By comparing FIGS. 1 and 2 , it becomes clear that the pivoting activation lever 10 is constructed and is active itself as a friction element 9 at least in some sections or positions and forms a friction contact on an inside 14 of the housing 6 over at least one part of its pivoting path that extends between the two end positions of FIGS. 1 and 2 and that the restoring spring 7 is arranged and mounted between a stop 15 located on the lever arm 13 of the activation lever 10 and a position 16 of the housing 6 set apart from this stop in the extension direction of the spring 7 , wherein the distance between the stop 15 and the position 16 for the pivoting of the pivot lever 10 is reduced from the position shown in FIG. 1 into the position visible in FIG. 2 and increased again for an opposite movement, that is, it changes when the pedal 2 is activated. The front end if the lever arm 13 used as the stop 15 for the compression spring 7 extends at an acute angle α to a tangent t on an outer side of the lever arm 13 in a region of the front end.
From FIGS. 1 and 2 it becomes very clear that the restoring spring 7 resets the pedal again when the pressure on the pedal 2 is relaxed or released, as is known by users of such pedals.
The outer side of the activation lever 10 extends approximately concentric to its pivot bearing 11 and can move according to FIGS. 1 and 2 with friction along the housing wall 8 that it acts upon at least in some regions, that is, it contacts the housing wall 8 and can slide along this wall with friction when the pedal is activated. In this way, the pivoting activation lever 10 itself is used as a friction element 9 , that is, it has a double function.
As a stop 15 for the restoring spring 7 constructed as a compression spring, the front end of the lever arm 13 interacting with this spring 7 is used, wherein this front end of the lever arm 13 acting as the stop 15 for the compression spring 7 extends at an acute angle to a tangent on the arc-shaped outer side of this lever arm 13 that could be contacted in the region of this front end. The acute angle is then located between the end side used as the stop 15 and the part of the tangent that extends in the direction of the lever arm 13 , so that an angle projecting past the front end after the opposite side is obtuse.
The spring force of the compression spring 7 here has a force component F that presses the outer side of the activation lever 10 and primarily the lever arm 13 onto the housing wall 8 , wherein a correspondingly large friction force is produced.
The outer side of the activation lever 10 and, in particular, the outer side of the lever arm 13 acted upon by the restoring spring 7 and the housing wall 8 contacted by this lever am have a circular-arc-shaped profile in the displacement direction, so that a corresponding movement of the activation lever 10 about its pivot bearing 11 is easily possible.
The position 16 of the housing 6 for supporting the restoring spring 7 is constructed in the embodiment as a slanted face that rises at an angle β inward from the adjacent arc-shaped part of the housing wall 8 such that it is arranged approximately parallel to this end face acting as a stop 15 in at least one displacement position of the activation lever 10 and its slanted end face. Here, in FIG. 2 one sees that the slanted end face of the activation lever 10 and its lever arm 13 and the slanted counter-support position 16 provided in the housing 6 for the compression spring 7 are arranged approximately parallel to each other when the pedal 2 is pressed down, that is, in the full-load position, and have their smallest distance to each other, so that the restoring spring 7 located in-between has its greatest possible compression.
The lever arm 13 of the activation lever 10 interacting with the restoring spring 7 constructed as a helical spring is arranged so that it can pivot, on its side, on the activation lever 10 and is connected to the rest of the activation lever 10 by means of a hinge 17 that is, in the embodiment, a material weakening (indicated at 17 in FIG. 1 ) in the form of a film hinge. Here, the pivot axis of this hinge 18 for the lever arm 13 is arranged parallel to that for the activation lever 10 and also parallel to the pivot axis 3 of the pedal 2 , so that the force of the restoring spring 7 can press the lever arm 13 relative to the rest of the activation arm 10 outward against the housing wall 8 , in order to achieve the desired friction force with great certainty. Thus, primarily the lever arm 13 forms the friction element 9 .
The counter friction face or housing wall 8 of the housing 6 with a circular-arc-shaped profile in longitudinal section is here arranged eccentric to the center axis of the pivot bearing 11 of the activation lever 10 in the sense that the friction increases with increasing pivoting of the pedal 2 . Through simple geometric relationships, the friction force thus can be influenced in a desired way.
In both figures, one sees that for a force acting on the first lever arm 12 by the pedal 2 , a transmission element 19 is provided that extends as a connection between the bottom side of the pedal 2 and the lever arm 12 of the activation lever 10 and attaches to the activation lever 12 and to the pedal with a positive-fit connection. Thus, the pedal 2 cannot be lifted from the housing, wherein contaminants can be prevented from entering into the region of the pivot axis 2 .
The positive-fit connection between the transmission element 19 and the lever arm 12 of the activation lever 10 is formed by a suspension or locking or insertion part 20 that is located on the transmission element 19 and that can be locked or inserted in a fitting recess 21 and, indeed, at an angle that is greater than 90 degrees and thus prevents undesired unhinging. This positive-fit connection between the transmission element 19 and the lever arm 12 , however, can be detached by an opposite unhinging movement.
The transmission element 19 is here connected in an articulating fashion to the pedal 2 and to the lever arm 12 , thus, for the pivoting of the pedal 2 and the activation lever 10 , on its side, corresponding compensation movements can be performed. The engagement position 24 of the transmission element 19 on the one lever arm 12 of the activation lever 10 is here set farther apart from the pivot axis 3 of the pedal 2 than the engagement position 25 of the restoring or compression spring 7 on the other lever arm 13 , so that the pedal 2 can attach to the activation lever 10 at a correspondingly large distance from its pivot axis 3 , that is, with favorable lever relationships.
It should also be mentioned that the rigid connection between the pedal 2 and lever arm 10 has the advantage that a neutral stop 22 can be provided acting directly on the second lever arm 12 and the neutral point is precise accordingly, because the starting position of the pedal 2 according to FIG. 1 is then simultaneously the neutral position. Here, the neutral stop 22 is arranged in the embodiment on the housing 6 adjacent to the pivot bearing 11 of the activation lever 10 between this pivot bearing 11 and the contact position of the transmission element 19 , which also produces a compact construction and interacts with the lever arm 13 in the neutral position ( FIG. 1 ).
It should also be mentioned that the transmission element 19 can be constructed so wide in the extension direction of the pivot axis 3 of the pedal 2 and the pivot bearing 11 that it covers and closes the angular space 23 (cf. FIG. 1 ) between itself and the pivot axis 3 of the pedal 2 at the side. Thus, large parts cannot be led from the free end of the pedal into this angular space 23 and cannot block the pedal movement.
The pedal arrangement 1 with a standing pedal 2 has a friction element 9 that can be pressed against a housing wall 8 of the housing holding the associated parts and that is formed by an activation lever 10 and, in particular, by one of two lever arms 12 and 13 belonging to it and arranged on both sides of its pivot bearing 11 , wherein this activation lever 10 simultaneously interacts with one or several restoring springs or compression springs 7 that cause a return of the activation lever 10 and via a transmission element 19 of the pedal 2 when the force on the pedal 2 is relaxed or released. The activation lever 10 or one of its lever arms here forms itself the friction element 9 , which reduces the number of parts that are required. | A pedal arrangement ( 1 ) with a standing pedal ( 2 ) features a friction element ( 9 ) which can be pressed against a housing wall ( 8 ) of the housing ( 6 ) accommodating the associated parts; the friction element is formed by an actuating lever ( 10 ) with two lever arms ( 12 and 13 ) arranged on both sides of its pivot bearing ( 11 ). The actuating lever ( 10 ) cooperates simultaneously with one or a plurality of restoring springs or compression springs ( 7 ) which cause a backward adjustment of the actuating lever ( 10 ) after cessation or reduction of the force on the pedal ( 2 ) and via a transmission element ( 19 ) of the pedal ( 2 ). The actuating lever ( 10 ) or one of the lever arms thereof thus itself forms the friction element ( 9 ) which reduces the number of required parts. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a focusing apparatus of an electron microscope and more particularly to a focusing apparatus of an electron microscope which conducts the correction of astigmatism automatically.
Regarding a usual apparatus of focusing as the preceding stage of correction of astigmatism in the electron microscope wherein the correction of astigmatism is conducted automatically, i.e., a apparatus of determining a circle of least confusion, a description is made in U.S. Pat. No. 4,214,163 according to which the circle of least confusion is determined by the following procedures.
(1) An electron beam is made to scan in the direction X on a sample, a signal inversely corresponding to the radius of the electron beam is obtained in each scan, and an exciting current I 1 , for a focusing lens whereby the signal is turned to be maximum is determined.
(2) The electron beam is made to scan in the direction Y on the sample, a signal inversely corresponding to the radius of the electron beam is obtained in the same way as the above, and an exciting current I 2 for the focusing lens whereby the signal is turned to be maximum is determined.
(3) The mean value (I 1 +I 2 )/2 is calculated from aforesaid exciting currents I 1 and I 2 for the focusing lens, and the exciting current for the focusing lens is set at his mean value (I 1 +I 2 )/2.
By the apparatus described above, the circle of the electron beam focused on the sample becomes the circle of least confusion. The position of this circle of least confusion is equivalent to the position of a focus obtained when the astigmatism is corrected.
In the prior art, as described above, the electron beam is made to scan is each of the directions X and Y, the exciting current for the focusing lens whereby a variation component of a current of a secondary electron or the like generated from the sample on the occasion is turned to be maximum is determined in each scan, and the exciting current for the focusing lens at the time when the circle of least confusion is formed is determined from the mean value of the exciting currents thus determined. The variation component of the secondary electron current is generated by a shape or a pattern on the surface of the sample.
According to this apparatus, however, there occurs a problem that the exciting current for the focusing lens corresponding to the circle of least confusion can not be determined exactly when the shape or pattern on the surface of the sample is non-isotropic as in a small part of IC pattern, for example.
FIG. 3 shows the relationship between the focusing lens exciting current applied when an electron beam is made to scan on the sample in each of the directions X and Y with the current varied and an electron beam radius corresponding signal at this time.
By the way, the electron beam radius corresponding signal means a signal inversely corresponding to the radius of the electron beam and is obtained as a variation component of the current of secondary electrons generated from the sample. The more the electron beam is focused on the sample, the bigger the electron beam radius corresponding signal becomes.
This figure shows particularly a case ((b) of the FIG. 3) wherein the maximum value being an extremely large point is not obtained when scanning is conducted in the direction Y, since the variation component of the shape or pattern on the surface of the sample is small, while the maximum value I 1 , being the extremely large point is obtained ((a) of the FIG. 3) when the scanning is conducted in the direction X.
In the case when the shape of the surface on the sample is non-isotropic and therefore the maximum value being the extremely large point does not appear distinctly, as described above, the aforesaid exciting currents I 1 and I 2 can not be determined exactly according to the prior art, and consequently it is very difficult to exactly determine the exciting current for the focusing lens corresponding to the circle of least confusion.
While the apparatus of scanning wherein the electron beam is made to scan in the direction X and Y separately is described in the above-described example, two extremely large points are obtained as shown in FIG. 5(a) even when the electron beam is made to scan circularly, on condition that the shape of the sample is isotropic, and therefore the exciting current for the focusing lens corresponding to the circle of least confusion can be determined exactly by taking the mean value of said points. When the shape of the sample is non-isotropic, however, the two extremely large points can not be obtained as shown in FIG. 5(b) for the focusing lens corresponding to the circle of least confusion can be determined exactly.
SUMMARY OF THE INVENTION
An object of the present invention is to furnish a focusing apparatus of an electron microscope which enables the solution of the above-described problem and the exact and simple determination of the exciting current for the focusing lens corresponding to the circle of least confusion.
In a scanning electron microscope wherein the correction of astigmatism is conducted automatically, the above-stated object is attained by providing a detecting means to detect an information generated from a specimen by scanning the specimen with an electron beam, and by determining a focusing lens optimum exciting current which is determined from the position of the centroid of an area surrounded by a curve of the electron beam radius corresponding signal showing the relationship between the exciting current for the focusing lens and the electron beam radius corresponding signal and by a prescribed straight line.
Moreover, said object is attained by determining a current as an approximate value of the aforesaid focusing lens optimum exciting current which is determined from the position of the center of two intersecting points of the curve of the electron beam radius corresponding signal showing the relationship between the exciting current for the focusing lens and the electron beam radius corresponding signal and of a prescribed straight line.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified block diagram showing the principal structural elements of a scanning electron microscope to which the present invention is applied.
FIGS. 2(a), 2(b), 2(c) and 2(d) are graphs for illustrating the principle of focusing in the scanning electron microscope to which the present invention is applied.
FIGS. 3(a), 3(b), 5(a) and 5(b) are graphs showing the relationship between a focusing lens exciting current and an electron beam radius corresponding signal.
FIG. 4 is a schematic view of tracks of scanning in the case when an electron beam is made to scan in arbitrary directions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention will be described hereunder by using drawings.
FIG. 1 is a simplified block diagram showing the principal structural elements of a scanning electron microscope to which the present invention is applied.
In the figure, numeral 1 denotes an electron beam, which is focused finely on a sample 3 by a focusing lens 2. Numeral 14 denotes a focusing lens driving circuit for driving the focusing lens 2, and it is connected to a control circuit 7 which will be described later.
4 and 5 denote deflecting coils for making the aforesaid electron beam scan in the directions X and Y, respectively, and 10 and 11 deflecting coil exciting circuits for driving said deflecting coils 4 and 5 respectively.
Both of said deflecting coil exciting circuits 10 and 11 are connected to the control circuit 7.
8 and 9 denote X-direction and Y-direction astigmatism correcting coils respectively, and 12 and 13 astigmatism correcting coil exciting circuits for driving said astigmatism correcting coils 8 and 9 respectively.
Both of said astigmatism correcting coil exciting circuits 12 and 13 are connected to the control circuit 7.
Numeral 6 denotes a detector detecting a signal of a secondary electron or the like generated form the sample 3 by the application of the aforesaid electron beam, and the detector is connected to a focusing lens optimum exciting current determining circuit 15.
The focusing lens optimum exciting current determining circuit 15 sets an exciting current for the focusing lens corresponding to a circle of least confusion of the basis of an output signal from the aforesaid detector 6, and outputs a set value to the control circuit 7.
The control circuit 7 controls the aforesaid focusing lens driving circuit 14, the deflecting coil exciting circuits 10 and 11 and the astigmatism correcting coil exciting circuits 12 and 13.
In the scanning electron microscope which has the above-stated construction and to which the present invention is applied, the aforesaid electron beam 1 is made to scan circularly on the sample 3 by varying an exciting current for the deflecting coils 4 and 5. The detector 6 detects an image signal of a secondary electron, a thermoelectron, an absorption electron or the like generated from the sample 3 and outputs the image signal to the focusing lens optimum exciting current determining circuit 15.
Said focusing lens optimum exciting current determining circuit 15 converts the aforesaid image signal into a signal corresponding to the spot radius of the electron beam 1.
Herein, an integral value of a variation of the image signal generated from the detector 6 is used as the signal corresponding to the spot radius of the aforesaid electron beam 1.
The image signal delivered from the aforesaid detector 6 shows a sharper variation as the thickness of the electron beam 1 in the scanning direction (in the tangential direction in the case of circular scanning) on the sample 3 becomes smaller, and therefore the image signal on the occasion contains a large amount of variation component. This means, as a consequence, that, when the variation component of the aforesaid image signal is taken out as the signal corresponding to spot radius of the electron beam 1 and only a varied part of said variation component is integrated for each one scanning, the thickness of the spot radius of the electron beam 1 in the scanning direction becomes smaller as the integral value obtained by the integration (hereinafter called an electron beam radius corresponding signal) becomes larger.
The aforesaid focusing lens optimum exciting current determining circuit 15 determines the relationship between the intensity of current supplied to the focusing lens driving circuit 14 and the signal corresponding to the electron beam on the occasion, determines a focusing lens exciting current corresponding to the circle of least confusion from this relationship and outputs same to the control circuit 7.
While generating the focusing lens exciting current corresponding to the aforesaid circle of least confusion to the focusing lens driving circuit 14, the control circuit 7 controls the deflecting coil exciting circuits 10, 11 and the astigmatism correcting coil exciting circuits 12, 13.
A method of determining the focusing lens exciting current corresponding to the circle of least confusion by the scanning electron microscope of the present invention will be described in detail hereunder by using FIG. 2.
This figure shows the relationship between the integral value of the electron beam radius corresponding signal and an exciting current for the focusing lens driving circuit 14 on the occasion when the electron beam is made to scan circularly on the sample, showing particularly the case when the two extreme large points do not appear distinctly since the shape of the sample is non-isotropic.
In the case when the two extreme large points do not appear distinctly as the above, it is very difficult to determine exactly the exciting current for the focusing lens corresponding to the circle of least confusion, according to the prior art.
FIG. 2(a) is a graph for illustrating a focusing operation according to one embodiment of the present invention.
First, the relationship between the electron beam radius corresponding signal obtained from the variation of the secondary electron emitted from the specimen in each circular scan of said electron beam on the specimen and the exciting current for the focusing lens on the occasion, is determined.
For simplification of description, the aforesaid relationship is represented herein as a curve Y=f(I x ).
Subsequently, an exciting current I s for the focusing lens corresponding to the maximum value V 1 being the extreme large point of said curve Y=f(I x ) is determined, further electron beam radius corresponding signals V 3 =f(I s +ΔI) and V 2 =f(I s -Δ I ) obtained when an increase and a decrease are made by a certain value ΔI from said exciting current I s as the center value are determined, and the minimum value of these signals is set as V 0 ·V 0 =V 3 in the present embodiment, since V 2 >V 3 .
While the electron beam radius corresponding signals V 2 and V 3 are described as determined by making the increase and decrease by the equal amount ΔI from the focusing lens exciting current I s corresponding to the maximum value V 1 , which is set as the center value, values of the increase and decrease are not necessarily equal, but they may be arbitrary values respectively on condition that said exciting current I s be made to exist within the limits of these increase and decrease.
Successively, the centroid G 1 of a region (a hatched part) surrounded by a straight line Y=V 0 and the aforesaid curve Y=f(I x ) is determined. Then an exciting current I gl for the focusing, lens corresponding to said position of the centroid G 1 is the exciting current corresponding to the circle of least confusion.
The above-mentioned centroid G 1 can be determined by a proper method known publicly (also in other embodiments to be described in the following).
Another embodiment of the present invention will be described hereunder by using FIG. 2(b).
After the minimum value V 0 is determined in the same way as in the above-described case of FIG. 2(a), an electron beam radius corresponding signal
V.sub.s =(V.sub.1 -V.sub.0)α+V.sub.0
is determined from the aforesaid extreme large point V 1 and the minimum value V 0 , and the centroid G 2 of a region (a hatched part) surrounded by a straight line Y =V s and the aforesaid curve Y=f(I x ) is determined. The inventor of the present invention confirmed that it is desirable, on the occasion, that the value α is set within the limits of 0.1 to 0.5 and an exciting current I g2 for the focusing lens corresponding to the position of said centroid G 2 is the exciting current corresponding to the circle of least confusion.
A still another embodiment of the present invention will be described hereunder by using FIG. 2(c).
After the straight line V s =(V 1 -V 0 )α=V 0 is determined in the same way as in the above-described figure (b), intersecting points of the straight line Y=V s and the aforesaid curve Y=f(I x ) are denoted by I 3 and I 4 respectively, and the centroid of region (a hatched part) surrounded by a straight line X=I 3 , a straight line X=I 4 and a straight line Y=V t parallel to the X axis and 0<V t <V s is denoted by G 3 . An exciting current I g3 for the focusing lens corresponding to the position of said centroid G 3 , thus obtained, may also be used as the exciting current corresponding to the circle of least confusion.
The present embodiment of FIG. 2(c) shows the case when V t is set to be equal to 0.
Besides, as an approximate value of the aforesaid gravity, the middle point of the aforesaid intersecting points I 3 and I 4 may be taken also for an exciting current I g4 for the focusing lens corresponding to the circle of least confusion, as shown in FIG. 2(d).
Although the case when the circular scanning is taken as the scanning method of the electron beam is cited in the foregoing description, the present invention is not limited thereto, and an ordinary method of scanning in the directions X and Y, scanning in the shape of a closed loop, or scanning of the electron beam in a number of arbitrary directions as shown in FIG. 4, may be adopted as well. The aforesaid curve of the electron beam radius corresponding signal is determined from the mean value of electron beam radius corresponding signals obtained on the occasion, and thereafter the exciting current for the focusing lens corresponding to the circle of least confusion is determined in the same way as in the foregoing embodiments.
In other words, any method of scanning may be adopted, provided that the focusing apparatus of an electron microscope is employed wherein the exciting current for the focusing lens is determined from the position of the centroid of an area surrounded by the curve of the electron beam radius corresponding signal corresponding to the exciting current for the focusing lens obtained when the electron beam is made to scan with said exciting current varied, and by a prescribed straight line, or from the intersecting points of the curve and the line.
When the exciting current for the focusing lens corresponding to the circle of least confusion is determined as described above, the control circuit 7 fixes at this exciting current the intensity of current supplied to the focusing lens driving circuit 14 and then executes the so-called correction of astigmatism to further lessen the radius of the aforesaid circle of least confusion.
It is clear that the application of the above-described present invention to the correction of astigmatism enables the exact and simple correction of astigmatism, compared with the prior-art case.
Moreover, the repetition of the focusing operation of the focusing lens and the correction of astigmatism described above enables the implementation of further exact focusing.
Although only the case when the present invention is applied to the scanning electron microscope is mentioned in the above description, the present invention is not limited thereto, but can be applied also to transmission electron microscope apparatuses, provided that a means to make the electron beam scan in one direction at least is attained thereto.
According to the present invention, as described above, it is possible to furnish the focusing apparatus of an electron microscope which enables the exact and simple determination of the exciting current for the focusing lens corresponding to the circle of least confusion in the stage of the focusing operation conducted before the operation of correction of astigmatism even when the shape of a sample is non-isotropic and when the maximum value being the extreme large value of the curve of the electron beam radius corresponding signal does not appear distinctly. | A focusing apparatus of electron microscope for focusing an electron beam through a focusing lens onto a sample, having a deflecting means for making the electron beam scan on the sample, an astigmatism correcting means of the electron beam, a detecting means for detecting the 2nd electrons from the sample when the sample is scanned by the electron beam, and an optimum exciting current determining means of the focusing lens. The optimum exciting current is obtained by determining the position of the centroid of an area surrounded by a curve Y=f (I) and a fixed straight line. The curve Y shows the relationship between the exciting current for the focusing lens and an electron beam radius corresponding signal which is obtained on the basis of a signal from the detecting means and inversely corresponds to a radius of the electron beam on the surface of the sample.
The focusing apparatus enable the exact and simple determination of the optimum exciting current for the focusing lens corresponding to the circle of least confusion. | 7 |
BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to the formation of holes of relatively large diameter in soils such as silty clays, which are of such a composition and density as to be susceptible to compaction or displacement by application of a high intensity ramming force in relatively small increments.
2. Description of the Prior Art
Large diameter shafts on the order of 2 ft. to 15 ft. or more in diameter are commonly formed in such soft soils by sinking an open ended cylindrical steel shell or casing. Earth is removed from within the causing by means of an auger type excavating device or a grab type (clam shell) excavator. Vertical ramming force, occasionally with the addition of rotational, oscillatory, or vibratory forces, is often necessary to force the casing down into the soil. The soil presses tightly against the outer surface of the casing due to soil displacement and compaction. This increases frictional forces acting on the outer surface of the casing and makes downward moving of the casing difficult.
Underreaming tools may be employed in an effort to overcome the severe frictional forces tending to resist downward movement of the casing. These tools remove soil from beneath the lower edge of the casing and so remove resistance of the soil against this lower edge. But unless the soil is virtually self-supporting, friction will again build up along the outer surface of the casing resisting its downward movement.
In self-supporting soil, such as very stiff clay, the casing may be unnecessary. However, because soil density varies greatly and is of indeterminate quality, the reliability of this method is suspect. Personnel are not permitted to enter an uncased hole due to the danger of partial collapse of the hole. The uncertain results of this method, together with the attendant expense of loss of construction time in the event of a partial collapse, must always be considered as a possibility.
Present methods described above require massive equipment. A disposal cycle auger-type excavator, i.e., one which is raised out of the hole periodically to spin-off excavated soil, requires from 20 H.P. to 30 H.P. per foot of hole diameter and is typically capable of excavating holes up to six feet in diameter to a maximum practical depth of about 100 ft. In easily augered self-supporting soil, production rates up to 20 ft./hour may be achieved. Where casing of the hole is required, as in unstable soil, equipment requirements are increased and production rate greatly reduced. The cost of disposal cycle auger-type excavator equipment ranges from $60,000 to $150,000 and up.
Grab type excavators with which a shield is invariably employed, require somewhat less horsepower but achieve lower production rates. Equipment cost, including shield placing equipment, is somewhat greater than disposal cycle auger-type excavators. While both types of equipment are capable of penetrating very dense soil strata including those containing some cobbles and boulders and even low strength rock, they are unsuited to placing large diameter holes through soft soil at great depth, say on the order of 100 ft. and over. This unsuitability stems from uneconomically high power requirement, and from the progressively greater time and cost required for soil removal, as hole depth increases.
With the aid of pre-drilling techniques, very heavy steel casings can be driven to great depths through soil. These techniques are used in the construction of oil well drilling platforms in deep water. Equipment for driving these tubular casings up to 42" in diameter to depths of 400 ft. weigh as much as 300 tons and cost on the order of $1,000,000 and up. Equipment for driving such casings to depths of 1,000 ft., which will be required in the near future, is not available commercially at this time.
SUMMARY OF THE INVENTION
An object of this invention is to provide a method and apparatus for forming large diameter holes in soil by compaction and/or displacement of the soil.
Another object is to provide a method and apparatus for forming such a hole without the necessity of removing the soil therefrom.
Another object is to provide apparatus for forming such a hole in soil which apparatus is much lighter and more economical than equipment that is presently available.
Another object is to provide a method and apparatus for forming such a hole, the walls of which are compacted by ramming and so are far more stable and less susceptible to collapse than the walls of a similar hole from which earth has been excavated by customary means.
A further object is to provide a method and apparatus for enlarging the diameter of an existing hole.
Another object is to provide a method and apparatus for forming a hole in the earth which employs means providing instantaneous engineering data on the actual in situ strength of soil strata traversed, which data may be used in calculating the load carrying capacity of bearing members placed within the hole so formed.
According to the present invention, a tool is provided consisting of two or more ram assemblies, stacked one above the other, each comprising ramming means which may be actuated by any conventional means. From the bottom to the top of the tool, the ram assemblies or the strokes of their respective ramming means are successively longer and the ramming means are actuated either simultaneously or sequentially, with or without rotation of the entire tool, to compress or displace the soil to form a hole of incrementally increasing size. To permit entry of the lowest ram assembly into the soil, the soil beneath it is removed, for example by preboring with an auger, or displaced, for example, by rotating or driving a tapered point beneath the ram assembly into the soil.
Cementitious fluid such as a slurry of portland cement and water may be injected into the soil below or adjacent to the ram assemblies to assist in maintaining sidewall stability of the hole as the tool is advanced. A shield slightly smaller than hole size may be introduced into the hole immediately above the uppermost ram assembly to prevent collapse of the hole sidewalls.
By way of example, one embodiment of tool comprises a point tapering up to a diameter of 12", a series of ten ram assemblies, each having ramming means comprising one or more cylinders actuated by hydraulic fluid at a pressure within the range of about 5,000 to 10,000 psi. The ram assemblies range successively upward in length from 12" to 48" in 4" increments, each with a ramming means stroke slightly longer than 4" so mounted as to displace slightly more than 2" of soil on opposite sides of the ram assembly, with the ramming means at its extended position. The end of each ramming means is 4" in depth and has an arcuate ramming surface so selected as to displace slightly more than 30° of arc. The uppermost ram assembly is followed by a shield of 50" inside diameter.
The hole is advanced by activating the ramming means and then rotating the entire tool, including the ram assemblies and shield, in five 30° indexed steps, and actuating the ramming means at each step. For reasons explained more fully hereinafter, it may be desirable in certain instances to repeat the indexed steps a second time, with the tool radially displaced with reference to the first set of indexed steps. Thereafter the tool is lowered 4" into the hole formed by the ramming action.
This sequence of operation is repeated until the hole has been advanced to full depth after which the ram assembly is retracted and withdrawn with the shield, or through it, if the shield is to remain in place.
In non-cohesive soil, e.g., sand, cementitious fluids or slurries, such as Portland cement and water, or a drilling fluid consisting of a suspension of bentonite in water may be injected through the ram assemblies to act as a soil binder, inhibiting collapse of the rammed soil. The suspension may be passed upwardly through the annulus between the shield and the rammed soil, where it may function as a lubricating fluid to ease rotation of the shield as it is advanced downward into the hole.
In accordance with another embodiment of the invention the ram assemblies are of the same length, with each next higher ramming means having a stroke 4" longer than that of the next lower ramming means.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, with parts in section, of a tool of the present invention showing the arrangement of ram assemblies and shield;
FIG. 2 is a perspective view of ramming means in the form of one double acting ram of one of the ram assemblies illustrated in FIG. 1;
FIG. 3 is a diagram illustrating a typical sequence of operation of a single double acting ram of one of the ram assemblies illustrated in FIG. 1;
FIG. 4 is a sectional view of the ram assemblies of FIG. 1 and the hole formed by one operational cycle of the ram assemblies;
FIG. 5 is a fragmentary plan view illustrating an alternate embodiment of the present invention;
FIG. 6 is a fragmentary perspective view with parts in section, of a partially completed diaphragm wall and the employment of the tool of the present invention for constructing such a wall;
FIG. 7 is a fragmentary plan view of another alternate embodiment of ram assembly; and
FIG. 8 is a fragmentary elevation view of another alternate embodiment of tool in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1, it will be seen that the hole forming tool of the present invention, designated generally as 11, comprises a series of integrally connected, vertically disposed ram assemblies designated generally as 12, the lowermost of which is secured to lead point 13, which in the embodiment illustrated takes the form of an auger. The uppermost of ram assembly 12 is drivingly connected to shaft 14.
Hole forming tool 11 as illustrated in FIG. 1 is provided with an optional following shield 15, suitably connected for rotation with shaft 14, by braces 20 drivingly but releasably interconnecting shaft 14 with the inner surface of shield 15.
The hole forming tool is further provided with line 16 and pump 17 for removing drilling fluid and excavated soil from the situs, and line 27 for injecting drilling fluid or a soil stabilizing slurry of portland cement, which discharges through aperture 28 in lead point 13. In order to prevent drilling fluid or cementitious slurry discharged from aperture 28 from entering the interior of shield 15, the shield is provided with a fluid impervious diaphragm 18 disposed in sealing engagement with the shaft 14, and with the interior walls of shield 15 through peripheral seal 19.
Turning to FIG. 2, which illustrates in detail one of ram assemblies 12 shown in FIG. 1, it will be seen that the ram assembly comprises ramming means, which in the embodiment illustrated, takes the form of double acting hydraulic cylinder 21 whose piston rods 21a are in operative engagement with diametrically opposed ram shoes 22. The cylinder and ram shoes are so mounted that each ram shoe 22 moves outwardly a fixed and equal distance, so that the pressure of the surrounding soil, designated P s , on one ram shoe 22 is counterbalanced by a pressure of equal magnitude on the opposed ram shoe, thereby maintaining centering and alignment of the entire assembly.
The ram assembly further comprises enclosing ring 25 to prevent contamination of the operating mechanism by the surrounding soil.
Hydraulic fluid under pressure is supplied (from a source not illustrated) to double acting cylinder 21 through fluid pressure lines 23, one of which is provided with pressure gauge 24.
Another feature of the invention is the provision of ram shoe position indicators designated generally as 26 which electrically record, and transmit to the tool operator the distance ram shoes travel following pressurization of cylinder 21. In the embodiment illustrated the indicator takes the form of a resist wire 26a mounted on ram shoe 22, having one end permanently connected to lead 26b, and making sliding contact with wiper 26c connected to lead 26d. An ohmmeter (not shown) is connected to the distal ends of leads 26b, 26d, which provides a readout of the distance the ram shoe has moved, as a function of the resistance tapped between the leads.
Referring to FIG. 3, the operation of ram assembly 12 is as follows. With ram shoes 22 aligned with sectors a-a' as illustrated in the figure, hydraulic fluid under pressure (from a source not illustrated) is admitted through lines 23 (FIG. 2) actuating the pistons of the double acting cylinder, causing ram shoes 22 to move radially outwardly a distance S/2, thereby compacting soil segments a-a'. Ram shoes 22 are then retracted, for example by the use of return springs or the application of hydraulic pressure to the outbound surfaces of the pistons, and the tool is indexed through an angle of 30°, placing ram shoes 22 in registry with segments b-b'. Hydraulic fluid under pressure is again introduced into lines 23 (FIG. 2), causing the double acting cylinder and its associated piston rods to force ram shoe 22 outwardly a distance S/2, thereby compacting soil segments b-b'.
The cycle continues by the tool being serially indexed in 30° increments to compact soil segments c-c', d-d', e-e' and f-f'.
It will be noted that due to the geometry involved, small wedges of soil g (FIG. 3) will remain uncompressed after one complete cycle of indexing ram shoes 22. If desired or necessary, these segments can be compressed by running the tool through a second indexed cycle, radially offset from the first cycle. For example, a 15° offset for the second indexed cycle would place ram shoe 22 in a position where its actuation would compress a segment g.
Alternatively, the creation of wedges g can be avoided by incrementally indexing the tool through an arc of somewhat less than 30°. Thus, ram shoe 22 would be indexed from segment a to segment b in FIG. 3 through a suitable arc such that the left edge of ram shoe 22 will contact the outer periphery of the hole at or slightly to the left of the base of wedge g.
It will be appreciated that the avoidance of creating wedges g can also be effected by retaining the 30° indexing arc, while providing ram shoes 22 which are sufficiently over-sized to provide a slight overlap of contact area at the outer periphery of the hole.
Upon completion of the cycle or cycles by any of the procedures described above, the tool 11 may be lowered further into the excavation a distance h equal to the height of ram shoes 22 (see FIG. 2).
FIG. 4 shows the relative dimensioning of the ram assemblies, and how this dimensioning interacts to provide an incremental increase in the diameter of the excavation. The lowermost ram assembly with its ramming means in the retracted position has a diameter of d and an effective diameter with its ramming means in the extended position, of d+s. The next above ram assembly with its ramming means in the retracted position has a diameter d+s and an effective diameter of d+2s with its ramming means in the extended position. The next above ram assembly with its ramming means in the retracted position has a diameter of d+2s and an effective diameter of d+3s with its ramming means in the extended position. Finally, the uppermost ram assembly with its ramming means in the retracted position has a diameter of d+3s and an effective diameter of d+4s with its ramming means in the extended position.
It will be seen that as each of the ram assemblies is indexed through its 360° cycle, the entire tool can be lowered into the excavation a height h which is equal to the height of ram shoe 22.
Where it is desirable or necessary to employ a drilling fluid to act as a vehicle for removal of displaced soil, fluid is introduced through line 27 and discharged into the excavation through aperture 28 in lead point 13. The fluid may then be pumped out employing pump 17 and line 16.
In some instances it may be desirable to utilize the drilling fluid as a lubricating agent, particularly where following shield 15 is employed. In such circumstances, a valve (not illustrated) can be placed in line 16 and the discharge flow of drilling fluid through line 16 can thereby be partially or completely blocked, forcing the drilling fluid around the periphery of ram assemblies 12 and into the space between the excavation and the outer wall of following shield 15.
To assist in maintaining side wall stability of the ram in the soil, a soil stabilizing fluid such as a slurry of portland cement and water may be injected into the excavation. To this end, the slurry may be introduced into line 27 and discharged through aperture 28 in lead point 13.
In order to prevent drilling fluid and soil stabilizing fluid from passing upwardly through the interior of the following shield 15, there is provided liquid impermeable diaphragm 18 disposed in liquid sealing engagement with the shaft 14, and through seal 19, in liquid sealing engagement with the interior surface of following shield 15.
Following shield 15 may be dispensed with where the excavation is formed in soil which is securely stabilized by ramming action. Where soil conditions dictate the use of following shield 15, it is convenient to transmit torque to the shaft 14 from beyond the outer surface of the shield, for example, by applying a turning force to members 29. The force is transmitted to shaft 14 by braces 20. Rotation of shield 15 provides the additional advantage of lessening the tendency of the shield to bind in its frictional engagement with the surrounding soil. This facilitates the advancement of the shield into the soil as well as its later removal if required. To permit operation of the hole forming tool without the shield, it is necessary to provide suitable means (not illustrated) for releasably securing the shield to braces 20, or for releasably securing braces 20 to shaft 14.
After hole forming tool 11 has been advanced to full desired depth, ram assemblies 12, or at least the uppermost ram assembly, is fully retracted and the tool may be removed by application of upward hoisting force on the tool. A hardenable cementitious slurry such as mortar or concrete may be injected through line 27 and discharged through aperture 28 in lead point 13, as the tool is withdrawn, to form a structural bearing member. Shield 15, if used, may be left in place or withdrawn.
To start the excavation of a hole, tool 11 is advanced into a pilot hole having a diameter approximately equal to the retracted diameter d of the lowermost ram assembly. The pilot hole may be formed by conventional means such as a displacement screw on lead point 13, which is advanced into the soil by rotating shaft 14. In soft soil, the pilot hole may be formed simply by lowering tool 11 and permitting lead point 13 to sink into the soil under the weight of the tool. In hard soil, it may be necessary to inject drilling fluid under high pressure into line 27 and to remove the drilling fluid and displaced soil through line 16 and discharge pump 17.
Under circumstances where it is desirable to operate the tool without a lead point, it is necessary to separately predrill a hole at least equal in diameter to the retracted diameter of the lowermost ram assembly.
By way of example, and with reference to FIGS. 2, 3, cylinder 21 may be actuated by hydraulic fluid at pressures in the range of 5,000 to 10,000 psi. The working surface area of ram shoe 22 and its ratio with the surface area of the piston in the cylinder 21 may be selected so as to permit application of a ramming force against the soil on the order of 1,000 psi. Since the flow rate of the hydraulic fluid is relatively low, on the order of one-quarter to one-half gallon per minute per cylinder, overall horsepower requirements of the ram assemblies may be as low as two and one-half horsepower per foot of hole diameter.
The embodiment described above utilizes horizontally opposed ram wing means movable radially with respect to the shaft of the hole forming tool. The invention contemplates hole forming tools in which the movement of the ram wing means follows different paths with respect to the shaft of the tool, and one such arrangement is illustrated in FIG. 5. Here, the ramming means comprises ram shoe 30 which is pivotally mounted at 31 to shell 32. The free end of ram shoe 30 is connected to piston rod 33 which in turn is connected to hydraulic cylinder 34. The location of ram shoe 30 in its extended position is illustrated in phantom lines.
The invention may also be used to advantage in the formation of noncircular apertures. One such application is the construction of diaphragms of concrete within a soil body as illustrated in FIG. 6. Here the hole forming tool comprises shaft 35 upon which are mounted a series of vertically disposed, stepped ram assemblies 36 which, by incremental ramming action of ram shoes 37 enlarge a small slot shaped hole initiated by lead point 38. Drilling fluid may be pumped through shaft 35 and discharged from aperture 39 in lead point 38 to lubricate passage of the tool through the soil, and to aid in the compaction, displacement and/or removal of soil particles. Following shield 40 may be used to maintain stability of the side walls of the hole during its formation.
In operation, it may be convenient to first drive into the soil structure steel member 41 which serves as a reaction member against which ram assemblies 36 push during formation of the first concrete diaphragm panel 42. Once this first panel is formed and the concrete has hardened, the panel itself serves as a reaction member, during formation of the adjacent panel. The leading edge of each panel may be shaped, for example as illustrated at 43, to provide alignment means for the formation of succeeding concrete panels.
A further embodiment of the invention is illustrated in FIG. 7. Here the hole forming tool comprises shaft 44, and a ram assembly designated generally as 44a, having ramming means comprising a series of hydraulic cylinders 45 disposed radially and symmetrically with respect to shaft 44. Each hydraulic cylinder 45 is of the single acting variety, and through piston rod 46, actuates ram shoe 47.
The ram wing means thus described, consisting of six ram shoes, each actuated by its own hyraulic cylinder, permits simultaneous actuation of all cylinders 45. Since each cylinder is opposed by a separately actuated cylinder 180° out of phase with it, simultaneous operation of opposed cylinders provides a counter-balancing of identical forces in opposite directions, maintaining the centering and alignment of the hole forming tool.
The advantage of the arrangement illustrated in FIG. 7 is that the tool need be indexed less frequently to effect an enlargement of the entire periphery of the excavation. Thus, with hydraulic cylinders 45 actuated in the positions illustrated in FIG. 7, ram shoes 47 will compact soil segments a. By indexing the tool a first time, and actuating hydraulic cylinders 45, ram shoes 47 will compact soil segments b. By indexing the tool a second time and actuating hydraulic cylinders 45, ram shoes 47 will compact soil segment c. In this manner, the entire periphery of the aperture, consisting of soil segments a, b and c, is compacted with only two indexing steps of the hole forming tool. Further, it will be seen that sufficient overlap of ramming trajectory is provided so that substantially continuous soil compression is effected along the periphery of the hole.
In the various embodiments illustrated above, the ram assemblies and the retracted positions of the corresponding ramming means have been fashioned stepwise, while the length of movement of ram wing means from the retracted position to the extended position have been held constant. FIG. 8 illustrates an embodiment of the hole forming tool in which the reverse is true.
With reference to FIG. 8, it will be seen that the hole forming tool comprises shaft 48 upon which are mounted a series of ram assemblies 49 and lead point 50. It will be noted that the superposed ram assemblies are all of identical diameter. It will be noted however that the distance the ram shoes 51 move from a retracted to an extended position varies incrementally. Thus, the lowermost ram shoe 51 moves a distance s/2 from its retracted position to its extended position while the next above ram shoe 51 moves a distance of s. The uppermost ram shoe 51 moves a total distance of 4s from its retracted position to its extended position. In all other respects the operation of the ram assembly illustrated in FIG. 8 is substantially the same as that described in connection with the embodiment illustrated in FIGS. 1-4.
As previously indicated the method and apparatus of the present invention may also be used to enlarge an existing hole. Such an existing hole may be one which was drilled in a relatively small diameter to satisfy one purpose, and which now can serve a new function if enlarged.
In some situations it may be desirable to form a pilot hole for example of diameter d (FIG. 4), by conventional means, before employing the method and apparatus of the present invention. This has the effect of reducing the amount of soil compaction which must be accomplished by the method and means of the present invention. This could be advantageous when operating in soils which are difficult to compact.
If the existing hole has been filled with drilling mud to effect dimensional stability of the hole, it would be advantageous to retain lead point 13. If the existing hole is empty, and extends to the desired depth, the lead point can be dispensed with.
It will be appreciated that other embodiments, modifications, variations and applications of the invention will occur to those having ordinary skill in the art. For example, hole forming tools can be designed to form asymmetrical excavations as well as circular excavations. Further, the excavations need not be vertical as generally illustrated in the figures accompanying the application, but may be horizontal and at any angle between the horizontal and vertical. | A hole is formed in soil by penetrating it with a tool comprising a shaft having a tapered point or auger of relatively small cross section attached to its lower end, and a series of outwardly pressing rams mounted on the shaft above the tapered point. The rams are effective successively to enlarge incrementally by outward compaction or displacement of the soil, the hole initially formed by the tapered point or auger. Full hole dimension above the tool is maintained by reason of the fact that the soil is incrementally compacted and compressed to resist collapse. If desired, the integrity of the hole may be preserved with the aid of a following shield, or the hole may be filled with soil stabilizing fluid such as drilling mud. After formation of the hole, the tool is withdrawn and the hole may be filled with concrete to form a load supporting column or it may be left as an open shaft.
The method and apparatus may also be used to enlarge the diameter of an existing hole. | 4 |
BACKGROUND OF THE INVENTION
This invention relates to a smoothing iron with a shoe and a soleplate that are connected with each other with an adhesive.
A smoothing iron of this type is known in which the iron's shoe is cast. Then a soleplate is fastened to the shoe. For fastening, applicant has knowledge of a variety of approaches. For example, the soleplate may be riveted to the shoe, such riveting being in particular possible in a steam discharge port of the soleplate. In addition, the possibility exists to weld bolts to the soleplate which pass through the shoe. These bolts may then be caulked to the shoe or alternatively, they may be provided with a thread in which case the connection between the shoe and the soleplate is established by means of a nut engaging the bolt. Equally, the shoe and the soleplate may also be welded together--as by means of a laser beam. Apart from these types of fastening, it is also known from GB-A-2 225 345 to secure a soleplate member and a cover plate together by means of an adhesive--for example, on silicone basis. These joining methods may also be applied in combination.
It is an object of the present invention to improve the attachment of a soleplate to a shoe of a smoothing iron.
SUMMARY OF THE INVENTION
According to the present invention, this object is accomplished by changing the spacing between the shoe and the soleplate across the are of the shoe.
As becomes apparent, this invention is capable of solving hitherto existing problems in a surprisingly simple manner. In the securing of the shoe to the soleplate, difficulties reside in that the fastening of the shoe to the soleplate presents problems in cases where adhesive bonding over a surface area is chosen, because mechanical stresses may occur due to different coefficients of thermal expansion of the shoe and the soleplate. Also, mechanical stresses may occur in cases where the soleplate's smoothing surface is coated. The coating preferably serves the purpose of imparting higher hardness and improved sliding ability to the smoothing surface. However, the coating may have a coefficient of thermal expansion that differs from that of the soleplate material. In this case, a bimetal effect occurs, that is, the soleplate experiences a deflection.
The adhesive which is preferably an adhesive on the basis of silicone has a certain elasticity also in dried or cured condition. With different relative distances of the shoe to the soleplate at different locations, the elasticity of the joint between the shoe and the soleplate at these different locations is also different. Where this distance is wider, a thicker adhesive layer between the shoe and the soleplate results. Because of this thicker adhesive layer and the adhesive's elasticity, the joint between the shoe and the soleplate has at these locations a higher elasticity than at the locations where the adhesive layer is thinner. Accordingly, by proper arrangement of these different relative distances of the shoe to the soleplate, it is possible for the shoe and the soleplate to operate in opposition to each other when heated, without this impairing the durability of the adhesive bond between the shoe and the soleplate. This has a particularly advantageous effect when the soleplate has a bimetal effect on heating and/or has a coefficient of thermal expansion differing from that of the shoe.
Advantageously, therefore, the different relative distances are dimensioned such that at the locations where a wider distance occurs between the soleplate and the shoe because of a bimetal effect of the soleplate upon heating, the relative distance of the shoe to the soleplate is wider also in unheated condition. The same applies in cases where the coefficients of thermal expansion of the shoe and the soleplate differ. Conveniently, in this case the relative distance of the shoe to the soleplate shows higher values at those locations where a larger displacement results on account of the different coefficients of thermal expansion upon heating.
According to one embodiment of the invention, a flexible connection is provided between the shoe and the soleplate, the flexibility increasing as the distance from a line increases. In the advantageous embodiment described, the flexibility increases in the longitudinal direction of the smoothing iron.
In another embodiment, starting from a line passing through the center of gravity of the iron's area, the flexibility increases in either direction away from the line.
In another advantageous configuration the flexibility of the connection between the shoe and the soleplate increases in the transverse direction of the smoothing iron.
Advantageously that, starting from this line through the center of gravity of the iron's area, the flexibility increases in either direction away from the line.
In the longitudinal direction of the lines, the distances transverse to the lines where the relative distances of the shoe to the soleplate result may have different values. Thus, for example, it is possible to make provision for a specified relative distance of the shoe to the soleplate along the outer edges of the smoothing iron. At the forward end of the iron, the specified distance then results at a smaller distance transverse to the line in the iron's longitudinal direction than at the rear end of the iron. Correspondingly, a greater distance results transversely to a line in the transverse direction of the iron in the center of this line, in which the specified relative distance of the shoe to the soleplate is achieved, than it does in the proximity of the points where this line intersects the outer edges of the smoothing iron.
In still another embodiment the additional mechanical fastening enables the shoe and the soleplate to be attached to each other in a particularly secure manner. Spot fastening or localized fastening has the advantage of enabling the shoe and the soleplate to be floatingly held in the area surrounding this mechanical fastening, thus preventing or reducing mechanical stresses.
In another embodiment, the shoe can be provided with steps, wherein the spacing between the shoe and the soleplate changes discontinuously across the steps. The spacing can be set to specific predetermined values.
In yet another embodiment it proves advantageous that a direct metal-to-metal contact exists between the shoe and the soleplate when the iron is cold or has cooled off. This ensures a particularly good heat transfer. Particularly advantageously, these locations are arranged within, or in close proximity to, the areas where the relative distance of the shoe to the soleplate is the largest. By reason of the adhesive's reduced heat transfer as compared with that obtained by metal-to-metal contact, it is thus possible to ensure good heat transfer also at locations where the heat transfer would be otherwise reduced because of the thickness of the adhesive layer. Moreover, in such a configuration of a smoothing iron it is also ensured that the shoe and the soleplate are at a constant relative distance during assembly, also when the shoe and the soleplate are pressed against each other. In this arrangement, the locations where direct contact exists between the shoe and the soleplate serve as spacing means. Deformation of the soleplate during assembly can be thereby avoided.
With the smoothing iron according to claim 10, the manufacturing process of the iron may be carried into effect particularly readily. By suitably shaping the mold of the shoe it is comparatively easy to shape the underside of the shoe correspondingly thereby greatly simplifying the manufacturing process. Advantageously, provision may be made to the effect that in a stepwise variation of the relative distance of the shoe to the soleplate the transitions between these areas do not extend vertically but are inclined at an angle of 10°, approximately, relative to the vertical, thus enabling the mold to be removed readily on completion of the casting operation.
In another advantageous embodiment, the outsides of the smoothing surface have a larger relative distance of the shoe to the soleplate is obtained than in the inward area of the smoothing surface. By arranging for the steam distribution duct to separate these two areas, the iron can be manufactured with particular ease. In addition, mechanical stresses are prevented from occurring in the transition between these areas of different elasticity of the connection between the shoe and the soleplate, because the steam distribution duct forms the transition. In the area of this steam distribution duct, there is no connection at all between the shoe and the soleplate.
In yet another embodiment good heat transfer from the shoe to the soleplate is ensured also in the outer area of the smoothing surface. Because the area of direct contact between the shoe and the soleplate adjoins the inside of the steam distribution duct, a sufficient surface area is ensured for establishing an adhesive bond in the area between the steam distribution duct and the outer edge of the smoothing surface.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention illustrating the basic principle are shown in the accompanying drawings in which:
FIG. 1 is a first embodiment of a smoothing iron;
FIG. 2 is a second embodiment of a smoothing iron; and
FIG. 3 is a third embodiment of a smoothing iron.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1 is a vertical section of a smoothing iron taken in the longitudinal direction. In the illustration of FIG. 1, the iron has a shoe 101 with an underside 102 shaped in convex fashion. A soleplate 103 is joined to this shoe 101 by means of a layer of adhesive 104. Integrally cast within the shoe 101 is a heating means 105 for heating the shoe 101. The heat is transferred from the shoe 101 to the soleplate 103 whose underside 106 forms the smoothing surface. The underside 106 may be coated. In the embodiment of FIG. 1, the coating of the underside 106 has a lower coefficient of thermal expansion than the material of the soleplate 103.
As the shoe 101 is heated, transferring the heat to the soleplate 103 through the adhesive layer 104, the coefficient of thermal expansion of the coating on the underside 106 of the soleplate 103, which is lower than the coefficient of thermal expansion of the soleplate 103, causes the soleplate 103 to deflect in concave manner. This is illustrated in FIG. 1 by the dot-and-dash lines representing the soleplate 103 in heated condition. At the forward end 107 and at the rearward end 108 of the iron, the relative distance of the shoe 101 to the soleplate 103 is the largest because of the deflection. The relative distance of the shoe 101 to the soleplate 103 was the largest at these two ends also prior to the deflection of the soleplate 103 on heating. Because the adhesive layer 104 is the thickest in the area of the forward and rearward ends 107, 108 of the iron when not heated, it is precisely at these ends 107, 108 where the elasticity of the adhesive layer 104 is the highest. Accordingly, the deflection of the soleplate 103 resulting from the bimetal effect is prevented to an only lesser degree than would be the case with an adhesive layer 104 of constant thickness. Overall, therefore, the adhesive layer 104 is subjected to less mechanical stress, thus prolonging the life of the adhesive layer 104.
As becomes further apparent from FIG. 1, the location where the thickness of the adhesive layer 104 is at its minimum is relocated in the direction of the rearward end 108 of the iron as seen when looking from the center in the longitudinal direction of the iron. As a result, this location is arranged approximately in the proximity of the center of gravity of the smoothing surface area.
FIG. 2 shows likewise a vertical section of a smoothing iron taken in the longitudinal direction. In contrast to the representation of FIG. 1, however, the shoe 201 shown in FIG. 2 has its underside not shaped in convex manner. Rather, the iron of FIG. 2 has a first area 202 in which the shoe 201 and the soleplate 203 are disposed at a specified first relative distance, and a second area 205 in which the shoe 201 and the soleplate 203 are disposed at a specified second relative distance which is greater than the specified first distance. In this embodiment, the first area 202 extends in advantageous manner over the center of gravity of the smoothing surface area.
Secured to this shoe 201 is a soleplate 203 by means of an adhesive layer 204. Integrally cast within the shoe 201 is a heating means 207 for heating the shoe 201. The heat is transferred from the shoe 201 to the soleplate 203 whose underside forms the smoothing surface. The underside may be coated. In the embodiment of FIG. 2, the coating of the underside has a lower coefficient of thermal expansion than the material of the soleplate 203.
As the shoe 201 is heated, transferring the heat to the soleplate 203 through the adhesive layer 204, the coefficient of thermal expansion of the coating on the underside of the soleplate 203, which is lower than the coefficient of thermal expansion of the soleplate 203, causes the soleplate 203 to deflect in concave manner. This is illustrated in FIG. 2 by the dot-and-dash lines representing the soleplate 203 in heated condition. At the forward end and at the rearward end of the iron, the relative distance of the shoe 201 to the soleplate 203 is the largest because of the deflection. The relative distance of the shoe 201 to the soleplate 203 was the largest at these two ends also prior to the deflection of the soleplate 203 on heating. Because the adhesive layer 204 is the thickest in the forward and rearward areas of the iron when not heated, it is precisely in these areas where the elasticity of the adhesive layer 204 is the highest. Accordingly, the deflection of the sole-plate 203 resulting from the bimetal effect is prevented to an only lesser degree than would be the case with an adhesive layer 204 of constant thickness. Overall, therefore, the adhesive layer 204 is subjected to less mechanical stress, thus prolonging the life of the adhesive layer 204.
The slight chamfer of the edges in the transition from the first area 202 to the second area 205 has the effect of affording ease of manufacture of the shoe 201 in a mold. The chamfer of these edges in the transition region is 10°, approximately, relative to the vertical. In an extension of the embodiment of FIG. 2 shown, it is also possible to make provision for several steps, resulting in several areas each at a different relative distance of the shoe 201 to the soleplate 203.
FIG. 3 shows a vertical section of a smoothing iron taken in a direction transverse to the longitudinal direction. The underside of the shoe 301 is shaped such that areas 304, 305 in which an adhesive layer is present between the shoe 301 and the soleplate 303 differ each in their relative distance of the shoe 301 to the soleplate 303. Further areas 306, 307 are formed in which the shoe 301 and the soleplate 303 are in direct contact with each other.
In the area 307, a connection exists between the shoe 301 and the soleplate 303 at the joint 308. In the embodiment of FIG. 3 shown, this joint is produced by a laser beam welding technique. In this process, the shoe 301 and the soleplate 303 are pressed against each other. Then a laser beam is directed to the shoe 301 from above. This laser is advantageously an NdYAG laser. It causes melting of the shoe 301 in the area upon which the laser beam impinges. Melting also occurs on the upper surface of the soleplate 303 material. The shoe 301 and the soleplate 303 thus coalesce at this location. Area 307 is the area surrounding this laser welded joint 308. This prevents adhesive material from adversely affecting the welded joint.
Adjoining the area 307 is the area 304 in which a layer of adhesive is present between the shoe 301 and the soleplate 303. In the transition region from the area 304 to the area 307, an overflow channel 309 for receiving adhesive material is arranged. In the event of an excessive amount of adhesive being applied, this excess adhesive material would be urged, for example, also into the area 307 when the shoe 301 and the soleplate 303 are pressed together. This could have a detrimental effect on the welded joint. The overflow channel 309 serves to obviate this risk. Excess adhesive can be received by this overflow channel 309. The overflow channel 309 is thus not completely filled with adhesive. In the direction of the outer edge of the smoothing surface, the area 304 is adjoined by the area 306 in which direct contact exists between the shoe 301 and the soleplate 303. The adhesive used is of the type containing silicone and has comparatively good heat transfer properties. Yet this heat transfer is still worse than the heat transfer at the locations of direct contact between the shoe 301 and the soleplate 303. In addition, this area 306 has the effect of largely preventing the soleplate 303 from being deflected in convex fashion as it is attached to the shoe 301. In the absence of a support in the area 306, the shoe 303 would be without an abutment because of the elasticity of the adhesive layer.
A circumferential steam discharge duct 302 is arranged adjacent to the area 306 in the direction of the outer edge of the smoothing surface. This steam discharge duct 302 communicates with a steam generating chamber (not shown). After the water is changed to steam in the steam generating chamber, the steam enters the steam discharge duct 302. The soleplate 303 includes holes (not shown) disposed along the length of the steam discharge duct 302, through which holes the steam may escape to strike the article being ironed.
In the direction of the outer edge of the smoothing surface, the steam discharge duct 302 is adjoined by the area 305 in which an adhesive layer is present between the shoe 301 and the soleplate 303. The adhesive layer in the area 305 is of greater thickness than the adhesive layer in the area 304.
Thus, when a concave deflection of the soleplate 303 occurs by reason of a coefficient of thermal expansion of the coating of the soleplate 303 that is lower than the coefficient of thermal expansion of the soleplate 303, a reduced mechanical resistance operates in opposition to this concave deflection at the outer edge of the smoothing surface because of the higher elasticity of the adhesive layer there. The mechanical load imposed on the adhesive layer is thereby reduced.
A distance of between 0.1 and 0.2 mm, approximately, in particular 0.15 mm, has proven to be suitable between the shoe and the soleplate in the area filled with adhesive and in which this distance is the smallest. Advantageously, the distance between the shoe and the soleplate is between 0.5 and 1.0 mm, approximately, in particular between 0.6 and 0.8 mm, in the area filled with adhesive and in which this distance is the largest. In the areas filled with adhesive completely, a ratio of the largest distance to the smallest distance of 5 to 10, approximately, results. | The invention is directed to a smoothing iron having a shoe and a soleplate, in which the shoe and the soleplate are joined to each other by an adhesive. The spacing between the shoe and the soleplate varies across the shoe. The space between the shoe and the soleplate is filled with the adhesive. No prior mechanical treatment or heating of the shoe and/or the soleplate is required. | 3 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to direct part markings on workpieces and electro-optically reading such markings by image capture and, more particularly, to improvements in aiming, ranging and illuminating such markings, as well as calibrating imaging readers during manufacture, and self-calibrating imaging readers during reading of such markings or other indicia.
2. Description of the Related Art
Direct part marking (DPM) allows workpieces to be directly marked, identified and traced to their origin, and its use is growing in the automotive, aerospace, electronics, medical equipment, tooling, and metalworking industries, among many others. Despite the ability to control very tight specifications on element size, width, spacing and so on, the lack of sharp contrast of machine-readable optical DPM codes directly marked on metal, plastic, leather, glass, etc., workpieces prevents traditional moving laser beam readers from electro-optically reading the DPM codes reliably. These moving beam readers emit a laser beam which reflects off the metal or glass workpieces as bright light.
To counter a variety of problems, such as lack of contrast, difficulty of maintaining precise element specifications, limited available marking areas, and a large amount of data to be encoded, the art proposed the use of matrix codes, especially the DataMatrix code, which reduces the required marking element size, precision and area, as well as contrast so that markings are able to be directly made on parts with, for example, steel or aluminum surfaces, and also proposed the use of imaging readers which use solid-state arrays similar to those used in digital cameras to capture an image of the marking. A microprocessor is used to analyze and decode the captured image of the matrix code.
Yet, the use of imaging readers, especially handheld readers, for reading marked workpieces has proven to be challenging. Contrast is still often less than desirable. Ambient lighting conditions are variable. Illumination from on-board illuminators is directed at variable angles. Reflections from ambient light sources and illuminators often appear in the field of view of the reader. Unlike machine-readable codes printed in one color (for example, black) on paper of another color (for example, white), DPM codes are typically difficult for a human operator to even find on the workpieces, which often have complicated shapes to further complicate finding the DPM code and aiming the reader directly at the DPM code for reading.
SUMMARY OF THE INVENTION
Objects of the Invention
Accordingly, it is a general object of this invention to provide an improved aiming system for an imaging reader to read DPM on workpieces.
More particularly, it is an object of the present invention to provide an improved ranging system for an imaging reader to read DPM on workpieces.
Still another object of the present invention is to provide an improved illuminating system for an imaging reader to read DPM on workpieces.
An additional object of the present invention is to provide a calibrating system for an imaging reader to read DPM on workpieces, or other optical codes.
It is yet another object of the present invention to provide a self-calibrating system for an imaging reader to read DPM on workpieces, or other optical codes.
Features of the Invention
In keeping with the above objects and others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a method of, and a reader for, electro-optically reading direct part marking (DPM). In accordance with this invention, a solid-state imager is operative for capturing light over a field of view from the DPM located in a range of working distances relative to the reader. A first light projector is operative, upon activation by an operator, for example, by manually depressing a trigger, and prior to operation of the imager, for projecting a first light pattern in the field of view throughout the range. A second light projector is operative, also upon operator activation and prior to operation of the imager, for projecting a second light pattern in the field of view throughout the range in superimposition with the first light pattern. The light patterns are preferably visually different and have a predetermined visual relationship at a target plane within the range. A handheld housing supports the imager and the projectors, and is movable to a reading position in which the predetermined visual relationship is obtained to enable the imager to capture light from the DPM located in the vicinity of the target plane. For example, the human operator may perform the movement of the housing.
Preferably, the first light projector includes a first laser and a diffractive optical element for configuring the first light pattern as an aiming pattern having a marker, and the second light projector includes a second laser for configuring the second light pattern as a laser spot. In this case, the predetermined visual relationship is an overlap between the laser spot and the marker. Also, the marker is preferably crosshairs, and the aiming pattern preferably includes a frame at least partly surrounding the crosshairs.
In another preferred embodiment, the first light projector includes a first laser and a first diffractive optical element (DOE) for configuring the first light pattern as a first frame bounding a first central marker, and the second light projector includes a second laser and a second DOE for configuring the second light pattern as a second frame bounding a second central marker. The predetermined visual relationship is one of an overlap between the first and second markers and a contact between the first and second frames.
Another feature resides in an illuminator in the housing for illuminating the DPM during image capture by the imager. The imager may be located at a centerline of the housing. Alternatively, the imager and the illuminator are located at opposite sides away from a centerline of the housing. An off-center illuminator creates enhanced and emphasized shadows in the DPM and enhances contrast.
Yet another feature resides in storing coordinates of an overlapped point of two markers (including one marker and one laser spot) within the field of view to calibrate the reader, and to provide additional information to improve image capture and processing.
Still another feature resides in storing coordinates of the markers (including laser spots) within the field of view during successive readings to self-calibrate the reader.
The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an imaging reader for electro-optically reading by image capture direct part markings on workpieces in accordance with this invention;
FIG. 2 is a diagrammatic plan view of an aiming and ranging system for use in the reader of FIG. 1 ;
FIG. 3 is a perspective, schematic view of details of the system of FIG. 2 ;
FIG. 4 is a perspective view of various light patterns produced by the system of FIG. 2 during use;
FIG. 5 is a diagrammatic plan view of a ranging and focusing system for use in the reader of FIG. 1 ;
FIG. 6 is a perspective view of various light patterns produced by the system of FIG. 5 during use;
FIG. 7 is a view analogous to FIG. 2 , but of a different embodiment; and
FIG. 8 is a diagrammatic view depicting operation during automatic self-calibration in accordance with this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference numeral 10 in FIG. 1 generally identifies a handheld imaging reader for electro-optically reading DPM on workpieces. The reader 10 includes a housing 12 in which the various aiming, ranging, illuminating, calibrating and self-calibrating systems, as described in detail below in accordance with this invention, are incorporated. The housing 12 includes a generally elongated handle or lower handgrip portion 14 and a barrel or upper body portion 16 having a front end at which a light-transmissive window 18 is located. The cross-sectional dimensions and overall size of the handle 14 are such that the reader can conveniently be held in a user's hand. The body and handle portions may be constructed of a lightweight, resilient, shock-resistant, self-supporting material such as a synthetic plastic material. The plastic housing may be injection molded, but can be vacuum-formed or blow-molded to form a thin hollow shell which bounds an interior space whose volume is sufficient to contain the various systems of this invention.
A manually actuatable trigger 20 is mounted in a moving relationship on the handle 14 in a forward facing region of the reader. The user's forefinger is normally used to actuate the reader by depressing the trigger. A flexible electrical cable 22 may be provided to connect the reader to remote components of the code reading system. In alternative embodiments, the cable may also provide electrical power to the systems within the reader. In preferred embodiments, the cable 22 is connected to a host 24 which receives decoded data from the reader. In alternative embodiments, a decode module 26 may be provided exterior to the reader. In such an embodiment, decoded data from the decode module 26 may be transmitted to further host processing equipment and databases represented generally by box 28 . If the cable 22 is not used, then a wireless link to transfer data may be provided between the reader 20 and the host 24 , and an on-board battery, typically within the handle, can be used to supply electrical power.
An alternative embodiment incorporates a display and a keyboard, and optionally a wireless transceiver, preferably with an on-board decoder. The decoded data is then either transferred to a remote host computer in real time, or saved to an internal memory such that the stored data can be transferred to a host computer at a later time in batch mode, when the reader is physically connected to such a connected host computer.
A solid-state imager 30 , as shown in FIG. 2 , is mounted within the housing 12 and preferably is a two-dimensional, charge coupled device (CCD) or complementary metal oxide semiconductor (CMOS) array of cells or sensors operative for capturing light over its field of view from the DPM through the window 18 and into a lens assembly 32 . The sensors produce electrical signals corresponding to a two-dimensional array of pixel information for an image of the DPM. The imager 30 and lens assembly 32 are aligned along a centerline or an optical axis 34 generally centrally located within the body portion 16 . As shown in FIG. 2 , the lens assembly 32 has a fixed focus and enables image capture over a range of working distances between close-in distance WD 1 and far-out distance WD 2 relative to the window 18 . The imager and lens assembly are capable of acquiring a full image of the DPM in lighting conditions from two lux to direct sunlight. Exposure time is about 15 milliseconds. Resolution of the array can be of various sizes although VGA resolution of 640×480 pixels is preferred.
An illumination source 36 for the imager 30 is also provided to provide an illumination field for the imager. The source 36 preferably constitutes a plurality of light emitting diodes energized by power supply lines in the cable 22 , or via the on-board battery. The source 36 is preferably pulsed in synchronism with the imager 30 .
In accordance with the known art as exemplified by U.S. Pat. No. 6,340,114, an aiming and framing system employs a laser source and a diffractive optical element (DOE). In accordance with this invention, the aiming and framing system is enhanced to also function as a ranging system, which is employed to improve performance of the imaging reader by assisting the user in locating the ideal target plane within the working range at which to read the DPM. In DPM, the working range is often short and, as described above, the poor contrast, the complicated shapes of the workpieces, the variable ambient lighting conditions, and so on, make it difficult for the user to find the DPM and aim the reader directly at the DPM.
As shown generally in FIG. 2 , and in more detail in FIG. 3 , an aiming system or first light projector includes a laser diode 38 , a focusing lens 40 , and a DOE 42 . The diode 38 preferably has an output power of 5 milliwatts, a wavelength of 650 nanometers, and emits a laser beam 44 through the lens 40 , and optionally for reflection off a fold mirror 46 , through the DOE 42 . The DOE 42 produces multiple diverging beamlets which exit the window 18 along optical axis 45 to project an aiming pattern through the working distance range as, for example, represented in FIG. 3 by a hypothetical target plane 48 . The target plane 48 should be taken to correspond to any particular target plane in which the DPM might lie within the working distance range.
As shown in FIG. 3 , the beamlets emanating from the DOE 42 project continuous lines or lines of spots in the direction of the target plane. These lines or spots are arrayed in a particular pattern suitable for providing a useful aiming frame to assist an operator in pointing the handheld reader at a target DPM code. An aiming frame 52 consists of four corner markers. Each of these corner markers itself consists of two intersecting continuous lines or lines of spots. The lines intersect at a 90° angle forming corners of a frame which corresponds generally to the angular field of view of the lens 32 . Where spots are employed, the spots which form the corners are preferably four in each line, each line sharing the corner-most dot. A center marker 50 consists of two intersecting continuous lines or lines of spots, the lines intersecting at a 90° angle, thereby resembling crosshairs. Diffractive optics aiming creates a bright, crisp aiming pattern which provides ready feedback to the operator regarding image framing and centering and is similar to the aiming pattern found in many camera viewfinders.
As described so far, an aiming pattern consisting of a frame 52 and crosshairs 50 is generated at a hypothetical reference plane 48 within a range of working distances between WD 1 and WD 2 . As shown in FIG. 4 , the aiming pattern expands as the distance between the DPM and the reader increases in a manner consistent with the expanding field of view of the imager 30 . Pattern 54 is closer to the reader. Pattern 58 is further from the reader. Pattern 56 is located between the patterns 54 , 58 .
Another laser diode 60 and another focusing lens 62 constituting a second light projector are mounted in the reader of FIG. 2 and are operative to emit a laser beam along optical path 64 to produce a beam spot 66 in the field of view of the imager 30 within the aiming patterns 54 , 56 , 58 . The second light projector adds the functionality of ranging. The center of the working distance range, i.e., the ideal distance to the target plane, is indicated by an overlap between the beam spot 66 and the crosshairs 50 , and is depicted in FIG. 4 by pattern 56 . In pattern 54 , the beam spot 66 is shifted to the right of the crosshairs 50 , thereby indicating that the DPM is located in a target plane too close to be read. In pattern 58 , the beam spot 66 is shifted to the left of the crosshairs, thereby indicating that the DPM is located in a target plane too far to be read.
In use, once the trigger 20 is depressed to initiate decoding, the light projectors are energized, and the user sees the beam spot 66 and the aiming pattern on the workpiece and moves the handheld reader toward or away from the workpiece until the beam spot 66 overlaps the crosshairs 50 . The user has now found the ideal distance to the DPM to be read and, of course, has centrally located the DPM within the aiming pattern. The imager is alternately activated with the aiming and ranging system after depression of the trigger such that when image quality is sufficiently good, a successful decode would be accomplished, even if the operator is still adjusting the distance between the reader and the workpiece.
The lens 32 of FIG. 2 need not be fixed, but could be movable, as schematically depicted in FIG. 5 , between a pair of positions. Dual-focus readers, such as disclosed in U.S. Pat. No. 6,726,105 and U.S. Pat. No. 6,336,587 are used in order to enable the imager 30 to capture images at a near focus position or a far focus position, thereby greatly extending the working range. An alternative embodiment, as shown in FIG. 5 , indicates the range for both focal positions and includes two groups of laser diodes 68 , 70 , two focusing lenses 72 , 74 , and two DOEs 76 , 78 . Each diode, lens and DOE group creates an aiming pattern in a manner analogous to that described above for diode 38 , lens 40 , and DOE 42 in connection with FIGS. 2–3 . In this embodiment, the aiming pattern is different and comprises a diamond shaped frame 80 , 82 (instead of, or in addition to, four corners 52 ) and a central dot (or, alternatively, the crosshairs 50 ) for each group.
As shown in FIG. 6 , frames 80 , 82 from both groups expand in size as a function of increasing distance from the reader. The “near focus” position is indicated when the near corners of the diamond shaped frames 80 , 82 touch. The “far focus” position is indicated where the central dots within the frames 80 , 82 overlap. A “too close” position is indicated by a separation between the frames.
Thus, in use, a focus position is chosen, either by the user or via a programmed controller, prior to image capture based on a variety of criteria such as the code type (e.g., paper or DPM), or the code size (e.g., low- or high-density DPM). The user moves the handheld reader toward or away from the DPM until a desired focus position is indicated, or until a successful image capture and decode are achieved.
FIG. 7 depicts another embodiment similar to that shown in FIG. 2 , except that the imager 30 is not centrally located along a centerline of the body portion 16 of the reader, but instead is located remotely from the centerline. Also, the light source 36 is positioned off-center within the reader. The angle of illumination is thus more oblique. Oblique illumination creates distinct and contrasting highlights and shadows which greatly improve the visibility of DPM produced by laser etching or dot-peening of workpieces. A ranging system is not shown in FIG. 7 for simplicity. The illumination feature does not preclude or demand the ranging system.
The aiming and ranging systems assist the user to improve reader performance. They are turned off during image capture, a necessary step in decoding DPM. This is because the laser beams are very bright compared to any other source of illumination, and thus, if left on, would saturate the parts of image where they are illuminating, and thus prevent the DPM code from being properly decoded. However, due to manufacturing variations, the aiming systems of different readers do not necessarily aim at the same image coordinates. One objective of the present invention is to allow a user to use the aiming system to point to the DPM code during scanning, and have the reader know to where the user is pointing to facilitate setting the exposure of the imager and finding the code. To function as such, each imager must be calibrated during manufacture.
In the calibration process, the exact locations of the aiming pattern, through different working distances, are captured in the image, and recorded as calibration data in a permanent memory of the reader. This process can be automated, by capturing images, at different working distances, of a known, such as uniform, background, (e.g., a plain piece of paper), but with the aiming pattern turned on during image acquisition.
Additionally, when the reader contains a secondary light projector for ranging purposes, the calibration data can contain the exact location of the point where the two light patterns or markers meet. This data is obtained by capturing an image with the target at the exact plane where the patterns or markers meet, overlap, or assume some predetermined relationship.
Depending on the design, however, it is possible for the calibration data to be invalidated by motion between the imager and the aiming system. Such motion could be caused by shock impact. In other words, while the calibration data is expected to be intact over a period of usage, the relative position and/or orientation of the imager and the aiming system may shift such that the calibrated data does not indicate where the aiming pattern is trained at anymore. This is expected to be less of a problem for longitudinal shift, or shift along the optical axis, as there is always a working range in which the codes would come into clear enough focus. However, the problem is more pronounced for lateral shift, as a small relative rotation could mean a large discrepancy between the location of the DPM code in the image and the location indicated by the calibration data. It is thus advantageous to perform calibration on a set interval during use, or to perform it whenever the imager shows reduced performance that cannot be attributed to other, more obvious, reasons, such as a dirty window.
One preferred method to correct the problem of “calibration lateral shift or drift” is an automatic recalibration (ARC) method described herein. By “automatic”, it is meant that the user is not required to knowingly and actively participate in the method. The ARC necessarily differs from normal calibration done in the factory, as it is not assured that the target being scanned is in perfect focus. However, as can be proven mathematically, the trajectory of the laser dot 66 in the image, while the laser dot is imaged at different focal distances, forms a straight line 84 as depicted in FIG. 8 . The same is also true for a straight line 86 along which the centers of the crosshairs 50 lie. The straight line 86 is the desired line of calibration. The intersection of these two straight lines 84 , 86 is the desired calibration point 88 .
Therefore, to perform ARC, a set of images at different distances is taken, while the laser ranging features are turned on (same as in normal calibration). The images can be taken at different times, such as one image every time after the imager has performed a successful DPM reading. The images are not stored; rather, the coordinates (of two light patterns, such as the laser spot and the laser crosshairs) found from within them are stored. The set of coordinates derived this way are gradually updated to keep track of the “calibration drift”, thus achieving ARC. Using this method, it is not necessary that an image be taken with the two laser-features overlap.
To successfully perform ARC as described here, two design constraints must be considered. First, the two laser beams should not be coplanar with the optical axis of the imager; otherwise, the two trajectories would be co-linear, and ARC as described here would not work. The other is that the two laser patterns that are meant to meet each other at the exact focus must be easily distinguishable. This second condition is satisfied by the first ranging feature discussed above, but not the second, unless the center dot in one of the patterns is changed into something else, such as crosshairs. Alternatively, the second condition can be replaced by one that enables images to be taken with only one laser projector turned on at a time, thus avoiding confusion between the two.
It will be understood that each of the elements described above, or two or more together, also may find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in an imaging reader for electro-optically reading DPM, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims. | Performance of an imaging reader for electro-optically reading direct part markings on workpieces is enhanced by ensuring that such markings are read in the vicinity of an ideal, focused, target plane, and by enhancing the contrast of such markings. Calibration and self-calibration of the reader improve performance. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for investigating causes of abnormal events in support of plant operations, which method is used in a plant operation supporting device, wherein an investigation of a cause of an abnormal event in the plant operation supporting device is performed using a relationship between the abnormal event and a plurality of factors causing this abnormal event, a fault tree chart showing relationships among the factors and events deriving them, and event evaluation values indicating a frequency or possibility of occurrence of the deriving event.
2. Description of the Related Art
FIG. 3 is a flow chart showing a diagnostic process in the plant operation supporting device.
First, if an abnormal event is detected in step S1, then in step S2 a cause of the abnormal event is investigated. During this investigation, use is made of relationships between abnormal events stored in a cause investigation knowledge base 1, and a fault tree chart (hereinafter called FT chart) 1a showing relationships among possible factors causing these abnormal events, deriving events, and factors for the deriving events. Then in step S3, a countermeasure is searched in order to solve the cause found in step S2. At this time, countermeasures which may be considered as candidates for dealing with each factor are searched in a countermeasure-search knowledge base 2. In step S4, it is checked if any problem would occur when an operator executes the countermeasures searched in step S3. For this, use is made of items to be checked regarding the countermeasures obtained from a countermeasure-checking knowledge base 3. Then in step S5, the operator is advised of the determined cause and the countermeasures to be taken.
Conventionally, diagnosis has been performed mainly using a MYCIN method in the investigation of the cause of the abnormal event in step S2. This MYCIN is the name of a product operated in a computer for dealing with medical diagnosis developed by Shortliffe at Stanford University in 1976, and recently this is employed not only in medical diagnosis, but also in a wide range of fields such as investigation of causes for abnormal events occurring in plants. FIG. 4 is a drawing explaining this MYCIN technique. According to the MYCIN technique, common abnormal events may be illustrated by an FT chart in FIG. 4.
In FIG. 4, factors 10A to MOA possibly cause an abnormal event 100A. Deriving events 11A to 1NA derive factor 10A, and deriving events M1A to MKA derive factor MOA.
Symbols R attached to factors 10A to MOA are empirically obtained weight coefficients having values of 0 to 1. R i indicates a strength of a relationship between abnormal event 100A and each of factors 10A to MOA. If the corresponding abnormal event 100A always occurs when the relevant factor occurs, R i takes a larger value. R ij indicates strengths of relationships between factors 10A to MOA and deriving events 11A to MKA. If the corresponding deriving event always occurs when the relevant factor occurs, R ij takes a larger value.
V is an event evaluation value indicating the frequency or possibility of occurrence of a deriving event. V 11 to V MK are, as illustrated in 11a, calculated using a threshold function.
According to the MYCIN method, when an abnormal event occurs, certainty values CF of factors possibly causing this abnormal event are obtained by means of equation (2) described below, and the factor having the largest certainty value CF is diagnosed as a cause of the currently occurring abnormal event.
CF.sub.i =R.sub.i (1-R.sub.i1 V.sub.i1)(1-R.sub.i2 V.sub.i2) . . . (1-R.sub.ij V.sub.ij) (2)
As described above, conventionally, the MYCIN method has been utilized in the plant operation supporting device for investigating causes of abnormal events. In ordinary plants, however, when a-factor causing such an abnormal event occurs, deriving events similar to it deriving other factors often occur. Therefore, the MYCIN method only allows indication of probable factors causing the current abnormal event, and it has not been possible to identify a true cause among those probable factors.
FIG. 5 is a view showing a lubricating oil system of a steam turbine for the purpose of illustrating the above-described problem more in detail. In the drawing, 4a is a high-pressure turbine, 4b is a low-pressure turbine, 5 is a generator connected to these, 6 is an oil cooler, 7 is an oil temperature control valve, 11 is a cooling water temperature, 21 is a cooling water pressure, 31 is a lubricating oil supplying temperature, 41 is a thrust bearing waste oil temperature, and 51 is a waste oil temperature of each bearing. This is a system in which when an abnormal event called "increase in steam turbine bearing temperature" occurs due to an increase in the cooling water temperature, the temperatures of the lubricating oil, thrust bearing waste oil and bearing waste oil will also increase correspondingly. In this case, as shown in an FT chart of "increase in steam turbine bearing temperature" in FIG. 6, when diagnosis is performed using the MYCIN method, weight coefficients R 1 to R 5 of factors 10B to 50B are all 1.0 with respect to an abnormal event 10B "increase in a steam turbine bearing temperature", weight coefficients of deriving events 11B to 51B are also all 1.0 and event evaluation values V 11 to V 51 are shown as in the case of a later described table. As a result, not only the "increase in the cooling water temperature", but also such other factors as "oil temperature control valve failure", "thrust bearing abnormal event", "bearing abnormal event", and the like are cited as possible factors causing the current abnormal event, and it is impossible to further narrow the factors and find a true cause by means of the MYCIN method.
Therefore, with the conventional plant operation supporting device using the MYCIN method, it has been very difficult for the operator to determine which countermeasure is relevant because all the countermeasures to deal with the indicated factors are displayed, and it has not been possible for the operator to take a countermeasure by referring to such output immediately after an abnormal event occurs. That is, it has been a far cry from an ideal state of the plant operation supporting device in which even an unskilled operator can operate the plant just as well as a highly skilled operator can do.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a method for finding a cause of an abnormal event in support of plant operations, wherein accuracy of finding the cause from the factors indicated according to the MYCIN method can be improved by narrowing down the factors using a new method in which AND diagnosis is proposed, while the MYCIN method allows only OR diagnosis.
A first aspect of the present invention provides a method for finding a cause of an abnormal event in support of plant operations in which the investigation of a cause of an abnormal event is performed in the plant operation supporting device, using a relationship between the abnormal event and a plurality of possible factors causing this particular abnormal event, a fault tree chart showing relationships among such factors and deriving events thereof, and event evaluation values indicating frequencies of occurrence of the deriving events, wherein a deriving event in the negative form negating deriving events which would not possibly occur if one of the factors is the cause of the abnormal event and which derives another factor different from said one of the factors is added to the fault tree chart as a deriving event of said one of the factors.
A second aspect of the invention provides a method for finding a cause of an abnormal event in support of plant operations according to the above first aspect, as an event evaluation value for each of the deriving events is provided as V ij a certainty CF i of each factor is calculated using equation (1), and a factor having the largest value among the calculated values of certainties CF i is adopted as the cause of the abnormal event.
According to the first aspect of the invention, in the method for finding a cause of an abnormal event in support of plant operations, with respect to events which would not possibly occur if one of a plurality of factors is a cause of the abnormal event and which derives other factors, a negative deriving event negating such deriving events of another factor different from said one of the factors is added to the fault tree chart as a deriving event of said one of the factors. Therefore, the amount of information concerning each factor to be used for investigating the cause of abnormal events increases, and the accuracy of finding the cause thereof improves.
According to the second aspect of the invention, in the method for finding a cause of an abnormal event in support of plant operations, if an event evaluation value V ij is given respectively for a case in which each deriving event occurs and for a case in which each deriving event does not occur, by means of equation (1), a factor having a largest certainty value CF i is determined with higher credibility to be the cause of the abnormal event.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a chart explaining the method for finding a cause of an abnormal event according to the present invention;
FIG. 2 shows an improved FT chart of a steam turbine bearing temperature increase relating to an example of the invention;
FIG. 3 is a flow chart showing a diagnosing process in a plant operation supporting device;
FIG. 4 is a chart explaining the method for finding a cause of an abnormal event using a MYCIN method;
FIG. 5 is a conceptual drawing for a steam turbine lubricating oil system; and
FIG. 6 shows a conventional FT chart of steam turbine bearing temperature increase.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
EXAMPLE 1
Explanation will now be made of the examples of the invention referring to the accompanying drawings.
FIG. 1 is a conceptual view of an example of the invention, in which with respect to each factor (only 10C is shown in the drawing), negative deriving events 12C to 1MC negating events which would not possibly occur if this factor 10C is a cause of the current abnormal event and which derive another factor are, as described later, obtained from 121C to 1MLC, and these are added to the FT chart shown in FIG. 4 as deriving events of factor 10C.
According to the invention, certainties or credibilities of factors cited as possible causes by means of the conventional MYCIN method are calculated using an equation described below, and a factor having the highest certainty is determined to be a cause of the current abnormal event. That is, existence of deriving events which would never occur if this factor is the cause of the abnormal event is checked, and when these have occurred, the certainty of this factor is automatically made low. By repeating this process, a factor whose certainty remains highest at the end is determined to be the cause of the current abnormal event.
An event evaluation value of a given factor 10C (indicating occurrence or non-occurrence of deriving events of this factor) V i1 is calculated using equation (2) below. This is the same as in the case of the conventional MYCIN method. In the equation, V i11 to V i1N are event evaluation values for deriving events 111C to 11NC of the factor 10C, and R i11 to R i1N are weight coefficients of the deriving events 111C to 11NC.
V.sub.i1 =R.sub.i1 ' 1-(1-R.sub.i11 V.sub.i11)(1-R.sub.i12 V.sub.i12) . . . (1-R.sub.i1N V.sub.i1n)! (2)
Then, event evaluation values of other factors indicated by 12C to 1MC (indicating occurrence or non-occurrence of deriving events of the other factors) V ij (j≧2) are similarly calculated using equation (3) below.
V.sub.ij =1-R.sub.ij ' 1-(1-R.sub.ij1 V.sub.ij1)(1-R.sub.ij2 V.sub.ij2) . . . (1-R.sub.ijN V.sub.ijN)! (3)
Based on the event evaluation values calculated by means of equations (2) and (3), certainties CF i of the respective factors are calculated by using equation (1).
CF.sub.i =R.sub.i •V.sub.i1.sup.Ri1/R •V.sub.i2.sup.Ri2/R. . . V.sub.iM.sup.RiM/R (1)
(R=R.sub.i1 +R.sub.i2 +. . . +R.sub.iM)
After the certainties of the factors are obtained, the factor having the highest value of certainty CF i among the calculated certainty values CF i is adopted as the cause of the current abnormal event.
EXAMPLE 2
Next, in order to describe the invention more in detail, explanation will be made of a case where the invention is applied for finding a cause of an abnormal event in the steam turbine lubricating oil system shown in FIG. 5.
FIG. 2 shows an FT chart relating to the abnormality of "high steam turbine bearing temperature" in which the invention is employed. In the drawing, a change is made to the conventional FT chart in such a way that added thereto are deriving events in the negative form negating deriving events, indicated by 32D, 33D, 42D and 52D, among those of other factors 20D to 50D, which would not possibly occur if a given factor is the cause of the abnormality.
For example, the cooling water temperature increase may be judged to be the cause of the abnormality when the cooling water temperature is found to be higher than the normal value (11 in FIG. 4). In this case, however, it is not possible to determine whether any troubles have occurred somewhere downstream from the point of monitoring the cooling water temperature in the flows of cooling water and oil, or whether additional problems have occurred, because given that the cooling water temperature is higher than the normal value, the abnormal event of having high steam turbine bering temperature occurs regardless of any occurrence or non-occurrence of problems in the down stream of the cooling water and oil flows.
On the other hand, by making judgement concerning the negative form of deriving events somewhere upstream from a given point and finding no abnormalities upstream, it is possible to check possible causes in the down stream. For example, if "cooling water temperature increase" (10D) and "insufficient flow of cooling water" (20D) have not occurred upstream of the cooling water and oil flows, the deriving events recast in the negative form (32D and 33D) and added to the FT chart are found to be true. If then the lubricating oil supply temperature is higher than the normal value (31D), "oil temperature control valve malfunction" (30D) is found to be the cause.
Thus, negative-form deriving events negating deriving events which may occur on the upstream side of a given factor in the system flow are added to the FT chart as deriving events of the given factor. In other words, negative-form deriving events which negates deriving events possibly occurring at a location upstream from a given factor are added to each of factors located in the down stream from that factor, so as to check any occurrences of problems downstream.
Here, when an increase in the cooling water temperature is the cause (or the factor in question), event evaluation values V ij of the deriving events are respectively obtained as shown in the following table:
______________________________________Deriving event Event evaluation value______________________________________V.sub.11Cooling water temperature > normal value LargeV.sub.21Cooling water pressure < normal value SmallV.sub.31Lubricating oil supply temperature > Largenormal valueV.sub.32Cooling water temperature ≦ Smallnormal valueV.sub.33Cooling water pressure ≧ normal value LargeV.sub.41Thrust bearing waste oil temperature > Largenormal valueV.sub.42Lubricating oil supply temperature ≦ Smallnormal valueV.sub.51Bearing waste oil temperature > Largenormal valueV.sub.52Lubricating oil supply temperature ≦ Smallnormal value______________________________________
A high cooling water temperature causes the temperatures of lubricating oil supply, thrust bearing waste oil, and so on to also increase, because these oil temperatures are affected by the temperature of the cooling water. These oil temperatures can be considered to be "downstream" in the system flow. Here, when an event evaluation value is indicated to be "large", it ranges approximately from 0.7 to 1.0, and when "small", it approximately ranges from 0.0 to 0.3.
Certainties of the factors respectively calculated using equation (1) are as follows:
______________________________________Factor Certainty______________________________________CF.sub.1 Cooling water temperature increase LargeCF.sub.2 Cooling water flow shortage SmallCF.sub.3 Oil temperature control valve failure MiddleCF.sub.4 Thrust bearing abnormality MiddleCF.sub.5 Bearing abnormality Middle______________________________________
Here, when a certainty is indicated to be "large", its value approximately ranges from 0.7 to 1.0, when "middle", it approximately ranges from 0.3 to 0.7, and when "small", it approximately ranges from 0.0 to 0.3.
Thus, the certainty or credibility of the cause, that of the cooling water temperature increase in this case, is highest, making it possible for the plant operation supporting device to identify the true cause.
It is clear from the foregoing description that according to the invention, by narrowing down the cited factors, the true cause can be found from factors cited when an abnormal event occurs, and an instruction can be given to an operator as to what countermeasure is appropriate to solve the abnormality, making it possible even for an unskilled operator to take a proper countermeasure when an abnormal event occurs in much the same way as a highly skilled operator would do.
Lastly, it should be understood that the examples given above are for illustrative purposes only and by no means intended to limit the scope of the present invention. For example, choice of specific values of R i and R ij and that of deriving events to be considered have to be made for each system. They are in no way limited to the values or choices shown in the examples. Other modifications are clearly possible for a person of ordinary skill in the art without departing the scope of the present invention. | The accuracy of finding a cause from factors cited by means of a MYCIN method by narrowing down such factors is improved. With respect to deriving events which would not possibly occur if a particular factor 10C among a plurality of factors is a cause of abnormal event 100C, negative deriving events 12C and 1MC negating these deriving events of the other factors which would not occur with factor 10C being the cause are added to a fault tree chart as deriving events of factor 10C. | 6 |
RELATED APPLICATIONS
[0001] The present application claims the benefit of provisional patent application Ser. No. 60/826,530 entitled “Medical Devices and Techniques for Deriving Cardiac and Breathing Parameters from Extra-thoracic Blood Flow Measurements and for Controlling Anesthesia Levels and Ventilation Levels in Subjects” filed Sep. 21, 2006.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to medical display devices for cardiac and breathing parameters of a subject derived from extra-thoracic blood flow measurements, in particular the invention relates to medical display devices for breath rate, heart rate, blood oxygenation, breath distention, and pulse distention measurements of a subject from a pulse oximeter system coupled to the subject and for controlling the ventilation levels and the anesthesia levels based upon such measurements.
[0004] 2. Background Information
[0005] As background, one type of non-invasive physiologic sensor is a pulse monitor, also called a photoplethysmograph, which typically incorporates an incandescent lamp or light emitting diode (LED) to trans-illuminate an area of the subject, e.g. an appendage, which contains a sufficient amount of blood. FIG. 1 schematically illustrates the photoplethysmographic phenomenon. The light from the light source 10 disperses throughout the appendage, which is broken down in FIG. 1 into non-arterial blood components 12 , non-pulsatile arterial blood 14 and pulsatile blood 16 , and a light detector 18 , such as a photodiode, is placed on the opposite side of the appendage to record the received light. Due to the absorption of light by the appendage's tissues and blood 12 , 14 and 16 , the intensity of light received by the photodiode 18 is less than the intensity of light transmitted by the LED 10 . Of the light that is received, only a small portion (that effected by pulsatile arterial blood 16 ), usually only about two percent of the light received, behaves in a pulsatile fashion. The beating heart of the subject, and the breathing of the subject as discussed below, creates this pulsatile behavior. The “pulsatile portion light” is the signal of interest and is shown at 20 , and effectively forms the photoplethysmograph. The absorption described above can be conceptualized as AC and DC components. The arterial vessels change in size with the beating of the heart and the breathing of the patient. The change in arterial vessel size causes the path length of light to change from d min to d max . This change in path length produces the AC signal 20 on the photo-detector, I L to I H . The AC Signal 20 is, therefore, also known as the photo-plethysmograph.
[0006] The absorption of certain wavelengths of light is also related to oxygen saturation levels of the hemoglobin in the blood transfusing the illuminated tissue. In a similar manner to the pulse monitoring, the variation in the light absorption caused by the change in oxygen saturation of the blood allows for the sensors to provide a direct measurement of arterial oxygen saturation, and when used in this context the devices are known as oximeters. The use of such sensors for both pulse monitoring and oxygenation monitoring is known and in such typical uses the devices are often referred to as pulse oximeters. These devices are well known for use in humans and large mammals and are described in U.S. Pat. Nos. 4,621,643; 4,700,708 and 4,830,014 which are incorporated herein by reference.
[0007] Current commercial pulse oximeters do not have the capability to measure breath rate or other breathing-related parameters other than blood oxygenation. An indirect (i.e. not positioned within the airway or airstream of the subject), non-invasive method for measuring breath rate is with impedance belts.
[0008] It is well established that it is critical to properly control anesthesia levels of a patient, or subject. In dealing with non-human subjects in animal research applications, having specialized anesthesiologists or specialized equipment is simply not an option for researchers. The use of breath-related parameters and heart-related parameters from easily applied non-invasive sensors to automate or assist in the control of proper anesthesia levels of a subject would be of great assistance. In a similar manner, simple, easy feedback for proper ventilation control from non-invasive, easily applied sensors in animal research applications would be very beneficial. Obviously, such advances would not be limited to animal research as non-invasive physiologic measurements can be very useful for human applications as well.
[0009] It is an object of the present invention to minimize the drawbacks of the existing systems and to provide medical devices and techniques for deriving cardiac and breathing parameters of a subject from extra-thoracic blood flow measurements and for controlling the ventilation levels and the anesthesia levels of a subject based upon said measurements.
SUMMARY OF THE INVENTION
[0010] It is noted that, as used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless expressly and unequivocally limited to one referent. For the purposes of this specification, unless otherwise indicated, all numbers expressing any parameters used in the specification and claims are to be understood as being modified in all instances by the term “about.” All numerical ranges herein include all numerical values and ranges of all numerical values within the recited numerical ranges.
[0011] The various embodiments and examples of the present invention as presented herein are understood to be illustrative of the present invention and not restrictive thereof and are non-limiting with respect to the scope of the invention.
[0012] At least some of the above stated objects are achieved with a method of utilizing a conventional pulse oximeter signal to derive breath rate. As understood by those of ordinary skill in the art a pulse oximeter is applied to the subject with a simple externally applied clip. Thus, in addition to getting oxygen saturation and heart rate from a pulse oximeter, the pulse oximeter according to the present invention can derive breath rate.
[0013] A measurement of breath rate from a pulse oximeter was first made commercially available in December 2005 by the assignee of the present application, Starr Life Sciences and is provided in the MouseOx™ device that was particularly designed for use with small mammals, namely rats and mice. In this device, the breath rate is obtained by screening out the frequency band around the heart rate point on the Fast Fourier Transform (known as FFT) that is used to identify the heart rate. The next largest amplitude to the left (or lower frequency) of the heart rate rejection band on the FFT was considered to be the breath rate. The value is then simply averaged then displayed on the screen to the user. Although useful there is room to greatly improve this calculation methodology to assure consistent accurate results.
[0014] The currently preferred breath rate algorithm works, in a general sense, by selectively filtering the heart rate from the light signal, then reconstructing the breath signal in the absence of the heart rate.
[0015] In addition to calculating a numerical breath rate using only pulse oximeter inputs, the present invention also provides a display of the breath rate signal, which is presented as the Breath Pleth (short for plethysmograph). The signal is derived from the inverse FFT of the calculations described above. It is preferred if the Breath Pleth signal is illustrated congruently with the heart signal. The reason for displaying the signals congruently is to avoid confusion over which signal represents breathing, and to illustrate the underlying breathing waveform in conjunction with the heart signal. The utility of this plot is to provide a visual sense of the relative breath rate as compared with heart rate, and to allow the user to see that the heart rate and breathing signals are superimposed on the raw infrared light signal. One can also deduce a relative magnitude between the signal strength due to the heart pulse, and that due to breathing.
[0016] In addition to the breath rate calculation from the pulse oximeter measurements, the present system provides additional breath and heart-related parameters other than the conventional heart rate and blood oxygenation. Namely the present system can calculate and display arterial distention measurements. The distention measurements are calculated using Beer's Law mathematics, in conjunction with the current calculation of oxygen saturation. There are two types of distention. The first, called pulse distention, is a measurement of the arterial distention which results from the blood pulse to the periphery due to cardiac pumping. The second, called breath distention, is a measurement of the arterial distention which results from the pulse of blood to the periphery due to breathing effort and its effect on thoracic arterial vasculature.
[0017] As will be described below, these measurements can be particularly useful to assist in control of anesthesia levels and ventilation controls. The user can employ the measured distention to assess the strength and quality of signals for making all sensor measurements. Further, the distention measurements, such as pulse distention, can be used to assess changes in peripheral blood flow either by changes in cardiac output or by changes in vaso-active response. The breath distention measurements may be used to assess intrapleural or intrathoracic pressure. The breath distention measurements may be used to assess work of breathing of the subject. The distention measurements may have many other clinical and research applications.
[0018] A measurement of pulse distention from a pulse oximeter was first made commercially available in December 2005 by the assignee of the present application, Starr Life Sciences and provided in the MouseOx™ device that was particularly designed for use with small mammals, namely rats and mice. Breath distention measurements from pulse oximetry systems have not been previously commercially available.
[0019] Preferably the measured pulse and breath distention measurements are displayed together on the same plot to the user. The utility of showing them together is that pulse distention can be used as a sort of baseline. The relative level of breath distention can then be used as an indicator of work of breathing. Since both are derived from changes in peripheral blood flow due to their respective mechanisms, if they both have the same magnitude, then both are affecting the peripheral blood flow by the same amount. In the general case, one would expect the blood pulse to provide a greater peripheral blood flow than would breathing effort. However, if breath distention is greater than pulse distention, the subject is likely laboring hard to breathe, a condition that often results form too much anesthesia.
[0020] The applicants have found that an increase in the breath distention measurement coupled with a decrease in the blood oxygenation and a drop in one or both of the breath rate and the heart rate is indicative of the subject moving to a higher or deeper anesthesia level. The technician can observe such trends and compensate accordingly. Additionally, appropriate thresholds can be incorporated into the system to provide alarms and/or automated anesthesia controls to automate the process. These parameters are also indicative of the subject moving to an undesired lower anesthesia level and the present system provides this information to the user as well. Alarms and/or automated anesthesia controls can be incorporated in response to detected significant movements in the anesthesia levels.
[0021] The applicants have found that “gasping” of the subject can be detected and is also typically indicative of a too high or deep of a level of anesthesia, and this can be used to control the anesthesia levels by giving appropriate feedback to the user. Further, applicants have found that, at least in mice, a breath distention measurement that is roughly equal to or less than the pulse distention is indicative of proper anesthesia levels and proper ventilation settings. An increase in the breath distention measurement relative to the pulse distention measurement can be used as an indicator for possible improper ventilation settings. Note that it is not necessary to compare pulse and breath distention measurements simultaneously to draw such conclusions, but viewing them together can show that the effect is only on one or the other distention measurement, and not both. The relative ratio between the breath distention and the pulse distention measurements and the blood oxygenation measurement can be used to indicate proper ventilator setting with thresholds being set to automate the system (i.e. measurements beyond the set thresholds will activate “alarms” and/or automate adjustments to the ventilator).
[0022] In one non-limiting embodiment of the present invention a method of displaying pulse oximetry information comprises the steps of a attaching a light source and a light signal receiver to an appendage of a subject; directing at least two light signals having distinct wavelengths from said light source at said appendage; receiving said light signals with said light signal receiver; generating at least one output signal from said received light signals; deriving a plurality of physiologic parameters including a breath signal from said received light signals, wherein the pulse oximetry system derives a breath signal of the subject from the at least one output signal; and displaying said plurality of physiologic parameters on a monitor, including a graphical display of the breath signal.
[0023] The method of displaying physiologic parameters may have the breath signal calculated by filtering the at least one output signal to remove heart rate component thereof, then reconstructing a breath signal in the absence of the heart rate components and wherein a breath rate is calculated using the breath signal. The breath components of the at least one output signal may be filtered prior to reconstructing the breath signal. The breath signal may be displayed congruently on the same graphical display with a signal that includes the heart components. A breath rate may be calculated using the breath signal and wherein the breath rate is displayed to the user.
[0024] In the method of displaying physiologic parameters the system may further calculate arterial pulse distention measurements and arterial breath distention measurements, and wherein the system displays the pulse and the breath distention measurements on the same graph. The system may graphically display breathing parameters in a first color and heart-related parameters in a second color.
[0025] One non-limiting embodiment of the invention provides a method of displaying physiologic parameters of a subject comprising the steps of: deriving a plurality of physiologic parameters of a subject including a breath signal of the subject, and a signal including components of the breath signal and the heart signal of the subject; and displaying a plurality of the derived physiologic parameters on a monitor, including a graphical display of the breath signal congruently on the same graphical display with the signal including components of the breath signal and the heart signal of the subject.
[0026] One non-limiting embodiment of the present invention provides a method of displaying physiologic parameters of a subject comprising the steps of: deriving a plurality of physiologic parameters of a subject including calculating arterial pulse distention measurements and arterial breath distention measurements; and displaying a plurality of the derived physiologic parameters on a monitor, including displaying the pulse and the breath distention measurements on the same graph.
[0027] One non-limiting embodiment of the present invention provides a method of displaying physiologic parameters derived in a non-invasive pulse oximetry system comprising the steps of: attaching a light source and a receiver to an external appendage of a subject; emitting at least two distinct wavelengths of light from the light source and directed at the appendage; receiving the light from the light source that has been directed at the appendage; generating received signals therefrom; deriving a plurality of physiologic parameters from the received signals, wherein the pulse oximetry system derives at least one breathing-related parameter and at least one heart-related parameter of the subject from the received signals; and displaying a plurality of the derived physiologic parameters on a monitor, including a graphical display of at least one breathing-related parameter and at least one heart-related parameter, and wherein breathing parameters in a first color and heart-related parameters in a second color.
[0028] These and other advantages of the present invention will be clarified in the brief description of the preferred embodiment taken together with the drawings in which like reference numerals represent like elements throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 schematically illustrates the photoplethysmographic phenomenon as generally known in the art;
[0030] FIG. 2 is a schematic view of a pulse oximeter system according to one aspect of the present invention in which the pulse oximetry system is designed for small mammals such as mice and rats;
[0031] FIGS. 3-4 are perspective views of the pulse oximeter of FIG. 2 coupled to a subject, namely a mouse;
[0032] FIG. 5 is a graph of a representative signal of the raw-time domain signal from the pulse oximeter of FIGS. 2-4 ;
[0033] FIG. 6 is a graph of an FFT of the signal of FIG. 5 ;
[0034] FIG. 7 is a graph of the FFT of FIG. 6 with the heart components thereof filtered out in accordance with the present invention;
[0035] FIG. 8 is a graph of the FFT of FIG. 7 with the breath component filter applied in accordance with one aspect of the present invention;
[0036] FIG. 9 is a graph of a calculated breath signal from the FFT of FIG. 8 ;
[0037] FIG. 10 is a representative sample of a combined display of the calculated breath signal and combined heart signal from the system according to the present invention;
[0038] FIG. 11 is a representative example of a display of the pulse distention measurement and breath distention measurement in accordance with the system of the present invention;
[0039] FIG. 12-14 are representative screen shots of the displayed parameters for properly anesthetized, under anesthetized and over anesthetized subjects, respectively.
[0040] FIG. 15 is a representative sample of a combined display of the calculated breath signal and combined heart signal from the system according to the present invention illustrating a gasping subject;
[0041] FIG. 16 is the raw-time domain signal from the pulse oximeter of FIGS. 2-4 , associated with the gasping subject of FIG. 15 ;
[0042] FIG. 17 is raw-time domain signal from the pulse oximeter of FIGS. 2-4 , associated with normal response for comparison with the gasping subject of FIG. 16 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0043] FIGS. 2-4 illustrate a pulse oximeter system 100 according to one aspect of the present invention in which the pulse oximetry system 100 is designed for subjects 110 , namely small mammals such as mice and rats. The system 100 includes a conventional light source 120 , conventionally a pair of LED light sources one being infrared and the other being red. The system 100 includes a conventional receiver 130 , typically a photo-diode. The light source 120 and receiver 130 are adapted to be attached to an external appendage of a subject 110 , and may be secured to a spring-biased clip 140 or other coupling device such as tape adhesives or the like. FIGS. 2-4 illustrate a specialized clip from Starr Life Sciences that is configured to securely attach to the tail of a subject 110 , but any conventional clip could be used. The system 100 is also coupled to a controller and display unit 150 , which can be a lap top computer. The use of a lap top computer as opposed to a dedicated controller and display system 150 has advantages in the research environment.
[0044] The system 100 will calculate the heart rate and blood oxygenation for the subject 110 as generally known in the art of photoplethysmograghy, and does not form the basis of the present invention. Where the subject 110 is a rodent, such as a mouse or rat, care must be taken to obtain accurate heart rate and oxygenation readings with conventional pulse oximeters due to the physiology of the subjects. Starr Life Sciences have developed pulse oximeters that accommodate rodents under the MouseOx™ brand name. For the purpose of this application the calculation of the pulse rate, pulse signal, and blood oxygenation will be considered as conventional.
[0045] A first measurement of breath rate from a pulse oximeter was first made commercially available in December 2005 by the assignee of the present application, Star Life Science and provided in the MouseOx™ device that was particularly designed for use with small mammals, namely rats and mice. In this first method, an FFT, represented in FIG. 6 , is created for a received signal from the infrared LED in the time-domain, represented in FIG. 5 . The breath rate is obtained by screening out the frequency band around the heart rate point on the FFT, represented in FIG. 6 , that is used to identify the heart rate. The heart rate is effectively the largest peak shown in the FFT. The peak to the right of the FFT represents a first harmonic of the heart rate. The peak to the left of the heart rate on the FFT represents the measured breath rate.
[0046] The frequency band around the heart rate peak is preferably proportional (through a linear function or other relationship) to the heart rate itself, whereby the band will become larger for larger heart rates. This expanding filter band will accommodate the spreading of the illustrated peak that is expected at the higher measured heart rates. The filtering of the band is required to be sure that the peak measuring algorithm does not merely select the cut-off point of the heart rate peak as a calculated, but erroneous, breath rate. The next largest amplitude to the left (or lower frequency) of the heart rate rejection band on the FFT is considered to be the breath rate in this original methodology. The breath rate value is then simply averaged then displayed on the screen to the user. Although useful there is room to greatly improve this breath rate calculation methodology to assure consistent accurate results.
[0047] A preferred breath rate algorithm works, in a general sense, by selectively filtering the heart rate from the infrared light signal, then reconstructing the breath signal in the absence of the heart rate.
[0048] Specifically, the algorithm for obtaining a breath signal is as follows: Similar to the first method, an FFT, represented in FIG. 6 , is created for a received signal from the infrared LED in the time-domain, represented in FIG. 5 . In FIG. 6 , the large spike is the heart rate, the small spike to the right is a harmonic of the heart rate, and the small spike to the left is the breathing signal. Consequently, the frequency located at the highest amplitude point in the FFT is considered to represent the heart rate. Because data used in the FFT occur over a span of time, the heart rate can naturally drift during this period, causing the frequency content at the peak amplitude point on the FFT to be spread over a few surrounding frequency bins.
[0049] The preferred breathing rate calculation method is to first remove all heart rate-derived frequency content from the FFT signal, called heart components of the signal. The algorithm chooses a lower threshold to the lower end of the peak heart rate frequency that defines the point above which all content will be removed. This can be done by digital filtering, but also by simply zeroing all frequency bins to the right of the lower threshold cutoff of the heart rate spike all the way to the end of the FFT. The lower threshold is chosen by an algorithm that is based on the mean value of the heart rate. The lower threshold is farther from the heart rate (i.e., the heart rate band of the FFT is larger) at high heart rates, and closer to the heart rate peak at low heart rates. It is desired to have the heart rate band to be as narrow as possible, in order to retain the largest possible breathing frequency spectrum. FIG. 7 illustrates a sample of the heart components removed from the FFT in the breathing rate calculation method of the present invention.
[0050] A peak detection algorithm is then used to identify the largest peak remaining in the FFT. The largest remaining peak is believed to be indicative of the breathing rate, however the preferred method performs a “breathing component filtering” on this remaining data.
[0051] This filtering application operates as follows: the initial breathing peak is compared with the rest of the remaining bandwidth. If the chosen breathing peak is “significantly stronger” than the others, then the breathing filtering is effectively a zeroing of all frequency bins a minimum number of bins to the right of this peak. The minimum number of bins has been found to be 0-3 and most preferably 2. This result is shown in FIG. 8 . Significantly stronger means that the value of the “breathing peak” is greater than a predetermined factor of ALL of the other values with the heart components removed. 1.5 has been used effectively as the predetermined factor for calculating the relative strength of the breathing peak. If the chosen peak is only “moderately stronger” than the remaining peaks, then the next highest peak to the left of the strongest breathing peak is selected, and then all points on the FFT a minimum number to the right of this new peak are zeroed out resulting, effectively, in a graph as shown in FIG. 8 (except the Breathing filter has “pushed” the remaining breathing signal components to the lower frequencies). “Moderately stronger” means that less than a critical number, such as ½, of all the remaining points (but at least some of the remaining points) fail to satisfy the significantly stronger requirement discussed above. Finally, if the original chosen breathing peak is only “weakly stronger” than the remaining peaks, then the breathing component filter will identify the next two highest peaks to the left of the strongest peak, choose the one further to the left, then zero all points a minimum number of bins to the right of this new peak. Weakly stronger will mean that more than a critical number, such as ½, of all the remaining points fail to satisfy the significantly stronger requirement discussed above.
[0052] The next step in the process is to conduct an inverse FFT on the remaining frequency content as shown in FIG. 8 . The breathing frequency is then contained in this time-domain signal, as represented in FIG. 9 . A peak and valley detection algorithm, graphically shown in FIG. 9 , is then used to find the breath rate. This breathing rate value is calculated from a number of separate, serial FFT-inverse FFT pairs, and is displayed on the screen to the user.
[0053] In addition to calculating a numerical breath rate, the present invention also provides a display of the breath rate signal, which is called the Breath Pleth (short for plethysmograph). The signal is derived from the inverse FFT calculations described above. An example of the Breath Pleth screen is given in FIG. 10 . In this picture, there are two plots. The underlying wave-shape represents the breathing waveform or signal. As it is depicted here, the actual plot of the breathing signal would be the envelope of that wave shape. The reason for displaying it in this manner is to avoid confusion over which signal represents breathing, and to illustrate the underlying breathing waveform in conjunction with the combined heart signal. This heart signal is presented in the other line waveform (at a significantly higher frequency). This signal contains not only the heart rate, but all frequency content in the received infrared light signal, and thus is referred to in this application as the combined heart signal and also the raw signal. The utility of this combined plot is to provide a visual sense of the relative breath rate as compared with heart rate, and to allow the user to see that the heart rate and breathing signals are superimposed on the raw infrared light signal. One can also deduce a relative magnitude between the signal strength due to the heart pulse, and that due to breathing. It is beneficial to have the breathing-related parameters in one color, e.g., blue, and the heart-related parameters in a distinct color, e.g., red. If a parameter being displayed is a combination of two, it can be displayed in the color that is the dominant component (e.g. combined heart and breath tracing could be colored as a heart-related parameter, e.g. red), or a third color such as a mixture of the colors used to display the components (e.g. purple). The color differentiation will further indicate to the researcher what the particular trace is displaying.
[0054] In addition to the breath rate calculation from the pulse oximeter measurements, the present system 100 provides additional breath and heart-related parameters other than the conventional heart rate and blood oxygenation. Namely the present system can calculate and display arterial distention measurements. Distention measurements are calculated using Beer's Law mathematics, in conjunction with the current calculation of oxygen saturation. There are two types of distention. The first, called pulse distention, results from the blood pulse to the periphery due to cardiac pumping. The second, called breath distention, results from the pulse of blood to the periphery due to breathing effort and its effect on thoracic arterial vasculature.
[0055] To describe the physical meaning of a distention, one must first consider the column of light that passes between the LED and photodetector located on either side of the sensor clip. This light is absorbed by all intervening tissue, but we are interested only in arterial blood. Restricting received light information to arterial blood is done by looking for a change in light signal strength at either heart or breathing frequencies. This change literally corresponds to a change in local blood flow between the sensor heads that occurs as a result of either a cardiac output pulse, or a breath effort effect on the thoracic vasculature.
[0056] Next consider a cylindrical volume of arterial blood, where the cross-sectional area of the cylinder is defined by the lateral dimensions of the light column, while the height is defined by the quantity of arterial blood in the direction of the light path within that lateral area. Distention is then simply the change in height of the cylinder between the peak and valley of the attendant change mechanism (heart pulse or breath effort). In other words, if looking at pulse distention, which is derived from the cardiac pulse, the distention is due to the height of the blood flow change between systole and diastole. Likewise, the breath distention is the change in height derived from the endpoints of the breathing effort from inhale to exhale. Both distention measurements are given in linear dimensional units (e.g. μm). Current commercial pulse oximeters, other than the current MouseOx™ product of Starr Life Sciences, do not provide the user the capability to measure either of these distention values, and there is no known alternative method for making either of these measurements.
[0057] Pulse distention can be used by the operator to assess the strength and quality of signals for making all sensor measurements to evaluate the operation of the system. Further, it can be used to assess changes in peripheral blood flow either by changes in cardiac output or by changes in vaso-active response. Pulse distention is calculated from Beer's Law. It uses the light strength measured at systole and diastole in its calculation. The algorithm is as follows: (a) All signal filtering, both analog and digital is removed from the received raw infrared light signal; (b) The peaks and valleys of the received infrared light signal are detected; (c) For every peak and valley pair, the ratio of the peak and valley magnitude is used in the Beer's Law formulation to obtain pulse distention; and a few pulse distention values are averaged, then displayed both numerically and graphically.
[0058] Breath distention is a new parameter for researchers to utilize. The utility of breath distention includes that it can be used to assess intrapleural or intrathoracic pressure, and that it may be used to assess work of breathing. Further, it may be used to assess the level of anesthesia. Breath distention is also calculated from Beer's Law. The breath distention is calculated from the inverse FFT signal as described above. A simple algorithm of its derivation is given as follows: (a) From the description of the breath rate calculation algorithm given above, we start with the FFT signal from which the heart rate is removed only ( FIG. 7 ), before additional frequency content clipping occurs with the breathing component filtering. Starting with this FFT, all original signal filtering, both analog and digital is removed by compensating the FFT amplitudes at each frequency bin, based on original filtering; (b) Once the filtering has been compensated, an inverse FFT is conducted; (c) The peaks and valleys of the inverse FFT time-domain breathing signal are identified; (d) All of the valid peaks are averaged, then all of the valid valleys are averaged; (e) From the average peak and valley pair for each FFT dataset, the Beer's Law calculation is used to find the breath distention; and (f) A few breath distention values are averaged, then displayed both numerically and graphically.
[0059] Pulse and breath distention will be displayed together on the same plot in the Monitor Subject screen such as the display of the lap top 150 , which is shown in FIG. 11 . The utility of showing the distention measurements together is that pulse distention can be used as a sort of baseline. The relative level of breath distention can then be used as an indicator of work of breathing. Since both are derived from changes in peripheral blood flow due to their respective mechanisms, if they both have the same magnitude, then both are affecting the peripheral blood flow by the same amount. In the general case, one would expect the blood pulse to provide a greater peripheral blood flow than would breathing effort. However, if breath distention is greater than pulse distention, the animal is likely laboring hard to breathe, a condition that often results form too much anesthesia.
[0060] The present system 10 effectively provides a method of controlling the anesthesia level and/or ventilator settings of a subject that is receiving anesthesia and/or respiratory support through a ventilator. The method comprises the steps of providing the non-invasive sensor system 100 configured to calculate arterial pulse distention measurements of the subject, and using the measured arterial pulse distention measurements as indicators for at least one of proper and improper levels of anesthesia or proper and improper ventilator control settings. This method may be clarified in a review of FIGS. 12-17 .
[0061] The applicants have found that an increase in the breath distention measurement coupled with a decrease in the blood oxygenation and a drop in one or both of the breath rate and the heart rate is indicative of the subject moving to a higher or deeper anesthesia level. The technician can observe such trends and compensate accordingly. Additionally, appropriate thresholds can be incorporated into the system to provide alarms and/or automated anesthesia controls to automate the process. These parameters are also indicative of the subject moving to an undesired lower anesthesia level and the present system provides this information to the user as well. Alarms and/or automated anesthesia controls can be incorporated in response to detected significant movements in the anesthesia levels.
[0062] FIG. 12 is a screen clipping of the display of the system 100 for a subject, specifically a mouse that is properly anesthetized. The pulse and breath distention are basically the same, the breath rate is stable and in the proper range. FIG. 13 is a screen clipping of a subject, again a mouse, that is too lightly anesthetized. This mouse is getting ready to wake up. The breath rate is increasing and the breath distention is much less than the pulse distention. FIG. 14 shows a screen clipping of a subject, again a mouse, that is too heavily anesthetized. This mouse is gasping and breathing at a very slow rate. This screen shot represents an extreme case and the breathing is very difficult to calculate because it is so slow. This results in that the breath distention is not updating often. However, when breath distention is able to update, as shown, it is much higher than pulse distention providing important feedback to the operator.
[0063] The applicants have found that “gasping” of the subject can be detected and is also typically indicative of a too high or deep of a level of anesthesia, and this can be used to control the anesthesia levels by giving appropriate feedback to the user. Further, the applicants have found that, at least in mice, a breath distention measurement that is roughly equal to or less than the pulse distention is indicative of proper anesthesia levels and proper ventilation settings. An increase in the breath distention measurement relative to the pulse distention measurement can be used as an indicator for possible improper ventilation settings. The relative ratio between the breath distention and the pulse distention measurements and the blood oxygenation measurement can be used to indicate proper ventilator setting with thresholds being set to automate the system (i.e. measurements beyond the set thresholds will activate “alarms” and/or automate adjustments to the ventilator). For example, consider FIGS. 15 and 16 , which illustrate the graphical displays indicative of a deeply anesthetized subject, again a mouse. The screen clipping of the breath pleth window display of FIG. 15 shows a subject mouse that is too heavily anesthetized. This mouse is gasping and breathing at a very slow rate. The user can see in this window is that the mouse is gasping by the effect on the pulse signal. The pulse signal displayed here actually contains both of the distentions. The pulse distention is low for most of these heart beats then it will calculate high for this gasping beat. The breath distention will be high because it only looks at the effects caused by breathing. These parameters can be effectively used as guidance for both anesthesia levels and ventilation control.
[0064] The present system 100 is not intended to be restrictive of the invention. For example, all of these parameters can be measured using a partially-deflated blood pressure cuff, impedance belts or an arterial line. Further, the filtering is described above using inverse FFTs, but it can be done also with traditional digital and analog filtering methods. Additionally, reflective oximetry sensors, implanted sensors, clip-less sensor, etc could be used. Only a light source (e.g., LED) and receiver (e.g., photodiode) are required.
[0065] Although the present invention has been described with particularity herein, the scope of the present invention is not limited to the specific embodiment disclosed. It will be apparent to those of ordinary skill in the art that various modifications may be made to the present invention without departing from the spirit and scope thereof. The scope of the present invention is defined in the appended claims and equivalents thereto. | Medical devices and techniques derive breath rate, breath distention, and pulse distention measurements of a subject from a pulse oximeter system coupled to the subject. These parameters together with the conventional physiologic parameters obtained from a pulse oximeter system can be used to assist in controlling the ventilation levels and the anesthesia levels of the subject. The development has human applications and particular applications for animal research. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 813,465, filed Jan. 3, 1986, now abandoned.
DESCRIPTION
1. Technical Field
This invention relates to the process of adding caprolactam to a polyhexamethylene adipamide and polypropylene mixture to eliminate yarn guide deposits formed during the spinning of polyhexamethylene adipamide and polypropylene fiber and the resultant fiber.
2. Background
Various methods have been employed in the past to achieve delustered melt-spun nylon filaments for textile fiber end users. These methods include modifying the filament cross-section as well as adding compounds such as titanium dioxide and polypropylene to the nylon. The segmentation of polypropylene within a nylon matrix imparts a dramatic delustered appearance to spun and drawn nylon filaments. It has been observed, however, that the cospinning of polypropylene with nylon 6,6 results in unacceptable polypropylene deposits forming on yarn guide surfaces. These deposits negatively affect fiber manufacturing by increasing draw point and spinning breaks, resulting in poor fiber spinning as well as decreased productivity. In attempting to improve the cospinning of polypropylene and nylon 6,6, a method was discovered to eliminate the deposits.
SUMMARY OF THE INVENTION
A process for eliminating yarn guide deposits by producing a nylon 6,6 and polypropylene fiber comprising the steps of: a) mixing 85-97.9% by weight nylon 6,6, 0.1-5% by weight polypropylene and 2-10% by weight nylon 6; b) melt spinning the mixture to form a fiber; and c) drawing the fiber has now been discovered. The yarn guide guides the fiber and is generally used to converge the fiber during melt spinning.
It is to be understood that in the mixing step a) above, nylon 6,6 refers to polyhexamethylene adipamide or its monomeric salt mixture of hexamethylene diamine and adipic acid. Likewise, it is to be understood that nylon 6 refers to polycaproamide or its monomer caprolactam.
In practicing this invention, as the percent of polypropylene is increased in the polymer blend, it is expected that the percent of nylon 6 should also be increased.
A preferred embodiment provides for eliminating yarn guide deposits which accumulate while cospinning polypropylene with nylon 6,6 by polymerizing a small amount of caprolactam monomer with hexamethylene diamine and adipic acid to form a random nylon 6,6/nylon 6 copolymer followed by melt injection of polypropylene into the copolymer melt prior to filament extrusion. The preferred range of components are: 94-97% by weight nylon 6,6, 2-4% by weight nylon 6 and 1-2% by weight polypropylene. In a further preferred embodiment, the fiber further comprises 0.01-0.5% by weight titanium dioxide.
There are alternate methods of adding the caprolactam during the cospinning of polypropylene with nylon. For example, the caprolactam could first be polymerized to nylon 6 and then melted and co-injected with the polypropylene into the nylon 6,6 homopolymer. Caprolactam could also first be polymerized to form nylon 6 and then melt injected into the nylon 6,6 flow upstream from the polypropylene injection port.
The Examples clearly show the advantage of caprolactam in eliminating yarn guide deposits when cospinning polypropylene with nylon 6,6.
TEST METHODS
Molecular weight of the polypropylene is reported as Number Average Molecular Weight and is measured by gel permeation chromatography using NBS-1475 linear polyethylene as the reference standard and orthodichlorobenzene as the solvent.
Melting point in degrees Centigrade was measured by Differential Scanning Calorimetry (DSC).
Softening point is reported in degrees Centigrade as determined by Differential Scanning Calorimetry.
Viscosity of the polypropylene is reported as the viscosity in centipoise (CP) as measured with a Brookfield Thermosel following ASTM-D-3236 at 190° C. and using Spindle No. 34 at 12 rpm.
Identification of polypropylene was by proton NMR and differential solubility analysis using both tetrachloroethylene and formic acid as solvents.
EXAMPLES
Example 1
A random copolymer of nylon 6,6/nylon 6 (96:4 weight ratio) was prepared by polymerizing hexamethylene diamine and adipic acid in the presence of 4% by weight caprolactam to 62 relative viscosity. Titanium dioxide was added at a level of 0.3% by weight to the copolymer. The nylon 6,6/nylon 6 copolymer containing 0.3% titanium dioxide was melted in a screw extruder, then fed through a transfer line to a meter pump, filter pack and spinneret in a conventional manner. During passage of the nylon copolymer through the transfer line, a pelletized polypropylene (molecular weight 6600, melt point of 156° C., viscosity of 320 CP and softening point of 139° C.) was melted and injected into the molten nylon copolymer in the transfer line at a level of 1.5 parts of polypropylene per 98.5 parts nylon copolymer. Fiber was spun at an extrusion rate of 123 grams/spinneret hole/hour as 330 trilobal filaments with a modification ratio of 2.9, cold drawn to 14 denier per filament and cut to 7.5 inch staple. During the fiber spinning process, yarn guide surfaces were carefully monitored and no deposits were noted.
Control A
Polyhexamethylene adipamide of 62 relative viscosity and containing 0.3% titanium dioxide was melted in a screw extruder, then fed through a transfer line to a meter pump, filter pack, and spinneret in a conventional manner. During passage of the polyhexamethylene adipamide through the transfer line, a pelletized polypropylene (molecular weight 6600, melt point of 156° C., viscosity of 320 CP and softening point of 139° C.) was melted and injected into the molten nylon polymer in the transfer line at a level of 1.5 parts of polypropylene per 98.5 parts nylon polymer. Fiber was spun at an extrusion rate of 123 grams/spinneret hole/hour as 330 trilobal filaments with a modification ratio of 2.9, cold drawn to 14 denier per filament and cut to 7.5 inch staple. During the fiber spinning process, white deposits quickly appeared on yarn guide surfaces. These deposits were shown to be polypropylene by proton NMR and solubility analysis using both tetrachloroethylene and formic acid.
Control B
Polyhexamethylene adipamide was melt extruded with 1.5% polypropylene as described in Control A, except that titanium dioxide was omitted. During the fiber spinning process, white deposits consisting of polypropylene quickly appeared on yarn guide surfaces.
Control C
Polyhexamethylene adipamide was melt extruded as described in Control A, except that polypropylene was injected at a level of 0.5%. During the fiber spinning process, white deposits consisting of polypropylene appeared on yarn guide surfaces.
Example 2
A random copolymer of nylon 6,6/nylon 6 (90:10 weight ratio) was prepared by polymerizing hexamethylene diamine and adipic acid in the presence of 10% by weight caprolactam to 62 relative viscosity. Titanium dioxide was added at a level of 0.3% by weight to the copolymer. The nylon 6,6/ nylon 6 copolymer containing 0.3% titanium dioxide was melted in a screw extruder, then fed through a transfer line to a meter pump, filter pack and spinneret in a conventional manner. During passage of the nylon copolymer through the transfer line, a pelletized polypropylene (molecular weight 6600, melt point of 156° C., viscosity of 320 CP and softening point of 139° C.) was melted and injected into a molten nylon copolymer in the transfer line at a level of 3.5 parts of polypropylene per 96.5 parts nylon copolymer. Fiber was spun at an extrusion rate of 122.9 grams/spinneret hole/hour as 332 trilobal filaments with a modification ratio of 2.3, cold drawn to 15 denier per filament and cut to 7.5 inch staple. During the fiber spinning process, yarn guide surfaces were carefully monitored and no deposits were noted. | A process for producing a nylon 6,6 and polypropylene fiber wherein deposits of polypropylene on the yarn guide surface are substantially eliminated by adding nylon 6. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to electrophysiological sensors and more particularly to an electrophysiological sensor system which allows the automatic authentication and configuration of the sensor.
When using biomedical sensors to acquire electrophysiological signals for recording and analysis, it is desirable to make certain information concerning the sensor available to the recording and analysis device (monitor). Useful information includes the configuration of electrodes on an electrode sensor, the date of manufacture of the sensor, the identity of the manufacturer and the manufacturer's lot number. A monitor can utilize this information to determine the manner in which to process the acquired data, or even whether to allow the use of the sensor at all (e.g., in the case of an expired sensor).
Such data is entered into the monitor manually by the user, by means of a keyboard, by using a bar code reader to enter data printed on a tag supplied with the sensor, or by various information programs. A simpler method to enter the data is to store the desired information in a memory device of some kind integrated into the sensor itself. The monitor then reads the information automatically, saving the user time and trouble. Various information programs running on the monitor use this information to determine not only the characteristics of the sensor for configuration purposes, but also to verify the viability of a limited life-time sensor, to verify its authenticity and to record various data acquired from the sensor.
The integration of memory devices with medical sensors is well known in the art. In U.S. Pat. No. 5,813,404, Devlin, et al. describe a biopotential electrode connector system in which the configuration of the electrode array is stored in a set of logic lines (jumpers) in the connector of an electrode interface cable. The arrangement described provides for only 8 unique codes, and thus the amount of information which may be stored is severely limited. Also in this invention, the connection of a sensor to the monitor is automatically detected. The monitor incorporates a pulse generator, the pulses of which are used to sense the status of the jumpers (jumpered or open). The determined code is subsequently used to configure the monitor for the particular electrode configuration. This method of automatic sensor detection is suitable for use with passive, hardwired jumpers, but requires a separate pulse generator circuit.
In U.S. Pat. No. 4,580,557, Hertzmann describes the use of coding resistors in the connector of a surgical laser system peripheral output device which serve to identify the particular peripheral device in use. The amount of information that may be stored is again very limited.
In U.S. Pat. No. 5,660,567, Nierlich et aL describe the use of a coding resistor incorporated into a separate module that plugs into the connector of an oximeter probe. Nierlich et aL use the resistor as a mans to code the center wavelength of the red probe emitter. The use of a resistor as a storage device severely limits the amount of information that may be stored.
In U.S. Pat. No. 5,058,558, Kaestle states that the place of application (finger, ear, nose, foot, toe, etc.) of an oximeter has an effect of the accuracy of the measurement. He therefore describes a system for coding the type of sensor (finger sensor, ear sensor, etc.) as a surrogate for the place of application. The code is preferably stored in a coding resistor incorporated in the sensor, which severely limits the amount of information that can be stored. An alternate embodiment would comprise a ROM (read-only memory) or customized integrated circuit, also located in the sensor. While providing more data storage capacity, this embodiment does not provide security for the stored information, nor does it provide the capability for the monitor to store data on the sensor. In addition, the alternate embodiment requires a custom semiconductor device rather than an off-the-shelf device.
In U.S. Pat. No. 4,942,877, Sakai and Hamaguri describe the use of a memory device in or on an oximeter probe; the exact location is not specified. In this probe, the memory device is used to store calibration data relating to the light emitting diode (LED) emitters. An EPROM (electrically programmable, read-only memory) or EEPROM (electrically erasable, programmable, read-only memory) memory device is used. This embodiment does not provide security for the stored information.
In U.S. Pat. No. 4,684,245, Goldring describes the use of a memory chip with a fiberoptic oximeter catheter to store calibration signals. The memory chip is not incorporated into the disposable catheter, but rather into an interface module which can be disconnected from the monitor for transport purposes, so that the calibration data is transported along with the catheter and may be reconnected to a different monitor without necessitating a recalibration.
In U.S. Pat. No. 5,357,953, Merrick, et al describe a similar system for storing calibration data in a separate memory device associated with an invasive optical blood gas analyzer sensor. The blood gas analyzer contains a processor and each disposable blood gas sensor is associated with a self-contained, non-integral non-volatile memory device preferably described as an EEPROM, and alternately as a RAM (random access memory), ROM (read-only memory) or EPROM. The memory device is used to store calibration data specific to the sensor with which it is associated, so that the sensor may be transferred to other blood gas analyzers without recalibration.
In U.S. Pat. No. 4,868,475, Respaut describes the use of a memory device in the transducer system of a scanning mechanical ultrasonic transducer system. The memory device is positioned in the plug of the transducer system connecting the transducer to the associated monitor. The memory device is preferably an EEPROM, but alternately an EPROM or PROM (programmable, read-only memory) and is used to store nonlinearity error information or other information concerning errors in the positioning or scan control for the particular transducer or other calibration information.
In U.S. Pat. No. 5,660,177, Faupel et aL describe an electrode for measuring DC biopotentials that incorporates an addressable chip mounted in either the connector or the cable. This chip, which may be an EEPROM, is designed to be addressed by the processor at a known address. At the start of monitoring, the monitor attempts to interrogate the chip by reading from the preestablished memory location that corresponds to the addressable chip. If the monitor is able to read the memory location corresponding to this address, it proceeds with the measurement program; if it can not read this location, it does not proceed with the measurement program. Faupel further discloses that the monitor may prevent reuse of the electrode by erasing the memory device. Faupel does not specify what information is stored in this memory device or whether the measurement program makes further use of it beyond verifying the presence of an electrode.
While all the devices described above are medical sensors that incorporate some form of memory, they are limited to simply storing calibration and/or configuration data. In contrast, an ideal electrophysiological signal sensor would have the capability to store specific data concerning the sensor itself, such as lot codes, the date of expiration and the sensor serial number, in addition to configuration data It would also encode the identity of the manufacturer and distributor and would encrypt the stored data in order to both protect its integrity and prevent the use of unauthorized substantially equivalent devices. None of the devices described in the patents cited above encrypt the stored data, identify the manufacturer or distributor, use a secure memory device or protect the associated monitor from use with an unauthorized sensor.
The ideal sensor, then, is one that incorporates means for the authentication of its source and the validation of the data stored in its memory. Such a “Smart Sensor” will be part of a sensor authentication and validation system, of which the monitor to which it is connected and which processes the acquired electrophysiological signals is an integral part. The software running in the associated monitor would not only read the data stored on the smart sensor, but also decrypt the data and use it to perform a series of authentications and validations which verify the source of the smart sensor and its physical integrity, while logging its characteristics and various data concerning the conditions of its use. The physical design of the smart sensor, the data stored on it and the accompanying encryption techniques would protect the smart sensor from counterfeiting and provide improved monitoring performance. In addition, such a smart sensor system allows selective functionality to be obtained from a single monitoring system, depending on various configuration codes stored on the smart sensor. Additional functionality may be added after the date of manufacture of the monitor by simply storing different configuration codes on the smart sensor and updating the monitor software.
Another challenge in designing a patient connected sensor which incorporates active electronics in close proximity to a patient is to prevent the application of excess electric current to the patient in both normal and fault conditions
SUMMARY OF THE INVENTION
The present invention provides a sensor system which includes a biopotential signal monitor, a smart sensor and the accompanying hardware and software interface which authenticates the source and validity of the smart sensor and also verifies that the smart sensor meets various criteria for use.
The smart sensor integrates an array of electrodes with a secure memory device. The array of electrodes, when placed on a body surface, is used to acquire biopotential signals from a subject. A plurality of electrodes making up the array are integrated onto the surface of a flexible substrate. A plurality of electrical conductors are printed on the surface of the array and provide an electrical conduction path from the electrodes to a terminal tab. The terminal tab is attached to a plastic molded interface platform which provides mechanical stiffness allowing the conductors on the tab to be inserted into the mating receptacle of a biopotential monitor. An off-the-shelf smart card semiconductor memory module containing ROM, PROM and EEPROM is also mounted on the interface platform. The smart card memory module contains in ROM a code unique to the purchaser of the memory module which can be used to validate the source of the smart sensor. Such source validation is not possible with standard ROM, PROM or EEPROM memory devices. The electrical contact pads on the memory module make contact with complementary contact points inside the mating receptacle when the interface platform and mating receptacle are joined. The use of off-the-shelf secure smart card modules has distinct advantages for the smart sensor, including the security provided by the module and the advantages to the construction of the smart sensor provided by the smart card module's physical configuration.
The smart sensor mating receptacle interfaces mechanically with the interface platform as a tab connection. This includes mechanical keying for proper orientation, a locking feature, contact areas for the smart card memory and the sensor traces, and prevention of ingress of liquids. The ingress of liquids into the receptacle is not desirable as it can result in an electrical hazard to the patient, as well as cause poor electrical performance of the instrumentation due to shorting between signal leads. Accordingly, a goal of this invention is a means to provide a reasonable seal to the ingress of liquids during both use and idle modes. For this purpose, an elastomer door is present at the entrance of the connector. In addition, an elastomer wiping surface is present that will remove any excess water from a mating part as it is inserted into the receptacle.
The system detects the presence of the sensor by detecting the electric current required to power the smart card memory module upon connection to the mating receptacle. This current can be detected in either the power conductor or the return conductor. When a current in excess of a threshold is detected, the monitor is signaled that a smart sensor has been connected to the mating receptacle. The monitor software then initiates a smart sensor authentication and validation sequence.
The presence of an active electronic device (the smart card memory module) on the smart sensor in close proximity to the patient poses unique design issues relating to maintaining patient safety in both normal and single fault conditions (so called “auxiliary current” in the IEC 60601 Standard (Standard 60601, Common Aspects of Electrical Equipment Used in Medical Practice, Ed. 2.0, The International Electrotechnical Commission, Geneva, Switzerland, 1988). Such a condition might result from a failure of the instrumentation amplifiers connected to the patient electrode leads, as well as a short between the conductors of the smart sensor, the mating receptacle or the intermediary cable connecting the smart sensor and the monitor. A failure might also result from the short-circuiting of the conductive leads on either the smart sensor or in the mating receptacle due to the ingress of fluid into these areas. Such a failure condition might result in the supply current of the memory module or instrumentation amplifiers being applied to the patient leads, with the resulting application of unacceptable levels of current being applied to the patient.
The smart sensor interface circuit prevents auxiliary current from being conducted through the patient in the event of a single fault in several ways. First, the system monitors the current in the patient ground, and turns power off to the smart sensor if excess current is detected. Second, an electrically grounded “guard” path is interposed between the smart sensor circuits and patient connected circuits both on the sensor and in the reusable mating receptacle. This guard path acts as a current sink in the event of a fault condition, harmlessly conducting the excess current away from the patient. The guard thus prevents contaminants on the surface from bridging between the memory module conductors and the patient conductors.
Various data concerning the origin and manufacture of the smart sensor are stored in the memory module. This data includes, but is not limited to, a key code, a manufacturer code, an original equipment manufacturer (OEM) code, a product shelf life code, a sensor type code, the sensor lot number and serial number and the usage count. All or a part of the data are stored in encrypted form A digital signature is also stored on the smart sensor. The monitor uses this stored data to authenticate the attached smart sensor.
When the smart sensor interface circuit detects the connection of the monitor, the monitor software reads the data from the smart sensor. The monitor software first verifies that the manufacturer code indicates that the smart sensor was manufactured by an authorized source.
Since it is anticipated that there will be multiple distributors of smart sensors and multiple licensed manufacturers of monitors, the monitor software will also check the OEM code against a look-up table to determine whether the smart sensor is allowed to be used with the specific monitor. If the data cannot be read from the smart sensor, or if the smart sensor did not originate at an authorized manufacturer, or if the OEM code does not correspond with one that is allowed to be used with the particular monitor, the monitor software refuses to proceed with monitoring. If all of the foregoing conditions are met, the monitor software next verifies the digital signature using one of several decryption keys specified by the key code and decrypts the smart sensor data If the digital signature cannot be verified or the data cannot be decrypted, the monitor software refuses to proceed with monitoring.
The monitor next logs the smart sensor identification data into its non-volatile memory. The monitor uses the smart sensor serial number to maintain a usage counter for each individual smart sensor that it authenticates. The usage counter records the number of times that a specific smart sensor has been authenticated. After successfully authenticating a smart sensor a preset maximum number of times, the monitor will refuse further authentications of that particular smart sensor. This allows reuse of the smart sensor to be limited for quality and infection control purposes, while still allowing for legitimate disconnection and reconnection and allows the monitor to warn the user if the connected smart sensor has already been used. This feature is important with devices with limited lifetimes or whose performance degrades with every use. The usage counter also provides a defense against multiple unauthorized smart sensors manufactured with the same serial number. A mirror usage counter is maintained in the smart sensor memory. The smart sensor and monitor usage counters are synchronized to the minimum of uses remaining between the two during the authentication process. This ensures that the current usage count reflects the sum of all prior usage independent of the monitor to which the smart sensor was connected.
In addition to the usage data, the monitor records in the log the time and date of use of each smart sensor. This data may be used by the manufacturer for customer service, quality control and product improvement purposes.
The monitor software next uses the sensor type code which indicates which of several possible data processing algorithms is appropriate for use with the specific smart sensor type. The monitor software next verifies that the smart sensor lifetime has not yet expired, notifying the user if the smart sensor is beyond its recommended shelf life. The monitor then proceeds with monitoring.
In an alternative embodiment, the monitor may use the smart sensor's memory module as a data archive, storing patient and performance data. The smart sensor may then be returned to the manufacturer, who may access the data stored in the memory for purposes of product improvement. Alternatively, the information may be transferred to a computer in the field.
In another alternative embodiment, the smart card module may be of the type containing an integral microprocessor. This modification would then provide the smart sensor with additional security by enabling it to respond to a “challenge” by the monitor. As part of the authentication process, the monitor may challenge the smart sensor by transmitting a random number to it. The smart sensor then encrypts the number and transmits it back to the monitor. The monitor subsequently decrypts the received number and compares it to the transmitted number; if the two match, the smart sensor is encrypting data using the correct algorithm and security key, rather than simply transmitting a stored data string.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the smart sensor of the present invention and mating receptacle.
FIG. 2 is a top plan view of the smart sensor shown in FIG. 1 .
FIG. 3 is a plan view of the underside of the smart sensor shown in FIG. 1 .
FIG. 4 ( a ) is a perspective exploded view of the plastic molded interface platform, showing the mounting of the terminal tab and smart card memory module, and ground guard.
FIGS. 4 ( b ) and 4 ( c ) are perspective views of the assembled plastic molded interface platform, showing the mounting of the terminal tab and smart card memory device, and ground guard.
FIG. 5 is a perspective view of a smart sensor consisting of several smart electrodes.
FIGS. 6 ( a ) and 6 ( b ) are perspective views of the plastic molded interface platform ready for insertion and fully inserted, respectively, into the mating receptacle.
FIG. 7 is a side cross-sectional view mating receptacle, showing the electrical contact surfaces, the living hinge door and the wiping surfaces of the receptacle.
FIG. 8 is a cross-sectional view of the mating connector showing the electrical contact surfaces.
FIG. 9 is an end elevational view of the smart sensor receptacle showing the hinged door and the rail alignment channels.
FIG. 10 ( a ) is a top plan view and FIG. 10 ( b ) is a bottom plan view of two alternate embodiments of the smart sensor in which the memory module is mounted on the top side and the underside of the flexible substrate respectively.
FIG. 11 is a schematic diagram of the ground fault detection circuit used in the smart sensor shown in FIG. 1 .
FIG. 12 is a schematic diagram of the ground guard protection circuit used in the smart sensor shown in FIG. 1 .
FIG. 13 is a schematic diagram of the smart sensor connection detection circuit.
FIG. 14 is a schematic diagram of an alternate embodiment of the smart sensor connection detection circuit.
FIG. 15 is a flowchart of the data string acquisition routine used by the smart sensor shown in FIG. 1 .
FIG. 16 is a flowchart of the digital signature validation algorithm used by the smart sensor shown in FIG. 1 .
FIG. 17 is a flowchart of the verification algorithm used by the smart sensor shown in FIG. 1 .
FIG. 18 is a flowchart of the data logging algorithm used by the smart sensor shown in FIG. 1 .
FIG. 19 is a flowchart of the usage count verification algorithm used by the smart sensor shown in FIG. 1 .
FIG. 20 is a flowchart of the type and expiration check algorithm used by the smart sensor shown in FIG. 1 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The mechanical aspects of the sensor system of the present invention are based on a plastic molded interface and mounting platform that serves as an assembly base for the various components of the system. The interface platform ensures that the system components are maintained in the correct relative alignment and provides sufficient mechanical stiffness to enable the terminal tab/smart sensor/interface platform assembly to be removably inserted into a mating receptacle. The union of the smart sensor 2 and the mating receptacle 6 achieves an electrical connection between the components of the smart sensor 2 and the associated monitor. The monitor may then perform analysis and/or recording of the acquired biopotentials.
Referring to FIG. 1, the perspective view shows the entire smart sensor assembly. This includes the smart sensor 2 with an integral plastic molded interface and mounting platform 4 , and the mating receptacle 6 . The plastic molded interface platform 4 serves as a structure to which a memory module and terminal tab of the sensor substrate are mounted and also holds these components in proper alignment for insertion into the mating receptacle 6 . The mating receptacle 6 is connected to a monitor (not shown) by a cable 8 . The mating receptacle 6 is sealed to prevent the ingress of liquids and provides a wiping action to prevent the insertion of a wet plastic sensor tab.
FIG. 2 shows the flexible substrate 10 that serves as a substrate for the electrodes 20 , 21 , 22 of the electrode array and the set of printed conductors which electrically connect the electrodes to the mating receptacle 6 . The positions of the array of three electrodes 20 , 21 , 22 are delineated by the circle locations. The plastic molded interface platform 4 serves as the connecting platform. A thumb grip 25 facilitates insertion of the molded interface platform 4 into the mating receptacle 6 .
FIG. 3 shows the three electrodes 20 , 21 , 22 from the bottom side. These electrodes contain conductive gel, a gel-retaining sponge 30 , 31 , 32 and self-prepping times of the type described in U.S. Pat. No. 5,305,746, the teachings of which are incorporated herein by reference. These electrodes incorporate gel blowout compartments 35 and salt-bridge barriers 38 ; these features provide a location for excess gel to expand into and prevent excess gel from short-circuiting adjacent electrodes or lifting the sensor off the skin. The plastic molded interface platform 4 serves as a mounting and interfacing platform for the smart card memory module 40 and the proximal end of the flexible circuit substrate 10 , referred to as the terminal tab 45 . Adhesively mounting the terminal tab and the memory module 40 on the interface platform holds these components in precise alignment to each other, so that the printed conductors 50 on the terminal tab 45 and the contact pads 42 of the memory module 40 are positioned to make the proper electrical contact upon insertion of the interface platform 4 into the mating receptacle 6 . The memory module 40 and the terminal tab 45 are mounted on the interface platform 4 so that they are physically and electrically separate. This prevents current from the electrical power supply of the memory module 40 from coming into contact with the patient-connected printed conductors 50 on the terminal tab 45 , acting to assure patient safety. A ground guard trace 55 that encircles the exposed contacts 53 of the printed conductors 50 serves as a further means of patient protection. The ground guard trace 55 acts as a current sink thus preventing an electrical path between the memory module 40 and the printed conductors 50 , as might occur in the event of ingress of liquid into the mating receptacle 6 .
The smart sensor plastic molded interface platform assembly is shown in FIG. 4 ( a ). The precisely formed plastic molded interface platform 4 is preferably molded of acrylonitrile butadiene styrene (ABS) plastic. The memory module 40 and the terminal tab 45 of the flexible plastic substrate are permanently attached to the interface platform 4 with a drop of liquid adhesive or a hot melt adhesive laminate. The memory module 40 has a protrusion (not shown) on the side opposite from the electrical contact pads 42 . The protrusion fits into an alignment cavity 430 on the interface platform 4 . This cavity 430 serves as a mounting point for the memory module 40 , ensuring proper positioning during manufacturing. If liquid adhesive is used, a drop is placed in the alignment cavity 430 and the memory module 40 is pressed into place, the adhesive attaching it firmly to the interface platform 4 . If hot melt adhesive is used, the laminate is die cut with the memory module 40 and placed into the alignment cavity 430 outline for further fixing with heat. The flexible plastic substrate 10 is preferably constructed of polyester, on one side of which are printed conductors 50 using conductive ink, preferably silver (Ag). These printed conductors 50 make connection to the biopotential electrodes 20 , 21 , 22 of the plastic substrate 10 . The terminal tab 45 is adhesively attached to the tab mounting point 440 of the interface platform 4 such that the side of the tab 45 bearing the printed conductors 50 is opposite the interface platform 4 . The interface platform 4 incorporates a raised portion 450 that presses the printed conductors 50 against the contact points (not shown) inside the mating receptacle 6 .
FIG. 4 ( b ) shows the underside of the interface platform 4 with the attached memory module 40 and terminal tab 45 . The smart card memory module 40 used in the invention incorporates integral electrical contact pads 42 on the module 40 itself. In the completed assembly, the surfaces of these pads 42 are aligned in the same orientation as the surfaces of the printed conductors 50 of the terminal tab 45 . The integration of the memory module contact pads 42 on the memory module 40 has the important advantage of obviating the need for additional printed conductors on the flexible substrate to provide an electrical connection point for the memory module 40 . A further advantage is that the electrical paths of the memory module connections are independent of those that connect the electrodes 20 , 21 , 22 to contact points in the mating receptacle 6 . Separation of the memory module conduction path from that of the electrodes 20 , 21 , 22 isolates the patient from the electrical paths of the memory module 40 , significantly enhancing patient safety. The relative placement of the memory module 40 and terminal tab 45 ensures that the printed conductor patient leads 50 will not momentarily come into contact with the memory module power supply and logic lines on the contact pads 42 during insertion and removal of the interface platform 4 from the mating receptacle 6 . Physical separation of the analog signals carried on the printed conductor patient leads 50 and the digital signals on the memory module contact pads 42 enhances the noise immunity of the acquired signals. Further enhancing patient safety is an additional printed conductor 55 that serves as a grounded guard trace. The ground guard serves as a collection path for any stray electrical current that might result from a fault condition. It is placed between the contact pads 42 of the memory module 40 and the printed conductor patient leads 50 in such a manner that it provides a barrier to any current that might leak from the memory module contact pads 42 .
FIG. 4 ( c ) shows the top of the interface platform 4 . In this view, the side of the flexible substrate 10 opposite that bearing the printed conductors may be seen 420 . To facilitate connection to the mating receptacle 6 , the interface platform 4 incorporates a finger grip 475 which indicates where the interface platform 4 should be grasped. This helps to avoid finger contact with the exposed electrical contact surfaces on the underside of the interface platform 4 , thus minimizing the risk of poor connection impedances due to residual epidermal oils. The interface platform 4 also incorporates a finger stop 480 which enables the user to exert the moderate degree of force necessary to firmly slide the interface platform into the mating receptacle. Integrated into the upper surface of the interface platform 4 is a pair of keyed alignment rails 485 along each side of the portion of the interface platform 4 that is inserted into the mating receptacle 6 . The rails 485 ensure that the interface platform 4 can be inserted into the receptacle 6 in only one possible alignment. Also incorporated into the interface platform 4 are a retaining depression 490 and retaining restraint 495 , which act together to retain the interface platform 4 within the mating receptacle 6 .
It should be recognized that various alternative embodiments of the smart sensor may be constructed by substituting individual electrodes for some or all of the electrodes in the electrode array, by providing individual interface platforms for some or all of the electrodes, and by varying the location of the memory module. Individual electrodes substituted for some or all of the electrodes of the electrode array may have individual interface platforms, or may connect to a common interface platform, or a combination of the two. The memory module 40 may be placed on the electrode array substrate 10 , on one of the individual electrodes 20 , 21 , 22 , in a cable connecting the electrode array to a mating receptacle or monitor, or on or in an interface connector attached to the electrode array and connecting it to the mating receptacle. Alternatively, smart electrodes may be constructed by placing memory modules 40 on the substrate 10 carrying an individual electrode 15 as shown in FIG. 5, on each individual electrode 20 , 21 , 22 , or on or in the interface connector of the smart electrode 18 ; a set of smart electrodes may then be connected by individual or common interface connectors to a mating receptacle 6 or monitor, creating a smart sensor. Such alternate embodiments are functionally equivalent to the preferred embodiment described above.
Electrical connection between both the printed conductors 50 connecting to the electrodes 20 , 21 , 22 , the memory module 40 and the associated monitor (not shown) are achieved by means of a mating receptacle 6 . The mating receptacle 6 contains numerous features specific to this invention and is an integral part of the smart sensor system of the present invention. A view of the interface platform 4 properly aligned for insertion into the mating receptacle 6 is shown in FIG. 6 ( a ). The mating receptacle 6 may be attached to a biopotential signal monitor (not shown) containing a processor either directly or by means of an intermediary connecting cable 8 . Referring now to FIG. 6 ( b ), the interface platform 4 is inserted into the mating receptacle 6 until the finger stop 480 makes contact with the end face 540 of the mating connector 6 . The portion 550 of the interface platform 4 that is inserted includes both the attached memory module 40 and the attached end of the terminal tab 45 bearing the printed conductors 50 . Upon insertion, both the contact pads 42 on the memory module 40 and the printed conductors 50 on the terminal tab 45 make contact with electrical contact points (not shown) within the mating receptacle 6 . This establishes an electrical connection between the printed conductors 50 of the electrode array 20 , 21 , 22 and the memory module 40 on one hand, and the internal conductors (not shown) of the connecting cable 8 of the signal monitor on the other.
Referring now to FIG. 7, the mating receptacle 6 also incorporates a beryllium-copper retaining finger 630 that engages the retaining depression 490 when the interface platform 4 is fully inserted into the mating receptacle 6 . When opposing forces are exerted in line with the smart sensor 2 and connecting cable 8 of the mating receptacle 6 , the retaining finger 630 exerts a counter force against the retaining restraint 495 , preventing the interface platform 4 from being inadvertently withdrawn from the receptacle 6 . Pressing on the release button 560 lifts the retaining finger 630 out of the retaining depression 490 and clear of the retaining restraint 495 , so that the interface platform 4 may be removed from the receptacle 6 and the smart sensor 2 disconnected when desired. In the case of the accidental application of an excessive pulling force on the smart sensor 2 , the retaining finger 630 will yield and the interface platform 4 will then detach to prevent patient injury caused by a falling monitor.
FIGS. 7 and 8 illustrate several additional features of the mating receptacle 6 . A cross section through the mating receptacle 6 perpendicular to the plane of the interface platform mounting surface is shown in FIG. 7 . The opening into which the interface platform 4 is inserted is normally sealed by the hinged door 610 made of thermoplastic elastomer. The door 610 serves to bar liquids from entering the mating receptacle 6 when the interface platform 4 is not inserted, an important feature in a hostile environment such as an operating room. The action of inserting the interface platform 4 into the mating receptacle 6 pushes the door 610 open and out of the way. Liquids are further barred from entry into the receptacle by two wiping surfaces 620 . These act to wipe off any liquid that may be on the surface of the interface platform 4 and which poses a potential short-circuit risk. These wiping surfaces 620 are part of the thermoplastic elastomer outer sleeve 640 of the mating receptacle 6 . This soft sleeve 640 minimizes pressure indentations in a patient's skin when the mating receptacle 6 is positioned such that a patient is lying on it. Also visible in this view are the electrical contact points 638 for the exposed contacts of the printed conductors 53 and the electrical contact points 635 for the memory module contact pads 42 . The hinged door 610 is normally held in the closed position. The electrical contact points are also shown from a different orientation in FIG. 8 . FIG. 9 shows an end-on cross-sectional view through the hinged door 610 from the direction of the end of the mating receptacle 6 which accepts the interface platform 4 . The rail alignment channels 650 receive the keyed alignment rails 485 , ensuring proper alignment of the interface platform 4 as it is inserted into the mating receptacle.
In an alternate embodiment shown in FIG. 10 ( a ), the memory module 40 is mounted directly on the flexible substrate 10 , opposite the side bearing the electrodes. In contrast to the preferred embodiment, the memory module 40 is mounted with its contact pads 42 against the flexible substrate 10 . Additional printed conductors 50 are provided on the flexible substrate on the same side as the memory module 40 to connect the contact pads 42 of the memory module 40 to exposed contacts on the terminal tab 45 for connection to the monitor via a mating connector. The terminal tab 45 thus has exposed contacts on both sides. In this embodiment, the mating connector contains additional electrical contact points for the printed conductors electrically connected to the memory module 40 in place of contact points for the memory module contact pads 42 . Alternatively, in the embodiment shown in FIG. 10 ( b ), the memory module 40 is mounted on the same side of the flexible substrate 10 as the electrodes. This design simplifies the smart sensor construction by requiring printed conductors 50 on only one side of the flexible substrate 10 . Adequate insulation must be provided, however, to protect the patient from a possible fault condition arising from the close proximity to the skin of the smart sensor current supply conductor.
Referring now to FIG. 11, the patient interface circuits 811 incorporate a ground fault detection circuit 833 . In the event of a detected ground fault, the Field Programmable Gate Array (FPGA) 818 shuts down the power to the memory module 40 . If the fault is still detected, the FPGA 818 then shuts down the power supplying the instrumentation amplifier 810 and alerts the monitor 840 that a shutdown has occurred. The sequential shutdown of first the memory module 40 and then the instrumentation amplifier 810 allows the monitor to localize the failure to either of these components. A hard re-boot is necessary to restore monitoring.
A potential single fault condition is the failure of the insulation between the smart chip power connection V+ 808 and one of the patient connections 804 , 805 . This could occur, for example, if the mating receptacle 6 were to be wet with a conductive solution such as saline. An electrical path represented by resistor 809 would form an electrical bridge between the memory module power line 819 and the patient connection, e.g. 804 . Current would flow through the patient 800 as indicated by the arrows, traveling through patient connection 804 , patient electrode impedances 801 , 803 , through ground electrode connection 806 , and into the ground of the instrumentation amplifier 810 . The International Electrotechnical Commission has set the maximum permissible current at 50 micro-amperes in a single fault condition, defined as “patient auxiliary current.” Current in excess of this limit is detected in the present invention by using sense resistor 812 to convert the current flow from the patient to ground into a voltage. This current-proportional voltage is amplified by the circuit consisting of operational amplifier 815 and resistors 813 , 814 . Comparators 816 , 817 compare the amplified current-proportional voltage to reference voltages 830 , 835 and output digital signals 820 , 821 which indicate whether or not the patient auxiliary current has been exceeded. Reference voltages 830 , 835 are equal in magnitude, but of opposite sign; 835 is positive, 830 is negative with respect to ground. The magnitude of reference voltages 830 , 835 is equal to the magnitude of the output voltage of operational amplifier 815 when the current through sense resistor 812 is 50 micro-amperes. If the polarity of the current through sense resistor 812 is positive, signal 820 will be at the negative saturation voltage of comparator 816 if the output voltage of amplifier 815 is greater than reference voltage 835 , and at the positive saturation voltage of comparator 816 if the output voltage of amplifier 815 is less than reference voltage 835 . Similarly, if the polarity of the current through sense resistor 812 is negative, signal 821 will be at the positive saturation voltage of comparator 817 if the output voltage of amplifier 815 is greater than reference voltage 830 , and at the negative saturation voltage of comparator 817 if the output voltage of amplifier 815 is less than reference voltage 830 . Thus, currents in excess of 50 micro-amperes are detected by the condition of either of signals 820 , 821 being low, as detected by the Field Programmable Gate Array (FPGA) 818 . In the event of detection of auxiliary current in excess of the detection threshold, the FPGA 818 responds by de-asserting signal line 822 , signaling switch 823 to disconnect power to the memory module 40 . Thus the power to the memory module 40 is disconnected and the auxiliary current ceases. FPGA 818 then notifies the monitor 840 of the event. The monitor causes an error message to be displayed on the monitor display, signaling the user to rectify the condition. A button on the monitor must be pressed for operation to continue; this button initiates a hard re-boot of the entire monitor system.
If the source of the current were something other than the smart sensor power line 819 the fault would continue to be detected even after switch 823 is opened. In such a case FPGA 818 notifies the monitor 840 , which shuts off power to the patient interface circuits 811 , causing the current to cease. The monitor displays an error message signaling the operator to rectify the condition. The monitor software must be re-booted for operation to continue.
Although the ground fault detection circuit 833 in the preferred embodiment is only in the patient ground circuit, those skilled in the art will recognize that any patient connected circuit could contain a fault sensing circuit.
Referring now to FIG. 12, the patient interface circuits 811 incorporate a ground guard conductor 55 that surrounds the patient-connected conductors 834 , 838 . In the normal operating condition, insulation is achieved between the memory module power conductor 819 and the patient conductors 834 , 838 by physical separation. This insulation can be compromised in a fault condition such as the wetting of the connector with a conductive solution such as saline, which may result in current flowing from the memory module power conductor 819 into the patient-connected conductors 834 , 838 . To prevent this condition, an exposed electrical guard conductor 55 is interposed between the memory module power conductor 819 and the patient-connected conductors 834 , 838 . In a fault condition, an electrical path represented by resistor 825 would then form an electrical bridge between the power line 819 and the guard conductor 55 . Current would flow as indicated by the arrows from the memory module power line 819 , through the bridge 825 into the ground guard conductor 55 and though the ground conductor 826 into the patient interface circuit ground 836 . Thus the current would be shunted harmlessly away from the patient.
It can be seen that the guard combined with the ground fault detector would enable the system to detect any condition that compromises the insulation in the sensor. One such condition is the wetting of the sensor. Thus the preferred embodiment comprises a wetness detector for the sensor connector.
Referring now to FIG. 13, the method for detecting the connection of the smart sensor to the monitor will now be described. The presence or absence of the connection of a smart sensor 2 to the patient interface circuits 811 is detected by monitoring the electric current flow in memory module power line 819 . This current also flows through resistor 827 , creating a voltage that is sensed by comparator circuit 832 . In the absence of a connection of a smart sensor 2 to the patient interface circuits 811 , no electric current flows in memory module power line 819 . The resistors 828 , 829 , 831 , 837 are selected such that in the case of no current flow in memory module power line 819 , there will be negligible current flow through resistor 827 , and further such that the voltage at the negative (−) input to the comparator 832 is less than the voltage at the positive (+) input of the comparator 832 . In this state, the comparator outputs a logic high to FPGA 818 . Upon connection of the smart sensor 2 to the patient interface circuits 811 , electric current flows in memory module power line 819 . This increases the current flow through resistor 827 , the relative voltages at the input to the comparator 832 reverse and the comparator outputs a logic low, indicating the presence of the smart sensor. The FPGA 818 notifies the monitor 840 , which then initiates the authentication sequence.
Referring now to FIG. 14, an alternate embodiment to detect the connection of a smart sensor 2 to the patient interface circuits 811 makes use of a dedicated conductor loop 839 in the smart sensor, each end of which connects to contacts in the mating receptacle. One of these contacts would be connected to the voltage supply of the monitor through a current limiting and sensing resistor 824 , the other would be connected to ground. Current flow through the resistor 824 is detected using the comparator 832 and the resistors 828 , 829 , 831 , 837 , whose values are selected in the manner described above so that the output of comparator 832 is a logic high when no smart sensor is connected and a logic low when a smart sensor is connected, causing current to flow.
The smart card memory module 40 is preferably of the type designed for use in pre-paid phone cards, in which the security of the data on the card is of paramount importance. Examples of suitable memory modules are the SLE 4436 manufactured by Siemens AG, Munich, Germany, or alternately the type PCF2036 manufactured by Phillips Electronics NV, Amsterdam, The Netherlands. The memory on such modules is divided into 3 segments; ROM, PROM, and EEPROM, including a counter. These modules provide for memory retention for at least 10 years without power application.
Smart card technology provides unique benefits in this application; such modules are ideally suited to this invention due to the inherent security provided by its design and operation. The small size of the smart card memory module die (1 mm 2 ) ensures that flexing of the interface platform 4 will not fracture it. In addition, the physical layout of the wire leads from the die make it difficult to physically or electrically probe the module (e.g., with an oscilloscope) in order to sample the bi-directional transmitted data. As a further security measure, the smart card memory module 40 is shipped to the manufacturer in a locked state to provide security during delivery. In the locked state, it is not possible to read from or write to the memory module 40 ; the smart sensor manufacturer using a transport code generated by the manufacturers of the smart card module must first enable it. The smart sensor manufacturer unlocks the memory module 40 during the programming stage of the manufacturing process. Further, once the memory module 40 is relocked, it may be written to only once (with the exception of the counter). This provides an additional layer of security, as the data on the memory module 40 cannot subsequently be changed. Those skilled in the art will recognize that many different smart card-type memory modules 40 may be used in its place.
The manufacturer of the smart card memory module 40 also writes a binary data string referred to as a Manufacturer Code to a read-only (ROM) area of the memory module 40 . This code is unique to those memory modules 40 sold to the purchaser (the manufacturer of the smart sensor 2 ) and only that purchaser (the smart sensor manufacturer) may purchase modules containing this code. Because this code is in ROM, it may not be altered and thus serves as an identifier of the source of products containing the smart card memory module.
The use of a smart card memory module 40 is further differentiated from a typical semiconductor memory device (e.g., an SGS-Thomson ST24C02, a 2 Kilobit EEPROM) by a different communication protocoL The difference in protocols between the smart card memory module 40 and an EEPROM prevents the construction of a counterfeit smart sensor using a non-smart card memory module 40 .
A further advantage of the smart card memory module 40 is that a portion of the counter memory is PROM. In order to facilitate the stored value applications for which the smart card memory module 40 is designed, a portion of the counter memory space is read only PROM. The initial value in the PROM is set during manufacturing programming. During subsequent use, individual bits of the PROM may be set to zero, but cannot be reset to 1. The remainder of the counter is EEPROM and again, the initial value is set during manufacturing programming. Like the PROM, during subsequent use individual bits of the EEPROM may be set to zero. Additionally, the EEPROM may be reset to a 1's by writing to the PROM.
A portion of the EEPROM section is designated as a usage counter to track the number of times the smart sensor 2 has been authenticated, each bit representing one use. In the preferred embodiment, 16 bits are used. These bits are set to 1's during manufacturing programming. In addition, a bit within the PROM is used to indicate whether the smart sensor 2 has been used the maximum number of times (the use bit); this bit is set to 1 during programming.
During each smart sensor authentication process, the monitor verifies that the PROM use bit is set to a 1 and that the number of remaining uses, as represented by the number of usage counter bits set to 1, is greater than zero. Each time the smart sensor 2 is successfully authenticated, one of the usage counter bits is set to zero, decrementing the number of allowable uses by one. The usage counter bits are set to zero starting with the least significant and progressing to the most significant. When the last usage counter bit is set to zero (after 16 uses in the example), the monitor writes to the PROM use bit, setting it to zero and resetting the usage counter bits to 1's. This effectively prevents the subsequent use of the smart sensor 2 (beyond the present use), since the condition that the PROM use bit be 1 will fail Further, since it is not possible to reset the use bit to a 1, the usage counter cannot be “reloaded”.
Numerous pieces of data are written to the smart sensor 2 during the manufacturing process. This data includes, but is not limited to, a key code, an OEM code, a lot code (incorporating the date of manufacture), a shelf life code, a sensor type code, and serial number. In addition, part of the memory module counter is configured as a usage counter, and is set to the maximum number of allowable sensor uses, preferably 16 in the current embodiment. Together with the manufacturer code, this data is collectively referred to as the device data.
In order to protect the integrity of the smart sensor 2 , some of the device data is encrypted before it is written to the smart sensor 2 . The encryption process and the related generation of a digital signature are integral features of the smart sensor 2 , which protect it from counterfeiting by an unauthorized source. In general, encryption systems operate by using a specific mathematical algorithm to scramble a data sequence or “message” so that the contents of the message are unintelligible unless that message is decrypted by a related algorithm. A security key encryption algorithm is one that uses a “key” (E), a specific alphanumeric sequence that determines how the algorithm scrambles the message. Thus, for a specific data sequence or “message” (M), the encrypted message C is generated by applying the encryption algorithm f e to the message M using the key E.
C=f e (E,M)
The original message M may be recovered from the encrypted message C by applying the related decryption algorithm f d to C using the decryption key D.
M=f d (D,C)
There are two general classes of encryption algorithms, symmetric and asymmetric. Symmetric algorithms use the same key for encryption and decryption; that is, E=D. Asymmetric algorithms use different encryption and decryption keys. Symmetric algorithms are typically computationally less intensive but have the weakness that the same key is used both to encrypt and decrypt the message. Thus knowledge of the decryption key and of the decryption algorithm (both of which might be obtained by reverse engineering the monitor software) would allow a potential counterfeiter to produce smart sensors with validly encrypted device data.
A particular class of asymmetric encryption algorithms are the Public Key algorithms. In these algorithms, the encryption and decryption keys are a mathematically related pair, but the mathematical relationship between the keys is such that it is not possible to derive one of the keys from knowledge of the other key. Thus, one key (the “Public” key) may be made public knowledge without compromising the security of the other key (the “Private” key). In the case of the present invention, the public key is embedded in the monitor software and used to decrypt the data, while the private key is used to encrypt the data and is kept secret by the smart sensor manufacturer.
It would seem that public key encryption would provide an authentication of the source of the smart sensor, since if it is possible to properly decrypt the message using the monitor's public key, it must have been encrypted by the related private key, the only possessor of which is the smart sensor manufacturer. However, the only test in this case of whether a decryption is “proper” is whether the message is meaningful. Given the relatively simple nature of binary codes (as opposed to natural text), the possibility that an incorrect decryption might be accepted as correct is relatively high. This might result from the use of an incorrect key for encryption or decryption, or the corruption of the message stored on the smart sensor. Thus, while encryption provides message confidentiality, it does not provide authentication of the source of the message, nor does it provide authentication of the integrity of the data.
The source of the smart sensor 2 is authenticated and the integrity of its data validated by using a “digital signature.” Signature generation requires the use of a “hash” function (h), which operates on a message to produce an output sequence that is specific to the content of the message itself. If the message M changes, so will the hashed message h(M). In the case of a public key algorithm, the digital signature (S) is generated using a signature generation function f s , which typically uses both the private (E) and public (D) keys as well as the hashed message h(M). The signature is typically made up of 2 data sequences, S 1 and S 2 .
(S 1 ,S 2 )=f s (E,D,h(M))
The message M is encrypted using the private key. The encrypted message C is then written to the smart sensor 2 along with the digital signature (S 1 ,S 2 ). Upon reading the data from the smart sensor 2 , the monitor first decrypts the message using the public key to obtain M. The digital signature is then verified by the signature verification function f v which first applies the hash function to M and then uses h(M) in conjunction with the internally stored public key (D) and the components of the signature to verify that the derived value is equivalent to one of the signature components.
S 2 ≡f v (D,S 1 ,S 2 ,h(M))
If this equality is true, the signature is validated. This will occur if and only if the public key D and the private key E used to encrypt the data are the unique related pair and if the message M used to verify the signature is the same as that used to generate the signature. Thus, if the signature can be verified, it must have been generated using the unique private key that corresponds to the public key used for the verification. Since the only holder of the correct private key is the authorized smart sensor manufacturer, successful signature verification ensures that the smart sensor 2 indeed originated at an authorized source. In addition, the successful verification of the signature means that the message used to verify the signature must be the same as that used to create the signature (otherwise h(M) would be different). Thus, successful verification of the signature validates the integrity of the data stored on the smart sensor 2 .
During the monitor manufacturing process, a particular public key is embedded within the monitor software. Separately, during the smart sensor 2 manufacturing process, the device data corresponding to each smart sensor 2 is first formatted as a single binary sequence, referred to as the device data string. The device data string corresponding to each smart sensor 2 is encrypted using the public and private keys and the Public Key encryption algorithm. Each encrypted device data string is thus unique since it includes the smart sensor 2 serial number. In addition, both the public and private keys are in conjunction with the device data string to generate a digital signature. The digital signature is also formatted as a binary sequence. After the smart sensor memory module is unlocked using the transport code in the course of its manufacture, the encrypted binary device data string and the binary digital signature are combined to form a single binary sequence (the sensor data string) which is written to the memory module.
Device Data String:
Manufacturer
Key
OEM
Lot
Shelf
Sensor
Serial
Code
Code
Code
Code
Life
Type
Number
Sensor Data String:
Device Data String
Digital Signature
Use of a public key algorithm provides a significant defense against smart sensor counterfeiting. Even if a potential counterfeiter obtained the public key and the decryption algorithm by reverse engineering the monitor software, a valid digital signature could not be generated without the private key. The private key is used only in the manufacturing process and is not stored in the monitor software; thus, it is not available to the counterfeiter. Further, the private key cannot be easily computed from the public key. If either the key or the encryption algorithm becomes compromised, the smart sensor manufacturer may, by issuing a new revision of monitor software, expire existing keys and issue new keys to the existing installed monitor base to minimize any possible security impacts.
Multiple public/private key pairs may be used to provide different decryption keys for smart sensors distributed by different OEMs. The decryption key in use is coded by the key code, which is stored in the smart sensor memory. The public keys corresponding to each of the stored key codes may be integrated into the monitor software. The authentication program will use the key code to either determine the correct public key to be used for decryption and digital signature validation before the decryption process begins or to promptly expire a key.
Efforts to “break” the encryption code and determine the private key are exceedingly computationally intensive, and a successful effort would yield only the single private code currently in use. When the key pair in use is changed, the “code breaking” effort would have to be repeated to obtain the new private key. For this reason, security can be greatly enhanced by changing the public/private key pairs at regular intervals. To this end, the smart sensor system allows for regular changes in the set of public keys in use by the authentication program by subsequent updates to the monitor software. The private key is changed in the manufacturing process, and this change is reflected in the key codes.
Various public key encryption algorithms are well known in the state of the art, such as those implementing the RSA algorithm described by R. L. Rivest, A Shamir, and L. M. Adleman, in “A Method for Obtaining Digital Signatures and Public-Key Cryptosystems”, Communications of the ACM, volume 21, pages 120-126, February 1978 and the Discrete Logarithm algorithm described by T. ElGamal, in “A public key cryptosystem and a signature scheme based on discrete logarithms”, Advances in Cryptology—Proceedings of CRYPTO'84, Springer Verlag Lecture Notes in Computer Science 196, pages 10-18, 1985. Further, digital signature algorithms are similarly well known in the state of the art, such as the Digital Signature algorithm (DSA) described in National Institute of Standards and Technology, “Digital Signature Standard”, FIPS Publication 186, 1993 and the improved ElGamal algorithm described by C. P. Schnorr in “Efficient signature generation by smart cards”, Journal of Cryptology, volume 4, pages 161-174, 1991. However, those skilled in the art will recognize that any public key encryption/decryption method and digital signature method may be used.
While the embodiment described above utilizes the encryption of the data message written to the smart sensor 2 , it is recognized that the digital signature method will function equivalently well if the message is written to the smart sensor 2 in unencrypted form, or alternately if the message is written in hashed form.
Referring now to FIG. 15, the algorithm used by the monitor to authenticate the smart sensor 2 will now be described. Each time the smart sensor 2 is disconnected from and reconnected to the same or a different monitor or each time the monitor is restarted, the monitor first resets the data string acquisition routine and waits for the detection of a smart sensor connection at the mating receptacle 6 in step 902 . The detection is performed by the monitor's sensor interface electronics, shown in FIG. 13 . It consists of a current sensing circuit that monitors the current in the power conductor of the smart sensor memory module 40 . Upon detection of a smart sensor connection in step 904 , the data acquisition routine interrogates the smart sensor in step 906 , requesting that the smart sensor 2 transmit the stored sensor data string. The smart sensor 2 responds to this request by sending the sensor string to the monitor in step 908 . After receiving the sensor data string from the smart sensor 2 in step 910 , the data acquisition routine passes the string to the digital signature validation routine in step 912 .
Referring now to FIG. 16, the digital signature validation routine first parses the sensor data string into its constituent parts, the digital signature string and the device data string in step 920 . Then in step 922 , it uses the manufacturer code to verify the smart sensor memory module 40 is one that was purchased by the smart sensor manufacturer. If this condition is not met, the test is repeated up to 3 more times in step 924 . After the fourth failure, a message indicating that the connected sensor is an illegal device is displayed on the monitor screen in step 926 and the monitor will terminate the authentication program and refuse to proceed with data collection in step 928 . If the manufacturer code is determined in step 922 to be valid, the digital signature validation routine uses the decryption algorithm and the embedded public key to decode the device data string in step 930 . In step 932 , the system next validates the digital signature using the validation algorithm, the device data string and the embedded public key. The validation algorithm then determines, in step 934 , whether or not the signature is valid, and thus produced by an authorized source. If valid, the signature is accepted; if not, validation is attempted up to 3 more times 16 . If the validation fails 4 times, the monitor displays a message on its screen indicating to the user that monitoring will not proceed in step 926 and monitoring is disabled in step 928 . Upon acceptance of the signature, program control is then transferred to the Sensor Verification Check in step 936 .
Referring now to FIG. 17, in step 940 , the authentication software verifies that the value of the sensor type code corresponds to one of the possible values stored in a look-up table in the authentication software. If the sensor code is a valid value, then the smart sensor 2 is accepted as authentic in step 942 . Otherwise, a message indicating that the connected sensor is an illegal device is displayed on the monitor screen in step 944 and the monitor will terminate the authentication program and refuse to proceed with data collection in step 946 .
It is anticipated that while the smart sensor 2 will be made by a single manufacturer or various authorized subcontractors, different versions of the monitor may be manufactured or distributed by different licensed manufacturers (OEMs) using the smart sensor interface circuit 811 and monitoring software supplied by the smart sensor manufacturer. The OEMs may also distribute smart sensors. It is therefore desirable to allow only smart sensors distributed by a specific OEM to be used with the monitors manufactured by the same OEM. The identity of the distributor will be encoded in the smart sensor 2 in the OEM code. If the smart sensor's manufacturer code is determined to be valid in step 942 , the authentication software, in step 948 , next checks the OEM code against a look-up table to determine whether that OEM code is allowed to be used with the specific monitor. If the particular smart sensor 2 is not authorized for use with the particular monitor, a message to that effect is displayed on the monitor screen in step 944 and the monitor will terminate the authentication program and refuse to proceed with data collection in step 950 .
The monitor maintains a log of the set of smart sensor parameters in its internal nonvolatile memory, with a separate entry for each smart sensor 2 which has been authenticated by a given monitor, as determined by the smart sensor serial number and lot code. The logged parameters include the current date and time, the sensor type, the OEM code, and the smart sensor serial number and lot code. A usage counter is also associated with each entry in the log. Sufficient memory is reserved in the nonvolatile memory for this purpose to enable the log to contain entries from some large number of smart sensors 2 ( 200 in the preferred embodiment); when the log is full, the oldest entry is deleted to create memory space for the newest entry. A representative of the manufacturer may download the sensor usage log onto a personal computer. The manufacturer may use this data to resolve quality control issues.
Referring now to FIG. 18, if the smart sensor OEM code is one that is authorized for the particular monitor, the authentication software checks if a record in the log has the serial number and lot code of the current smart sensor 2 in step 950 . If so, the existing record is used for the currently connected smart sensor. If such a record does not exist, a new log entry is created and its fields are loaded with the data values obtained from the device data string in step 952 . The current date and time are also recorded. After creation of the record or if such a record does exist, the monitor software next updates the usage counters.
The smart sensor 2 is designed to be disposable and therefore re-use of a smart sensor 2 on a different patient may degrade performance, as well as posing a potential infection risk. However, limited reuse must be allowed, as a smart sensor 2 may be disconnected and reconnected to the same or a different monitor several times in order to accommodate patient movement, transfer, etc. The monitor therefore utilizes the usage counter in each record in the log to determine whether a particular smart sensor 2 has been used more than an allowable number of times and also to warn the user of the reuse status of the connected smart sensor.
The usage counter in the smart sensor 2 and that in the log of the monitor to which the smart sensor 2 is connected are maintained as mirror images. By maintaining the usage counter in the smart sensor 2 memory as well as in the monitor memory, the integrity of the usage count is preserved when the smart sensor 2 is disconnected and then reconnected to a different monitor. This would occur, for example, when a patient who was first monitored in the operating room was transferred to an intensive care unit (ICU) where monitoring was to be continued using a different monitor. If the smart sensor 2 and monitor usage counters contain different counts for the same smart sensor serial number and lot code, as would occur when a previously used smart sensor 2 is reconnected to a different monitor, both counters are reset to the value of the counter indicating the smallest number of remaining uses.
After logging the smart sensor data, the authentication software, in step 954 first synchronizes the usage counters by determining the number of remaining allowable uses and writing that value to the usage counters maintained in the monitor's smart sensor log and on the smart sensor 2 . If a new record has just been created for the current smart sensor 2 (identified by serial number and lot code), the number of remaining allowable uses is calculated as the minimum of the value in the usage counter of the connected smart sensor 2 and the maximum number of allowable uses. If there is a pre-existing record in the log with the same serial number and lot code as that of the currently connected smart sensor 2 , the number of remaining allowable uses is calculated as the minimum of the value in the usage counter of the monitor's smart sensor log and the value of the usage counter on the connected smart sensor 2 in step 956 . The usage count field in the log and the usage counter in the smart sensor 2 are then both updated with the calculated number of remaining allowable uses in step 958 .
Referring now to FIG. 19, in step 960 the authentication software next tests whether the value of the synchronized usage counters (the number of uses remaining) is less than the maximum number allowable but greater than 0; if so, the monitor will display a message to the user in step 962 with the number of previous uses and will warn that the performance of the smart sensor 2 may be unreliable. The authentication software then tests whether the value of the synchronized usage counters is zero in step 964 . If so, the maximum number of uses has been reached and the monitor will alert the user in step 966 and disallow the use of the smart sensor 2 in step 968 . If the usage counter is greater than zero, the authentication software will decrement both usage counters in step 970 . This sensor usage check thus prevents a smart sensor 2 from being used more than the allowable number of times, regardless of which monitor the smart sensor 2 has been connected to. This outcome is obtained even if the usage counter on the smart sensor 2 was reset to the initial value by an unauthorized method; the actual number of times that smart sensor 2 has been used is logged in the monitor and will be reloaded onto the smart sensor 2 when it is reconnected.
In the preferred embodiment, different electrode configurations on the electrode array may require the use of different processing algorithms. In addition, different algorithms might be used with the same electrode configuration for different applications, such as surgical monitoring, monitoring in the intensive care unit (ICU), or monitoring pediatric patients. This information may be coded as a numeric value in the sensor type code on the smart sensor 2 .
Referring now to FIG. 20, the monitor uses the sensor type code to select one of several internal processing algorithms appropriate to the specific smart sensor 2 and application in step 980 . The sensor type code may also be used to switch the inputs to the monitor's instrumentation amplifiers if a signal is to be multiplexed.
The monitor next conducts a sensor expiration check. In step 982 , the monitor compares the current date to the date of manufacture plus the shelf life (both read from the smart sensor memory module 40 ) plus a preset “grace period” to determine if the age of the smart sensor 2 is significantly greater than its recommended shelf life. If so, the monitor will display a message in step 984 directing the user to replace the sensor and will disallow use of the smart sensor 2 in step 986 . The grace period is a preset time period, preferably one month, used to allow use of a smart sensor 2 after duly notifying the user of the potentially impaired performance. If the monitor determines in step 988 that the smart sensor 2 is beyond its expiration date, but not beyond the grace period, the monitor will display a warning to that effect on its display in step 990 before proceeding with monitoring in step 992 .
A particular alternate embodiment of the smart sensor system uses the smart sensor memory module 40 as a means of customizing software in the monitor 840 . In the case in which the monitor 840 calculates a diagnostic index in the manner taught by Chamoun, et aL in U.S. Pat. 5,458,117 which is assigned to the assignee of the present application and the teachings of which are incorporated herein by reference, the index coefficients may be stored in the smart sensor memory module 40 and transferred to the monitor 840 during the configuration procedure. These coefficients would then be used by the monitor 840 to calculate the diagnostic index Specific smart sensors intended for different applications may have different sets of coefficients stored in their memory modules during the manufacturing process. For example, in the case of a monitor which computes a diagnostic index quantifying the effect of anesthetic agents on the electroencephalogram, one model of smart sensor may be loaded with a first set of coefficients optimized for adult surgical use, a second model of sensor might be loaded with a second set of coefficients optimized for pediatric surgical use, and a third model of sensor might be loaded with a third set of coefficients optimized for use on adults in an intensive care unit environment. In this way, the functionality of the monitor may be customized depending on the type of smart sensor that is connected to it.
In a second alternate embodiment, the smart sensor memory module 40 may be used as a means of upgrading that portion of the monitor software that calculates the diagnostic index. In this embodiment, not only may different coefficients of the various variables in the diagnostic index be optimized for different applications, but the mathematical structure of the diagnostic index itself may be varied; ie., the variables in the index, their coefficients, and how they are combined may all be specified. This embodiment will greatly expand the flexibility of the smart sensor system by removing restrictions on the mathematical structure of the diagnostic index.
In a third alternate embodiment, the entire monitor software may be stored in the smart sensor memory module. In this embodiment, the monitor software may consist of only sufficient software to transfer the contents of the smart sensor memory module to the monitor 840 and then to run that software. Such software will include that portion which calculates the diagnostic index, as well as the portions that handle data acquisition, data display, communication with the user, etc.
All three of these alternate embodiments will allow new versions of diagnostic indices to be distributed as part of the smart sensor, rather than as an independent monitor software upgrade. This will simplify the task of upgrading the monitor software, as well as decreasing the associated cost. It will also ensure that each user of the smart sensor system has the latest monitor software available. While the memory capacity requirements for the third alternate embodiment cannot be satisfied by existing smart card memory modules, it is anticipated that the memory capacity of such devices will expand rapidly in the years ahead.
While the foregoing invention has been described with reference to its preferred embodiments, various alterations and modifications will occur to those skilled in the art. All such alterations and modifications are intended to fall within the scope of the appended claims. | A sensor system which includes a biopotential signal monitor, a smart sensor and the accompanying hardware and software interface which authenticates the source and validity of the smart sensor and also verifies that the smart sensor meets various criteria for use. | 0 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of co-pending U.S. application Ser. No. 12/207,913, filed on Sep. 10, 2008, which claims the benefit of U.S. Provisional Application Nos. 60/993,706 filed Sep. 14, 2007; and 61/135,402 filed Jul. 21, 2008, which applications are hereby incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
[0002] This invention relates to a system and method for maximizing the energy savings in AC induction motors at every load, more particularly one that uses a digital signal processor that calibrates control lines to determine the most efficient operational characteristics of the motors.
[0003] In prior systems and methods related to energy saving motor controllers using control lines of a motor, constant phase angle and/or constant power factor control were used to determine the control lines. This meant that the control lines were horizontal and the motor controllers were not able to control the motor to specific calibrated operating point at every load to maximize energy savings.
[0004] Thus, a need exists for a method and system for AC induction motors which controls the motor to a specific calibrated operating point at every load. Operating points taken across all loads will define a control line or a control curve. Furthermore, a need exists for a method and system for AC induction motors which is capable of recognizing when a motor begins to slip and is about to stall and uses that information to determine calibrated control line so as to maximize energy savings at every load.
SUMMARY OF THE INVENTION
[0005] The primary object of the present invention is to provide a system and method of maximizing energy savings in AC induction motors at every load.
[0006] Another object of the present invention is to provide a system and method which recognizes when a motor begins to slip and when the motor is about to stall.
[0007] A further object of the present invention is to provide a system and method which controls the motor to a specific calibrated operating point at every load.
[0008] Another object of the present invention is to provide a motor controller that is capable of observing the operational characteristics of AC induction motors.
[0009] A further object of the present invention is to provide a motor controller capable of making corrections to the RMS motor voltage as an AC induction motor is running and under closed loop control.
[0010] Another object of the present invention is to provide a motor controller capable of responding to changes in the load of an AC induction motor in real-time.
[0011] The present invention fulfills the above and other objects by providing a motor controller system and method for maximizing the energy savings in the motor at every load wherein a motor is calibrated at one or more load points, establishing a control line or curve, which is then programmed into a non-volatile memory of the motor controller. A digital signal processor (DSP) a part of a closed loop architecture of the motor controller possesses the capability to observe the motor parameters such as current, phase angles and motor voltage. This DSP based motor controller is further capable of controlling the firing angle/duty cycle in open-loop mode as part of a semi-automatic calibration procedure. In normal operation, the DSP based motor controller performs closed-loop control to keep the motor running at a computed target control point, such that maximum energy savings are realized. The method described here works equally well for single phase and three phase motors.
[0012] The preferred implementation of this method uses a DSP to sample the current and voltage in a motor at discrete times by utilizing analog to digital converters. From these signals, the DSP can compute key motor parameters, including RMS motor voltage, RMS current and phase angle. Furthermore, the DSP based motor controller can use timers and pulse width modulation (PWM) techniques to precisely control the RMS motor voltage. Typically the PWM is accomplished by using power control devices such as TRIACs, SCRs, IGBTs and MOSFETs.
[0013] The above and other objects, features and advantages of the present invention should become even more readily apparent to those skilled in the art upon a reading of the following detailed description in conjunction with the drawings wherein there is shown and described illustrative embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] In the following detailed description, reference will be made to the attached drawings in which:
[0015] FIG. 1 is a block diagram of a digital signal processor (DSP) with hardware inputs and outputs of the present invention showing hardware inputs and outputs;
[0016] FIG. 2 is a block diagram of a DSP-based motor controller of the present invention;
[0017] FIG. 3 is a diagram showing a phase rotation detection method of the present invention;
[0018] FIG. 4 is a flow chart showing a phase rotation detection method of the present invention;
[0019] FIG. 5 is a graph showing power control device outputs for positive phase rotation;
[0020] FIG. 6 is a graph showing power control device outputs for negative phase rotation;
[0021] FIG. 7 is a block diagram of a window comparator;
[0022] FIG. 8 is a schematic of the window comparator;
[0023] FIG. 9 is a graph of a current waveform and zero-cross signals;
[0024] FIG. 10 is a schematic of a virtual neutral circuit;
[0025] FIG. 11 is a graph showing power control device outputs for single phase applications;
[0026] FIG. 12 is a three-dimensional graph showing a three-dimensional control line of the present invention;
[0027] FIG. 13 is a three-dimensional graph showing a control line projected onto one plane;
[0028] FIG. 14 is a graph showing a two-dimensional plotted control line;
[0029] FIG. 15 is a graph showing a sweeping firing angle/duty cycle in a semi-automatic calibration;
[0030] FIG. 16 is a graph showing a directed sweep of a firing angle/duty cycle;
[0031] FIG. 17 is a graph showing plotted semi-automatic calibration data;
[0032] FIG. 18 is a graph showing plotted semi-automatic calibration data;
[0033] FIG. 19 is a graph showing plotted semi-automatic calibration data;
[0034] FIG. 20 is a flow chart of a semi-automatic high level calibration;
[0035] FIG. 21 is a flow chart of a semi-automatic high level calibration;
[0036] FIG. 22 is a flow chart of a manual calibration;
[0037] FIG. 23 is a flow chart of a fixed voltage clamp:
[0038] FIG. 24 is a graph showing a RMS motor voltage clamp;
[0039] FIG. 25 is a graph showing a RMS motor voltage clamp;
[0040] FIG. 26 is a flow chart of a stall mitigation technique; and
[0041] FIG. 27 is a graph showing the stall mitigation technique.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] With reference to FIG. 1 , a block diagram of a digital signal processor (DSP) 1 and hardware inputs and outputs of the present invention is shown. The DSP 1 can observe the operational characteristics of a motor and make corrections to root mean square (RMS) voltage for the motor that is running and under closed loop control. Hardware inputs 2 capture phase zero crossing inputs 36 , phase line voltage 37 , phase motor voltage 38 and current 9 and passed through the DSP 1 for processing and then onto power control devices through the power control device outputs 14 .
[0043] Referring now to FIG. 2 , a block diagram of a system and method of the DSP-based motor controller 4 of the present invention is shown. First, the motor controller 4 reads the voltages 37 of each phase A, B and C and current 9 to capture the zero-crossing inputs 36 . At this point voltage 13 and current 9 may be converted from analog to digital using converters 62 .
[0044] Next, computations 63 of motor phase angle for each phase are calculated to yield an observed phase angle 5 . Next, a target phase angle 10 which has been derived from a preprogrammed control line 6 is compared to the observed phase angle 5 . The difference between the target phase angle 10 and observed phase angle 5 yields a resulting phase error signal 11 which is processed by a digital filter called a proportional integral derivative (PID) controller 12 which has proportional, integral and differential components. The output from the PID controller 12 is the new control voltage 13 to the motor 3 , which can be obtained through the use of power control devices 33 , such as TRIACs, SCRs, IGBTs or MOSFETS, to yield power control device outputs 14 of RMS motor voltage 13 supplied with line voltages 50 for each phase for maximum energy savings.
[0045] In this closed loop system, the voltage 13 of each phase of the motor 3 and the current are continually monitored. The motor controller 4 will drive the observed phase angle 5 to the point on the calibrated control line 6 corresponding to the load that is on the motor. At this point, maximum energy savings will be realized because the control line 6 is based on known calibration data from the motor 3 . The motor controller 4 can control the motor 3 just as if a technician set the voltage 13 by hand. The difference is that the DSP 1 can dynamically respond to changes in the load in real-time and make these adjustments on a cycle by cycle basis.
[0046] Referring now to FIG. 3 , in a three-phase system, the motor controller 4 is used to automatically determine the phase rotation. Zero-crossing detectors on the line voltages provide an accurate measurement of the angle between the phase A line voltage zero crossings 15 and the phase B line voltage zero crossings 16 . For positive phase rotation 18 , the angle is nominally 120° and for negative phase rotation 19 , the angle is nominally 60°.
[0047] Referring to FIG. 4 , a flow chart for phase rotation detection is shown. After a power-on-reset (POR) 20 , it is easy for the motor controller 4 to determine positive phase rotation 18 and the negative phase rotation 19 . First, the time is measured from phase A line voltage zero crossings to phase B line voltage zero crossings 39 . Next it is determined if the time is greater than or less than 90 degrees 40 . If it greater than 90 degrees, than it is an ACB rotation 42 . If the time is less than 90 degrees, than it is an ABC rotation 41 . The motor controller 4 of the present invention can control three-phase or single-phase motors with the same basic software and hardware architecture. For the three-phase case, depending on the phase rotation, the motor controller 4 can drive power control device outputs 14 .
[0048] Referring now to FIG. 5 which shows power control device outputs for positive drive rotation, the motor controller drives phase A power control device outputs 14 and phase B power control device outputs 14 together during the phase A line voltage zero crossings 15 turn-on time as indicated by the oval 22 a. Similarly, the motor controller drives power control devices which drive phase B 16 and phase C power control device outputs 14 together during the phase B turn-on time as indicated by the oval 22 b. Finally, the motor controller 4 drives phase C 17 and phase A power control device outputs 14 together during the phase C power control device outputs 14 turn-on time as indicated by the oval 22 c. Note that the example shown in FIGS. 5 and 6 depicts a firing angle/duty cycle 23 of 90°.
[0049] Referring now to FIG. 6 which shows the TRIAC drive outputs for negative phase rotation, the motor controller 4 drives phase A power control device outputs 14 and phase C power control device outputs 14 together during the phase A line voltage zero crossings 15 turn-on time as indicated by the oval 22 c. Similarly, the motor controller 4 drives phase B 16 and phase A power control device outputs 14 together during the phase B line voltage zero crossings 16 turn-on time, as indicated by oval 22 a. Finally, the motor controller drives phase C power control device outputs 14 and phase B power control device outputs 14 together during the phase C line voltage zero crossings 17 turn-on time, as indicated by oval 22 b.
[0050] Now referring to FIG. 7 , a block diagram of a window comparator is shown. The DSP based motor controller of the present invention uses the window comparator 88 to detect zero-crossings of both positive and negative halves of a current wave form. When RMS motor voltage is reduced by the motor controller, it if difficult to detect zero crossings of current waveform because the current is zero for a significant portion of both half cycles. First, motor current is provided 89 , a positive voltage is provided 90 as a reference for a positive half cycle and a negative voltage is provided 91 as a reference. Next, the current, positive voltage and negative voltage are presented to two comparators 92 and are then passed through an operation (OR) gate 93 to create a composite zero-cross digital signal 94 .
[0051] As further illustrated in FIG. 8 , a schematic of the window comparator 88 is shown. The motor current is provided 89 , a positive voltage is provided 90 as a reference for a positive half cycle and a negative voltage is provided 91 as a reference. Next, the current, represented as a positive voltage and negative voltage, is processed by two comparators 92 and are then passed to an OR gate 93 to create a composite zero-cross digital signal 94 .
[0052] Further, FIG. 9 shows graphs of a current waveform 95 , a positive voltage half cycle 96 , a negative voltage half cycle 97 and an OR function 98 .
[0053] Now referring to FIG. 10 , a schematic of a virtual neutral circuit is shown. A virtual neutral circuit may be used as a reference in situations where three phase power is available only in delta mode and there is no neutral present for use as a reference. The virtual neutral circuit comprises three differential-to-single-ended amplifiers 77 . Because phase to phase voltages are high, input resistors 78 are used to form a suitable attenuator 79 together with feedback resistors 80 and ground reference resistors 81 . Because the danger exists of a loss of phase, protection diodes 82 are used to protect the differential-to-single-ended amplifiers 77 . The differential-to-single-ended amplifiers 77 are coupled to a summing amplifier 83 through DC blocking capacitors 84 and summing resistors 85 together with the feedback resistor 80 . The output of the summing amplifier 83 is boosted by amplifier 27 thereby providing a low impedance output which is at neutral potential. Additional resistors divide a supply rail thereby allowing the summing amplifier 83 to handle alternating positive and negative signals. An alternate connection is available in the event that a neutral 86 is available along with a jumper block for alternate neutral connection 87 .
[0054] Referring now to FIG. 11 showing a power control device output 14 for a single-phase application, the output 14 for phase A is turned on each half-cycle based on a power control device output 14 derived from the voltage zero-crossing input 15 . The power control device output 14 for phase B line voltage zero crossings and phase C line voltage zero crossings are disabled in the DSP 1 and the hardware may not be present. The power control device outputs 14 are not paired as they were in the three-phase case.
[0055] Referring now to FIG. 12 which illustrates a three-dimensional control line for the motor operating space of a motor bounded by an observed phase angle 5 on the y-axis. A controlled firing angle/duty cycle 23 showing the decrease in voltage is shown on the x-axis and the percent load 24 on a motor is shown on the z-axis.
[0056] Every motor operates along a parametrical control line 25 within its operating space.
[0057] For example, when a given motor is 50% loaded and the firing angle/duty cycle 23 is set to 100°, a phase angle 5 of approximately 55° is observed.
[0058] The parametrical control line 25 shown in FIG. 12 is defined by five parametric operating points 26 ranging from a loaded case 44 in the upper left corner, to an unloaded case 45 in the lower right corner. Furthermore, the parametrical control line 25 has special meaning because it is the line where a motor is using the least energy possible. If the firing angle/duty cycle 23 is increased and the motor voltage 13 decreased then a motor would slow down and possibly stall. Similar results would be seen if the load on the motor 3 is increased.
[0059] As illustrated in FIG. 13 , the parametric control line 25 may be parameterized and projected onto one plane described by phase angle 5 in the vertical direction and the firing angle/duty cycle 23 in the horizontal direction.
[0060] Further, as shown in FIG. 14 , the parametrical control line 25 may be displayed on a two-dimensional graph. On the x-axis, increasing firing angle/duty cycle 23 may be equated with a decreasing motor voltage. This is because small firing angle/duty cycles result in high voltage and large firing angle/duty cycles result in low voltage. The motor controller will drive the observed phase angle 5 to the point on the control line 25 that corresponds to the load presently on a motor. To accomplish this, a DSP computes the phase angle 5 between the voltage and current.
[0061] Referring back to the block diagram of FIG. 2 , the DSP 1 then computes the next target phase angle 5 based on the present value of the RMS voltage 13 , or equivalently the present value of the firing angle/duty cycle. The difference between the observed phase angle and the target phase angle 10 results in a phase angle error, which is processed through a proportional-integral-differential (PID) controller 12 or similar device to generate a new control target. This control target changes the voltage in such a way as to minimize the phase angle error. The target phase angle 10 is dynamic and it changes as a function of the firing angle/duty cycle.
[0062] As stated above, the motor controller 4 will drive the observed phase angle 5 to the point on the control line 25 that corresponds to the load presently on the motor 3 . This operating point 26 provides the maximum energy savings possible because the control line 25 is calibrated directly from the motor 3 that is being controlled.
[0063] This preferred method for calibration is called semi-automatic calibration. The semi-automatic calibration is based on the DSP 1 sweeping the control space of the motor. As shown in FIG. 15 , sweeping the control space means that the DSP increases the firing angle/duty cycle 23 and records the current 9 and firing angle/duty cycle 23 of each phase at discrete points along the way. Thus, in this manner it is possible to see the beginning of the stall point 21 of the motor. A well-defined linear portion of observed calibration data curve obtained from sweeping the control space 7 , which is used to determine points on the control line 6 , has a constant negative slope at lower firing angle/duty cycles 23 . Then, as the firing angle/duty cycle 23 continues to increase, the current 9 begins to flatten out and actually begins to increase as the motor 3 begins to slip and starts to stall, called the “knee” 31 .
[0064] As shown in FIG. 16 , subsequent sweeps can be directed at smaller ranges of motor voltages to “zoom in” on the knee. The motor controller 4 requires multiple sweeps in order to get data that is statistically accurate. There is a tradeoff between the number of sweeps and the time required to calibrate the control line 25 . A measure of the quality of the calibration can be maintained by the DSP 1 using well known statistical processes and additional sweeps can be made if necessary. This is true because the DSP 1 has learned the approximate location of knee 31 from the first sweep.
[0065] There is little danger of stalling during the semi-automatic sweep because of the controlled environment of the setup. A technician or operator helps to insure that no sudden loads are applied to the motor 3 under test while a semi-automatic calibration is in progress.
[0066] The process of sweeping the control space can be performed at any fixed load. For example, it can be performed once with the motor 3 fully loaded and once with the motor 3 unloaded. These two points become the two points that define the control line 25 . It is not necessary to perform the calibration at exactly these two points. The DSP 1 will extend the control line 25 beyond both these two points if required.
[0067] There are many numerical methods that can be applied to find the stall point 21 in the plot of the current motor voltage 23 . As shown in FIG. 17 , the preferred method is to use the “least squares” method to calculate a straight line that best fits the accumulated data. tabulated from the first five motor voltages 23 .
[0068] The continuation of this method is shown in FIG. 18 . Using the previous data points the value of the current 9 may be predicted. Graphically, the DSP 1 is checking for one or more points that deviate in the positive direction from the predicted straight line.
[0069] As shown in FIG. 19 , the DSP 1 is looking for the beginning of the knee in the curve. The first point that deviates from the predicted control line may or may not be the beginning of the knee 31 . The first point with a positive error may simply be a noisy data point. The only way to verify that the observed calibration data curve obtained from sweeping the control space 7 is turning is to observe data obtained from additional sweeps.
[0070] Semi-automatic calibration may be performed in the field. Referring now to FIG. 20 , a flow chart showing how semi-automatic calibration is performed is shown. First the motor 3 is placed in a heavily loaded configuration 44 . Ideally this configuration is greater than 50% of the fully rated load. Next a calibration button 32 on the motor controller 4 is pressed to tell the DSP 1 to perform a fully-loaded measurement. The DSP 1 runs a calibration 46 which requires several seconds to explore the operating space of the motor 3 to determine the fully-loaded point. The motor controller 4 indicates that it has finished this step by turning on an LED.
[0071] Next the motor 3 is placed in an unloaded configuration 45 . Ideally this configuration is less than 25% of the rated load. Then a calibration button 32 on the motor controller 4 is pressed 47 to tell the DSP 1 to perform an unloaded measurement. The DSP 1 runs the calibration 46 to determine the unloaded point. The motor controller 4 indicates that it has finished calibrating both ends 47 of the control line 25 by turning on a light emitting diode (LED). The DSP 1 then determines the control line 48 using the two measurements and applies this control line when it is managing the motor 3 . The values of the control line 25 are stored in non-volatile memory 49 .
[0072] FIG. 21 shows a more detailed flow chart of the semi-automatic calibration. First a first calibration sweep is run 46 with the motor voltage set at a certain degree 51 , depending on if it is a first sweep or previous sweeps have been run 106 , in which the motor controller measures the motor 52 until the motor controller detects a knee 53 . If a knee 53 is detected the firing angle/duty cycle is decreased by two degrees 54 and the phase angle and the motor voltage are recorded to the memory 55 . This process is repeated to obtain at least four sweeps 56 to get a computed average value 57 of the phase angle and the firing angle/duty cycle. If during any step along the calibration sweep, the knee is not detected, then the firing angle/duty cycle is increased by at least one degree 58 and the nest step is measured 59 .
[0073] An alternative method for calibration is called manual calibration. FIG. 22 shows a flow chart of manual calibration. First a motor is placed on a dynamometer 70 . Next the motor is connected to a computer for manual control 71 which allows the motor to be run in a open-loop mode and the firing angle/duty cycle of the AC induction motor to be manually set to any operating point. Then the motor is placed in a fully unloaded configuration 45 . Next the firing angle/duty cycle is increased and the RMS motor voltage is reduced 72 until the motor is just about to stall. The firing angle/duty cycle and phase angle are recorded and this becomes a calibrated point which is recorded 73 . Then the motor is started with drive elements fully on 74 . Then the motor is placed in a fully loaded configuration 44 . Next the firing angle/duty cycle is increased or decreased until the RMS motor voltage is chopped by the motor controller 75 until the motor is just about to stall. The firing angle/duty cycle are recorded and this becomes another calibrated point which is recorded 73 . Finally the two calibrated points are used to form a control line 76 .
[0074] When the RMS line voltage is greater than a programmed fixed-voltage, the DSP controller clamps the RMS motor voltage at that fixed voltage so energy savings are possible even at full load. For example, if the mains voltage is above the motor nameplate voltage of 115V in the case of a single phase motor then the motor voltage is clamped at 115V. This operation of clamping the motor voltage, allows the motor controller to save energy even when the motor is fully loaded in single-phase or three-phase applications.
[0075] FIG. 23 shows a flow chart of the fixed voltage clamp. First a phase error is computed 64 . Next a voltage error is computed 65 . Then the RMS motor voltage of the AC induction motor is determined and compared to a fixed voltage threshold 66 . If the RMS motor voltage is greater than the fixed voltage threshold then it is determined whether or not control target is positive 67 . If the control target is positive then a voltage control loop is run 68 . If the RMS motor voltage of the AC induction motor is less than a fixed-voltage threshold , then the a control line closed loop is run 69 and the entire process is repeated. If the control target is determined not to be positive then a control line loop is run 69 and the entire process is repeated again.
[0076] In some cases, it may not be possible to fully load the motor 3 during the calibration process. Perhaps 50% is the greatest load that can be achieved while the motor is installed in the field. Conversely, it may not be possible to fully unload the motor; it may be that only 40% is the lightest load that can be achieved. FIG. 24 shows an example of both load points being near the middle of the operating range. On the unloaded end 45 at the right of the control line 25 , the DSP 1 will set the fixed voltage clamp 60 of the voltage at minimum voltage 35 . When the load on the motor increases, the DSP 1 will follow the control line moving to the left and up the control segment 61 . This implementation is a conservative approach and protects the motor 3 from running in un-calibrated space.
[0077] As further shown in FIG. 25 , on the fully loaded end 44 at the left, the DSP 1 will synthesize a control segment 61 with a large negative slope. This implementation is a conservative approach and drives the voltage to full-on.
[0078] Referring now to FIG. 26 , the DSP-based motor controller uses a special technique to protect a motor from stalling. First, the DSP actively monitors for a significant increase in current 99 which indicates that load on the motor has increased. Next, if a significant increase is observed 100 then the DSP turns motor voltage to full on 101 . Next, the DSP will attempt to reduce motor voltage to return to the control 102 and the DSP returns to actively monitoring for a significant increase in current 99 . This technique is a conservative and safe alternative to the DSP attempting to track power requirements that are unknown at that time.
[0079] As further shown in FIG. 27 , a graph of the stall mitigation technique, the load on the motor is represented on an x-axis and time is represented on a y-axis. The bottom line represents the load on the motor 103 and the top line represents the power applied to the motor by the DSP 104 . Prior to point a 105 , the DSP is dynamically controlling the motor at a fixed load. In between point a 105 and point b 30 , the load on the motor is suddenly increased and the DSP turns the motor voltage to full on. At point c 34 , the DSP reduces the motor voltage to point d 43 .
[0080] Although a preferred embodiment of a motor controller method and system for maximizing energy savings has been disclosed, it should be understood, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not be considered limited to what is shown and described in the specification and drawings. | A motor controller and method for maximizing the energy savings in an AC induction motor at every load wherein the motor is calibrated at two or more load points to establish a control line, which is then programmed into a non-volatile memory ( 30 ) of the motor controller. A DSP-based closed-loop motor controller observes the motor parameters of the motor such as firing angle/duty cycles, voltage, current and phase angles to arrive at a minimum voltage necessary to operate the motor at any load along the control line. The motor controller performs closed-loop control to keep the motor running at a computed target control point, such that maximum energy savings are realized by reducing voltage through pulse width modulation. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method and apparatus for automatically attaching a collarette, display and label to a garment body by synchronizing sewing and material feeding.
2. Description of the Prior Art
Garments such as shirts or blouses are typically manufactured using manual labor. Garment pieces are cut out of stock material, trimmed to proper dimensions, and then sewn together on a sewing machine by a sewing machine operator.
Often in garment manufacturing, a piece of material, known in the art as a "collarette", is folded and sewn around the garment neck to form a continuous collar. The conventional method of sewing a collarette to a garment neck is performed by a sewing machine operator in the following manner. First, the collarette is cut to a size slightly shorter than the garment neck edge where the collarette is to be sewn. Then, the operator positions the collarette on top of the garment body, places the material under a sewing machine and starts sewing. While sewing, the operator must continually maintain the alignment of the collarette and garment body to obtain an evenly manufactured finished product. Additionally, the operator must pull and stretch the collarette during the sewing operation. Stretching the collarette in such a manner will cause the completed garment and collarette to lie flat and have no wrinkles or gathers around the neck when worn.
The operator may also be required to attach a label (e.g. a manufacturer's identifier having the manufacturer's name and product information) to the garment with the same stitch being used to attach the collarette to the garment. To perform this operation, the operator must carefully position and hold the label in the desired location while sewing.
Additionally, the operator may be required to sew a small strip of material, known in the art as a "display", to the inside of the garment neck to flatten and cover the seam joining the collarette and label to the garment body (the "joining seam"). The display is used to cover the area inside the garment where the joining seam would be partially visible after the garment is packaged for sale, i.e., on the inside back portion of the garment neck. To sew a display to a garment the operator must carefully position and hold the display on top of the collarette and garment body while sewing.
Further complications to the above-described conventional sewing operation are encountered when the joining seam is to be hidden from view from the outside of the garment (i.e. the side of the garment away from the body of the wearer). To hide the joining seam, an operator must layer the collarette, display, and label on top of the garment body and use an "overedge stitch" to join the pieces together. The resulting "overedge seam" is then hidden from the outside of the finished garment. To sew a collarette, label, and display to a garment body with an overedge stitch an operator must first manually arrange and layer the materials one on top of the other as follows: garment body, collarette, display, and label. The operator then passes the layered materials through the sewing machine, maintaining them in constant alignment while stretching the collarette as described above. If desired, a second sewing operation is then performed to attach the loose edge of the display to the garment body with a top stitch to assure that the display covers the overedge seam and a portion of the label.
The manual process of sewing a collarette, display, and label to a garment body is difficult and tedious. The quality of the finished product is often variable and is largely dependent on the experience and skill of the sewing machine operator Moreover, the conventional process is time consuming due to the need to precisely arrange and sew the materials together.
It is therefore an object of the present invention to provide a new method and apparatus for automatically attaching a collarette and other materials to a garment body.
Another object of the present invention is to provide a new method and apparatus capable of attaching a collarette, display, and label to a garment body in an efficient and precise manner without the need of manual assistance to feed and maintain alignment of the materials during the sewing operation.
It is a still a further object of the present invention to provide a new and improved method and apparatus capable of attaching a collarette, display, and label to a garment body such that the resulting product is of a consistently high quality, but manufactured using less time and manpower.
SUMMARY OF THE INVENTION
The above-described and other objects of the invention are met by providing an apparatus for attaching a collarette, display, and label preferably incorporating a sewing machine having a sewing head, a collarette feed means, a display feed means, a label feed means, a leading and trailing edge detector means, a stitch count means, and a controller means to control each device and perform necessary calculations.
In a preferred embodiment, an operator places garment body on the sewing machine where the leading edge detector means detects the presence of the garment body and signals the controller means to commence sewing. As the garment is being fed through the sewing machine, the collarette material is stretched and automatically fed and sewn to the garment body by the collarette feed means and sewing head. Once sewing commences, the controller means in combination with the stitch counting means counts the total number of stitches sewn. When the total stitch count equals a first predetermined stitch count, the controller means commands the display feed means to move to the sewing area and begin feeding the display material to the sewing head. When the total stitch count equals a second predetermined stitch count, the controller means commands the label feed means to automatically feed a label to the sewing area. When the total stitch count equals a third predetermined stitch count, the controller means commands the display feed means to move away from the sewing area to terminate the sewing of the display material. Finally, when the trailing edge detector means detects the end of the garment body, the sewing machine stops sewing.
By using predetermined stitch counts for the display and label feeding and maintaining a total stitch count during the sewing operation, the present invention is able to synchronize the commencement and termination of mechanical feeding of the display and label to achieve a consistently even manufactured product in less time using less manpower.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in greater detail below by use of reference to the accompanying drawings, wherein:
FIG. 1 is of a completed garment having a collarette, display, and label;
FIG. 2 is a planar view of the layered arrangement of garment body, collarette, display and label as they are sewn together using an overedge stitch;
FIG. 3 is a side view of the layered arrangement of FIG. 2;
FIG. 4 is a left side view of an embodiment according to the present invention;
FIG. 5 is a top view of the embodiment of FIG. 4;
FIG. 6 is a front view of the embodiment of FIG. 4; and
FIG. 7 is a flow chart of the operation of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, FIG. 1 shows the components of a completed garment having a collarette 22, display 24 and label 26 which are fashioned from known materials used for shirts, blouses, or the like. The sizes and dimensions of the various pieces are based on the desired sizes and dimensions of the finished product. For example, in an average T-shirt, the width of collarette 22 is typically in the range of 1 3/16" to 1 7/16" and the width of display 24 is typically 7/16" to 1/2" wide. As will become readily apparent to those skilled in the art, the widths of the collarette and display can be easily varied.
Label 26, which provides the purchaser or wearer with information concerning the garment (e.g., size, manufacturer, washing instructions), may be made from various known materials such as nylon, cloth, or the like. The size of label 26 is usually dependent on the amount and the size of the writing present.
As shown in FIG. 1, display 24 and label 26 are affixed in a position such that display 24 covers the overedge seam (not shown) which would be visible along the inside the garment neck when the garment is placed on its back. Also shown is top stitch 33 used in a second sewing operation to sew the base end of the display over the overedge seam.
FIG. 2 is a planar view illustration of the layering of garment body 20, collarette 22, display 24, and label 26 as fed through the apparatus of the present invention. The layering allows the garment body, collarette, display, and label to be sewn together with a single overedge stitch. The overedge stitch, known in the art as a 540 SSa-1 stitch, forms an overedge seam 28. To assure proper placement of display 24, the display is preferably sized so as to overlap shoulder seam 32 by approximately 3/4". As will become readily apparent to those skilled in the art, the overlap distance can be varied as desired. Line of feed ("L.O.F.") arrow 1 indicates the direction the garment body, collarette, display and label are fed through the sewing apparatus of the present invention.
FIG. 3 is a side view illustration of the layering of FIG. 2 as fed through the sewing apparatus of the present invention.
A preferred embodiment of the present invention is illustrated in the side, top, and front views of FIGS. 4, 5, and 6 respectively.
Frame 34 is used to support the various elements of the present invention. A controller 36 having a control panel 37 is attached to frame 34 as shown. In the preferred embodiment, a Model ASCS 202/3 controller manufactured by SAHL of Austria, is used as controller 36 and control panel 37. The control panel 37 is used to allow an operator to input to the controller certain predetermined garment parameters such as size. Motor 38 is used to drive a sewing machine 39 having a sewing head 40. In the preferred embodiment, a 39500 series sewing machine, manufactured by Union Special Corporation of Chicago, Ill., is used.
Rolls 56, 58 and 60 are used to provide a continuous supply of collarette 22, label 26, and display material 24 respectively. As will become readily apparent to those skilled in the art, the supply of these materials may be from flat continuous strips of folded material, commonly called festooning. The size and dimension of supply rolls 56, 58 and 60 are dependent on the materials used. Additionally, thread supply spools 102, 104 and 106 supply thread to sewing head 40 in a known manner.
Collarette feed motor 62 is used to drive collarette feed rollers 63 which maintain the collarette material in tension between the rollers 63 and the sewing head 40. The tension created effectively stretches the collarette material as it is being sewn to the garment body so that the completed garment and collarette will lie flat and have no wrinkles or gathers around the neck when worn.
Display feeder 65 is used to fold the display material and to guide same into the sewing area so as feed the display material 24 on top of the collarette material 22 and under presser foot 80 and sewing head 40. The resulting adhesion between the collarette 22 and the display 24 while under sewing head 40 causes the display material to unroll from display supply roll 60 and feed under the sewing head 40. Pneumatic display feed inserter 64 is used to move display feeder 65 into and out of the sewing area on command from the controller 36. Plate 67 is used to help guide the collarette material under the display feeder 65 and presser foot 80.
Label feeder 70 is used to cut labels from supply roll 56 and feed same to sewing head 40. In the preferred embodiment, a Model SES 170, GP Label Dispenser, manufactured by SAHL is used. The label feeder comprises a motor (not shown) to drive label arm 72, a pneumatic gripper 74 for gripping a label 26, and a hot wire knife 76 for cutting labels from label supply roll 58. On command from controller 36, the label arm 72 and gripper 74 grab a label 26 from the hot wire knife 76 and deliver same under presser foot 80 to sewing head 40.
Leading and trailing sensors 82 and 84, having light emitting diodes (LED's) and photodetectors, are used to detect the leading and trailing edge of a garment body 20. When no garment body is present, light from the LED's is reflected from reflective material patch 94 and detected by the photodetectors. The sensors then signal to controller 36 a "no garment" status signal. When a garment is placed in the sewing area, the light is no longer reflected and therefore not detected by the photodetectors. The sensors then signal to controller 36 a "garment present" status signal. Stitch counter 90 is used to count each revolution, which represents one stitch, of sewing head 40 and signals same to controller 36 which maintains a total stitch count for each sewing operation.
In the preferred embodiment, all motors, pneumatic devices, and sensors are digital devices. Nevertheless, as will become readily apparent to those skilled in the art, analog devices can be used.
Once a device is configured as described above, the sewing method of the present invention can performed as described below.
To begin, an operator feeds the collarette and display material through their respective feed mechanisms to effectively prime the apparatus for commencement of a sewing operation.
The operator then measures in inches the appropriate garment size parameters. Referring to FIG. 2, the operator measures the distance from the leading garment neck edge to the start of display (d s ), the distance from the leading garment neck edge to the start of label (d l ), and the length of display (d d ). The operator then converts the measurements to stitch counts (n x ) by using the following equation: n x =d x x s, where s is the number of stitches per inch the sewing head 40 performs. In a preferred embodiment, s has the value of approximately 12 stitches per inch (s=12).
The operator then activates the controller via the control panel to start a sewing operation. Referring to the flow chart of FIG. 7, the controller executes the series of steps illustrated therein and described as follows. The controller begins at step 201 where the operator inputs via control panel 37 the number of stitches to be sewn before the start of the display (n s ) and label (n l ) and the number of stitches to be sewn for the display (n d ).
The controller then advances to step 203 where it waits for a garment to be detected, i.e. loaded on to the sewing machine 39. The operator then manually loads the garment body 20 until its edge is under presser foot 80. It will become apparent to those skilled in the art that the loading of the garment body may be accomplished by mechanical or automated mechanisms. As the garment body 20 and collarette 22 are maneuvered under presser foot 80, leading edge sensor 82 detects the presence of the garment and signals to the controller 36 that a garment is present as described above. The controller then advances to step 205 where the controller directs sewing head 40 to commence sewing the collarette 22 to the garment body 20. In the preferred embodiment, the sewing operation does not actually begin until the operator presses on a foot switch (not shown). The foot switch acts as a separate safety feature and control mechanism. Both the garment body and collarette are urged under presser foot 80 by forces generated by feed dogs (not shown) under the garment body material. The frictional interference between the collarette material 22 and the garment body 20 also assists in maintaining the position of the collarette and garment body under presser foot 80. Additionally, as described above, collarette feed rollers 63 maintain tension between the rollers 63 and the sewing head 40.
The controller then advances to step 207 where the total stitch count (N) is determined by controller 36 by adding each stitch count signal from stitch counter 90. Next, a determination is made at step 209 as to whether the total stitch count (N) is equal to the number of stitches to count before inserting the display (N=n s ). If true, the controller advances to step 211 where it commands the display inserter 64 to move the display feeder 65 into the sewing area as described above. The frictional interference between the collarette 22 and display 24 causes the display to be drawn under presser foot so to be sewn to the collarette 22 and the garment body 20. The controller then returns to step 207 to update the total stitch count as described above. If the total stitch count is not equal to the number of stitches to count before inserting the display, the controller advances to step 213.
At step 213, a determination is made as to whether the total stitch count (N) is equal to the number of stitches to count before inserting the label (N=n l ). If true, the controller advances to step 215 where the controller 36 activates the label feeder 70. At this time, the label feed arm 72 brings a pre-cut label 26 into the sewing area and positions same on top of the display 24 and under the sewing head 40. After the label has started to be sewn to the garment, label arm 72 returns to its vertical position to grab another label 26 with grippers 74 from hot wire knife 76. Label arm 72 then moves down to a position just above sewing head 40 to await the next label insertion command from controller 36. The controller then returns to step 207 to update the total stitch count as described above. If the total stitch count is not equal to the number of stitches to count before inserting on the label, the controller advances to step 217.
At step 217 a determination is made as to whether the total stitch count (N) is equal to the number of stitches to count to stop feeding the display material (N=n s +n d ). If true, the controller advances to step 219 where it activates the display inserter 64 to move the display feeder away from the sewing area. A trimmer (not shown) attached to right side of sewing head 40 cuts the display material as the display feeder 65 moves away from the sewing area. The controller then returns to step 207 to update the total stitch count as described above. If the total stitch count is not equal to the number of stitches to count to remove the display, the controller advances to step 221.
At step 221 the controller checks whether the trailing edge sensor 84 has signalled a "no garment present". If true, after predetermined number of stitches, presser foot 80 is raised, and if the trailing edge sensor 84 still does not detect another garment body, sewing head 40 is turned off and the first sewing operation will have completed a full cycle. If the trailing edge of the garment is not detected, the controller returns to step 207 to update the total stitch count as described above.
As will become readily apparent to those skilled in the art, the display feeder and label feeder can be deactivated to vary the finished product. For example, the label feeder 70 can be deactivated so that when the apparatus is operated, only a collarette and display will be sewn to the garment body. Similarly, the display feeder can be deactivated such that only a collarette and label will be sewn to the garment body.
Additionally, as will become apparent to those skilled in the art, the synchronization of display and label feeding need not be dependant on stitch count. For example, timed synchronization can be used to command the display feeder and label feeder at the appropriate predetermined times.
Furthermore, as will become readily apparent to those skilled in the art, a second sewing operation on the garment can be performed to sew the loose end of the display down over the overedge seam 32 with a top stitch 33.
Alternate related embodiments for practicing the invention are disclosed in co-pending U.S. patent application U.S. Ser. No. 07/711,315, filed Jun. 6, 1991 for AN IMPROVED METHOD AND APPARATUS FOR AUTOMATICALLY ATTACHING A COLLARETTE, DISPLAY, AND LABEL TO A GARMENT BODY, commonly assigned to Union Special Corporation, the disclosure of which is hereby incorporated by reference.
Although illustrative preferred embodiments have thus been described herein in detail, it should be noted and will be appreciated by those skilled in the art that numerous variations may be made within the scope of this invention without departing from the principle of the invention and without sacrificing its advantages. The terms and expressions have been used as terms of description and not terms of limitation. There is no intention to use the terms or expressions to exclude any equivalents of features shown and described or portions thereof and the invention should be interpreted in accordance with the claims which follow. | A method and apparatus for attaching a collarette, display, and label incorporating the use of a sewing machine having a sewing head, a collarette feed means, a display feeder, a label feeder, leading and trailing edge detectors, a stitch counter, and a controller to control each device and perform necessary calculations is disclosed. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to apparatus and methods for the recording of alphameric information. More specifically, it relates to digital computing systems employing text input capabilities.
Text input capabilities for digital computers such as word processing systems are well known. They most commonly comprise a micro-processor based computer running under an operating system having handlers for a variety of peripheral input and output devices. The available word processing systems often belong to a family, each adapted to function on specific hardware on which the system operates. Each of the programs may have unique manners of accessing the associated input/output peripheral units, although many manage their input/output functions through commercially available operating system function calls.
The typical text editor associated with a word processing system, in addition to inputting character strings as they are typed by pressing a sequence of keys on a keyboard, also has the facility of passing certain routines to execution by the overall system when called for by multiple keystrokes, typically a so-called "function key" and additional following keystrokes. In addition there may be specific so-called function keys which are dedicated to call for the performance of certain tasks within the overall word processing system.
One of the useful features of some text input systems is the incorporation of stored text into the typing stream by typing only a few keys. For example, a system comprising an IBM PC computer together with a software package known as KeyWorks has the ability to utilize in combination two keys, one of which may be a dedicated function key, to call into the program subroutines for inserting fairly large text segments.
It is an object of the present invention to provide an improved keyboard input system wherein the user can create a library of short expressions, typically one or a few keystrokes, which, when typed in the normal manner and followed by a space or other delimiters, cause the substitution of a predetermined passage of text into the stream of text.
It is a further object of the present invention to utilize a modified keyboard handler subset of the overall system to implement the aforesaid invention so that a single keyboard input system will function with any word processing system making conventional calls upon the keyboard handler.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The preferred embodiment of the present invention comprises a microprocessor based digital computer having a hard disk or diskette based, file oriented word processing system that receives input from a keyboard imput device through normal operating system input function calls to a keyboard handler routine. The word processing system is also adapted to output text strings to a display device, typically a cathode ray tube or liquid crystal based device, which is also capable, in response to keyboard input to delete text characters from the display. The preferred embodiment of the present invention provides a keyboard input/output subroutine of a keyboard handler routine having an enlarged text buffer region so that a particular text passage of reasonable size (long form) can be temporarily stored therein. During operation of the program the typist types a short form comprising one to five characters followed by a space, which is output to a display device such as a CRT device. A count is kept of all non-space characters. When a space is typed the last word typed is compared to a library of stored short forms.
If a short form match is found in the library of short forms, a number of deletions equal to the short form's character count is placed in the keyboard buffer followed by the full text corresponding to the library entry which is indexed by the particular short form. This string of information in the keyboard buffer is then passed character by character to the word processing package under word processor control resulting in deletion of the short form and the insertion of the text string represented by the short form as if keyed in by the operator. Since the keyboard handler is used, the system operator in conjunction with any program which makes standard operating system calls upon the keyboard handler.
In this manner a typist can type in a completely normal manner without having to break his or her typing pattern to resort to specific function keys and directly insert into the program any particular grouping of stored characters.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a logic diagram of the Initialization sequence of the present invention.
FIG. 2 is a continuation of the logic diagram of FIG. 1.
FIG. 3 is a logic diagram of the Keyboard Input/Output Driver interrupt routine of the present invention.
FIG. 4 is a logic diagram of a portion of the keyboard hardware interrupt routine of the present invention.
FIG. 5 is a logic diagram of a continuation of the logic diagram of FIG. 4.
DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
A logic diagram of the preferred embodiment is depicted in FIG. 1. The system may be used with an 8088, 8086, 80286, or 80288 microprocessor based personal computer such as the IBM PC.
FIG. 1 shows the initialization logic where the invention is invoked from a disk operating system (DOS). A check is first made to determine whether the system is already resident in memory through previous use. This can be determined by examining the value of the low memory pointer which identifies the amount of memory made resident by DOS. If the system is already resident, a message so indicating is sent to the screen and DOS is set to invoke the system menu feature, and the system exits from the initialization stage.
If the system is not already resident, a further check is made to determine whether the system's configuration data is available on a DOS default directory. If it is not, an error message is printed and the system exits to DOS.
Internal tables are loaded with configuration data to establish memory allocation for short forms and long forms and an array of pointers to the text of appropriate size is constructed.
The operator is then offered the option of selecting the key combinations to be used for deleting characters, for toggling the system on and off, and for line feeding. The keyboard buffer is then moved and expanded.
Selection is made of a library of word lists comprising short and long forms if more than one library is present.
Upon finding the word list, short and long forms are read from the list and pointers to the words are loaded into tables. Once the list is exhausted, the table of pointers is sorted to shorten the access time to a particular entry.
For a system employing calls to DOS functions via interrupts, two low memory interrupt (e.g., 9 and 16) values are saved and replaced with pointers to the resident keyboard driver and keyboard interrupt routines of FIGS. 3-6. The resident size of the system is then retrieved and the system exits via the operating system which can then automatically invoke the system.
FIG. 2 is a logic diagram for the keyboard driver. It is invoked for example through interrupt 16. A check is made for text entry modes of word processors that introduce dummy characters into the text stream or which empty the keyboard buffer when recording special characters, e.g., carriage returns. If those modes are sensed, the dummy characters are bypassed or the deletion of the buffer is faked so as to avoid emptying the keyboard buffer. This is important to preserve the integrity of the long forms.
Another interrupt, e.g. interrupt 9, is used to invoke the keyboard. This interrupt saves the status of the machine and checks whether there is any information to clear on the screen, for example, after a short form followed by a space has been typed and has been recognized as a short form. If so, the keyboard buffer is filled with the number (obtained from a counter) of delete characters necessary to delete the short form from the screen and the count of the number of characters to clear is reset to zero.
If the key struck was not a text character but was the short form expansion toggle, then a short form expansion flag is toggled and the status of the toggle is displayed. If the flag is set, a count will be made of the number of characters of the short form that must be erased from the screen upon receipt of the next keyboard interrupt. If the flag is clear the characters forming a potential short form are saved. The machine status is then restored and the toggle character disregarded. This ends the interrupt.
If the short form expansion toggle has not been struck, then a check is made to see whether the insert toggle has been struck which allows access to insertion of new short and long forms into the libraries. If it has, the insert flag is toggled and a check is made as to whether or not the insert mode is being entered. If it is, then the status of the system is set, the machine status is restored and the character disregarded followed by a return to the program. If not going into the insert mode, a check is made as to whether the short form or the long form is invalid so that an error message may be displayed and a return made to display the status of the system. If the short or long form is valid, the short form is converted to upper case and its text inserted into the table of text and its location inserted into the table of pointers. The internal count of characters that must be erased is set and the table of pointers to the text is sorted. An option is offered the user at this point to make the entry of the short and long forms part of the library file and then there is a return to the program.
If the insert toggle has not been struck, a check is made whether a control character has been struck. If it has there is an exit to the standard operating system interrupt. If not, a check is made as to whether a delimiter was struck.
If the delimiter was struck, a check is made as to whether the insertion mode is on. If it is not on, a test is made as to whether the text expansion mode is on. If either of these two is on, the text of the substiuuted form table is searched for a match. If the expansion mode is not on, the characters forming a potential short form are cleared and there is an exit to normal interrupt processing.
If the delimiter was not struck, a check is made as to whether the PTF flag which determines if the system has been asked whether changes are to be made in the retained library has been set. If not, the character is added to the short form expression and there is an exit to normal system interrupt processing. If the PTF flag has been set, a check is made as to whether the form should be made part of the saved libraries. Then, the internal count is set for the number of characters that must be erased to clear the screen. The machine status is restored, the last character disregarded, and return is made to the word processing program. | A word processing system employing text substitution wherein the typist defines short forms, which when typed as normal text initiate text substitution of the short form by a long form. | 6 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/EP2009/050781 filed Jan. 23, 2009, and claims the benefit thereof. The International Application claims the benefits of European Application No. 08002768.3 EP filed Feb. 14, 2008. All of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention refers to a turbomachine rotor with a pretensioning device for pretensioning a rotor blade, to the rotor blade with the pretensioning device and to a method for assembling the turbomachine rotor.
BACKGROUND OF INVENTION
[0003] A gas turbine is a thermal turbomachine in which fossil fuels, such as natural gas, are conventionally combusted. The gas turbine can be used for example in a gas and steam power plant which is provided for covering peaks loads in a mains network. As a result, the gas turbine is run in non-steady state operation, as a result of which the individual components and component parts of the gas turbine are subjected to transient loads. On account of the high power density of the gas turbine, high requirements with regard to the strength of highly loaded components are to be fulfilled in order to ensure a long service life of these components and long maintenance cycles and also a low demand for replacement parts.
[0004] The gas turbine, has a compressor with a compressor rotor and a turbine with a turbine rotor, wherein the compressor rotor and the turbine rotor are interconnected via a shaft in a torsionally fixed manner. The compressor rotor and/or the turbine rotor are conventionally designed in an axial type of construction, i.e. a multiplicity of wheel disks are slid on the shaft one behind the other. A rotor blade row is fastened on the outer peripheries of the wheel disks in each case. Each rotor blade row has a large number of rotor blades which in each case have an aerodynamically effective blade airfoil and a blade root. The blade root is inserted into a groove which is located on the outer periphery of the wheel disk so that the rotor blade is retained in a form-fitting manner on the blade root especially in the radial direction of the gas turbine rotor.
[0005] For the form-fitting retention of the rotor blade, the blade root and the groove have dovetail profiles or fir-tree profiles which correspond to each other. These profiles are arranged in a manner extending in the axial direction of the gas turbine rotor so that for installing the rotor blade this is inserted by its blade root into the groove in the axial direction of the gas turbine rotor. Between the blade root and the profile of the groove a clearance is provided so that the blade root can be inserted into the groove free of wear. Induced by the clearance, the rotor blades can move during operation of the gas turbine, which leads to a characteristic rattling of the rotor blade. This applies particularly to a large and heavy rotor blade, as is provided especially in the first rotor blade rows of the compressor of the high performance gas turbine.
[0006] The rotor blade is conventionally installed in the groove with pretension in order to avoid the rattling. However, installation can be made difficult on account of the pretension, especially in the case of the large and heavy rotor blade.
[0007] Furthermore, the pretension in the wheel disk and in the blade root causes a mechanical stress which is conventionally compensated by a stable and solid construction of the wheel disk and of the blade root. Provision can be made in the groove for an axial locking plate with which the rotor blade is secured and additionally pretensioned against axial displacement. However, the axial locking plate may be formed too weak for the large and heavy rotor blade.
[0008] Such an axial locking plate is known from U.S. Pat. No. 2,786,648 and U.S. Pat. No. 4,102,602. The slotted ends of the plate in these cases project beyond the ends of the groove. At each end, the teeth which are created as a result of the slots are bent reciprocally outwards and inwards in each case in order to avoid axial displacement of the rotor blade along the groove. Moreover, the plate is curved in the middle in order to retain the rotor blade in the groove in a pretensioned state.
[0009] Furthermore, instead of the aforesaid plate, it is known from U.S. Pat. No. 5,123,813 to provide a dowel-like construction with a screw between the bottom of the retaining groove and the underside of the blade root for creating the pretension. Patent specification DE 834 408 features a further variant in which the pretensioning device for rotor blades of a turbine is created by means of a screwable double wedge which is provided between groove bottom and blade root.
[0010] Fastening of the locking blade of a blade ring, the blades of which are inserted into a circumferential groove with undercut flanks through a filling opening, is known from DE 11 56 419. For fastening the locking blade, provision is made for a plurality of radial grub screws which are screwed in each case into a thread which is arranged in halves in each case on an end face of the blade root of the locking blade on one side and in the flank of the filling opening on the other side. According to an alternative development, it is possible to use dowel pins which are inserted in holes which exist in halves and which are provided in the end faces of the locking blade and in the end faces of those rotor blades which are adjacent to the locking blade.
[0011] Moreover, a fastening plate for a rotor blade which is axially inserted in a retaining groove is known from GB 2 026 101.
SUMMARY OF INVENTION
[0012] It is an object of the invention to create a turbomachine rotor, a rotor blade, and a method for assembling the turbomachine rotor, wherein the turbomachine rotor can be operated with high stability and efficiency without rattling of the rotor blades.
[0013] The turbomachine rotor has grooves which are distributed uniformly along the periphery and in which a rotor blade is inserted by a blade root in each case so that the rotor blade is retained in a form-fitting manner by the groove in the radial direction, and has a pretensioning device which is supported both on a bottom of the groove and on the blade root and which exerts a pretensioning force upon the blade root in the radial direction, wherein the pretensioning device is installed in such a way that the pretensioning force is adjustable in the assembled state of the turbomachine rotor.
[0014] As a result, when assembling the turbomachine rotor, i.e. during the axial insertion of the blade root into the groove, it is made possible for the pretensioning force to be provided at a low value and in the assembled state of the turbomachine rotor for the pretensioning force to be adjusted to a high value as predetermined. Therefore, during insertion of the blade root into the groove the pretensioning force is advantageously low so that wear on the blade root and in the groove on account of installation of the rotor blade is prevented.
[0015] Furthermore, the expenditure of force during insertion of the blade root into the groove is advantageously low so that during installation of the rotor blade only low stress peaks in the blade root and in the wheel disk occur. Consequently, these stress peaks during the stress calculation of the blade root and of the turbomachine rotor hardly need to be taken into consideration and the installation of the rotor blade in the turbomachine rotor is simple.
[0016] The pretensioning device, moreover, has at least one adjusting screw, with which by applying a predetermined tightening torque the pretensioning force can be adjusted in the assembled state of the turbomachine rotor.
[0017] By means of the adjusting screw, adjusting the predetermined pretensioning force is made possible via the setting of a tightening force of the adjusting screw. As a result, the pretensioning force can be applied to the rotor blade via the tightening torque. The adjusting screw is preferably provided with a fine thread so that an accurate force transfer of the adjusting screw from the tightening torque to the pretensioning force is made possible.
[0018] Furthermore, by the provision of the adjusting screw, removal of the rotor blade by loosening the adjusting screw is made possible so that removal of the rotor blade is simple. Therefore, quick reinstallation of the rotor blade with care for the material is made possible.
[0019] Also, provision is made in the blade root for at least one threaded hole which on the underside of the blade root facing the bottom of the groove leads into this, wherein at least one adjusting screw is screwed into the at least one threaded hole so that it projects on the blade root by its end and is indirectly supported on the bottom of the groove.
[0020] Consequently, the adjusting screw penetrates the blade root through the threaded hole and is fixed therein so that by supporting the screw end indirectly on the bottom of the groove the pretensioning force is applied to the blade root in the radial direction.
[0021] The grooves which are distributed along the periphery are preferably arranged in a wheel disk of the turbomachine rotor. As a result of this, a modular turbomachine rotor can be disclosed.
[0022] The pretensioning device preferably has a support plate which is arranged on the bottom of the groove at least in the region of the one adjusting screw so that the adjusting screw and the support plate are in touching contact.
[0023] The support plate lies in the groove directly on the bottom so that an additional groove does not need to be provided in the bottom of the groove for the support plate.
[0024] Furthermore, the bottom of the groove is covered by the support plate in the region of the adjusting screw so that the bottom of the groove is only in indirect contact with the end of the adjusting screw via the support plate. Therefore, the end of the adjusting screw damaging the bottom of the groove, especially when turning the adjusting screw, is prevented.
[0025] Furthermore, it is preferred that the at least one threaded hole, by its end which faces away from the underside of the blade root, leads out on one of the end faces of the blade root so that the threaded hole is inclined away from the longitudinal axis of the turbomachine rotor by an acute angle.
[0026] As a result, the threaded hole is accessible on the end face of the blade root so that from there the adjusting screw can be adjusted after installation of the rotor blade onto the wheel disk. Furthermore, since the threaded hole extends from the end face of the blade root to the bottom of the blade root, the threaded hole penetrates the blade root in a mechanically low-stressed region. Consequently, by the provision of the threaded hole in the blade root this is compromised little in its strength.
[0027] On account of the inclination of the adjusting screw by the acute angle, the pretensioning force which is applied by the adjusting screw has an axial and a radial component. This is advantageous since, as a result, both the radial pretensioning force and an axial force are applied for locking the rotor blade in the wheel disk. Consequently, both a radial and an axial fastening of the rotor blade are ensured. Via the degree of inclination of the adjusting screw, the distribution of the force which is transmitted by the adjusting screw can be distributed to the axial and radial fastening.
[0028] It is preferred that the support plate has at least one offset with a flat flank, which is formed in such a way that the end of the adjusting screw butts by the end face against the flat flank. The end face of the end of the adjusting screw is preferably also formed flat so that during the flat abutment of the screw end against the flank the surface pressure is low. As a result, an extreme mechanical loading of the support plate by the adjusting screw is prevented, as a result of which an undesirable distortion of the support plate on account of the action of the adjusting screw does not occur so that jamming of the adjusting screw is prevented.
[0029] It is preferred that the blade root has a first threaded hole with a first adjusting screw and a second threaded hole with a second adjusting screw, wherein the first threaded hole leads out on the one end face of the blade root and the second threaded hole leads out on the other end face so that the first threaded hole is inclined away from the longitudinal axis of the turbomachine rotor by a first acute angle and the second threaded hole is inclined away by a second acute angle.
[0030] As a result, the two adjusting screws are arranged in an oppositely inclined manner to relation to each other so that the axial force components which are applied to the support plate act against each other. Consequently, a stable fastening of the blade root in the groove can be advantageously achieved, wherein a little to no resulting axial force acts upon the blade root.
[0031] Also, it is preferred that the support plate has the first offset with the first flank, against which butts the end of the first adjusting screw, and the second offset with the second flank, against which butts the end of the second screw.
[0032] Therefore, the rotor blade is locked by its blade root in a form-fitting manner in the axial direction via the adjusting screws on the flanks of the offsets of the support plate.
[0033] It is preferred that the first angle and the second angle have the same value.
[0034] As a result, the pretensioning device is formed symmetrically in the plane perpendicular to the axial direction of the turbomachine rotor so that the distribution of the pretensioning forces in the pretensioning device is symmetrical. Therefore, the pretensioning device, the blade root and the wheel disk are evenly stressed.
[0035] Furthermore, it is preferred that the support plate has a back section between the two offsets, which by its convex side faces the blade root.
[0036] The support plate is preferably produced from an elastic material. Induced by the pretensioning forces, which are exerted by the adjusting screws upon the flanks of the offsets, these are pressed in the direction towards the bottom of the groove. As a result, the back section is bent so that the back section by its convex side presses onto the underside of the blade root. Consequently, the pretensioning forces which the adjusting screws exert upon the support plate are transferred to the blade root. Therefore, the pretensioning of the rotor blade is increased.
[0037] Also, it is preferred that the back section is pre-bent before its installation so that in the assembled state of the turbomachine rotor the back section presses onto the underside of the blade root.
[0038] As a result, the support plate has a spring action in the direction towards the underside of the blade root, as a result of which a pretensioning reserve is created for the event of settling, i.e. if during operation the distance between the underside of the blade root and the bottom of the groove increases. Furthermore, the pre-bending of the back section enables a good frictional engagement in the assembled state via the surface contact which is formed by the adjusting screws. Via the rigidity and the thickness of the support plate, the pretensioning reserve can be predefined. By adjusting the adjusting screws, the pretensioning reserve can be further varied in the assembled state.
[0039] It is preferred that on the first offset the support plate has a first leg section which extends away from the back section, and on the second offset has a second leg section which extends away from the back section.
[0040] Consequently, the effect is achieved of the support plate being supported flat, and therefore with low surface pressure, on the bottom of the groove. The first leg section preferably has a first projection and the second leg section has a second projection, wherein the projections project from the groove over the wheel disk. As a result, the support plate in the assembled state can be gripped from the outside by the projections so that removal and reinstallation of the rotor blade can be carried out in a simple manner.
[0041] Furthermore, it is preferred that the projections are arranged in an angled-down manner in relation to the leg sections so that the turbomachine rotor or the wheel disk are in engagement with the support plate and consequently is fixed in the axial direction of the turbomachine rotor.
[0042] As a result, the support plate is fixed on the wheel disk in the axial direction, especially even if the rotor blade is not yet inserted into the groove of the wheel disk when assembling the turbomachine rotor. Therefore, when assembling the turbomachine rotor, the support plate, which is positioned in the groove on the bottom, does not have to be fixed from the outside if the rotor blade root is inserted into the groove. The projection can preferably be bent round or turned over.
[0043] It is preferred that the at least one adjusting screw is secured against inadvertent rotation by a securing means.
[0044] As a result, the adjusting screw accidentally becoming loose during operation of the turbomachine rotor is prevented. The securing means can preferably be an adhesive. Alternatively or in addition to this, the adjusting screw can be prick-punched in the rotor blade by a center punch blow.
[0045] The geometrical dimensioning of the support plate, of the adjusting screws and of the tightening torque is matched to the mass of the rotor blade.
[0046] The rotor blade according to the invention, which is provided for installing in a groove which is located on the outer periphery of a turbomachine rotor and extends in the axial direction, has a blade root with two end faces which lie opposite each other and are arranged perpendicularly to the longitudinal axis of the blade root, and with a blade root underside which extends between the two end faces, wherein the blade root has a first threaded hole and a second threaded hole, wherein the two threaded holes lead out on the underside of the blade root on one side, and on the other side the first threaded hole leads out on the one end face of the blade root and the second threaded hole leads out on the other end face so that the first threaded hole is inclined away from the longitudinal axis of the turbomachine rotor by a first acute angle and the second threaded hole is inclined away by a second acute angle.
[0047] The support plate for pretensioning a rotor blade of a turbomachine rotor has a longitudinal direction and has two opposed offsets, which are arranged along this, with a planar flank in each case, between which the support plate has a back section.
[0048] The method according to the invention for assembling a turbomachine rotor features the steps: providing the turbomachine rotor with grooves which are distributed along the periphery and extend essentially in the axial direction of the turbomachine rotor, and with rotor blades which are arranged therein in each case, and with a support plate; inserting the rotor blade into the groove so that the blade root engages in the groove and so the rotor blade is retained in a form-fitting manner in the groove in the radial direction; inserting the support plate into the groove between the underside of the blade root and the bottom of the groove; screwing of the first adjusting screw into the first threaded hole and screwing the second adjusting screw into the second threaded hole until the adjusting screws contact their corresponding offsets; tightening down the two adjusting screws with a predetermined tightening torque in order to pretension the rotor blade in the groove in the radial direction with a predetermined pretensioning force.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] Preferred exemplary embodiments of a turbomachine rotor according to the invention and of a support plate are explained in the following text with reference to the attached schematic drawings.
[0050] In the drawing:
[0051] FIG. 1 shows a cross section through the turbomachine rotor in the region of a blade root,
[0052] FIG. 2 shows a longitudinal section of the turbomachine rotor in the region of the blade root,
[0053] FIG. 3 shows a support plate in the uninstalled state,
[0054] FIG. 4 shows the support plate in the installed state.
DETAILED DESCRIPTION OF INVENTION
[0055] As is apparent from FIGS. 1 and 2 , a turbomachine rotor 1 has a multiplicity of rotor blades 2 and a wheel disk 16 . The rotor blades 2 are fastened on the periphery of the wheel disk 16 so that a rotor stage of the turbomachine rotor 1 is formed.
[0056] The rotor blade 2 is produced in one piece and has a blade airfoil 3 and a blade root 4 . The blade airfoil 3 is aerodynamically effective, for example in a compressor or a turbine of a turbomachine. The blade root 4 serves for fastening the blade airfoil 3 on the wheel disk 16 .
[0057] The blade root 4 , in a plane which is perpendicular to the rotational axis of the turbomachine rotor, has a fir-tree profile-like cross section, and in a plane in which lies the rotational axis of the turbomachine rotor, has a rectangular cross section. The rectangular cross section of the blade root 4 is formed by a longitudinal side, which the blade airfoil 3 adjoins, two end faces facing away from each other which in each case are perpendicular to the rotational axis of the turbomachine rotor 1 , and a blade root underside 15 which is arranged essentially parallel to the rotational axis of the turbomachine rotor 1 and facing away from the blade airfoil 3 . In the corner regions of the blade root 4 , which lie in the region of the edges which are formed by the end faces and the underside 15 of the blade root, the blade root 4 has mechanically low-stressed regions 5 and 6 .
[0058] The first mechanically low-stressed region 5 of the blade root 4 is penetrated by a first threaded hole 7 and the second mechanically low-stressed region 6 of the blade root 4 is penetrated by a second threaded hole 8 , wherein the two threaded holes 7 , 8 lead out on the underside 15 of the blade root and the first threaded hole 7 leads out on the one end face of the blade root 4 and the second threaded hole 8 leads out on the other end face of the blade root 4 . A first adjusting screw 9 is screwed into the first threaded hole 7 and a second adjusting screw 10 is screwed into the second threaded hole 8 . The first adjusting screw 9 has a first end 11 and the second adjusting screw 10 has a second end 12 , wherein the screw ends 11 , 12 are located in each case outside the blade root 4 on the underside 15 of the blade root.
[0059] The two threaded holes 7 , 8 and also the two adjusting screws 9 , 10 are arranged in an inclined manner in relation to each other so that the first threaded hole 7 with the rotational axis of the turbomachine axis 1 includes a first angle 13 and the second threaded hole 8 with the rotational axis of the turbomachine rotor 1 includes a second angle 14 . The two threaded holes 7 , 8 are arranged in relation to each other in such a way that the two ends 11 , 12 of the two adjusting screws 9 , 10 are arranged in a manner in which they face each other. The first angle 13 and the second angle 14 are acute angles in each case and are of equal size in value. The wheel disk 16 has a groove 17 with a bottom 18 which is in engagement with the blade root 4 . The shape of the groove 17 is formed in such a way that it encloses the longitudinal sides of the blade root 4 and the underside 15 of the blade root in a form-fitting manner so that the rotor blade 2 , by means of the fir-tree profile of the blade root 4 , is retained in a form-fitting manner in the groove 17 in the radial direction and in the circumferential direction of the turbomachine rotor 1 . The groove 17 and the blade root 4 are formed in such a way that during installation of the turbomachine rotor 1 the rotor blade 2 can be inserted by its blade root 4 essentially in the axial direction of the turbomachine rotor 1 . With the turbomachine rotor 1 assembled, the end faces of the blade root 4 terminate essentially planar with the end faces of the wheel disk 16 .
[0060] The groove 17 is dimensioned in such a way that a gap is formed between the bottom 18 of the groove and the underside 15 of the blade root. A support plate 19 , which in its middle has a back section 20 which is formed by a first offset 21 and a second offset 22 , is inserted into the gap. A first leg section 25 is connected to the first offset 21 and a second leg section 26 is connected to the second offset 22 , wherein the leg sections 25 , 26 butt against the bottom 18 of the groove and the back section 20 butts against the underside 15 of the blade root. The back section 20 and the leg sections 25 , 26 are arranged in alignment with each other.
[0061] The first offset 21 has a first flank 23 and the second offset 22 has a second flank 24 , wherein the first screw end 11 butts against the first offset 21 and the second screw end 12 butts against the second offset 24 . Both the first screw end 11 and the first flank 23 , and also the second screw end 12 and the second flank 24 , are formed in a planar manner so that the contact between the adjusting screws 10 , 11 and the support plate 19 is created via a contact surface. The two adjusting screws 9 , 10 are screwed into their threaded holes 7 , 8 and tightened down with a predetermined tightening torque in such a way that a predetermined force is exerted by the adjusting screws 9 , 10 upon the flanks 23 , 24 and therefore upon the support plate 19 in each case. The force has a radial component and an axial component, wherein if the two adjusting screws 9 , 10 are tightened down with the same tightening torque the axial components cancel each other out. The radial components form a predetermined pretensioning force with which the blade root 4 is pretensioned in the groove 17 in a predetermined manner.
[0062] A first projection 27 is provided on the first leg section 25 and a second projection 28 is provided on the second leg section 26 , wherein the projections 27 , 28 extend away from the groove 17 over the wheel disk 16 . The two projections 27 , 28 are arranged in an angled-down manner in relation to the leg sections 25 , 26 in the direction towards the middle of the turbomachine rotor 1 so that by the projections 27 , 28 the support plate 19 , lying on the bottom 18 of the groove, is arranged in a fixed manner in the axial direction of the turbomachine rotor 1 .
[0063] The support plate 19 is shown in FIGS. 3 and 4 , wherein the first projection 27 is arranged as an extension of the first leg section 25 and the second projection 28 is arranged as an extension of the second leg section 26 .
[0064] In FIG. 3 , the support plate 19 is shown in the uninstalled state and in FIG. 4 shown in the installed state. The support plate 19 is manufactured in a pre-bent condition so that the support plate 19 in the uninstalled state has a convex contour. If the support plate 19 , as it is shown in FIG. 4 , is installed in the groove 17 together with the blade root 4 , then the support plate 19 is pressed straight so that the support plate 19 , on account of spring properties, exerts a spring force upon the blade root 4 . In the case of a method for assembling the turbomachine rotor 1 , the rotor blade 2 is inserted into the groove 17 essentially in the axial direction of the turbomachine rotor 1 until the end faces of the blade root 4 are arranged in alignment with the end faces of the wheel disk 16 . The support plate 19 , according to the embodiment which is shown in FIG. 3 , is inserted in the gap which is formed between the underside 15 of the blade root and the bottom 18 of the groove until the two projections 27 and 28 project from the wheel disk 16 . Then, the first adjusting screw 9 is screwed into the first threaded hole 7 and the second adjusting screw 12 is screwed into the second threaded hole 8 until the first screw end 10 contacts the first flank 23 and the second screw end 12 contacts the second flank 24 . The adjusting screws 9 , 10 are subsequently tightened down with the predetermined tightening torque. The projections 27 and 28 are then bent in the direction towards the middle of the wheel disk 16 so that the projections 27 , 28 butt against the wheel disk. | A turbomachine rotor, a rotor blade and a method for assembling a turbomachine rotor are provided. The turbomachine rotor includes a rotor blade with a blade root, a wheel disk with a groove in which the blade root engages such that the rotor blade is maintained in the groove in a positive fit in a radial direction. Further, a pretensioning device is provided, which is supported on the wheel disk as well as on the blade root and which exerts a pretensioning force on the blade root in the radial direction. The pretensioning device is designed such that the pretensioning force can be adjusted when assembling the turbomachine rotor. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to radio telephony, and more specifically to a method and system for using compound ring tunes to identify to the user of a mobile station communicating through wireless communications network certain characteristics of an incoming call.
BACKGROUND OF THE INVENTION
[0002] Mobile communication is rapidly increasing in popularity. Originally, mobile communication was available only in specialized applications such as ship-to-shore radio, police radio, or short range walkie-talkies. The advent of the modern mobile network, however, has made this form of communication much more available, practical, and affordable to large segments of the global population. In some locations, it is even more popular and reliable than standard wireline telephone systems. Naturally, the mobile nature of this form of communication has contributed to its popularity.
[0003] A mobile telecommunication system is one that uses a wireless channel to establish the connection between an individual subscriber and a communication network. The wireless network infrastructure is typically, though not necessarily a series of fixed switches, routers, and other hardware interconnected in a hierarchical fashion. In this sense, it may resemble a traditional wireline system. Calls to or from a subscriber are routed through this hardware to their destination. Calls to or from other networks leave and enter through gateways, so that the wireless network subscribers can connect to almost any other device connected to a publicly accessible telephone or computer network.
[0004] FIG. 1 is functional block diagram illustrating the relationship of selected components of a typical wireless communication network 100 , such as one that might advantageously be used in accordance with an embodiment of the present invention. Base stations 105 - 110 are each shown to be connected with an antenna 111 - 116 . Each antenna is intended to handle communications within a selected area, sometimes referred to as a cell. (For this reason the portable subscriber radios used in such a network are often called “cellular” or simply “cell” phones.) For example, in FIG. 1 cell phones 11 , 12 , and 13 are shown to be in communication with antennas 111 , 112 , and 113 , via radio channels 1 , 2 , and 3 , respectively.
[0005] The broken lines in FIG. 1 represent cell boundaries. These boundaries do not represent the precise range of their associated antennae, of course, and are not always regular in shape or consistent in size. And although only six cells are delineated, there are typically many more in the network coverage area. Cell phones may and often do move from cell to cell, and their network communications are generally transferred from one network antenna to another though a process called handover.
[0006] Base station controllers (BSCs) 120 and 125 are in communication with, and generally control the operations of base stations 105 - 107 and 108 - 110 , respectively. The base station controllers are in turn connected with a mobile switching center (MSC) 130 , which handles call routing and provides a connection to other network MSCs (not shown) and gateway MSCs such as G-MSC 135 . A visitor location register, here VLR 140 , maintains information relating to cell phones in the area services by the associated MSC. (A home location register (HLR) (not shown), may be provided to track the location and other information related to all network subscribers.)
[0007] The “wireless” part of a wireless network is therefore the connection between the subscriber and the network infrastructure though which calls to or from the subscriber are routed. This connection is normally made through radio channels, meaning that each subscriber will be equipped with a device having a radio transmitter and receiver. A mobile telephone is simply a radio for engaging in voice communication through a wireless network. Despite being radios, however, mobile telephones do not ordinarily communicate directly with one another but rather through the network. The network will employ at least one, any normally a great many base stations for connecting with subscriber devices.
[0008] At this point, it should also be noted that as the terms for radio telephones, such as “cellular (or cell) phone” and “mobile phone” are often used interchangeably, they will be treated as equivalent herein. Both, however, are a sub-group of a larger family of devices that also includes, for example, computers and personal digital assistants (PDAs) that are also capable of wireless radio communication in a radio network. In the context of the present invention, being able to communicate with a wireless network connotes the ability to receive a call intended for one or more mobile stations, although in some but not all embodiments the mobile station will require as well the ability to transmit and to initiate calls. This family of devices will for convenience be referred to as “mobile stations” (regardless of whether a particular device is actually moved about in normal operation).
[0009] FIG. 2 is a perspective view of a mobile station 200 such as one that might advantageously be used in accordance with an embodiment of the present invention. Mobile station 200 is a radio telecommunication device for use in a radio telecommunication network such as the one described above in reference to FIG. 1 . The internal circuitry and components (not shown in FIG. 2 ) of mobile station 200 are contained in a casing, or enclosure, that typically includes two or more sections, which are sometimes referred to as covers. Referring to FIG. 2 , mobile station 200 has an enclosure 201 that includes front cover 220 and back cover 222 , which are removably fastened together at joint 205 when the phone is assembled. Attached battery 224 provides a portable power source, and antenna 226 aids in transmitting and receiving radio signals. A plurality of small openings 242 formed in front cover 220 serve as a port for the voice-communication speaker (not shown), which is mounted beneath them. At the opposite end of mobile station 200 , microphone port 244 likewise permits entry of sound directed at the actual microphone (not shown) mounted inside. Power port 246 is for plugging in an external power adaptor and headphone port 248 for connecting an external headset and perhaps a microphone for hands-free operation.
[0010] The keypad 210 is a user interface including a plurality of openings, through which protrude keys such as alphanumeric keys 211 , call control keys 212 (CALL) and 213 (END), scroll key 214 and function keys 215 and 216 . As their names imply, these keys perform various duties in the phone's operation, with the alphanumeric keys 211 having a standard telephone keypad role, and the function and scroll keys used in connection with display 234 . That is, the functions of the function keys and the scroll keys are variable and determined by the application state that the mobile phone is in, which is often translated into a word or icon displayed next to the key on display 234 . Keys having a function that may be changed in this way are often called ‘softkeys’. Other keys shown in FIG. 2 are power switch 219 and volume control key 217 .
[0011] Display 234 is typically a liquid-crystal display (LCD) device. The LCD itself is protected by a plastic window pane 232 , which is mounted to cover the display and protrude into window 230 , an opening formed in front cover 220 . As illustrated in FIG. 2 , display 234 presents to the user such information as current softkey functions, telephone numbers, signal strength, and other information useful to the operation being performed. The protective window pane 232 is typically a component separate from the LCD, its chassis, and other portions of the internal assembly.
[0012] FIG. 3 is a flow diagram illustrating an exemplary method 300 of providing an incoming call alert according to the prior art. At START, it is presumed that a mobile station such as the one shown in FIG. 2 is operable to communicate with a wireless network such as the mobile station 200 shown in FIG. 1 . The process begins when the alert, or ring-tune database is initialized (step 305 ). In most cases, this is done by the manufacturer, or by another along the distribution chain and before the instrument is provided to the user (sometimes also referred to as a wireless-service subscriber). At its most basic level this step involves programming the mobile station to ring when a call notification is received from the network. That is, once the network has identified that a call to one of its subscribers has been initiated and determined the current location of the subscriber, a call notification is sent that the mobile station must acknowledge before the call can actually be terminated. The ring tune is an alert that the mobile station will actuate to let the subscriber know that a call is being placed.
[0013] Assuming this basic case, that the ring tune is established when the subscriber first obtains the mobile station, certain user options are still available. For example, the user may wish to have a silent alert for incoming call notification. This option is useful when knowledge of calls is desired even though the user is in a location or setting where an audible alert would be inappropriate. The silent alert is normally accomplished using a vibrating function resident in the mobile station, although a light on the mobile station or other visible device may be used as well. Of course, the silent and the audio alert may be used at the same time. In another example, the audio alert function may be adjusted from loud to soft, or set to sound once but not continuously. Typically, these alert preferences may be changed from time to time by the subscriber, and may form part of a ‘profile’ or set of preferences, that the user may optionally select as a group. (For simplicity, however, in the context of the present disclosure the set of preferences constituting the profile may contain only a single element.)
[0014] The next step 310 in the process therefore is to receive a profile selection. Again, the profile may be set by the manufacturer as a default selection, and is in this sense received before the subscriber first obtains the mobile station. In practice, however, many subscribers frequently use their ability to switch from one profile to the other. The process continues as the user actually receives notification from the network that an incoming call is being received (step 315 ). Note that this notification may come directly from the subscriber's network, or if the subscriber is outside of its network coverage area then through whatever network is being used to complete the call. When an incoming call is detected, the appropriate ring is generated (step 320 ) according to the current profile selection. The ring tune is generated until the user accepts the call or until a predetermined ring time has elapsed.
[0015] Contemporary mobile stations are frequently provided with the ability to generate a variety of different ring tunes, each having a different pattern. The user is able to select one, and to change their selection as desired. Often such selections are assigned to a profile, as mentioned above. Whatever ring tune has been selected is then used when an incoming call is received. To switch ring tunes, the user simply selects another from those available or switches profiles. In some applications, the user may even select a number of ring tunes and associate them with different callers or call groups. In this way, for example, a caller may be able to discern from the different ring whether an incoming call is business-related or personal.
[0016] As alluded to above, however, mobile stations may be used for functions other than ordinary phone calls. They may also be used to send and receive text or voice messages that are delivered when the message target is available (and are not frustrated by lack of immediate availability). Facsimile transmission may also be accomplished, as can other types of data communication such as retrieval of Internet-accessible Web sites. A subscriber who uses their mobile station for both business and personal communications (as many do) may be inundated with calls that, if announced identically, represent a significant distraction as they are sorted through. Even assigning diverse ring tones to certain call groups may not provide a satisfactory call-management aid; there are only so many tunes available and where there are many their selected association may be difficult to remember. Needed therefore is a way to provide incoming-call alerts that are capable of provide the user with information regarding the incoming call that is as comprehensive as possible. The present invention provides just such a solution.
SUMMARY OF THE INVENTION
[0017] In one aspect, the present invention is a method of providing an enhanced ring-tune alert that provides information to a subscriber regarding the communication characteristics of an incoming call, the method including the steps of detecting an incoming call and the communication characteristics, such as call type and call origin associated with the call, associating one or more of these characteristics with a specific ring-tune enhancement, and generating an enhanced ring-tune by applying the enhancement to a base ring tune. Note the enhancement, and for that matter the base ring tune may be audible or may include or even be limited to other alert effects such as vibration.
[0018] Varying types of ring-tune enhancement may be used, either alone or in combination. In a temporally-compounded enhanced ring tune, a secondary ring-tune segment associated with a particular communication characteristic of the incoming call is appended to the beginning or the end (or both) of the base ring tune, and of course even more than two such appendages may be applied where appropriate. A tonal enhancement involves modifying or adjusting the quality of the base ring tune, such as by changing voices, without altering its recognizable nature. Applying an accompaniment enhancement, on the other hand, involves the addition (or in some cases the subtraction) of accompanying parts to the base ring tune. A stylistic enhancement may also be used so that a recognizable base tune is annunciated in a style that can be separately recognized and provide an indication to the user of one or more communication characteristics. A tempo enhancement involves varying the tempo of the base ring tune, or of an otherwise enhanced ring tune, to identify a communication characteristic. As should be apparent, these various enhancements may also be used in combination with each other.
[0019] Ring-tune enhancements may be provided with a mobile station to the subscriber, or may be downloaded to the mobile station though a wireless connection or to another device connected to an Internet based server. In some instances existing mobile stations may be modified at services centers to be able to operate according to the present invention.
[0020] In another aspect, the present invention is an apparatus for providing an alert to the user of a mobile station including a ring-tune database for storing ring-tune enhancements, a detector for detecting incoming calls and determining communication characteristics associated with them, and a controller for associating incoming-call communication characteristics with ring tune and directing a ring-tune generator to generate a ring-tune alert based on the association.
[0021] In yet another aspect, the present invention is a system for providing an alert including at least one mobile station operable to communicate with the infrastructure of a wireless network through a network base station, including a ring-tune database accessible by the base station, which monitor calls directed at the mobile station and determines their communication characteristics so that a ring-tune controller may associate the communication characteristics with one or more ring-tune enhancements from the ring tune database and direct a ring-tune generator to generate an enhanced ring tune. In one embodiment, the ring-tune database and ring-tune controller are part of the network infrastructure, and provide instructions to a ring-tune generator located in a mobile station in order to effect application of the appropriate enhancement based on the network's knowledge of the communication characteristics off a call directed to the mobile station.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] For a more complete understanding of the present invention, and the advantages thereof, reference is made to the following drawings in the detailed description below:
[0023] FIG. 1 is functional block diagram illustrating the relationship of selected components of a typical wireless communication network, such as one that might advantageously be used in accordance with an embodiment of the present invention.
[0024] FIG. 2 is a perspective view of a mobile station such as one that might advantageously be used in accordance with an embodiment of the present invention.
[0025] FIG. 3 is a flow diagram illustrating an exemplary method of providing an incoming call alert according to the prior art.
[0026] FIG. 4 is a functional block diagram of a mobile station illustrating selected components for use in providing enhanced ring tunes in accordance with an embodiment of the present invention.
[0027] FIG. 5 is a flow diagram illustrating a method of providing a ring-tune alert according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0028] FIGS. 1-5 , discussed herein, and the various embodiments used to describe the present invention are by way of illustration only, and should not be construed to limit the scope of the invention. Those skilled in the art will understand the principles of the present invention may be implemented in any similar mobile stations, in addition to those specifically discussed herein.
[0029] The present invention presents an innovative manner of effecting call alerts to provide easily understandable information regarding the nature of incoming calls. Various embodiments for practicing the present invention will now be described.
[0030] FIG. 4 is a functional block diagram of mobile station 200 of FIG. 2 illustrating selected internal components for use in providing enhanced ring tunes in accordance with an embodiment of the present invention. Mobile station 200 includes transmit circuitry 405 and receive circuitry 410 for sending and receiving a variety of different types of communications through antenna 226 . Although for simplicity only one set of circuitry is shown for each of these respective functions, however, the mobile station 200 may be capable of communicating in a plurality of ways, such as with a wireless network and also with nearby Bluetooth devices.
[0031] A controller 415 is provided for controlling the operation of transmit circuitry 410 and receive circuitry 415 and other operations of mobile station 200 as well. In an alternate embodiment (not shown) separate coordinated controllers may be provided to deal with selected functions. Database 420 is a memory storage device and in this illustration is intended to include both short-term and long-term memory functions. Database 420 , for example, may be used to store contact information such as the telephone numbers of individuals and organizations, and other associated information such as addresses, email addresses, facsimile numbers, and so forth.
[0032] Ring-tune database 425 may also be incorporated into database 420 , but in FIG. 4 is shown separately for the purposes of illustration. In accordance with the present invention, ring-tune database 425 is used for storing ring-tune components. These ring-tune components (such as a base ring tune and ring-tune enhancements), will now be described in more detail.
[0033] A ring tune is a device, usually but not necessarily audible, that is used to announce the receipt on an incoming call. If audible, the sound is produced by a speaker in, or connected with the mobile station. Preferably separate speakers are used for reproducing voice information and for producing ring tones, but this disclosure focuses on the speaker that annunciates ring-tones and it is immaterial whether it is used for voice as well. Receipt of an incoming call is signaled by a network notification message that is ordinarily acknowledged by the mobile station. Some form of acknowledgement is desirable as the network will otherwise have some difficulty determining that the target mobile station is operating in a given area and powered up to received a call.
[0034] In accordance with the embodiment illustrated in FIG. 4 , an incoming call detector 430 is provided to detect the receipt of an incoming call notification. Directed by controller 415 , incoming-call detector determines as much information regarding the incoming call as it is able, for example the type of communication being received and the identity of the caller. (Of course it is able to do so at this point only when such information is provided in the call notification.) Message generator 435 will then generate a return message acknowledging that the incoming-call notification message has been received. Ring-tune generator 440 , which may be incorporated with controller 415 or may be a separate component, then generates a ring-tune alert appropriate to the communication information. The generation of a ring-tune, in accordance with an embodiment of the present invention, involves preparing whatever signal or instructions are required to cause the annunciation of the desired ring-tune. Device interface 445 provides the interface between the ring-tune generator 440 and the device or devices that will be performing the annunciation. These devices (not shown) typically include a speaker, often a separate one from that used for voice communication, and a vibration generator.
[0035] Incoming-call information may include the type and source of the call. The communication type simply indicates the form of communication being attempted, for example a standard telephone call. Or the incoming communication may be a page message, a short-message service (SMS) message, or some other form of text or voice message. In contrast to a telephone call, however, these types of communication may be accepted for delivery automatically instead of waiting for the subscriber's indication of willingness to have the call terminated (that is, connected). The communication type may also be a facsimile transmission or an email message. These recited types, of course, are illustrative rather then exclusive, and there may be others as well. It is expected though not required that the communication type will be determinable from the notification message because the recipient device will have to at some point be prepared to receive and process the communication itself.
[0036] The communication source indicates the origin of the intended communication. The origin may be determinable as to the specific device or person calling, or may be generally determined as with calls from a certain company or area. The communication source will generally be determined in one of a number of ways. First, the notification message may include standard caller-ID information such as a telephone number. In that case, the caller-ID information identifies the source device specifically, and may be used to identify the caller as well. That is, the caller-ID information may be compared to information stored in database 420 , which will associate identifiers such as telephone numbers or email addresses with names of persons or organizations. Even if there is no such stored information, of course, the caller-ID information provides at least some indication of the call source, and may be more comprehensive than simply a telephone number alone.
[0037] Another way of obtaining call-source information is from the incoming-call notification itself if it in fact contains more detailed source information than what is provided with caller-ID. In this case, a distinctive enhanced ring tune may be generated from the information provided based on the ring-tune information stored in ring-tune database 425 . In one embodiment, a caller is able to provide this information for inclusion in the incoming-call notification message so that the correct enhanced ring-tune results even if they are calling from an unknown telephone number. Third, a query may be formulated by message generator 435 to ask for more information about incoming communication if the system permits such inquiries. In this case, the mobile station may store any received information in the database 420 for future reference and to eliminate the need for redundant future inquiries. Storage of information retrieved in this way may be accomplished automatically, without any further action by the subscriber, or alternately such information may be retained only if the subscriber responds affirmatively when queried.
[0038] However the incoming-communication information is obtained, the ring-tune generator 425 generates a specific ring tune based upon the information available to it. In accordance with the present invention, the ring tune generator 425 is operable to assemble enhanced ring tunes in order to efficiently signal to the user known information regarding the incoming call. The various enhancements will now be described in more detail. In this description, the term ‘base ring tune’ will be used to describe a ring that would typically be used absent application of the present invention. This may be but is not necessarily the default ring initially set by the manufacturer or seller. The base ring tune may be used on its own we well, for example where no incoming-call information is available. In addition, there may be any number of base ring tunes that are selectable by the user.
[0039] A first type of enhanced ring tune is the temporally-compounded ring. In this embodiment, a preamble may be appended to the ring tune in order to indicate something about the nature of the call. This preamble is a secondary ring tune that is distinguishable from the base. For example, a specific communication type may always cause generation of a certain preamble, regardless of its origin. In this way the user immediately knows that the incoming call is an email as opposed to a phone call. The advantage of employing the distinguishing preamble is that the base ring tune itself may be varied to indicate other call information, such as origin. Naturally, the preamble could also be used to identify the origin and the base ring tone varied to indicate type. In another embodiment, the secondary ring tune could be appended to sound after the base ring tune.
[0040] Generally speaking, ring tunes are cyclic, with a chosen sound sequence repeating itself at regular intervals. Where the base ring tune operates in this manner, the preamble could be generated to append to each repetition. Alternately, it may only be appended to the first ring and the mobile station would thereafter use only the base ring. In yet another alternative, the preamble could be appended periodically to the base ring tune, skipping a predetermined number of rings before being appended again. Note that as used herein, “appended” refers to the use of a secondary ring tune that is conjoined or concatenated with the base ring tune, usually either before or after (“preamble” is set before, and an “appendix” after). Note also, however, that the secondary ring tune may also be inserted within the base ring tune, in essence interrupting it and dividing it into two or more pieces.
[0041] A second type of ring-tune enhancement involves applying tonal variation to the base ring tune according to the known communication information. Subtle variations may be available but difficult for the average user to distinguish from one another. A more pronounced variation may be applied by changing the voice (or voices) used for annunciating the ring tone. Voices can be thought if in terms of different musical instruments even though the mobile station is only using its ring-tone speaker to replicate the sound characteristics of various instruments. For example, a trumpet sound may signal an incoming telephone call, while a flute indicates that an SMS message is being received. The different voices may also be used to signal call origin as well; a saxophone indicating a communication from a spouse, for example. More general categories could also be used, such as an organ sound to signal the arrival of work-related email.
[0042] The enhancements described above may of course be used in combination to provide more variety for applying ring-tune labels to certain classes of communication. In addition, there is no requirement that a single scheme be used. That is, a series of preambles may be programmed for indicating the communication types of business-related information, one preamble for faxes, another for email, and so forth, but no preamble would be applied to communications from family members, who would instead simply be identified by using different voices with no regard to communication type.
[0043] Needless to say, the system of ring tune enhancements of the present invention could get very involved, and trying to uniquely identify all variations may become so complex that any advantage is lost. In a preferred embodiment, however, the enhancements could be applied one at a time. The user would then over time become used to particular enhancements before adding more. Adjustments could be made to accommodate changing conditions or needs. Some users would of course be more adept at remembering the distinctions than others, so each user is able to create a ring-tune scheme that they are comfortable with. Unless explicitly claimed, however, there is no requirement that all of the enhancements described above be available to each or any subscriber.
[0044] In some instances no correlation between incoming-call characteristics and ring-tune enhancements may be found. This may be due to the absence of any determinable characteristics, or may simply occur because no association with the received characteristics has been requested. Although the un-enhanced base ring tone could be generated for such instances, in a preferred embodiment an enhanced ring tone is assigned so that the subscriber is made aware that an attempt to provide information has been made. Different enhanced ring tones may be assigned, for example one to incoming calls providing communication characteristics, and another to those supplying no communication-characteristic information or to those refusing to provide such information when requested. By the same token, certain enhanced ring tones may be associated with incoming calls for which some, though less than all desirable information is detectable.
[0045] In another embodiment (not shown), the present invention is a ring-tune alert scheme for use on a computing device such as a personal computer (PC). While a PC may fall within the definition of a “mobile station” as that term is used herein, it is also described here separately for clarity. Although PC users are generally aware when email is downloading through a dial up connection, the ring-tune scheme of the present invention may be implemented to announce the arrival of a text message or VoIP call, or of an email arriving through a continually-maintained connection. In this embodiment, the ring-tune may be played at the computer itself, or at a remote device accessible to the user.
[0046] FIG. 5 is a flow chart illustrating a method 500 of providing a ring-tune alert according to an embodiment of the present invention. At Start it is presumed that a mobile station operable in accordance with the present invention is operating in a wireless network. The ring-tune database 425 is initialized (step 505 ) so that appropriate ring-tune enhancements can be made. This step may be performed when the telephone is manufactured or by the user, and should be alterable to accommodate the user's changing needs. In operation, the detector 430 then waits until an incoming call is detected (step 510 ). Incoming-communication information is then determined (step 515 ), which can be done in a number of ways as described above. An appropriate enhancement is then applied to the base ring tune (step 520 ) and an enhanced ring tune is generated (step 525 ). The process then continues and awaits the detection of another incoming communication.
[0047] The preferred descriptions are of preferred examples for implementing the invention, and the scope of the invention should not necessarily be limited by this description. Rather, the scope of the present invention is defined by the following claims. | A manner of providing ring-tune alerts to announce the arrival of incoming communications at a communication device such as a mobile station operable in a wireless communication network. When notification an incoming communication arrives at the mobile station, the mobile station detects the type and origin of the communication and then composes a ring tune enhanced to provide incoming call information to the subscriber. The enhancement may include temporarily compounding the ring tune, tonal or stylistic enhancement, applying compound accompaniment, or applying tempo variation. The ring-tune components may be installed by the manufacturer or distributor of the instrument, or may be downloaded by the subscriber. The communication device may also be a personal computer operable to communicate through a communication network such as the Internet. | 7 |
This application claims the benefit of the filing date of U.S. Provisional Application No. 60/661,737, filed Mar. 15, 2005.
BACKGROUND OF THE INVENTION
The present invention relates generally to sensing and displaying aircraft operability conditions, and more particularly to an inexpensive system that can provide flight data in the event of a primary instrument failure in general aviation aircraft.
Failure of a navigation system in general aviation (GA) aircraft presents a potentially dangerous scenario for pilots operating under instrument meteorological conditions (IMC). In a typical instrument-equipped GA aircraft, the displays include an attitude indicator (AI) and heading indicator (HI) that are both powered by an on-board vacuum-driven system. In such systems, the AI provides the only direct indication of aircraft pitch and bank attitude, and serves as the focal point of the pilot's instrument scan while performing what is commonly referred to as “attitude instrument flying”. An electric turn coordinator (TC, also referred to as a turn-and-slip or needle-and-ball in older installations) acts as a supporting and backup instrument for yaw rate (i.e., rotation about a vertical axis), roll rate (i.e., rotation about a longitudinal axis), and the balance of gravitational and centrifugal accelerations.
Experience shows that GA aircraft vacuum systems can be expected to fail on average about every 500 hours of operations. Many GA aircraft are not equipped with a standby vacuum system or a fault indicator to alert the pilot that the vacuum system or related equipment has suffered a failure. To make matters worse, a typical vacuum pressure gauge, which does provide an indication of an on-board vacuum failure, is usually small and placed in an obscure area of the instrument panel, well outside a pilot's normal instrument scan pattern. When the vacuum system does fail, the AI very slowly (usually imperceptibly) drifts into a false state in both pitch and bank, while “drift” errors slowly accumulate on the HI. The slow nature of the failure of these instruments almost invariably goes unnoticed by the pilot until suspicions are aroused by other factors, such as altitude/airspeed variations, wind/engine noise, or the like. Quite often the aircraft is in an unusual attitude by this time, and the confused and disoriented pilot is then called upon to recover the aircraft to a safe flight condition. This recovery must be based on the pilot's ability to integrate the indications of numerous instruments, all with serious inherent operational limitations (i.e., lags, etc.), and several of which (i.e., the gyroscopic instruments), probably unknown to the pilot, are providing misleading information. This type of “partial-panel” instrument flying is an exceptionally difficult task that few pilots perform willingly or well, and several documented studies have indicated that a significant percentage of aircraft mishaps arise from this situation, with a large majority of them proving to be fatal.
In a situation involving the loss of the AI and HI, a pilot may still glean certain information (for example, direction of turn) from the TC. Usually this instrument contains a single rate gyro mechanically linked to an indicator, for example displaying an aircraft tail-on profile against a fixed horizon line or scribe marks to indicate aircraft yaw or roll rate (in the case of a TC), or a single needle to indicate yaw rate (in the case of a turn-and-slip indicator). There is typically also an integral mechanical inclinometer (i.e., a free-moving ball in a liquid-filled tube) to indicate whether the gravitational forces are balanced by the centrifugal forces as a measure of the “quality” of the turn.
The TC is generally adequate for controlling aircraft bank angle in level flight or in turns of moderate rate. It is also useful in determining the correct direction to roll the aircraft to return to wings-level flight after entering an unusual attitude, as long as the ball in the mechanical inclinometer is near the center and the aircraft has not already rolled past 180° in one direction. Nevertheless, the TC provides no clues to aircraft pitch attitude. In situations involving loss of the AI and HI, this vital flight parameter must be inferred from observing the airspeed indicator, altimeter, and/or the vertical speed indicator (VSI). While the airspeed indicator may be correlated with known aircraft performance characteristics and current power level to gain insight into whether the nose is above or below the horizon, such method is rather imprecise. Likewise, the VSI is useful in maintaining level flight but has inherent lags that make precise control difficult. For example, while it is taught that VSI reversals indicate near-level flight in highly dynamic situations, the inherent lags and the fact that the instrument may be pegged at its upper or lower limit at the time of the reversal, reduce this technique to educated guesswork. The lower degree of lag in the altimeter, coupled with a lower likelihood of it being pegged, make it less problematic than the VSI in this regard. Despite this, the altimeter is not a panacea, as a reversal in the altimeter merely indicates near level flight, giving no direct indication of a level aircraft attitude, as angle-of-attack (AOA) variations may result from the combination of aircraft design, weight, acceleration and airspeed. Rapidly changing flight conditions (for example, acceleration and airspeed), in combination with lags inherent in other instruments such as the VSI, typically result in the pilot “chasing” the instruments during a dynamic upset recovery. The difficulty of a pilot performing flawlessly under such complex conditions is exacerbated by compelling yet erroneous pitch and bank information being provided by the AI that is situated at or near the center of the pilot's field-of-view.
Even if a pilot were to recover from the scenario mentioned above such that straight-and-level flight has been reestablished, there remains the problem of directional control. As mentioned above, a vacuum failure will also disable the gyroscopic HI. This leaves only a conventional magnetic (i.e., wet) compass for heading control, where such compass is susceptible to many degrading phenomena including deviation, variation, magnetic dip, acceleration error, northerly turning error and oscillation error. Compounding these inaccuracy problems is that the compass is frequently located well outside the normal instrument scan pattern, such as on the instrument glare shield or high on the windscreen.
A human-factors analysis of this problem clearly shows that one of the critical factors mitigating against safe partial-panel instrument flight is the necessity to modify the familiar instrument scan pattern and to correlate multiple instrument indications in order to form a clear picture of the flight situation; that is, to gain and maintain situation awareness. A contributing factor is that, in these circumstances, many instruments are being used for other than their primary intended purpose, and that they are not intuitive or optimally designed for that application. Clearly one approach to improving this situation is to “fuse” all the required critical information for partial-panel instrument flight into a single, intuitive, optimized display.
Accordingly, what is needed is a navigation system that can integrate various flight conditions (especially aircraft position information) into a single display to reduce pilot workload. What is further needed is a display that is reliable, relatively inexpensive to manufacture and easy to operate.
BRIEF SUMMARY OF THE INVENTION
These needs are met by the present invention, wherein a display and a method of providing information to a user of the display are disclosed. In accordance with a first aspect of the present invention, a backup system provides flight navigation information to a user (such as a pilot) so that, in the event of partial or complete inoperability of a primary flight instrument system, the backup system can provide flight condition information to the user in a single discrete location. In addition, the backup system can also complement the primary system when the latter is working properly. The system includes a source of electrical power, numerous flight data collection sensors and a processor that can take at least some of the sensed data and manipulate it in such a way to generate the desired flight condition information. The system also includes a display that conveys the generated flight condition information in such a way to provide a pilot with a reduced cognitive (for example, visual) workload relative to having to scan multiple displays or related indicators of flight information. The flight condition information that can be displayed includes at least the flight path angle, aircraft turn rate and lateral acceleration.
Optionally, the sensors can be used to measure one or more of aircraft speed, altitude, acceleration and change in angular position. In the present context, a change in an aircraft's angular position involves rotation about one or more of the three orthogonal aircraft body axes. The sensors configured to measure speed and altitude may be pneumatic sensors, and these pneumatic sensors may be one or more pressure sensors arranged as a sensor suite, including static and dynamic pressure sensors. The sensors used to measure an aircraft acceleration may include one or more accelerometers, where the accelerometer can be used to sense aircraft lateral acceleration. The sensors may also include an outside air temperature sensor. For example, the rate gyros may include, separately or collectively, a roll-rate gyro, a pitch-rate gyro, and a yaw-rate gyro. Each of the rate gyros can be arranged to sense rotation about one of the three orthogonal aircraft body axes. The processor may be configured as a controller, and may be coupled to one or more memory devices. Various incorporated information for manipulating the sensed data into a form suitable for display as flight navigation includes standard atmospheric data, flight test data, and data relating to various components or the aircraft as a whole. The flight condition information conveyed by the display may additionally include heading information, which can be represented in the processor by a formula derived from a measured and calculated aircraft turn rate. The flight condition information conveyed by the display further may additionally include airspeed information, altitude information, and altitude-rate information. In another option, the flight path angle may be corrected to minimize lags between displayed values and actual real-time conditions. In yet another option, the flight condition information relating to lateral acceleration can be signally coupled to processor (in the case of an electrical-based lateral acceleration display), or could be decoupled from the processor, in the case of a mechanical-based (i.e., ball suspended in a fluid) lateral acceleration display. In other words, a mechanical lateral accelerometer can be used with the present system, and such an accelerometer need not be signally coupled to the processor, instead functioning as a stand-alone (i.e., autonomous) display of lateral acceleration.
According to another aspect of the invention, a device for displaying aircraft flight condition information is disclosed. The device includes a primary display and a standby (i.e., backup) display. The primary display may include at least one of attitude indicator and heading indicator. The standby display is configured to convey at least flight path angle, turn rate and lateral acceleration information in such a way as to provide a pilot with a reduced cognitive workload in event of a failure of the primary display. Optionally, the standby display can also convey heading, altitude and airspeed information. In another option, the standby display can be coupled to the sensors, source of electrical power and processor of the previous aspect to function autonomously.
According to yet another aspect of the invention, a method of providing flight condition information to a user is disclosed. The method includes collecting flight data, manipulating at least some of the flight data such that it can be used as the flight condition information, and displaying the flight condition information to include at least flight path angle, lateral acceleration and aircraft turn rate. Examples of the collected flight data include that similar to what was discussed in conjunction with the previous aspects.
Optionally, heading, altitude and airspeed information can also be displayed. Furthermore, the displayed flight path angle, lateral acceleration and aircraft turn rate information may make up secondary flight condition information that can be viewed by a user in event of failure of an aircraft primary flight instrument, or as a complement to a primary display, regardless of whether or not the primary display is functioning properly. The secondary flight condition information may be provided by a backup system such as the one according to the previous aspect, which includes a source of electrical power, numerous sensors, a processor signally coupled to the sensors to manipulate the sensed flight condition information, and a display signally coupled to the processor. The sensors may be configured to measure at least one of an aircraft speed, altitude, acceleration and change in angular position, as previously discussed. In one particular embodiment, the sensors configured to measure one or both of the aircraft speed and altitude are made from pneumatic sensors. In addition, the sensors configured to measure at least one of the aircraft acceleration and the aircraft change in angular position comprise at least one sensor responsive to aircraft lateral acceleration and at least one sensor responsive to aircraft roll rate, yaw rate or both roll rate and yaw rate.
According to still another aspect of the invention, a method of displaying estimated aircraft heading information is disclosed. The method includes collecting and subsequently manipulating data corresponding to an aircraft yaw rate such that upon manipulation, the data is in a form that can be displayed. In addition, the method includes collecting or assuming (collectively referred to as retrieving) data corresponding to at least one of an aircraft pitch angle and an aircraft roll angle, and adjusting the aircraft yaw rate data with the retrieved aircraft pitch and/or roll angle data, and displaying the estimated aircraft heading information. An example of when the retrieval of pitch angle and roll angle information is from assumed (rather than collected) information is when a particular pitch and roll condition acts as a given For example, a level flight at a twenty degree bank angle is an assumed condition that could form the basis of retrieved information that could be used to adjust the collected (i.e., measured) yaw rate data.
Optionally, the collected aircraft pitch angle is derived from a calculated flight path angle, such as was discussed in the previous aspects. The method further includes establishing a reference heading from which any displayed value can be based, determining a rate of change of the flight path angle, determining an aircraft bank angle based on the rate of change of the flight path angle and aircraft angular rates, determining a substantially horizontal aircraft turn rate, manipulating the substantially horizontal aircraft turn rate and coordinating the reference heading with the manipulated substantially horizontal aircraft turn rate to produce the estimated aircraft heading information.
According to yet another aspect of the invention, a system configured to provide flight condition information is disclosed. The system includes a source of electrical power, a plurality of sensors configured to collect flight data, a processor signally coupled to the sensors such that it operates on at least a portion of the collected flight data to generate the flight condition information, and a display signally coupled to the processor such that the display conveys the flight condition. The flight condition information includes at least flight path angle, turn rate, and lateral acceleration. In one preferable (although not necessary) form, the system makes up a primary flight condition information system such that a redundant system (such as a vertical gyro-based system) is not necessary. The flight condition information system is incorporated into an aircraft that includes a fuselage, wheels, propulsion system and one or more wings and related flight control surfaces.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The following detailed description of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
FIG. 1 shows a notional GA aircraft placed within a corresponding Cartesian coordinate system with corresponding roll, pitch and yaw rotational axes fixed to the body of the aircraft;
FIG. 2A shows a side elevation view of the aircraft of FIG. 1 with a notional pitch attitude, flight path angle and angle of attack;
FIG. 2B shows a front elevation view of the aircraft of FIG. 1 with a notional roll angle;
FIG. 2C shows a top view of the aircraft of FIG. 1 with a notional yaw angle;
FIG. 3 shows a block diagram depicting the relationship between components of a flight instrument system according to an aspect of the present invention; and
FIG. 4A shows the display of FIG. 3 , indicating an aircraft in level flight with no banking or rolling;
FIG. 4B shows the display of FIG. 3 , indicating an aircraft in descending flight in a right turn; and
FIG. 5 shows a variation of the display of FIG. 3 , indicating an aircraft in level flight with no banking or rolling, and also depicting airspeed, magnetic heading and altitude.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIG. 1 and FIGS. 2A through 2C , a general aviation aircraft 1 is aligned along its three principal orthogonal aircraft body axes x, y and z is shown, where the three axes generally coincide with a Cartesian coordinate system with its vertex at the aircraft's center of gravity (CG). Referring with particularity to FIG. 2A through 2 C, the aircraft's pitch, roll and yaw deviations from earth-referenced inertial axes are shown. In FIG. 2A , flight path angle is designated by angle γ (gamma), which is defined as the direction of travel (shown as velocity vector V) of aircraft 1 relative to the X (i.e., horizontal) inertial axis. Because of variations in aircraft weight, maneuver, and configuration, the pitch angle of aircraft 1 (the vertical angle between the x and X axes) can be significantly different than its flight path angle γ. AOA is defined as the angle between the velocity vector and the aircraft's longitudinal axis x, projected onto the aircraft's x-z plane In FIG. 2B , the bank angle φ of aircraft 1 is a measure of how much the aircraft 1 is tilted (banked) relative to the horizontal inertial axis X. The bank angle φ is normally positive in a right bank, as shown. FIG. 2C shows yaw angle ψ, which provides an indication of aircraft heading if the X inertial axis is aligned to north.
Referring next to FIG. 3 , a block diagram showing the cooperation of the various components of the flight instrument system 10 are shown. System 10 includes a source of electrical power 20 , two pressure sensors 30 (including a static pressure sensor 30 A and a dynamic (pitot) pressure sensor 30 B), a rate gyro system 40 , one or more accelerometers 50 , an optional outside air temperature sensor 60 , one or more analog-to-digital converters 70 to receive analog signals from the pressure sensors 30 , rate gyro system 40 , accelerometer 50 , and optional outside air temperature sensor, 60 and convert these to digital signals for a digital processor 80 , which may be in the form of a programmable logic controller (PLC), or similar computer-based calculation and control device. In addition, the processor 80 (or some of its ancillary components, including the aforementioned PLC or other controller) may be configured to monitor other system parameters that could be used to provide necessary information to the pilot. In one embodiment, the processor 80 can correlate sensed signals with values represented in a lookup table or related data storage device (neither of which are shown). All control functions may be integrated into the processor 80 in the form of replaceable modules that can execute the steps of a software or firmware program. Examples of such modules may include storage modules, linkage modules, processor or logic modules, as well as others.
User-operated controls 90 provide basic input from the pilot, and can be used to vary aspects of the display. Display 100 is used to convey visual information to the pilot pertaining to the flight status of aircraft 1 . As with the other components making up system 10 , display 100 is electronically powered, and receives its display instructions from processor 80 based on the outputs of the several sensors (i.e., pressure 30 , gyros from rate gyro system 40 , accelerometer(s) 50 , and optional outside air temperature 60 ). Typically the aircraft 1 electrical system will provide the electrical power 20 to the system, although an internal battery backup (not shown) may also be included. Power conditioning is provided as necessary for various system electronic components through DC-DC converters (not shown).
As shown in the block diagram, two low-cost pressure sensors 30 A, 30 B are employed. One of these sensors ( 30 A) is open to the ambient atmosphere to provide a measure of aircraft barometric altitude. The second pressure sensor ( 30 B) is actually a differential sensor, sensing the difference between ambient barometric pressure and dynamic pressure provided through a pitot tube, thereby providing a measure of airspeed. Such an instrument may be integrated with the aircraft's existing pitot-static system (not shown). The next sensor is a part of a three-axis orthogonal microelectromechanical (MEMS) rate gyro array system 40 . The primary function of the gyro array system 40 is to sense aircraft roll, yaw, and pitch rates. It should be noted that one single-axis gyro, mounted near the aircraft's vertical plane at an angle to the vertical and longitudinal axes, is sufficient for sensing any combination of roll and yaw motions, and represents the minimum sensor set for operation of the system 10 . As will be discussed in more detail below, a full set of separate orthogonal roll, yaw, and pitch gyros can be used to provide enhanced heading estimation. Alternatively, a full set of orthogonal accelerometers and at least one rate-gyro may provide similar enhanced heading estimations. Also as will be discussed in more detail below, the optional outside air temperature sensor 60 may be used for enhanced calculation of airspeeds, as well as minor improvement in the calculation of the flight path angle (FPA), described in more detail below.
Referring next to FIGS. 4A , 4 B and 5 , display 100 is preferably a color electronic display, such as an active matrix liquid crystal display (AMLCD). Although the size of the display 100 is not critical, it will be appreciated by those skilled in the art that it may be sized to serve as a “form-fit-function” replacement for a standard TC or related instrument. For example, in the event display 100 were to be relied on as a primary display, it could be made larger. FIG. 4A depicts a notional display format for an electronic TC 110 , which combines the elements a turn-rate indicator, a sideslip indicator 120 and simple flight path angle indicator (the latter labeled in degree increments above and below the horizontal). Electronic TC 110 includes pitch information that generally mimics the attitude of a conventional AI, although it displays FPA, also referred to as climb-dive angle, rather than pitch angle like the AI, and a combination of roll and yaw rates rather than bank angle like the AI. Electronic TC 110 shows a horizon line at zero degrees on the screen, a lighter background representing climb angle above the horizon (indicated in this depiction by positive numbers on the left side of the screen), and a darker background color to indicate dive angle below the horizon (indicated in this depiction by negative numbers on the left side of the screen). In one form, the lighter background may present a blue color (generally representative of the sky, for example), while the darker background may present a brown color (generally representative of the ground, for example). The colors and reference marks used for electronic TC 110 are only notional, and may be altered without deviating from the spirit of the invention. Electronic TC 110 depicts FPA using a conventional “inside-out” technique, such that the horizon moves up or down appropriately to indicate FPA while the aircraft silhouette remains stationary. This approach emulates that used by conventional AIs so that the aircraft symbol 101 positioned directly on the horizon indicates level flight, rather than level pitch attitude as on an AI. In an alternate embodiment, electronic TC 110 can be configured to depict climb-dive rate, rather than angle. In this embodiment, the position of the reference aircraft symbol remains fixed in the center of the display, while the reference background moves.
Referring with particularity to FIG. 4B , the reference aircraft symbol 101 in the center of display 100 indicates roll and yaw rates by rotating in the appropriate direction in the electronic TC 110 . This “outside-in” mechanization (moving aircraft/stationary horizon) in roll has been proven to be especially intuitive for flight instruments. In the flight situation depicted in FIG. 4B , the aircraft symbol 101 indicates that aircraft 1 is turning to the right at a rate of three degrees per second with a five degree descending flight path. It should be noted that the rotation of the aircraft symbol 101 does not directly represent aircraft roll attitude (bank angle), but rather roll/yaw rate. Processor 80 incorporates an algorithm that combines the appropriately weighted outputs of both the roll-rate and yaw-rate gyros of rate gyro system 40 , either or both of which may be smoothed/filtered by the use of commonly known digital smoothing techniques (not shown, but forming a portion of processor 80 ), to calculate rotation of the aircraft symbol 101 . As the aircraft 1 begins to roll at the start of a turn, most of the rotation of the aircraft symbol 101 will be due directly to roll rate, and will nearly mirror the actual roll attitude of the aircraft 1 . Once the roll angle stabilizes and the turn begins, the output of the rate gyro system 40 will provide the primary data source for positioning the aircraft symbol 101 . The notional tick marks (shown, for example, as a three degree per second (i.e., two minute turn) located on either side of electronic TC 110 provide references for zero and standard turn rates. The combination of roll and yaw rate on electronic TC 110 gives the pilot a qualitative indication of the bank angle of aircraft 1 .
Sideslip indicator 120 , situated at the bottom of display 100 , is preferably an electronic representation of the standard mechanical inclinometer (ball) found on conventional TCs, although it will be appreciated that the more conventional mechanical inclinometer can be used in the present system 10 in conjunction with display 100 to present visual indicia to the user. In the event conventional mechanical inclinometer is used in the present system 10 , it is understood that the lateral accelerometer and signal communication between the inclinometer and the digital processor 80 are not required. Accelerometer 50 can be arranged as a lateral accelerometer, the output of which can be used as an input parameter for processor 80 . As with other sensed data, the output from accelerometer 50 may be smoothed or filtered by the use of commonly known digital smoothing techniques. The two vertical reference lines 120 A, 120 B in the center of the sideslip indicator 120 , set at roughly the diameter of the indicator ball 120 C, provide a reference for coordinated flight. The sensitivity of the sideslip indicator 120 may be adjustable as desired through manipulation of software loaded into processor 80 .
Referring again to FIG. 2A , FPA is shown by angle γ, which is the vertical angle between the horizon (i.e., the horizontal axis X) and the velocity vector V of aircraft 1 . FPA is normally positive in a climb. Note that FPA is different than the aircraft attitude shown by an AI in that the latter shows where the aircraft 1 is pointing (indicated, for example, by the aircraft's longitudinal x-axis), while the former shows where aircraft 1 is going. Stated another way, the pitch of an aircraft is the vertical angle formed between the horizon and the longitudinal axis x of aircraft 1 , where the longitudinal axis x is defined as a straight line through the center of gravity of the aircraft 1 parallel to the fuselage and extending out the nose and tail. The angle between the longitudinal axis x (where the aircraft is pointed) and the FPA (where the aircraft is going) projected onto the aircraft's vertical (x-z) plane is referred to as the angle-of-attack AOA.
Referring next to FIG. 5 , an enhanced electronic TC 110 is shown, now including (in addition to that shown in FIGS. 4A and 4B ) digital airspeed 130 on the left (reading 132 knots), a heading scale 140 on top (reading 298 degrees magnetic) and barometric altitude 150 on the right (reading 4,500 feet above sea level). These displays are notional, and it will be appreciated by those skilled in the art that other arrangements of these parameters can be used. For example, the digital format for airspeed 130 and altitude 150 were chosen only to minimize the display area; simulated analog dials or tapes (which may be preferable from a human-factors standpoint) could also be used if a large display area were employed. In another example, a depiction of vertical speed or trends in airspeed or altitude, in either digital or simulated analog format, could also be included. In yet another example, desired units for airspeed (i.e., knots, miles per hour, etc.) may be changed. In addition to airspeed 130 , electronic TC 110 might also offer the option of displaying calibrated airspeed (CAS), true airspeed (TAS), or both. TAS calculations would be enhanced with inclusion of information taken from an optional outside air temperature sensor 60 , while values of the measured outside air temperature may also be displayed. Both CAS and TAS are discussed in more detail below.
The chosen mechanization for the heading scale 140 is inside-out, so that the headings increase to the right. This is generally the preferred approach, consistent with most modern HIs, but opposite to the operation of the wet compass and many early directional gyros. Nevertheless, the heading scale 140 could be reversed without deviating from the spirit of the invention. Simple controls 90 (shown in block form in FIG. 3 ), for example, of the touch-sensitive or push-button ON/OFF, and INCREASE/DECREASE types, can be provided so that the enhanced display components may be selected, deselected, or adjusted as desired. Such controls 90 could also be used to set the altitude 150 depicted on electronic TC 110 to match the aircraft altimeter, as well as to synchronize the heading scale 140 to an on-board wet compass or an optional magnetometer. It will be appreciated that in situations where electronic TC 110 becomes the primary flight reference, having all the required flight parameters (such as, rate/direction of turn, FPA, airspeed, altitude, and heading) in a single display provides a powerful advantage for the instrument scan of a pilot.
Referring again to FIG. 3 in conjunction with FIGS. 4A , 4 B and 5 , electronic TC 110 displays flight information of aircraft 1 based on information generated by an embedded processor 80 based on the outputs of multiple sensors made up of pressure sensors 30 , rate gyro system 40 , accelerometer(s) 50 and optional outside air temperature sensor 60 . At a minimum, the sensors must be capable of sensing altitude, airspeed, lateral acceleration, and yaw and roll rates, while performance may be improved by the addition of a pitch-rate gyro (as part of rate gyro system 40 ) and outside air temperature sensor 60 . All of the sensors are placed on-board of aircraft 1 , although some of the parameters, such as the altitude and speed, may be based on a Global Positioning System (GPS) or other technology. As mentioned above, the outputs from any of these sensors may be smoothed/filtered by the use of commonly known digital smoothing techniques. For example, the output of the static-pressure sensor 30 A is converted to barometric altitude by the embedded processor 80 , using a standard atmospheric model provided by the sensor manufacturer. In one form, the standard atmospheric model may be stored as data in a lookup table or related mass storage device, or reduced to a mathematical formula that can be embedded in the software (not shown) that is loaded onto processor 80 . Improved accuracy may be obtained by incorporating a software calibration curve derived from flight-test data. The rate of change in altitude is calculated from the altitude-sensor data by software differentiation algorithms well known to those familiar with the art. These results may be smoothed/filtered to generate a climb-rate or descent-rate estimate.
Concurrent with the above calculations, an estimate of indicated airspeed (IAS) is calculated. The information is based on the output of the dynamic pressure sensor 30 B by use of a standard model provided by the sensor manufacturer. Measurement accuracy may be further enhanced by correcting IAS for inherent pitot-static system errors by use of a software calibration curve derived from flight tests or from data provided by the aircraft manufacturer. As with the standard atmospheric model data discussed above, other manufacturer-provided or flight test-generated data may be stored in a lookup table or related mass storage device, or by a mathematical formula. When IAS is corrected by such data, it is referred to as calibrated airspeed (CAS), which may then lead to true airspeed (TAS), which may be calculated using the standard formula:
TAS = CAS σ
where σ is the ratio of ambient air density to sea-level air density, and may be calculated by inserting the system's best estimate of altitude into a standard atmospheric digital model. Further standard corrections may be applied to adjust this model for non-standard temperature conditions (which could be based on outputs from an optional outside air temperature sensor 60 ), compressibility effects, or both. Once climb/descent rate and TAS are known, FPA may be calculated by:
FPA =sin −1 (climb rate/ TAS )
It should be noted that FPA calculated by this method is not wind corrected, and small errors could exist when the headwind/tailwind speed is significant in relation to aircraft speed. Nevertheless, the error is negligible for small FPAs, and this issue is not expected to be a factor in the operational utility of the instrument.
Due primarily to inertial effects, there is an inherent time lag between a change in aircraft pitch angle and FPA. Since the pilot typically controls aircraft FPA indirectly by controlling pitch attitude, rather than by controlling FPA directly, this lag between aircraft attitude and FPA tends to make vertical control more difficult when performed by monitoring FPA alone. To overcome this inherent characteristic and reduce the tendency toward pilot-induced oscillation (PIO), electronic TC 110 can incorporate the values sensed by the rate gyro system 40 (which may include a pitch-rate gyro) to reduce the lag in the displayed FPA. The output from the rate gyro system 40 is converted to an estimate of aircraft pitch rate by use of a standard calibration curve provided by the sensor manufacturer. This technique modifies the displayed FPA by adding a component of pitch rate. In its simplest embodiment, pitch rate q, modified by an appropriate gain K may be added directly to the instantaneous FPA to derive a “quickened” FPA for display by electronic TC 110 such that:
FPA displayed =FPA instantaneous +Kq
The optimal value of K depends on numerous characteristics, including that of the aircraft 1 design, the design of the flight instrument system 10 , as well as the pilot's technique. The gain K is simply a multiplier, the value of which is set to optimize pilot response while using the electronic TC 110 . An optimal value may be determined by control-system theory, simulation, or flight tests. An alternative technique is to replace the information taken from the pitch-rate gyro of the rate gyro system 40 with that from a vertical accelerometer in a similar manner.
A more sophisticated quickening approach for displaying FPA is to modify the display with a function of pitch rate q that diminishes (washes out) over a short time interval roughly equivalent to the inherent delay in FPA relative to aircraft pitch-angle changes. Typically the optimal time for this washout to occur is a few seconds (for example, between approximately two an four seconds), but a suitable value for any application may be determined by control-theory calculations, simulation, or flight test. This method integrates pitch rate q over each data sampling time interval i during the preceding washout period to calculate a pitch increment Δθ i during each of those time intervals. The pitch increment Δθ i of each time interval i is then multiplied by a function that decreases the value of that pitch increment Δθ i logarithmically with the passage of time to generate an uncorrected pitch contribution of that time interval. Additionally, each pitch contribution is multiplied by the cosine of the estimated average aircraft bank angle (discussed below) during that time interval i to generate a corrected pitch contribution. All of the corrected pitch contributions for the washout period are then summed and added to the instantaneous FPA value to calculate the FPA value to be displayed at a given time. Such a quickened FPA may be calculated by the formula:
FPA displayed = FPA instantaneous + ∑ i = 0 T washout [ cos ( φ i ) ΔΘ i ⅇ - K Δ t i ]
where φ i is the average aircraft bank angle during time interval i, Δθ i is the integral of pitch rate q during time interval i, K is a constant, Δt i is the elapsed time since time interval i, and T washout is the time period over which the quickening component is to be considered. Again, the optimal value of K depends on numerous characteristics, including that of the design of aircraft 1 and the design of the flight instrument system 10 , and may be determined by control-theory calculations, simulation or flight test. In essence, this method estimates the error between the aircraft's pitch attitude at any time and its FPA at that instant, and adds this estimated error to the FPA before display. Such resulting display may be considered to be a “pseudo-pitch” display, since it tends to follow aircraft pitch-angle changes closely during maneuvering flight.
By displaying available barometric altitude and airspeed information in addition to the basic flight-path/turn-rate information, electronic TC 110 can facilitate instrument flight. It may further be desirable to adjust the displayed altitude for sea-level barometric pressure. Although a direct barometric-pressure input mode could be provided, it may be preferable (in light of the need for calibration) to allow direct adjustment of altitude displayed by electronic TC 110 , which could be adjusted to match the aircraft's standard barometric altimeter, which has been adjusted for sea-level barometric pressure. Corrected altitude can then be used by the processor 80 to provide more accurate calculations of TAS and FPA.
In addition to air-data parameters, the provision of separate roll-rate, yaw-rate, and pitch-rate gyros in the electronic TC 110 allows estimation of aircraft bank angle and display of a surrogate heading indication. A means of adjusting displayed aircraft heading to match the wet compass or an optional magnetometer is provided, as is currently the practice with most vacuum-driven HIs. In its simplest embodiment, aircraft heading can be updated from a known value by reference to the output of a yaw-rate gyro in rate gyro system 40 alone. In this embodiment, yaw rate is integrated digitally by software algorithms well known to those skilled in the art to calculate an estimate of heading change. Since yaw rate sensed by the rate gyro system 40 is referenced to the aircraft 1 , while heading change is reference to the earth, accuracy may be improved by providing a correction for aircraft roll and/or pitch angles by use of equations well known by those skilled in the art. The estimate of FPA derived by the flight instrument system 10 may be used as a surrogate for aircraft pitch attitude, and the assumption of a typical bank angle for turns provides for some improvement in the estimate of heading change. If further improvement of heading accuracy is desired, more sophisticated techniques may provide further enhancement to heading accuracy.
For example, if the assumption is made that AOA of aircraft 1 is zero and unchanging, a relationship exists among the aircraft angular rates, FPA (γ), the rate of change in FPA ({dot over (γ)}) and turn rate ({dot over (Ψ)}). These assumptions are not typically in great error during mild aircraft maneuvering. The current embodiment of the flight instrument system 10 , which may include rate gyros for all three planes, makes it possible to exploit this relationship to derive estimates of aircraft bank angle and turn rate. The difficulty with estimating horizontal turn rate using only a rate gyro is the absence of a vertical-horizontal reference. Under conventional systems, the usual way to get such information is through an expensive, failure-prone vertical gyro, which significantly adds to the cost of an HI display. The present invention overcomes this difficulty by allowing for a simple, inexpensive way to estimate aircraft bank angle. The relationship above essentially uses {dot over (γ)} as this vertical-horizontal reference. This is possible since FPA and {dot over (γ)} always lie in the vertical plane. The value of {dot over (γ)} may be calculated by digitally differentiating the estimate of FPA by software algorithms well known to those familiar with the art. Under these conditions, aircraft bank (i.e., roll) angle φ may be estimated by the following algorithm:
If r≧0, then
sin(φ)=(− r {dot over (γ)}+ q √{square root over ( r 2 +q 2 −{dot over (γ)} 2 )})/( r 2 +q 2 )
If r<0, then
sin(φ)=(− r {dot over (γ)}− q √{square root over ( r 2 +q 2 −{dot over (γ)} 2 )})/( r 2 +q 2 )
where q is the previously-discussed aircraft pitch rate, positive nose-up (derived from a pitch-rate gyro), r is the aircraft yaw rate, positive nose-right (derived from a yaw-rate gyro), γ is the previously-discussed FPA, positive nose-up, calculated by the air-data system or by other means, {dot over (γ)} is the previously-discussed rate of change in FPA, positive for increasing FPA (calculated by digitally differentiating γ), and φ is the previously-discussed aircraft bank angle, positive right-wing down. Once sin(φ) is known, cos(φ) can be easily determined from the trigonometric identity:
cos(φ)=√{square root over (1−sin 2 (φ))}
such that aircraft turn rate in the horizontal plane can be estimated as:
{dot over (Ψ)}−[ q sin(φ)+ r cos(φ)]/cos(γ).
Once the horizontal turn rate {dot over (Ψ)} is estimated, this value may be digitally integrated by algorithms well known to those skilled in the art to derive an estimate of current aircraft heading, based on some known reference (i.e., starting) heading, as with standard HIs. A similar technique that exploits the relationship among aircraft accelerations, FPA, and the second derivative of altitude may be substituted without deviating from the spirit of the invention. In this alternate case, the second derivative of altitude provides the vertical reference. In either case, the use of digital differentiation may result in considerable “noise” in the resulting values of {dot over (γ)} or the second derivative of altitude. Considerable reduction in this noise, and greatly improved turn-rate estimates, may be provided by digital filtering techniques, such as the Kalman filtering technique that is well-known to those skilled in the art. Further improvements may be obtained by using quickened values of γ for deriving {dot over (γ)} in a manner generally similar to that of determining a quickened FPA (discussed above).
In summary, the present system 10 can employ an airspeed sensor, one or more rate gyros, and an altitude sensor to estimate the heading of aircraft 1 . In situations where either an HI or vacuum system failure occurs, the aircraft 1 heading estimated by any of the techniques described above is vastly superior to reliance on a wet compass alone. In addition, the present system 10 is less costly than systems that rely upon external sources of information, such as the aforementioned GPS. Flight instrument system 10 is further equipped with a means for the pilot to adjust the displayed heading periodically to a known or estimated heading to compensate for any system heading drift that may occur over time. As an option, a magnetometer may be coupled to the flight instrument system 10 to provide an input for magnetic heading, where the magnetometer estimates magnetic heading by sensing the earth's magnetic field and applying a calibration algorithm provided by the magnetometer manufacturer. Since a magnetometer without attitude compensation is subject to similar errors as those of the wet compass, a means must be developed to ensure that magnetometer corrections are applied to the estimate of heading only when the aircraft is near straight-and-level flight. This may be accomplished by providing the pilot with a synchronizing control to align the displayed heading with the magnetometer heading estimate. A software algorithm may also be included that restricts magnetometer corrections to the displayed heading only when both the gyro-derived and the magnetometer-derived heading estimates are changing only at very slow rates. During these periods, the gyro-derived heading estimate is corrected toward the magnetometer-derived estimate at a fixed rate. This technique results in automatic correction of the displayed heading by the magnetometer during periods of near straight-and-level flight, and more accurate gyro-based heading estimates during maneuvering flight.
While certain representative embodiments and details have been shown for purposes of illustrating the invention, it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention, which is defined in the appended claims. | A device for providing flight condition information and a method of displaying such information. In one form, the device functions as a backup system to provide flight condition information in the event of partial or complete inoperability of a primary flight instrument system, or to complement such primary flight instrument system. Numerous sensors collect flight data, which can pass through devices to convert and manipulate the data to produce flight condition information that can be displayed in such a way as to reduce a pilot's cognitive workload. The information displayed includes at least flight path angle, lateral acceleration, and turn rate. Additional information that may be displayed includes heading information, as well as information relating to airspeed and altitude, among others. In another form, the device can be part of either a primary or backup system. | 1 |
RELATED APPLICATIONS
[0001] This is a continuation patent application that claims priority to PCT patent application number PCT/GB2005/004036, filed on Oct. 20, 2005, which claims priority to PCT/GB2005/03823 filed on Oct. 5, 2005, the entirety of which are herein incorporated by reference.
FILED OF INVENTION
[0002] The present invention relates to a method for predicting or monitoring the response of a patient to an ErbB receptor drug, for example gefitinib, which targets the epidermal growth factor receptor (EGFR). The method provides a sensitive and specific screen for mutations in genomic DNA occuring at low concentrations in bio-fluids such as serum. the method is suitable for detecting mutations that are known to increase ErbB tyrosine kinase receptor activity and appear to correlate with a response to ErbB receptor drug treatment.
[0003] ErbB receptors are protein tyrosine kinases (TKs) belonging to the TK superfamily, the members of which a regulate signaling pathways controlling growth and survival of cells. The ErbB family of receptors consists of four closely related subtypes: ErbB1 (epidermal growth factor receptor [EGFR]), ErbB2 (HER2/neu), ErbB3(HER3), and ErbB4)HER$) (Cell. 2000; 103:211-255).
[0004] Signaling from the EGFR for example, is triggered by the binding of growth factors such as epidermal growth factor (EGF), resulting in the dimerization of EGFR molecules or heterodimerization with other closely related receptors such as HER2/neu. Autophosphorylation and trasnphosphorylation of the receptors through their tyrosine kinase domains leads to the recruitment of downstream effectors and the activation of proliferative and cell-survival signals (Exp. Cell. Res. 2003; 284:31-53. When overexpressed or activated by mutations, ErbB receptor TKs can lead to the development of breast cancer, non-small-cell lung caner (NSCLC), colorectal cancer, head and neck cancer, and many other solid tumours (Exp. Cell. Res. 2003; 284:122-130). EGRF is overexpressed in 40 to 80 percent of non-small cell lung caners and many other epithelial cancers (N. Engl. J. Med. 2004; 350(21):2129-2139). Anticancer therapy has been designed to target the products of such genes in order to inhibit their activity. The drug gefitinib for example, is a potent inhibitor of the EGFR family of tyrosine kinase enzymes such as ErbB1 and was approved in Japan on Jul. 5, 2002 for treatment of inoperable or recurrent NSCLC.
[0005] Patents vary in their responses to any prescribed medications, both with respect to how well it works (its efficacy) and adverse reactions to it (side effects). In the case of gefitinib, patients exhibit a differential response to the tyrosine kinase inhibitor treatment including a group of about 10 percent of patients that have a rapid and often dramatic clinical response (N. Engl. J. Med.2004; 350(21):2129-2139). Accordingly there is a need to identify pre-treatment those patients who will respond to the drug and also to identify post treatment those patients that are responding to the drug, so that the medicine can be targeted more effectively.
[0006] It has recently been discovered that a subgroup of patients with non-small cell lung cancer has specific mutations in the EGFR gene which appear to correlate with clinical responsiveness to the tyrosine kinase inhibitor gefitinib (Science 2004; 304:1497-1500). These mutations lead to increased growth factor signalling and confer susceptibility to the inhibitor. It is thought that screening for such mutations in lung cancers may identify patients who will have a response to gefitinib (J. Clin. Oncol. 23; 2493-2501). However, to date, the only way that mutations can be measured reliably is by analysis of solid tissue samples by taking a tumour biopsy from the patient. This is a difficult procedure, is very unpleasant for the patient and sometimes impossible when a tumour is inoperable.
[0007] Another problem in screening patients for mutations is the difficulty in detecting mutant genes among an excess of wild-type genes. This is a known problem in the art and especially important given that identification of mutant DNA at low concentration could be critical for early detection of a tumour or to identify the appropriate course of treatment for a patient at an early stage (Clin Cancer Res. 2004; 10(7):2379-85). Accordingly, there is a need for less invasive and more reliable ways to monitor and predict the response of patients to ErbB receptor drugs, for example before embarking them on a therapy that may be very effective, but for only a small percentage of those patients.
SUMMARY OF THE INVENTION
[0008] We have found a method of reliably detecting ErbB receptor mutations in bio-fluid samples taken from patients, that can be used to predict a patients' response or survival benefit from an ErbB receptor drug. In particular, the presence of a mutation that alters the tyrosine kinase activity of an ErbB receptor indicates that a patient may respond positively to the drug whilst the presence of only the wild type allele indicates that the patient may not respond to an ErbB receptor drug.
[0009] According to the first aspect of the invention there is provided a method for detecting ErbB mutations comprising the steps of:
(a) providing a bio-fluid sample from a patient (b) extracting DNA from said sample; and (c) screening said DNA for the presence of one or more mutations in the receptor.
[0013] Preferably the method for detecting ErbB mutations described above comprises detection of one or more mutations in an ErbB receptor that alter the tyrosine kinase activity in said receptor.
[0014] Most preferably the ErbB receptor in the above described method is EGFR.
[0015] The present inventors have found that measurement of mutations in bio-fluid samples in patients may be used both to predict and to monitor the effects of ErbB receptor drugs in vivo.
[0016] In a preferred aspect, the invention provides a method for predicting the response of a patient to an ErbB receptor drug comprising the steps of:
(a) providing a bio-fluid sample from a patient (b) extracting DNA from said sample (c) screening said DNA for the presence of one or more mutations that alter tyrosine kinase activity in the receptor
[0020] In another embodiment of the invention there is provided a method for monitoring the response of a patient to an ErbB receptor drug comprising the steps of:
(a) providing a bio-fluid sample from a patient (b) extracting DNA from said sample (c) screening said DNA for the presence of one or more mutations that alter tyrosine kinase activity in the receptor.
[0024] As will be understood by those skilled in the art, monitoring of a response to an ErbB receptor drug allows the response of a patient to whom the drug has already been administered to be assessed; thus, it is applied to patients post-treatment. However, prediction of a response is carried out in patents not exposed to an ErbB receptor drug, and is carried out pre-treatment.
[0025] In another embodiment the method comprises the steps described above wherein the prediction of the response of a cancer patient to an ErbB receptor drug predicts the survival benefit to the patient.
[0026] Preferably a method of predicting a response to an ErbB drug as described above further comprises the step of:
(d) concluding that patients in which both mutated and wildtype alleles are detected will respond positively to an ErbB receptor drug, whereas patients in which only wild type alleles are detected will not respond positively to the drug.
[0028] In another embodiment the method of screening described above comprises use of polymerase chain reaction with allele specific primers that detect single base mutations, small in-frame deletions or base substitutions.
[0029] Preferably the method of screening involves use of real time polymerase chain reaction (real time-PCR) with allele specific primers that detect single base mutations, small in-frame deletions or base substitutions.
[0030] In a further embodiment the method of predicting a response to an ErbB drug is as described above wherein a first primer pair is used to detect the wild type allele and a second primer pair is used to detect the mutant allele; and wherein one primer of each pair comprises:
(a) a primer with a terminal 3′ nucleotide that is allele specific for a particular mutation; and (b) possible additional mismatches at the 3′ end of the primer.
[0033] Preferably, one primer in each pair as described above further comprises:
(a) a single molecule or nucleic acid duplex probe containing both a primer sequence and a further sequence specific for the target sequence; (b) a fluorescent reporter dye attached to the 5′ end of the probe in close proximity with a quencher molecule within said single molecule or nucleic acid duplex; (c) one or more non-coding nucleotide residues at one end of said probe; (d) wherein said reporter dye and quencher molecule become separated during amplification of the target sequence.
[0038] Advantageously, the probe is a Scorpion® probe.
[0039] Preferably the method according to the invention uses a technique capable of detecting a mutant sequence present at 10% of the level of wild type sequence. More preferably the technique can detect mutant sequence at 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.1% or 0.01% of the levels of the wild type sequence.
[0040] The fluorescent probe system described above has the advantage that no separate probe is required to bind to the amplified target, making detection both faster and more efficient than other systems. The present invention demonstrates that the use of Scorpion® primers in an ARMS amplification system enhances the sensitivity of methods used to detect EGFR mutations (See Example 4).
[0041] Preferably the bio-fluid described in the method above is any one of blood, serum, plasma, sweat or saliva. Advantageously, the bio-fluid is serum.
[0042] Most previous studies looking at the correlation between EGFR mutations and NSCLC progression demonstrated such mutations in operative resected tumour samples taken after commencement of treatment, for a retrospective study. However the difficulty in sampling inoperable NSCLC tumours from patients at an earlier stage has hampered attempts to perform prospective studies with the potential to select patients before the commencement of treatment.
[0043] However, the present invention provides a method of detecting mutant EGFR from cancer patients' samples other than tumour specimens. The sampling of bio-fluids is less invasive than previous methods of analysing EGFR mutations in cancer patients. In contrast to collection of tumour samples, serum samples for example, can be collected easily and tests can be repeated. Furthermore, tumour cells are known to release DNA into the circulation, which is enriched in the serum and plasma, allowing detection of mutations and microsatellite alterations in the serum DNA of cancer patients (Cancer Res. 1999; 59(1):67-70).
[0044] In a further embodiment of the invention, the ErbB receptor drug is an ErbB receptor tyrosine kinase inhibitor. Preferably the ErbB receptor drug is an EGFR tyrosine kinase inhibitor. In a preferred method, the EGFR tyrosine kinase inhibitor is selected from a group consisting of gefitinib, erlotinib (Tarceva, OSI-774, CP-358774), PKI-166, EKB-569, HKI-272 (WAY-177820), lapatinib (GW2016, GW-572016, GSK572016), canertinib (CI-1033, PD183805), AEE788, XL647, BMS 5599626, ZD6474 (Zactima™) or any of the compounds as disclosed in WO2004/006846 or WO2003/082290.
[0045] In another embodiment of the invention the ErbB receptor drug is an EGFR inhibitor. Preferably, the EGFR inhibitor is an anti-EGFR antibody selected from the group consisting of cetuximab (Erbitux, C225), matuzumab (EMD-72000), panitumumab (ABX-EGF/rHuMAb-EGFR), MR1-1, IMC-11F8 or EGFRL11.
[0046] Preferably, the method of any preceding claim comprises an ErbB receptor drug used as monotherapy or in combination with other drugs.
[0047] In a most preferred embodiment, the EFGR tyrosine kinase inhibitor drug is selected from a group consisting of gefitinib, erlotinib (Tarceva, OSI-774, CP-358774), PKI-166, EKB-569, HKI-272 (WAY-177820), lapatinib (GW2016, GW-572016, GSK572016), canertinib (CI-1033, PD183805), AEE788, XL647, BMS 5599626, ZD6474 (Zactima™) or any of the compounds as disclosed in WO2004/006846 or WO2003/082290.
[0048] The mutations in the invention are found to occur as insertions, deletions or substitutions of nucleic acid. The mutations preferably occur in the tyrosine kinase domain of an ErbB receptor. Preferably the mutations occur in the tyrosine kinase domain of EGFR. Preferably, the mutations are selected from the group of EGFR mutations listed in Table 5. Advantageously the mutations cluster around the ATP binding site in exons 18, 19, 20 or 21 of EGFR. Preferably the mutations are selected from the group of EGFR mutations listed in Table 5. In a most preferred embodiment, the mutations are E746_A750del in exon 19 and L858R in exon 21 of EGFR.
[0049] Approximately 30 mutations in exon 18-21 of EGFR have been detected in lung tumour specimens. Among the NSCLC-associated EGFR mutations detected in tumour specimens, the 15-bp nucleotide in-frame deletions in exon 19 (E746_A750del) and the point mutation which is a replacement of leucine by arginine at codon 858 in exon 21 (L858R) account for approximately 90% of these mutations (Cancer Res. 2004; 64:8919-8923, Proc. Natl. Acad. Sci USA 2004; 101:13306-13311).
[0050] Advantageously the patient suffers from a cancer selected from the group consisting of non-solid tumours such as leukaemia, multiple myeloma or lymphoma, and also solid tumours, for example bile duct, bone, bladder, brain/CNS, glioblastoma, breast, colorectal, cervical, endometrial, gastric, head and neck, hepatic, lung, muscle, neuronal, oesophageal, ovarian, pancreatic, pleural/peritoneal membranes, prostate, renal, skin, testicular, thyroid, uterine and vulval tumours.
[0051] In another embodiment of the invention, the method as described above further comprises the step of:
(e) screening said DNA for the presence of one or more mutations in components of the downstream signalling pathway of an ErbB receptor.
[0053] A second aspect of the invention encompasses a composition comprising a first primer pair which is used to detect the wild type allele and a second primer pair which is used to detect the mutant allele of an ErbB receptor wherein one primer of each pair further comprises:
(a) a primer with a terminal 3′ nucleotide that is allele specific for a particular mutation; and (b) possible additional mismatches at the 3′ end of the primer. (c) a single molecule or nucleic acid duplex probe containing both a primer sequence and a further sequence specific for the target sequence; (d) a fluorescent reporter dye attached to the 5′ end in close proximity with a quencher molecule within said single molecule or nucleic acid duplex; (e) one or more non-coding nucleotide residues at one end of said probe; (f) wherein said reporter dye and quencher molecule become separated during amplification of the target sequence.
[0060] A third aspect of the invention comprises use of a primer specific for ErbB receptor in an assay conducted in a bio-fluid for predicting the response of a patient to an ErbB drug.
[0061] Preferably the use described above includes manufacture of a composition for testing a bio-fluid for predicting the response of a patient to an ErbB drug.
[0062] Advantageously, the above-described use further comprises the steps of:
(a) extracting DNA from said sample (b) screening said DNA for the presence of one or more mutations that alter tyrosine kinase activity in the receptor.
DESCRIPTION OF THE FIGURES
[0065] FIG. 1 Sensitivity of detection for mutations of E746_A750del and L858R using EGFR Scorpion Kit. (a) Standard DNA with E746_A750del were used at various volumes of 10,000 pg (10 4 ), 1,000 pg (10 3 ), 100 pg (10 2 ), 10 pg (10 1 ) and 1 pg (10 0 ). Standard DNA with wild type (Wild) and distilled water (D.W.) were used as negative controls at the same experiment. (b) Standard DNA with E746_A750del at concentrations from 1 pg to 10,000 pg were mixed with 10,000 pg of standard DNA with wild type at a ratio of 1:1 (10 0 ), 1:10 (10−1), 1:100 (10 −2 ), 1:1,000 (10 −3 ) and 1:10,000 (10 −4 ). (c) Primary curve and 2nd derivative curve represented from standard DNA with E746_A750del at a volume of 10,000 pg. The 2nd derivative represents the rate of change in the slope of the growth curve. The threshold cycle is defined as a cycle number at the highest peak of the 2nd derivative curve (the vertical line in FIG. 1 c ). (d) Standard curves were derived by plotting the Ct of each curve (shown in FIGS. 1A and 1B ) against the log of the standard DNA volume.
[0066] FIG. 2 Detection of E746_A750del in genomic DNA derived from lung cancer cell lines. (a) PC-9 with E746_A750del and A431 with wild type. (b) 11 — 18 with L858R and A431
[0067] FIG. 3 Progression free survival (A) and overall survival (B) with respect to the EGFR mutation status of non-small cell lung cancer. (*) Log-rank test.
DETAILED DESCRIPTION OF THE INVENTION
[0068] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art (e.g., in cell culture, molecular genetics, nucleic acid chemistry, hybridisation techniques and biochemistry). Standard techniques are used for molecular, genetic and biochemical methods. See, generally, Sambrook et al., Molecular Cloning: A Laboratory Manual, 2d ed. (1989) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, N.Y. and Ausubel et al., Short Protocols in Molecular Biology (1999) 4 th Ed, John Wiley & Sons, Inc.; as well as Guthrie et al., Guide to Yeast Genetics and Molecular Biology, Methods in Enzymology, Vol. 194, Academic Press, Inc., (1991), PCR Protocols: A Guide to Methods and Applications (Innis, et al. 1990. Academic Press, San Diego, Calif.), McPherson et al., PCR Volume 1 N.Y.), and Gene Transfer and Expression Protocols, pp. 109-128, ed. E. J. Murray, The Humana Press Inc., Clifton, N.J.). These documents are incorporated herein by reference. Oxford University Press, (1991), Culture of Animal Cells: A Manual of Basic Technique, 2nd Ed. (R. I. Freshney. 1987. Liss, Inc. New York, N.Y.), and Gene Transfer and Expression Protocols, pp. 109-128, ed. E. J. Murray, The Humana Press Inc., Clifton, N.J.). These documents are incorporated herein by reference.
Biomarkers
[0069] Various biological markers, known as biomarkers, have been identified and studied through the application of biochemistry and molecular biology to medical and toxicological states. Biomarkers can be discovered in both tissues and biofluids, where blood is the most common biofluid used in biomarker studies (Proteomics 2000; 1:1-13, Physiol. 2005; 563:23-60).
[0070] A biomarker ran be described as “a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention”. A biomarker is any identifiable and measurable indicator associated with a particular condition or disease where there is a correlation between the presence or level of the biomarker and some aspect of the condition or disease (including the presence of, the level or changing level of, the type of, the stage of, the susceptibility to the condition or disease, or the responsiveness to a drug used for treating the condition or disease). The correlation may be qualitative, quantitative, or both qualitative and quantitative. Typically a biomarker is a compound, compound fragment or group of compounds. Such compounds may be any compounds found in or produced by an organism, including proteins (and peptides), nucleic acids and other compounds.
[0071] Biomarkers may have a predictive power, and as such may be used to predict or detect the presence, level, type or stage of particular conditions or diseases (including the presence or level of particular microorganisms or toxins), the susceptibility (including genetic susceptibility) to particular conditions or diseases, or the response to particular treatments (including drug treatments). It is thought that biomarkers will play an increasingly important role in the future of drug discovery and development, by improving the efficiency of research and development programs. Biomarkers can be used as diagnostic agents, monitors of disease progression, monitors of treatment and predictors of clinical outcome. For example, various biomarker research projects are attempting to identify markers of specific cancers and of specific cardiovascular and immunological diseases.
[0072] The term ‘ErbB receptor drug’ used herein includes drugs acting upon the erbB family of receptor tyrosine kinases, which include EGFR, ErbB2 (HER), ErbB3 and ErbB4. In an embodiment the ErbB receptor drug is an ErbB receptor tyrosine kinase inhibitor. In a further embodiment the ErbB receptor drug is an EGFR tyrosine kinase inhibitor. Examples of EGF receptor tyrosine kinase inhibitors include but are not limited to gefitinib, Erlotinib (OSI-774, CP-358774), PKI-166, EKB-569, HKI-272 (WAY-177820), lapatinib (GW2016, GW-572016), canertinib (CI-1033, PD183805), AEE788, XL647, BMS 5599626 or any of the compounds as disclosed in WO2004/006846, WO2003/082831, or WO2003/082290. In particular, gefitinib (also known as Iressa™, by way of the code number ZD1839 and Chemical Abstracts Registry Number 184475-35-2) is disclosed in International Patent Application WO 96/33980 and is a potent inhibitor of the epidermal growth factor receptor (EGFR) family of tyrosine kinase enzymes such as ErbB1.
[0073] In another embodiment the ErbB receptor drug is an anti-EGFR antibody such as for example one of cetuximab (C225), matuzumab (EMD-72000), panitumumab (ABX-EGF/rHuMAb-EGFr), MR1-1, IMC-11F8 or EGFRL11. The ErbB receptor drugs mentioned herein may be used as monotherapy or in combination with other drugs of the same or different classes. In a particular embodiment the EGF receptor tyrosine kinase inhibitor is gefitinib.
[0074] ‘Survival’ encompasses a patients' ‘overall survival’ and ‘progression-free survival’. ‘Overall survival’ (OS) is defined as the time from the initiation of gefitinib administration to death from any cause. ‘Progression-free survival’ (PFS) is defined as the time from the initiation of gefitinib administration to first appearance of progressive disease or death from any cause.
[0075] ‘Response’ is defined by measurements taken according to ‘Response Evaluation Criteria in Solid Tumours’ (RECIST) involving the classification of patients into two main groups: those that show a partial response or stable disease and those that show signs of progressive disease.
[0076] ‘Amplification’ reactions are nucleic acid reactions which result in specific amplification of target nucleic acids over non-target nucleic acids. The polymerase chain reaction (PCR) is a well known amplification reaction.
[0077] ‘Cancer’ is used herein to refer to neoplastic growth arising from cellular transformation to a neoplastic phenotype. Such cellular transformation often involves genetic mutation; in the context of the present invention, transformation involves genetic mutation by alteration of one or more Erb genes as described herein.
[0078] The term ‘probe’ refers to single stranded sequence-specific oligonucleotides which have a sequence that is exactly complementary to the target sequence of the allele to be detected.
[0079] The term ‘primer’ refers to a single stranded DNA oligonucleotide sequence or specific primer capable of acting as a point of initiation for synthesis of a primer extension product which is complementary to the nucleic acid strand to be copied. The length and sequence of the primer must be such that they are able to prime the synthesis of extension products.
[0080] The present application describes -ErbB nucleic acid mutants. As used herein, the term ‘ErbB receptor mutants’ is used to denote a nucleic acid encoding any member of the ErbB family of tyrosine kinase receptors. The term ‘ErbB receptor’ thus encompasses all known human ErbB receptor homologues and variants, as well as other nucleic acid molecules which show sufficient homology to ErbB receptor family members to be identified as ErbB receptor homologues. Preferably, EGFR is identified as a nucleic acid having the sequence for EGFR shown as SEQ ID NO.1.
[0081] The term ‘nucleic acid’ includes those polynucleotides capable of hybridising, under stringent hybridisation conditions, to the naturally occurring nucleic acids identified above, or the complement thereof. ‘Stringent hybridisation conditions’ refers to an overnight incubation at 42° C. in a solution comprising 50% formamide, 5×SSC (750 mM NaCl, 75 mM trisodium citrate), 50 mM sodium phosphate (pH 7.6), 5×Denhardt's solution, 10% dextran sulphate, and 20 pg/ml denatured, sheared salmon sperm DNA, followed by washing the filters in 0.1×SSC at about 65° C.
Methods for Detection of Nucleic Acids
[0082] The detection of mutant nucleic acids encoding ErbB receptors can be employed, in the context of the present invention, to predict the response to drug treatment. Since mutations in ErbB receptor genes generally occur at the DNA level, the methods of the invention can be based on detection of mutations in genomic DNA, as well as transcripts and proteins themselves. It can be desirable to confirm mutations in genomic DNA by analysis of transcripts and/or polypeptides, in order to ensure that the detected mutation is indeed expressed in the subject.
[0083] Mutations in genomic nucleic acid are advantageously detected by techniques based on mobility shift in amplified nucleic acid fragments. For instance, Chen et al., Anal Biochem 1996 Jul. 15; 239(1):61-9, describe the detection of single-base mutations by a competitive mobility shift assay. Moreover, assays based on the technique of Marcelino et al., BioTechniques 26(6): 1134-1148 (June 1999) are available commercially.
[0084] In a preferred example, capillary heteroduplex analysis may be used to detect the presence of mutations based on mobility shift of duplex nucleic acids in capillary systems as a result of the presence of mismatches.
[0085] Generation of nucleic acids for analysis from samples generally requires nucleic acid amplification. Many amplification methods rely on an enzymatic chain reaction (such as a polymerase chain reaction, a ligase chain reaction, or a self-sustained sequence replication) or from the replication of all or part of the vector into which it has been cloned. Preferably, the amplification according. to the invention is an exponential amplification, as exhibited by for example the polymerase chain reaction.
[0086] Many target and signal amplification methods have been described in the literature, for example, general reviews of these methods in Landegren, U., et al., Science 242:229-237 (1988) and Lewis, R., Genetic Engineering News 10:1, 54-55 (1990). These amplification methods can be used in the methods of our invention, and include polymerase chain reaction (PCR), PCR in situ, ligase amplification reaction (LAR), ligase hybridisation, Qbeta bacteriophage replicase, transcription-based amplification system (TAS), genomic amplification with transcript sequencing (GAWTS), nucleic acid sequence-based amplification (NASBA) and in situ hybridisation. Primers suitable for use in various amplification techniques can be prepared according to methods known in the art.
Polymerase Chain Reaction (PCR)
[0087] PCR is a nucleic acid amplification method described inter alia in U.S. Pat. Nos. 4,683,195 and 4,683,202. PCR consists of repeated cycles of DNA polymerase generated primer extension reactions. The target DNA is heat denatured and two oligonucleotides, which bracket the target sequence on opposite strands of the DNA to be amplified, are hybridised. These oligonucleotides become primers for use with DNA polymerase. The DNA is copied by primer extension to make a second copy of both strands. By repeating the cycle of heat denaturation, primer hybridisation and extension, the target DNA can be amplified a million fold or more in about two to four hours. PCR is a molecular biology tool, which must be used in conjunction with a detection technique to determine the results of amplification. An advantage of PCR is that it increases sensitivity by amplifying the amount of target DNA by 1 million to 1 billion fold in approximately 4 hours. PCR can be used to amplify any known nucleic acid in a diagnostic context (Mok et al., (1994), Gynaecologic Oncology, 52: 247-252).
Self-Sustained Sequence Replication (3SR)
[0088] Self-sustained sequence replication (3SR) is a variation of TAS, which involves the isothermal amplification of a nucleic acid template via sequential rounds of reverse transcriptase (RT), polymerase and nuclease activities that are mediated by an enzyme cocktail and appropriate oligonucleotide primers (Guatelli et al. (1990) Proc. Natl. Acad. Sci. USA 87:1874). Enzymatic degradation of the RNA of the RNA/DNA heteroduplex is used instead of heat denaturation. RNase H and all other enzymes are added to the reaction and all steps occur at the same temperature and without further reagent additions. Following this process, amplifications of 10 6 to 10 9 have been achieved in one hour at 42° C.
Ligation Amplification (LAR/LAS)
[0089] Ligation amplification reaction or ligation amplification system uses DNA ligase and four oligonucleotides, two per target strand. This technique is described by Wu, D. Y. and Wallace, R. B. (1989) Genomics 4:560. The oligonucleotides hybridise to adjacent sequences on the target DNA and are joined by the ligase. The reaction is heat denatured and the cycle repeated.
Qβ Replicase
[0090] In this technique, RNA replicase for the bacteriophage Qβ, which replicates single-stranded RNA, is used to amplify the target DNA, as described by Lizardi et al. (1988) Bio/Technology 6:1197. First, the target DNA is hybridised to a primer including a T7 promoter and a Qβ 5′ sequence region. Using this primer, reverse transcriptase generates a cDNA connecting the primer to its 5′ end in the process. These two steps are similar to the TAS protocol. The resulting heteroduplex is heat denatured. Next, a second primer containing a Qβ 3′ sequence region is used to initiate a second round of cDNA synthesis. This results in a double stranded DNA containing both 5′ and 3′ ends of the Qβ bacteriophage as well as an active T7 RNA polymerase binding site. T7 RNA polymerase then transcribes the double-stranded DNA into new RNA, which mimics the Qβ. After extensive washing to remove any unhybridised probe, the new RNA is eluted from the target and replicated by Qβ replicase. The latter reaction creates 10 7 fold amplification in approximately 20 minutes.
[0091] Alternative amplification technology can be exploited in the present invention. For example, rolling circle amplification (Lizardi et al., (1998) Nat Genet 19:225) is an amplification technology available commercially (RCAT™) which is driven by DNA polymerase and can replicate circular oligonucleotide probes with either linear or geometric kinetics under isothermal conditions.
[0092] In the presence of two suitably designed primers, a geometric amplification occurs via DNA strand displacement and hyperbranching to generate 10 12 or more copies of each circle in 1 hour.
[0093] If a single primer is used, RCAT generates in a few minutes a linear chain of thousands of tandemly linked DNA copies of a target covalently linked to that target.
[0094] A further technique, strand displacement amplification (SDA; Walker et al., (1992) PNAS (USA) 80:392) begins with a specifically defined sequence unique to a specific target. But unlike other techniques which rely on thermal cycling, SDA is an isothermal process that utilises a series of primers, DNA polymerase and a restriction enzyme to exponentially amplify the unique nucleic acid sequence.
[0095] SDA comprises both a target generation phase and an exponential amplification phase.
[0096] In target generation, double-stranded DNA is heat denatured creating two single-stranded copies. A series of specially manufactured primers combine with DNA polymerase (amplification primers for copying the base sequence and bumper primers for displacing the newly created strands) to form altered targets capable of exponential amplification.
[0097] The exponential amplification process begins with altered targets (single-stranded partial DNA strands with restricted enzyme recognition sites) from the target generation phase.
[0098] An amplification primer is bound to each strand at its complementary DNA sequence. DNA polymerase then uses the primer to identify a location to extend the primer from its 3′ end, using the altered target as a template for adding individual nucleotides. The extended primer thus forms a double-stranded DNA segment containing a complete restriction enzyme recognition site at each end.
[0099] A restriction enzyme is then bound to the double stranded DNA segment at its recognition site. The restriction enzyme dissociates from the recognition site after having cleaved only one strand of the double-sided segment, forming a nick. DNA polymerase recognises the nick and extends the strand from the site, displacing the previously created strand. The recognition site is thus repeatedly nicked and restored by the restriction enzyme and DNA polymerase with continuous displacement of DNA strands containing the target segment.
[0100] Each displaced strand is then available to anneal with amplification primers as above. The process continues with repeated nicking, extension and displacement of new DNA strands, resulting in exponential amplification of the original DNA target.
[0101] Once the nucleic acid has been amplified, a number of techniques are available for detection of single base pair mutations. One such technique is Single Stranded Conformational Polymorphism (SSCP). SCCP detection is based on the aberrant migration of single stranded mutated DNA compared to reference DNA during electrophoresis. Mutation produces conformational change in single stranded DNA, resulting in mobility shift. Fluorescent SCCP uses fluorescent-labelled primers to aid detection. Reference and mutant DNA are thus amplified using fluorescent labelled primers. The amplified DNA is denatured and snap-cooled to produce single stranded DNA molecules, which are examined by non-denaturing gel electrophoresis.
[0102] Chemical mismatch cleavage (CMC) is based on the recognition and cleavage of DNA mismatched base pairs by a combination of hydroxylamine, osmium tetroxide and piperidine. Thus, both reference DNA and mutant DNA are amplified with fluorescent labelled primers. The amplicons are hybridised and then subjected to cleavage using Osmium tetroxide, which binds to an mismatched T base, or Hydroxylamine, which binds to mismatched C base, followed by Piperidine which cleaves at the site of a modified base. Cleaved fragments are then detected by electrophoresis.
[0103] Techniques based on restriction fragment polymorphisms (RFLPs) can also be used. Although many single nucleotide polymorphisms (SNPs) do not permit conventional RFLP analysis, primer-induced restriction analysis PCR (PIRA-PCR) can be used to introduce restriction sites using PCR primers in a SNP-dependent manner. Primers for PIRA-PCR which introduce suitable restriction sites can be designed by computational analysis, for example as described in Xiaiyi et al., (2001) Bioinformatics 17:838-839.
[0104] Furthermore, techniques based on WAVE analysis can be used (Methods Mol. Med. 2004; 108:173-88). This system of DNA fragment analysis can be used to detect single nucleotide polymorphisms and is based on temperature-modulated liquid chromatography and a high-resolution matrix (Genet Test. 1997-98; 1(3):201-6.)
[0105] Real-time PCR (also known as Quantitative PCR, Real-time Quantitative PCR, or RTQ-PCR) is a method of simultaneous DNA quantification and amplification (Expert Rev. Mol. Diagn. 2005(2):209-19). DNA is specifically amplified by polymerase chain reaction. After each round of amplification, the DNA is quantified. Common methods of quantification include the use of fluorescent dyes that intercalate with double-strand DNA and modified DNA oligonucleotides (called probes) that fluoresce when hybridised with a complementary DNA.
[0106] Specific primers known as ‘Scorpion® primers’ can be used for a highly sensitive and rapid DNA amplification system. Such primers combine a probe with a specific target sequence in a single molecule, resulting in a fluorescent detection system with unimolecular kinetics (Nucl. Acids Res. 2000; 28:3752-3761). This has an advantage over other fluorescent probe systems such as Molecular Beacons and TaqMan®, in that no separate probe is required to bind to the amplified target, making detection both faster and more efficient. A direct comparison of the three detection methods (Nucl. Acids Res 2000; 28:3752-3761) indicates that Scorpions® perform better than intermolecular probing systems, particularly under rapid cycling conditions. The structure of one version of a Scorpion® primer is such that it is held in a hairpin loop conformation by complementary stem sequences of around six bases which flank a probe sequence specific for the target of interest (Nat. Biotechnol. 1999; 17:804-807). The stem also serves to position together a fluorescent reporter dye (attached to the 5′-end) in close proximity with a quencher molecule. In this conformation, no signal is produced. A PCR-blocker separates the hairpin loop from the primer sequence, which forms the 3′-end of the Scorpion®. The blocker prevents read-through, which would lead to unfolding of the hairpin loop in the absence of a specific target. During PCR, extension occurs as usual from the primer. After the subsequent denaturation and annealing steps, the hairpin loop unfolds and, if the correct product has been amplified, the probe sequence binds to the specific target sequence downstream of the primer on the newly synthesised strand. This new structure is thermodynamically more stable than the original hairpin loop. A fluorescent signal is now generated, since the fluorescent dye is no longer in close proximity to the quencher. The fluorescent signal is directly proportional to the amount of target DNA.
[0107] An alternative Scorpion® primer comprises a duplex of two complementary labelled oligonucleotides. One oligonucleotide of the duplex is labelled with a 5′ end reporter dye and carries both the blocker non-coding nucleotide and PCR primer elements, while the other oligonucleotide is labelled with a 3′ end quencher dye. The mechanism of action is then essentially the same as the Scorpion® hairpin primer described above: during real-time quantitative PCR, the 5′ end reporter and 3′ end quencher dyes are separated from each other leading to a significant increase in fluorescence emission.
[0108] Scorpions® can be used in combination with the Amplification Refractory Mutation System (ARMS) (Nucl. Acids Res. 1989; 17:2503-2516, Nat. Biotechnol. 1999; 17:804-807) to enable single base mutations to be detected. Under the appropriate PCR conditions a single base mismatch located at the 3′-end of the primer is sufficient for preferential amplification of the perfectly matched allele (Newton et al., 1989), allowing the discrimination of closely related species. The basis of an amplification system using the primers described above is that oligonucleotides with a mismatched 3′-residue will not function as primers in the PCR under appropriate conditions. This amplification system allows genotyping solely by inspection of reaction mixtures after agarose gel electrophoresis. It is simple and reliable and will clearly distinguish heterozygotes at a locus from homozygotes for either allele. ARMS does not require restriction enzyme digestion, allele-specific oligonucleotides as conventionally applied, or the sequence analysis of PCR products.
EXAMPLE 1
Clinical Trials and Collection of Blood Serum Samples
[0109] The present study was carried out as a correlative study in a multicenter clinical phase II trial for gefitinib monotherapy. The study was conducted with the approval of the appropriate ethical review boards based on the recommendations of the Declaration of Helsinki for biomedical research involving human subjects. Japanese patients with stage IIIB or IV histologically or cytologically proven chemotherapy-naïve NSCLC were enrolled in this trial. Gefitinib was orally administrated to all patients at a fixed dosage of 250 mg daily. Efficacy was assessed using the “Response Evaluation Criteria in Solid Tumours (RECIST)” guidelines (J. Natl. Cancer Inst. 2000; 92:205-216).
[0110] Twenty-eight patients were enrolled between Oct. 23, 2002, to Aug. 3, 2003 (Table 1). All patients were evaluated for response and followed for progression free survival and overall survival. Blood samples (2 ml) from 27 patients were collected before the initiation of gefitinib administration. Serum DNA was extracted in all 27 samples at concentrations of up to 1720 ng/ml.
[0111] Sample collection and DNA extraction. Blood samples from the 26 NSCLC patients were collected before the initiation of gefitinib administration. Separated serum was stocked at −80° C. until use. Serum DNA was extracted and purified using Qiamp Blood Kit (Qiagen, Hilden, Germany), with the following protocol modifications. One column was used repeatedly until the whole sample had been processed. The resulting DNA was eluted in 50 μl of sterile bidistilled buffer. The concentration and purity of the extracted DNA were determined by spectrophotometry. The extracted DNA was stocked at −20° C. until use.
EXAMPLE 2
Use of Scorpion Primers and the Amplification Refractory Mutation System (ARMS) to Detect E746 A750 del and L858R EGFR Mutations
Sensitivities of EGFR Scorpion® Kit
[0112] Preliminary experiments are performed to evaluate the sensitivities of EGFR Scorpion Kit ( FIG. 1 ). All curves using E746_A750del standard DNA at a volume from 1 pg to 10,000 pg were increased by reaching up to 45 cycles ( FIG. 1 a ). When wild standard DNA and water were used as negative controls, the curves were not increased and continued flat at reaching to 50 cycles ( FIG. 1 a ). Using diluted E746_A750del standard DNA with wild standard DNA at ratio from 10 0 to 10 −5 , all curves which indicated the presence of E746_A750del were increased by reaching up to 45 cycles ( FIG. 1 b ). Standard curves in the range of measured volumes in this study were linear with r 2 values of 0.997 and 0.987. Both slopes of curves were almost parallel ( FIG. 1 c ). Ct of diluted E746_A750del standard DNA with wild DNA was close to that of only E746_A750del standard DNA in every volume of E746_A750del standard DNA. Although peak fluorescence level of diluted E746_A750del standard DNA with wild DNA was lower than without wild DNA standard at ratio less than 10 −3 , the presence of E746_A750del were clearly detected. The curves of DNA with E746_A750del at an amount of up to 1 pg were unaffected by interfusion of DNA of wild type EGFR. In the cell based experiments using genomic DNA of human cancer cell lines, the signal using DNA derived from the PC-9 cells was detected and that from the A431 cells was not detected as expected ( FIG. 2 ).
[0113] We used EGFR Scorpion™ Kit (DxS Ltd, Manchester, UK) which combined two technologies, namely ARMS™ and Scorpion™, to detect mutations in real time PCR reactions. Four kinds of scorpion primers for detections of E746_A750del, L858R and wild type in both exon 19 and exon 21 were designed and synthesized by DxS Ltd (Manchester, UK). The sequences of the scorpion primer for E746_A750 del and L858R were based on the GenBank-archived human sequence for EGFR (accession number: AY588246). All reactions were performed in 25 μl volumes using 1 μl of template DNA, 7.5 μl of Reaction buffer mix, 0.6 ml of Primer mix and 0.1 ml of Taq polymerase. All regents are included in this kit. Real time PCR were carried out using SmartCycler® II (Cepheid, Sunnyvale, Calif.) in the following conditions which were initial denaturation at 95° C. for 10 minutes, 50 cycles of 95° C. for 30 seconds, 62° C. for 60 seconds with fluorescence reading (set to FAM that allows optical excitation at 480 nm and measurement at 520 nm) at the end of each cycle. Data analysis was performed with Cepheid SmartCycler software (Ver. 1.2b). The threshold cycle (Ct) was defined as the cycle at the highest peak of the 2nd derivative curve, which represented the point of maximum curvature of the growth curve. Both Ct and maximum fluorescence (Fl) were used for interpretation of the results. Positive results were defined as follows: Ct≦45 and Fl≧50. These analyses were performed in duplicate for each sample. To confirm the sensitivities for the detection of E746_A750del, we used the standard DNA which was included in EGFR Scorpion Kit. Standard DNA with E746_A750del at a volume of 1, 10, 100, 1,000 or 10,000 pg, and the mixture of standard DNA with wild type at 10,000 pg and standard DNA with E746_A750del at a volume of 1, 10, 100, 1,000 or 10,000 pg were used. For quantification, a standard curve was generated by plotting the cycle number of Ct against the log of the DNA volume of the known standards. The linear correlation coefficient (R 2 ) values and the formula of the slopes were calculated. DNA for the positive control were extracted from a Japanese human adenocarcinoma PC-9 cell line known to contain E746_A750del and a human epidermoid carcinoma A431 cell line known to contain a wild type in exon 19 and 10,000 pg of their DNA were used.
EGFR Mutation Status of Serum DNA Detected by ARMS
[0114] E746_A750del or L858R of serum DNA derived from twenty-seven NSCLC patients was examined. Wild type in both exon 19 and exon 21 were detected from all serum samples. E746_A750del was detected in samples of 12 patients. L858R was detected in one patient (Table 2). Totally, EGFR mutations were detected in 13 out of 27 (48.1%) patients. The histological subtypes of original tumours were summarised in Table 3a in the 23 patients with the EGFR mutation in serum. The 11 out of 23 (47.8%) cases of adenocarcinoma, 1 out of 2 cases of squamous cell carcinoma, and 1 out of 2 cases of large cell carcinoma were positive for EGFR mutations. EGFR mutation status was not correlated statistically with histogocal type. EGFR mutation was more frequently detected in the samples derived from women patients than those of men (7 of 10; 70% vs 6 of 17; 29.4%, Table 3b).
[0000] EGFR Mutation Status in Serum and Response to gefitinib
[0115] The EGFR mutation was significantly more frequently observed in the samples from the patients who showed a partial response (PR) or stable disease (SD) (11 out of 17 cases, 75%) than in samples from patients with progressive disease (PD, 2 out of 10 cases, 18%) (p=0.046, Fisher's exact test, Table 3c).
EXAMPLE 3
EGFR Mutation Status in Serum and Impact on Survival
[0116] Statistical analysis. Fisher's exact test was used to compare the presence of EGFR mutations in NSCLC patients with different characteristics, including gender, tumour type and response to gefitinib. Regarding analyses of response to gefitinib, patients were categorised into two groups of partial response or stable disease (PR/SD) and progressive disease (PD) depending on the RECIST criteria. We compared Kaplan-Meier curves for overall survival and progression-free survival using the standard log-rank test. Overall survival (OS) was defined as the time from the initiation of gefitinib administration to death from any cause; patients known to be still alive at the time of the analysis were censored at the time of their last follow-up. Progression-free survival (PFS) was defined as the time from the initiation of gefitinib administration to first appearance of progressive disease or death from any cause; patients known to be alive and without progressive disease at the time of analysis were censored at the time of their last follow-up. A P value of 0.05 was considered to be statistically significant. The statistical analyses were performed using the Stat View software package, version 5.0.
[0117] Median PFS of all of the patients treated with gefitinib was 98 days and median OS was 306 days. The patients with EGFR mutations in serum showed significantly longer median PFS compared with the patients without EGFR mutations (200 days v 46 days, P=0.005, FIG. 3 a ). The patients with EGFR mutations showed longer median OS compared with the patients without EGFR mutations, although there was no statistical significance (611 days v 232 days, P=0.078, FIG. 3 b ). These results suggest that serum EGFR mutation behaves as an prognostic factor for progression free survival and overall survival as well as a predictor of response in the patients treated with gefitinib.
EXAMPLE 4
EGFR Mutation in Serum Analysed by Direct Sequence and in Comparison with ARMS
[0118] The deletional mutation (E746_A750del) was detected by direct sequence in serum DNA extracted from 10 out of 27 patients (37.0%).
[0119] PCR amplification and direct sequencing. Amplification and direct sequencing were performed in duplicate for each sample obtained from serum and tissue specimen. PCR was performed in 25 μl volumes using 15 μl of template DNA, 0.75 units of Ampli Taq Gold DNA polymerase (Perkin-Elmer, Roche Molecular Systems, Inc., Branchburg, N.J.), 2.5 μl of PCR buffer, 0.8 mM dNTP, 0.5 μM of each primer, and different concentrations of MgCl 2 , depending on the polymorphic marker. The sequences of primer sets and schedules of amplifications were followed as described previously (Nuc. Acids Res. 1989; 17:2503-2516). The amplification was performed using a thermal cycler (Perkin-Elmer, Foster City, Calif.). Sequencing were performed using an ABI prism 310 (Applied Biosystems, Foster City, Calif.). The sequences were compared with the GenBank-archived human sequence for EGFR (accession number: AY588246).
[0120] No point mutation in exons 18, 19, 20 and 21 was detected in the PCR products from serum samples. The serum EGFR status detected by direct sequence was not correlated statistically with neither the histological type, the gender, the responsiveness of gefitinib (Table 3), and the survival benefit (PFS: P=0.277, OS: P=0.859, suppl data 2). The EGFR mutation status by direct sequence was consistent with those by ARMS in 15/27 (55.6%) of the paired samples. EGFR mutations (E746_A750del) in four cases were positive by direct sequence and negative by ARMS. Eight cases were negative by direct sequence and positive by ARMS.
EXAMPLE 5
EGFR Mutations in Tumours in Comparison with Those in Serum
[0121] Twenty tumour samples were obtained from the 15 patients retrospectively.
[0122] Tissue sample collection and DNA extraction. Tumour specimens were obtained on protocols approved by the Institutional Review Board. Twenty paraffin blocks of tumour material, obtained from 15 patients for diagnoses before treatment, were collected retrospectively. 11 tumour samples were collected from primary cancer via trans bronchial lung biopsy, 1 was resected by operation, 9 were from metastatic sites (4 from bone, 3 lymph nod, 1 brain and 1 colon). All specimens underwent histological examination to confirm the diagnosis of NSCLC. DNA extraction from tumour samples was performed using DEXPAT™ kit (TaKaRa Biomedicals, Shiga, Japan).
[0123] Sequencing of exons 19 and 21 in EGFR were performed under the same PCR conditions. The tumour samples from 12 patients were sequenced (Table 4). EGFR mutations were detected in 4 cases (25.0%); Three of them were 15 bp deletion (E746_A750del) in exon 19 and one case was L858R in exon 21. Histological type of patients with EGFR mutations were adenocarcinoma in 3 and large cell carcinoma in 1. The responses to gefitinib in these four patients were PR in 2, SD in 1, and PD in 1 patient. Other three samples were not evaluated because of low amplification of PCR products.
[0124] Pairs of tumour samples and serum samples were obtained from 11 patients retrospectively (Table 4). The EGFR mutation status in the tumours was consistent with those in serum of 8/11 (72.7%) in the paired samples. The E746_A750del was positive in the tumour and negative in the serum in two patients, and the E746_A750del was negative in the tumour and positive in the serum in a patient.
[0000]
TABLE 1
Patient characteristics
(n)
No. of. Patients
28
Age (years)
Median
64
Range
44-87
Sex
Male
18
Female
10
PS
0
19
1
7
2
2
Stage
IIIB
3
IV
25
Histology
Ad
23
Scc
2
Large
2
Response
PR
9
SD
8
PD
11
PS, performance status; Ad, adenocarcinoma; Scc, squamous cell carcinoma; Large, large cell carcinoma; PR, partial response; SD, stable disease; PD, progressive disease.
[0000]
TABLE 2
Patients' Characteristics and EGFR Mutant Status Detected
from Serum DNA Using EGFR ARMS-Scorpion Method
Exon 19
Exon 21
Response
Gender
Histology
Wild
E746_A750deI
Wild
L858R
PR
M
Ad
+
−
+
+
PR
F
Ad
+
+
+
−
PR
M
Ad
+
−
+
−
PR
F
Ad
+
+
+
−
PR
M
Ad
+
+
+
−
PR
F
Ad
+
−
+
−
PR
M
Ad
+
+
+
−
PR
F
Ad
+
+
+
−
PR
F
Ad
+
+
+
−
SD
M
Large
+
−
+
−
SD
F
Ad
+
+
+
−
SD
M
Ad
+
−
+
−
SD
F
Ad
+
−
+
−
SD
F
Ad
+
+
+
−
SD
M
Ad
+
−
+
−
SD
F
Ad
+
+
+
−
SD
M
SCC
+
+
+
−
PD
F
Scc
+
−
+
−
PD
M
Ad
+
−
+
−
PD
M
Ad
+
−
+
−
PD
M
Large
+
+
+
−
PD
M
Ad
+
−
+
−
PD
M
Ad
+
−
+
−
PD
M
Ad
+
−
+
−
PD
M
Ad
+
−
+
−
PD
M
Ad
+
+
+
−
PD
M
Ad
+
−
+
−
SD, stable disease; PD, progressive disease; PR, partial response; M, male; F, female; Ad, adenocarcinoma; Large, large cell carcinoma; Scc, squamous cell carcinoma; +, Curve detected by SmartCycler; −, Curve not detected by SmartCycler;
[0000]
TABLE 3
Frequency of EGFR mutations in serum DNA from lung
cancer patients according to histology (a), gender
(b), and response to gefitinib (c). Total 27 samples
were obtained from 28 patients before treatment.
EGFR Scorpion Kit
Direct sequence
+
−
+
−
a Histology and EGFR Mutant States
Ad
11
12
8
15
Non Ad
2
2
P > 0.999
2
2
P > 0.999
b Gender and EGFR Mutant States
Female
7
3
5
5
Male
6
11
P = 0.120
5
12
P = 0.415
c Response to gefitinib and EGFR Mutant States
PR/SD
11
6
8
9
PD
2
8
P = 0.046
2
8
P = 0.231
Ad, adenocarcinoma PR, partial response; SD, stable disease; PD, progressive disease;
[0000]
TABLE 4
EGFR mutation status in tumour samples and serum samples. Pairs of both
tumour samples and serum samples were obtained from 12 patients.
EGFR mutation status
EGFR Scorpion Kit
Exon 19
Exon 21
Gender
Histology
Response
Tumour sample
Wild
Mutation
Wild
Mutation
M
Large
SD
Wild
+
−
+
−
F
SCC
PD
Wild
+
−
+
−
M
Adeno
PD
Wild
+
−
+
−
M
Adeno
PR
L858R
+
−
+
+
F
Adeno
SD
Wild *
+
+
+
−
M
Large
PD
E746-A750 del
+
+
+
−
M
Adeno
PD
Wild
+
−
+
−
M
Adeno
PD
Wild
+
−
+
−
M
Adeno
SD
E746-A750 del *
+
−
+
−
F
Adeno
PR
E746-A750 del *
+
−
+
−
M
Adeno
PD
Wild
+
−
+
−
M, male; F, female; SD, stable disease; PD, progressive disease; PR, partial response; Scc, squamous cell carcinoma; Ad, adenocarcinoma; Large, large cell carcinoma
* patients who have different states of EGFR mutation from tumour-derived DNA and serum- derived DNA.
[0000]
TABLE 5
Position
Wild type
Mutant
Protein
688
L
P
694
P
L/S
709
E
K
709
E
V
715
I
S
720
S
F
718
L
P
719
G
S/C/A/D
724
G
S
730
L
F
733
P
L
735
G
S
742
V
A
delE746_A750
delE746_S752V
delE746_P753insLS
delL747_A750insP
delL747_T751insP
746
E
K
del750_754
751
T
I
752
S
Y
755
A
P
del756_758
761
D
N
768
S
I
769
V
L
770
D
N
772
H
L
772
P
S
773
V
M
776
R
C
778
G
F
781
C
R
783
T
I
784
S
F
790
T
M
792
L
P
798
L
F
810
G
S
820
Q
STOP
826
N
S
834
V
M
835
H
Y
836
R
C
847
T
I
850
H
N
851
V
A
853
I
T
857
G
R
858
L
M
858
L
R
859
A
T
861
L
Q
863
G
D
864
A
T/V
866
E
K
873
G
E
877
P
S
880
W
STOP
882
A
T
893
H
Q
895
S
G
897
V
I
958
R
P
Nucleotide
2063
C
T
2080
C
T
2081
C
T
2118
C
T
2125
G
A
2126
A
T
2142
G
A
2144
T
G
2153
T
C
2155
G
T/A/C
2156
G
C/A
2159
C
T
2169
C
T
2170
G
A
2188
C
T
2198
C
T
2203
G
A
2225
T
C
2236
G
A
del2247_2262
2252
C
T
del2268_2275
2281
G
A
2303
T
G
2305
G
C
2308
G
A
2314
C
T
2326
C
T
2340
C
T
2341
T
C
2348
C
T
2351
C
T
2364
C
T
2369
C
T
2375
T
C
2392
C
T
2406
C
T
2428
G
A
2421
C
T
2458
C
T
2477
A
G
2484
G
A
2500
G
A
2502
G
A
2503
C
T
2506
C
T
2508
C
T
2523
G
A
2540
C
T
2548
C
A
2552
T
C
2553
C
T
2563
A
T
2565
G
A
2569
G
A
2570
G
T
2571
G
T
2572
C
A
2575
G
A
2582
T
A
2588
G
A
2588
T
C
2590
G
A
2591
C
T
2596
G
A
2607
C
T
2618
G
A
2629
C
T
2639
G
A
2644
G
A
2676
C
T
2679
C
A
2683
A
G
2689
G
A
2877
A
G | The invention provides a method of detecting ErbB receptor mutations comprising the steps of providing a bio-fluid sample from a patient; extracting DNA from said sample; and screening said DNA for the presence of one or more mutations that alter tyrosine kinase activity in the receptor. | 2 |
BACKGROUND OF THE INVENTION
In general, an integrated circuit (IC) refers to an electrical circuit contained on a single monolithic chip containing active and passive circuit elements. As should be well understood in this art, ICs are fabricated by diffusing and depositing successive layers of various materials in a preselected pattern on a substrate. The materials can include semiconductive materials such as silicon, conductive materials such as metals, and low dielectric materials such as silicon dioxide. The semiconductive materials contained in IC chips are used to form such conventional circuit elements as resistors, capacitors, diodes and transistors.
ICs are used in great quantities in electronic devices such as digital computers because of their small size, low power consumption and high reliability. The complexity of various ICs ranges from simple logic gates and memory units to large arrays capable of complete video, audio and print data processing. As the semiconductor industry strives to meet technological demands for faster and more efficient circuits, IC chips and assemblies are created with reduced dimensions, higher operating speeds and reduced energy requirements. As IC signal speeds increase, timing errors and pulse width deviations within such signals may constitute a greater portion of a signal period that the signal itself.
Timing fluctuations in integrated circuits are generally referred to as “jitter”. Jitter can be broadly defined in certain interpretations as the variation of a signal edge from its ideal position in time, and can be an important performance measure for integrated circuit signals, including serial links and clock signals. For serial link qualification, jitter is decomposed into its various components, which may be divided into three types: random jitter (RJ), data-dependent jitter (DDJ) and periodic jitter (PJ). Each of these components is correlated with physical sources and impact bit error rate (BER) differently. Random jitter is typically due to device noise sources, e.g., thermal and flicker noise, and is assumed to be unbounded with Gaussian distribution. The combination of DDJ and PJ are bounded and can be traced back to deterministic sources such as transmission path bandwidth limitations and cross-coupling.
The continued demand for GHz processors and high-capacity communications system has resulted in an increasing number of low-cost high volume ICs clocked at GHz rates and beyond and/or equipped with multi-Gb/s serial interfaces. Circuits achieving such clock and/or data rates are characterized by very stringent timing specifications, often dictated by governing standards. Many of these standards specify maximum limits on jitter components for the transmitter (jitter generation) and minimum tolerable limits for the receiver (jitter tolerance). One major purpose of specifying limits on jitter components is to provide faster ways to estimate BER and to provide a better interoperability measure when the devices are used in a system environment.
Qualifying a transmitter requires measurement of transmitter jitter components, while receiver testing necessitates generation of data streams with controlled amounts of RJ, DDJ and PJ. As such, the need exists for features and steps to both generate jitter for receiver testing and to measure jitter for transmitter testing.
SUMMARY OF THE INVENTION
The present subject matter provides a system and method for generation of signals with controlled timing variations (i.e., signal jitter). One type of signal jitter that is injected into such test signals in accordance with embodiments of the present invention is data-dependent signal jitter. Other types that may be incorporated include periodic jitter and random jitter.
It is an object of the present subject matter to provide techniques for the signal injection of deterministic jitter in a controlled and programmable fashion. It is also desired in some embodiments of the present technology to provide steps and features for random jitter injection having programmable RMS values without causing a substantial amount of amplitude noise. Features for providing both large amplitude (multiple UI) low frequency and low amplitude high frequency periodic jitter injection may also be included in some exemplary embodiments.
It is another object of certain embodiments of the present invention to provide DDJ signal generation technology that eliminates a need for bulky and difficult-to-control DDJ injection filters. An example of a prior art system employing a DDJ injection filter is presented later. This may be done in some embodiments by replacing tunable filters with a programmable arbitrary waveform generator (AWG), which significantly enhances DDJ injection control and flexibility. Varied exemplary embodiments of a system and method for generating test signals with injected jitter are hereafter presented.
In one exemplary embodiment of the present invention, a system for generating a test signal with controllable amounts of signal jitter includes at least three signal generators. A first signal generator (e.g., a pattern generator) is configured to generate a data signal characterized by a given data pattern having a preselected bit rate and pattern length and that is periodically repeated at a first frequency. The first signal generator also generates a trigger signal having a known relationship with the data pattern that is then coupled to the second signal generator. The second signal generator (e.g., an arbitrary waveform generator (AWG)) generates a periodic modulation signal having a main harmonic frequency that is substantially equal to the bit rate of the data signal generated by the first signal generator divided by the pattern length of the data signal. The third signal generator (e.g., a phase modulator or a pulse generator with a controllable delay line input) receives the modulation signal from the second signal generator and generates a clock signal that is phase modulated based on the timing of the modulation signal. Such phase modulation may be effected by phase modulation means such as a controllable delay line within the pulse generator. The clock signal is then provided as an input to the first signal generator to adjust the timing of the data signal.
In more particular embodiments of the aforementioned signal generation system, a reference clock generator may be provided and coupled to selected of the signal generators to ensure synchronized operation among various elements of the system. Fourth and/or fifth signal generators may also be provided for generating signals for combining with the modulation signal generated by the second signal generator before such modulation signal is provided as input for the third signal generator. A fourth signal generator may correspond to a random Gaussian noise generator to simulate the effects of random jitter, and a fifth signal generator may provide a signal representative of periodic signal jitter.
Yet another embodiment of the presently disclosed technology concerns a method of generating a test signal with controllable amounts of signal jitter. Such a method includes steps of establishing a data pattern, bit rate and pattern length for a data signal. A modulation signal is then generated having a repetition frequency that is substantially equal to the bit rate divided by the pattern length established for the data signal. Subsequent steps correspond to modulating the phase of a clock signal by the modulation signal and generating a data signal with the data pattern and pattern length provided in the establishing step and with a bit rate defined by the modulated clock signal from the modulating step.
In other related embodiments, a trigger signal representative of selected data signal characteristics (e.g., bit rate, pattern length, frequency) may be provided to a signal generator that subsequently performs the generation of the modulation signal. Another step of ensuring the phase consistency of the generated modulation and data signals may also be implemented.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate one or more embodiments of the present subject matter, and together with the description serve to explain certain principles of the disclosed technology. Additional embodiments of the present subject matter may incorporate various steps or features of the above-referenced embodiments, and the scope of the presently disclosed technology should in no way be limited to any particular embodiment. Additional objects, features and aspects of the present subject matter and corresponding embodiments are discussed in greater detail below.
BRIEF DESCRIPTION OF THE DRAWINGS
A full and enabling disclosure of the present subject matter, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended drawings, in which:
FIG. 1 provides a schematic diagram representation of exemplary hardware components of a known test setup used for generation of test signals with injected random, periodic, and data-dependent jitter;
FIG. 2 . provides a graphical illustration of an exemplary signal generated with the known test setup of FIG. 1 , specifically depicting extra signal edges due to excessive amplitude noise;
FIG. 3 provides a schematic diagram representation of exemplary hardware components of a test setup in accordance with one embodiment of the present invention, specifically utilized for generation of test signals with injected random, periodic, and data-dependent jitter;
FIG. 4 provides a graphical illustration of exemplary signals depicting aspects of the DDJ injection technology employed in the test setup of FIG. 3 ;
FIG. 5 provides respective graphical representations of RMS random jitter measurements on a logarithmic scale versus the noise generator attenuation in decibels taken using different time measurement devices in accordance with the present invention;
FIG. 6 provides a graphical representation of random jitter (RJ) levels versus data-dependent jitter (DDJ) levels for a specific exemplary test setup in accordance with the present invention, specifically exemplifying the RJ insensitivity to DDJ;
FIG. 7 provides a graphical representation of random jitter (RJ) levels versus injected peak-to-peak periodic jitter (PJ) levels for a specific exemplary test setup in accordance with the present invention;
FIG. 8 provides a graphical representation of measured data-dependent jitter (DDJ) versus the voltage amplitude of an arbitrary waveform generator (AWG) for a specific exemplary test setup in accordance with the present invention; and
FIG. 9 provides a graphical representation of measured data-dependent jitter (DDJ) versus injected levels of periodic jitter (PJ) for a specific exemplary test setup in accordance with the present invention.
Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the present subject matter.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
Reference will now be made in detail to presently preferred embodiments of the disclosed technology, one or more examples of which are illustrated in the accompanying drawings. Each example is provided by way of explanation of the present technology, not limitation of the present technology. In fact, it will be apparent to those skilled in that art that modifications and variations can be made in the present technology without departing from the spirit and scope thereof. For instance, features illustrated or described as part of one embodiment may be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present subject matter covers such modifications and variations as come within the scope of the appended claims and their equivalents.
Referring now to the drawings, FIG. 1 shows a known exemplary test setup used for jitter injection in some prior art applications. An RF generator 10 coupled to a function generator 12 is used as a stable clock source. The output of a noise generator 14 is superimposed on the clock signal via combiner 16 to add random jitter. DDJ filter 18 is embodied by such exemplary components as a low-pass multiple-pole filter or a long cable, or other component that provides an effective source of DDJ. The FM or PM modulation capability of RF generator 10 acts as a sinusoidal jitter source. The exemplary setup of FIG. 1 , although sufficient for some applications, lacks flexibility for use in multiple applications (requiring different bit rates and data patterns) because of several issues.
A first reason that the exemplary test setup of FIG. 1 lacks flexibility for use in multiple applications relates to the observation that superimposition of random noise with an RF signal works well as a source of RJ only for small RJ injection (typically 0.02 UI) where UI corresponds to a unit interval or average bit rate for a given signal). As the noise level is increased to generate larger RJ, the possibility of encountering spurious edges that would cause false edges away from the bit transition increases due to amplitude noise. Even some known limiting amplifiers may not eliminate such sharp glitches. As shown in FIG. 2 , when RJ is injected in signal 20 at location 22 , false edges (such as edge 24 ) due to excessive noise amplitude violate phase modulation conditions, which affect jitter measurement accuracy with varying degrees depending on the measurement method used. In addition, the amount of injected jitter depends on the RF or pulse generator effective rise/fall time, which necessitates time-consuming calibration when testing different bit rates or test conditions.
A second limitation of the exemplary test setup of FIG. 1 results since the use of filters or long cables typically is limited to specific bit rates for a given amount of DDJ. Cables and filters have to be adjusted and calibrated for different bit rates specified for each I/O standard. Furthermore, most RF generators are capable of low to medium frequency FM or PM modulation (typically less than 10 MHz). However, in serial communication links, often the real PJ components that require testing are due to coupling clock sources in the range of 20 MHz to 400 MHz.
Due to the aforementioned limitations of the known exemplary test setup of FIG. 1 , an improved system and method for providing jitter injection is presented in accordance with the subject invention. More particularly, exemplary jitter injection technology based on wide band phase modulation (e.g., controllable delay line) or direct timing synthesis is presented in accordance with embodiments of the present invention. Such technology provides RJ injection having programmable RMS values without causing amplitude noise. Such technology further provides a programmable amount of DDJ for any bit-rate and pattern. This technique employs programmable AWGs instead of tunable filters, thus significantly enhancing DDJ injection control and flexibility. Some exemplary embodiments of the present invention are capable of both large amplitude (multiple UI) low frequency and low amplitude high frequency PJ injection.
Referring now to FIG. 3 , an exemplary embodiment of a test setup for providing programmable jitter injection in accordance with the present invention is provided. A clock source 26 , for example an RF generator, is used for low jitter bit clock generation. A first signal or function generator 27 is provided to modulate the clock source 26 . Subsequently, a phase modulator 28 modulates the bit clock for jitter injection. An example of a phase modulator 28 corresponds to a controllable delay line within a pulse/pattern generator, such as an Agilent 81133 pattern generator. The resulting “jittery” clock signal output by phase modulator 28 drives a pattern generator 30 to provide a high-speed data signal with repeating pattern and controlled jitter. An example of a pattern generator corresponds to an Advantest D3186 pattern generator. RJ is simulated by the output of a Gaussian noise generator 32 , such as a NoiseCom PNG7109 noise generator. The output of noise generator 32 is Gaussian noise with 1 GHz bandwidth, which emulates high bandwidth Gaussian random jitter as is specified in many standards. Periodic jitter is simulated by the output of an additional signal/function generator 34 , such as an Agilent 8648A device. Signal generator 34 acts as the PJ source, with capability to inject up to 500 ps peak-to-peak periodic jitter. Finally, DDJ is generated by an arbitrary waveform generator (AWG) 36 , such as a Tektronix AWG610. Special calibration may be required if there is any delay between the pattern trigger signal and the first edge of the pattern, and/or if there is any non-linearity or bandwidth limitations in the phase modulator (e.g., delay line). Calibration may be performed by measuring injected DDJ with a DDJ measurement device (e.g., an oscilloscope or TIA/CTIA) on a per-edge basis and computing the difference relative to expected per-edge DDJ. This difference can be added to the pre-programmed level in the AWG 36 .
The above jitter generation devices provide signals that are combined via combiner 38 before being provided to the delay control input of phase modulator 28 to inject jitter in the clock source. A reference clock 40 , for example one configured for operation at 10 MHz or other predetermined frequency, may also be employed as a clock reference for selected other components in the exemplary test setup of FIG. 3 .
The exemplary test setup illustrated in FIG. 3 provides two jitter injection mechanisms. The first is the PM and/or FM modulation capability of the clock source 26 . This is primarily used to inject low frequency PJ with multiple unit interval (UI) variation(s) to test receiver tolerance to PJ up to a few MHz range. The second mechanism uses a delay line modulation approach, which effectively provides high bandwidth phase modulation. The exemplary phase modulator 28 includes such a delay control. The exemplary test setup of FIG. 3 employed with an Agilent 81133 pulse generator 28 can be used for a bit error rate test if peak-to-peak jitter at a BER=10-12 is less than 500 ps because the Agilent 81133 can accommodate only ±250 ps jitter modulation. For total jitter more than 500 ps, delay lines with a wider modulation range may need to be utilized.
A significant aspect of the test setup of FIG. 3 concerns the AWG 36 , which is used as a DDJ source for data signals with a repeated pattern. In accordance with embodiments of the present invention, the output of AWG 36 is set such that its frequency is equal to the data bit rate of the signal generated by pattern generator 30 divided by the pattern length in bits. For example, referring now to FIG. 4 , assume that the pattern generator 30 of FIG. 3 is configured to output a data signal 42 represented by the solid lines in the first waveform of FIG. 4 . Data signal 42 consists of a given data pattern having ten rising and falling edges that is repeated at periodic intervals. It should be appreciated that a variety of data patterns and bit lengths may be utilized by pattern generator 30 in accordance with various embodiments of the present invention, and the specific values may be programmed and changed as desired by a user. A trigger signal 44 that corresponds to the initial iming of the data pattern in data signal 42 is provided as an output from pattern generator 30 to the input of AWG 36 . Referring still to the example of FIG. 4 , the output of AWG 36 is then the DDJ modulation signal 46 , which effectively corresponds to a periodic signal having a frequency that is matched in a substantially exact fashion to the frequency of the pattern repetition rate of data signal 42 . DDJ modulation signal 46 may also contain some high frequency harmonics to ensure more realistic DDJ is injected. This is especially advantageous when testing receivers because of the receiver selective response to different jitter frequency components. A resulting data signal with DDJ, such as would be output on signal line 39 of pattern generator 30 is represented by the dashed line 48 in FIG. 4 .
In the manner described above with respect to FIGS. 3 and 4 , a periodic jitter is effectively generated that is static relative to the data pattern, which emulates the behavior of DDJ. A common 10 MHz external reference clock 40 is used to ensure that the sampling clock of the AWG 36 is locked to the bit clock generator 26 . It is also essential to ensure phase consistency of the pattern relative to the AWG output to ensure that edge shift for each pattern edge is consistent from one repetition of the test to the next. Without such consistency, the AWG phase could be random relative to a specific edge of the pattern when the test starts, which will result in different DDJ readings for each repetition of the test. The phase consistency requirement may be met through a combination of software and hardware trigger capabilities present in the Tektronix 610 AWG or other comparable AWGs. This includes using the pattern trigger signal of the pattern generator 30 to trigger the AWG output. Once the test is completed, software disables the output. Upon reception of a start command from a central test program, the software enables the output, but the output will not start until the pattern edge trigger arrives. This setup provides a flexible DDJ injection method, where DDJ amplitude and shape (location of DDJ lines in a jitter histogram) can be programmed through the AWG.
To characterize transmitters and/or verify the jitter injection methodology such as that described above with respect to FIGS. 3 and 4 for receiver testing, jitter has to be decomposed to its subcomponents. A number of different methodologies have been proposed for jitter measurement, including using real-time (RT-) and equivalent-time (ET-) digital sampling oscilloscopes (DSO), bit error rate testers, and time interval analyzers. Jitter measurement with an oscilloscope typically takes several tens of second to minutes because many voltage samples must be taken to extract edge displacement information with sufficient accuracy, leading to long acquisition time in the case of the ET-DSO, or excessive processing time in the case of the RT-DSO. Time interval analyzers (TIAs), on the other hand, provide the ability to optimize the sampling process by directly sampling edge timing, which results in much faster measurements. Traditional TIAs are based on single-shot time interval measurement, in which each time interval is measured as the difference between a start and stop event. Such TIAs require a pattern marker/trigger signal for fast jitter decomposition. In accordance with the present subject matter, modified TIAs referred to as continuous time interval analyzers (CTIAs) may be utilized to obtain jitter measurements. With CTIAs, all the edge timings are measured relative to a common reference. A CTIA equipped with flexible and programmable arming modes allows implementation of fast and more flexible jitter measurement methodologies without the need for any hardware generated arming/trigger signal. This eliminates the need for a hardware clock recovery circuit, whose jitter can impact measurement results. Instead, a flexible event control mechanism provides an embedded or virtual marker capability that allows focused measurement of specific edges within a data stream. The CTIA's fast measurement capability without any marker signal makes it a great candidate for production testing of multi-Gbps ICs.
In a particular exemplary verification setup for validating the jitter injection system and methodology described above with respect to FIGS. 3 and 4 , RJ, DDJ and PJ were injected into a serial data stream having an exemplary bit rate of 2.5 Gbps and employing a K28.5 repeating data pattern and jitter measurement was subsequently obtained. In such embodiment, jitter measurements were obtained using a real time digital sampling oscilloscope (RT-DSO), an equivalent time digital sampling oscilloscope (ET-DSO), and time interval analyzer such as the Femto 3200 brand CTIA. FIG. 5 shows the RMS RJ measured using the TDS7404 brand RT-DSO such as offered for sale by Tektronix and the GT4000 brand CTIA as offered for sale by Guide Technology Inc. The vertical axis is in logarithmic scale because the noise generator attenuation is selected in db. Both exemplary measurement instruments show that the injected RJ scales with the Gaussian noise level, resulting in an expected linear relationship between the noise generator attenuation and the injected RJ.
Referring now to FIG. 6 , a graphical representation of random jitter (RJ) levels versus data-dependent jitter (DDJ) levels for a data signal having a K28.5 repeating data pattern, a bit rate of 2.5 Gbps, and a noise generator attenuation of 27 dB are depicted. FIG. 6 illustrates that the RJ measurement is not sensitive to different DDJ values injected and the variations in FIG. 6 are within the statistical variations of the measurement. FIG. 7 , which illustrates random jitter (RJ) levels versus injected peak-to-peak periodic jitter (PJ) levels for an exemplary data signal utilizing a K28.5 repeating data pattern and a bit rate of 2.5 Gbps, shows that the RJ measurements vary slightly as PJ is injected into the data stream. This is mainly due to the slight non-linearity of the Agilent 81133 delay line modulation, which reduces the noise power when the total variation becomes significant relative to the 250 ps delay line modulation limit. RJ test times less than 50 ms are achievable because of the CTIA optimized sampling and processing capability.
DDJ is measured in the exemplary results of FIGS. 8 and 9 with the CSA11801C brand ET-DSO from Tektronix using the 20 GHz sampling heads to reduce the oscilloscope impact on the DDJ. The DDJ measurements for a 2.5 Gbps data signal versus AWG amplitude in FIG. 8 show that the DDJ increases proportionally with the amplitude of the AWG output, which validates the DDJ injection method. The DDJ is also measured with the GuideTech Femto 3200 CTIA using internal calibration to remove the effects of CTIA bandwidth limitation. CTIA measurements substantially match that of an ET-DSO, and generally provide much faster measurements. For a typical PRBS7 pattern with 64 edges, the CTIA can estimate the DDJ in less than 100 ms, while the ET-DSO takes several minutes for the same number of edge samples. FIG. 9 illustrates that the CTIA-measured DDJ variations for different amounts of PJ in a K28.5 pattern 2.5 Gbps data signal is within expected statistical fluctuations, except for a slight decrease in the DDJ for large values of the PJ, which is due to the non-linearity of the delay line modulator used in the exemplary test setup of FIG. 3 . In addition, the DDJ measurement repeatability is within +/−1 ps, which is sufficient for many testing applications. The total RJ and DDJ measurement time with oscilloscopes is in the range of a few seconds (2 s to 20 s), whereas a CTIA can complete the same measurement in 200 ms to 500 ms.
The results presented in the graphical illustrations of FIGS. 5-9 , respectively, clearly show the effectiveness of the proposed jitter generation method to inject RJ, PJ, and especially DDJ in a controlled and independent fashion. The jitter measurement results also demonstrate ability of the CTIA to measure the RJ and DDJ very accurately in less than a few hundred milliseconds, which is at least an order of magnitude faster than oscilloscopes measurements.
While the specification has been described in detail with respect to specific embodiments of the invention, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily conceive of alterations to, variations of, and equivalents to these embodiments. These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention. | A system and related method for generating a test signal with controllable amounts of signal jitter includes a pattern generator, a programmable arbitrary waveform generator (AWG) and a phase modulator. The pattern generator is configured to generate a data signal characterized by a given data pattern, bit rate and pattern length. A trigger signal representative of initial timing information associated with the data signal is provided to the AWG which subsequently generates a modulation signal with a frequency equal to the bit rate divided by the pattern length of the data signal. This modulation signal is provided to the phase modulator, along with a reference clock signal, and the phase modulator generates a modulated clock signal controlled by a phase modulation means (e.g., a controllable delay line) fed by the modulation signal. The resultant jittery clock signal is then provided to the pattern generator to adjust the timing of the data signal and to generate a signal representative of a data signal with data-dependent jitter characteristics. Additional inputs to the delay line of the pulse generator may include a random Gaussian noise signal for providing random jitter and a periodic signal for providing periodic jitter. | 6 |
BACKGROUND OF THE INVENTION
[0001] This invention is generally related to a mounting nut for securing a faucet to a mounting surface. More particularly, this invention is directed towards a flexible mounting nut that simplifies installation of a faucet assembly.
[0002] Typically, a faucet assembly includes at least one threaded pipe for connection to a water source. The threaded pipe is connected to a water hose with a water connection fitting. The faucet is then secured to a mounting surface by a mounting nut. The mounting nut typically includes a flange that is larger in diameter than the opening through which the threaded pipe is installed. Because the mounting nut has a flange that is greater than the outer diameter of the opening through the mounting surface, the water connection along with any other connections must be performed under the sink.
[0003] The under sink environment is typically a confined space that complicates assembly of the required connections. Typically the order of installation includes inserting the faucet assembly and threaded pipe through an opening then securing the faucet within the opening with a mounting nut. After the mounting nut has been assembled to the threaded pipe can the water fitting connected. The water fitting is an important connection and often must be leak tested prior to completion of the assembly task. The faucet is installed behind the sink and is therefore in a very difficult location in which to manipulate a wrench and make the desired water connection. The confined space complicates and adds difficulty to the job.
[0004] Some devices have been developed to aid in the mounting of a faucet assembly. Several of these devices allow mounting of the faucet assembly with much of the assembly conducted above the mounting surface. One such device includes a collapsible nut that can be fitted through the opening in the mounting surface and then is tightened to expand flanges to a diameter greater than the opening. However this device requires a special rotatable threaded member that is rotatable from above the mounting surface. Conventional faucet assemblies typically do not include such a feature. Therefore, to include such a mounting aid, the faucet assembly itself must be entirely redesigned.
[0005] Another device that addresses this problem includes the use of a threaded mounting nut without a flange. The threaded mounting nut is installed to the water tube and left there during installation of the water fitting. The mounting nut portion is of a diameter that allows the nut to be inserted through an opening in the mounting deck. Once the water connections have been and the faucet assembly has been inserted into the openings within the mounting deck a c-shaped washer is inserted between the mounting nut and the bottom of the mouthing surface. The mounting nut is then tightened upwards against the c-shaped washer through the faucet assembly to the mounting surface. This device has the disadvantage of requiring manipulation of not only the nut, but of the washer within the cramped under sink environment.
[0006] Accordingly, there is a need for a simplified mounting device that is adaptable for use on current faucet assemblies and that aids mounting of a faucet assembly to a mounting surface.
SUMMARY OF THE INVENTION
[0007] This invention is a mounting nut with an expandable opening providing for sliding of the mounting nut over a water connection fitting and onto a threaded water pipe for securing a faucet assembly to a mounting surface.
[0008] A faucet assembly includes a threaded water pipe that is connected to a water supply by a water connection fitting. The water connection fitting includes an outer diameter smaller than an opening in a mounting deck such that the water connection fitting may slide through the mounting deck. Prior to installation or attachment of the water fitting to the threaded water tube, the mounting nut is dropped or fed over the water tube. The hinged nut is of such a diameter that it may not extend through the opening within the mounting surface.
[0009] During installation the water connection fitting is fed through the opening and attached to the threaded water tube of the faucet assembly. The connection to the faucet assembly can then be tested to ensure watertight integrity. This step is conducted above the mounting surface to ease installation of the faucet assembly and limit the installation steps required under the mounting surface. Once the integrity of the water connection has been verified, the faucet assembly, along with the water connection fitting is inserted through the opening. The hinged nut is then slid over the water connection fitting onto the threaded water pipe.
[0010] Once the mounting nut approaches the bottom surface of the mounting deck the sides that have been extended from each other due to the hinge of the nut are compressed against each other. Further engagement with the bottom surface of the mounting deck compresses the sides of the mounting nut to provide positive engagement against the threaded water pipe. The mounting nut includes features providing for hand tightening or for tightening with a tool. The now collapsed and tightened mounting nut secures the faucet to the mounting surface.
[0011] Accordingly, the mounting nut of this invention provides for quick mounting of a faucet that can be accomplished quickly and easily in the under sink environment.
[0012] These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a schematic view of a faucet assembly prior to mounting to the deck.
[0014] FIG. 2A is a side view of a threaded water pipe with a water connection fitting and a mounting nut.
[0015] FIG. 2B is a side view of a threaded water pipe with the mounting nut over the water connection fitting.
[0016] FIG. 2C is a side view of a threaded water pipe with the mounting nut expanded over the water connection fitting.
[0017] FIG. 2D is a side view of a threaded water pipe with the mounting nut over the water connection fitting and against the mounting deck.
[0018] FIG. 2E is a side view of a threaded water pipe with the mounting nut against the mounting deck.
[0019] FIG. 2F is a side view of a threaded water pipe with the mounting nut tightened against the mounting deck.
[0020] FIG. 3 is a perspective view of the faucet assembly with the mounting nut secured against the underside of the mounting deck.
[0021] FIG. 4 is a cross-sectional view of the mounting nut.
[0022] FIG. 5 is a cross-sectional view of the mounting nut in an open position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Referring to FIG. 1 , a faucet assembly 10 includes a faucet 12 having a threaded water pipe 20 . The threaded water pipe 20 is attached to an inlet hose 22 by way of a water connection fitting 24 . The water connection fitting 24 secures to the threaded water pipe 20 and supplies water to the faucet 12 . The faucet 12 is mountable to a sink deck 11 . The sink deck 11 includes a top-mounting surface 14 and a bottom-mounting surface 16 . The inlet hose 22 is attached at an end opposite the water connection fitting 24 to a water supply source. Although a flexible hose attached to the connection fitting 24 is shown other types of water connection conduits such as a rigid pipe or plastic pipe will also benefit from this invention. The sink deck 11 includes an opening 18 for the threaded water pipe 20 . The threaded water pipe 20 extends through the opening 18 and allows the faucet 12 to sit on the top-mounting surface 14 .
[0024] The water connection fitting 24 provides a secure and watertight seal to the threaded water pipe 20 . A mounting nut 26 secures the faucet 12 to the sink deck 11 . The mounting nut 26 includes a hinge 32 . The hinge 32 provides for expansion of the mounting nut 26 to provide for sliding over the water connection fitting 24 . In this way the water connection fitting 24 can be installed to the faucet 12 at a location above the top-mounting surface 14 . Installation of the water connection fitting 24 above the top mounting surface 14 eases and simplifies installation. As is appreciated, manipulation of tools required to tighten the water connection fitting 24 to the threaded inlet pipe 20 is difficult in the confined under sink environment typical of such installations. The mounting nut 26 of this invention allows the water connection to be accomplished entirely above the top-mounting surface 14 .
[0025] If hose 22 is connected to the water supply source first, then nut 26 must be slide over hose 22 before fitting 24 is fed through the opening 18 . If the hose 22 not connected to the water supply source, the nut 6 can be slide over the hose 22 from the water supply source end.
[0026] Installation of the faucet assembly 10 according to this invention proceeds by first feeding the water connection fitting 24 through the opening 18 in the sink deck 11 . The distal end of the inlet hose 22 is already connected to the water supply source. The water connection fitting 24 disposed above the top-mounting surface 14 is threaded onto the threaded water pipe 20 . When this connection is complete water can be turned on to provide for testing of the water connection. Testing is desirable to assure a proper watertight seal and faucet functionality.
[0027] Once the water connection has been established and tested, the faucet 12 is mounted to the top mounting surface 14 . This is accomplished by inserting the water connection fitting 24 and threaded pipe 20 through the opening 18 in the sink deck 11 .
[0028] Referring to FIG. 2A , the threaded water pipe 20 is shown inserted through the opening 18 such that the faucet 12 is sitting on the top-mounting surface 14 in an unsecured condition. The mounting nut 26 is then moved upward along the inlet hose 22 towards the bottom-mounting surface 16 . The mounting nut 26 includes a flange 30 . The flange 30 is larger than the opening 18 for securing the faucet 12 against the sink deck 11 . The mounting nut 26 includes the hinge 32 that provides for bending along a center line and increasing an inner opening to a size large enough to slide over the water connection fitting 24 .
[0029] Referring to FIGS. 2B, 2C and 2 D, the mounting nut 26 is shown slid over the water connection fitting 24 . Once the mounting nut 26 has been slid over the water connection fitting 24 it is slid upward towards the bottom-mounting surface 16 . The mounting nut 26 may still be bent about the hinge 32 in order to speed assembly. The mounting nut 26 does not need to be engaged to the threads until the flange 30 abuts the bottom mounting surface 16 . As appreciated, the threaded water pipe 20 includes a plurality of threads along its entire length. The entire length of the threaded water pipe 20 is often longer than required to accommodate different sink deck configurations. Accordingly, the mounting nut 26 can be quickly moved upwards to the bottom-mounting surface 16 before engaging any of the threads of the threaded water pipe 20 .
[0030] Referring to FIGS. 2E and 2F , once the mounting nut 26 engages the bottom mounting surface 16 , the flange 30 abuts the bottom mounting surface 16 and drives the mounting nut 26 to a collapsed or installed and secured position. A force applied by the operator may be required to initially engage the threads 28 with the threaded water pipe 20 . In this collapsed position the sides of the mounting nut 26 compress about the threaded water pipe 20 . As the sides compress about the threaded water pipe 20 internal threads 28 of the mounting nut 26 engage threads of the threaded water pipe 20 and allow the mounting nut 26 to be threaded upward toward the faucet 12 . The mounting nut 26 is increasingly tightened against the bottom mounting surface 16 such that portions of the mounting nut 26 are compressed further. The compression of the mounting nut 26 produces the desired engagement with threads of the threaded water pipe 20 .
[0031] Installation of the mounting nut 26 is aided by a plurality of tabs 34 disposed about the mounting nut 26 . The tabs 34 provide for hand tightening of the mounting nut 26 to the mounting surface 16 . In some applications, the mounting nut 26 may be sufficiently tightened against the bottom-mounting surface 16 by hand. However, the mounting nut 26 is also configured to receive a fastening tool to tighten the mounting nut 26 beyond that possible by hand.
[0032] Referring to FIG. 3 , the example faucet 12 is shown secured to the sink deck 11 . The mounting nut 26 is secured and abuts against the bottom mounting surface 16 . The flanges 30 of the mounting nut 26 are fully engaged to the bottom mounting surface 16 . Further, the compression against the bottom mounting surface 16 has provided compression of the internal threads of the mounting nut 26 to produce the desired securing engagement with the threaded water pipe 20 .
[0033] Referring to FIG. 4 , a cross section of the mounting nut 26 is shown and illustrates the internal threads 28 . Preferably, the mounting nut 26 is fabricated from a flexible plastic material. The mounting nut 26 includes the hinge portion 32 . The hinge 32 is of wall thickness less than the remaining portions of the mounting nut 26 . The hinge 32 connects a first side 40 to a second side 42 . The first side 40 and the second side 42 are essentially identical. The hinge 32 provides for the bending of the first side 40 relative to the second side 42 . As appreciated, the specific configuration of the plastic hinge for the mounting nut 26 that attaches the first and second sides 40 , 42 can vary from the example illustrated for a specific application.
[0034] FIG. 4 shows the mounting nut 26 in a position where the threads 28 would engage the threaded water pipe 20 . In the secured position an inner diameter 38 of the internal threads 28 is in a position to engage the threaded water pipe 20 . This inner diameter can be modified to meet the requirements of a specific threaded water pipe. However, as appreciated the faucet 12 typically includes a commonly sized water pipe 20 . This commonly sized water pipe 20 is standard in order to fit the standard inlet water connection fitting 24 .
[0035] Typically, the water connection fitting 24 is a standard known size compatible with most faucet assemblies 12 . The water connection fitting 24 is an industry standard size. However, the mounting nut 26 can be modified to provide the beneficial and advantageous features of this invention to other applications. Further, although this invention is being shown and described for installation of a faucet, other applications that require the mounting of a water control fixture to a surface along with attachment of a water source connection will also benefit form the inventive mounting nut 26 of this invention.
[0036] Referring to FIG. 5 , the mounting nut 26 is shown in an open position for sliding over the water connection fitting 24 (not shown). In the open position the inner opening 36 is greater than the inner opening 38 shown in FIG. 4 . The inner opening 36 provides the additional space required for sliding the mounting nut 26 over the water connection fitting 24 . The inner opening 36 is a threaded diameter and the inner opening 36 is a hexagon shaped opening within an elliptical hole. Further, the flexible configuration of the hinge 32 and the plastic material with which it is connected provides some flexibility for the mounting nut 26 to squeeze over and around the water connection fitting 24 . The mounting nut 26 will slide over the water connection fitting 24 either all at once or by a rocking motion where one of the first and second sides 40 , 42 is passed over the water connection fitting 24 followed by the other side.
[0037] The mounting nut 26 of this invention is preferably fabricated from a plastic material and provides a clamshell configuration that is flexible enough to vary the inner opening 36 , 38 and squeeze or slide over a water connection fitting and then threaded onto the threaded water pipe 20 . This provides for above the sink deck 11 assembly and testing of the water connection to the faucet assembly 12 . This reduces the time required and actions needed within the confined under sink environment. The reduction of time in the confined under sink environment eases installation and produces greater efficiencies for professional installers.
[0038] Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention. | The mounting nut includes a first segment and a second segment attached by a hinge portion. The hinge portion provides for expansion of the mounting nut to bend onto itself in a clamshell like manner. The hinged mounting nut is slidable over a water connection fitting such that the mounting nut can be slid over the water connection fitting and up against the bottom-mounting surface to secure a faucet assembly to a sink deck. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on French Patent Application No. 02 02 770 filed Mar. 5, 2002, the disclosure of which is hereby incorporated by reference thereto in its entirety, and the priority of which is hereby claimed under 35 U.S.C. §119.
BACKGROUND OF THE INVENTION
[0002] 1 Field of the Invention
[0003] The present invention relates to a data switching system for a satellite telecommunication system including a plurality of user terminals sending data to a plurality of coverage areas. The data can be transmitted in the form of packets and switched by the switching system on board a satellite. The satellite can be a geostationary or non-geostationary satellite. The packets can be asynchronous transfer mode (ATM) cells, but the device can be adapted for any type of fixed length or variable length packet.
[0004] The invention also relates to a transmission device, a transmission method, and a switching method.
[0005] 2. Description of the Prior Art
[0006] A telecommunication system 100 shown in FIG. 1 includes a plurality of user terminals 2 , 7 that take the form of ground stations communicating with each other via a satellite 3 with a switch 11 on board. The role of the satellite 3 is to provide very long links 6 where the investment in cable would be unrealistic for financial or technical reasons. The onboard switch 11 therefore receives at its input ports uplinked data or data, i.e. data uplinked from the various ground stations 2 to the satellite 3 , and distributes from its output ports downlinked data, i.e. data downlinked from the satellite 3 to other ground stations 7 . The terminals 2 that send to the same input port of the switch 11 are grouped in the same geographical coverage area 1 , also referred to as a spot or beam. Similarly, the terminals 7 that receive data from the same output port of the switch 11 are grouped in a coverage area 8 . The coverage areas are not necessarily separate: it is possible for a terminal 7 to be in several coverage areas at the same time, for example. In particular, the coverage area can transport a stream of data whose final destination is common to a plurality of terminals. The switch 11 advantageously switches the data stream to the output port connected to the common coverage area instead of duplicating said data stream to the various coverage areas, thereby economizing on downlink resources.
[0007] This facility can be used for multicast data streams, for example, or for collective control data.
[0008] The user terminals 2 are very often in competition for resources, i.e. for the uplink and downlink bandwidth of the satellite 3 .
[0009] Many devices known in the art offer a solution to the problem of dynamic management of the uplink and downlink resources of a satellite system providing dynamic connectivity between coverage areas via the satellite.
[0010] One solution to uplink resource management is to use a demand assignment multiple access (DAMA) controller based on a dynamic resource allocation protocol which assigns user terminals frequencies and time slots when said terminals express the requirement to send data in the form of packets on uplinks from a terminal to a satellite by sending requests to that effect to the DAMA controller. A switch on board the satellite then distributes data packets arriving on a plurality of uplinks to a plurality of downlinks.
[0011] In the case of downlink resource management, a distinction is drawn between two categories of satellite systems providing dynamic connectivity between coverage areas via the satellite. A first solution consists of making the uplink access patterns and the downlink access patterns completely compatible for a given period during which the switch effects deterministic and a priori switching of the data streams at each of its outputs. There is no situation of conflict for access to the downlink resources since the controller defines the patterns to achieve this. The calculation of the compatibility of the uplink and downlink access patterns results from a synthesis of all the requests from user terminals with the available resources. This calculation is effected by a controller, which can be an onboard controller, although this is not essential, for a defined period during which the patterns are fixed. Any modification of the characteristics of the uplink data stream from a user terminal (for example the bit rate or the destination) generates a new request from said terminal to the switching controller. The controller then proposes new access patterns to the uplinks and the downlinks, compatible with the new configuration. As a result of this, the user terminals are highly interdependent. One consequence is to impede the agility with which the satellite system can respond to a modification of the characteristics of the data stream. This solution uses “deterministic” switching: the position of the packet of the data in an uplink frame pattern determines its destination, so that no address analysis is necessary on board the satellite. This reduces the complexity on the satellite's onboard systems, and the switching unit can be a circuit switch, possibly on the ground.
[0012] To address the problems of the interdependence of the terminals and degraded switching agility, justified by increasingly volatile traffic characteristics (unpredictable arrival of data in bursts, short data streams with diversification of destinations), a second solution consists of decoupling the uplink access patterns from the downlink access patterns. The data is grouped into packets which are provided with a header containing an address correlated with a target user terminal. Thanks to this header, the packets are self-switched in the satellite switch. A controller manages access to the uplinks and, after analyzing the address, the switch switches the data on board the satellite and applies statistical multiplexing at each of its outputs. However, statistical management of access to the downlinks leads to the following problem: conflict results if many packets are addressed to the same output at the same time (i.e. must be supported by the same downlink from the satellite to one or more user stations). The conflict is resolved by means of a buffer memory associated with scheduling algorithms. The buffer memory has a finite capacity and if that capacity is exceeded a phenomenon known as congestion results. A first solution to this problem is to increase the size of the buffer memory, representing a penalty in terms of the onboard weight and power consumption balance. A second solution is to include a device for controlling access to the downlinks. The objective of these control mechanisms is to limit the bit rate characteristics of the user terminals whose streams are in competition on a given downlink, either preventively or reactively. This solution is distinguished from the deterministic switching referred to above in the sense that the downlink access pattern is not strictly defined, and the arrangement of the packets remains statistical, although the probability of congestion is reduced by the action of said mechanisms.
[0013] From the point of view of onboard complexity, the introduction of the buffer memory and the step of analyzing the destination address have a decisive consequence for onboard implementation. In particular, the use of regenerative processing, which consists of demodulating, decoding (correcting transmission errors), and analyzing the data and then coding and modulating the data using digital technology, is indispensable. These technologies are relatively new, however, and often considered risky. Moreover, the processing capacity of digital equipment leads to a multiplication of the number of equipment units, at the expense of onboard mass and power consumption.
[0014] The systems described above are confronted with new demands related to the evolution of the Internet. The increase in the number of autonomous systems, their geographical distribution and the nature of future applications (high bit rates, multiple quality/priority levels, non-connected mode) induce the following constraints:
[0015] a requirement for interoperability between networks (reducing adaptation mechanisms),
[0016] a high transmission capacity,
[0017] hierarchical management of streams in non-connected mode, and
[0018] increasingly complex management of addresses (and routes).
[0019] Deterministic switching solutions offer high transmission capacity with relative interoperability because the transmission links are transparent (independent of the waveform). However, management of the streams is somewhat inflexible. Statistical switching solutions offer more flexible management of the streams and addresses, but their processing capacity is low and their waveform dependence represents a penalty in terms of interoperability.
[0020] The present invention aims to provide a solution in this direction.
[0021] To meet the above requirements, the payload of the satellite must be able to:
[0022] switch data at high bit rates (hundreds of megabits per second) from different beams (several tens of beams),
[0023] establish and manage dynamically and hierarchically the routes for the packets in transit with no concept of connection (by default, managing the addresses for the switches), and
[0024] offer the possibility of managing the protocols of the network layer (i.e. of the Internet) to ensure good integration into the terrestrial networks and relative autonomy (this is known as “seamless” integration).
SUMMARY OF THE INVENTION
[0025] To this end, the invention provides a data switching system for a satellite in a satellite data transmission system adapted to relay from a terrestrial sending area to a terrestrial receiving area via the satellite data including payload data and associated control data which comprises respective switching requests and is adapted to provide data on the switching of the payload data, which system includes means for analyzing data on the basis of a signal conveying the control data and means for switching the payload data as a function of the result of the analysis of the associated control data to at least one of a plurality of sending ports for sending it to the receiving area, wherein the data analyzer means are adapted to analyze only the control data and the payload data is not analyzed.
[0026] Thus prior to the analysis (demodulation, decoding), the system according to the invention adjusts the processing capacity to suit the only category of data to be analyzed, namely switching requests (fields containing the addresses of the packets and packets necessary for signaling, for example).
[0027] Thanks to the invention, the great majority of the data switched (payload data) transits in a “passive” manner, not meriting regenerative processing. Because of a pointing mechanism described in this application, the packet header data continues to be correlated with the payload data.
[0028] In one embodiment the analyzer means include extractor means for extracting data necessary for analyzing control data carried by the signal followed by control means adapted to configure the switching means as a function of extracted switching data.
[0029] In one embodiment the extractor means include means for demodulating and decoding control data.
[0030] In one embodiment the signal carrying the data is an FDMA frequency division multiplex signal, first frequency channels are assigned to payload data, second frequency channels are assigned to control data, and the extractor means include frequency division demultiplexer means followed by filter means adapted to supply the data content of the second frequency channels to the control means.
[0031] In one embodiment the signal carrying the data is a TDMA time division multiplex signal, first groups of time windows are reserved for the payload data, second groups of time windows are dedicated to the control data, and the extractor means include time division demultiplexer means adapted to supply the data content of the second groups to the control means.
[0032] One embodiment of the switching system includes means for generating and transmitting a reference clock for timing the sending of control data packets on board the satellite and payload and control data packets on the ground.
[0033] One embodiment of the switching system includes estimator means for estimating the quality of synchronization, referred to as control data packet centering, whereby centering data can thereafter be transmitted to a ground station for centering payload and control data packets to be sent by the station, and/or the characteristics of control data demodulation and decoding on board the satellite, and/or the downlink loads, and/or the status of the equipment on board the satellite.
[0034] One embodiment of the switching system includes delay means for delaying any payload data packet in transit in the switching section of the satellite with time delays that are controlled and activated by the analyzer means.
[0035] The invention also provides a data transmission device for ground stations of a satellite data transmission system adapted to relay from sending ground stations to receiving ground stations via the satellite data including payload data and associated control data constituting respective switching requests and adapted to provide data on the payload data, which device includes adapter means for transporting the data addressed to the satellite and in which device the control data is analyzed separately from the payload data packets on board the satellite.
[0036] One embodiment of the switching system includes means for generating payload data bursts, means for generating control data constituting switching requests each pointing to associated payload data, and means for frequency and/or time division multiplexing the data to assign first channels to payload data and second channels to control data.
[0037] In one embodiment the first and second frequency channels are respectively combined in the same first group and the same second group.
[0038] The invention further provides a method of transmitting data in a satellite data transmission system adapted to relay from a terrestrial sending area to a terrestrial receiving area via the satellite data including payload data and control data constituting respective switching requests and adapted to provide data on the switching of the payload data to be carried out on board the satellite, the method transmitting payload data on first channels and control data on second channels.
[0039] In one embodiment the control data is sent in advance of the associated payload data, the advance time being reduced by the maximum time for analyzing and calculating on board the satellite a switching configuration resulting from all the switching requests.
[0040] In one embodiment the payload data and the control data are sent simultaneously.
[0041] In one embodiment the payload data is sent in the form of packets separated by periods of silence constituting guard times characteristic of the capacity of the satellite to switch from one switching configuration to another.
[0042] In one embodiment data incoming from or outgoing to the exterior of the satellite system undergoes conversion of the transport format to ensure compatibility with the data transport format specific to the satellite system.
[0043] In one embodiment the switching requests generated assure propagation of the quality of service concept through the satellite system if the quality of service concept exists outside the satellite system.
[0044] In one embodiment the switching requests generated assure correct switching of payload data so that, from a point of view external to the satellite system, the payload data is switched to destinations defined by address data contained in the routing request and associated with the payload data before entering the satellite system, thereby establishing a correspondence between output ports of the satellite and address data associated with the payload data before entering the satellite system.
[0045] In one embodiment the sending of payload and control data is clocked by signals from a reference clock on board the satellite and carried by a downlink control channel.
[0046] In one embodiment characteristics of the payload data stream in terms of payload bit rate are controlled using an uplink and downlink resource management indicator carried on a downlink control channel.
[0047] In one embodiment the sending characteristics of the modulated signal in terms of bit timing, phase, and power are controlled using a demodulation and decoding indicator conveyed by a downlink control channel.
[0048] In one embodiment the centering of payload data packets is controlled by separating the payload data packets by a guard time common to all of the satellite system, the guard times being presented to the satellite at the same time in order to change the switching configuration without interruption of service, synchronization using centering data from a downlink control channel.
[0049] The invention further provides a method of switching data for a satellite in a satellite data transmission system adapted to relay from a terrestrial sending area to a terrestrial receiving area via the satellite data including payload data and associated control data constituting respective switching requests and adapted to provide data on the switching to be applied to the payload data, the method analyzing only the control data, and not the payload data, and switching the payload data to different sending ports to the receiving area as a function of the analyzed switching requests.
[0050] In one embodiment conflict situations that can arise at the same output port are resolved using time reassignment, frequency reassignment or port reassignment.
[0051] In one embodiment, in the event of reassignment, a routing request associated with a redirected payload data packet contains a high priority recommendation.
[0052] The invention will be better understood and other features will become apparent in the light of the following description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] [0053]FIG. 1, already described, shows a system for transmitting data between two coverage areas via satellite.
[0054] [0054]FIG. 2 is a block diagram of a first embodiment of an edge node on the ground and also shows the spectrum of the signals received and sent by the node.
[0055] [0055]FIG. 3 shows one embodiment of a receiver station.
[0056] [0056]FIG. 4 shows one embodiment of a switching system according to the invention.
[0057] [0057]FIG. 5 shows some components of the FIG. 4 switching system in more detail.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0058] In this application, components having identical or similar functions are identified by the same reference number in the various figures.
[0059] [0059]FIG. 2 is a block diagram of a first embodiment of an edge node on the ground.
[0060] An edge node is an access point of the network for collecting and/or broadcasting data from and/or to a subscriber access node and broadcasting and/or collecting data to and/or from one or more core nodes centralizing the data. In FIG. 1, for example, the terminals 2 and 7 are edge nodes and the satellite 3 is a core node, the user access points, which are aligned with the continuous lines connected to the terminals 2 , 7 , not being shown. Hereinafter, given their position in the system, the edge nodes are called intermediate nodes. It will emerge hereinafter that there is a master-slave relationship between the satellite and the stations; among other things, the satellite supplies the packet synchronization clock to the stations 2 , 7 .
[0061] As mentioned above, each port represents all of the stream of data transmitted by an edge node, here a terminal 2 referred to hereinafter as a ground station.
[0062] According to the invention, each port comprises a set of carriers, assembled to form:
[0063] a data channel group (DCG) made up of data channels, and
[0064] a control channel group (CCG) made up of control channels.
[0065] These ports are emulated by appropriate means in the ground stations 2 (edge access point), whose role is to process the data received in order to format the incoming traffic. To this end, the processing operations include:
[0066] reception of IP packets by a network adapter 13 ,
[0067] assembly into bursts and then division into packets (see below) of payload data having common characters or attributes (same output port, same quality of service (QoS), etc.), this operation being carried out in a generator 14 of bursts 16 ,
[0068] generation and transmission of switching requests (including the location in time and space of the arrival of the burst on board, the length, the destination address of the associated payload data burst, priority data, etc.); the switching request is sent in advance of the associated data burst on a channel of the control channel group, this operation being carried out in a control packet generator 15 ,
[0069] where applicable, transmission of dedicated control data (signaling, maintenance protocol, for example) on a channel of the control channel group, and
[0070] after a particular period, sending payload data bursts on an available channel 17 from the data channel group.
[0071] The header of a data burst is transmitted first on the control channel (CC) and is followed, after the predetermined period, by the associated data burst on a parallel data channel (DC). For correct transmission of the data burst, the data header must contain all the data necessary for the controller on board the satellite to switch it.
[0072] Each packet header is transmitted as a fixed length burst header packet (BHP). The BHP must be transmitted before the corresponding burst with an offset of predetermined duration τ. This time interval allows resolution of the switching request in the controller. The parameters that influence the offset are explained hereinafter.
[0073] The control and data channels are connected to a satellite adapter 18 whose main functions are packet synchronization, known as packet centering, modulation, coding and frequency division multiplexing.
[0074] To simplify scheduling on board the satellite, the data bursts are transmitted on a slot-synchronized path. The bursts are divided into fixed size packets known as slots and are separated by time periods known as guard times. The packet synchronization (centering) data in the associated time interval is contained in a channel referred to hereinafter as the telemetric channel (TMC), transmitted by the satellite, as described below, and received in the station 2 by a receiver 19 .
[0075] The centering data means that the satellite transmission system can be entirely synchronous, the payload data packets on the uplinks all starting at the same time. A period of silence between the payload data packet allows the satellite to progress from one switching plan to another. This period of silence, referred to as the guard time, is respected by all of the stations sending to the satellite. All the uplinks feature this period of silence at the same time.
[0076] The satellite can change the switch from one switching configuration to another for a time period compatible with the guard time between payload data packets.
[0077] For reasons connected with switching implementation and performance, the size of the payload data packets is fixed and common to all the stations. However, payload data packets of varying size can be envisaged, with the switching request for each payload data packet informing the switching controller of the transit time of the associated payload data packet on board the satellite.
[0078] The TMC can also convey other data useful for efficient operation of the system: thus the TMC can carry an indicator of the estimated characteristics of the demodulation and decoding of the control data on board the satellite, an indicator of the downlink loads estimated by the switching control unit, or an estimation indicator defining the status of units on board the satellite. Following an estimation, the above indicators are generated by an estimator 290 described hereinafter with reference to FIG. 5.
[0079] The upper part of FIG. 2 shows the spectrum 21 of the signal received by the station 2 , including the data channel group (DCG), the TMC, and the spectrum 22 of the sent signal corresponding to the multiplexed signal of the data channel group (DCG) with the CC.
[0080] [0080]FIG. 3 shows one embodiment of a receiver station 20 . The signal sent by the satellite is received by the receiver station, in which a satellite receiver unit 23 carries out the operations of signal detection, in particular by means of the TMC signal, frequency division demultiplexing, demodulation and decoding. These operations are known in the art, and are not described in detail in this application.
[0081] Following these operations, the packets are recombined into bursts 24 which are transmitted to an IP network packet generator 25 . The bursts 24 enable the restoration of IP packets, using means known in the art, for example an indicator contained in each burst identifying the IP destination packet or packets contained in the burst, or a network controller, not shown, allocating each burst its destination by appropriate means. A network adapter 26 configures the resulting packets in accordance with the network protocols.
[0082] [0082]FIG. 4 shows one embodiment of a switching system 27 conforming to the invention integrated into the satellite.
[0083] Ports {port1, port2, port3} representing, as mentioned above, all of the data streams transmitted by respective edge nodes 2 , are received at corresponding inputs of the satellite. Each port includes a data channel group (DCG) and a control channel group (CCG).
[0084] The payload data channels of each port are received by respective inputs of the switch 28 and the control data channels (including the BHP) of the same ports are directed to corresponding inputs of the controller 29 .
[0085] After demodulation and decoding, the BHP are then analyzed by a scheduling unit 30 for assigning the payload data bursts to which the BHP point to output ports of the satellite, as a function of parameters indicated in the BHP, such as the duration and the destination of the payload data bursts, their QoS, their priority, etc.
[0086] The unit 30 then controls the switching of the payload data bursts in transit “transparently” (without demodulation/decoding) in the switch 28 so that they reach the respective appropriate output ports.
[0087] A clock generator 31 generates the TMC centering data which is multiplexed by the data multiplexer 32 with the other data from the unit 30 . Thus the switching planes of the switch 28 and the downlink ports 33 are clocked by a common clock.
[0088] The controller, and more particularly the unit 30 , operate in the following manner on each group of payload data to which the BHP points:
[0089] if an output channel is available in the output port targeted by the BHP, the block 30 configures the operation of the switch so as to switch the data group in question to the indicated output, or
[0090] if an output channel is not immediately available in the output port, the controller can delay the data group with onboard delay means until a data channel becomes available.
[0091] Thus conflict situations at the output ports are managed by the unit 30 . The methods of resolving such conflicts are therefore as follows:
[0092] temporal reassignment of payload data packets: some payload data packets in conflict with others are delayed, as mentioned above and described in more detail below, by time delay means (for example buffer memory, delay line),
[0093] frequency reassignment of the payload data packets: each port consisting of a group of frequency channels, if payload data packets arrive at the same output port and on the same data frequency channel, under the control of the unit 30 , the switch 28 performs a frequency conversion in order to present at the same time the payload data packets previously in conflict on different data channels of the same output port,
[0094] port reassignment: if the quality of service associated with the data packets allows it, the switching unit 30 can elect to modify the output port for data packets in conflict, in order to reduce the instantaneous load on the output port suffering congestion; the redirection output port is chosen according to the following criteria:
[0095] a) its availability, and
[0096] b) the stations 7 covered by the beam associated with the redirection port are capable of detecting the redirected payload packets and forwarding them to the satellite on data channels with priority data in the associated switching requests preventing infinite looping.
[0097] [0097]FIG. 5 shows in detail the switch 28 and its interconnections with the 1 5 controller 29 . The stream of data from the n sending stations representing the various ports {port1; port2; . . . portn} is symbolized by an arrow 35 . This multiplex stream is demultiplexed and then transposed to lower frequencies compatible with subsequent equipment units in the processing system. N groups of channels each comprising p+1 channels (there is not necessarily the same number of channels in each group) then reach respective channel switching units 36 . In fact, each unit 36 is made up of p+1 switching submatrices each dedicated to an input channel and an output channel of the corresponding unit 36 . Each channel switching unit has p inputs for receiving the associated group of channels and p outputs. The control channel (CC) of the group is isolated and directed to an input of a multicarrier demultiplexer demodulator decoder (MCDDD) unit 37 . The unit 37 receiving the n control channels of the n groups of channels, its function is demultiplexing, demodulating (by means of a demodulator unit 371 ) and decoding (by means of a decoder unit 372 ) these channels. This unit also has the function of establishing an estimate for centering control data intervals relative to the master clock of the controller. Once the control data has been recovered as raw data, the data is analyzed by the controller 29 , and especially by the scheduler 30 , as explained with reference to FIG. 4. Analysis of the various control data switching requests produces instructions to the controller, firstly Scom1 to the p submatrices of the n channel switching units 36 and secondly Scom2 to the p switching submatrices of ports of an n×n port switching matrix 38 . The matrix orients the various payload data channels to the appropriate ports or spots as a function of their destination and the availability of ports.
[0098] The controller also supplies the centering (TMC) signals in a modulator/coder unit 39 . The n outputs of the unit 39 supply the centering data for the n TMC included in the n groups of channels at the output of the matrix 38 . Of course, the centering data is supplied in the form of telemetry packets (TMP) clocked by the master clock 31 . The n groups at the output of the matrix 38 are then subjected to a first operation of multiplexing and transposition to higher frequencies by a multiplexer/converter unit 40 . The signals leaving each of the n units 40 are then multiplexed and transposed to higher frequencies appropriate to radio transmission by a unit 41 .
[0099] The time delays referred to above for analyzing switching requests can be provided either at the level of each submatrix of the channel switching units 36 or at the level of the submatrices of the port switching matrix 38 .
[0100] It should be emphasized that the controller can also include means controlled and activated by the controller for destroying any “unswitchable” payload data packet at the input of the switch.
[0101] One embodiment of the burst encapsulation protocol is as follows:
[0102] Data arriving from outside the satellite system is transported in network packets (typically IP packets). The size of these packets varies, and is often not controlled. A first step therefore consists of constructing bursts of data by aggregating these network packets. The aggregation criteria include the same destination, the same QoS, etc. The size of the bursts can be fixed or variable, and the time to construct the burst can also be a determination criterion. For example, in the case of a Voice over IP (VOIP) QoS, the time delay authorized for the network packets is very short. For this reason, when constructing data bursts, the time of arrival of the network packets determines the time of closure of the bursts and therefore their size. The minimum size of the bursts is fixed by the transport capacity of the transport packets (see below) and the maximum size is often determined by the maximum size of a network packet. The assembly of network packets into bursts is described in a burst preamble, indicating the number and size of the network packets assembled in the burst, this preamble therefore enabling the network packets to be reconstituted in the unit 25 . These mechanisms operate at the level of the burst layer.
[0103] For reasons connected with synchronization and simplification of the satellite system, a burst segmentation step can be introduced. The bursts are divided into packets of fixed size that constitute the “segments”. A segment preamble is attached to the segment, including an indicator identifying the burst in the system to which the segment is attached, as well as the rank of the segment in the burst. The combination of the segment and the segment preamble is then processed (coded) for protection against transmission errors. Once coded, the segment and preamble combination can have added to it “single word” data that is sometimes required by the demodulator algorithms implemented in the satellite receiver unit 23 . From the physical layer point of view, the payload data packets that are switched by the switch 28 correspond to these fixed size coded packets accompanied by their single word.
[0104] In the context of the present invention, the control data (switching requests) has been described as being included in a frequency channel different from that or those containing the associated payload data. In a preferred embodiment, the control data frequency channel is transmitted in advance of the payload data, which economizes on memory space on board the satellite. It is clear that the essence of the invention consists in the possibility of dissociating the control data from the payload data so that it can be processed differently. Consequently, the invention also covers the case, not described, of control and payload data transmitted in TDMA or even CDMA mode, the control data being transmitted in advance of the associated payload data on the same frequency channel or a different frequency channel. | A data switching system for a satellite in a satellite data transmission system which relays from a terrestrial sending area to a terrestrial receiving area via the satellite data including payload data and associated control data which constitutes respective switching requests and provides data on the switching of the payload data. The system analyzes data on the basis of a signal conveying the control data and switches the payload data as a function of the result of the analysis of the associated control data to at least one of a plurality of sending ports for sending it to the receiving area. Only the control data is analyzed. The payload data is not analyzed. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER PROGRAM LISTING COMPACT DISC APPENDIX
[0003] Not Applicable.
BACKGROUND OF THE INVENTION
[0004] 1. Field of the Invention
[0005] The present field of the invention relates to neck and bow ties that look like they are manually tied, but in truth, are simply clamped about the neck and can be removed quickly and easily without having to untie the tie, or undo or unclip any mechanical device.
[0006] 2. Description of the Prior Art
[0007] Neck or bow ties are a common fashion accessory and are often required apparel for many types of businesses or social engagements. There are two concerns that are addressed by the invention presented. 1—Properly tying a neck or bow tie can be a frustrating and time consuming process. 2—A traditional neck tie can pose a danger for the wearer within certain types of businesses. For those who work in correctional facilities, law enforcement, or even transportation industries such as airlines, a neck tie can quickly become a dangerous liability in a hostile environment. A necktie becomes a tool of control or even death by an aggressor who chooses to use it as such. In addition, some businesses require individuals to wear neck ties while running equipment that could catch and pull the tie into machinery while being operated thereby causing injury and even death.
[0008] Existing pre-tied ties such as “zipper” ties, “break away” ties that clasp in the back with velcro, or “clip on” ties are encumbered with their own disadvantages. Some don't look like they are actually tied about the neck. Some are cumbersome to put on and take off. Some don't adequately address the safety issues raised.
[0009] The primary intention of this invention is to make the putting on and taking off a neck or bow tie more simple and safe than any other product or potential product available.
BRIEF SUMMARY OF THE INVENTION
[0010] (See FIGS. 1-7 ) An easily removable pre-tied necktie which either consists of an elongated piece of fabric that has been either tied or formed to look like a tied necktie knot ( 2 ), or a piece of fabric that has been tied or formed to look like it has been tied in the form of a bow tie ( 4 ). From either style (neck or bow tie) of the knot formation ( 6 )—two ends of material extend out of the knot, and once fully open, horizontally form a U shape, or nearly complete circle ( 8 ). These ends may or may not touch each other at the back of the neck.
[0011] Within, or attached to, the knot and the two horizontal ends that extend horizontally out of the said knot is a unique clamping device ( 10 ) which causes it to form around the shape of the neck and remain there until pulled off.
[0012] In addition, there is the option of the various designs of neck or bow ties being attachable and removable from the unique clamping device. ( FIG. 7 )
OBJECTS OF THE INVENTION
[0013] It is therefore an object of the present invention to provide a pre-tied neck or bow tie that appears to be tied about the neck but that can easily and quickly be put on or taken off simply by pushing the tie on or pulling it off.
[0014] It is a further object of the present invention to provide a unique clamping device that makes it possible to put the tie on without tying, clasping, zipping, or hooking any mechanism that would encircle the neck.
[0015] It is a still further object of the present invention to provide a unique clamping device that automatically and comfortably conforms itself to whatever size of neck it is on.
[0016] It is a still further object of the present invention to provide a unique clamping device that makes it possible to take the tie off without untying, unclasping, unzipping, or unhooking any mechanism.
[0017] It is a still further object of the present invention to make it possible to put on the tie or take it off without pulling it over the wearer's head.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0018] FIG. 1 : Unique clamping device similar to sunglasses.
[0019] FIG. 2 : Unique clamping device similar to necklaces with memory wire.
[0020] FIG. 3 : Unique clamping device similar to a “slap bracelet” or measuring tape.
[0021] FIG. 4 : Unique clamping device similar to a spring, either round, flat, or of another shape.
[0022] FIG. 5 : Unique clamping device with multiple hinges.
[0023] FIG. 6 : Unique clamping device that is similar to a U-shaped hair band.
[0024] FIG. 7 : Unique clamping device with detachable knot and tie.
[0025] (NOTE: Whether shown in the Figures or not, all variations of the clamping devices can work with both a neck tie, or a bow tie.)
DETAILED DESCRIPTION OF THE INVENTION
[0026] (Comprising FIGS. 1-7 ) A pre-tied neck tie fabric ( 2 ) or bow tie fabric ( 4 ) in the usual customary form and design as viewed when tied and worn about the neck. The knot ( 6 ) consists of an elongated piece of fabric that has been either tied or formed to look like a a tied knot resembling the Four-in-one, Half-windsor, Full-windsor or bow tie style knots. For the necktie, a wide and narrow piece of fabric falls vertically from the knot and in front of the wearer's shirt ( 2 ). The bow tie consists of a horizontal fabric in the shape of a fabric bow ( 4 ). From either knot formation ( 6 ), two ends of material extend out of the knot horizontally forming a U shape ( 8 ). These ends may or may not touch each other at the back of the neck.
[0027] Within, or attached to the two horizontal ends ( 8 ) of fabric that extend horizontally out of the said knot ( 6 ) is a unique clamping device ( 10 ) which causes these two pieces of material, or neck band or loop as it were, to form around the shape of the neck and remain there until pulled off. This unique clamping device ( 10 ) runs through or behind the knot ( 6 ) and through or behind the U-shaped loop of the tie that encircles or nearly encircles the neck ( 8 ). These ends may or may not overlap each other behind the neck of the wearer, but also do not connect to each other with any device. The material for this unique clamping device ( 10 ) may be metal, plastic, a composite, or some other substance deemed fit. In all cases, it is reflexive, has memory, is spring like, and or is mechanical.
[0028] On the right hand side in FIGS. 2-4 , the unique clamping device is shown at rest ( 12 ), it may then shown opened to spread around the neck ( 14 ), and finally in its approximate position once around the neck ( 16 ).
[0029] In FIG. 1 , an example of a hinged clamping device is shown. It is comprised of 2 hinges ( 20 ) with its main pieces ( 18 ) folding and unfolding like a pair of sunglasses.
[0030] FIG. 2 utilizes memory wire ( 26 ) sewn into a fabric ( 24 ).
[0031] In FIG. 3 , a metal or plastic material is shown similar to that which is used in “slap bracelets” and or metal measuring tapes.
[0032] FIGS. 4 and 6 utilizes a reflexive, spring like material of either plastic or metal.
[0033] FIG. 5 is comprised of a series of slightly curved panels ( 18 ) that are hinged together ( 20 ) such that they want to curl inward and require force to spread outward. Or it could be as simple as having one hinge in the middle. There could be either, and/or an elastic band ( 22 ) within the inside of the hinged pieces ( 18 ) such that it would spring inward.
[0034] FIG. 7 shows a variation of the unique clamping device and neck or bow tie. Different designs of neck or bow ties ( 2 & 4 ) are attached or removed from the same unique clamping device ( 10 ) Represented in any of the previous unique clamping devices.
DRAWINGS PARTS LIST
[0035] Description of numbers as found in FIGS. 1 - 7 :
2 . Primary visible part of a neck tie excluding the knot 4 . Primary visible part of a bow tie tie excluding the knot 6 . Knot of neck or bow tie 8 . Horizontal end pieces of fabric that would normally encircle the neck from a neck or bow tie knot. 10 . The unique clamping device in any of its proposed variations 12 . Clamping device closed, or at rest 14 . Clamping device spread open to go around the neck 16 . Clamping device as it would appear around the neck 18 . Hinges 20 . Panels 22 . Elastic band 24 . Memory wire 26 . Fabric covering 28 . Fabric with a nap | A pre-tied necktie or bow tie that appears to be manually tied and fully encircling the neck but that is in reality comprised of a unique clamping device that clamps around the front of the neck beneath the collar enabling it to be quickly and easily put on or removed from the neck without pulling it over the head and without connecting or unconnecting the ends. | 0 |
This is a continuation of application Ser. No. 08/493,921 filed on Jun. 23, 1995 and now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to padded briefs for various apparel such as undergarments, trousers, and the like. More particularly, the present invention relates a new improved padded brief for men having removable pads.
2. Description of the Prior Art
Innovations for padded clothing apparel have a long history of use in the clothing industry and have enjoyed considerable success. For example, the padded brassiere for women has been in use in the United States and throughout the world for several decades and padded shoulder inserts, while generally newer in the art, have also enjoyed success.
Placing pads and the like into various clothing apparel can offer several advantages over non-padded apparel; added protection, enhanced shape, and added comfort and support. For example, a padded brassiere can enhance a woman's breast appearance or size by, depending on the exact positioning of the pad, providing additional undersupport for the breast thereby creating the illusion of larger breasts or, if the pads are positioned entirely over the breasts, by filling the wanting areas of the bra itself thereby creating the same illusion.
Although the "cod piece" has been around since the early 1600's, recently, several innovations for men's apparel have found their way into the padded apparel art. For example, one innovation provides an extra pad sewn into the front portion of a man's brief creating the illusion of a larger penile member. Other recent innovations include pads sewn into the rearward portion of a man's brief thereby creating the illusion of a fuller rearend (gluteus maximus) and/or providing support and protection for the same.
The main disadvantage to the above-mentioned male clothing products is that the pad or pads are permanently sewn or secured to the brief. Furthermore, the prior art devices don't allow for adjustability depending upon an individual's particular preference; various shaped and/or sized padding cannot be removed and/or inserted into the brief when desired.
While apparently generally acceptable for their intended functions, so far as is known, none of the prior art devices afford an improvement in padded briefs or undergarments comprising a garment shell having a frontal side and a rearward side and at least one pad removably attached and/or insertable at the rearward side of the padded brief and a means for removably attaching and/or inserting at least one pad at the rearward side of the padded brief.
In particular, and by and large, the prior art devices offer no adjustability or flexibility in use.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improvement on a men's padded brief or underpants having at least one pad removably positioned at the rearward side of the padded brief to enhance and/or enlarge the appearance of the wearer's rear end.
It is another object of the present invention to provide such a men's padded brief which is economical to manufacture, adjustable, flexible, yet durable, and relatively of simple construction and design.
Another object of the invention is to provide a padded brief which can be worn and easily adjusted in a delicate and safe and comfortable manner.
Still another object of the present invention to provide a padded brief in which the padding comes in several different shapes and sizes and is interchangeable depending upon an individual's particular preference.
Yet still, it is another object of the present invention to provide a men's padded brief having a resilient pad which can be inserted and secured in a relatively simple and quick manner.
Certain of the foregoing and related objects are attained in accordance with the present invention by the provision of an improved men's padded brief for various apparel such as underpants, boxer shorts, trousers, and the like. The improved padded brief comprising a garment shell having a front side and a rear side, the rear side having at least one pad removably mountable thereto and means for removably mounting the pad onto the rear side of the brief, whereby it will be positioned generally opposite to the rear end of the wearer thereby enlarging the appearance thereof
Preferably, the pad is removably mounted on the inner face of the rear side of the garment shell. Advantageously, the means for removably mounting the pad to the garment shell includes at least one garment panel secured to the inner face of the rear side forming at least one side pocket or sleeve in which the pad is removably insertable. Most desirably, the garment panel defines two pockets wherein two pads are provided each of which is insertable within an opposite one of the pockets. In some instances, however, it may be desirable to have several pockets and/or several differently shaped pads secured at different locations along the inner face of the rear side.
In a particular preferred embodiment of the present invention, the pockets and side panels are of semicircular shape. However, in some instances it may be desirable to have circular, oval, rectangular, or oddly shaped pockets, or, it may be desirable to have custom formed pockets for a particular user.
In the preferred embodiment, the panel is sewn onto the inner face of the garment shell, but it may be desirable to have the panel secured by Velcro, adhesive, snap-fit and/or other fastening means.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will become apparent from the following detailed description considered in connection with the accompanied drawings which disclose one embodiment of the present invention. It should be understood, however, that the drawings are designed for the purpose of illustration only and not as a definition of the limits of the invention.
In the drawings, wherein similar reference characters denote similar elements throughout the several views:
FIG. 1 is a rear elevational view of a men's padded brief embodying the present invention having a garment shell with two pads removably positioned therein;
FIG. 2 is a side elevational view of the padded brief shown in FIG. 1; and
FIG. 3 is a front elevational view of the brief rear panel illustrating insertion of one of the removable pads into one of the pair of pockets provided on the inside front face of the rear panel.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now in detail to the appended drawings, and in particular FIGS. 1 and 2, therein illustrated is an improved men's padded brief embodying the present invention generally designated by reference numeral 10. Brief 10 includes a garment shell 12 having a front side 14 and rear side 16, an upper circumferential elastic waistband 17 defining an upper opening and two leg openings 19a and 19b. The front side 14 of brief 10 is provided with a convenient slotted front opening 15 and the rear side 16 has pockets 20a and 20b formed on the inside or front face 16a thereof in which pads 18a and 18b are removably inserted, respectively.
FIG. 2 shows brief 10 in use or as worn and highlighting pad 18b with a preferred contour shape which is removably contained within pocket 20b. Pads 18a and 18b can be designed in a variety of shapes and sizes to accommodate the needs and desires of a particular user to create the desired effect; i.e., a fuller rear end.
Turning now to FIG. 3, the generally semicircular pockets 20a and 20b are sewn or stitched onto the inside face 16a of rearward side 16 with pocket openings 22a and 22b located adjacent to the rear end 24 of the crotch panel 25. Advantageously, pockets 20a and 20b are of generally semi-circular or arched shaped design and are preferably oppositely disposed on either side of mid-seam 26. Mid-seam 26 extends vertically from the rear end 24 of the crotch panel 25 to waistband 28. Desirably, pockets 20a and 20b have their respective base portions (diameters) positioned parallel to mid-seam 26 to create a more "natural" look. Pocket openings 22a and 22b generally of sufficient size and dimension to allow complimentary configured semi-circular foam pads 18a and 18b to be easily and facially inserted and removed therefrom while at the same time, providing sufficient retention to hold the same in proper position when the garment is worn; i.e., typically, the openings will be smaller than the greatest width of the resilient pads which can then be compressed to squeeze through the opening and then "re-expanded" to their normal size to completely fill the associated pocket. In a preferred embodiment, pocket openings 22a and 22b may be formed from elastic material to create the desired releasable retentive effect.
Various modifications may be made as will be apparent to those skilled in the art. For example, while the pads 18a and 18b are preferably made from sponge or foam rubber material, other resilient materials may be used as well such as soft plastic, feathers, cloth, leather and the like. In addition, pockets 20a and 20b although preferably made from the same cloth as garment shell 12, may be formed from a different material or provided with additional cushioning for comfort and/or added shape.
Moreover, pads 18a and 18b may be secured using alternate means for attachment such as Velcro, buttons, snaps and the like or other fastening systems. In addition, pads 18a and 18b may be of different shapes and/or sizes depending upon particular preference. In another embodiment, a single pad 18a or 18b might be designed to cover the entire desired portion to create a more natural look or a particular desired effect. Advantageously, pockets 20a and 20b are vertically disposed with each respective bottom opening, 22a and 22b, located substantially towards the bottom portion of the brief but other orientations (lateral, opening towards or at the top, or any combination thereof) may be desirable.
The invention is specifically designed for men's briefs but can be also be used with men's boxers, pants or trousers.
The pads 18a and 18b are preferably generally contour-shaped for their intended purpose; to create the illusion of a fuller rearend. Other embodiments can include a variety of different shapes and sizes depending upon particular preference and desirability.
Accordingly, while only one embodiment of the present invention has been illustrated in the appended drawings, it is to be understood that various modifications may be made as will be apparent to those skilled in the art. | A padded brief especially for men comprising a garment shell having a front side and a rear side and at least one pad removably mountable on the rear side of the padded brief. | 0 |
BACKGROUND OF THE INVENTION
Tall resilient unitary loads, such as large deformable tires for construction vehicles, or other large deformable approximately cylindrical loads such as straw bales, have previously been transported in tall vertical orientations either in a vertically uncompressed condition, as exemplified by U.S. Pat. Nos. 8,061,942 and 8,434,778, or in a vertically compressed condition as exemplified by U.S. Pat. No. 6,532,718.
A problem with the foregoing vertically uncompressed condition is that the tall height of the unitary load can prevent its insertion into commonly-used standard closed-top cargo-carrying containers. Such vertically uncompressed condition can also interfere with the load's passage under low-overhead obstacles.
Conversely, the foregoing vertically compressed condition presents a difficult problem of increased cost of time and machinery necessary to compress and then insert tall unitary loads into a closed-top cargo-carrying container prior to travel, and later decompress and remove the load from the container upon arrival at its destination.
Accordingly what is needed is an economical and effective system which can quickly vertically compress and insert tall resilient unitary loads into a standard closed-top cargo-carrying container having a lower interior height than the height of the uncompressed loads, and later quickly extract the compressed loads from their containers at their delivery destinations.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a side view of an example of a novel lift truck-mountable load handling clamp assembly, in accordance with the present invention, which is capable of satisfying the foregoing needs.
FIG. 2 is a front view of the exemplary clamp assembly of FIG. 1 .
FIG. 3 is a top view of the exemplary clamp assembly of FIG. 1 .
FIG. 4 is a side view of the exemplary clamp assembly of FIG. 1 shown preparing to engage an exemplary large-diameter resilient load in accordance with the present invention.
FIG. 5 is a side view of the exemplary clamp assembly of FIG. 1 shown vertically compressing the exemplary large-diameter resilient load of FIG. 4 and subsequently rotationally pulling the compressed load rearwardly toward the clamp assembly by horizontal retraction of the upper arm of the clamp assembly to more firmly grip the load.
FIG. 6 is a simplified schematic side view of the load handler of FIG. 5 exemplifying its subsequent insertion of the compressed resilient load of FIG. 5 into a vertically restricted open end of an exemplary conventional closed-top cargo-carrying container.
FIG. 7 exemplifies the load handler's subsequent deposit of the compressed load inside the open end of the container while still compressing the load.
FIG. 8 exemplifies the load handler's subsequent partial decompression of the load inside the cargo-carrying container permitting the load to expand upwardly.
FIG. 9 exemplifies the load handler's subsequent rolling of the partially decompressed load further into the cargo-carrying container into contact with a previously-inserted load and releasing the load from the grasp of the load handler.
FIG. 10 exemplifies extraction of the load handler from the load.
FIG. 11 exemplifies extraction of the load handler from the cargo-carrying container.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
A novel type of load handling clamp assembly is exemplified herein for compressing, loading and unloading of tall resilient unitary loads, such as large deformable tires for construction vehicles or other large deformable approximately cylindrical loads such as straw bales, by resiliently deforming them into curved shapes capable of being efficiently loaded, transported and unloaded in standard closed-top cargo-carrying containers having restricted heights normally unsuitable for transporting such tall loads. Although the particular embodiment of the clamp assembly exemplified herein is mounted on a conventional load handling lift truck, it should be understood that lift truck mountability, while desirable, is not intended herein to exclude alternative possibilities of incorporating the novel load handling clamp assembly integrally into self-propelled vehicles such as Automated Guided Vehicles, or into stationary clamping machines.
FIGS. 1-11 show side, front and top views, respectively, of one nonexclusive example of a load handling clamp, generally indicated as 10 , which satisfies the foregoing requirements of the improved system. It will be apparent to the skilled person that alternative variations of FIGS. 1-11 would also satisfy the foregoing requirements, and such variations are also intended to be covered hereby.
With reference to FIGS. 1-3 , the foregoing load handling clamp 10 includes a load-supporting carriage assembly generally indicated as 12 which is preferably supported on a conventional load-handling lift truck (not shown) by a conventional downwardly-facing elongate slidable hook 14 of a transversely-slidable load-supporting carriage 16 . The hook 14 and carriage 16 are slidable transversely on a slide member 18 , which supports the carriage hook 14 as shown in FIGS. 2 and 3 , in response to the selective extension or retraction of a side-shifting hydraulic cylinder 19 or other type of side-shifting actuator such a hydraulically or electrically-driven screw. It should be noted that hydraulically and/or electrically-driven actuators are considered to be interchangeable as actuators for purposes of the present invention.
The slide member 18 is supportably mounted on a conventional carriage of a lift truck (not shown) which can selectively raise or lower the entire carriage assembly 12 in a conventional hydraulic or electric manner in response either to a lift truck operator's manual command or automatically in response to lift truck programming, or a combination of both, as desired. The carriage assembly 12 preferably rigidly supports a lower forwardly-extending load clamping arm 20 as shown in FIGS. 1 and 2 , which is selectively vertically movable in response to the lift truck's raising or lowering of the carriage assembly 12 . The clamping arm 20 could also, or alternatively, be vertically pivotally supported on the carriage assembly 12 if desired.
With further reference to FIGS. 1-3 , protruding slidably upward from the carriage assembly 12 is an upper load clamping arm assembly, indicated as 22 , which opposes the lower load clamping arm 20 . The upper clamping arm assembly 22 is selectively vertically extensible and retractable with respect to the load-supporting carriage assembly 12 and lower load clamping arm 20 by a vertical hydraulic cylinder 24 as seen in FIG. 2 . Also, at the top of the upper clamping arm assembly 22 , multiple horizontally side-by-side hydraulic cylinders 26 are provided as seen in FIG. 3 to selectively horizontally extend or retract, in unison, an upper clamp arm 28 which is horizontally slidably supported on rail assembly 30 . The upper clamp arm assembly 22 utilizes the side-by-side multiple horizontal cylinders 26 in order to provide a powerful horizontal linear extension and retraction capability of the upper clamping assembly, while minimizing its vertical space requirement and thrust resistance by means of a gradual vertically offsetting clamp arm section 28 a . Thus the upper clamp arm 28 selectively slidably opposes the lower clamp arm 20 by means of the vertical hydraulic cylinder 24 , and also is selectively extensible and retractable horizontally with respect to the lower clamp arm 20 by means of the multiple horizontal hydraulic cylinders 26 which must extend and retract the clamp arm 28 in the extremely limited space between the top of the load and the top of a closed-top container, as explained hereafter. The multiple horizontal cylinders 26 could alternatively be replaced by a typical telescopic cylinder arrangement.
With reference to FIG. 4 , in a typical loading operation a resilient unitary load, such as a tall deformable construction tire 32 , can be approached along a direction 34 by a conventional lift truck upon which is mounted the above-described carriage 16 and its attached load handling clamp assembly 10 . Prior to such approach, the clamp arms 20 and 28 will have been spread apart by the cylinder 24 such that they can encompass the load 32 as shown in FIG. 4 , and the upper clamp arm 28 , 28 a will have been extended forwardly by the hydraulic cylinders 26 as also shown in FIG. 4 . The lower face of arm 20 will have been lowered preferably so as to touch, or be very close to, the surface upon which the tire 32 or other type of load is supported.
Thereafter the forwardly extended upper clamp arm 28 , 28 a can be moved downwardly, by retraction of the cylinder 24 , into contact with the top of the load 32 to compress it vertically, after which the hydraulic cylinders 26 can retract the upper clamp arm 28 , 28 a rearwardly thereby forcing the load to rotate clockwise as shown in FIG. 5 . Such rotation rolls the load toward the carriage 16 thereby securing the load more positively between the clamp arms, while also increasing the lift truck's counterbalanced load-lifting capacity by moving the load closer to the lift truck's front axle.
Such vertical compression of the load continues until the load is compressed to a height, as exemplified in FIG. 6 , whereby the top of the compressed load can fit below the horizontal roof beam or “header” 32 of a closed-top container 36 when lifted slightly by the lift truck to be inserted into the container 36 as shown in FIG. 6 . Then the compressed load is lowered onto the container floor by the lift truck as shown in FIG. 7 .
In FIG. 8 , the upper clamp arm 28 is raised by the cylinder 24 and the load is thereby preferably permitted to expand partially within the container while retaining sufficient compression to frictionally engage the load to push the load forwardly into the container. Thereafter the load can be further rolled forwardly, if needed, by extension of the upper clamp arm 28 as shown in FIG. 9 , thereby releasing the lower clamp arm 20 from beneath the load as also shown in FIG. 9 and facilitating subsequent retraction of the clamp arms from the load.
In FIG. 10 , the upper clamp arm 28 is retracted from the roll and lowered by the cylinder 24 to below the top of the container opening defined by the bottom of the foregoing “header” 32 of the container. In FIG. 11 the clamp 10 is retracted from the container, enabling closing of the container and shipment of the load therein.
Unloading of the container at its destination is by means of a substantial reversal of the foregoing steps of FIGS. 4-11 .
The terms and figures which have been employed in the foregoing specification are used therein as examples and not as limitations, and there is no intention, in the use of such terms and figures, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow. | A load handler is capable of loading and unloading tall unitary resilient loads such as large construction tires or other tall compressible loads such as bales normally considered incompatible for shipment in standard closed-top containers, to enable such compatibility economically. The load handler has a pair of vertically spaced load clamping arms, the upper arm being capable of rotating such a resilient load selectively onto or off of the lower arm while the load is compressed between the load clamping arms. | 1 |
BACKGROUND OF THE INVENTION
This invention relates to swimming pool vacuum cleaners.
Debris in swimming pool water, including fine particulate matter settled on the bottom of a pool, is conventionally removed by vacuum suction. Turbulence introduced by vacuum action tends to resuspend the fine particulate material in the pool water, dispersing it so that it is removed from the suction area of the vacuum apparatus and causing the pool water to become cloudy. Chandler, U.S. Pat. No. 3,949,442 and Broadwater, U.S. Pat. No. 4,338,697 disclose pool vacuums designed to avoid turbulence.
Pansini, U.S. Pat. No. 3,961,393, and Martin, U.S. Pat. No. 3,444,575 disclose pool vacuum heads incorporating water pump systems for creating an upwardly ascending vortex within the confines of the head unit to assist in capturing the fine particulate material before it can become dispersed and resuspended in the pool water; Smith, U.S. Pat. No. 4,018,483, discloses a directed pressure flow inlet and return system to dislodge dirt; and Combest, U.S. Pat. No. 4,254,525 discloses brush elements that work in conjunction with a rib structure to create a vortex that increases scrubbing water flow.
SUMMARY OF THE INVENTION
In general the invention features a device for removing foreign matter from a water-filled pool comprising a vacuum head equipped with a conduit connectable between suction means and a chamber-defining housing, and at least one agitation member rotatably connected to the inside of the chamber in position to be rotated by fluid suctioned from the chamber into the conduit, such that turbulence caused by the rotation dislodges fine particulate material from a pool surface.
In preferred embodiments, the agitator member is an elongated blade attached to the inside of the chamber by an axial shaft to rotate in a generally horizontal plane, the blade having fluid-deflecting surfaces pitched with respect to the shaft axis. Bristles are attached to the downward facing surfaces of the agitation member(s) and the vacuum head housing to dislodge particles from the pool surfaces and to contain particles within the chamber; and the head includes a partition member in the housing to define inner and outer chamber portions, the partition being supported from the housing by a plurality of narrow struts and having at least one port to communicate suction between the inner and outer chamber. The port(s) are adapted to receive removable agitator member(s) to rotate freely therewithin and to enhance turbulence in the vicinity of the ports. Agitator member(s) can optionally be dismounted and replaced with cover(s) to block the flow of water through a given port(s).
Alternately, the partition is supported from the housing to allow the partition to move vertically between an upper position, in which the partition seals against the housing to block liquid flow from the outer chamber to the conduit, and a lower position, in which the partition is spaced from the outer chamber to allow liquid flow from the outer chamber to the conduit. The partition support is resiliently biased toward the lower position, vertical partition movement to the upper position occurring in response to downward pressure on the vacuum head. A flange extends downwardly from the housing to sealingly co-operate with a peripheral groove in the partition when the partition is in its upper position, and the ports are equipped with resiliently hinged covers which cover the ports when the partition is in its lower position, and which pivot about the hinge to uncover the ports when the partition is in its upper position.
Turbulence created by rotation of the water current-driven agitator member(s) is localized within the vacuum head housing, preventing suspended particles from escaping the influence of the vacuum and mixing with pool water outside the vacuum head. This turbulence additionally tends to impede uniform channeling of water currents, distributing the effects of suction more evenly over the pool surface area defined by the vacuum chamber perimeter.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
I first briefly describe the drawings.
DRAWINGS
FIG. 1 is a perspective view of a pool vacuum head partially broken away.
FIG. 2 is a plan view of a pool vacuum head from below.
FIG. 3 is a detailed view of an agitator member for the vacuum head shown in FIGS. 1 and 2, partially in section.
FIG. 4 is a detailed view of a port plug, partially in section.
FIG. 5 is a perspective view of an alternate embodiment of a pool vacuum head partially broken away.
FIG. 6A and 6B are cross-sectional views of FIG. 5 taken along 6--6.
STRUCTURE
Referring to FIG. 1, swimming pool vacuum cleaner head 10 rests on a pool floor surface 36, and comprises a housing 12 that defines a suction chamber in communication with a suction tube conduit 14. Extension handle 52 is pivotally attached to the outside of housing 12. Within the chamber is a partition 16 having a plurality of (e.g., three) ports 18 whose angled walls 44 define a conical profile in partition 16. Each port 18 houses a shaft-mounted agitator member 20 designed to rotate freely in either direction. The agitator member 20 is driven solely by water flow, without any independent power source.
Housing 12, similar in shape to that of inner partition 16, is somewhat larger overall, such that partition 16 nests inside it with sufficient clearance that water under influence of the suction applied to conduit 14 may pass freely between the two. Thus, partition 16 forms an inner chamber (between the partition and the pool floor) and an outer chamber (between the partition and the housing) within housing 12.
Partition perimeter 22, as well as the bottom edge 26 of housing 12, are rimmed by rows of stiff bristles 32, 62 which aid in loosening fine particulate material from the surface 36 of the pool floor, and whose tips contact surface 36 to serve as support means for the cleaner head 10. Spacing between individual bristles 32, 62 is sufficiently narrow to impose a confining effect on water turbulence created within the perimeter of operating vacuum head housing 12, and yet is sufficiently wide to allow suctioned water to flow through the inner chamber, the outer chamber, or both before exiting the pool via conduit 14.
Referring to FIG. 2, partition 16 is supported by and separated from housing 12 by a plurality of bridging struts 24 which extend between the outer edge of perimeter 22 and the inner wall of downwardly slanted edge 26 of the housing 12.
Referring to FIG. 3, an agitation blade member 20 turning under the influence of vacuum suction creates turbulance in its vicinity which disturbs fine particulate material 28 and entrains material 28 in the water flowing from the pool via ports 18 and suction conduit 14. Optionally, the downward facing surface of each member 20 is provided with a row of fine scrubbing bristles 30 for dislodging particulate material from the pool floor surface 36, and for contributing to localized turbulance. These bristles 30 terminate slightly above the surface 36 to be cleaned such that contact with the pool floor surface 36 is made only when the user exerts downward pressure on the head 10, causing the partition/housing bristles 32, 62 to flex. Bristles 30 are sufficiently flexible to permit continued rotation of agitation member 20 even when light contact with surface 36 is made, i.e., the bristles 30 readily flex rather than produce increased friction with pool surface 36. Agitator member 20 comprises a central hub 39 mounted on a screw 38, a mounting bracket 34, and a pair of radiating blades 42 which are placed equidistant and axially about hub 39, and twisted so that each blade 42 forms part of a helical surface that is pitched with respect to the shaft axis.
Agitation member(s) 20 can optionally be removed from vacuum head 10 and replaced with port cover(s) 40, shown in FIG. 4, mounted by a screw 38, thereby eliminating flow of suctioned water through port(s) 18. Annular flange 43 extending from the upper surface of cover 40 mates with a corresponding groove 41 peripheral to each port 18 on the underside of partition 16 to facilitate sealing and to concentrically align each cover 40 with each port 18.
Use
In use, suction conduit 14 is coupled to an external vacuum source, and head 10 is submerged in a water-filled pool to rest on the floor 36 of the pool below water level. Vacuum head 10 is made to move along surface 36 by means of lateral pressure exerted by the user on handle 52. Downwardly extending bristles 32, 62 contact surface 36 with their tips and provide a means of support for vacuum head 10, as well as a scrubbing action effecting removal of material adhered to or settled onto the wall's surface. Vacuum applied to suction conduit 14 causes water surrounding head 10 to flow between each of the bristles 32, 62 into the area defined by projecting lip 26 of casing 12, where it exits the pool via conduit 14. The water flowing under the influence of the applied vacuum causes agitator members 20 to rotate creating a sphere of turbulence which is confined by projecting bristles 32 adjacent to the pool floor surface. Particulate material 28 loosened by this action is drawn by the current into conduit 14 via ports 18 and thereby removed from the pool. Absent such rotation, the water flow adjacent partition 16 would assume paths of least resistance that generally comprises narrow current pathways across the pool surface 36 into ports 18, leaving particulate material undisturbed on the areas of surface 36 not contacted by the currents.
ALTERNATE EMBODIMENT
An alternate embodiment shown in FIGS. 5, 6A, and 6B, has the features of the preferred embodiment except for the modifications described below which serve to direct water flow to selected regions within vacuum head 10. Partition 16 is suspended from the inner surface 56 of outer chamber 12 by tension members 69; stiff bristles 62 are replaced by angled springy bristles 54; ports 18 are fitted with hinged covers 50; and the inner surface 56 of housing 12 is fitted with projections 58 and barrier rim 64.
In the alternate embodiment, suctioned water flow is alternately directed either in a path through ports 18, or in a path between partition 16 and housing 12, but is unable to flow in both paths simultaneously. Vacuum head 10 resting on surface 36 is supported by springy bristles 54, which are sufficiently long to prevent contact of partition bristles 32 with surface 36 in the absence of downward force. In response to lateral forces applied by user to move head 10 over surface 36, bristles 54 flex somewhat, but not enough to allow bristles 32 to contact surface 36. Under these conditions, spring-loaded covers 50 are closed, and suctioned water flows through the region 66 defined by partition 16, and inner surface 56 of housing 12. However, when scrubbing action is desired, downward pressure exerted by the user simultaneous with applied lateral forces, causes bristles 54 to bend substantially whereby bristles 32 firmly contact surface 36. Bristles 32 resist bending under sustained downward pressure, and thus transfer the applied force via partition 16 to tension members 69 whose resilient springs 68 readily compress.
Compression of springs 68 enables barrier 64 to mate with recess 70 and projections 58 to contact tabs 60 at the same moment, overcoming the opposing force provided by springs 74 and resulting in the opening of ports 18 and the diversion of suctioned water from region 66 to flow through ports 18. Recess 70 is provided an O-ring 72 to facilitate a seal with barrier 64. The underside of cover 50 is adapted to receive an O-ring 49 positioned to contact the upper edge of port 18 which is recessed with a semi-circular groove 19 in which O-ring 49 is seated when cover 50 is in the closed position. In the absence of active scrubbing, bristles 32 have no contact with surface 36 and springs 68 and 74 respectively provide sufficient resilience to separate barrier 64 from recess 70 and to maintain covers 50 in position blocking ports 18, providing flow of suctioned water exclusively through region 66. By restricting the area through which suctioned water may pass, an increase in relative suction is achieved over that of the preferred embodiment, in which flow of suctioned water is unrestricted.
The above described description provides specific features of one vacuum head according to the invention. A description of general features of a vacuum head is provided in Braukmann, U.S. Pat. No. 4,498,206 which is hereby incorporated by reference.
Other features and embodiments are within the following claims. | A device for removing foreign matter from a water-filled pool comprising a vacuum head equipped with a conduit connectable between suction means and a chamber-defining housing, and at least one agitation member rotatably connected to the inside of said chamber in position to be rotated by fluid suctioned from said chamber into said conduit such that turbulance caused by said rotation may dislodge fine particulate material from a pool surface. | 4 |
This is a continuation of application Ser. No. 244,911, now abandoned, filed Mar. 18, 1981 which is a Rule 60 continuation of Ser. No. 9,360, filed Feb. 5, 1979, also abandonded.
BACKGROUND OF THE INVENTION
The present invention relates to a fuel injection system for an internal combustion engine, and more particularly it relates to a fuel injection system in which an amount of fuel supplied to an internal combustion engine is electrically controlled.
In a fuel metering system for an internal combustion engine, it is well known that an electromagnetic valve which opens to inject a pressurized fuel is disposed in each of a group of intake manifolds communicating with respective cylinders of the engine and that a pressure regulator is provided to regulate a pressure of the pressurized fuel at a constant value. The electromagnetic valve is activated in synchronized relation with the rotation of a crankshaft of the engine and an opening interval of time τ(τ=K'·Qa/N where K': constant) is determined by an electric control circuit in response to a rotation speed N of the crankshaft and an amount of air Qa sucked through an intake pipe communicating with the intake manifolds. From cost saving spirits, this conventional fuel injection system is not desirable, since as many electromagnetic valves as the number of cylinders are necessitated.
To provide a fuel injection system which is low in manufacturing cost, it is suggested that the electromagnetic valve is disposed singly in the intake pipe and that the electromagnetic valve is activated by the electric control circuit at least as many times as the number of suction strokes of the engine. According to this suggestion, an allowable maximum opening interval of time τ M of the electromagnetic valve under the maximum rotation speed (6,000 r.p.m.) of the crankshaft is determined as follows on an assumption that the engine is in a four-cylinder four stroke type.
τ.sub.M =1/((6,000/60)·(1/2)·4)=0.005 (sec.)
Since the maximum opening interval of time of the electromagnetic valve is required in general to be four times longer than the minimum opening interval of time of the electromagnetic valve,. the minimum opening interval of time τ m at the maximum rotation speed (6,000 r.p.m.) is limited as follows.
τ.sub.m =τ.sub.M /4=0.00125 (sec.)
Since the electromagnetic valve has a response delay time, generally some 0.001 (sec.), from closing to opening, the response delay time is not negligible relative to the minimum opening interval of time τ m . This means that a precise fuel metering cannot be performed by the electromagnetic valve.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide an improved fuel injection system which is low in manufacturing cost and precise in fuel metering operation.
According to the present invention, an electromagnetic valve activated at least as many times as the number of suction strokes in an engine is disposed upstream of a throttle valve in an intake pipe and a pressure regulator is provide to regulate a pressure of pressurized fuel supplied to the electromagnetic valve in proportion to an intake pressure present at a position downstream of the throttle valve. This arrangement is effective to keep the response delay time of the electromagnetic valve negligible relative to the minimum opening interval of time of the electromagnetic valve in the following manner.
Assuming that the electromagnetic valve is activated as many times as the number of suction strokes in the engine, an amount of fuel q F supplied to the engine in each opening of the electromagnetic valve is determined as follows: ##EQU1## where k 1 represents a constant, P F represents a difference in pressures of fuel present at an inlet and outlet of the electromagnetic valve, and τ represents an opening interval of time of the electromagnetic valve. The amount of fuel q F may be expressed as follows:
q.sub.F =q.sub.a /M (2),
where q a represents an amount of air sucked into each cylinders in each suction stroke and M represent an airfuel ratio of mixture. From these equations (1) and (2), the opening interval of time τis expressed as follows. ##EQU2## The amount of air q a sucked into each cylinder is expressed q a =k 2 ·(Q a /N) (k 2 :constant), and an intake pressure P I present at the downstream of the throttle valve is expressed as P I =k·(Q a /N) (k: constant) in an absolute pressure notation. Further, the pressure difference P F is expressed as P F =k 3 ·P I +P O -P, where k 3 represents a constant, P O represents a constant, P O represents in absolute pressure notation an initial pressure of fuel supplied to the inlet of the electromagnetic valve, and P represents in absolute pressure notation a pressure present at the outlet of the electromagnetic valve. In view of these equations, the opening interval of time τ expressed by the equation (3) is expressed as follows: ##EQU3## where K represent a constant. Since the amount of air q a is expressed as q a =k 4 ·P I (k 4 :consant), the equation (4) may be expressed as follows in an alternative form: ##EQU4## where K 1 and K 2 represnet constants.
It should be noticed in the equations (4) and (5) that, since the initial pressure P O of the pressurized fuel is constant and the pressure P present at the throttle upstream in substantially equal the atmospheric pressure, the opening interval of time τ changes in response to the intake pressure P I present downstream of the throttle or the quotient Q a /N between the amount of air Q a and the rotation speed N. That is, the opening interval of time τ is required to change in proportion to the square root value √P I or √Q a /N. This means that, although the maximum value of the intake pressure P I or the quotient Q a /N is generally four times larger than the minimum value, the required range of change in the opening interval of time τ may be smaller than the range of change in the intake pressure P I or the quotient Q a /N. Therefore, the minimum opening interval of time of the electromagnetic valve may be lengthened to keep the response delay time of the electromagnetic valve more negligible.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a schematic diagram showing a first embodiment of the present invention;
FIG. 2 is an electric wiring diagram of an electric control circuit used in the first embodiment shown in FIG. 1;
FIG. 3 is an electric wiring diagram of a function generator used in the electric control circuit shown in FIGS. 1 and 2;
FIG. 4 is a characterized chart showing an input-output characteristic of the function generator shown in FIG. 3;
FIG. 5 is a schematic diagram showing a second embodiment of the present invention; and
FIG. 6 is a sectional view showing a modification of a pressure regulator used in the first and second embodiments respectively shown in FIGS. 1 and 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring first to FIG. 1 in which a first embodiment of a fuel injection system according to the present invention is shown, numeral 1 designates a multi-cylinder engine which sucks air into each cylinder during the suction stroke. The air is sucked through an air filter 2, a throttle valve 3 and an intake manifold 4. Fuel supplied from a fuel reservoir 5 is pressurized by a fuel pump 6 and is supplied to the fuel inlet of an electromagnetic valve 7. The fuel outlet of the electromagnetic valve 7 is disposed at the upstream of the throttle valve 3 provided in an intake pipe of the engine 1. Since the presence decrease in the air filter 2 is negligible, the pressure P present at around the fuel outlet of the electromagnetic valve 7, or at the upstream of the throttle valve 3, is substantially equal to the atmospheric pressure.
The pressure of fuel supplied to the inlet of the electromagnetic valve 7 is regulated by a fuel pressure regulator 8. Pressure regulation in the pressure regulator 8 is performed in response to the intake pressure P I present at the downstream of the throttle valve 3. The pressure regulator 8 is provided with a flexible diaphragm 82 which partitions the regulator 8 into a fuel chamber 82a and a vacuum chamber 82b and moves a needle valve 81 for bypassing the pressurized fuel from the fuel pump 6 to the fuel reservoir 5. The fuel chamber 82a provided at one side of the diaphragm 82 receives the pressurized fuel which acts upon the diaphragm 82, and the vacuum chamber 82b provided at the other side of the diaphragm 82 receives the intake pressure P I present downstream of the throttle valve 3. In the pressure regulator 8, a spring 83 is provided in the vacuum chamber 82b to bias the needle valve 81 to close. Assuming that the atmospheric pressure is introduced into the vacuum chamber 82b the spring 83 determines the initial pressure P O of fuel supplied to the electromagnetic valve 7. The diaphragm 82 moves to open the valve 81 in response to the intake pressure P I which is lower than the atmospheric pressure so that the pressured fuel is regulated at a valve which is lower than the initial pressure P O .
For detecting operating conditions of the engine 1, an air flow meter 9 which produces an electric intake air analog voltage V a indicative of the amount of sucked air and a rotation angle detector 10 which produces an electric angular pulse voltage v indicative of a predetermined angular rotation of a crankshaft 1a are provided. flow meter 9 provided upstream of the intake pipe comprises a measuring plate which is disposed in the intake pipe and biased by a biasing spring so that the biased measuring plate moves in response to the flow of sucked air, and a potentiometer associated with the measuring plate for converting the movement of the measuring plate into the analog voltage. Rotation angle detector 10 which produces the pulse voltage v at each suction sroke comprises an inductor 10a provided on the crankshaft 1a of the engine 1, and an electromagnetic pick-up 10b provided to face the inductor 10a. With the engine 1 having four cylinders, the pulse voltage v is produced each time the crankshaft 1a attains a half rotation. In addition, an oxygen detector 12 which produces an electric ratio voltage V.sub.λ indicative of the air-fuel ratio of air-fuel mixture supplied to the engine 1 and a temperature detector 14 which produces electric temperature voltage indicative of the temperature of engine coolant are provided at a downstream of a three-way catalyst 13 and on a radiator 15, respectively. An electric control circuit 11 connected to receive these voltages calculates a required interval of time τ of the electromagnetic valve 7.
Referring next to FIG. 2 in which the electric control circuit 11 is shown in detail, numeral 24 designates a frequency-voltage coverter which converts the number of pulse voltages v produced from the rotation angle detector 10 into an analog rotation voltage V N indicative of the rotation speed of the crankshaft 1a. Numeral 22 designates a first divider which divides the intake air voltage V a produced from the air flow meter 9 by the rotation voltage V N . Numeral 25 designates a second divider which divides the rotation voltage V N by the intake air voltage V a to produce an output voltage indicative of a value (P O -P)/k·k 3 )·(V N /V a ) (P O-P )/k·k 3 ) being constant). Numeral 26 designates a constant voltage generator which produces a constant voltage V 1 . Numeral 27 designates an adder which adds the constant voltage V 1 to the output voltage (P O -P)/(k·k 3 )·(V N / V a ) of the second divider 25. Numeral 28 designates a third divider which devides the output voltage V a /V N of the first divider 22 by the output voltage (V 1 +(P O -P)/k·k 3 ))·(V N /V a ) of the adder 27. Numeral 29 designates a square root calculator which calculates a square root value ##EQU5## from the output voltage of the third divider 29. Numeral 31 designates a function generator which generates a function voltage V M proportional to a desired air-fuel mixture ratio M. The rotation speed voltage V N is applied to the function generator 31 so that the air fuel ratio M may be determined in response to the rotation speed N of the engine 1. In addition, a coolant temperature voltage V t indicative of the coolant temperature T w detected by the coolant temperature detector 14 and an oxygen cencentration voltage V.sub.λ indicative of the oxygen concentration in exhaust gases may be applied so that the air-fuel ratio M may be determined more precisely as described later. Numeral 32 designates a fourth divider which divides the output voltage of the square root calculator 29 by the air-fuel ratio voltage V M of the function generator 31 to produce a fuel voltage ##EQU6## This fuel voltage V F represents in an analog voltage form the opening interval of time τ obtained in the equation (4) which determines the amount of fuel q F injected in each operation of the electromagnetic valve 7. Numeral 33 designates a voltage-controlled timer pulse generator which produces the timer pulse voltage having the interval of time T synchronized with the pulse voltage v applied from the rotation angle detector 10. This interval of time T is varied in proportion to the fuel voltage V F and includes desirably a constant interval corresponding to the response delay time of the electromagnetic valve 7. With this timer pluse voltage being applied to the electromagnetic valve 7, the opening interval of time of the electromagetic valve 7 activated at every suction strokes of the engine 1 is controlled to a value τ obtained in the equation (4). Model 4450 manufactured by TELEDYNE INC. in U.S.A. may be used as the dividers 23, 25, 28 and 32, and model 4353 manufactured by TELEDYNE INC. in U.S.A. may be used as the square root calculator 29.
The function generator 31 is shown in detail in FIG. 3, in which numerals 103 and 104 designate comparators which produce high level voltage, respectively, when the rotation speed voltage V N is above a predetermined rotation voltage V N1 corresponding to a low rotation speed N 1 and is below a predetermined rotation voltage V N2 corresponding to a high rotation speed N 2 . These high level output voltages are applied to an AND gate 105 which responsively closes an analog switch 124. Numeral 121 designates a comparator which discriminates whether the voltage V.sub.λ is above or below a predetermined value. The output voltage of the comparator 121 is integrated by an integrator comprising a resistor 122 and a capacitor 123. An integration output voltage is applied to an adder 125 through the analog switch 124. The adder 125 adds a constant bias voltage to the integration output voltage to produce a first air-fuel ratio voltage V M1 . Accordingly, when the rotation speed N is higher and lower than the speeds N 1 and N 2 , respectively, the analog switch 124 closes and the output voltage V M1 of the adder 125 indicates that the air-fuel ratio M of mixture supplied to the engine 1 is to be controlled at the stoichiometric air-fuel ratio. When the rotation speed N is below or above the speed N 1 or N 2 , respectively, the output voltage V M1 is determined by a voltage divider 126. The temperature voltage V t produced from the temperature detector 14 is applied to a differential amplifier 141 which produces a second air-fuel ratio voltage V M2 . The output voltages V M1 and V M2 are applied to a low voltage selector comprising two diodes 151 and 152 and a resistor 153. The selector selects lower one of two input voltage V M1 and V M2 .
The function pattern of the air-fuel ratio voltage V M determined by the above-described function generator 31 is shown in FIG. 4 in which the abscissa and the ordinate represent the rotation voltage V N and the air-fuel ratio voltage V M , respectively. When the temperature voltage V t is equal to or above a predetermined value V t0 after engine warm-up, the function pattern is determined as shown by the line F-G-H-I-J-L. With V t being equal to a predetermined value V t1 smaller than V t0 , the function pattern is determined as shown by the line M-P. As the temperature voltage V t is increased from V t1 toward V t0 , the function pattern M-P moves upward in FIG. 4 so that the air-fuel ratio voltage V M is modulated within a hatched region in FIG. 4.
Referring to FIG. 5 in which a second embodiment of the fuel injection system according to the present invention is shown, it should be noted that a venturi portion comprising a large venturi 101 and a small venturi 102 is provided in the intake pipe at the upstream of the throttle valve 3. The fuel outlet of the electromagnetic valve 7 is communicated with the small venturi 102 via a fuel nozzle 103. It should be further noted that an intake pressure detector 9' is disposed at the downstream of the throttle valve 3 to produce an intake pressure voltage V p applied to an electric control circuit 11' and that the oxygen detector 12 and the temperature detector 14 are disposed upstream of the catalyst 13 and on the engine 1, respectively. The second embodiment other than these is the same as the first embodiment. The electric control circuit 11' which receives the intake pressure voltage V p from the pressure detector 9' may be designed with ease in view of the first embodiment to calculate the required opening interval of time τ in response to the intake pressure P I present at the downstream of the throttle valve 3. Therefore, no further description relating to the control circuit 11' is made.
In the second embodiment, the venturi portion 101 and 102 and the fuel nozzle 103 are effective to atomize the fuel metered by the electromagnetic valve 7 into small particles. When the intake pressure P I is low due to small opening of the throttle valve 3, the pressure of fuel metered by the electromagnetic valve 7 remains low. Therefore, the fuel is likely to be injected from the fuel nozzle 103 in large particles. However, since the venturi portion is provided where the fuel is injected, the fuel injected is atomized favorably by the air flowing through the venturi portion at comparatively high speeds. When the intake pressure P I is high due to large opening of the throttle valve, the pressure of fuel metered by the electromagnetic valve 7 is kept high. Therefore, the fuel injected from the fuel nozzle 103 is atomized into small particles more favorably.
In the first and second embodiments, it should be noticed that, since the pressure in the vacuum chamber 82b of the pressure regulator 8 changes at most from the atmospheric pressure to the minimum intake manifold vacuum pressure, a fuel pressure change larger than one atmosphere may not be obtained with the diaphragm 82 having a fuel pressure receiving area and an intake pressure receiving area equal to each other. To obtain a larger fuel pressure change, the pressure regulator 8 may be modified as shown in FIG. 6. The pressure regulator 8 is provided with two diaphragms 821 and 822 which receive the fuel pressure and the intake vacuum pressure, respectively. With the diaphragms 821 and 822 the respective pressure receiving areas S 1 and S 2 of which are in such a relation as S 1 >S 2 , a pressure change of the fuel supplied to the inlet of the electromagnetic valve 7 may be increased in accordance with the difference between the areas of the diaphragms 821 and 822. In FIG. 6, numeral 86 designates a bypass outlet which bypasses the fuel supplied from the fuel pump 6 through a fuel inlet 85 to the fuel reservoir 5. The amount of fuel which is to be bypassed through the bypass outlet 86 is regulated by the needle valve 81. The diaphragms 821 and 822 are spaced from each other by a predetermined value. Numeral 88 designates an atmosphere inlet which introduces the atmospheric pressure into an atmospheric pressure chamber 82c provided between the fuel chamber 82a and the vacuum chamber 82b. The intake vacuum pressure P I is supplied through an inlet 87 to vacuum chamber 82b. Assuming that the area of the diaphragm 821 is γ times larger than that of the diaphragm 822, the change of the fuel pressure is γ times larger than that of the intake manifold pressure P I . This modified pressure regulator 8 is effective to decrease the required range of change in the opening interval of time of the electromagnetic valve 7.
The present invention is not limited to the embodiments described hereinabove but may be modified without departing from the spirit of the invention. As one of modifications, the electromagnetic valve which intermittently meters the fuel may be energized at a constant frequency when the rotation speed of the engine is high. | In a fuel injection system which electrically controls an amount of pressurized fuel supplied to an internal combustion engine, an electromagnetic valve which opens to inject the pressurized fuel is disposed at an upstream of a throttle valve in an intake pipe so that a group of cylinders of the engine is supplied with fuel therefrom. A pressure regulator is provided to regulate a pressure of the pressurized fuel in proportion to an intake pressure present at a downstream of the throttle valve. | 5 |
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/006,809, filed on Jan. 31, 2008.
FIELD OF THE INVENTION
[0002] The invention relates to the manipulation and control of pipe stands used in for instance the petrochemical industry. In particular, the invention relates to the control of pipe stands, as they are disengaged from drill strings on extraction from a well bore.
BACKGROUND OF THE INVENTION
[0003] On the completion of the drilling of a well bore, which maybe up to several hundred metres deep, the removal of pipes can be a time consuming exercise. Further, as the pipes are of a considerable size, for instance up to 200 mm (9⅝″) in diameter and up to 9.1 metres (30′) long these pipes also present problems in handling in an efficient and safe manner. This is particularly so for applications where a pipe stand (that is 3 pipes joined) are stored, and so having a section 27.4 metres (90′) in length.
[0004] As the pipes are withdrawn, one method of controlling and storing the pipe stand is to individually lift them into a rack as the drill string is extracted. However, the time taken for each pipe to be moved in such a manner, can be a considerable. Further it is a logistically difficult exercise to both lift and move a pipe into a rack particularly for the first pipe within the rack as the lateral distance to be moved maybe significant. It follows that during this activity accidents may occur during replacement within the rack and therefore present a safety problem.
SUMMARY OF INVENTION
[0005] It is therefore an object of the present invention to improve either speed of handling or safety, as compared to systems of the prior art.
[0006] In a first aspect the invention provides a racking assembly for receiving and storing at least one pipe, the racking assembly comprising a setback assembly including a selectively rotatable member having a plurality radial slots sized to receive a first portion of the at least one pipe in sliding engagement, and a base placed distal from the selectively rotatable member and coupled thereto so as to permit mutual rotation, said base arranged to support the at least one pipe on a support face of said base; a barrier located about a peripheral edge of the base, such that the setback assembly rotates relative to the barrier, said barrier arranged to prevent the at least one pipe from moving radially from said base, said barrier having a gap sized to permit selective lateral movement of the at least one pipe; wherein mutual rotation of the selectively rotatable member and the base permit alignment of the gap and a selected slot of said selectively rotatable member, and so permitting the pipes stands to be moved laterally into said setback assembly.
[0007] In a second aspect the invention provides a method of receiving and storing at least one pipe, the method comprising the steps of: providing a setback assembly, said setback assembly including a selectively rotatable member with a plurality radial slots and a base placed distal from the selectively rotatable member and coupled thereto so as to permit mutual rotation; engaging the pipe in any of said slots and; moving the pipe laterally so as to slide along said slot and be placed on said base.
[0008] In a third aspect the invention provides a guide assembly for receiving a pipe and moving said pipe to an outlet position, the assembly comprising a first and second support assembly for engaging the pipe, said assemblies in spaced relation to engage distal portions of said pipe; said support assemblies arranged to rotate as a single entity so as to rotate the pipe from an engaging position to the outlet position.
[0009] In a fourth aspect the invention provides a method for receiving a pipe and moving said pipe to an outlet position, the method comprising the steps of: engaging the pipe with a first and second support assembly, said assemblies in spaced relation to engage distal portions of said pipe; rotating said support assemblies and so rotating the pipe from an engaging position to the outlet position.
[0010] In a fifth aspect the invention provides a pipe delivery system comprising a base to which pipes are delivered; a support block for supporting a plurality of pipe; said base having at least one slot sized to allow the support block to project from or retract into said base, said slot further sized to prevent said pipe to pass there through; wherein the support block is arranged to move along said slot, projecting from said slot with said pipe and to selectively retract below said base so as to position the pipe on said base.
[0011] In a sixth aspect the invention provides a method of delivering a plurality of pipes to a base, the method comprising the steps of: supporting the plurality of pipes on a support block; projecting the support block from a slot in said base; moving the support block along said slot whilst projecting from said slot with said pipes and; selectively retracting below said base so as to position the pipes on said base.
[0012] In one aspect, the invention provides for a more direct lateral placement of the pipe or pipe stand, instead of, for instance, a lift and drop system. This may increase the speed of positioning; as well avoid injury during the dropping step.
[0013] In a further aspect the lateral movement or delivery of the pipe into the rack may be provided as array of pipes (or pipe stands) with the delivery system moving several pipe stands in one movement into the rack in a controlled environment.
[0014] It will be noted that the invention is equally applicable to the storage of both pipes and pipe stands. Accordingly, these terms may be interchanged without limiting the scope of the invention, unless specifically identified as such.
BRIEF DESCRIPTION OF DRAWINGS
[0015] It will be convenient to further describe the present invention with respect to the accompanying drawings to illustrate possible arrangements of the invention. Other arrangements of the invention are possible and consequently the particularity of the accompanying drawings is not to be understood as superceding the generality of the preceding description of the invention.
[0016] FIGS. 1A to 1C show various views of a setback assembly according to one embodiment of the present invention;
[0017] FIGS. 2A and 2B show various views of storage racks according to a further embodiment of the present invention;
[0018] FIGS. 3A and 3B show a guide assembly according to a further embodiment of the present invention;
[0019] FIGS. 4A to 4D show various views of a racking assembly according to a further embodiment of the present invention;
[0020] FIGS. 5A to 5F show a delivery system according to a further embodiment of the present invention.
DETAILED DESCRIPTION
[0021] FIGS. 1A , 1 B and 1 C show a racking assembly designed to receive and store pipes, or pipe stands, as they are removed from a well centre. Drill strings comprise individual pipe stands which are connected as the bore is drilled deeper in order to meet the exploration or hydrogen extract objective. On completion of the objective the drill string will be removed with the pipe stands each disconnected from the drill string as each pipe stand fully emerges from ground, or water in the case of drilling from a ship.
[0022] Each pipe can be up to 6 meters (30′) long and up to 200 mm (9⅝″) in diameter, with a pipe stand typically relating to 3 pipes connected in series and so 3 times the length. Further the wall thickness of the pipe may be considerable such as up to 25 mm and therefore each pipe stand will be of significant weight. The target rate of disengaging each pipe stand and storing ready for further withdraws of the drill string is 60 stands an hour, or one minute per stand. It will be appreciated that this is a significant rate and may not be achieved by many, if any, existing systems. Accordingly the present invention seeks to accelerate the rate of processing of the pipe stands and therefore includes features arranged to either accelerate such processing or maintain acceptable rates at far higher levels of safety than are currently available according to the prior art.
[0023] FIGS. 1A to 1C show one embodiment of the present invention. A racking assembly 5 includes a fingerboard assembly 10 at the top of the racking assembly 5 with a base assembly 15 at the bottom. In this embodiment the racking assembly includes two parallel setback assemblies made up of a fingerboard 25 a , 25 b corresponding to a base 20 a , 20 b . Each setback assembly acts independently in this case and in fact the invention requires only one such setback assembly with the second setback assembly increasing the overall storage capacity of the device.
[0024] The fingerboard 25 a , 25 b is connected to the corresponding base 20 a , 20 b by a vertical shaft 45 a , 45 b . The shaft ensures that each fingerboard and base rotates together, that is mutual rotatability.
[0025] The racking assembly 5 further includes a pair of racker arms 35 , 40 which engage an upper and lower portion of a pipe stand (not shown) and deliver the pipe stand to the fingerboard and base. In this embodiment a guide assembly, in this case slot machine assembly 30 , 32 are included however the racking assembly according to the present invention does not require the intermediate guide assembly.
[0026] For convenience the racker arms 35 , 40 are mounted to a guide assembly shaft 50 . In a further embodiment the racker arms may be conveniently place elsewhere and in fact for further convenience additional pairs of racker arms may be included so as to further engage pipe stands as they become available, subject to the speed and availability of the racking assembly to accommodate such pipe stands, at a faster rate.
[0027] Further shown in this embodiment are fingerboard pushers 26 a , 26 b which act to facilitate positioning of the pipe stands once engaged, should this be required. FIGS. 2A and 2B show setback assembly, and in particular the fingerboard assembly 10 and base assembly 15 in greater detail. The fingerboard assembly 10 comprises a fingerboard plate 11 with the two fingerboards 25 a , 25 b rotatable within the plane of fingerboard plate 11 .
[0028] Further included is a recess in which the top guide assembly 30 is located with an inlet 65 through which the upper part of the pipe stand enters the guide assembly as manipulated by the upper racker arm 35 . As will be explained in greater detail later, the guide assembly 30 engages the pipe stand as it enters the inlet 65 and rotates so as to deliver the pipe stand to a slot 60 which has been rotated to correspond to the outlet 75 . As will further be discussed later, in this embodiment a pipe delivery system such as a cam lifter 55 may act to facilitate the more rapid placement of each pipe stand by the guide assembly placing several pipe stands on the cam lifter 55 before said pipe stands are delivered as an array of pipes into the corresponding slot 60 .
[0029] FIG. 2B shows the base assembly 15 having two bases 20 a , 20 b which correspond to the aforementioned fingerboards 25 a , 25 b . As the pipe stand is delivered to the racking assembly the bottom portion of the pipe stand is simultaneously engaged by the lower racker arm 40 and delivered to the bottom guide assembly 32 . The top and bottom guide assemblies are synchronized to rotate together to deliver the pipe stand to, in this embodiment, a cam lifter 55 for placement within the assembly. A key feature of the racking assembly according to the present invention is the base arrangement whereby a barrier 21 a , 21 b is positioned about an edge of the base. The barrier is fixed relative to the base such that the base will rotate maintaining the barrier in the same position. The barrier 21 a , 21 b includes a gap 90 though which the lower portion of a pipe stands may pass. Thus the racking assembly according to the present invention does not require a “lift and drop” placement such as that known in the prior art. A racking system is disclosed in WO02/18742, the contents of which are incorporated herein. This system requires each pipe stand to be lifted and then dropped into a corresponding lower fingerboard so as to be secured. Further the lifting and lowering is achieved by racker arms which must be controllable to a sufficient degree so as to correspond to the slot within the bottom fingerboard. Not only is it time consuming the lifting and lowering may involve a safety issue given the weight of each pipe stand and the pressure of maintaining a steady storage rate of pipe stands.
[0030] By comparison, the racking assembly according to the present invention merely slides each pipe into place and thus eliminating the “lift and drop” approach of the prior art. Each pipe stand or array of pipe stands located within individual slots of the top fingerboard 25 a , 25 b are maintained in position by the fingerboard plate 11 at the top and by the barrier 21 a , 21 b at the lower portion. A further advantage includes the ease of manufacture of the base as compared to a lower fingerboard according to the prior art, having several slots formed to accommodate the respective pipe stands.
[0031] FIGS. 3A and 3B show respective detail views of the upper guide assembly 30 and lower guide assembly 32 according to a further aspect of the present invention. The guide assembly 30 , 32 acts as an intermediary placement mechanism. It will be appreciated that the guide assembly 30 , 32 may also be incorporated into different racking assemblies. Whilst there is distinct advantage in the use of the racking assembly 5 with the guide assembly 30 , 32 , advantage can also be gained by using the guide assembly in other systems. Equally the racking assembly 5 also has advantage without the guide assembly 30 , 32 compared to the prior art which of course can benefit further by combining these two key elements.
[0032] FIG. 3A shows the top guide assembly 30 having a pipe guide 72 which is shaped to guide the shaft of the pipe stand directly below the spigot head of the pipe. Not shown are latches that act to keep the pipe stand in place, and so acting as a mechanical lock, for added prevention of the pipe slipping out of position. Other types of guidance assemblies will be appreciated and the invention is not restricted to this particular type as shown for this embodiment. The pipe stand enters the void 95 through a gap 65 and once engaged with the gripper 72 will rotate about bearing 100 until the pipe stand corresponds with the outlet gap 70 . In this embodiment the fingerboard has been rotated so as to present a vacant slot 60 to receive the pipe stand once engaged.
[0033] FIG. 3B shows the bottom guide assembly 32 which in this case includes a pipe gripper 82 with a support plate 80 . The pipe stand is lifted onto the support plate 80 by the racker arms and then subsequently engaged by the upper gripper 72 and lower gripper 82 so as to control the rotation of the pipe stand by the guide assembly. Slot 81 is further provided, in this embodiment, to assist with the eventual placement of the pipe stand into the setback assembly, and corresponds to slot 215 in the base, as shown in FIG. 5B . The lower guide assembly 32 includes a further bearing 105 which assists with rotation under controlled conditions and corresponds to the rotation of the upper guide assembly 30 . As the pipe stand is rotated the lower of the pipe stand is placed upon in this embodiment a delivery system (not shown) which will be described in further detail later. The guide assembly according to the present invention does not require a delivery system such as that shown in FIG. 3B . However, in combination with the delivery system according to a further aspect of the present invention provides further advantage rather than using other processes according to the prior art. Thus on rotation of the pipe stand, the pipe stand may enter through gap 90 so as to be placed on the base 20 a.
[0034] The use of racker arms for engaging a pipe stand is known and is a useful way of engaging a pipe or pipe stand during detachment from the drill string. After detachment of the pipe or pipe stand from the string, the racker arms may also be used for placement, albeit an inaccurate, given the size and weight of such an object. To better control the placement and storage of the pipe stand, the guide assembly, has fewer degrees of freedom and a shorter lever arm and so having a better design both in terms of strength and accuracy. Accordingly, placement of a pipe stand may be more accurate and faster than the use of the racker arms of the prior art. Thus whilst the guide assembly in one embodiment may provide an intermediate step, the speed by which pipe stand can be placed accurately as compared to the use of racker arms provides a distinct advantage over the prior art.
[0035] As mentioned whilst the invention is broad enough to include one setback assembly, the arrangement shown in FIGS. 1A to 1C show two setback assemblies working in parallel. One use of the dual setback assemblies may be to allow the first setback assembly to reach capacity which, subject to weight constraints, may be completely full or partially full. Once at capacity, the guide assembly or racker arms may deliver pipe stands to the second setback assembly until that reaches the capacity or the drill string has been completely withdrawn and the pipe stands stored.
[0036] FIGS. 4A to 4D show a further embodiment of the present invention with a different type of racker assembly 110 . In fact the embodiment shown in FIGS. 4A to 4D is similar to that shown in FIGS. 1A to 1C whereby two setback assemblies are provided. However together with a first set of racker arms 125 , 130 as provided with the earlier embodiment, there is also provided a second set of racker arms 135 , 140 . Further two sets of guide assemblies 145 , 155 , 150 , 160 are provided with each corresponding to one of the pairs of racker arms. The embodiment shown in FIGS. 4A to 4D is intended to show an arrangement that can accommodate two well centres within the same racking assembly 110 . In this embodiment, the first guide assembly 145 , 155 works with the first pair of racker arms 125 , 130 to service the first well centre. It follows that the second guide assembly 150 , 160 works with the second pair of racker arms 135 , 140 to service the second well centre. This arrangement may therefore have the first well centre service by the first setback assembly 111 and the second well centre service by the second setback assembly 112 . Alternatively, subject to logistics and control systems the first setback assembly 111 may receive pipe stands from both well centres until it has reached capacity and then the second setback assembly 112 will receive pipe stands from both well centres until each drawstring has been extracted and stored. Which particular process to adopt will depend on the circumstances and is not a limitation of the present invention.
[0037] In a further aspect of the present invention, a further device which acts to increase the speed of placement of pipe stand both safely and accurately is shown in FIGS. 5A to 5F .
[0038] FIG. 5A shows a slot 197 in the finger board 196 into which several pipes 191 have been slid. A first support assembly, in this case a rotatable guide 195 is in the process of delivering a pipe 190 to the slot 197 , having rotated about bearing 175 . The first support assembly acts to support the upper. As will be explained in more detail, the pipe has previously been received through a gap 180 having been delivered by a set of racker arms (not shown).
[0039] With regard to the process of insertion into the setback assembly, FIG. 5C shows a cut away view of the base to display the delivery system 200 in more detail. Here a different embodiment of the guide assembly 177 delivers several pipe stands 210 on top of a block 205 . Rather than placing the pipe stands directly in the slot, placement on the block allows several pipe stands to be placed, so that they can be delivered to the racking assembly an array. Thus the block acts both as a “buffer” for collecting pipe stands as well as a means to deliver into the racking assembly and so may accommodate a greater number of pipe stands within a given time without causing a bottleneck for the guide assembly which in itself acts to free the racker arms as quickly as possible. Thus a further advantage of the guide assembly and delivery system individually, and in combination, is to avoid bottlenecks in “upstream” systems.
[0040] Thus the delivery system includes the block 205 which in this embodiment is placed upon a series of vertically oriented actuators (such as hydraulic rams) 220 . The extension of the actuators 220 allows the block to move up and down relative to the base which is important in the means of delivery of the pipe stand. The block and actuators are located upon a trolley 230 which includes rollers 235 . When the block has reached its capacity (either by weight of length) of pipe stands the delivery system moves into slots 215 within the base so as to bring the pipe stands into a closely packed arrangement on the base directed radially from the centre. In a further embodiment, the block will be of sufficient size to contain a sufficient number of pipe stands to completely fill each radial line of storage of the base which of course must correspond to slots within the corresponding fingerboard.
[0041] Once the block has reached the inner position as shown in FIG. 5C , the actuators 220 retract as shown in FIG. 5E . As the slot 215 in the base is sized to allow the block to project from and retract within the base, as the actuators 220 retracts and the block also retracts leaving the pipes, which are too large to pass through the slots, placed on the support face 245 of the base. The delivery system can then move the block in a retracted position using the trolley back to its original position for receiving further pipe stands.
[0042] In one embodiment the block may retract through the base so as to allow free rotation of the base without inference from the block. Alternatively, the trolley may permit the block to move completely out of the base so again may permit the base to rotate without interfering with the block.
[0043] In an alternative embodiment, the actuators may be replaced by upstands which are rotatable about a hinge. On rotation of the upstands, the block retracts beneath the support face, in a similar manner to the retraction of the actuators.
[0044] FIG. 5F shows partially completed storage of the pipe stand 252 which the first base 250 and second 255 both receiving pipe stand. | A racking assembly for receiving and storing at least one pipe, the racking assembly comprising a setback assembly including a selectively rotatable member having a plurality radial slots sized to receive a first portion of the pipe(s) in sliding engagement, and a base placed distal from the selectively rotatable member and coupled thereto so as to permit mutual rotation, the base arranged to support the pipe(s) on a support face of the base; a barrier located about a peripheral edge of the base, such that the setback assembly rotates relative to the barrier, the barrier arranged to prevent the pipe(s) from moving radially from the base, the barrier having a gap sized to permit selective lateral movement of the pipe(s); where mutual rotation of the selectively rotatable member and the base permit alignment of the gap and a selected slot of the selectively rotatable member, and so permitting the pipe stands to be moved laterally into the setback assembly. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to transistor design, and, in particular, a transistor with carbon inplants used to vary the collector-to-emitter breakdown voltage. (BV CEO ).
2. Background of the Invention
Electrostatic discharge (ESD) protection of radio frequency (RF) products is important as application frequencies exceed 1 GHz. Below 1 GHz application frequency, the ability to simultaneously achieve excellent ESD protection and performance objectives was possible in most CMOS, BiCMOS, and SOI applications. As semiconductor applications extend beyond 1 GHz applications from 10 to 100 GHz, providing ESD protection and satisfying performance goals will increase in difficulty. Today, high speed data rate wired, wireless, test equipment and disk drive applications are extending well above 1 GHz. Today, Silicon Germanium (SiGe) technology produces heterojunction bipolar transistors that show significant increases in unity current gain cutoff frequency (f T ) every technology generation. As shown by the discussion that follows regarding the Johnson Limit, a transistor's BV CEO is a function of that transistor's unity current gain cutoff frequency.
With transistors whose unity current gain cutoff frequency f T exceed 10 GHz, the ability to provide ESD protection without impacting performance will be a significant challenge. For RF applications, ESD elements must have low capacitance, a high quality factor (Q), linearity and low noise. These criteria can not be satisfied by many of today's ESD solutions (e.g., silicon controlled rectifiers (SCR), and MOSFET transistors) leaving diode and diode configuration elements as a key choice for RF applications.
ESD Power Clamps between power rails are important for RF products because RF applications and BiCMOS chips can be small chips (e.g. low chip capacitance) and the need to scale the size of ESD structure small to reduce loading effects at the pin. Hence, using RF diode-based solutions, the current must flow through the chip power grid back to the ground plane. As a result, low impedance ESD power grids with low and/or scalable trigger solutions are needed for RF semiconductor chips. To provide an ESD solution that naturally scales with the BiCMOS technology, and utilizes the limitation of bipolar transistors, ESD power clamps were designed which take advantage of the Johnson Limit of SiGe HBT devices.
Relation Between Unitary Gain Cutoff Frequency and BV CEO :
A fundamental relationship exists between the frequency response of the transistor and maximum power applied across the transistor element known as the Johnson Limit. The Johnson Limit in its power formulation is given as
( P m X c )½ƒ T = E m v s / 2π
where Pm is the maximum power, X C is the reactance X c =½ P f T C bc , f T is the unity current gain cutoff frequency, E m is the maximum electric field, and v s is the electron saturation velocity. In this form, the formulation states that there is an inverse relationship between the maximum power and frequency response This can also be expressed in terms of maximum voltage, V m
V m ƒ T = E m v s / 2π
This formulation states that the product of the maximum velocity an electron can traverse a medium and the maximum electric field across that region is a constant. It also states that there is an inverse relationship between the transistor speed and the allowed breakdown voltage. Graphically, this is shown as follows:
Based on the Johnson Limit condition, as BiCMOS SiGe technologies scale to provide a higher unity current gain cutoff frequency f T , the BV CEO of the transistor decreases. Hence from the Johnson Limit equation,
V* m ƒ* T =V m ƒ T = E m v s/ 2π
where V* m f* T is associated with a first transistor and V m f T is associated with a second transistor. The ratio of breakdown voltages can be determined as
V m * V m = f T f T * [ t5 ]
Using this Johnson relationship, an ESD power clamp can be synthesized where a trigger device with the lowest breakdown voltage can be created by using the highest cutoff frequency (f T ) transistor and a clamp device with the highest breakdown device will have the lowest cutoff frequency (f T ).
However, it is possible to further lower the breakdown voltage of the trigger transistor by introducing carbon into the structure of the transistor.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to providing carbon in the structure of an SiGe transistor to modulate the redistribution of dopants in the base-collector region of the transistor, thus lowering the BV CEO of the transistor. Carbon atoms placed in the base region of a SiGe transistor influence the transient enhanced diffusion (TED) of dopants in the silicon lattice in the vicinity of the base-collector region. In the base-collector region, the base region contains boron, germanium and silicon atoms. In the collector region, the dopants can be arsenic, phosphorus, and antimony, or other n-type dopants. Placing carbon in the region below the base-collector junction region causes the dopants to diffuse either toward or away from the junction area, thereby changing the BV CEO of the transistor. The BV CEO of the transistor can be further decreased by increasing the collector's doping concentration.
A transistor with a lowered BV CEO can be used as the trigger portion of a trigger-clamp ESD protection circuit.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 shows a transistor of one embodiment of the present invention, with carbon implanted in the collector of the transistor.
FIG. 2 shows a transistor of another embodiment of the present invention, with carbon implanted in the collector in close proximity to the extrinsic base.
FIG. 3 shows a transistor of another embodiment of the present invention, with carbon implanted in collector and the sub-collector of the transistor.
FIG. 4 shows a transistor of another embodiment of the present invention, with an N+ pedestal formed in the collector of the transistor, with the carbon implant in proximity to the extrinsic base.
FIG. 5 shows a transistor of another embodiment of the present invention, with an N+ pedestal formed in the collector of the transistor, with a carbon implant in both the collector and the N+ pedestal.
FIG. 6 shows a Darlington-configured trigger/clamp ESD protection circuit.
FIG. 7 shows another embodiment of an ESD protection circuit.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the SiGe HBT structure for a transistor to be used in a trigger-clamp ESD protection circuit. The SiGe HBT devices are designed on a p− substrate ( 22 ). A n++ subcollector ( 20 ) is then formed over the p− substrate ( 22 ). An n− collector ( 24 ) is then formed over the n++ subcollector. The n− dopants in the n− collector ( 24 ) can be arsenic, phosphorus, and antimony, or any other type n− dopant. Shallow trench isolation areas ( 26 ) are then formed in the n− collector. The base ( 25 ) is formed by providing a ultra-high vacuum chemical vapor deposition (UHV/CVD) SiGe deposited film on the silicon surface. The extrinsic base is then formed by forming p+ ( 28 ) areas adjacent to the n− collector. An emitter ( 32 ) is then formed to overlap the p+ ( 28 ) extrinsic base areas and the n− collector ( 24 ).
A carbon implant ( 34 ) is then placed in various regions of the transistor. This carbon implant ( 34 ) promotes the migration of the n-type dopants in the collector away from the region of the p+ ( 28 ) extrinsic base and n− collector junctions. The carbon implant ( 34 ) can be placed above the n++ subcollector ( 20 ), at varying distances from the base/collector junctions. In FIG. 1 , the carbon implant ( 34 ) is implanted in the n− collector ( 24 ) at a distance further from the p+ extrinsic base ( 28 ) than is implanted the carbon implant ( 34 ) in FIG. 2 . Additionally, FIG. 3 shows the carbon implant ( 34 ) can be placed such that the carbon is implanted in both the n− collector ( 24 ) and the n++ subcollector ( 20 ). The carbon implant can also be placed below the collector in the subcollector (Not Shown).
As discussed above, the carbon implant ( 34 ) in the n− collector region ( 24 ) influences the diffusion of the n− dopants located in the n− collector in the vicinity of the base-collector junctions of the transistor. The carbon implant leads to a high current density which forces the space charge region of the base-collector junction to get pushed into the collector region. Such an effect tends to reduce the frequency response of the transistor, and thus raise BV CEO . To reduce this effect, an n+ pedestal region ( 36 ) is implanted through the emitter window of the SiGe HBT. Implanting this n+ pedestal maintains a high f T deviceâ″ which in turn maintains a low BV CEO .
The influence the carbon implant will have on BV CEO is a function of the distance between the carbon implant ( 34 ) and the base region. As the carbon implant is placed closer to the base region, the n− dopants in the n− collector ( 24 ), under the influence of the carbon atoms present in the carbon implant ( 34 ), diffuse away from the n− collector ( 24 ) p+ ( 28 ) extrinsic base junction. As this n− dopant diffusion rate increases, the breakdown voltage of the n+ emitter ( 32 ) to n− collector ( 24 ) is lowered. Thus, one can control the magnitude of the lowering of BV CEO that the carbon implant ( 34 ) effects by varying the proximity of the carbon implant ( 34 ) to the base-collector junction.
For configuration of the ESD protection circuit, electrical connections are established in this structure. The contact ( 38 ) on the N+ region is the emitter contact. The collector contact (not shown) is achieved outside of the isolation using a N+ sinker contact, a n+ reachthrough contact, an N-well implant, or other means known in the art.
In FIG. 6 , a transistor with a carbon implant is used as a trigger device ( 48 ) in an ESD protection circuit. The emitter of the trigger device ( 48 ) is connected to the bias resistor ( 40 ). The collector region of the trigger device ( 48 ) is connected to the VDD ( 42 ) power supply. FIG. 6 shows the base of the trigger device ( 48 ) as floating, but the base can be biased or connected to other circuit elements. The base of the clamp device ( 59 ) is connected to the emitter of the trigger device ( 48 ). The collector of the clamp device ( 50 ) connected to VDD ( 42 ). The emitter of the clamp device ( 50 ) is connected to either a ballast resistor ( 44 ) or V SS power supply ( 46 ).
FIG. 6 shows an example of Darlington configured bipolar ESD power clamp. For a power clamp, the clamp device ( 50 ) must have a high breakdown voltage in order to address the functional potential between the VDD power supply and ground potential. This power clamp requires a f T above the ESD pulse frequency to discharge the current effectively. For the trigger device ( 48 ), a low breakdown voltage device is needed in order to initiate base current into the clamp device at an early enough voltage.
The SiGe HBT ESD Power Clamp network trigger network consists of a high f T SiGe HBT with a bias resistor. When the transistor collector-to-emitter voltage is below the breakdown voltage, no current is flowing through the trigger transistor. The bias resistor holds the base of the SiGe HBT clamp transistor to a ground potential. With no current flowing, the output clamp can be visualized as a “grounded base” npn device between the power supplies. When the voltage on V CC exceeds the collector-to-emitter breakdown voltage, BV CEO , in the high f T , low BV CEO SiGe HBT, current flows into the base of the SiGe HBT high breakdown device. This leads to discharging of the current on the V CC electrode to the V SS ground electrode.
Table I shows Human Body Model (HBM) results from a Darlington configured SiGe transistor power clamp. A 47 GHz/4 V BV CEO trigger device supplies the 27 GHz/6 V BV CEO clamp device. A 7 Ω ballast resistor was used for each leg of the clamp device. A 7 kΩ bias resistor was used below the trigger device to limit the current. In this power clamp, the trigger device had an open base configuration allowing early breakdown of the trigger circuit.
Table I. HBM test results of two stage Darlington circuit with low breakdown trigger and high breakdown clamp device.
Size
HBM
Trigger
Clamp
(μm)
(kV)
47 GHz
27 GHz
53.9
1.7
108
3.1
216
5.3
532
8.5
In the measurements, a fixed emitter width was used where the emitter length was increased for the ESD power clamp scaling. The measurements show increasing HBM results with the emitter length.
Machine model (MM) ESD testing of the SiGe HBT power clamps demonstrated the ESD response of the Darlington clamp circuit to a shorter rise time and higher current. Table 2 shows the MM ESD results for the SiGe HBT with the high frequency/low breakdown trigger and high breakdown/low frequency clamp network with the base floating. For machine model (MM) testing, the SiGe HBT ESD power clamp performance was also acceptable achieving 1.2 kV MM results for a 532 Âμm emitter length (clamp length). Comparing the HBM and MM results, the SiGe HBT clamp demonstrates a HBM/MM ratio of 8.8 for the smaller clamps and 7.08 for the largest clamp structure tested. This is consistent with other ESD measurements in that typical comparison between HBM/MM ratio is between 5 and 10. In the case of the shorted emitter-base case, the response of the network with structure scaling was evident in some MM tests whereas in HBM testing, no scaling was observed.
Table II. MM test results of the two stage Darlington circuit with low breakdown trigger and high breakdown clamp device (base trigger floating).
Size
MM
Trigger
Clamp
(μm)
(kV)
47
27 GHz
53.9
0.2
108
0.35
216
0.60
532
1.20
It is evident that the high frequency SiGe HBT trigger is responsive to both HBM and MM pulse widths enabling these Darlington power clamps for RF applications. As the Carbon dose is increased, the trigger voltage is reduced.
In FIG. 7 , another ESD protection network is shown. The Carbon-modulated breakdown SiGe transistor ( 52 ) is defined such that its emitter is connected to ground and its collector is connected to the input pad ( 54 ). The base of the transistor is connected to a resistor ( 56 ) which is connected to the ground. The embodiment allows for a low voltage trigger breakdown voltage compared to the circuit. This provides ESD protection to the circuit by having a trigger voltage below the breakdown voltages of the circuit elements which need ESD protection. It is understood that this embodiments can be modified by providing additional transistors in series.
The foregoing description encompasses only the preferred embodiment of the present invention. The following claims and their equivalents define the scope of the invention. | Selectively implanting carbon in a transistor lowers the collector-to-emitter breakdown (BV CEO ) of the transistor. This transistor, with the lowered BV CEO , is then used as a “trigger” device in an Electrostatic Discharge (ESD) power clamp comprising a first low breakdown trigger device and a second high breakdown clamp device. ESD power clamps are constructed using epitaxial base pseudomorphic Silicon Germanium heterojunction transistors in a common-collector Darlington configuration. | 7 |
This is a division of application Ser. No. 08/410,028, filed Mar. 24, 1995, now U.S. Pat. No. 5,674,394, which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a system for obtaining autologous plasma from a patient during surgery. The invention further relates to a method for preparing fibrin gel and other hemostat or tissue sealant preparations from the autologous plasma.
2. Background Information
Preparations of human coagulation factors including fibrinogen and thrombin, have been used extensively in surgery over the last ten years. These biological fibrin sealants (also known as fibrin glue, fibrin adhesive, or fibrin tissue sealant) promote hemostasis and wound healing by sealing leakage from tissues, sutures, staples, and prostheses and are particularly useful during open heart surgery in heparinized patients. The sealants also have limited use as an adhesive for the bonding of tissues and they reduce the amount of blood required for transfusions by controlling intraoperative bleeding. Their effectiveness is reflected in the extensive range of surgical applications for which they have been used, including cardiovascular surgery, plastic surgery, orthopedics, urology, obstetrics and gynecology, dentistry, maxillofacial and ophthalmic surgery.
Fibrin sealant products can be prepared from pooled human plasma. However, such preparations potentially risk transmission of HIV, hepatitis B and other serologically transmitted illnesses. Also, in some instances these preparations could cause immunologic reactions.
As an alternative, some hospitals are preparing fibrin sealant in-house using the patient's own blood (autologous) or single-donor (homologous) plasma as a source of fibrinogen and Factor XIII. The components are typically prepared by freezing plasma at temperatures below -20° C. overnight, slowly thawing the material at 0-4° C., centrifuging, and transferring the cryoprecipitate to a syringe or spray container. The procedure usually requires several hours, making the product unavailable for emergency cases. The lengthy manipulations currently required to generate fibrin sealant also introduce the risk of contaminating the product and transmitting viral infections to the technicians involved.
The thrombin, usually purified from bovine plasma, can be obtained commercially and is typically prepared in a separate syringe or spray container. The two solutions are delivered simultaneously or alternately to generate fibrin sealant at the site of the wound.
The hemostatic efficacy of fibrin glue has been well established. Autologous fibrin gel, made from plasma rather than a fibrinogen-containing precipitate, appears to have comparable hemostatic properties to traditional fibrin glue as well as valuable sealant properties. For instance, fibrin gel is useful in sealing air leaks in pulmonary procedures.
In preparing fibrin gel, plasma is typically obtained from autologous blood following centrifugation for about ten minutes to separate blood cells from anticoagulated blood, followed by removal of the plasma. Centrifugation in the operating room, however, may be inconvenient because of the required instrumentation, potential for aerosolization with its concomitant contamination risks, and difficulty in decontaminating instrumentation between procedures. If centrifugation takes place external to the OR, aseptic transport of the plasma fraction to the operative site is required.
Hollow fiber devices permitting separation of plasma from blood without the need for centrifugation have been used for plasma exchange therapy (PET). In PET, the separated plasma is eliminated and the separated blood cells with replacement fluids are returned to the patient.
Recently, hollow fiber filtration technology has been developed to meet the requirements of cell separation from cell cultures--including shear-sensitive mammalian cells--while allowing free passage of soluble proteins. This membrane technology offers an alternative to centrifugation, precipitation and conventional filtration techniques for bioseparations, eg. The processing of fermentation products, and is available for small volume applications. Sterilizable, disposable filtration modules are available from at least one manufacturer.
SUMMARY OF THE INVENTION
The described invention uses compact, small-volume disposable filtration technology to separate plasma from blood. In contrast to PET applications, the separated blood cells trapped by the filter are disposed of along with the filter. The separated plasma is used as a source of autologous material--eliminating the risk of cross-infection of immunological consequences. Preparation of the plasma requires no instrumentation and can be performed quickly and conveniently at the time and location of the surgical or medical procedure for which the material will be used. Specific uses for the autologous plasma obtained in this manner include preparation of fibrin gel and other hemostatic/tissue sealant formulations based on proteins and or clotting factors.
A single use system for obtaining autologous plasma according to the present invention comprises a plasma separator for separating plasma from whole blood. The plasma separator comprises a single use filter unit having a first inlet and a second inlet in fluid communication with each other, an outlet, and a filtration membrane separating the inlets from the outlet. The filtration membrane is selectively permeable to blood plasma. A manually operable, single use first pump comprises a receiving chamber connected to the first inlet. The receiving chamber has a manually moveable wall for altering the volume of its receiving chamber. A manually operable, single use second pump comprises a receiving chamber connected to the second inlet-and a manually moveable wall for altering the volume of its receiving chamber. A flow path is defined along the membrane between the first and second pumps. Thereby, whole blood can be repeatedly exchanged between the receiving chambers in the first and second pumps, past the membrane, to cause plasma to flow across the membrane and out of the outlet.
Preferably, the membrane comprises one or more hollow fibers, each of the one or more fibers having a lumen therethrough, and the flow path extends through the lumens of the one or more fibers. Also preferably, the filter unit comprises an elongated housing having a first end and a second end with the one or more hollow fibers extending axially therethrough. Each of the one or more fibers has an outer surface, the housing has an inner surface and an interior space is thus formed between the outer surfaces of the fibers and the inner surface of the housing. Pottings at the first and second ends of the housing secure the fibers therein and separate the lumens from the interior space. The first pump connects to the housing first end and the second pump connects to the housing second end, each with its respective receiving chamber in fluid communication with the lumens of the hollow fibers. The outlet is in fluid communication with the interior space whereby when the blood is pumped through the lumens of the hollow fibers by the first and second pumps, the plasma flows through the membrane into the interior space of the housing and out of the outlet. Preferably, the first and second pumps comprise syringes. A collection syringe preferably connects to the outlet for receiving the plasma.
The system can further comprise an applicator for preparing and applying fibrin gel in a medical procedure. The applicator comprises a first injector containing a thrombin solution, a second injector containing the plasma, the plasma containing an amount of fibrinogen, and a manifold in communication with the first and second injectors for applying the thrombin solution and plasma simultaneously to a site on a body. Preferably, the first and second injectors comprise syringes. Also, the syringe forming the second injector is preferably the collection syringe.
The system can be provided in a sealed sterile package containing the plasma separator and the fibrin applicator; and instructions for obtaining whole blood from a patient in the first syringe, manually pumping the whole blood in alternating fashion between the first and second syringes and collecting plasma from the whole blood in the collection syringe, and simultaneously applying the plasma thus collected along with a solution of thrombin to a site on a body.
A method, according to the invention, for preparing fibrin gel from autologous plasma comprises the steps of: extracting a quantity of blood from a patient; providing a single use filter unit having first and second inlets and an outlet; providing first and second manually operable pumps, each having a receiving chamber with a manually moveable wall; placing the receiving chambers of the first and second pumps into fluid communication with the first and second inlets, respectively; disposing a membrane selectively permeable to blood plasma between the first and second inlets, thereby forming a flow path along the membrane between the first and second inlets and isolating them from the outlet; alternatingly and manually moving the moveable walls in the first and second pumps to provide an alternating flow between the first and second inlets along the membrane; passing the plasma through the membrane to an outlet of the filter unit; collecting the plasma; and disposing of the filter unit.
The method preferably further comprises the steps of mixing the plasma with thrombin to form fibrin gel and applying the fibrin gel to a site on a body. Preferably, the plasma and a solution containing the thrombin are simultaneously applied to the body site to form the fibrin gel.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a filter for preparing autologous plasma according to the invention;
FIG. 2 is a sectional view taken along lines 2--2 of FIG. 1;
FIG. 3 is a sectional view taken along lines 3--3 of FIG. 1; and
FIG. 4 is a perspective view of a fibrin gel applicator according to the invention.
DETAILED DESCRIPTION
Turning now to the drawings, FIGS. 1 and 4 illustrate a system 10 for preparing fibrin gel from autologous plasma. The system 10 comprises in gross a plasma separator 12 (FIG. 1) and a fibrin gel applicator 14 (FIG. 4).
Concentrating on FIG. 1, the plasma separator comprises a filter unit 16, a first retentate syringe 18 at a filter unit first end 20 and a second retentate syringe 22 at a filter unit second end 24. A collection syringe 26 affixes to a central portion 28 of the filter unit 16. Each of the syringes 18, 22 and 26 is of a type commonly used in the medical field and comprises a tubular body 30, a plunger 32 with an elastomeric head 34, and a Luer fitting 36 on the syringe body 30.
Turning now to FIGS. 2 and 3, the filter unit 16 comprises an elongated tubular housing 38 having female luer fittings 40 at its first and second ends 20 and 24. A right angle adapter 42 connects to each of the luer fittings 40 and provides a male luer fitting 44 for receiving the retentate syringes 18 and 22. A central fitting 46 is provided in the filter unit central portion 28 and receives the collection syringe 26.
One of skill in the art will appreciate that the retentate syringes 18 and 22 may attach to the housing 38 in various other fashions and orientations. For instance, appropriate mating luer fittings (not shown) may be provided at the filter unit first and second ends 20 and 24 for directly receiving the retentate syringes 18 and 22 without the need for separate adapters 42, and of course the retentate syringes 18 and 22 may be axially oriented with respect to the housing 38.
A plurality of hollow fiber filter membranes 48 extend axially through the housing 38. As best seen in FIG. 3, each of the fibers 48 has an interior lumen 50 and outer surface 52. The housing 38 has an interior surface 54 and an interior space 56 is defined between the fiber outer surfaces 52 and the housing inner surface 54. A plug or potting 58 at each of the filter unit first and second ends 20 and 24 retains the fibers 48 within the housing 38 and separates the lumens 50 from the interior space 56.
Preferably, the housing 38 is formed of polysulfone and the potting 58 is formed of polyurethane. Of course, other materials suitable for use in medical devices may be substituted therefor. Preferably, the parts housing 38 is formed as a single unit, or if formed of separate parts is bonded using sonic welding to avoid the use of solvent bonding. The fibers 48 are preferably formed of a mixed cellulose ester membrane, polysulfone membrane, or other suitable material as is known in the art.
The pores (not shown) in the membrane fibers 48 are preferable sized to pass blood plasma without allowing erythrocytes or leukocytes to pass. The membrane pore size may or may not exclude blood platelets. For instance, the fibers 48 having a maximum pore size of 0.55 microns, a lumen diameter of 0.3 to 1.0 mm, a lumen length of 9.0 cm and a total membrane surface area of at least 4 square cm provides sufficient separation of plasma from whole blood without causing undo hemolysis. Preferably, flow through the fibers 48 is laminar. Sufficient surface area is important to achieving relatively quick separation of plasma from whole blood. Preferably, about 2 ml of plasma should be separable from 4 ml of whole blood in about 2 minutes.
Turning to FIG. 4, the fibrin gel applicator 14 may be of any type commonly know for simultaneously applying blood plasma along with a solution of thrombin. The Wolff et al. U.S. Pat. No. 5,104,375, issued Apr. 14, 1992, discloses a locking holder for a pair of syringes and a method for using the syringes to simultaneously apply blood plasma and a solution of thrombin to produce fibrin gel. The disclosure of this patent is incorporated by reference.
The applicator 14 comprises a first injector syringe 60 for containing a solution of thrombin, and a second injector syringe 62 for containing blood plasma. Each of the first and second injector syringes 60 and 62 connects to a manifold 64 which directs the flow of thrombin solution and plasma to a distal outlet 66. Proximal ends 68 of the first and second injector syringes 60 and 62 are connected by a brace 70 which holds the first and second injector syringes 60 and 62 in parallel relationship to one another. A bridge 72 interconnects plungers 74 in the first and second injector syringes 60 and 62. A finger rest 76 extends laterally from the brace 70 for easy engagement by a user's index and middle finger and an upper surface 78 of the bridge 72 easily engages a user's thumb, whereby both the first and second injector syringes 60 and 62 may be easily actuated in a single-handed operation.
Each of the components of the system 10 which come into contact with whole blood or plasma should be treated with an anticoagulant such as sodium citrate, EDTA, or heparin to prevent premature clot formation. Thus, the syringes 18, 22 and 26, the filter unit 16 and the fibrin applicator 14 should preferably be treated with an anticoagulant.
The plasma separator 12 and fibrin applicator 14 are most conveniently provided in a sterile condition within a sterile package (not shown) containing instruction for obtaining whole blood from a patient, separating plasma from the whole blood, and applying the plasma and the thrombin solution simultaneously to produce fibrin gel. In such an arrangement, the first retentate syringe 18 has a standard blood collection needle tip (not shown) and contains an anticoagulant. For instance, a 10 ml syringe preferably contains 0.1 ml of a 46.7% trisodium citrate anticoagulant. Also, the collection syringe 26 preferably serves as the first injector syringe 60. Thrombin and a hemostatic agent to overcome the anticoagulant are provided for use in the second injector syringe 62. Preferably, 1000 units of thrombin in 9 ml of normal saline plus 0.5 ml of a 10% calcium chloride solution are mixed and packaged within the second injector syringe 62.
In use, a quantity of whole blood is withdrawn from a patient using the first retentate syringe 18 with the trisodium citrate therein. The needle is removed from the first retentate syringe 18 and its luer fitting 36 connected to the luer fitting 40 at the filter unit first end 20. The second retentate syringe 22 is similarly affixed to the filter unit second end 24. The collection syringe 26 is then affixed to the central fitting 46. By alternatingly depressing the plungers 32 on the first and second retentate syringes 18 and 22, the blood is forced to flow back and forth through the lumens 50 of the membrane fibers 48. This flow and a resulting slightly elevated pressure within the lumens 50 causes the plasma in the blood to migrate across the fibers 48 and into the interior space 56. The central fitting 46 is in fluid communication with the interior space 56 and thus receives the blood plasma.
After a sufficient amount of plasma has been accumulated in the collection syringe 26, it is removed from the filter unit 16 and inserted into the manifold 64 of the fibrin applicator 14. The solution of thrombin containing calcium chloride and the blood plasma are then simultaneously applied to a site on the body with the fibrin applicator 14. As the plasma and thrombin solutions mix, they create a fibrin gel which can be used in any number of medical procedures.
In one test, disposable tangential flow filtration units such as the filter unit 24 were used to separate plasma from canine blood. The plasma was collected within a few minutes and when combined with thrombin, formed a cohesive gelatinous clot. Clot formation as measured in a fibrinometer occurred in less than one second. In a second test, a 0.2 micron filter was used, and 1.8 ml of plasma was easily separated from approximately 4.0 ml of whole citrated porcine blood in two minutes. Clotting characteristics were similar to the first experiment.
While the invention has been described with regard to a particular embodiment thereof, those skilled in the art will understand, of course, that the invention is not limited thereto since modifications can be made by those skilled in the art, particularly in light of the foregoing teachings. Reasonable variation and modification are possible within the foregoing disclosure of the invention without the departing from the spirit of the invention. | A system for preparing autologous plasma comprises a single use filter unit having two inlets in fluid communication with each other, an outlet, and a filtration membrane selectively permeable to blood plasma separating the inlets from the outlet. Manually operable, single use pumps, preferably syringes, connect to the inlets. A flow path is defined along the membrane between the pumps, whereby, whole blood can be repeatedly exchanged between the two pumps, past the membrane, to cause plasma to flow across the membrane and out of the outlet. A syringe can collect plasma from the outlet. Plasma thus collected can be simultaneously applied with a thrombin solution to a site on the body, thereby forming a fibrin gel. | 8 |
BACKGROUND OF THE INVENTION
The present invention relates to a novel potato variety and to the tubers, plants, plant parts, tissue culture and seeds produced by that potato variety.
The publications and other materials used herein to illuminate the background of the invention and, in particular cases, to provide additional details respecting the practice, are incorporated by reference and for convenience, are referenced in the following text by author and date and are listed alphabetically by author in the appended bibliography.
The potato is the world's fourth most important food crop and by far the most important vegetable. Potatoes are currently grown commercially in nearly every state of the United States. Annual potato production exceeds 18 million tons in the United States and 300 million tons worldwide. The popularity of the potato derives mainly from its versatility and nutritional value. Potatoes can be used fresh, frozen or dried, or can be processed into flour, starch or alcohol. They contain complex carbohydrates and are rich in calcium, niacin and vitamin C.
To keep the potato industry growing to meet the needs of the consuming public, substantial research and development efforts are devoted to the modernization of planting and harvesting of fields and processing of potatoes, and to the development of economically advantageous potato varieties. Through crossbreeding of potatoes, researchers hope to obtain potatoes with the desirable characteristics of good processability, high solids content, high yield, resistance to diseases and pests and adaptability to various growing areas and conditions.
The U.S. acreage planted in potatoes has declined since the 1960s and 1970s, and this decline, coupled with increasing consumption, must be offset by higher useable yields. In some areas, diseases and pests damage crops despite the use of herbicides and pesticides. The problem of the golden nematode in the United States, presently endemic to portions of New York State, is one example of the destruction to susceptible potato varieties. Potato varieties with high yields, disease resistance and adaptability to new environments can eliminate many problems for the potato grower and provide more plentiful and economical products to the consumers.
For the potato chip processing industry, potatoes having high solids content, disease resistance, good shipping qualities and good finished chip color can increase production volumes and efficiencies and product acceptability. Potato varieties which yield low-solids tubers result in unnecessary energy usage during the frying process. Moreover, as solids content increases, the oil content of fried products decreases, which is a favorable improvement. Potato varieties in the warm southern tier of states are most in need of solids improvement overall, while those varieties grown and stored in the colder northern tier of states are most in need of the ability to recondition after cool or cold storage to increase their value for use in the potato chip industry. Reconditioning is necessary to elevate the temperature of the potatoes after cold storage and before further processing.
The research leading to potato varieties which combine the advantageous characteristics referred to above is largely empirical. This research requires large investments of time, manpower, and money. The development of a potato cultivar can often take up to eight years or more from greenhouse to commercial usage. Breeding begins with careful selection of superior parents to incorporate the most important characteristics into the progeny. Since all desired traits usually do not appear with just one cross, breeding must be cumulative.
Present breeding techniques continue with the controlled pollination of parental clones. Typically, pollen is collected in gelatin capsules for later use in pollinating the female parents. Hybrid seeds are sown in greenhouses, and tubers are harvested and retained from thousands of individual seedlings. The next year a single tuber from each resulting seedling is planted in the field, where extreme caution is exercised to avoid the spread of virus and diseases. From this first-year seedling crop, several “seed” tubers from each hybrid individual which survived the selection process are retained for the next year's planting. After the second year, samples are taken for density measurements and fry tests to determine the suitability of the tubers for commercial usage. Plants which have survived the selection process to this point are then planted at an expanded volume the third year for a more comprehensive series of fry tests and density determinations. At the fourth-year stage of development, surviving selections are subjected to field trials in several states to determine their adaptability to different growing conditions. Eventually, the varieties having superior qualities are transferred to other farms and the seed increased to commercial scale. Generally, by this time, eight or more years of planting, harvesting and testing have been invested in attempting to develop the new and improved potato cultivars.
Long-term, controlled-environment storage has been a feature of the northern, principal producing areas for many years. Potatoes harvested by October must be kept in good condition for up to eight months in temperatures that may drop to −30 degrees C. at times and with very low relative humidity in the outside air. Storages are well insulated, not only to prevent heat loss but also to prevent condensation on outside walls. The circulation of air at the required temperature and humidity is automatically controlled depending on the purpose for which the potatoes are being stored. Sprout inhibition is now largely carried out in storage as it has been found to be more satisfactory than the application of maleic hydrazide (MH30) in the field.
Proper testing of new plants should detect any major faults and establish the level of superiority or improvement over current varieties. In addition to showing superior performance, a new variety must be compatible with industry standards or create a new market. The introduction of a new variety will increase costs of the tuber propagator, the grower, processor and consumer; for special advertising and marketing, altered tuber propagation and new product utilization. The testing preceding release of a new variety should take into consideration research and development costs as well as technical superiority of the final variety. Once the varieties that give the best performance have been identified, the tuber can be propagated indefinitely as long as the homogeneity of the variety parent is maintained. For tuber propagated varieties, it must be feasible to produce, store and process potatoes easily and economically.
Thus, there is a continuing need to develop potato cultivars which provide good processability out of storage, with minimal bruising, for manufacturers of potato chips and other potato products and to combine this characteristic with the properties of disease resistance, resistance to pests. The present invention addresses this need by providing the new variety as described herein.
SUMMARY OF THE INVENTION
According to the invention, there is provided a novel potato cultivar of the genus and species, Solanum tuberosum, designated FL1930. This invention thus relates to the tubers of potato variety FL1930, the plants and plant parts of potato variety FL1930 and to methods for producing a potato plant produced by crossing the potato variety FL1930 with itself or another potato variety. This invention further relates to hybrid potato seeds and plants produced by crossing the potato variety FL1930 with another potato plant.
In another aspect, the present invention provides for Single Gene Converted plants of FL1930. The single gene transferred may be a dominant or recessive allele. Preferably, the single gene transferred will confer such traits as herbicide resistance, insect resistance, resistance for bacterial, fungal or viral disease, uniformity and increase in concentration of starch and other carbohydrates, decrease in tendency of tuber to bruise and decrease in the rate of conversion of starch to sugars. The single gene transferred may be a naturally occurring gene or a transgene introduced through genetic engineering techniques.
DETAILED DESCRIPTION OF THE INVENTION
A novel potato cultivar of the present invention, which has been designated FL1930, has been obtained by selectively crossbreeding parental clones through several generations. The immediate parents of FL1930 were cultivars designated FL1850 and FL 1291. The variety FL1850 was chosen as a breeding parent because of its excellent chip appearance after long periods in cold storage, its high solids and early maturity, and resistance to the “golden” cyst nematode ( Globodera rostochiensis Race Rol). Variety FL1291 was chosen as a breeding parent because of its high yields, and its potential for scab and bruise resistance.
As a chipping variety for fresh use, FL1930 is most similar to the variety Atlantic. FL1930 can be distinguished from Atlantic with regard to the following traits: the color of the corolla inner and outer surface of FL1930 is darker than that of Atlantic, the anthers on FL1930 are yellow-orange, while those of Atlantic are yellow according to the Royal Horticultural Society (RHS) color chart, FL1930 has a pale yellow tuber flesh color whereas Atlantic has white, and the average glycoalkaloid levels in FL1930 are 5.45 mg/100 g fresh tuber compared to 9.9 mg/100 g in Atlantic. FL1930 matures earlier than Atlantic (110 DAP vs.115 DAP). Like Atlantic, FL1930 has weak stem and petiole anthocyanin coloration, a medium leaf silhouette, intermediate foliage density, semi-erect growth habit. FL 1930 and Atlantic have similar tuber skin textures, shape, and eye depth (though the distribution of tuber eyes is evenly distributed in FL1930, with medium-prominant tuber eybrows, compared to the primarily apical eye distribution and slight eybrow prominance of Atlantic), and similar terminal leaflet shape. FL1930 and Atlantic also have similarly high tuber specific gravities (1.080-1.089); high specific gravities are advantageous for chipping and other frying applications, as they reduce the total energy and time required for the frying operation. Like Atlantic, FL1930 is resistant to golden cyst nematode.
In addition to the specific gravity of the tubers of this invention, they also have an advantageous shape for commercial operations. The tubers are generally round/oval in shape and have a size which is suited to the manufacture of potato chips. On average, these tubers have a mean length of 63.1 millimeters (range: 50-81 millimeters); a mean width of 56.4 millimeters (range: 45-68 millimeters); and a mean thickness of 46.7 millimeters (range: 40-57 millimeters) based upon a 100-tuber sample. Of course, the size of the tubers can vary over a relatively wide range depending on growing conditions and locations. The slightly flattened shape of the tubers is advantageous, because it facilitates alignment in the slicing apparatus.
Field trials of FL1930 have proved it to have competitive solids, yield equal to or higher than that of Atlantic, very low bruising potential and a beautiful fresh chip appearance.
In addition to the morphological characteristics and disease and pest resistance as described above, the plants of this invention are characterized by their protein “fingerprint” patterns. The protein “fingerprint” is determined by separating tuber proteins on an electrophoretic gel under certain defined conditions. The pattern of the proteins, attributable to their differential mobilities on the electrophoretic gel, have been found to be characteristic of the particular plant involved. This pattern has thus been termed a “fingerprint.” Isozyme fingerprints of all available North American potato varieties have revealed that no two varieties have the same pattern for the enzymes tested. (Douches and Ludlam, 1991, “Electrophoretic characterization of North American Potato Cultivars,” Am. Potato J. 68:767-780). The isozyme fingerprint of FL1930 (Table I) has been established as unique among North American varieties. These techniques generally involve extracting proteins from the tuber and separating them electrophoretically.
TABLE I
Isozyme electrophoresis fingerprints of FL1930 compared to Atlantic
Variety
Mdh-1
Mdh-2
Pgdh-3
Idh-1
Pgi-1
Aps-1
Got-1
Got-2
Pgm-1
Pgm-2
Dia-1
Prx-1
Prx-3
Adh-1
Atlantic
2223
2223
1122
1112
2222
1111
4444
3555
1112
2223
1112
1144
—
2222
FL1930
2224
2222
1222
—
2222
—
3344
3355
1113
2223
—
—
1111
—
Procedures and allelic designation used are according to Douche, D.S. and K. Ludlam, 1991, “Electrophoretic characterization of North American Potato Cultivars,” Am. Potato J. 68:767-780.
Potato variety FL1930 has the following morphologic and other characteristics.
VARIETY DESCRIPTION INFORMATION
1.
uz,3/19 Classification: Solanum Tuberosum L.
2.
Plant characteristics: (Observed at beginning of bloom)
Growth habit:
Semi-erect (30°-45°
with ground)
Type:
Intermediate
Maturity (Days after planting - DAP):
110
Maturity Class:
Early (100-110 DAP)
3.
Stem Characteristics: (Observed at early first bloom)
Stem (anthocyanin coloration):
Weak
Stem (wings):
Medium
4.
Leaf Characteristics: (Observed fully developed leaves located in the
middle one-third of plant):
Leaf (color):
Olive-green/137A RHS
Leaf (pubescence density):
Medium
Leaf (silhouette):
Medium
Petioles (anthocyanin coloration):
Weak
Terminal leaflet (shape):
Broadly ovate
Terminal leaflet (shape of tip):
Acuminate
Terminal leaflet (shape of base):
Cordate
Terminal leaflet (margin waviness):
Slight
Primary leaflets (average pairs):
4
Primary leaflets (shape of tip):
Acuminate
Primary leaflets (shape):
Medium ovate
Primary leaflets (shape of base):
Cordate
5.
Inflorescence Characteristics:
Corolla (shape):
Rotate
Corolla (inner surface color):
Purple (78A RHS)
Calyx (anthocyanin coloration):
Absent
Anthers (shape):
Pear-shaped cone
Stigma (shape):
Capitate
Stigma (color):
137A RHS
6.
Tuber Characteristics:
Skin (predominant color):
Tan
Skin (texture):
Rough (flaky)
Tuber (shape):
Round/oval
Tuber (thickness):
Medium Thick
Tuber (length):
63.1 mm (average)
Tuber (width):
56.4 mm (average)
Tuber (thickness):
46.7 mm (average)
Tuber eyes (depth):
Intermediate
Tuber (primary flesh color):
160C RHS
Tuber (prominence of eyebrows):
Medium prominence
7.
Reaction to Diseases:
Bacterial ring rot, foliar reaction
Susceptible
Bacterial ring rot, tuber reaction
Susceptible
Potato Virus Y
Moderately susceptible
8.
Reaction to Pests:
Golden nematode Globodera rostochiensis
Resistant
Persons of ordinary skill in the art will recognize that when the term potato plant is used in the context of the present invention, this also includes derivative varieties that retain the essential distinguishing characteristics of FL1930, such as a Single Gene Converted plant of that variety or a transgenic derivative having one or more value-added genes incorporated therein (such as herbicide or pest resistance). Backcrossing methods can be used with the present invention to improve or introduce a characteristic into the variety. The term backcrossing as used herein refers to the repeated crossing of a hybrid progeny back to the recurrent parents. The parental potato plant which contributes the gene for the desired characteristic is termed the nonrecurrent or donor parent. This terminology refers to the fact that the nonrecurrent parent is used one time in the backcross protocol and therefore does not recur. The parental potato plant to which the gene or genes from the nonrecurrent parent are transferred is known as the recurrent parent as it is used for several rounds in the backcrossing protocol. In a typical backcross protocol, the original variety of interest (recurrent parent) is crossed to a second variety (nonrecurrent parent) that carries the single gene of interest to be transferred. The resulting progeny from this cross are then crossed again to the recurrent parent and the process is repeated until a potato plant is obtained wherein essentially all of the desired morphological and physiological characteristics of the recurrent parent are recovered in the converted plant, in addition to the single gene transferred from the nonrecurrent parent.
The selection of a suitable recurrent parent is an important step for a successful backcrossing procedure. The goal of a backcross protocol is to alter or substitute a single trait or characteristic in the original variety. To accomplish this, a single gene of the recurrent variety is modified, substituted or supplemented with the desired gene from the nonrecurrent parent, while retaining essentially all of the rest of the desired genes, and therefore the desired physiological and morphological constitution of the original variety. The choice of the particular nonrecurrent parent will depend on the purpose of the backcross. One of the major purposes is to add some commercially desirable, agronomically important trait to the plant. The exact backcrossing protocol will depend on the characteristic or trait being altered or added to determine an appropriate testing protocol. Although backcrossing methods are simplified when the characteristic being transferred is a dominant allele, a recessive allele may also be transferred. In this instance, it may be necessary to introduce a test of the progeny to determine if the desired characteristic has been successfully transferred.
Likewise, transgenes can be introduced into the plant using any of a variety of established recombinant methods well-known to persons skilled in the art.
Many single gene traits have been identified that are not regularly selected for in the development of a new variety but that can be improved by backcrossing and genetic engineering techniques. Single gene traits may or may not be transgenic, examples of these traits include but are not limited to: herbicide resistance; resistance to bacterial, fungal or viral disease; insect resistance; uniformity or increase in concentration of starch and other carbohydrates; enhanced nutritional quality; decrease in tendency of tuber to bruise; and decrease in the rate of starch conversion to sugars. These genes are generally inherited through the nucleus. Several of these single gene traits are described in U.S. Pat. No. 5,500,365, U.S. Pat. No. 5,387,756, U.S. Pat. No. 5,789,657, U.S. Pat. No. 5,503,999, U.S. Pat. No. 5,589,612, U.S. Pat. No. 5,510,253, U.S. Pat. No. 5,304,730, U.S. Pat. No. 5,382,429, U.S. Pat. No. 5,503,999, U.S. Pat. No. 5,648,249, U.S. Pat. No. 5,312,912, U.S. Pat. No. 5,498,533, U.S. Pat. No. 5,276,268, U.S. Pat. No. 4,900,676, U.S. Pat. No. 5,633,434 and U.S. Pat. No. 4,970,168, the disclosures of which are specifically hereby incorporated by reference.
DEPOSIT INFORMATION
A deposit of the Frito-Lay, Inc. proprietary potato cultivar FL1930 microtubers disclosed above and recited in the appended claims has been made with the American Type Culture Collection (ATCC), 10801 University Boulevard, Manassas, Va. 20110. The date of deposit was Sep. 11, 2002. The deposit was taken from the same deposit maintained by Frito-Lay, Inc. since prior to the filing date of this application. All restrictions upon the deposit have been removed, and the deposit is intended to meet all of the requirements of 37 C.F.R. § 1.801-1.809. The ATCC accession number is PTA- 4657. The deposit will be maintained in the depository for a period of 30 years, or 5 years after the last request, or for the effective life of the patent, whichever is longer, and will be replaced as necessary during that period. | A novel potato cultivar of the genus and species Solanum tuberosum, designated FL1930, is disclosed. The invention relates to the tubers of potato variety FL1930, to the plants of potato variety FL1930, to the seeds of potato variety and to methods for producing hybrid potato variety. The invention further relates to potato variety tubers, seeds and plants produced by crossing the potato variety FL1930 with another potato plant, and to Single Gene Converted plants. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to continuous, random dyeing apparatus for carpet or the like and, more particularly, to apparatus for continuously dispensing a liquid onto a moving web in an irregular and random pattern.
2. Description of the Prior Art
A recent trend in manufacturing tufted carpet involves finishing a single color carpet in such a way that although the single color remains the dominant base tone, additional color patterns are applied thereto. To be most effective, the color patterns should not appear in regularly recurring portions but should form a certain unified irregularity or randomness which is aesthetically pleasing to the eye. This type of coloring has further achieved significance in other fabrics, as for example decorative fabric materials. Accordingly, although the remaining discussion will be directed to carpets, it will be appreciated by those skilled in the art that it is equally applicable to any textile material and to moving webs generally.
A number of methods have been proposed for the continuous, random application of color to carpet. In order for any such method to be economically feasible, the application speed must be adequate and the application of the dye must be easily controlled in any number of various patterns. The methods of application and control must be relatively simple as well as being easy to maintain. However, none of the methods proposed heretofore have satisfied all of these requirements.
One method of producing a random pattern on carpet has been commonly designatd as "space dyeing". In this method, the yarn is dyed various colors and shades of colors along its length. This dyed yarn is then tufted into the carpet. The disadvantages of this method are that it is costly to space dye the yarn and, once the yarn is space dyed, there is only a limited control of the random pattern which is obtainable once the tufting of the carpet begins.
Another process, referred to as "Tak" dyeing, for applying dyes to carpet in random patterns is disclosed in U.S. Pat. No. 3,731,503. According to this patent, an oscillating wiper blade channels dye into streams which fall towards the moving carpet, which streams are divided by a moving wire member supported on a circular band. Some of the dye falls and is distributed on the teeth of an adjustable comb-like device, from which the dye falls to the carpet in an irregular pattern. The remaining dye falls directly onto the carpet after being divided by the circulating band. The problem with this process is that the machinery involved is complex in nature. This leads to difficulty in pattern control as well as a substantial expense to purchase and maintain the machinery.
Jet printing is another method of applying random patterns to carpet. According to this method, an array of spray nozzles, which spray different colors, are moved from place to place above a moving carpet. In addition, the nozzles are controlled as to whether they are open or closed. The patterns are programmed via an electronic device. The disadvantages associated with this method are that the equipment is expensive, the nozzles become clogged, and maintenance costs of the electronic and mechanical equipment is high.
A process referred to as rotary screen printing is also used to apply dye to carpet in a random pattern. In this process, a hollow rotary drum is used which has small holes etched through the surface thereof to the hollow portion, in any desired pattern. Dye is forced through these holes which are in contact with the carpet surface as the drum rotates. The main disadvantage here is that the resultant pattern is very rigid. In addition, the cost of the etched drums and the equipment needed to run them is expensive.
SUMMARY OF THE INVENTION
According to the present invention, these problems are solved by a novel method and apparatus for the continuous, random application of color to carpet or the like. The present method and apparatus produce a carpet which is aesthetically pleasing. The application speed is sufficient to make the present process economically feasible. In addition, the application of the dye can be easily controlled in any number of various patterns. The method of application control is relatively simple as well as being easy to maintain.
Briefly, the above objectives are achieved by using a rotating drum and a wiper engaging the outer surface thereof to control the flow and pattern of dye to a length of carpet. The drum is mounted for rotation on its axis and has a plurality of cavities extending partially thereinto, from the outer surface thereof. The cavities can have various depths, sizes, and patterns. This permits control of dye penetration and pattern size. The dye is conducted to one side of the drum where it fills the cavities. As the drum rotates, only the dye in the cavities passes below the wiper where such dye falls onto the moving carpet. The pattern is formed by adjusting the carpet feed speed in relation to the drum speed and the distance between the drum and the carpet. In this manner, the pattern is easily controlled and varied. By using a plurality of drums with cavities having different depths, sizes, and patterns, a truely random affect can be achieved. With such an apparatus, the speed of the carpet is relatively high due to the simplicity of mechanical synchronization. Because of the small number of moving parts, equipment and maintenance costs are relatively low.
It is therefore an object of the present invention to provide a continuous, random dyeing apparatus for carpet or the like.
It is a further object of the present invention to provide apparatus for continuously dispensing a liquid onto a moving web in an irregular and random pattern.
It is a still further object of the present invention to provide a continuous, random dyeing apparatus for carpet or the like which is economically feasible.
It is another object of the present invention to provide a continuous, random dyeing apparatus for carpet or the like in which a high degree of control over the random nature of the pattern is obtainable.
It is still another object of the present invention to provide a continuous, random dyeing apparatus for carpet or the like which is simple in structure, inexpensive, and easy to maintain.
Still other objects, features, and attendant advantages of the present invention will become apparent to those skilled in the art from a reading of the following detailed description of the preferred embodiment constructed in accordance therewith, taken in conjunction with the accompanying drawings wherein like numerals designate like parts in the several figures and wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view, in highly simplified form, of a continuous, random dyeing apparatus for carpet or the like constructed in accordance with the present invention; and
FIGS. 2 and 3 are enlarged sectional views taken along the lines 2--2 and 3--3, respectively, in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, there is shown apparatus, generally designated 10, for the continuous, random dyeing of carpet or the like. Apparatus 10 is designed to apply dye, in liquid form, to a length of carpet 11 as carpet 11 moves through apparatus 10 in the direction of the arrows shown. As is known in the art, carpet 11 includes a backing 12 and pile 13.
Apparatus 10 includes a first pair of elongate rollers or drums 14 and 15 mounted for rotation on parallel, spaced-apart shafts 14' and 15', respectively, carpet 11 extending over drum 14, between drums 14 and 15, and under drum 15. After extending beneath drum 15, carpet 11 extends above elongate drums 21-23 which are mounted for rotation on parallel spaced-apart shafts 21'-≦', respectively, and operate to support carpet 11 as it passes through apparatus 10. Drums 14, 15, and 21-23 are approximately coplanar.
Positioned above the plane of drums 14, 15, and 21-23 are three more elongate rollers or drums 16-18 mounted for rotation on parallel spaced-apart shafts 16'-18', respectively. Drums 15-18 are virtually identical and have outer surfaces made from a relatively hard material, such as plastic, metal, or wood, such outer surfaces being relatively smooth. Each of drums 15-18 has a plurality of cavities 24 extending partially thereinto, from the outer surface thereof, in various depths, sizes, and patterns, as shown. The patterns may be the same or different, as will be described more fully hereinafter. Drum 14 is preferably made from a relatively soft, resilient material, such as rubber.
With reference to FIGS. 1 and 2, apparatus 10 includes means, generally designated 25, for conducting a liquid, such as a dye, onto one side of drum 15, above the intersection between drums 14 and 15. According to one embodiment of the invention, means 25 includes an elongate pipe 26 having a plurality of holes 27 in the bottom thereof and means (not shown) for pumping a liquid 28 into pipe 26. As seen in FIG. 2, liquid 28 falls from holes 27 onto carpet pile 13 as carpet 11 extends between drums 14 and 15.
With reference to FIGS. 1 and 3, apparatus 10 includes wiper means, generally designated 30, engaging the outer surface 31 of drum 16, longitudinally along one side thereof. According to the preferred embodiment of the invention, wiper means 30 includes an elongate, planar wiper blade 32 made from a resilient material, such as rubber, one side edge of blade 22 engaging outer surface 31 of drum 21.
Apparatus 10 further includes means, generally designated 33, forming a trough along said one side of drum 16. According to the preferred embodiment of the invention, means 33 includes a side plate 34 positioned in parallel, spaced relationship relative to drum 16, a pair of end plates 35 secured to side plate 34 and engaging surface 31 of drum 16, at opposite ends thereof, and a bottom plate 36, one side edge of which is connected to side plate 34 and the ends of which are connected to end plates 35. The other side edge of plate 36 is spaced from drum 16. Trough forming means 33 also includes wiper blade 32 which is secured to bottom plate 36 by means such as rivets 37.
Apparatus 10 further includes means, generally designated 38, for conducting a liquid 39, such as a dye, into trough forming means 33. According to the preferred embodiment of the invention, liquid conducting means 38 includes an elongate pipe 40 having a plurality of holes 41 in the bottom thereof and means (not shown) for pumping liquid 39 into pipe 40. As seen in FIG. 3, liquid 39 falls from holes 41 into trough forming means 33.
Apparatus 10 includes trough forming means 42 and 43 and liquid conducting means 44 and 45 associated with drums 17 and 18, respectively, which are identical in all respects to trough forming means 33 and liquid conducting means 38, respectively, associated with drum 16. Accordingly, any discussion of drum 16 and the means associated therewith will be equally applicable to drums 17 and 18 and the means associated therewith.
Finally, apparatus 10 includes drive means, generally designated 46, for rotating drums 15-18 on shafts 15'-18', respectively, in the direction of the arrows shown. While each of such drums may be provided with a separate drive means, it is most economical and therefore preferable to use a single drive means 46 for all of such drums. Specifically, shafts 15'-18' may each support at least one gear 47. A first drive chain 48 connected between a power source (not shown) and one of the gears 47 mounted on shaft 15' may be utilized to drive drum 15. A second chain 49 connected between gears 47 mounted on shafts 15' and 16' may be used to drive drum 16 with drum 15. Finally, a third chain 50 interconnecting gears 47 mounted on shafts 16'-18' may be used to drive drums 17 and 18 with drum 16.
In operation, drums 14 and 15 are optional parts of apparatus 10 and function to apply a solid base color to pile 13 of carpet 11 and, in addition, a darker shade of the same color in a random pattern. This enhances the overall appearance of carpet 11 when it exits from apparatus 10. More specifically, carpet 11 enters apparatus 10 over the top side of drum 14, pile side up, and then is squeezed between drums 14 and 15. Pipe 26 conducts dye 28 onto pile 13 of carpet 11, at the intersection between carpet 11 and drum 15. In the absence of cavities 24 in drum 15, drums 14 and 15 would function to squeeze carpet 11 therebetween and limit the amount of dye that can pass with carpet 11 between drums 14 and 15. However, since dye 28 is dispensed directly onto carpet 11, the entire width of carpet 11 is coated so that the end result is a solid base color being applied to the face side of carpet 11.
On the other hand, and in addition, a quantity of dye 28 fills each cavity 24 and this quantity of dye 28 passes between carpet 11 and drum 15, past the intersection between drums 14 and 15, as shown in FIG. 2. This additional quantity of dye 28 soaks into pile 13. Thus, since the face side of carpet 11 which passes below cavities 24 in drum 15 receives a greater quantity of dye 28, the result is a darker shade of the same color being applied to carpet 11 in the random pattern of cavities 24 in drum 15.
As shown in FIGS. 1 and 3, liquid conducting means 38, 44, and 45 conduct dye into trough forming means 33, 42, and 43, respectively. For example, dye 39 which is collected in trough forming means 33 is distributed into the cavities 24 in surface 31 of drum 16 as drum 16 rotates past wiper blade 32. Wiper blade 32 functions to prevent any of dye 39 from passing below the intersection between wiper blade 32 and surface 31 of drum 16, except for the quantity of dye 39 which fills cavities 24. The dye 39 which fills cavities 24 passes below wiper blade 32 and is thrown down onto carpet pile 13, both by gravity and the centrifugal force generated by the rotation of drum 16. A similar effect occurs with regard to drums 17 and 18.
The end result is similar to other types of space dyeing apparatus, but the result is accomplished in a simpler and more economically feasible manner. Specifically, the pattern which is attainable is readily controlled by controlling the depths, sizes, and shapes of the cavities 24 in drums 16-18, by controlling the speeds of rotation of drums 16-18, which speeds may be the same or different, by controlling the speed of carpet 11 through apparatus 10, and by controlling the distance between carpet 11 and drums 16-18.
As mentioned previously, the operation of drums 17 and 18 is the same as that described above with respect to drum 16. Furthermore, three drums are shown for illlustration purposes only, any number of drums being possible. The use of multiple drums allows for different cavity shapes and sizes and different dye colors. The rotary speeds of all drums 15-18 can be controlled independently for even greater versatility in the random pattern application.
Wiper means 30 need not be a wiper blade, but could be soft surface rollers engaging the outer surfaces of drums 16-18. In such case, dye could be conducted to drums 16-18 in the same manner as liquid conducting means 25 conducts dye 28 to drum 15.
Shafts 14'-18' and 21'-23', liquid conducting means 25, 38, 44, and 45, and trough forming means 33, 42, and 43 may be supported in any suitable manner, such as within a single machine housing (not shown). Where required, excess dye flowing over the outer edges of any of drums 15-18 may be collected in a suitable recirculating system (not shown) and pumped back into liquid conducting means 25, 38, 44, and 45 for reuse.
It can therefore be seen that according to the present invention, the problems encountered heretofore are solved by a novel method and apparatus for the continuous, random application of color to carpet or the like. Apparatus 10 and the method embodied therein produces a carpet which is aesthetically pleasing to the eye. The application speed is sufficient to make apparatus 10 economically feasible. In addition, the application of dye can be easily controlled in any number of various patterns. The method of application control is relatively simple as well as being easy to maintain.
While the invention has been described with respect to the preferred physical embodiment constructed in accordance therewith, it will be apparent to those skilled in the art that various modifications and improvements may be made without departing from the scope and spirit of the invention. Accordingly, it is to be understood that the invention is not to be limited by the specific illustrative embodiment, but only by the scope of the appended claims. | Continuous, random dyeing apparatus for carpet or the like comprising a plurality of elongate drums mounted for rotation on parallel, spaced axes, each drum having a plurality of cavities extending partially thereinto from the outer surface thereof, wiper means engaging the outer surface on one side of each drum, along a line parallel to the axis thereof, means for rotating the drums in a direction such that the one sides thereof move downwardy, and means for conducting a dyeing liquid to the intersections between each drum and its associated wiper means. The liquid fills the cavities in the drums, on the one sides thereof, as the drums rotate and the liquid in the cavities passes below the wiper means and is dispensed below the drum onto a carpet moving therebelow. | 3 |
BACKGROUND OF THE INVENTION
This invention relates to the measurement of currents in an operating circuit and, in particular, to the measurement of such currents without breaking the circuit.
The most straightforward method of measuring the electrical current in an operating circuit is to break the circuit at some point and insert a current measuring device such as a current meter. The circuit is then reestablished through the current measuring device and the current measured.
Breaking the circuit and inserting the measuring device is typically inconvenient at best and often very difficult. In the case of an electronic circuit on a printed circuit board, for example, it may involve cutting circuit traces or unsoldering components.
In the case of ac currents, it is common to sense large current inductively in order to avoid the problems of inserting the measuring device into the circuit. Unfortunately, this is of little help for small ac currents and for dc currents.
DC currents are sometimes sensed with magnetic sensors such as Hall-effect devices. This avoids the problems of inserting the measurement device into the circuit. Unfortunately, this method works poorly for small currents and it is difficult to get reliable and accurate results.
SUMMARY OF THE INVENTION
The present invention provides a method for the accurate and reliable measurement of currents in a circuit without breaking the circuit to insert a measuring device.
The method for measuring current I 0 in a circuit includes selecting an element in the circuit having a low resistance with respect to the remainder of the circuit, This element remains connected in the circuit.
A current source is connected in parallel with the element. The current source has an output current and a current control input for controlling the output current.
A voltage measuring device is connected in parallel with both the element and the current source. The voltage measuring device has a voltage measurement output for providing a voltage measurement across the element and a voltage measurement control input for controlling the voltage measurement process.
A control device is connected to the current control input and the voltage measurement control input.
A calculation device having a calculation control input is connected to the control device.
A first current I 1 is driven through the element with the current source and a first voltage V 1 across the element is measured with the measuring device, all in response to the control device. The first current is at or near zero.
A second current I 2 is driven through the element with the current source and a second voltage V 2 across the element is measured with the measuring device, all in response to the control device. The second current is greater than the first current.
A value for the current I 0 is calculated with the calculation device in response to the control device according to ##EQU1##
The calculated value is provided to a user or to an automated test system in response to the control device.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an electrical circuit for practicing the method of the invention.
FIG. 2 is a combination block and schematic diagram of a system for practicing the method of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, an operating circuit 10 to be tested is arbitrarily divided into a resistive element 12 and the remainder of the circuit 14. An unknown current I 0 passes through the element 12 creating a voltage drop V 0 . From Ohm's Law, the element 12 has a resistance R equal to the ratio of V 0 to I 0 , or ##EQU2##
A current source 16 is connected in parallel with the element 12 along with a voltage measuring device 18.
Assuming for a moment that all of the current I from the source 16 passes through the element 12, the follow analysis applies.
If a first value for I, I 1 is driven through the element 12, the voltage V takes on a value V 1 , where
V.sub.1 =V.sub.0 +I.sub.1 ·R
If a second value for I, I 2 (greater than I 1 ) is driven through the element 12, the voltage V takes on a value V 2 , where
V.sub.2 =V.sub.0 +I.sub.2 ·R
Subtracting these two equations and solving for R gives ##EQU3##
The current I 0 can then be expressed as ##EQU4##
As an alternative, if the current I 1 is at or near zero (e.g., 10 nanoamperes), then V 1 =V 0 to a high degree of accuracy and the equation for I 0 becomes ##EQU5##
It was assumed above that all of the current I passes through the element 12. The current I actually splits between the two parallel branches constituted by the element 12 and the remainder of the circuit 14. However, if the resistance R of the element 12 is low enough relative to the resistance of the remainder 14, then this assumption can be made as accurate as desired.
Unfortunately, the components of a circuit 10 normally thought of as resistive elements (e.g., resistors) do not typically satisfy this assumption and the above analysis fails.
However, it has been discovered that with proper selection of the "element" this method can be made to produce excellent results.
With a precision dc current source and voltage measuring device (e.g., a Keithley Instruments Model 2001 source/measure unit), resistances as low as one microhm, currents as low as ten picoamperes and voltages as low as ten nanovolts can be measured.
This makes it possible to find resistive elements 12 in the circuit 10 that satisfy the requirement of having a low resistance with respect to the remainder 14 of the circuit 10. Such elements, for example, as component leads, wires and printed circuit traces, or even portions thereof can be used as the element 12.
An exemplary range for the resistance of these elements is one milliohm to ten ohms. The voltage drop across these elements during operation of the circuit is typically in the range of 100 nanovolts to 0.2 volts.
The method of the invention works for ac currents as well as dc currents, but the present state of the resolution and accuracy of ac measurement devices limits the utility of the method for ac currents.
Referring to FIG. 2, to determine the current I 0 present in the circuit 10, the resistive element 12 is selected in the circuit 10 such that the resistance of the element 12 is low with respect to the remainder 14 of the circuit 10. The element 12 may be, for example, a component lead, wire or printed circuit trace, or a portion thereof that contains the current I 0 .
The current source 16 is connected in parallel with the element 12.
The voltage measuring device 18 is also connected in parallel with the element 12.
A control device 20 communicates with the current source 16 and the measurement device 18. The control device 20 controls the value of the current I produced by the current source 16 and the measurement of the voltage V by the measuring device 18.
The control device 20 also controls a calculation device 22 that performs calculations with the values of the current I and the voltage V.
The control device 20 may be, for example, a microprocessor and associated components such as RAM, ROM and buffers.
The calculation device 22 may be, for example, a separate microprocessor or part of the control device 20.
The control device 20 also controls displaying measured and calculated values on a display 24.
The control device 20 also controls the transmission of status information, measured and calculated values to an automated test system 26.
The automated test system 26 may also provide control signals to the control device 20 and to many similar devices with associated source and measure devices. This allows many parameters of a circuit to be measured simultaneously.
In one embodiment of the invention, a current I 1 is driven through the element 12 by the source 16 as directed by the control device 20. The current I 1 is selected to be at or near zero.
The resulting voltage V 1 across the element 12 is measured by the measuring device 18 as directed by the control device 20.
Similarly, a larger current I 2 is driven through the element 12 and a voltage V 2 measured.
Under direction of the control device 20, the values I 1 , V 1 , I 2 , and V 2 are passed to the calculation device 22 and I 0 calculated according to ##EQU6##
The control device 20 directs the value I 0 to be displayed on the display 24 and/or passed to the automatic test system 26.
As an alternative embodiment, the current I 1 can be substantially greater than zero, but an additional step of measuring the initial voltage V 0 across the element 12 (the voltage V when the current I is zero) is added.
In this embodiment, the values V 0 , I 1 , V 1 , I 2 , and V 2 are passed to the calculation device 22 and I 0 calculated according to ##EQU7##
In either of the above two embodiments, the measurements may be made in any order.
It should be evident that this disclosure is by way of example and that various changes may be made by adding, modifying or eliminating details without departing from the fair scope of the teaching contained in this disclosure. The invention is therefore not limited to particular details of this disclosure except to the extent that the following claims are necessarily so limited. | A current in a circuit is measured without breaking the circuit. A relatively low resistance element in the circuit such as a component lead is chosen. A current is forced through the element and the voltage drop measured. Another current is forced through the element and the voltage drop measured. The values of these currents and voltages are used to determine the original current in the circuit. | 6 |
BACKGROUND OF THE INVENTION
The present invention generally relates to annular seals, such as dynamic seals of the type used in turbomachinery. More particularly, this invention relates to a fixture and inspection method by which dimensional characteristics of an annular seal can be ascertained prior to installation.
Labyrinth-type packings and brush seals are widely used in steam turbines and in aircraft and industrial gas turbines to provide dynamic seals between rotating and static turbine components, such as the rotor and diaphragm inner web of a steam turbine. Traditional labyrinth packing comprises a series of teeth that project radially inward from the inner circumference of a static component and toward but out of contact with the adjacent rotary component, thereby defining a series of partial barriers that create a tortuous axial flow path immediately adjacent the surface of the rotary component. Brush seals comprise fibers or bristles that, similar to the teeth of a labyrinth packing, project radially inward from the inner circumference of a static component toward a rotary component. In contrast to labyrinth packings, brush seals are normally intended to be in rubbing contact with the adjacent circumferential surface of the rotary component, creating a substantially continuous barrier to flow around the circumference of the rotary component. In this regard, brush seals provide a more effective barrier to secondary flow losses, i.e., provide better sealing performance, as compared to labyrinth packings, and therefore have the potential for significantly improving section performance. However, because their sealing performance relies on rubbing contact, the conformance of a brush seal to its design dimensions and tolerances, particularly its internal diameter and concentricity, is important.
Brush seals have been developed that are manufactured as a full-annular structure and then cut to create multiple arcuate segments that can be later reassembled during installation to reestablish the original annular seal structure. In a particular example, a brush seal formed of high strength polymer (e.g., KEVLAR®) is sectioned along its diameter to create two semicircular (180-degree) arcuate segments. The flexible nature of the polymeric material along with residual stresses (in the back structure supporting the bristles) that are redistributed during cutting causes each segment to have altered inner diameter (ID) dimensions. As a result, dimensional inspection of the seal in its “free” (uninstalled) state is difficult and leads to an increased risk of seals that do not conform with design dimensions and tolerances. Though the seal can be inspected after its segments are reassembled during final installation, such an approach can be impractical because of the limited space of typical turbine installations and the difficulty with which such an inspection can be performed in the field.
In view of the above, it would be desirable to verify the dimensional characteristics of a segmented brush seal (as well as other annular seals) without the requirement to install the seal prior to inspection.
BRIEF SUMMARY OF THE INVENTION
The present invention provides a fixture assembly and inspection method by which the internal diameter and/or concentricity of a segmented annular seal can be readily inspected and optionally measured prior to final installation.
According to a first aspect of the invention, the fixture assembly comprises a base and at least two fixture segments supported on the base. When assembled, the fixture segments define an annular fixture housing having an outer rim and a groove adjacent the outer rim and defined in an interior circumference of the fixture housing. The groove has a cross-sectional shape corresponding to a cross-sectional shape of the annular seal. The fixture assembly further comprises means for assessing at least one dimensional characteristic of the annular seal when installed in the groove of the fixture housing and as the assessing means is moved along the interior circumference of the fixture housing.
According to a second aspect of the invention, the inspection method comprises assembling at least two fixture segments on a base to define an annular fixture housing having an outer rim and a groove adjacent the outer rim, defined in an interior circumference of the fixture housing, and having a cross-sectional shape corresponding to a cross-sectional shape of the annular seal. After installing the multiple arcuate segments in the groove of the fixture housing so as to assemble the annular seal therein, at least one dimensional characteristic of the annular seal is assessed by causing an inspection device to move along the interior circumference of the fixture housing.
From the above, it can be appreciated that an advantage of the present invention is that a relatively uncomplicated, split fixture housing is employed that enables a flexible, multi-segment annular seal, such as a polymeric brush seal of a turbomachine, to be dimensionally inspected relative to one or more critical data while the seal is in a simulated installed condition. Another advantage is that the fixture assembly can be portable, permitting the inspection method to be performed in the field. The fixture assembly and inspection method can be employed to quantitatively and/or qualitatively ensure the concentricity of the inner diameter of the seal and/or compliance with maximum and minimum diametrical dimensions of the seal.
Other objects and advantages of this invention will be better appreciated from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 represents a cross-sectional view of a seal assembly for a turbomachine and containing a brush seal assembly of a type that can be inspected in accordance with the present invention.
FIG. 2 represents a perspective view of a fixture assembly in accordance with a first embodiment of this invention.
FIG. 3 is an exploded view of the fixture assembly of FIG. 2 .
FIG. 4 is a cross-sectional view of the fixture assembly of FIG. 2 .
FIG. 5 represents a perspective view of a fixture assembly in accordance with a second embodiment of this invention.
FIG. 6 is a cross-sectional view of the fixture assembly of FIG. 5 .
FIG. 7 is a perspective view of an inspection block of the fixture assembly of FIG. 5 .
FIGS. 8 and 9 are cross-sectional and perspective views, respectively, of inspection blocks in accordance with alternative embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view through an annular seal assembly 10 of a type that can be inspected with fixture assemblies and methods of this invention. The seal assembly 10 is representative of seals used in steam turbines between axially adjacent stages of such turbines to minimize leakage between a rotor to which buckets are mounted and a casing that surrounds the rotor and from which nozzle partitions are supported. As is well known by those skilled in the art, various turbine configurations and applications are possible and within the scope of this invention. As such, the particular type of installation intended for the seal assembly 10 will not be discussed in any detail.
As represented, the seal assembly 10 comprises a housing 13 that contains a brush seal assembly 12 situated within a groove 15 between a pair of teeth 14 , the latter being of the type associated with labyrinth-type packings. It should be understood that the seal assembly 10 of FIG. 1 is merely intended to be exemplary of the type of annular seal that can be inspected in accordance with this invention, and that other annular seal types and configurations are also within the scope of the invention. When the seal assembly 10 is installed in its intended turbomachine, the brush seal assembly 12 is axially positioned between the teeth 14 relative to the axis of the turbomachine. As such, the labyrinth teeth 14 serve as backup seals to the brush seal assembly 12 , and are therefore preferred but optional components of the seal assembly 10 . Consistent with brush seals of the types used in turbomachinery, the brush seal assembly 12 represented in FIG. 1 is adapted to continuously maintain a prescribed gap or pre-determined contact with the surface with which it is intended to seal, e.g., the rotor of a turbomachine, thereby effecting a better seal than possible with a labyrinth packing. For this reason, the brush seal assembly 12 is represented as comprising bristles 16 that, when the seal assembly 10 is installed in a turbomachine, project radially inward for rubbing contact with the rotor. As known in the art, the brush seal bristles 16 and the labyrinth teeth 14 may be formed of a variety of materials, with KEVLAR® and other high-temperature, high-strength polymeric materials being notable examples for the brush seal assembly 12 and its bristles 16 if used in advanced technology turbomachinery, while ductile metals are preferred for the teeth 14 and the housing 13 surrounding and supporting the brush seal assembly 12 . Other materials that could foreseeably be used in the seal assembly 10 include carbon fiber materials.
Seal assemblies of the type represented in FIG. 1 are typically installed in a groove of a stationary structure of a turbomachine, such as a diaphragm inner web of a steam or gas turbine. When installed in this manner, the outer circumferential surface 18 of the seal assembly 10 is received in the groove so that the teeth 14 and bristles 16 extend radially inward toward the rotor of the turbine. Because the sealing performance of the seal assembly 10 relies largely on maintaining a prescribed gap or pre-determined rubbing contact between the bristles 16 and the rotor, the bristles 16 establish a critical inner diameter (ID) and concentricity of the seal assembly 10 .
FIGS. 2 through 4 depict a fixture assembly 20 adapted for assessing the inner diameter and/or concentricity of the brush seal assembly 12 of the seal assembly 10 in accordance with a first embodiment of the invention. As represented in FIGS. 2 through 4 , the fixture assembly 20 comprises a pair of fixture segments 21 that, when assembled and secured to a base 30 , form a fixture housing 22 having an annular shape. The fixture segments 21 and fixture base 30 can be fabricated from a wide variety of materials, and various fastening techniques can be employed to secure the fixture segments 21 to the fixture base 30 so as to provide sufficient strength and rigidity to house the brush seal assembly 12 and support the equipment used to assess the brush seal assembly 12 . As evident from FIG. 4 , the fixture housing 22 includes a groove 24 located in its interior circumference 26 near an outer rim 28 of the fixture housing 22 . The fixture groove 24 is configured and sized to coincide with the diameter, width, and depth of the groove 15 of the seal assembly 10 in which the brush seal assembly 12 will be housed when installed on its intended turbomachine. Furthermore, the rim 28 of the fixture housing 22 is preferably shaped and sized to simulate the upper tooth 14 of the seal assembly 10 in FIG. 1 .
In FIGS. 2 and 3 , the brush seal assembly 12 is shown as being installed in the groove 24 for inspection by an armature assembly 32 . The armature assembly 32 is represented as including a bar 34 pivotally mounted to the fixture base 30 so that at least one of its opposing ends will pass adjacent the groove 24 of the fixture housing 22 and the brush seal assembly 12 when installed in the groove 24 . The bar 34 is depicted as having a bore 36 preferably located midway along its length, and a bushing 38 within the bore 36 that receives a pin 40 secured to the fixture base 30 and by which the bar 34 is rotatably supported above the base 30 . A clamp 42 secures the bar 34 to the pin 40 to ensure that the bar 34 rotates within a plane perpendicular to the pin 40 and parallel to a plane containing the fixture groove 24 and therefore the brush seal assembly 12 installed in the fixture groove 24 .
A micrometer 44 is shown in FIGS. 2 and 3 as being mounted with a holder 46 to one end of the bar 34 , so that the micrometer 44 is oriented and positioned to measure the inner diameter (ID) of the brush seal assembly 12 as established by its bristles 16 . The micrometer 44 can be of any suitable type, such as a dial indicator, comparator, non-contacting measurement device, etc., capable of providing an indication of variations in the ID of the seal assembly 10 as the bar 34 is rotated on its axis of rotation established by the bushing 38 and pin 40 . Measurement indications of the micrometer 44 can be provided electronically or visually, such as with a dial. As the bar 34 is rotated on the pin 40 , the output of the micrometer 44 can be used to obtain precise quantitative dimensions of the inner diameter of the brush seal assembly 12 , or provide a qualitative assessment of conformance (“go-no go”) to the minimum and maximum ID dimensions permitted for the assembly 12 .
FIGS. 5 and 6 depict a fixture assembly 50 adapted for assessing the inner diameter and/or concentricity of the brush seal assembly 12 in accordance with a second embodiment of the invention. Similar to the fixture assembly 20 of FIGS. 2 through 4 , the fixture assembly 50 is represented as comprising a pair of fixture segments 51 that, when assembled and secured to a base 60 , yield a annular fixture housing 52 . Also consistent with the previous fixture assembly 20 , the fixture housing 52 can be seen in FIG. 6 to have an internal groove 54 located in its interior circumference 56 near an outer rim 58 of the housing 52 , and configured and sized to coincide with the diameter, width, and depth of the groove 15 that houses the brush seal assembly 10 within the seal assembly 10 of FIG. 1 . Furthermore, the rim 58 of the fixture housing 52 can be shaped and sized to simulate the upper tooth 14 of the seal assembly 10 in FIG. 1 . In contrast to the embodiment of FIGS. 2 through 4 , the fixture assembly 50 of FIGS. 5 and 6 is equipped with an inspection block 62 intended to qualitatively assess the brush seal assembly 12 installed in the groove 54 on the basis of conformance (“go-no go”) to the minimum and maximum ID dimensions permitted for the seal assembly 12 .
The inspection block 62 is represented in FIGS. 5 and 6 as being supported from the rim 58 of the fixture housing 52 by a pair of rollers 64 rotatably mounted to the block 62 so that a contoured surface 66 of the block 62 abuts the inner circumference of the rim 58 and a rib 74 axially spaced below the rim 58 . For this reason, the contoured surface 66 preferably has a radius of curvature approximately equal to that of the interior circumference of the rim 58 and rib 74 . As seen in FIG. 7 , a pair of bores 76 are present in the contoured surface 66 by which the rollers 64 can be rotatably mounted with shafts (not shown). As also seen in FIG. 7 , a channel 68 is defined in the contoured surface 66 beneath the bores 76 . The position of the channel 68 relative to the rollers 64 is such that the channel 68 is axially aligned with the brush seal bristles 16 of the brush seal assembly 12 installed in the fixture groove 54 , and the width of the channel 68 is sized to accommodate the width of the bristles 16 . By precisely sizing the radial depth of the fixture groove 54 relative to the inner circumferences of the rim 58 and rib 74 of the fixture housing 52 , as the inspection block 62 travels around the housing 52 with the contoured surface 66 abutting the rim 58 and rib 74 , the channel 68 will pass a precise predetermined distance from the bottom of the groove 54 and have a precise position relative to the brush seal assembly 12 installed in the groove 54 .
The depth of the channel 68 is sized to enable the block 62 to assess the inner diameter and concentricity of the seal assembly 12 (established by the bristles 16 ) in one of several ways. For example, the depth of the channel 68 can be sized to coincide with the minimum ID of the brush seal assembly 12 , such that by moving the block 62 (e.g., by hand) along the circumference of the fixture housing 52 , an out-of-tolerance ID condition can be ascertained by detecting rubbing contact between the bristles 16 and the bottom of the channel 68 . Detection of rubbing contacts can be facilitated by placing a contact-sensitive material 70 in the bottom of the groove 68 , as depicted in FIG. 8 , to assist in detecting if the bristles 16 have contacted the groove 68 . The material 70 may be a pressure-sensitive adhesive tape whose adhesion to the groove 68 following inspection will indicate if and to what extent the bristles 16 made interference contact with the bottom of the groove 68 . Another alternative for the material 70 is a powder such as chalk applied to the bottom of the groove 68 , by which a brush seal assembly 12 with an undersized ID can be detected by visually inspecting its bristles 16 to see if any powder has been transferred to the bristles 16 . A second inspection block 62 whose channel 68 has a depth sized to coincide with the maximum ID of the seal assembly 10 is then used to determine an out-of-tolerance maximum ID condition by the absence of rubbing contact between the bristles 16 and the bottom of the channel 68 .
FIG. 9 depicts an alternative configuration for the groove 68 , in which a step 72 is present to define two different depths corresponding to the minimum and maximum allowable ID's for the brush seal assembly 12 . As shown in FIG. 9 , two staggered sets of bores 76 are provided in which the two rollers 64 can be selectively mounted to axially align one of the channel depths with the brush seal bristles 16 of the brush seal assembly 12 installed in the fixture groove 54 . With this approach, a single inspection block 62 is able to simultaneously detect out-of-tolerance minimum and maximum ID conditions. This approach can also make use of the contact-sensitive material 70 of FIG. 8 .
While the invention has been described in terms of a particular embodiment, it is apparent that other forms could be adopted by one skilled in the art. For example, while the fixture housings of the invention are shown and described as comprising two fixture segments, the housings could be divided into any number of segments. Furthermore, though the invention has been described in reference to a brush seal for a turbomachine, the invention can find application for use with other types of annular-shaped seals. Therefore, the scope of the invention is to be limited only by the following claims. | A fixture assembly and inspection method by which the internal diameter and/or concentricity of a segmented annular seal can be readily inspected and optionally measured prior to final installation. The fixture assembly has at least two fixture segments supported on a base, by which an annular fixture housing is defined having an outer rim and a groove with a cross-sectional shape corresponding to a cross-sectional shape of the annular seal. The fixture assembly further includes a device or apparatus for assessing at least one dimensional characteristic of the annular seal when installed in the groove of the fixture housing and as the assessing device/apparatus travels along the interior circumference of the fixture housing. | 5 |
INCORPORATION BY REFERENCE
[0001] The following documents are incorporated herein by reference as if fully set forth: U.S. application Ser. No. 11/079,068, filed Mar. 14, 2005; and Swiss Patent Application No. 00909/04, filed May 28, 2004.
BACKGROUND
[0002] The subject matter of the present invention is a device and a method for acquiring and processing measurement quantities in a sewing machine.
[0003] It is known that in sewing machines a camera can be provided that monitors the article being sewn during the sewing process. In this way, differences in quality that may be caused by different transport characteristics of different types of sewn articles can be acquired.
[0004] As is disclosed for example in DE 19850742, the camera can be used to determine the position of two adjacent stitch points of the sewing needle on the article being sewn. A comparator device determines deviations of the actual values from stored target values for the position of these stitch points, and influences the advance of the material in such a way that subsequent stitch points deviate as little as possible from the desired target positions.
[0005] Although the characteristics of the article being sewn, which can vary greatly, in interaction with the device for transporting the article being sewn are not the only factors responsible for the problem-free functioning of a sewing machine, up until now a camera has been used only to monitor the article being sewn.
SUMMARY
[0006] Therefore, the object of the present invention is to create a device and a method for using a camera to acquire and process measurement quantities in a sewing machine that ensure problem-free operation of the sewing machine.
[0007] This objective is achieved by a device and a method for acquiring and processing measurement quantities in a sewing machine. With the method according to the present invention and the device according to the present invention, sewing machine elements and their disposition on the sewing machine can be monitored. Thus, for example, items of information concerning the type of particular sewing machine elements and their correct disposition on the sewing machine can be acquired. The acquisition and evaluation take place using one or more cameras connected to an image processing unit. According to the position of the camera, or of an imaging optical system allocated to the camera, imaging information on sewing machine elements can be acquired from the inside of the lower arm (e.g., spool, spool capsule, or throat plate) or from above the throat plate (e.g., sewing needle, sewing foot, throat plate, hoop). The cameras and/or the imaging optical systems, or parts thereof, can be situated so as to be capable of movement. They can for example be mounted so as to be capable of pivoting about one or more pivot axes, and/or so as to be capable of movement along an axis of translation. Changes of position can be brought about for example using step motors or other drive means that can be controlled by the sewing machine control unit. The image information is evaluated by an image processing unit. The image processing unit can use features, or comparison or target quantities, that are stored in a target quantity memory. In a preferred construction of the present invention, the image processing unit can in addition also store information or target quantities in the target quantity memory. Such target quantities can for example include color or character codes, or information concerning shape, contour, structure, or position of a sewing machine element.
[0008] The image processing unit can be functionally connected with the sewing machine control unit or can be a component thereof. The image processing unit can check for the presence and/or the correct mounting of one or more sewing machine elements and/or their spatial position on the sewing machine. Various functions of the sewing machine control unit that use the information from the image processing unit can contribute to the automation, simplification, or improvement of operating, monitoring, and control tasks, the issuance of warnings when errors occur or the execution of certain subsequent operations, the prevention of accidents, or the ensuring or improvement of the quality of the sewing process.
[0009] In addition to the acquisition and evaluation of information concerning sewing machine elements that are components or accessories of the sewing machine, the image processing unit can also be fashioned for the acquisition and evaluation of information concerning sewing elements. The category of sewing elements includes the article being sewn and the threads used for the processing of the article being sewn before and after the processing. The information concerning sewing elements can also be used by the sewing machine control unit in particular for the controlling or regulation of sewing processes, for example for influencing the longitudinal and/or transverse movement of a material transport device.
[0010] The camera can also be used to determine criteria of comparison for the target quantity memory. Alternatively, or in addition, such features or target quantities can also be read into the target quantity memory via an interface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention is explained in more detail in the following with reference to the drawing Figures.
[0012] FIG. 1 shows a sewing machine in a side view;
[0013] FIG. 1A is a detail view taken from FIG. 1 in the indicated area A in the area of the shuttle in an enlarged, partially exploded view;
[0014] FIG. 2 shows a schematic diagram of a part of a sewing machine having an acquisition device;
[0015] FIG. 3A is a view of a first throat plate;
[0016] FIG. 3B is a view of a second throat plate;
[0017] FIGS. 4A-4D are views of four different types of sewing feet;
[0018] FIG. 5A shows a side view of a sewing machine with a correctly fastened sewing foot;
[0019] FIG. 5B shows a side view of a sewing machine with an incompletely fastened sewing foot;
[0020] FIG. 5C shows a side view of a sewing machine in which the sewing foot lies flat;
[0021] FIG. 5D shows a side view of a sewing machine in which the sewing foot lies obliquely;
[0022] FIGS. 6A-6I are views of nine different sewing needle types.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] FIGS. 1 and 1A schematically show a sewing machine 1 having a base 3 , a pedestal 5 that is fastened to and supported on base 3 , and a free or lower arm 7 fastened thereto, as well as upper arm 9 . A display unit 10 , or a display screen and operating elements 12 , are situated laterally on the upper arm 9 . The front end of upper arm 9 is formed as a sewing machine head 11 . On the lower side of sewing machine head 11 , extends a needle bar 13 having a needle holder 15 , a sewing needle or needle 17 placed in needle holder 15 , a sewing foot holder 19 having a sewing foot 21 placed therein, and a threading device 23 . Two cameras 25 , represented by broken lines, are integrated into the sewing machine head 11 , or in an additional module 27 that is fastened laterally thereon and that can be removed, in such a way that they can acquire one or more of the sewing machine elements or parts thereof that are visible between the sewing machine head 11 and the lower arm 7 . An additional camera 25 , likewise represented by broken lines, is situated in the front area of the lower arm 7 in such a way that it can acquire sewing machine elements or parts thereof that are visible there. Alternatively, cameras 25 can also be situated in other areas of the sewing machine 1 , for example in the area of the pedestal 5 or of the upper arm 9 . In addition, optical elements, such as for example light waveguides 29 , lenses 31 , or mirrors for the formation of an acquisition area, can be placed on the camera 25 . In this way, even unfavorably situated areas of acquisition can be imaged using a camera 25 . Cameras 25 can thus be situated on the sewing machine 1 where there is available space for them, largely independent of their areas of acquisition. In this way, even sewing machine elements that are difficult to access can be acquired. In the simplest embodiment of the present invention, one camera 25 is sufficient. A plurality of cameras 25 can however also work together in such a way that objects such as sewing machine elements or sewing elements can be acquired from a variety of directions.
[0024] The designation “sewing machine elements” includes components and accessory parts that are situated fixedly on the sewing machine 1 as well as parts and accessories that can be detached from the sewing machine; for example, the needle bar 13 , the needle holder 15 , the needle 17 , the sewing foot holder 19 , the sewing foot 21 , the threading device 23 , a throat plate 33 , a hook 35 , a bobbin case 37 placed in the hook 35 , or a bobbin 39 placed in the bobbin case 37 that is empty or is partially or completely equipped with thread. For better visibility of the sewing machine elements, in FIG. 1 a cover 41 , situated on the front side of the lower arm 7 , is opened. Additional possible sewing machine elements include detachable work supports, straightedges, additional apparatuses, or hoops (not shown).
[0025] FIG. 2 shows a schematic diagram of the design of the device for acquiring measurement quantities. The cameras 25 can for example comprise black-and-white or color CCD or CMOS image sensors having a one- or two-dimensional array of light-sensitive pixels. They are connected to an image processing unit 43 that processes the image information acquired by the cameras 25 . Alternatively, a separate image processing unit 43 can be allocated to each of the cameras 25 . This image processing unit can for example be completely or partially integrated on the same chip as the camera 25 .
[0026] The image processing unit 43 is functionally connected to a target quantity memory 45 , for example in a non-volatile flash memory. In addition, there is a functional connection between the image processing unit 43 and the sewing machine control unit (called machine control unit 47 for short). Of course, the image processing unit 43 can also be integrated completely or partially into the machine control unit 47 . The machine control unit 47 comprises a plurality of interfaces, for example to operating elements 12 , to the display unit 10 , to an acoustic signal transducer 49 , and to main drive 51 , which, depending on the design of the sewing machine 1 , is used for example to drive the needle bar 13 and the hook 35 .
[0027] In FIGS. 3A and 3B , two different throat plates 33 are shown having stamped-in length scales and pass-through slots 53 for a clutch feed 34 ( FIGS. 5C and 5D ). The two throat plates 33 differ in the size or length of a needle pass-through opening 55 and/or of a code 57 that is printed or stamped on the upper side and/or the underside of the throat plate 33 . The code 57 can for example be fashioned as a bar code, as a number, or as a color code, and is uniquely assigned to a particular type of throat plate.
[0028] In FIGS. 4A-4D , four different types of sewing feet are shown. They differ not only in their shape or design, but also by a visibly printed or stamped code 57 in the form of a number. The code “1” characterizes a back-transport foot for useful and decorative stitching, code “2” designates an overlock foot, code “9” designates a darning foot, and code “37” designates a patchwork foot.
[0029] Sewing machine elements need not necessarily be characterized with a code, if a unique identification is also possible on the basis of other features.
[0030] In FIGS. 5A and 5B , the fastening of a sewing foot 21 to the sewing foot holder 19 is shown schematically. Here, a cup-type recess 59 on the upper side of the sewing foot 21 is pushed from below over a peg 61 that protrudes downward on the sewing foot holder 19 . Subsequently, the sewing foot 21 is clamped fast on the sewing foot holder 19 using a knee lever 63 . If the sewing foot 21 is not seated properly on the sewing foot holder 19 , this can be recognized for example by a lowered and/or oblique position of the sewing foot 21 , or by a changed pivot position of the knee lever 63 in comparison with a position it should have when the sewing foot 21 is correctly fastened.
[0031] FIGS. 5C and 5D show the different positions of the sewing foot 21 , or of a sewing foot sole 22 coupled to the sewing foot 21 at the bottom, for the case of a flat seating on clutch feed 34 ( FIG. 5C ) and during the crossing of a seam 65 of an article 67 that is being sewn.
[0032] FIGS. 6A-6I show a plurality of different types of sewing needles. They comprise differing features, such as for example needle diameter d, type of point (cutting point, rounding diameter of a ball point), number of needles 17 in the case of multiple needles, distances s between individual needles 17 of such a group, shape of the needles (e.g., round needles, sword-shaped needles). Needles 17 shown in FIGS. 6A-6I are, respectively: a sword-shaped needle 17 a , a drilling needle 17 b , a double needle 17 c , a needle 17 d having a cutting point, a needle 17 e having a fine point, two needles 17 f and 17 g having medium ball points, a needle 17 h having a fine ball point, and a universal needle 17 i having a slightly rounded point.
[0033] In the target quantity memory 45 there may be stored, in suitable form, target quantities and/or comparative values and/or criteria for comparing measurement quantities that are acquired by the cameras 25 and prepared by the image processing unit 43 .
[0034] One or more of the cameras 25 can be situated such that, in addition to at least one sewing machine element, they can also acquire sewing elements or parts thereof before, during, or after the processing by the sewing machine 1 . The term “sewing elements” includes for example the article being sewn 67 , threads such as the upper thread and the bobbin thread, a hem, seam, or stitching pattern on the article being sewn 67 , a pattern for a hem or a stitching pattern, or the like. Partial areas of such sewing elements are also designated as sewing elements. Sewing elements can thus be brought into the stitch formation area between the lower arm 7 and the upper arm 9 during sewing and/or embroidering and/or quilting or similar processes, and can be processed or acquired there.
[0035] In the target quantity memory 45 , as target quantities or comparison quantities there can be stored information concerning sewing machine elements, or individual features of such sewing machine elements, such as their situation, size, color, shape, and position, e.g. in relation to the sewing machine 1 or in relation to other sewing machine elements. Thus, for example concerning the sewing feet 21 an item of visual information can be stored concerning how they can be recorded by one of the cameras 25 when the sewing foot 21 is correctly fastened to the sewing foot holder 19 . Alternatively, or in addition, an image of the contours or edges of a sewing foot 21 fastened in this way to the sewing foot holder 19 , or of a code 57 situated on the sewing foot 21 , can also be stored. Instead of, or in addition to, the items of visual information concerning correctly mounted sewing machine elements, typical images of incorrectly mounted sewing machine elements can also be stored in the target quantity memory 45 . The image processing unit 43 can process the items of image information recorded by the camera or cameras 25 in accordance with the rules given in a program memory (not shown) as to whether and, if so, which, of the features stored in the target quantity memory 45 agree sufficiently with the features acquired by the camera or cameras 25 , or deviate from these features. If an agreement of features can be determined, the image processing unit 43 can also check the position and orientation thereof. If the image processing unit 43 determines for example that a sewing foot 21 has the number three as code 57 , but that this number three is not situated in the expected orientation and/or at the expected location in the image segment recorded by the associated camera 25 , this is an indication that the sewing foot 21 is not correctly fastened to the sewing foot holder 19 . An additional indication of an incorrectly mounted sewing foot 21 can be the determination that the knee lever 63 on the sewing foot holder 19 is in an open position ( FIG. 5B ). The image processing unit 43 can cause the machine control unit 47 to warn the user, by means of a warning tone or a warning message spoken by a synthesized voice, of the problem of an incorrectly mounted sewing foot 21 . Alternatively, or in addition, a warning message can also be outputted on the display device 10 , indicating the determined problem. Analogous to the determination as to whether and which sewing foot 21 is fastened to the sewing foot holder 19 , and whether the fastening is free of problems, the present and correct fastening of other sewing machine elements can also be checked. In addition to, or instead of, warning messages, the machine control unit 47 can also initiate other measures. Such processes may include those described non-definitively below:
Through comparison of the camera image with image information stored in the target quantity memory 45 , the image processing unit 43 recognizes that a particular type of sewing foot is correctly placed in the sewing foot holder. This information is relayed to the machine control unit 47 . Subsequently, the machine control unit 47 displays for selection on the display 10 , which is fashioned as a touch screen, only sewing stitches or stitch types that are compatible with this sewing foot type. On the basis of data requested by the image processing unit 43 , the machine control unit 47 recognizes that a double needle 17 c has been placed in the needle holder 15 , and that a throat plate 33 that is not compatible with this needle type is fastened to the lower arm 7 , for example by a snap connection, screw connection, or magnetic connection. As a first measure, the machine control unit 47 prevents the main drive 51 from being able to be activated, or decouples the needle bar 13 from the main drive 51 . As a further measure, a warning is outputted on the display 10 and/or the acoustic signal generator 49 , as described above. The machine control unit 47 receives from image processing unit 43 a communication that a foreign object, such as for example a pin, a scissors, or the finger of a person, is situated in the stitch formation area under the needle 17 . As described, the machine control unit 47 prevents the sewing process from starting. Of course, safety-relevant quantities can also be acquired in redundant or parallel fashion by additional acquisition means. The machine control unit 47 initiates the storing of data currently acquired by the image processing unit 43 in a temporary working memory (not shown) and continuously updates these data. The sequence and frequency of these updatings and/or of the acquisition of individual sewing machine elements by the image processing unit 43 can depend for example on actions of the operator such as the operation of the foot switch for starting the sewing process, on a possible risk of injury, and on the risk of damage to the sewing machine 1 . The machine control unit 47 signals the image processing unit 43 to acquire items of information such as for example the presence, the correct mounting, or the type of various sewing machine elements.
[0041] Analogous to items of information concerning the sewing machine elements, the image processing unit 43 can also acquire, process, and store in the target quantity memory 45 items of information concerning sewing elements, their structural features, and their situation and orientation, for example in relation to the sewing machine 1 or in relation to sewing machine elements. Thus, for example, for one or more different types of material or fabric, and for particular orientations of the material given a flat seating on the lower arm 7 in the area of the throat plate 33 , the typical directions of the thread orientations, the thread thickness, and/or the distance between adjacent threads and/or the number of threads per length unit in one or more directions or dimensions, and/or the color, can be stored. In addition, in the target quantity memory 45 images can be stored of the upper thread threaded in the needle 17 , or of the course of the upper thread in the area of the needle 17 or in the area between the sewing machine head 11 and the throat plate 33 , as well as images of the bobbin thread in the area of the hook 35 .
[0042] In the following, additional sewing elements or features of such sewing elements are stated in a non-conclusive list:
Color of threads or of seams, Thickness of threads or of seams, Thread orientation without and with broken thread, Brightness, color, shape, design, contour, structure, size, position, or orientation of a sewing element or of a part thereof, Seam appearance (in particular, the design of a seam, the thread entry and/or knotting), Various types of material, seated flatly, Embroidery pattern or images, or applications, Shapes or contours of the article being sewn, with correct and/or incorrect (e.g. bunched or twisted) seating.
[0051] The storing of features or target quantities of the sewing machine elements and the sewing elements can for example take place from an external data carrier via a communication interface of the sewing machine 1 , the data carrier being able to be connected to the sewing machine 1 directly or via a communication network and/or via the Internet (not shown).
[0052] Alternatively, or in addition, the image processing unit 43 can be designed to acquire images of sewing elements and of sewing machine elements that are positioned correctly on the sewing machine 1 , and to store them in the target quantity memory 45 . For this purpose, the user activates a learning mode at one of the operating elements 12 . Subsequently, the cameras 25 acquire, in immediate succession, an image of the correctly positioned sewing machine element or sewing element and an image without this element. From these images, the image processing unit determines an image of the element itself as a difference between the images. This image of the element can be stored in the target quantity memory 45 directly or after a subsequent further processing by the image processing unit 43 using known image processing methods, such as edge extraction or Fourier transformation. Information concerning the sewing machine elements that have been detached from the sewing machine 1 or are fastened correctly or incorrectly on the sewing machine 1 or on the mounting devices thereof can for example be stored in the target quantity memory 45 . The target value memory 45 can also include information concerning a plurality of possible dispositions, operating positions, or orientations of sewing machine elements on the sewing machine 1 .
[0053] In addition to the target quantity memory 45 , the sewing machine 1 can comprise a data memory unit (not shown). This can be physically identical with the target quantity memory 45 , or can alternatively be fashioned as an additional storage medium. In the data memory, images recorded by the camera or cameras 25 can be stored as needed. In this way, for example current sewing operations can be documented, or patterns can be stored. In addition, the sewing machine 1 can comprise a modem, or in general a communication interface, for the creation of communication connections via a network and/or the Internet. Images recorded by the cameras 25 of a problem situation can thus easily be communicated to a help desk, for example. In the reverse direction, images, or any information, can be loaded into the data memory via the Internet. In order to support or facilitate operational steps, such as for example the threading of a thread into the eye of the needle 17 , or the precise positioning of the article being sewn 67 under the needle 17 , images acquired by the camera or cameras 25 can also be displayed on an LCD and/or on the display unit 10 .
[0054] The cameras 25 can be fashioned such that both the acquisition of individual images and also of rapid image sequences are possible. The image processing unit 43 can be fashioned such that, in particular, the following monitoring, auxiliary, storage, measurement, control, or regulatory functions are possible in connection with the machine control unit 47 :
monitoring of the upper thread and/or of the bobbinthread for thread breakage, monitoring of the advance of the material, recognition of stretching and/or twisting or bunching, i.e., the drawing together of the material, monitoring of the thread entry and/or of the knotting of the bobbin thread and upper thread, recognition of shifting of the position of the material during the processing of a stack having a plurality of layers of material, monitoring of the seam quality, recognition of different types of material, recognition of the movement of the material (magnitude, direction). This information can be used to determine the slippage, i.e., a deviation of the actual movement of the material from the desired movement. In particular, it can be used as a measurement quantity and the controlling of the material transport device. acquisition of the positions of individual patterns or features on the material; use of this information in order to control position during embroidery. acquisition or measurement of patterns (size, shape). Use of this information to influence pattern formation, for example in the creation of buttonholes, acquisition of the brightness or of the illumination of the article being sewn 67 ; use of this measurement quantity as a regulating quantity for regulating the brightness of a sewing light (not shown), acquisition and storing of images of the current sewing operation (archiving, documentation), acquisition of images for communication to a help desk (e.g., by means of a modem that is integrated in the sewing machine 1 or that can be connected thereto), acquisition and imaging of sewing machine elements and/or sewing elements, or parts thereof, on an LCD or on the display unit 10 , e.g. as an auxiliary means during threading, or for the precise positioning of the article being sewn 67 under the needle 17 during embroidery.
[0069] With the device according to the present invention and the method according to the present invention, during operation of the sewing machine 1 safety can be increased, errors can be prevented, operation can be simplified and/or automated, and the quality can be improved. | A method and the device for acquiring and processing measurement quantities in a sewing machine ( 1 ) using at least one camera ( 25 ), situated on a sewing machine ( 1 ), for the acquisition and processing of image data for sewing machine elements and sewing elements. An image processing unit connected downstream from the camera ( 25 ) processes the images supplied by the camera ( 25 ), taking into account data stored in a target quantity memory, and influences the behavior of the machine control unit dependent on the result of the processing. | 3 |
FIELD OF THE INVENTION
This application pertains to a device for filling in a hole in a gypsum board wall member to retain a spackled patch.
BACKGROUND OF THE INVENTION
Due to negligence, accidents, or anger people find from time to time that a doorknob being opened inwardly smashes into the adjacent wall often making at least an indentation and often a hole in the wall member. Such holes are difficult to patch, as there is a no base for SPACKLE to stick to. The device of this invention fits in the hole between the injured front interior wall member and the rear wall member of the wall to provide a substrate for receipt of SPACKLE such that the hole can be completely filled in and painted or papered over as needed.
There is also a need to fill in holes even bigger than a conventional doorknob. This device permits holes as large as six inches in diameter to be filled in prior to spackling.
It is a first object to define a device to fill in a hole made by a doorknob.
It is a second object to provide a device that is mounted between an interior injured wall member and the wall member spaced away adjacent thereto.
It is a third object to provide a device that permits the user to fill a hole in the wall between a void front wall member and its sister spaced away interior member.
It is a fourth object to provide a device that permits the hole from a doorknob impression to be readily filled in.
It is a fifth object to provide a support for Spackle for the repair of apertures in a wall having been injured by projectile such as a fist, a fast-moving doorknob or even a bullet.
The device of this invention indeed serves as a base for the repair of such holes in an interior gypsum board wall. And a novice can carry out the job.
The invention accordingly comprises the device possessing the features, properties, the selection of components which are amplified in the following detailed disclosure, and the scope of the application of which will be indicated in the appended claims.
For a fuller understanding of the nature and objects of the invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
A device for filling the hole in the interior gypsum board wall member to retain a spackled patch. The device is formed from four members made of various materials such as but not limited to plywood, sheets plastic, chipboard, water resistant corrugated board and cardboard, and artists' board assembled in a specific fashion and of specific dimensions for two of the members. A first member, designated the master plate, is adhered to the interior of the injured wall, followed by the insertion through the master plate of two body members each of which is a tongue bearing centrally inter-engaged body section, having a an interlocking disk thereon. The so engaged body members with disk thereon are designated a material receiver. The disk carrying engaged members (material receiver) is rotated into a secure position. Spackle or plaster is added; paper or paint is applied to yield a non-discernible repair.
It is a first object to provide a low cost, easy to install wall hole repair device.
It is a second object to provide a wall hole repair device that yields an invisible repair once paint or wallpaper is applied.
Other objects of the invention will in part be obvious and will in part appear hereinafter.
BRIEF DESCRIPTION OF FIGURES
FIG. 1 is a front plan view of the master plate body portion.
FIG. 2 is a plan view of the circular front central section of this invention.
FIG. 3 is a plan view of the body member A.
FIG. 4 is a plan view of the body member B.
FIG. 5 is a rear plan view of the master plate.
FIG. 6 is a side elevation of the inventive device disposed in a wall.
FIG. 7 is a rear perspective device of the assembled invention of this application.
FIG. 8 is a front perspective view of the assembled invention of this application.
FIG. 9 is a top perspective view of the assembled invention.
FIG. 10 is a rear perspective view of the installed invention in a wall.
FIG. 11 is a front perspective view of the assembled installed invention.
FIG. 12 is a view of an alternative construction of the master plate.
FIG. 13 is a perspective view of several of two body members formed as an integrated unit as by casting.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The device 10 of this invention is intended to serve as a support for spackle in the repair of an interior gypsum wall board that has an aperture therein due to the door handle having impacted against the wall member, for such reasons as the failure of anger management, accident or due to negligence.
In this patent application the term interior wall refers to two closely spaced wall members, each usually made of gypsum board. The device of this invention as described fits between the two spaced gypsum board members of the wall.
In FIG. 1 , a sheet of artists' foam board or the suitable material cut to the desired size is designated as the master plate, 15 is seen on its obverse side. This side may be made distinguishable from the reverse side by providing for the presence of the score line 28 , which, if present, is scribed from the outer edge of the plate 15 , through the center of either pair of rectangular openings 17 the purpose for which will be discussed infra. The center opening 16 of the master plate is about two inches in diameter, is seen which opening communicates with a series of small rectangular openings 17 disposed at each of the 90 degree positions around the center opening. These four slots 17 radiate outwardly from the opening 16 , ninety degrees apart. Disposed adjacent to each pair of rectangular openings 16 is a piece of self adhesive tape 19 approximately 1 inch by 1.5 inches. A peelable cover sheet 20 is disposed over each adhesive layer to prevent the glue from sticking to other than the desired surface, which in this case is a piece of gypsum board. As will also be discussed infra in the section of this application dealing with installation the overall size of the artist foam board or other board is not critical, but should be between about 4.75 to 6 inches for ease of packaging and ease of use.
In FIG. 2 the central section is seen. This section is a piece of artist foam board 18 that has been removed from the master plate 15 and modified. The central section 18 has a central internal x-shaped cutout therein designated 38 .
In FIGS. 3 and 4 , the body members, 12 , 13 comprising the mating planar tongue bearing body sections 21 and 23 are seen. These are die cut sections also of artists' foam board that are of the same physical dimensions. The width of each of 21 and 23 designated 21 W and 23 W respectively may be about 2.5 inches, while the depth of each 21 D and 23 D respectively may be about 3 inches, though the depth excludes the tongue to be discussed next.
The depth measurements of 21 D and 23 D constitute the distance from the inside of the broken front wall (re the wall to be repaired) measured to the inside surface of the spaced adjoining area or room interior wall, minus the thickness of the master plate 15 . These are the depth measurement for both the 2×4-studded walls and 2×6-studded walls.
Each body member's body section has a centrally disposed rectangular tongue that is contiguous with and attached to the respective front edge 27 , 29 per FIG. 4 , respectively of the width of the body section. Such tongues 22 , 25 are in the same respective plane as each of the body sections and are about ½ inch in depth and 1 inch in width, which is a smaller diameter than the width of the body section. The two body sections differ in that section 21 has an inwardly directed slot 24 on the rear width edge opposite its tongue directed parallel to the side edges; while body section 25 has an inwardly directed slot 26 on the front edge through the tongue into the body. Both slots 24 , 26 are of equal extension. When engaged, the two body sections are vertically engaged along their central axis to form a plus sign (+) shaped unit;
In FIG. 5 , the reverse side of the master plate 15 is seen. Here the score line 28 is not seen. “Only the center opening and the center opening and the communicating 90 degrees apart little rectangular slots or openings are seen.”
In FIG. 6 , a side elevational view of an assembled unit of this invention is seen. The two-interlocked body sections 21 , 23 are assembled to form a cross, and the two outer edges of each of the body sections are disposed within a respective slot 17 . The central section or disk 18 seen in FIG. 2 is disposed via its cross opening 38 upon the crossed tongues 22 , 25 and rests on the respective front edges 27 , 29 of the body sections 21 , 23 . The respective crossed tongues protrude through the T-slot 38 in central section 18 . When the disk is placed on the plus sign (+) crossed body sections, a material receiver is defined see also FIG. 2 .
FIG. 7 illustrates the reverse side of the master plate 15 and the crossed interconnected main sections 21 and 23 having the master plate 15 disposed thereon. The master plate 15 is placed thereon from the bottom of the edge of the main sections that do not have a tongue, by aligning the four 90 degrees spaced slots with the crossed body sections, 21 , 23 . When installation is to transpire, this should be done from the obverse side of the master plate 15 .
In FIG. 8 , the device of this invention is seen in a partially assembled condition, but not in an in-wall environment. The front or obverse face of the master plate 15 is seen with the self-adhesive tabs 19 still covered over. Plate 15 is spaced back from the edge of the disk 18 . During installation it, 18 is disposed a distance back from the front edges of members 21 and 23 and placed thereon in the hole in the gypsum board.
It is also to be seen that while in FIG. 8 the assembly of the two members shown in FIGS. 3 and 4 have been carried out, and the center section has been placed thereover. It is also within the scope of the invention to mold the two members, 18 21 , and 23 , with the center section thereon, as one preformed member. See FIG. 13 wherein the preformed unitary structure 101 has its three components designated in the 100 series numbers, 118 , 121 , and 123 respectively.
While the unitary structure 101 falls within the scope of the invention as to utilization, a different packaging is required but with less assembly by the user.
FIG. 9 is a mirror image of FIG. 6 and need not be discussed further.
FIG. 10 , is a view that simulates a wall thickness. Designator 30 B stands for the backside of the gypsum board wall 30 having a hole 32 therein to be repaired. Surrounding the hole 32 is a pair of spaced studs 36 , 40 , which is present. A cross beam 41 may be disposed, but need not be, between the two studs aforementioned. Device 10 is seen through the pseudo wall 42 , which is spaced from the front wall's backside 30 B. The pseudo wall here 42 is a sheet of clear acrylic that simulates the second spaced piece of gypsum board, which helps define the space 44 between the two gypsum board sheets making up a wall thickness of a room.
The right side part of FIG. 10 illustrates a previously installed unit of this invention as seen from within the wall between the opposed gypsum boards, in front of back wall shown here as being clear. Reference will be made back to FIG. 10 at the completion of the discussion of the individual figures.
FIG. 11 illustrates the front side of the wall 30 , namely 30 A. Thus, the busted in segment of the wall 30 as designated 32 in the left of FIG. 10 is seen on the right in FIG. 11 . The position of the previously installed unit of the invention 10 is also reversed from FIG. 10 to FIG. 11 . The relative position of the master plate 15 subsequent to installation is visible in FIG. 10 . As can be seen, the master plate and the disk are coplanar post installation.
In FIG. 12 the master plate 115 is seen. Here the entire surface of the foam board or other material 118 is covered over by an adhesive layer 119 . The cutaway lines reveal the presence of the underlying layer 118 . The central opening 116 three 120 degree apart radiating outwardly slots 117 . A peelable cover layer to protect the adhesive from unintentional contact would be used but is not shown.
In FIG. 13 , the two body sections are seen in perspective formed as an integral unit, 121 as by casting or molding of resin with three legs instead of four. In addition it may also be possible to have the disk or central section also integrally molded in place on the unified body section 121 and such is contemplated by this invention.
Installation
In order to set up the device of this invention within its work environment,—between two spaced sections of gypsum board, a set of steps must be carried out, though not necessarily in the same order as recited. After removing the adhesive cover layers 20 , the master plate 15 is folded along the score line 28 , if present, and disposed through the opening equivalent to 32 where the hole was made as by a doorknob impact, or a punch or other mode into the front wall member 30 to require a repair to be made. The master plate with its circular opening and four ninety degree apart radiating outward slots is held through the center opening 16 with a pair of fingers, and then opened such that the four uncovered adhesive tabs face the operator. The plate is brought toward the viewer to make contact between the exposed adhesive tabs and the wall 30 B to attach the master plate 15 into position.
By folding the master plate such that the glue containing sections move away from each other, the four cover plates may be removed prior to disposition through opening 32 , this way contact of one adhesive tab with another such tab is avoided.
After the master plate is positioned affixed to wall 30 B, the two body sections A and B, designated 21 and 23 are inter-engaged and placed into the four slots 17 , moving rearwardly part way away from the user. Disk 18 is placed over the crossed body sections A and B to yield a material receiver. The rearward journey of the two inter-engaged body sections with the disk is restarted and continued until impact is made with wall 41 . This point in time should coincide with the location of the disk almost approaching a coplanar status with the master plate 15 . The crossed tongues should be the only parts of the two inter-engaged body sections now visible.
Using two fingers, on the two tongues, the inter-engaged body sections, are rotated about 45 degrees, once the front edges 27 and 29 clear the slots 17 , to lock the main body sections between the two pieces of gypsum board constituting the injured wall member and the rear wall member of the wall. See FIG. 10 , right side. The rearward travel to the inter-locked body sections is continued until the disk 18 becomes coplanar with the body section. See FIG. 11 . Note the lack of coordination in FIG. 11 of the two tongues and the slots 17 . Once the device 10 is locked into position, such that it cannot fall rearwardly down into the void between the two spaced gypsum board wall members, Spackle or plaster can be applied over the disk and the showing portion of the master plate. These serve as a backer plate for the reception of the Spackle or plaster and as a permanent brace to strengthen and resist future impacts from a doorknob. Once filled and dried, the spackle or plaster does not require feathering and can be sanded and painted to complete the repair of the impacted doorknob or fist, or other source of the hole. Reference is made to designator 35 in FIG. 11 , which illustrates a completed repair.
It is believed that other step orders can be carried out to place device 10 between the spaced sheets of gypsum board, though more difficulty may be encountered in doing so.
While artists' foam board has been mentioned as the preferred material for the structure, other materials such as sheet styrene or other plastic may be employed for all sections as will as chipboard, plywood, and cardboard. A waxed corrugated board to prevent swelling from the moisture of the Spackle may also be utilized for all parts of the invention.
Any latex paint or oil paint may be applied to the patch created by the use of this device.
Earlier, it has been indicated that the device 10 is suitable for the repair of holes having a diameter as large as about six inches. This is based upon two facts. First, the most common diameter for doorknobs found in the USA is about two inches in diameter. Thus, if the hole radiates out from a central point of impact, an allowance of an extra two inches of damage to the left and right of the knob yields or six inch diameter circle. Accordingly, the master plate 15 has been sized preferably at 6×6 inches before folding in anticipation of such possible drywall crackages. Obviously, the master plate can be enlarged laterally to cover larger spans up to perhaps sixteen inches wide, but with the same depth.
In the discussion supra concerning FIG. 1 , an alternative mode of construction is seen in the side view FIG. 12 . Here a self-adhesive layer 119 is disposed over the entire master plate 115 . The self-adhesive layer 119 is overlaid with a peel off cover layer 120 . Such a variant can be produced by a spraying technique for the adhesive layer 119 rather than having the tab 19 laid in place by hand or machine. This format works for a four-legged unit as well as the three-legged unit shown.
Other modes of attachment of the master plate are also contemplated, such as a layer of removable adhesive overlaid on the master plate 15 though one having a stronger adhesive quality than is used on Post-it® notes is needed. Removable adhesive is suggested or slow drying adhesive to compensate for errors of the person doing the repairs.
Previous reference has been made to a score line. This line may be actually required, depending upon the material employed of the master plate. The benefit of having a score line is that a fold generally along such a line as desired is ensured. In certain materials, due to the preexistence of the ¼ hour opening and the center opening, a true fold may be easily accomplished. Such is not the case however wherein the substrate for the master plate 15 is sheet plastic, or a plywood segment. Card stock or corrugated board should fold easily in contrast without the need for a true score line 28 .
While in general the same material will be used for all of the elements of this invention, they need not be so manufactured.
Since certain changes may be made in the described apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | A device for patching wall holes caused by a doorknob or other item impact, which device is assembled in situ between the injured wall member and an adjacent rear wall member. A master plate having a circular opening with four ninety-degree apart radiating outward slots, is adhered to the interior face of the injured wall over the opening. Two inter-engageable body sections each having a tongue are centrally inter-engaged at right angles and retained by placement of a disk designated the central section having a central internal cross-shaped cutout over the engaged tongues. The disk bearing engaged body sections are recessed into the master plate up to the tongues, rotated and locked into position between the wall members. Spackle or plaster is applied, allowed to dry, and then painted/papered to yield a non-discernable repair is applied, allowed to dry and then painted or papered over to yield a non-discernible repair. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
BACKGROUND OF THE INVENTION
[0003] This invention relates to a nutritional or dietary supplement which stimulates metabolism to an anabolic state to increase skeletal muscle mass and reduce body fat content.
[0004] The sports nutrition industry encompasses a range of products including protein powders, supplemented amino acids, hormones, and products known as pro-hormones, hormone mimicking chemicals, that might differ only slightly in structure from the hormones that they are supposed to mimic. All of these products are designed to promote extra muscle tissue growth (anabolism). The methods for achieving extra muscle tissue growth vary by the agent involved. However, each and every agent utilized in sports nutrition will increase muscle tissue growth by either directly triggering muscle protein synthesis, as in the case of hormones and prohormones, triggering production of anabolic hormones in the body, or decreasing the time necessary for the body to repair and rebuild muscle tissue after exercising (decreased recovery times). In all cases the goal of sports nutrition supplements is to build more muscle tissue faster and to prevent injuries.
[0005] The most common form of dietary supplementation in the sports nutrition industry is protein powder. Virtually every athlete and want-to-be athlete supplements their daily diet with extra protein in the form of powders or ready-to-drink protein shakes. Protein is metabolized by the body to its building blocks—amino acids. The amino acids can then be used by the body to synthesize needed proteins and anabolic hormones for synthesis of new muscle tissue. These protein powders, however, are not sufficient in most cases to produce the large, muscular athletic bodies seen today. Consequently, many serious athletes will supplement their normal/protein shake diet with additional assistance—hormones, pro-hormones, and amino acids.
[0006] Use of amino acid supplementation is very common among serious athletes. Many consumers will supplement their dietary regime with glutamine and creatine, as well as other amino acids. Amino acid supplementation, however, is not thought to be much more effective than protein supplementation in helping an athlete to achieve real lean tissue gains. Very few dedicated athletes report significant benefits from amino acid supplementation. Despite numerous written reports of controlled clinical trials showing the benefits of amino acid supplementation, the effects are not as pronounced under real-life dietary/training conditions as they are in controlled clinical studies. Therefore, amino acid supplementation is not considered to be a viable option for gaining muscle mass.
[0007] Use of hormones (examples: Testosterone, Growth Hormones) have been banned by most international amateur and professional athletic organizations. Athletes that test positive for use of hormones to augment their natural physical abilities are usually suspended or banned from competition. Consequently, hormones are not considered to be an attractive, legal, or healthy option for serious athletes.
[0008] In the past 10 years, the use of pro-hormones has risen significantly. Pro-hormones were originally developed to circumvent testing methods for the banned hormones. As an example, androstenadiole (Andro) was originally developed in Eastern Europe during the cold war to assist athletes from Iron Curtain countries to gain extra muscle mass while allowing them to pass Olympic drug testing procedures for banned substances. Andro has a steroid-like effect on the metabolism, causing the body to produce more muscle tissue than it would otherwise produce and, therefore, is significantly anabolic, like the banned steroids and growth hormones. Olympic drug testers, however, had no idea of the existence of Andro and, therefore, had no method for testing or detecting its use by an athlete. Eastern European athletes used Andro for years with impunity. Only recently, after the fall of the Iron Curtain did the full story of Andro come to light. Athletes in the USA started to use Andro. However, with an increase in the use of Andro (and other pro-hormones like it) came a move to ban these pro-hormones in sports. Each year a new list of banned pro-hormones is published by the International Olympic Committee and other professional and amateur sports organizations, and each year new pro-hormone products are developed to replace the banned substances. Use of pro-hormones is simply a short term method for cheating organized sports testing methods and is not a long term option for athletic performance or the health of the athlete. Pro-hormones are agents that possess chemical structures very close to anabolic hormones, such as the steroidal compounds or growth hormones. The purpose of a pro-hormone is to provide an anabolic reaction in the body similar to anabolic steroids without putting the athlete in danger of failing a banned substance drug test. Since nobody can predict the long term health risks of prolonged use of pro-hormones, sports organizations and legislatures worldwide continue to ban pro-hormones as they increase in use. Consequently, pro-hormone supplementation is not a desirable method for gaining increased muscle mass as one cannot rely on being able to use pro-hormones in future years and, from a medical viewpoint, they are probably not healthy alternatives.
[0009] Numerous companies have concentrated on developing safe supplements that will augment muscle tissue growth and which do not contain banned substances or substances that are likely to be banned from sports in the future. To date, most of the products have contained one or two active ingredients and have not been as successful at forming muscle tissue as expected.
BRIEF SUMMARY OF THE INVENTION
[0010] We have developed a new product that can be used as a supplement for sports nutrition and also as a general population dietary supplement for aging people. The product is a combination of a high glycemic sugar or carbohydrate, vitamin B6, electrolytic minerals, and amino acids some of which have neuromodulating properties and some of which are muscle cell volumizers. The amino acids included in the nutritional supplement include the amino acids include glutamine, taurine, creatine, cysteine, glycine, leucine, and arginine. The amino acids having neuromodulating properties is chosen from the group consisting of glutamine, taurine, glycine, and cysteine, and combinations thereof. The amino acids having cell volumizing properties is chosen from the group consisting of creatine, taurine, and glycine, and combinations thereof.
[0011] In a preferred blend, the nutritional supplement includes by weight, about 40% to about 65%, glycemic carbohydrate or sugar; about 10% to about 30% Glutamine; about 10% to about 30% Creatine; about 7.1% glycine; about 2.4% taurine; about 2.4% leucine; about 1.2% cysteine; about 0.2% arginine; about 1.4% citrate; about 0.2% Sodium Chloride; about 0.2% Potassium Chloride; about 0.01% to about 0.04% vitamin B6; and about 2.4% Flavor, sweetener, and color. On a per serving (or single dose) basis, the components of the supplement are calculated so that each serving supplies about 23 grams of high glycemic carbohydrate, about 6.66 grams of glutamine, about 5 grams of creatine, about 3 grams of glycine, about 1 gram of taurine, about 1 gram of leucine, about 0.5 grams of cysteine, about 100 mg of arginine, about 60 mg potassium, about 50 mg sodium, and about 200% of the USRDA for Vitamin B6. The pH of the total blend when dispersed into 16 ounces of water was 4.6.
[0012] The theory behind the product is that all of the ingredients combine to produce an anabolic (body building) metabolic reaction when the product is consumed. The high glycemic sugar stimulates production of insulin. The manufactured insulin increases absorption of the nutrients through the intestinal walls and helps to transport the amino acids to skeletal muscle tissue cells. Once at the muscle cells, the insulin assists in transporting the amino acids from the bloodstream into the muscle cells. These amino acids are the primary building blocks of skeletal muscle tissue. Once inside the muscle cells, the amino acids also attract water and water soluble nutrients, such as the electrolyte minerals, by osmosis to the muscle cells. The result is larger, more functional skeletal muscle tissue. At the same time, other included gluconeogenic amino acids and the vitamin 136 play a role in maintaining blood sugar levels in the presence of the increased insulin and throughout the remainder of the day so that the cells have sufficient energy to utilize the amino acids for protein synthesis, muscle tissue growth, improving athletic performance, and to help prevent skeletal injury. We have tried to minimize the doses of each ingredients, providing efficacious amounts of each ingredient but not exceeding safe and healthy limits. Due to the synergism between the active ingredients that we have encountered, it is not necessary to exceed safe and healthy limits for any of the ingredients. It is doubtful that any extra benefits could be realized, even if one were to significantly increase usage levels of many of the ingredients in the formula.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The following detailed description illustrates the invention by way of example and not by way of limitation. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what I presently believe is the best mode of carrying out the invention. Additionally, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.
[0014] We have developed a product that would includes a number of anabolic metabolism precursors. During the development of the product, we sought to manufacture a supplement that would assist the body in manufacturing muscle tissue. The mixture comprises only ingredients that are thought to be safe and are common in many other supplements. These ingredients, by themselves, have been shown to have some effect on muscle tissue growth and are considered to be safe and will not be subject to future bans or health risks. However, the mixture, unexpectedly, has a synergistic effect on anabolism when consumed. Subjects that have experimentally used the mixture not only report muscle tissue growth but also report loss of body fat, increased stamina, increased strength, feeling younger, and improved athletic performance.
[0015] The mixture comprises a simple, high glycemic sugar with specific quantities of the amino acids Glutamine, Taurine, Creatine, Cysteine, Glycine, Leucine, and Arginine. The mixture also includes electrolytic sodium, potassium, and Vitamin B6. The combination of these ingredients in an optimum ratio creates a synergistic reaction that stimulates the metabolism to an anabolic state.
[0016] The high glycemic simple sugar is provided to stimulate a short term, fixed amount of insulin production in the body. Insulin has long been recognized as an anabolic hormone if it is released at the proper time in the body. If insulin is released at the wrong time into the bloodstream, it can be a destructive, or catabolic, hormone. When a high glycemic (insulin producing) sugar is consumed, the body manufactures insulin. The amount of insulin produced is dependent on the quantity and glycemic nature of the carbohydrate consumed. When the body produces insulin, the insulin stimulates the intestines to increase nutrient transport across the intestinal wall and into the blood stream. Insulin also activates cell transporters, bringing them to the cell surface so that they can assist in moving nutrients from the bloodstream into cells. If timed properly, insulin release has been shown to assist in the efficient transport of amino acids from the intestines into muscle cells. If timed poorly, insulin release has been shown to increase the transport of fats into cells for storage, thereby increasing body fat content. It is very important for an athlete desiring to build new skeletal muscle while minimizing body fat content to time the release of insulin properly. Some bodybuilders, for instance, have been known to avoid high glycemic foods in order to minimize their body's production of insulin, and then inject themselves with insulin at specific times of the day to take advantage of properly timed insulin release. Due to the difficulty in controlling insulin release and the associated risks of increasing stored fat, many athletes including, but not limited to, bodybuilders, have chosen to avoid high glycemic foods and limit their overall insulin production. While limiting insulin production can effectively help to maintain a low body fat content, the anabolic effects of insulin amino acid transport to muscle cells will also be limited or non-existent, making it more difficult for an athlete to add new skeletal muscle. We chose to include an insulin stimulating carbohydrate in our formula so that the body would manufacture sufficient insulin to help transport amino acids and other nutrients to muscle cells for a 60 to 90 minute time period after consumption. Such sugars would come from the family of high glycemic carbohydrates of sucrose, glucose, dextrose, fructose, and some complex carbohydrates such as white flour, potato starch, rice starch, etc.
[0017] The amino acids included in the mixture have all been shown individually to have significant effects on anabolism, muscle tissue growth and athletic performance. Creatine is synthesized in the body from the amino acids glycine and arginine. Creatine can be found concentrated in muscle tissue and has been shown to be crucial in regulating energy flow within skeletal muscle tissue. Creatine also increases a muscle cell volume by attracting water to muscle cells. Carefully controlled clinical studies have demonstrated that daily dietary supplementation of 5 gram doses of creatine can result in increased skeletal muscle mass. However, in actual daily life practice, supplementation with creatine does not work as effectively. Consequently, many manufacturers have formulated creatine containing products with creatine contents well in excess of the clinically recommended 5 gram per day doses, with some products containing as high as 50 grams of creatine per dose. There is no scientific evidence to show that increased doses of creatine will result in increased muscle growth, but many athletes consume large doses of creatine every day in an effort to obtain the desired effect from the creatine. In recent years, there have been some negative papers written concerning creatine supplementation, many of them dealing with the larger than recommended daily doses. Creatine draws water to skeletal muscle tissue, and can take that necessary moisture away from other skeletal tissue, such as tendons, ligaments, and bone. Some investigators have suggested that supplementation with larger doses of creatine every day can result in “dry” bones, tendons, and ligaments and increase the risk of injury from broken bones and/or torn ligaments. The mixture preferably uses the clinically proven dose of 5 grams of creatine to avoid the extra risk of “drying” out bones and connective tissues while maintaining the benefit of creatine. The creatine can be provided as creatine monohydrate, buffered creatine, N-acetyl-creatine, creatine phosphate, creatine citrate, creatine glycerol phosphate, or any other source of creatine.
[0018] Glutamine is strongly concentrated in cells in the central nervous system, intestines, and skeletal muscle. Glutamine has been shown to play an important role in maintaining intestinal health (improving nutrient absorption), formation of skeletal muscle tissue, and regulating muscle protein turnover. Glutamine is the most common amino acid found in skeletal muscle tissue. Glutamine is also an important precursor of glutathione, the body's own free radical scavenger. Studies have shown that increased levels of intracellular glutathione lead to increased skeletal muscle mass. Recent studies have shown that persons under stress (this would include hard training athletes) demonstrate depletion of glutamine and that supplementation with up to 20 grams of glutamine per day will improve metabolic performance and muscle tissue growth. A recent investigator reported that doses of from 2 to 10 grams of glutamine can result in as much as 15% extra skeletal muscle mass. One can either use L-glutamine or peptide bonded glutamine. Peptide bonded glutamine is preferred as the glutamine source because studies have shown that peptide bound amino acids are more efficiently absorbed across the intestinal wall than are free amino acids (i.e., L-glutamine).
[0019] Taurine is a sulfur containing amino acid found primarily in meat but that can also be manufactured by the body from cysteine. Like creatine and glutamine, taurine is found primarily concentrated in skeletal muscle tissue and is the second most common amino acid found in skeletal muscle tissue. Taurine, like, creatine increases muscle cell volume by boosting cell hydration. Investigators recently have claimed that taurine may also assist in stimulating protein synthesis. Other investigators have claimed that taurine can enhance amino acid transport into muscle cells. The exact function of taurine is not fully understood at this time, but it is known that human maternal milk contains substantial quantities of glutamine, creatine, and taurine as free amino acids. It is thought that these three amino acids play an important part in postnatal development, tissue repair, and growth in infant human beings. The first few years of life are of interest in sports nutrition. The first two years in a human's life are a significant growth and anabolic time, with most humans growing approximately half of the cell numbers that their bodies will have when they are adults. There is no other stage in human life where the cell growth is as explosive. Since a primary principle in sports nutrition is to increase cell growth so that the athlete can generate muscle tissue faster, one should look at the nutrients that are prevalent in the postnatal diet of human beings so that one can accelerate cell growth in the adult human. All three amino acids are present in the mixture because they appear to play an important role in generating and repairing skeletal muscle tissue.
[0020] Glycine is not considered to be an essential amino acid because it can be synthesized in the body from either threonine or serine. Glycine, however, has been shown to serve a number of important functions in the body. Glycine, like creatine and taurine, draws water to muscle cells and is a muscle cell volumizer due to the hydration function. Glycine, along with glutamine and cysteine, is a precursor of the very important glutathione production in the body. Glycine plays an important role in the control of gluconeogenesis, or the manufacture of blood sugar from amino acids in the liver, and prevention of hypoglycemia. Glycine, then, becomes important in a sports nutrition product where we are trying to stimulate insulin production. The manufactured insulin has the potential to decrease blood sugar and, therefore, body energy levels. Glycine plays a regulatory role in helping to maintain constant blood sugar levels. In higher doses, glycine has been shown to stimulate the release of growth hormone by the body—another anabolic benefit. Glycine is also used in the body to synthesize hemoglobin, which plays an important role in oxygen carrying capacity for athletes. Glycine also can be methylated in the body to become part of the one-carbon metabolic pathway. The one-carbon metabolic pathway is extremely important for the synthesis of anabolic, androgenic steroidal hormones as well as cortisone-like hormones. The methylation of glycine, that stimulates the one-carbon metabolic pathway is, in turn, stimulated by the presence of sufficient glycine. Glycine has also been reported to help trigger the release of oxygen to be used for energy in cell growth and replication, thereby helping to decrease tissue repair times, promoting faster recovery of the body after exercising. The dose of glycine has been carefully selected to accomplish all of the above. Glycine can be added in the form of L-glycine or peptide bonded glycine.
[0021] Cysteine is one of two sulfur containing amino acids commonly found in food sources. Of the two, methionine and cysteine, cysteine is the most metabolically valuable and the least common. Cysteine, in combination with glycine and glutamine, is a precursor to the manufacture of glutathione in the body. Glutathione is an important metabolic hormone that has been implicated in strengthening the immune system as well as increasing skeletal muscle mass. Cysteine also plays an important role in role in maintaining liver function and is currently being investigated for its role in maintaining blood sugar levels in hypoglycemics. Cysteine has been implicated in assisting with the storage and utilization of glycogen in muscle tissue. Cysteine has also been shown to have a synergistic metabolic function when combined with Vitamin B6. One can utilize L-cysteine or other, easier to handle forms, such as N-acetyl-cysteine, as the source for cysteine. N-acetyl-cysteine is preferred as the source for cysteine because studies have shown that N-acetyl-cysteine is more efficiently utilized by the body than L-cysteine after being consumed as part of a meal.
[0022] Leucine is a side branched chain amino acid that must be consumed daily through the diet in adequate quantities to meet the body's requirements. Leucine has been shown to assist in prevention of muscle wasting. Leucine has also been shown to have anabolic effects through prevention of muscle tissue breakdown and by stimulating protein synthesis in muscle tissue, as well as helping to prevent skeletal muscle injury. Leucine is also a gluconeogenic active agent. Leucine can act to assist in maintaining serum glucose levels for body energy during times of glucose depletion. Leucine, however, is only effective when taken in therapeutic dosage levels. We add leucine to the formula at therapeutic dosage levels. We prefer to use L-leucine in this formula, although one could also use leucine bonded to other amino acids.
[0023] Arginine is a vitally important non-essential amino acid. Arginine can be used by the body to synthesize ornithine. Ornithine has been shown to stimulate the release of human growth hormone. The release of growth hormone, in turn, promotes greater skeletal muscle mass. Arginine had also been shown to decrease tissue repair times. Decreased tissue repair times equate to faster recovery after exercise in sports nutrition. Arginine is provided in the form of L-arginine.
[0024] Vitamin B6 is involved in a wide variety of metabolic functions in the body. For example, Vitamin B6 is necessary for synthesis of more than 100 enzymes that assist in protein metabolism. Vitamin B6 has been shown to amplify the functions of peptides and amino acids in the body, demonstrating synergistic reactions with a number of amino acids. Vitamin B6 is also necessary for the manufacture of hemoglobin—that portion of blood responsible for the transport of oxygen throughout the body. Vitamin B6 has also been shown to actually increase the oxygen carrying capacity of hemoglobin, a very important factor in improving athletic performance. Vitamin B6 has also been shown to increase cell growth, including muscle tissue cells. The increased cell growth translates directly to faster muscle tissue repair times and faster recovery times after exercise. Vitamin B6 has been shown to assist in the conversion of stored carbohydrates to glucose for use in manufacturing energy required by a hard training body. Vitamin B6 is also a necessary agent for the body to manufacture carnitine, a nitrogen containing, short chain carboxylic acid. Carnitine is sometimes referred to as an amino acid but it is technically a cross between an amino acid and a vitamin. Studies have demonstrated that carnitine assists in the transport of fats from storage to the mitochondria where the fat is metabolized for energy. In sports nutrition; it is thought that the enhanced fat oxidation promoted by carnitine spares stored carbohydrates, allowing them to be utilized at more convenient times such as during hard training. Recently, researchers reported that carnitine may reduce lactic acid production in muscle tissue during aerobic exercise, thus leading to decreased recovery times after exercise. Many studies have shown that supplementing the diet with L-carnitine does not seem to produce the beneficial results listed above. Consequently, it appears that the only effective method for obtaining the benefits of carnitine is to provide the body with the tools necessary for the manufacture of carnitine. Of those tools, Vitamin B6 is the least common and most easily depleted. For our purposes, one can use any one of three forms of Vitamin B6—pyridoxine, pyridoxal, or pyridoxamine. The most common form of Vitamin B6, pyridoxine hydrochloride, is preferred.
[0025] The main purpose of exercise is to stimulate muscle tissue through contraction and extension of the muscle fibers. Each contraction and extension, if performed under stress, will cause some damage to the muscle tissue. This damage is then repaired after exercise is stopped and the repair cycle usually leads to formation of additional muscle tissue resulting in muscle growth. Muscle contraction and extension is accomplished via nerve stimulation of the muscle fibers. To ensure optimum operation of the nervous system, and therefore optimum contraction and extension of muscle fibers, some of the amino acids included in the formula, glutamine, taurine, glycine, and cysteine have neuromodulating properties. In addition to the neuromodulating properties of the amino acids, we have included sodium and potassium in the formula. Sodium and potassium are both widely known to be an integral part of nervous system transmissions. Sodium and potassium are also integral parts of the body's transport mechanism across cell membranes. It is the sodium active transport system and the potassium membrane transport system that helps to move the high glycemic sugar through the intestinal walls and the amino acids to muscle cells.
[0026] The last active ingredients included in the mixture are citric acid and sodium citrate. Both are contributors of citrate ion and they taste better when used in combination with each other, as is common practice in the food industry. Citrate is an important intermediate chemical in the ATP energy cycle known as the Krebs cycle or the Citric Acid cycle. The Krebs cycle is the metabolic process by which the body derives its required energy for all body functions, including repair of muscle tissue and muscle protein synthesis. It is hoped that inclusion of a citrate ion donating agent will stimulate the Krebs cycle process, thereby promoting more energy for the body to use for manufacturing additional muscle tissue. There is also some investigative evidence to support claims that free amino acids, such as are included in the mixture, are more efficiently absorbed and utilized by the body when they are consumed at a slightly acid pH.
[0027] For the purposes of consumer acceptance, flavors, color, and an artificial sweetener are added to the mixture. None of the flavors, the color, or the artificial sweetener are necessary ingredients, however.
[0028] As an example: We made a blend consisting of the following formula:
[0029] 55.03% Glucose
[0030] 15.86% Peptide Bonded Glutamine
[0031] 11.90% Creatine Monohydrate
[0032] 7.15% L-glycine
[0033] 2.38% L-taurine
[0034] 2.38% L-leucine
[0035] 1.19% N-acetyl-cysteine
[0036] 0.24% L-arginine
[0037] 0.72% Citric Acid
[0038] 0.71% Sodium Citrate
[0039] 0.24% Sodium Chloride
[0040] 0.24% Potassium Chloride
[0041] 0.01% Pyridoxine Hydrochloride
[0042] 2.41% Flavor, sweetener, and color
[0043] The ingredient levels were calculated so that each serving supplied 23 grams of high glycemic carbohydrate, 6.66 grams of peptide bonded glutamine, 5 grams of creatine, 3 grams of glycine, 1 gram of taurine, 1 gram of leucine, 0.5 grams of cysteine, 100 mg of arginine, 60 mg potassium, 50 mg sodium, and 200% of the USRDA for Vitamin B6. The pH of the total blend when dispersed into 16 ounces of water was 4.6.
[0044] A supply of 30 servings, 42 grams per serving, was provided to a number of athletes and to persons with stressful occupations, such as firemen. They were instructed to consume one serving each day dissolved in 16 ounces of cold water. They were further advised that the product would function best when it was consumed on an empty stomach—either one hour prior to eating a meal or 3 to 4 hours after eating a meal. Most people consumed the product first thing in the morning before they ate anything else for the day. A few of the testers consumed the product just prior to starting their exercise regime and others consumed the product immediately after exercising.
[0045] The feedback received from the test subjects indicated that the product was significantly anabolic. The product produced significant performance improvements in most test subjects within the first 48 to 72 hours. Bicycle racers reported that they were able to significantly reduce their racing times in specified length races. People who regularly worked out in gyms lifting weights reported that they were able to perform more lift repetitions with the same amount of weight than they had been able to before they started consuming the mixture. One subject reported that he was able to perform significantly higher numbers of sit-ups and push-ups after he started consuming the mixture. One subject reported losing 2 inches off of his waist and gaining an inch (at least) in his arm muscles in just weeks after he started consuming the mixture. A 55 year old gym owner reported that he was able to turn back the clock and felt like he was 10 years younger while working out after he started consuming the mixture. A professional bodybuilder reported that he was able to lose 2% of his body fat and gain 15 pounds of muscle tissue in just two weeks. He gave all credit for his transformation to the mixture. Almost all of the test subjects reported that they felt that their muscles had extra volume within days after they started using the mixture. Almost all of the test subjects reported that their exercise workouts were easier, requiring less effort than normal. Almost all of the test subjects reported that they were not as sore post-exercise as they would be normally. In general, the feedback suggests that the mixture allows an athlete to improve performance, perform tasks easier, recover from exercise faster, lose body fat, and gain muscle mass faster. These are the same benefits that are attributed to anabolic agents such as steroidal or cortisone-like hormones. The reports we received exceeded any benefits that would have been expected if one were to supplement their daily diet with each of the ingredients separately. The results our test subjects were realizing could only be achieved through a synergistic reaction of the ingredients so that they each amplified the functions of the other ingredients.
[0046] Of course, some of the formula ingredient usage levels could probably be modified without significantly altering the metabolic function of the blend. For instance, it is probably possible that the high glycemic carbohydrate content could be varied between 40% and 65% of the formula. The glutamine content could be varied from perhaps 10% of the formula to as much as 30% of the formula without sacrificing the end result. One could always increase the amount of creatine delivered (as much as triple) and still achieve the same result. One could increase the arginine content considerably without sacrificing functionality of the product. The other amino acids, however, are being delivered in just about the right amounts. The sodium, potassium, and citric acid/sodium citrate combination are also being delivered at the proper levels. One could probably quadruple the Vitamin B6 content without sacrificing the metabolic benefits of the product. We, however, subscribe to the theory that even though a small quantity of an ingredient is shown to be beneficial, it does not necessarily mean that larger doses would be equally as good or even better. We have tried to minimize the doses of each ingredients, providing efficacious amounts of each ingredient but not exceeding safe limits. Due to the synergism between the active ingredients that we have encountered, it is not necessary to exceed safe and healthy limits for any of the ingredients. It is doubtful that any extra benefits could be realized even if one were to significantly increase usage levels of many of the ingredients in the formula. Others could try to circumvent the protection of this technology by utilizing ingredient levels outside the range of the example above, but they would not be able to show an improvement to the technology by doing so. The ingredient levels we have chosen are the healthy and efficacious dose minimums and appear, from all apparent reports, to be sufficient to result in anabolic benefits for athletes. The synergistic reaction observed comes from the unique combination of all of the ingredients.
[0047] As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | A nutritional supplement for sports nutrition and also as a general population dietary supplement for aging people is provided. The nutritional supplement is a combination of a high glycemic sugar or carbohydrate, vitamin B6, electrolytic minerals, and amino acids some of which have neuromodulating properties and some of which are muscle cell volumizers. The amino acids included in the nutritional supplement include the amino acids include glutamine, taurine, creatine, cysteine, glycine, leucine, and arginine. The amino acids having neuromodulating properties is chosen from the group consisting of glutamine, taurine, glycine, and cysteine, and combinations thereof. The amino acids having cell volumizing properties is chosen from the group consisting of creatine, taurine, and glycine, and combinations thereof. The combination of the ingredients has a synergistic effect of increasing muscle mass, increasing physical abilities (strength, stamina, and endurance), and decreasing body fat. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a rehabilitation footwear, especially to a rehabilitation footwear that can fix bones of an injured foot and has adjustable functions according to different stages of recovery and rehabilitation.
[0003] 2. Description of the Prior Art
[0004] An injured person's foot after surgery, fracture, sprain or contusion needs to be fixed with plaster to fix soft tissues as well as bones in a right position. The purpose of using plaster is to prevent the soft tissues and the bones from shifting and causing a secondary injury and to enhance rehabilitation of the foot. To enhance rehabilitation of the soft tissues and the bones of the injured person, a rehabilitation footwear is available on the market. Conventional rehabilitation footwear includes an ankle rehabilitation footwear and a rehabilitation footwear. The ankle rehabilitation footwear is used for protecting a sole and an ankle of the foot. The high leg rehabilitation footwear is used for protecting a shank of the leg. The ankle rehabilitation footwear is restricted to rehabilitate an injured region of the sole and ankle of the foot. On the other hand, the high leg rehabilitation footwear is designed with an adjustable or nonadjustable height. The high leg rehabilitation footwear with adjustable height can be adjusted according to the injured region of the foot. However, the high leg rehabilitation footwear with adjustable height lacks a design for full cover protection and for different recovery stages of the foot. In other words, the conventional rehabilitation footwear lacks the adjustable function based on the recovery stages of the foot to enhance the recovery rate of the soft tissues as well as the bones of the injured person.
[0005] To overcome the shortcomings, the present invention provides a rehabilitation footwear to mitigate or obviate the aforementioned problems.
SUMMARY OF THE INVENTION
[0006] The main objective of the invention is to provide a rehabilitation footwear with an adjustable function according to the recovery stages of an injured person's foot.
[0007] The rehabilitation footwear in accordance with the present invention has a shoe body, multiple fasteners, a back guard pad, a front guard pad, two supporting frames and an encircling band.
[0008] The shoe body comprises multiple buckles and two concave grooves.
[0009] Each of the multiple fasteners comprises a buckle ring and a band ring. The buckle ring is fastened with one of the multiple buckles of the shoe body.
[0010] The back guard pad comprises a lower back guard pad, a middle back guard pad, and an upper back guard pad. The lower back guard pad comprises two protrusion parts, multiple holes and multiple perforations. The two protrusion parts of the back guard pad are interlocked with the two concave grooves of the shoe body. The middle back guard pad comprises multiple buckles and multiple clasps. The multiple buckles of the middle back guard pass through the multiple holes of the lower back guard pad and are fastened with the buckle rings of the multiple fasteners. The multiple clasps of the middle back guard are clasped with the perforations of the lower back guard pad. The upper back guard pad comprises multiple buckles and multiple clasps. The multiple buckles of the upper back guard pad pass through the multiple holes of the lower back guard pad and are fastened with the buckle rings of the multiple fasteners. The multiple clasps of the upper back guard pad are clasped with the multiple perforations of the lower back guard pad.
[0011] The front guard pad comprises a lower front guard pad, a middle front guard pad, and an upper front guard pad. The lower front guard pad comprises a clasp. The middle front guard pad comprises a perforation clasped with the clasp of the lower front guard pad. The upper front guard pad comprises a perforation clasped with the clasp of the lower front guard pad.
[0012] Each of the two supporting frames comprises a protrusion part and multiple band rings. The protrusion part of each of the two supporting frames is interlocked with each of the two concave grooves of the shoe body.
[0013] The encircling band passes through the multiple band rings of the two supporting frames that are positioned correspondingly to each other.
[0014] A full-cover rehabilitation footwear is built up by combination of the shoe body, the lower back guard pad, the upper back guard pad, the lower front guard pad and the upper front guard pad, and fixed with the injured person's foot by the encircling band passing through the band rings of the multiple fasteners corresponding to each other.
[0015] A supporting-type rehabilitation footwear is built up by combination of the shoe body, the lower back guard pad, the middle back guard pad, the lower front guard pad and the middle front guard pad, and fixed with the injured person's foot by the encircling band passing through the band rings of the multiple fasteners corresponding to each other.
[0016] A frame-type rehabilitation footwear is built up by combination of the shoe body and the two supporting frames, and fixed with the injured person's foot by the encircling band passing through the multiple band rings of the two supporting frames corresponding to each other.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a perspective exploded view of a rehabilitation footwear in accordance with the present invention;
[0018] FIG. 2A is an enlarged view of a lower back guard pad of the rehabilitation footwear in FIG. 1 ;
[0019] FIG. 2B is an enlarged view of an upper back guard pad of the rehabilitation footwear in FIG. 1 ;
[0020] FIG. 3 is a side view of the rehabilitation footwear in FIG. 1 ;
[0021] FIG. 4 is a perspective view of a first embodiment of the rehabilitation footwear in accordance with the present invention;
[0022] FIG. 5 is a perspective view of a second embodiment of the rehabilitation footwear in accordance with the present invention; and
[0023] FIG. 6 is a perspective view of a third embodiment of the rehabilitation footwear in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The First Embodiment
[0024] With reference to FIG. 1 , a first embodiment of a rehabilitation footwear in accordance with the present invention comprises a shoe body 10 , a back guard pad 1000 , a front guard pad 2000 , a first fastener 11 , a second fastener 12 , a third fastener 13 , a fourth fastener 14 , a fifth fastener 15 , a sixth fastener 16 , a seventh fastener 17 , an eighth fastener 18 , a first fill A and a second fill B.
[0025] The shoe body 10 comprises two lateral sides and a back end respectively corresponding to bilateral sides and a heel of a human's foot. The two lateral sides and the back end of the shoe body 10 form a capacity space for accommodating the human's foot. The two lateral sides comprise a first buckle 111 , a second buckle 122 , a third buckle 133 , and a fourth buckle 144 . The back end of the shoe body 10 comprises a first concave groove 155 and a second concave groove 166 .
[0026] The back guard pad 1000 comprises a lower back guard pad 20 and an upper back guard pad 30 . The lower back guard pad 20 comprises three lateral sides connected with each other at nearly right angle, allowing to be formed a lower capacity space for accommodating a back of a human's shank. The lower capacity space comprises a lower end and an upper end. Two of the lateral sides of the lower back guard pad 20 opposite each other and corresponding to the lower end of the lower capacity space extend and form a first protrusion part 201 and a second protrusion part 202 . The first protrusion part 201 and the second protrusion part 202 are respectively interlocked with the first concave groove 155 and the second concave groove 166 of the shoe body 10 , allowing the back guard pad 1000 to be fixed with the shoe body 10 . The two opposite lateral sides of the lower back guard pad 20 comprise a first hole 203 and a second hole 204 . The two lateral sides of the lower back guard pad 20 opposite each other and corresponding to the upper end of the capacity space extend outwards and form a small capacity space.
[0027] With reference to FIG. 1 and FIG. 2A , the small capacity space corresponding to the two lateral sides of the lower back guard pad 20 opposite each other forms a third hole 205 , a fourth hole 206 , a fifth hole 207 , a sixth hole 208 , a first perforation 209 , a second perforation 210 , a third perforation 211 and a fourth perforation 212 .
[0028] The upper back guard pad 30 comprises three lateral sides connected with each other at nearly right angle, allowing to be formed an upper capacity space for accommodating the back of the human's shank. The upper capacity space comprises a lower end and an upper end. Two of the lateral sides of the upper back guard pad 30 opposite each other and corresponding to the upper end of the upper capacity space comprise a first upper buckle 301 and a second upper buckle. The two lateral sides of the upper back guard pad 30 opposite each other and corresponding to the lower end of the upper capacity space comprise a third upper buckle 303 and a fourth upper buckle. The third upper buckle 303 and the fourth upper buckle respectively pass through the first hole 203 and the second hole 204 of the lower back guard pad 20 .
[0029] With reference to FIG. 1 , FIG. 2A and FIG. 2B , the two lateral sides of the upper back guard pad 30 opposite each other and corresponding to the lower end of the upper capacity space extend outwards and form protrusion structures. One of the protrusion structures is a protrusion structure 30 A. The protrusion structure 30 A comprises a surrounding a recess, and the first fill A is placed in the recess of the protrusion structure 30 A. The protrusion structure 30 A is fitted into the small capacity space of the lower back guard pad 20 . The other one of the protrusion structures is identical to the protrusion structure 30 A and positioned oppositely to the protrusion structure 30 A of the upper back guard pad 30 . The other one of the protrusion structures comprises a surrounding wall having a recess, and the second fill B is placed in the recess of the other one of the protrusion structures. The protrusion structure 30 A and the second fill B are fit into the small capacity space of the two opposite lateral sides of the lower back guard pad 20 . The first fill A comprises a first bump A 1 and a second bump A 2 . The second fill B comprises a third bump B 1 and a fourth bump. The first bump A 1 passes through the third hole 205 of the lower back guard pad 20 , and the second bump A 2 passes through the fourth hole 206 of the lower back guard pad 20 . The third bump B 1 passes through the fifth hole 207 of the lower back guard pad 20 , and the fourth bump passes through the sixth hole 208 of the lower back guard pad 20 .
[0030] Two lateral sides of the surrounding wall of the protrusion structure 30 A comprise a first clasp 305 and a second clasp 306 formed toward outside of the recess. The first clasp 305 passes through and is clasped with the first perforation 209 of the lower back guard pad 20 . The second clasp 306 passes through and is clasped with the second perforation 210 of the lower back guard pad 20 , allowing the lower back guard pad 20 to be fixed with the upper back guard pad 30 .
[0031] With reference to FIG. 1 and FIG. 3 , the first fastener 11 , the second fastener 12 , the third fastener 13 , the fourth fastener 14 , the fifth fastener 15 , the sixth fastener 16 , the seventh fastener 17 and the eighth fastener 18 each comprises two ends. One end of each of the first fastener 11 , the second fastener 12 , the third fastener 13 , the fourth fastener 14 , the fifth fastener 15 , the sixth fastener 16 , the seventh fastener 17 and the eighth fastener 18 comprises a buckle ring respectively corresponding to the first buckle 111 , the second buckle 122 , the third buckle 133 , the fourth buckle 144 , and the first upper buckle 301 , the second upper buckle, the third upper buckle 303 and the fourth upper buckle of the upper back guard pad 30 . The other end of each of the first fastener 11 , the second fastener 12 , the third fastener 13 , the fourth fastener 14 , the fifth fastener 15 , the sixth fastener 16 , the seventh fastener 17 and the eighth fastener 18 comprises a band ring, allowing an encircling band 80 to be passed through. The encircling band 80 comprises a fabric hook and loop fastener.
[0032] With reference to FIG. 1 and FIG. 3 , the front guard pad 2000 comprises a lower front guard pad 50 and an upper front guard pad 60 . The lower front guard pad 50 comprises a front end and a back end. The back end of the lower front guard pad 50 comprises a clasp 501 . The upper front guard pad 60 comprises a front end. The front end of the upper front guard pad 60 comprises a clasp 601 .
[0033] With reference to FIG. 1 and FIG. 4 , a method for using the first embodiment comprises:
[0034] (1) putting an injured person's foot wrapped in a rehabilitation strap 90 on a surface 10 A of the shoe body 10 , and placing the back of the injured person's shank in the lower capacity space of the lower back guard pad 20 and the upper capacity space of the upper back guard pad 30 .
[0035] (2) fastening the first fastener 11 , the second fastener 12 , the third fastener 13 , and the fourth fastener 14 respectively with the first buckle 111 , the second buckle 122 , the third buckle 133 and the fourth buckle 144 .
[0036] (3) placing the lower front guard pad 50 on an instep of the injured person's foot, such that the front end of the lower front guard pad 50 is corresponding to a tiptoe of the injured person's foot.
[0037] (4) passing the encircling band 80 through the band rings of the first fastener 11 and the second fastener 12 , and the band rings of the third fastener 13 and the fourth fastener 14 , separately.
[0038] (5) fixing the injured person's foot between the shoe body 10 and the lower front guard pad 50 by attaching the fabric hook and loop fastener of the encircling band 80 .
[0039] (6) passing the third upper buckle 303 , the fourth upper buckle, the first clasp 305 and the second clasp 306 through the first hole 203 , the second hole 204 , the first perforation 209 and the second perforation 210 of the lower back guard pad 20 , respectively, allowing the first clasp 305 and the second clasp 306 to be clasped respectively with the first perforation 209 and the second perforation 210 of the lower back guard pad 20 .
[0040] (7) fastening the buckle ring of the fifth fastener 15 , the sixth fastener 16 , the seventh fastener 17 and the eighth fastener 18 with the third upper buckle 303 , the fourth upper buckle, the first upper buckle 301 and the second buckle of the upper back guard pad 30 , respectively, allowing the lower back guard pad 20 to be fixed with the upper back guard pad 30 .
[0041] (8) placing the upper front guard pad 60 on a front of the injured person's shank, and clasping the clasp 601 of the upper front guard pad 60 with the clasp 501 of the lower front guard pad 50 .
[0042] (9) passing the encircling band 80 through the band rings of the fifth fastener 15 and the sixth fastener 16 , and the band rings of the seventh fastener 17 and the eighth fastener 18 , separately, allowing the injured person's shank to be fixed between the lower back guard pad 20 , the upper back guard pad 30 and the upper front guard pad 20 .
[0043] The first embodiment allows soft tissues as well as bones of the injured person's foot to be protected by fixing in a full-cover rehabilitation footwear, and avoids shifting of the soft tissues and bones to enhance recovery.
The Second Embodiment
[0044] With reference to FIG. 1 and FIG. 5 , a second embodiment of the rehabilitation footwear in accordance with the present invention comprises a shoe body 10 , a back guard pad 1000 , a front guard pad 2000 , a first fastener 11 , a second fastener 12 , a third fastener 13 , a fourth fastener 14 , a fifth fastener 15 , a sixth fastener 16 , a first fill A and a second fill B.
[0045] The shoe body 10 comprises two lateral sides and a back end corresponding to bilateral sides and a heel of a human's foot, respectively. The two lateral sides and the back end of the shoe body 10 form a capacity space for accommodating the human's foot. The two lateral sides comprise a first buckle 111 , a second buckle 122 , a third buckle 133 , and a fourth buckle 144 . The back end of the shoe body 10 comprises a first concave groove 155 and a second concave groove 166 .
[0046] The back guard pad 1000 comprises a lower back guard pad 20 and a middle back guard pad 40 . The lower back guard pad 20 comprises three lateral sides connected with each other at nearly right angle, allowing to be formed a lower capacity space for accommodating the back of the human's shank. The lower capacity space comprises a lower end and an upper end. Two of the lateral sides of the lower back guard pad 20 opposite each other and corresponding to the lower end of the lower capacity space extend and form a first protrusion part 201 and a second protrusion part 202 . The first protrusion part 201 and the second protrusion part 202 are respectively interlocked with the first concave groove 155 and the second concave groove 166 of the shoe body 10 , allowing the back guard pad 1000 to be fixed with the shoe body 10 . The two opposite lateral sides of the lower back guard pad 20 comprise a first hole 203 and a second hole 204 . The two lateral sides of the lower back guard pad 20 opposite with each other and corresponding to the upper end of the capacity space extend outwards and form a second small capacity space.
[0047] With reference to FIG. 1 and FIG. 2A , the second small capacity space corresponding to the two opposite lateral sides of the lower back guard pad 20 forms a third hole 205 , a fourth hole 206 , a fifth hole 207 , a sixth hole 208 , a first perforation 209 , a second perforation 210 , a third perforation 211 and a fourth perforation 212 .
[0048] The middle back guard pad 40 is smaller than the upper back guard pad 30 and comprises three lateral sides connected with each other at nearly right angle, allowing to be formed a middle capacity space for accommodating the back of the human's shank. The middle capacity space comprises a lower end and an upper end.
[0049] The two lateral sides of the middle back guard pad 40 opposite each other and corresponding to the lower end of the middle capacity space comprise a first middle buckle 401 and a second middle buckle. The first middle buckle 401 and the second middle buckle pass through the first hole 203 and the second hole 204 of the lower back guard pad 20 , respectively.
[0050] Two of the lateral sides of the middle back guard pad 40 opposite each other and corresponding to the upper end of the middle capacity space extend outwards and form protrusion structures. One of the protrusion structures is a second protrusion structure 40 A. The second protrusion structure 40 A comprises a surrounding wall having a second recess, and the first fill A is placed in the second recess of the second protrusion structure 40 A. The second protrusion structure 40 A is fitted into the small capacity space of the lower back guard pad 20 . The other one of the protrusion structures is identical to the second protrusion structure 40 A and positioned oppositely to the second protrusion structure 40 A of the middle back guard pad 40 . The other one of the protrusion structures comprises a surrounding wall having a recess formed threin, and the second fill B is placed in the recess of the other one of the protrusion structures. The second protrusion structure 40 A and the second fill B are fit into the small capacity space of the two opposite lateral sides of the lower back guard pad 20 . The first fill A comprises a first bump A 1 and a second bump A 2 . The second fill B comprises a third bump B 1 and a fourth bump. The first bump A 1 passes through the third hole 205 of the lower back guard pad 20 , and the second bump A 2 passes through the fourth hole 206 of the lower back guard pad 20 . The third bump B 1 passes through the fifth hole 207 of the lower back guard pad 20 , and the fourth bump passes through the sixth hole 208 of the lower back guard pad 20 .
[0051] Two lateral sides of the surrounding wall of the second protrusion structure 40 A comprise a third clasp 403 and a fourth clasp 404 formed toward outside of the recess. The third clasp 403 passes through and is clasped with the first perforation 209 of the lower back guard pad 20 . The fourth clasp 404 passes through and is clasped with the second perforation 210 of the lower back guard pad 20 , allowing the lower back guard pad 20 to be fixed with the middle back guard pad 40 .
[0052] The first fastener 11 , the second fastener 12 , the third fastener 13 , the fourth fastener 14 , the fifth fastener 15 , the sixth fastener 16 , the seventh fastener 17 and the eighth fastener 18 each comprise two ends. One end of each of the first fastener 11 , the second fastener 12 , the third fastener 13 , the fourth fastener 14 , the fifth fastener 15 , the sixth fastener 16 , the seventh fastener 17 and the eighth fastener 18 comprises a buckle ring corresponding respectively to the first buckle 111 , the second buckle 122 , the third buckle 133 , the fourth buckle 144 , and the first middle buckle 401 , the second middle buckle of the middle back guard pad 40 . The other end of each of the first fastener 11 , the second fastener 12 , the third fastener 13 , the fourth fastener 14 , the fifth fastener 15 , and the sixth fastener 16 comprises a band ring, allowing an encircling band 80 to be passed through. The encircling band 80 comprises a fabric hook and loop fastener.
[0053] With reference to FIG. 1 and FIG. 5 , the front guard pad 2000 comprises a lower front guard pad 50 and a middle front guard pad 70 . The lower front guard pad 50 comprises a front end and a back end. The back end of the lower front guard pad 50 comprises a clasp 501 . The middle front guard pad 70 comprises a front end. The front end of the middle front guard pad 70 comprises a clasp 701 .
[0054] A method for using the first embodiment comprises:
[0055] (1) putting an injured person's foot wrapped in the rehabilitation strap 90 on the surface 10 A of the shoe body 10 , and placing the back of the injured person's shank in the lower capacity space of the lower back guard pad 20 and the upper capacity space of the upper back guard pad 30 .
[0056] (2) fastening the first fastener 11 , the second fastener 12 , the third fastener 13 , and the fourth fastener 14 respectively with the first buckle 111 , the second buckle 122 , the third buckle 133 and the fourth buckle 144 .
[0057] (3) placing the lower front guard pad 50 on an instep of the injured person's foot, such that the front end of the lower front guard pad 50 is corresponding to a tiptoe of the injured person's foot.
[0058] (4) passing the encircling band 80 through the band rings of the first fastener 11 and the second fastener 12 , and the band rings of the third fastener 13 and the fourth fastener 14 , separately.
[0059] (5) fixing the injured person's foot between the shoe body 10 and the lower front guard pad 50 by attaching the fabric hook and loop fastener of the encircling band 80 .
[0060] (6) passing the first middle buckle 401 , the second middle buckle, the third clasp 403 and the fourth clasp 404 through the first hole 203 , the second hole 204 , the first perforation 209 and the second perforation 210 of the lower back guard pad 20 , respectively, allowing the third clasp 403 and the fourth clasp 404 to be clasped respectively with the first perforation 209 and the second perforation 210 of the lower back guard pad 20 .
[0061] (7) fastening the buckle rings of the fifth fastener 15 and the sixth fastener 16 with the first middle buckle 401 , the second middle buckle of the middle back guard pad 40 , respectively, allowing the lower back guard pad 20 to be fixed with the middle back guard pad 40 .
[0062] (8) placing the middle front guard pad 70 on a front of the injured person's shank, and clasping the clasp 701 of the middle front guard pad 70 with the clasp 501 of the lower front guard pad 50 .
[0063] (9) passing the encircling band 80 through the band rings of the fifth fastener 15 and the sixth fastener 16 , and the band rings of the seventh fastener 17 and the eighth fastener 18 , separately, allowing the injured person's shank to be fixed between the lower back guard pad 20 , the middle back guard pad 40 and the upper middle guard pad 70 .
[0064] According to recovery of the injured person's foot, when ready for the next rehabilitation stage, the rehabilitation footwear of the fist embodiment can be replaced by the second embodiment. The rehabilitation footwear of the second embodiment allows the soft tissues as well as bones of the injured person's foot to be protected by fixing in a supporting-type rehabilitation footwear further for enhancing the rate of recovery.
The Third Embodiment
[0065] With reference to FIG. 1 , a third embodiment of the rehabilitation footwear in accordance with the present invention comprises a shoe body 10 , frames, a first fastener 11 , a second fastener 12 , a third fastener 13 , a fourth fastener 14 , a fifth fastener 15 and a sixth fastener 16 .
[0066] The shoe body 10 comprises two lateral sides and a back end corresponding to bilateral sides and a heel of a human's foot, respectively. The two lateral sides and the back end of the shoe body 10 form a capacity space for accommodating the human's foot. The two lateral sides comprise a first buckle 111 , a second buckle 122 , a third buckle 133 , and a fourth buckle 144 . The back end of the shoe body 10 comprises a first concave groove 155 and a second concave groove 166 .
[0067] The frames comprise a first supporting frame 100 and a second supporting frame 110 . Each of the first supporting frame 100 and the second supporting frame 110 comprises a lower end, a middle end, an upper end and two lateral sides.
[0068] The lower ends of the first supporting frame 100 and the second supporting frame 110 extend and respectively form a first protrusion part 1001 and a second protrusion part 1101 . The first protrusion part 1001 of the first supporting frame 100 and the second protrusion part 1101 of the second supporting frame 110 are respectively interlocked with the first concave groove 155 and the second concave groove 166 of the shoe body 10 . The two lateral sides of the middle end of the first supporting frame 100 comprise a first band ring 1001 A and a second band ring 1001 B; the two lateral sides of the upper end of the first supporting frame 100 comprise a third band ring 1001 C and a fourth band ring 1001 D. The two lateral sides of the middle end of the second supporting frame 110 comprise a fifth band ring 1101 A and a sixth band ring 1101 B; the two lateral sides of the upper end of the second supporting frame 110 comprises a seventh band ring 1101 C and an eighth band ring 1101 D.
[0069] The first fastener 11 , the second fastener 12 , the third fastener 13 , the fourth fastener 14 , the fifth fastener 15 and the sixth fastener 16 each comprise two ends. One end of each of the first fastener 11 , the second fastener 12 , the third fastener 13 , the fourth fastener 14 , the fifth fastener 15 and the sixth fastener 16 comprises a buckle ring corresponding respectively to the first buckle 111 , the second buckle 122 , the third buckle 133 , the fourth buckle 144 , allowing an encircling band 80 to be passed through. The encircling band 80 comprises a fabric hook and loop fastener.
[0070] With reference to FIG. 1 and FIG. 6 , a method for using the first embodiment comprises:
[0071] (1) wrapping an injured person's foot with the rehabilitation strap 90 and placing the injured person's foot on the surface 10 A of the shoe body 10 .
[0072] (2) fastening the first fastener 11 , the second fastener 12 , the third fastener 13 , and the fourth fastener 14 respectively with the first buckle 111 , the second buckle 122 , the third buckle 133 and the fourth buckle 144 .
[0073] (3) passing the encircling band 80 through the band rings of the first fastener 11 and the second fastener 12 , and the band rings of the third fastener 13 and the fourth fastener 14 , separately.
[0074] (4) fixing the injured person's foot with the shoe body 10 by attaching the fabric hook and loop fastener of the encircling band 80 .
[0075] (5) passing the encircling band 80 through the first band ring 1001 A of the first supporting frame 100 and the fifth band ring 1101 A of the second supporting frame 110 , separately; passing the encircling band 80 through the second band ring 1001 B of the first supporting frame 100 and the sixth band ring 1101 B of the second supporting frame 110 , separately; passing the encircling band 80 through the third band ring 1001 C of the first supporting frame 100 and the seventh band ring 1101 C of the second supporting frame 110 , separately; finally, passing the encircling band 80 through the fourth band ring 1001 D of the first supporting frame 100 and the eighth band ring 1101 D of the second supporting frame 110 , separately, allowing the injured person's shank to be fixed between the first supporting frame 100 and the second supporting frame 110 .
[0076] According to recovery of the injured person's foot, when ready for next rehabilitation stage, the rehabilitation footwear of the second embodiment can be replaced by the third embodiment. The rehabilitation footwear of the second embodiment allows the soft tissues as well as bones of the injured person's foot to be protected by fixing in a frame-type rehabilitation footwear further for enhancing the rate of recovery. | A rehabilitation footwear comprises a shoe body, multiple fasteners, a lower back guard pad, an upper back guard pad, a lower front guard pad, an upper front guard pad, and two supporting frames. A full-cover rehabilitation footwear can be built up by combining the shoe body, the lower back guard pad, the upper back guard pad, the lower front guard pad, and the upper front guard pad together with the multiple fasteners. A supporting-type rehabilitation footwear can be built up by combining the shoe body, the lower back guard pad, the middle back guard pad, the lower front guard pad, and the middle front guard pad together with the multiple fasteners. A frame-type rehabilitation footwear can be built up by combining the shoe body and the two supporting frames together with the multiple fasteners. An adjustable rehabilitation footwear is provided. | 0 |
DESCRIPTION
1. Technical Field
The invention relates to a method for determining optical errors, in particular in the refractive power, in large-area panes composed of a transparent material such as glass, by evaluation of the observed image, comprising the steps of projecting of a pattern composed of regular sequences, with the sequences comprising at least two different light intensities, and arrangement of the pane in the beam path of the projection.
2. Prior Art
EP-A-0 416 302 describes such a method. In this method, an illuminated flat grid is imaged via an objective on a reference grid, a pane to be checked is arranged in the beam path between the flat grid and the reference grid, and the superimposed image composed of the image from the flat grid and the reference grid is investigated; in this case, the flat grid is imaged on a reference grid whose surface size is smaller than that of the pane to be examined, and the superimposed image is recorded a plurality of times by a video camera in order subsequently to be evaluated using a phase-shift method, in which the recorded brightness distribution is used as a measure of the refractive power of the pane.
An extremely high level of complexity is required to carry out this method. In practice, the flat grid is generally a cruciform grid which is formed from alternating opaque strips and transparent strips, with the transparent strips being exactly as wide as the opaque strips, and with two such strip patterns being superimposed offset through 90° with respect to one another. The pane to be examined is arranged in the beam path and is imaged on the reference grid, which is a linear grid, and likewise comprises transparent and opaque lines, to be precise with the same width ratio as the flat grid. A first practical problem arises when the lines of the two grids coincide exactly; in order to avoid this situation, lines which are semi-opaque and semi-permeable are in practice generally used as the flat grid rather than opaque lines. This reduces the contrast.
In order to allow evaluation of the resulting moiré image using the phase-shift method, the superimposed image of the flat grid which is imaged on the reference grid has to be imaged three times. In this case, the reference grid must be shifted twice, in each case by one third of the width of a line pair, so that, overall, at least three records are required in order to determine the phase shift in one dimension (for example the horizontal) of the pane. If it also desired to determine the refractive power of the pane in a dimension running at right angles to this (for example the vertical), three records of the resultant moiré image must be made once again, from a second reference grid. Thus, overall, six records are required in order to allow the refractive power of the pane to be determined using the phase-shift.
The apparatus for carrying out the method is correspondingly complex, since shifting the reference grid by one third of the width of a line pair on the reference grid must be carried out really precisely. The same is true for the second record, at right angles to the first, since it is difficult to avoid an undesirable moiré effect occurring due to positioning errors. A large amount of time is required to measure the refractive power, owing to the complex handling.
In addition, the known method can lead to undesirable moiré fringes on the “pixel period” of the camera (see column 4, lines 36-40) if the illumination pattern or the reference pattern make up a multiple of one period of the pixels. Measures therefore have to be taken to avoid the occurrence of this constellation, since these undesirable additional moiré images corrupt the evaluation of the image of the pane.
EP-A-0 559 524 describes another method, namely for testing the transparency in particular of laminated glass after the initial assembly process and before autoclaving, that is to say at a time at which the initial assembly, or the interlayer, as a rule has a milky color which impedes light transmission. This transmission method uses a light source arranged on one side (underneath) the initial assembly and a camera on the other side of the initial assembly in order to monitor the test image produced. The test image produced by the light source and projected is a line pattern comprising a small number of lines. A mean value from all the observed values is used as the basis for deciding whether a laminated glass pane is “good” or “poor”. No specific imaging rule for the lines on the camera and its pixels is proposed. It is also impossible to detect errors in the refractive power, small inclusions or the like, since they have only a minimal effect on the measured mean value over the entire observed image.
The mathematical derivatives of angles originating from measured moiré images as well as a summary of the various moiré techniques are given in the article by Selb, M., and Höfler, H. in “Vision & Voice Magazine”, Volume 4, (1990), No. 2, pages 145-151. This article also deals with high-resolution moiré topography measurements by gratings imaged directly onto a CCD chip, that is to say with single-stage imaging without a reference grating.
DESCRIPTION OF THE INVENTION
The object of the invention is to specify a method as claimed in the preamble of claim 1, using which optical errors in at least one dimension of a pane can be determined without a reference grid.
This object is achieved by the features in the descriptive steps of the claims, including imaging the pattern onto a camera, with a sequence of the pattern in each case being imaged onto a number of adjacently arranged pixels of the camera, and the number being an integer multiple of the sequence.
A sequence of the pattern can be defined by a periodic sequence of two or more light intensities. In the simplest case, this is a sequence in which light and dark strips, preferably of identical width, alternate with one another and form a light/dark sequence. However, it is also possible for the sequence to be composed of three, four or more strips, which have a regular sequence with intensity minima and maxima that are always equidistant.
In order to produce these sequences it is, on the one hand, possible to produce the light intensities by the local light permeabilities of a physical grid, by means of a light source arranged behind the grid. Where the grid is opaque, the light intensity is zero and the point is dark; where the grid is completely transparent, the light intensity assumes a maximum. The use of a physical grid as in the prior art, that is to say comparable to a large screen or filter, is adequate for sharp light/dark sequences. However, semi-transparent filters must be provided to produce sequences with strips of different brightness, which filters would possibly have to have three or more different light permeabilities, reproduced very precisely.
A light wall is preferably provided in an apparatus for carrying out the method, which light wall is used in the method according to the invention for projecting a pattern with regular sequences, and can be used instead of a light source with a grid. The light wall is expediently composed of a large number of individual LEDs which can be actuated as required individually, in blocks or in lines and columns in order either to illuminate or not to illuminate in accordance with a light/dark profile, or in order to emit different intensities as a function of a suitable characteristic. Similar light walls are used, for example, as display panels in sports stadiums. It is self-evident that the apparatus for determining optical errors, comprising a light wall composed of a plurality of light areas which can be actuated individually as a flat grid which is projected onto a pane whose refractive power is intended to be determined also works when it is used with a reference grid from the prior art. It is self-evident that, in principle, the light/dark sequence can be displayed with either or the two grids. It is furthermore self-evident that the sequences can also be enlarged via lenses, before the actual projection takes place.
If the number of adjacently arranged pixels according to the invention exceeds the total of two, it is self-evident that the pixels cannot all be arranged adjacent to one another in every situation; instead, the intention is that the pixels be arranged to be adjacent in pairs, in such a manner that they form a cohesive sub-line or sub-matrix which is free of unassociated pixels.
The method according to the invention preferably provides for an integer multiple, preferably a set of three pixels arranged alongside one another, to correspond to a light/dark sequence, preferably a light/dark pair, which is imaged by the pane onto the camera. The line pair width of the projected illumination pattern is thus precisely that multiple of the width of a pixel of the camera, so that moiré fringes are formed on the camera itself. The use of light/dark pairs has the advantage that the projection can be achieved very easily by the corresponding provision of a grid having only two different light permeabilities, expediently respectively opaque and transparent regions, so that good contrast is achieved.
This effect is used according to the invention to make it possible to dispense with a reference pattern, which, on its own, greatly simplifies the equipment required for an apparatus for carrying out the method, in particular the space required for the equipment.
It should be realized that there are a number of possible ways for evaluating the illumination pattern. On the one hand, the light intensity which is recorded by each pixel can be used as the basis for further processing. The precise width relationships allow periodically recurring intensity distributions to be produced, from whose disturbance the deflection angle causing the disturbance can easily be determined. A disturbance may be determined either by a comparison without a pane/with a pane or, if the initial points of the line pairs are aligned precisely with a set of three pixels, using the knowledge of the nominal light intensities at each point. In the latter case, it is preferably possible to dispense with a device with a test norm or the like.
Another approach to further processing of the lighting pattern, which is preferred owing to its very good resolution, is to use the moiré image that occurs on the pixels of the camera. The moiré image which is detected on the camera results from superimposition of two brightness distributions with a specific periodicity, in which case the approximate profiling of sinewave of the moiré structure can be recognized on the “grid” of pixels over the width of a line pair of the sequence which corresponds to a light/dark period. It is therefore possible to make use of the fact that moiré phenomena can be used to determine deformations in the pattern, for example resulting from refraction in the pane, with a resolution that is many times higher and is evident as a phase shift of the moiré image, that is to say as compression or expansion in the sinusoidal curve produced by the moiré image.
If, according to a first preferred development of the invention, a line pair of the lighting pattern is imaged on a set of three adjacent pixels, this thus results in 3 moiré image strips for each line pair; there is then no need to shift a reference pattern by one third with respect to the projected pattern and, instead of this, it is advantageously possible to use the value of the second and third pixels as the value for the record shifted through 120° and 240° (or −120°). These moiré image strips, offset through 120° (one third of a complete sine wave) and detected by the pixels of the camera can, after simple conversion, be expressed mathematically as curves that are dependent on a sine function.
Variations in the refractive power of the panes, for example a windshield of a motor vehicle, lead to variations in the maxima and minima which occur as a result of the moiré phenomenon and can easily be determined as a phase shift in the sine wave; if the distance between the camera and the pane is known, this can be used to determine the angle through which the light that passes through the pane is refracted. The refractive power in dioptrins can thus be determined by simple further mathematical processing (differentiation). This is of major importance, particularly for determining the refractive power of a windshield, since deflection of the view in the vertical plane has an adverse effect on the view straight ahead, while deflection of the light in the horizontal plane has an adverse effect on the view to the side. DIN 52305 and ECE 43 quote limits for the maximum permissible refractive power of the glass, and these can be used as threshold values for a comparison as to whether a tested windshield is accepted or rejected.
If the method according to the invention makes use of a pattern which arranges sequences superimposed on one another both in the horizontal plane and in the vertical plane, then a matrix camera can be used to carry out a simultaneous evaluation of the refractive power both for the vertical plane and for the horizontal plane, without the camera or a reference grid having to be rotated for this purpose. The same measured values of the pixels of the camera can be used as the basis of the evaluation, which results in a large amount of memory space being saved for each evaluation, and the measurement data can be archived in a compact form. If the number of pixels associated with a light/dark pair is increased, by a factor of, for example, four (five) or more, this allows an evaluation to be carried out using a phase-shift method shifted in each case by 90° (72°) or corresponding fractions of these figures. In the case of four pixels, the additional degree of freedom which becomes available also allows the frequency shift to be determined easily, in addition to the position and intensity extremes.
According to a second preferred development of the invention, it is possible to achieve the same resolution as for a set of three pixels by imaging on only two respectively adjacent pixels in the camera. The pattern that needs to be provided for this purpose is only slightly more complex.
In a first variant, it is possible to form a pattern with sequences composed of three light intensities, in which case this sequence can be formed, for example, as three equidistant strips of a grid. The light permeabilities of the grid may each differ by a factor as, for example, 1%, 10%, 100%, or 10% as well as 0%, 30% as well as 33%, 90% as well as 100%. The signal detected by the two pixels can then likewise lead back to a sine wave, which allows subsequent evaluation using phase-shift methods. Alternatively, the light intensities are prod ed by fields of a light matrix whose lighting intensities differ in lines and/or columns.
In another variant, it is possible to provide at least one “strip which can be switched off” which is transparent, for example, only for light at a specific wavelength (of a specific color) in each sequence of the grid. By alternately illuminating firstly with light passing through and secondly with absorbed light, the size ratio of the light/dark sequence is varied in a defined manner while maintaining its “grid constant” that is relevant for the moiré phenomenon, by which means phase shifts in the moiré image can be evaluated very easily. For example, the grid for producing the light/dark sequence is composed of strips which are all of the same width and are alternately completely opaque, transparent for red light but not for green, and completely transparent. It is possible first of all to make one record each with illumination using red or green light, and then to use both images as the basis for the evaluation. It is easier to illuminate alternately with red and green in a rapid frequency sequence, as a result of which the “strip which can be switched off” appears respectively light and dark. Phase evaluation using a modified phase-shift method can be carried out by integration of the light intensity in the pixel (which detects only light/dark, that is to say is independent of the color of the light).
A third advantageous development of the invention is for at least three adjacent strips (lines or columns) of the grid pattern (which then form a sequence) to be illuminated in each case successively, with a corresponding number of records, that is to say at least three, being made of the pane, and each sequence being imaged on a pixel (or on an integer multiple of this) . This development can be carried out both with illumination, as already described above, of a grid having light permeabilities which are dependent on the light color, and with a physical filter, which is in each case shifted by the width of one strip (it is self-evident that the strips are then at equidistant intervals). Light walls such as those described above can be used particularly advantageously and ensure a rapid sequence of the three records with a position which is always reproducible at the same time. Furthermore, this light wall can also be used to make records of the horizontal refractive power immediately after those for the vertical refractive power. This development has the advantage that, on the one hand, it is possible to continue to use existing evaluation software while, on the other hand, only a relatively small number of camera pixels are required, so that it can be carried out cheaply. A matrix light panel also allows, for example, the exposure time of the camera and the duration of the illumination in the grid to be synchronized for a number of, for example, mutually inverse, records. If a pane is scanned using a line-scan camera, each sequence can then be illuminated once for each scanned line, as a result of which it is possible to evaluate each recorded sequence virtually on-line, and the camera need be moved or pivoted only once to scan the pane.
According to a further preferred development of the invention, it is possible, on the basis of the method explained above, to design an apparatus for determining the refractive power in car window panes, in particular windshields, in such a manner that the grid has, for example, a pattern with a strip sequence composed of red, green and blue in the otherwise transparent material, so that the corresponding light color does not pass through the respective strip, and a camera records this strip as “dark”. A color camera thus allows a light/dark strip pattern (one sequence for two adjacent pixels in each case) shifted by one third to be recorded for each of the three colors directly, and the resultant moiré image to be evaluated later. It is self-evident that the sequence of the three colors is then imaged on at least one pixel in the camera, or on a multiple thereof. Alternatively, it is also possible then to illuminate the grid alternately, for example by means of LEDs, with the three corresponding colors, so that the respectively corresponding strip appears dark, and the two other strips appear light. If a black-and-white line-scan or matrix camera is used, it is then expedient to base the evaluation to determine a phase on more than one record with the camera.
The methods according to the invention allow the desired refractive power indices to be determined very precisely and very quickly and are thus particularly suitable for use on motor vehicle panes composed of prestressed glass or of laminated safety glass as well as for flat glass manufactured in the form of float glass, drawn glass or rolled glass, acrylic glass or PVC, LCD displays etc. However, it is also possible to use the methods according to the invention to investigate the refractive power of other transparent materials as may be used, in particular, for vision aids composed of glass or plastics and for large telescope mirrors, for transparent canopies in aircraft or motor cycle helmets etc.
Further refinements of the invention can be found in the following description and the dependent claims.
The invention is explained in more detail in the following text with reference to outline sketches which are illustrated in the attached figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows schematically the beam path of an apparatus for carrying out the method according to the invention.
FIG. 2 and FIG. 3 show the relationship between sequences of a lighting pattern and camera pixels for a single-dimensional and a two-dimensional method, respectively.
DESCRIPTION OF PREFERRED EXEMPLARY EMBODIMENTS
Referring now to FIG. 1, a light source 1 can be seen which illuminates an illuminated grid 2 which is designed as a cruciform grid and from which parallel light strikes the windshield 3 arranged in the beam path. It is self-evident that, instead of the windshield 3 , it is also possible to measure any other object which is transparent at least for light at specific wavelengths, preferably in the visible band.
The cruciform grid 2 splits the light arriving from the light source 1 in such a manner that only a quarter of the light passes through, while the remaining three quarters of the light is prevented from passing through by horizontal opaque strips and vertical opaque strips which cross one another and bound the transparent squares. The edge length of the transparent squares and of the opaque strips is identical. This results in the light/dark pattern as can be seen in FIGS. 2 and 3.
The dimensions of the grid 2 correspond roughly to the size of the object to be measured.
The grid 2 is imaged through the windshield 3 directly and without the interposition of a reference grid on a camera 4 , which records the light/dark intervals on the windshield. It is self-evident that, instead of opaque and transparent lines, it is also in general possible to use lines of different transparency, possibly also with respect to just one specific frequency spectrum, to which the camera 4 is sensitive.
In the case of an “ideal” windshield, the image of the cruciform grid 2 would be projected onto the camera without being changed. The cruciform grid 2 and the camera 4 are matched to one another in such a manner that one pair of light/dark strips is in each case imaged onto three adjacent pixels in the camera 4 , as can be seen more clearly in FIGS. 2 . and 3 . Based on the individual pixels, which are denoted P i,j (FIG. 2) and P i,j,k (FIG. 3 ), where i is the i-th strip pair in the cruciform grid (and the i-th set of three pixels), j is the j-th pixel (j=1, 2 or 3) in the set of three in the direction of the strip and, in the case of a matrix camera, k is the k-th pixel (k=1, 2 or 3) at right angles to the extent of the j-th pixel for in each case one line in the matrix of pixels; it is self-evident that a line index also exists. These pixel addresses can also be addressed individually in the subsequent evaluation of the matrix.
In the case of an ideal image on the camera 4 , the fact that the grid frequency of the camera pixels and the grid frequency of the illuminated grid 2 are multiples of one another leads to a regular moiré phenomenon, which is registered at the camera. Phase shifts as well as expansions and compressions of the sine wave can be determined simply by converting the values measured by the pixels into a sine-wave function.
If, owing to light refraction in the pane, the image on the camera 4 is no longer ideal, but has discrepancies, the moiré phenomenon is disturbed at the camera pixels and can be detected as a phase shift at the output of the camera pixels, thus allowing the angle through which the light beam has been deflected to be determined, with little effort. Based on this angle, it is possible by differentiation to determine the refractive power of the windshield in the vertical direction, which influences the view straight ahead, and in the horizontal direction, which influences the view to the side.
By choosing the ratio of one grid line pair (that is to say 2 lines, one bright and one dark) to 3 pixels, this allows a very good ratio of the width dimensions to one another, as a result of which the resolution of the measured values becomes very high, and the maximum permissible size of the windshield 3 which can be measured becomes very large. The equipment complexity for the apparatus remains low.
It is self-evident that, instead of light/dark pairs or of the cruciform grid 2 , grids with a plurality of brightness steps can be used in a comparable manner by sequences with more than two light intensities. The number of pixels per light/dark pair or sequence may also be four, five, . . . in a corresponding manner.
It is furthermore self-evident that, instead of the arrangement having a light source 1 and a grid 2 , a panel corresponding to the size of the grid and having an LED matrix could also be used, which would advantageously make it possible to drive the individual LED strips via specific electrical contacts. Other means for producing a light pattern may also be used instead of an illuminated grid. The grid has the advantage that simple geometric shapes such as lines can be produced cheaply even if the precision requirements are stringent. | The invention relates to a method for detecting optical errors, especially in refractive power, in large surface panels made of transparent material such as glass, by evaluating an observed image. The steps of the inventive method include: projection of a defined model consisting of regular sequences, whereby the sequences includes two varying light intensities and arrangement of the panel in the optical path of projection. The inventive method enables detection of optical errors in at least one dimension of a panel without a reference screen by projecting the model onto a camera, whereby a model sequence is respectively represented on a certain number of adjacent camera pixels and the number is an integral multiple of the sequence. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a divisional of U.S. patent application Ser. No. 10/780,877, filed Feb. 19, 2004, which is incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is directed generally to photolithography. More particularly, the present invention relates to wafer alignment in a photolithographic system.
[0004] 2. Related Art
[0005] Photolithography (also called microlithography) is a semiconductor device fabrication technology. Photolithography uses radiation, such as ultraviolet or visible light, to generate fine patterns in a semiconductor device design. Many types of semiconductor devices, such as diodes, transistors, and integrated circuits, can be fabricated using photolithographic techniques. Exposure systems or tools are used to implement photolithographic techniques, such as etching, in semiconductor fabrication. An exposure system typically includes an illumination system, a reticle (also called a mask) or spatial light modulator (SLM) for creating a circuit pattern, a projection system, and a wafer alignment stage for aligning a photosensitive resist-covered semiconductor wafer. The illumination system illuminates a region of the reticle or SLM with a preferably rectangular slot illumination field. The projection system projects an image of the illuminated region of the reticle circuit pattern onto the wafer.
[0006] As semiconductor device manufacturing technology advances, there are ever increasing demands on each component of the photolithography system used to manufacture the semiconductor device. This includes increasing demands on the accuracy of the wafer alignment. A wafer is typically mounted on a wafer chuck, also referred to as a wafer table. During exposure, the features being exposed on the wafer need to overlay existing features on the wafer. To achieve overlay performance, the wafer is aligned to the wafer stage prior to exposure. Any movement of the wafer relative to the wafer stage after alignment results in overlay errors.
[0007] During exposure, the wafer is heated locally due to the energy transferred to the wafer from the exposure beam. This heating causes the wafer to expand. If the wafer expansion is unchecked, the expansion exceeds overlay error requirements. Clamping the wafer to the wafer chuck reduces the amount the wafer expands. The wafer chuck is typically designed to have a larger thermal mass than the wafer and is manufactured of a material which has very low thermal expansion. This results in relatively little expansion of the wafer chuck relative to the wafer. The wafer chuck is also typically designed to be much stiffer than the wafer, such that if the wafer is sufficiently clamped to the wafer chuck, the thermal expansion of the wafer is reduced.
[0008] If the clamping force between the wafer and the wafer chuck is not sufficient to prevent wafer expansion, the wafer can slip on the wafer chuck and larger wafer expansion will occur, resulting in larger overlay errors.
[0009] Slipping due to wafer expansion can be reduced by tightly clamping the wafer to the surface of the wafer chuck with a vacuum. This creates a frictional force between the wafer and the wafer chuck. However, if the wafer expansion force exceeds the frictional force, the wafer will slip, causing an overlay error. In extreme ultraviolet (“EUV”) systems, the chances of slipping increase because the environment surrounding the wafer during exposure is also a vacuum. Electrostatic clamping, which is much weaker than vacuum clamping, must thus be used in lieu of a vacuum clamp.
[0010] Therefore, what is needed is a system and method for reducing the effects of wafer expansion during exposure.
SUMMARY OF THE INVENTION
[0011] The present invention reduces wafer slipping by uniformly expanding the wafer chuck after the wafer has been attached. This creates an initial stress on the interface between the wafer and the wafer chuck, rather than a zero stress interface. Because the wafer chuck expands in relation to the wafer, the initial stress is opposite that caused by wafer expansion during exposure. As the wafer heats up from exposure, the initial stress will first be reduced to a zero-stress interface. Only after this point will the expansion of the wafer create an expansion stress on the interface between the wafer and wafer chuck. Ideally, the amount of heating without wafer slipping could be doubled with the present invention.
[0012] The wafer table expansion can be achieved in several ways. In one embodiment, a sealed circular tube, or annular ring, is attached to the circumference of the wafer chuck. The annular ring is then pressurized. The annular ring expands when pressurized, thereby expanding the wafer chuck to which it is attached. In a similar embodiment, the annular ring is not attached to the edge of the wafer chuck, but is embedded inside the wafer chuck through a groove or cavity.
[0013] In another embodiment, a plurality of force actuators is attached to the edge of the wafer chuck. These force actuators act on the wafer chuck to expand it.
[0014] The expansion of the wafer chuck can also be thermally induced. In one embodiment, a heater is directly attached to the wafer chuck. In another embodiment, a proximity heater is placed near the wafer chuck. In still another embodiment, the wafer chuck is made out of an electrically conductive material, and is connected to a power source. In a further embodiment, the wafer is heated before attachment, so that it is warmer relative to the wafer chuck. In this embodiment, when the wafer is attached to the wafer chuck, they reach a thermal equilibrium. As the wafer cools, it contracts and thus creates an initial stress opposite that of an expansion stress. The expansion from each of these embodiments results in nearly uniform expansion of the wafer, similar to an overall magnification of the wafer, and thus can be compensated for in lithographic exposure tools.
[0015] Further embodiments, features, and advantages of the present invention, as well as the structure and operation of the various embodiments of the present invention, are described in detail below with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS/FIGURES
[0016] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate the present invention and, together with the description, further serve to explain the principles of the invention and to enable a person skilled in the pertinent art to make and use the invention.
[0017] FIG. 1 is a flowchart of a method according to an embodiment of the present invention.
[0018] FIG. 2A is an illustration of a wafer attached to a wafer chuck.
[0019] FIG. 2B is an illustration of a wafer chuck expanding in relation to a wafer.
[0020] FIG. 2C is an illustration of a wafer attached to an expanded wafer chuck.
[0021] FIG. 2D is an illustration of a wafer expanding in relation to an expanded wafer chuck.
[0022] FIG. 3A is an illustration of an expansion system according to an embodiment of the present invention.
[0023] FIG. 3B is a cross-section illustration of the expansion system shown in FIG. 3A .
[0024] FIG. 4A is an illustration of another expansion system according to an embodiment of the present invention.
[0025] FIG. 4B is a cross-section illustration of the expansion system shown in FIG. 4A .
[0026] FIG. 5 is an illustration of another expansion system according to an embodiment of the present invention.
[0027] FIG. 6A is an illustration of an expansion system using a heater according to an embodiment of the present invention.
[0028] FIG. 6B is an illustration of another expansion system using a heater according to an embodiment of the present invention.
[0029] FIG. 6C is an illustration of another expansion system using a heater according to an embodiment of the present invention.
[0030] FIG. 6D is an illustration of another expansion system using a heater according to an embodiment of the present invention.
[0031] The present invention will be described with reference to the accompanying drawings. The drawing in which an element first appears is typically indicated by the leftmost digit(s) in the corresponding reference number.
DETAILED DESCRIPTION OF THE INVENTION
[0032] While specific configurations and arrangements are discussed, it should be understood that this is done for illustrative purposes only. A person skilled in the pertinent art will recognize that other configurations and arrangements can be used without departing from the spirit and scope of the present invention. It will be apparent to a person skilled in the pertinent art that this invention can also be employed in a variety of other applications.
[0033] In current lithography systems, wafer slipping is reduced by tightly clamping the wafer to the surface of a wafer chuck. One method of clamping the wafer is by creating a vacuum between the wafer and the wafer chuck.
[0034] This works because there is a pressure differential between the vacuum and the surrounding environment. In extreme ultra-violet (“EUV”) lithography, however, the environment surrounding the wafer during exposure is also a vacuum. This prevents using a vacuum as a clamping force.
[0035] Alternatively, electrostatic clamping is used to clamp the wafer to the wafer chuck. A disadvantage of typical electrostatic clamping is that the amount of force achieved with electrostatic clamping is inherently limited.
[0036] Electrostatic clamping is also related to the time taken to clamp and release the wafer. As a result, electrostatic clamping tends to provide between 1/10 and 1/15 the clamping force of vacuum clamping. This means that the frictional force between the wafer and the wafer chuck also decreases to 1/10 to 1/15 the frictional force in a vacuum system.
[0037] In most systems, the interface between the wafer and the wafer chuck is approximately a zero stress interface at the time of clamping. This means that there is no force on the interface to counteract the frictional force between the wafer and the wafer chuck. When the wafer is exposed, energy in the exposure beam heats the wafer and causes the wafer to expand. When some parts of the wafer are being exposed while others are not, the expansion causes the wafer to slip if it is not sufficiently clamped. Slipping occurs because the thermally-induced expansion stress exceeds the frictional force holding the wafer in place. This introduces error into the system. In a system where electrostatic clamping is used, the frictional force is low, and the expansion stress does not need to be very large to overcome the frictional force.
[0038] For EUV systems, wafer heating is likely to be higher than in non-EUV systems. This is a result of a significant amount of non-exposure energy included in the EUV exposure beam being transferred to the wafer. Most of this energy is in the form of infrared (“IR”) radiation. In some exposures, IR energy at the wafer may equal that of the energy needed to expose the wafer (also referred to as the “dose energy”). This effectively doubles the heating at the wafer compared to non-EUV systems.
[0039] These factors result in a situation where there is 1/10 to 1 / 15 the resistance to slipping as compared to a vacuum system, and twice the heating. Wafer slipping thus becomes much more likely, causing the dose limit determined by overlay to be small in comparison with the dose allowed for non-EUV systems.
[0040] FIG. 1 is a flowchart of a method 100 according to an embodiment of the present invention. Method 100 allows application of a larger dose energy before wafer slipping becomes a threat. Although the present invention will be described herein with reference to EUV systems using electrostatic clamping, one skilled in the art will recognize that the present invention may also be used in non-EUV systems and/or lithography systems using clamping methods other than electrostatic clamping.
[0041] In step 102 , a wafer is attached to a wafer chuck in a lithography system. In one embodiment, the wafer is attached using electrostatic clamping. In another embodiment, the wafer is attached using vacuum clamping.
[0042] In step 104 , the wafer chuck is uniformly expanded. This creates an initial stress on the interface between the wafer and the wafer chuck. During exposure, due to heat transfer, the size of a wafer increases with respect to the wafer chuck. By expanding the wafer chuck prior to exposure, the size of the wafer is effectively decreased with respect to the chuck. Therefore, the initial stress caused by wafer chuck expansion is opposite the stress caused by wafer expansion. The initial stress may be almost equal to the frictional force between the wafer and the wafer chuck. In this embodiment, additional stress would overcome the frictional force, and cause the wafer to slip prior to exposure. However, by keeping the initial stress just below the magnitude of the frictional force, slippage is prevented.
[0043] In step 106 , the wafer is aligned to the wafer stage of a lithography system. This alignment centers the wafer in an exposure beam path, and ensures proper focus and alignment of a lithography pattern during exposure.
[0044] In step 108 , the wafer is exposed, causing the wafer to expand. Because the expansion stress is opposite that of the initial stress, expanding the wafer first acts to relieve the initial stress. Only after relieving the initial stress is a new expansion stress created as a result of the wafer getting larger with respect to the wafer chuck.
[0045] If the initial stress is almost equal to the frictional force between the wafer and the wafer chuck, the exposure dose may be almost doubled compared to a system having no initial stress.
[0046] FIGS. 2A to 2 D illustrate the succession of method 100 . FIG. 2A illustrates a wafer 202 attached to a wafer chuck 204 (not to scale). Wafer 202 is attached via a clamping method, such as vacuum clamping or, in a preferred embodiment, electrostatic clamping.
[0047] FIG. 2B illustrates the expansion of wafer chuck 204 , as occurs in step 104 . Wafer chuck 204 expands uniformly in all directions, as indicated by arrows 206 . During expansion, the size of wafer chuck 204 increases with respect to wafer 202 .
[0048] FIG. 2C illustrates a configuration of wafer 202 and wafer chuck 204 immediately before wafer 202 is exposed. Because of the wafer chuck expansion, there is an initial stress between wafer 202 and wafer chuck 204 . Because wafer chuck 204 attempts to stretch wafer 202 as wafer chuck 204 expands, the initial stress on wafer 202 may be referred to as an outward force.
[0049] FIG. 2D illustrates the expansion of wafer 202 due to heating during exposure. As wafer 202 increases in size, the outward force is relieved. At some point during the wafer expansion, wafer 202 reaches a point where there is zero stress between wafer 202 and wafer chuck 204 . If wafer 202 continues expanding past this point, an inward force is created on wafer 202 . As long as the magnitude of this inward force does not exceed that of the frictional force between wafer 202 and wafer chuck 204 , wafer 202 will not slip. Wafer chuck 204 also expands due to heating during exposure. The expansion of wafer chuck 204 lessens the expansion rate of wafer 202 relative to wafer chuck 204 . Thus, the magnitude increase of the inward force created on wafer 202 is also lessened.
[0050] In a preferred embodiment, wafer 202 is a round wafer. In this embodiment, wafer 202 expands uniformly while heating. Since the expansion is uniform, there is no imbalance of the inward force on wafer 202 , and the likelihood of slipping is lessened. Further, if the wafer expands uniformly, the exposure pattern can be magnified to compensate for the change in size. Compensation would be difficult if sections of the wafer expanded non-uniformly.
[0051] FIG. 3A is an illustration of an embodiment of a system of the present invention. An annular tube 302 is attached to the outside of wafer chuck 204 . In one embodiment, annular tube 302 is a metal tube. In another embodiment, annular tube 302 is manufactured from a plastic. Annular tube 302 includes a cavity 306 . Cavity 306 can be filled with either liquid or gas. When annular tube 302 is pressurized, it expands. Since annular tube 302 is attached to the edge of wafer chuck 204 , wafer chuck 204 uniformly expands with it. FIG. 3B is a cross-section of the illustration in FIG. 3A , taken at line 304 . As shown, annular tube 302 is attached to the edge of wafer chuck 204 .
[0052] FIG. 4A is an illustration of another embodiment of the present invention. Similar to the above embodiment, an annular ring 402 having cavity 406 is attached to wafer chuck 204 . In this embodiment, annular ring 402 is attached inside a cavity or groove in wafer chuck 204 . Because annular ring 402 is embedded into wafer chuck 204 , there is a lesser chance of annular ring 402 detaching from wafer chuck 204 . In addition, non-uniformities caused by materials used to attach the annular ring to the edge of wafer chuck 204 are avoided. FIG. 4B is a cross-section of the illustration in FIG. 4A , taken at line 404 . In one embodiment, annular ring 402 is fully enclosed in the structure of wafer 204 , as shown in FIG. 4B . In another embodiment, annular ring 402 is only partially embedded in wafer chuck 204 , as in a groove.
[0053] FIG. 5 is an illustration of another embodiment of the present invention. In this embodiment, a plurality of force actuators 502 are attached on one end to a fixed support 504 , and on the other end to wafer chuck 204 . The actual number of force actuators 502 used is variable. In one embodiment, force actuators 502 are distributed evenly and symmetrically around wafer chuck 204 . When force actuators 502 are activated, they pull on wafer chuck 204 . In this manner, force actuators 502 act together to exert a uniform force on wafer chuck 204 that is outward with respect to wafer chuck 204 . This outward force causes uniform expansion of wafer chuck 204 .
[0054] FIGS. 6A through 6D illustrate various embodiments of the present invention in which wafer chuck 204 is expanded through heating. In the embodiment of FIG. 6A , a contact heater 602 directly heats wafer chuck 204 . As the temperature of wafer chuck 204 increases, wafer chuck 204 expands. Contact heater 602 may be as large as needed in comparison to wafer chuck 204 to cause uniform heating and expansion throughout wafer chuck 204 . Although this embodiment provides direct heat flow, the attachment of heater 602 may inhibit the expansion of wafer chuck 204 .
[0055] FIG. 6B illustrates another embodiment of the present invention. In this embodiment, a proximity heater 604 is placed near a surface of wafer chuck 204 . Proximity heater 604 may heat via thermal or electromagnetic radiation. Since proximity heater 604 does not come in contact with wafer chuck 204 , it does not inhibit expansion of wafer chuck 204 . As shown in FIG. 6C , proximity heater 604 may vary in size and heat distribution as needed for uniform expansion of wafer chuck 204 .
[0056] FIG. 6D illustrates another embodiment of the present invention in which a heater is used. In this embodiment, wafer chuck 204 is manufactured from an electrically conductive material. A power source 606 is connected to wafer chuck 204 by leads 608 and 610 . As power passes through wafer chuck 204 , it heats up and expands. Leads 608 and 610 may be flexible so as to allow the free expansion of wafer chuck 204 . Power source 606 may be a variable power source.
[0057] In a further embodiment, wafer 202 is heated before being attached to wafer chuck 204 , so that it is warmer than wafer chuck 204 . In this embodiment, when wafer 202 is attached to wafer chuck 204 , they reach thermal equilibrium. As wafer 202 cools, it contracts and thus creates an initial stress opposite that of an expansion force.
[0058] In each of the heating embodiments, a temperature sensor can be mounted on wafer stage 204 to monitor the expansion. A control circuit may be attached to the heater to precisely control or adjust the heating process.
[0059] While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not limitation. It will be apparent to persons skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents. | A method and apparatus for correcting overlay errors in a lithography system. During lithographic exposure, features being exposed on the wafer need to overlay existing features on the wafer. Overlay is a critical performance parameter of lithography tools. The wafer is locally heated during exposure. Thermal expansion causes stress between the wafer and the wafer table, which will cause the wafer to slip if it exceeds the local frictional force. To increase the amount of expansion allowed before slipping occurs, the wafer chuck is uniformly expanded after the wafer has been loaded. This creates an initial stress between the wafer and the wafer table. As the wafer expands due to heating during exposure, the expansion first acts to relieve the initial stress before causing an opposite stress from thermal expansion. The wafer may be also be heated prior to attachment to the wafer chuck, creating the initial stress as the wafer cools. | 7 |
This application is a continuation of my applications Ser. Nos. 103,432 and 310,831 filed Jan. 4, 1971, and Nov. 30, 1972, both now abandoned respectively.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to apparatus for protecting a partially or fully submerged metallic structural element against corrosion from air, water or a combination of both.
2. Description of the Prior Art
It is common to protect the submerged portion of a metallic structural element from corrosion by cathodic methods. Such cathodic protection is expensive and only protects the submerged portion of the metallic element and not the portion thereof in the splash zone. Corrosion protection has also been provided for both the submerged and air-exposed portions of such metallic elements by means of noncorrosive coatings. When such coatings fail, however, they cannot readily be replaced on the submerged portion of the metallic element, and it is expensive to replace such coatings on the splash zone portion of such element. It has also been proposed to add concrete sleeves around such metallic elements. This process is quite expensive, and additionally, such concrete sleeves are difficult to install. For section of metallic elements above water and exposed to air and mixture, the usual practice has been to apply noncorrosive coatings, such as paints, metallic coatings, epoxies and the like to protect against corrosion. These methods have been expensive and the service life is limited.
SUMMARY OF THE INVENTION
The present invention is characterized by a pliable watertight and airtight encasement which is wrapped about the length of a metallic structural element to be protected from water and air corrosion in a sealing relationship with respect to both water and air. This arrangement prevents corrosion of the covered portion of the metallic element. Filler blocks are provided where the metallic element is not of cylindrical transverse cross-section. Such filler blocks have a circular outer edge so as to permit the encasement to be snugly wrapped around and then secured to such blocks.
For the installation of this pliable waterproof and airtight sealed encasement, any existing surface corrosion deposits will not be removed as this corrosion coating provides an initial surface protection of the base metal surface. This corrosion deposit will only be made sufficiently smooth to provide a reasonably snug contact of the encasement with the metallic element surface.
The advantages of this invention are the use of proven, long life materials of proven corrosion resistance, no surface cleaning required, the installation can be made in-place on any metallic element, whether above water, at the splash zone or completely below water without any interferences with operations of the structure, in installation is very simple and easy to apply, the cost is far below other present corrosion protective methods and the service life will greatly exceed that now being realized with other methods. It is estimated that this design of pliable sheet encasement will provide a service life of over 30 years.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view showing apparatus embodying the present invention being applied to a metallic structural element;
FIG. 2 is a broken perspective view of such apparatus;
FIG. 3 is a side view of said apparatus being secured to the structural element;
FIG. 4 is a side view showing the appearance of said apparatus after it has been applied to a structural element;
FIG. 5 is a broken side elevational view taken in enlarged scale and particularly showing the end seals of such apparatus;
FIG. 6 is a horizontally exploded fragmentary view taken in further enlarged scale showing an end sealing arrangement which may be utilized with said apparatus;
FIG. 7 and 8 are views similar to FIG. 6 showing how the sealing rings are applied;
FIG. 9 is a horizontal sectional view taken on line 9--9 of FIG. 1;
FIG. 10 is a horizontal sectional view taken in enlarged scale along line 10--10 of FIG. 3;
FIG. 11 is a side elevational view showing how the apparatus of the present invention is applied to an H-shaped metallic structural element;
FIG. 12 is a view similar to FIG. 1, but showing a V-shaped element;
FIG. 13 is a view similar to FIG. 11, but showing the use of spacers with an H-shaped element where circular wrapping is not used;
FIG. 14 is a view similar to FIG. 13 but showing another form of spacer arrangement;
FIG. 15 is a horizontal sectional view taken in enlarged scale along line 15--15 of FIG. 11;
FIG. 16 is a vertical sectional view taken in cross-section along line 16--16 of FIG. 15;
FIG. 17 is a horizontal sectional view taken in enlarged scale along line 17--17 of FIG. 12;
FIG. 18 is a vertical sectional view taken along line 18--18 of FIG. 17;
FIG. 19 is a horizontal sectional view taken in enlarged scale along line 19--19 of FIG. 13;
FIG. 20 is a horizontal sectional view taken in enlarged scale along line 20--20 of FIG. 14;
FIG. 21 is a horizontal sectional view similar to FIG. 17, but showing a different configuration of the spacers;
FIG. 22 is a side elevational view showing how concrete, mastic, epoxies, or other sealing materials can be utilized to seal the lower end of an encasement of the present invention; and
FIG. 23 is a side view showing a seal between two modular units of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to the drawings and particularly FIG. 1 thereof, there is shown a metallic structural element M which is shown partially submerged in seawater to a level indicated at 40. A pliable water and airtight encasement E is shown being applied to a submerged portion of element M and the splash zone portion of such element above the submerged portion. The encasement E includes a substantially rectangular sheet of synthetic plastic material 41. A suitable synthetic plastic is polyvinyl chloride. Other similar materials, however, will prove satisfactory. The sheet 41 has a width throughout its length exceeding the corresponding circumference of the element M. The vertical edges of the encasement sheet E are stiffened or rigidly reenforced against bending by a pair of vertically extending pole pieces 46 and 48.
Referring now additionally to FIG. 2, both of the pole pieces 46 and 48 are semicylindrical and are formed of wood, metal, synthetic plastic or the like. The flat side of each pole piece is rigidly affixed as by the stapling or cement to its respective edge of the encasement sheet 41. The pole pieces 46 and 48 permit the sheet to be readily manipulated for placement around the structural element M. Along the flat sides of pole pieces 46 and 48 are attached strips 49 of polyurethane foam, polyether foam, neoprene foam, mastic or any other suitable material that, when compressed, will form a waterproof and air proof longitudinal seal. With the encasement sheet E partially wrapped around the columnar element M in the manner shown in FIG. 1., the lower ends of the pole pieces 46 and 48 are releasably joined by means of a lower socket 50 secured to the lower end of one of the pole pieces 46. Thereafter, the lower end of the other pole piece 48 is inserted in the socket 50 in a nonrotational manner. Next, the two pole pieces are brought together to define a substantially cylindrical unit.
Referring now to FIG. 3, the joined-together pole pieces may then be tightened by means of wrenches 52, such wrenches rotating the pole pieces about their vertical axes. During this tightening operation, the strips 49 will be compressed to form a longitudinal waterproof and air proof seal against the entry of corrosive media. Referring now to FIG. 4, thereafter a plurality of wrapping bands 53 are applied to vertically-shaped points along the encasement E to retain it upon the element M.
Upper and lower sealing bands are provided for the upper and lower edges of the encasement sheet E, such bands being designated 54 and 56 in FIGS. 1 and 3, and showing as bulges 54 and 56 in FIG. 3. These sealing bands 54 and 56 are wrapped about the structural element M at points corresponding to the upper and lower edge portion of the encasement sheet 41 when the latter has been installed upon element M. Such seal bands 54 and 56 are preferably formed of a material having physical characteristics such that it will have a memory and may be compressed to a fraction of its unconfined volume and thereafter it will exert a pressure in its attempt to regain its original uncompressed shape. Suitable materials are polyurethane foam, polyether foam, neoprene foam or other readily compressible materials with high resilience and with a memory such that they will continually exert a sealing pressure while compressed. It should be understood that the material of the upper and lower sealing bands are compressed by the encasement sheet 41 when the latter is installed.
Referring again to FIG. 4 and additionally to FIG. 5, the wrapping bands 53 are of like construction. Conveniently, these bands will take the form of a noncorrosive plastic, synthetic or metallic strap which is tightened about the element M by means of a suitable hand tool, and the ends of such band thereafter rigidly secured together by means of a clamp or clip 58. It will be apparent that other sealing arrangements may be utilized.
With the wrapping bands 53 in position, the encasement E will be firmly retained upon the element M. The upper and lower wrapping will serve to compress the upper and lower edge of encasement sheet 41 and the foam seal bands against the element E and in this manner effect a water and airtight seal at the upper and lower edges of the encasement E. Accordingly, the portion of the element M covered by the encasement E will be effectively sealed against contact with both seawater and air. Corrosion from these elements will thereby be effectively prevented.
Referring now to FIGS. 6, 7 and 8, the arrangement for sealing the end portions of the encasement E to the exterior surface of the element M is disclosed in detail. It will be noted from these drawings that the interior of the element M may be filled with concrete 60.
Referring particularly to FIG. 8, after the wrapping bands 53 have been tightened and wedged together by means of the clip 58, a tapered pin 62 may be driven through a bore 64 formed centrally through the clip 58 and an aligned bore 66 formed in the element M to be thereafter embedded in the concrete 60. This will provide effective securement for the wrapping band 53 to the element. The pin 62 may be formed of fiberglass or some other suitable noncorrosive material. Alternate commercial banding methods can also be used.
Referring now to FIGS. 11 and 15, there is shown a metallic structural element M-1 having a noncontinuous transverse cross-sectional configuration, i.e., said element is of generally H-shaped configuration. In order to provide a smooth, continuous exterior cross-sectional profile to receive the encasement E, a pair of filler blocks 68 and 70 are inserted between the opposed cavities 72 and 74 defined by the legs of the element M-1. The filler blocks 68 and 70 extend approximately the length of encasement E and may be formed of wood or any other suitable corrosion resistant material. If wood is used, it should be chemically treated to resist marine borers, dry rot and fungus decay in a conventional manner. Additionally, it should be noted that if wood is used, such wood may be covered with a suitable synthetic plastic such as polyvinyl chloride. The filler blocks could also be formed of molded, noncorrosive synthetic plastic.
The encasement E is generally similar to that shown and described hereinbefore, including pole pieces 46 and 48. As indicated in FIG. 15, however, the pole pieces are maintained against rotation by means of a noncorrosive nail or pin 76 which is driven through the pole and into one of the filler blocks 70. Wrapping bands 53 similar to those shown and described hereinbefore are employed to retain the encasement E in place on element M-1, with the upper and lower edges thereof sealed relative to such element by sealing bands such as those designated 54 and 56 hereinbefore. Alternatively, a sealant such as a conventional mastic may be employed.
Referring now to FIGS. 12, 17 and 18, there is shown a metallic structural element M-2 of generally V-shaped transverse cross-section. A longitudinally extending filler block 80 is provided for the space between the legs of the element M-2. This filler block 80 extends for approximately the length of the encasement E, such encasement E being similar to that shown and described hereinbefore. As with the form of the invention shown in FIGS. 11 and 15, the pole pieces are affixed to the filler block 80 by means of a nail or pin 76.
Referring now to FIGS. 13 and 19, there is shown a generally H-shaped metallic structural element M-1 similar to that shown in FIGS. 15 and 14. In this form of the invention, however, the filler blocks do not extend longitudinally a length approximating the length of the encasement E. Instead, filler blocks 84 are provided only at the upper and lower portion of the encasement E. These filler blocks 84 are of arcuate configuration and serve to define a cylindrical transverse cross-section for receiving seals and wrapping bands 53 at the upper and lower portions of the encasement E. A suitable sealant (not shown) is interposed between the outer curved edges 86 of the filler blocks 84. A suitable nail or pin 76 is driven through the pole pieces 46 and 48 into one of the filler blocks 84, as indicated in FIG. 19.
Referring now to FIGS. 14 and 20, a generally H-shaped structural element M-1 is again shown. In this form of the invention, however, filler blocks 90 having a profile similar to the filler blocks 84 are provided. However, the filler blocks 90 extend longitudinally the approximate length of the encasement E to form a cylindrical edge surface 91. A nail or pin 76 is again driven through the pole pieces 46 and 48 to secure such pole pieces to the element M-1. Suitable sealing means (not shown) are provided underneath the wrapping bands 53.
Referring now to FIG. 21, there is shown a metallic structural element M-2 of generally V-shaped transverse cross-section similar to that shown in FIGS. 12, 17 and 18. In FIG. 12, however, the element M-2 is shown provided with a pair of filler blocks 92 and 94 secured to the exterior surfaces of the legs of such element and a third filler block 96 of semicylindrical profile. The filler blocks 92, 94 and 96 cooperate to define a cylindrical edge surface 98 for receiving the encasement E. A nail or pin 76 is extended through the pole pieces 46 and 48 into the filler block 96.
Referring now to FIG. 22, there is shown a cylindrical metallic columnar element M which is driven into the earth 100 and extends upwardly through a body of water. The lower portion of an encasement E of the type described hereinabove the foam 54 and seal band 53, is covered with a hand-packed quantity of concrete or mortar 102 to assist in the sealing of the lower portion of the encasement E.
Referring now to FIG. 23, there is shown a sidewall of a metallic structural element M, provided with a pair of like upper and lower encasements E-1 and E-2, respectively. These upper and lower encasements define modular encasement units. The pole pieces 46 and 48 of the upper and lower encasement units E-1 and E-2 are sealed by means of a single foam seal band 104 and a pair of wrapping bands 53.
Various modifications and changes may be made with respect to the foregoing detailed description without departing from the spirit of the present invention. | Apparatus for protecting a partially or fully submerged metallic structural element against corrosion from water, air or a combination of both. A pliable watertight and airtight encasement is wrapped around the portion of the element to be protected. Seal means are utilized to seal the edges of the encasement against water and air. If the encasement is of an irregular shape, fillers are secured to the structural element, such fillers having a circular configuration, and the encasement is wrapped around the fillers. | 4 |
This application claims priority under 35 U.S.C. §§119 and/or 365 to No. 197 27 507.9 filed in Germany on Jun. 30, 1997; the entire content of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of electric drives. It refers to a control system for a drive having an asynchronous motor, in particular for a railroad vehicle, which control system comprises a first control loop for motor control and a second control loop, which is connected to the first control loop and has an adhesion controller.
Such a control system, in which the motor control is torque-based and the nominal torque for motor control is emitted by the higher-level adhesion controller on the basis of the rotation speed measured on the motor shaft, is known from the prior art.
2. Discussion of Background
In the case of electrically driven locomotives having torque-controlled drive motors in the form of asynchronous motors (ASM), wheel-slip situations can occur, in which the drive wheels spin to a greater or lesser extent in an uncontrolled manner. This results in unstable operation, in which the maximum possible traction between the wheel and rail is not achieved. At the same time, the drive wheels and the rails are subject to increased wear.
A large number of solution proposals as well as practically implemented methods exist to overcome the problem. One known torque-based control system is shown, by way of example, in FIGS. 1 to 4: the method is based on a cascade of two control loops, which can be seen in the schematic illustration in FIG. 1. The control system 100 comprises the process 104, the motor controller 103, the adhesion controller 102 and, possibly, an intermediate-circuit antiphase controller 101. For its part, according to FIG. 2, the process 104 comprises an invertor 108, which is connected on the input side via an intermediate-circuit capacitor 107 to a DC intermediate circuit 105 and is controlled via switching commands S R , S S and S T , and an asynchronous motor 113, which is supplied by the invertor 108 and, via a motor shaft 112, a gearbox 114 and a wheel 115, attempts to transmit power via appropriate friction to the rail 116. A rotation speed sensor 111 is fitted on the motor shaft 112, measures the rotation speed n shaft of the motor shaft 112, and emits this rotation speed n shaft to the control system for further processing. Other input variables required for the control system are two of the three phase currents i R and i S , which are tapped off from the supply cables via current sensors 109 and 110, as well as the intermediate-circuit voltage u d , which is measured by a voltage sensor 106 in the intermediate circuit 105.
The variables u d , i R ,s and n shaft obtained from the process 104 are fed back to the motor controller 103. By comparison with a predetermined dynamic nominal torque value M s ,nom, these variables are used in the motor controller 103 to derive the control commands S R ,S,T for the invertor 108, and to pass said commands to the process 104. The derivation is carried out, for example, in the starting range in accordance with the block diagram (illustrated in FIG. 3) of the so-called indirect self-control system ISR, as is known from the document Elektrische Bahnen [Electric railroads] 89(1991), Issue 3, pages 79-87: a so-called motor monitor 117, that is to say a computation circuit which contains models of the invertor 108 and of the asynchronous motor, uses the said input variables to calculate an actual stator flux value Psi act and an actual torque value M act for the asynchronous motor 113.
A flux controller 118 uses the difference between a predetermined nominal stator flux value Psi nom and the actual stator flux value Psi act to derive a stator flux correction value k Psi . A torque controller 119 uses the difference between a predetermined dynamic nominal torque value M s ,nom and the actual torque value M act to derive a dynamic nominal stator frequency f s ,nom which, together with a steady-state nominal stator frequency f T ,nom produces the nominal stator frequency f nom . The nominal stator frequency f T ,nom is obtained via an initial controller 120 from the nominal torque value M s ,nom and by superimposition of the rotation speed n shaft . A first calculation block 121 uses the input variables k Psi and f nom to calculate the change ΔPsi in the stator flux vector, and a second calculation block 122 uses this to calculate the voltage vector u of the motor voltage, while a downstream pulse-width controller 123 uses this to derive the necessary switching commands S R ,S,T for the invertor 108. In other rotation speed ranges, the variables are derived in a different manner, for example using the method of direct self-control DSR (once again, see the abovementioned document in this context).
The upper control loop described in FIG. 1 forms an inner control loop which allows highly dynamic control of the torque of the traction motor or motors. Superimposed on this is a second, lower control loop, which contains an adhesion controller 102. The adhesion controller 102 is intended to stabilize the drive in the case of varying friction conditions between the wheel 115 and the rail 116 and, if required, to attempt to find the traction maximum. For this purpose, it contains a traction force and slip controller as well as a device to search for the traction maximum. The interface between the two control loops is the dynamic nominal torque value M s ,nom and the measured rotation speed n shaft of the motor shaft, or of the rotor of the traction motor. The dynamic nominal torque value M s ,nom may in this case be composed of the steady-state nominal torque value M T ,nom emitted by the adhesion controller 102 and an additional torque correction signal M s ,ud from an intermediate-circuit connection, which is derived from the intermediate-circuit voltage u d by an additional intermediate-circuit antiphase controller 101 for damping oscillations in the DC intermediate circuit 105.
The superimposed second control loop, together with the adhesion controller 102, derives its information about the slip state from the rotation speed signal n shaft , and is therefore provided with good rotation speed detection. In the case of the known control system structure according to FIG. 1, it is thus disadvantageous that the control system generally fails at low traction speeds (low rotation speeds n shaft ) since, on the one hand, the rotation speed information in this range is inadequate (number of pulses per revolution) and, on the other hand, actual rotation speed sensors 111 have non-ideal characteristics (eccentricity, signal noise resulting from pulse tolerances etc.). In practice, a very high, undesirable maintenance cost is required to overcome these problems.
Furthermore, in order to achieve low-wear operation, active damping of the drive mechanism is required, since the mechanical spring/mass system of the drive generally has only very weak damping. Owing to the said non-ideal characteristics of the rotation speed signal n shaft , this is often not feasible, or is feasible only to an inadequate extent.
Finally, control methods using an impressed torque--as is shown in FIG. 4--are not able to use the falling branch of the wheel slip characteristic or traction characteristic A (power F plotted against the difference between the wheel and rail speeds dv) to set a stable operating point, for example for a power level F' and a speed difference dv nom , since the increasing rotation speed is no longer counteracted by a higher load torque. Stabilization by means of a rotation speed controller is extremely time-critical, and the unavoidable dead time in the rotation speed measurement stimulates oscillations about the operating point (dashed lines in FIG. 4).
SUMMARY OF THE INVENTION
Accordingly, one object of the invention is to provide a novel control system for a drive having an asynchronous motor, in which stable, low-wear operation is possible at any operating point in the region of the traction maximum, and which manages in particular to as great an extent as possible without rotation speed sensors.
In the case of a control system of the type mentioned initially, the object is achieved in that the motor control system is designed as a stator frequency control system, in that an actual torque value for the asynchronous motor is derived within the motor controller, and in that the two control loops are connected to one another in such a way that the actual torque value from the motor controller is used as the actual value for adhesion control, and such that the adhesion controller presets a nominal stator frequency value for motor control.
The essence of the invention is a new split in the coupling between motor control and adhesion control, which split is linked to a preset stator frequency (nominal stator frequency). This has the following advantage: during operation, the load torque which is generated by the friction process and acts on the wheels is provided with stochastic stimuli. The advantage of the asynchronous motor is its steep rotation speed/torque characteristic (characteristic K in FIG. 5, which is comparable to FIG. 4), which permits only small rotation speed changes (dv 1 →dv 2 ) for load torques (F 1 →F 2 ) which are varying severely. This characteristic is utilized by presetting the stator frequency according to the invention, and uncontrolled acceleration of the wheelset is no longer possible. In the dynamic situation, the rotation speed fluctuations are considerably less, and, in the steady state, a natural operating point is produced between the motor characteristic K and the traction characteristic A. This provides the precondition for the superimposed adhesion controller to be able to set and optimize the wheel/rail operating point without any limitations.
One preferred embodiment of the control system according to the invention is distinguished by the fact that a motor monitor is provided within the motor control system and uses models to calculate the actual torque value from a plurality of input variables, that the asynchronous motor emits its mechanical power on a motor shaft at a rotation speed, that the asynchronous motor is supplied with appropriate phase currents from a controllable invertor, that the invertor is connected on the input side by means of the intermediate-circuit voltage to a DC intermediate circuit, and that the motor monitor takes the rotation speed, the phase currents and the intermediate-circuit voltage as input variables for calculating the actual torque value.
Modern bogie drives have very light damping, by virtue of their design. Mechanical oscillations of the rotor are also always evident as oscillations in the machine torque. In modern motor control systems, the motor monitors calculate this torque with good resolution and dynamic response from the purely electrical variables of the current and voltage. The application to mechanical damping can thus, in this embodiment, be derived from the already existing torque signal, and allows active damping of mechanical torsional oscillations without evaluating the rotation speed signal.
One preferred development of this embodiment is distinguished by the fact that a mechanical antiphase controller for damping oscillations of the mechanical drive run is provided within the second control loop, wherein the mechanical antiphase controller has the actual torque value as an input variable, wherein the mechanical antiphase controller emits at the output a frequency correction signal from mechanical damping, wherein the adhesion controller emits at the output a nominal stator frequency value, and wherein the nominal stator frequency value emitted to the motor controller is produced by superimposing the nominal stator frequency value and the frequency correction signal from mechanical damping, and possibly a frequency correction signal from an intermediate-circuit connection.
Other embodiments result from the dependent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
FIG. 1 shows the control structure of a torque-based asynchronous motor drive control system with adhesion monitoring, according to the prior art;
FIG. 2 shows examples of details of the process 104 from FIG. 1;
FIG. 3 shows details of the motor controller 103 from FIG. 1, using the example of indirect self-control (ISR);
FIG. 4 shows the definition of the operating point on the wheel slip characteristic or traction characteristic for a torque-based asynchronous motor control system;
FIG. 5 shows the definition of the operating point on the wheel slip characteristic or traction characteristic for a stator-frequency-based asynchronous motor control system according to the invention;
FIG. 6 shows the control structure, comparable to FIG. 1, according to a first preferred exemplary embodiment, for a control system according to the invention;
FIG. 7 shows the details, comparable to FIG. 3, of the motor control system from FIG. 6, using the example of indirect self-control (ISR);
FIG. 8 shows details of the motor controller 103 from FIG. 1, using the example of direct self-control (DSR) in the weak-field region (high rotation speeds);
FIG. 9 shows the design, comparable to FIG. 8, for a stator-frequency-based motor control system according to FIG. 6;
FIG. 10 shows details of the motor controller 103 from FIG. 1, using the example of direct self-control (DSR) for medium rotation speeds;
FIG. 11 shows the design, comparable to FIG. 10, for a stator-frequency-based motor control system according to FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, FIG. 6 shows a preferred exemplary embodiment for a control system according to the invention in the form of a schematic control structure comparable to FIG. 1. The control system 140 once again comprises two control loops 141 and 142. The control loop 141 comprises the process block 104 and the block for the actual motor control, which is composed of a stator frequency controller 127 and a motor monitor 128. The control loop 142 is responsible for controlling the adhesion and comprises an adhesion controller 125, an intermediate-circuit antiphase controller 124, and a mechanical antiphase controller 126. According to the invention, the dynamic nominal stator frequency value f s ,nom and the nominal torque value M act (calculated by the motor monitor 128) are interchanged as signals at the interface between the motor controller and adhesion controller. The process block 104 comprises the control path with the invertor, traction motor (ASM), drive mechanism and wheel/rail contact. This is actuated by the motor controller switching commands S R ,S,T. The output signals from the process 104 are the known variables for managing the motor control process, namely the phase currents i R ,S, the intermediate-circuit voltage u d and the rotation speed of the motor shaft n shaft . The motor monitor 128 estimates the machine states that cannot be measured, such as the actual torque value M act and the actual stator flux value Psi act . The motor monitor 128 thus has the same task and the same design as the torque-based control method mentioned initially.
As already mentioned, the stator frequency controller 127 together with the motor monitor 128 represent the motor controller. The stator frequency controller 127 contains the high-dynamic-response control system for the stator frequency, the magnetization (the stator flux) and limitation of the machine torque. Hidden in the block are the various control algorithms for the voltage control range and field attenuation, which will be explained in more detail further below on the basis of the example, as well as the changeover between the methods. The stator frequency controller supplies the switching commands S R ,S,T as the output for the invertor.
The mechanical antiphase controller 126 is provided for active damping of torsional oscillations in the drive run. The resonant frequencies in the torsion mechanism are filtered out from the torque signal (input variable: actual torque value M act ) by presetting the stator frequency. The mechanical antiphase controller uses this to provide a frequency correction signal f s ,damp, and applies this signal to the nominal stator frequency value f T ,nom of the adhesion controller 125. The dynamic nominal stator frequency value f s ,nom resulting from this then provides active damping of torsional oscillations.
The intermediate-circuit antiphase controller 124 uses the intermediate-circuit voltage u d signal to derive a frequency correction signal f s ,ud, and likewise applies this correction signal to the nominal stator frequency value. This results in active damping of oscillations in the intermediate-circuit voltage. Such damping is particularly important for DC vehicles.
The described control blocks 124 to 128 ensure that an operating point preset by the traction controller can be used in a stable manner with a corresponding nominal traction force value F nom . In particular, this prevents slipping processes resulting from the steep gradient of the drive characteristic of the lower-level system (asynchronous motor with stator frequency control). It is thus possible for the higher-level traction control system no longer to have to influence the nominal stator frequency value f T ,nom in a highly dynamic manner and, instead of this, it is possible for it to concentrate on setting the optimum operating point.
The traction control system described in this way thus has two main tasks: if the engineer's traction force requirements are low, it operates as a traction force control system in that it matches the stator frequency to the vehicle speed. If the preset traction force F nom can no longer be achieved with insufficient traction, a search algorithm is activated. This varies the operating point in an attempt to reach optimum traction and to utilize conditioning effects from wheel/rail pairing. In this case, it is possible to use proven methods, such as those known from the document Elektrische Bahnen [Electric railroads] 91(1993), Issue 5, pages 163 et seq. In order to search for the traction maximum, it is possible, for example, to vary the stator frequency and to set the search direction on the basis of the torque reaction.
The stator frequency controller 127 from FIG. 6 has the object of controlling the speed on the track and the magnitude of the stator flux vector (stator flux space vector) Psi. In principle, any torque control method can be converted into stator frequency control for this purpose. However, it is necessary to draw a distinction between synchronous and asynchronous pulsing methods for the invertor. In the case of synchronous methods, the switching frequency is a multiple of the stator frequency. In contrast, the asynchronous methods are generally distinguished by the stator flux and torque being controlled independently. The magnitude or trajectory control of the stator flux space vector also has to be retained for stator frequency control. This leads to the vector on the envisaged path curve in the stator-fixed coordinate system (circle, hexagonal, 18-sided figure etc.), and ensures a stable operating point.
In the case of stator flux control with a circular path curve, the angular velocity is preset by the torque controller 119 for torque-based control (FIG. 3). For conversion to stator frequency control according to FIG. 6, the torque controller--as shown in FIG. 7--is eliminated and the dynamic nominal stator frequency value f s ,nom is preset directly by the adhesion controller (124, 125, 126 in FIG. 6).
In the case of synchronous methods, in which the switching frequency is a multiple of the stator frequency, as is the case, for example, with direct self-control (DSR) in the weak-field region, a change from torque-based control to stator-frequency-based control takes place as indicated in the case of the change from FIG. 8 to FIG. 9. In the case of torque-based control in FIG. 8, the motor monitor 129 calculates the stator flux vector Psi and the actual torque value M act . A flux calculator 130 uses the stator flux vector Psi to calculate the components in a fixed coordinate system, and these are then supplied to flux comparators 131 and compared with a nominal flux value Psi nom . A drive circuit 132 uses the resultant comparator signals to derive the required switching commands S R ,S,T for the invertor. The nominal stator flux value Psi nom is obtained by multiplying a rated stator flux value Psi rate by a flux correction value, which is produced by superimposing the output variables from a torque controller 133 and an initial controller 134.
In the case of the corresponding stator-frequency-based control system in FIG. 9, the torque controller and the initial controller are replaced by a stator frequency controller 135. The stator frequency controller 135 compares the actual stator frequency value f s ,act which, in the case of asynchronous clock pattern, is already known from the start or can be derived easily from the clock pattern, with the nominal stator frequency value f s ,nom and, instead of the torque controller, produces the necessary flux correction value, which is multiplied by the rated stator flux value Psi rate .
In the direct self-control (DSR) method, a two-point torque controller 137 is used, according to FIG. 10, to decide for a torque-based control system whether a torque-raising external voltage or a torque-reducing zero voltage is preset (traction mode). A clock frequency controller 136 compares the nominal clock frequency value f t ,nom and an actual clock frequency value f t ,act and on this basis sets the two-point hysteresis of the torque controller 137. In the case of stator flux control systems whose path curves are optimized to the switching frequency (for example which are hexagonal), the track speed of the flux space vector must be controlled in order to achieve the same torque response at the steady-state stator-frequency-controlled operating point as in the case of torque control. A two-point flux controller 139 is therefore used for the change to stator-frequency-based control according to FIG. 11, and this changes the track speed along a nominal value function which is predetermined by a nominal value sensor 138 within each sector. The nominal value sensor 138 takes account of the applied flux path curve (hexagon, 18-sided figure etc.) and the load dependency (distortion flux). The mean track speed, which results from the two invertor states of zero voltage and external voltage, is slaved to the desired nominal value within a tolerance band. The width of the tolerance band (two-point hysteresis) is once again predetermined by the clock frequency controller 136.
Overall, the control system according to the invention results in:
an improved dynamic response (that is to say more traction force, better damped mechanical oscillations in the drive mechanism, shorter control time); and
simplified introduction to service (fewer parameters, conceptually and physically better solution approach with stator frequency preset).
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
______________________________________LIST OF DESIGNATIONS______________________________________100 Control system (torque-based)101,124 Intermediate-circuit antiphase controller102,125 Adhesion controller103 Motor controller104 Process105 DC intermediate circuit106 Voltage sensor (intermediate-circuit voltage)107 Intermediate-circuit capacitor108 Invertor109,110 Current sensors (phase current)111 Rotation speed sensor (motor shaft)112 Motor shaft (ASM)113 Asynchronous motor (ASM)114 Gear box115 Wheel116 Rail117,128 Motor monitor118 Flux controller119 Torque controller120 Initial controller121 Calculation block (flux change)122 Calculation block (stator voltage)123 Pulse-width control126 Mechanical antiphase controller127 Stator frequency controller129 Motor monitor130 Flux calculator131 Flux comparators132 Drive circuit (invertor)133 Torque controller134 Initial controller135 Stator frequency controller136 Clock frequency controller137 Torque controller138 Nominal value sensor139 Flux controller140 Control system (stator-frequency-based)141 Control loop (motor control)142 Control loop (adhesion control)A Traction characteristicdv Difference between the wheel and rail speedsdv.sub.nom Nominal difference between the wheel and rail speedsF,F.sub.1,F.sub.2 Traction forcef.sub.s,act Actual stator frequency valuef.sub.s,nom Nominal stator frequency value (dynamic)f.sub.s,damp Frequency correction signal from mechanical dampingf.sub.s,ud Frequency correction signal from the intermediate-circuit connectionf.sub.T,nom Nominal stator frequency value from the adhesion controllerf.sub.t,act Actual clock frequency valuef.sub.t,nom Nominal clock frequency valueF.sub.act Actual traction force valueF.sub.nom Nominal traction force valuei Stator current vectori.sub.R,S Phase current (asynchronous motor)K ASM characteristic (steady-state)k.sub.Psi Stator flux correction valueM.sub.act Actual torque value (motor monitor)M.sub.s,nom Nominal torque value (dynamic/motor controller)M.sub.T,nom Nominal torque value (static/adhesion controller)M.sub.s,ud Torque correction signal (intermediate- circuit connection)n.sub.shaft Rotation speed (motor shaft)Psi Stator flux vectorPsi.sub.act Actual stator flux value (motor monitor)Psi.sub.rate Rated stator flux valuePsi.sub.nom Nominal stator flux valueΔPsi Change (stator flux vector)S.sub.R,S,T Switching command (invertor)u.sub.d Intermediate-circuit voltage______________________________________ | In the case of a control system (140) for a drive having an asynchronous motor, in particular for a railroad vehicle, which control system (140) comprises a first control loop (141) for motor control, and a second control loop (142) which is connected to the first control loop (141) and has an adhesion controller (125), an improved control response is obtained in that the motor control system is designed as a stator frequency control system (127), and in that an actual torque value (M act ) for the asynchronous motor is derived within the motor control system, and in that the two control loops (141, 142) are connected to one another in such a manner that the actual torque value (M act ) from the motor control system is used as the actual value for the adhesion controller (125), and in that the adhesion controller (125) presets a nominal stator frequency value (f s ,nom) for the motor control system. | 8 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of applicant's application Ser. No. 304,015, filed Sept. 21, 1981, now abandoned, which, in turn, was a continuation-in-part of applicant's application Ser. No. 108,485 filed Dec. 31, 1979, now abandoned.
BACKGROUND OF THE DISCLOSURE
The field of the invention is camshafts of the type used in automotive or truck engines and the invention relates more specifically to tools for facilitating the insertion of camshafts during the repair or rebuilding of an engine.
During the process of inserting a camshaft into an engine and especially during the insertion of a camshaft in a large diesel engine, there is a likelihood that one or more of the camshaft bearings will be damaged by contact with one of the camshaft lobes. The camshaft is fabricated from steel and the bearing material, being much softer than steel, is easily nicked if one of the lobes is permitted to drop against the bearing. Since a diesel camshaft can weight in excess of 100 pounds and is generally inserted horizontally during most replacement operations, it is difficult to hold the camshaft along the exact axial line of the bearings so that there would be no inadvertent contact between a camshaft lobe and a camshaft bearing. A second mechanic is usually necessary to support the camshaft and even then damage to the bearings is quite likely. Furthermore, the possibility of injury to the mechanic's hand is always present during this insertion.
SUMMARY OF THE INVENTION
It is thus an object of the present invention to provide a device for facilitating the insertion of a camshaft into an engine and reducing the likelihood that the camshaft bearings will be damaged by contact with the lobes of the camshaft.
The present invention is for an improved camshaft of the type having a plurality of journals. The improved camshaft has a removable sleeve positioned between at least one set of adjacent journals. The outer surface of the sleeve does not extend past the imaginary cylinder formed by joining the outer surfaces of the two adjacent journals. The sleeve is supported by the portion of the camshaft positioned between the two adjacent journals. The sleeve has at least a portion of its outer surface lying along a line parallel to the axis of the camshaft positioned near the imaginary cylinder so that the camshaft may be inserted through a plurality of camshaft bearings while being supported by the sleeve thereby reducing the possibility that the camshaft bearings will be damaged by contact with one or more of the camshaft lobes. After the camshaft has been inserted, the sleeve is removed and discarded or saved for future use. The present invention is also for the method of using the tool described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side-elevational view of the improved camshaft of the present invention inserted in an engine shown in phantom lines.
FIG. 2 is an enlarged fragmentary view of one end of the improved camshaft of FIG. 1.
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2.
FIG. 4 is a fragmentary exploded perspective view of the portion of the camshaft shown in FIG. 2.
FIG. 5 is a cross-sectional fragmentary view of a portion of an alternate configuration of the sleeve portion of the camshaft of FIG. 1.
FIG. 6 is an exploded perspective view showing one end of the camshaft of the present invention.
FIG. 7 is a cross-sectional view taken along line 7--7 of FIG. 6.
FIG. 8 is a perspective view of an alternate embodiment of the sleeve of the camshaft of FIG. 6.
FIG. 9 is a perspective view of an alternate embodiment of the sleeve of the camshaft of FIG. 6.
FIG. 10 is a cross-sectional view taken along 10--10 of FIG. 9.
FIG. 11 is a perspective view of an alternate configuration of the camshaft and sleeve assembly of FIG. 6.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a camshaft, generally indicated by reference character 10, is shown inserted in engine 11. Engine 11 is shown in phantom lines and the camshaft before insertion is also shown in phantom lines to the right of engine 11. After insertion, the camshaft is supported by camshaft bearings 12-16 which hold journals 17-21 of the camshaft 10. Camshaft lobes, indicated by reference 22, are conventional and positioned between the journals. The central shaft of camshaft 10 is indicated by reference character 23.
A first embodiment of the sleeve which facilitates the insertion of the camshaft has an upper half 25 and a lower half 26. The sleeve shown in the drawings has a cylindrical outer surface which is only slightly smaller in outside diameter than the outside diameter of the journals. The outside diameter of the sleeve should not be so large that it will bind in any of the camshaft bearings but should be large enough so that it covers the outside of each of the camshaft lobes. As is evidenced from FIG. 1 of the drawings, the camshaft having the sleeve comprised of sleeve halves 25 and 26 may be readily inserted through camshaft bearing 16 and after journal 17 has passed through camshaft bearing 16, the camshaft will be supported by lower sleeve half 26 until journal 17 has entered camshaft bearing 15. Similarly, lower half 26 will support the camshaft in camshaft bearing 15 until journal 17 has entered camshaft bearing 14. Although it is possible that each section of the camshaft may be protected by a sleeve, for some camshaft designs, the most important portion for protection is the first space equivalent to that shown in FIG. 1 between journals 17 and 18. Since this one sleeve will support that end of the camshaft which is inserted first into the engine, the other end of the camshaft, namely the end adjacent journal bearing 21 may, for some camshaft designs, be readily supported by the mechanic who is inserting the camshaft. Whether or not a single sleeve will support the leading end of the camshaft depends on the relative spacing between the journals on the camshaft. If the spacing is non-proportional and the distance between the first and second journals is shorter than the distance between another adjacent pair of journals, it is preferable to at least have a sleeve between the second and third journals.
The sleeve shown in FIGS. 1 through 5 is comprised of two-half cylinders shown best in FIG. 4 of the drawings. These half cylinders have a plurality of grooves which are positioned to accept and be supported by the lobes 22 of the camshaft.
While the sleeve shown in the drawings is supported both by the camshaft lobes and the shaft, it is possible that the sleeve could be fabricated to be supported entirely by the central shaft 23 of camshaft 10. Similarly, the sleeve could be supported by the lobes alone. It is important however that the sleeve be strong enough to support the weight of the camshaft when the camshaft is being inserted. Since the sleeve is used only during insertion and is removed after the camshaft has been inserted, it may be made from a relatively inexpensive material such as acrylonitrile, butadiene, styrene, terpolymer (ABS) or other thermo-plastic material such as polyvinyl chloride, impact polystyrene, nylon or the like.
Since the sleeve is only necessary for supporting the camshaft, it is not necessary that the sleeve completely surround the camshaft as shown in the drawings. That is, the sleeve could be comprised only of lower half 26 and still function satisfactorily as long as the sleeve was positioned in the lower or underside portion of the camshaft during insertion. The sleeve may be held to the camshaft merely by friction between the sleeve and the camshaft lobes as shown in FIGS. 2 and 3. Alternatively, the sleeve can be made from two sleeve halves such as shown in FIG. 5 and indicated by reference characters 30 and 31 which snap together and are held to the shaft in that way. Alternatively, the sleeve could be snapped on to the central shaft 23. For instance, the lower half 26 could have an extension member which would snap onto shaft 23 as shown in FIG. 9 and described below. Various configurations of sleeves which comprise only half of the circumference of the shaft are shown in FIGS. 6 through 11. In FIG. 6, sleeve 32 has a spring clip 33 is held to the bottom of sleeve 32 by a screw 34. Spring clip 33 is held in a groove 35 formed along the inner surface of sleeve 32. Sleeve 32 has two lobe receiving grooves 36 and 37. As shown in FIG. 7, sleeve 32 rests against lobes 22a and 22b and thus can readily support the end of camshaft 10 as it is inserted through the bearings of the engine. Spring clip 33 snaps around the shaft 23 and holds sleeve 32 securely in place.
An alternate means of holding the sleeve to the camshaft is indicated in FIG. 8. Sleeve 38 has a quantity of grease 39 deposited in the bottom thereof and as the sleeve 38 is pressed against the camshaft, the grease is spread out into grooves 40 and 41 and forms a seal which holds the sleeve in place during installation. Whatever method is used for holding this sleeve to the camshaft, the method should be such that the sleeve is readily removable after the camshaft has been inserted in the engine. The sleeve is accessible within the engine after installation since the engine is always disassembled during this operation.
As stated above, the sleeve may either support the camshaft by contact with the lobes, by contact with the shaft or by contact with both the lobes and the shaft. The configuration shown FIG. 9 is designed to support the camshaft by contact with the central shaft 23. Thus, sleeve 42 contacts the central shaft 23 at rings 43, 44, 45 and 46. Grooves 47 and 48 permit the lobes to be accepted but do not provide support. As mentioned above, the sleeve itself can hold the camshaft and ears 49, which are an integral part of sleeve 42, grasp the shaft 23 as shown in FIGS. 9 and 10.
An alternate method of holding sleeve 38 onto a camshaft as shown in FIG. 11. A removable band 50 rests in a groove 51 formed in the outer surface of sleeve 38 and surrounds shaft 23 of camshaft 10. Band 50 may be a rubberband which is slipped over the end of the camshaft and sleeve or may be a tie band such as a wire or plastic covered wire. After the camshaft has been inserted the sleeve 38 is removed by breaking the rubberband or by untying or breaking the band. It is of course important that band 50 not extend beyond the outer surface of sleeve 38 since this fits tightly through the bearings in the engine.
The sleeve of the present invention has another benefit when it is placed on the camshaft by the manufacturer before packaging. The sleeve helps prevent the rubbing off of corrosion inhibitors during shipping and handling, reducing the possibility of rust buildup on the cam lobes.
While the sleeve halves shown in the drawings are cylindrical and slightly smaller in outside diameter than the imaginary cylinder drawn between the outer surfaces of journals 17 and 18, the outside shape of the sleeve need not be cylindrical. For instance, only a portion of the lower half of sleeve 26 need lie near the imaginary cylinder between the outer surfaces of journals 17 and 18 and the sleeve would nonetheless be functional. It is only necessary that the sleeve have a support area which prevents the lobes 22 from contacting the camshaft bearings 12 and 16. This can be accomplished by the provision of sleeves of various shapes comprising obvious variants of the cylindrical sleeve shown in the drawings. The device of the present invention greatly reduces the time it takes to install a camshaft in an engine. A time study was made testing the device of the present invention to assist in the removal of a camshaft from an engine in the horizontal position. The time to remove the camshaft with the use of the tool was thirty-five seconds, whereas without the tool the time for the task was seven minutes. It would be impractical however for one man to remove a camshaft from an engine in the horizontal position without the present tool since damage to the bearings would be almost inevitable. Thus it is common practice for two men to remove a camshaft and the time which this task takes is two minutes and thirty seconds with two men. Thus the use of the device of the present invention greatly reduces the time for camshaft removal so that the removal by one man unassisted is still far faster than the conventional method. Similarly, installation time with the device of the present invention takes one man about thirty seconds. Installation is not practical by one man without the device of the present invention and the time required for two men without the device is about two minutes and twenty seconds. In addition to the time savings there is also a safety improvement. When two men are installing or removing a camshaft, it is quite easy for the mechanic who is supporting the camshaft within the engine to injure his fingers as he is trying to hold the camshaft as it is being passed through the bearings. This is completely eliminated with the device of the present invention since it requires no internal support.
The present embodiments of this invention are thus to be considered in all respects as illustrative and not restrictive; the scope of the invention being indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims therefore are intended to be embraced therein. | An improved camshaft having a plurality of journals with a removable sleeve positioned between at least one set of adjacent camshaft bearing journals. The sleeve has an outer surface which does not extend past the outer surface of the two adjacent journals and presents a continuous cylinder spanning the space between adjacent cam bearings thereby assisting in the insertion of the camshaft into an engine. After insertion into the engine, the sleeve is removed. | 8 |
BACKGROUND OF THE INVENTION
[0001] The present invention is directed toward food cooking ovens. More particularly, the present invention is directed to rotisserie ovens having horizontally and vertically oriented cooking elements.
[0002] Indoor household use rotisserie ovens are in wide use in the United States. Because most use hot electrical elements to radiantly cook foods such as meats, fish, foul, and vegetables; they commonly share cleaning problems associated with splattering, vaporizing, and recondensing of greases and oils. Cleaning typically is made yet more difficult by the presence of hard-to-reach areas such as nooks and crannies around heating elements. Further, grease may condense between inner and outer oven walls and in other inaccessible areas, potentially creating unpleasant odors and breeding grounds for bacteria.
[0003] Part of the problem is that most of these devices have twin, inner and outer, oven wall construction. Such construction does not allow these devices to be immersed in water for cleaning because water would collect in the spaces between the inner and outer walls. Immersion in water for cleaning is also prevented by the presence of integrally connected electrical components.
[0004] Many outdoor rotisseries have single thickness walls encasing their oven cavities. A particularly innovative embodiment of this outdoor construction uses a single thickness oven wall construction and removable electrical components. Such device relies on an outer frame to support the oven cavity and its electrical components. Consequently this device is more expensive to construct than a device which does not rely on an outer frame. In addition, the scale of this device appears to make it difficult to wash the oven cavity in a kitchen sink.
[0005] Other problems indoor household use rotisseries have include lack of versatility. As an example, horizontal spit countertop rotisseries, are good for cooking chickens, but are inappropriate for cooking pizzas. By contrast, horizontal turntable rotisseries, may cook pizzas, but are inappropriate for chickens. And none of these devices can cook breads.
[0006] It would be desirable to have a single device which cook a variety of foods and overcomes the aforementioned problems.
SUMMARY OF THE INVENTION
[0007] In accordance with the present invention, there is provided a cooking system which is able to cook a variety of foods.
[0008] In accordance with the present invention, there is provided an indoor use oven which has construction features and scale which make the cleaning process easier. Further, in accordance with the present invention, there is provided a cooking system which is able to rotate cooking foods about either a horizontal or vertical axis, which makes its application more versatile. The cooking system also provides apparatus for cooking breads and bread sticks. The cooking system of the present invention includes a scale appropriate for cleaning in a typical kitchen sink, use of removable electrical components and single oven wall construction, both to allow cabinet washing and/or immersion for cleaning, and a locking tab manufacturing detail which creates an inexpensive, light weight, oven cavity, which is easy to clean and also permits oven cavity washing and/or immersion in water.
[0009] Still further, in accordance with the present invention, there is provided cooking system. The cooking system comprises housing means defining an interior chamber, the housing means including an opening adapted to receive a food product into the interior chamber. The housing means further defines a port adapted to matingly receive a removable heating element therethrough. The cooking system also comprises door means adapted to selectively seal the opening and a control box. The control box includes a control box housing and an elongated, electrical resistance heating element secured to the control box housing so as to extend outwardly from an exterior therof. The control box also includes means adapted to selectively secure the control box housing to an exterior of the housing means such that the heating element is received through the port so as to extend into the interior chamber relatively proximate to a selected interior portion of the housing means and a motor. The control box further includes a mechanical coupling operatively engaged to the motor, which mechanical coupling is positioned so as to be adapted to provide a mechanical link therewith to an associated object disposed in the interior chamber and means adapted to selectively receive electrical energy into the at least one of the heating element and the motor.
[0010] In a preferred embodiment, the cooking system further comprises means adapted for securing, within the interior chamber, at least one rotatable member to the mechanical coupling so as to be linked therewith such that mechanical energy from the motor is transferred to the rotatable member through the mechanical coupling. In more preferred embodiment, the rotatable member is at least one of a rotisserie and a turntable for moving food associated therewith relative to the electrical resistance element when disposed in the interior chamber.
[0011] Preferably, the housing includes means adapted for receiving a drip pan therein, which drip pan is oriented so as to receive drippings from food disposed in the interior chamber while being heated by the heating element. In addition, the control box includes a settable timer adapted for selectively activating at least one of the rotatable member and the heating element for a selected duration.
[0012] In a preferred embodiment, the control box includes a settable timer adapted for selectively activating at least one of the rotatable member and the heating element for a selected duration. In addition, the control box includes a lighting element adapted to project light into the interior chamber when the control box is secured to the exterior of the housing.
[0013] Still other objects and aspects of the present invention will become readily apparent to those skilled in this art from the following description wherein there is shown and described a preferred embodiment of this invention, simply by way of illustration of one of the best modes suited for to carry out the invention. As it will be realized, the invention is capable of other different embodiments and its several details are capable of modifications in various obvious aspects all without from the invention. Accordingly, the drawing and descriptions will be regarded as illustrative in nature and not as restrictive.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The accompanying drawings incorporated in and forming a part of the specification, illustrate several aspects of the present invention, and together with the description serve to explain the principles of the invention. In the drawings:
[0015] FIG. 1 is a forward, upper, right hand perspective view of a preferred embodiment of the present inventions;
[0016] FIG. 2 is a right side perspective view of the preferred embodiment shown in FIG. 1 with a hand positioned to remove control box from oven cavity;
[0017] FIG. 3 is a forward, lower perspective view of the preferred embodiment shown in FIG. 1 , with control box being removed;
[0018] FIG. 4 is a right side perspective view of the preferred embodiment shown in FIG. 1 with back wall and floor removed to show construction details;
[0019] FIG. 5 is an enlargement of FIG. 4 as indicated in FIG. 4 ;
[0020] FIG. 6 is a left, upper perspective view of the preferred embodiment shown in FIG. 1 with its door slid under the oven cavity and vertical axis turntable being installed;
[0021] FIG. 7 is the same view as shown in FIG. 6 with turntable fully installed;
[0022] FIG. 8 is the same view as shown in FIG. 6 but with reflector installed;
[0023] FIG. 9 is the same embodiment shown in FIG. 8 but taken from a lower viewpoint;
[0024] FIG. 10 is a perspective view of the same embodiment shown in FIGS. 6 to 9 but with different turntable; and
[0025] FIG. 11 shows an upper left perspective view of part of spit assembly with the left axle exploded.
[0026] FIG. 12 shows a perspective view of a spit assembly used to cook bread and other farinaceous products.
[0027] FIG. 13 is a perspective view of the spit assembly shown in FIG. 12 with one end removed.
[0028] FIG. 14 is a perspective view of a spit assembly used to cook multiple breads and other farinaceous products simultaneously.
[0029] FIG. 15 is a perspective view of the spit assembly shown in FIG. 14 , but with both end portions removed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The present invention is directed to rotisserie ovens having horizontally and vertically oriented cooking elements. Referring to FIG. 1 , a preferred embodiment of the present invention is shown. The cooking system of the present invention is a metal enclosure 10 including an essentially horizontal metal floor 70 and metal roof 74 , a generally vertical metal back 72 , and two essentially vertical side walls, left oven wall 68 and right oven wall 56 , and a glass door 34 .
[0031] Spit assembly 20 is suspended within oven cavity 28 by spit supports 30 . Heating element 32 provides the heat to cook foods within oven cavity 28 . Spit supports 30 have forward rest positions 88 which provide the user an easy place to set down spit assembly 20 before sliding it into cooking position 90 . Spit supports 30 as well as heater support 66 are attached to oven cavity 28 walls by means of tabs 92 on the supports sliding into slots 94 located on the walls.
[0032] Drip pan 40 is covered by drip pan cover 42 , and in combination they function to catch grease and oils dripped from cooking foods. Drip pan cover 42 also functions to prevent fires which might occur by limiting the amount of oxygen that can reach fats and oils contained within drip pan 40 .
[0033] In operation, door 34 is lowered and slid beneath the unit as shown in FIGS. 6 to 9 described in detail below. The door is also suitably removed.
[0034] Control box 36 contains countdown timer 38 which turns off operation of the unit by any suitable means at a time preset by the user.
[0035] Feet rests 44 help stabilize a warming and heating tray (not shown) which is suitably rested on top of the unit.
[0036] Rails 46 provide support for the embodiment on a countertop as well as provide tracks to slide door 34 beneath oven cavity 28 . Rails 46 , by spacing oven cavity 28 off of a countertop, help prevent excessive heat from reaching such a countertop.
[0037] Door handles 47 provide a cool, easy to grasp handle for raising and lowering door 34 . The door handles also provide protection against breakage for glass panel 48 which comprises most of door 34 . The door handles are suitably comprised of PBS or other high temperature plastic. Glass panels, including tempered glass panels, are most vulnerable to breakage when impacted on their corners or edges. Or handles 46 by protruding beyond the corners, the forward and back surfaces, and the edges of glass panel 48 help protect against impact to corners and edges which might otherwise break glass panel 48 . Likewise, pivot pin 50 runs along the bottom of glass panel 48 and protrudes beyond both its lower corners, to provide similar protections as door handles 47 .
[0038] To facilitate both cleaning and use, dimension 22 is between 10½ inches and 16 inches. For similar reasons dimension 24 is between 9 inches and 14 inches, and dimension 26 is between 8½ inches and 14 inches. Such dimensions allow the embodiment to be cleaned in or around a kitchen sink, while still providing adequate interior space for cooking on a horizontal spit such popular foods such as: turkeys, chickens, roast beef, leg of lamb, and other common foods. It also allows a vertical axis turntable within the oven cavity which is sufficiently large to cook such foods as: pizzas, cookies, hors d'oeuvres, and other popular food items.
[0039] As shown in FIGS. 2 and 3 , control box 36 is rigidly connected to heating element 32 , and both may be pulled away from oven cavity 28 by gripping control box 36 in recesses 52 and 54 , and simultaneously squeezing latch 58 to uncouple control box 36 from right oven wall 56 .
[0040] Latch 58 is partially contained within upper recess 52 , and includes leaf spring 60 which may be pressed toward lower recess 54 by finger pressure. Such pressing moves cantilevered tip 62 of leaf spring 60 downward (arrow 53 ) within tapered hole 64 located on right oven wall 56 , and thus uncouples latch 58 from right oven wall 56 . This permits control box 36 and rigidly attached heating element 32 to be pulled away from right oven wall 56 as shown in FIG. 3 .
[0041] Heater support 66 provides support to heater element 32 and rigidly attached control box 36 when they are attached to right oven wall 56 . Heater support 66 also helps prevent warpage and distortion of heater element 32 when it is cooking. Both of these benefits are partially due to the free sliding movement of heater 32 within both upper hole 80 and lower hole 82 of heater support 66 which helps to compensate for expansion and contraction of heater 32 when it is heated and cooled in use.
[0042] Heater support 66 also helps direct the movement of heater element 32 and rigidly attached control box 36 when they are being attached to, or removed from, right oven wall 56 , as shown in FIG. 3 . This makes it much easier to install and remove control box 36 from right oven wall 56 .
[0043] Also helping in this; forward pin 76 and rear pin 78 , both of which from right rail 84 , project into forward hole 81 and rear hole 83 respectively, both holes located on the bottom of control box 36 . This pin-in-hole disposition also helps to support control box 36 when it installed on oven cavity 28 .
[0044] Ventilated heat resistant support 86 which is integrally attached to control box 36 , helps reduce the amount of heat reaching the interior of control box 36 .
[0045] Light 112 is part of control box 36 and is protected from breakage and from producing glare outside of oven cavity 28 by guard 114 . Light 112 illuminates food being cooked within oven cavity 28 .
[0046] Left oven wall 68 , right oven wall 56 , roof 74 , floor 70 , and back wall 72 may be of a single or multiple ply, and may be constructed of any appropriate material. As examples, they may be constructed from steel or aluminum or other metal or other materials such as high temperature plastics; any of which may or may not be coated with such materials as: electroplated metal, nonstick coating, paints or other finishes. They may also be fabricated using any appropriate method. As examples, they may be: stamped, drawn, molded, pressure formed, or otherwise constructed. Alternative construction techniques to those taught herein are well-known in the art and thus are not described in this document.
[0047] As a more specific example, perimeter walls 68 56 74 70 and 72 may be constructed from single ply 0.022 inch thick mild steel with a nonstick coated interior and a high temperature paint coated exterior. The outer shell for control box 36 might be molded from 0.120 inch mean wall thickness polypropylene plastic, with ventilated heat resistant support 86 constructed from stamped and drawn 0.022 inch galvanized steel painted on its exterior with heat resistant paint.
[0048] Perimeter walls 68 56 74 70 and 72 might be attached together as shown in FIGS. 4 and 5 . As illustrated, tabs 96 slide into and become aligned within slots 98 . Further, tabs 96 have resilient members 100 which lock tabs 96 within slots 98 merely by pushing tabs 96 into slots 98 . This has advantages of being: simple, extraordinarily strong, inexpensive, accurate, and consistently repeatable in manufacture, when compared against other manufacturing methods such as welding, screwing, riveting, or drawing. It also has the advantage of producing a relatively smooth and even finish detail which may be easy to clean and which may have no or few projecting sharp edges or points.
[0049] FIGS. 6 and 7 illustrate the installation of turntable 104 within oven cavity 28 . Drive gear 106 engages perimeter gear 108 of turntable 104 to provide rotary motion to turntable 104 whenever drive gear 106 is rotating. Thus, instead of drive gear 106 engaging gear teeth on spit assembly 20 to provide horizontal axis rotisserie cooking, drive gear 106 engages perimeter gear teeth 108 on turntable 104 to provide vertical axis rotisserie cooking. Such versatility allows for both vertical and horizontal axis rotisserie cooking with attended advantages already stated.
[0050] FIG. 6 shows removable stationery axil pin 110 installed in oven cavity 28 with turntable 104 being lowered onto stationery axil pin 110 . FIG. 7 shows turntable 104 after it has been fully installed.
[0051] As an alternative, turntable 104 could be powered by its own dedicated motor which could either be installed in the cabinet, as an example below the floor; or under turntable 104 . If such a motor were electrically powered, a low or high voltage electrical cord could go out around the door in the front, or go through the floor, or plug into the cabinet.
[0052] To help in cooking, reflector 116 may be introduced into oven cavity 28 . Reflector 116 rests on spit supports 30 and engages heating element 32 using tabs 118 . Tabs 120 engage cooking position 90 to limit fore an aft movement of reflector 116 . Reflector 116 helps even out the heat distributed radiated onto turntable 104 . Blocking/support member 122 which is attached to reflector 116 also helps make the heat directed onto turntable 104 even by blocking radiant heat emanating from heating element 32 which otherwise might burn food on the perimeter of turntable 104 . Blocking/support member 122 also connects and provides structure between reflector 116 and tabs 118 .
[0053] As already mentioned, several different foods may be cooked on turntable 104 . As examples, and not by way of any limitation, pizzas, cookies, cake layers, and hors d'oeuvres may all be cooked as well as many others known to those in the art. As further examples, and not by way of any limitation, American pancakes and flapjacks can be cooked. Also, French crepes may be cooked on turntable 104 . The crepes may be cooked directly on the flat upper surface of turntable 104 in a manner similar to making American pancakes, or, as shown in FIG. 10 , dome shaped turntable 124 may be used to cook the crapes, perhaps in the traditional French manner as known to those of the art.
[0054] Dome shaped turntable 124 may also be used for cooking meats and vegetables. Here, thinly sliced pieces of food may be placed on top of turntable 124 with a result that during cooking, greases and oils are shed from the food over the dome shaped cooking surface. To help in this, a torus shaped drip tray may be inserted around pin 110 . Projections from the upper surface of turntable 124 , including, but not limited to, an outer perimeter wall or dimples or projections in the domed surface, might help in stabilizing foods placed on the dome shaped surface to keep them from sliding off. A raised texture on the upper surface of dome shaped turntable 124 might also help in separating greases and oils away from food being cooked.
[0055] Referring to FIGS. 1 and 11 , and to U.S. Pat. Nos. 6,142,064 and 6,568,316 and associated patents, spit assembly 20 includes spit plate 126 , as well as axle pin 128 which is surrounded by cylindrical sleeve 130 . Cylindrical sleeve 130 is self lubricated and rotates independently of axil pin 128 . Axil pin 128 is integrally connected to spit plate 126 and captures cylindrical sleeve 130 between spit plate 126 and head 132 of axil pin 128 . When food is being cooked, cylindrical sleeve 130 rests into cooking position 90 of spit supports 30 . This arrangement helps reduce noises when spit assembly 20 is rotating including: squeaking, rubbing, and other noises.
[0056] Depending on specifics, such as ambient temperature, and greases, chemicals, and oils to which it might be exposed, cylindrical sleeve 130 might be fabricated from any of many different materials known in the art. Such materials include by way of example, and not by way of any limitation: Teflon, brass, self lubricated bearing materials, acetyl plastic or other materials known to those with knowledge of the art. As an even more specific example, Teflon provides both high heat resistance as well as resistance to chemicals, greases, and oils. It is also good at absorbing sound generated by movement.
[0057] Because it's removable and covers so much interior space, spit plate 126 on spit assembly 20 may be coated on inside surface 134 with a nonstick coating to make cleaning of oven cavity 28 easier. The unusual arrangement of having a large plate at one end of, or large spit plates on both ends of, spit assembly 20 means that it provides a substantial inner liner for oven cavity 28 . This inner liner, when coated with a nonstick coating, is easily removable and easy to clean. Outside surface 136 of spit plate 126 may also be coated with an easy to clean surface to facilitate cleanup. As described in earlier U.S. Pat. Nos. 6,142,064 and 6,568,316, spit assembly 20 may have two spit plates. Either or both spit plates on spit assembly 20 may be treated in the manner described above.
[0058] Referring to FIGS. 12 and 13 , a preferred embodiment spit assembly is shown which is used to cook breads and other farinaceous products. Cylindrical wire screen perimeter wall 150 is attached on one end to solid circular wall 152 which has cylindrical spit axil 154 at its center. Capping the other end of cylindrical wall 150 is removable cap 156 which is geared on its outer circular periphery, and which is penetrated on its face by holes 158 , 160 , 162 , and 164 . Wire protrusions 166 , 168 , 170 , and 172 which are connected to the open end of cylindrical wall 150 respectively protrude into each of these holes, and help secure and center removable cap 156 to cylindrical wire screen perimeter wall 150 . On the center of its face which is opposite cylindrical perimeter wall 150 , removable cap 156 has a second cylindrical spit axil which is not shown in the figures.
[0059] The preferred embodiment shown in FIGS. 12 and 13 may be constructed of any of a variety of materials known to those knowledgeable in the art. As an example, and not by way of any limitation, perimeter wall 150 might be constructed of aluminum screen of a window screen size match, with solid circular wall 152 constructed of stamped, 0.06 in. aluminum. Removable cap 156 might be constructed of steel, and coated with either chromium or a nonstick surface such as Teflon.
[0060] Wire protrusions 166 , 168 , 170 , and 172 , might be constructed of 0.1 in. chromium plated steel wire. Cylindrical axil 154 might be constructed of chromium or Teflon coated steel.
[0061] In operation, a user would remove cap 156 from perimeter wall 150 and insert an uncooked bread loaf. Cap 156 would then be replaced over the open end of perimeter wall 150 , and the entire assembly would then be placed in a rotisserie oven similar to that described earlier in this document. After cooking, the entire preferred embodiment would then be removed from the rotisserie oven, and removable cap 156 taken off to allow the then cooked bread loaf to be removed for serving.
[0062] The preferred embodiment shown in FIGS. 12 and 13 has at least the advantage that cooking is done evenly on all sides of the bread. Variants of the embodiment also appeared to cook breads significantly faster than use of a conventional oven.
[0063] FIGS. 14 and 15 show a preferred embodiment to cook breadsticks. Perforated cylindrical walls 174 , 176 , 178 , and 180 are lodged between spit plates 182 and 184 which cap each of the cylindrical walls' respective ends. Spit rods 186 and 188 suspend ands support cylindrical walls 174 , 176 , 178 , and 180 between spit plates 182 and 184 by means of penetrating intermediate support plates 190 and 192 as shown in FIGS. 14 and 15 .
[0064] In use, spit plate 182 is removed, thus opening the ends of cylindrical walls 174 , 176 , 178 , and 180 . An uncooked breadstick is then placed inside at least one of the cylindrical walls. Spit plate 182 is then replaced and the entire assembly placed into a rotisserie oven such as described earlier in this document. Here it is cooked. After cooking, the entire assembly is removed from the oven and spit plate 182 removed so that the cooked breadsticks can be removed for serving.
[0065] This preferred embodiment may be constructed using materials and techniques described for the previous preferred embodiment.
[0066] Besides being able to be used to cook breads as described, both of the above described embodiments may be used for other purposes. As examples, and not by way of any limitations, they may be used to: cook rolls and other shapes of bread, roast coffee beans, pop popcorn, roast nuts, or roast or cook other food articles.
[0067] What has been described herein are specific preferred embodiments of the present inventions. Many changes and variations will be easily derived from the descriptions contained herein by those knowledgeable in the art. As examples, and not by any way of limitation: embodiments might be constructed at any desirable scale; embodiments might be freestanding, without need of a countertop to support them; embodiments might have oven cavities of different shapes such as a cylinder on its side or a vertical cylinder; control boxes might be located on the top, bottom, or front of the embodiment; horizontal and/or vertical spits might utilize only a single rod, or might have more than two rods; the spit drive might utilize a socket coupled to the end of the spit rod to rotationally power the spit assembly; heating elements other than the rod type electric one shown might be utilized including gas or liquid powered elements or less conventional electric heating elements such as quartz or solid-state elements; or embodiments might be built into household ovens.
[0068] Such variations and many others would be readily apparent to one knowledgeable in the art and hence should be considered as obvious from the descriptions contained herein. | Indoor use rotisserie ovens which have construction features and scale which make the cleaning process easier. Shown are indoor use rotisserie ovens which also may rotate cooking foods about either a horizontal or vertical axis, which makes their applications more versatile. Construction features include: a scale appropriate for cleaning in a typical kitchen sink, use of removable electrical components, and single oven wall construction, all to allow easy cabinet cleaning. Also shown is a locking tab manufacturing detail which creates an inexpensive, light weight, oven cavity, which is easy to clean and also permits oven cavity washing and/or immersion in water. This manufacturing detail also is easy to handle by the end-user without projecting sharp edges. Self lubricated spit assembly axles are shown as well to help deaden sound. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates in general to an epoxy resin composition. More particularly, it relates to an epoxy resin composition containing a non-halogen, non-phosphorus flame retardant.
2. Description of the Related Arts
In recent years, environmental safety and in particular the air pollution has attracted worldwide attention. In this connection, electric and electronic appliances are required to be more environmentally friendly in addition to the requirement of high flame retardancy. To be more specific, the electric and electronic appliances are required to be resistant to flame and, at the same time, not to generate noxious gases. It has been customary in the past to use a glass/epoxy as a substrate of a printed circuit board on which electric and electronic appliances are to be mounted. In general, a brominated epoxy resin containing bromine as a flame retardant is used for forming the substrate of the printed circuit board.
The brominated epoxy resin certainly exhibits high flame retardancy. However, it generates noxious hydrogen bromide, polybromine dibenzofurans, and poybromine dibenzodioxins when burned. Moreover, antimony trioxide (Sb 2 O 3 ), a synergist commonly used in company with brominated epoxy resin has recently been labeled as a suspected carcinogen.
To overcome this difficulty, epoxy resin compositions containing non-halogen flame retardants such as nitrogen compounds, phosphorus compounds have been developed. However, these flame retardants have the disadvantage that, in the instance of fire, they disintegrate releasing corrosive and partly toxic compounds like nitrogen oxide and derivatives of phosphoric acid. Thus, changing the brominated flame retardants into phosphorus or nitrogen-containing flame retardants does not achieve the goal of an environmentally friendly retardant.
The present invention is intended to provide an epoxy resin composition which does not contain a halogen, phosphorus, or nitrogen element but exhibits good flame retardancy.
SUMMARY OF THE INVENTION
Therefore, an object of the invention is to provide a halogen-free epoxy resin composition containing a non-halogen, non-phosphorus flame retardant, which does not release corrosive or toxic compounds in the instance of fire and at the same time has good flame retardancy.
The above and other objects are achieved by providing an epoxy resin composition comprising:
(a) 100 parts by weight of an epoxy resin;
(b) 40-60 parts by weight of a phenolic novolac hardener; and
(c) 5-60 parts by weight of a silica-novolac hybrid resin solution as a flame retardant.
In the present invention, the silica-novolac hybrid resin solution (c) is a reaction product obtained by a sol-gel reaction between (c1) an organosilane and (c2) a phenolic novolac resin.
The flame-retardant epoxy resin composition of the present invention is suitable for application in printed circuit board industry to make environmental-friendly prepregs. Besides, the epoxy resin composition can find applications in other electronic industry as packaging materials.
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below.
The epoxy resin composition of the present invention contains a bisphenol A type epoxy resin as the component (a). As widely known to the art, the bisphenol A type epoxy resin is a reaction product between bisphenol A and, for example, epichlorohydrin. The bisphenol A type epoxy resin used in the present invention generally has an epoxy equivalent between 150 and 1000. The bisphenol A type epoxy resin used in the present invention is commercially available including, for example, EPIKOTE series manufactured by Yuka Sell Inc., Japan, and ARALDITE series manufactured by Ciba Geigy Inc. It is possible to use a single kind or a plurality of different kinds of the bisphenol A type epoxy resin in the resin composition of the present invention.
According to another aspect of the invention, the component (a) can be a mixture of a bisphenol A type epoxy resin and a novolac type epoxy resin. As widely known in the art, the novolac type epoxy resin is a resin obtained by a reaction between a novolac resin and epichlorohydrin. The novolac type epoxy resin used in the present invention should desirably have a softening point of 70-130° C., more preferably, 80-100° C. Such a resin is commercially available from, for example, Novolac epoxy series sold by Dow Company. It is possible to use a single kind or a plurality of different kinds of the novolac type epoxy resin in the resin composition of the present invention.
In the resin composition of the present invention, a phenolic novolac hardener is used as the component (b). The phenolic novolac resin is obtained by a condensation reaction between a phenolic compound and formaldehyde, which is carried out in the presence of an acidic catalyst. The phenolic compounds used for producing the novolac resin by the reaction with formaldehyde including, for example, phenol, cresol, and bisphenol A. The phenolic novolac resin used in the present invention has a molecular weight ranging from 100 to 30,000, more preferably, from 300 to 3,000. The phenolic novolac resin desirably has at least two phenolic hydroxyl groups in its molecule. It is possible to use a single kind or a plurality of different kinds of the phenolic novolac resin in the resin composition of the present invention.
The resin composition of the present invention contains a silica-novolac hybrid resin solution as a flame retardant (c). The silica-novolac hybrid resin solution is a reaction product obtained by a sol-gel reaction between (c1) an organosilane and (c2) a phenolic novolac resin. To be more specific, the silica-novolac hybrid resin is obtained by reacting a phenolic novolac resin with a nano-scale silica cluster derived from the organosilane, so that the phenolic novolac bonds to hydroxyl groups on the silica cluster to form a silica-based, multi-functional novolac resin.
The organosilanes (c1) used for producing the flame retardant of the present invention have the following general formula:
R 1 n Si(OR 2 ) 4−n
wherein n is 0, 1, 2, or 3; R 1 is alkyl having a terminal functional group selected from epoxy, alkenyl, amino, carboxy, or hydroxy; and R 2 is alkyl. Illustrative of organosilanes suitable for use herein are tetraethyl orthosilicate (TEOS), 3-aminopropyltriethoxy silane, and glycidyloxypropyltrimethyl silane.
The phenolic novolac resin (c2) is obtained by a condensation reaction between a phenolic compound and formaldehyde, which is carried out in the presence of an acidic catalyst. The phenolic compounds used for producing the novolac resin by the reaction with formaldehyde including, for example, phenol, cresol, and bisphenol A. The phenolic novolac resin used in the present invention has a molecular weight ranging from 100 to 30,000, more preferably, from 300 to 3,000. The phenolic novolac resin desirably has at least two phenolic hydroxyl groups in its molecule.
In carrying out the sol-gel reaction, the molar ratio of organosilane (c1) to phenolic novolac (c2) is preferably from 2 to 20, more preferably from 4 to 16. The reaction is suitably carried out in the presence of an acidic or basic catalyst such as hydrochloric acid, sulfuric acid, acetic acid, or ammonium hydroxide. The amount of the catalyst used is preferably in a range of 0.1-2 parts by weight, based on 100 parts by weight of the epoxy resin (a). The reaction is suitably carried out at a temperature ranging from 30 to 90° C., more preferably from 60 to 80° C.
The flame retardant of the present invention can form a supporting structure to support chars generated by phenolic novolac resins when burned, thereby separating inflammable components (e.g., epoxy resins) from heat.
The epoxy resin composition of the present invention may further comprise a curing accelerator (d) commonly used for accelerating the curing of an epoxy resin. To be more specific, the curing accelerator (d) includes, for example, imidazole compounds such as 2-ehtyl-4-methylimidazole and 1-benzyl-2-methylimidazole; and tertiary amines such as N′,N-dimethylbenzylamine (BDMA). These compounds can be used singly or in the form of a mixture. The curing accelerator should be used in a small amount as far as the accelerator is sufficient for accelerating the curing of the epoxy resin. The amount of the curing accelerator used is preferably between 0.1 and 1 parts by weight based on 100 parts by weight of the epoxy resin (a).
A prepreg can be manufactured from the epoxy resin composition of the invention by the ordinary method. Specifically, the resin composition is diluted with a suitable organic solvent to prepare varnish, followed by coating or impregnating a porous glass substrate such as a glass nonwoven fabric or a glass woven fabric with the varnish and subsequently heating the substrate to obtain a desired prepreg. Examples of suitable organic solvents for the dilution include N,N-dimethylformamide, acetone, isopropanol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, butanol, and methyl ethyl ketone. The prepreg thus obtained can be used for manufacturing a cooper-clad laminate, a multi-layered laminate, and a printed circuit board by conventional methods well known in the art.
Without intending to limit it in any manner, the present invention will be further illustrated by the following examples. In the examples, all parts and percentages are by weight unless otherwise specified.
PREPARATION EXAMPLE
A silica-novolac hybrid resin as a flame retardant was prepared by a sol-gel process as follows.
A mixture consisting of 100 parts of TEOS, 25.2 parts of polydimethylsilane (PDMS), 0.18 parts of hydrochloric acid, and 18.9 parts of isopropanol was stirred for 5 minutes, followed by addition of 18.9 parts of a phenolic novolac resin and 18.9 parts of propanol, and subsequently heating the resulting mixture at 60° C. for 60 minutes. Then, the reaction mixture was cooled at room temperature to obtain the desired silica-novolac hybrid resin solution.
EXAMPLE 1
66 parts by weight of methyl ethyl ketone (MEK) acting as a solvent was added to a mixture consisting of 100 parts of NPEL-128E (a bisphenol A type epoxy resin available from Nan Ya Plastics Corporation, having an epoxy equivalent of 184-190), 45 parts of a phoenolic novolac resin, 50 parts of the silica-novolac hybrid resin solution prepared in Preparation Example, and 0.3 parts by weight of 2-ethyl-4-methylimidazole, so as to prepare an epoxy resin varnish containing 65% of the resin solid component.
EXAMPLE 2
The same procedure as described in Example 1 was repeated except that 100 parts of NPEL-128E were replaced by 50 parts of NPEL-128E and 50 parts of Novolac epoxy 438 (a novolac epoxy resin available from Dow Company).
EXAMPLE 3
53 parts by weight of methyl ethyl ketone acting as a solvent was added to a mixture consisting of 100 parts of NPEL-128E, 42 parts of a phoenolic novolac resin, 100 parts of the silica-novolac hybrid resin solution prepared in Preparation Example, and 0.3 parts by weight of 2-ethyl-4-methylimidazole, so as to prepare an epoxy resin varnish containing 65% of the resin solid component.
EXAMPLE 4
The same procedure as described in Example 3 was repeated except that 100 parts of NPEL-128E were replaced by 50 parts of NPEL-128E and 50 parts of Novolac epoxy 438.
A glass cloth was impregnated with the epoxy resin varnish prepared in each of Examples 1-4, followed by drying the cloth to obtain a prepreg. Four prepregs thus obtained were evaluated for the flame retardancy according to UL-94. As shown in Table 1, all four prepregs exhibited an excellent flame retardancy of V-0.
TABLE 1
Composition
Ex.1
Ex.2
Ex.3
Ex.4
Epoxy 828
100
50
100
50
Novolac epoxy 438
0
50
0
50
Novolac
45
45
42
42
Flame retardant
50
50
100
100
Curing accelerator
0.3
0.3
0.3
0.3
MEK
66
66
53
53
Flame retardancy
V-0
V-0
V-0
V-0
While the invention has been particularly shown and described with reference to the preferred embodiment thereof, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the invention. | The present invention discloses an epoxy resin composition with a non-halogen, non-phosphorus flame retardant, which comprises (a) 100 parts by weight of an epoxy resin; (b) 40-60 parts by weight of a phenolic novolac hardener; and (c) 5-60 parts by weight of a silica-novolac hybrid resin solution as a flame retardant. | 7 |
TECHNICAL FIELD
This application relates generally to software application systems and more particularly to a software application system for loading software on demand.
BACKGROUND OF THE INVENTION
Computer systems often involve downloading applications and data from a server system for use on a client system. The applications or data may be downloaded only once and then stored on the client computer or they may be downloaded each time the application or data is used. In present application download systems, the client computer initiates a launch mechanism for a desired application, and the compressed bits for the entire application are streamed down from the server and onto the client system. The bits are then decompressed, installed, and executed. Such systems allow no overlap between download time and the execution. The client computer waits until the entire application has been downloaded before beginning execution of the program. Also, a client computer utilizes only about twenty percent of an application's total size during a typical user scenario. Thus, about eighty percent of the downloaded application code is unnecessary. While applications are typically cached after they are initially downloaded, the first time download wastes significant bandwidth resources. Also, the time for starting up many applications is extremely long for clients without high-speed connections to servers.
Some systems have used a process called paging, in which an application is split into pages of equal size and each page is downloaded as it is needed by the application. However, such systems often require download of code that is unnecessary because it happens to be on the same page as the requested code. This again wastes bandwidth resources and time. It may also have adverse effects on the operation of the application because the downloaded pages are not arranged in a logical manner.
SUMMARY OF THE INVENTION
In accordance with the present invention, the above and other problems are solved by supplying portions of program code or program data of a computer program as the portions are needed by the program. Rather than downloading and running an entire program on a computing system, the computing system runs a smaller program skeleton. The computing system generally downloads the portions of computer program and inserts them into the skeleton, as they are needed.
In accordance with other aspects, the present invention relates to a method of supplying program units of a computer program, as the program needs the program units. The program units are portions of program code or data of the program. The method includes running a program skeleton. The program skeleton is derived from the program, but has a program stub where a program unit associated with the program stub may be inserted. Upon encountering the program stub while running the program skeleton, the method includes getting the program unit associated with the program stub and inserting the program unit at the program stub in the program skeleton.
In accordance with still other aspects, the present invention relates to a method of supplying funclets of a computer program from a server computer system to a client computer system as the funclets are needed by the program. The method includes receiving a plurality of requests for funclets during a test period and determining whether a tested probability of requests for a first funclet being followed by requests for a second funclet is at least a predetermined probability. If the tested probability is at least the predetermined probability, then the method also includes sending the first funclet and the second funclet to the client computer system in response to a request from the client computer system for the first funclet after the test period.
The invention may be implemented as a computer process, a computing system or as an article of manufacture such as a computer program product or computer readable media. The computer program product may be a computer storage media readable by a computer system and encoding a computer program of instructions for executing a computer process. The computer program product may also be a propagated signal on a carrier readable by a computing system and encoding a computer program of instructions for executing a computer process.
These and various other features as well as advantages, which characterize the present invention, will be apparent from a reading of the following detailed description and a review of the associated drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a system for supplying software on demand according to a preferred embodiment of the present invention.
FIG. 2 illustrates a computing system, such as a system that can be used for the client and server systems of FIG. 1 .
FIG. 3 illustrates an operational flow for preparing an application for use with an embodiment of the present invention.
FIG. 4 illustrates a portion of an application, showing how that portion could be divided into funclets according to an embodiment of the present invention.
FIG. 5 illustrates an operational flow of three funclet divisions of an original program and the corresponding features of the resulting program skeleton and the resulting run time version of the program.
FIG. 6 illustrates an operational flow of an embodiment of the loading process.
FIG. 7 illustrates an operational flow of the initialization operation from FIG. 5 .
FIG. 8 illustrates an operational flow of the get and patch funclet operation from FIG. 5 .
FIG. 9 illustrates an operational flow of the working thread of a CLIENTSERVICE module according to an embodiment of the present invention.
FIG. 10 illustrates an operational flow of the working thread of a LDN.SVR module according to an embodiment of the present invention.
FIG. 11 illustrates the results of an optimization test for determining whether two or more funclets should be joined in a LDN according to an embodiment of the present invention.
FIG. 12 illustrates two funclets joined together in a LDN, such that a server will send both funclets in response to a request for the first funclet.
DETAILED DESCRIPTION OF THE INVENTION
The logical operations of the various embodiments of the present invention are implemented (1) as a sequence of computer implemented acts or program modules running on a computing system and/or (2) as interconnected machine logic circuits or circuit modules within the computing system. The implementation is a matter of choice dependent on the performance requirements of the computing system implementing the invention. Accordingly, the logical operations making up the embodiments of the present invention described herein are referred to variously as operations, structural devices, acts or modules. It will be recognized by one skilled in the art that these operations, structural devices, acts and modules may be implemented in software, in firmware, in special purpose digital logic, and any combination thereof without deviating from the spirit and scope of the present invention as recited within the claims attached hereto.
An embodiment of the present invention separates portions of operational code and/or data of a computer program to be downloaded into program units referred to herein as “funclets.” Funclets are preferably defined in accordance with the logic of a particular program so as to avoid downloading unneeded code or data and to optimize the performance of the program on the client system. Rather than downloading an entire program from a server system to a client system, a program skeleton is downloaded and the funclets from the program are downloaded as they are needed by the program, as described below.
Referring now to FIG. 1 , a software on demand system 10 includes a client system 12 and a server system 14 . The client system 12 receives or already has a program skeleton 20 , which includes the general binary code structure of a corresponding program. However, the majority of the code or data from the program is missing from the skeleton 20 . More specifically, the program skeleton 20 is missing the funclets. In place of each funclet is a program stub or binary stub, which includes a call to a LDRRT (loader run time) module 22 requesting the missing funclet. The program skeleton 20 will be significantly smaller than the original program. For example, in the use of a particular word processing application, the original program is 8.8 MB, while the resulting skeleton is only 225 KB. The LDRRT module is preferably a .DLL program. The client system 12 can have multiple program skeletons with each having a corresponding LDRRT module. Alternatively, a single LDRRT can correspond to multiple programs. The LDRRT module 22 is able to communicate with a CLIENTSERVICE module 24 in addition to communicating with the application skeleton 20 . The CLIENTSERVICE module 24 is preferably an executable program, although it may be some other type of program, such as a .DLL program.
The CLIENTSERVICE module 24 is able to communicate with an LDN (Loader.net) cache 26 . The LDN cache 26 is preferably a portion of the memory on the client system 12 . The LDN cache 26 contains funclets that have been downloaded previously onto the client system 12 . The CLIENTSERVICE module 24 is able to retrieve funclets from, save funclets to, or delete funclets from the LDN cache 26 .
The CLIENTSERVICE module 24 is also able to communicate with an LDN.SVR (Loader.net server) module 30 on the server system 14 . The LDN.SVR module 30 receives requests for funclets from the CLIENTSERVICE module 24 and retrieves the desired funclets from an LDN storage 32 . The LDN 32 is preferably a portion of a storage medium, such as a hard disc, on the server system 14 . The LDN 32 preferably includes all the funclets from the original program.
The computer systems 12 and 14 may be represented by the computer system 100 shown in FIG. 2 . In its most basic configuration, computing system 100 is illustrated in FIG. 2 by dashed line 106 encompassing the processor 102 and the memory 104 . Additionally, system 100 may also include additional storage (removable and/or non-removable) including, but not limited to, magnetic or optical disks or tape. Such additional storage is illustrated in FIG. 2 by removable storage 108 and non-removable storage 110 . Computer storage media, such as memory 104 , removable storage 108 or non-removable storage 110 includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Memory 104 , removable storage 108 and non-removable storage 110 are all examples of computer storage media. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by system 100 . Any such computer storage media may be part of system 100 . Depending on the configuration and type of computing device, memory 104 may be volatile, non-volatile or some combination of the two.
System 100 may also contain communications connection(s) 112 that allow the device to communicate with other devices. Additionally, system 100 may have input device(s) 114 such as keyboard, mouse, pen, voice input device, touch input device, etc. Output device(s) 116 such as a display, speakers, printer, etc. may also be included. All these devices are well known in the art and need not be discussed at length here.
Computer system 100 typically includes at least some form of computer readable media. Computer readable media can be any available media that can be accessed by system 100 . By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer readable media.
Referring now to FIG. 3 , before an application program is used with the software on demand system 10 , the original application 230 is processed in a binary preparation operation 232 , which preferably includes processing both binary code and data of the original application 230 . The binary preparation operation 232 is described in more detail in U.S. patent application Ser. No. 10/146,635 entitled “Preparation for Software on Demand System,” which is filed on even date with the present application and is incorporated herein by reference. The binary preparation operation 232 receives the original application 230 and yields the application skeleton 20 and the funclets 234 to be stored in the LDN 32 , all corresponding to the original application 230 .
The funclets 234 are preferably defined in accordance with the logic of the original application 230 . Each funclet 234 preferably has only a single entry point so that each funclet will have only a single corresponding binary stub. However, each funclet 234 may have multiple exit points. FIG. 4 illustrates a portion 240 of the process flow of the original application 230 . An entry operation 242 calls a query operation 244 , such as an “IF” operation. The query operation 244 may call either a first post-query operation 246 or a second post-query operation 248 . Upon completion, the active post-query operation 246 , 248 calls a common return operation 250 . As is shown, the query operation 244 and the first post-query operation 246 may be combined into a first funclet 260 because it is highly likely that entry into the query operation 244 will result in a call to the first post-query operation 246 based on the logic of the application 230 . The second post-query operation 248 defines a second funclet 262 , and the return operation 250 defines a third funclet 264 . By thus defining the funclets according to the process flow of the original application 230 , the downloading of unnecessary data or code is minimized. Note that the second post-query operation 248 and the return operation 250 would preferably not be included in a single funclet because the resulting funclet would have two entry points (one from the query operation 244 into the second post-query operation 248 and another from the first post-query operation 248 into the return operation 250 ).
Referring now to FIG. 5 , the original application 230 includes the first funclet 260 , the second funclet 262 , and the third funclet 264 . The binary preparation operation 232 replaces the first funclet 260 , the second funclet 262 , and the third funclet 264 from the original application 230 with a first binary stub 270 , a second binary stub 272 , and a third binary stub 274 , respectively. In a preferred embodiment, each binary stub 270 , 272 , 274 includes a call to the LDRRT module 22 and unused space filled with zeros to replace the missing funclet 260 , 262 , 264 , respectively. While running the application, the application skeleton 20 is loaded into run time memory, such as the RAM of the client system 12 . The application skeleton 20 thus forms the basis for a run time application 280 .
When a binary stub 270 , 272 , 274 is encountered in the run time application 280 , and the corresponding funclet 260 , 262 , 264 and preferably any dependent funclets (e.g., funclets which include only data and are referenced by code or data within the corresponding funclet 260 , 262 , 264 ) are retrieved and decompressed, the corresponding funclet 260 , 262 , 264 and any dependent funclets are “patched” into the run time application 280 . In other words, the binary stub 270 , 272 , 274 is replaced with a “jump” command and the corresponding funclet 260 , 262 , 264 and any dependent funclets. Thus, the retrieved funclet 260 , 262 , 264 is inserted in the same place in the run time application 280 as it was in the original application 230 . Accordingly, the performance of the run time application 280 is not hindered by the inserted funclets.
As shown in FIG. 5 , only the first binary stub 270 and the third binary stub 274 have been encountered during the present run of the run time application 280 . Thus, the first binary stub 270 and the third binary stub 274 have been replaced with the first funclet 260 and the third funclet 264 , respectively. The second binary stub 272 remains in the run time program because the second funclet 262 has not yet been retrieved to replace the second binary stub 272 .
Referring now to FIG. 6 , the operational flow of the software on demand system 10 of FIGS. 1–5 will be described generally. In initialize operation 306 , the particular client system 12 is initialized as described below with reference to FIG. 7 . In encounter stub operation 310 a binary stub 270 , 272 , 274 is encountered while running the run time application 280 . In get and patch operation 320 , the system 10 gets the funclet 260 , 262 , 264 corresponding to the encountered binary stub 270 , 272 , 274 and patches it into the run time application 280 as described below with reference to FIG. 8 . Return control operation 330 then returns control and the run time application 280 operates normally until it encounters another binary stub 270 , 272 , 274 .
When the run time application 280 is closed, the LDRRT module 22 for that application preferably closes and prompts the CLIENTSERVICE module 24 to also close its communications with that LDRRT module 22 . If no other LDRRT modules are running, the CLIENTSERVICE module 24 preferably closes at that time. However, many applications do not have closing operations that allow the LDRRT module 22 to inform the CLIENTSERVICE module 24 when the run time application 280 is closing. In fact, the run time application 280 and the corresponding LDRRT module 22 may simply disappear from run time memory when the application closes. The CLIENTSERVICE module 24 preferably detects the absence of the run time application 280 and the corresponding LDRRT module 22 . The CLIENTSERVICE module 24 then either closes down communications with that LDRRT module 22 or closes the CLIENTSERVICE module 24 altogether, as is appropriate.
Referring now to FIG. 7 , the initialize operation 306 will be described in more detail. When the application is started, the LDRRT module 22 for that application sends an initialization call to the CLIENTSERVICE module 24 in call to client service operation 340 . In query operation 350 , the CLIENTSERVICE module 24 determines whether the LDN cache 26 is present on the client system 12 . If the LDN cache 26 is not present, then the CLIENTSERVICE module 24 prompts the client system 12 to create the LDN cache 26 in cache create operation 360 . After either the cache has been created in cache create operation 360 or the CLIENTSERVICE module 24 has determined that the cache was already present in query operation 350 , return control operation 362 returns control.
The application can begin to run as soon as the initialization operation 306 described above is accomplished and the application skeleton 20 is loaded in run time memory (either after being downloaded or being loaded from memory or storage of the client system 12 ). In traditional systems, an application would not run until the entire application had been downloaded. The time to download the application skeleton 20 is significantly less than the time to download the entire application. Thus, the time savings from using the system 10 can be significant, especially when using large applications in downloading systems with slow connections.
Referring now to FIG. 8 , get and patch funclet operation 320 will be described in more detail. Call to LDRRT operation 410 calls the LDRRT module 22 with a request for a specific funclet 260 , 262 , 264 to replace an encountered binary stub 270 , 272 , 274 . Call to CLIENTSERVICE operation 412 then calls the CLIENTSERVICE module 24 with a request from the LDRRT module 22 for the desired funclet 260 , 262 , 264 . A cache query operation 414 determines whether the desired funclet 260 , 262 , 264 is in the LDN cache 26 .
If the cache query operation 414 determines that the desired funclet 260 , 262 , 264 is not in the LDN cache 26 , then a compose and send request operation 416 composes a request for the desired funclet 260 , 262 , 264 and sends it to the LDN.SVR module 30 on the server system 14 . In a preferred embodiment, the request is in HTML format and includes the identification of the skeleton and the identification of the requested funclet. A get funclet from LDN operation 418 gets the desired funclet 260 , 262 , 264 from the LDN 32 on the server system 14 . A pass funclet to CLIENTSERVICE operation 420 then transmits the funclet from the server system 14 to the client system 12 over a communications link. A receive funclet from server operation 430 receives the funclet within the CLIENTSERVICE module 24 of the client system 12 . A store funclet in cache operation 432 then stores the desired funclet 260 , 262 , 264 in the LDN cache 26 on the client system 12 . Preferably, the desired funclet 260 , 262 , 264 remains compressed when it is stored in the LDN cache 26 .
If the cache query operation 414 determines that the desired funclet 260 , 262 , 264 is in the LDN cache 26 , then a get funclet from cache operation 440 gets the funclet from the LDN cache 26 and passes it to the CLIENTSERVICE module 24 .
Whether the desired funclet 260 , 262 , 264 was retrieved from the LDN cache 26 or from the LDN 32 , a pass funclet to LDRRT operation 442 passes the funclet to the LDRRT module 22 that requested the funclet 260 , 262 , 264 . A decompress funclet operation 444 then decompresses the funclet, and a patch funclet operation 446 patches the funclet into the run time application, as described above with reference to FIG. 3 .
FIG. 9 illustrates the operation of a CLIENTSERVICE module 24 worker thread. The CLIENTSERVICE module 24 worker thread continuously circles between a grab operation 450 , a send operation 452 , and a receive operation 454 . The grab operation 450 pulls a request from a request queue containing requests for funclets that are waiting to be sent to the server system 14 ; the send operation 452 then sends the request that was previously grabbed to the server system 14 ; and the receive operation 454 receives a funclet from the server system 14 .
The grab operation 450 only grabs a request if one is available from the queue. If one is not available, then the thread continues to the send operation 452 without grabbing a request. If no request was grabbed in grab operation 450 , then the thread continues to the receive operation 454 without sending a request. Likewise, if a funclet is not available from the server system 14 during the receive operation 454 , then the thread proceeds to the grab operation 450 without receiving a funclet.
As funclets are received from the server system 14 , the CLIENTSERVICE module 24 is able to recognize the desired funclet and route it to the requesting LDRRT module 22 even if the funclets are received from the server system 14 in a different order than the requests for those funclets were sent. Also, the CLIENTSERVICE module 24 is preferably able to process requests from multiple LDRRT modules, and each LDRRT module 22 and the CLIENTSERVICE module 24 are preferably able to process requests from multiple threads of a single application.
FIG. 10 illustrates the operation of a LDN.SVR module 30 worker thread. The LDN.SVR module 30 worker thread continuously circles between a grab operation 460 , which pulls a request from a request queue containing requests for funclets that are waiting to be executed. A get operation 462 then gets a funclet corresponding to the request from the LDN 32 . A send operation 464 then sends the funclet to the client system 12 , where it is received by the receive operation 454 of the CLIENTSERVICE working thread.
The grab operation 460 only grabs a request if one is available from the queue. If one is not available, then the thread continues to the get operation 462 without grabbing a request. If no request was grabbed in grab operation 460 , then the thread continues to the send operation 464 without getting a funclet from the LDN 32 . Likewise, if no funclet was retrieved from the LDN 32 in get operation 462 , the thread proceeds to the grab operation 460 without sending a funclet.
The LDN.SVR module 30 is preferably able to process requests from multiple client systems and send the desired funclets to the client system 12 from which each request was received.
The server system 14 preferably performs tests to determine the probability that a particular funclet will be requested immediately following a request for another particular funclet. FIG. 11 illustrates the results of tracking a particular funclet for such a test. As shown, the server system 14 tracks the identity 470 of the subject funclet, shown in FIG. 11 as funclet 1 . The server system 14 preferably counts the total number of requests 472 for the subject funclet during the test. The server system then tracks the identity 474 of each follower funclet (i.e., a funclet that is requested immediately after the subject funclet), and the number of times 476 it has immediately followed the subject funclet (i.e., a request for the following funclet was received immediately following a request for the subject funclet). The server system 14 preferably determines whether a following funclet meets a predetermined minimum probability of being requested immediately following the subject funclet. As an example, the test might determine whether the probability of the following funclet immediately following the subject funclet is at least ninety percent. For the results illustrated in FIG. 11 , only funclet 2 would meet this test because it followed funclet 1 eighteen out of twenty times that funclet 1 was requested, indicating that the probability of requests for funclet 1 being followed by requests for funclet 2 is ninety percent.
As illustrated in FIG. 12 , once a following funclet 480 meets the probability test for the subject funclet 490 , the following funclet 480 is preferably included within the subject funclet 490 in the LDN 32 . Accordingly, every time the server system 14 receives a request for the subject funclet 490 , the server system 14 sends the following funclet 480 along with the subject funclet 490 . This increases the efficiency of the system 10 by predicting and filling requests before they are sent and thereby decreasing the number of requests that need to be sent and processed. Preferably, the testing described above is performed by the server system 14 during slow times when the server system 14 is receiving and processing few, if any, requests.
The probability of the following funclet 480 may later decrease so that it is no longer advantageous to send the following funclet 480 with the subject funclet 490 every time the subject funclet 490 is requested. Thus, preferably the server system 14 periodically removes the following funclet 480 from within the subject funclet 490 in the LDN 32 . Subsequently, the server system 14 again performs the test described above with reference to FIG. 11 . The server system 14 places the following funclet 480 back within the subject funclet 490 in the LDN 32 only if the following funclet 480 meets the probability test.
Although the invention has been described in language specific to computer structural features, methodological acts and by computer readable media, it is to be understood that the invention defined in the appended claims is not necessarily limited to the specific structures, acts or media described. As an example, it may be desirable to use the system 10 without the client system 14 having any cache at all, such as in a situation where storage resources on the client system 14 are limited. Also, it may be desirable for the server system 14 to monitor the number of times that the client computer runs a particular application. In this case, a header in a necessary funclet can prevent the client system 12 from caching that particular funclet. Thus, each time the client system runs the particular application, the client system 12 must request the necessary funclet from the server system 14 . The server system 14 can thereby monitor the number of requests for the necessary funclet. Therefore, the specific structural features, acts and mediums are disclosed as exemplary embodiments implementing the claimed invention.
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various other changes in the form and details may be made therein without departing form the spirit and scope of the invention. | A method of supplying program units of a computer program as the program needs the program units includes running a program skeleton. The program skeleton is derived from the program, but has a program stub where a program unit associated with the program stub may be inserted. Upon encountering the program stub, the method includes getting the program unit associated with the program stub and inserting the program unit at the program stub. A method of supplying funclets of a computer program from a server computer system to a client computer system includes receiving a plurality of requests for funclets during a test period. If a tested probability of requests for a first funclet being followed by requests for a second funclet is at least a predetermined probability, then the method also includes sending the first funclet and the second funclet to the client computer system in response to a request from the client computer system for the first funclet after the test period. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
This application is a divisional application of U.S. patent application Ser. No. 09/491,551, filed Jan. 26, 2000 now U.S. Pat. No. 6,678,406, the disclosure of which is incorporated by reference herein.
FIELD OF THE INVENTION
This invention relates to the processing of two-dimensional color images. More particularly, the invention relates to methods for assigning to each pixel of such an image a symbol representing a selection from a limited set of colors.
ART BACKGROUND
It is well known from studies of color perception that any color can be reproduced in a suitable display device as a combination of three primary colors. Thus, for purposes of image storage, transmission and display, it is convenient to represent the color of each pixel of a digitized image by specifying three coefficients, each representing the contribution from a respective primary color. Because human beings perceive a continuous range of colors, it would, in principle, require an infinite amount of information to specify any one particular color. That is, each of the three coefficients would be of unlimited length.
Such a representational system would of course be impractical. However, it has been found sufficient, for many purposes, to replace the continuous range of colors by a discrete set of colors. The specification of a discrete set of colors is referred to as “color quantization.” For example, a so-called full-color display system allocates eight bits to each of the three primary color coefficients. Therefore, each color in such a system is specified by a total of 24 bits, and the total number of specifiable colors is therefore 2 24 , or about seventeen million separate colors.
In fact, there are many applications in which an even smaller selection of colors suffices. Thus, for example, a string of fewer than 24 bits, typically of only 8, 12, or 16 bits, represents each displayable color in most currently available display monitors. Here, we refer to each such string as a “symbol.”
Typically, some subset of available colors, referred to as the “color codebook,” is selected from the full color set. The selection may be the same for all images, in which case the color codebook is said to be “image independent.” Alternatively, the selection may be specially adapted for individual images or groups of images. In that case, the color codebook is said to be “image dependent.”
Each symbol serves as an index into the color codebook, for retrieving a corresponding color. Thus, a given symbol does not necessarily bear a direct relation to the three primary color coefficients that would be used in a display to reconstruct the corresponding color. Instead, the information necessary for reconstruction would be retrieved from stored information.
In fact, the symbols in many conventional color codebooks are randomly assigned and bear no correlation with the underlying colors. As a consequence, the digital processing of color information in conventional systems cannot take place directly at the symbolic level. Instead, each symbol must be converted to a point in a multidimensional color space for processing.
By contrast, the “color” values of gray-scale images fall along a single axis, i.e., a one-dimensional space. As a consequence, each pixel of such an image is readily assigned a symbol that relates directly to the quantized gray-scale value of that pixel. Simple and computationally fast algorithms are available for performing spatial filtering and other processing of gray-scale images that have been color-quantized in such a manner.
Until now, however, there has lacked any method for quantizing color images that affords similar advantages of simple and computationally fast image-processing algorithms that operate, at least partially, in the symbolic domain.
SUMMARY OF THE INVENTION
We have invented a new method of color quantization. According to our method, a luminance value is selected from a discrete set of quantized luminance values, and a chrominance value is selected from an ordered discrete set of quantized chrominance values. A color symbol is composed from an index of the selected luminance value and an index of an ordinal position of the selected chrominance value, and the color symbol is stored.
In particular embodiments of our invention, the discrete sets of quantized luminance and chrominance values are obtained by quantizing a continuous three-dimensional color space. This is done, in effect, by partitioning the color space into planes of constant luminance, and sampling each resulting plane at a substantially uniform spatial distribution of discrete points.
Significantly, an order is imposed on the sampled points in each plane. Symbols are assigned to the sampled points. Each assigned symbol identifies the luminance level and the ordinality of the corresponding point in color space.
The resulting set of symbols bears a close relationship to the structure of the underlying color space. As a consequence, processing of the color information can be carried out, at least partially, at the symbolic level. This affords advantages of simple and computationally fast processing enjoyed hitherto only in the processing of gray-scale images.
Advantageously, the sampled three-dimensional color space is a space in which the Euclidean distance between two points corresponds to the perceptual difference in color between those points. Within each constant-luminance plane, the sampled points advantageously constitute a spiral lattice. In such a lattice, the radial position of the n'th point is a real power of n, and the angular position of the n'th point is a multiple of n given by 2πnγ, where γ is a real number, preferably in the vicinity of a Markoff irrational number. In specific embodiments of the invention, the spiral lattice is a Fibonacci lattice, i.e., a spiral lattice in which the radial position is given by the square root of n, and γ is approximately equal to
± 5 - 1 2 .
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an exemplary Fibonacci lattice useful in the practice of the invention in certain embodiments.
FIG. 2 is a detail of the Fibonacci lattice of FIG. 1 .
FIG. 3 is a flow diagram illustrating the steps of color quantization according to the invention in certain embodiments.
FIG. 4 represents a portion of a constant-luminance plane which is to be searched in accordance with the procedure of FIG. 3 .
FIG. 5 is a flow diagram of a color-averaging procedure according to the invention in certain embodiments.
FIG. 6 is a schematic diagram of one stage of an image coder that incorporates principles of the present invention.
FIG. 7 is a schematic diagram of a color coder that includes multiple stages of the kind illustrated in FIG. 6 .
FIG. 8 is a flow diagram of an exemplary procedure for applying color-quantization principles of the present invention to color data obtained from an image-capturing device.
DETAILED DESCRIPTION
It has long been known that perceivable colors can be represented as points in a three-dimensional space. One approach to such representation makes use of three so-called “tristimulus values” as the coordinates of a point representing a given color. The tristimulus values are related in a simple manner to three additive primary colors that, when combined with appropriate weights, produce the given color. Because the set of three primary colors is not unique, any particular system of tristimulus values must be related to the particular selection of primary colors. One example of a color space based on tristimulus values is the RGB color space.
Color spaces based on tristimulus values have certain advantages because, e.g., they can be used to describe the colors of images received from a scanner or images to be displayed on a printer, monitor, or other display device, with relatively simple intermediate processing. However, such color spaces are disadvantageous for representing human perception of colors, because they are not perceptually uniform. That is, human judgment of the difference between two colors does not correlate well with the Euclidean distance between points in such color spaces.
By contrast, color spaces such as Lab and Luv are perceptually uniform, because a given Euclidean distance between a pair of points represents a given perceptual distance, regardless of position within the space. Each of these spaces is characterized by a luminance axis L and a pair of axes (a,b or u,v, respectively) that represent chrominance. Roughly speaking, luminance relates to the brightness of an image element, and chrominance relates to its hue. The Lab and the Luv color spaces are described, e.g., in G. Wyszecki and W. S. Stiles, Color Science , John Wiley, New York, 1982. (See especially pages 164-169.)
Through known techniques, it is readily feasible to obtain the coordinates of a point in a perceptually uniform space such as Lab or Luv from the coordinates of a point representing the same color in a space, such as the well-known RGB space, that is based on tristimulus values. As will be appreciated by those skilled in the art, the respective spaces are related through a non-linear transformation that can be expressed in terms of a spatially dependent line element or metric. Such transformations are described, for example, in Wyszecki and Stiles, Color Science , cited above.
The exemplary implementation described below uses the Lab color space. Those skilled in the art will appreciate that extensions are readily made to other perceptually uniform color spaces such as the Luv color space.
As a first step in quantizing the color space, the luminance axis is sampled into N L discrete levels, N L an integer. Each discrete level has a respective index l and luminance value L l . The luminance index is exemplarily assigned by counting l=1, 2, . . . , N L , with the index 1 assigned to the lowest discrete luminance. Thus, each luminance index defines a respective plane of constant luminance L l .
In each plane of constant luminance, N p points are selected, N p an integer. The selection of points is carried out by constructing a spiral of the form:
r=sn δ
θ=2 πnγ+φ,
wherein r is the radial coordinate, θ is the angular coordinate, s is a scale factor (which may be 1), δ and γ are real numbers, φ is an offset angle (which may be 0), and n is a free parameter. A point is selected wherever n assumes an integral value from, e.g., 0 to N p −1. The resulting set of points constitutes a spiral lattice in the constant-luminance plane. The chrominance index of each point is, e.g., the value of n at that point.
Those skilled in the art will appreciate that both the radial coordinate and the angular coordinate can be subsumed into a complex-valued coordinate z, given by z=sn δ e j(2πnγ+φ) , where j 2 =−1.
Although an adequate color palette can be obtained with the scale factor s set to 1 and the offset angle φ set to 0, either or both of these can be set to other values. The scale factor can be adjusted for finer or coarser sampling of the colors in the plane. The offset angle can be adjusted, for example, to assure that points, rather than interstices, of the spiral lattice fall at colors of particular importance.
When the exponent δ is set to ½, the resulting spiral lattice covers the plane uniformly; that is, averaged over a sufficiently large region, there is a constant number of lattice points per unit area. If constant area coverage is not required, δ can be set to other values, and can even be made a function of position on the plane.
The factor γ is important for controlling the distribution of points in the lattice. If γ is a rational number expressed as a ratio of least integers, then as n climbs through values greater than the denominator of such ratio, the points of the spiral lattice will arrange themselves along spokes radiating from the origin. This is undesirable because it does not provide coverage of the plane that is uniform at a relatively fine level. Greater uniformity is achieved when γ is an irrational number, and particularly when γ belongs to the class of irrational numbers known to mathematicians as Markoff irrational numbers. As explained below, it is especially advantageous to choose for the value of ±γ a particular Markoff number, namely the golden ratio
5 - 1 2 .
(It should be noted that γ may assume positive or negative values. For simplicity, but not limitation, it will be assumed in the following discussion that γ takes on positive values.)
Of course infinite precision is not available in a computing machine for representing an irrational number. At best, any computational representation of an irrational number will actually be a rational number in the neighborhood of the irrational number, obtained from it by rounding or truncation. However, provided the denominator in the ratio representation of such a rational number is sufficiently large, the difference in effect upon the spiral lattice will be negligible.
Although the procedure described above will result in a three-dimensional lattice of N L ·N p points, not every point will necessarily correspond to a perceptible color. That is, only a limited region of, e.g., the RGB space contains valid colors. Thus, after constructing the lattice, we discard each point that does not represent a valid color. This is readily achieved, for example, by discarding each point whose r, g, or b coordinate in RGB space falls outside of the allowed range from 0 to 1. An exemplary color palette that we have used with good results has 139 points remaining after this discarding step.
We refer to the spiral lattice that results when s is constant, δ=½, and
γ = ± 5 - 1 2 ,
as a Fibonacci lattice. A Fibonacci lattice is shown in FIG. 1 . It will be evident from the figure that through each point of the lattice, it is possible to draw a pair of spirals, one clockwise and the other counterclockwise, that sink toward the origin (n=0). The index difference between successive points is 21 for the clockwise spiral and 13 for the counterclockwise spiral. For example, the figure shows clockwise spiral 15 and counterclockwise spiral 20 passing through the point n=5. We refer to these spirals as the “dominant spirals.”
It will also be evident from the figure that each point of the Fibonacci lattice has six nearest neighbors that form a roughly hexagonal neighborhood around the central point. Such a neighborhood, around the point n=22, is shown as neighborhood 25 in FIG. 1 . Greater detail of neighborhood 25 is shown in FIG. 2 , to which further reference is made below.
It will also be evident from FIG. 1 that the index difference between each point and each of its nearest neighbors is a Fibonacci number, i.e., a member of the well-known Fibonacci series 1, 1, 2, 3, 5, 8, 13, 21, 34, . . . . In FIG. 2 , for example, the index difference is shown between the point n=22 and each of its nearest neighbors. FIG. 2 shows that within neighborhood 25 , this index difference is 5, 8, 13, or 21.
We now introduce two parameters of the spiral lattice. The minimum distance d min is the Euclidean distance between the highest-index lattice point and its nearest neighbor along the larger dominant spiral, i.e., along the dominant spiral that has the greater Fibonacci number. Thus, for example, the highest-index point of the lattice of FIG. 1 is the point n=89. Of the two dominant spirals 15 and 30 that pass through the point n=89, the larger spiral is spiral 15 since the Fibonacci number of spiral 15 is 21, whereas the Fibonacci number of spiral 30 is only 13. The codebook minimum distance D min is defined by considering the Euclidean distances between all pairs of points of the underlying color space, e.g., the Lab space, sampled by the three-dimensional lattice and corresponding to valid colors. D min is the smallest such distance. Thus, D min is the smaller of: (a) d min ; and (b) the least distance along the luminance axis between adjacent constant-luminance planes.
Quantization Procedure
Given a pixel p whose color coordinates in the Lab space are L p , a p , b p , it is advantageous to quantize the color of pixel p by finding the lattice point having the least Euclidean distance from the point in the Lab space having those given coordinates. Such quantization is an example of what is known as total square error (TSE) quantization.
An exemplary quantization procedure will now be described with reference to FIG. 3 . The Lab coordinates of the input point are obtained (block 100 ). Then the discrete luminance level nearest L p is found (block 105 ). Let the selected level have luminance value L and luminance index l. Then a search is carried out (block 110 ) for the lattice point in the selected constant-luminance plane that has the smallest TSE, i.e., that lattice point having the least Euclidean distance to the projection of the point (L p , a p , b p ) onto the selected plane.
The properties of the Fibonacci lattice are advantageously used to confine the search to a limited portion of the plane, and thus to shorten the computational time that would otherwise be required to carry out the search. Specifically, as indicated in FIG. 4 , it is sufficient to limit the search region 120 to a ring around the origin having a middle radius of approximately r p =√{square root over (a p 2 +b p 2 )} and a width slightly larger than d min . Thus, the ring inner radius may be taken as r p −αd min and the outer ring radius as r p +βd min , where α and β are adjustable parameters, exemplarily both of value 0.5. Because of the order in which the points of the spiral lattice are indexed, and because the radial coordinate is related to the index such that n=(r/s) 2 , it is sufficient to search over only those points whose indexes range from the closest integer at or below (r p −αd min ) 2 /s 2 to the closest integer at or above (r p +βd min ) 2 /s 2 . Moreover, the search is readily limited to an angular sector of the ring. For example, it is advantageous to limit the search to those lattice points whose angular coordinates lie within the same quadrant as the angular coordinate of the point (a p , b p ).
After the quantized luminance and chrominance indices are determined, they are readily combined into a color symbol, as indicated at block 115 of FIG. 3 . One useful form for such a symbol is an ordered pair or multiplet comprising the luminance and chrominance indices. However, a form which in many cases will be more useful because it is more compact is a weighted sum of the luminance and chrominance indices. For example, let N p denote, as above, the number of points in each spiral lattice before discarding invalid colors. Let l and n denote the luminance and chrominance indices, respectively. Then one useful form for the color symbol is N p l+n. From the knowledge of N p , both l and n are readily extracted from a color symbol of this form.
Ordered Dithering
It has long been known that when broad image areas perceived to have constant color are quantized, the reconstructed image, using quantized colors, tends to exhibit false contours that interrupt the constant-color areas. The reason for this is that quantization algorithms will generally ignore a small (and thus imperceptible) color gradient until the accumulated change in color exceeds a threshold. Then, a new color value is assigned. As a result, a perceptible gradient appears in the reconstructed image between the sub-threshold and the supra-threshold regions. It has also been recognized that false contouring can be suppressed by quantizing, in place of the original image, an intermediate image to which random, or pseudorandom, noise has been added. Such a process of adding noise is referred to as ordered dithering.
Ordered dithering is readily integrated into our quantization procedure. To form the intermediate image, a matrix D of noise amplitudes ν(i,j) is added to the original image. D is exemplarily a square matrix of some dimension M. The noise amplitude added to pixel i,j of the original image is ν(i mod M,j mod M). The distribution of noise amplitudes desirably has zero mean, and its energy spectrum desirably has its minimum at the lowest spatial frequencies. The amplitude of the noise is selected such that areas of constant color are quantized into a variety of neighboring colors, thus reducing the appearance of false contouring.
In the context of our approach to color quantization, noise is readily added simply by substituting quantized colors in randomly selected pixels. That is, in each selected pixel, the original point of the color lattice is replaced by a neighboring point. Typically, the new point will be one of the Fibonacci neighbors, i.e., one of the two nearest neighbors along each of the dominant spirals (thus, four in all); a point on an adjacent constant-luminance plane that lies directly above or below a nearest neighbor along a dominant spiral; or a point on an adjacent constant-luminance plane that lies directly above or below the original point. Thus, the corresponding noise amplitudes ν(i,j) are readily determined from the lattice parameter d min or the lattice parameter D min , both defined above. Significantly, color substitutions at the same luminance value are readily performed by simply adding to or subtracting from the chrominance index the Fibonacci number corresponding to one of the dominant spirals.
Difference and Average of Two Color Values
Computation of the Euclidean distance between two points of the three-dimensional lattice is simplified because of the relationship between the radial coordinate r and the index n. Thus, the projections of a pair of lattice points of respective chrominance indices m and n onto a common constant-luminance plane are separated by a Δ mn given by Δ mn =s[m+n−2√{square root over (mn )} cos [2π(m−n)γ]] 1/2 . A luminance difference Λ mn is readily obtained from the respective luminance values L m , L n according to Λ mn =[L m −L n ] 1/2 . A total difference diff(m, n) is then readily obtained as diff(m,n)=√{square root over (Λ mn 2 +Δ mn 2 )}. Various alternative difference formulations are readily definable. In many cases, however, it will be useful to define the total difference as a combination of luminance and chrominance differences, and it will often be useful to define the luminance difference as a function of L m −L n , or of the absolute value thereof.
A difference formulation Diff(m, n) that is especially useful is obtained by normalizing diff(m, n) to the lattice parameter D min , defined above. That is,
D iff ( m , n ) = d iff ( m , n ) D min .
The difference formulation Diff(m, n) may be understood as the least number of steps on the lattice required for a path between the m'th and n'th points.
When gray-scale images are processed, an average of two gray-scale values is readily obtained by, e.g., taking the mean of the two values and rounding to the nearest integer. However, such an averaging procedure is not generally satisfactory when applied directly to color symbols in a three-dimensional, quantized color space. In particular, the rounded mean of a pair of chromaticity indices may be the index of color value relatively distant from both of the colors that were to be averaged.
One solution to this problem is to compute the mean between corresponding points in the underlying Lab space, and then to quantize the result as explained above. The values of the Lab coordinates needed for such a computation may be stored locally in, e.g., a look-up table, or they may be computed from the quantized values of the colors that are to be averaged.
An alternative solution uses the structure of the Fibonacci lattice. According to the alternative solution, we define a new average av(m, n) between colors indexed m and n, respectively. Our new average applies only to chrominance. The corresponding luminances can be averaged by, for example, taking the mean of the luminance values and quantizing to the constant-luminance plane nearest the resulting mean value.
The alternative solution for chrominance averaging will now be described with reference to FIG. 5 . The average av(m, n) is defined by
a v ( m , n ) = 1 2 ( m ′ + n ′ ) ,
where m′ and n′ are points of the Fibonacci lattice selected as explained below.
As indicated at block 125 , the initial settings for m′ and n′ are m and n, respectively. An initial determination (block 130 ) is made whether m and n have the same parity. The two indices will have the same parity if both are odd or both are even.
If one of m and n is odd and the other even, one of the two indices must be replaced by a neighbor of opposite parity. In this regard, a neighbor of a given point is a Fibonacci neighbor, i.e., one of the following: one of the two nearest neighbors along each of the dominant spirals (thus four in all); a point on an adjacent constant-luminance plane that lies directly above or below a nearest neighbor along a dominant spiral; or a point on an adjacent constant-luminance plane that lies directly above or below the original point.
To minimize the distance between the original quantized color and its substitute, it is advantageous first to attempt to substitute the original lattice point having the larger index, as indicated by blocks 140 and 145 of the figure. The lattice point to be substituted, unless it lies at the outer edge of the lattice, will have two nearest neighbors on each of the dominant spirals that pass through it. Of these four neighbors, the closest acceptable neighbor should be chosen (block 160 ). If no neighbor is acceptable (corresponding to the negative outcome of the test in block 155 ), then the original lattice point having the smaller index is considered in the same way for substitution, as indicated in block 150 .
If there is no substitution, then the candidate lattice points for averaging are the original lattice points. If substitution takes place, the candidate points are one original and one substituted point or, as explained below, two substituted points.
The mean index is then taken by summing the indices of the candidate lattice points and dividing by two. Block 165 illustrates this step for substituted points, and block 175 illustrates this step for unsubstituted (i.e., original) points. Because the candidate lattice points at this step necessarily have the same parity, their sum is even and their mean is an integer, and thus the mean is an index of a point of the lattice. However, the resulting mean index may or may not lie within an acceptable angular range. That is, the angular coordinates of the original lattice points define a closed angular range (i.e., the smaller angular range between the two lattice points, not exceeding 180°), and the mean index is acceptable only if it has an angular coordinate lying on that range. If the angular coordinate of the mean index lies outside of that range, the mean index is rejected, as indicated by the negative outcomes of the tests in blocks 170 and 180 .
Several options are available if the mean index is rejected. One option is to discard the current substitution as indicated at block 172 , return to the original lattice points, and to try a new substitution. If no single-point substitution results in an acceptable mean index, as indicated by the positive outcome of the test in block 135 , then double substitution is attempted, as indicated at block 185 .
A second option is here referred to as the “rewind” procedure. According to the rewind procedure, a search of the constant-luminance plane is carried out within a ring-shaped region containing the radius at which lies the lattice point having the mean index. The search is limited to the smaller angular range (i.e., the range that does not exceed 180°) defined by the two original lattice points. The inner and outer radii of the ring-shaped region are determined, for example, as for the quantization procedure described above. The object of the search is to find the lattice point, within the acceptable angular range, whose radial coordinate is nearest the radial coordinate of the mean-index lattice point.
Gradient Operators and Edge Detection
In the processing of gray-scale images, edges are readily detected by evaluating a gradient between pixel values in a given neighborhood. However, it is much more difficult to devise an acceptable edge detector for color images. The difficulty arises because three dimensions, and not simply the single gray-scale dimension, are required to describe color, and because human perception tends to place edges differently for different color components of the same image. However, by using the difference operator diff(m, n) defined above, we have found a simple way to extend conventional gray-scale gradient operators for the processing of color images. Significantly, our extended gradient operators operate directly on the color symbols, i.e., on the luminance and chrominance indices, and thus they are relatively economical in the use of computational resources.
One example of a conventional horizontal gradient operator H x and vertical gradient operator H y takes the form of the pair of 3×3 windows below:
H x = [ - a 0 a - b 0 b - c 0 c ] , H y = [ - a - b - c 0 0 0 a b c ]
Each of these operators is scanned across the image. At each position in the scan, nine pixels of the image are overlain by corresponding elements of the operator. At each position in the scan, the gradient at the pixel underlying the element in the second row and second column of the operator is evaluated as a weighted sum. The gray-scale value of each pixel overlain by an element is weighted by that element and added to the sum. The weights a, b, and c may take on various values, depending on the class of operator that is used. For example, (a, b, c) for the Prewitt operator is (1, 1, 1); for the Sobel operator it is (1, 2, 1), and for the isotropic operator it is (1, √{square root over (2)}, 1). Thus, at a pixel location (i, j), wherein i denotes the row of the image where the pixel lies and j denotes the corresponding column, the horizontal gradient g x (i,j) is given by
g x ( i,j )= a[I ( i −1 ,j +1)− I ( i −1 ,j −1)]+ b[I ( i,j +1)− I ( i,j −1)]+ c[I ( i +1 ,j +1)− I ( i +1 ,j −1)] a
nd the vertical gradient g y (i,j) is given by
g y ( i,j )= a[I ( i −1 ,j −1)− I ( i +1 ,j −1)]+ b[I ( i −1 ,j )− I ( i +1 ,j )]+ c[I ( i −1 ,j +1)− I ( i +1 ,j +1)]
where I(i,j) denotes the gray-scale value at pixel (i,j).
For the color image, having color symbol P(i,j) at pixel (i,j), we define analogous color gradient operators {tilde over (g)} x (i,j) and {tilde over (g)} y (i,j) by:
{tilde over (g)} x ( i,j )= a ·Diff[ P ( i −1 ,j +1), P ( i −1 ,j −1)]+ b ·Diff[ P ( i,j +1), P ( i,j −1)]+ c ·Diff[ P ( i +1 ,j +1), P ( i +1 ,j −1)];
{tilde over (g)} y ( i,j )= a ·Diff[ P ( i −1 ,j −1), P ( i +1 ,j −1)]+ b ·Diff[ P ( i −1 ,j ), P ( i +1 ,j )]+ c ·Diff[ P ( i −1 ,j +1), P ( i +1 ,j +1)].
The corresponding vector gradient has a magnitude
g ~ ( i , j ) = g ~ x 2 ( i , j ) + g ~ y 2 ( i , j )
and a direction
θ ~ ( i , j ) = tan - 1 g ~ y ( i , j ) g ~ x ( i , j ) .
Compression and Coding of Color-Quantized Images
FIGS. 6 and 7 show an illustrative image coder that incorporates principles described above. The purpose of the coder is to perform multiresolution decomposition of a color-mapped image. The output of the coder is a low-resolution approximation of the original color map, and a set of images representing details at different levels of resolution, and along different directions.
The illustrative image coder has multiple decomposition levels D 1 , D 2 , . . . , D L . The input to the i'th level D i consists of an image a i−1 (m,n), where m and n represent pixel row and column coordinates, respectively. The input a 0 (m,n) to the first decomposition level represents the raw image. One decomposition level of the coder is shown in FIG. 6 .
With reference to FIG. 6 , each row or column of the input image is filtered at block 200 with a one-dimensional low-pass filter, and then subsampled at block 205 by a factor of two. Similarly, each row or column is filtered at block 210 with a one-dimensional high-pass filter, and then subsampled at block 215 by a factor of two. The low-pass output of the i'th level is denominated d i (m,n), and the high-pass output is denominated a i (m,n). Exemplary filtering operations, which are described below, are performed on the color symbols, i.e., on the luminance and chrominance indices. Because the filtering operations involve taking one-half the sum or difference of index pairs, it is desirable to carry out substitutions, as described above, to assure that each pair contains chrominance indices of the same parity. In the present context of image coding, we refer to such substitutions as “rounding” operations. In FIG. 6 , the rounding operations are indicated at block 220 .
At each decomposition level, we also compute an edge map e i (m,n), as indicated in block 225 of FIG. 6 . Any suitable edge-detection operator can be used to compute the edge map. One example is the gradient operator described above. An exemplary implementation uses the magnitude of the vector gradient to detect edges. Those skilled in the art will appreciate that in alternate implementations, one-dimensional gradients may be used. As indicated at block 230 of FIG. 6 , the raw output e i (m,n)of edge detector 225 is subjected to binary quantization. Exemplarily, for a given pixel (m,n), the output s i (m,n) takes the value 1 if e i (m,n) exceeds a quantization threshold T i for the pertinent decomposition level, and s i (m,n) takes the value 0 if e i (m,n) does not exceed the quantization threshold. We refer to the quantized output s i (m,n) as the “significance map.” As will be explained below, the significance maps are used at a subsequent stage of the image coder for quantizing a set of detail signals.
As noted above, low-pass filtering is performed at block 200 , and high-pass filtering is performed at block 210 . Each filter is exemplarily a one-dimensional perfect reconstruction filter. Exemplary such filters are the Haar filters having weights (½, ½) for the low-pass filter and (½, −½) for the high-pass filter. Thus, for example, if p′ 1 represents the rounded color symbol at the (m,n) pixel position and p′ 2 represents the rounded color symbol at the (m,n+1) pixel position, then the outputs a i (m,n)and d i (m,n), which respectively represent the average and difference along the horizontal direction, are given by:
a i ( m , n ) = p 1 ′ + p 2 ′ 2 ; d i ( m , n ) = p 1 ′ - p 2 ′ 2 .
Each of the outputs a i , d i , and s i represents an image. The resolution of each of these images along the direction of decomposition is two times lower than the resolution of the input image a i−1 . The output image a i is taken as the input to the (i+1)'th decomposition, which is carried out in the direction orthogonal to that of the i'th decomposition. Thus, a total of L decompositions are carried out in alternating directions, as indicated by blocks 235 of FIG. 7 , which are labeled D 1 , D 2 , . . . , D L .
The overall result consists of: the image approximation a L (m,n), which has L/2 lower resolution than the original color map; the set {d i } of L detail signals; and the set {s i } of L significance maps, i=1, . . . , L. The detail signals and significance maps are taken as input to the quantizer Q, indicated at block 240 of FIG. 7 .
At quantizer 240 , each detail signal d i is set to 0 if its corresponding significance coefficient s i is 0. If the corresponding significance coefficient is 1, then d i is passed through unchanged, subject to the rule described below. We have found that signal compression can be improved by taking advantage of spatial redundancy between detail coefficients. Specifically, we assume that if a detail signal d i (m,n) is insignificant at the i'th scale relative to the threshold T i , i.e., if the corresponding significance coefficient is 0, then the detail coefficients at the two finer scales, i.e., at the (i−1)'th and (i−2)'th scales, are also likely to be insignificant at the (m, n) pixel location. Accordingly, quantization is carried out on the coarsest scales first. When a detail signal at a given level is quantized to zero, the corresponding detail signals at the two next finer levels are also automatically set to zero, and the corresponding significance coefficients are set to zero.
The significance maps for all levels, as output from quantizer 240 , are first run-length coded as shown at block 245 , and then entropy coded, as shown at block 250 , using conventional coding techniques. The detail signals for all levels, as output from quantizer 240 , are entropy coded using conventional coding techniques, as indicated at block 255 . The image approximation a L (m,n) is first predictive coded, as indicated at block 260 , and then entropy coded, as indicated at block 265 , using conventional coding techniques.
Because the reconstructed image will contain only colors from the original quantized color palette, there is no need to perform additional quantization at the decoder. As a consequence, the coding scheme described here makes it possible to employ a decoder of relatively low complexity while maintaining relatively high image quality and bit rates.
Exemplary Implementation
The input colors for a typical color monitor are expressed in terms of primary-color values r, g, and b in the RGB representation. Each input value, is related to the corresponding displayed intensity via a non-linear relationship. For example, the input red value r is related to the displayed red intensity I r by r=(I r ) γ , where γ is typically about 2.3. (This parameter is unrelated to the lattice parameter γ discussed above.) Typical image-capturing devices compensate for the nonlinearity between each input primary and its luminance by providing pre-distorted output. That is, the output of such a device is subjected to the inverse transformation, such as: r=(I r ) 1/γ . Such predistorted primary colors are often referred to as “gamma-corrected colors.”
With reference to FIG. 8 , an exemplary implementation of our color-quantization procedures begins at block 300 with the step of obtaining a set of gamma-corrected RGB colors for each of one or more pixels of an image. At block 305 , the gamma correction is removed. At block 310 , the color data are transformed into the well-known XYZ color space using a linear operator. In the XYZ space, known techniques are used to normalize the data with respect to the illumination white point (block 315 ). At block 320 , the color data are converted to the Lab representation via a nonlinear transformation. Such a procedure is described, for example, in Wyszecki and Stiles, Color Science , cited above. At block 325 , the raw colors are mapped to an appropriate palette of quantized colors as described above in connection with FIGS. 3 and 4 .
One exemplary palette of 1024 quantized colors is readily generated from the following parameters:
γ = 5 - 1 2 ;
δ=0.5; φ=0.1 rad; N L =28 ; N p =124 {L l }={0,4,10,15,20,25,31,35,40,44,49,52,56,60,64,68, 72,76,80,85,88,92,95,97,98,99,100}.
A smaller exemplary palette, having only 91 colors, is readily generated from the following parameters:
γ = 5 - 1 2 ;
δ=0.5; φ=0.05 rad; N L =7 ; N p =56 {L l }={0,10,40,65,85,94,100}. | A method for assigning a color symbol to an image pixel comprises selecting a luminance value from a discrete set of quantized luminance values; selecting a chrominance value from an ordered discrete set of quantized chrominance values; and composing a color symbol from an index of the selected luminance value and an index of an ordinal position of the selected chrominance value. In particular embodiments of the invention, each discrete chrominance value is selected from a Fibonacci lattice on a constant-luminance plane in a perceptually uniform color space such as Lab or Luv. | 7 |
BACKGROUND OF THE INVENTION
Field of the Invention - This invention relates to an inorganic compound characterized by the compositional formula Li 2 Gd 4 (MoO 4 ) 7 and bearing the preferred name of dilithium heptamolybdotetragadolinate. It further pertains to single crystals of the subject compound and to methods for making crystals of the compound.
SUMMARY OF THE INVENTION
In recent times there has been considerable activity in the area of inorganic single crystal growth by reacting rare earth oxides with molybdenum or tungsten oxides at elevated temperatures. Such single crystals of rare earth molybdates or rare earth tungstates often exhibit paramagnetic and ferroelectric properties. Some such single crystals have also been found to be ferroelastic. As an example, it is noted that gadolinium molybdate, Gd 2 (MoO 4 ) 3 , exhibits ferroelastic properties. It has been suggested in the prior art that single crystals are useful as synthetic gemstones and it is true that crystals of the material claimed herein find use in such an application. Single crystals of the material claimed herein also find practical application in the fields of electro-optics, display, computer memory, logic, light gate, light modulation, and the like.
The material of this invention has a composition of definite stoichiometry and is made by combination of definite amounts of particularly specified materials in a process requiring closely-controlled time and temperature conditions.
It is an object of this invention to provide the title compound--dilithium heptamolybdotetragadolinate--having the molecular formula Li 2 Gd 4 (MoO 4 ) 7 .
It is further an object of this invention to provide the title compound in single crystal form. Additional objects are to provide methods for making the compound and for making the compound in single crystal form.
DETAILED DESCRIPTION OF THE INVENTION
Critical aspects of the invention include the kinds and amounts of starting materials and the temperatures and times for the process of manufacture.
The starting materials are gadolinium oxide (Gd 2 O 3 , molecular weight 362.5), molybdenum trioxide (MoO 3 , molecular weight 143.9, melting point 795°C.), and lithium molybdate (Li 2 MoO 4 , molecular weight 173.8, melting point 705°C.) and they are used in a respective mole ratio of 2:6:1.
The process for manufacturing crystals of the title material can be conducted by techniques of slow cooling, crystal pulling, zone melting, and the like.
The process herein resides in, first, preparing the title material in polycrystalline form and, next, growing single crystal material from the polycrystalline material.
It has been discovered that the title material can be prepared by firing the starting materials, in appropriate mole ratios, at a temperature of about 800 to 1150 degrees centigrade. The firing temperatures must be selected to be above the melting points of the molybdenum trioxide and the lithium molydbate and below any temperatures of instability. For example, molybdenum trioxide sublimes at near about 1150 degrees centigrade and firing at above that temperature would result in stoichiometric imbalance by sublimation of that component.
EXAMPLE 1
To prepare the title material in polycrystalline form, a powder charge of 41.14 parts, by weight, gadolinium oxide; 49.0 parts, by weight, molydbenum trioxide; and 9.86 parts, by weight, lithium molybdate and mixed together in an open platinum crucible and heated at about 500° centigrade for a few hours to drive off adsorbed water and organic contaminants. The crucible is then fitted with a tight platinum cover and the charge is fired at about 825° centigrade. The firing is maintained at that temperature for about six hours to assure completion of the reaction and establishment of molecular homogeneity in the composition. The firing temperature could be varied from about 800° centigrade to about 1150° centigrade; but, at this stage in the procedure, it is not advisable to raise the firing temperature much higher than 1100° centigrade because such high temperature could melt the composition, as it is formed and, on cooling, the composition might be difficult to remove from the crucible. After completion of the firing period, the composition is rapidly cooled to room temperature in an uncontrolled manner and ground to a fine powder. During the period of maintaining the temperature, a thermal reaction occurs and the title compound is formed. The ground powder is polycrystalline dilithium heptamolybdotetragadolinate and has a melting point of about 1125°-1130° centigrade.
It should be noted that the gadolinium oxide has a very high melting temperature and does not melt at any time during formation of the title compound. The molybdenum trioxide and lithium molybdate melt and react with the solid gadolinium oxide to yield the title compound.
The starting materials are all commercially available. For example, each can be obtained from ROC/RIC, Inc., Sun Valley, California.
EXAMPLE 2
A portion of the polycrystalline material of Example 1 is melted at about 1150 degrees centigrade in a tightly lidded platinum crucible and that temperature is maintained for some time to achieve an equilibrium in the system. Six hours is an adequate time. The temperature of the melt can range from about 1130° to 1250° centigrade. The lower temperature is established by the melting point of the material and the upper temperature is established for reasons of practicality such as consideration of possible reaction of the melt with the crucible material, limitations of the heating apparatus itself, needless use of excess energy to heat to, and excess time to cool from, higher temperatures, and the like.
Then, cooling is commenced at a rate of about 2.5° degrees centigrade per hour and continued until the temperature reaches about 850° to about 500° centigrade. It is noted that the melt is completely solidified well above a temperature of 1000° centigrade. The slow rate of cooling beyond the fusion point of the title material is necessary to relieve internal stresses in the crystals by annealing the crystal structure. The optimum cooling rate over the crystallization and annealing temperature range is determined by well-known criteria. At the fusion temperature, the slower the removal of thermal energy, the more likely it is that larger single crystals will be formed because slower cooling promotes a fewer number of crystal nucleation sites. Moreover, fused materials cooled rapidly from the higher temperatures suffer internal crystal lattice stresses resulting in strains such as dislocations, twinning, low angle grain boundaries and the like. The annealing cooling rate may be varied from less than about 0.5° to about 5° centigrade per hour. The theoretically ideal cooling rate would be just short of zero; but, of course, the slow cooling must be set at a practical rate and is a matter of economy with regard to the time required for completion. It is desirable to cool as slowly as possible to secure the largest crystal size and yet complete the growth within a reasonable time.
The next cooling step, sometimes termed post-annealing, is conducted at a rate of about 100° centigrade per hour and continues from the lowest annealing temperature of about 850° to about 500° centigrade. Both the annealing and the post-annealing steps are performed to homogenize the crystals and avoid excess internal stresses. The lowest post-annealing temperature can be varied from about 400° to 600° centigrade and is not so critical as the lowest annealing temperature. On completion of the post-annealing step, the furnace is shut off and the material is thereby rapidly cooled to room temperature (about 20°-25° centigrade) with no control.
The above cooling procedure can be conducted as a single step at the rate of about 0.5° to about 5° centigrade per hour, or perhaps slightly faster at lower temperatures, down to about 400°-660° centigrade, over a time period of about 100-200 hours.
Single crystals are isolated from the cooled charge by crumbling the charge and separating the single crystals from polycrystalline material using a magnifying glass to aid in visual inspection of the materials. The single crystals are transparent with well-formed crystal faces and the polycrystalline material is opaque. Furthermore, the single crystal material is birefringent when viewed through a polarizing microscope and the polycrystalline material is not birefringent.
Single crystals made by this slow cooling process are as large as 4 millimeters on a short axis by 6 millimeters on a long axis.
EXAMPLE 3
In this Example, large single crystals of the title material are made by means of a vertical crystal pulling technique usually attributed to J. Czochralski in "Zertschrift fuer Physikalische Chemie", Volume 92, page 219 (1918). The Czochralski technique is well known and is generally described in texts relating to the crystal growth art. For example, the technique is described in "The Growth of Single Crystals" by R. A. Laudise published by Prentice-hall, New Jersey (1970).
A portion of the polycrystalline material of Example 1 is charged in a platinum crucible and is heated to about 1120° centigrade. The temperature is then adjusted to that required to just melt the charge and then the melt is maintained at that temperature for more than about an hour to equilibrate the system. A platinum rod about 2 millimeters in diameter is fixed in a chuck equipped for rotation and for carefully controlled, constant, vertical pulling travel. The rod is rotated at about 60 revolutions per minute, contacted with the melt to permit nucleation of a seed crystal and the rod is then adjusted up and down to cause the seed crystal to form a proper neck, in accord with known technique. The pulling is commenced and is controlled at a rate of about 2 millimeters per hour. As the rod is pulled, the crystal material is pulled and cooled, drawing additional material from the melt to be cooled and included in formation of the crystal. The crystal of this example is about 1 centimeter in diameter and the pulling is continued to yield a length of about 3 centimeters.
The diameter of the platinum rod can be varied as desired;--a thicker rod decreasing the time required for obtaining a seed crystal but increasing the likelihood of obtaining more than a single seed.
The rod rotation can be varied considerably but should preferably not exceed about 100 revolutions per minute. Single crystals of the title material have also been made using rotation rates of about 10 and about 35 revolutions per minute.
The crystal pulling rate can, also, be varied from, for example, about 1 to about 5 millimeters per hour;-- again, the extremes being matters of practical consideration. As a general rule, as faster pulling rate results in a crystal of smaller diameter.
Dilithium heptamolybdotetragadolinate is transparent, birefringent and yellow in color. It has a tetragonal crystal structure of a=b=5.192 angstroms and c=11.31 angstroms. It exhibits ferroelectric domains when viewed along the c-axis through a polarizing microscope and is paramagnetic at room temperature (20°-25° centigrade), with an absolute value of magnetic susceptibility of 59.55 × 10.sup. -6 cm.sup. 3 /g. While it is believed that the title material is ferroelastic, the extent of ferroelasticity has not been determined.
The title compound represents one member of a family of rare-earth, alkali-metal, molybdates. Rare earths which can be substituted for gadolinium include: Samarium, Europium, Terbium, Dysprosium, Holmium, Erbium, Thulium and Ytterbium. Alkali metals which can be substituted for Lithium are: Sodium, Potassium, Rubidium and Cesium. | Dilithium heptamolybdotetragadolinate, Li 2 Gd 4 (MoO 4 ) 7 , is disclosed, along with three methods to prepare it. Two of the three methods are useful for growing single crystals of the material. The material exhibits electro-optic, paramagnetic and ferroelectric properties. | 2 |
RELATED APPLICATIONS
This application claims priority from provisional application Ser. No. 60/640,978, entitled “FREQUENCY BASED CONTROL OF AN ULTRASONIC WELDING SYSTEM,” filed Jan. 3, 2005, and from provisional application Ser. No. 60/641,048, entitled “GAP ADJUSTMENT FOR AN ULTRASONIC WELDING SYSTEM”, filed Jan. 3, 2005, both of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to a method and system for determining a gap between a vibrational body and a fixed point, and more particularly to a system and method arriving at such a determination based upon the resonant frequency of the vibrational body.
BACKGROUND
In ultrasonic welding (sometimes referred to as “acoustic welding” or “sonic welding”), two parts to be joined (typically thermoplastic parts) are placed proximate a tool called an ultrasonic “horn” for delivering vibratory energy. These parts (or “workpieces”) are constrained between the horn and an anvil. Oftentimes, the horn is positioned vertically above the workpiece and the anvil. The horn vibrates, typically at 20,000 Hz to 40,000 Hz, transferring energy, typically in the form of frictional heat, under pressure, to the parts. Due to the frictional heat and pressure, a portion of at least one of the parts softens or is melted, thus joining the parts.
During the welding process, an alternating current (AC) signal is supplied to a horn stack, which includes a converter, booster, and horn. The converter (also referred to as a “transducer”) receives the AC signal and responds thereto by compressing and expanding at a frequency equal to that of the AC signal. Therefore, acoustic waves travel through the converter to the booster. As the acoustic wavefront propagates through the booster, it is amplified, and is received by the horn. Finally, the wavefront propagates through the horn, and is imparted upon the workpieces, thereby welding them together, as previously described.
Another type of ultrasonic welding is “continuous ultrasonic welding”. This type of ultrasonic welding is typically used for sealing fabrics and films, or other “web” workpieces, which can be fed through the welding apparatus in a generally continuous manner. In continuous welding, the ultrasonic horn is typically stationary and the part to be welded is moved beneath it. One type of continuous ultrasonic welding uses a rotationally fixed bar horn and a rotating anvil. The workpiece is fed between the bar horn and the anvil. The horn typically extends longitudinally towards the workpiece and the vibrations travel axially along the horn into the workpiece. In another type of continuous ultrasonic welding, the horn is a rotary type, which is cylindrical and rotates about a longitudinal axis. The input vibration is in the axial direction of the horn and the output vibration is in the radial direction of the horn. The horn is placed close to an anvil, which typically is also able to rotate so that the workpiece to be welded passes between the cylindrical surfaces at a linear velocity, which substantially equals the tangential velocity of the cylindrical surfaces. This type of ultrasonic welding system is described in U.S. Pat. No. 5,976,316, incorporated by reference in its entirety herein.
In each of the above-described ultrasonic welding techniques, the workpieces to be joined are disposed between the horn and the anvil, during the welding process. One way to weld is by fixing a gap between the horn and the anvil. The gap between the horn and anvil creates a pinching force that holds the workpieces in place while they are being joined. For the sake of yielding a uniform and reliable welding operation, it is desirable to maintain a constant gap between the horn and the anvil.
During operation, one or more components of the horn stack, including the horn, itself, generally experience an elevation in temperature. Thus, the horn stack generally experiences thermal expansion. As the horn stack expands, the gap between the horn and the anvil is decreased—a result inimical to the aforementioned goal of yielding a uniform and reliable welding operation.
As the foregoing suggests, presently existing ultrasonic welding schemes exhibit a shortcoming, in that the gap between the horn stack and the anvil grows narrower, during successive welding operations.
SUMMARY OF THE INVENTION
Against this backdrop, the present invention was developed. A method includes positioning a horn proximal to an anvil, so that a gap is established between the horn and the anvil. A force is applied to the horn, so as to urge the horn toward the anvil. A deformable stop is positioned at a location, such that application of the urging force causes a member operatively connected to the horn to abut the deformable stop, and to deform the stop. The urging force is iteratively adjusted during operation of the horn, so as to adjust the extent of the deformation of the deformable stop, and to maintain the gap between the horn and the anvil substantially constant.
According to another embodiment, a system includes a mount including a translation member and a fixed elastic deformable stop. A horn is coupled to a source of ulstrasonic energy. The horn is operatively connected to the translating member. An anvil is separated from the horn by a gap. A force applicator is configured to urge the horn toward the anvil, and to cause a member operatively coupled to the horn to contact and deform the elastic deformable stop by varying degrees, so that the gap between the horn and the anvil remains substantially constant during operation of the system.
According to yet another embodiment, a system includes a horn separated from an anvil by a mounting system. A source of ultrasonic energy is coupled to the horn. The system also includes a means for substantially maintaining the separation at a constant length, while the horn experiences thermal expansion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts an embodiment of a simple ultrasonic welding horn stack coupled to an energy source.
FIG. 2 depicts an embodiment of a mounting system coupled to the ultrasonic welding horn stack of FIG. 1 .
FIG. 3 depicts an embodiment of a system for determining a length of a gap between a horn and an anvil.
FIG. 4A depicts an exemplary embodiment of a table that may be used as a part of a gap-determining unit.
FIG. 4B depicts an exemplary embodiment of a method of determining a gap length.
FIG. 5A depicts an embodiment of a simple rotary ultrasonic welding horn for use in a continuous ultrasonic welding operation.
FIG. 5B depicts an exemplary embodiment of a method of determining a gap length.
FIG. 6 depicts an exemplary embodiment of a system for maintaining a substantially constant gap between a welding horn and an anvil.
FIG. 7 depicts an exemplary embodiment of a system for adjusting a gap between a horn and an anvil in an ultrasonic welding system.
FIG. 8A depicts an exemplary embodiment of a system for maintaining a susbtantially constant gap between a horn and an anvil in an ultrasonic welding system.
FIG. 8B depicts another exemplary embodiment of a system for maintaining a susbtantially constant gap between a horn and an anvil in an ultrasonic welding system.
FIG. 9A depicts an exemplary embodiment of a force-determining unit.
FIG. 9B depicts another exemplary embodiment of a force-determining unit.
FIG. 10 depicts an exemplary embodiment of a system for adjusting a gap between a horn and an anvil in an ultrasonic welding system.
FIG. 11A depicts the surface of a horn driven by an acoustic signal propagating along the longitudinal axis of the horn.
FIG. 11B depicts the surface of a horn driven by an acoustic signal of smaller magnitude than that of FIG. 11A , as that signal propagates along the longitudinal axis of the horn.
FIG. 12A depicts an exemplary embodiment of a system for controlling the gap between a horn and an anvil.
FIG. 12B depicts another exemplary embodiment of a system for controlling the gap between a horn and an anvil.
FIG. 13 depicts an exemplary embodiment of a method for combining the operations of an adjustor and an amplitude determination module.
FIG. 14 depicts another exemplary embodiment of a method for combining the operations of an adjustor and an amplitude determination module.
DETAILED DESCRIPTION
Various embodiments of the present invention will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the invention, which is limited only by the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the claimed invention.
FIG. 1 depicts an example of a simple horn stack 100 that is coupled to an AC source of electrical energy 102 . As can be seen from FIG. 1 , the horn stack 100 includes a converter 104 , a booster 106 , and an ultrasonic welding horn 108 . During operation, the AC source supplies electrical energy to the converter 104 , which responds thereto by compressing and expanding at a frequency equal to that of the AC signal. Therefore, acoustic waves travel through the converter 104 to the booster 106 . As the acoustic wavefront propagates through the booster 106 , it is amplified, and is received by the welding horn 108 . (In some embodiments, the horn 108 is designed to achieve a gain, eliminating the need for a booster 106 .) Finally, the wavefront propagates through the horn 108 , whereupon it is imparted to workpieces (not depicted in FIG. 1 ) that are positioned between the welding horn 108 and an anvil 110 . Other examples of horn stacks are known in the art, and function with the following systems, schemes, and methods disclosed herein.
The horn 108 is separated from the anvil 110 by a distance labeled “Gap” in FIG. 1 . The process of imparting frictional energy to the workpieces causes the various elements of the horn stack 100 to elevate in temperature. As the elements of the horn stack 100 elevate in temperature, they exhibit thermal expansion, meaning that the gap between the horn 108 and the anvil 110 is likely to change in dimension, depending upon the particular manner in which the horn stack 100 is mounted.
FIG. 2 depicts a simplified exemplary mounting scheme for the horn stack 100 of FIG. 1 . The mounting scheme makes use of a rigid, generally tripartite, frame 200 . The frame 200 includes a first portion 202 upon which the anvil 110 is mounted, and a second portion 206 that is adjoined to a nodal point on the horn stack 100 . For example, the second portion 206 of the frame is depicted in FIG. 2 as being coupled to the midpoint 208 of the booster 106 . A third portion 204 of the frame 200 extends between the first and second portions 202 and 206 .
The mounting system 200 maintains a substantially fixed distance between a workpiece-supporting surface 210 of the anvil 110 and a portion of the horn stack 100 . In this case, the mounting system 200 maintains a substantially fixed distance between the upper surface 210 of the anvil 110 and the midpoint/nodal point 208 of the booster 106 . Therefore, should the horn stack 100 expand during operation, the horn stack 100 expands outwardly from the midpoint 208 of the booster 106 , along the longitudinal axis of the stack 100 , as indicated by the arrows labeled “Expansion” in FIG. 2 . It is understood that a variety of other mounting systems may also maintain a substantially fixed distance between the upper surface 210 of the anvil 110 and a portion of the horn stack 100 , and such other mounting systems are within the scope of the present application.
Given the mounting arrangement of FIG. 2 , thermal expansion of the converter 104 and upper portion of the booster 106 produces no effect on the gap length (because of the position of these elements relative to the point 208 at which the frame 200 joins the stack 100 , these elements are free to expand upwardly, i.e., away from the anvil 110 ). On the other hand, the gap length is affected by expansion of the lower portion of the booster 106 and by expansion of the horn 108 —as these elements expand, they expand toward the anvil 110 , and the gap contracts.
According to one embodiment, the converter 104 and booster 106 are maintained at a substantially constant temperature. For example, the converter 104 and booster 106 may be cooled by a cooling system, such as by one or more fans that circulate relatively cool air to the surfaces of the converter 104 and booster 106 , so as to substantially maintain their temperatures, and to thereby substantially suppress their thermal expansion. Therefore, according to such an embodiment, any change in length of the horn stack 100 may be considered as being substantially due to expansion of the welding horn 108 .
Furthermore, according to some embodiments, the horn 108 is cooled by a cooling system, so as to suppress or reduce its propensity to heat up during operation. Generally, such a scheme does not totally eliminate thermal expansion of the horn 108 , meaning that it still exhibits some degree of thermal expansion, which should be accounted for, if the gap length is to be maintained substantially constant.
It is known that the length of a given body is inversely proportional to the given body's resonant frequency. Stated another way, as a body grows in length, it exhibits a lower resonant frequency. Therefore, as the horn stack 100 grows in length, as occurs, for example, by virtue of thermal expansion, it exhibits a lower resonant frequency. Specifically, the length of a body, l, is related to its resonant frequency, f by the following equation:
l ≈ E / ρ 2 f ,
where E represents the modulus of elasticity of the object, and where ρ represents the density of the object. If the object is compound (e.g., is made up of multiple parts or has various sections made from different materials, etc.), E and ρ may be assigned values representing the behavior of the materials, considering its various parts (e.g., may be a weighted average, etc.).
According to some embodiments, the energy source 102 detects the resonant frequency, f, of the horn stack 100 , in order to generate an AC signal equal in frequency thereto. For example, the energy source 102 may deliver a sinusiodal signal exhibiting a particular peak-to-peak voltage (or root-mean-square voltage) to the horn stack 100 . While keeping the peak-to-peak (or RMS) voltage of the sinusoidal signal constant, the energy source 102 adjusts the frequency of the signal, and seeks out the frequency at which the least current is drawn by the horn stack 100 —this frequency is the resonant frequency of the horn stack 100 . Accordingly, per such embodiments, the resonant frequency of the stack 100 may be obtained from the energy source 102 . According to other embodiments, the resonant frequency of the stack 100 may be detected by observation of the stack 100 with a detector.
Upon obtaining the resonant frequency of the horn stack 100 , the overall length of the stack 100 may be obtained by relating, in a manner similar to the aforementioned physical principles, resonant frequency to horn stack length. Given that the converter 104 and booster 106 are cooled, so as to substantially suppress the effects of thermal expansion thereupon, the length of the horn stack 100 can be related to the gap length. For example, according to the scheme of FIG. 2 , the gap length and the length of the horn 108 , l, are related by the following equation:
gap length≈ D−l,
where D is an approximately constant value that represents the length between the top of the horn 108 and the workpiece-supporting surface 210 of the anvil 110 .
FIG. 3 depicts a system for determining the length of the gap between a welding horn 108 and the workpiece-supporting surface 210 of the anvil 110 . The system of FIG. 3 includes an ultrasonic power supply 300 (e.g., an electrical power supply that delivers an AC signal to converter, which, in turn, transduces the signal into an acoustic wave) that delivers an acoustic signal to a horn (and booster) 302 . The ultrasonic power supply 300 is controlled by a controller circuit, such as by a processor in data communication with a memory device that stores firmware/software controlling the operation of the ultrasonic power supply 300 . Alternatively, the controller circuit may be embodied as a hardware-based control loop. In either event, the controller of the ultrasonic power supply 300 identifies the resonant frequency of the horn stack, and commands power supply signal generation circuitry therein to cooperate with the converter to yield an acoustic signal equal in frequency thereto. The controller within the power supply 300 may interface to a gap-determining unit 304 .
The gap-determining unit 304 receives the resonant frequency of the horn stack, and generates a quantity standing in known relation to the gap length. According to one embodiment, the gap-determining unit 304 is a software module executing upon a processor coupled to a memory unit. The gap-determining unit 304 may execute upon the same processor upon which the firmware controlling the ultrasonic power supply 300 executes. Alternatively, it may execute upon a different processor that is in data communication therewith. In either event, the software/firmware executed by the gap-determining unit 304 may function according to the schemes (below) discussed with reference to FIGS. 4A-5B .
According to an alternative embodiment, the gap-determining unit 304 may receive the resonant frequency of the horn stack from a source other than the ultrasonic power supply 300 . For example, the system may include a detector 306 that observes the horn stack, measures the resonant frequency thereof, and communicates the resonant frequency to the gap-determining unit 304 . In the discussion that follows, it is assumed that the resonant frequency originates from the ultrasonic power supply 300 , for the sake of example only.
FIG. 4A depicts a scheme by which the gap-determining unit 304 may operate. The gap-determining unit 304 may include a table 400 stored in a memory device. The table 400 is organized according to resonant frequency, and relates a gap length G to a resonant frequency, ƒ. Thus, upon receiving a resonant frequency, ƒ, the gap-determining unit 304 uses the resonant frequency to access the table 400 , and to determine a gap length G corresponding to the resonant frequency, ƒ. For example, assuming that the gap-determining unit 304 receives a frequency of ƒ 2 as an input, the unit 304 responds by accessing the table 400 to identify a row corresponding to frequency ƒ 2 . Upon identification of the row, the gap length entered therein, G 2 , is returned. Optionally, the table 400 may be accessed to determine the length of the horn stack 100 , L, or to determine any other quantity standing in known relation to the gap length. Assuming that the gap-determining unit 304 receives a value f x as an input, and assuming that ƒ x falls between successive table entries (i.e., ƒ i <ƒ x <ƒ i+1 ), then the gap-determining unit 304 may access the table 400 to obtain gap length values G i and G i+1 , and may interpolate between the two values to arrive at a gap length corresponding to the resonant frequency, ƒ x .
The various entries in the table 400 may be populated ex ante by a heuristic process, in which the length of the horn stack 100 and the length of the gap are recorded for each frequency, ƒ, within the table 400 . Alternatively, the various entries in the table 400 may be populated by theoretical calculation, in a manner similar to that described above.
FIG. 4B depicts another scheme by which the gap-determining unit 304 may operate, theoretical computation. For example, the gap-determining unit 304 may begin its operation by receiving the resonant frequency of the horn stack 100 , ƒ, as shown in operation 402 . Thereafter, the unit 304 responds by calculating the length of the horn 108 , L, based upon the resonant frequency, such as by use of an equation based upon the physical principles underlying the equation shown in operation 404 . Finally, as shown in operation 406 , the unit 304 may relate the length, L, determined in operation 404 , to a gap length, based upon knowledge of the particular geometric constraints arising from the mounting scheme employed. For example, in the context of the the mounting scheme of FIG. 2 , the gap length may be found as:
Gap Length= D−L,
where D represents the distance between the top of the horn 108 and the workpiece-supporting surface 210 of the anvil 110 , and L represents the length of the horn.
FIG. 5A depicts an example of a welding horn 500 that is used for continuous ultrasonic welding. The horn 500 therein includes a longitudinal axis 502 about which the horn 500 may rotate. The horn 500 is constrained by a mounting system (not depicted in FIG. 5A ), so that a gap is maintained between the horn and the anvil 504 . The horn stack may be mounted at any nodal point on the system. The longitudinal axis 502 of the horn is substantially parallel to the workpiece-supporting surface 506 of the anvil 504 .
The aforementioned principle of determining the length of the gap between a horn and an anvil based upon the resonant frequency of the horn stack is applicable to the horn 500 of FIG. 5 . As materials expand thermally, they do so in equal proportions in all directions. Therefore, the following technique, depicted in FIG. 5B , may be used to determine the length of the gap between the horn and the anvil.
Initially, as shown in operation 508 , the resonant frequency of the horn stack is received. Thereafter, the length of the horn 502 , L, is determined based upon the frequency, in like manner as described above (operation 510 ). As before, the horn stack of FIG. 5A is cooled so that the converter (not depicted in FIG. 5A ) and booster (not depicted in FIG. 5A ) remain at substantially constant temperatures during operation, thereby suppressing their thermal expansion and the effects on the system resonant frequency.
Since the horn 500 expands proportionally in all dimensions, the ratio between its length, L, and its radius, B, remains constant. Therefore, after calculation of the length of the horn 502 , its radius may be arrived at by multiplication of the length by the aforementioned ratio, B, as shown in operation 512 . Finally, the length of the gap may be determined by subtracting the radius from the distance, D, between the longitudinal axis of the horn 500 and workpiece-supporting surface 506 of the anvil 504 , as shown in operation 514 .
It should be noted that the results of the method described with respect to FIG. 5B may be stored within a table, as described with reference to FIG. 4A . Thus, the gap length, or any value standing in known relation thereto, may be obtained by virtue of accessing such a table, based upon the resonant frequency of the horn stack.
FIG. 6 depicts a control system for maintaining a substantially constant gap between a horn and an anvil, based upon observation of the resonant frequency of the horn stack. The system includes a horn stack 600 and a power supply 602 coupled thereto. According to one embodiment, the power supply 602 determines the resonant frequency of the horn stack 600 , as described above.
Coupled to the horn stack is a position adjustor 606 . The position adjustor 606 adjusts the horn stack 600 , either toward or away from the anvil, under the control of an input signal. A known relationship exists between the input signal delivered to the adjustor 606 and its response thereto. The position adjustor 606 is in data communication with a control signal generator 604 . The control signal generator 604 receives the resonant frequency of the horn stack as an input, and generates a control signal that is delivered to the position adjustor 606 . The control signal generator 604 yields a control signal that maintains a substantially constant gap between the anvil and the horn, given the resonant frequency of the horn stack 600 and the relationship between the response of the position adjustor 606 and its input signal.
The control signal generator 604 may be embodied as a controller circuit, such as a processor in data communication with a memory device that stores firmware/software in accordance with the aforementioned principles. It may alternatively be embodied as an ASIC yielding the aforementioned control signal so as to maintain a substantially constant gap. In the following portion of the disclosure, a particular embodiment of a position adjustor is disclosed. It is not necessary to use the position adjustor disclosed below for practice of the invention. Also, the preceding portion of the specification was directed toward particular methods of determining the length of a horn or the length of a gap, based upon the resonant frequency of the horn stack. According to other embodiments, such determinations may be arrived at by measurement of the temperature of the horn stack, or of its various components.
FIG. 7 depicts an exemplary embodiment of a system for adjusting the gap between a horn and an anvil. The system therein includes a horn 700 oriented above a workpiece-supporting surface 702 of an anvil 704 . In the depicted embodiment, the longitudinal axis LA of the horn 700 is substantially perpendicular to the support surface 702 of the anvil 704 .
The frame 706 also includes a force-receiving plate 712 that is coupled to the frame 706 by a pair of members 714 . A force is applied to the force-receiving plate 712 by a force applicator (not depicted in FIG. 7 ). The force urges the horn 700 toward the anvil 704 . The direction of the force is indicated by the arrow 713 . The force has the effect of causing a contact surface 716 to abut an elastic deformable stop 718 . The force exerted upon the elastic deformable stop 718 causes the stop 718 to deform, and to thereby exhibit a downward deflection (i.e., a deflection in the direction of the anvil 704 ). Generally, the greater the force applied to the plate 712 , the greater the downward deflection exhibited by the stop 718 . The greater the deflection exhibited by the stop 718 , the smaller the gap between the horn 700 and the anvil 704 .
To maintain a constant gap between the horn 700 and the anvil 704 , the following scheme may be employed. While the horn 700 is at its unelevated temperature, an initial force is applied to the plate 712 , to cause the gap between the horn 700 and the anvil 704 to be established at an “ideal” length. As the horn 700 thermally expands during operation, the gap grows smaller. To counteract this effect, the force applied to the plate 712 is reduced, causing the stop 718 to exhibit a lesser deflection, meaning that the horn 700 and frame are translated upwardly (i.e., away from the anvil). Thus, the gap between the horn 700 and the anvil 704 may be maintained substantially constant by controlled application of force to the plate 712 . To ensure the functionality of this scheme the initial force applied to the plate 712 should be of sufficient magnitude to cause the stop 718 to exhibit a deflection at least as great in extent as the expected thermal expansion to be counteracted.
The deformable stop 718 is elastic, and preferably has a relatively high modulus of elasticity. By selection of a material having a relatively high modulus of elasticity, a circumstance is set up in which the force required to deflect the stop 718 is relatively great compared to the process force (i.e., the force exerted by the horn on the workpiece). Such an arrangement provides for ease of control design. According to one embodiment, the stop 718 may be made of steel, or another suitable material. According to one embodiment, the force exerted upon the stop 718 does not cause the material therein to exit its elastic range (i.e., the stop 718 will return to its original shape upon withdrawal of the force). Further, according to one embodiment, the stop 718 exhibits a deflection that is proportional to the force applied thereto, i.e., there exists a linear relationship between the force applied to the stop 718 and the extent of deflection exhibited thereby.
FIG. 8A depicts an example of a control system for use with the exemplary adjustment system of FIG. 7 . (The various units 804 - 810 of FIG. 8A , dicussed below, may be embodied as software modules stored in a computer-readable medium and executed by a processor, or may be embodied as dedicated hardware, such as one or more application-specific integrated circuits, or as a field-programmable gate array. Further, the units 804 - 810 may be combined or divided as a matter of design choice.) As can be seen from FIG. 8A , the system includes a horn 800 that is coupled to a source of ultrasonic power 802 . A gap-determining unit 804 determines the gap between the horn 800 and an anvil (not depicted in FIG. 8 ). According to one embodiment, the gap-determining unit 804 obtains the resonant frequency of the horn stack from the power source 802 , and determines the gap therefrom. According to another embodiment, the gap-determining unit 804 detects the resonant frequency of the horn 800 by observation thereof. According to yet another embodiment, the gap determining unit 804 arrives at the gap length by measurement of the temperature of the horn, inferring horn length therefrom, and arriving at the gap length on the basis of the horn length.
The gap length arrived at by the gap-determining unit is supplied to a force-determining unit 806 . The force-determining unit 806 determines the force to be exerted upon the frame (e.g., plate 712 in FIG. 7 ), in order to maintain the gap at a substantially constant length. The force arrived at by the gap-determining unit 806 is supplied to a control signal generator 808 . The control signal generator 808 develops a control signal, and communicates that control signal to a force applicator 810 . The force applicator 810 exhibits a known relationship between the received control signal and the force it exerts. Thus, the control signal generator 808 develops the control signal in light of that relationship.
FIG. 8B depicts exemplary embodiments of the gap determining unit 804 and force determining unit 806 . (As was the case with the units of FIG. 8A , the various units of FIG. 8B , dicussed below, may be embodied as software modules stored in a computer-readable medium and executed by a processor, or may be embodied as dedicated hardware, such as one or more application-specific integrated circuits, or as a field-programmable gate array. Further, the units of FIG. 8B may be combined or divided as a matter of design choice.) As can be seen from FIG. 8B , the gap determining unit 804 includes a length determining unit 812 and a gap finding unit 814 . The length determining unit 812 receives the resonant frequency of the horn stack, and applies one of the methods described with reference to FIGS. 4A and 4B to find the length of the horn. Thereafter, the length of the horn is received by the gap finding unit 814 . The gap finding unit 814 arrives at the gap length, by virtue of knowledge of the length of the horn and the particular geometry imposed by the mounting scheme (e.g., the gap length may be equal to the difference between the length from the top of the horn to the workpiece-supporting surface and the horn length, Gap=D−L).
After arrival at the gap length, this value is provided to the force-determining unit 806 . The force-determining unit 806 arrives at the force to be applied to the frame, in order to keep the gap substantially constant. The force arrived at is a function of, amongst other things, the length of the stop, L stop , the modulus of elasticity of the stop, E, the cross-sectional area of the stop, A, the difference between the initial gap length and the gap length as arrived at by the gap determining unit 804 , Δ, and the assembled system deflection.
FIG. 9A depicts a scheme by which the force-determining unit 806 may operate. The force-determining unit 806 may include a table 900 stored in a memory device. The table 900 is organized according to resonant gap length, G, and relates a force F to a gap length, G. Thus, upon receiving a gap length, G, the force-determining unit 806 uses the gap length to access the table 900 , and to determine a force F corresponding to the gap length, G. For example, assuming that the force-determining unit 806 receives a gap length of G 2 as an input, the unit 806 responds by accessing the table 900 to identify a row corresponding to gap length G 2 . Upon identification of the row, the force entered therein, F 2 , is returned. Optionally, the table 900 may be accessed to determine the control signal, C, to be delivered to the force applicator 810 , or to determine any other quantity standing in known relation to the force to be exerted on the frame. Assuming that the force-determining unit 806 receives a value G x as an input, and assuming that G x falls between successive table entries (i.e., G i <G x <G i+1 ), then the force-determining unit 806 may access the table 900 to obtain force values F i and F i+1 , and may interpolate between the two values to arrive at a force corresponding to the gap length, G x .
The various entries in the table 900 may be populated ex ante by a heuristic process, in which the force to be applied to the frame and the control signal corresponding thereto are expirementally determined for each gap length, G, within the table 900 . Alternatively, the various entries in the table 900 may be populated by theoretical calculation, in a manner similar to that described below with reference to FIG. 9B .
FIG. 9B depicts another scheme by which the force-determining unit 806 may operate, theoretical computation. For example, the force-determining unit 806 may begin its operation by receiving the gap length calculated by the gap determining unit 804 , CG, as shown in operation 902 . Thereafter, the unit 806 responds by calculating the difference between the initial gap, IG, and the calculated gap, CG, as shown in operation 904 . This difference, Δ, refers to the amount by which the deflection of the stop must be reduced in order to return the gap to its initial length. Thus, in operation 906 , the new force to be applied to the frame, F new , may be arrived at by solving for F new in the equation shown therein.
FIG. 10 depicts another exemplary embodiment of a system for adjusting the gap between a horn and an anvil. Welding system 1010 has a welding unit 1030 fixed to support surface 1017 and an anvil 1021 fixed to support surface 1018 . Welding system 1030 includes horn 1032 , which is supported by horn support 1020 and is moveable in relation to surface 1017 , a fixed stop 1055 having support plate 1056 , which are fixed in relation to surface 1017 , and an expandable pneumatic bladder 1061 .
Bladder 1061 is used to apply the force to move horn support 1020 and horn 1032 toward anvil 1021 ; the force is controlled by adjusting the air pressure in bladder 1061 . As surface 1025 contacts fixed stop 1055 , support plate 1056 deflects slightly under the applied force.
In one specific example, the minimum allowable force to weld a desired product is 600 pounds (about 272 kg), which is generated by 30-psig (about 207 kPa) air pressure in bladder 161 . The desired fixed gap is 0.0020 inch (about 0.05 mm).
In operation with a titanium horn, it was determined that the temperature will increase from room temperature by a maximum of 50° F. (about 27.7° C.), which will increase the horn length by 0.0010 inch (about 0.025 mm). As a result, the gap between horn 132 and anvil 121 is reduced to 0.0010 inch (about 0.025 mm), if no compensation is made. The deflection of support plate 156 is known to be 0.0010 inch (about 0.025 mm) per 675 pounds force (about 306 kg-force). Therefore, the applied force with a room temperature horn must be at least 1125 pounds (about 510 kg), or 60 psig (about 414 kPa). As the horn operates and increases in length, the applied air pressure is reduced from 60 psig (about 414 kPa) to 30 psig (about 207 kPa) to keep the gap between horn and anvil constant.
A welding apparatus, generally configured to control the distance between the anvil and the horn by utilizing a deformable stop assembly, includes an anvil with a fixed stop, a horn, and a force applicator mounted so as to be able to apply force to press the horn against the fixed stop such that elastic deformation of the fixed stop provides fine control over the gap between the horn and the anvil. The apparatus may include a sensing system to monitor a specific property of the horn and control the force applied to the horn so as to hold the gap between the horn and the anvil at a fixed value despite changes in the specific property. The property monitored could be, for example, temperature, length, or vibration frequency of the horn.
The use of a deformable, yet fixed stop to compensate for the horn length increase, due to thermal expansion, can be used with a rotary anvil, stationary anvil, rotary horn, stationary horn, or any combination thereof.
In use, the workpieces to be joined would be positioned between the horn and the anvil, energy would be applied to the horn and the horn would be energized, and a force would be applied to the horn to urge the horn against the fixed stop such that elastic deformation of the fixed stop provides fine control of the gap between the horn and the anvil.
To employ the methods discussed above, one can determine data for a system, and then fit it into equations that can be used in the control system for a particular unit. Applicants have used the following method for the system described above, but this method can be applied to other systems of different configurations. The equations can be derived using engineering principles or using measured data from an individual system.
Equations 2-5 were best fits to linear systems of the two variables. The slope and intercept of the equations were determined empirically from best fitting measured data of the system. Measuring the relationship between the variables can similarly yield the slope and intercept of any particular system. It is preferred that the systems behave linearly in the operating regions, but if the systems are non-linear, a second order or higher equation can be used.
Applicants have developed and used the method described following for control of a gap during ultrasonic welding.
First, for a rotary ultrasonic system as described above, the following parameters were determined.
(1) Horn diameter=6.880″
(2) Ambient temp. ° F.=65° F.
(3) Frequency at ambient temp.=19.986 KHz
(4) Pressure at which gap is set at=72.5 psig.
(5) Gap set point for the process=2 mils (1 mil=0.001 inch).
The material properties of the horn are also known,
(6) Coefficient of Thermal Expansion, α
α Titanium =5.4×10 −6 deg F./inch/inch
α Aluminum =5.4×10 −5 deg F./inch/inch
When the system is energized and operating, the horn will increase in temperature. So next, one determines what would be the temperature, T final , at which there will be no gap left (i.e., 2.0 mil gap goes to zero, e.g., contact between horn and anvil) when welding continuously. This temperature is found by solving Equation 1:
T
final
=
(
2
*
IG
*
10
-
3
D
*
α
)
(
Equation
1
)
In Equation 1, T final is the temperature at which the Gap vanishes, IG is the initial gap (in mils) set and measured when the system is set-up and not in operation, D is the outer diameter of the rotary horn, and α is the coefficient of thermal expansion of the horn material. Solving Equation 1 using the above inputs for an aluminum horn gives a temperature of 172.7 deg F. where the gap will go to zero based on heating of the horn during operation. Thus, if the horn heats to 172.67° F., then there will be no gap left. Hence there is an upper bound for temperature. The upper bound for any given system can be found using equation 1 for a rotary system. One of ordinary skill in the art will also appreciate that a similar equation can also be derived for other geometries, and an upper operating temperature for avoiding a vanishing gap can be determined.
As it is difficult to measure the temperature on a dynamic resonating state of a horn, Applicants developed using a surrogate that gives an indirect, but accurate, measurement of temperature. Instead of directly measuring temperature, the frequency of the horn is determined by measuring the frequency of the horn during operation, and then determining temperature by using Equation 2 following:
λ min =−0.0017 *T final +20.096 (Equation 2)
In Equation 2, λ min is the minimum frequency at which the horn can be operated before the gap goes to zero, and the coefficients of the linear equations have been determined empirically by experiment. Solving Equation 2 for the input parameters, the gap will go to zero when the frequency of the horn drops to less than 19,802 Hertz. Since the frequency of the horn is a parameter than can be measured easily using standard equipment commonly used by those of ordinary skill in the art, one can determine using Equations 1 and 2 the minimum operating frequency of a rotary system that will keep the gap from closing, which can result in product damage and also damage the horn and/or anvil due to the contact.
Using Equations 1 and 2, one now has the ability to relate gap to temperature and temperature to frequency. Hence, one can relate the gap to frequency. During normal operation, when the material is in the gap (or nip), it is difficult to measure the gap, but using the above principles, the frequency can be used to determine the gap. The relationship between the frequency of the horn and the gap between the horn and anvil can be determined using Equation 3 (which can be solved for either the gap as a function of frequency or vice versa) following:
λ=0.0965*Gap+19.7925 (Equation 3)
In Equation 3, λ is the horn frequency and the Gap is measured in mils (1 mil=0.001 inches). Solving Equation 3 for a gap of 1 mil gives a frequency of 19,889 Hertz. Note that there is now a way to determine the gap change as a function of frequency. Using the information thus determined by Equations 1-3, the force applied to the horn/anvil arrangement can be controlled to keep the operating gap constant as the temperature and frequency of the horn change during operation of the welding assembly.
To control the gap and keep it a constant operating value, the pressure applied to the system is controlled, thereby compensating for thermal expansion of the horn as it heats during operation. Referring back to the example above, when the gap is reduced to 1 mil, one needs to reduce the pressure exerted on the system so that the system can keep or get back to original gap setting of 2 mils. Hence, to compensate for the thermal expansion, the pressure is reduced to get the gap to go back to 2 mils.
To reduce the pressure properly, one first needs to determine the relationship between pressure and frequency, as shown by Equation 4 following:
P compensation =−367.3404*λ+7412.7731− P setpoint (Equation 4)
where P compensation is the reduction in pressure (in pounds per square inch gage) on the system, λ is the frequency determined from Equation 3, and P setpoint is the pressure at the initial gap set point.
For example, using the above parameters, one can determine the pressure reduction needed to move restore an initial gap of 2 mils when the horn expands 1 mil due to thermal expansion.
Example: What is the pressure compensation needed if the gap changed to 1 mil?
First calculate the frequency for gap at 1 mil from Equation (3) (that value is 19.889 KHz, as previously determined). Then substituting the values into Equation 4 yields,
P
compensation
=
-
367.3404
(
19.889
)
+
7412.7731
-
72.5
=
106.7399
-
72.5
P
compensation
=
34.24
psig
(
reduction
in
operating
pressure
)
After the pressure has been determined, to compensate for thermal expansion, it can be verified what is the gap at that pressure compensation. This gap should be roughly equal to initial gap plus the gap change due to thermal expansion. To verify, first the relationship between the Pressure and Gap is determined by Equation 5 following:
P Compensation =35.461*(Gap@Pressure Compensation)+142.205 (Equation 5)
For example, at a pressure compensation of 34.24 psig (from Equation 4), one can rearrange Equation 5 and solve for the Gap:
Gap@Pressure Compensation=(34.24−142.205)/−35.461=3.045 mils
Thus, one can validate the model because the Initial Gap was set at 2.0 mils and the gap change was 1 mil. Therefore, to compensate for a 1 mil expansion due to heating of the horn during operation, one would open the gap by 1 ml, thereby restoring the original 2.0 mil gap.
Thus, using the equations (or deriving their equivalents for linear horns or other geometries) discussed above for determining the operating parameters, one can determine the operating limits for a rotary ultrasonic welding process. For example, the operating temperature limit is found using Equation 1 and value of Gap set point (target). The operating frequency limit of the ultrasonic horn is found using Equation 2 and using the value of Temperature limit from Equation 1. The frequency at gap change is found using Equation 3 and using the value of the gap as input. The temperature at gap change is found using Equation 2, but using the value of frequency determined from Equation 3. The Pressure Compensation for Gap change is found using Equation 4 but using value of Frequency from Equation 3. The Gap at Pressure Compensation (at Ambient Temperature) is found using Equation 5, but using the value of Pressure Compensation from Equation 4.
There exists yet another scheme by which the gap between a horn and an anvil may be controlled. As mentioned previously, in the context of ultrasonic welding, a horn is driven by an acoustic signal, generally in the realm of 20,000 to 40,000 Hz. FIG. 11A depicts the surface 1100 of a horn, as an acoustic wave propagates along its longitudinal axis. The direction of propagation of the acoustic wave is depicted by the arrow 1102 . As can be seen from FIG. 11A , as an acoustic wave propagates along the longitudinal axis of the horn, the surface 1100 of the horn is perturbed, and exhibits a standing waveform 1104 thereupon. The standing waveform 1104 exhibits a peak-to-peak amplitude, referred to as the “displacement” exhibited by the horn surface. The peak-to-peak amplitude, or surface displacement, is a function of the amplitude of the acoustic signal propagating along the horn. Of course, the amplitude of the acoustic signal is a function of the amplitude of the electrical signal supplied to the converter coupled to the horn. Thus, the displacement exhibited by the surface 1100 of the horn is a function of the amplitude of the electrical signal delivered to the converter. Typically, the greater the amplitude of the electrical signal delivered to the converter, the greater the amplitude of the acoustic signal propagating along the horn; the greater the amplitude of the acoustic signal, the greater the displacement exhibited on the surface 1100 of the horn.
As can be seen from FIG. 11A , the gap between the surface 1100 of the horn and the surface of the anvil 1106 is a function of the displacement. As the horn exhibits greater surface displacement, the gap between the surface of the horn and the surface of the anvil diminishes.
Before proceeding further, it is pointed out that FIGS. 11A and 11B are not drawn to scale, and that some features therein, such as the surface displacement have been exaggerated for the sake of illustration. (A typical horn may exhibit a surface displacement of approximately 2-3 mils, when operating under normal conditions, for example.)
For the sake of discussion, the amplitude of the voltage signal stimulating the surface displacement shown in FIG. 11A is termed Amplitude 1 . FIG. 11B depicts the horn surface 1100 of FIG. 11A , as it appears when stimulated by a voltage signal having an amplitude of Amplitude 2 (Amplitude 2 is less than Amplitude 1 ). As can be seen from comparison between FIGS. 11A and 11B , the gap between the surface of the horn 1100 and the anvil 1106 grows when the amplitude of the voltage signal stimulating the horn diminishes, because the surface of the horn 1100 is not so greatly displaced toward the anvil.
As mentioned previously, during a typical welding operation, a horn may exhibit a surface displacement on the order of 3 mils, for example. However, the welding operation may yield satisfactory product, even if the surface displacement is reduced by, for example, 33%. Thus, per the aforementioned example, the welding operation may be performed with the horn exhibiting a displacement of as little as 2 mils. It follows, then, that the welding operation may be initiated using an electrical signal of sufficient amplitude to stimulate a surface displacement of 3 mils. During operation, the horn experiences thermal expansion, meaning that the gap between the horn and the anvil diminishes as the horn expands towards the anvil. To counteract this effect, the amplitude of the electrical signal stimulating the horn may be attenuated, so as to yield a surface displacement less than the original 3 mils, thereby maintaining a substantially constant gap. Of course, in the context of an operation that requires at least 2 mils of displacement to produce an appropriate product, the electrical signal should not be attenuated to such an extent that the surface of the horn exhibits less than the required 2 mils of displacement.
An exemplary embodiment of a system for controlling the gap between a horn and an anvil is depicted in FIG. 12A . As can be seen from FIG. 12A , the system includes a horn 1200 (which, in turn, includes the converter and booster), which is supplied with an AC electrical signal from a power supply 1202 . The power supply 1202 communicates the resonant frequency of the horn 1200 to a gap determining module 1204 . (As described previously, the power supply 1202 detects the resonant frequency of the horn stack and drives the horn stack at that frequency.)
The gap determining module 1204 determines the length of the gap (or, may determine the change in the gap, or may determine any other value standing in known relation to the length of the horn), based upon the resonant frequency, as described previously. Thereafter, the gap length (or change therein) is supplied to an amplitude determining module 1206 . In response, the amplitude determining module identifies the proper amplitude of the electrical signal to be delivered by the power supply, in order to maintain the gap substantially constant. The amplitude may be retrieved from a look-up table, or may be arrived at by calculation. The amplitude determined thereby is communicated to a control signal generation module 1208 , which generates an appropriate command or control signal to cause the power supply 1202 to adjust the amplitude of the signal to that selected by the amplitude determination module 1206 .
As described previously, each of the modules 1204 - 1208 may be embodied as dedicated hardware, such as one or more ASICs cooperating with one another. Alternatively, the modules 1204 - 1208 may be embodied as software/firmware stored in a memory, and executed by a processor in communication therewith. If embodied as firmware/software, the instructions making up the modules 1204 - 1208 may be executed by the same processor, or may be executed by a plurality of processors, as a matter of design choice.
Another exemplary embodiment of a system for controlling the gap between a horn and an anvil is depicted in FIG. 12B . The system of FIG. 12B takes advantage of two different schemes by which the gap may be adjusted: (1) controlling the position of the horn, itself; and (2) controlling the amount of surface displacement exhibited by the horn. As can be seen from FIG. 12B , the system includes a horn 1210 (which, in turn, includes the converter and booster), which is supplied with an AC electrical signal from a power supply 1212 . The power supply 1212 communicates the resonant frequency of the horn 1210 to a gap determining module 1214 . (As described previously, the power supply 1212 detects the resonant frequency of the horn stack and drives the horn stack at that frequency.)
The gap determining module 1214 determines the length of the gap (or, may determine the change in the gap, or may determine any other value standing in known relation to the length of the horn), based upon the resonant frequency, as described previously. Thereafter, the gap length (or change therein) is supplied to an amplitude determining module 1216 and to an adjustor 1220 . The adjustor 1220 is a system that can alter the position of the horn, such as the adjusting systems shown in FIGS. 7 and 10 , which adjust the position of the horn by varying the deformation of an elastic stop by varying degrees. As was the case in the embodiment of FIG. 12A , the amplitude determining module 1216 identifies the proper amplitude of the electrical signal to be delivered by the power supply, in order to maintain the gap substantially constant. However, the amplitude determining unit 1216 cooperates with the adjustor 1220 to jointly adjust the position and/or adjust the amplitude of the AC signal delivered by the power supply 1212 , in order to achieve the end goal of substantially maintaining a constant gap.
For example, according to one embodiment, the amplitude determination unit 1216 and adjustor 1220 operate according to the method depicted in FIG. 13 . As shown therein, both modules 1216 and 1220 receive the gap length, or change therein, from the gap determining unit 1214 , as shown in operation 1300 . Thereafter, (assuming the embodiment in which the adjustor 1220 comprises a force applicator that forces the horn against a deformable elastic stop), the amplitude determination unit 1216 receives from the adjustor 1220 the force applied thereby (operation 1302 ). Next, as shown in operation 1304 , the force is compared to the lower limit of the acceptable force for the welding operation. If the force is still above the limit, then the adjustor 1220 determines the new force required for application, and adjusts the force accordingly (operation 1306 ). On the other hand, if the force has reached the lower limit, then the force should not be reduced any further, and control is passed to operation 1308 , in which it is determined whether the amplitude of the surface displacement has reached its lower limit. If not, control is passed to operation 1310 , whereupon the amplitude determining module 1216 identifies the proper amplitude of the electrical signal to be delivered by the power supply, in order to maintain the gap substantially constant. The amplitude determined thereby is communicated to a control signal generation module 1218 , which generates an appropriate command or control signal to cause the power supply 1212 to adjust the amplitude of the signal to that selected by the amplitude determination module 1216 . On the other hand, if the amplitude of the surface displacement has reached its lower limit, then control is passed to operation 1312 , and an alarm is generated to indicate that the gap cannot be maintained at a constant length without either reducing the process force beneath its acceptable limit, or reducing the surface displacement of the horn beneath its acceptable limit.
Although the operations of FIG. 13 are described as being performed by amplitude determination module 1216 , the operations may be performed by any of the modules depicted in FIG. 12B , or may be performed by another module dedicated to coordinating the operations of the amplitude determination module 1216 and the adjustor 1220 .
Further, it is to be noted that, in operation 1302 , the adjustor 1220 may communicate the position of the horn to the module performing the method of FIG. 13 . Then, in operation 1304 , the position of the horn may be compared to a positional limit expressing the capacity of the adjustor 1220 to withdraw the horn from the anvil. In other words, in operation 1304 , it is determined whether the adjustor 1220 has withdrawn the horn from the anvil as the adjust 1220 is able to do so.
According to another embodiment, the amplitude determination unit 1216 and adjustor 1220 operate according to the method depicted in FIG. 14 . As shown therein, both modules 1216 and 1220 receive the gap length, or change therein, from the gap determining unit 1214 , as shown in operation 1400 . Thereafter, (again assuming the embodiment in which the adjustor 1220 comprises a force applicator that forces the horn against a deformable elastic stop), the amplitude determination unit 1216 receives from the adjustor 1220 the force applied thereby (operation 1402 ). Next, as shown in operation 1404 , whereupon it is determined whether the amplitude of the surface displacement has reached its lower limit. If not, control is passed to operation 1406 , whereupon the amplitude determining module 1216 identifies the proper amplitude of the electrical signal to be delivered by the power supply 1212 , in order to maintain the gap substantially constant. The amplitude determined thereby is communicated to a control signal generation module 1218 , which generates an appropriate command or control signal to cause the power supply 1212 to adjust the amplitude of the signal to that selected by the amplitude determination module 1216 . On the other hand, if the amplitude of the surface displacement exhibited by the horn has reached the lower limit, then the force should not be reduced any further, and control is passed to operation 1408 , in which it is determined whether the force value received during operation 1402 is at the lower limit of the acceptable force for the welding operation. If the force is still above the limit, then the adjustor 1220 determines the new force required for application, and adjusts the force accordingly (operation 1410 ). On the other hand, if the force has reached the lower limit, then control is passed to operation 1412 , and an alarm is generated to indicate that the gap cannot be maintained at a constant length without either reducing the process force beneath its acceptable limit, or reducing the surface displacement of the horn beneath its acceptable limit.
Although the operations of FIG. 14 are described as being performed by amplitude determination module 1216 , the operations may be performed by any of the modules depicted in FIG. 12B , or may be performed by another module dedicated to coordinating the operations of the amplitude determination module 1216 and the adjustor 1220 .
Further, it is to be noted that, in operation 1402 , the adjustor 1220 may communicate the position of the horn to the module performing the method of FIG. 14 . Then, in operation 1408 , the position of the horn may be compared to a positional limit expressing the capacity of the adjustor 1220 to withdraw the horn from the anvil. In other words, in operation 1408 , it is determined whether the adjustor 1220 has withdrawn the horn from the anvil as the adjust 1220 is able to do so.
Upon reading and understanding the foregoing process for controlling an ultrasonic welding system, one of ordinary skill in the art will appreciate that gap control for a system can be achieved by measuring the operating frequency of the horn, and then adjusting the force, for example, pressure, that controls the gap. The specific equations can be derived or determined empirically for any horn geometry, including linear and rotary horns.
The various embodiments described above are provided by way of illustration only and should not be construed to limit the invention. Those skilled in the art will readily recognize various modifications and changes that may be made to the present invention without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the present invention, which is set forth in the following claims. | A system and method for adjusting the gap between a horn and an anvil in an ultrasonic welding system includes the act of positioning a horn proximal to an anvil, so that a gap is established between the horn and the anvil. A force is applied to the horn, so as to urge the horn toward the anvil. A deformable stop is positioned at a location, such that application of the urging force causes a member operatively connected to the horn to abut the deformable stop, and to deform the stop. The urging force is iteratively adjusted during operation of the horn, so as to adjust the extent of the deformation of the deformable stop, and to maintain the gap between the horn and the anvil substantially constant. | 1 |
This application is a U.S. national phase application under 35 U.S.C. of §371 of International Application No. PCT/EP2013/066354, filed Aug. 5, 2013, which claims priority to DE10 2012 107 199.3, filed on Aug. 6, 2012; the disclosures of which are all hereby incorporated by reference herein.
FIELD OF THE INVENTION
The invention relates to a method for producing carbon-coated metal oxide particles and also to their use as electrode material for lithium ion batteries.
BACKGROUND OF THE INVENTION
Lithium ion batteries currently constitute the leading technology within the field of rechargeable batteries, and they dominate the battery market for portable electronics. Applications for lithium ion batteries in electrical vehicles or in storage technologies for wind or solar energy, for example, nevertheless necessitate the development of rechargeable battery technologies and active materials having significantly higher specific energies and capacities than have hitherto been available commercially or at all. There is therefore need not only for an improvement of existing electrode materials, but also for development of new materials with suitability as the active material for lithium ion batteries.
New electrode materials follow in principle two different mechanisms of lithium acceptance, either the reversible formation of an alloy with lithium, as in the case of silicon, tin, antimony, aluminum, or zinc, or the so-called conversion reactions, such as for cobalt oxide, nickel oxide, iron oxide, or copper oxide, for example. Alloy-forming materials, however, suffer severe changes in volume as a result of lithium acceptance and release, thereby destroying the material and causing a loss of electronic contact between active material and current collector. Nevertheless, materials which form reversibly alloys with lithium are currently viewed as the more promising for short-term industrial applications. In 2005, for example, Sony announced the marketing of the Nexelion™ battery, which is based on an Sn—Co—C composite as anode material. Research is presently focused on silicon-based or tin-based electrode materials, whereas zinc, as a potential replacement for the graphite normally used commercially as anode material, is finding little attention, despite promising results achieved with ZnO—Fe 2 O 3 —, ZnO 1-x S x —, and Al 2 O 3 -doped thin-film ZnO structures. However, the electrodes in question have been produced by means of complex methods such as magnetron sputtering, and only thin layers of the active material are characterized. These layers are poorly suited as active material for lithium ion cells with high energy density. Apart from the less-suitable methods of electrode production for industrial applications, furthermore, the materials exhibit an inadequate specific capacity. Moreover, the irreversible formation of Li 2 O in the first cycle leads to a loss of capacity.
Specification U.S. Pat. No. 3,330,697 further describes the so-called Pecchini process for producing perowskitic compounds. Disadvantages of this, however, include firstly the volume expansion that occurs and secondly the formation of nitrogen-containing gases in the course of this combustion-based synthesis process starting from metal nitrates.
SUMMARY OF THE INVENTION
It was an object of the present invention, accordingly, to provide a method for producing a ZnO-based electrode material that is suitable for use as electrode material with enhanced specific capacity and cycling stability in a lithium ion battery.
This object is achieved by a method for producing carbon-coated particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14, comprising the following steps:
a) mixing stoichiometric amounts of a Zn salt and of a transition metal salt with a sugar in a solvent; b) drying the mixture from step a); c) calcining the dried mixture from step b); d) mixing the M x Zn 1-x O particles obtained from step c) with a sugar in a solvent; e) carbonizing the mixture from step d).
The method of the invention provides a simple and cost-effective synthesis opportunity for carbon-coated, transition metal-doped zinc oxide particles having a size in the nanometer range. The steps of the method can be performed under mild conditions and without costly and inconvenient apparatus-based operations. This further permits an industrial implementation that is easily realizable. Especially in comparison to the known wet-chemical Pecchini process for producing perowskitic materials, which uses nitrate solutions in a stoichiometric mixture, the expansion in volume can be reduced by the sole use of sugar as growth inhibitor for the particles. In addition it is possible to avoid the disadvantage of the formation of nitrogen-containing gases in combustion-based synthesis processes starting from metal nitrates.
It has further been found, surprisingly, that the use of carbon-coated particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14 as electrode material, more particularly for lithium-based energy storage devices, can provide, these being distinguished by a significantly increased specific capacity and superior cycling stability relative to the use of zinc oxide.
The term “calcining” refers in the sense of the present invention, generally, to a thermal treatment step in the presence of oxygen, such as in the presence of air, for example; in other words, the heating of a material with the goal of its decomposition. The material to be decomposed is the sugar in accordance with the invention. The term “carbonizing” refers in the sense of the present invention to a thermal treatment step for converting a carbon source, more particularly a sugar as carbon-containing starting material, into a carbon-containing residue in the absence of oxygen or hydrogen.
The method is more particularly a method for producing an electrode material, more particularly for lithium-based energy storage devices, comprising carbon-coated particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14.
The term “particle” is used in the sense of the present invention synonymous to “particle”. The term “M x Zn 1-x O particles” refers in the sense of the present invention to zinc oxide compounds doped with the transition metal M. The ratio of transition metal M to zinc here may be in the range from x≧0.02 to ≦0.14:1-x, preferably in the range from x≧0.05 to ≦0.13:1-x, more particularly 0.1:0.9. The ratio of transition metal M to zinc, more particularly of iron to zinc, may also be in the range from x≧0.04 to ≦0.13:1-x, preferably in the range from x≧0.06 to ≦0.12:1-x.
The term “stoichiometric amount” refers in the sense of the present invention to the amount of the zinc salt and transition metal salt required in each case, in accordance with the ratio of the equivalent weights, for producing the respective M x Zn 1-x oxide. To produce M 0.1 Zn 0.9 O, accordingly, 0.9 mol of zinc(II) gluconate and 0.1 mol of iron gluconate were used.
The salts of zinc and transition metal are preferably water-soluble organic salts. Organic salts have the advantage that the organic counterion can be removed from the reactant mixture at the calcining stage, more particularly in the form of carbon dioxide. The term “water-soluble” in the sense of the present invention means that the salt can be dissolved to an extent of at least 0.5 mol/l in water. Preference is given to readily soluble salts having a solubility of greater than 1 mol/l. In preferred embodiments of the method, the salts of zinc and transition metal are an organic salt selected from the group comprising gluconates, citrates, acetates, formates, butyrates, lactates, glycolates, tartrates, propionates and/or succinates. Preference is given to gluconates, citrates, and acetates, more particularly gluconates. Zinc gluconates and transition metal gluconates are readily soluble in water.
The sugar is preferably a mono-, di- or polysaccharide, more particularly selected from the group comprising glucose, fructose, sucrose, lactose, starch, cellulose and/or derivates thereof. Especially preferred is sucrose. Sugars dissolve well in water. The water-soluble di- or monosaccharides such as sucrose and lactose and also glucose and fructose are therefore preferred.
The solvent is preferably water. With preference no citric acid is added to the sugar solution. This has the advantage that there is a lower expansion in volume in the course of calcining. It has further been found that when water is used as solvent, without addition of citric acid, smaller particles have been obtainable that with addition of citric acid. It has also been possible to record a lower level of agglomeration of the particles.
For example, first of all solutions of the sugar and of the separately or jointly dissolved salts in the solvent can be prepared, and then the solution of the metal salts can be added to the sugar solution. It is preferred for stoichiometric amounts of the zinc salt and of the transition metal salt to be dissolved jointly. The sugar is preferably dissolved in small amounts of water, to give a viscous solution. The ratio of the concentration of the metal ions and of the sugar is preferably in the range from 1:1 to 1:50, preferably in the range from 1:2 to 1:20, more preferably in the range from 1:4 to 1:10, more particularly 1:6. A ratio of 1:6 has emerged as being an especially suitable ratio for achieving particle growth in the desired size range and preventing oxidation of the transition metals.
The mixing may take place at ambient or room temperature. The drying of the mixture prior to calcining takes place preferably at a temperature in the range from ≧70° C. to ≦300° C., more preferably in the range from 120° C. to ≦300° C., very preferably in the range from ≧150° C. to ≦300° C. Drying may be performed in the air. Drying before calcining has the advantage that there is no further expansion in volume during the calcining of the dried mixture. Prior to drying, the solvent can first of all be evaporated, at 150° C. to 180° C., for example. By this means the sugar can be dehydrated.
As a result of the calcining, the sugar and also the organic anions of the metal salts are removed from the mixture, and zinc oxide particles doped with the transition metal of the formula M x Zn 1-x O, are formed. In preferred embodiments, the calcining is performed at a temperature in the range from ≧300° C. to ≦500° C., preferably in the range from ≧350° C. to ≦450° C., more preferably in the range from ≧400° C. to ≦450° C. These temperatures are able to ensure that reduction of the metal cations to the pure metal can be avoided.
Advantageously in this way it is possible to obtain transition metal-doped zinc oxide particles having a size in the nanometer range. The particles preferably have a spherical or ball shape. More particularly, the transition metal-doped zinc oxide particles can have an average diameter in the range from ≧10 nm to ≦200 nm, preferably in the range from ≧15 nm to ≦50 nm, more preferably in the range from ≧20 nm to ≦30 nm. The term “average diameter” refers to the average value of all diameters or arithmetically averaged diameters, relative to all particles. Particles having a size in the nanometer range are able to provide high specific surface area. This permits a large contact area of the particles with an electrolyte, and hence a large number of possible reaction sites with the Li + ions present in the electrolyte.
The calcined particles may optionally be comminuted or pulverized, in a mortar, for example.
Without being tied to any particular theory, it is assumed that the sugar as growth inhibitor brings about the formation of transition metal-doped zinc oxide having a particle size in the nanometer range. The transition metal-doped zinc oxide particles obtained from the calcining can be used as electrode material. It is nevertheless preferable for the particles to be provided with a carbon coating in the ongoing method. A carbon coating leads advantageously to a significant enhancement of the electronic conductivity of the material.
For this purpose, the M x Zn 1-x O particles can again be mixed with a sugar in a solvent. The sugar is preferably a mono-, di-, or polysaccharide, more particularly selected from the group comprising glucose, fructose, sucrose, lactose, starch, cellulose and/or derivatives thereof. Especially preferred is sucrose. It is preferable to use the same sugar for calcining and carbonizing. The solvent is preferably water. For example, the sugar can be dissolved in the solvent and then the transition metal-doped zinc oxide particles can be added and dispersed with the sugar dispersed in the solvent. The term “dispersing” means the mixing of at least two substances which undergo little or no dissolution in one another or chemical bonding with one another, an example being the distribution of the particles as a disperse phase in a sugar solution as a continuous phase. A distribution as uniform as possible of the particles in an aqueous sugar solution is preferred, in order to obtain as uniform as possible wetting of the particles with the sugar. The dispersing may be performed, for example, in a ball mill, over a period of 1 to 2 hours, as for example for 1.5 hours. The sugar is preferably dissolved in small amounts of water, to give a viscous solution. Sugar and transition metal-doped zinc oxide particles are preferably mixed in a ratio by mass in the range from 1:50 to 10:1, more preferably in the range from 1:10 to 2:1, very preferably in the range from 1:2 to 1:1, more particularly at 3:4.
The mixture is preferably dried before the carbonizing. By this means the sugar can be dehydrated. Drying may take place at a temperature in the range from ≧18° C. to ≦100° C., preferably in the range from ≧20° C. to ≦80° C., more preferably in the range from ≧23° C. to ≦50° C. Drying may be performed in particular at ambient temperature, as for example in the range from ≧18° C. to ≦23° C. The drying may be carried out in the air. The dried mixture may optionally then be comminuted or pulverized in a mortar, for example. By this means, sugar-wetted particles which have undergone sticking or clumping as a result of the drying can be parted from one another again.
Thereafter the mixture is carbonized. The carbonizing forms a carbon coating on the transition metal-doped zinc oxide particles. The carbonizing is preferably performed under an inert gas atmosphere, of argon, nitrogen, or mixtures thereof, for example. By this means it is possible to prevent unwanted secondary reactions such as oxidation of the carbon coating. In preferred embodiments the carbonizing is performed at a temperature in the range from ≧350° C. to ≦700° C., preferably in the range from ≧400° C. to ≦600° C., more preferably in the range from ≧450° C. to ≦550° C. Advantageously, these conditions are mild, and so there is no further reduction of the doped zinc oxides. The temperatures and conditions are more particularly selected such that both zinc and the transition metal are not reduced to the pure metals.
The carbonizing may be performed, for example, for a period in the range from ≧1 h to ≦24 h, preferably in the range from ≧2 h to ≦12 h, preferably in the range from ≧3 h to ≦6 h. After the carbonizing, the carbon-coated particles obtained may be comminuted or pulverized, by mortaring, for example.
The method using sugar provides, in particular, a mild method for producing carbon-coated M x Zn 1-x O particles. The method further has the advantage of releasing only CO 2 , which is nontoxic. With sugar as carbon source and water as solvent, favorable starting materials can be used. Moreover, the method does not require any costly and inconvenient apparatus, meaning that industrial application can be realized easily and quickly.
The carbon-coated M x Zn 1-x O particles can be used in particular as electrode material for the production of anodes for lithium ion batteries.
The carbon coating applied by the carbonizing results advantageously in a significant increase in the electronic conductivity of the material. This is a great advantage particularly for subsequent use as electrode material in lithium ion batteries, since it enables very good to good charge states of the active material to be achieved even in the case of very high applied current densities. Furthermore, the carbon coating is able to act as a buffer for the volume expansion and volume reduction which occur in the course of lithiation and dilithiation. This raises the cycling stability of the electrode and results in a higher achievable cycle number at virtually constant capacity. Furthermore, the carbon coating not only contributes to a significant improvement in the electronic conductivity, but also is electrochemically active itself within the potential range utilized, and is able to store lithium ions. The carbon cladding, moreover, prevents physical contact of the nanoparticles and therefore actively counteracts particle agglomeration in the course of electrode production and cycling.
A particular advantage is that sucrose can be converted to amorphous carbon by the carbonizing procedure. Amorphous carbon not only possesses a high electronic conductivity, but at the same time is permeable to the electrolyte and to the lithium ions. Furthermore, amorphous carbon is especially suitable for cushioning an expansion in volume of the particles during the charging and discharge of the electrodes.
A further subject of the invention relates to carbon-coated particles, obtainable by the method of the invention, of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14.
As active material, the carbon-coated M x Zn 1-x O particles obtainable with the method of the invention are notable for superior cycling stability in the electrodes produced from them, and significantly increased specific capacity and significantly reduced loss of capacity in the first cycle, relative to the use of zinc oxide. Moreover, electrodes based on the use of M x Zn 1-x O particles, and more particularly those based on the use of carbon-coated M x Zn 1-x O particles, as active material, exhibit a superior specific capacity for increasing applied current densities, which are higher by a factor of around three than those achievable when using ZnO. In comparison to graphite as well, which is presently the most widely used anode material, specific capacities which are more than twice as high can be achieved for a wide bandwidth of applied current densities.
In the M x Zn 1-x O particles, x is between 0.02 and 0.14. Higher proportions of transition metal can lead to a phase transition of the doped zinc oxide particles in the course of calcining. The ratio of transition metal M to zinc may be preferably in the range from x≧0.05 to ≦0.13:1-x, more particularly 0.1:0.9. The transition metal M is preferably iron or cobalt. The ratio of transition metal M to zinc, more particularly of iron to zinc, may also be in the range from x≧0.04 to ≦0.13:1-x, preferably in the range from x≧0.06 to ≦0.12:1-x. Particularly preferred particles are carbon-coated Co 0.1 Zn 0.9 O and Fe 0.1 Zn 0.9 O particles. Further particularly preferred particles are carbon-coated Co 0.12 Zn 0.88 O and Fe 0.12 Zn 0.88 O particles. It has been found, for example, that in the range 0.02≦x≦0.12, the iron fraction was advantageous for the achievable specific capacity and discharge rate. Overall, a transition metal fraction with these ranges, more particularly of 0.02≦x≦0.12 is advantageous for an electrode produced from this material.
The fraction of carbon, based on the total weight of the carbon-coated M x Zn 1-x O particles, is preferably in the range from 0.5 wt % to ≦70 wt %, preferably in the range from 2 wt % to ≦30 wt %, more preferably in the range from ≧5 wt % to ≦20 wt %. It has been found that in a range from ≧5 wt % to ≦20 wt % of carbon, with increasing carbon content, the density and crystallinity and also the specific surface area showed an advantageous combination, especially in the range from ≧12 wt % to ≦20 wt % of carbon. The carbon-coated particles preferably have a BET surface area in the range from ≧1 m 2 /g to ≦200 m 2 /g, more preferably in the range from ≧50 m 2 /g to ≦150 m 2 /g, very preferably in the range from ≧70 m 2 /g to ≦130 m 2 /g.
Advantageously there is no substantial increase in the average diameter of the transition metal-doped zinc oxide particles as a result of the carbonizing procedure. Hence the carbon-coated, transition metal-doped zinc oxide particles can have an average diameter in the range from ≧15 nm to ≦250 nm, preferably in the range from ≧20 nm to ≦80 nm, more preferably in the range from ≧25 nm to ≦50 nm.
The invention further relates to the use of M x Zn 1-x O particles, more particularly of carbon-coated particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14, as electrode material for electrochemical energy storage devices, more particularly alkali metal ion batteries or supercapacitors.
A further subject of the invention relates to an electrode material for electrochemical energy storage devices, more particularly alkali metal ion batteries or supercapacitors, comprising M x Zn 1-x O particles, more particularly carbon-coated particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14.
A further subject of the invention relates to an electrode comprising M x Zn 1-x O particles, more particularly carbon-coated particles of M x Zn 1-3 O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14.
Electrodes just comprising particles of M x Zn 1-3 O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14 are notable for an increased specific capacity, improved cycling stability and a reduced irreversible capacity loss at the start, relative to the use of zinc oxide. More particularly, electrodes comprising carbon-coated M x Zn 1-x O particles are notable for a further significant increase in the specific capacity and in the cycling stability, and also for reduced irreversible capacity loss at the start.
In the M x Zn 1-x O particles, x is between 0.02 and 0.14. The ratio of transition metal M to zinc may be preferably in the range from x≧0.05 to ≦0.13:1-x, more particularly 0.1:0.9. The transition metal M is preferably iron or cobalt. The ratio of transition metal M to zinc, more particularly of iron to zinc, may also be in the range from x≧0.04 to ≦0.13:1-x, preferably in the range from x≧0.06 to ≦0.12:1-x. Particularly preferred particles are carbon-coated Co 0.1 Zn 0.9 O and Fe 0.1 Zn 0.9 O particles. The fraction of carbon, based on the total weight of the carbon-coated M x Zn 1-x O particles, is preferably in the range from 0.5 wt % to ≦70 wt %, preferably in the range from 2 wt % to ≦30 wt %, more preferably in the range from ≧5 wt % to ≦20 wt %. The carbon-coated particles preferably have a BET surface area in the range from ≧1 m 2 /g to ≦200 m 2 /g, more preferably in the range from ≧50 m 2 /g to ≦150 m 2 /g, very preferably in the range from ≧70 m 2 /g to ≦130 m 2 /g. Additionally the carbon-coated, transition metal-doped zinc oxide particles can have an average diameter in the range from ≧15 nm to ≦250 nm, preferably in the range from ≧20 nm to ≦80 nm, more preferably in the range from ≧25 nm to ≦50 nm.
For the description of the particles, reference is made to the description above. These particles form the material of the electrode which is commonly identified as active material and which carries out, for example, reversible acceptance and release of lithium. This material may further comprise binders and additives. Correspondingly, the active material of an electrode may be formed from the particles or consist substantially thereof. The active material is usually applied to a metal foil, such as a copper foil or aluminum foil, for example, or to a carbon-based current collector foil which acts as a current collector. Since the active material accounts for the substantial part of the electrode, the electrode may in particular also be formed of or based on M x Zn 1-x O particles, more particularly carbon-coated M x Zn 1-x O particles. An electrode of this kind is commonly referred to as a composite electrode. In preferred embodiments the electrode is a composite electrode comprising M x Zn 1-x O particles, more particularly carbon-coated M x Zn 1-x O particles, binder, and optionally conductive carbon.
In the case of carbon-coated M x Zn 1-x O particles there is no need to use additional carbon for producing an electrode. Advantageously, the carbon network of the carbon coating is able to provide sufficient electrical conductivity on the part of the electrode. Provision may be made, however, to add further carbon for producing an electrode. This allows the conductivity of the electrode to be increased further.
Carbon may also be added prior to carbonizing, and may for example be dispersed in the sugar solution together with the M x Zn 1-x O particles themselves. Preference is given to adding carbon only during the production of an electrode. With preference, conductive carbon can be added at a weight ratio of particles to carbon in the range from ≧1:10 to ≦40:1, preferably in the range from ≧7:3 to ≦20:1, and especially particularly at a weight ratio in the range from ≧3:1 to ≦4:1. Examples of preferred carbon-containing materials are carbon black, synthetic or natural graphite, graphene, carbon nanoparticles, fullerenes, or mixtures thereof. One carbon black which can be used is available, for example, under the trade name Ketjenblack®. A carbon black which can be used with preference is available, for example, under the trade name Super P® and Super P Li®. The carbon-containing material may have an average particle size in the range from 1 nm to 500 μm, preferably from 5 nm to 1 μm, more preferably in the range from 10 nm to 60 nm. The average diameter of the carbon particles may 20 μm or less, preferably 15 μm or less, more preferably 10 μm or less, very preferably in the range from 10 nm to 60 nm.
The fraction of uncoated or carbon-coated M x Zn 1-x O particles, based on the total weight of particles, binder, and conductive carbon, is preferably in the range from ≧10 wt % to ≦98 wt %, more preferably in the range from 50 wt % to ≦95 wt %, very preferably in the range from ≧75 wt % to ≦85 wt %. The fraction of added conductive carbon based on the total weight of the composite electrode made up of uncoated or carbon-coated M x Zn 1-x O particles, binder, and conductive carbon, is preferably in the range from ≧0 wt % to ≦90 wt %, more preferably in the range from 2 wt % to ≦50 wt %, very preferably in the range from ≧5 wt % to ≦20 wt %.
The composite electrode may further comprise binders. Suitable binders are, for example, poly(vinylidene difluoride-hexafluoropropylene) (PVDF-HFP) copolymer, polyvinylidene fluoride (PVDF), polyethylene oxide (PEO), styrene-butadiene rubber (SBR), carboxymethylcellulose (CMC), as for example sodium carboxymethylcellulose (Na-CMC), or polytetrafluorethylene (PTFE) and cellulose, more particularly natural cellulose, and also suitable combinations of different binders. A preferred binder is carboxymethylcellulose (CMC), such as sodium carboxymethylcellulose (Na-CMC). The composite electrode preferably comprises carboxymethylcellulose as binder. Carboxymethylcellulose is more eco-friendly and more cost-effective by comparison with binders used in customary commercial batteries. In particular, carboxymethylcellulose is water-soluble. Hence carboxymethylcellulose permits the use of water as a dispersion medium for electrode production. Furthermore, in contrast to the use of fluorene-containing binders, carboxymethylcellulose allows easy recycling of the electrode materials at the end of the life cycle of the batteries, by pyrolysis. The composite electrode, based on the total weight of uncoated or carbon-coated M x Zn 1-x O particles, binder, and optionally conductive carbon, preferably has a binder fraction in the range from ≧1 wt % to ≦50 wt %, more preferably in the range from ≧2 wt % to ≦15 wt %, more preferably in the range from ≧3 wt % to ≦10 wt %. For example, the fraction of binder may be 5 wt %, based on the total weight. The dry weight of a mixture of uncoated or carbon-coated M x Zn 1-x O particles, binder, and conductive carbon may for example have 75 wt % of carbon-coated M x Zn 1-x O particles, 20 wt % of conductive carbon black, and 5 wt % of binder, carboxymethylcellulose for example, based on the total weight of the mixture.
The production of an electrode may comprise the steps of mixing the uncoated or carbon-coated M x Zn 1-x O particles with carbon black, and mixing the solids mixture with a binder in solution in solvent—for example, carboxymethylcellulose in solution in water—and applying the mixture to a conductive substrate, and drying the resulting electrodes. The mixture may be applied, for example, with a wet film thickness in the range from ≧20 μm to ≦2 mm, preferably in the range from ≧90 μm to ≦500 μm, more preferably in the range from ≧100 μm to ≦200 μm. The surface coverage of the electrode may be in the range from ≧0.2 mg cm −2 to ≦30 mg cm −2 , preferably in the range from ≧1 mg cm −2 to ≦150 mg cm −2 , more preferably in the range from ≧2 mg cm −2 to ≦10 mg cm −2 .
A further subject of the invention relates to an electrochemical energy storage device, more particularly an alkali metal ion battery or a supercapacitor, preferably primary lithium batteries, primary lithium ion batteries, secondary lithium ion batteries, primary lithium polymer batteries, or lithium ion capacitors, comprising an electrode of the invention.
The term “electrochemical energy storage device” encompasses single-use batteries (primary storage cells) and rechargeables (secondary storage cells). In the general terminology, however, rechargeables are frequently designated likewise using the term “battery”, which is widely used as a generic term. For example, the term “lithium ion battery” is used synonymously with “rechargeable lithium ion battery”. Lithium-based energy storage devices are preferably selected from the group comprising primary lithium batteries, primary lithium ion batteries, secondary lithium ion batteries, primary lithium polymer batteries, or lithium ion capacitors. Preference is given to primary and secondary lithium ion batteries.
Furthermore, however, the transition metal-doped zinc oxide particles can also be used independently of electrochemical energy storage devices. A further subject of the invention relates to the use of particles of M x Zn 1-x O wherein M is a transition metal selected from the group comprising Fe, Co, Ni, Mn and/or Cu and 0.02≦x≦0.14 as color pigment for ceramic materials or applications. In particular, Fe x Zn 1-x O and Co x Zn 1-x O particles are highly suitable for use as color pigments, on account of their intense yellow-orange and/or green color.
Examples and figures which serve for illustrating the present invention are indicated hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
The figures, in this context, show the following:
FIG. 1 shows X-ray diffractograms. FIG. 1 a ) shows the X-ray diffractogram of the Fe 0.1 Zn 0.9 O particles and also the signals of the JCPDS files of Co 0.15 Zn 0.85 O; FIG. 1 b ) shows that of the carbon-coated Fe 0.1 Zn 0.9 O particles, and also, likewise, the signals of the JCPDS file for Co 0.15 Zn 0.85 O.
FIG. 2 shows scanning electron micrographs (200 000× magnification) of the Fe 0.1 Zn 0.9 O particles obtained after calcining, in FIG. 2 a ) and also, in FIG. 2 b ), shows the carbon-coated Fe 0.1 Zn 0.9 O particles obtained after carbonizing with sugar.
FIG. 3 shows in FIG. 3 a ) the X-ray diffractogram of the Co 0.1 Zn 0.9 O particles and also the signals of the JCPDS file of Co 0.15 Zn 0.85 O, and also, in FIG. 3 b ), shows a scanning electron micrograph (200 000× magnification) of the Co 0.1 Zn 0.9 O particles.
FIG. 4 shows in FIG. 4 a ) the X-ray diffractogram of the ZnO particles and also the signals of the JCPDS file of ZnO, and also, in FIG. 4 b ), shows a scanning electron micrograph (200 000× magnification) of the ZnO particles.
FIG. 5 shows the capacity characteristics of a composite electrode comprising zinc(II) oxide particles over 100 cycles with increasing charge and discharge rates.
FIG. 6 shows the capacity characteristics of a composite electrode comprising Fe 0.1 Zn 0.9 O particles over 100 cycles with increasing charge and discharge rates.
FIG. 7 shows the capacity characteristics of a composite electrode comprising carbon-coated Fe 0.1 Zn 0.9 O particles over 100 cycles with increasing charge and discharge rates.
FIG. 8 shows the capacity characteristics of a composite electrode comprising Co 0.1 Zn 0.9 O particles over 21 cycles with increasing charge and discharge rates.
FIG. 9 shows the voltage profile of a composite electrode comprising carbon-coated Fe 0.1 Zn 0.9 O particles against metallic sodium.
FIG. 10 shows the capacity characteristics of composite electrodes comprising carbon-coated Fe x Zn 1-x O particles over 70 cycles with increasing charge and discharge rates. In this figure, FIG. 10 a ) shows the capacity characteristics of Fe 0.12 Zn 0.88 O particles, FIG. 10 b ) that of Fe 0.1 Zn 0.9 O particles, FIG. 10 c ) that of Fe 0.08 Zn 0.92 O particles and FIG. 10 d ) that of Fe 0.06 Zn 0.94 O particles.
DETAILED DESCRIPTION OF THE INVENTION
Example 1
Production of Carbon-Coated Fe 0.1 Zn 0.9 O Particles
a) Production of Fe 0.1 Zn 0.9 O Particles
Stoichiometric amounts of 8.204 g of zinc(II) gluconate hydrate (ABCR, 97% purity) and 0.965 g of iron gluconate dihydrate (Sigma-Aldrich, 98% purity) were dissolved in 100 ml of deionized water (Millipore) to give a total metal ion concentration of 0.2 M. This solution was added slowly with stirring to a 1.2 M solution of sucrose (Acros Organics, 99+%) in deionized water. After a further 15 minutes of stirring at room temperature, the solvent was evaporated at 150° C. to 180° C. The solid obtained was then dried at 300° C. for 10-20 minutes. The dried solid was then roughly comminuted by hand, and heated in an air atmosphere at 450° C. for 3 hours. During this time, the temperature was increased in an oven (R50/250/12, Nabertherm) with a heating rate of about 2.5° C. to 3° C. min −1 , corresponding to a heating-up time of 2.5 hours. After the calcining, the sample obtained was briefly mortared by hand, giving a very fine powder after just about 30 seconds.
The morphology of the Fe 0.1 Zn 0.9 O particles obtained after calcining was determined by X-ray powder diffractometry (XRD) using a Bruker D8 Advance (Cu-Kα radiation, λ=0.154 nm) X-ray diffractometer. FIG. 1 a ) shows the X-ray diffractogram of the particles obtained, and also the signals of the JCPDS file (Joint Committee of Powder Diffraction Standards) for Co 0.15 Zn 0.85 O with P63mc space group (JCPDS 01-072-8025). As can be seen from FIG. 1 a ), the signals observed for the calcined Fe 0.1 Zn 0.9 O particles were unambiguously assignable to the signals of Co 0.15 Zn 0.85 O, which has a virtually identical structure and was therefore utilized as reference, since there is no corresponding reference available for iron-doped zinc oxide.
b) Carbon Coating of the Fe 0.1 Zn 0.9 O Particles
0.75 g of sucrose (Acros Organics, 99+%) was dissolved with stirring in 3.5 ml of deionized water. Then 1 g of the Fe 0.1 Zn 0.9 O particles from step a) was added and the mixture was homogenized for 1.5 hours in a ball mill (Vario-Planetary Mill Pulverisette 4, Fritsch) at 800 rpm. The resulting mixture was dried in the air at 80° C. overnight and then heated in an argon atmosphere at 500° C. for 4 hours with a heating rate of about 3° C. min −1 . The solid obtained was then mortared by hand.
The morphology of the carbon-coated Fe 0.1 Zn 0.9 O particles (Fe 0.1 Zn 0.9 O—C) was determined again by X-ray powder diffractometry. FIG. 1 b ) shows the X-ray diffractogram of the carbon-coated particles obtained, and also the signals of the JCPDS file for Co 0.15 Zn 0.85 O. As can be seen from FIG. 1 b ), the signals observed for the carbon-coated particles again corresponded unambiguously to the signals of Co 0.15 Zn 0.85 O, whose crystal structure is virtually identical to that of Fe 0.1 Zn 0.9 O. This shows that the carbonizing with sucrose has not adversely affected the phase purity of the Fe 0.1 Zn 0.9 O particles. The absence of further reflections such as for graphitic carbon shows additionally that a coating of amorphous carbon has been formed.
The presence of carbon was confirmed by means of CHN elemental analysis (CHN-O-Rapid, Heraeus). The fraction of carbon was determined by thermogravimetric analysis (TGA) under O 2 (TA Instruments Q5000) to be 18.6 wt %, based on the total weight of the particles.
FIG. 2 a ) shows further a scanning electron micrograph (ZEISS Auriga® electron microscope, 200 000 times magnification) of the nanoparticulate Fe 0.1 Zn 0.9 O obtained after calcining, while FIG. 2 b ) shows the carbon-coated Fe 0.1 Zn 0.9 O particles obtained after carbonizing with sugar. From the scanning electron micrograph, the average diameter of the Fe 0.1 Zn 0.9 O particles was determined as being about 20 nm to 30 nm. A comparison of the micrographs shows that the particle size after carbonizing was still in the range from 25 nm to 40 nm and was therefore largely preserved even after the carbon coating procedure.
Example 2
Production of Co 0.1 Zn 0.9 O Particles
Stoichiometric amounts of 4.102 g of zinc(II) gluconate hydrate (ABCR, 97% purity) and 0.449 g of cobalt(II) gluconate dihydrate (ABCR, >97% purity) were dissolved in 50 ml of deionized water (Millipore) to give a total metal ion concentration of 0.2 M. This solution was added slowly with stirring to a 1.2 M solution of sucrose (Acros Organics, 99+% purity) in deionized water. After a further 15 minutes of stirring at room temperature, the solvent was evaporated at 150° C. to 180° C. The solid obtained was then dried at 300° C. for 10 to 20 minutes. The dried solid was then roughly comminuted by hand, and heated in an air atmosphere at 400° C. for 3 hours. During this time, the temperature was increased in an oven (R50/250/12, Nabertherm) with a heating rate of about 2.5° C. to 3° C. min −1 , corresponding to a heating-up time of 2.5 hours.
The morphology of the Co 0.1 Zn 0.9 O particles was determined by X-ray powder diffractometry (XRD) using a Bruker D8 Advance (Cu-Kα radiation, λ=0.154 nm) X-ray diffractometer. FIG. 3 a ) shows the X-ray diffractogram and also the signals of the JCPDS file (Joint Committee of Powder Diffraction Standards) for Co 0.15 Zn 0.85 O with P63mc space group (JCPDS 01-072-8025). As can be seen from FIG. 3 a ), the signals observed for the calcined particles were unambiguously assignable to the signals of Co 0.15 Zn 0.85 O, which serves in this case too as a reference, since the crystal structure is therefore virtually identical and there is no in-house reference available for Co 0.1 Zn 0.9 O.
FIG. 3 b ) shows a scanning electron micrograph (ZEISS Auriga® electron microscope, 200 000 times magnification) of the Co 0.1 Zn 0.9 O particles obtained. From the micrograph, the average diameter of the Co 0.1 Zn 0.9 O particles was determined as being about 25 nm to 40 nm.
Example 3
Production of ZnO Particles
4.558 g of zinc(II) gluconate hydrate (ABCR, 97% purity) were dissolved in 50 ml of deionized water (Millipore) to a metal ion concentration of 0.2 M. This solution was added slowly with stirring to a 1.2 M solution of sucrose (Acros Organics, 99+% purity) in deionized water. After a further 15 minutes of stirring at room temperature, the solvent was evaporated at 150° C. to 180° C. The resulting solid was then dried at 300° C. for 10 to 20 minutes. The dried solid was then roughly comminuted by hand and heated under an air atmosphere at 450° C. for 3 hours. During this time the temperature was increased in an oven (R50/250/12, Nabertherm) with a heating rate of about 2.5° C. to 3° C. min −1 , corresponding to a heating-up time of 2.5 hours.
The morphology of the ZnO particles was determined by X-ray powder diffractometry (XRD) using a Bruker D8 Advance (Cu-Kα radiation, λ=0.154 nm) X-ray diffractometer. FIG. 4 a ) shows the X-ray diffractogram of the particles obtained, and also the signals of the JCPDS (Joint Committee of Powder Diffraction Standards) file for ZnO with P63mc space group (JCPDS 01-071-6424). As can be seen from FIG. 4 a ), the signals observed for the calcined particles were clearly assignable to the signals of ZnO. FIG. 4 b ) shows a scanning electron micrograph (ZEISS Auriga® Electron microscope, 200 000 times magnification) of the ZnO particles obtained. From the micrograph, the average diameter of the ZnO particles was determined as being about 25 nm to 40 nm.
Example 4
Electrode Production
For the production of electrodes, the uncoated and carbon-coated Fe 0.1 Zn 0.9 O particles produced according to examples 1a and 1b, and also the uncoated Co 0.1 Zn 0.9 O and ZnO particles produced according to examples 2 and 3, were used with conductive carbon and carboxymethylcellulose (CMC) as binder, in a weight ratio of 75:20:5.
First of all, sodium carboxymethylcellulose (CMC, WALOCEL™ CRT 2000 PPA 12, Dow Wolff Cellulosics) was dissolved in deionized water, giving a solution containing 1.25 wt % of carboxymethylcellulose. The particles produced according to examples 1 to 3 and Super P® conductive carbon (TIMCAL®, Switzerland) as conductivity additive were added and the mixture was homogenized using a ball mill (Vario-Planetary Mill Pulverisette 4, Fritsch) at 800 rpm for 2 hours. The suspension thus obtained was applied with a doctor blade, with a wet film thickness of 120 μm, to copper foil (Schlenk). The electrode was dried in air at 80° C. for 2 hours and then at room temperature (20±2° C.) for 12 hours.
Subsequently, circular electrodes with a diameter of 12 mm and an area of 1.13 cm 2 were punched out and dried under reduced pressure at 120° C. for 12 hours. The surface coverage was approximately 1.8 to 2.2 mg cm −2 . The surface coverage was determined by weighing of the pure foil and of the electrodes punched out.
Electrochemical Investigations
The electrochemical investigation of the electrodes produced according to example 4 took place in three-electrode Swagelok™ cells with lithium metal foils (Chemetall, “battery grade” purity) as counter electrodes and reference electrodes, or, in example 9, with sodium metal foils as counter electrode and reference electrode. The cell was assembled in a Glovebox (MBraun) filled with an inert argon gas atmosphere and having an oxygen content and water content of less than 0.5 ppm. An electrolyte-impregnated stack of nonwoven polypropylene web (Freudenberg, FS2226) was used as separator in a 1 M solution of LiPF 6 in a 3:7 mixture, based on the weight, of ethylene carbonate and diethyl carbonate (“battery grade” purity, UBE, Japan) as electrolyte.
Because lithium foil was used as counterelectrode and reference electrode, the reported voltages are based on the Li + /Li reference. Only in example 9 are the reported voltages based on the Na + /Na reference. All Electrochemical investigations were conducted at a temperature of 20° C.±2° C. The potentiostat/galvanostat used was a Maccor 4300 battery test system.
Comparative Example 5
Electrochemical Investigation of the Comparative Electrode Based on ZnO
In the first cycle, the cells were discharged and charged with a constant current density of 0.024 A/g to a cut-off potential of 0.01 V and 3.0 V respectively. Thereafter, for 10 cycles in each case, a current density of 0.048; 0.095; 0.19; 0.48; 0.95; 1.90; 4.75; and 9.50 A/g was applied to the electrodes and the cell was discharged and charged to a potential of 0.01 V and 3.0 V respectively. The applied current density was then lowered again to 0.095 A/g.
FIG. 5 shows the capacity characteristics of the composite electrode comprising ZnO particles at rising charge and discharge rates over 100 cycles. At the start, the electrode showed a reversible specific capacity of about 685 mAh/g and an irreversible capacity loss of more than 700 mAh/g. The specific capacity obtained then dropped off rapidly, before stabilizing at above 200 mAh/g for an applied current density of 0.19 A/g. When the applied current density was increased further in steps, the specific capacity obtained continued to drop off, before going to just above 0 mAh/g for an applied current density of 9.5 A/g. When the applied current density, finally, was lowered to 0.095 A/g again, a specific capacity of about 310 mAh/g was obtained, which corresponds approximately to the theoretical specific capacity of ZnO (329 mAh/g), if the zinc present just forms an alloy with lithium reversibly.
Example 6
Electrochemical Investigation of an Electrode Containing Fe 0.1 Zn 0.9 O Particles
In the first cycle, the cells were discharged and charged with a constant current density of 0.024 A/g to a cut-off potential of 0.01 V and 3.0 V respectively. In analogy to example 5, thereafter, for 10 cycles in each case, a current density of 0.048; 0.095; 0.19; 0.48; 0.95; 1.90; 4.75; and 9.50 A/g was applied to the electrodes and the cell was discharged and charged to a potential of 0.01 V and 3.0 V respectively. The applied current density was then lowered again to 0.095 A/g.
FIG. 6 shows the capacity characteristics of the composite electrode comprising Fe 0.1 Zn 0.9 O particles at rising charge and discharge rates over 100 cycles. At the start, the electrode showed a reversible specific capacity of about 900 mAh/g and an irreversible capacity loss of about 500 mAh/g. The specific capacity obtained then dropped off slightly to start with, before stabilizing at about 730 mAh/g for an applied current density of 0.048 A/g. When the applied current density was increased further in steps, the specific capacity obtained dropped off gradually, before going to 0 mAh/g for an applied current density of 9.5 A/g. When the applied current density, finally, was lowered to 0.095 A/g again, a specific capacity of about 650 mAh/g was obtained, which corresponds approximately to twice the theoretical specific capacity of ZnO (329 mAh/g), but dropped off continuously thereafter.
The electrodes therefore exhibited a cycling stability and specific capacity improved significantly relative to ZnO.
Example 7
Electrochemical Investigation of an Electrode Containing Carbon-Coated Fe 0.1 Zn 0.9 O Particle Particles
In the first cycle, the cells were discharged and charged with a constant current density of 0.024 A/g to a cut-off potential of 0.01 V and 3.0 V respectively. In analogy to examples 5 and 6, thereafter, for 10 cycles in each case, a current density of 0.048; 0.095; 0.19; 0.48; 0.95; 1.90; 4.75; and 9.50 A/g was applied to the electrodes and the cell was discharged and charged to a potential of 0.01 V and 3.0 V respectively. The applied current density was then lowered again to 0.095 A/g.
FIG. 7 shows the capacity characteristics of the composite electrode carbon-coated Fe 0.1 Zn 0.9 O particles on increasing charge and discharge rates over 100 cycles. At the start, the electrode showed a reversible specific capacity of about 810 mAh/g and an irreversible capacity loss of about 450 mAh/g. The cycling stability was significantly improved relative to the uncoated particles and also to the zinc oxide reference. In relation to shortened charging times and/or higher applied current densities as well, a significant improvement in the material was achieved. Thus, for example, even for an applied current density of 1.9 A/g, a specific capacity of about 350 mAh/g was obtained, which corresponds approximately to the theoretical capacity of graphite (372 mAh/g), but which as a general rule is not achieved for the same current density (corresponding to a charge rate of 5 C, meaning that the cell was fully charged or discharged in about 12 minutes)
Where, lastly, the applied current density was lowered to 0.095 A/g again, an extremely stable specific capacity of about 730 to 740 mAh/g was obtained, which corresponded to more than twice the theoretical specific capacity of ZnO (329 mAh/g) and approximately to twice the theoretical specific capacity of graphite (372 mAh/g).
The electrodes therefore showed, over all of the current densities applied, a cycling stability and specific capacity improved significantly relative to ZnO and also relative to the uncoated Fe 0.1 Zn 0.9 O particles.
Example 8
Electrochemical Investigation of an Electrode Comprising Co 0.1 Zn 0.9 O Particles
In the first cycle, the cells were discharged and charged with a constant current density of 0.024 A/g to a cut-off potential of 0.01 V and 3.0 V respectively. Thereafter, a current density of 0.048 and 0.095 A/g was applied to the electrodes, for 10 cycles in each case, and the cell was discharged and charged to a potential of 0.01 V and to 3.0 V respectively.
FIG. 8 shows the capacity characteristics of the composite electrode comprising Co 0.1 Zn 0.9 O particles on increasing charge and discharge rates over 21 cycles. At the start, the electrode showed a reversible specific capacity of about 970 mAh/g and an irreversible capacity loss of about 370 to 380 mAh/g. The cycling stability was therefore improved further relative to the uncoated Fe 0.1 Zn 0.9 O particles and also to the zinc oxide reference. When the applied current density was doubled, in each case after ten cycles, the specific capacity obtained remained approximately constant at about 940 mAh/g, and was therefore almost three times as high as the theoretical capacity of ZnO (329 mAh/g) and also higher by a factor of 2.5 than the theoretical capacity of graphite (372 mAh/g).
The electrodes therefore exhibited a cycling stability and specific capacity substantially better than for ZnO. The specific capacity and cycling stability of the electrode based on Co 0.1 Zn 0.9 O are likewise better than those of the electrode based on uncoated Fe 0.1 Zn 0.9 O particles.
Example 9
Electrochemical Investigation of an Electrode Comprising Carbon-Coated Fe 0.1 Zn 0.9 O Particles Against Sodium Metal
In the first cycle, the cells were discharged and charged with a constant current density of 0.1 A/g to a cut-off potential of 0.01 V and 3.0 V respectively.
FIG. 9 shows the voltage profile of the composite electrode comprising carbon-coated Fe 0.1 Zn 0.9 O particles for the first two cycles. At about 150 mAh/g, the specific capacity obtained was indeed well below the specific capacity obtainable when using lithium-based systems, but is at least comparable with the current standard anode materials for sodium-based battery systems, for which cost advantages are generally rated higher than high energy densities.
As can be seen from the complete overlap of the two charging operations, the storage of sodium ions in electrodes produced accordingly was highly reversible, moreover.
Against sodium metal as well, therefore, the electrodes based on coated Fe 0.1 Zn 0.9 O particles exhibit a stable specific capacity and are therefore generally also suitable as a new anode material for sodium ion-based battery systems.
Example 10
Production of Carbon-Coated Fe x Zn 1-x O Particles with Varying Iron Content
Fe x Zn 1-x O particles were produced as described in example 1, step a), with the stoichiometric amounts of zinc(II) gluconate hydrate and iron gluconate dihydrate being adapted so as to give calcined Fe 0.02 Zn 0.98 O particles, Fe 0.04 Zn 0.96 O particles, Fe 0.06 Zn 0.94 O particles, Fe 0.08 Zn 0.92 O particles, Fe 0.1 Zn 0.9 O particles, and Fe 0.12 Zn 0.88 O particles.
Determination of the morphology by X-ray powder diffractometry revealed all of the samples to be phase-pure with a particle crystallinity that dropped slightly as the iron content went up.
Determinations were also made of the BET surface area of the particles and of their density, For this purpose, the specific surface area of solids was determined by means of nitrogen gas adsorption by the Brunauer-Emmett-Teller (BET) method. For this purpose an ASAP 2020 (Accelerated Surface Area and Porosimetry Analyzer, Micromeritics) was used. The density of the samples analyzed was determined using an AccuPyc II 1340 Gas Pycnometer (Micromeritics, helium).
The BET surface area and density found in the samples are collated Table 1 below:
TABLE 1
BET surface area
Density
Sample
[m 2 /g]
[g/cm 3 ]
Fe 0.12 Zn 0.88 O
98 ± 0.3
5.5 ± 0.1
Fe 0.1 Zn 0.9 O
88 ± 0.3
5.4 ± 0.1
Fe 0.08 Zn 0.92 O
80 ± 0.1
5.4 ± 0.1
Fe 0.06 Zn 0.94 O
74 ± 0.1
5.3 ± 0.1
Fe 0.04 Zn 0.96 O
64 ± 0.1
5.4 ± 0.1
Fe 0.02 Zn 0.98 O
47 ± 0.1
5.5 ± 0.1
It was found that the density of the particles was in each case close to the density of ZnO, of 5.6 g/cm 3 .
The particles were subsequently coated with about 20 wt % of carbon, based on the weight of the particles, by mixing them with sucrose and carrying out carbonization, as described in example 1, step b).
Example 11
Electrochemical Investigation of Electrodes Containing Carbon-Coated Fe x Zn 1-x O Particles with Varying Iron Content
Carbon-coated Fe 0.06 Zn 0.94 O, Fe 0.08 Zn 0.92 O, Fe 0.1 Zn 0.9 O and Fe 0.12 Zn 0.88 O particles produced according to example 10 were used for the electrochemical investigation. Electrode production took place as described in example 4.
In the first cycle in each case, the cells were discharged and charged with a constant current density of 0.05 A/g (1 C{circumflex over (=)}1 A/g) to a cut-off potential of 0.01 V and 3.0 V respectively. Thereafter, for ten cycles in each case, a current density of 0.05; 0.1; 0.2; 0.5; 1; 2 and 5 A/g was applied to the electrodes, and the cell was discharged and charged to a potential of 0.01 V and to 3.0 V respectively. The applied current density was then lowered again to 0.1 A/g.
FIG. 10 shows the capacity characteristics of the composite electrodes comprising the carbon-coated Fe x Zn 1-x O particles on increasing charge and discharge rates over 70 cycles. Here, FIG. 10 a ) shows the capacity characteristics of the Fe 0.12 Zn 0.88 O particles, FIG. 10 b ) those of the Fe 0.1 Zn 0.9 O particles, FIG. 10 c ) those of the Fe 0.08 Zn 0.92 O particles, and FIG. 10 d ) those of the Fe 0.06 Zn 0.94 O particles. A comparison shows that for these particles, a higher iron content generally had a positive influence on the specific capacity achieved, for all discharge rates.
As can be inferred from FIG. 10 , the electrodes comprising particles having an iron content in the range from Fe 0.08 Zn 0.92 O to Fe 0.12 Zn 0.88 O all exhibited a very good specific capacity and cycling stability over the current densities applied.
Example 12
Production of Carbon-Coated Fe 0.1 Zn 0.9 O Particles with Varying Carbon Content
Fe 0.1 Zn 0.9 O particles were produced as described in example 1, step a), and subsequently coated with carbon as described in example 1, step b), by mixing them with sucrose and carrying out carbonization, the amounts of sucrose being adapted so as to give Fe 0.1 Zn 0.9 O particles coated in each case with 5 wt %, 12 wt %, 16 wt %, and 20 wt % of carbon, based on the total weight of the particles.
The morphology of the uncoated and coated particles was subsequently determined by X-ray powder diffractometry. It was found that the crystallinity of the particles rose with falling carbon content. Furthermore, the BET surface area of the particles and their density were determined as described in example 10. The BET surface area and density determined for the particles are collated in Table 2 below:
TABLE 2
Carbon content
BET surface area
Density
Sample
[wt %]
[m 2 /g]
[g/cm 3 ]
Fe 0.1 Zn 0.9 O
20
92 ± 2.1
3.6 ± 0.1
Fe 0.1 Zn 0.9 O
16
98 ± 1.6
3.7 ± 0.1
Fe 0.1 Zn 0.9 O
12
79 ± 0.8
4.2 ± 0.1
Fe 0.1 Zn 0.9 O
5
62 ± 0.2
4.9 ± 0.1
Fe 0.1 Zn 0.9 O
0
88 ± 0.3
5.4 ± 0.1
It was found that the BET surface area varied, with the specific surface area in a range from ≧12 wt % to ≦20 wt % of carbon being higher than for 5 wt % of carbon, whereas the density rose with falling carbon content. This shows that particles having a carbon fraction in the range from 5 wt % to 20 wt %, especially in the range from 12 wt % to 20 wt %, hold out the expectation overall of a good active material for electrodes with high capacity.
The research which led to this invention was supported by external funding from the Seventh Framework Programme of the European Union (FP72007-2013) under Project No. ORION 229036. | The invention relates to a method for producing carbon-coated, transition metal-doped zinc oxide particles and the use thereof as electrode material for alkali metal ion batteries and, in particular, lithium ion batteries. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
The present patent application is a divisional of U.S. patent application Ser. No. 12/349,384, filed on Jan. 6, 2009, now U.S. Pat. No. 8,360,781 and entitled “HAZARDOUS MATERIAL RESPONSE SYSTEM, METHOD OF USING SAME AND METHOD OF TRAINING FOR SAME,” which claims the benefit of U.S. Provisional Patent Application Ser. No. 61/088,658, filed on Aug. 13, 2008 and entitled “HAZARDOUS MATERIAL RESPONSE SYSTEM, METHOD OF USING SAME AND METHOD OF TRAINING FOR SAME,” the disclosure of which are incorporated by reference herein in their entireties.
BACKGROUND OF THE INVENTION
First responders must make rapid decisions in life-saving and life-threatening situations when dealing with hazardous materials that have been improperly released into the environment. This is especially true now with the threat of international terrorism. Prior to dealing with an actual terrorist or other incident involving suspected or known chemical hazards, emergency personnel must be adequately trained to properly react to the various types of hazardous events, for both their safety as well as public safety.
Given this, responders must rapidly process information during a hazardous incident and make the appropriate decisions for action based upon his own cognitive abilities to mentally process such information with or without the help of additional resources. Although training manuals and field manuals may be available, timely access and processing of this information remains elusive, and decisions made on this less-than-optimal information may prove detrimental. The known detection methods give the responder a variety of information, however, it is important for the responder to understand what he or she is using and why. Further, it is important for the responder to quickly and efficiently conduct the risk assessment of a hazardous incident in minutes.
Hazardous Material (HazMat) Responders experience “information overload” that often results in responders over analyzing available research material causing incidents to be time-consuming, extremely costly, and labor intensive. Implementing change in existing methods to make efficient risk based decisions on virtually any known or unknown chemical incident in minutes creates tremendous opportunities and dramatic challenges, often concurrently. There exists a need in the art for novel methods of quick risk assessment of chemical incident in civil and combat situations. There is a need to integrate the required functional elements in order to respond adequately to a terrorist threat or chemical incident involving suspected or known or unknown chemical hazards.
The description herein of disadvantages and problems associated with known methods is in no way intended to limit the scope of the embodiments described in this document to their exclusion. Indeed, certain embodiments may include one or more known methods or method steps without suffering from the so-noted disadvantages or problems.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method of rapid risk assessment of virtually any substance involved in a hazardous material emergency based entirely on its name. The instant specification discloses techniques that allow for the rapid classification of hazardous materials in order to enable safe and efficient risk based response to a hazardous material emergency. The invention also provides techniques that give rapid risk assessment of unknown chemicals by employing the same system, but in reverse order.
It is an object of the present invention to provide a method of training a user to respond to a hazardous material emergency comprising providing in a fixed medium a representation separating two or more chemicals on the periodic chart into a first group or a second group, wherein the first group of elements are chemical constituents of hazardous materials that possess one or more of the following properties: solid, not flammable, no lower explosive limit (LEL), no upper explosive limit (UEL), no flashpoint, no ionizing potential, when mixed with water they create a corrosive solution, the solution is basic, (pH paper turns blue when exposed to the chemical in solution), initial isolation distance for the material is 75 feet, the exposure limits unit of measurements are mg/m 3 ; and wherein the second group of elements are chemical constituents of hazardous materials that possess one or more of the following properties: solid, liquid or gas, flammable, possess a LEL, posses an UEL, have a flashpoint, have ionizing potential, acidic (pH paper turns red when exposed to the chemical in solution), exposure limits unit of measurements are in parts per million PPM; and directing the user to rapid risk assessment of the hazardous material depending on the classification of the substance into the first group or the second group. The first group of chemicals have a first name that is selected from the following: lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium. The first group may further comprise chemicals with second names selected from: nitride, phosphide, carbide, and hydride. Chemicals not in the first group are in the second group. The second group of chemicals also include those that have a first name that is selected from the following: hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon. The first group is also referred to, herein, as substances that are “below the line” and the second group is also referred to, herein, as substances that are “above the line”. The significance of these terms is explained in greater detail below.
It is an object of the present invention to provide a method of responding to a hazardous material emergency comprising providing in a fixed medium a representation separating chemicals of a first group from chemicals of a second group. For example, according to some embodiments, a method of responding to a hazardous material emergency is provided that comprises providing in a fixed medium a representation separating two or more elements selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium and/or two or more moieties selected from the group consisting of nitride, carbide, hydride, and phosphide into a first group, and two or more elements selected from the group consisting of hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon into a second group.
According to some embodiments, the method further comprises analyzing the name of a hazardous material to determine whether a first word in the name of the hazardous material is an element recited in the first group, or whether a second word in the name of the hazardous material is a chemical moiety recited in the first group, or whether the first word in the name of the hazardous material is an element recited in the second group.
According to some embodiments, the methods of the present invention further directs a hazardous material responder to respond to the hazardous material according to a first method when the first word of the name of the hazardous material is an element recited in the first group or the second name is a chemical moiety recited in the first group.
According to some embodiments, the method of the present invention directs the hazardous material responder to respond to the hazardous material according to a second method when the first word of the name of the hazardous material is not an element recited in the first group, or when the second name of the hazardous material is not a chemical moiety recited in the first group, or when the first name of the hazardous material is an element recited in the second group.
In one preferred embodiment, the method of responding to a hazardous material emergency involves the use of a fixed medium that is a periodic chart of the elements in which a marking is made separating elements lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium from hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon.
In another preferred embodiment, the fixed medium includes a list of elements consisting of at least five members of the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium.
In a further preferred embodiment, the fixed medium includes a list of elements consisting of at least ten members of the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium.
In yet another preferred embodiment, the fixed medium comprises a list of elements consisting of at least twenty members of the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium.
In one embodiment, the method of responding to a hazardous material emergency comprises a representation separating elements selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium, and moieties selected from the group consisting of nitride, carbide, hydride and phosphide into a first group, and elements selected from the group consisting of hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon into a second group.
In one preferred embodiment, the representation separates five or more elements selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium, and/or two or more moieties selected from the group consisting of nitride, carbide, hydride, and phosphide into a first group, and five or more elements selected from the group consisting of hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon into a second group.
In another preferred embodiment, the representation separates ten or more elements selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium, and ten or more elements selected from the group consisting of hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon into a second group.
In another preferred embodiment, a method of responding to a hazardous material emergency is provided that comprises analyzing the name of a hazardous material, and where the first word of the name of the hazardous material is an element recited in the first group, or where the second name is a chemical moiety recited in the first group, a hazardous material responder responds, or is directed to respond, to a non-flammable hazardous material. The method may also comprise analyzing the name of a hazardous material, and where the first word of the name of the hazardous material is not an element recited in the first group, or where the second name of the hazardous material is not a chemical moiety recited in the first group, or where the first name of the hazardous material is an element recited in the second group, the hazardous material responder responds, or is directed to respond, to a flammable hazardous material.
In another embodiment, a method of responding to a hazardous material emergency is provided that comprises analyzing the name of a hazardous material, and where the first word of the name of the hazardous material is an element recited in the first group or where the second name is a chemical moiety recited in the first group, a hazardous material responder responds, or is directed to respond, to a hazardous material without an upper or lower explosive level. In a further embodiment, where the first word of the name of the hazardous material is not an element recited in the first group, or where the second name of the hazardous material is not a chemical moiety recited in the first group, or where the first name of the hazardous material is an element recited in the second group, the hazardous material responder responds, or is directed to respond, to a hazardous material with an upper or lower explosive level.
In another embodiment, a method of responding to a hazardous material emergency is provided that comprises analyzing the name of a hazardous material, and where the first word of the name of the hazardous material is an element recited in the first group, or where the second name is a chemical moiety recited in the first group, a hazardous material responder responds, or is directed to respond, to a hazardous material without a flashpoint. In a further embodiment, where the first word of the name of the hazardous material is not an element recited in the first group, or where the second name of the hazardous material is not a chemical moiety recited in the first group, or where the first name of the hazardous material is an element recited in the second group, the hazardous material responder responds, or is directed to respond, to a hazardous material with a flashpoint.
In yet another embodiment, a method of responding to a hazardous material emergency is provided that comprises analyzing the name of a hazardous material, and where the first word of the name of the hazardous material is an element recited in the first group, or where the second name is a chemical moiety recited in the first group, a hazardous material responder responds, or is directed to respond, to a hazardous material without an ionization potential. In a further embodiment, where the first word of the name of the hazardous material is not an element recited in the first group, or where the second name of the hazardous material is not a chemical moiety recited in the first group, or where the first name of the hazardous material is an element recited in the second group, the hazardous material responder responds, or is directed to respond, to a hazardous material with an ionization potential.
In yet another embodiment, a method of responding to a hazardous material emergency is provided that comprises analyzing the name of a hazardous material, and where the first word of the name of the hazardous material is an element recited in the first group, or where the second name is a chemical moiety recited in the first group, a hazardous material responder responds, or is directed to respond, to a hazardous material that is a base. In a further embodiment, where the first word of the name of the hazardous material is not an element recited in the first group, or where the second name of the hazardous material is not a chemical moiety recited in the first group, or where the first name of the hazardous material is an element recited in the second group, the hazardous material responder responds, or is directed to respond, to a hazardous material that is an acid.
In another embodiment, a method of responding to a hazardous material emergency is provided that comprises analyzing the name of a hazardous material, and where the first word of the name of the hazardous material is an element recited in the first group or the second name is a chemical moiety recited in the first group, a hazardous material responder responds, or is directed to respond, to a hazardous material with exposure limits expressed in mg/m 3 . In another embodiment, when the first word of the name of the hazardous material is not an element recited in the first group, or when the second name of the hazardous material is not a chemical moiety recited in the first group, or when the first name of the hazardous material is an element recited in the second group, the hazardous material responder responds, or is directed to respond, to a hazardous material with exposure limits expressed in ppm.
In yet another embodiment, a method of responding to a hazardous material emergency is provided that comprises analyzing the name of a hazardous material, and where the first word of the name of the hazardous material is an element recited in the first group or the second name is a chemical moiety recited in the first group, a hazardous material responder responds, or is directed to respond, to a hazardous material with an initial isolation of 75 feet if in solid form and 150 feet if in solution. In a further embodiment, where the first word of the name of the hazardous material is not an element recited in the first group, or where the second name of the hazardous material is not a chemical moiety recited in the first group, or where the first name of the hazardous material is an element recited in the second group, the hazardous material responder responds, or is directed to respond, to a hazardous material with an initial isolation of 75 feet if a solid, 150 feet if a liquid or 300 feet if a gas.
In a further embodiment, a method of responding to a hazardous material emergency of the present invention is provided, the method comprises providing in a second fixed medium a representation listing second names of hazardous materials, wherein a first word of the name of the hazardous material is an element recited in the first group or the second name is a chemical moiety recited in the first group, wherein the representation shows at least one hazard associated with the substance having each second name and appropriate detection equipment to evaluate risk associated with the hazardous material. The method further includes matching the second name of the hazardous material with the representation and employing the appropriate detection equipment on the hazardous material.
In one embodiment, the at least one property shown in the representation on the second fixed medium is selected from the group consisting of state of matter, flammability, explosive limits, flashpoint, ionizing potential, pH, exposure limit units and initial isolation.
It is yet another object of the present invention to provide a method of responding to a hazardous material emergency. According to some embodiments, the method comprises performing a test for the presence or absence of at least one physical property of the hazardous material wherein the test is selected from the group consisting of flammability, existence of explosive limits, existence of flashpoint, existence of ionizing potential, and acidic or basic pH, wherein if the test shows that the hazardous material is flammable, has explosive limits, has a flashpoint, has an ionization potential, personnel is directed to wear turn-out/SCBA or Level B personal protection equipment (PPE), and wherein if the test shows that the hazardous material is acidic, a user is directed to be equipped with Level A personal protection equipment (PPE), and wherein if the test shows that the hazardous material is not flammable, has no explosive limits, has no flashpoint, has no ionization potential or is basic, the user is directed to be equipped with turn-out/SCBA or Level B PPE.
In one embodiment, the test shows whether or not the hazardous material is flammable. In another embodiment, the test shows whether or not the hazardous material has explosive limits. In yet another embodiment, the test shows whether or not the hazardous material has a flashpoint. In yet another embodiment, the test shows whether or not the pH of the hazardous material is acidic, basic or neutral. In yet another embodiment, the test shows whether or not the hazardous material has an ionizing potential.
The present invention also provides a chart for responding to a hazardous material emergency. In one embodiment, a chart in a fixed medium shows a periodic table of the elements with a mark separating lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium from hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon. In one embodiment, the fixed medium is a printed page. In a further embodiment, the printed page is laminated. Optionally, the printed page is on watermarked or proprietary paper.
In another embodiment, the fixed medium is electronic. In some preferred embodiments, the electronic fixed medium is selected from the group consisting of a computer monitor, a television monitor, a cell phone monitor, and a personal digital assistant monitor.
It is another object of the present invention to provide the chart for responding to a hazardous material emergency wherein the mark is a line drawn to separate lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium from hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon on the periodic table of elements.
In one embodiment, the mark is contrasting backgrounds in squares on the periodic table of the elements separating lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hathium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium from hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon.
It is yet another object of the present invention to provide a chart for responding to a hazardous material emergency wherein a chart is in a fixed medium separating at least two elements selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium from at least two elements selected from the group consisting of hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon.
In one embodiment of the present invention, the chart consists of a list of at least two elements selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium.
In another embodiment of the present invention, the chart consists of a list of at least ten elements selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium.
In yet another embodiment of the present invention, the chart consists of a list of at least twenty elements selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium.
In yet another embodiment of the present invention, the chart consists of a list of elements selected from the group consisting of lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium.
In yet another embodiment of the present invention, the chart consists of a list of at least two elements selected from the group consisting of hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon.
In another embodiment, the chart consists of a list of at least ten elements selected from the group consisting of hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon.
In yet another embodiment, the chart consists of a list of elements selected from the group consisting of hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 provides an illustration of an embodiment of the hazardous material response method of the invention in four steps.
FIG. 2 shows a chart indicating which elements and chemical moieties are “above the line” or “below the line”.
FIG. 3 shows a chart indicating which elements and chemical moieties are “above the line” or “below the line”.
FIG. 4 shows a chart indicating potential hazards and appropriate tests for hazardous materials based upon the second word in the hazardous material name for hazardous materials classified as “above the line”.
FIG. 5 shows a chart indicating potential hazards and appropriate tests for hazardous materials based upon the second word in the hazardous material name for hazardous materials classified as “below the line”.
FIG. 6 shows a research form providing a framework to capture critical properties and characteristics found in other documentation.
DETAILED DESCRIPTION OF THE INVENTION
Before the present methods are described, it is understood that this invention is not limited to the particular methodology, protocols, and reagents described, as these may vary. It also is to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention that will be limited only by the appended claims.
Definitions
For the purposes of promoting an understanding of the embodiments described herein, reference will be made to preferred embodiments and specific language will be used to describe the same. The terminology used herein is for the purpose of describing particular embodiments only, and is not intended to limit the scope of the present invention. As used throughout this disclosure, the singular forms “a,” “an,” and “the” include plural reference unless the context clearly dictates otherwise. Thus, for example, a reference to “a chemical” includes a plurality of such chemicals, as well as a single chemical.
As used herein, the following acronyms have the following meanings: LEL for Lower Explosive Limit; UEL for Upper Explosive Limit; Fl.P for Flash Point; IDLH for Immediately Dangerous to Life and Health; IP for Ionization Potential; MW for Molecular weight; HazMat for Hazardous Materials; and ER for Exposure Routes.
The explosive limit of a gas or a vapor, is the limiting concentration (in air) that is needed for the gas to ignite and explode. There are two explosive limits for any gas or vapor: the lower explosive limit (LEL) and the upper explosive limit (UEL). At concentrations in air below the LEL, there is not enough fuel to continue an explosion; at concentrations above the UEL, the fuel to air ratio is too rich to trigger an explosion.
Personal Protection Equipment (PPE) is used by HazMat responders when they are called to respond to a HazMat emergency. There are three levels of PPE commonly used by HazMat responders: Turnout gear, Level A, and Level B. Turnout gear is equipment usually used by firefighters when responding to a fire. Turnout gear generally includes a fire protective jacket and pants as well as a helmet. Level A is used when the greatest level of skin, respiratory, and eye protection is required. Level A equipment may include, but is not limited to, the following: a positive pressure, full face-piece self-contained breathing apparatus (SCBA), or positive pressure supplied air respirator with escape SCBA; a totally-encapsulating chemical-protective suit including coveralls, long underwear, gloves and boots; a hard hat and optionally a disposable protective suit, gloves and boots, which may be worn over totally-encapsulating suit. Level B provides the highest level of respiratory protection, but a lesser level of skin protection. Level B equipment may include, but is not limited to, the following: a positive pressure, full face-piece self-contained breathing apparatus (SCBA), or positive pressure supplied air respirator with escape SCBA; hooded chemical-resistant clothing including overalls and long-sleeved jacket; coveralls; one or two-piece chemical-splash suit; and optionally disposable chemical-resistant overalls; gloves; boots; boot-covers; a hard hat and face shield.
The HazMat Response System
FIG. 1 shows a schematic summarizing how the HazMat Response System of the invention works. If the chemical name of the material being analyzed is known, then the system is used as represented from the left side of the schematic. If not, it is begun at the right side of the schematic. We first describe how the HazMat Response System works when the chemical name is known.
As shown in FIG. 1 , the first step is to use the information conveyed by the proprietary “Smart Chart” of the HazMat Response System of the invention. ( FIG. 2 ). In one embodiment, this information is contained in the “Smart Chart” as shown in FIG. 2 . In other embodiments, this information is contained in other fixed media allowing a HazMat responder to quickly determine at the scene of a HazMat emergency if the material is “above the line” or “below the line”. An example of one other such fixed medium is shown in FIG. 3 . These fixed media are also able to be used electronically. Thus, these representations of elements and chemical moieties being above and below the line are also shown on computer, cell phone or personal digital assistant (PDA). These fixed media need not separate all of the listed elements into two groups. In some embodiments of the invention, only the most commonly encountered elements and/or chemical moieties need to be represented in the fixed medium. The fixed medium may list any number of elements from two elements or fixed moieties to all of them. Examples of numbers of elements of moieties represented include 2, 5, 10, 15, 20, 25, 50, 60, 70, 80, 90 and 100.
The “line” is indicated on the periodic table of elements shown in FIG. 2 . The materials with elements in their first names, shown below the heavy marking, are considered “below the line”. Also materials that have one of the four chemical moieties in the “water reactive diamond” above the periodic table of elements in their second name are also considered “below the line”. The elements that are considered “below the line” are lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, scandium, yttrium, lanthanum, titanium, zirconium, hafnium, vanadium, nobelium, tantalum, chromium, molybdenum, tungsten, manganese, technetium, rhenium, iron, ruthenium, osmium, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, mercury, aluminum, gallium, indium, thallium, germanium, tin, lead, antimony, bismuth, and polonium. The chemical moieties that are considered “below the line” are nitride (ammonia), carbide (acetylene), hydride (hydrogen) and phosphide (phosphine). Materials that are classified as “below the line” include those that, generally, are solid at room temperature, are non-flammable, have no LEL or UEL, have no flashpoint, no ionizing potential, and are bases. For these materials, the units used to measure their exposure limits, e.g. their immediately dangerous to life and health (IDLH) level or permissible exposure limits (PELs), are mg/m 3 . The materials with elements in their first name, shown not to be below the heavy marking, are considered “above the line”. The elements that are considered “above the line” are hydrogen, boron, carbon, silicon, nitrogen, phosphorus, arsenic, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine, iodine, astatine, helium, neon, argon, krypton, xenon, and radon. Materials that are classified as “above the line” include those that are liquids or gases, are flammable, have LEL and UEL, have a flashpoint, have an ionizing potential and are acids. For these materials, the units used to measure their exposure limits, e.g. their immediately dangerous to life and health (IDLH) level or permissible exposure limits (PELs), are parts per million (ppm).
Based on the information provided by a material being classified as above or below the line, personnel responding to a HazMat situation can quickly determine the initial PPE necessary for the material. If a material is classified as “above the line”, turn out/SCBA or Level A PPE is generally necessary. If a material is classified as “below the line”, a turn out/SCBA or Level B PPE is generally necessary. Moreover, the initial isolation zone for a material classified as “below the line” is generally a 75 foot radius if a solid and a 150 foot radius if a liquid, while a material classified as “above the line” generally has an initial isolation zone of a 150 foot radius if it is a liquid and of 300 foot if it is a gas.
Additional information can then be acquired to deal with the hazardous material after a perimeter has been created. For example, for materials classified as “above the line”, additional tests can be performed based on the ending of the second name of the material. FIG. 4 shows detection equipment that is used to detect the concentration of hazardous material and the associated hazard. These tests include potassium iodide (KI) tests to detect oxidizers, tests of pH, tests for toxic industrial chemicals (TIC), tests involving photoionization detectors (PID), flame ionization detectors (FID), tube chips used to detect various hazards, and combustible gas indicators (CGI). For materials classified as “below the line”, different tests can be performed based on the ending of the second name of the material. FIG. 5 shows tests that are used to detect the concentration of hazardous material and the associated hazard.
In other embodiments of the HazMat Response System of the invention, a four step system can be used in reverse if the name of the compound is not known. Upon entering the site of a HazMat emergency, a HazMat responder may not know what the hazardous material is, and whether the hazardous material is above or below the line. Because of the differences between hazardous materials that are above or below the line, a HazMat responder can perform any one of a number of simple tests to determine the salient hazards. If the HazMat is a solid then turn out/SCBA or Level B PPE should be used to protect HazMat responder personnel, whereas with a gas or liquid, turn out/SCBA or Level A PPE is used. The tests shown above in FIGS. 3 and 4 can be used to ascertain what hazardous material is present and what sort of response should be made to the hazardous material.
The invention also provides methods of training HazMat responders to use the HazMat Response System of the invention. The training includes familiarizing HazMat responders with the fixed media that are used to quickly ascertain whether a hazardous material is “above” or “below the line”. This familiarization is performed by providing for the HazMat responders to be trained a copy of one or more fixed media used to quickly ascertain whether a hazardous material is “above” or “below the line” and instructing them how to use the media. These fixed media can be any of those described herein, including representations as shown in FIGS. 2 and 3 . The training further includes familiarizing HazMat responders with fixed media showing selected physical properties of hazardous materials and tests that should be performed to characterize the threat posed by these materials. Examples of such fixed media are shown in FIGS. 4 and 5 , herein.
EXAMPLES
Example 1
Determination of Hazard Information for Hazardous Materials
The HazMat Response System of the invention is used to respond to any hazardous material. Below, example of various materials and how the system directs a response to them are shown.
Calcium oxide would be considered “below the line” using the HazMat response system of the invention, because the name “calcium” is in the first name of the material and it is below the line as described above. This shows to a HazMat responder that this material is a solid, it is not flammable, it has no LEL/UEL, it has no flashpoint or ionization potential, it is a base, the IDLH or PEL is measured in mg/m 3 and that the initial isolation is 75 feet. Based on having “oxide” in the second name of the material, the HazMat responder would also know to test pH because the material generally acts as a weak base. ( FIG. 4 ). The HazMat responder would also know to use a PPE of turn out/SCBA or Level B.
Potassium cyanide would also be considered “below the line” using the HazMat response system of the invention, because the name “potassium” is in the first name of the material. As above, for calcium oxide, this shows to a HazMat responder that this material is a solid, it is not flammable, it has no LEL, it has no flashpoint or ionization potential, it is a base, the IDLH or PEL is measured in mg/m 3 and that the initial isolation is 75 feet. Based on having “cyanide” in the second name of the material, the HazMat responder would also know to test pH, test with a tube or chip and CGI to determine the amount of potassium cyanide present because of the toxicity of the substance. ( FIG. 4 ). The HazMat responder would also know to use turn out/SCBA or Level B PPE.
Vinyl chloride would be considered to be “above the line” using the HazMat response system of the invention, because the name “vinyl” is not one of the names present “below the line”. The HazMat response system of the invention shows to a HazMat responder that this material is a liquid or gas, it is flammable, it has an LEL and UEL, it has a flashpoint and ionization potential to consider, it is an acid, the IDLH or PEL is measured in ppm and that the initial isolation is 150 feet if a liquid and 300 feet if a gas. Based on having “chloride” in the second name of the material, the HazMat responder would also know to test with a temperature gun, pH paper, a PID, an FID, a tube chip and a CGI to acquire a concentration of the material because it has the potential to be toxic, flammable and corrosive. ( FIG. 3 ). The HazMat responder would also know to use a turnout/SCBA or Level A PPE (below 1% of LEL).
Ethylene oxide would also be considered to be “above the line” using the HazMat response system of the invention, because the name “ethlyene” is not one of the names present “below the line”. The HazMat response system of the invention shows to a HazMat responder that this material, like vinyl chloride, is a liquid or gas, it is flammable, it has an LEL and UEL to consider, it has a flashpoint and ionization potential to consider, it is an acid, the IDLH or PEL is measured in ppm and that the initial isolation is 150 feet if a liquid and 300 feet if a gas. Based on having “oxide” in the second name of the material, the HazMat responder would also know to test with a temperature gun, a PID, an FID, a tube or chip and a CGI to acquire a concentration of the material to because it has the potential to be flammable. ( FIG. 3 ). The HazMat responder would also know to use turnout/SCBA or Level B PPE (below 1% of LEL).
Hydrogen cyanide would also be considered to be “above the line” using the HazMat response system of the invention, because the name “hydrogen” is not one of the names present “below the line”. The HazMat response system of the invention shows to a HazMat responder that this material, like vinyl chloride, is a liquid or gas, it is flammable, it has an LEL and UEL to consider, it has a flashpoint and ionization potential to consider, it is an acid, the IDLH or PEL is measured in ppm and that the initial isolation is 150 feet if a liquid and 300 feet if a gas. Based on having “cyanide” in the second name of the material, the HazMat responder would also know to test for pH and with a temperature gun, a PID, an FID, a tube or chip and a CGI to acquire a concentration of the material to because it has the potential to be toxic, corrosive and flammable. ( FIG. 3 ). The HazMat responder would also know to use turnout/SCBA or Level A PPE if corrosive gas and below 1% of LEL. | This application describes methods for responding to a hazardous material based upon its properties and/or its chemical name. This application also describes methods of teaching hazardous material responders how to use the method of responding to a hazardous material based upon its properties and/or its chemical name. | 6 |
BACKGROUND
1. Field of the Invention
The present invention is directed to a vented ink reservoir for facilitating gaseous communication between an interior of an ink reservoir and an external environment; and, more particularly to a vented ink reservoir utilizing a semipermeable membrane to enable the ingress and/or egress of gas with respect to an interior volume of the ink reservoir, where the ink reservoir includes a backpressure regulator housed therein that prevents weeping from one or more printhead nozzles in fluid communication therewith.
2. Background of the Invention
Inkjet pens consist of a jetting structure and an ink containing structure. These structures can be combined into a single integrated cartridge, or separated into tanks and printheads. In either situation, the ink that is fed to the jetting structure must be kept at a negative pressure with respect to pressure outside the pen to prevent the ink from running out of the pen due to gravity, also known as weeping.
Several methods are known for the control of this negative pressure, also known as “backpressure”. In some inkjet structures the backpressure is provided by capillary action from a foam sponge, while other structures seal up the system and use a regulation device or a bubble-generating device to allow air to replace spent ink within the system while maintaining a reasonable range of backpressures. Still further systems are sealed off and start at a moderate backpressure and increase in backpressure until the jetting device can no longer pull ink from the reservoir.
Prior art techniques have attempted to control backpressure by providing a collapsible bag acting as the reservoir. The volume of the bag decreases in proportion to the volume of ink leaving the reservoir. However, these collapsible bags require multiple seals and have been found to be problematic to fabricate.
SUMMARY OF THE INVENTION
The present invention is directed to a semipermeable membrane operatively coupled to an ink reservoir vent that allows gaseous communication between an external atmosphere and an interior of the ink reservoir. The semipermeable membrane inhibits liquid ink from passing therethrough, but enables the ingress or egress of gas to provide a venting function.
In an exemplary embodiment, the present invention is teamed with an internal backpressure regulator. The backpressure regulator is submerged within the reservoir and relies, at least in part, upon the pressure differential between the exterior and interior of the regulator for normal operation. The invention allows the ingress of gas into and the egress of gas out of the ink reservoir to approximate equalization of the pressure between the interior of the reservoir and the exterior environment to maintain a sufficient gradient between the inside and outside of the regulator. A more detailed explanation of the backpressure regulator can be found in co-pending U.S. patent application Ser. No. 10/465,403, the disclosure of which is hereby incorporated by reference.
It is a first aspect of the present invention to provide an inkjet assembly that includes a vented ink reservoir for containing a liquid ink therein, where the vented ink reservoir defines an internal volume occupied at least in part by a semipermeable membrane in fluid communication with a vent that automatically adjusts for pressure differentials by enabling gaseous diffusion between an environment external to the vented ink reservoir and the internal volume of the vented ink reservoir, while inhibiting liquid diffusion therethrough.
In a more detailed embodiment of the first aspect, at least a portion of the semipermeable membrane is adapted to be above a highest level of the liquid ink within the internal volume of the vented ink reservoir. In another more detailed embodiment, the semipermeable membrane is operatively coupled to the ink reservoir by impulse sealing. In yet another more detailed embodiment, the semipermeable membrane includes polytetrafluoroethylene. In a further detailed embodiment, the semipermeable membrane defines a non-circular gaseous throughput. In yet a further more detailed embodiment, the semipermeable membrane is angled with respect to a level of ink within the ink reservoir. In another detailed embodiment, the semipermeable membrane includes a cross-sectional area for gaseous throughput ranging from between about 0.5 cm 2 to about 6 cm 2 . In yet another more detailed embodiment, the vented ink reservoir includes a cap mounted to a tank, and the semipermeable membrane is mounted to the cap. In still a further more detailed embodiment, the cap includes a raised hump providing a space adapted to trap gas therein above a highest level of liquid ink within the vented ink reservoir, and at least a portion of the semipermeable membrane extends into the space provided by the raised hump.
In a more detailed embodiment of the first aspect, a bottom surface of the cap partially defining the internal volume includes a downwardly extending closed wall seating the semipermeable membrane thereto to define a gaseous cavity within the internal volume. In a further detailed embodiment, a bottom surface of the cap includes a downwardly extending closed wall to which the semipermeable membrane is mounted thereto to define a gaseous cavity within the internal volume, and a top surface of the cap includes a humped portion corresponding to a raised space within the bottom surface of the cap adapted to be occupied by a trapped gas, where at least a portion of the semipermeable membrane is in gaseous communication with the trapped gas. In yet a further detailed embodiment, the gaseous cavity formed by the downwardly extending closed wall occupies a portion of the raised space. In a more detailed embodiment, the cap includes an ink inlet adapted to be in fluid communication with the internal volume of the vented ink reservoir. In another more detailed embodiment, the cap includes a serpentine tunnel extending therealong in fluid communication with the vent.
It is a second aspect of the present invention to provide a method of regulating the pressure between an interior volume of an ink container and an external environment, where the method includes the steps of: (a) positioning a semipermeable membrane within an ink container, where the semipermeable membrane includes a first surface in fluid communication with an interior volume of the ink container and an opposing surface in fluid communication with an external environment; (b) mounting the semipermeable membrane to the ink container; and (c) regulating a pressure differential between the interior volume and the external environment automatically and concurrently by facilitating gaseous diffusion and inhibiting liquid diffusion across the semipermeable membrane.
In a more detailed embodiment of the second aspect, the interior volume is occupied by, at least in part, a liquid ink, and at least a portion of the semipermeable membrane is positioned above a highest level of the liquid ink within the interior volume. In another more detailed embodiment, the interior volume is occupied by, at least in part, a liquid ink, and the semipermeable membrane is angled with respect to a level of the liquid ink within the interior volume. In yet another more detailed embodiment, the semipermeable membrane is operative to facilitate gaseous diffusion while the first surface is in concurrent fluid communication with a liquid ink and a gas. In a more detailed embodiment, a surface area available for gaseous diffusion through the semipermeable membrane is non-circular. In a further detailed embodiment, an additional step of reducing an amount of ink vapor leaving the interior volume of the ink container by reducing a volumetric flow of gas passing in proximity to the opposing surface of the semipermeable membrane is provided. In still a further more detailed embodiment, the regulating step includes providing a serpentine passageway for gaseous travel, wherein the serpentine passageway includes a first end terminating approximate the opposing surface of the semipermeable membrane and a second end terminating approximate the external environment. In yet a further more detailed embodiment, the semipermeable membrane includes polytetrafluoroethylene. In yet another detailed embodiment, the semipermeable membrane includes a cross sectional area for gaseous exchange ranging from about 0.5 cm 2 to about 6 cm 2 . In even a further detailed embodiment, the mounting step includes the step of sealing the semipermeable membrane to the ink container by impulse sealing.
It is a third aspect of the present invention to provide a method of mounting a porous substrate, concurrently inhibiting liquid diffusion therethrough and enabling gaseous diffusion therethrough, to a nonporous substrate concurrently inhibiting gaseous and liquid diffusion therethrough, where the method includes the steps of: (a) positioning a porous substrate adjacent to a nonporous substrate; (b) moving a pressure source adjacent to the porous substrate to sandwich the porous substrate between the pressure source and the nonporous substrate; (c) applying thermal energy in a pulse adjacent to the porous substrate to melt a portion of the nonporous substrate; and (d) removing the thermal energy source to solidify the portion of the nonporous substrate, interlocking the porous substrate and nonporous substrate to inhibit fluid communication therebetween, where the porous substrate facilitates gaseous diffusion therethrough, but inhibits liquid diffusion therethrough.
It is a fourth aspect of the present invention to provide an ink reservoir cap adapted to be mounted to an ink tank to provide a vented ink reservoir automatically regulating the internal pressure therein, where the ink reservoir cap includes a cap body adapted to be mounted to an ink tank to provide a vented ink reservoir, the cap body and ink tank define an interior volume available for ink occupation with the cap body seating a semipermeable membrane over a vent extending therethrough, where the membrane is housed within the interior volume to provide gaseous communication, but restrict liquid communication, between an external environment and the interior volume of the vented ink reservoir.
In a more detailed embodiment of the fourth aspect, the cap body further includes a filler conduit adapted provide fluid communication between an ink source and the interior volume of the vented ink reservoir. In another more detailed embodiment, the cap body further includes a raised space in fluid communication with the semipermeable membrane, the raised space adapted to trap a volume of gas above a highest level of liquid ink within the vented ink reservoir. In a more detailed embodiment, at least a portion of the semipermeable membrane is adapted to be in gaseous communication with gas within the raised space. In a further detailed embodiment, the cap body further includes a plurality of alignment pins adapted to align the cap body with respect to the ink tank prior to mounting the cap body onto the ink tank. In still a further more detailed embodiment, the cap body and the ink tank include a channel and a corresponding rib adapted to interact with the channel to provide an interface adapted to be fluidically sealed and provide a vented ink reservoir.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a vented ink reservoir in accordance with a first exemplary embodiment of the present invention;
FIG. 2 is a cross-sectional view of the vented ink reservoir of the first exemplary embodiment of the present invention;
FIG. 3 is an elevated, perspective view of the top of an ink reservoir cap in accordance with a second exemplary embodiment of the present invention;
FIG. 4 is a bottom view of the ink reservoir cap of FIG. 3 ; and
FIG. 5 is a bottom, perspective view of the ink reservoir cap of FIG. 3 .
DETAILED DESCRIPTION
The exemplary embodiments of the present invention are described and illustrated below as ink cartridges (reservoirs) utilizing at least one semipermeable membrane to regulate the volumetric flow of gas between an interior of an ink cartridge and an exterior environment. The various orientational, positional, and reference terms used to describe the elements of the inventions are therefore used according to this frame of reference. However, for clarity and precision, only a single orientational or positional reference will be utilized; and, therefore it will be understood that the positional and orientational terms used to describe the elements of the exemplary embodiments of the present invention are only used to describe the elements in relation to one another.
Referring to FIGS. 1–2 , a first exemplary embodiment includes an ink reservoir cap 10 mounted to an ink tank 12 to provide a partially sealed ink reservoir 14 having an interior volume 16 available for holding liquid ink. A raised rib 18 running about the perimeter of a top surface 20 of the upper opening of the tank 12 is adapted to provide a seat for, and be received within, a complementary channel 22 extending along an underneath surface 24 of the cap 10 . An alignment pin 26 extending downwardly from the cap 10 is adapted to be received within a socket 28 concurrently as the raised rib 18 is received within the channel 22 . The cap 10 is mounted to the tank 12 by sealing an interface 30 between the rib 18 and the channel 22 using a conventional technique after the cap 10 has been aligned and seated upon the tank 12 as discussed above. Such conventional techniques are known by those of ordinary skill and include, without limitation, adhesive, laser welding, and vibration welding.
Referencing FIG. 2 , a closed wall 32 extends from the underneath surface 24 of the cap 10 that partially defines a gaseous cavity 34 in gaseous communication with an external environment 36 . A bottom surface 38 of the closed wall 32 , opposite the surface 24 , is beveled uniformly along a plane to provide a planar surface onto which a semipermeable membrane 40 is mounted thereto. In the present exemplary embodiment, the semipermeable membrane 40 is a solid rectangle that overlies the oblong shaped, closed wall 32 completely covering over the entire exposed area to partially define the gaseous cavity 34 . To bond the membrane 40 thereto, an impulse sealing electrode is aligned with the bottom surface 38 of the closed wall 32 and sandwiches the membrane 40 therebetween. Thereafter, an electric current is applied for a fraction of a second to the impulse sealing electrode causing material at the bottom surface 38 to become viscous. In this viscous state, the material at the bottom surface 38 bonds to the membrane 40 , resulting in a liquid-tight seal between the closed wall 32 and the membrane 40 . Those of ordinary skill are familiar with other methods may be utilized to mount the membrane 40 to the closed wall 32 such as, without limitation, press fitting and insert molding.
The cap 10 includes a humped portion 41 adjacent to the cavity 34 to provide a raised space 42 within the interior volume 16 of the reservoir 14 . In the present embodiment, the gaseous cavity 34 extends partially within the space 42 . The cap 10 also includes an inlet orifice 46 to facilitate filling/refilling the reservoir with ink. The space 42 , as shown in FIG. 2 , provides a step-up in height (with respect to the inlet orifice 46 ) that ensures that some gas will remain within the reservoir 14 and in communication with gas within the gaseous cavity 34 by way of the semipermeable membrane 40 when the ink is at its highest level. In the orientation shown in FIG. 2 , ink would spill out of an inlet orifice 46 (presuming no plug was inserted therein) before displacing the volume of gas occupying the space 42 . Because the gaseous cavity 34 extends at least partially within the raised space 42 , at least a portion of the membrane 40 will be exposed to gas occupying the reservoir 14 even when the ink is “full”. As the level of ink within the reservoir 14 drops from usage, a larger and larger area of the membrane 40 becomes exposed for gaseous transfer between the interior 16 of the reservoir 14 and the gaseous cavity 34 . Eventually, the entire membrane 40 is exposed for gaseous transfer between the cavity 34 and the interior 16 of the reservoir 14 .
A cylindrical venting conduit 48 is provided through the cap 10 and includes an opening 50 in direct communication with the gaseous cavity 34 and in fluid communication with the external environment 36 by way of a tunnel 54 . The tunnel 54 comprises a trench 56 originating at the cylindrical conduit 48 and traveling in a serpentine pattern within a top surface 62 of the cap 10 . The trench 56 is covered by a secondary structure 52 that provides an outlet 58 to the external environment 36 opposite the cylindrical conduit 48 . Exemplary secondary structures 52 include flat panels, flat panels having a corresponding trench formed therein, and corresponding concave structures operatively coupled to the cap 10 by an amendable process known to those of ordinary skill in the art.
After the cap 10 is mounted to the tank 12 , the reservoir 14 is filled with ink via the inlet orifice 46 . The inlet orifice 46 is in fluid communication with a first cylindrical conduit 64 extending down from the cap 10 into the interior 16 of the reservoir 14 , which transitions into a second cylindrical orifice 70 in direct fluid communication with the interior 16 of the ink reservoir 14 . A plug (not shown) is positioned within the first cylindrical conduit 64 after an appropriate volume of ink has been added to the reservoir 14 to seal the inlet orifice 46 . An appropriate volume of ink includes an amount of ink raising the level of ink within the reservoir 14 to abut the orifice 70 .
The inflow of ink into the reservoir 14 submerges an internal backpressure regulator 74 in fluid communication with a printhead 76 . The backpressure regulator 74 regulates the volume of ink passing between the reservoir 14 and the printhead 76 to prevent weeping when printing operations are no longer desired. The regulator 74 includes an inlet 78 that provides selective fluid communication between an interior 80 of the regulator 74 and the reservoir 14 . The ink stream flows through the regulator 74 , through an ink filter cap 82 , through an ink filter 84 , and is eventually delivered to a plurality of nozzles 86 on the face of the printhead 76 . The exterior of the backpressure regulator 74 is fully submerged when the ink reservoir 14 is full, and becomes partially submerged as ink within the reservoir 14 is consumed below a certain point. For a more detailed discussion of the operation of the backpressure regulator 74 , see co-pending U.S. patent application Ser. No. 10/465,403.
In a completely sealed reservoir, ink leaving the reservoir would decrease the internal pressure of the reservoir, as the internal volume of the reservoir remains the same, but the volume of ink within the reservoir has decreased. This gradual decrease in internal pressure within the reservoir decreases the pressure differential between the exterior of the regulator 74 and the interior 80 of the regulator. It is preferred to maintain this pressure differential between the exterior of the regulator 74 and the interior 80 of the regulator by enabling gaseous diffusion between the interior volume 16 and the external environment 36 .
The membrane 40 in accordance with the present invention allows gas to flow between the exterior environment 36 and the interior 16 of the reservoir 14 by way of the cylindrical venting conduit 48 , but substantially inhibits liquid (ink) from passing therethrough. Accordingly, the semipermeable membrane 40 may be a material having very small pores selectively allowing gas to flow therethrough, but inhibiting a liquid from passing therethrough. At extremely high pressure levels a liquid might be forced through the pores of the membrane 40 , but such pressures are seldom seen during normal printhead operation. The semipermeable membrane 40 may comprise a single material or a composite material and may also include multiple layers of a unitary or composite material. An exemplary material comprising the semipermeable membrane 40 in accordance with the present invention is a single layer polytetrafluoroethylene (PTFE) membrane from W. L. Gore & Associates (www.gore.com).
As with any porous material, there is a pressure drop associated with gas passing through the membrane 40 . Several factors may be considered to minimize the effect of this pressure drop on the backpressure regulator 74 . The area of the membrane 40 available for gaseous transfer is partially determinative of the volumetric flow of gas that can pass through the membrane 40 at a given pressure. To reduce production costs, however, it is desired that the area of the membrane 40 be relatively small. Thus, an optimization of this area accounts for productions costs versus the maximum potential volumetric flow rate of gas during normal operation of the printhead 76 .
An additional factor that may be considered is the shape of the membrane 40 exposed to the ink. The pressure drop may increase across the membrane 40 as the exposure to ink is increased. The shape of the membrane may determine, in part, how quickly the membrane 40 recovers from being directly exposed to ink and provides gaseous communication through those areas. A circular shaped membrane 40 may not be optimal as a single spherical bubble of ink might block the path of gas through the entire membrane 40 . The potential for the natural, spherical shape of the bubble to completely block the membrane becomes less likely as the shape of the membrane 40 deviates from being circular.
Referencing FIGS. 3–5 , a second exemplary ink reservoir cap 90 is shown that is adapted to be mounted to a corresponding structure, such as an ink tank, to provide a vented ink reservoir (similar to the embodiment shown in FIGS. 1 and 2 ). The ink reservoir cap 90 includes an ink inlet 92 and a serpentine channel 98 , adjacent to the ink inlet 92 , having a vent hole 100 at a first end, while a second end terminates on the top surface 94 of the cap 90 . The cap 90 is attached to the reservoir and includes a channel 98 adapted to be covered to create a serpentine tunnel venting to the external environment. A humped portion 106 of the cap 90 creates a space 108 that is above the top surface 94 . The humped portion 106 includes a planar, U-shaped top surface 110 being joined by eight side surfaces beveled at the adjoining ends.
Referencing FIGS. 4 and 5 , the bottom surface 96 includes a plurality of alignment posts 112 that are utilized to align the ink reservoir cap 90 onto the corresponding structure to provide an ink reservoir. A lip 114 protrudes from the bottom surface 96 to form a rectangular rib surrounding and abutting the alignment posts 112 that is adapted to be received by an interior wall of the corresponding structure.
A nodule 116 inside of the lip 114 includes a cylindrical wall 118 transitioning into a domed shaped end 120 in fluid communication with the ink inlet 92 . Adjacent to the nodule 116 is a continuous oval shaped wall 122 defining a cavity 124 adapted to be fluidically sealed by a semipermeable membrane (not shown) and provide a gaseous area. The top surface 126 of the wall is angled uniformly to receive the semipermeable membrane mounted thereto to inhibit liquid from entering the cavity 124 .
A portion 128 of the cavity 124 opposite the nodule 116 is located within the elevated space 108 . The space 108 is adapted to trap a minimum amount of gas within the reservoir when the reservoir is filled with ink to ensure that at least the portion of the cavity 124 is in gaseous communication with such trapped gas. If the pressure within the vented reservoir were to increase above that of the external environment, a percentage of the trapped gas would pass through the semipermeable membrane, into the cavity 124 , through the vent hole 100 , through the serpentine tunnel and into gaseous communication with an external environment. An opposite process would take place if the pressure within the vented reservoir were to decrease with respect to the external environment.
Following from the above description and invention summaries, it should be apparent to those of ordinary skill in the art that, while the methods and apparatuses herein described constitute exemplary embodiments of the present invention, the inventions contained herein are not limited to these precise embodiments and that changes may be made to them without departing from the scope of the invention as defined by the claims. Additionally, it is to be understood that the invention is defined by the claims and it is not intended that any limitations or elements describing the exemplary embodiments set forth herein are to be incorporated into the meanings of the claims unless such limitations or elements are explicitly recited in the claims. Likewise, it is to be understood that it is not necessary to meet any or all of the identified advantages or objects of the invention disclosed herein in order to fall within the scope of any claim, since the invention is defined by the claims and since inherent and/or unforeseen advantages of the present invention may exist even though they may not have been explicitly discussed herein. | An inkjet assembly comprising a vented ink reservoir for containing a liquid ink therein, the vented ink reservoir defining an internal volume occupied at least in part by a semipermeable membrane in fluid communication with a vent that automatically adjusts for pressure differentials by enabling gaseous diffusion between an environment external to the vented ink reservoir and the internal volume of the vented ink reservoir, while inhibiting liquid diffusion therethrough. A method is also disclosed for mounting the semipermeable membrane to at least one of an ink reservoir cap and an ink tank. | 1 |
Pursuant to 35 U.S.C. §120, this application is a C.I.P of the filing date of the previously-filed U.S. patent application Ser. No. 09/666,695, filed Sep. 21, 2000, now U.S. Pat. No. 6,422,406.
FIELD OF THE INVENTION
This invention relates to storage and display racks and more particularly—but not exclusively—to wire wine racks which may be easily and quickly assembled and disassembled without the need for tools.
BACKGROUND OF THE INVENTION
For convenience of expression, the inventive rack will hereinafter be called a “wine rack”; although, it should be apparent that the inventive rack has many uses other than for storage of wine. The wine rack may have almost any convenient size and shape. In general, the dimensions of a wine shelf might be in the nature of 14″×48″ and, perhaps 84″ tall. An example of such racks may be found in U.S. Pat. Nos. 4,546,887 and 2,622,741.
Regardless of the assembled size, it is desirable to have a rack which may be shipped broken down into its component parts in a relatively small box. Also, it should be very easy to quickly assemble the rack into its useable form or to disassemble it for storage. Once it is assembled, it should be secure and stable.
SUMMARY OF THE INVENTION
A particularly useful form of construction which meets these criteria is a rack made of a plurality of preferably cold rolled steel wires which intersect each other and are preferably welded together at each point where the wires intersect. In the preferred embodiment, the wires form an orthogonal matrix to form shelves and panels.
Accordingly, an object of the invention is to provide a rack having the features described above. Here an object is to provide such a rack which is especially adapted for wine or bottle storage but which may also be used for other purposes. For example, four rack shelves might provide for wine storage while a fifth shelf might store other things such as glasses, napkins, nuts, chips, and the like. Hence, flexibility of design and usage is desirable.
In keeping with an aspect of the invention, these and other objects are provided by a series of wire panels and shelves which easily fit together without the need for tools. The shelves may be assembled in either a flat and completely horizontal position for general storage or on a slant for wine bottle storage. Once the shelves are in position, a suitable number of A-frames may be secured to each shelf in order to receive rows of bottles between the slanting sides of the A-frame, forming space-efficient storage compartments.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of an assembled inventive wine rack having two exemplary sets of A-frames on each of three shelves;
FIG. 2 is a perspective view of two feet attached to vertical corner posts of a wine rack;
FIG. 3 is a side elevation of plastic shelf supporting collars which are positioned on a corner post;
FIG. 4 is a perspective view of a first step in assembling a rack;
FIG. 5 is a perspective view of a wine rack with a plurality of shelves in place on the vertical corner posts and at the start of a back panel installation;
FIG. 6 is a perspective view of a wine rack with a back panel being snapped into place;
FIG. 7 is a perspective view giving a detail of a hook used to hold the back panel in its final position;
FIG. 8 is a side elevation view showing two corner posts ready to receive a side panel;
FIG. 9 is a side elevation showing an assembly of the corner posts and A-frames;
FIG. 10 is a front elevation of an A-frame which provides support for bottles stored on a rack shelf;
FIG. 11 is a front elevation which shows a pyramid of bottles stored in an A-frame mounted on a shelf;
FIG. 12 is a back elevation of substantially the same equipment that is shown in FIG. 11 with the back panel in place to prevent either the bottles from falling off the back of the shelves; and
FIG. 13 shows a full shelf having two sets of A-frames, arranged to support 62 bottles.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows the inventive wine rack having four exemplary shelves 22 - 28 and a top panel 30 . A suitable space 32 is provided to receive any additional shelves or stacked items such as ice buckets, napkins, glasses, etc., as the user of the shelves may elect. As here shown, two sets of bottle supporting A-frames 34 , 36 have been secured to shelf 24 in order to receive wine bottles. Similar A-frames are shown secured to the other shelves 26 , 28 .
The entire wine rack 20 is preferably made of shelves and panels comprising two layers of cold rolled steel wire or rods which intersect each other in an orthogonal matrix and are preferably welded together at each crossing or intersection. These wires are shown and are hereinafter described as being in the preferred orthogonal orientation; however, the wires may have many different orientations such as diagonal or even simple spaced wires parallel to each other. The method of assembly (or disassembly) should be apparent from a study of the following specification and the drawings explained therein.
The corner posts 38 - 44 (FIG. 4) are, in effect, hollow tubes or pipes having circumferential grooves or channels, such as 46 (FIG. 3) formed periodically along the length of the posts. These grooves may appear at one inch intervals for most corner posts.
A plastic collar 48 (FIG. 3) has at least one internal ridge which fits into a selected one or more of the circumferential grooves or channels on the corner posts. For example, U.S. Pat. No. 5,127,342 discloses an adjustable shelving system with a type of collar that can be used in connection with the present invention. Then, a second collar 50 slips over the collar 48 in order to lock it into place. The collars on the front corner posts 38 , 42 may be placed in circumferential channels which are an inch or two lower than the vertical positions of the collars on the rear posts, thereby providing slanting shelves (see shelf supports at 24 - 28 in FIG. 8) for supporting wine bottles with their corks in a higher position. Or, they may be placed in the same relative vertical positions on both the front and rear posts, thereby providing horizontal shelves. A number 52 may appear between grooves on the corner posts to assist in positioning the collars, these numbers 52 preferably extend along the entire length of the corner posts (see FIG. 13 ).
To begin the assembly, the collars 48 , 50 are put into place and feet 54 , 56 (FIG. 2) are attached to the bottom of the corner posts 38 - 44 . Then, the corner couplers 53 of shelf 22 are fitted over the plastic collars 48 , 50 . Both the collars and corner couplers 53 may be simple, tapered, ring-shaped members with the couplers 53 fitting over the tapered collars 48 , 50 and resting on a circumferential stop 58 . The nesting taper of the collar 50 and coupler 53 carries most of the shelf weight.
Any suitable number of shelves 24 - 30 (FIG. 5) are added to the corner posts 38 - 44 in a similar manner, either filling it completely or leaving space 32 for uses other than the storage of bottles.
The rack is now ready for a back panel 60 to be installed. For this, both the top and the bottom of the panel have upwardly facing open hooks thereon. FIG. 7 shows the bottom hook 62 . The top of the panel also has upwardly facing hooks 64 (best seen on the side panel (FIG. 8 )).
As shown in FIG. 5, first the hooks 62 on the bottom of back panel 60 are hooked under an edge of a shelf, such as bottom shelf 24 , for example. Then, the back panel is bowed outwardly (FIG. 6) in order to lower the upwardly facing hooks on the top of the back panel 60 so that they may be slipped under an edge of a shelf, such as top shelf 30 . The bowed back panel is released and its resilience drives the upwardly facing hooks to be captured under the shelf.
The construction of the back panel is preferably an orthogonal matrix of wires which may be welded together at each cross point. Any other suitable geometric configuration may also be used. This arrangement provides a back panel having a number of rectangular openings such as 66 (FIG. 1 ). The only requirement is that these openings should be small enough to prevent the wine bottles from falling off the back of the shelves.
The shelves are now ready to receive their side panels (FIGS. 8, 9 ). As here shown, the shelves slant downwardly from 70 on rear post 44 to 72 on the front post 42 . This way, corks will remain wet when the wine bottles are laid on the rack with their neck pointing toward the rear of the rack (i.e., toward rear corner post 42 ). For example, the shelf supports may be located as follows:
POSITION ON REAR
POSITION ON FRONT
SHELF
POST
POST
Shelf 26
56″
55″
Shelf 28
71″
70″
Shelf 30
86″
85″
Of course, other spacings could also be provided. Or, the shelves could also be level and horizontal if the collars of FIG. 3 are positioned at the same height on the front and rear posts.
The side panels 68 (FIGS. 8, 9 ) are installed in approximately the same manner that is shown in FIGS. 5, 6 for the back panel. FIG. 9 shows the side panel 68 in place on the rack. Again, the side panel is here shown, by way of example, as an orthogonal matrix of wires preferably welded together at each cross point, although other configurations could also be used.
The shelves are now ready to receive the bottle supporting A-Frames 34 , 36 (FIG. 10 ). These frames are formed by resilient wire arms 71 bent at an acute angle 74 at an apex with two free ends 76 opposite the apex. A number of cross members 78 - 82 extend across and are welded to each wire arm 71 to form the A-frame 34 .
FIGS. 1 and 9 show a front view and side view, respectively, of an exemplary wine rack, here having three shelves 24 - 28 for storing wine bottles. A plurality of A-frames 34 , 36 , are secured to the shelves in a side-by-side relationship. A pyramid of bottles may be supported under each set of the A-frames and an inverted pyramid may be supported between two sets of A-frames (FIG. 13 ).
The lower portion or free ends 76 of the wire members 71 are adapted to fit between and grasp the individual wire members which form the shelf surface or matrix on each individual shelf. A pair of cross members 78 which extend across the lower free ends 76 of each arm of the A-frames capture and hold between them an individual wire member on the shelf surface to secure the A-frame to the shelf. To install the A-frames shown in FIGS. 11-13, the bent wires 71 are spread apart and the pair of cross members 78 on the free ends of the wires 71 are fitted over the wires that form the shelves. Then, the A-frame wires 34 are released whereupon the resilience of the wires 71 cause them to return to normal with the shelf wire captured between the cross members 78 . When the cross members are disposed on the outside of the A-frame (FIG. 13 ), the two arms are squeezed together, inserted into the shelf wiring, and released. Then, each of the cross members 78 captures a shelf wire adjacent the free ends of A-frame wires 34 .
FIGS. 11-13 show a rear view of a shelf 114 with an A-frame in place. The bottom of a wine bottle 116 is shown. By an inspection, it is seen that, the width of the space between the A-frame arms is adequate to receive a first row 121 (FIG. 11) comprising a fixed number (here four) of bottles 116 . The second row 122 includes one less (three) bottle. In a similar manner, the third row 124 includes one less (two) bottle. Finally, the top “row” 126 is a single bottle completing the pyramid 128 of bottles. It is obvious from an inspection of FIGS. 11-13 that the dimensions of the A-frame are such that the entire pyramid is held securely in place.
FIG. 12 is a view similar to FIG. 11, except that it is taken looking through back panel 60 . The spacing between the wires of the matrix forming the back panel is such that a wire is always in a position to prevent a bottle from sliding through and protruding behind the back panel.
From FIG. 13, it is seen that the space 138 between two adjacent A-frame sides 132 and 134 is adapted to receive an inverted pyramid 140 of bottles, while the A-frames also form end zones 142 , 144 .
Those who are skilled in the art will readily perceive various modifications which fall within the scope and spirit of the invention. Therefore, the appended claims are to be construed to include all equivalent structures. | A number of panels and shelves are formed of wires which are arranged to intersect. These panels and shelves are secured together to form a rack for holding bottles, which rack is supported by four corner posts. The vertical placement of the shelves is adjustable along the height of the corner posts by use of adjustable support collars which fit around each post and are captured by each corner of a shelf. A plurality of A-frames are removably secured to the shelves to form areas or compartments in which the bottles or the like may be stored. The A-frames are positioned next to each other so as to support an inverted pyramid of bottles between them. | 0 |
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This patent application claims the benefit of U.S. Patent Application No. 60/487,627, filed Jul. 15, 2003.
FIELD OF THE INVENTION
The present invention relates generally to prepaid or stored value cards used for purchasing good and services, and more particularly to a system and method for activating or changing the value of an account associated with such a card without requiring additional technology to be added to existing point-of-sale terminals.
The invention permits the sale or issuance of prepaid cards by activating the card and/or loading a specific amount of funds or points on the account associated with the card at any outlet where credit or debit cards are accepted as forms of payment or identification, or at any outlet where a device with the capability to authorize or capture a credit/debit card transaction can be installed.
BACKGROUND OF THE INVENTION
Stored value cards, such as pre-paid gift cards and the like, are well known in the art. Such cards are typically associated with an account maintained at a financial institution that issued the card. It will be appreciated by persons of skill in the art that the term “card” as used herein does not refer to any specific form factor. Rather a “card” may be any physical or virtual device that can be linked to an account. For example, the term “card” as used herein should be understood to mean a traditional card, such as a CR80, or any number of other formfactors such as contactless fobs and the like.
Prior to using the card for purchasing goods and services from a seller or merchant, a stored value card user typically deposits, or “stores,” a sum of money into the account associated with the card. Once the card is used to purchase goods and services, the cost of those goods and services is debited from the account. If the cost of the purchase exceeds the monetary sum stored in the account, the debit transaction usually cannot not proceed until more funds are added to the account. Accordingly, stored value cards are distinguishable from charge/credit cards in which the financial institution extends credit by paying the merchant or seller and then later seeks reimbursement from the card holder.
Activation and tracking of the accounts associated with prepaid cards may be accomplished in several different ways. In one commonly used method, a centrally located host computer system, including one or more computer platforms, tracks all transactions involving the prepaid card. Activation of the card, as well as all debit and funding transactions, are communicated from various retail points of sale to the centrally located host computer system, which is maintained by the card-issuing financial institution. To activate the card, or to debit or credit the account associated with the card, the card issuer must first develop a network of point-of-sale devices that communicate with the card issuer's host computer systems. Processing the prepaid card through the point-of-sale terminal causes the terminal to transmit messages over the network to the host computer system, which messages inform the host computer to activate, credit or debit the prepaid account.
Prior art approaches to implementing centrally tracked prepaid cards involved hardware and/or software that was customized for the purpose of administering such cards. For example, a dedicated point-of-sale terminal for prepaid cards may be employed to generate the special messages associated with prepaid cards. In certain situations, existing point-of-sale terminals may be extended to accommodate prepaid cards without significant hardware modification, but even for such extendible terminals, extensive software modifications are required to permit the terminals to generate the special messages used by the host computer system to implement prepaid accounts. Accordingly, there is a need for an improved system and method for activating and/or changing the status of an account associated with a prepaid card without requiring dedicated hardware or software at the point-of-sale or without requiring extensive modifications to existing point-of-sale terminals.
SUMMARY OF THE INVENTION
The invention comprises a system and method for activating and changing the status of a prepaid card through the use of industry-standard messages, such as those described in ISO/IEC 8583. Most retailers use point-of-sale terminals to process debit/charge/credit card transactions, which terminals generate and receive industry standard messages based on input from the retailers.
For example, a seller may accept payment for a sale by swiping the card holder's card through the terminal's card reader, inputting to the terminal the amount of the purchase to be charged, and pressing the appropriate keys on the terminal to indicate that the transaction involves a charge against the card holder's account. The point-of-sale terminal accepts this input from the seller and generates the industry standard electronic message that is transmitted to the appropriate financial institution. The electronic message includes, for example, the number of the card, the transaction type, and the amount of the purchase. In the event of a return or credit, the seller likewise swipes the card, inputs the amount of the return or credit, and presses the appropriate keys to indicate that the transaction is to be credited to the account associated with the card. Such transactions, and the standard messages associated with such transactions, are well-known.
In the inventive system and process, industry standard messages are employed to activate and/or change the status of prepaid cards. For example, industry standard funding, credit, return, or void transactions, which are commonly implemented in most point-of-sale terminals, may be used to activate and/or load value into an account associated with a prepaid card. The “back-office” computing platforms receive these industry standard messages, detect that the messages relate to a prepaid or stored value card account, and interpret the messages in context. Through the use of industry standard messages, no hardware or software modifications are required to the point-of-sale terminals that are widely used throughout the world. Instead, only the back-office computing platforms, which are centrally located, need be modified.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram representing the hardware and software components common to a card processing/transaction network but configured to enable a prepaid or stored value card and to carry out the inventive process.
FIG. 2 is a flow chart illustrating the steps of the inventive process.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the figures, wherein like reference numbers refer to like elements, there is illustrated in FIG. 1 the hardware and software components of an exemplary network that may be used to process prepaid card transactions as well as ordinary charge/credit transactions. The network includes one or more point-of-sale terminals 100 remotely located with sellers and merchants of goods and services. The terminals 100 are electronic devices that typically include a keypad and a visual display. To process the cards, the terminals also typically include a card reader that can read a machine-readable medium on the card, such as a magnetic strip. Other examples of reading machines and machine-readable mediums include optical and electronic storage technologies. In some embodiments, the terminal may be a special purpose device designed around the card reader, while in other embodiments the terminal may be a general purpose personal computer having a card reader attached thereto. Other implementations and embodiments are well-known to persons of skill in the art, such as the use of a key fob as a “card” input device.
The terminals 100 communicate with a front-end computing platform, identified as Distributed CAS (Card Authorization System) Platform (“DCP”) 110 , maintained by a card-issuing financial institution. The communication between the terminals and the front-end computing platform occurs over existing telecommunication networks via electronic, radio, and/or satellite communication links. The front-end platform, DCP 110 , further is in communication with a Card Authorization System/Transaction Processing Front End platform (“CAS/TPF”) 120 , which is also maintained by the card-issuing financial institution. The CAS/TPF platform 120 , in turn, is in communication with a back-end computing platform, such as DCP 130 , that is in communication with a Stored Value Card Authorization Platform (“SVCAP”) 140 . The back-end DCP 130 and SVCAP 140 are also maintained by the card-issuing financial institution. Accordingly, front-end DCP 130 and CAS/TPF platform 120 are denoted as front-end components of the network while the back-end DCP 130 and SVCAP 140 are denoted as back-end components. The front-end and back-end DCPs and the platforms can be incorporated in any suitable computer system such as personal computers, servers, and mainframes.
It will be appreciated that the above described computer system is only an exemplary description of a possible “back office” or host computing system and that other configurations may be used to facilitate the present invention. Accordingly, the above described system including the front-end DCP 110 , CAS/TPF 120 , back-end DCP 130 and SVCAP 140 are not to be construed as limitations on the present invention. Instead, any suitable computing platform to process the relevant data messages may be employed.
Referring to FIG. 2 , to activate and/or credit the prepaid card in accordance with the teachings of the invention, in a first step 200 of the process the customer who is desirous of activating or changing the status of a prepaid card will tender payment, e.g., cash, a personal check, or a credit card, to the seller or merchant. The customer may also present a preexisting card to the seller. If the customer is activating a new prepaid card, the initially inactivated card may be in the possession of the seller and turned over to the customer after activation. The “card” may have any suitable shape or form including, without limitation, a CR80 standard card size or a key fob.
The prepaid card may be issued by the financial institution (hereinafter card issuer) responsible for maintaining the computer platforms and system described with reference to FIG. 1 . The card may already be associated with an account maintained by the card issuer or may require initialization of a new account with the card issuer to complete the activation of the card. Accordingly, the card user may replenish an existing account or initialize a new account. Additionally, the value added to the card may be a pre-defined amount (i.e., predefined value gift cards or cards ranging in value over multiple increments) or may vary according to the amount desired by the customer/card user.
In the second step 210 of the process, the seller or merchant processes the prepaid card through the point-of-sale terminal during which a card number is read from the card. The card number is associated with an account tracked by a host computer system, such as that described in connection with FIG. 1 . The system uses the card number to associate a particular card with a particular account. Also entered by the seller or merchant into the point-of-sale terminal is the value of the monetary funds tendered. In the third step 220 , the seller or merchant activates the credit transaction feature, which may be accomplished, for example, by depressing a button denoted “Credit” on the keypad.
The operations performed by the point-of-sale terminal are well-known and apply to the debit/charge/credit card transactions for which the terminal has been programmed. The credit transaction feature generates a credit message to be sent from the point-of-sale terminal 100 to the host computer systems. The credit message is typically in an industry standard format, such as a funding, credit, void, or return format as well as other formats such as those defined by ISO/IEC 8583. The credit message also includes information identifying the card number and the amount of the funds that were tendered. In the embodiment of FIG. 1 , the front-end DCP 110 receives the message from the point-of-sale terminal and sends the credit message to the CAS/TPF platform 120 . The CAS/TPF 120 may also send the data message onto the back-end DCP 130 and the SVCAP 140 for further processing. The path of the credit message through the network is denoted by the arrows referenced 150 . The host computer system thereafter processes the data message received from the point-of-sale terminal.
FIG. 1 generally illustrates a real time transmission of information from the point-of-sale terminal to the host computer but it will be appreciated by persons of skill in the art that batch processing of information may also be employed. That is, the credit message may be sent from the point-of-sale terminal 100 to the front-end DCP 110 immediately, or the credit message may be delayed for batch processing. In the latter process, sellers and merchants may submit multiple debit and credit transactions to the financial institutions bundled together as a batch and transmitted to the host computer according to a predetermined frequency. Sending the credit messages via batch processing, however, may result in a delay as to when the stored funds become available.
To update the account, the software running on the host computer interprets the data message as intending to credit the value of the tendered funds to the designated account. The host computer may so interpret the data message based on information within the message itself, such as the card number, which may heuristically indicate that the account pertains to a stored value card. An account balance associated with the card is maintained in a computer database 122 that is also part of the host computer. Crediting of the account by the card issuer corresponds to step 230 of the process in FIG. 2 . The card issuer settles fund transfers with the seller through a separate transaction. Settlement between the card issuer and seller may occur on a periodic, predetermined basis.
If the information contained in the credit message does not correspond to an active account presently maintained on the host computer, the software running on the host computer interprets this as an attempt to activate a new prepaid card. The host computer thereafter validates the card number, creates a new account, designates that account as corresponding to the associated prepaid card, and credits to the account the amount indicated by the credit message. The new prepaid card issued to the customer is thereby activated.
In another embodiment, to provide additional security and protection regarding issuing and activating new prepaid cards, the credit message received by the host computer may only trigger the card issuer's computer system to change the status of the new card from “inactive” to “pending active.” Fully activating the card requires another trigger mechanism such as having the cardholder contact the card issuer. This also allows the card issuer to obtain more information about the card user such as their name, address, and phone number that cannot be transmitted to the card issuer through the existing point-of-sale terminal.
An advantage of the new process is that the card issuer 's records of the account are updated to reflect the credit without having to modify the point-of-sale terminals and other components located with and/or owned by the sellers or merchants. Another advantage is that prepaid cards can be activated and new accounts created by using the existing point-of sale terminals. All modifications necessary to implement the new system and method are made to the components maintained by the card issuer.
In a further embodiment of the new process, as represented by step 240 of FIG. 2 , the network can be used to transmit a “notification” message from the back-end components to the point-of-sale terminal. The notification message informs the card holder that the account associated with the card has been credited. In a further embodiment, the notification message may also verify the amount credited to the account.
To implement the notification message, the host computer including, for example, the CAS/TPF platform, back-end DCP, and SVCAP make use of the existing authorization code feature in the network. Specifically, when processing a charge/credit transaction, the point-of-sale terminal sends an authorization request along with the charge/credit account information to the computer platforms maintained by the financial institution. The host computer determines if the respective charge/credit account has sufficient credit to proceed with the transaction. If so, the host computer invokes the authorization code feature that transmits an authorization code back to the point-of-sale terminal authorizing the transaction.
Once the front-end and back-end components determine that the value credited has been stored in the respective account, the host computer invokes the software responsible for transmitting the authorization code to the point-of-sale terminal. The transmission of the authorization code through the network components is designated by the reference arrows 152 in FIG. 1 . The seller or merchant, being aware that a credit transaction was just processed for a stored value card, is able to interpret the authorization code received by the point-of-sale terminal as the notification message. The seller or merchant will relay the notification message to the card user to verify to the card user completion of the credit transaction.
The inventive system and method may be implemented as described in the following example. It is assumed for purposes of this discussion that the seller has been provided with inactive prepaid cards packaged in a manner compatible with this solution and that a customer has entered the store and chosen to purchase a fixed amount prepaid card from the seller.
The seller prepares the transaction request as a credit transaction and swipes the prepaid card packaging through the existing point-of-sale equipment. This terminal generates an industry standard message, e.g., ISO/IEC 8583 format, and transmits the message to the host system. The host system, as illustrated generally in FIG. 1 , thereafter receives the transaction request and, based on the context of the message and information stored in the computer platforms, determines special processing is required (activation). The prepaid card is activated and the value of the prepaid card is determined by the business rules in place for this product. In addition, any seller fees owed to or by the host product/system owner might be recorded at this time or deferred until the next scheduled batch process from the seller.
The host computer systems thereafter indicates a successful activation to the seller using an industry standard return message, e.g., ISO/IEC 8583 format. The seller collects the value of the prepaid card (and any other fees) from the customer, and the customer leaves the store with the activated prepaid card and relevant receipts. The customer may thereafter use the card at any location where the card issuer 's financial products are accepted. It is noted that the sequence of the above steps is exemplary only and may be modified. For example, the seller may request payment before the point-of-sale terminal transmits the message to the host computer system.
All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein. The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms “comprising,” “having,” “including,” and “containing” are to be construed as open-ended terms (i.e., meaning “including, but not limited to,”) unless otherwise noted. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.
Preferred embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. | A system and method for activating and funding prepaid cards at the point of sale by making innovative use of existing point-of-sale devices and existing credit/debit card acceptance networks and processes. The invention obviates the need to implement new/different technology at point-of-sale terminals that are widely used at retail outlets. This invention makes use of the existing credit and charge card systems and processes, including industry standard message formats, to settle funds and fees between the seller and the issuer of the prepaid card, thus further reducing the expense and time-to-market for product distribution. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of application Ser. No. 10/053,013, filed Jan. 18, 2002, entitled “LOCATION BASED SECURITY MODIFICATION SYSTEM AND METHOD,” which is incorporated herein by reference in its entirety.
BACKGROUND
[0002] The disclosure relates generally to the field of wireless communication. More particularly, the disclosure relates to a method or system for providing a level of data security dependent on the location of the user of a wireless device.
[0003] Wireless networks, in general, have grown in both capability and use. More and more people rely on wireless devices in their professional and personal lives. Professionals often rely on wireless devices to have instant access to information while they are away from the office. Professionals use wireless devices to access email, calendars, contact lists, a company intranet, web-enabled applications, business and local news, and other information. Individuals often use wireless devices to stay in touch with friends and family and to access information which may aid them in their daily activities.
[0004] As people use wireless networks more, they are also more frequently storing and accessing sensitive data on portable devices and/or over wireless networks. This information can include personal information, financial information, or company confidential information. The information can either be stored on the remote portable device or it can be stored on a server and accessed using the remote portable device over a wireless network. Both the device and the transmission can be susceptible to interference, interception, or tampering.
[0005] A wide number of various techniques have evolved to try and protect the data that is stored on handheld devices and transmitted over wireless networks. Examples of the techniques include: authentication, authorization, encryption, and data integrity verification. Authentication refers to verification of the identity of a person or process from which a message, data request, or access request originates. Authorization refers to the process of determining what functionality or access to information is available to that particular person or process. Encryption refers to encoding information in such a manner such that the information is not decipherable by someone intercepting the information. Data integrity attempts to ensure that the data has not been modified or damaged during a transmission.
[0006] Unfortunately, providing security has costs associated with it. Generally in a network, data is sent in discrete units called “packets”. Packets of data are generally required to be of fixed size by most current network protocols. If the data is being transmitted from a remote location, security information may be required on every packet sent and received from a handheld device. This allows less space for data in each individual packet. Thus, filling packets with security information has the effect of reducing the effective transmission rate. This reduction is especially noticeable on a wireless network where the transmission rates are already vastly slower compared to a wired network.
[0007] Even if data is not being sent over a remote network, providing security has costs. Authentication and authorization can require the user to enter a password every time the data needs to be accessed. The data will remain unlocked for a period of time, but security can require that the data be locked again after a period of time or on the happening of an event such as shutting off the handheld device. Encryption requires that the data be organized such that it is not normally readable. Unfortunately, this process takes time, and prior to accessing the information, the data must be decrypted. And then again, after the access is complete, the data must be re-encrypted.
[0008] Albeit security is important to protect information, especially sensitive information such as credit card numbers, financial information, or corporate proprietary information, however, the absolute highest level of security is not necessary at all times. For example, when in a shopping mall, it may be useful to be able to access personalized shopping information with only minimal security. Also, while the user is at the office, there may be no reason to provide heavy security for company proprietary information.
[0009] Accordingly, there is a need for a method or system for providing different levels of security for different subsets of data based on the location of a portable network node or portable electronic device. There is also an increased need to protect the data transmissions and the devices from any or all of interference, interception, and or tampering.
[0010] It would be desirable to provide a system and/or method that provides one or more of these or other advantageous features. Other features and advantages will be made apparent from the present specification. The teachings disclosed extend to those embodiments which fall within the scope of the appended claims, regardless of whether they accomplish one or more of the aforementioned needs.
SUMMARY OF THE INVENTION
[0011] One exemplary embodiment relates to a method of adjusting security for a network user node in communication with a network based upon the location of the node. The method is performed by determining the location of a network user node, selecting a single level of security from a group of more than two security levels based on the determined location, and modifying the security protection for the network user node based upon the selected level of security.
[0012] Another exemplary embodiment relates to a computer system for modifying security settings for a network user node based on the location of the node. The computer system includes a location sensing device having a communicative coupling with the system for determining the location of a network user node, a storage device for storing a table of security modifications to be performed according to one of a plurality of locations for the network user node, the security modifications including more than two levels, a processor coupled to a storage device for processing information, storing the information on a storage device, and generating a security modification instruction, and a communication device capable of transmitting a data signal to the network user node containing instructions to modify the security protection for the node.
[0013] Another exemplary embodiment relates to a method of adjusting security for a network user node having a processor, a memory coupled to the processor, a wireless transceiver, and a location determining device in communication with a network based upon the location of the node. The method includes receiving location information using a network user node, and using the network user node to modify security protection for data to a single level from a group of more than two levels based upon the location information.
[0014] Another exemplary embodiment relates to a system implemented on a network user node for modifying security settings based on the location of the node. The system includes a system for determining the location of the network user node coupled to the network user node, a processor for processing information, storing information on a storage device, and accessing a table of security modification instructions, the table including more than two unique security modifications, and a storage device coupled to the network user node for storing a table of security modifications to be performed based on a plurality of locations for the network user node. Alternative exemplary embodiments relate to other features and combination of features as may be generally recited in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention is illustrated by way of example and not limitation using the figures of the accompanying drawings, in which the references indicate similar elements and in which:
[0016] FIG. 1A is a general block diagram of a network user node in communication with a wireless network in accordance with an exemplary embodiment;
[0017] FIG. 1B is a general block diagram of a network user node with an associated location sensor system in accordance with an exemplary embodiment;
[0018] FIG. 1C is a general block diagram of a network user node in communication over a wireless network using wireless access points;
[0019] FIG. 2 is a flow diagram illustrating a process of using the location of a network user node to set security levels;
[0020] FIG. 3A is an exemplary embodiment of a table showing security level settings indexed by location;
[0021] FIG. 3B is an exemplary embodiment of a record stored in the table shown in FIG. 3A .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] A system and method for using location information to change security settings for a mobile network node is described. In the following description, for purposes of explanation, numerous specific details are set forth to provide a through understanding of exemplary embodiments of the invention. It will be evident, however, to one skilled in the art that the invention may be practiced without these specific details. In other instances, structures and devices are shown in block diagram form to facilitate description of the exemplary embodiments.
[0023] FIG. 1A is a general block diagram 100 of a network user node 110 (or multiple network user nodes 110 ) in communication over a wireless network 120 with a remote computing system 130 in accordance with an exemplary embodiment. In an exemplary embodiment, remote computing system 130 is associated with a location sensing system 140 .
[0024] Network user node 110 can be a handheld computer, a handheld personal digital assistant, a laptop computer, a wireless cellular digital phone, a pager, or any other such device. Network user node 110 can be communicatively coupled to a wired or wireless network 120 .
[0025] In an exemplary embodiment wireless network 120 is the Internet. In alternative embodiments, wireless network 120 is any type of network such as, a virtual private network, an intranet, an Ethernet, or a netware network. Further, wireless network 120 can include a configuration, such as, a wireless network, a wide area network (WAN) or a local area network (LAN).
[0026] Remote computing system 130 can be any computing system including a central processing unit (CPU), a storage device, and a communication system. Remote computing system 130 can be communicatively coupled to location sensing system 140 . The communication between remote computing system 130 and location sensing system 140 can be achieved over a standard wired network, a wireless network, or any other communication system.
[0027] Location sensing system 140 can include a global positioning satellite system (GPS), an access node triangulation system, an access point sensing system, or any other system capable of detecting the location of network user node 110 . Location sensing system 140 includes a communication system to transmit the location information to remote computing system 130 .
[0028] FIG. 1B is a general block diagram 101 of network user node 110 with associated location sensor system 140 in accordance with an exemplary embodiment. Diagram 101 illustrates an alternative embodiment, wherein network user node 110 is directly associated with location sensing system 140 . In an exemplary embodiment location sensing system 140 is a GPS system. Location sensing system 140 can be any system capable of determining location and sending a data signal containing that information to network user node 110 .
[0029] FIG. 1C is a general block diagram 102 of a network user node 110 in communication over wireless network 120 with wireless access point 150 and wireless access point 155 . Wireless access points 150 and 155 may be but are not limited to IEEE 802.11 wireless access points, Bluetooth wireless access points, etc. Network user node 110 is in communication with wireless access points 150 and 155 over communications network 110 . Network user node 110 can obtain location information based upon the location of the wireless access point that is being accessed over wireless network 110 . In an exemplary embodiment, network user node 110 can receive timing information sent from wireless access point 150 to calculate the distance between the network user node 110 and wireless access point 150 . Network user node 110 can perform the same process with wireless access point 155 . Based upon stored location information and the distance from the two wireless access points, the location of network user node 110 can be determined. Alternatively location could be determined by determining the distance and direction of a signal received from just one of wireless access points 150 and 155 . In a further alternative, a gross approximation of network user node 110 may be determined by using the known location of the access point 150 with which user node 110 can communicate.
[0030] Examples have been illustrated above for some exemplary embodiments for determining the location of network user node 110 . These embodiments are shown for illustrative purposes only. Any method wherein the location of network user node 110 is determined with greater or lessor specificity is contemplated.
[0031] FIG. 2 illustrates a flow diagram 200 illustrating an exemplary embodiment of a method of using location information to update security settings on network user node 110 .
[0032] In a step 210 , the location of network user node 110 is obtained from location sensing system 140 or using wireless access points or an alternative location detection system. The network user node's location can be obtained using global positioning satellite (GPS) signals, information regarding the location of the current access point for the network user node, a signal triangulation method, or any other method capable of detecting the location of a network user node with greater or lesser specificity.
[0033] In a step 220 the location information is verified. If the location either could not be determined or is found to be an unacceptable value, network user node 110 could be configured to display a notice to this effect and apply default security settings for network user node 110 in a step 222 . Following the application of the default security levels, step 210 is once again performed and an attempt to determine the location of network user node 110 is once again made. Alternatively, step 210 can be performed after an interval of time has passed or upon the occurrence of some event such as powering on network user node 110 or attempting to access new functionality or data.
[0034] If the location value is properly determined and is an acceptable value in step 220 , a step 224 is performed wherein the location is referenced in a table 300 of security settings indexed by location, described below in reference to FIG. 3 A. Table 300 can be stored on a storage apparatus in association either with remote computer system 130 in communication with network user node 110 over wireless network 120 or on a storage apparatus associated with network user node 110 . Table 300 can be implemented using a processor and a storage means to create and store a series of records or a linked list. Alternatively table 300 can be implemented using a database or any other suitable method wherein information can be stored, indexed, and easily retrieved.
[0035] A determination is made in a step 230 to determine if the current location of network user node 110 is stored in table 300 of security settings indexed according to location. If the location is not found, an optional step 240 can be performed.
[0036] In step 240 , a new record 350 described below in reference to FIG. 3B , can be created for storage in table 300 . In step 240 the user is queried to determine if they want to create new record 350 containing security settings for the location determined in step 210 . In one exemplary embodiment the user can be queried using a display associated with network user node 110 . In an alternative embodiment the user can be queried using a series of communications sent from remote computing system 130 over wireless network 120 to network user node 110 . The query would give the user location information and the user would have the option of setting at least one security level setting for that location from a set of more than two different security levels (i.e. the level of security is chosen from more than just security on or security off). The security level setting could include restrictions or complete blocks on access to either network user node 110 as a whole, information stored on the network user node 110 , or any subset of information stored on the network user node 110 . The security setting could also include restrictions or blocks on access to information available on a remote system accessible using network user node 110 over wireless network 120 .
[0037] If the user does wish to create new record 350 , a step 242 is performed wherein the information is gathered through the user interface of the network user node 110 and used to populate a new record 350 with an index based on the location information determined in step 210 . In an exemplary embodiment, the user could have the option of expanding or shrinking the location setting to define the complete space wherein the new security settings should apply. Following the entry of the record information, a step 244 is performed wherein new record 350 is stored in table 300 .
[0038] If the user does not wish to create new record 350 in step 240 , the system will apply default security levels in a step 222 . Following application of the default security levels the system and method will return to step 210 to once again determine the location of network user node 110 . Alternatively, step 210 can be performed after an interval of time has passed or upon the occurrence of some event such as powering on network user node 110 or attempting to access new functionality or data.
[0039] If location was determined in step 220 and found in the table in step 230 , an optional step 250 may be performed wherein instructions to update the security settings for network user node 110 are transmitted from remote computing system 130 over wireless network 120 to network user node 110 . In alternative embodiments, illustrated above in reference to FIGS. 1B and 1C , this step is not required.
[0040] After the proper security instructions are obtained, a step 260 is performed wherein the security settings for network user node 110 are modified according to the information stored in the record. Following the update of the security settings, a step 210 is once again performed to determine the location of network user node 110 . Step 210 can be performed immediately to create a continuous looping and updating of the security levels for network user node 110 based upon location, or alternatively the security settings can be updated after certain intervals of time, or the security settings can be updated upon the occurrence of some event such as a powering on of network user node 110 or attempting to access new data or functionality.
[0041] FIG. 3A shows an exemplary embodiment of a table 300 for storing information regarding security settings for network user node 110 indexed according to location. This table can be stored on remote computing system 130 . Alternative, table 300 can be stored on a storage apparatus associated with network user node 0 .
[0042] Each entry in table 300 is represented by a record, described in detail below with reference to FIG. 3B . Table 300 represents a complete listing of all records that are stored on the storage system.
[0043] In addition to user defined records based upon location, table 300 stores a record 310 for default security settings. Record 310 is referenced in step 222 , described above in reference to FIG. 2 , to apply security settings when either the location is unknown or the location is known but not represent by a record in table 300 . In an alternative embodiment, one record can be used when location is undetermined, while another can be used when location is not represented by a record stored in table 300 .
[0044] FIG. 3B represents new record 350 for storing security level information to be associated with a location. Record 350 may contain several entry fields for storing information relevant to security level settings for any one particular location. In an exemplary embodiment record 350 contains entry fields for the name of the location, the coordinates of the location, the security settings for the network user node at that location, the default security settings for that location, the security settings for a subset of information at that setting and any other security information that the user may wish to associate with a given location. The location information stored in new record 350 can be a single point or a range wherein the security settings will apply.
[0045] While the detailed drawings, specific examples and particular formulations given describe exemplary embodiments, they serve the purpose of illustration only. The hardware and software configurations shown and described may differ depending on the chosen performance characteristics and physical characteristics of the computing devices. For example, the type of computing device, data structures, or devices used may differ. The systems and methods shown and described are not limited to the precise details and conditions disclosed. Furthermore, other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the exemplary embodiments and the steps of the exemplary embodiments without departing from the scope of the invention as expressed in the appended claims. | A method or system for providing a level of data security dependent on the location of the user of a wireless device is disclosed. One exemplary embodiment relates to a method of adjusting security for a network user node in communication with a network based upon the location of the node. The method is performed by determining the location of a network user node, selecting a single level of security from a group of more than two security levels based on the determined location, and modifying the security protection for the network user node based upon the selected level of security. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of Korean Patent Application No. 2011-0021419, filed on Mar. 10, 2011 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] Embodiments of the present invention relate to a refrigerator having an ice maker installed at a door to make water or ice and a control method for the same.
[0004] 2. Description of the Related Art
[0005] A refrigerator is an apparatus which includes refrigeration cycle components therein to refrigerate or freeze foods stored therein using cool air generated from an evaporator among the refrigeration cycle components.
[0006] In a recent refrigerator, a refrigerating chamber with a relatively high use frequency is disposed at an upper section of the refrigerator while a freezing chamber is disposed at a lower section of the refrigerator. A dispenser is installed at a refrigerating chamber door to open/close the refrigerating chamber in order to dispense ice through the dispenser.
[0007] In such a refrigerator, an ice maker is also installed to make ice to be discharged through the dispenser, and the ice maker is advantageously disposed at a higher position than the dispenser in consideration of discharging the ice. Therefore, an ice making chamber is defined at one side of an upper portion of the refrigerating chamber using a thermal insulation wall, and the ice maker is installed in the ice making chamber.
SUMMARY
[0008] Therefore, it is an aspect to provide a refrigerator in which larger space of a refrigerating chamber becomes available and a method to control such a refrigerator.
[0009] Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.
[0010] In accordance with one aspect, a refrigerator includes a main body comprising a refrigerating chamber at an upper section thereof and provided with a freezing chamber at a lower section thereof, an ice making tray disposed in an upper space of an ice making chamber defined in the refrigerating chamber, a first storage container in a lower space of the ice making chamber to store ice falling from the ice making tray, and a second storage container in a freezing chamber to store ice transferred from the ice making tray, and the main body includes a guide channel to guide, when the first storage container enters an ice-full state, ice falling from the ice making tray to the second storage container in the freezing chamber.
[0011] The guide channel may be formed in a recessed way into a side wall of the main body, and the refrigerator may further include a channel cover removably installed to the side wall of the main body to cover the guide channel.
[0012] The refrigerator may further include a guide member to selectively guide ice removed from the ice making tray to any one of the guide channel and the first storage container, and a driving device to rotate the guide member.
[0013] The guide member may be rotatably installed to the side wall of the main body to guide the ice to any one of the guide channel and the first storage container depending on a rotation angle thereof.
[0014] The refrigerator may further include a refrigerating chamber door to open or close the refrigerating chamber, and a dispenser disposed in the refrigerating chamber door to guide discharge of the ice.
[0015] The refrigerator may further include a conveying auger disposed in the first storage container to enable ice in the first storage container to be discharged through the dispenser.
[0016] In accordance with another aspect, provided is a method to control a refrigerator comprising a refrigerating chamber at an upper section thereof and provided with a freezing chamber at a lower section. The method includes controlling an ice making operation of an ice maker to make ice in an ice making chamber defined in the refrigerating chamber to accommodate the ice maker, and guiding the ice to a first storage container in a lower space of the ice making chamber and a second storage container in the freezing chamber such that the ice is first guided to the first storage container until the first storage enters an ice-full state, and then to the second storage container until the second storage container enters an ice-full state.
[0017] The method may include determining whether the first storage container is in an ice-full state, beginning, upon determining that the first storage container is not in an ice-full state, to make ice using the ice maker, and guiding the ice made by the ice maker to the first storage container until the first storage container reaches an ice-full state.
[0018] The method may further include upon a determination that the first storage container is in an ice-full state, determining whether the second storage container is in an ice-full state. Upon determination that the second storage container is not in an ice-full state, to make ice using the ice maker, and guiding the ice made by the ice maker to the second storage container until the second storage container reaches an ice-full state.
[0019] The method may further include, after the second storage container reaches an ice-full state, terminating production of the ice using the ice maker.
[0020] The method may further include determining whether the first storage container is in an ice-full state, on a determination that the first storage container is in an ice-full state, determining whether the second storage container is in an ice-full state. Upon determining that the second storage container is not in an ice-full state, to make ice using the ice maker, and guiding the ice made by the ice maker to the second storage container until the second storage container reaches an ice-full state.
[0021] As described above, after the first storage container disposed in the ice making chamber reaches an ice-full state, the ice is transferred through the guide channel to the second storage container provided in the freezing chamber and then is stored therein. In this way, the size of the ice making chamber may be greatly reduced while a sufficient amount of the ice may be stored, resulting in securing a larger available space in the refrigerating chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] These and/or other aspects of the invention will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:
[0023] FIG. 1 is a cross-sectional view of a refrigerator according to one embodiment of the present invention;
[0024] FIG. 2 is a perspective view of a refrigerator according to one embodiment of the present invention;
[0025] FIG. 3 and FIG. 4 are cross-sectional views in operations of an ice maker employed in a refrigerator according to one embodiment of the present invention;
[0026] FIG. 5 is a cross-sectional view of a second storage container employed in a refrigerator according to one embodiment of the present invention;
[0027] FIG. 6 is a block diagram for controlling a refrigerator according to one embodiment of the present invention; and
[0028] FIG. 7 is a flowchart of controlling a refrigerator according to one embodiment of the present invention.
DETAILED DESCRIPTION
[0029] Reference will now be made in detail to the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
[0030] Below, a refrigerator according to one embodiment of the present invention will be described in detail with reference to the accompanying drawings.
[0031] As shown in FIG. 1 and FIG. 2 , a refrigerator according to one embodiment of the present invention includes a main body 10 which forms the appearance of the refrigerator and in which a plurality of food storage chambers, for example, two storage chambers 10 A and 10 B, are installed to be separated from each other. In this embodiment, the food storage chambers 10 A and 10 B are vertically partitioned such that the upper storage chamber 10 A forms a refrigerating chamber to store food in a refrigerated state and the lower storage chamber 10 B forms a freezing chamber to store food in a frozen state.
[0032] A pair of doors 20 A, 20 B is installed at both sides of an upper section of the main body 10 so that each of one-side ends of the doors is installed to the main body 10 in a pivotable way. In this manner, using the pair of doors 20 A, 20 B, the refrigerating chamber 10 A can be opened or closed. In the freezing chamber 10 B, a freezing chamber door 20 B is installed to move between an extended position and a retracted position so that the freezing chamber 10 B has a drawer type structure.
[0033] In a rear side of a lower section of the main body 10 , there is a machine chamber 10 D accommodating a compressor 11 to compress refrigerant, a condenser (not shown) in which the refrigerant and air exchange heat with each other and the refrigerant becomes cool, and an expansion valve (not shown) to expand the refrigerant in a pressure-reducing manner. In rear sides of the refrigerating and freezing chambers 10 A and 10 B, there are disposed evaporators 12 A and 12 B to generate cool air and two blowing fans 13 A and 13 B to enable the cool air generated from the evaporators to be supplied into the refrigerating and freezing chambers 10 A and 10 B. In this example, to cool the refrigerating and freezing chambers 10 A and 10 B independently, the two evaporators 12 A and 12 B are respectively disposed at the rear sides of the refrigerating and freezing chambers 10 A and 10 B.
[0034] The refrigerator includes an ice maker 30 to make ice and a dispenser 40 positioned in the refrigerating chamber door 20 A to guide outward discharge of ice made by the ice maker 30 . Since it is advantageous in discharging the ice that the ice maker 30 is positioned above the dispenser 40 , an ice making chamber 10 C is defined at one side of an upper portion of the refrigerating chamber 10 A by a thermal insulation wall, and the ice maker 30 is installed in the ice making chamber 10 C. Although not shown, an ice making switch is installed at the refrigerating chamber door 20 A to allow users to select an ice making operation.
[0035] The ice maker 30 includes an ice making tray 31 disposed at an upper space of the ice making chamber 10 C in which ice is made, a scraper 32 to separate ice from the ice making tray 31 , a heater 33 (refer to FIG. 3 ) to allow ice in the ice making tray 31 to be removed easily from the tray, a first storage container 33 disposed at a lower space of the ice making chamber 10 C to receive ice removed from the ice making tray 31 and store it, a conveying auger 35 rotatably installed in the first storage container 33 to guide, via its rotation, ice to be discharged to the dispenser 40 , and a conveying motor to rotate the conveying auger 35 .
[0036] The dispenser 40 includes a discharge portion 42 which is a space formed by making a depression from a front face of the refrigerating chamber door 20 A toward an inner side of the refrigerating chamber door 20 A and which has a discharge opening 41 for discharge of an object and thus from which the object is discharged. The dispenser 40 also includes an opening/closing member 43 to open or close the discharge opening 41 , an actuating lever 44 installed in the discharge portion 42 to operate the opening/closing member 43 and at the same time operate the conveying auger. The dispenser also includes a discharging channel 45 to guide ice discharged from the first storage container 33 to the discharge opening 41 .
[0037] The above-mentioned ice making chamber 10 C is defined at one side of and within the refrigerating chamber 10 A. Therefore, the larger the size of the ice making chamber 10 C, the smaller the size of the refrigerating chamber 10 A, resulting in limitation of the size of the first storage container 34 to a certain level.
[0038] For this reason, in this embodiment of the invention, a guide channel 10 E is installed to guide ice removed from the ice making tray 31 to the freezing chamber 10 B, and a second storage container 14 is provided in the freezing chamber 10 B to receive the ice transferred along the guide channel 10 E and store it.
[0039] The guide channel 10 E, as shown in FIG. 3 to FIG. 5 , is recessed into a side wall of the main body 10 . An upper end of the guide channel 10 E communicates with one side of a lower space of the ice making tray 31 while a lower end of the guide channel 10 E communicates with the second storage container 14 . As shown in FIG. 2 , a channel cover 15 is installed on the side wall of the main body 10 in a detachable manner from the side wall so as to cover a portion of the guide channel 10 E. Thus, if it is necessary to clean the guide channel 10 E, the channel cover 15 is separated from the side wall of the main body 10 to expose the guide channel 10 E and clean the same.
[0040] The second storage container 14 is formed in a drawer type and is installed in the freezing chamber 10 B in a movable manner. At one side of the second storage container 14 , a transfer opening 14 a through which the ice is transferred to the container 14 is provided so as to communicate with the lower end of the guide channel 10 E.
[0041] Ice made in the ice maker 30 first fills the first storage container 34 until the first storage container 34 is completely filled with the ice. Thereafter, the ice is guided to the second storage container 14 to fill the same.
[0042] To this end, a guide member 16 is disposed at the upper end of the guide channel 10 E to enable transfer of the ice falling from the ice making tray 31 to a selected one of the first storage container 34 and the guide channel 10 E.
[0043] The guide member 16 is installed at the side wall of the main body 10 in a rotatable manner and enables, by rotation thereof, such transfer of the ice falling from the ice making tray 31 to the selected one of the first storage container 34 and the guide channel 10 E depending on a rotation angle thereof. A driving device 17 such as a motor, etc. is installed at the main body 10 to rotate the guide member 16 .
[0044] For sensing ice amount, a first ice amount sensor 18 A- 18 B is disposed in the ice making chamber 10 C to sense ice amount of the first storage container 34 , and a second ice amount sensor 19 A- 19 B is disposed in the freezing chamber 10 B to sense ice amount of the second storage container 14 . In this embodiment, the first ice amount sensor 18 A- 18 B includes a light-emitting unit 18 A and a light-receiving unit 18 B. The second ice amount sensor 19 A- 19 B includes a light-emitting unit 19 A and a light-receiving unit 19 B.
[0045] As shown in FIG. 6 , the refrigerator includes a control unit 100 to control the ice maker 30 and the guide member 16 , a first ice amount sensing unit 110 including the first ice amount sensor 18 A and 18 B, a second ice amount sensing unit 120 including the second ice amount sensor 19 A and 19 B, and a guide member driver 130 including the driving device 17 .
[0046] Now, a method of controlling such a refrigerator will be described in detail with reference to FIG. 7 .
[0047] As mentioned above, the refrigerator according to this embodiment the ice made in the ice maker 30 first fills the first storage container 34 until the first storage container 34 is completely filled with ice, and thereafter is guided to the second storage container 14 to fill the same.
[0048] For this purpose, it is first checked whether the ice making switch is in an ON state ( 200 ), and then if the ice making switch is in an ON state, the amount of ice in the first storage container 34 is sensed using the first ice amount sensor 18 A and 18 B ( 201 ).
[0049] It is determined whether the first storage container 34 is in an ice-full state ( 202 ). Upon a determination that the first storage container 34 is not in an ice-full state, the ice maker 30 begins to make ice ( 203 ). The ice made by the ice maker 30 is guided to the first storage container 34 by rotating the guide member 16 to a closed position using the driving device 17 ( 204 ).
[0050] The operation ( 204 ) of guiding the ice made by the ice maker 30 to the first storage container 34 continues until it is determined that the first storage container 34 is in an ice-full state. As the ice is being guided to the first storage container 34 the amount of ice contained within the first storage container is sensed again ( 205 ). It is determined again if the first storage container 34 is in a full state ( 206 ). Such operations ( 204 , 205 and 206 ) are repeated until it is determined that the first storage container 34 is in an ice-full state.
[0051] Upon a determination that the first storage container 34 is in an ice-full state, the amount of ice in the second storage container 14 is sensed using the second ice amount sensor 19 A and 19 B ( 207 ). It is determined whether the second storage container 14 is in an ice-full state ( 208 ). Upon a determination that the second storage container 14 is in an ice-full state, the ice making operation terminates ( 209 ). Upon determining that the second storage container 14 is not in an ice-full state, the ice made by the ice maker 30 is guided to the guide channel 10 E by rotating the guide member 16 to an open position using the driving device 17 ( 210 ). The ice guided to the channel 10 E is transferred to the second storage container 14 through the transfer opening 14 a . Once ice is guided to the second storage container 14 , the amount of ice in the second storage container 14 is again sensed ( 211 ). It is again determined whether the second storage container 14 is in an ice-full state ( 208 ). Such operations ( 208 , 210 and 211 ) are repeated until it is determined that the second storage container 14 is in an ice-full state and thus the ice making operation terminates ( 209 ).
[0052] At the operation ( 202 ) of determining whether the first storage container 34 is in an ice-full state and it is determined that the first storage container 34 is in an ice-full state, the amount of ice in the second storage container 14 is sensed using the second ice amount sensor 19 A and 19 B ( 212 ). Subsequently, it is determined whether the second storage container 14 is in an ice-full state ( 213 ). Upon determining that the second storage container 14 is not in an ice-full state, the ice maker 30 begins to make ice ( 214 ).
[0053] After the ice making operation ( 214 ), ice made by the ice maker 30 is guided to the guide channel 10 E by rotating the guide member 16 using the driving device 17 ( 210 ). Once ice is guided to the second storage container 14 , the amount of ice in the second storage container 14 is again sensed ( 211 ) and then it is again determined whether the second storage container 14 is in an ice-full state ( 208 ). Such operations ( 208 , 210 and 211 ) are repeated until it is determined that the second storage container 14 is in an ice-full state.
[0054] Using the above-mentioned method, the first storage container 34 is first filled with ice and, thereafter, the second storage container 14 is filled with ice.
[0055] Although a few embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents. | A refrigerator including a main body provided with a refrigerating chamber at an upper section and with a freezing chamber at a lower section, an ice making tray disposed in an upper space of an ice making chamber defined in the refrigerating chamber, a first storage container disposed in a lower space of the ice making chamber to store ice falling down from the ice making tray, and a second storage container disposed in a freezing chamber to store ice transferred from the ice making tray. The main body includes a guide channel to guide, when the first storage container reaches an ice-full state, ice falling from the ice making tray to the second storage container in the freezing chamber. The size of the ice making chamber is greatly reduced while a sufficient amount of the ice may be stored, thus securing a larger available space in the refrigerating chamber. | 5 |
RELATED APPLICATION
This continuation application claims the benefit of U.S. patent application Ser. No. 09/151,342, filed Sep. 11, 1998 now abandoned.
FIELD OF THE INVENTION
The invention relates to bioreactors used to culture a wide variety of microorganisms and organisms such as algae, for various purposes from filtering dissolved wastes in water, digesting organic wastes to producing pharmaceutical end-products.
BACKGROUND OF THE INVENTION
U.S. Pat. Nos. 5,055,186 and 5,593,574 granted Oct. 8, 1991 and Jan. 14, 1997, respectively, to VanToever, relate to bioreactor systems, primarily biofilter system, using fluidized pellet media Although such systems are effective, efforts to scale up the systems have encountered some difficulties, particularly when the objective is to provide a bioreactor system having maximum possible effective surface area for cultural bacteria and other microorganisms to provide a system which is self cleaning and relatively maintenance free as much as possible and to provide a system which operates with low energy consumption.
More particularly, the revolving downflow injector design described in U.S. Pat. No. 5,593,574 works adequately with shallow filter media beds. The concept of fluidizing only a narrow zone of media at any given time rather than the conventional method of continually fluidizing the entire bed of media enabled a drastic decrease in the energy required for fluidization
Nevertheless, efforts to scale-up such downflow injector filters with greater tank diameters, (>1 m) and media bed depths, (>1 m), using this design, required significant increases in pump size to provide sufficient energy to fluidize the pellets. Since the low density plastic pelleted media is buoyant, (specific gravity of 0.91-0.93 relative to water), the downward directed jets of filtrate must have sufficient force to counter the buoyancy and flotation of the media in order to fluidize the bed. With increased bed depth, the energy required increased significantly. By increasing the pressure and flow of filtrate, deep beds could be fluidized but at exceedingly high, if not, prohibitive operating costs.
Additionally, the increased turbulence caused by the high energy injection would frequently cause media pellets to wash out of the filter.
Extensive efforts have lead to the development of a new, much superior configuration.
Initially efforts focused on slowing the rotation of the downflow filtrate injector system represented by U.S. Pat. No. 5,593,574. The fluidization of a given zone is not instantaneous and a period of time is required for the jets of filtrate to penetrate and fluidize a given cross section of media. Efforts to improve the system included the use of low speed gear motors to slow and accurately control the speed of rotation to ensure complete fluidization. With larger beds, that is, with media beds greater than 1 meter in diameter, rotational speeds of ¼ rpm and filtrate flows of approximately 600/1/min/m 2 of filter bed surface area were required. However, faster rotational speeds tended to result in incomplete fluidization of the media Further, in order for downward directed jets of filtrate to fluidize the media, the jets had to have sufficient energy to counteract the upward flotation, (buoyance), of the media as well as to counteract the friction in the media bed.
Accordingly, it would be advantageous to provide an injector system to fluidize the media bed which would ensure that all areas of the filter media bed receive as uniform a flow of filtrate as possible and which could be expanded radially or indepth to encompass larger media beds.
The earlier U.S. Pat. Nos. 5,055,186 and 5,593,574 referred to above, utilize plastic media pellets and the system to which this invention is directed also depends on the use of plastic media pellets. The purpose of the media is to provide an optimal ‘engineered’ surface area for culturing bacteria, fungi and other microorganisms, while at the same time providing the maximum possible effective surface area per unit volume of filter at a reasonable cost. The desired microorganisms require a surface to colonize and with the appropriate nutrients and environment a diverse ecological mix of species establishes and grows to create a biofilm. The biofilm adheres to the substrate—media pellets—and will generally flourish and grow until it plugs the interstitial spaces between the supporting media and blocks the flow of nutrients to the microorganisms. Additionally, particulates in the filtrate also adhere to the “sticky” biofilm through a number of mechanisms and serve to accelerate the plugging of the filter. An effective filter therefore has to continually harvest excess biofilm and particulates in order to maintain an optimal biofilm which is constantly in a growth phase condition, rather than one that cycles between “start-up-growth-plugging- crashing-cleaning-start-up”. The fluidized bed design can provide an environment wherein excess biofilm is continually scoured off the media, while sufficient shelter is provided to provide an adequate environment for maintenance of a continually self renewing, optimally, thin biofilm.
Conventional fluidized beds generally utilize randomly configured support media such as sand and plastic material. Creased or grooved media pellets are disclosed in the above-noted U.S. patents. Nevertheless, it would be advantageous to have media pellets which have very specific characteristics and which are manufactured to a specific engineered design to optimize film growth and to be compatible with the radial flow injection system developed.
The filter design relies on the buoyancy of the media pellets to maintain the media bed within the filter. Insufficient buoyancy or excessively high filtrate flow rates which result in excess downflow velocities will wash the media out of the filter outlet. Earlier attempts to screen the outlets of the filters proved futile since the biofilm grows rapidly and plugs the screens.
Biofilms for example, have a specific gravity of approximately 1.07 relative to water. The low density plastic pellet has a selected specific gravity in the range of 0.91 to 0.93 so that it floats in water. The media pellet must therefore be designed with sufficient mass so that the ratio of the maximum supportable biofilm mass, to the pellet mass remains less than one or the pellets will sink.
An apparently obvious solution would be to decrease the density of the plastic and increase the buoyancy. A small increase in buoyancy, however leads to drastic increases in the energy required to fluidize the media, especially in the start-up phase when there is no biofilm present to counter the buoyancy of the pellets. Since energy consumption is a critical factor in determining the success of the bioreactor design, significant increases in buoyancy of the media pellets is not a cost effective option.
All characteristics of the pellet must be considered together to achieve a successful design. A balance must be achieved between the cost of materials and manufacturing, the effective surface area for biofilm culture per unit volume of filter and the dimensions of the sheltered grooves which determines the biofilm biomass relative to the mass of plastic per pellet as this relationship determines pellet buoyancy once the biofilm is established. The design of the pellets must be such to minimize interlocking of pellets which increases energy requirements for fluidization. Further, the pellets must be as small as possible to minimize surface area per unit volume while providing adequate mass for buoyancy as described.
Accordingly, it would be advantageous to have pellet media which have proven to be an acceptable compromise between the various design parameters noted above, particularly in fluidized bed systems as set forth herein.
SUMMARY OF THE INVENTION
In order to secure greater uniformity in the fluidization of pellets by filtrate, a new approach was investigated wherein the filtrate would be injected horizontally to fluidize the media, as this would eliminate the buoyancy factor. The design developed provides for orifices in a central, vertical rotating, main manifold directing pumped filtrate in horizontal streams or a ‘jets’ out towards the periphery of the filter bed. Since the main manifold is located in the centre of the cylindrical bed and rotates about the central vertical axis there is virtually no friction to overcome in order to turn it. The central or main manifold rotates slowly enough to permit the jets to horizontally fluidize a zone of media from the centre extending out to the perimeter of the reactor. With the previous filter design noted in the background of the invention, as the filter depth of the media bed increased, the downward pressure and flow required for each filtrate jet also increased in order to fluidize the media bed. With the new design, the horizontal distance from the central manifold to the periphery is constant with depth and with equal spacing of the orifices or nozzles on the central manifold, each jet from the orifices fluidizes an equivalent sized zone of media. To fluidize deeper media beds for a given filter diameter requires simply extending the length of the central manifold and adding more orifices, each with equivalent flow and pressure. The flow required to fluidize a given diameter of filter bed increases linearly with depth while pressure remains essentially constant with the radial flow design. With the previous downflow design, pressure and flow requirements increased with depth, therefore increasing energy costs for operation.
Further, it was desirable to develop simple mechanisms to rotate the central manifold and control the speed of rotation. Speed control is relatively important in this design since a period of time is required for the horizontal jets to penetrate the media bed and totally fluidize a given zone all the way to the periphery of the bed.
Rotational speed controls developed for some previous dowmflow designs relied on expensive low speed gear motors and relatively complex mechanical configurations. Given the often corrosive, environments in which the filters operate (often salt water) the costs were significant. Significant maintenance was required and mechanical failures were more frequent than desired. The goal was therefore to develop a simple design which would be inexpensive and dependable.
Accordingly, in the present design, jets of filtrate from the vertical rotating central manifold fluidize an arcuately narrow vertical zone of media pellets in a radial direction from the centre to the periphery of the filter. The pressurized jets of filtrate work their way through the media bed until the pellets in a narrow vertical zone are completely fluidized. Fluidization of the zone of media from the centre to the periphery however requires several seconds.
The viscosity of the media is very low in the fluidized zone relative to the adjacent non-fluidized zone. The injector system of the invention utilizes this viscosity differential and the time lag for fluidization of a given zone, as a basis for rotational speed control.
A second vertically extending manifold, a thrust injector or thrust manifold, is located at the outer perimeter of the filter bed and is preferably connected to the vertical central manifold by horizontal support manifolds which are above and below the media bed. The thrust manifold is offset so that the horizontally directed filtrate jets from the central manifold are directed ahead of it. Orifices are located down the side of the thrust manifold and are oriented horizontally perpendicular to the central manifold orifices, that is, oriented generally in a tangential direction to the bed of media Thrust created by the pumped filtrate emerging from the thrust manifold orifices pushes the thrust manifold forward into the low viscosity, fluidized zone created by the jets from the central manifold. The central manifold is therefore continually creating a low viscosity zone rotationally in front of the thrust manifold, so very limited thrust is required to move the vertical thrust manifold ahead. The viscosity of the unfluidized bed of media will not allow the thrust manifold to move forward beyond the zone fluidized by the jets from the central manifold. Since the two manifolds are physically connected by the support manifolds and in fluid communication with each other, a positive feedback control is established and the injection system rotational speed is therefore self governed and ensures that the thrust manifold cannot rotate unless complete fluidization of the zone in front of the thrust manifold by the jets from the central manifold is achieved from the centre to the periphery of the bed. With each complete revolution of the manifold through the pelleted media, the entire bed is thoroughly fluidized and the filtrate is uniformly distributed to all biofilm surfaces in the filter media bed.
Filtrate flow rates can be increased substantially if desired and additional thrust manifolds can be added to the central manifold. The distance that a pressurized jet of filtrate can effectively penetrate a bed of media is limited, for example, approximately 0.5 m, before the energy is significantly dissipated. To fluidize wider diameter beds of media, the horizontal support manifolds can be extended by additional support manifolds and additional or secondary vertical injectors or manifolds can be added between the additional support manifolds at intervals, for example, at intervals of approximately 0.5 m These vertical secondary manifolds are similar in design to the central manifold. However, each of the secondary manifolds is offset from the one immediately inward thereof in order for the filtrate jets of the radially inward manifold to fluidize the arcuate zone in front of the manifold and thus enable it to move forward. Only the radially outermost manifold need be of the thrust manifold configuration since the maximum torque is achieved by providing thrust at the inner periphery of the tank.
The new injector system could also be potentially applied to larger filter bodies of circular or other polygonal shapes. A number of injector units could be supported on a frame above a bed of media and the injectors would each act to fluidize overlapping cells of media. A pipe manifold system would be used to uniformly distribute the filtrate to each of the multiple injector heads.
Further, it will be apparent that the new injector system can be retrofitted to existing bioreactor systems. A manifold structure comprising the central manifold with radially directed openings in association with an offset thrust manifold suitably supported and capable of ejecting filtrate in accordance with the above, can be easily incorporated into an existing bioreactor tank with minimal piping restructuring.
The disclosed method of injecting the filtrate is very efficient and minimizes the flow requirements in comparison with other and conventional fluidization techniques which fluidize the entire bed and require very high flow rates with large pumping rates and energy consumption.
As with the previous bioreactor designs, solids consisting of excess sheared biofilm and fine particulates settle and are flushed daily from the system via a bottom drain valve. This flushing is the only required maintenance for the bioreactor as it is otherwise self-cleaning.
With respect to the media pellets, applicant has found that pellets having certain physical parameters and optical dimension ranges are to be preferred for the most efficient operation of the bioreactor herein. A simple configuration of a pellet is preferable, which can be manufactured in a one step, low cost extrusion process, the extruded length with appropriate grooves/ridges being sliced to produce the final pellets. Although pellets fabricated by combinations of other manufacturing processes, such as injection or extrusion, combined with secondary stamping or roll forming of surface configurations, are recognized as possible, designs of pellets which are compatible with one step extrusion are more cost effective to fabricate. Nevertheless, the pellet design is not a random design but is engineered to very specific criteria to be described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature and mode of operation of the present invention will now be more fully described in the following detailed description taken with the accompanying drawings wherein:
FIG. 1 is an elevational view of a bioreactor according to the invention, with the front wall of the tank removed for the purposes of clarity.
FIG. 2 is a top plan view thereof
FIG. 3 is an enlarged view of the lower bearing or support system for the central or main manifold of the bioreactor taken around line 3 — 3 of FIG. 1 .
FIG. 4 is an elevational view, partly in section, of the central support and trust manifold of the embodiment of FIG. 1 .
FIG. 5 is a partial sectional view of the manifold of FIG. 4, taken along line 5 — 5 of FIG. 4 .
FIG. 6 is a top view of a second embodiment of the invention showing a manifold structure and ejector system with a secondary manifold.
FIG. 7 is an elevational view, partly in section, of the central manifold support manifolds, secondary manifold and thrust manifold of the embodiment of FIG. 6 .
FIG. 8 is a partial sectional view of the manifold of FIG. 7 taken along line 8 — 8 of FIG. 7 .
FIG. 9 is a top view of a further embodiment of the bioreactor system wherein the bioreactor is housed within a housing having a light system associated therewith.
FIG. 10 is an elevational view of the embodiment of FIG. 9 .
FIG. 11 is a top view of a larger tank of a bioreactor system with a plurality of manifold fluidizing ejector systems.
FIG. 12 is a schematic view of the manufacture of pellet media
FIGS. 13 and 14 are plan elevational views of shapes of preferred pellet media manufactured to specified criteria.
FIG. 15 is a partial sectional view of the pellet of FIG. 13 along lines 15 — 15 showing the formation of biofilm
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning to FIG. 1, a bioreactor 20 is illustrated in elevational view with the front wall of the tank 22 removed. Bioreactor tank 22 has an upper cylindrical portion 24 and a lower conical portion 26 . Tank 22 is supported by supports 28 , only two being shown. Tank 26 would have other like supports 28 , front and back, but they have been omitted for the sake of clarity. Peripherally outwardly of tank 22 is cylindrical housing 30 , the spacing between housing 30 and tank 22 being sufficient to accommodate associated piping and conduits to be described further herein. Tank 22 contains filtrate 34 to be filtered and a low density media bed 36 of pellets 38 floating in the upper portion of the filtrate 34 .
Cone shaped baffle 40 is supported by filtered effluent manifold 42 , which manifold has opening 44 , through which filtered or processed effluent may flow. Filtered or processed effluent is removed from the bioreactor 20 , through opening 44 and as shown by arrows 46 , through conduit junction 50 and outlet conduit 52 . Outlet conduit 52 has a level control opening 56 through which filtered or processed effluent can be removed for use elsewhere, for example, filtered water, in an aquaculture system as disclosed in U.S. Pat. No. 5,593,574. However, the bioreactor system is operable with other forms of filtrate than water.
Bottom 60 of conical tank portion 24 concentrates solid waste, which is mainly scoured excess growth from media pellets 38 . The solid wastes are periodically removed via conduit 62 and valve 64 in known fashion. Conduit 66 and valve 68 provide means for cleaning and flushing out the tank system.
Inlet pump 70 is located to pump filtrate to be processed in the bioreactor from a source, (not shown), through conduit 72 into a manifold system associated with tank 22 .
Conduit 72 extends upwardly from pump 70 and connects at T connector 74 with vertical and horizontal filtrate inlet conduits 76 and 78 . Vertical conduit 76 continues upward between tank 22 and housing 32 and is in fluid communication with upper, horizontal conduit 80 which crosses diagonally the top of tank 22 and is in fluid communication with conduit 84 which extends downwardly on the other side of tank 22 inside housing 32 to T connector 86 . Horizontal filtrate inlet conduit 78 extends diagonally across and within tank 22 and connects with connector 86 . It will be appreciated that conduit 78 is sealed with respect to tank 22 where it enters and exits the wall of the tank 22 . Upper and lower central manifold connectors 90 and 92 are associated with conduits 78 and 82 and rotatably support central manifold 100 through bushing slip joints 102 and 104 . Manifold 100 is along the axis of tank 22 . Slip joints 102 , 104 are similar and only the bottom joint 104 is shown in detail in FIG. 3 . Connector 92 has vertical portion 108 with upper end 110 . Liner 114 has splash guard 116 peripherally secured thereto and the liner has portions extending above and below splash guard 116 at 118 and 120 respectively. Lower portion 118 closely fits within section 108 and liner 114 is held in position by guard 116 on the upper end 110 of conduit portion 108 . The lower end 126 of central manifold 100 has bushing insert 128 secured thereto, bushing insert 128 being sized to rotate around extension portion 118 and supported at its lower end 129 by the splash plate 116 and capable of rotation about lower portion 118 . The slip joint 102 at the top end is essentially the reverse of joint 104 with a slight gap or space, (e.g. from ¼ to ½″), between the top end of the bushing insert and splash plate. Cylindrical portion 130 of connector 86 and cylindrical section 132 of connector 92 are removably plugged to permit flushing or clean out of the manifold, as desired.
As seen in FIGS. 1 and 4, a manifold structure or system 136 is shown including central manifold 100 having a plurality of openings or nozzles 140 spaced along a substantial portion of its length, which openings or nozzles 140 are directed radially outwardly and aligned in a substantially vertical plane. Extending radially outwardly from manifold 100 are upper support manifold 142 and lower support manifold 144 which connect via connectors 146 , 148 with a vertical thrust manifold 150 adjacent the inner periphery of tank 22 . Manifold 150 is parallel with central manifold 100 . Upper conduit 142 has downward openings or nozzles 152 and thrust manifold 150 has a plurality of horizontally directed openings or nozzles 156 .
Turning to FIGS. 2 and 5, it will be apparent that thrust manifold 150 is offset from the plane defined by the central manifold 100 and upper and lower conduits 142 , 144 . It will also be noted from FIG. 5 that connector 146 also has downwardly directed openings or nozzles 160 . Removable cap 162 of connector 146 provides for clean out of the thrust manifold 150 . Liquid forced from horizontally directed openings 156 in thrust manifold 150 tends to rotate the filtrate manifold structure 136 comprising of the central manifold 100 , thrust manifold 150 and upper and lower support manifolds 142 , 144 in a counterclockwise direction as seen in FIG. 2 . Downwardly directed nozzles 152 and 160 provide additional means for agitating and fluidizing the media bed to permit movement of pellets. Although not shown, upwardly directed nozzles or openings could be incorporated in lower support manifold 144 .
Liquid to be processed, filtrate, is pumped by pump 70 into manifold structure 138 through conduits 72 , 76 , 78 and 80 .
Filtrate pumped into central manifold 100 ejects radially outwardly from openings or nozzles 140 . Filtrate is also forced via support manifolds 142 , 144 to thrust manifold 150 and out openings or nozzles 156 . Filtrate is also ejected from nozzles 152 and 160 of upper support manifold 142 and connector 146 . As noted in the Summary of the Invention, filtrate ejected from nozzles 140 of central manifold 100 fluidizes pellet media over a zone or sector 164 , (FIG. 2 ), commencing with a radial plane defined by the plane of nozzles 140 and resulting jets of filtrate 138 outwardly from the central manifold 100 . Zone 164 rotates as the manifold structure 138 rotates.
The radially outwardly directed filtrate ejected from the central manifold nozzle 140 fluidizes the pellets in front of the thrust manifold thereby allowing it to move easily through the fluidized pellets 38 in front of it.
FIGS. 6-8 illustrate a further embodiment wherein like features to those of FIGS. 1-5 are referred to with an “a” designation. Tank 22 a is larger in diameter and there are two portions to the rotatable filtrate manifold structure 166 . The manifold structure 166 has a secondary vertical manifold 170 with nozzles 172 projecting horizontally and radially outwardly. Secondary manifold 170 is supported by support manifolds 142 a and 144 a through upper and lower connectors 174 , 176 , upper connector 174 having nozzles 178 similar to nozzles 160 a . As noted previously, as a tank increases in diameter, horizontal jets of fluid directed by nozzles 140 a in the central manifold 100 a are not effective in agitating and fluidizing pellets sufficiently in front of the thrust manifold 150 a to allow it to move easily through the fluid, so a secondary vertical manifold, such as 170 , with radially directed nozzles 172 is used. However, in order to provide suitable fluidization of media in front of secondary vertical manifold 170 to permit it to move through bed 36 , the secondary manifold 170 is itself offset from central manifold 100 a . As seen in FIGS. 6 and 8, jets from nozzles 172 of the secondary manifold 170 provide fluidization of media in front of thrust manifold 150 a which is offset again from the secondary manifold 170 . It will be apparent that additional “secondary” manifolds can be incorporated as may be appropriate for larger tanks. Further, if deeper beds are used, additional nozzles or openings in the central, thrust and any secondary manifolds can be provided.
FIGS. 9 and 10 illustrate a modification of the bioreactor which may be particularly useful when the bioreactor is an algae or the like bioreactor. Similar features to those in FIGS. 1 and 2 have like references with a designation “b”.
The main variation of the embodiment of FIGS. 9 and 10 is that the inner tank wall 22 b is light, transparent or translucent and surrounded by a generally rectangular outer housing 240 . Located within the space between tank 22 b and housing 240 and adjacent the corners thereof are lights 242 which provide light to promote the growth of algae microorganisms in bioreactor 20 b . Inside wall 250 of housing 240 is reflective to disperse light over the wall of tank 22 b.
It will be noted from FIGS. 9 and 10 that the bioreactor 20 b has filtrate inlet or conduit 252 supported from above by the walls of housing 240 and tank 22 b . Manifold structure 138 b is in effect hung from conduit 80 b with added support from the walls of tank 22 b where lower conduit 78 b passes through the walls of tank 22 b.
FIG. 11 illustrates in plan view a large tank or container 300 with a plurality of manifold systems 302 connected together. Inlet conduit 304 connects with three conduits 306 which cross the upper portion of tank 300 , each conduit 306 being associated with two bioreactor manifold structures 310 . Lower support conduits, (not shown), but similar to conduit 78 b in FIG. 10 are below conduits 304 .
Although conduits 306 are capable of supporting manifold structures 310 , it will be apparent to those skilled in the art that separate support means within tank or container 300 can be used to support manifold structures 310 . Each manifold structure 310 comprises a central main manifold 314 rotatably supported from conduit 306 , a lower support conduit, (not shown) and thrust manifold 318 , for rotation within the media bed 312 .
The manifold system 302 are shown laterally separated or spaced for the purposes of clarity in illustration. Tank 300 contains a large bed of media pellets 312 but only the pellets within each sweep 320 of manifold 310 and within the fluidized sector 322 are shown.
In an actual embodiment of the system shown in FIG. 11, conduits 30 b would be closer together to provide overlap of sweeps of manifold system 310 . This will be apparent if the middle conduit 306 was moved leftward in FIG. 11 toward dotted line 326 . Further, the force of the jets of filtrate from the manifolds have been found to actually extend further radially than schematically illustrated in FIG. 11 so that in practice, pellet media in comers 328 of tank 300 are effectively agitated.
Accordingly, conduit 30 b need not be spaced together as close as dotted line 328 may suggest in order to agitate all the media pellets 312 in tank 300 .
By way of illustration, in a 0.5 meter radius tank, applicant has found extremely effective, fluidization of pellets and bioreactor performance with a central manifold of about approximately 2 inches, (5 cm), diameter with frame and inlet conduits about approximately 1½ inches, (3.8 cm) and support and thrust manifolds of about 1 inch, (2.5 cm). The openings or nozzles are in the range of ⅜-½ inch range.
Turing now to the pellet media, the configuration of the filter media pellets having been refined and narrowly defined set of criteria for efficient operation of the bioreactor has been found.
Turning to FIGS. 12-14, these FIGURES relate to pellet media 330 and its manufacture which applicant has particularly found effective in bioreactors of the present design.
FIG. 12 schematically illustrates an extruder 334 with die 336 for extruding plastic material 338 with slicer 340 positioned such that the elongated extruded material 338 may be sliced into pellets 330 . Profiles of extruded material 338 and pellets 344 , 350 are shown in FIGS. 13 and 14, each figure comprising a and b figures showing the pellets in plan view and elevational view respectively.
FIG. 13 shows a generally rectangular pellet 344 with ridges 346 and grooves 348 on both sides.
FIG. 14 shows generally circular hollow pellet 360 , outer ridges 362 and grooves 364 .
The physical parameters and optimal dimensional ranges for the pellets include:
Specific Gravity— 0 . 91 - 0 . 95 relative to water
Size—(for disc shaped pellets) diameter 5-7 mm's—for rectangular pellets Width×Length, 5-7 mm's×5-7 mm's
Thickness in both cases 3-4 mm's
Grooves—Width 1 mm
Depth 1 mm
Ridge—Width>1.0 mm, preferably<than 1.25 mm's
Unit Pellet Weight—minimum range 0.05-0.07 gm's
Unit Pellet Volume—minimum range-0.055-0.077 ml's
Surface area per unit volume of media—1750 m 2 /m 3
Shape—A variety of shapes are possible which will maximize sheltered surface area per media pellet within the constraints of the above parameters. Simple configurations such as those shown in FIGS. 13 and 14 are preferable as they can be manufactured in a one step, low cost extrusion process.
It must also be recognized that a biofilm in a real world filter does not consist of a monoculture of one type of bacteria. It is instead an incredibly diverse eco-system including a wide range of microorganisms including bacterial, fungi, multicellular organisms and other algae, which all interact in metabolizing the waste stream and in consuming one another.
Applicant's bioreactor and the media developed are designed for culture of a wide range of microorganisms including algae which require a supporting surface and shelter.
The filter and media are not limited to bacterial cultures so that the size and configuration of the shelters, (media pellets), is critical to support these diverse microorganisms.
Applicant has found that the relatively range grooves—approximately 1.0 mm×1.0 mm are optimal for sheltering a wide range of microorganisms. FIG. 15 illustrates pellets 344 with biofilm 370 with a groove.
Applicant has found that with grooves approximately 1.0 mm in width and approximately 1.0 mm wide, biofilm develops to about 300i (microns) or 0.3 mm in depth which has been found optimal to provide growth of the various and diverse microorganisms. The width of the ridges, as noted above in the specified criteria, are wider than 1 mm but preferably less than 1.25 mm to avoid interlocking of the pellets together which could defeat the effectiveness of the agitation of the pellets and scouring of excess biofilm It will be appreciated that the general rectangular configuration of the grooves provides for good adhesion and growth of biofilm. The configuration of the grooves in the embodiment of FIG. 14 illustrates that the ridges are slightly wider than the grooves by the nature of the grooves being generally rectangular in configuration.
The pellet design is not a random design as in other patents but is engineered to very specific criteria as described.
The original maximum depth for a biofilm to allow diffusion of nutrients and oxygen is about 300i (microns). The grooves of the pellets therefore are designed with a cross sectional area which allows development, shelter and maintenance of an optimal biofilm thickness.
With a groove of less than 1 mm×1 mm, the scouring action of the fluidization process will remove excessive amounts of biofilm This design provides an optimal habitat for growth of microorganisms in a fluidized bed environment and therefore provides the maximum amount of biological activity per unit volume of filter media.
A randomly manufactured media cannot support as much biofilm and most of the surface of a randomly structured media would not be able to provide shelter to the microorganisms.
In operation, which will have been clear from the above description, the manifold assembly or system provides for good, controlled fluidization of the pellet media, rather under effective feedback control by the nature of the pellets in front of the thrust manifold being fluidized by jets from the main or central manifold. It will be apparent that provided the thrust manifold is mounted for controlled rotation with the central manifold whereby the jets of filtrate from the central manifold and/or from any secondary manifolds fluidize pellets in front of the thrust manifold (and/or secondary manifolds), the manifold structure will be effective. Accordingly, it will be apparent any form of support for cooperative rotation of the central and thrust manifolds is an obvious modification of the invention provided filtrate fluid is fed to the thrust manifold to cause rotation of the manifold structure. Nevertheless, the preferred embodiment is with support means which also act as manifolds for delivering fluid filtrate to the thrust manifold, whether the support manifolds have nozzles or not.
Other modifications to the invention will be apparent to those skilled in the art which fall within the scope of the invention as defined in the appended claims. | Disclosed is a bioreactor apparatus having a bed of buoyant media pellets floating within a filtrate to be processed. The apparatus includes a tank having a peripheral wall for containing filtrate and a bed of media pellets. A central manifold is rotatably supported within the tank the central manifold being mounted for rotation about a vertical axis and having a plurality of longitudinally spaced openings intermediate its ends, the openings adapted to eject filtrate in a generally horizontal direction and along a substantially vertical plane toward the wall of the tank. A thrust manifold, generally parallel to the axis of the central manifold has a plurality of longitudinally spaced openings intermediate its ends directed horizontally and generally perpendicularly to the plane. The thrust manifold is supported in association with the central manifold inwardly adjacent the tank wall and offset rearwardly of the plane to rotate with the central manifold. Filtrate is fed to the central manifold and the thrust manifold, whereby the plane of filtrate ejected by the central manifold fluidizes a vertical zone of pellet media around and in front of the thrust manifold and rotation of the central manifold and thrust manifold is caused by filtrate ejected from the openings in the thrust manifold. The invention also comprehends specially designed pellet media for optimum performance. The manifolds may be structural for retrofitting in existing bioreactors. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relatesto a seal device for pressure sealing the textile product inlet and outlet of a high pressure steamer adapted for the high pressure hygro-thermic treatment of textile products.
2. Description of the Prior Art
High pressure steamers which apply a saturated steam of high temperature and high pressure to textile products for high temperature and high pressure treatment have been known. Further, as for seal devices for introducing the textile products into the steamer and guiding them to the outside of the steamer, the inventors of the present invention have conducted studies over a long period of time and have filed many applications for patents for such sealing devices. In the latest one of the seal devices which have been developed by the inventors, there are provided a pair of rubber seal rolls; and seal plates which shut the inside of a steamer from the outside thereof at a position as close as possible to the pressed contact point between the pair of rubber seal rolls.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a seal device which is an improvement on the above mentioned previous seal device of a high pressure steamer and which is of a simpler construction and yet is more effective than the previous seal device.
In accordance with this invention, air pressure higher than the internal pressure of a high pressure steamer is applied to the internal pressure receiving faces of a pair of rubber seal rolls which are disposed in pressed contact with each other at an opening of a penetrating hole provided at the textile product inlet or outlet and which are thus arranged to close the opening. The action of steam heat on the rubber seal rolls is thus shut out by the air pressure with a simple construction and yet an effective sealing is ensured.
The above and further objects and advantages of this invention will be apparent from the following detailed description of preferred embodiments taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
All of the accompanying drawings illustrate the invented seal device for a high pressure steamer.
FIG. 1 is a cross-sectional view showing a first embodiment of the seal device of the invention.
FIG. 2 is a cross-sectional views showing a second embodiment.
FIGS. 3 and 4 are sectional enlarged view showing an essential part of the second embodiment.
FIG. 5 is a cross-sectional view showing a third embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Embodiment EXAMPLE I
Referring to FIG. 1, reference numeral 1 indicates a drum body of a high pressure steamer. A seal block 4 is mounted on a seal packing 3 on a cloth material inlet 2 into the high pressure steamer drum body 1. A penetrating hole 5 is provided through the seal block 4. A pair of rubber seal rolls 6 and 6' are freely rotatably disposed on the upper side of the seal block 4. The pair of rubber rolls 6 and 6' are arranged in pressed contact with each other to close an upper opening of the penetrating hole 5. Further, the lower sides of a pair of curved elastic seal plates 7 and 7' are secured through retainers 10 to the edge part, i.e. a pressure receiving face, of the upper opening of the penetrating hole 5 provided in the seal block 4 while the upper sides of the seal plates 7 and 7' are elastically pressed against the rubber seal rolls 6 and 6'. In this embodiment, the seal plates 7 and 7' are made of stainless steel, though the present invention is not limited to the use of any specific materials for the seal plates. A cylindrical duct 8 is disposed inside of the penetrating hole 5. The inside of the cylindrical duct 8 is arranged to allow a cloth material to pass therethrough. Between the inner face of the penetrating hole 5 and the outer circumferential face of the cylindrical duct, there is formed an air passage 9 for passing a pressure gas therethrough. The upper opening part of the cylindrical duct 8 extends close to pressure contact area between the seal rubber rolls. The lower opening part of the cylindrical duct 8 is secured to a flange portion 11 on the inner wall of the cloth material inlet 2. Air pressure higher than the internal pressure of the steamer drum body is allowed to come into the air passage 9 through an air pressure supply port 12. A pressure reduction exhaust port 13 is provided in the lower part of the cylindrical duct 8. An end seal plate 14 is arranged in pressed contact with the end faces of rubber seal rolls 6 and 6' and those of the seal plates 7 and 7'. Numeral 15 indicates drain preventing plates and 16 a cloth material to be treated. The above description covers the arrangement for the cloth material inlet. A cloth material outlet is arranged in the same manner as the cloth material inlet.
The embodiment of the above described structural arrangement operates in the following manner:
The cloth material is introduced into the steamer drum body 1 through the pressed contact area between the rubber seal rolls and the cylinder duct 8. Then, air pressure higher than the internal pressure of the steamer drum body is supplied to the air pressure passage 9. The air pressure repulses the internal steam pressure of the steamer drum body and acts on the pressure receiving faces of the rubber seal rolls to prevent the steam in the steamer drum body from acting on these pressure receiving faces and thus to protect the rubber seal rolls from being heated by the steam heat. A gas mixture gas consisting of the air of the air pressure and the steam in the vicinity of the pressure receiving faces of the rubber seal rolls is gradually expelled through the pressure reduction exhaust port 13 to always have fresh air applied to the pressure receiving faces of the seal rubber rolls.
As described in the foregoing, in this embodiment, air pressure supplied from the outside acts on the faces of rubber seal rolls which are receiving the internal steam pressure of the drum body. The air pressure thus prevents the steam heat from readily acting on the pressure receiving faces of the rubber seal rolls and thus to effectively protect the rubber seal rolls from being heated and having thermal expansion so that a durable seal device can be obtained.
Embodiment EXAMPLE II
In FIGS. 2 through 4, reference numeral 21 indicates a high pressure steamer drum body adapted to treat a cloth material under high humid heat. A seal block 24 is securely mounted on a cloth material inlet 22 of the high pressure steamer drum body 21 with a seal packing 23 therebetween. Inside the seal block 24, there is provided a penetrating hole 25 which communicates with the inside of the steamer drum body 21. A pair of rubber seal rolls 26 and 26' are freely rotatably supported by the upper side of the seal block 24. The upper opening of the above mentioned penetrating hole 25 is closed by the pair of rubber seal rolls 26 and 26' and by an end face seal plate 38 which is in contact with the end faces of the rubber seal rolls 26 and 26'. Further, the lower ends of a pair of arc-shaped elastic seal plates 27 and 27' are secured to the upper opening edge portion of the penetrating hole 25 of the seal block 24 through retainers 30. The upper outside faces of these seal plates 27 and 27' are elastically pressed into contact with the rubber seal rolls 26 and 26'. No particular restriction is imposed on the material of the seal plates 27 and 27'. However, in this embodiment, they are made of stainless steel. A cylindrical duct 28 which is formed to have a narrowed upper end portion is disposed inside the penetrating hole 25. The inside of the cylindrical duct 28 is arranged to allow a cloth material to pass therethrough. A gas passage 29 which allows a pressure gas to pass therethrough is formed between the outer circumferential face of the cylindrical duct 28 and the inner face of the penetrating hole 25. Further, the upper end opening portion of the cylindrical duct 28 extends to the vicinity of the pressed contact area between the pair of the rubber seal rolls. The lower end opening portion of the cylindrical duct 28 is secured to the flange portion of the seal block 24.
A cooling water-washing tank 32 is arranged so that the lower part of the seal rubber rolls 26 and 26' is immersed in it. Washing water jet nozzles 33 provide washing water to the pressed contact area between the seal rubber rolls 26 and 26' and the seal plates 27 and 27' from an area between the seal rubber rolls 26 and 26'. Wiping rolls 34 and 34' are in pressed contact with the upper parts of the seal rubber rolls 26 and 26' while washing brush rolls 35 and 35' are in pressed contact with the side parts of the seal rubber rolls 26 and 26'. Correction air jet pipes 36 snd 36' are mounted on the edge of the upper end opening of the cylindrical duct 28. The air jetted from this pair of correction jet pipes 36 and 36' serves to correct a cloth material 37 being introduced into the cylindrical duct 28 through the seal rubber rolls 26 and 26' so that it has in a vertical posture and thus prevents the cloth material 37 from tending to be wound on the seal rubber rolls. Air pressure supply ports 39 provide air pressure to the gas passage 29.
FIGS. 2 and 3 show an example of embodiment wherein the correction air jet pipes 36 and 36' are mounted on the edge of the upper end opening of the cylindrical duct 28. However, this invention is not limited to such arrangement but the correction air jet pipes 36 and 36' may be mounted, for example, on the upper end edge of the elastic seal plates 27 and 27' to jet air to the cloth material 37 as shown in FIG. 4.
In the present embodiment, as described in the foregoing, a pair of correction air jet pipes 36 and 36' are arranged, with spacing between them, on the upper end edge of the cylindrical duct 28 or at each of the elastic seal plates 27 and 27' in positions as close as possible to the pressed contact area between the seal rubber rolls and to their pressure receiving faces which receives the internal pressure of the steamer body. These pipes extend in parallel with the axes of the seal rubber rolls and are provided with nozzles arranged in the longitudinal direction thereof. The cloth material is guided between the two correction air jet pipes while jet air is applied to both sides of the cloth material to correct the travelling direction of the cloth material and to prevent the cloth material from being wound on the seal rubber rolls.
Embodiment EXAMPLE III
In FIG. 5, a reference numeral 41 indicates a high pressure steamer drum body adapted to treat a cloth material 42. A seal block 45 is secured to a cloth material inlet 43 of the drum body 41 with a seal packing 44 between them. Inside the seal block 45, there is provided a penetrating hole 46 which communicates with the inside of the steamer drum body 41. A pair of rubber seal rolls 47 and 47' are freely disposed on the upper side of the seal block 45 and are arranged in pressed contact with each other. An upper end opening of the penetrating hole 46 is closed by the pair of rubber seal rolls 47 and 47' and also by an end face seal plate 48 which is in contact with one end face of each seal rubber roll. The lower end edges of a pair of elastic seal plates 49 and 49' each of which is curved into an arc like shape are secured by retainers 50 to the upper opening edge portions of the penetrating hole 46 of the seal block 45. The upper end outer face portions of the seal plates 49 and 49' are pressed elastically into contact with the seal rubber rolls 47 and 47'. In this embodiment, the seal plates 49 and 49' are formed of stainless steel plates, though the material for the seal plates is not particularly limited to stainless steel. An outer cylindrical duct 51 is disposed inside the penetrating hole 46 and is formed with a narrow upper end portion leaving gap passage (a) between it and the inner circumferential face of the penetrating hole 46. Within the outer cylindrical duct 51, there is provided an inner cylindrical duct 52 which leaves a gap passage (b) between it and the inner circumferential face of the outer cylindrical duct 51. Flanges 51' and 52' are formed respectively at the lower end of the outer and inner cylindrical ducts 51 and 52 and are secured to the edge of the opening in the lower side of the seal block 45. The upper open end of the inner cylindrical duct 52 are positioned to be as close as possible to the pressed contact area between the rubber seal rolls 47 and 47'. Further, the upper open end of the outer cylindrical duct 51 is positioned a little lower than the position of the upper open end of the inner cylindrical duct 52. At the upper open ends of the outer and inner cylindrical ducts 51 and 52, there are formed hooked portions 51" and 52" which are directed toward the space between the seal rubber rolls and the elastic seal plates. A fluid supply pipe 53 is arranged to communicate with the gap passage (b) while a fluid discharge pipe 54 is arranged to communicate with the gap space (a).
Although the following parts are not essential to this invention, a cooling water-washing tank 55 is arranged with the seal rubber rolls 47 and 47' immersed therein; water removing rolls 57 are arranged to be in contact with the seal rubber rolls; and wiping endless cloth belts 58 are provided for wiping the seal rubber rolls 47 and 47'.
The structural arrangement being as above mentioned, this embodiment operates in the following manner: The pair of seal rubber rolls are rotated in the directions of arrows respectively. At the same time, fluid pressure such as pressure air or pressure water is supplied from the fluid supply pipe to the gap passage (b). When, for example, pressure air not exceeding 100° C. is supplied as fluid pressure to the gap passage (b), the pressure air spouts out of the upper ends of both cylindrical ducts 51 and 52 and jets toward spaces between the seal rubber rolls and the seal plates. The pressure air supplied between the seal rubber rolls and the seal plates is taken in as the seal rubber rolls rotate to give a lubricating effect. Surplus pressure air between the seal rubber rolls and the seal plates is discharged by the exhaust pipe 54 through the gap passage (a). The same seal effect can be obtained with pressure water employed in place of the pressure air.
As described in the foregoing, in accordance with the present invention, fluid pressure such as water or a gas is arranged to spout in to the pressed contact area between the rubber seal rolls and the seal plates in the rotating direction of the seal rubber rolls. Thus, the pressure fluid is gradually taken in between the seal rubber rolls and the seal plates. The pressure fluid taken in between the seal rubber rolls and the seal plates has a lubricating effect on the rotation of the rubber seal rolls to enhance the wear resistance of the rubber seal rolls. Water or pressure air not exceeding 100° C. is thus employed as a lubricant for the purposes of: Obtaining the above states lubricating effect; protecting the cloth material from being soiled; and economization of heat energy. When water is used for this purpose, moisture is imparted to the seal rubber rolls and the seal plates for a lubricating effect. When pressure air not exceeding 100° C. is used, the temperature of the pressure air is lower than the temperature of gas (102° C. or above) of the inside of the steamer body. Therefore, collision between the pressure air of less than 100° C. and the gas within the drum body of 102° C. or above produces highly humid air which sticks to the seal rubber rolls and the seal plates to give a lubricating effect.
The surplus portion of the pressure fluid other than the portion taken in between the seal rubber rolls and the seal plates is discharged to the outside through the gap passage (a). Therefore, the pressure fluid such as water or steam never comes to stick to the cloth material 42, so that uneven treatment of the cloth material can be prevented. | A seal device having a pair of rubber seal rolls arranged in pressed contact with each other at a cloth material passing port of a drum body of a high pressure steamer adapted for hygro-thermic treatment of textile products such as a cloth material. Seal plates which are formed with a flexible and elastic metal or synthetic resin sheet and upper or lower sides of which are secured to edge portions of the cloth material passing port disposed in parallel with the pair of seal rubber rolls while the other sides are in pressed contact with the seal rubber rolls. An air chamber formed in a triangular cross-sectional shape connects a pressed contact point between the rubber seal rolls respectively to contact points between the seal plates and the seal rubber rolls, and air pressure is supplied to the air chamber through an air supply passage. A pair of correcting air jet pipes are spaced across the cloth material and arranged to blow air to both sides of the cloth material to correct its posture for preventing it from being wound on the surface of the seal rubber rolls after it has passed these rolls. A passage is provided for expelling to the outside a surplus portion of the air supplied to the air chamber to prevent it from coming into the drum body. | 3 |
FIELD OF INVENTION
The present invention relates to employment services and, in particular, to online recruiting or employment services.
BACKGROUND OF THE INVENTION
The rapid expansion of job postings on the Internet has created a large amount of employment related information, which spans hundreds of thousands of web sites. Initially, companies began posting their open job positions on their own corporate web sites. A job seeker could then readily access new employment opportunities by visiting a company's web site. As an increasing number of company web sites began to post their open jobs, however, the job search process grew proportionally. For example, a job seeker searching for a “software developer” position would have had to identify and visit the web site of every company that might have such open job positions. Thus, this growth resulted in a task that was cumbersome and time consuming for the job seeker.
In order to help address these issues, job board web sites have evolved on the Internet. The original purpose of a job board was to provide a single web site where companies could visit to post their open job positions and job seekers could visit to search for new employment opportunities. The job board concept helped the job seekers by creating a central location that a job seeker could visit to search for jobs.
Unfortunately, however, the concept increased the work and cost for companies. In addition to maintaining job postings on their own corporate web sites, companies were now required to visit the job board sites to repost, update and delete their job position information as appropriate. The accuracy of the job board information was affected when companies changed their job information, filled open position, etc., but failed to update the corresponding job board postings. These job boards also often charged a fee to the companies for this posting service. In addition, these job boards only contained job positions from companies that had actively posted jobs on the sites. In other words, companies that did not know about the job boards would have been prevented from listing the company's open positions and, consequently, eliminated opportunities for the job seekers as well as the company itself.
Most recently, the aggregation, accuracy, and freshness of job board postings have been addressed through various web spidering or crawling technologies. The technology of web site spidering or crawling consists of a process in which content from a set of source web sites is retrieved automatically. This content is typically retrieved for purpose of being indexed into a search engine web site in order to provide Internet users a central web site to use as a search tool. The type of content that is spidered is generally not filtered so the search engine web site often has indexed content from a wide variety of source web sites. New web sites that contain content to be spidered have to register with the search engine web site before their content is retrieved and indexed into the search engine. Once a new site is registered into the set of source web sites to spider, the search engine web site will periodically spider the site to search for new or updated content to index.
In these updated models, the job board periodically sends out spiders to the web sites of companies that register with the job board web site. The purpose of these spiders is to retrieve and input the latest job posting information from the company web sites and thereby automatically update the job information listed on the job board. The method, however, creates a disadvantage for companies and job seekers because the sites do not post the numerous job positions from the companies that do not register with or know of the job board web site. As such, the Internet contains a vast amount of job postings which exist only on company job boards and which are not being collected and displayed by the job board web sites.
Another new approach to job posting aggregation is the master search engine site. In this approach, the master web site collects a job seelcer's search criteria and submits it to multiple other job board web sites. The master search engine site aggregates the individual sites and presents the results to the job seeker in a single format. An advantage to this method is that the job seeker only needs to visit a single site to perform a job search. The disadvantages of this approach are that, as described above, only a subset of the job board sites on the Internet are actually searched and individual company job postings are completely omitted. Furthermore, in these types of searches, the formatting of the results can vary thereby causing the job seeker to become confused when presented with search results.
An additional feature of prior art job board web sites is the electronic notification of new job opportunities. When a new job is posted that fits within his selected category information, the job seeker automatically receives notification of the new job via email. A limitation to this system is that user may miss employment opportunities which are filtered outside of the selected category information.
Another drawback of the prior art systems relate to the search engines used for identifying a position of interest to the job seeker. The prior art systems use a table, key word or boolean driven search engine. The search engines use a pull-down menu, keyword or boolean search methodology that has a limited ability to implement intelligent searches. For instance, a job seeker may be in search of a position in a specific technical field. A search of job postings with one or two keywords may identify many unrelated jobs. It may be very time consuming for the job seeker to review every identified job posting. The effort becomes even greater when compounded by the number of such searches to be completed at each of the numerous online employment sites. The job seeker may use additional keywords to reduce the number of unrelated job postings. However, the additional keywords often have the effect of reducing certain of the job postings, which may be of interest to the job seeker, but do not necessarily contain all of the designated keywords. In other words, the search strategy may have become too restrictive. Therefore, the job seeker ends up accessing only a small fraction of jobs currently available on the Internet.
Along with the evolution of job board related web sites, the prior art systems have provided job seekers the ability to post electronically their resumes. These systems have increased the amount of resumes available online. This increase has created web sites, which collect resumes into searchable databases. These web sites often sell subscription access to their databases, which employers and recruiters purchase in order to search for qualified candidates. However, these web sites suffer from the same disadvantages and limitations as described in the job posting process: a) companies and job seekers must visit the web sites to add and update information; b) searches are limited to narrowly targeted keywords; and c) job seeker resumes are sorted into restrictive categories.
Furthermore, if these companies do not post at the job board web sites, without adequate traffic to their corporate web site and employment pages, employers cannot, on their own, reach a sufficient number of qualified candidates. As a result, the employers must choose to either pay the third party job board web sites to post a portion of their jobs online, making these opportunities accessible to a larger candidate pool, or miss many qualified candidate. Despite this investment, however, the factors listed above still limit the effectiveness of the job boards and prevent many qualified candidates from matching with the opportunities employers have paid to list.
In summary, there are deficiencies in the current state of the art in the Internet based employment process. The gap between job board listings and actual online jobs is growing rapidly. Companies develop and add recruiting pages to their own web sites much faster than the rate at which the top job boards add clients. Moreover, the gap between unique job board listings and unique jobs available online is expanding at an even faster pace, as companies that use job boards often post the same opening to between six and ten sites. Furthermore, the current web site job boards fail to aggregate completely all job postings on the Internet. Even the sites that aggregate a larger amount of the available job listings are limited by the search engine technology currently used by those job boards. In addition, the current prior art systems are deficient in their information exchange capabilities. Job board web sites rely on companies and/or job seekers to continually visit the job board web sites and update the applicable information.
SUMMARY OF THE INVENTION
The object of the present invention is a method of managing employment data to provide enhanced access via the Internet to the employment data.
A further object of the present invention is to provide a more thorough and precise searching of the employment data.
Still a further object of the present invention is to update automatically the employment data collected by the present invention.
Still yet a further object of the present invention is to format the employment data so as to allow for a more accurate and efficient search of the employment data.
Still yet a further object of the present invention is to match automatically users to fulfill employment needs.
In general, the present invention consists of several key subsystems. These subsystems are based on existing software technology, information spidering and concept based searching, which is new in its application to the Internet related employment industry.
The present invention builds on the technology of job spidering and aggregation and incorporates it into the employment field. For example, the working set of web sites which this system spiders includes the entire Internet directory (“Dot Com database”). Thus, both companies and job boards are included in the job posting collection. Furthermore, the use of spidering technology is extended to resume collection as well as spidering of job postings. This allows the creation of a much more comprehensive and complete database of the available employment data.
The present invention also applies a concept based search engine to the employment search and match problem. As noted above, prior art search engine web sites are commonly based on keyword search engine technology. In its simplest form, a keyword search takes a set of comma delimited user input words and scans its document set for one or more word or partial word matches. Keyword searches, however, have been enhanced to include word count statistics, i.e., how often a word appears in a document increases its relevancy, and boolean operators, i.e., a user can search for specific terms to return documents that must contain both words. Unfortunately, these searches remain as simple word pattern matching technology, and the casual Internet user does not necessarily possess a clear understanding of query word relevancy or boolean logic.
In order to improve the user search experience, concept based search engines were created. The premise of a concept based search engine is that it is able to “learn” thematic information regarding the documents that it indexes. This learning is typically accomplished by applying Bayesian reasoning and neural network technology to each document when it is indexed. Users are often able to search the database by using full sentence, natural language queries instead of keyword sets and boolean logic. As a concept based search engine learns its document set, it can also make distinctions and relations. This learned information allows a user to search effectively for information without knowing exactly what is being sought or how the query should be phrased.
Another important feature of a concept based search engine is that the user will always be provided with some form of results. The results from such a search engine are typically returned in descending weight order. A result with 100% weight is highly relevant to the user's query, while a result with 1% weight contains little or no relevance to the search. This behavior is a key feature of the concept based search engine, because it allows a programmatic decision to be made based on the “goodness” of a particular result.
The use of a concept based search engine in the present invention eliminates the need for the user to categorize a job posting or resume into a fixed category list and to rely on simple keyword based searches to find information, thereby providing an accurate and thorough search result. The present invention then automatically spiders job and resume related web sites for content, indexes the content into its concept based search engines, matches the content between jobs and resumes, and notifies companies and job seekers of new mutual opportunities. This process occurs continuously to maximize the timeliness and freshness of the information exchange.
Also, the present invention is able to accept a wide range of job posting formats and resume formats. The format of a job posting or resume will vary, often significantly, from web site to web site and job seeker to job seeker. By enhancing the process with newly developed software, which targets the online employment information, the system is able to index this diverse data into a common format. Once in a common format, matches within the data between job postings and resumes are efficiently performed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a functional block diagram of the system of the present invention.
FIG. 2 shows a functional flowchart for creating and accessing a database of employment data available on the Internet.
FIG. 3 shows a flow chart for determining if the visited web sites meet the employment criteria.
FIG. 4 shows a flow chart for updating automatically the employment data stored in the database.
FIG. 5 shows a flow chart for formatting and parsing the employment data.
FIG. 6 shows a flow chart for adjusting the revisitation period of the visited web sites.
FIG. 7 shows a flowchart showing the aging and deletion step.
FIG. 8 shows a flow chart for collecting subscriber search criteria and conducting a concept-based search using the criteria.
FIG. 9 shows a flowchart of matching the employment data and notifying the users.
FIG. 10 provides a table depicting employment data.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 , a system 10 of managing employment data is shown. The system 10 includes a dedicated spidering server 12 , a dedicated search, retrieve and process server 14 and a database 16 . The system 10 provides users (not shown) with the ability to search, via the Internet 18 , for employment data located at public job boards 20 , corporate web sites 22 and other web sites 24 . Users are provided access to the system 10 via user Internet connections 26 . The Internet connections 26 may be personal computers, for example.
The dedicated spidering server 12 is used to search the Internet for the employment data. FIG. 10 provides a table showing an example of employment data 28 or information available via the Internet 18 . Once the employment data is located, relevant information is loaded into the database 16 . The dedicated search, retrieve and process server 14 provides the user the ability to search the database 16 for employment data. Users include corporation representatives seeking to fill a position, agents working for the corporations, as well as individuals seeking an employment position. The process server 14 also conducts automatic searches of the database for matching employment data (i.e., matching jobs and resumes).
It will become clear from FIG. 2 that the database 16 of FIG. 1 represents multiple databases having individual functions. FIG. 2 discloses a process or functional block diagram of the present invention. In particular, FIG. 2 discloses a process which dynamically retrieves and indexes large amounts of web employment data and processes this information in an efficient and timely manner. The Dot Corn database 30 contains a listing of all the active domain names on the Internet 18 . The prequalify dictionary 32 consists of a concept based search engine that has been loaded with template documents to identify web pages that contain job posting or resume information. The site prequalification step 34 receives input from the Dot Corn database 30 and the prequalify dictionary 32 . The site prequalification step 34 filters web sites that contain job postings or resumes. The output of step 34 includes URL records, which are stored in the active spider's database 36 . Step 34 is shown in greater detail in FIG. 3 . Step 3.2 of FIG. 3 begins with reading the prequalify dictionary 32 . Step 3.3 reads the next record from the Dot Corn data base 30 . Step 3.5 consists of determining whether the record is scheduled for a check. At step 3.6, each record is checked against the Internet domain named service (DNS) to verify whether an active web site exists for the domain name. In the event it is determined that an active web site does not exist, then step 3.13 consists of scheduling the web site or record for a future check. In the event the web site is active, step 3.8 consists of fetching the content of the web site. Step 3.10 consists of checking the site content against the prequalify dictionary 32 . The prequalify dictionary 32 contains a concept base search engine which has been configured with template sample documents of job postings and resumes. Each page of site content that is retrieved at step 3.8 is presented as a query input to the prequalify dictionary concept based search engine at step 3.10. The search engine returns a rated percent result, which indicates how relevant a particular site page is with respect to job postings or resumes. If a web site is determined to contain documents of sufficient relevancy, the site is stored in the active spider's database 36 , enabling the site to be regularly spidered for its content. The retrieve content is stored in the spidered content database 38 . If a web site does not exist or has no relevant content, it is scheduled at step 3.13 for a future check, at which time the site prequalification step 34 will revisit the site to repeat the foregoing process.
The site prequalification step 34 contains several key operating parameters, including the maximum number of pages to retrieve from a single web site, the amount of time to spend spidering a single web site and a threshold relevancy wait that is used to indicate whether the site contains job postings or resumes of related content. Critical to this step is the configuration of the prequalify dictionary 32 , as its document set is the mechanism that controls which web sites are accepted as valid and which are rejected. The architecture of a site group prequalification step 34 is readily scalable, as in practice several services can be operating in parallel on the Dot Corn data base 30 to perform the web site validation process. By scaling services in this manner, the information scan rate of the millions of records of the Dot Corn database 30 is easily controlled.
The periodic spidering step 40 of FIG. 2 is responsible for running each of the spiders in the active spider's database 36 on a regular, scheduled basis. FIG. 4 discloses the periodic spidering step 40 in greater detail. Step 4.2 consists of reading the next record from the active spider's database 36 . Step 4.4 determines whether the web site corresponding to the record is scheduled to be spidered. In the event the web site is scheduled to be spidered, step 4.5 fetches the site content. Step 4.7 determines whether the newly fetched content has changed from the corresponding content previously stored in the spidered content database 38 ( FIG. 2 ) to determine whether the web site has changed. If a change has occurred, the new content is stored in the spider content database 38 for further processing.
If it is determined at step 4.6 that the spider fails when accessing a particular web site, step 4.9 consists of identifying the site as “failed” and removing the sit& from the active spider's database 36 . Step 4.10 updates the Dot Corn database 30 to schedule the site to be requalified at a later time.
Step 40 is designed to run continuously to ensure that when the content of each source site changes, it is quickly updated in the spider content database 38 . Thus, the timeliness and freshness of the information is preserved. Step 40 is readily scalable, as in practice several services can be operated and parallel to perform this spidering process. As additional spiders are created, additional service can be added to handle the new load.
The content processing step 42 of FIG. 2 consists of further processing the content, which is temporarily stored in the spider content database 38 . The processing dictionary 44 consists of a concept based search engine, which is similar to the prequalify dictionary 32 . The search engine has been loaded with additional template documents that enable spidered content to be parsed and scrubbed prior to being loaded into the searchable content database 46 . The content processing step 42 is shown in greater detail in FIG. 5 . The content processing step 42 is responsible for processing each retrieved document into a format that is suitable for indexing into the searchable content database 36 . The processing dictionary 44 contains a concept based search engine, which has been configured with documents that contain specific job titles, job descriptions and resume descriptions. The dictionary 44 is used to measure the relevance of each spidered content document to determine whether it should be classified as a job-posting, resume or irrelevant, at which time the content is discarded. Another task of step 42 is the parsing and analysis of web pages, which contain multiple sets of information. For example, a single web page, which contains 15 different job postings, is broken down into 15 separate documents utilizing available advanced document parsing technology. Each document would contain its own title and specific job location information. The improved content results in a search experience that is clear and concise to the user.
Step 5.2 consists of reading the processing dictionary 44 . Step 5.3 consists of reading the next record from the spidered content data base 38 . Step 5.5 strips the document of its hypertext markup language (HTML) commands. The stripped document is evaluated by step 5.6 for its length requirements, and is scanned at step 5.7 and 5.8 to identify the location information (city, state, and zip code), and the e-mail address information.
The document is then presented as query input through the processing dictionary 44 . The concept based search engine is used to further identify the document as a job posting or resume as well as determine its title information and amount of different information which the document may contain (see step 5.9). Documents that do not meet minimum relevancy requirements as a job posting or resume are discarded (step 5.10 and 5.12). Documents that pass the noted criteria are indexed into the searchable content database 46 as a job posting or resume (step 5.13).
After a document passes through this process, its record in the searchable content database 46 represents a uniform entry, which is consistent with the other records. The content processing step 42 is designed to run continuously as new information is placed into the spidered content database 38 . Thus, the timeliness and freshness of the information is preserved. Step 42 is readily scalable, as in practice several servers can be operating in parallel to perform the content processing. As the input spidering process information flow increases, additional servers can be added to handle the new content processing load.
The spider adaptation step 48 of FIG. 2 is responsible for dynamically adjusting the operating parameters of each spider. The adaptation step 48 is shown in greater detail in FIG. 6 . Step 6.2 consists of reading the next site of which the content was previously processed and stored in the searchable content database 46 . In the event it is determined at step 6.4 that the particular spider failed or retrieved irrelevant content (not job posting or resume related content), then step 6.10 sets the spider status as “failed” in the active spider data base 36 , and at step 6.11, the Dot Corn data base 30 is updated to requalify the failed site at a later time.
Step 6.5 compares the content retrieved at step 6.2 with the content previously stored in the searchable content database 46 . Step 6.6 determines whether the changed limit has been exceeded. Based on the amount of changes that have occurred, the spider schedule will be adjusted accordingly. In the event the change limit has been exceeded, then step 6.12 will set the spider to run again the following day. In the event the change limit has not exceeded, then step 6.7 and 6.8 will increase the spider frequency for that particular site by an additional day if the delay is presently less than 30 days. The spider adaptation step 48 is designed to run continuously as a feedback loop between the content processing step 42 and the periodic spidering step 40 . Step 48 is readily scalable, as in practice several servers can be operating in parallel to perform this step 48 . As the input spidering process information flow increases, additional service can be added to handle the new load.
The aging and deletion step 50 is responsible for expiring old information in the searchable content database 46 . The aging and deletion step 50 is shown in greater detail in FIG. 7 . Step 7.2 reads the next record from the searchable content data base 46 . Step 7.4 determines whether the document date has expired. In the event the document date has expired, step 7.5 deletes the document from the searchable content database 46 . Step 50 ensures that old web sites that have been removed from the Internet are identified, and their content document sets are purged from the overall system. The aging and deletion step 50 is designed to run continuously, and it is readily scalable, as in practice several servers can be operating in parallel to perform this aging and deletion step. As the input spidering process information flow increases, additional servers can be added to handle the new load.
The result of the foregoing provides a searchable content database 46 of job positions and resumes, which may be “manually” searched by users as well as searched via an automatic process.
The “manual” search is initiated at the user search step 52 and continues with the concept phase step 54 , the keyword phase step 56 and concludes with the search results 58 . FIG. 8 discloses additional details as to the user search. Step 8.2 consists of reading the user search input. Step 8.3 determines whether the title, description or key words have been entered. However, the user may further include information such as the city, state, range of location and number of results returned, etc. The concept phase step 54 occurs at step 8.6 whereupon concept searching is conducted upon the searchable content database 46 using the user input. The results are processed at step 8.8 whereupon traditional text processes and techniques are used on the result to produce a filtered result set. Step 8.9 determines whether the quantity of the results meets the users specified quantity in order to determine whether the search may be concluded.
The user search step provides a front-end, manual interface for job seekers and employers or recruiters to search for employment data, i.e., job postings or resumes, respectively. The job seeker's search is provided as a free service, whereas the resume search is sold as a subscription service.
The user search is designed to run on user demand, and is readily scalable, as in practice several servers can be operating in parallel to service multiple user search requests. As the number of new users searching the system increases, additional servers can be added to handle the new load.
The automatic match step 60 is responsible for identifying matches between the employer's (job postings) and job seekers (resumes). As matches are identified, both the employer and job seeker are notified via e-mail. FIG. 9 discloses the automatic match step 60 in greater detail.
Step 9.2 consists of reading the next new job posting from the searchable content database 46 . Step 9.4 consists of using the contents of the new job posting as query input to perform a concept based search on the resumes in the searchable content data base 46 . The results of this search consist of a set of resumes that meet a relevant percent rate with respect to the job posting content. The candidates of these resumes are identified as “good matches” for a particular job posting. At steps 9.6 and 9.7, the employer corresponding to the new job posting and the candidates corresponding to the identified resumes, are contacted via e-mail.
Step 9.8 consists of reading the next new resume from the searchable content data base 46 . At step 9.10, the contents of the new resume are used as query input to perform a concept based search on the job postings in the searchable content database 46 . The results of this search consist of a set of job postings that meet a relevant percent rate with respect to the resume content. The jobs are identified as “good matches” for the particular candidate. Steps 9.12 and 9.13 consist of contacting the employers corresponding to the job posting results, and the candidate corresponding to the new resume.
When a candidate receives an e-mail message containing the job description(s), the candidate is able to access the job posting details, company information, etc. free of charge. Once the candidate reviews this information, the candidate may choose to apply to a job, also free of charge. When an employer or recruiter receives the e-mail message identifying an eligible candidate(s) and the qualification summaries, the employer or recruiter may elect to purchase a web site subscription, which allows access to each candidate's resume and contact information. Furthermore, when an employer or recruiter subscribes to the web site and accesses various candidate information, the employer or recruiter may also elect to engage recruiting services to assist in pursuing the candidate.
The automatic match step 60 is designed to run continuously as new job postings and resumes are added to the searchable content database 46 . The match step 60 is scalable, as in practice several servers can be operated in parallel to perform this matching and e-mail notification process. As the input information flow to the searchable content database 46 increases, additional servers can be added to handle the new load. | The present invention provides a method of managing employment data so as to provide access to the employment data via the Internet ( 18 ). The method including the steps of determining whether a web site ( 22, 24 ) contains employment data, formatting, parsing and storing the employment data and corresponding URL into a database, automatically searching the database ( 16 ) for matching employment data, and contacting the employer representative as to the matched employment data. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention broadly relates to the preparation of microemulsions of biologically active, and often labile, materials. In a preferred aspect, this invention relates to the preparation of biocidal concentrates which can be used to prepare aqueous microemulsions of fungicides useful in the protection of wood surfaces or for incorporation into metal working fluids, and to prepare aqueous microemulsions for use as insecticides, herbicides, slimicides, or algaecides.
2. Description of Related Art
Microemulsions are dispersions of one liquid phase in a second immiscible phase. They can be water continuous (o/w) or oil continuous (w/o) where "oil" denotes an organic liquid (or liquids) of low water solubility. A unique property of microemulsions is that the interfacial tension between the two phases is very low. In the prior art, obtaining this low interfacial tension was thought to require very specific combinations of "oil" (water immiscible organic liquid) and surfactants and water. The particle size of the dispersed phase of a microemulsion is extremely small, usually less that 1000-2000 Å. Since this size is small in relation to the wave length of visible light, microemulsions appear opalescent or more usually optically clear. Microemulsions typically are stable against phase separation for long time periods, e.g. often times for periods measured in years. In contrast, normal macroemulsions, where a milky appearance results from emulsion particles being in the 1-20 μ range, phase separation typically occurs within hours to weeks after the emulsion is prepared.
As described in the prior art, optimum solubilization of an oil to give an o/w microemulsion occurs within a narrow composition range of oil, surfactant, cosurfactant and water. Some investigators have stressed the essential role played by a co-surfactant in the formation of a microemulsion. J Am. Chem. Soc., (1991), 113: 9621-9624.
A typical example is given in Microemulsion Theory and Practice, Ed. L. M. Prince, Academic Press (1977) describing the system p-xylene, sodium lauryl sulfate, pentanol and water. In fact, the prior art indicates that the use of several surfactants is usually required to produce a microemulsion. When one of the surfactants is soluble in the water phase and the other is soluble in the organic phase, each one has only a marginal effect on the other, and their combined effect may be large enough to reduce the interfacial tension to near zero at finite concentrations. Thus, although microemulsions are obtainable with certain surfactant combinations and within finite concentration ranges of these surfactant combinations, at present, formulating such microemulsions is essentially still an art. When the composition is outside the microemulsion range, as defined by a phase diagram, multiphase regions exist. The consequence is that dilution of a microemulsion composition with water often leads to formation of a macroemulsion or multiphase, unstable systems. In a practical sense it is desirable to define a microemulsion composition that will remain clear and not phase separate when further diluted with water.
An oil in water micellar solution can result when a small amount of "oil" is added to an aqueous solution of a surfactant and water. If the amount of surfactant is great in relation to the "oil" (say>5:1), the oil can migrate to the interior of a surfactant micelle without greatly disturbing it. Such solubilizing of the oil in a surfactant micelle can result in a clear micellar solution and the solution will very often retain clarity when further diluted in water. Because of the large excess of surfactant in such micellar solutions, the proportions of the various constituents in such compositions are not as critical as with microemulsions. Even so, a microemulsion represents a much more efficient way of solubilizing an oil.
European Patent Application 0648414 describes the preparation of a microemulsion concentrate containing a nonpolar water immiscible solvent, at least one ethoxylated surfactant and at least one sulfated anionic cosurfactant. The concentrate is fully water dilutable to form a microemulsion.
U.S. Pat. No. 5,242,907 involves the use of a formulation of microemulsions comprising an oil, a surfactant, and a co-surfactant. This patent deals primarily with forming a microemulsion of cypermethrin, a pyrethoid-type material.
U.S. Pat. No. 5,444,078 describes mixtures of active ingredients that are substantially insoluble in water combined with a water immiscible solvent for the active ingredients, and a surfactant-cosurfactant system composed of sulfonated ionic surfactants and ethoxylated alcohols.
WO 93/14630 describes the treatment of timber with microemulsions containing pesticides such as pyrethroids, or fungicides such as iodopropargyl butyl carbonate (IPBC) and/or propiconazole. The formulations include an oil, together with a surfactant, a co-surfactant and sodium hydroxide and calcium chloride.
U.S. Pat. No. 5,013,748 is concerned with the preparation of liquid organic concentrates, and emulsions and microemulsions made therefrom, produced using as the active biocidal ingredients a very specific set of triazol fungicides and quaternary ammonium fungicides, and at least one benzimidazole fungicide mixed with one or more isothiazolones, together with a liquid carrying agent composed of an alkanol of up to six carbon atoms and a saturated monocarboxylic acid containing from one to six carbon atoms.
U.S. Pat. No. 4,973,352 claims the preparation of microemulsions of herbicides such as phenoxyphenoxycarboxylic acid ester combined with a salt of bentazone (3-isopropyl-1H-benzo-2,1,3-thiadiazin-y-one 2,2-dioxide) using at least one emulsifier and one or more organic solvents. The examples cited contain, in every case, at least two emulsifiers.
U.S. Pat. No. 4,954,338 describes microemulsions of isothiazolones prepared with the use of an anionic surfactant together with a non-ionic co-surfactant and a polyoxyethylene-polyoxypropylene block copolymer.
U.S. Pat. No. 4,904,695 relates to the preparation of microemulsions of insecticides in formulations containing a surfactant blend, a thickening agent, an anti-freeze and a defoamer.
WO 90/03111 is directed to the use of siloxane based surfactants for the preparation of microemulsions of pyrethroids. It requires the use of water, oil, a surfactant and a co-surfactant.
WO 90/03112 describes a method of protecting crops by treating them with a microemulsion prepared from a pyrethroid pesticide, an oil, a surfactant and a co-surfactant.
U.S. Pat. No. 5,037,653 (WO 88/07326) describes the preparation of ready-to-use microemulsions consisting of a pesticide, water, an anionic cosurfactant, a non-ionic surfactant and oil. It does not describe preparation of base solutions e.g., a concentrate, which can be diluted with water or added to water to form a microemulsion.
U.S. Pat. No. 4,567,161 is directed to the preparation of microemulsions of herbicides, fungicides, etc., through the use of a combination of phospholipids and a co-surfactant consisting of an ethoxylated glycerin ester.
It will be realized that there is a plethora of prior art for the preparation of microemulsions. In the main, however, the prior art teaches that an oil or water-immiscible solvent, a surfactant, usually a non-ionic surfactant, and a co-surfactant (usually an anionic surfactant) are required.
The amount of surfactant required, as indicated in these prior art formulations, generally varies from about 10 times the weight of the labile ingredient, e.g., a pesticide, up to about 200 times its weight. In certain prior art disclosures, the stability of the microemulsion is not considered or reported. In most of the prior art disclosures, the preparation of the microemulsion is carried out by separately adding each ingredient to the full complement of water, a procedure that often is not practical for industrial or agricultural applications.
BRIEF DESCRIPTION OF THE INVENTION
The present invention involves the use of a single surfactant which simultaneously acts as a solvent for the biologically active, and generally labile biocidal compound, such as a fungicide (iodopropargyl butyl carbamate (IPBC) for example), and which by itself yields a stable microemulsion, a micellar solution or a molecular solution on mixing with water. Such materials are referred to herein as "solvating surfactants." No co-surfactants are needed, and preferably no co-surfactants are employed to produce a stable, water miscible composition. Use of an additional water immiscible solvent, an oil, a non-polar solvent, etc., is also unnecessary, though such a constituent may be advantageous in some circumstances as hereinafter described.
Consequently, the present invention is directed, in a first aspect, to a water miscible composition or concentrate consisting essentially of a solvating surfactant selected from the group consisting of an alkoxylated castor oil, an alkoxylated hydrogenated castor oil and an alkoxylated rosin, and having a biologically active, biocidal material dissolved in said solvating surfactant. The present invention also is directed to a microemulsion, a micellar solution or a molecular solution of the biologically active biocidal material prepared simply by adding water to the above-described concentrate composition and mixing.
The class of solvating surfactants employed in the present invention, i.e., alkoxylated, e.g., ethoxylated castor oils, alkoxylated, e.g., ethoxylated hydrogenated castor oil and alkoxylated, e.g., ethoxylated rosin, are good solvents for a variety of generally labile biocidally active compounds including IPBC; benzisothiazolones; propaconazole; propiconazole (CAS-60207-90-1); permethryn (CAS-52645-53-1), (3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane carboxylic acid (3-phenoxyphenyl)-methyl ester)!; deltamethrin (CAS-52918-63-5) (3-(2,2-dibromoethenyl)-2,2-dimethyl-cyclopropane carboxylic acid cyano (3-phenoxyphenyl) methyl ester!; cypermethrin (CAS-52315-07-8) (3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane carboxylic acid cyano (3-phenoxyphenyl) methyl ester)!; chlorpyriphos (CAS-2921-88-2) (Allethrin)(0,0-diethyl O-(3,5,6Trichloro-2-pyridinyl) phosphorothiate)!; tebuconazole (CAS-107534-96-3); 8-hydroxyquinoline (CAS-148-24-3); 2-(hydroxymethylamino) ethanol (CAS-65184-12-5); iodopropynyl cyclohexyl carbamate; Irgarol (n-cyclopropynyl-N 1 -(1,1-dimethylethyl)-6-(methylthio)- 1,3,5-triazine-2,4-diamine); 2,4-dichloro phenoxyacetic acid, butyl ester; 2,4,5-trichlorophenoxy acetic acid, ethyl ester; 2,4 dichlorbutyric acid, ethyl ester; Chlordane; piperonyl butoxide; bromoxynil (3,5-dibromo-4-hydroxy benzonitrile ester of n-octanoic acid); Thanite®: isobornylthiocyanoacetate; iodo propargyl succinate; terbutryn (CAS-886-50-0) (2-tert-butylamino-4-ethylamino-6-methylthio-1,3,5 -triazine)!; 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one; 1,4-dichloro-2,5 -dimethoxy benzene (Chloroneb); orthophenylphenol; azaconazole; cyperconazole; Amical (diiodomethyl-p-tolyl sulfone); IF-1000 (iodopropynyl phenylether); Cyfluthrin (CAS-68359-37-5); beta cyfluthrin (CFAS68359-37 -5); lambda-cyhalothrin (CAS-91465-08-6); cyhexatin (CAS-13121-70-5); cyphenothrin (CAS-39515-40-7); endosulfan (CAS-115-29-7); (1,4,5,6,7,7-hexachloro 8,9,10-trinorborn-5 -en-2,3-ylene bismethylene) sulfide (IUPAC); fenitrothion (CAS-122-14-5); and many other bactericides, fungicides, herbicides, algacides, acaricides, and the like, or combinations of two or more of these materials.
In its broadest aspect, the present invention is directed to preparing a microemulsion of any biocidal material that is water insoluble, but which can be dissolved in the solvating surfactant of the present invention.
To prepare the concentrate composition of the invention, the biocidal biologically active material, such as a pesticide, is dissolved in the solvating surfactant, such as an ethoxylated castor oil, at room temperature or at a slightly elevated temperature such as in the range of 50°-75° C. Solutions of the biocidal material in the solvating surfactant containing up to about 25% by weight of the biocidally active material may be prepared, depending upon the individual material. Combinations of two or more of the biocidal biologically active materials also may be dissolved in the aforementioned solvating surfactants to form a concentrate solution which yields a microemulsion, a micellar solution or a molecular solution when mixed with water. The aqueous compositions formed from mixing the concentrate with water are clear solutions that remain stable for periods up to two months or more. Microemulsions of this invention are generally stable indefinitely. In an alternate embodiment, an oil or an organic solvent also may be included in the concentrate composition to reduce its viscosity at high solute concentrations.
DETAILED DESCRIPTION OF THE INVENTION
Castor oil is a pale yellow to colorless, transparent viscous liquid obtained by cold-pressing the seeds of the castor bean, Ricinus communis. By far, the chief component of the fixed oil is the triglyceride (ester) of ricinoleic acid, with minor amounts of oleic, linoleic, palmitic and stearic acid glycidal esters. Ricinoleic acid is a C 18 , unsaturated (hydroxy) fatty acid. Hydrogenation of castor oil produces a hard, white wax having a molecular weight of about 932 and a melting point of 86°-88° C. Rosin is mainly composed of resin acids of the abietic and pimaric types.
Alkoxylated castor oil, alkoxylated hydrogenated castor oil and alkoxylated rosin are prepared by reacting the oil with an alkylene oxide under conditions well known to those skilled in the art. The ethylene oxide adducts of castor oil, hydrogenated castor oil and rosin are widely available commercially. In particular, ethoxylated castor oil is available from Chemiax Inc. as Chemax CO-30, CO40, and CO-80; from Witco Corp. as DeSonic 30C and 40C from Rhone-Poulenc as Alkamuls CO-40; from Henkel Inc. as Trylons and from Cas Chem., Inc. and BASF.
In the context of the present invention the "biocidal biologically active material" is any compound having microbiocidal activity, e.g., fungicidal, bactericidal and the like activity, herbicidal activity, e.g., algaecidal and the like activity, pesticidal activity, e.g., acaricidal, insecticidal, miticidal, and the like activity, or plant growth regulating activity. Generally, the solubility of the active material in water is less than 10,000 ppm and more often is less than 1000 ppm at room temperature. The biocidally active material also is soluble in the solvating surfactant in an amount of at least about 10 weight percent, and preferably at least about 15 weight percent. It is unlikely that the concentration of the biocidally active material in the solvating surfactant will exceed 40%. The actual limit on the concentration of the biocidally active material in the solvating surfactant is determined by its solubility in the surfactant and the optional use of a co-solvent. More usually, the concentrate composition will contain from about 5 to 25 weight percent of the biocidal active material.
Suitable candidates for the active material are IPBC; benzisothiazolones; propaconazole; propiconazole (CAS-60207-90-1); permethryn (CAS-52645-53 -1), (3-(2,2 -dichloroethenyl)-2,2-dimethylcyclopropane carboxylic acid (3-phenoxyphenyl)-methyl ester)!; deltamethrin (CAS-52918-63-5) (3-(2,2-dibromoethenyl)-2,2-dimethyl-cyclopropane carboxylic acid cyano (3-phenoxyphenyl) methyl ester!; cypermethrin (CAS-52315-07-8) (3-(2,2-dichloroethenyl)-2,2-dimethylcyclopropane carboxylic acid cyano (3-phenoxyphenyl) methyl ester)!; chlorpyriphos (CAS-2921-88-2) (Allethrin)(0,0-diethyl O-(3,5,6-Trichloro-2-pyridinyl) phosphorothiate)!; tebuconazole (CAS107534-96-3); 8-hydroxyquinoline (CAS-148-24-3); 2-(hydroxymethylamino) ethanol (CAS-65184-12-5); iodopropynyl cyclohexyl carbamate; Irgarol (n-cyclopropynyl-N 1 -(1,1-dimethylethyl)-6 -(methylthio)-1,3,5-triazine-2,4-diamine); 2,4-dichloro phenoxyacetic acid, butyl ester; 2,4,5-trichlorophenoxy acetic acid, ethyl ester; 2,4 dichlorbutyric acid, ethyl ester; Chlordane; piperonyl butoxide; bromoxynil (3,5-dibromo-4-hydroxy benzonitrile ester of n-octanoic acid); Thanite®: isobornylthiocyanoacetate; iodo propargyl succinate; terbutryn (CAS-886-50-0) (2-tert-butylamino-4 -ethylamino-6-methylthio-1,3,5-triazine)!; 5-chloro-2-methyl-4-isothiazolin-3-one, 2-methyl-4-isothiazolin-3-one; 1,4-dichloro-2,5-dimethoxy benzene (Chloroneb); orthophenylphenol; ˜(RS) -3-allyl-2 -methyl-4 okocyclopent-2-enyl (IRS) Cu; trans chrysan the math (IUPAC); azaconazole; cyperconazole; Amical (diiodomethyl-p-tolyl sulfone); IF-1000 (iodopropynyl phenylether); Cyfluthrin (CAS-68359-37-5); beta cyfluthrin (CFAS-68359-37-5); lambda-cyhalothrin (CAS-91465-08-6); cyhexatin (CAS-13121-70-5); cyphenothrin (CAS-39515-40-7); endosulfan (CAS-115-29-7); (1,4,5,6,7,7-hexachloro 8,9,10-trinorborn-5-en-2,3-ylene bismethylene) sulfide (IUPAC); fenitrothion (CAS-122-14-5).
Other materials which function as binders, film formers, or catalysts such as cobalt octoate 12% (cobalt salt of 2-ethylhexanoic acid diluted to 12% cobalt metal in mineral spirits.), alkyd resins (60% solution in mineral spirits) and urea-formaldehyde resins (CAS-28931-47-7) may be incorporated in the emulsion base either individually of in combination with one or more biologically active materials.
As illustrated in the examples which follow, the concentrate compositions of the present invention are improved by including an additional co-solvent oil such as castor oil, linseed oil olive oil, and the like or other solvents such as toluene, xylene, super high flash naphtha and ethyl benzene. In particular, by adding castor oil to a composition of an ethoxylated castor oil and IPBC the stability of any microemulsion, micellar solution or molecular solution made using the concentrate is enhanced. Without the added castor oil, a higher ratio of alkoxylated castor oil solvating surfactant to active biocide is required to yield a stable concentrate composition that can be mixed with water to provide a suitable microemulsion, micellar solution or molecular solution. With the added castor oil, the concentrate composition can contain a higher content of the biocidal material. Sources of castor oil based surfactants include: Cremophor El and Cremophor RH 410 (BASF); Trylon 5909 (Henkel); and Surfactol 365. Surfactant AR-150 (Hercules, Inc.) can be used as an ethoxylated resin surfactant.
The concentrate composition generally will be mixed with water in an amount of from 1:1 parts by weight water to parts by weight concentrate up to about 1000:1 water to concentrate, and more usually in the range of from 10:1 to 100:1. Consequently, the concentration of biocidal material in the aqueous composition will generally fall between about 0.01 to 10 percent by weight and more usually 0.1 to 1 weight percent.
The water miscible biocidal concentrate compositions of the present invention have potential application in a variety of circumstances including, but not limited to disinfectants, sanitizers, cleaners, deodorizers, liquid and powder soaps, skin removers, oil and grease removers, food processing chemicals, wood preservation, polymer latices, paint lazures, stains, mildewcides, hospital and medical antiseptics, medical devices, metal working fluids, cooling water, air washers, petroleum protection, paper treatment, pulp and paper slurries, paper mill slimicides, petroleum products, adhesives, textiles, pigment slurries, latexes, leather and hide treatment, petroleum fuel, jet fuel, laundry sanitizers, agricultural formulations, inks, mining, nonwoven fabrics, petroleum storage, rubber, sugar processing, tobacco, swimming pools, photographic rinses, cosmetics, toiletries, pharmaceuticals, chemical toiletries, household laundry products, diesel fuel additives, waxes and polishes, oil field applications, and many other applications where water and organic materials come in contact under conditions which allow the growth of undesired microorganisms.
The following examples are presented to illustrate and explain the invention. Unless otherwise indicated, all references to parts and percentages are based on weight.
EXAMPLE 1
An ethoxylated castor oil (90 g.) (CAS No. 61791-12-6) (an ethoxylated castor oil containing 40 moles of ethylene oxide) is warmed to 30° C. while agitating. Iodopropargyl butyl carbamate (IPBC) (10 g) (CAS No. 55406-53-6), a well-known fungicide, is added with agitation. The mixture is stirred until the IPBC is completely dissolved. The solution then is allowed to cool gradually to room temperature. The product is a clear pale amber viscous solution containing 10% by weight of IPBC. The solution (1.25 g) is dissolved in tap water (24 g.) to yield a clear microemulsion containing 0.5% IPBC.
EXAMPLE 2
Ethoxylated castor oil (80 g) (containing 40 mols of ethylene oxide) is mixed with 2-(hydroxymethylamino) ethanol, 12 g (CAS No. 65184-12-5) a liquid bactericide (sold under trade name Troysan 174). After a homogeneous solution is formed, IPBC (12 g) is added and the mixture is stirred until the IPBC is completely dissolved. This composition (1.0 g) was added with agitation to tap water (22.5 g) to yield a clear microemulsion containing 0.5% IPBC and 0.5% 2 -(hydroxymethylamino) ethanol.
EXAMPLE 3
1,2-benzisothiazolin-3-one (10 g.) was added to an ethoxylated castor oil (90 g.) (40 mols of ethylene oxide) and the mixture was warmed to 35° C. and stirred until a clear solution was obtained. The product was a clear, light amber solution containing 10% of the preservative, 1-2-benzisothiazolin-3-one.
This product (1.25 g.) was added to tap water (24 g.) while stirring to yield a clear microemulsion containing 0.5% 1,2-benzisothiazolin-3-one.
EXAMPLE 4
Permethrin (5 g.) was dissolved in an ethoxylated castor oil (90 g.) (40 mols of ethylene oxide) to form a clear, slightly viscous liquid.
This solution (1.25 g.) then was added to tap water (24 g.) to form a 0.25% active microemulsion.
EXAMPLE 5
IPBC (6.6 g.) and terbutryn (3.4 g.) were added to an ethoxylated (40 mols) castor oil (90 g.). The mixture was warmed to 30° C. and stirred until solution was complete. The product was a light, amber solution. This solution (1.25 g.) was added to tap water (24 g.) to form a microemulsion containing 0.165% terbutryn and 0.34% of IPBC.
EXAMPLE 6
Iodopropargyl butyl carbamate (IPBC) (10 g.) was dissolved in an ethoxylated hydrogenated castor oil (90 g.) by warming to 50° C. On cooling, the product changed to a pasty white solid containing 10% of IPBC.
The pasty solid was added to water (23.75 g.) with agitation to produce a clear solution containing 0.5% of IPBC.
EXAMPLE 7
IPBC (11 g.) was dissolved in an ethoxylated rosin (CAS No. 8050-33-7) (89 g.) by warming the mixture at 45° C. An amber colored solution containing 11% IPBC was obtained.
This product (1.1 g.) was dissolved in water (23.9 g.) to yield a clear, very pale amber solution containing 0.5% IPBC.
EXAMPLE 8
IPBC, 15 g is dissolved in 55 g of Cremophor EL and 30 g of Castor Oil. (Cremophor E1 is an ethoxylated castor oil containing 35 moles ethylene oxide to one mole castor oil) the concentrated product is a pale amber liquid containing 15% IPBC.
The concentrated product (3.3 g) is added to 96.7 g of water and stirred to yield a clear aqueous solution containing 0.5% IPBC. There has been no sign of precipitation nor turbidity after one month's storage.
EXAMPLE 9
IPBC (10 g.) was dissolved by agitation at room temperature in an ethoxylated castor oil (80 g.). To this solution was added an alkyd resin solution (10 g.) having 60% solids dissolved in a super high flash naphtha. The product is a clear very pale amber solution.
This product (1.25 g.) was added to water (23.75 g.) to yield a clear solution containing 0.5% IPBC, and has remained stable for more than two months.
Another portion of this product, (0.62 g.) was further added to water (24.4 g.) to yield a clear solution containing 0.25% IPBC, and has also remained stable for more than two months.
EXAMPLE 10
10 g of Castor Oil, 7.0 g, IPBC, and 3 g Propiconazole were added to 90 g of an ethoxylated (40 mols) Castor Oil (Surfactol 365, a product of Cas Chem., Inc., CAS No. 61791-12-6).
The mixture was warmed to 30° C. and stirred until a clear solution was obtained. The concentrate product, a clear pale amber solution, contained 3% of Propiconazole and 7% IPBC.
0.62 g of this solution was added to 24.4 g of tap water. The mixture was stirred until a perfectly clear microemulsion was obtained containing a total of 0.25% active ingredients--(30% Propiconazole, 70% IPBC).
EXAMPLE 11
3.3 g Irgarol, 6.7 g IPBC and 30 g, Castor oil were mixed with 60 g ethoxylated (40 mols) Castor oil. The mixture was heated to 30° C. and stirred until a clear solution was obtained.
1.25 g of the concentrated product, a clear pale amber liquid, was mixed with 23.75 g tap water. A clear water-like microemulsion was obtained containing 0.5% active ingredients. This microemulsion was stored at room temperature and has remained clear for 2 weeks.
EXAMPLE 12
2 g of IPBC was dissolved in 7 g Cremophore RH-40 (Ethoxylated Hydrogenated Castor oil containing 40 moles Ethylene Oxide) by warming to 45° C. When solution was complete, 1 g of Castor oil was added. The product is a clear pasty liquid containing 20% IPBC.
1.25 g of this product was added to 98.75 g water with rapid agitation to yield a clear solution containing 0.25% IPBC. This solution has remained clear for one month.
EXAMPLE 13
IPBC, 10 g was dissolved in a solution consisting of Super High Flash Naphtha, 5 g, and Trylon 5909 (Product of Henkel Corp.) (CAS#61791-12-6), 85 g. by agitation at room temperature. The concentrate product, a very pale amber liquid, contains 10% IPBC.
5 g of this product was added, with agitation, to 95 g water to yield a clear microemulsion.
EXAMPLE 14
Terbutryn (3 g.) (2-(tert-butylamino) -4-(ethylamino)-6-(methylthio)-S-triazine) (CAS No. 886-50-0) was dissolved in an ethoxylated castor oil (80 g.) by warming and agitating the mixture at 30° C. There was then added castor oil (10 g.) and IPBC (7 g.). The mixture was agitated until solution was complete. The product, a clear liquid, contained 7% IPBC and 3% terbutryn.
This clear liquid product (1.25 g.) was mixed with water (23.75 g.) to yield a clear solution containing 0.15% terbutryn and 0.35% IPBC. The solution has remained stable for more than two months.
EXAMPLE 15
IPBC 15 g, was dissolved in a solution consisting of toluene, 7 g, and Surfactol 365, 78 g, by agitating at 35° C. A clear very pale amber solution containing 15 % IPBC was obtained.
33 g of this solution was placed in a 200 ml beaker and agitated while 67 g of water was added. At first the solution increased in viscosity, but quickly formed a clear microemulsion containing 5.0% IPBC.
EXAMPLE 16
7 g IPBC and 3 g of 8-Hydroxyquinoline are added to 90 g Surfactol 365 and the mixture stirred while warming to 50° C. A clear light amber solution was obtained containing 7% IPBC and 3% 8-Hydroxyquinoline.
3 g of this solution was added to 97 g water while stirring. A clear microemulsion was obtained containing 0.21% IPBC and 0.09% 8-Hydroxyquinoline. This microemulsion has remained clear after one month.
EXAMPLE 17
10 g of propyl-4-hydroxy benzoate, (CAS-94-13-3), and 10 g iodopropynyl butyl carbamate were dissolved by stirring and heating to 45° C. in 80 g Cremophor El.
A clear solution was obtained containing a total of 20% active ingredients. It remains clear on cooling and aging.
5 gm of this solution was added to 95 gm water and the mixture agitated to obtain a very slightly opalescent clear solution containing 0.5% propyl-4-hydroxy benzoate and 0.5% iodopropynyl butyl carbamate. This solution has remained stable for 4 weeks.
EXAMPLE 18
7.5 g o-phenylphenol, (CAS-90-43-7) and 7.5 g iodopropynyl butyl carbamate were added to 85 g Cremophor El.
The mixture was stirred and heated to 50° C. until a clear solution was obtained. This solution remains clear on cooling to room temperature and aging.
4 gm of this solution were added to 96 g water to yield a clear microemulsion.
EXAMPLE 19
10 g o-phenyl phenol was dissolved in 90 g Cremophor El by stirring and warming to 60° C. A clear solution containing 10% o-phenylphenol is obtained.
3 g of this solution was stirred into 97 g water to yield a clear microemulsion that remained stable for at least one month, and contains 0.3 % o-phenylphenol.
While certain specific embodiments of the invention have been described with particularity herein, it will be recognized that various modifications thereof will occur to those skilled in the art and it is to be understood that such modifications and variations are to be included within the preview of this application and the spirit and scope of the appended claims. | A water miscible composition consisting essentially of a solvating surfactant selected from the group consisting of an alkoxylated castor oil, an alkoxylated hydrogenated castor oil and an alkoxylated rosin, and a biocidal biologically active material dissolved in said solvating surfactant useful to prepare aqueous microemulsions, micellar solutions or molecular solutions of said biocidal biologically active material upon mixing with water. | 8 |
FIELD OF THE INVENTION
This invention relates to wide bandwidth linear motor systems and, more particularly, to a linear motor having a coil support structure wherein secondary resonances are suppressed, thereby permitting wide bandwidth operation.
BACKGROUND OF THE INVENTION
Linear motors are widely used for a variety of applications. In one group of applications, high speed, or accurate waveform tracking, and accurate positioning are required from the linear motor. Stable operation without overshoot or oscillation is also a requirement. An example of such an application is a linear motor used to drive the tuning plunger in a high frequency, high power magnetron oscillator. The magnetron oscillator is commonly used in a radar transmitter, and the tuning plunger controls the transmitted frequency. The transmitted frequency may be varied in accordance with different frequency control waveforms, including rapid steps between frequencies and gradual frequency variations. In such an application, the speed, position accuracy and stability of the linear motor which drives the tuning plunger are of utmost importance.
Linear motors for such applications typically include a circumferential coil on a cylindrical support which is rigidly attached to a linearly movable shaft, and means for producing a radial magnetic field which intersects the conductors of the coil. When a current is applied to the coil, the magnetic field exerts an axial force on the coil, causing linear motion.
It is customary to place the linear motor in a servo loop to provide well-controlled operation. The position of the movable shaft is sensed by a position sensor and fed back for comparison with a desired position signal. An error signal produced by the comparison is supplied to an amplifier for energizing the coil to correct the position of the shaft. It is well-known that the bandwidth of a servo loop, which determines the rate at which the shaft position can be changed, depends on the loop gain. However, when servo loop has high closed loop gain, the tendency for instability and oscillation is increased. A second servo loop, where velocity is measured and applied to the amplifier as a negative or damping feedback, can be used to control oscillation.
A second limitation to the usable gain occurs in the structure of the motor. The motor force element is connected mechanically to a position sensor and a velocity sensor through a structure which exhibits resonant characteristics. Thus, sensors which normally return a negative feedback signal to the servo can return an amplified in-phase signal to the servo loop, thereby causing oscillation. The secondary resonance cannot be permitted to function since it is damaging to the motor structure and consumes large amounts of servo power. It is not necessary that the servo and force element be separated by the secondary resonance element as long as the secondary resonance can introduce a large signal into the sensor.
The simplest solution to the secondary resonance problem is to reduce the forward gain until the secondary oscillation ceases. This also reduces the effect of servo bandwidth and directly reduces servo performance. Another solution is to use an electronic notch filter in the feedback loop to suppress oscillations at the secondary resonance frequency. This solution is superior to the reduction of gain, but also tends to reduce bandwidth since the filter is likely to exhibit a broad continuation of gain over a wide bandwidth, causing a reduction in the desired operating range. Mechanical damping can also be used but adds mass which reduces servo performance.
It is a general object of the present invention to provide a novel wide bandwidth linear motor system.
It is another object of the present invention to provide a novel linear motor system wherein secondary resonances are suppressed.
It is a further object of the present invention to provide a novel wide bandwidth linear motor system wherein secondary resonances are suppressed without adversely affecting motor performance.
It is a further object of the present invention to provide a linear motor having a coil support which is subdivided into separate coil support elements for suppression of secondary resonances.
SUMMARY OF THE INVENTION
According to the present invention, these and other objects and advantages are achieved in an improved linear motor for driving a shaft connected to a load with linear motion along the shaft axis. The linear motor comprises a movable coil assembly, including a cylindrical coil support coaxial with the shaft, a bushing of smaller diameter than the coil support attached to the shaft, a plurality of radial ribs connecting the bushing to the coil support, and a coil comprising multiple turns of a conductor wound circumferentially around the coil support. The linear motor further includes means for producing a radial magnetic field intersecting the coil and means for supplying electrical current to the coil. The improvement to the linear motor of the present invention comprises the cylindrical coil support being subdivided into at least two separate coil support elements, each connected by at least one of the radial ribs to the bushing, whereby secondary resonance of the coil assembly is suppressed.
The coil support is preferably subdivided by a plurality of axial gaps into generally arc-shaped coil support elements. When the improved linear motor of the present invention is used in a servo loop, oscillation caused by secondary resonance of the coil assembly is suppressed and wide bandwidth operation is obtained.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the present invention together with other and further objects, advantages and capabilities thereof, reference may be had to the accompanying drawings which are incorporated herein by reference and in which:
FIG. 1 illustrates a linear motor system including a linear motor in a servo loop;
FIGS. 2A-2D graphic representations of the performance of prior art systems which have secondary resonance;
FIGS. 3A and 3B illustrate the improved coil assembly in accordance with the present invention; and
FIGS. 4A and 4B illustrate the performance of the linear motor system in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
A linear motor system is shown in FIG. 1. A linear motor 10 moves a drive shaft 12 with linear motion along a shaft axis 14. The shaft 12 is connected to a load 16 having a mass M. The linear motor 10 includes a coil assembly 20 rigidly attached to the shaft 12. The coil assembly 20 includes a bushing 22 attached to the shaft 12, a cylindrical coil support 24 coaxial with the shaft 12 and a plurality of radial ribs 26 extending from the smaller diameter bushing 22 to the larger diameter coil support 24. The radial ribs 26 position the coil support 24 relative to the shaft 12. A coil 28 consists of a conductor wound with multiple circumferential turns around the cylindrical coil support 24.
The linear motor 10 further includes means for producing a radial magnetic field B which intersects the coil 28 at right angles. The magnetic field B is produced by a magnet assembly including a magnet 30 and magnetic pole pieces 32, 34 connected to the magnet 30. The magnet 30 and the pole pieces 32, 34 shown in FIG. 1 are symmetrical figures of revolution about axis 14. The pole piece 32 has a cylindrical inner surface located outside the coil 28, while the pole piece 34 has a cylindrical outer surface located inside the coil support 24. The cylindrical inner surface of pole piece 32 and the cylindrical outer surface of pole piece 34 in combination define an annular gap 36 in which the magnetic field B subsists.
As a result of the relative orientations of the magnetic field B and the conductors of coil 28, a current through coil 28 produces a force on coil 28 along the axis 14. By controlling the current in the coil 28, linear movement of the shaft 12 and the load 16 are precisely controlled.
A linear motor of the type shown in FIG. 1 is commonly utilized in a servo loop to obtain precisely controlled operation. The elements of the servo loop are shown in block diagram form in FIG. 1. An amplifier 40 supplies current to the coil 28. A position sensor 42, such as a linear variable differential transformer attached to the shaft 12, senses the position of the shaft 12 and the load 16 and supplies a feedback signal representative of shaft position to one input of an adder circuit 44. The adder circuit 44 receives a position command signal of opposite phase from the feedback signal at another input. The position command signal is supplied from a system controller. The position command signal and feedback signal are added to produce a difference or error signal output which is supplied to the amplifier 40. Any difference between the desired position and the actual position results in the linear motor 10 being energized until the error signal becomes zero. The servo loop described above can be stabilized by the use of a velocity sensor 46 such as a linear variable transformer coupled to the shaft 12. Velocity sensor 46 produces a voltage representative of the shaft 12 velocity which is fed back to the amplifier 40 and causes a reduction in gain in relatively high velocity conditions.
In a position control servo loop of the type shown in FIG. 1, wide servo bandwidth is required to provide rapid movement and accurate waveform tracking. The servo bandwidth is defined as the one-half amplitude response of a sine wave of increasing frequency. For example, a servo loop having a 300 Hz bandwidth can position the load at a 300 Hz rate when a sine wave command signal is applied, but cannot provide a 300 Hz square wave response since the required higher frequency Fourier components are highly attenuated.
The servo bandwidth is determined by the usable loop gain and can be defined by the following equation ##EQU1## where f=servo bandwidth in Hz
K s =servo constant in pounds per inch
M=mass in pounds second 2 per inch
The servo constant or loop gain, K s , is defined as follows
K.sub.s =G K.sub.m K.sub.f (2)
where
G=gain of amplifier in amps per volt
K m =motor constant in pounds per amp
K f =feedback constant in volts per inch
Increasing the loop gain, K s , increases the servo bandwidth for a given load of mass M. However, the increase in loop gain K s is limited by the stability of the servo loop which will tend to oscillate. A second servo loop can be used to control the instability where velocity is measured by the sensor 46 and applied to the amplifier 40 as negative or damping feedback.
Another limitation to the usable gain occurs in the structure of the linear motor 10. The motor force element, coil assembly 20, is connected mechanically to position sensor 42 and to velocity sensor 46 through a structure which normally exhibits resonant characteristics. Thus, each sensor 42, 46, which should normally return a negative feedback signal to the servo loop, can return an amplified positive, or in-phase, feedback signal to the servo loop. The positive feedback signal will cause the loop to oscillate. This mechanical resonance, referred to herein as secondary resonance, is described in detail hereinafter. A graphical representation of the amplitude and phase response of the servo loop as a function of frequency is shown in FIG. 2A. The secondary resonance occurs at a frequency above the normal bandwidth of the servo loop and can cause loop oscillation at that frequency. The secondary resonance is damaging to the motor structure and consumes large amounts of servo power. Prior art solutions such as reduction of gain or increasing the strength of the motor structure to avoid resonance have not been satisfactory.
The effect of the secondary resonance in prior art systems on system response is illustrated with reference to FIGS. 2B-2D. A step position command input is shown in FIG. 2B. The position feedback signal from the position sensor 42 is shown in FIG. 2C. In this case, the response includes an undesirable oscillation 50 on the positive going portion as a result of the secondary resonance. In FIG. 2D, the loop gain of the servo system has been reduced to alleviate the effect of the secondary resonance. However, in this case the bandwidth is also reduced and the position feedback signal does not reach full amplitude, as indicated at 52. A desired response would follow the pulse shown in FIG. 2B as closely as possible.
The coil assembly 20 is shown in more detail in FIGS. 3A and 3B. The coil support 24 is a relatively thin-walled cylindrical member of lightweight material such as aluminum, titanium or beryllium having circumferential ribs 56 at opposite ends of the cylindrical surface for retaining the coil 28 in position. The conductors of the coil 28 are coated with epoxy for mechanical stability. Since the travel of the coil assembly 20 is typically limited to less than one inch, electrical connections to the coil 28 are made by arcuate leads of flexible material, such as speaker wire. The coil support 24 is connected to central bushing 22 by radial ribs 26.
It has been found that the secondary resonance described above is caused by a resonant flexing of the coil assembly 20. The flexing of the coil assembly 20 occurs in the form of axial deflection of the ribs 26, as indicated by the dashed lines in FIG. 3A, resulting from opposing forces exerted on opposite ends of the ribs 26. At the outer end of the ribs 26, a force is exerted on the coil 28 and the coil support 24 by the magnetic interaction inherent in the operation of the motor. An opposing force is exerted on the bushing 22 by the shaft 12 in the load 16. Therefore, the coil assembly 20 does not act as a rigid body, but flexes with a resonant frequency which adversely affects the operation of the servo loop.
In accordance with the present invention, the secondary resonance is suppressed by subdividing the cylindrical coil support 24 into separate coil support elements 24a, 24b, 24c, 24d as shown in FIG. 3B. The coil support 24 is divided by axial gaps 60 which completely separate the elements 24a, 24b, 24c and 24d. The axial gaps 60 can be made by saw-cutting through the finished coil support 24 or can be made by any other convenient technique. Each of the coil support elements 24a, 24b, 24c and 24d is connected to the bushing 22 by at least one of the ribs 26. The adjacent coil support elements are interconnected in a lossy and relatively flexible manner by the turns of the coil 28 and the epoxy coating over the coil 28. Since the coil support elements 24a, 24b, 24c and 24d are loosely and flexibly connected, independent flexing occurs with the overall result that secondary resonance of the assembly 20 is highly suppressed.
It will be understood that the coil assembly can have any number of radial ribs and that the coil support can be subdivided into any convenient number of separate elements. The gaps 60 are not necessarily axial, provided that the coil support is subdivided into a plurality of separate elements.
In one example of the present invention, the coil 28 consists of 1815 centimeters of 0.014×0.042 inch wire attached to the coil support 24 by an epoxy resin such as Epo-Teck 360T. At low frequencies up to 150 Hz, the coil assembly acts as a rigid mass. The total moving mass is 455 grams, of which the coil 28 is 65 grams, and the coil support 24 and the ribs 26 are 40 grams. The resonant behavior of the coil assembly is seen by considering the central shaft to be the reference, and the outer mass of the coil 28 and coil support 24 the resonant element, with the ribs 26 as beam-like springs. Since the coil support 24, absent the gaps 60, is a solid ring, the ribs 26 act as parallel springs with resonance depending on the in-phase action of each spring. After cutting of the gaps 60, the coil support comprises separate elements separated by the gaps 60, but coupled by the epoxy-held wires of the coil 28. The ribs 26, which were previously held in tight phase control by the solid coil support 24, now depend on the wires of the coil and the epoxy which holds the coil together to maintain phase. This connection is very lossy to high frequency mechanical resonance and causes a low mechanical Q or high internal damping, thereby greatly suppressing the resonance and permitting higher servo bandwidth.
A position command response of a servo loop incorporating the present invention is shown in FIGS. 4A and 4B. A pulse position command is provided to the loop as shown in FIG. 4A. The loop response is shown in FIG. 4B. The response reaches full amplitude in a short time due to the wider bandwidth and does not exhibit oscillatory behavior.
While there has been shown and described what is at present considered the preferred embodiments of the present invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the scope of the present invention as defined by the appended claims. | A wide bandwidth linear motor system suitable for high performance applications such as driving the tuning plunger of a magnetron oscillator. The linear motor includes a coil assembly with a structure which suppresses secondary resonances, thereby permitting the linear motor to be used in a wide bandwidth servo control loop. The coil assembly includes a cylindrical coil support, a bushing coaxial with the coil support for attachment to the linear motor shaft, a plurality of radial ribs connecting the coil support to the bushing and a coil having multiple turns wound circumferentially around the coil support. The coil support is subdivided by axial gaps into at least two separate coil support elements, each connected by a radial rib to the bushing. Resonance of the coil support and the coil is suppressed by the separate coil support elements and the lossy connection therebetween. | 7 |
BACKGROUND OF THE INVENTION
This invention relates generally to improved electronic switches, and specifically to those incorporating capacitive sensing technology, and to the manner in which an activation or operation event is defined.
In recent years, electronic products have increasingly incorporated intelligent switches to realize more functionality than a simple on/off action. One area where this is especially evident is in portable lighting products, such as headlamps, key-ring lights and torches, although certainly not limited to this field only. Due to inventions such as that contained in U.S. Pat. No. 6,249,089 to Bruwer, more and more products now have features previously only realizable with a more complex user interface. However, a large number of these implementations still make use of mechanical structures to make or break current, be it push buttons, tactile dome switches or large pole type structures. Such mechanical switches may suffer from a number of drawbacks. They can be prone to wear and tear. It can be costly to manufacture them in a robust/rugged manner which is immune to harsh environment use. To realize a waterproof product may require a dedicated flexible membrane over the mechanical switch, with all the associated challenges and cost implications.
Capacitive sensing technology has also increased in prevalence recently. One of the more evident fields of deployment is in mobile telephones and laptop computers. However, inherent to the technology is the possibility of inadvertent activation. This, coupled with the universal user requirement of haptic feedback on switch location, has possibly kept capacitive switches out of a large number of possible applications, notably the above mentioned fields of portable lighting and automotive controls. Only placing a typical capacitive sensing switch in a recess does not solve the problem of inadvertent activation satisfactorily. A user's clothing, or other dielectric objects, might penetrate the recess and activate the switch.
The invention disclosed hereafter purports to overcome the drawback of inadvertent activation, thereby allowing use of capacitive switching technology in fields heretofore unattractive for some reason, and to overcome some of the drawbacks of mechanical switches.
SUMMARY OF THE INVENTION
In its simplest form the present invention may be viewed as a capacitive sensing based electronic switch which incorporates an integrated circuit with processing ability, and that can only be activated or operated by a user action in a dedicated area. That is, switch activation/deactivation only occurs if more than one criteria are satisfied, with a capacitively sensed touch being at least one of the criteria, and timing plus sequence of sequentially sensed touches on different capacitive sensors or sensed channels being at least another, with circuitry integral to the switch performing processing of measured data and filtering according to the relevant criteria.
The present invention further comprises a user interface by which the user may select various operating modes or functions. Similar to intelligent switches of the prior art, disclosed in patents such as U.S. Pat. No. 6,490,089, U.S. Pat. No. 7,084,526 and U.S. Pat. No. 7,265,494 awarded to one of the present inventors, the user interface of the present invention may be defined by the electronic switch and the manner in which it is operated within a certain period of time. The circuitry integral to the embodiment of the present invention typically monitors the inherent capacitive sensing electrodes, and applies time and sensed capacitance based filtering algorithms to establish the intention or mode/function selection of the user, as described hereafter during disclosure.
A typical two channel Capacitive Swipe Switch (CSS) according the present invention monitors the sensed capacitance of the two channels. If the capacitance of only one channel changes significantly from the reference value, a possible swipe action detection algorithm may be started. (In capacitive sensing technology, a reference value is established by calculating the average of the measured capacitance over a certain period. This reference value is then used to compensate for environmental changes. The reference value is also known as the Long Term Average or LTA). To successfully detect and annunciate a swipe action, the capacitance change of the one channel typically needs to be accompanied by a specific, subsequent capacitance change at the other channel, within certain timing constraints. It is possible to realize two channel surface capacitive sensing or two channel projected capacitive sensing swipe switches according the present invention.
The number of capacitance sensing channels used to implement a CSS according the present invention need not be constrained to two. For instance, if three surface capacitance measurement channels are used, a swipe action may typically be identified by a first channel experiencing touch indicating capacitance change, followed by touch indicating capacitance change at the center channel and then at the third channel, all subject to certain timing criteria. The capacitance decrease at each channel may be accompanied by a capacitance increase at a subsequent channel in the perceived swipe direction. For instance, if a charge transfer sensing process is used in the afore-mentioned three surface channel CSS, the following should typically occur if a swipe is made from left to right. First, the counts of all channels should be proximate to the reference value. As the user touches the left-hand sensor, its counts may decrease correspondingly, while the center and right-hand sensor counts should remain relatively high. As the user moves his/her finger to the right, the counts of the center sensor may start to decrease, as the left-hand sensor counts increase. With the user finger over the center sensor, its counts should be at a minimum, indicating a touch, and if the structure is symmetric, the counts of the left- and right-hand sensors should equally deviate from the reference value. As the user finger moves toward the right-hand sensor, the counts for the center electrode should increase, and that of the right-hand sensor should decrease correspondingly. If the above sequence occurs within certain timing constraints, a swipe action may be annunciated. The timing constraints may determine the allowed range in speed over the sensors.
The above exemplary three sensor surface CSS may also be implemented with projected capacitance sensing technology, according the present invention, with the associated changes in capacitance and counts.
Proximity sensing may be used to identify the possible intention of a user to start a swiping action, and what the starting point and direction will be, according the present invention. As the user finger approaches one of the sensors of the CSS, the capacitance of the particular sensor should start to change well in advance of a physical contact event. With adequate sensitivity, this change may be used to sense user approach and activate visual, audible or haptic indicators to inform the user of the product status, and/or to wake the system from a standby or low power mode.
In step with the main goal of the present invention to prevent inadvertent activation, active driven shields or grounding may be used with the CSS. Grounding or active shield electrodes may be realized on both sides of the CSS, preventing inadvertent activation from a direction orthogonal to the preferred swipe directions. Alternatively, active driven shield or ground electrodes may be placed on all four sides of the CSS. This should demarcate the area wherein swipes will be accepted more effectively.
A further measure disclosed by the present invention to prevent inadvertent activation is to place the CSS within a recess or trough substantially lower than the surface of the product hosting it. To activate the CSS, a user has to place his/her finger within the recess and perform a swiping action within certain timing constraints. This should reduce the chances of inadvertent activation significantly, since contact with the flat surfaces of the product above the recess should not result in a contact detection hence lowering the probability of an accidental swipe activation dramatically.
Yet another method of the present invention to prevent inadvertent activation is to essentially combine two CSS's into one unit, and to test for simultaneous swipes in opposing directions, as typically obtained in a pinching movement by a user's fingers. For example, the user may place two of his/her fingers at the outer edges of the CSS, in a lengthwise sense. By moving his/her fingers simultaneously towards each other, two simultaneous swipes may be effected. For a surface capacitance implementation, the counts of subsequent sensors along the paths of the swipes should decrease to a minimum, followed by a return to the reference count value. If the CSS tests for the above, subject to certain timing requirements, a double swipe or pinching movement may be detected. The chances of illegal dielectric probes or material performing this action within the timing constraints should be very low, which improves immunity to inadvertent switch activation.
Since the present invention needs to maintain the functionality and intelligence of any prior art switches it might replace, a method is required to enter or program specific modes of operation for the product containing the CSS. It is proposed that this may be achieved by testing for a certain amount of complete swiping actions within a specific period, or for a specific delay between subsequent complete swiping actions, or for a specific swipe direction or for a combination of the three methods. In a further embodiment a user may swipe the recessed CSS to switch the hosting unit on, and then use simple touch gestures on any or a specific part of the CSS to step through available modes. A second swipe may be used to exit the mode selection. Alternatively, if a specific period elapses after the last touch or swipe action, the unit may automatically exit mode selection, requiring a new swipe to enter it again, or to switch it off. According the present disclosure, it may also be possible to use a specific swipe gesture made on the CSS to enter a setup mode for the product containing said CSS. Once in a setup mode, touches on any number of electrodes of the CSS may be used to select certain operating parameters for the product, which may then be stored in non-volatile memory. Once the setup mode is exited, in a manner as described above, the power to the product may be removed without loss of the setup stored in the memory.
In one embodiment of the present invention, dual loads (e.g. two types of light sources like spot/diffused or white/red) L 1 and L 2 may be controlled with one CSS. For example, from an OFF state, a swipe in a particular direction, for example Left to Right (LTR) will switch load 1 (L 1 ) ON. Further LTR swipes may result in different modes of L 1 being selected (dimming, flash, OFF etc). A swipe from Right to Left (RTL) at any time will typically result in L 1 being turned OFF. In a further embodiment a swipe LTR after a predetermined period (T 1 ) of inactivity on the switch (e.g. 1.5 seconds), will also result in an OFF condition.
To control load L 2 a user may, from an OFF state, perform a RTL swipe gesture over the same CSS, which may result in load 2 (L 2 ) being turned ON. Similar to the control for L 1 , further RTL swipes within the period T 1 may result in different operating modes of L 2 being selected. When load 2 is activated, a swipe from LTR at any time will result in L 2 being switched OFF.
Once either load is switched on with a LTR or RTL swipe, an extended period of touch within period T 1 (or any other period if so selected) on an electrode or on multiple electrodes of the switch may result in a gradual dimming function or other mode change being selected. For example, a touch on the left side may increase light intensity and a touch on the right side may dim the light output. In some embodiments a touch after a period where no switch activity occurred may result in no change in the function, status or condition of the product.
The above disclosed teaching of the present invention on swipe direction based control need not be constrained to dual loads, but may be applied to a single load as well (for example, but not limited to, a single LED light source). In such an embodiment of the present invention, a swipe in the LTR direction may control said single load in a manner similar to that disclosed above. However, a swipe in the RTL direction may then:
1. Be ignored to reduce probability of false activation. 2. Result in low power activation of load. 3. Result in flashing or emergency mode activation. 4. Activate an auto off mode, i.e. will switch off after a predetermined period of time, with or without an auto-off warning. In some embodiments a touch or proximity event detection in the period wherein or after the auto off warning was given will reset the auto off timing.
Further, if the above disclosure of dual load control with a single CSS according the present invention is embodied in a product such as a headlamp, the swipe switch activation mechanism may be indicated to the user with a dual direction arrow. And if L 1 is a white and L 2 is a red light, then half of the arrow in the direction required to switch L 1 on may be white in color and the other half of the arrow, in the direction required to switch L 2 on, may be red in order to clearly indicate the functionality to the user. A similar graphical guide may be used to indicate flashing functionality to the user, where the half arrow in the direction required to select a flashing mode may be broken. The concept is to use the directional designation to clearly indicate the function to the user in the arrows or at the end of the arrow.
The presently disclosed invention also teaches that unique locking and unlocking functions may be implemented with a CSS, as follows—after the device is turned OFF, (or for example ON then OFF) and the electrodes (or a specific electrode) is touched for an extended period or in a specific sequence (for example 1, 3, 2) the load will momentarily activate and then the product cannot be activated with the normal procedure. I.e. a more elaborate or secure activation procedure is required. To unlock an extended period of touch may be required on an electrode (or any electrode). This may be advantageous as the sleep time between measurements may be extended to improve (decrease) power consumption. That is, the capacitive measurement circuit may have a slower response time, thus reducing power consumption, and still detect the extended period of touch required for unlocking. The product may react with an indication to the user (for example a light source may flash) of the start of a time window after which a swipe action or actions within a predetermined period, and in a specific direction or directions is required to unlock the switch. A locking function as disclosed has advantages in terms of power consumption and guarding against unwanted activation whilst a product is packaged for example.
In another embodiment, if a sequence of electrode touches followed by a valid swipe is required to lock or unlock, they may be individually (in sequence) indicated with backlighting to guide the user. Locking and unlocking functionality as disclosed may find good application to various products such a personal products (e.g. toothbrush, shaver, hairdryers), head lamps, key chain lights, automotive interior lights, flash lights, home light switches, fans, cook tops or hubs, kettles, clothing irons and power tools. Incorporation of the disclosed locking and unlocking functionality in products where safety is a concern may prove especially advantageous.
Another possibility for application of the capacitive swipe switches according to the presently disclosed invention is in remote controls. For example a remote control may select between TV and audio, or may in fact have two swipe switches forming a cross, where the four directions each select a specific product or function. This configuration may be useful for other products and function selections as well.
Having a swiping action available as well as dedicated touches, the present invention may allow for realization of more intelligent switches than in the state of the art. In prior art, the only parameters from which to determine the user's intention were the switch state, the period between subsequent state changes, and the number of times a state change has occurred for a specific switch. By including the difference between a simple touch and a swipe, and the swipe direction, it is clear that significant options and interfacing capabilities may be added at very low cost.
For example, a CSS may be used in a product such as any toy, light (flash light, flash clip etc) or other consumer product to implement a demonstration mode. I.e. a function can be activated on a temporary basis when the product is in its packaging and when taken out of the packaging the normal functionality can be easily installed or activated. That is, only unlatched activation of a load for the duration of a touch on a sense electrode can be performed while the product is in its undamaged packaging used for distribution and sales. For example the commercial packaging (clam shell) may be such that only a single electrode can be touched, hence a swipe action cannot be completed by the user.
In the demonstration mode a touch may, for example, activate the LED of a flashlight or flash clip type product. When the touch is removed, the LED is switched OFF. However, when removed from the packaging, a first swipe action may restore normal activation (without requiring a touch to stay ON) and disable the demonstration mode.
As a CSS according the present invention is a capacitive or other form of sensing device, without any mechanically moving parts, it should to a large extent overcome the wear and tear drawback of traditional mechanical switches. Further, it should be possible to enclose the CSS completely within a fairly thick dielectric layer, significantly enhancing ruggedness at very low cost. Because no moving parts are required, waterproofing of products utilizing a CSS should become very simple.
Due to these enhancements, CSS technology disclosed by the present invention should find natural application in a large number of fields. The below examples are given in an exemplary manner, and should not be construed as limiting in any way.
In portable lighting devices such as key-ring lights and torches, a recessed CSS according the present invention may work well. By removing the requirement for a mechanical switch, which may require movement through the casing (using rubber or other soft membrane), the cost of product housings for these two and other applications may be significantly reduced, while increasing waterproofing, durability and ruggedness. If a CSS is used to replace the traditional pushbutton of a headlamp, a recess is not necessarily required, although it may offer further protection against accidental activation when the product is packed with other items, for instance in a backpack or suitcase. In addition, during normal headlamp operation, users typically want to adjust the beam angle of the headlamp. This may be done by gripping the headlamp between thumb and forefinger, and tilting the unit up or down. In such, and other, instances the addition of a blocking sense channel to the CSS might be beneficial. For instance, if the sensor of the blocking channel is placed where the user will place his/her thumb during headlamp adjustment, it may be used to alert the CSS that the present touch on the CSS is not a swipe attempt, and should be ignored. This is just an example of blocking channel use, and should not be considered to be limited to headlamps. The additional channel may just as easily be used as an enabling channel. For example, a key-ring light may have a sensor on the opposite side of the swipe sensors. As the key-ring light or flash clip is typically touched on both sides when activated, a touch on one side may be a requirement for a swipe detection and annunciation.
In the application of the present invention to portable lighting products, capacitive sensing may be utilized to determine the manner in which the product is being held, or worn, and adjust functionality accordingly. For instance, capacitive sensing may be utilized to determine whether a user is wearing a headlamp on his/her head. If this is found to be the case, the Battery Power Monitor (BPM) functionality of the headlamp may be adjusted to provide an indication of remaining battery power by flashing the main light of the headlamp in a specific manner, as opposed to activation of BPM indicators situated on the body of the headlamp, as is often done in prior art headlamps. By flashing the main light of the headlamp, the user is provided with visual BPM feedback which does not require removal of the headlamp to view it, unlike the traditional BPM indicators contained on the body of headlamp.
Another application of the technique disclosed above may be found in portable music players used while exercising. By capacitively sensing that the player is, for example, strapped to the user's arm, or hip, audible feedback may be provided to the user as he or she operates the device, negating the requirement for the user to look at the display of the device, which may be impractical or distracting while exercising. For example, this may enable rapid selection of a preferred song or setting, without having to listen to short sections of music before a selection can be made.
Another advantage of a recessed CSS is that it may provide a haptic indication to a user attempting to find the switch while wearing thick gloves, often the case in outdoor environments. In headlamp applications, such haptic feedback may be also be provided by placing the electrodes of the CSS underneath the edge formed where slanting and horizontal or vertical outer surfaces join. Alternatively, the CSS electrodes may be placed within the headband of the headlamp, requiring the user to make swipes over the headband material, as not much haptic sensitivity is required to differentiate between the body of a headlamp, and the headband.
The present invention may also be deployed in automotive applications. For example, a recessed CSS according the present invention may work well to replace the traditional mechanical switches used to control window height. Normal capacitive sensing switches are typically not used for this application, since window control buttons are typically contained within door handles or arm rests, and inadvertent activation by the user's arm is likely. In addition to improving durability, waterproofing and increased immunity to inadvertent activation, a recessed CSS according the present invention may also improve ease of use and functionality. For example, if the user wants to lower the window, a light swiping action, which may require very little exerted force, may start the action. Once the window is at the preferred height, a second swipe or touch may halt window descent. Alternatively, the user may swipe and hold his/her finger on the CSS, and the window descent may be halted when the user removes his/her finger. Or the user may start with two brief swipes to lower the window completely. This method of operation may also apply to raising the window, with the controller keeping track of the window position. Alternatively, a swipe in a direction may start the window in a direction (up/down), and then a touch on a specific sensor may cause further movement in a specific direction. It should be noted that the above exemplary embodiment where a user swipes and holds his/her finger, and then removes it after a certain time to lower or raise a window to a specific point is similar to a scroll gesture performed with a user input device such as a computer mouse, where a user clicks, drags and releases, and the teachings of the present invention are not limited to control of an automobile's window height. For example, such a swipe, prolonged touch and release gesture may also be performed on a small button, on the order of 6 mm by 6 mm, and which contains a CSS with only two or three electrodes per dimension (for e.g. up/down), to perform a scrolling function which may be used to navigate through a list of items displayed by a mobile electronic device. Said CSS may further be used to determine any or all of the following: direction of a swipe, speed of a swipe, length of a swipe and repetition rate of swipes
In automotive window controls, the arm rest or another surface close to the driver often contains switches to control all of the windows in the vehicle. According the presently disclosed invention, this large number of mechanical switches, typically expensive, may be replaced with a single CSS unit, which may be recessed, and a number of recessed single channel touch switches. The single channel touch switches may or may not use actively driven shields that may be situated on the upper surface of the material into which said touch switches are recessed, or areas of conductive material which are grounded. Due to their recessed nature, and the possibility of actively driven shields, or grounded material, guarding them, the chances of inadvertent activation of said single channel touch switches should be fairly small. But even if they are inadvertently activated, no window repositioning should result, as will become clear from the following disclosure of typical operation. To lower a specific window, a user may activate the corresponding single channel touch switch by inserting his/her finger into the recess. This typically needs to be followed by a swiping action on said CSS unit within a specific period. The swiping action may be used to confirm the touch on the single touch switch, and that a window repositioning needs to be done, or it may be used as confirmation and for a complete window repositioning in the direction indicated by the swiping action. E.g. if the swiping action was in a first direction, the window may be completely lowered, and if the swiping action was in a second direction, in opposition of the first direction, the window may be completely raised. In another exemplary instance, the swiping action may be followed by a partial swipe, or touch to the corresponding single touch switch, to lower or raise the window. Once the user moves his/her finger away from the CSS or single touch switch, the window repositioning is terminated. According to the present invention, it may be possible to realize the above disclosed control of automobile window position using surface capacitance sensing, projected capacitance sensing, a combination of surface and projected capacitance sensing, charge transfer based measurements, other capacitive sensing techniques or other sensor technologies, such as IR sensing, piezoelectric sensors, heat sensors etc. Further, a large number of operational combinations with touches on said single sensors and touches or swipes on said swipe action based switch is possible that still fall within the scope of the presently disclosed invention.
It may further be possible to realize simple touch switches which utilize specific recess characteristics to prevent inadvertent activation, according the present invention. For example, if two surface capacitance electrodes are placed in an oval recess which is formed in such a manner that the electrodes are covered by the lip of the recess, with actively driven shields, or grounded conductive material, that may or may not be placed on the outer surface of the material which contains the recess, inadvertent activation may become very difficult. To activate the switch via either of the two channels, the engaging probe need not only be inserted vertically into the recess, but also angled to engage the respective electrode underneath the lip of the recess. The chances of illegal material or probes performing this action should be quite small. The above disclosed two channel recessed switch may be used effectively in the control of automotive vehicle window height. To lower a specific window, the user inserts applies his/her finger into the corresponding recess, and for example angles it backwards and apply pressure with his/her fingertip onto the area underneath the recess lip that contain the first electrode. To raise said window, the user will typically insert his/her finger into said recess, angle it forwards and apply pressure with his/her fingertip onto the area containing the second electrode. Due to the actively driven shield, or grounded, material on the outer surface of the material containing the recess, the user may engage said outer surface without activation of the touch switch. Further, according to the present invention, a blocking electrode may be placed in the center of the recess, at its lowest point. If a user inserts his/her finger, or another legal probe, vertically into said recess, the blocking electrode is engaged, and any change in window height is not permitted. If the user angles his/her finger forwards or backwards, the blocking electrode is not engaged anymore, and window height may be changed, depending on which of the two electrodes situated underneath the overhanging lips of the recess is engaged. The preceding disclosure may work well to replace prior art mechanical switches typically contained in vehicle arm rests. The above example is purely provided for illustration, and should not be considered as limiting. Other implementations, for instance using projective capacitance sensors, or other sensing technologies, or other recess shapes, are possible according the present invention.
In yet another embodiment of the invention being presently disclosed, use may be made of a single channel capacitive sensor, or a sensor based on another technology, in a simple recess to form an electronic switch for a product which may have high immunity to inadvertent activation. Active driven shields, or grounded conducted material, may or may not be used on the surface of the material in which the recess exists. To operate said switch, the user needs to insert an engaging probe, which may or may not be his/her finger, or another member, into said recess, and physically contact or be in close proximity to the electrode of said single channel sensor for a sufficient period. Such an embodiment may find good application for example in an automotive vehicle, and specifically to operate the interior light often situated on the ceiling of the vehicle's roof. Typically, a user needs to reach backwards with his/her hand to operate said interior lights of the prior art. If the user is the driver of the vehicle, and struggles to find the mechanical switch of prior art interior lights, this may cause distraction, with road safety implications. An interior light utilizing an electronic switch with a single channel sensor within a simple recess, as disclosed, may assist the user with improved haptic feedback, as recess may be more easily identifiable by touch alone. Further, it may be possible to use proximity sensing to visually indicate said interior light, or other devices containing such a recessed switch, to users other than the driver of said vehicle.
Other automotive CSS applications that come to mind, in no limiting manner whatsoever, are control of interior lights, audio visual controls and GPS controls. All of these automotive applications are not critical controls, but should they malfunction due to inadvertent activation could distract drivers, with possible fatal consequences. To a certain extent, recessed CSS's should therefore improve the state of the art of automotive safety. For instance, it may be easier to accidentally bump a mechanical audio control to a maximum setting with a waving/moving hand, than to swipe a recessed CSS in specific manner, or repeat a number of swipes, to achieve the same result. The CSS type operation may also be employed specifically for speed control, audio system control and other controls typically found on a vehicle steering wheel.
All of the above automotive applications may also benefit from the inherent waterproofing of a CSS according the present invention, as it could be easier to clean and easier to manufacture.
Capacitive Swipe Switches according to the present invention may also be incorporated in consumer products such as electrical toothbrushes, shavers, toys, hair dryers, kitchen appliances, washing machines and fridges. All of these are listed in an exemplary manner, and the list should by no means be seen as exhaustive or limiting. For instance, in a hair-dryer, a CSS may be used to increase safety. If a normal capacitive switch is used, a small child might operate the hair drier by mistake, and cause damage or injury. However, if a recessed CSS is employed that requires a very specific sequence of swipes, the chances of a child recreating this sequence by mistake may be small.
Electrical toothbrushes and shavers may not only benefit from the inherent waterproofing of a CSS according to the present invention, but also from the reduced risk of inadvertent activation when the units are transported etc.
Another potential application field for CSS may be extremely low cost digital music players. To date, these have employed push-button or prior art capacitive sensing switches. As such, to enable the user to carry the unit in his/her pocket or bag without inadvertent activation, a dedicated key-locking mechanism may be required. If CSS's are employed in such devices, having dedicated key-locking mechanisms may become obsolete, resulting in a simpler implementation and lower possible cost.
Yet another possible application of a CSS according to the present invention is in small form factor mains power supply units, such as those typically used to charge portable devices, for instance, but not limited to, mobile telephones, digital cameras, laptop computers, e-book readers etc. Often, users may leave the power supplies plugged into a multi-plug mains socket after removing their fully charged portable device. But due to other devices still plugged into the multi-socket, the wall switch may not be set to the off position. This may result in the power supply wasting power unnecessarily in a standby condition. Alternatively, users may plug their power supplies out to avoid wasting power in standby. However, this may require going through the trouble of finding the correct power supply and plugging it in again if the specific portable device needs to be recharged. If Capacitive Swipe Switches are incorporated into such small form factor portable mains power supplies, users may easily and safely switch the power supply into an extremely low power state once the portable device has been fully charged and unplugged. Further, due to the inherent isolation of a CSS, it may be possible to add a programmable user interface at low cost to small form factor mains power supplies, which may improve their user friendliness, safety and efficiency.
The present invention further teaches the use of specific surface patterns for the dielectric used as isolation between the touching object, typically a user's finger, and the capacitive electrodes inherent to the electronic switches presently being disclosed. These surface patterns may be used to improve user guidance, provide haptic feedback and decrease the risk of inadvertent activation. In a first exemplary embodiment, the pattern typically consists of a plurality of ridges, possibly rounded on top, with height much smaller than the typical width of a user's finger, said ridges traversing the length of the CSS in a direction parallel to the required swiping direction, and spaced apart over the capacitive electrodes in a direction orthogonal to the required swipe direction. The plurality of ridges that lie parallel to the required swipe direction may be combined with a plurality of ridges on both sides which are diagonal to the required swiping direction, and of which the diagonal angles are opposing, to form the disclosed pattern. The diagonal ridges have sides which may be slanted when approached in a direction similar to the required swiping direction, and which are essentially vertical when approached in a dissimilar direction. It is also within the scope of the present invention to possibly make said diagonal ridges higher than the parallel ridges, and let the height of the diagonal ridges decrease towards the parallel ridges, thereby possibly forming a guiding slope towards the parallel ridges. The surface pattern as described above should intuitively guide a user to the location of the CSS, and the required swiping direction. If a user swipes his/her finger in a direction dissimilar to the required swiping direction, the diagonal ridges should provide increased impediment to the action, due to their diagonal angle and encountered vertical sides.
In a second exemplary embodiment of the disclosed surface patterns, the center of the CSS, in a lengthwise sense, is marked by change in the angle of the diagonal ridges of typically ninety degrees or more. This change occurs simultaneously on both sides of the CSS and the parallel ridges. Therefore a user may be assisted in determination of the center pint of the CSS via tactile feedback. This may be helpful if the user needs to activate specific touch electrodes, but do not have visual feedback to place his/her fingers in an exact manner.
A third exemplary embodiment of dielectric surface patterns, as disclosed by the present invention, comprises the use of elevated ridges which flare at both lengthwise ends of the CSS. These ridges form a funnel like structure at the entry and exit points for the CSS. In addition, their height may slowly increase from their distant ends to a maximum point in juxtaposition with the first/last capacitive electrodes. This is accompanied, in a width sense, by a sharply angled slope on the inner side which faces the capacitive electrodes, and a low angled slope on the opposing, outer sides. If a user finger approaches the CSS with such a surface pattern arrangement, it may be guided in an intuitive way to the required swipe location, and possibly direction.
In yet a fourth exemplary embodiment of dielectric surface patterns to enhance Capacitive Swipe Switches, according to the present invention, a CSS and surface pattern may be realized which comprise a 180 degree direction reversal. A plurality of ridges which lie parallel to the required swiping direction are enclosed on both sides by ridges which are diagonal to the required swiping direction, as disclosed above. However, the required swiping direction changes by 180 degrees along the course of the CSS. The parallel and diagonal ridges also reflect this direction change, thereby guiding the user's finger along the required swipe path. Such a direction reversal in the required swiping action should substantially improve the immunity of the CSS to inadvertent activation.
Another exemplary embodiment of the present invention utilizes the above disclosed guided direction reversal in conjunction with four or more capacitive sensing channels and ridge patterns in the surface of the dielectric between the engaging probe, which may be a user's finger, and the sensing electrodes. Such an embodiment may enable the realization of two of more secondary, independent CSS units within a primary CSS unit that contains four or more sensing channels. The ridge patterns, similar to that disclosed in the previous discourse, guide the engaging probe, which may be a user's finger, along a path which experiences a full or partial reversal in direction. Should the engaging probe form a complete swiping action, or other required action, along the required path, including full or partial reversal in direction, the two or more secondary CSS units may be unlocked or enabled for operation. The user may then use an engaging probe, which may be his/her finger, to operate each of the secondary CSS units independently, in a manner similar to that disclosed earlier by this application. A second activation of the primary CSS, along the required direction reversal path, guided by said surface ridge patterns, may be used to disable or lock the secondary CCS units. Many other implementations similar to the immediately disclosed exemplary embodiment may be possible according to the presently disclosed invention, for instance, but not limited to, using other sensing technologies or more sensing channels, or other geometric patterns and required direction changes.
In yet another exemplary embodiment of the presently disclosed invention, a mobile telephone's on-ear detection capacitive sensing electrodes are replaced with a CSS, as taught in the preceding discourse. Typically, such on-ear detection capacitive sensing electrodes are used to detect when a user places his/her mobile telephone against his/her ear after answering a call. Once said placement has been detected, the visual interface of the telephone may be turned off, to conserve power, as it is generally not possible for a user to view the visual interface while the phone is close to his/her ear. Or the on-ear detection may be used to ignore inputs to the user interface while the phone is placed on or close to the user's ear. However, by replacing the traditional on-ear capacitive sensing electrodes in a mobile phone with a CSS, as taught by the present invention, an advantageous integration of functionalities may be realized. Most state of the art mobile telephones have some sort of method or mechanism by which to lock the user interface of said telephones. In such a locked state, all or most inputs to said interface is ignored, to avoid unintended activation of phone functions, for example while being carried in a user's pocket, or bag. Said mechanisms or methods include pressing a specific sequence of buttons, dragging an icon on a touchscreen to a specific location or executing a previously registered gesture on a touchscreen. Although these work well, they exhibit some drawbacks, for instance it may be difficult for the user to remember said sequence of button presses, and the display of an icon consumes additional power. By integrating the functions of on-ear detection and a locking/unlocking mechanism, through the use of a CSS, the user only has to remember to make a swipe movement at a location close to the speaker of the phone, and due to the extremely low power consumed by typical CSS Implementations, very little power may be consumed to test for possible unlocking events while the mobile telephone is in a locked state. Further, by placing one of the electrodes of the CSS closer to a specific area of the telephone, for instance closer to the touchscreen, if employed, it may be possible to prevent inadvertent activation of the locking/unlocking functionality during normal telephone use, by using said electrode as a blocking electrode. That is, if a specific change in measured capacitance only occurs for the blocking electrode, and not for the other electrodes of the CSS, a change in the logic state of the CSS output is prohibited.
As briefly discussed earlier, the present invention teaches that a small CSS based button may be realized, with typical surface area on the order of 6 mm by 6 mm. Such a button may use only two or three electrodes per dimension (for e.g. up/down) and capacitance measurements, for example, but not limited to, surface capacitance or mutual capacitance measurements, to detect and validate user swipe gestures, to determine the direction of a swipe, to determine speed of a swipe, to determine length of a swipe, to determine repetition rate of swipes, to detect user proximity gestures, to detect user touch gestures which are essentially static in location and exert less than a specific predetermined minimum pressure, and to detect user touch gestures which are essentially static in location but exert pressure equal to or more than a predetermined minimum value. Further, the present invention teaches that a conventional electrical contact make/break means or a capacitance measurement may be used to detect said user gestures which exert more than a minimum pressure, and that tactile feedback may be provided upon occurrence of such gestures, similar to a click experienced with conventional snap dome electromechanical buttons. The present invention further teaches that said CSS used in said button may have sufficient resolution, while employing a minimum number of capacitance sensing electrode structures, to detect capacitance changes due to the ridges and valleys of a user's fingerprint. The teachings of the invention disclosed in provisional filing ZA 2012/05814, titled “Fingerprint based capacitive motion sensor” by the present inventor, and hereby incorporated in its entirety, may be used to realize such a CSS based button which can discern motion of fingerprint ridges and valleys.
According to the present invention, it is envisaged that a small CSS button as disclosed above may be used on a mobile phone, with said button located on the side of said mobile phone, for example. To adjust volume up or down during a call, a user may simply swipe his/her finger over said CSS button. So select a particular function, for example to end a call, the user may depress said CSS button with more a predetermined minimum pressure until tactile feedback similar to a click is received. In addition, said CSS button may be used to scroll through a list of displayed items by performing a partial swipe gesture, and pausing on the CSS button with a prolonged touch. Once a preferred item or location in said list is reached, the user may simply press said CSS button with more than a predetermined pressure to select. Alternatively, a user may navigate a displayed list of items by a number of consecutive swipes, within a certain period, in a particular direction. The present invention further teaches that said user may use a number of consecutive swipes in a particular direction to control movement of a displayed cursor or pointer, wherein each detected swipe results in a step by said cursor or pointer in the direction of said detected swipe. Tap and double tap gestures may also be used, according the present invention, to select displayed items that was highlighted on the screen using the electronic capacitive swipe switch. In fact, a rich collection of user interfacing gestures may be facilitated by a CSS button as disclosed by the present invention, given the possible combinations of a simple touch, a valid swipe in one or the other direction, taps, double taps and gestures with more than a predetermined minimum pressure. Naturally, application of a CSS button as disclosed is not limited to mobile phones, but may be advantageously applied to a large number of other products, for example tablet and laptop computers, e-readers, white goods such as washing machines, fridges, audio-visual systems and others, according to the present invention.
The above disclosure has been made in an effort to fully describe the invention at hand, and should not be seen, construed or interpreted as limiting in any manner whatsoever. As will be evident to those of normal skill in the arts affected by the present invention, other embodiments may be possible that still fall within the scope and spirit of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is further described by way of examples with reference to the accompanying drawings in which:
FIG. 1 shows a prior art headlamp incorporating an intelligent switch based on a mechanical pushbutton.
FIG. 2 shows a prior art key-ring light incorporating an intelligent switch based on a mechanical pushbutton.
FIG. 3 shows a prior art projected capacitive switch.
FIG. 4 shows an electrode arrangement and the typical measured capacitance for a two channel surface CSS according to the present invention.
FIG. 5 shows an electrode arrangement and the typical measured capacitance for a three channel surface CSS according to the present invention.
FIG. 6 shows recessed CSS electrode arrangement according to the present invention.
FIG. 7 shows shielding for the electrodes of a CSS according to the present invention.
FIG. 8 shows a recessed CSS according to the present invention used in exemplary manner in a key-ring light.
FIG. 9 shows a CSS with a blocking channel, according to the present invention, used in exemplary manner in a headlamp, as well as the typical use of shielding electrodes. It also illustrates dual loads that may be controlled with one CSS.
FIG. 10 shows a recessed CSS according to the present invention used in exemplary manner to control window height in an automobile.
FIG. 11 shows a prior art low cost digital music player that uses mechanical buttons, and a digital music player incorporating Capacitive Swipe Switches according to the present invention.
FIG. 12 shows the electrode arrangement and typical measured capacitance for a CSS that tests for simultaneous swipe actions in opposing directions to reduce the chance of inadvertent activation.
FIG. 13 shows exemplary dielectric surface pattern details, to guide the user of the CSS, according to the present invention.
FIG. 14 shows another exemplary dielectric surface pattern according to the present invention, which may be used to guide a CSS user, with an angle reversal for the diagonal ridges at the lengthwise center point, indicating relative finger position to the user.
FIG. 15 shows the use of elevated ridges which flare in a funneling manner to guide users towards the CSS, and the correct swiping location, according to the present invention.
FIG. 16 shows how surface dielectric patterns may be used according to the present invention to guide a user of a CSS which have a 180 degree direction reversal, for increased immunity to inadvertent activation.
FIG. 17 shows the exemplary use of a four channel surface capacitance CSS with dielectric surface patterns to guide a user along a reversal in required swiping direction, and the realization of two independent two channel CSS units, according to the present invention.
FIG. 18 shows the exemplary use of a recessed CSS and five touch switches to control a vehicle's window position, according to the present invention.
FIG. 19 shows the exemplary use of active driven shields and overhanging material to realize intelligent capacitive sensing based electronic switches with blocking electrodes for control of a vehicle's window position, according to the present invention.
FIG. 20 shows an exemplary electronic switch according to the present invention that utilize a single channel capacitive sensor within a simple recess to improve immunity against inadvertent activation.
FIG. 21 shows an exemplary CSS according to the present invention along with various functionality indications which may be used on the body of products, or elsewhere, to clarify use.
FIG. 22 shows an exemplary embodiment of the present invention in a head lamp, where the CSS is placed in the elastic headband, as well as the use of dual loads and BPM indicators.
FIG. 23 shows exemplary use of edges in a product housing to provide haptic indication of CSS location to a user.
FIG. 24 shows the exemplary use of a CSS to facilitate the function of on-ear detection in conjunction with a user interface locking/unlocking function.
FIG. 25 shows an exemplary embodiment of a CSS button on a mobile phone.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIGS. 1 and 2 show a typical headlamp ( 1 ) and key-ring switch ( 5 ) according to the prior art. As mentioned above, these may typically employ mechanical switches ( 2 ) and ( 4 ) to facilitate user interfaces, with the stated drawbacks and challenges. It should be noted that prior art mechanical switches may also be prone to inadvertent activations, for instance when the unit is carried in user's trouser pocket, or in a backpack.
FIG. 3 illustrate a typical capacitive switch of the prior art, in this case using projected, or mutual capacitance measurements. If electrode ( 9 ) is a transmitter, and electrode ( 10 ) is a receiver electrode, both covered by dielectric material ( 8 ) and supported by substrate ( 7 ), electric field patterns may typically be as illustrated by ( 11 ). As the user finger ( 12 ) approaches the electrode pair, it should perturb the electric field patterns, resulting in reduced coupling and measured capacitance. This is illustrated by the bar graph of FIG. 3 . When using the structure as a switch, a threshold has to be set. If the sensed capacitance falls below the threshold, a touch action may be deemed to have occurred. Even with sophisticated software and signal processing, such switches of the prior art may be prone to inadvertent activation, as it may be difficult for the switch to discern whether it is a user's finger or an illegal object perturbing the field pattern. It is may also be impossible for the switch to discern if the user's finger touched with the purpose of activating the switch, or just in the course of handling the product. Surface capacitive switches of the prior art may suffer from the same drawback.
FIG. 4 illustrates the typical electrode arrangement and measured capacitance for a CSS according to the present invention. The illustrated embodiment is for a two channel, surface (or self) capacitance structure using a charge transfer measurement process, as is well known to those skilled in the art of capacitive sensing. This should not serve as limiting, as two channel projected (or mutual) capacitance structures, and other implementations of capacitive measurements (e.g. relaxation oscillators), or other sensing methods may also be used according the present invention. Electrodes ( 13 ) and ( 14 ) may be juxtaposed on the surface of the hosting device, along a line typically defined by the preferred swiping direction. Electrodes ( 13 ) and ( 14 ) may, or may not, be covered by a dielectric material. If a user places his/her finger in area ( 15 ), central to the line running through both electrodes ( 13 ) and ( 14 ), the counts for electrodes ( 13 ) and electrodes ( 14 ) should remain unaltered proximate to the reference value, as illustrated. However, as the user begins a swiping action toward electrode ( 13 ), the counts for electrode ( 13 ) should start to decrease, with the counts for electrode ( 14 ) remaining largely unaltered. If the user finger reaches area ( 16 ), the counts for electrode ( 13 ) should be at a minimum, and those for electrode ( 14 ) should still be more or less unaffected. As the user finger moves towards the center of the CSS structure, the counts for electrode ( 13 ) should start to increase again. In conjunction, if the lengthwise spacing between the electrodes is small enough, the counts of electrode ( 14 ) may start to decrease. Otherwise, counts for electrode ( 14 ) may stay roughly unaltered with reference to the LTA value. With a small enough spacing, the counts for both electrodes ( 13 ) and ( 14 ) should be at an intermediate level if the user's finger is in area ( 17 ), as shown. Continuing the swiping action towards the right, the user's finger will next be across area ( 18 ), which should result in counts for electrode ( 13 ) to be proximate to the reference value, and that for electrode ( 14 ) at a minimum. Once the user's finger reaches area ( 19 ), the counts for both electrodes should be proximate to the reference value, and the swiping action is complete.
According to the present invention, a swipe/switch activation event will only be annunciated if the above sequence fulfils specific timing and other criteria. For instance, a minimum period may be set within which the whole sequence must be completed. Or it may be required that the user pause in the center, resulting in intermediate count levels to be detected for a minimum time, followed by a decrease in counts for electrode ( 14 ). Or the filtering algorithm may be set-up to two requires two fast swipes to the right, followed by a slow swipe to the left before a swipe/switch activation event will be annunciated. Various other filtering algorithms may be contrived using swipe speed and direction, all covered by the presently disclosed invention.
FIG. 5 illustrates the typical electrode arrangement and measured capacitance for a three channel CSS according to the present invention, utilizing surface (or self) capacitance sensing. This embodiment is purely exemplary, and not limiting, as projected (or mutual) capacitance sensing embodiments according to the presently disclosed invention may be possible, as well as embodiments using more than three channels or sensors. The embodiment of FIG. 5 not only differs from that of FIG. 4 in the number of channels, but also in the spacing between electrodes. Electrodes ( 20 ), ( 21 ) and ( 22 ) may be spaced far enough from each other to incorporate “dead zones” between them. If a user finger is in proximity to these zones, the counts for the electrodes may be similar to that measured when no finger is present. Operation of the CSS in FIG. 5 is similar to that described above for FIG. 4 , with the difference of the dead zones and the number of channels/sensors. Incorporation of the dead zones may allow a binary representation of the channel status, with a “0” representing a count value below a certain threshold, and proximity of the user's finger, and a “1” representing a count value above an upper threshold, proximate to the reference value, and the absence of the user's finger. In this manner, if a finger swipes from region ( 23 ) via regions ( 24 ), ( 25 ), ( 26 ), ( 27 ) and ( 28 ) to region ( 29 ), the resulting data train should be 111, 011, 111, 101, 111, 110 and 111. This may greatly simplify the realization of filtering algorithms in software.
The CSS structures presented in FIGS. 4 and 5 , and others according to the presently disclosed invention, may be used to facilitate intelligent user interfaces, and selection of various operating modes, similar to intelligent switches of the prior art. However, one of the benefits of the present invention is that it may offer far more parameters with which to select modes and interface to the user. As mentioned above, the manner in which a swipe event is detected and declared may be made dependent on parameters such as swipe time, pauses, direction and repetition. In addition, one may use a swipe event just to enter a mode selection mode. In this mode, each sensor or channel may be assigned to a specific function or mode. If parameters such as periods between subsequent touches on different channels, or the number of times a specific channel is touched within a specific period are added, it becomes clear that a CSS may potentially be used to realize quite complex programming features, and select between a large number possible modes.
FIG. 6 illustrates a further method according to the present invention which may be used to avoid inadvertent activation. If the CSS electrodes, in this case consisting of surface electrodes ( 30 ) and ( 31 ), are placed within a recess ( 32 ) formed in supporting substrate ( 33 ), immunity to inadvertent activation may be increased. To activate the CSS, a dielectric probe not only has to perform a swiping action that satisfy the filtering algorithms employed, but also have to penetrate recess ( 32 ) for the duration of the swiping action. It is envisaged, in no limiting fashion, that this might be especially effective in applications such as key-ring lights.
To further improve immunity to inadvertent activation, the presently disclosed invention teaches that shielding electrodes may be employed, as illustrated in exemplary manner in FIG. 7 for the electrodes of a two channel CSS ( 38 ). Shielding electrodes ( 34 ), ( 35 ), ( 36 ) and ( 37 ) may, dependent on the shielding requirement, be connected to system ground or to actively driven shield channels, as is known to those skilled in the art of capacitive sensing. If shielding from dielectric objects to the sides of electrodes ( 39 ) and ( 40 ) is required, only electrodes ( 34 ) and ( 35 ) may be used. For shielding against dielectric objects present at the lengthwise extremities of the swiping area, electrodes ( 36 ) and ( 37 ) may be used. If all four shielding electrodes are used, substantial shielding from dielectric objects outside the direct boundary of the CSS may be achieved. Naturally, connection of the shield electrodes to system ground may result in reduced touch sensitivity, as electrodes ( 39 ) and ( 40 ) may then couple strongly to these electrodes.
FIG. 8 illustrates incorporation of a CSS according to the presently disclosed invention into a key-ring light ( 41 ). By placing two surface capacitance sensing electrodes ( 45 ) and ( 46 ) into a recess ( 44 ), wide enough to accommodate a user's finger, and using filtering algorithms to detect a swiping action, a CSS may be realized by which the light output of light source ( 42 ), typically, but not limited to, an LED, may be controlled. Such an implementation may facilitate lower cost, better waterproofing, more durability and a smaller chance for inadvertent activation, as noted previously in this disclosure. In one embodiment, the user may use a swiping action from electrode ( 45 ) to electrode ( 46 ), or vice versa, to switch the light output from zero to maximum, or vice versa. Or a number of swipes may be used to select between various light output levels, or pulsed light options. Another embodiment may use a single swipe action to change the key-ring light mode from non-responsive to a mode where a touch on either electrode ( 45 ) or ( 46 ) can select between various light output levels and sequences. The embodiment illustrated by FIG. 8 should serve purely as an example embodiment, and is by no means limiting. For instance, projective capacitance sensing technology may be used, or three or more channels, or shielding electrodes etc.
An embodiment of the present invention in a headlamp is illustrated by FIG. 9 in an exemplary manner. The output of light source ( 48 a ), typically, but not limited to, an LED, may be controlled by CSS ( 49 ), in this case a three channel, surface capacitance sensing unit. Shielding electrodes ( 47 ) may assist to decrease the chances of inadvertent activation of the CSS. To allow the user to grip the headlamp between thumb and forefinger without accidental or inadvertent switching, a blocking channel and electrode ( 50 ) may be provided. If a touch is sensed on blocking electrode ( 50 ), the CSS may enter a non-responsive mode which may last until the touch on blocking electrode ( 50 ) is removed. This may allow the user to grip the headlamp and adjust the light beam angle by tilting the unit up or down, for example. Another embodiment may be to use the blocking electrode ( 50 ) not only to block out touches, but to select between various modes, if preceded by a swipe action on CSS ( 49 ) within a specific maximum period. The embodiment illustrated by FIG. 9 is once again purely exemplary, and not limiting, with various other headlamp embodiments that fall under the teachings of the presently disclosed invention possible.
For the exemplary embodiment presented in FIG. 9 , the present invention further teaches that multiple light sources, for instance ( 48 a ), ( 48 b ) and ( 48 c ) may be controlled with a single CSS ( 49 ). For example, to control the main light source ( 48 a ) from an off-state, the user may execute a swipe gesture from right to left (RTL) on CSS ( 49 ), followed by any number of swipe gestures RTL or left to right (LTR), or specific touch gestures on the various electrodes of the CSS within a pre-determined period, depending on the setup of the device. Conversely, to control the secondary light sources ( 48 b ) and ( 48 c ) from an off-state, the user may execute a swipe gesture from LTR, followed by any number of LTR or RTL swipe gestures, or touches on the electrodes of CSS ( 49 ) within a pre-determined period. Naturally, the above disclosure is purely exemplary, and should not be seen as limiting, as a large number of swipe gesture and touch combinations may be used in conjunction with timing constraints to control multiple light sources. It also stands to reason that the use of one CSS to control multiple loads as disclosed is not just limited to lighting loads, but may be applied to the control of a large number of electrical loads, for example audio and visual loads, electrical machine control, heating and cooling control etc.
FIG. 10 depicts an embodiment of the present invention in the control module for a vehicle's electric windows. Typically, the controls to lower/raise the window ( 52 ) of a vehicle door ( 51 ) down/up may be contained within the arm rest ( 53 ) of said door. As such, the driver or passenger arm or hand may be prone to often make physical contact with the controls. If capacitive sensors held by the prior art are used as user interface for the controls, the chances of inadvertent activation may therefore be quite high. However, a recessed CSS ( 54 ) as illustrated may reduce this risk significantly. To lower/raise the window, a user needs to place his/her finger within the recess of CSS ( 54 ), and perform a swiping action. This may start the window movement. To further control or stop window movement, a large number of actions may be performed that fall within the present invention. For example, the user may perform a second swiping action, or use individual touches, or pause in the process of making a swipe etc. All of these are exemplary. It may be possible to realize other embodiments of CSS based vehicle electric window control according the teachings of the presently disclosed invention.
Yet another embodiment of the present invention is shown by FIG. 11 . The present state of the art holds low cost digital music players similar to ( 55 ) shown on the left of FIG. 11 . Typically, these may employ traditional mechanical buttons ( 56 ), or prior art touch switches, with all the drawbacks set out in the previous discourse. A USB or other type of connector ( 59 ) may typically be provided to load digital music data onto the player. Audio output may be provided at a jack, typically for connection to earphones ( 57 ). The right hand side of FIG. 11 shows an embodiment of the present invention into such a low cost digital music player, with the traditional buttons replaced by CSS's ( 60 ), ( 61 ) and ( 62 ). For fast forward or rewinding operations, the swipe direction may suffice to start the operation, with a tap halting it. A further tap may result in reverting to the prior action (fast forward/rewind) or another action. Two taps in quick succession during a fast forward or rewind operation may be used to increase the speed or tempo.
FIG. 12 shows another CSS embodiment of the present invention which may be used to further improve immunity against inadvertent activations. The embodiment illustrated uses four surface capacitance sensors or channels. To declare a switch activation, the embodiment requires that simultaneous swipes be made by two fingers, in opposing directions. This may be achieved by, for example, a pinching movement. For instance, if a user places his/her middle finger ( 63 ) at position ( 69 ), and his/her forefinger ( 64 ) at position ( 77 ), the counts for all four sensors would typically be at the reference or LTA value. By moving his/her fingers towards each other, the counts for electrodes ( 65 ) and ( 68 ) should decrease to a minimum value, with counts for electrodes ( 66 ) and ( 67 ) staying at the reference value. Next, the counts for electrodes ( 65 ) and ( 68 ) should simultaneously return to the reference value, accompanied by a simultaneous decrease in the counts for electrodes ( 66 ) and ( 67 ). Lastly, counts for electrodes ( 66 ) and ( 67 ) should return simultaneously to the reference, resulting in counts for all four electrodes being at this value. By testing for the above within certain timing constraints, the CSS may declare a switch activation event. The increased immunity of this embodiment to inadvertent activation may be based on the fact that the chance of two illegal/unintentional dielectric probes or other material performing swipe actions simultaneously in opposing directions is low. One could envisage that an illegal/unintentional unidirectional swipe action by for instance objects packed with a product into a backpack, and which satisfy timing constraints, may occur. But having opposing illegal/unintentional swipes that satisfy the required timing constraints should be highly unlikely. An embodiment as in FIG. 12 may be applied to, but definitely not limited to, products like headlamps, handheld torches, electric window controls, electrical tooth brushes, electric shavers and all manner of critical switches which, for safety or energy conservation reasons, cannot afford inadvertent activation.
FIG. 13 illustrates an exemplary embodiment of the present invention which comprises the possible use of a specific dielectric surface pattern to guide a user during operation of a three channel surface capacitance swipe switch. Electrodes ( 92 ) to ( 94 ) are typically covered by a dielectric material, which provide isolation to the user's finger. Ridges are formed in said dielectric material above electrodes ( 92 ) to ( 94 ), with the ridges running in parallel to the required swiping direction. Frontal view ( 89 ) show these ridges as ( 85 ), ( 86 ) and ( 87 ) above electrode ( 91 ). The top ends of ridges ( 85 ), ( 86 ) and ( 87 ) may or may not be rounded. Alongside said parallel ridges may be a plurality, which may be a large number, of diagonally opposed ridges, as illustrated by ( 80 ), ( 82 ), ( 84 ) and ( 88 ). Said diagonal ridges may have sides which are slanted when approached in the required swiping direction ( 90 ), but essentially vertical or overhanging in the reverse direction, illustrated at ( 83 ). To further assist the user during location of the center of the CSS, in a width sense, the top sides of the diagonal ridges may slope towards the center, as illustrated by ( 84 ) and ( 88 ). When a user's finger ( 79 ) approaches the CSS illustrated from point ( 81 ), the illustrated pattern should intuitively guide it towards the width wise center of the CSS and to the parallel ridges and electrodes, in part due to the sloping top sides of the diagonal ridges. Due to the angle of the diagonal ridges, and their slanting sides in only one direction, an attempt to swipe the CSS in a reverse direction of that required should result in the user experiencing tactile impediment. The illustration in FIG. 13 is purely exemplary, and should not construed to be limiting. For instance, the dielectric surface pattern illustrated in FIG. 13 may also be used with a projected capacitance swipe switch, according the presently disclosed invention, or changes may be made to the pattern, or more or less sensing channels may be used without departing from the scope of the present disclosure.
It is foreseeable that a user may need to locate the length wise center, or another point or electrode of the CSS, without having visual feedback. For instance, if a swiping action is used in headlamp to activate a function selection mode, and touches on specific electrodes of the CSS select the various functions, the user may require to know exactly where his/her finger is. In headlamps held by the prior art, the raised and distinctive nature of the employed mechanical switches provided sufficient tactile feedback to allow exact location. However, if a CSS is employed with a smooth dielectric material between user finger and electrode, such exact location may be difficult. FIG. 14 discloses in an exemplary manner how this need may be addressed. By changing the angle of diagonal ridges, as illustrated by ( 95 ) and ( 98 ), abruptly at a certain point along the length of the CSS, for instance at ( 97 ) in FIG. 14 , the user may sense the exact position of his/her finger ( 99 ) via tactile feedback. In the example of FIG. 14 , the user may be able to determine the location of electrode ( 101 ) fairly accurately without visual feedback.
FIG. 15 shows another exemplary embodiment of the present invention which utilize elevated ridges to guide a user towards the CSS. Ridges ( 105 ) and ( 109 ) lie primarily parallel to the electrodes of the CSS, and the required swiping direction ( 107 ). However, they may also flare in a funnel like manner at their two ends, as illustrated in exemplary manner. This should allow fingers or probes moving along diagonal lines ( 108 ) or ( 106 ), for instance, to find the required swiping direction ( 107 ) and the start of the CSS with fair ease, and without visual feedback, as illustrated in exemplary manner at ( 110 ). Further, according the presently disclosed invention, it is also envisaged that the inner and outer edges of elevated ridges ( 105 ) and ( 109 ) may slope at dissimilar angles. As illustrated, the inner edge of the ridges may drop abruptly towards the electrodes, such as ( 111 ), but the outer edges may slope gently towards supporting substrate ( 112 ). This should further facilitate the location and use of the CSS without visual feedback.
FIG. 16 shows an embodiment of the present invention which should increase immunity to inadvertent activation substantially. Ridges which are respectively parallel and diagonal to the required swiping direction, as disclosed in the preceding discourse, may be used with the addition of a full or partial reversal in the required swiping direction. FIG. 16 illustrates such an arrangement, using a three channel surface capacitance CSS, in an exemplary manner. Typically, a user's finger ( 113 a ), or other probe, may start proximate to electrode, ( 114 ). Due to the haptic feedback provided, it should be guided along direction ( 113 b ) past electrodes ( 117 ) and ( 115 ), without the requirement for visual feedback. The likelihood of such a direction reversal occurring naturally, due to illegal probes or dielectric material touching the CSS, within the timing constraints of the CSS, should be quite small, possibly increasing immunity to inadvertent activation or operation of the CSS substantially.
FIG. 17 illustrates an exemplary embodiment that utilizes four surface capacitance electrodes to realize two secondary two channel CSS units within a primary four channel CSS unit, all contained within a surface ridge guided swipe path that includes a reversal in required direction. Electrodes ( 122 ), ( 123 ), ( 124 ) and ( 125 ) form the primary CSS unit, containing first and second secondary CSS units, formed by electrode pair ( 122 ) and ( 123 ) and pair ( 124 ) and ( 125 ) respectively. Surface ridges, typically shown by ( 127 ) and ( 128 ), guide the engaging probe, which may be a user's finger, as illustrated by ( 121 ), along the required swiping direction. An exemplary operation may be as follows. The unit is enabled or unlocked by a complete swipe along path ( 118 ), starting at electrode ( 122 ) and ending at electrode ( 124 ) or vice versa. Once enabled, the user may swipe his/her fingers along either path ( 119 ) or path ( 120 ), or make specific touches, to operate or control associated circuitry. Due to ridges in the surface of the dielectric material that cover the electrodes, some of which is shown by ( 128 ) and ( 127 ), a user should be able to locate and follow paths ( 118 ), ( 119 ) and ( 120 ) without visual feedback. To disable or lock the two secondary CSS units, a user may perform another complete swiping action along path ( 118 ) of the primary CSS unit, after which the CSS secondary units may be ignorant to any actions performed on them exclusively. It is envisaged that an embodiment such as that disclosed by FIG. 17 may be applied to control automotive vehicle window height, where a user unlocks the window control by swiping along path ( 118 ), and lowers or raise the window through shorter swipes along paths ( 119 ) or ( 120 ) respectively. The present invention is not limited to the above exemplary embodiment, with embodiments that use projective capacitance or other sensing technologies along with the principle disclosed by FIG. 17 possible according the teachings of the present invention.
FIG. 18 illustrates yet another exemplary embodiment of the present invention that may be used to control automotive vehicle window height. Arm rest ( 131 ) may be that of the driver, and will typically contain controls for all four windows of the vehicle. If a recessed CSS, similar to that disclosed during earlier discourse, and illustrated in exemplary manner by surface capacitance electrodes ( 137 ), ( 138 ) and ( 139 ) and recess ( 140 ), is placed along with five, recessed, single channel surface capacitance switches ( 132 ), ( 133 ), ( 134 ), ( 135 ) and ( 136 ) into arm rest ( 131 ), a cost-effective and durable window height control interface may be realized. The invention is not limited to surface capacitance sensing in this regard, and include the possible use of projected or other capacitance sensing methods.
Exemplary implementations of said single channel, recessed touch switches are illustrated at ( 144 ) and ( 147 ). In the example presented at ( 144 ), sensing electrode ( 141 ) is contained within a recess in the surface of material ( 143 ), with recess sidewalls, as illustrated by ( 142 ), angling sharply upwards. Shields ( 145 ) and ( 146 ) are actively driven, as is known in the art of capacitive sensing, to ensure that electrode ( 141 ) is shielded from engaging material or probes on the surface of material ( 143 ). It is also possible to not use active shield technology, but merely ground material ( 145 ) and ( 146 ) by connection to system ground, and achieve sufficient shielding. Another example of a possible implementation of said recessed, single channel touch switches are illustrated at ( 147 ), where the surface of material ( 148 ) gradually slopes upward towards the lip of the recess, with sidewalls, as illustrated by ( 150 ), forming a sharply opposing angle, and sensing electrode ( 149 ) contained within the recess. Actively driven shields ( 151 ) and ( 152 ) are again used to protect electrode ( 149 ). These may again be material that is only grounded and do not use active shield technology, as discussed above.
Operation of the embodiment disclosed by FIG. 18 may be as follows, presented in an exemplary manner, without the imposition of a limit. To control a specific window's height, the user may activate one of the respective single channel switches ( 133 ), ( 134 ), ( 135 ) or ( 136 ) by inserting his/her finger into the recess, and pressing down. This will typically need to be followed by a swiping action within recess ( 140 ) along CSS electrodes ( 137 ), ( 139 ) and ( 138 ) within a specific period, with the swiping direction determining whether the window will be raised or lowered. A number of possible actions to control window position and motion may be possible. For example, the user may follow a first swiping action by a dedicated touch to a demarcated area above either electrodes ( 137 ), ( 139 ) or ( 138 ), with a touch to each area resulting in different window operating functions, for example, but not limited to, a fast raise event, a fast lower event or a mid-point stop event. Alternatively, the user may use a touch on one of the respective single channel, recessed switches ( 133 ), ( 134 ), ( 135 ) and ( 136 ) to select a particular window, perform a swiping action along the recessed CSS to start the process of raising or lowering the window, and a second touch on the specific single channel, recessed switch to halt window motion at a desired point. Many other combinations to control window motion and position using the disclosed combination of single channel, recessed touch switches and a shared, recessed CSS is possible according the present invention. A fifth single channel, recessed touch switch, such as illustrated in exemplary manner at ( 132 ), may be used to lock all windows, or perform a similar action simultaneously on all windows. Visible feedback may be provided to the user, in the arm rest or at another location, to indicate the status of the window control interface contained within arm rest ( 131 ), according the present invention.
FIG. 19 illustrates another exemplary embodiment of the present invention for a possible interface to control automotive vehicle window position and motion. In this case, a simplified approach is used, without use of a CSS, to provide a control interface for all the windows of a vehicle, typically contained within the driver side arm rest, illustrated by ( 155 ). Four recessed touch switches ( 157 ), ( 160 ), ( 161 ) and ( 162 ) may be provided in said arm rest. Each touch switch may utilize two capacitive sensing electrodes, as illustrated in exemplary manner by ( 156 ) and ( 159 ), a specifically shaped recess, as illustrated in exemplary manner by ( 168 ), and a blocking electrode, as illustrated in exemplary manner by ( 158 ). The upper surface of arm rest ( 155 ) that normally comes into contact with the drivers arm, hand or fingers may be partially or fully covered by conductive material, illustrated by ( 165 ) and ( 169 ), which may be connected to actively driven shield circuitry, or to system ground. In the example presented, electrodes ( 156 ), ( 159 ) are surface capacitance sensing electrodes. Naturally, the disclosed invention is not limited to surface capacitance sensing technology in this regard, and includes use of projected or mutual capacitance or other capacitance sensing technologies.
Exemplary operation of the embodiment disclosed by FIG. 19 may be described as follows, without limiting effect. To operate a particular window, a user may simply insert his/her finger ( 164 ) vertically into the respective recess, as illustrated, resulting in blocking electrode ( 158 ) being engaged. If blocking electrode ( 158 ) is sufficiently engaged by finger ( 164 ), any activation of the circuitry that controls the position of window ( 154 ) may be inhibited. Further, due to the recess shape and the possible use of actively driven shields or grounded material, illustrated by ( 165 ) and ( 169 ), electrodes ( 156 ) and ( 159 ) should not be sufficiently engaged by finger ( 164 ) in a vertical orientation to cause a threshold crossing capacitance change. The recess shapes used in the disclosed exemplary embodiment are such that the sensing electrodes may be covered partially or fully by an overhanging lip, which may or may not have an active shield or grounded material on it. The presence of active shields or grounded material close to the user's finger, when placed vertically into the recess, may reduce sensitivity to said finger. And the location of the electrodes under the lip should ensure that said electrodes are a sufficient distance away from the engaging vertical finger. To activate the circuitry that controls window position, the user may simply angle his/her finger forward or backwards, and press against the area underneath which the respective electrode is situated. This results in said finger moving away from said blocking electrode, and if said recess is properly designed, said blocking electrode should not be sufficiently engaged by said finger anymore, with the blocking function subsequently terminated, and activation of the circuitry which controls window motion allowed. For instance, to raise a window, the user may angle his/her finger forward, and press, as illustrated at ( 171 ). Conversely, to lower a window, the user may angle his/her finger backwards, and press, as illustrated at ( 172 ). It is evident from the example presented by FIG. 19 that finger ( 164 ) does not engage blocking electrode ( 158 ) in a substantial manner when angled forwards or backwards as illustrated at ( 171 ) and ( 172 ) respectively. Once again, a large number of mode or function selections are possible. For example, two brief taps on the forward electrode ( 171 ) may result in an auto-raise event, halted by a third tap on electrode ( 171 ). According the present invention, visual indication may be given to the user when proximity of a probe is detected by either of the two capacitance sensing channels of the recessed switch. In this manner, accidental activation may be further prevented.
As with the exemplary embodiment disclosed by FIG. 18 , the embodiment in FIG. 19 may incorporate the use of a fifth, or more, single channel, recessed touch switch ( 163 ). This may be used to lock all the other touch switches in the interface, or to select specific modes or functions. Visual feedback corresponding to the operation of switch ( 163 ), and the state of the control interface may be provided to the user. Due to the capacitive technology employed, a window control interface as presented in FIG. 19 may offer improved reliability, due to the absence of moving parts, and may be low cost, with high immunity to inadvertent activation. It also presents an interface which is close in operation to some prior art mechanical switch implementations, which should assist with user acceptance.
FIG. 20 presents an exemplary embodiment of the present invention that comprises use of a single channel surface capacitance sensor to realize an electronic switch for a product that may have high immunity to inadvertent activation. Surface capacitance electrode ( 175 ) is contained by recess ( 176 ), formed into supporting material ( 174 ), and typically placed at the bottom of the recess. To operate said switch, the user must insert the engaging probe, which may be his/her finger ( 173 ), or another member, into recess ( 176 ), and make physical contact with the, for example, dielectric material covering electrode ( 175 ), or be in close proximity. This should result in sufficient change in the measured capacitance, or another parameter, to declare an activation/operation event, and change the state of said electronic switch accordingly. Due to the recess, and a dedicated probe insertion action required from the user, an embodiment such as that presented in FIG. 20 may exhibit high immunity to inadvertent activation. To further reduce the risk of inadvertent activation, use may be made of actively driven shield or grounded conductive material on the surface of supporting material ( 174 ). The embodiment disclosed in FIG. 20 is purely exemplary, and other capacitive sensing technologies, for example projected or relaxation oscillator based capacitance sensing, or other sensing technologies may be used without departing from the spirit and scope of the presently disclosed invention.
FIG. 21 illustrates a number of swipe switch functionality indications that may be used on the body or housing of a product, or elsewhere, to clarify use of said swipe switch, according the present invention. CSS ( 180 ) makes use of three electrodes ( 177 ), ( 178 ) and ( 179 ). The number of electrodes used to form the CSS need not be constrained to two, but may be any number, with a minimum of two electrodes. As disclosed previously, a number of functions may be realized with a CSS according the present invention, dependent on the direction of the initial swipe gesture. For example, if a single CSS is used to control two light sources, one white, and one color, a swipe from electrode ( 179 ) to electrode ( 177 ), in other words RTL, may be used to control the white light source, as shown at ( 181 ) of indication ( 183 ). Conversely, a swipe from ( 177 ) to ( 179 ), or LTR, may be used to control the color light source, as shown at ( 182 ) of indication ( 183 ). Alternatively, CSS ( 180 ) may be used to control the intensity of a single light source. An indication as illustrated at ( 187 ) may be used to clarify CSS functionality for a user, where a swipe RTL will result in less intensity, shown by ( 188 ) and a swipe LTR will result in increased light intensity, shown by ( 189 ). Or an indication as shown at ( 184 ) may be used to clarify functionality if CSS ( 180 ) is used to control the flashing period of a light source. In this embodiment, a swipe from electrode ( 177 ) to ( 179 ) via electrode ( 178 ), or LTR, will result in shorter flashes, as indicated at ( 186 ), and a swipe from RTL will result in longer flashes, as shown at ( 185 ). If a CSS of the present invention is used to control a load other than a lighting load, an indication such as shown by ( 190 ) may be used to clarify functionality for a user. A swipe from LTR will result in more electrical energy being transferred to the load, as indicated at ( 192 ), and a swipe RTL will result in less electrical energy being transferred to the load, as shown at ( 191 ).
In FIG. 22 , the exemplary placement of a CSS in the elastic headband ( 196 ) of a headlamp ( 200 ) according to the present invention is shown. Said CSS may consist of electrodes ( 193 ), ( 194 ) and ( 195 ), and may make use of flexible interconnect ( 197 ) to the body of the headlamp. The circuitry required to monitor said electrodes, and annunciate swipe, touch or proximity events may be contained within the body of the headlamp, or may be located near the electrodes in the headband. The latter embodiment may be beneficial, as it implies that interconnect ( 197 ) will only be used for digital communication, and not for capacitive sensing, and as such, will not be influenced by the users hand. The illustration is purely exemplary, and any number of electrodes and configurations may be used to implement the CSS, without departing from the scope and spirit of the presently disclosed invention.
FIG. 22 further illustrates the possibility to control multiple light sources, as taught by the present invention. Headlamp ( 200 ) contains a primary light source ( 198 ), for example with high brightness, used as a spotlight, and a secondary light source ( 199 ), for example of lower intensity, with a wider illumination angle. In addition, a number of color LED's, as illustrated by ( 201 ), may be contained within the body of the headlamp, and used to facilitate a BPM function. According the presently disclosed invention, and in an exemplary embodiment, if all the light sources are in an off-state, and the user swipes from electrode ( 193 ) to electrode ( 195 ) via electrode ( 194 ), or LTR, control of primary light source ( 198 ) with swipe gestures in any direction or touches on specific electrodes within a pre-determined period may be facilitated. Conversely, if all light sources are in an off-state, and the user swipes from RTL, control of secondary light source ( 199 ) with swipe gestures or touches on specific electrodes within a pre-determined period may be facilitated. Indicators ( 201 ) may be used to implement a BPM function, according the present invention. For example, if all light sources are in an off-state, the user may determine battery state by making a prolonged touch on a specific electrode of the CSS, followed by a specific swipe gesture on the CSS. It will be apparent to those of skilled in the arts of capacitive sensing and portable lighting products that a large number of control functions may be realized according the present invention using a CSS, swipe direction and duration, number of touches and their duration, proximity detection events and combinations thereof.
FIG. 23 illustrates, in an exemplary manner, how edges in the product housing or body may be used to provide haptic feedback which may assist a user to determine the location of a specific CSS. In the embodiment shown, a CSS, consisting of electrodes ( 203 ), ( 204 ) and ( 205 ) and associated circuitry, is contained within a product housing ( 202 ), in this case a headlamp. Said electrodes are substantially underneath edge ( 207 ) of product housing ( 202 ), shown by the cross section taken along line AA′. Therefore, a user wearing thick gloves, for example, may feel for the diagonal face in the body of the headlamp, and then execute a swipe gesture along the top edge ( 207 ) of said diagonal face to activate the CSS, and control light source ( 206 ). The illustrated embodiment is purely exemplary, and should not serve to be limiting on the present disclosure, with any number of electrodes used to construct the CSS, as well as any number of edges or the orientations thereof possible, and still falling within the scope and spirit of the presently disclosed invention. The invention is also not limited to a specific capacitive sensing technique or electrode arrangement, and may use charge transfer, relaxation oscillator, impedance voltage division or any other relevant capacitive sensing technique to sense self or mutual capacitance in embodiments of the present invention.
FIG. 24 illustrates an exemplary embodiment where a CSS is employed in a mobile telephone ( 208 ). Said telephone has a casing ( 209 ), a touchscreen ( 211 ), a microphone opening ( 210 ) and a speaker opening ( 215 ). In the example shown, three capacitive sensing electrodes ( 212 ), ( 213 ) and ( 214 ) are used, along with the required circuitry, not shown, to form a CSS. Said CSS are used to facilitate both the on-ear detection and locking/unlocking function typically found in state of the art mobile telephones. When a user receives a call, typical user interfaces of state of the art phones will allow the user to answer said call via the user interface, independent of whether the phone is in a locked or unlocked state. Normally, such an answering action is followed by the user placing telephone ( 208 ) against or close to his/her ear. This may be detected via the resulting change in measured capacitance of electrodes ( 212 ), ( 213 ) and ( 214 ). The requirement for the annunciation of an on-ear event may be based on a specific change in measured capacitance for only one of the three electrodes, or any combination of two electrodes, or all three electrodes, due to the pre-knowledge that a call has been answered. Once an on-ear event has been detected and declared, said telephone may de-activate it's visual output, or use the information to ignore all further user interface inputs until the on-ear event is cleared. When the user ends said call, electrodes ( 212 ), ( 213 ) and ( 214 ) may be used to facilitate a CSS, as taught by the preceding disclosure. Said CSS may be used to lock or unlock said telephone's user interface. By performing a specific swiping gesture on or in proximity to the CSS, the user may lock or unlock said user interface. Said swiping gesture may be any one or combination of the large number of possible gestures, some of which has been described during the earlier discourse of the present disclosure. Further, surface patterns in the casing ( 209 ), similar to that disclosed earlier, or others, may be used in the vicinity of electrodes ( 212 ), ( 213 ) and ( 214 ) to provide haptic feedback and guidance to the user concerning operation of the CSS. When mobile telephone ( 208 ) is in a state where the user interface is unlocked or locked, one or more of the electrodes may be used to facilitate a blocking function on the logic state of the output of the CSS. For instance, when a call is being answered, said telephone may prohibit any change in the output of the CSS, to prevent inadvertent unlocking of the user interface. Or when said telephone's user interface is in an unlocked state, and the user is engaging touchscreen ( 211 ), sufficient capacitance change in any one of the electrodes ( 212 ), ( 213 ) and ( 214 ) which has been placed closer to said touchscreen may be used to determine that the user is probably engaging said touchscreen, and not said CSS, and therefore prohibit any change in the logic state of the CSS's output. In the above, electrodes ( 212 ), ( 213 ) and ( 214 ) may be used to sense changes in either self-capacitance or mutual capacitance.
In FIG. 25 , yet another exemplary embodiment of the present invention in a mobile telephone is shown. At ( 216 ), a mobile telephone with a touchscreen ( 217 ), a microphone opening ( 218 ), a casing ( 219 ) and a speaker opening ( 220 ), typical of mobile telephones presently commercially available, is illustrated. In addition, a CSS based button ( 221 ), as taught by the present invention, is situated on the side of said telephone, as an exemplary location. At ( 222 ), a more detailed view of said CSS based button is presented. CSS based button ( 228 ) typically has dimensions to allow its outer face to fit into an area on the order of 6 mm by 6 mm, and is contained by a recess ( 224 ) in the side wall ( 223 ) of the casing of said mobile telephone. Button ( 228 ) is supported by a spring loaded structure with similar characteristics to a snap dome structure, and as such, if a user applies more than a predetermined minimum pressure to said button, it will suddenly deflect significantly, and may provide a tactile click, as users have become accustomed to in mobile products. Said spring loaded structure also ensures that CSS based button ( 228 ) has some resilience to deflection, and returns to its starting position. A number of capacitance sensing electrodes will typically be situated on the outer face of said CSS based button ( 228 ), in the present exemplary embodiment, three electrodes are utilized as shown by ( 225 ), ( 226 ) and ( 227 ) to sense up/down swipes. Said electrodes may be used to sense proximity events, touches with less than a predetermined minimum pressure, touches with more than a predetermined minimum pressure and swipe gestures. When a user exerts more than a predetermined minimum pressure, resulting in rapid deflection of CSS based button ( 228 ), the event may be detected via normal electrical contact make or break means, or via capacitive sensing means, according the present invention. Specifically, means as taught in WO 2011/130755, by the present inventor, and hereby incorporated in its entirety, may be used to effect an inverse change in measured mutual capacitance when said button is pressed with more than a predetermined minimum pressure, said inverse being relative to the change in measured mutual capacitance when pressure less than a predetermined minimum is applied to said button.
According to the present invention, electrodes ( 225 ), ( 226 ) and ( 227 ) may be used to detect swipes in a vertical direction, that is, in the mobile telephone's lengthwise direction. Users may thus swipe up or down over CSS based button ( 228 ). Further, the present invention teaches that electrodes ( 225 ), ( 226 ) and ( 227 ) and the associated capacitive sensing circuitry of said CSS based button ( 228 ) may be such as to allow swipe or motion detection based on the movement of a user's fingerprint ridges and valleys, as taught in provisional filing ZA 2012/05814, titled “Fingerprint based capacitive motion sensor” by the present inventor, and hereby incorporated in its entirety.
Exemplary operation of CSS based button ( 228 ) may be as follows. It may be used as a proximity sensor, and wake said mobile telephone from a power saving sleep mode upon detection of a proximity event followed by a touch with less than a minimum pressure, as an example. During a telephone call, a user may swipe up or down over said CSS based button ( 228 ) to adjust speaker volume up or down, respectively. To navigate a displayed list of items, a user may make a partial swipe over said CSS based button ( 228 ), and pause with a prolonged touch during the swipe. This will result in a scrolling function being performed, as an example. To halt the scrolling function at a specific point in said displayed list of items, the user may simply remove his/her finger from CSS based button ( 228 ). Alternatively, a user may navigate a displayed list of items by a number of consecutive swipes, within a certain period, in a particular direction. The present invention further teaches that said user may use a number of, consecutive swipes in a particular direction to control movement of a displayed cursor or pointer, wherein each detected swipe results in a step by said cursor or pointer in the direction of said detected swipe. The above may be followed by a tap or a touch with more than a minimum pressure to select. As is evident, a rich collection of possible user gestures, that may control a large number of functions of a mobile telephone, or another mobile electronic device, may be facilitated by a CSS based button as illustrated by FIG. 25 , if one takes into account that it can sense swipes in two directions, taps, double taps, touches of longer duration and touches with more than minimum pressure. Further, the present invention also teaches that it may be used as a very effective lock and unlock interface if used to sense swipes based on the motion detection of fingerprint ridges and valleys. For example, to unlock said mobile telephone, a user may simply swipe his/her fingerprint over CSS based button ( 228 ). By using information characteristic to fingerprint ridges and valleys, as described in ZA 2012/05814, said CSS based button ( 228 ) may accurately determine if a seemingly valid swipe gesture was made by a fingerprint or by other non-valid material such as that of a jacket pocket, preventing erroneous unlocking of said mobile telephone.
In the aforementioned and the presented claims, a swipe or swiping action means a specific sequence of actions by an engaging probe within a certain period, said probe directed by a user, and where said probe may be a member of the user, for example a finger. | A capacitive sensing-based electronic switch, which incorporates an integrated circuit with processing capability, which can only be activated by user action in a dedicated area, whereby switch activation occurs only if, at least, a touch is capacitively sensed and criteria based on timing plus sequential touches on capacitive sensors are satisfied. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to rope light and more particularly to such a rope light having a multi-circuit arrangement with improved characteristics.
[0003] 2. Description of Related Art
[0004] Conventionally, lamps on a single-circuit of a rope light can be turned on/off by means of a controller coupled between two electrical wires. Also, lamps on a double-circuit of the rope light can be turned on/off by means of the controller coupled among three electrical wires (i.e., increase of an additional electrical wire). Likewise, three-circuit of the rope light can be turned on/off by means of the controller coupled among four electrical wires, etc. In an extreme example, six-circuit of the rope light can be turned on/off by means of the controller coupled among seven electrical wires, resulting in a bulkiness of the rope light.
[0005] In U.S. Pat. Nos. 6,406,166, 6,527,412, and 6,502,955 there are disclosed a chasing rope light. For example, U.S. Pat. No. 6,406,166 (the prior art) is characterized in that two illuminating units each having a plurality of illuminators (e.g., LEDs) are provided in a single-circuit of the rope light having two electrical wires, and three (or four) illuminating units are provided in a double-circuit (or multi-circuit) thereof having three electrical wires (see FIGS. 4, 5 and 6 ). Also, a diode is provided in each of the illuminating units. The diode is adapted to permit current to flow in only one direction in a conducted state if a sufficient voltage is applied thereon. As shown, any two adjacent diodes are disposed oppositely with respect to polarity. As such, the purpose of controlling the lightening sequence of the illuminating units in a multi-circuit arrangement of the rope light can be obtained. In other words, the lightening sequence of the illuminating units in the multi-circuit arrangement of the rope light is totally controlled by diodes which are thus essential to the prior art.
[0006] However, the prior art, by incorporating a plurality of diodes, suffered from several disadvantages. For example, (1) the prior art did not know that an LED is also adapted to permit current to flow in only one direction in a conducted state if a sufficient voltage is applied thereon. Thus, provision of LEDs as illuminators is sufficient to control the lightening sequence of the illuminating units. In other words, provision of diodes as on/off device in controlling the lightening sequence of the illuminating units is not necessary. To the worse, it results in an increase in the manufacturing cost, an increase of size, and a limitation on the number of circuits in the rope light.
[0007] (2) As shown in FIGS. 3 and 7 of the prior art, the illuminators are preferably implemented as LEDs as described in the specification. Instead, the illuminators are lamps as shown. Hence, it is concluded that the LEDs as described in the specification are simply lamp-based LEDs. Typically, the lamp-based LED or simply lamp has two rigid pins adapted to fixedly insert in a circuit board rather than that described in FIGS. 3 and 7 which show the lamps are coupled in series. The pins of the illuminators have to be bent outward to couple to the conductive wire prior to wrapping around the electrical wires 20 A, 20 B (see FIGS. 3 and 7 ). Thus, two problems are occurred. One is that the pins are susceptible of damage in the bending process. As such, the lamp, as encapsulated by epoxy, tends to malfunction in bending. It is known that the pin is rigid while the electrical wire is non-rigid. Hence, when the electrical wire is wrapped around the pin it is very difficult (or even impossible) of tightly securing them together, though the pins are not damaged by bending. Such wrapping is not reliable as viewed by an experienced electrical technician. Instead, per wire connecting rules of electrical engineering it requires that first mounts a small copper socket in the pins of a LED, and then secures them together by soldering in order to fasten the pins and the electrical wire together. This has a benefit of being capable of withstanding an increased stress. However, the technique of mounting the socket in the pins has disadvantages of being tedious, time consuming, and cost ineffective, though it is applicable.
[0008] (3) Of course, it is possible of wrapping a wire around the pins of the lamp-based LED. However, in view of the accompanying drawings of the prior art, such coupled LEDs may be too large to mount in the rope light, though it is applicable in view of FIG. 3 . However, as shown in FIG. 7 , a portion of the long pin is exposed. Hence, a bending of the LED will cause a short circuit in the exposed portion of the pin. Moreover, the illuminators are preferably LEDs as described in the specification. But, there is no disclosure about how to avoid the use of diode and stress exerted on the pins and the rope light.
[0009] Thus, it is desirable to provide an improved rope light in order to overcome the above drawbacks of the prior art.
SUMMARY OF THE INVENTION
[0010] It is an object of the present invention to provide a rope light having a multi-circuit arrangement. By utilizing the rope light, advantages such as elimination of diodes, simple circuit arrangement, saving of electrical wires, compactness, control the lightening sequence of illuminating units, and reduction of manufacturing cost can be obtained.
[0011] It is another object of the present invention to provide a rope light having a benefit of controlling on/off of LEDs (light emitting diodes) by means of a relative small number of electrical wires. For example, it is possible of controlling the on/off of six LEDs by means of three electrical wires.
[0012] It is a further object of the present invention to provide a rope light in which an illuminating unit thereof is implemented as a plate-shaped LED or COB (chip on board) type LED which is fixed on a circuit board by soldering extended conductive wires on the circuit board. By utilizing the rope light, benefits such as improvement of electrical connection to LEDs, increase of stress withstanding capability, simplification of circuit arrangement, significant saving of electrical wires, lightweight, and compactness can be obtained.
[0013] The above and other objects, features and advantages of the present invention will become apparent from the following detailed description taken with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a circuit diagram of a first preferred embodiment of rope light according to the invention where a single-circuit arrangement is illustrated;
[0015] FIG. 2 is a perspective view of the rope light shown in FIG. 1 ;
[0016] FIG. 3 is an equivalent circuit diagram of a second preferred embodiment of rope light according to the invention where a multi-circuit arrangement is illustrated;
[0017] FIG. 4 is a circuit diagram of the second preferred embodiment of rope light;
[0018] FIG. 5A is a perspective view illustrating a first alternative mode of the rope light having a square section;
[0019] FIG. 5B is a perspective view illustrating a second alternative mode of the rope light having a flat, rectangular section;
[0020] FIG. 5C is a perspective view illustrating a third alternative mode of the rope light having an oval section;
[0021] FIG. 6 is an equivalent circuit diagram of a third preferred embodiment of rope light according to the invention where a multi-circuit arrangement is illustrated; and
[0022] FIG. 7 is a table showing on-off sequence of the illuminating units in different electrical wires according to the second preferred embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0023] The invention is directed to a rope light having a multi-circuit arrangement. The invention is devised by distinguishing itself from the narrow prior art after considerable research and experimentation. Also, the inventor adopts the most advanced semiconductor manufacturing technology and fully understands the properties of LED. The rope light of the invention is characterized as follows: No provision of diodes. Instead, the illuminators are implemented as LEDs which are served as both illuminating devices and diodes. As such, component cost of the rope light is greatly reduced due to, as stated above, the elimination of diodes. Also, the manufacturing process is shortened in time and the manufacturing cost is reduced. The LED is implemented as a plate-shaped LED, COB type LED, SMD (surface mounting) LED, or LED dice bonding which is again fixed on a circuit board by soldering extended conductive wires on the circuit board. As such, benefits such as facilitation of the manufacturing process, improvement of electrical connection to LEDs, prevention of short circuit of electrical wires, increase of stress withstanding capability, compactness, significant saving of illuminators, lightweight, and flexibility can be obtained.
[0024] The rope light of the invention should operate in conjunction with connector and controller. However, they are well known. Thus a detailed description thereof is omitted herein for the sake of brevity.
[0025] Referring to FIGS. 1 and 2 , a rope light having a multi-circuit arrangement constructed in accordance with a first preferred embodiment of the invention comprises two electrical wires 11 , 12 , a first illuminating unit 21 including a plurality of LEDs between the electrical wires 11 and 12 , a second illuminating unit 22 including a plurality of LEDs also between the electrical wires 11 and 12 and in parallel with the first illuminating unit 21 , and a controller (not shown) electrically coupled to the electrical wires 11 , 12 . As shown, a positive terminal of the first illuminating unit 21 is electrically coupled to the first electrical wire 11 while a negative terminal thereof is electrically coupled to the second electrical wire 12 . To the contrary, a positive terminal of the second illuminating unit 22 is electrically coupled to the second electrical wire 12 while a negative terminal thereof is electrically coupled to the first electrical wire 11 . When connecting with the controller (not shown) for providing different current directions between the electrical wires 11 and 12 , the LEDs of the first illuminating unit 21 will be lightened up sequentially with the LEDs of the second illuminating unit 22 off if the current is positive. To the contrary, the LEDs of the second illuminating unit 22 will be lightened up sequentially with the LEDs of the first illuminating unit 21 off if the current is negative. A flashing effect of the rope light is observed when ac (alternating current) is fed to the electrical wires 11 and 12 . In other words, the invention can achieve the flashing effect without the provision of diodes.
[0026] Referring to FIG. 2 specifically, the rope light is enclosed in an outer cover layer 40 which has a flat rectangular, square, or oval section as detailed later. Moreover, the LEDs may be replaced by lamps, Christmas bulbs, strip bulbs, or ornamental bulbs in other embodiments. In the embodiment, each of the illuminating units 21 , 22 is implemented as a COB type LED, SMD LED, or LED dice bonding which is again fixed on a small circuit board by soldering. As shown, two conductive wires extended from the circuit board are inserted into an elongated, axial groove 33 of an elongated mounting strap 30 . The mounting strap 30 has two side ridges 31 , 32 with the electrical wires 11 , 12 disposed therein respectively. The illuminating units 21 , 22 are thus electrically coupled to the electrical wires 11 , 12 . The outer cover layer 40 is then formed around the mounting strap 30 by means of injection molding. By configuring as above, the rope light of the invention is structurally strong enough while possessing an acceptable degree of flexibility.
[0027] Referring to FIGS. 3 and 7 , a second preferred embodiment of the invention is illustrated. A leak current will be generated between positive and negative terminals of a circuit when a load (e.g., illuminator) therebetween is lightened up. For example, a leak current will be generated between the positive and the negative terminals of the electrical wires 11 , 12 . The leak current will flow from the first electrical wire 11 to the second electrical wire 12 via the illuminating units 26 and 24 . As such, the illuminating units 24 and 25 (or the illuminating units 23 and 26 ) should be eliminated for preventing the leak current if the illuminators thereof are implemented as typical lamps. Otherwise, the illuminating units 24 and 25 (or the illuminating units 23 and 26 ) may lighten up undesirably. For overcoming this problem, all illuminators are implemented as LEDs by the invention while maintaining the original multi-circuit arrangement. This is because an LED is adapted to permit current to flow in only one direction (i.e., very small resistance) in a conducted state while blocking current from flowing in an opposite direction (i.e., very large resistance or off) if a sufficient, predetermined voltage is applied thereon. As shown in FIG. 7 , when positive voltage is applied to the first electrical wire 11 with respect to the second electrical wire 12 , the illuminating unit 21 will be lightened up while other illuminating units are off (i.e., open circuit). To the contrary, when positive voltage is applied to the second electrical wire 12 with respect to the first electrical wire 11 due to the characteristic of ac, the illuminating unit 22 will be lightened up while other illuminating units are off (i.e., open circuit). Likewise, when positive voltage is applied to the second electrical wire 12 with respect to the third electrical wire 13 , the illuminating unit 23 will be lightened up while other illuminating units are off (i.e., open circuit). To the contrary, when positive voltage is applied to the third electrical wire 13 with respect to the second electrical wire 12 , the illuminating unit 24 will be lightened up while other illuminating units are off (i.e., open circuit). Similarly, when positive voltage is applied to the third electrical wire 13 with respect to the first electrical wire 11 , the illuminating unit 25 will be lightened up while other illuminating units are off (i.e., open circuit). To the contrary, when positive voltage is applied to the first electrical wire 11 with respect to the third electrical wire 13 , the illuminating unit 26 will be lightened up while other illuminating units are off (i.e., open circuit). Thus, it is possible of controlling on/off of six LEDs by means of three electrical wires according to the multi-circuit arrangement of the invention.
[0028] Referring to FIG. 4 , a second preferred embodiment of the invention is shown. The second preferred embodiment substantially has same structure as the first preferred embodiment. The differences between the first and the second preferred embodiments, i.e., the characteristics of the second preferred embodiment are detailed below. A third electrical wire 13 is added. Also, the illuminating units of the rope light comprise six LEDs 21 , 22 , 23 , 24 , 25 , and 26 . The first illuminating unit 21 comprises a plurality of LEDs between the electrical wires 11 and 12 . The second illuminating unit 22 comprises a plurality of LEDs also between the electrical wires 11 and 12 and in parallel with the first illuminating unit 21 . The positive terminal of the first illuminating unit 21 is electrically coupled to the first electrical wire 11 while the negative terminal thereof is electrically coupled to the second electrical wire 12 . To the contrary, the positive terminal of the second illuminating unit 22 is electrically coupled to the second electrical wire 12 while the negative terminal thereof is electrically coupled to the first electrical wire 11 . Likewise, the third illuminating unit 23 comprises a plurality of LEDs between the electrical wires 12 and 13 . The fourth illuminating unit 24 comprises a plurality of LEDs also between the electrical wires 12 and 13 and in parallel with the third illuminating unit 23 . The positive terminal of the third illuminating unit 23 is electrically coupled to the second electrical wire 12 while the negative terminal thereof is electrically coupled to the third electrical wire 13 . To the contrary, the positive terminal of the fourth illuminating unit 24 is electrically coupled to the third electrical wire 13 while the negative terminal thereof is electrically coupled to the second electrical wire 12 . Similarly, the fifth illuminating unit 25 comprises a plurality of LEDs between the electrical wires 13 and 11 . The sixth illuminating unit 26 comprises a plurality of LEDs also between the electrical wires 13 and 11 and in parallel with the fifth illuminating unit 25 . The positive terminal of the fifth illuminating unit 25 is electrically coupled to the third electrical wire 13 while the negative terminal thereof is electrically coupled to the first electrical wire 11 . To the contrary, the positive terminal of the sixth illuminating unit 26 is electrically coupled to the first electrical wire 11 while the negative terminal thereof is electrically coupled to the third electrical wire 13 .
[0029] Referring to FIGS. 5A, 5B , and 5 C, the rope light having a section of square 3 , flat rectangle 4 , and oval 5 are shown respectively. The rope light in each of FIGS. 5A, 5B , and 5 C is constructed substantially the same as that shown in FIG. 2 except that the former has three electrical wires and three pairs of LEDs while the latter has only two electrical wires and two pairs of LEDs.
[0030] Moreover, in the embodiment shown in FIGS. 5A, 5B , or 5 C, the electrical wires 11 , 12 are fixed in the side ridges 31 , 32 respectively while the electrical wire 13 is disposed under the mounting strap 30 . Next, couple six LEDs 21 to 26 among the electrical wires 11 , 12 , and 13 as illustrated in FIG. 4 . Finally, the outer cover layer 40 having a section of square 3 , flat rectangle 4 or oval 5 is formed around the mounting strap 30 by means of injection molding. By configuring as above, the rope light of the invention is structurally strong enough while possessing an acceptable degree of flexibility. Referring to FIG. 6 , it is possible of controlling the on/off of 12 LEDs by means of four electrical wires 11 , 12 , 13 , and 14 . Similarly, it is possible of controlling the on/off of 20 LEDs by means of five electrical wires. In short, the invention can control on/off of a plurality of LEDs by means of a relative small number of electrical wires as compared with the prior art.
[0031] While the invention herein disclosed has been described by means of specific embodiments, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope and spirit of the invention set forth in the claims. | A rope light having a multi-circuit arrangement is disclosed. The light comprises a plurality of electrical wires longitudinally extended therealong; and one or more pairs of first and second illuminating units, each pair being electrically coupled between any two electrical wires, each illuminating unit including a plurality of LEDs coupled in series, and the first and the second illuminating units in each pair being connected in parallel. Applying AC source between any two electrical wires sequentially will lighten up the first and the second illuminating units in each pair alternately by enabling current to flow through the LEDs in each illuminating unit toward a predetermined direction when the LEDs are conducted. The invention can control on/off of a plurality of LEDs by means of a relative small number of electrical wires. | 5 |
RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional Patent Application Nos. 61/993,541, filed on May 15, 2014, 61/993,563, filed on May 15, 2014, and 61/993,569, filed on May 15, 2014, the disclosures of which are incorporated by reference herein in their entirety.
BACKGROUND OF THE DISCLOSURE
[0002] Semiautomatic firearms for 22 caliber rimfire cartridges are extremely popular as evidenced by the many makes and models available. Semiautomatic rifles for higher power rimfire cartridges, for example .17 HSR and .17 WSM are not presently available. Previous commercial models for these rimfire cartridges proved to be unreliable and prone to malfunctions. Mechanisms, particularly the trigger assemblies, safety mechanisms and cycling mechanisms typically used for conventional .22 caliber ammunition are not believed to be robust and reliable enough for these higher powered rimfire cartridges.
[0003] A reliable semiautomatic firearm with suitable mechanisms to mitigate misfires and out of breech firings and other malfunctions would be welcomed.
SUMMARY OF THE DISCLOSURE
[0004] Various embodiments of semiautomatic firearms with robust and redundant systems for reducing malfunctions are disclosed, suitable for use with, for example, higher powered rimfire cartridges, such as .17 HSR and .17 WSM. The embodiments disclosed herein may also be utilized in firearms that fire centerfire cartridges and in .22 caliber firearms. A safety trigger is provided that is passively actuated in advance of a firing trigger. The safety trigger maintains redundant safety mechanisms that prevent inadvertent or accidental actuation of the firing trigger. Accordingly, the firing trigger can be configured for actuation with a very low magnitude or “soft” pull without compromising safety. That is, conventional firearms require substantial pull to be actuated in order to assure that the trigger doesn't misfire during otherwise routine handling. For the disclosed embodiments, the safety trigger assures that the firearm is discharged only upon deliberate actuation of the firing trigger. In one embodiment, a trigger pull adjustment mechanism provides adjustment of the pull of the firing trigger to a desired force required by the operator. The disclosed trigger pull adjustment mechanism reduces the number of components and complexity of the machined parts over conventional trigger pull adjustment mechanisms.
[0005] In some embodiments, a firearm with a safety trigger component must be retracted prior to the firing trigger being retracted to fire the firearm, the safety trigger providing a plurality of firing inhibitors. In one embodiment, the safety trigger component includes a direct hammer catch positioned in an interfering or catch position when the safety trigger is in an unretracted position and one or more additional firing inhibitors controlled by the safety trigger. In various embodiments, a firing inhibitor controlled by the safety trigger is a sear portion block. In some embodiments, the safety trigger moves a sear blocking portion between a blocking position and a non-blocking position with respect to the sear portion. Optionally, the sear portion is part of a unitary trigger component. In some embodiments, the safety trigger controls a firing trigger block that is positioned to prevent the pivoting of the firing trigger component about the pivot axis, thus inhibiting the retraction of the firing trigger.
[0006] Structurally, various embodiments of a trigger assembly of a firearm is disclosed, the trigger assembly including passive and redundant safety mechanisms to prevent unintentional firing when the firearm is in a firing mode. In some embodiments, the trigger comprises: a hammer rotatable about a first axis, the hammer including structure defining a capture feature; a firing trigger component rotatable about a second axis and including a first finger hook portion, the firing trigger component including a sear portion releasably coupled to the hammer; and a safety trigger component rotatable about the second axis and including a second finger hook portion, the second finger hook portion extending forwardly of the first finger hook portion. In some embodiments, a first of the redundant safety mechanisms includes a catch portion defined on the safety trigger component and, when the safety trigger is in a battery position, is aligned for arresting the capture feature of the hammer as the hammer rotates to prevent discharge of the firearm. In some embodiments, a second of the redundant safety mechanisms includes a blocking member operatively coupled with the safety trigger component for maintaining the blocking member in a blocking position when the safety trigger component is in a battery position, the blocking member blocking an underside of the firing trigger component when in the blocking position to prevent release of the sear portion from the hammer, the blocking member being operatively coupled with the safety trigger component for moving the blocking member out of the blocking position by moving the safety trigger out of the battery position to enable release of the sear portion from the hammer. In one embodiment, a rearward deflection of the safety trigger component causes rotation of the blocking member.
[0007] In certain embodiments, the blocking member includes an arcuate base portion rotatable about a third axis, the arcuate base portion defining a recess and being operatively coupled with the safety trigger component for rotation about the third axis. In one embodiment, the arcuate base portion blocks the underside of the firing trigger component from being actuated when the safety trigger component is in the battery position, and the recess aligns with the firing trigger when the safety trigger component is rotated out of the battery position to enable the firing trigger to release the hammer.
[0008] In some embodiments, the blocking member includes a lever portion operatively coupled with the safety trigger component for rotation about a third axis, wherein the lever portion blocks the underside of the firing trigger component to prevent disengagement of the firing trigger component from the hammer, the lever portion being maintained in the blocking position by the safety trigger when the safety trigger is in the battery position, the lever portion being selectively rotatable out of the blocking position by rotating the safety trigger out of the battery position. Alternatively or in addition, the trigger assembly comprises a manual safety mechanism actuated by a push button forward of the first finger hook portion and laterally actuated for selectively placing the firearm in one of a safety mode and a firing mode, the manual safety mechanism being operatively coupled to the blocking member for preventing the safety trigger component from moving the blocking member out of the blocking position when in the safety mode, and enabling the safety trigger component to move the blocking member out of the blocking position when in the firing mode.
[0009] For embodiments including the fore-mentioned manual safety mechanism, the blocking member can include an arcuate base portion rotatable about a third axis, the arcuate base portion defining a recess and being operatively coupled with the safety trigger component for rotation about the third axis, wherein: the arcuate base portion blocks the underside of the firing trigger component from being actuated when the safety trigger component is in the battery position and when the firearm is in the safety mode and in the firing mode; and the recess aligns with the firing trigger when the firearm is in the firing mode and the safety trigger component is rotated out of the battery position to enable the firing trigger to release the hammer. Optionally, the lever portion that extends from the arcuate base portion of the blocking member.
[0010] In some embodiments, the blocking member includes a lever portion operatively coupled with the safety trigger component for rotation about a third axis, wherein the lever portion blocks the underside of the firing trigger component to prevent disengagement of the firing trigger component from the hammer, the lever portion being maintained in the blocking position by the safety trigger when the safety trigger is in the battery position and the firearm is in the firing mode, the lever portion being selectively rotatable out of the blocking position when the firearm is in the firing mode by rotating the safety trigger out of the battery position. In some embodiments, the lever portion contacts the firing trigger when the safety trigger is in the battery position.
[0011] In various embodiments, the firearm includes a bolt assembly translatable forwardly and rearwardly, the bolt assembly including a firing pin that is offset from the barrel axis for firing rimfire cartridges, and wherein the chamber is configured for necked cartridges. Some embodiments provide for arresting the hammer to facilitate semi-automatic operation. In various embodiments, a trigger pull adjustment mechanism is provided for adjusting a pull required to actuate the firing trigger component.
[0012] In various embodiments of the disclosure, a firearm having a fully cocked configuration and a triggered configuration is disclosed, comprising: a hammer including a sear engagement portion; a biasing element operatively coupled with the hammer that shifts the hammer from a first orientation that corresponds to the fully cocked configuration to a second orientation that corresponds to the triggered configuration; a firing trigger component including a sear portion that engages the sear engagement portion of the hammer when the trigger assembly is in the fully cocked configuration, the firing trigger component being actuatable for disengagement of the sear portion from the sear engagement portion, enabling the biasing element to shift the hammer from the first orientation to the second orientation; a safety trigger component selectively movable between a blocking position and a non-blocking position; and a blocking member that engages the safety trigger component and is moveable by the safety trigger component between a first position wherein the safety effector member prevents actuation of the firing trigger component when the safety trigger component is in the blocking position and a second position wherein the safety effector member enables actuation of the firing trigger component when the safety trigger component is in the non-blocking position.
[0013] The safety trigger component can optionally comprise a catch that prevents the hammer from reaching the second orientation from the first orientation when the safety trigger component is in the blocking position. The manual safety mechanism can include a safety bar accessible from outside the housing. In some embodiments, a housing contains the hammer and the biasing element, wherein the blocking member is selectively engageable with the housing to prevent the safety trigger component from moving the safety effector member. The blocking member can operatively coupled with a manual safety mechanism that selectively engages the safety effector member with the housing. The firing trigger component can be actuatable by rotation about a pivot, the pivot being operatively coupled with the housing.
[0014] In various embodiments of the disclosure, a semiautomatic firearm is presented having a fire trigger with a curvature and a central slot and a safety trigger disposed in the slot and having a curvature conforming to the curvature of the fire trigger, the fire trigger having a normal position and a fire position rearward of the normal position, the safety trigger having a normal position extending forwardly of the normal position of the fire trigger, and a fire position at or rearwardly of the normal position of the fire trigger, the safety trigger associated with at least two firing inhibitors, the firing inhibitors in a inhibiting position when the safety trigger is in the normal position and in a non-inhibiting position when the safety trigger is in the fire position.
[0015] Various embodiments of the disclosure include a hammer that pivots about a pivot axis and has capture features on opposing sides. In some embodiments, the hammer includes a first engagement portion that operates as a hammer to prevent the hammer release unless a safety trigger is retracted, and the hammer includes a second engagement portion as an arrestor that prevents automatic firing action and captures the hammer should the firing trigger remain retracted during a recoil cycle.
[0016] Some embodiments of the disclosure include a semi-automatic firearm suitable for high powered rimfire cartridges that incorporates a trigger assembly with a plurality of firing inhibitors to minimize misfires and out-of-breach firings of cartridges and that still allows for a low pressure trigger pull that can be adjusted by the user, for example, field adjustable.
[0017] Some embodiments disclose a semiautomatic firearm having a fire trigger with a curvature and a central slot and a safety trigger disposed in the slot and having a curvature approximating the curvature of the fire trigger, the safety trigger being connected to a plurality of firing inhibitors that each have an inhibiting position and a non-inhibiting position.
[0018] In various embodiments, a semiautomatic firearm is disclosed having a fire trigger with a curvature and a central slot and a safety trigger disposed in the slot and having a curvature substantially conforming to the curvature of the fire trigger, the fire trigger having a battery position and a fire position rearward of the battery position, the safety trigger also having a battery position extending forwardly of the battery position of the fire trigger, and a fire position at or rearwardly of the battery position of the fire trigger, the safety trigger associated with at least two fire inhibitors, the fire inhibitors being in an inhibiting position when the safety trigger is in the battery position and in a non-inhibiting position when the safety trigger is in the fire position.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1 is a side elevational view of a firearm in an embodiment of the disclosure.
[0020] FIG. 2 is an exploded view of the firearm of FIG. 1 .
[0021] FIG. 3 is an exploded view of receiver and barrel of the firearm of FIG. 1 .
[0022] FIG. 4 is a detail view of the trigger assembly, bolt assembly, chamber, and barrel of a firearm with the receiver removed in an embodiment of the disclosure.
[0023] FIG. 5A is an exploded view of the trigger assembly of FIG. 3 with trigger component cluster depicted as removed from a trigger mechanism housing.
[0024] FIG. 5B is a top perspective view illustrating the interior of the trigger mechanism housing of FIG. 5A .
[0025] FIG. 6 is an elevational view of a firearm with the stock and trigger assembly housing removed in an embodiment of the disclosure.
[0026] FIG. 7 is an exploded view of principal components of the trigger assembly in an embodiment of the disclosure.
[0027] FIG. 8 is a rear cutaway perspective view of the stock and trigger assembly of FIG. 6 with portions of the stock and trigger mechanism housing removed for illustration.
[0028] FIG. 9 is a forward looking right side perspective view of the principal components of the trigger assembly of FIG. 6 in isolation.
[0029] FIG. 10 is a rearwardly looking left side perspective view of the principal components of the trigger assembly of FIG. 6 in isolation. FIG. 11 is a upwardly looking perspective view of the hammer assembly in isolation with the hammer spring extended.
[0030] FIG. 12 is a perspective view of a hammer, a shaft, a bushing, and a rotational spring in assembly in an embodiment of the disclosure.
[0031] FIG. 13 is a side elevation schematic view of trigger assembly components in a battery position, illustrating a cocked configuration of a firing sequence, where a firing trigger and a safety trigger are in a battery position in an embodiment of the disclosure.
[0032] FIG. 14 is the trigger assembly components of FIG. 13 in an enabled configuration of a firing sequence, where the firing trigger is in a battery position and the safety trigger rotated out of the battery position in an embodiment of the disclosure.
[0033] FIG. 15 is the trigger assembly components of FIG. 13 in a fired configuration of a firing sequence, where the safety trigger and the firing trigger are in a firing position in an embodiment of the disclosure.
[0034] FIG. 16 is the trigger assembly components of FIG. 13 where a firing trigger and a safety trigger are in a battery position and the safety trigger catches the hammer to prevent firing in an embodiment of the disclosure.
[0035] FIGS. 17-19 are a side elevation schematic views of the trigger assembly components and the operation of a blocking member during the firing sequence of FIGS. 13-15 in an embodiment of the disclosure.
[0036] FIGS. 20-22 are side elevational schematic views of the trigger assembly components during a cocking sequence to restore the trigger assembly from the triggered configuration to the fully cocked configuration in an embodiment of the disclosure.
[0037] FIG. 23 is a reverse front perspective view of the trigger assembly components and illustrating the arresting mechanism that facilitates semi-automatic operation in an embodiment of the disclosure.
[0038] FIG. 24 is a side elevational view of the trigger assembly components and arresting mechanism of FIG. 23 .
[0039] FIG. 25 is a side reverse rear perspective view of the trigger assembly components and arresting mechanism of FIG. 23 .
[0040] FIG. 26 is a schematic elevational view of operation of the arresting mechanism where the triggers become or remain actuated during the cocking of the firearm.
[0041] FIGS. 27-31 are side elevational schematic views of the trigger assembly components during the cocking sequence of FIGS. 20-22 , illustrating operation of the arresting mechanism in an embodiment of the disclosure.
[0042] FIG. 32 is a partially exploded cutaway view of a trigger pull adjustment mechanism in an embodiment of the disclosure.
[0043] FIG. 33 is an enlarged perspective view of a firing trigger return spring for the trigger pull adjustment mechanism of FIG. 32 in an embodiment of the disclosure.
[0044] FIG. 34 is a perspective view of an adjustment tool for use with the trigger pull adjustment mechanism of FIG. 32 in an embodiment of the disclosure.
[0045] FIG. 35 is a sectional view of the trigger pull adjustment mechanism of FIG. 32 in assembly and operation of the adjustment tool of FIG. 34 in an embodiment of the disclosure.
DETAILED DESCRIPTION
[0046] Referring to FIGS. 1-6 , a firearm 30 generally comprises a trigger assembly 32 , a barrel 34 mounted in a stock 36 and connecting to a receiver 37 . A firearm housing 38 formed of the receiver 37 and stock in this embodiment, engages and extends rearwardly from the barrel 34 and houses a breech 42 and the trigger assembly 32 . The breech 42 is above and forward of the trigger assembly 32 and rearwardly of the barrel. The barrel 34 has a body portion with a smaller outer diameter male threaded portion 40 defining a firing chamber 41 concentric about a barrel axis 43 , the male threaded portion 40 threadably engaging with a female threaded portion 42 of the receiver 37 . In one embodiment, the chamber is configured for necked cartridges, such as the .17 HSR and .17 WSM. A locking nut 44 can threadably engage a larger outer diameter threaded portion 46 of the barrel and tighten against the forward end 48 of the receiver 37 .
[0047] A bolt assembly 52 is slidingly engaged within the receiver 37 and includes a cartridge retraction mechanism 51 , and a manual handle 56 . A cycling spring assembly 55 connects between the bolt assembly and the rearward end 57 of the trigger assembly. A trigger guard 56 extends from the housing 38 .
[0048] The trigger assembly 32 is depicted in detail and various views throughout the figures. The trigger assembly 32 is housed within the firearm housing 38 comprising primarily the stock 36 . The trigger assembly 32 has a trigger mechanism housing 58 which receives a trigger component cluster 59 as best shown in FIG. 5A . The trigger component cluster 59 are generally movable components and pivot about shafts that are supported by the firearm housing 38 . The cluster 59 is depicted in various views without the housing 38 for purposes of clarity. The firearm housing 38 is advantageously formed from injection molding polymers and may have specific metal inserts therein for reinforcement, for example at the rearward projection 60 that is inserted in a cooperating aperture 61 in the rearward end of the receiver 37 .
[0049] Referring to FIGS. 5A-12 , within the trigger mechanism housing 58 , the trigger component cluster 59 generally includes a hammer 82 , a firing trigger component 84 , a safety trigger component 86 , an arrestor 88 , and a manual safety mechanism 90 . The hammer 82 includes a head portion 92 and a cam portion 94 having separated by a stem portion 96 . The cam portion 94 defines an aperture 98 that is mounted to and rotates about a bushing 100 and shaft 101 to define a hammer pivot 102 that actuates about a rotational axis 104 . In one embodiment, the cam portion 94 further includes an arcuate cam surface 105 and a sear engagement portion 106 , the sear engagement portion 106 having a radially extending bearing face 108 . The cam portion 94 can also define a flat 110 that extends at an angle θ from the bearing face 108 . In one embodiment, the angle θ is an obtuse angle. The hammer 82 is also coupled with a biasing element 112 which, in some embodiments, is a rotational spring 114 (FIGS. 11 and 14 - 22 ) that is rotated about and coupled to the hammer pivot 102 with the free ends engaged, for example, with the trigger mechanism housing 58 . The hammer 82 can also include a capture feature 116 . In various embodiments, the capture feature 116 includes an engagement surface 115 . A squared loop 117 in the rotational spring 114 can provide space at the projection for engagement of the projection with the safety trigger component, discussed below.
[0050] As best seen in FIGS. 6 , 7 , 8 , 9 , and 12 , the firing trigger component 84 includes a finger hook portion 122 and a sear portion 124 , the sear portion 124 having a sear surface or cam engagement surface 140 cooperating with and being configured to engage the sear engagement portion 106 and cooperating surface 108 of the hammer 82 . The firing trigger component 84 can be mounted to a trigger pivot 126 configured as a shaft or pin and defining a rotational axis 128 and extending from the trigger mechanism housing 58 along the rotational axis 128 . In some embodiments, the firing trigger component 84 further defines a slot 132 that extends into the finger hook portion 122 and lies on a plane that is substantially perpendicular to the rotational axis 128 . The firing trigger component 84 can also include an extended portion 134 that is engaged with a firing trigger return spring 136 that biases finger hook portion 122 of the firing trigger component 84 in the forward direction 81 . The return spring 136 may be engaged with a ledge or flange portion 137 of the trigger mechanism housing ( FIGS. 4 , 5 A, 5 B, 6 , and 8 ).
[0051] In some embodiments, the firing trigger component 84 includes a cam engagement surface 140 that engages the arcuate cam surface 105 of the hammer 82 .
[0052] The safety trigger component 86 can include a finger hook portion 142 and can be pivotally mounted to the trigger pivot 126 . In various embodiments, the finger hook portion 142 of the safety trigger component 86 is a flat structure, formed from, for example, sheet or plate, that is disposed in the slot 132 of the finger hook portion 122 of the firing trigger component 84 . The finger hook portion 122 of the safety trigger component 86 can also include an aperture 144 . The aperture 144 can be utilized for insertion of a pin or lock, effectively preventing movement of the trigger hook portion particularly with respect to the hook portion of the firing trigger component. As discussed further below, this prevents the firing trigger component 84 from being actuated.
[0053] In one embodiment, the safety trigger component 86 includes a catch portion 146 that is laterally adjacent to the hammer 82 . The catch portion 146 can resemble an inverted “J” shape, for example as depicted in FIGS. 2 and 3 . The safety trigger component 86 can also include an extended portion 148 that is engaged with a safety trigger component return spring 152 . The return spring 152 is attached to the ledge portion 137 of the trigger mechanism housing configured as a ledge. In one embodiment, the extended portion 148 of the safety trigger component 86 includes an arm 154 that extends out of the slot 132 and wraps over and partially around the extended portion 134 of the firing trigger component 84 , as best seen in FIG. 5A , 7 , 8 , and 9 . A spring receiving member 155 shaped as a projection receives the safety trigger return spring 152 .
[0054] Functionally, the safety trigger component return spring 152 exerts a return force on the extended portion 148 of the safety trigger component 86 urging the finger hook portion 142 of safety trigger component 86 to be rotated to a full forward position within the slot 132 of the firing trigger component 84 . In this unactuated or default orientation, the catch portion 146 is positioned so that the catch portion 146 is in a rotational path 162 ( FIG. 14 ) through which the capture feature 116 of the hammer 82 travels during firing and obstructs the hammer 82 . Accordingly, the catch portion 146 intercepts the capture feature 116 of the hammer 82 if the catch portion 146 of safety trigger component 86 has not first been rotated out of the rotational path 162 . Hence, the safety trigger component 86 provides an additional safety mechanism that helps prevent discharge of the firearm 30 in the event of an unintentional release of the hammer 82 —for example, during an impact event where the weapon becomes jarred to the extent that the sear portion 124 of the firing trigger component 84 slips off the sear engagement portion 106 of the hammer 82 .
[0055] During such an impact event, the safety trigger component 86 may undergo rotational displacement that is commensurate with the rotational displacement of the firing trigger component 84 . However, in various embodiments, the rotational displacement required to rotate the catch portion 146 out of the rotational path 162 of the capture feature 116 of the hammer 82 is substantially greater than the rotational displacement required for the sear portion 124 of firing trigger component 84 to disengage the sear engagement portion 106 of the hammer 82 (see discussion below). Accordingly, the safety trigger component 86 will generally still perform the function of intercepting the hammer 82 even if the safety trigger component 86 undergoes the same or even somewhat more rotational displacement than the firing trigger component 84 in an impact event.
[0056] In the depicted embodiments, the capture feature 116 is a lateral projection that extends laterally outward from the hammer 82 in a direction parallel to the rotational axis 104 , for capture by the inverted “J” or other concavity defined by the catch portion 146 . In other embodiments, the capture feature 116 can comprise a notch formed in the hammer 82 , and the catch portion 146 can include a projection that is captured within the notch (not depicted).
[0057] Referring to FIGS. 13 through 15 , an operation sequence of the hammer 82 , the firing trigger component 84 , the safety trigger component 86 , and the bolt assembly 52 from a fully cocked configuration 180 to a triggered configuration 182 is depicted in one embodiment of the disclosure. The FIGS. 13-16 depict the hammer 82 , firing trigger component 84 , and safety trigger component 86 at a mid-plane of the slot 132 , with various appurtenances removed for clarity of illustration.
[0058] In the fully cocked or “battery” configuration 180 ( FIG. 13 ), the sear portion 124 of the firing trigger component 84 is in forced engagement with the sear engagement portion 106 of the hammer 82 , the forced engagement being exerted by the biasing element 112 . The respective finger hook portions 122 and 142 of the firing trigger component 84 and the safety trigger component 86 are held in a forward most orientation by the respective return springs 136 and 152 ( FIGS. 6 , 8 , 9 ). In the fully cocked configuration 180 , the bolt assembly 52 is also in a firing position within the breech 42 , with a firing pin 54 exposed and outwardly extending relative to a rearward end 183 of the bolt assembly 52 . In one embodiment, the firing pin 54 is substantially parallel to but offset from the barrel axis 43 to facilitate firing of rimfire cartridges. Also in the fully cocked configuration 180 , a front edge 184 of the safety trigger component finger hook portion 142 extends distal to a front edge 186 of the firing trigger component finger hook portion 122 .
[0059] An actuation force 192 is applied to the front edge 184 of the safety trigger component finger hook portion 142 ( FIG. 14 ), for example by a squeezing motion applied by a finger of a user. The actuation force 192 causes the safety trigger component 86 to rotate about the trigger pivot 126 , so that the catch portion 146 is rotated out of the rotational path 162 of the capture feature 116 , thereby clearing the hammer 82 for an unobstructed rotation to the firing pin 54 . In the FIG. 14 depiction, the safety trigger component 86 is progressing toward a firing position, while the firing trigger is in a battery position.
[0060] The actuation force 192 then engages the firing trigger component 84 , thereby causing the firing trigger component 84 and the safety trigger component 86 to rotate effectively simultaneously about the trigger pivot 126 and into firing positions. The rotation of the firing trigger component 84 causes the sear portion 124 to rotate away from the hammer 82 and slide radially outward from the hammer pivot 102 along the sear engagement portion 106 . When the sear portion 124 slides off the sear engagement portion 106 , the hammer 82 is released and swings into contact with the firing pin 54 , thereby establishing the triggered configuration 182 where both the safety trigger component 86 and the firing trigger component 84 are in a firing position ( FIG. 15 ).
[0061] The positions of respective finger hook portions 122 and 142 of the firing trigger component 84 and the safety trigger component 86 for both the fully cocked configuration 180 and the triggered configuration 182 are presented in FIG. 15 , with the positions from the fully cocked configuration 180 being presented in phantom. Angular displacements α and β of the safety trigger component 86 and the firing trigger component 86 , respectively, are also overlaid onto FIG. 15 . By this illustration and for this embodiment, the angular displacement α of the safety trigger component 86 in transitioning from the fully cocked configuration to the triggered configuration is about three times greater than the angular displacement β of the firing trigger component 84 . As such, the safety trigger component 86 will generally still perform the function of intercepting the hammer even if the safety trigger component 86 undergoes the same or even somewhat more rotational displacement than the firing trigger component 84 in an impact event.
[0062] Referring to FIG. 16 , the functionality of the safety trigger component 86 during an abnormality such as an impact event is further illustrated in an embodiment of the disclosure. Consider an impact event where inertial forces cause a dynamic load 188 on the respective finger hook portions 122 and 142 of the firing trigger component 84 and the safety trigger component 86 , such that both finger hook portions 122 and 142 are rotationally displaced by the angular displacement β required to release the hammer 82 . At the angular displacement β, the catch portion 146 is still operational within the rotational path 162 of the capture feature 116 , and still functions to arrest the hammer 82 and prevent discharge of the firearm 30 .
[0063] Referring again to FIGS. 4 through 10 , and 12 , the trigger assembly 32 includes the manual safety mechanism 90 conventionally positioned forward of the firing trigger. The safety mechanism 90 includes a safety bar 194 with exposed push buttons 195 , 196 on each end, a shaft 197 integral with one of the push buttons 195 , 196 for aligning and securing the safety mechanism components together, and a rotatable blocking member 200 . A pin 198 may extend through apertures 199 , 201 in the shaft 197 and end button 196 to secure the manual safety mechanism 90 . The blocking member 200 can include a lever portion 202 that projects radially outward from an arcuate base portion 204 . The arcuate base portion 204 rotates freely about a blocking member pivot 206 defined by the shaft 197 . In one embodiment, a notch or recess 208 is formed on the arcuate base portion 204 to provide a non-blocking position for an engagement tab 209 proximate the sear portion 124 of the trigger component. The manual safety mechanism 90 is laterally slidable within the trigger mechanism housing 58 in apertures 210 , 213 on opposing sides of the housing 58 .
[0064] The safety trigger component 86 can include a fork 211 comprising a pair of protrusions 212 a and 212 b that contact the blocking member 200 . The firing trigger component 84 can include an underside 214 against which the lever 202 of the blocking member 200 registers. In the depicted embodiment, the underside 214 defines a recess 215 within which the lever 202 registers The firing trigger component 84 can further include a projection 216 that is proximate the arcuate base portion 204 of the blocking member 200 .
[0065] Referring to FIGS. 17 through 19 , operation of the blocking member 200 during discharge of the firearm 30 is depicted in an embodiment of the disclosure. In the fully cocked configuration 180 ( FIG. 9 ), the lever portion 202 of the blocking member 200 extends between the protrusions 212 a and 212 b and is engaged or nearly engaged within the underside 214 of the firing trigger component 84 . The protrusion 212 b of the safety trigger component 86 maintains the blocking member 200 in engagement/near engagement with the firing trigger component 84 , thereby preventing the firing trigger component 84 from rotating away from the hammer 82 . Also in the fully cocked configuration 180 , the arcuate base portion 204 of the blocking member 200 can also interfere with the projection 216 of the firing trigger component 84 , further preventing actuation of the firing trigger component 84 .
[0066] During actuation of the safety trigger component 86 , the protrusion 212 a rotates against blocking member 200 , causing the lever portion 202 to rotate away from the underside 214 of the firing trigger component 84 . The rotation of the blocking member 200 also causes the recess 208 of the arcuate base portion 204 to rotate into alignment with the projection 216 of the firing trigger component 84 ( FIG. 10 ). During continued actuation of the safety trigger component 86 and subsequent actuation of the firing trigger component 84 , the lever portion 202 has now been removed as an obstacle to rotation of the firing trigger component 84 ( FIG. 11 ), and the recess 208 now accommodates the projection 216 of the firing trigger component.
[0067] Accordingly, when the firearm 30 is in the fully cocked configuration, the safety trigger component 86 controls the orientation of the blocking member 200 . As the safety trigger component 86 is actuated, the blocking member 200 is oriented so as not to pose an obstruction to the firing trigger component 84 , freeing the firing trigger component 84 for rotation away from the hammer 82 and subsequent discharge of the firearm 30 .
[0068] Functionally, in the fully cocked configuration 180 , if an actuation force or “pull” is exerted on the firing trigger component 84 but somehow not exerted on the safety trigger component 86 , the blocking member 200 will maintain engagement with the firing trigger component 84 , thereby preventing rotation of the firing trigger component 84 and subsequent discharge of the firearm 30 . Thus, in one embodiment, the blocking member 200 can provide a redundant or additional safety mechanism against accidental discharge of the firearm 30 . Instead of relying solely on the friction between the sear portion 124 and the sear engagement portion 106 , the blocking member 200 provides a positive blocking force that helps prevent disengagement of the sear and the sear engagement portions 124 and 106 in an impact event. Moreover, the lever portion 202 engaging the recess in the trigger component prevents the pivoting of the component about the pivot. In some embodiments, the blocking member 200 can be the sole safety mechanism; that is, the blocking member 200 is utilized without the catch portion 146 instead of in addition to the catch portion 146 .
[0069] Referring to FIGS. 20 through 22 , restoring the trigger assembly 32 from the triggered configuration 182 to the fully cocked configuration 180 (referred to herein as “cocking”) is depicted in an embodiment of the disclosure. After discharge of the firearm 30 , the projection 216 of the firing trigger component 84 is seated in the recess 208 , held in place by the cam portion 94 of the hammer 82 ( FIG. 20 ). The seating of the projection 216 in the recess 208 prevents rotation of the blocking member 200 ; that is, in the triggered configuration 182 , the orientation of the blocking member 200 is not controlled by the safety trigger component 86 (as is the case in the fully cocked configuration 180 ), but instead is controlled by the firing trigger component 84 and hammer 82 . Accordingly, the blocking member 200 now acts against protrusion 212 b to hold the safety trigger component 86 in a pitched orientation, wherein the catch portion 146 is rotated away from the rotational path 162 of the capture feature 116 .
[0070] The bolt assembly 52 is motivated in the forward direction 80 by a force 222 , imparted, for example, manually by a gunman or by a blow back mechanism. This motivation causes the bolt assembly 52 to rotate the head portion 92 of the hammer 82 in the forward direction 80 , which further causes the cam portion 94 to rotate on the cam engagement surface 140 . The cam engagement surface 140 is maintained in contact with the cam portion 94 by a return force 224 imparted on the firing trigger component 84 by the firing trigger return spring 136 .
[0071] As the head portion 92 of the hammer 82 is rotated in the forward direction 80 , the capture feature 116 is rotated below the hook of the catch portion 146 ( FIG. 13 ), while the cam portion 94 of the hammer 82 maintains the interlock between the firing trigger component 84 and safety bar 200 (and therefore the pitched orientation of the safety trigger component 86 ).
[0072] At some point after the capture feature 116 of the hammer 82 is rotated below the hook of the catch portion 146 , the arcuate cam surface 105 of the cam portion 94 rotates off the cam engagement surface 140 ( FIG. 14 ). At this point, the arcuate cam surface 105 of the cam portion 94 releases the firing trigger component 84 . The firing trigger component 84 , motivated by the return force 224 generated by the firing trigger return spring 136 , then rotates (counterclockwise in FIG. 14 ) so that the cam engagement surface 140 is brought into contact with the flat 110 of the cam portion 94 ; the sear portion 124 of the firing trigger component 84 is brought adjacent to the sear engagement portion 106 of the hammer 82 . The release of the firing trigger component 84 by the arcuate cam surface 105 also causes the projection 216 of the firing trigger component 84 to become unseated from recess 208 of the blocking member 200 . Control of the orientation of the blocking member 200 is thereby transferred to the safety trigger component 86 , which, propelled by the return force 224 , rotates the blocking member 200 (clockwise in FIG. 22 ) into the underside 214 of the firing trigger component 84 .
[0073] Upon withdrawal of the bolt assembly from contact with the hammer 82 and into the firing position, the fully cocked configuration 180 of the firearm 30 is restored (e.g., FIG. 17 ), with the blocking member 200 preventing actuation of the firing trigger component 84 that is independent of actuation of the safety trigger component 86 , and the catch portion 146 poised to intercept the hammer 82 in case of unintentional release of the hammer 82 .
[0074] In one embodiment, and again in reference to FIGS. 4 through 10 and 12 , the blocking member 200 is part of a manual safety mechanism 230 that can be translated with the blocking member 200 laterally within the trigger mechanism housing 58 along a blocking member axis 234 . When part of the manual safety mechanism 230 , the lever 202 of the blocking member 200 can be selectively engaged with a stop 236 (best seen in FIGS. 5B and 6 ) that extends from the interior surface 44 of the trigger mechanism housing 58 along the right side wall 237 of the trigger mechanism housing 58 . In the embodiment illustrated, when the manual safety mechanism 230 is pushed in one direction (e.g., to the right in the depicted embodiments), the firearm 30 is configured in a “safety mode,” wherein the blocking member lever 202 is prevented from rotating out of the blocking position by the ramp or stop 236 .
[0075] When the manual safety mechanism 230 is pushed in an opposite direction (e.g., to the left in the depicted embodiments), the firearm is configured in a “firing mode,” wherein release of the sear portion 84 of the firing trigger component 84 from the sear engagement portion 106 of the hammer 82 is enabled. In the firing mode, the lever portion 202 is displaced off of the stop 236 , enabling rotation by the fork 211 of the safety trigger component 86 and rotation the lever portion 202 out of the blocking position with the underside 214 of the firing trigger component 84 . The lever 202 can be sized widthwise such that, during lateral movement of the blocking member 200 , the lever maintains engagement of the safety trigger fork 211 . Also, the lever 202 , when engaged with the underside 214 on the lower side of the firing trigger component 84 , can maintain blockage and/or engagement with the underside 214 during lateral actuation. Engagement with the underside 214 is lost only upon the rotation of the blocking member 200 .
[0076] It is further noted that aspects of the embodiments depicted in FIGS. 17 through 22 may be suited for automatic operation. (Herein, “automatic operation” is characterized as the continuous, round after round discharge of ammunition as long as the firing trigger component 84 is depressed.) For the embodiments of FIGS. 17 through 22 , as long as the triggers 84 and 86 are held in the firing position (depicted in FIG. 19 ), the sear portion 124 of the firing trigger component 84 will not be brought into engagement with the sear engagement portion 106 of the hammer 82 , and the catch portion 146 will not obstruct the hammer 82 in either rotational direction. Accordingly, certain aspects of the embodiment of FIGS. 179 through 14 can be utilized in an automatic firearm.
[0077] Referring to FIGS. 23 through 25 , an arresting mechanism 260 that facilitates semi-automatic operation (as opposed to automatic operation) is depicted in an embodiment of the disclosure. (Herein, “semi-automatic operation” is characterized by the automatic reloading of the firearm 30 , but the requirement to release and re-actuate the triggers 84 and 86 to initiate firing.)
[0078] In one embodiment, the arresting mechanism 260 involves interaction of at least four components: the bolt assembly 52 , the hammer 82 , the firing trigger component 84 , and an arrestor 88 . The arrestor 88 is pivotally mounted within the housing 38 and distal to the hammer 82 . In one embodiment, the arrestor 88 includes a claw portion 264 and a rocker arm portion 266 . The claw portion 264 can include a rounded head portion 268 and a radiused nose 272 . An arrestor return spring 274 can be operatively coupled to the arrestor 88 . In one embodiment, the arrestor 88 is pivotally mounted to the trigger pivot 126 .
[0079] In various embodiments, the arresting mechanism 260 can include a cavity 282 formed in the head portion 92 of the hammer 82 , the cavity 282 and head portion 92 further defining a lip portion 284 . In one embodiment, the firing trigger component 84 includes a lateral protrusion 286 that is part of the arresting mechanism, the lateral protrusion 286 being positioned to engage the rocker arm portion 266 of the arrestor 88 .
[0080] In one embodiment, the arrestor 88 is configured and positioned so that the claw portion 264 is engageable with the lip portion 284 of the cavity 282 when the hammer 82 is hyperextended in the forward direction 80 . Herein, the hammer 82 is considered “hyperextended” when the head portion 92 of the hammer 82 is displaced to be forward to where the head portion 92 is located when in the fully cocked configuration 180 .
[0081] Referring to FIGS. 26 through 31 , operation and function of the arresting mechanism 280 in a scenario where the triggers 84 and 86 become or remain actuated during the cocking of the firearm 30 is depicted in an embodiment of the disclosure. Functionally, the arresting mechanism 260 captures the hammer 82 and prevents the hammer 82 from automatically re-firing. To more closely resemble the views presented in FIGS. 23 through 25 , the FIGS. 26 through 31 are presented in an opposing side view relative to the views of FIGS. 17 through 22 . Also, for illustrative clarity, the biasing element 112 , as well as the various return springs 136 , 152 and 274 , are not presented in FIGS. 26 through 31 , though they may be present in certain embodiments. Also for illustrative clarity, only the components of the arresting mechanism 260 (i.e., the bolt assembly 52 , the hammer 82 , the firing trigger component 84 , and an arrestor 88 ) are depicted in FIGS. 26 through 29 .
[0082] When an actuation force 292 is applied to the triggers 84 and 86 , the lateral protrusion 286 of the firing trigger component 84 is pitched in the distal direction 81 . The arrestor 88 , being biased by the arrestor return spring 274 , follows the firing trigger component 84 , being stopped by the lateral protrusion 286 . When the firing trigger component 84 is depressed, the lip portion 284 of the cavity 282 encounters the rounded head portion 268 and/or radiused nose 272 of the claw portion 264 as the head portion 92 of the hammer 82 is rotated in the forward direction 80 during cocking of the firearm 30 ( FIG. 26 ). The interaction between the lip portion 284 and the rounded head portion 268 , radiused nose 272 of the claw portion 264 to rotate slightly in the forward direction 80 , such that the rocker arm portion 266 rotates off the lateral protrusion 286 of the firing trigger component 84 ( FIG. 27 ). As the head portion 92 of the hammer 82 becomes hyperextended, the lip portion 284 slips past the radiused nose 272 of the claw portion 264 , the arrestor 88 is rotated so that the rocker arm 266 is again in engagement with the lateral protrusion 286 of the firing trigger component 84 , motivated by a return force 294 ( FIG. 28 ) generated by the arrestor return spring 274 . The rotation causes the claw portion 264 to rotate at least partially into the cavity 282 .
[0083] The bolt assembly 52 then retracts back into the firing position, becoming disengaged from the hammer 82 ( FIG. 29 ). The disengagement causes the head portion 92 of the hammer 82 to rotate in the distal direction 81 until the lip portion 284 of the cavity 282 is hooked by an underside 296 of the claw portion 264 . The arresting mechanism 260 remains in equipoise as long as the firing trigger component 84 remains in the actuated position. In this way, the arresting mechanism 260 captures the hammer 82 and prevents the hammer 82 from automatically re-firing.
[0084] In one embodiment, upon removal of the actuation force 292 (e.g., when the gunman removes his finger from the firing trigger component 84 ), the return force 228 of the firing trigger return spring 136 causes rotation of the firing trigger component 84 so that the lateral protrusion 286 of the firing trigger component 84 is rotated upwards (clockwise in FIG. 30 ). The lateral protrusion 286 causes the rocker arm 266 of the arrestor 88 to also rotate upward, thereby decoupling the lip portion 284 of the cavity 282 from the underside 296 of the claw portion 264 . The lip portion 284 of the hammer 82 then slips past the radiused nose 272 of the claw portion 264 , being motivated by the biasing element 112 , thereby releasing the hammer 82 from the arrestor 88 .
[0085] The rotation of the firing trigger component 84 upon removal of the actuation force 292 also causes the cam engagement surface 140 to come into contact with the flat 110 of the cam portion 94 , which brings the sear portion 124 of the firing trigger component 84 proximate and adjacent to, but not in contact with, the sear engagement portion 106 of the hammer 82 ( FIG. 30 ). Upon release of the hammer 82 from the arrestor 88 , the head portion 92 of the hammer 82 further rotates in the distal direction 81 , until the bearing face 108 of the sear engagement portion 106 is fully registered against the sear portion 124 of the firing trigger component 124 ( FIG. 31 ). The trigger assembly 32 is then in the fully cocked configuration 180 .
[0086] It is further noted that, in various embodiments, if the firing trigger component 84 is not actuated when the hammer 82 reaches the hyperextended position, the arrestor 88 is not in a position to engage and/or secure the lip portion 284 of the hammer 82 . Accordingly, the arrestor 88 does not substantially interfere with the cocking operation if the firing trigger component 84 is not actuated.
[0087] The barrel and receiver may be conventionally manufactured from steel. In various embodiments, other metals may be used. The components of the trigger assembly cluster are generally conventionally formed from steel or other metals. In some instances, polymers may replace some components. For example the trigger mechanism housing may be made from polymers and composite materials. Metal inserts may be used for particular areas requiring high strength such as attachment locations. See projection 60 and the trigger guard 56 (see FIGS. 5A and 5B ). Also, see FIG. 3 the polymer access cover 290 has a metal insert 291 for strength and providing the catch surfaces. The polymer may be overmolded over the insert capturing the insert. The stock can be formed from polymers or wood or composite materials.
[0088] Referring to FIGS. 32 and 33 , a trigger pull adjustment mechanism 300 is depicted in an embodiment of the disclosure. The trigger pull adjustment mechanism 300 comprises an adjustable firing trigger return spring 302 disposed in place of the firing trigger return spring 136 (as depicted, for example, in FIG. 10 ) and operatively coupled to the ledge portion 137 and the firing trigger component 84 to exert a separating force therebetween. This separating force constitutes a component of the pull or actuation force required to actuate the firing trigger component 84 for releasing the hammer 82 .
[0089] In the depicted embodiment, the adjustable firing trigger return spring 302 includes an upper portion 304 and a lower portion 306 spiral wound about a spring axis 308 . A transition segment 312 can be formed in the lower-most spiral 314 of the upper portion 304 , the transition segment 312 passing through the adjustable firing trigger return spring 302 proximate the spring axis 308 . In one embodiment, the transition segment 312 is substantially linear over a portion thereof. In the way, the transition segment 312 obstructs what would otherwise be a clear passage through the adjustable firing trigger return spring 302 . The upper and lower portions 304 and 306 can be of different diameter, as depicted. Also in the depicted embodiment, the upper portion 304 terminates with a tail portion 316 that is substantially concentric with the spring axis 308 . The ledge portion 137 can define a mounting hole 318 within which the tail portion 316 is mounted in assembly.
[0090] In assembly, the lower portion 306 of the adjustable firing trigger return spring 302 is firmly seated within a through-hole 322 defined on the firing trigger component 84 . The firm seating of the lower portion 306 within the through-hole 322 can be accomplished by an interference fit between an inner wall 324 of the through-hole 322 and the lower portion 306 of the spring 302 as wound. The interference fit provides a high degree of friction between the inner wall 324 of the through-hole 322 and the lower portion 306 of the spring 302 , thereby fixing the compressed length of the spring 302 . In this embodiment, while the friction is sufficient to maintain the compressed length 302 of the spring when the firearm 30 is in the fully cocked configuration 180 (i.e., prior to actuation of the firing trigger component 84 ), the spring 302 In one embodiment, the through-hole 322 is tapered to augment the seating operation during assembly and rotation of the spring 302 during an adjustment.
[0091] Referring to FIG. 34 , an adjustment tool 330 for rotating the adjustable firing trigger return spring 302 is depicted in an embodiment of the disclosure. The adjustment tool 330 includes a shaft portion 332 with a slot 334 defined on one end thereof. A diameter 336 of the shaft portion 332 is dimensioned to readily pass through the interior of the lower portion 306 of the spring 302 . A width 338 of the slot 334 is dimensioned to receive the transition segment 312 of the spring 302 . Optionally, the adjustment tool 330 includes a handle portion 339 disposed proximate the end of the adjustment tool 330 that is opposite the slot 334 .
[0092] Referring to FIG. 35 , adjustment of the trigger pull adjustment mechanism 300 is depicted in an embodiment of the disclosure. In the depicted embodiment, access passages 342 are formed in the trigger guard 56 , sized to allow passage of the shaft 332 of the adjustment tool 330 . The adjustment tool 330 is inserted through the access passages 342 and the lower portion 306 of the adjustable firing trigger return spring 302 and brought into contact with the transition segment 312 . The adjustment tool is rotated and pushed against the transition segment so that the slot 334 is aligned with and accepts the transition segment 312 . With the transition segment 312 seated within the slot 334 , the adjustment tool 330 is rotated to overcome the friction between the lower portion 306 and the inner wall 324 of the through-hole 322 , thereby changing the compressive force of the spring 302 when in the battery position. By increasing the compression of the spring 302 , the restorative force generated by the spring 302 is increased, thereby increasing the pull required to actuate the firing trigger component 84 ; by decreasing the compression of the spring 302 , the restorative force generated by the spring 302 is decreased, thereby decreasing the pull required to actuate the firing trigger component 84 . The friction between the lower portion 306 and the inner wall 324 of the through-hole 322 is sufficient to maintain the adjusted compression of the spring 302 during operation of the firearm 30 .
[0093] Accordingly, the disclosed trigger pull adjustment mechanism 300 accomplishes adjustment of the trigger pull with fewer components and with reduced machining complexity. For example, conventional trigger pull adjustments utilize an additional set screw that requires a threaded hole for the compression adjustment. The trigger pull adjustment mechanism 300 eliminates the need for these components and attendant complexity.
[0094] Other adjustable trigger mechanisms can be implemented instead. Such mechanisms are illustrated, for example, in U.S. Pat. No. 6,553,706, owned by the owner of this application, the disclosure of which is hereby incorporated reference herein in its entirety except for express definitions and patent claims contained therein. See also U.S. Pat. Nos. 8,220,193 and 8,250,799, the disclosures of which are hereby incorporated reference herein in their entirety except for express definitions and patent claims contained therein.
[0095] The above references in all sections of this application are herein incorporated by references in their entirety for all purposes. For purposes of interpreting the claims, it is expressly intended that the provisions of Section 112, sixth paragraph of 35 U.S.C. are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.
[0096] All of the disclosures in this specification (including the references incorporated by reference, including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.
[0097] Each feature disclosed in this specification (including references incorporated by reference, any accompanying claims, abstract and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.
[0098] When “linked”, “coupled”, and “connected” are used herein, the terms do not require direct component to component physical contact connection, one or more intermediary components may be present.
[0099] Inventions flowing from the present disclosure are not restricted to the details of the foregoing embodiment(s). The inventions extend to any novel one, or any novel combination, of the features disclosed in this specification (including any incorporated by reference references, any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed The above references in all sections of this application are herein incorporated by references in their entirety for all purposes.
[0100] Although specific examples have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement calculated to achieve the same purpose could be substituted for the specific examples shown. This application is intended to cover adaptations or variations of the present subject matter. Therefore, it is intended that the invention be defined by the attached claims and their legal equivalents, as well as the following illustrative aspects. The above described embodiments are merely descriptive of its principles and are not to be considered limiting. Further modifications of the embodiments herein disclosed will occur to those skilled in the respective arts and all such modifications are deemed to be within the scope of the inventions. | A semiautomatic firearm with redundant systems for reducing misfirings. A safety trigger is provided that is passively actuated in advance of a firing trigger. The safety trigger maintains redundant safety mechanisms that prevent inadvertent or accidental actuation of the firing trigger. The firing trigger can be configured for actuation with a very low magnitude or “soft” pull without compromising safety. For the disclosed embodiments, the safety trigger assures that the firearm is discharged only upon deliberate actuation of the firing trigger. In one embodiment, a trigger pull adjustment mechanism provides adjustment of the pull of the firing trigger to a desired force required by the operator. The disclosed trigger pull adjustment mechanism reduces the number of components and complexity of the machined parts over conventional trigger pull adjustment mechanisms. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an apparatus for testing electrical equipment provided with multi-contact connectors, and more particularly, for an electrical connecting apparatus capable of testing without marring the conducting surface of the terminals on multi-contact connectors.
2. Discussion
Many kinds of electronic apparatus are designed, manufactured, and sold to be used in conjunction with other complex electronic equipment. Frequently much of that equipment has been made in a different location by a completely different manufacturer. Interconnection technology which has been developed over the years has produced a series of standard multi-pin connectors which are common throughout the industry. Thus, the purchaser knows that the connector on a computer printer, for example, from one source will match a receptacle on a computer from another source. An analogy can be made to the two-pronged plug on a common household electric lamp, which will match virtually any electrical receptacle in the country.
However, the voltages encountered in most electronic circuits are usually several orders of magnitude less than the 110 volts standard domestic electric service. These small voltages demand superb electric contact from one circuit to another; any contamination, corrosion, or misalignment of a single contact can result in failure of the involved circuitry.
The individual contacts on these standardized connectors are usually cylindrical, gold plated brass or other electrically conductive metal pins assembled in a regularly spaced array which fit with sliding engagement into mating receptacles of gold plated metallic tubes. Gold is usually the material of choice for all exposed surfaces of these connectors because of its superb electrical conductivity and excellent resistance to corrosion. However, gold is a relatively soft metal, and every insertion of a male connector pin into a female receptacle erodes the thin gold plate, so that after just a few cycles the underlying base metal can be exposed to atmospheric corrosion and potential subsequent circuit failure.
Thus, it is highly desirable for a manufacturer to ship to its customers connector apparatuses in an original, pristine condition, unmarred by any premature insertion into a mating receptacle. Offsetting this need is the necessity to thoroughly test the electrical circuitry of the manufactured article prior to shipment.
U.S. Pat. Nos. 2,158,630 and 3,414,814 teach spring-loaded contactors that just touch the surface of the end points of all circuit paths. U.S. Pat. No. 3,803,483 discloses a semiconductor structure for testing the inner connector networks on insulative surfaces which are to support integrated circuit chips in integrated circuit modules; and U.S. Pat. Nos. 4,225,819 and 4,232,262 disclose apparatuses for testing connectors to detect the presence of contaminating films and foreign materials on the contact terminals of a connector or the conducting fingers of a printed circuit board.
U.S. Pat. No. 4,229,691 discloses a method and apparatus for testing telephone cords which are terminated with modular plugs utilizing test probes brought into engagement with terminal blades on the plugs. U.S. Pat. No. 4,658,212 discloses an apparatus for examining the status of individual terminal pins in a connector by engaging the point of the pin with a spring driven test probe.
U.S. Pat. No. 4,734,651 discloses an apparatus for testing electrical continuity of electrical terminals of a multi-contact electrical connector by engaging a respective electrical test probe with each of the terminals and using a multiplexer to connect each test probe in turn to a continuity testing circuit under the control of a computer.
U.S. Pat. No. 4,757,254 discloses a high-speed, side access edge connector testing assembly wherein plural probe contacts are mounted to a movable, linear carriage so that the probe connectors can be moved into and out of contact with the edge connector of a unit under test.
SUMMARY OF THE INVENTION
The present invention provides an electrical connecting apparatus which supports a multiple pin connector under test so that the terminal pins of the connector can be electrically engaged without marring the connecting surface of said pins. The apparatus comprises a housing member which has a connector nesting cavity, and a cantilever clamp is supported by the housing member for retaining the connector under test in the nesting cavity. A contact assembly is provided for electrically contacting the pins of the connector, the contact assembly characterized as having a plurality of biased pin contactors disposed to touch the nonfunctional ends of the connector in a connected mode so as to make electrical contact while maintaining the pristine surface condition of the functional ends of the connector pins. An ejector device is disposed to eject the electrical connector from the connector nesting cavity in an unconnected mode.
An object of the present invention is to provide an apparatus for supporting a multiple pin connector under test so that electrical contact is made without physical defacement of the surface of the contact surfaces functional in the final application of the connector.
As will be shown hereinafter, it is Applicant's belief that Ozawa et al. and Hollister et al. (either singularly or in combination) do not disclose, teach or even suggest the electrical connecting apparatus as recited in each of Applicant's claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric, semi-detailed view of an electrical connecting apparatus constructed in accordance with the present invention and showing the placement of a connector under test.
FIG. 2 is an exploded isometric view of the connector nest assembly of the electrical connecting apparatus of FIG. 1.
FIG. 3 is a front elevational view of the connector nest assembly.
FIG. 4 is a side elevational view of the connector nest assembly.
FIG. 5 is a schematical representation of a typical biased pin connector.
DESCRIPTION
Referring to FIG. 1, shown therein is an electrical connecting apparatus 10 constructed in accordance with the present invention and comprising a connector nest assembly 12 preferably made of a plastic or other non-conducting material. As shown in FIGS. 2 through 4, the connector nest assembly 12 comprises a housing member 13 which is supported by a frame or the like (not shown) and which has a nesting cavity 14 suitably dimensioned to receive an electrical connector 16 under test. An ejector pin bore 18 extends through the housing member 13 and is appropriately sized to accommodate an ejector pin 20. A cantilever clamp 22 is fastened at one end thereof to the housing member 13 by pairs of attachment bolts 24, and washers 28 so that the outboard end of the clamp 22 is raised, or flexed, sufficiently by the connector 16 as the connector 16 is inserted into the nesting cavity 14.
The bolts 24 extend through holes in the cantilever clamp 22 and engage threaded holes 30 in the housing member 13 in sufficient depth to permit limited movement or flexing of the clamp 22. The clamp 22 is preferably made of a material which permits it to be subjected to repeated elastic bending. However, if desired, compression springs can be added under the bolts 24 to urge the clamp 22 toward the housing member 13 and to retain the connector 16 within the confines of the nesting cavity 14 in the connector nest assembly 12. The limits of the nesting cavity 14 are defined by an upper cavity side 32, an end cavity side 34, a lower cavity side 36 and a back cavity side 38.
The cantilever clamp 22 is preferably constructed of a transparent plastic, such as a polycarbonate, or other semi-rigid material which permits viewing the connector 16 under test to assure that it is properly seated in the nesting cavity 14. When so constructed, the clamp 22 is a semi-rigid or somewhat flexible member that is flexed sufficiently by action of the connector 16 as it is pushed into the nesting cavity 14 to permit passage thereof and to retain the connector 16 securely in the nesting cavity 14 until the connector 16 is ejected therefrom.
The ejector pin 20 is a rod member with a head portion 40 having a major diameter and a handle portion 42 having a minor diameter dimensioned to be slidingly received in the ejector pin bore 18 in the housing member 13. The distal end of the handle portion 42 is threaded to receive a thumb nut 44. A retraction spring 46 is disposed under the thumb nut 44. In its normal or rest position, the retraction spring 46 causes the ejector pin 20 to be withdrawn into the ejector pin bore 18 completely clear of the nesting cavity 14. Simple hand pressure against the thumb nut 44 will push the ejector pin 20 to assume its ejection position in which the ejector pin 20 extends into the nesting cavity 14 to eject the connector 16 from the nesting cavity 14 after completing the required tests. As shown, an ejector pin clearance path 18A is provided in the back cavity side 38 within the nesting cavity 14 for travel of the ejector pin 20.
As depicted in FIG. 1, a device 48 is under test. The device 48 has a cable 50 with the connector 16 secured to the distal end thereof. The connector 16 has a plurality of connector pins 52 which serve to provide electrical communication to the device 48 through the cable 50. The connector pins 52 have a front functional (connecting) end (not shown) and a back nonfunctional end 52. The back end is utilized to attach the individual connector pins 52 to individual conductors in the cable 50. It is to be understood that the depiction of the connector 16 and the connector nest assembly 12 is representative, and that a wide variety of sizes and shapes of connectors can be accommodated by the present invention.
A contact assembly 53 is provided for contacting a back, nonfunctional end 52A of the connector pins 52 and comprises a test contact holder 54 which is aligned with the connector 16 seated in the nesting cavity 14. The test contact holder 54 supports a plurality of biased pin contactors 56 (FIG. 5) positioned so that the nonfunctional end 52A of each of the connector pins 52 on the connector 16 is contacted by one of the biased pin contactors 56. Each biased pin contactor 56 has a terminal end 58, to which is attached a separate electrical conductor of a test cable 60, which in turn is attached to selected test equipment 62. Although not shown, the test cable 60 will normally be provided a slack loop or the like to accommodate travel of the contact assembly 53.
The biased pin contactor 56 utilized in the present invention is a typical contactor well known in the electronics industry, and is represented by the view in FIG. 5. All parts of the biased pin contactor 56 are usually constructed of electrically conductive metal which has been gold plated to enhance conductivity and to increase corrosion resistance. Such biased pin contactors 56 usually comprise a contact plunger 64 with a contact head 66 at its external end. The contact plunger 64 is slidingly engaged within a receiving tube 68, and a biasing spring 70 is disposed against an internal shoulder 72 inside the receiving tube 68 so that the contact plunger 64 is yieldingly supported by the tube while FIG. 5 represents the biasing spring 70 as pressing against the contact head 66, in most cases biased spring contactors will dipose the biasing spring entirely within the confines of the receiving tube with only the contact head end of the contact plunger extending from the receiving tube. However, the operation of the latter described biased pin contactor will be identical to the biased pin contactor 56. The terminal end 58 of the receiving tube 68 of the biased pin contactor 56 is provided for connection to the test cable 60.
Although other face styles are available and theoretically usable, the outside face of the contact head 66 in the preferred embodiment is conically concave, and the back, nonfunctional end 52A of each connector pin 52 approximates a dull point in shape. Hence, when the contact head 66 contacts its mating connector pin 52, at its nonfunctional end 52A, electrical communication is established, and the front end (not shown) of the connector pin is left untouched, thus leaving the functional surface of the connector pin in its original pristine condition.
The test contactor holder 54 of the contact assembly 53 is supported for sliding to and fro movement on bearing surfaces (not shown), and a positioning screw 74 is provided to selectively produce such reciprocating movement to the test contactor holding 54. The positioning screw 74 is bearingly connected to the test contactor holder 54 and is rotated by a reversing electric motor 76. Applying electric power to the motor 76 will rotate the positioning screw 74 to move the test contactor holder 54 forward until the biased pin contactors 56 are in electrical contact with the connector pins 52 of the connector 16 seated in the nesting cavity 14. At the end of the test cycle, the motor 76 is reversed, turning the positioning screw 74 in the opposite direction and moving the test contactor holder 54 away from the connector 16 under test.
To remove the connector 16 from the nesting cavity 14 of the connector nest assembly 12, once the test contactor holder 54 is retracted, the ejector pin 20, via hand pressure against its thumb nut 44, is pushed from its resting position (where it is disposed so as to not interfere with the connector 16 under test) to an ejection position whereat the head portion 40 extends into the nesting cavity 14 to eject the connector 16 from the connector nest assembly 12. The connector 16 is then removed and a new connector is inserted to repeat the test cycle.
It will be clear that the present invention is well adapted to carry out the objects and attain the ends and advantages mentioned as well as those inherent therein. While a presently preferred embodiment has been described for purposes of this disclosure, numerous changes may be made which will readily suggest themselves to those skilled in the art and which are encompassed in the spirit of the invention disclosed and as defined in the appended claims. | An electrical connecting apparatus supporting a multiple pin connector under test so that the connector pins of the connector can be electrically engaged without touching the functional connecting surface of the connector pins, the apparatus comprising a housing member with a connector nesting cavity and a cantilever clamp for retaining the connector under test in the nesting cavity. A contact assembly causes plural spring biased pin contactors to contact the connector in a connected mode so as to make electrical contact while maintaining the pristine surface condition of the functional ends of the connector pins, and an ejector pin is provided to eject the connector from the nesting cavity in following testing thereof. | 6 |
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