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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 12/439,785 filed Mar. 3, 2009, as a National Stage 35 U.S.C. §371 filing of International Application No. PCT/GB2007/003324 filed on Sep. 4, 2007 claiming priority from both United Kingdom Patent Application Nos. GB0711428.3 filed Jun. 13, 2007 and GB0617394.2 filed Sep. 4, 2006. The entire contents of the predecessor applications are incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] In brief, however, the present invention relates couplers for attaching an accessory, such as an excavator bucket, to an excavator arm of an excavator. Generally a coupler will comprise one or two jaws (or grooves, hooks or slots) and one or two latches for selectively securing (or releasing) one or two attachment pins of the accessory in the or each jaw (or groove, hook or slot).
BRIEF SUMMARY OF THE INVENTION
[0003] Many couplers have been developed in the art. Some are fully automatic, i.e. fully operable from within the cab of the excavator for both coupling and decoupling an accessory to or from the coupler and some are part automatic/part manual, requiring many or most operations for coupling and decoupling of an accessory to or from the coupler to be carried out from within the cab, but with one or more operations needing to be done instead at the coupler itself.
[0004] A part automatic and part manual coupler is disclosed in GB2359062. The coupler is attached remotely to the accessory, Le. from within the cab of the excavator. However, that attachment is made more secure by an additional manual step—the insertion of a safety pin into a position behind a pivoting latching hook of the coupler.
[0005] A fully automatic coupler is disclosed in GB2330570. It has a gravity operated blocking bar that is designed to fall behind the rear latching hook during normal use, whereby when the coupler is in use, and therefore in a normal, in-use or upright, orientation, the latching hook is prevented from being retracted by the presence of the blocking bar behind the latching hook. To release the accessory, however, that blocking bar is lifted from that blocking position either by a second hydraulic ram (Le. one that is not connected to the latching hook) or simply by inverting the coupler, Le. by moving the excavator arm and coupler into either the crowd position or to a position curled above the excavator arm (an unconventional position for an excavator arm to assume). In that inverted orientation, the blocking bar will fall away from its blocking position to allow the latching hook for the rear attachment pin then to be retracted by the latching hook's own hydraulic ram.
[0006] There are also many other couplers, either fully automatic or part automatic and part manual. See, for example, the couplers disclosed in the following publications: Australian Patent AU557890, German Utility Model DE20119092U, European Patent Applications EP0405811 and EP1318242, GB Patent Application GB2332417, U.S. Pat. No. 5,692,325 and U.S. Pat. No. 6,132,131, and PCT Publication WO99/42670.
[0007] The majority of prior art couplers have a first (or top) half that is for attaching the coupler to the excavator, and that attachment is generally to an excavator arm of the excavator. The coupler of EP0405813, however, is instead for attaching a digger bucket to the front end loader of the excavator. The couplers then have on the other or opposite side of the coupler two attachment pin engaging jaws, grooves, hooks or slots, whereby an accessory having a pair of attachment pins (such as an excavator bucket) can be attached to that coupler via the pair of attachment pins: one of the jaws, grooves, hooks or slots is for engaging a first or front attachment pin of the accessory and the other jaw, groove, hook or slot is for engaging the second or rear attachment pin of the accessory.
[0008] Couplers are also known for attaching accessories that have only one attachment pin. Those couplers have just one jaw, groove, hook or slot. Typically, however, the accessory then has the other jaw, groove, hook or slot for engaging a second attachment pin, which is instead positioned on the coupler.
[0009] Despite the existence of numerous designs of coupler, there is still an ever increasing demand upon the industry for the provision of even more security for fully automatic couplers, and for which couplers no manual steps need to be carried out by the user on the coupler for completing the securement or detachment of an accessory. A purpose for this drive is that it allows the user to remain within the safe environment of the cab of the excavator. This is important since accessories and couplers are typically quite large and heavy pieces of equipment, and thus they are potentially dangerous when being manipulated by an excavator.
[0010] For couplers having a pair of jaws, one of the jaws usually faces downwards, i.e. away from the first half of the coupler, and that jaw is usually referred to as the rear jaw—it is normally located, in use, the furthest away from the cab, and excavator arms usually extend from a rear of the excavator. Due to its position, and the way it faces in use, often that jaw is not visible from the cab. The other jaw, however, usually faces away from that rear jaw and towards the cab. It generally is also rotated by approximately 90° relative to the rear jaw, i.e. instead of pointing downwards, it usually points forwards. It is usually, in use, nearer to the cab than the rear jaw and thus it is usually referred to as the front jaw.
[0011] In many such prior art couplers a pivoting or sliding latching hook or latching plate is provided for the rear jaw for locking an attachment pin within that jaw. Thus, to couple the accessory to the coupler, a first or front attachment pin is first engaged into an open front jaw of the coupler, and the coupler is then rotated or manipulated relative to the accessory to position the second attachment pin into the coupler's open rear jaw. Then the latching hook or latching plate is driven rearwardly, for example by a hydraulic piston or a screwthread, to close the rear jaw to lock the rear attachment pin within the rear jaw. That in turn locks the front attachment pin in the front jaw.
[0012] Such a securement of the accessory to the coupler is entirely secure, subject to there being no failure of the respective components of the coupler. However, users of such couplers additionally demand back-up safety mechanisms to be incorporated into those couplers to provide assurances that an accessory cannot accidentally be decoupled from a coupler, even if the drive mechanism for the latching hook or the latching plate is accidentally retracted or in the event of a misuse of the coupler, or even in the event of a failure of a component of the coupler or the accessory. Further, there is a drive towards making the back-up safety features both automatic to implement and visible from within the cab. By being automatic, they cannot be omitted or forgotten by the user, and by being visible from the cab it is possible to assess their status from the cab, i.e. to carry out a remote visual check as to whether the safety features have adopted their correct back-up safety position for ensuring a backed-up securement between the coupler and the accessory. Further, the demand is for such couplers that still allow fully automatic coupling and decoupling of the accessory from the coupler.
[0013] It should also be observed that many prior art couplers have the provision for accommodating different accessories, i.e. ones having different distances between their respective attachment pins. That allows accessories from different manufacturers, or from different product ranges, to be accommodated by the coupler (it is commonplace for different buckets and other accessories from different manufacturers to have different distances between their pairs of attachment pins, i.e. different pin spacings). Prior art couplers generally achieve that by the provision of either a screwthread drive system or a hydraulic ram mounted between the two jaws, grooves, hooks or slots. The screwthread or a hydraulic ram can then move one or both of the jaws, grooves, hooks or slots relative to a frame of the coupler to accommodate the different pin spacings. Generally speaking, however, just one of the jaws, grooves, hooks or slots is moved by the screwthread or hydraulic ram, and that one is most frequently the rear one (or the latch associated therewith).
[0014] The securement of the two attachment pins within the two jaws is generally by a relative separation of the two pin-engaging components. That securement of the two fixed attachment pins of the accessory within the two jaws of the coupler can be referred to as a primary securement since it alone provides a securement of the accessory to the coupler. Such primary securement mechanisms are strong and thus are generally reliable since it is most unlikely that a component of it, such as either the screwthread or the hydraulic ram, or the hook or jaw themselves, will fail. That is because these items are all designed to meet the demands of the usual environment of use for the coupler. Indeed, these items are often “over-engineered” to provide a significant overload buffer). Despite that, however, it is usual to provide the above mentioned back-up safety (or failsafe) mechanisms to prevent the accessory from decoupling from the coupler in the unlikely event of such a failure.
[0015] Such safety back-up mechanisms, as known in the art, include at a most simple level, just a cover for the actuation circuit (usually in the cab of the excavator). That prevents accidental access to the actuation switches during use of the accessory. However, there is a demand for additional security. As such, failsafe mechanisms are provided in or on the coupler itself. See, for example, the coupler of EP1318242. It has a spring driven hook for the front jaw, which hook defaults to a closed state for securing a front attachment pin within the front jaw of the coupler. Therefore, even if the rear hook fails, the accessory is secured within the coupler. A problem with that coupler, however, is that if the decoupling command is given accidentally, the spring driven hook will automatically be retracted by the hydraulic ram as the sliding rear jaw reaches a fully retracted position. U.S. Pat. No. 6,132,131 and U.S. Pat. No. 5,692,325 similarly provide a latching hook for the front jaw that is driven by the rear jaw's hydraulic ram, and as such they also have that same problem. In GB2332417, however, a toggling dual-hook arrangement is provided—there are two moving hooks that are interconnected by a toggling arrangement to ensure that as one hook opens the other hook closes, and vice versa. This prevents both hooks from opening simultaneously. However, if either the link or one of the hooks fails, the coupling between the accessory and the coupler becomes vulnerable.
[0016] The present invention, therefore, seeks to provide coupler designs that are both fully controllable from within the cab, and that will allow improved security in the securement of the accessory to the coupler, i.e. preventing accidental decouplings, but while still allowing intentional decoupling operations to be carried out without undue burden.
[0017] According to a first aspect of the present invention there is provided a coupler for coupling an accessory to an excavator arm of an excavator, the coupler comprising a first portion for attaching the coupler to an excavator arm of an excavator and the coupler having a second portion adapted to receive an accessory with two attachment pins, wherein:
[0018] the second portion has two jaws, one for receiving a first attachment pin of an accessory and the other for receiving a second attachment pin of the accessory;
[0019] a first latch is associated with the first jaw for securing the first attachment pin within the first jaw when the first latch is in a latching position;
[0020] a second latch is associated with the second jaw for securing the second attachment pin within the second jaw when the second latch is in a latching position;
[0021] a third latch is provided that extends between the first and second latches, the third latch, when in a latching position, being adapted to resist movement of the first latch from a latching position into a non-latching position; and
[0022] when the third latch is in a non-latching position, the first latch is not resisted from moving between a latching position and a non-latching position by the third latch.
[0023] Preferably the second latch is linked or connected to the third latch.
[0024] Preferably the second latch is pivotally linked to the third latch. They may, however, be an integrally formed member.
[0025] In another arrangement, the second and third latches are separate components that are selectively engageable with each other by movements of one or both of those latches, and wherein the third latch also resists movement of the second latch from a latching position into a non-latching position when it is itself in a latching position but wherein it will not resist movement of the second latch from a latching position into a non-latching position when it is in some other predetermined position. Preferably that predetermined position cannot be assumed by the third latch while a first attachment pin is secured within the first jaw by the first latch. Preferably that is achieved by the provision of a flange on the first latch that restricts movement of the third latch while a first attachment pin is secured within the first jaw by the first latch.
[0026] Preferably the latching position of the third latch is its default position, i.e. the position it assumes during normal use of the coupler (i.e. non-inverted and with an attachment attached thereto).
[0027] Preferably the third latch is moveable from a latching position into a non-latching position by means of gravity by at least partially inverting the coupler. Alternatively, or additionally, a mechanical actuator may be provided for moving the third latch.
[0028] A biasing member may be provided to bias the third latch towards a latching position.
[0029] Preferably the third latch, in a latching position bears against the first latch.
[0030] One or more of the latches may comprise a solid bar and/or a hook.
[0031] One or more of the latches may comprise a pair of solid bars and/or hooks.
[0032] One or more of the latches may comprise a bifurcated bar or hook.
[0033] Preferably the first latch is moveable from a latching position into a non-latching position by a mechanical actuator, such as a hydraulic ram.
[0034] Preferably the second latch is moveable from a latching position for the second jaw into a non-latching position for the second jaw by means of gravity by at least partially inverting the coupler. Alternatively, or additionally, a mechanical actuator may be provided for moving the second latch.
[0035] A biasing member may be provided to bias the second latch towards a latching position.
[0036] The same biasing member and/or mechanical actuator may control the movements of both the second latch and the third latch since those latches are linked or connected together.
[0037] Preferably the second jaw has a recessed groove in its lower half.
[0038] Preferably the coupler can accommodate a range of pin spacings between the two attachment pins of the accessory by making the rear jaw significantly wider in side view than the front jaw (or wider than the diameter of a typical rear attachment pin for that size of coupler). In this manner, accessories from different manufacturers, with different pin spacings, can be attached to the coupler without modification of either the coupler or the accessory.
[0039] For adjusting the first latch, the mechanical actuator is preferably a hydraulic ram. It might, however, be a pneumatic ram or a screwthread drive mechanism.
[0040] Preferably the mechanical actuator is mounted within the confines of the coupler, generally between and slightly above the two jaws.
[0041] Preferably the first latch is a pivoting latching hook, or a pair of pivoting latching hooks.
[0042] Preferably the first latch pivots to move through an arc between a latching position and a non-latching position. In other embodiments it might be a plate that slides such that it moves linearly between a latching position and a non latching position.
[0043] Each jaw may be bifurcated. It is preferred, however, that the first jaw is a pair of jaws formed in the two sidewalls of the coupler. It is also preferred that the second jaw is a single piece jaw, for example a moulded jaw or a welded multi-part fabrication.
[0044] It should be noted that the term “jaw” should be interpreted to encompass similar attachment pin receiving members such as grooves, hooks or slots, or other similar terms that are to be found in the art. For example, a hook, a groove or a slot in the main body of a coupler can form a jaw.
[0045] Preferably the first latch has a latching face facing in a first direction for bearing against the first attachment pin and a second face facing away from that latching face. Preferably one or more flange is formed on that second face. Then, in its latching position, the third latch preferably rests on one or more of those flanges. Preferably the predetermined position lies beyond the position that the third latch assumes when resting upon that flange.
[0046] The end of the third latch adapted to rest on those flanges may have one or more stepped surfaces. It would be one or more of those stepped surfaces that would preferably rest on that or those flange(s).
[0047] The first latch is adapted to be moveable into a non-latching position from a latching position by retracting it generally in the direction that its second face faces. However, when a pin is not within the first jaw, the first latch is also able to move in the opposite direction beyond the position in which its latching face would have engaged an attachment pin had one been in the first jaw. By that additional range of motion, the flange or flanges on the first latch can be moved clear of the reach of the third latch. As a result the range of available motion for the third latch is also extended. That enables the third latch to be extended into the predetermined position, if desired.
[0048] The present invention also provides a method of attaching an accessory to a coupler on an excavator arm of an excavator, the method comprising:
[0049] a) providing an excavator with a powered excavator arm having a coupler on an end thereof, the coupler comprising two jaws and a latch for each jaw, one of the latches being powered for movement between a latching position and a non-latching position, and the other being moveable from a latching position into a non-latching position by fully extending the powered latch beyond a latching position, i.e. while there is no pin within that jaw, into a fully extended position while the coupler is in a normal, in use, orientation;
[0050] b) providing an accessory with two accessory pins thereon sized and spaced to fit into the two jaws of the coupler;
[0051] c) powering the powered latch to extend it into the fully extended position to move the other latch into a non-latching position;
[0052] d) manipulating the coupler to locate a first attachment pin of the accessory into the jaw associated with that other latch;
[0053] e) curling the accessory and coupler, using the excavator arm, so as to invert the coupler, thereby placing the accessory roughly above the coupler;
[0054] f) reverse powering the powered latch to retract the powered latch for opening its associated jaw, whereupon the second attachment pin locates into that jaw under the weight of the accessory;
[0055] g) powering the powered latch to extend it to a latching position for securing the second attachment pin in its jaw; and
[0056] h) uncurling the coupler, using the excavator arm. The attachment is now attached securely to the coupler.
[0057] In an alternative arrangement, the present invention provides a method of attaching an accessory to a coupler on an excavator arm of an excavator, the method comprising:
[0058] a) providing an excavator with a powered excavator arm having a coupler on an end thereof, the coupler comprising two jaws and a latch for each jaw, each latch being selectively moveable between a latching position and a non-latching position, wherein one of the latches is powered for movement between a latching position and a non-latching position, and the other is selectively resisted from movement from a latching position into a non-latching position by a third latch, wherein that third latch can be moved into a predetermined, non-latch-resisting position upon extending the powered latch beyond a latching position, i.e. while there is no pin within that jaw, into a fully extended position while the coupler is in a normal, in use, orientation,
[0059] b) providing an accessory with two accessory pins thereon sized and spaced to fit into the two jaws of the coupler;
[0060] c) powering the powered latch to extend it into the fully extended position for moving the third latch into its predetermined, non-latch-resisting position;
[0061] d) manipulating the coupler to locate a first attachment pin of the accessory into the jaw associated with the other latch;
[0062] e) curling the accessory and coupler, using the excavator arm, so as to invert the coupler, thereby placing the accessory roughly above the coupler;
[0063] f) reverse powering the powered latch to retract the powered latch for opening its associated jaw, whereupon the second attachment pin locates into that jaw under the weight of the accessory;
[0064] g) powering the powered latch to extend it to a latching position for securing the second attachment pin in its jaw; and
[0065] h) uncurling the coupler, using the excavator arm. The attachment is now attached securely to the coupler.
[0066] The present invention also provides a method of detaching an accessory from a coupler on an excavator arm of an excavator, the method comprising:
[0067] a) providing an excavator with a powered excavator arm having a coupler on an end thereof and with an accessory coupled thereto, the accessory having two accessory pins thereon located within two jaws of the coupler, and secured into those jaws by respective latches associated with each jaw, wherein one of the latches is powered for movement between a latching position and a non-latching position, and the other latch is moveable from a latching position into a non-latching position, when an attachment pin is not located within the other jaw, by fully extending the powered latch beyond a latching position into a fully extended position while the coupler is in a normal, in use, orientation;
[0068] b) curling the accessory and coupler, using the excavator arm, so as to invert the coupler, thereby placing the accessory roughly above the coupler;
[0069] c) reverse powering the powered latch to retract the latch for opening its associated jaw;
[0070] d) uncurling the coupler and attachment, using the excavator arm, to position the accessory below the coupler whereupon the attachment pin within the opened jaw exits the opened jaw under the weight of the accessory;
[0071] e) powering the powered latch to extend it into the fully extended position to move the other latch into a non-latching position to open the other jaw; and
[0072] f) manipulating the coupler relative to the attachment to remove the other attachment pin of the accessory from that other jaw.
[0073] Preferably the act of inverting the coupler and accessory to place the accessory roughly above the coupler serves to move a mechanical stop away from a latching position behind the powered latch.
[0074] Preferably the mechanical stop is linked to the other latch.
[0075] Preferably the movement of that powered latch into the fully extended position allows the mechanical stop to move beyond its own latching position into a final release position, or the above mentioned predetermined position, whereupon the other latch is released to be free to move into a non-latching position.
[0076] In an alternative arrangement, the present invention provides a method of detaching an accessory from a coupler on an excavator arm of an excavator, the method comprising:
[0077] a) providing an excavator with a powered excavator arm having a coupler on an end thereof and with an accessory coupled thereto, the accessory having two accessory pins thereon located within two jaws of the coupler, and secured into those jaws by respective latches associated with each jaw, each latch being selectively moveable between a latching position and a non-latching position, wherein one of the latches is powered for movement between a latching position and a non-latching position, and the other latch is selectively resisted from movement from a latching position into a non-latching position by a third latch, wherein that third latch can be moved into a predetermined, non-latch-resisting position upon extending the powered latch beyond a latching position, i.e. while there is no pin within that jaw, into a fully extended position while the coupler is in a normal, in use, orientation;
[0078] b) curling the accessory and coupler, using the excavator arm, so as to invert the coupler, thereby placing the accessory roughly above the coupler;
[0079] c) reverse powering the powered latch to retract the latch for opening its associated jaw;
[0080] d) uncurling the coupler and attachment, using the excavator arm, to position the accessory below the coupler whereupon the attachment pin within the opened jaw exits the opened jaw under the weight of the accessory;
[0081] e) powering the powered latch to extend it into the fully extended position to move the third latch into its predetermined, non-latch-resisting position;
[0082] f) moving the other latch into a non-latching position; and
[0083] g) manipulating the coupler relative to the attachment to remove the other attachment pin of the accessory from that other jaw.
[0084] Preferably step f) is achieved by recurling the accessory and coupler, using the excavator arm, so as partially to invert the coupler, thereby placing the accessory in a position that is substantially level with the coupler. That then allows the other latch to fall into a non-latching position under the influence of gravity if it is free to do so. It should be appreciated, however, that that other latch might instead be power operated, e.g. it may have its own actuator, such as a hydraulic ram.
[0085] It would also be desirable to provide just a simple supplementary failsafe or securement mechanism for couplers. Preferably the supplementary failsafe or securement mechanism will be able to ensure that an accessory will still be retained upon the coupler until that supplementary failsafe or securement mechanism is released even in the event of a catastrophic failure of the primary securement mechanism, e.g. the hydraulic ram or the screwthread, or even a moveable jaw, groove, hook or slot, or even in the event of an accidental or inadvertent release of that primary securement mechanism by the operator.
[0086] According to a further aspect of the present invention, therefore, there is provided a coupler for coupling an accessory to an excavator arm of an excavator, the accessory comprising at least one attachment pin for use in the coupling, the coupler comprising a first side for attaching the coupler to an excavator arm of an excavator and the coupler having a second side onto which the accessory will be coupled, the second side comprising a jaw for receiving the attachment pin of the accessory for connecting the accessory to the coupler by the engagement of the jaw with the attachment pin, wherein the jaw comprises a gravity-operated member having a first state—the jaw-open or jaw-unlocked state, and a second state—the jaw-closed or jaw-locked state, the gravity-operated member at least partially closing the jaw of the coupler when it is in its first state, said first state being achieved by the gravity-operated member when the coupler (and, when connected, the accessory) is in a normal, in-use orientation due to the influence of gravity on the gravity-operated member.
[0087] Preferably the two different states of the gravity-operated member are two different positions of the gravity-operated member. However, the gravity-operated member might instead simply remain in a constant normal position, instead switching between a rotatable or free state and a non-rotatable or more restricted state depending upon the orientation of the coupler.
[0088] The present invention, with its gravity-operated member, therefore has a jaw that can be selectively opened or closed (or unlocked and locked) dependent upon the orientation of the coupler since gravity will open or unlock the member in one orientation and will close or lock the member (with the jaw at least partially closed by the member) in other orientations.
[0089] It should be noted that the terms “jaw” should be interpreted to encompass similar pin receiving members such as grooves, hooks or slots, or other similar terms that are to be found in the art. For example, a hook can form a jaw, a groove or a slot, and similarly a groove is in essence just a slot. In view of that, and also for the sake of convenience, the single term “jaw” is used hereinafter.
[0090] Preferably, in a first orientation (e.g. the normal, in-use orientation) the member will fall under the influence of gravity into its closed position. However, upon reorienting the coupler, for example to an inverted position, the member will fall under the influence of gravity from that closed position into its open position. Instead of simply falling between two positions, however, the member may roll, slide or pivot between those positions. Alternatively, it might remain stationary, instead either being locked or unlocked from a particular closed position dependent upon the orientation (or path of motion between orientations) of the coupler.
[0091] When open (or unlocked), an attachment pin within the jaw, when not otherwise restrained, can be removed from the jaw. Similarly, an attachment pin can be inserted into the jaw. However, when closed, be that either completely or partially, or when locked, an attachment pin within the jaw cannot be removed from the jaw since the locked or closed member will block its path out of the jaw. It might be possible, however, dependent upon the chosen configuration of the locking/closing mechanism, to insert an attachment pin into the jaw even when the gravity-operated member is either closing the jaw or locking the jaw closed, e.g. by sliding it sideways into the jaw, rather than from the front of the jaw.
[0092] Preferably, the gravity-operated member is mounted onto the second side of the coupler either directly to the jaw, or onto a frame of the coupler, which frame carries the jaw.
[0093] Preferably the gravity-operated member is a pivotal member, mounted to the coupler about a pivot axis, the pivoting of the member moving it between its open and closed (or locked and unlocked) positions.
[0094] Preferably the first side is a top side of the coupler, the second side is a bottom side of the coupler, and the coupler also comprises a frame having two sideplates extending generally between the top and bottom sides of the coupler. Preferably the pivot axis runs perpendicular to those sideplates, i.e. in a transverse direction of the coupler. The axis might, however, extend in a longitudinal direction of the coupler (the above-mentioned pin-spacing is measured in the longitudinal direction of the coupler, whereas the attachment pins of an accessory extend in the transverse direction of the coupler).
[0095] The gravity operated member might comprise two pivoting axes, the first running in the transverse direction of the coupler and the second running in the longitudinal direction of the coupler. This allows the member to pivot in more than one direction. Even more pivoting directions can be achieved with a ball and socket joint.
[0096] Instead of pivoting, the member may slide or roll between its open and closed/locked and unlocked positions.
[0097] Preferably an accessory for coupling to the coupler comprises two attachment pins, the coupler thereby needing two jaws. One or more gravity-operated member as defined above may be provided for each or either jaw. However, preferably only one jaw has a gravity-operated member for closing the jaw, and most preferably it will just be the front jaw—usually the jaw without a hydraulically or mechanically driven latching hook or latching plate.
[0098] Preferably the other jaw (the rear jaw) points downwards and has a hydraulically or mechanically driven latching hook or latching plate, which, together with the first jaw, (which usually points forwards) provides a primary coupling mechanism for coupling the accessory to the coupler in a fixed orientation relative to the coupler. The gravity-operated member is then preferably a secondary securing mechanism (as a secondary securing mechanism, the gravity-operated member does not serve to couple the accessory to the coupler in a fixed orientation relative to the coupler, but instead merely serves to attach or tether the accessory to the coupler simply by retaining the attachment pin within the first jaw when the member is in its closed or locked position).
[0099] The coupler with two jaws may be in accordance with any of the other aspects of the invention described above.
[0100] Preferably, the gravity-operated member is not hook-shaped. The member instead is preferably a blocking bar, a blocking toggle or a blocking wedge.
[0101] By the term “gravity-operated”, it is intended that no spring or hydraulic member, or any other mechanical, hydraulic, magnetic or electrical biasing influence, is to be used, in normal use, to move the member from its closed or locked position into its open or unlocked position. Instead, simply gravity is to be relied upon for that purpose, whereby the coupler has to be at least partially inverted in order to release the gravity-operated member. Such an inversion of the coupler, sufficient for decoupling the accessory from the coupler, should not occur during the normal use of the coupler with an accessory attached thereto since it is unusual to operate an excavator arm and accessory in a manner that places the accessory suitably above the end of the excavator arm.
[0102] Similarly it is desired just to rely upon gravity to return the member to its closed or locked position. However, it is possible to provide a gravity-operated member that has a biasing member, such a spring, for assisting in ensuring that the gravity-operated member will fall, move into or assume its closed or locked state when the coupler is in its normal, in-use orientation. In such an embodiment, gravity would still be relied upon to overcome that biasing force in order for the member to assume its open or unlocked state.
[0103] Preferably, when the coupler comprises two jaws, the second or rear jaw is associated with a moveable latch and a mechanical stop for selectively locating behind that moveable latch for selectively restricting the movement of that moveable latch.
[0104] Preferably the mechanical stop is also operable under the influence of gravity.
[0105] Preferably, when the coupler is in a normal, in use, level orientation, i.e. with the two jaws approximately level with each other, with an accessory arranged below the coupler, and with an attachment pin of the accessory retained within the second jaw by the moveable latch, the mechanical stop tends, under the influence of gravity, to fall into a position resting against the moveable latch for restricting the movement of that moveable latch from that pin latching position.
[0106] Preferably, when the coupler is in an inverted position, the mechanical stop instead falls away from the moveable latch, into a non-latching position. That position allows the second latch to be retracted from its latching position for releasing the pin retained by it within the second jaw.
[0107] Preferably the mechanical stop, when it is resting against the moveable latch provided for the rear jaw, also provides a movement-restricting function for the gravity operated member, whereby the gravity operated member cannot be moved into a jaw-open position.
[0108] Preferably the mechanical stop, when the coupler is inverted, also provides against the gravity operated member a bias towards a front-jaw-closing position for that gravity operated member.
[0109] Preferably the mechanical stop has a third position that is only achievable by the mechanical stop while an attachment pin is not retained within the second jaw. Preferably that position is a position beyond the position assumed by the mechanical stop as it rests against the moveable latch for the rear jaw. Preferably that third position disengages the movement-restricting function of the mechanical stop in relation to the gravity operated member. Thus, while an attachment pin is secured within the rear jaw by the moveable latch associated therewith, the front jaw cannot be opened by movement of the gravity operated member. However, upon disengagement of the attachment pin from the rear jaw, the third position for the mechanical stop can be achieved, and thus the front jaw can also be opened.
[0110] Preferably the mechanical stop has a pivot axis and a first arm pointing from that pivot axis generally towards the gravity operated member for the front jaw, and a second arm pointing from that pivot axis generally towards the moveable latch for the rear jaw.
[0111] Preferably the two arms extend away from each other at an angle of greater than 90° (and less than 270°).
[0112] Preferably the arm that points generally towards the gravity operated member has a flange on it that is adapted to bear against a corresponding flange of the gravity operated member. The interaction between those flanges restrict the motion of the gravity operated member. Thus, when the mechanical stop is in its third position, the two flanges are separated with respect to each other such that they cannot bear against each other through the range of motion required by the gravity operated member for opening the front jaw.
[0113] Preferably the two flanges have opposing angled faces that bear against each other when the coupler is inverted for biasing the gravity operated member into or towards a locked or closed position.
[0114] For a pivoting mechanical stop that operates under the influence of gravity, the moment of inertia for the mechanical stop needs to be such that arm of the blocking bar extending towards the moveable latch for the rear jaw will tend to overbalance the other arm. For example, the arm of the blocking bar extending towards the moveable latch will tend to be significantly heavier or longer than the other arm.
[0115] Preferably the gravity operated member has a stop-surface adapted to bear against a corresponding surface of the coupler's frame when the gravity operated member is in a front-jaw-locking or closing position for preventing movement of the gravity operated member beyond that front-jaw-locking or closing position. Two such stop surfaces that are spaced apart may be provided to spread the loading across a larger area of the frame in the event of the accessory's weight being carried by that gravity operated member, e.g. if the accessory is incorrectly mounted onto the coupler.
[0116] Preferably the two stop surfaces are planar. More preferably they are not co-planar.
[0117] Preferably one of the stop surfaces is a forward facing surface, with the corresponding surface of the coupler's frame lying as a rearward facing surface of the frame, for example on a forwardly extending integral rail of the frame.
[0118] Preferably the second stop surface is provided on an underside of a third flange of the gravity operated member.
[0119] Preferably, the gravity-operated member is arranged such that it will be in its locked or closed state for most normal, in-use orientations and rotations of the coupler. Those normal, in-use orientations will usually range from a level orientation (i.e. where the two attachment pins are level) to perhaps at least 45° from that level orientation in a first or digging curl direction (i.e. moving towards the crowd position) and from the level orientation to perhaps at least 135° from that level orientation in an opposite curl direction—the emptying curl direction (i.e. up and over the excavator arm). Therefore the preferred embodiment of the present invention will keep its gravity-operated member in a locked or closed position through a range of angles of curl perhaps in excess of 180°.
[0120] In a more preferred embodiment, the member will only move to its open position in response to specific re-orientations of the coupler, such as a full inversion of the coupler (i.e. into a position curled up and above the excavator arm, which may be a rotation of more than 1700 in the emptying curl direction from the level orientation), or in response to lesser rotation, e.g. 600 or more in the digging curl direction (i.e. into or towards the crowd position). Adjusting the position of the pivot point of the member relative to the centre of gravity of the member provides for different angle ranges in that regard where the pivot axis runs transverse across the coupler, e.g. between sideplates of the coupler. Further, undesired rotations for the member can be avoided, or rotation limits can be provided, by pivot stops.
[0121] It should also be noted that the former of the two decoupling positions (i.e. a position curled up and above the excavator arm) is the less desirable position for the coupler during a decoupling of the accessory from the coupler. That is because it positions the coupler at a significantly more elevated position than that achieved in the crowd position. As a result, such a position would never be used in practice. It should also be noted that such a position serves no useful purpose, and thus is an unlikely position for an operator to put the coupler into.
[0122] It is also preferred that a decoupling of the accessory from the coupler is not an automatic result of a single act of (at least partially) inverting the coupler. With the preferred embodiment of the present invention, there is also a primary coupling mechanism, with the gravity operated member providing just a secondary securement function, for example of being an automatic tether. As a result, the mere reorientation of the coupler into a position that moves the gravity-operated member into an open or unlocked position will not actually decouple the accessory from the coupler. The primary coupling mechanism would also need to be disengaged or retracted before that could happen.
[0123] It should also be noted that when a coupler is in a fully inverted orientation (i.e. up above the excavator arm, and rotated by more than 1700 from the level orientation), the weight of the accessory will be bearing directly down onto the coupler. The weight of the accessory, therefore, should keep the accessory on the coupler.
[0124] The accessory also cannot be released while the weight of the accessory is forcing the attachment pin to press into the back of the jaw. That, therefore, is a preferred state for the coupler at the time of decoupling. That state is achieved for example by reorienting the coupler into the crowd position. Then, to withdraw the attachment pin from the jaw in that orientation, the weight of the accessory will be rested on the floor or the like, preferably in a stable manner (e.g. on a flat bottom surface of the accessory or on a stand for the accessory), and then the weight of the accessory on the ground is used to keep the accessory stationary while the jaw is disengaged from the attachment pin of the accessory by manipulation of the excavator arm and the coupler relative to that accessory in an appropriate manner (after disengagement of any primary coupling mechanism).
[0125] The present invention therefore allows the decoupling of an accessory from the coupler by the use of specific and deliberate reorientations and manipulations, which acts would not be carried out during normal excavation operations. As a result, the accessory cannot be decoupled from the coupler accidentally. Thus the present invention will provide remarkable reassurances to an excavator operator.
[0126] The present invention also provides various methods of coupling an accessory onto a coupler that is attached to an excavator arm of an excavator.
[0127] The present invention also provides various methods of uncoupling an accessory from a coupler that is attached to an excavator arm of an excavator.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0128] These and other preferred features and embodiments of the present invention will now be described purely by way of example with reference to the accompanying drawings in which:
[0129] FIG. 1 is a cut-away side elevation of a preferred embodiment of the present invention;
[0130] FIG. 2 is a schematic cut-away perspective of a preferred embodiment of the invention with two attachment pins of a bucket (part illustrated) secured within the two jaws of the coupler;
[0131] FIGS. 3 to 8 are schematic cut-away perspectives of the embodiment of FIG. 2 illustrating the preferred sequence of operations for firstly attaching an attachment to the coupler (Figs and. 3 to 5 and then for disengaging the attachment from the coupler ( FIGS. 6 to 8 );
[0132] FIG. 9 is a top perspective view of the preferred coupler, with an attached bucket (in part) illustrating the preferred elements of the coupler roughly in plan.
[0133] FIG. 10 shows a part sectional side elevation view of a coupler illustrating a further embodiment of the present invention;
[0134] FIG. 11 shows the same part sectional/side elevation view of the coupler of FIG. 10 , but in which the member is in its second, jaw-closed position;
[0135] FIG. 12 shows a front elevation view of the coupler of FIGS. 10 and 11 with the member in its jaw-closed position;
[0136] FIG. 13 is a detail side view of the gravity-operated member of FIGS. 10 , 11 and 12 ;
[0137] FIG. 14 is a front perspective view of a further embodiment of the present invention;
[0138] FIG. 15 is a schematic view of the embodiment of FIG. 14 showing an attachment pin of an accessory passing the member;
[0139] FIG. 16 is a front elevation view of the embodiment of FIG. 14 with the member in its jaw-closed position;
[0140] FIG. 17 is a side elevational view of a further coupler in accordance with the present invention;
[0141] FIG. 18 shows the internal working mechanisms of the coupler of FIG. 17 ;
[0142] FIG. 19 is a schematic view of the coupler of FIG. 17 with two attachment pins of an accessory secured thereto;
[0143] FIGS. 20 to 23 schematically illustrate the operational steps involved for attaching an accessory to the coupler of FIG. 17 ;
[0144] FIGS. 24 and 25 show the coupler of FIG. 17 , rotated by 45° from horizontal, for illustrating the movement restricting function of the mechanical stop for the gravity operated member;
[0145] FIGS. 26 to 30 schematically illustrate the operational steps involved for disengagement of an accessory from the coupler of FIG. 17 ; and
[0146] FIGS. 31 , 32 and 33 show details of the interactions between the gravity operated member and the frame of the coupler.
DETAILED DESCRIPTION OF THE INVENTION
[0147] Referring first of all to FIG. 1 , a cut-away side elevation of a preferred coupler 10 , showing the preferred internal working mechanisms for the coupler 10 of the present invention, is shown. The coupler 10 has a first, or upper, portion 12 and a second, or lower, portion 14 . The coupler also has a front 16 and a rear 18 . In normal use the front 16 points towards the cab of an excavator (not shown), whereas the rear 18 points away from the cab.
[0148] The upper portion 12 is adapted for connecting the coupler 10 onto the excavator arm of the excavator and it is displaced slightly forwardly relative to the lower portion 14 , as is conventional. In this illustrated embodiment, however, it is displaced further forward than would be conventional. That, however, is optional.
[0149] In the upper portion 12 , two pairs of holes 20 are provided, although only one of each pair is shown. Those holes 20 are for attachment of the coupler 10 to the excavator arm of the excavator by using a pair of attachment pins. That attachment is conventional in the art, and thus needs no further discussion.
[0150] The lower portion 14 , which is instead for coupling onto an accessory, such as an excavator bucket, instead uses a pair of jaws for that attachment. The first jaw, or the rear jaw 22 , and the second jaw, or the front jaw 24 , conventional as well for that purpose, and thus are sized to receive a further pair of attachment pins, this time fitted to the accessory.
[0151] As is conventional now, the rear jaw 22 is a downwardly facing jaw whereas the front jaw 24 is a forward facing jaw. Thus, with this arrangement, the basic principle behind coupling an accessory to the coupler is first to locate a front attachment pin of the accessory within the front jaw 24 and then to swing a rear attachment pin of the accessory into the rear jaw from below. Next, to prevent that second pin from just swinging out of the rear jaw, a pivoting latching hook, or first latch 26 , is associated with that rear jaw 22 such that it can be swung about a pivot 28 into a latching position across the rear jaw 22 to secure the second attachment pin within the rear jaw 22 . That then secures the accessory firmly onto the coupler 10 .
[0152] As is also conventional, in this preferred embodiment the pivoting latching hook 26 is driven into that latching position by a mechanical actuator such as a hydraulic ram 32 .
[0153] However, instead of a hydraulic ram, a pneumatic ram or a screwthread drive, or some other drive device, might be provided.
[0154] Further, instead of a pivoting latching hook, a sliding mechanism for that latch might 5 instead be provided.
[0155] The present invention is distinguished over prior art couplers, however, by the provision of a unique second latch 34 , and an attached third latch, or mechanical stop 36 . They are provided to interfere with the above basic principle of operation of the coupler so as to prevent inadvertent, or non-deliberate, disengagement of the accessory from the coupler 10 , while still allowing deliberate disengagement of the accessory from the coupler.
[0156] The second latch 34 is associated with the front jaw 24 and it is adapted selectively to close the front jaw 24 for securing an attachment pin within the front jaw 24 . Because of that latch 34 , before the accessory can be decoupled from the coupler 10 , steps have to be taken to cause that latch to retract for opening the front jaw 24 . Further details of those steps, and the more specific details of that second latch, will now be described in further detail with reference to FIGS. 2 to 8 .
[0157] As can be seen in FIG. 2 , which shows only one half of the second latch 34 , the second latch 34 is a pivotal plate connected via a hinge to a third element 36 . The plate is generally rectangular with a solid section and is preferably made from steel. Its hinge has a central axis 42 .
[0158] The second latch 34 can drop in and out of a latching position within the front jaw 24 by sliding generally linearly through a slot defined by two plates 48 , 50 . It can keeps a generally linear line of movement since it can pivot about its own pivot axis 42 , i.e. relative to the third element 36 . Further, its interaction with the two plates 48 , 50 within that slot defined therebetween, prevents rotation of the second latch 34 relative to main body of the coupler 10 , and relative to the front jaw 24 .
[0159] In an alternative construction, however, the second latch 34 and the mechanical stop 36 may be a single unitary element, thus not needing at least the front plate 48 of the two plates 48 , 50 .
[0160] The third element 36 is a mechanical stop 36 . As more clearly shown in FIG. 3 , in which the hydraulic ram 32 has been removed for clarity, the mechanical stop 36 is itself also a pivotal member—it is pivotally mounted relative to the main body 38 of the coupler 10 about a pivot pin (not shown) via a bearing hole 40 in the mechanical stop 36 . Thus the mechanical stop 36 can pivot relative to the main body 38 of the coupler 10 .
[0161] The mechanical stop 36 has a first arm with an end 56 that extends away from the bearing hole 40 away from the second latch 34 . It also has a second arm extending away from the bearing hole 40 , but instead towards the second latch 34 . That second arm carries the pivot axis 42 for the second latch 34 near its end and that axis is located directly above, or in line with, the slot defined between the two plates 48 , 50 of the front jaw.
[0162] As a result of that geometry (of the mechanical stop relative to the axes and the slot of the front jaw), it is through the pivoting motion of the mechanical stop 36 about the central axis of its bearing hole 40 , i.e. relative to the main body of the coupler, that the second latch 34 can be lifted or lowered generally linearly through the slot between the two plates 48 , 50 .
[0163] The pivotal movement of the mechanical stop 36 is illustrated by the arrows 44 in FIG. 3 .
[0164] The generally linear motion of the second latch 34 relative to the front jaw 24 is illustrated by the double headed arrow 46 also in FIG. 3 .
[0165] It is preferred that the first arm of the mechanical stop, i.e. the arm extending from the bearing hole 40 to the end 56 , is at least twice as long as the second arm of the mechanical stop 36 , i.e. the arm extending from the bearing hole 40 towards the second latch 34 . Similarly it is preferred that that first arm of the mechanical stop is at least twice as long as the second latch 34 . Those arrangements together should allow the second arm to have a greater moment of inertia about the bearing hole 40 than the second arm combined with the second latch 34 . Similarly, or alternatively, the first arm may simply be sufficiently heavier than the second arm and second latch combined to provide the desired greater moment of inertia for that first arm about the bearing hole 40 than the second arm and second latch 34 combined. This moment of inertia arrangement is desired so that gravity can always cause the first arm to drop and the second arm to lift, whenever the orientation of front and rear of the coupler is altered with respect to one another. This is the desired arrangement despite the fact that that arrangement tends to cause the second latch 34 to be permanently biased towards a non-latching position when the coupler 10 is in a normal use orientation, i.e. with the attachment being located underneath the coupler. That is because in normal use the second latch 34 will not be able to lift fully up into the roof of the front jaw 24 for opening the front jaw 24 due to the first latch 26 interfering with the range of motion available to the mechanical stop 36 . Instead, the second latch's normal position during use is as shown in FIG. 2 —it extends partially across the opening of the front jaw 24 . That is sufficient for “closing” the second jaw for locking an attachment pin within the second jaw. This feature is further explained below with regard to attaching and detaching an accessory to and from the coupler.
[0166] Returning, however, to the design of the second latch 34 , in preferred embodiments the second latch 34 is painted in a high visibility colour such as orange or red. That is preferred since the second latch is one of the safety features of the coupler that will nearly always be visible from the cab of the excavator—it at least partially extends across the opening of the front jaw 24 , and that opening generally faces towards the cab during normal use of accessories. The high visibility second latch 34 , therefore, acts as a visible marker for confirming the correct or secure attachment of an accessory to the coupler 10 , and that visual aid can be seen by the excavator operator from the within his cab.
[0167] For securing the rear attachment pin 54 within the rear jaw 22 , however, this preferred embodiment has a first latch 26 in the form of a pivoting latching hook. That pivoting latching hook is mounted for rotation about a pivot pin 28 and is moveable between a latching position and a non-latching position by a hydraulic ram 32 . That hydraulic ram 32 is the primary mechanism for holding that first latch 26 in its latching position. To assist with that and to add to the security of that, it is preferred that the hydraulic ram is provided with a check valve to prevent a release of the hydraulic pressure on the ram in the event of a hydraulic failure such as a cut in the hydraulic piping leading to it.
[0168] The mechanical stop 36 , however, provides a further backup to prevent the inadvertent or non-deliberate release or retraction of the first latch 26 into a non-latching position. To that end the mechanical stop 36 provides an interference function against that first latch 26 , as most clearly illustrated in FIG. 5 .
[0169] For providing that interference function, the first arm of the mechanical stop 36 extends away from the bearing hole 40 , and away from the second latch 34 , towards the first latch 26 . Further its length is long enough to bear against the first latch 26 when the first latch is in a latching position against an attachment pin. However, the first arm is not too long—it needs to be able to swing past the first latch 26 when the first latch 26 is fully extended, i.e. when there isn't an attachment pin within the rear jaw.
[0170] Because of the mechanical stop 36 , i.e. when the first latch is in a latching position against an attachment pin, the first latch 26 cannot be retracted even by the hydraulic ram 32 until that mechanical stop 36 has been moved from that interference position.
[0171] The movement of that mechanical stop 36 is achieved by inverting the coupler 10 , as shown in FIG. 4 , by fully curling the bucket and coupler under the excavator arm using the hydraulics of the excavator arm of the excavator. fu that inverted position, due to the moments about the bearing hole 40 , the mechanical stop 36 will rotate under the influence of gravity so as to move its end 56 that was in engagement with the first latch 26 away from the first latch 26 . That rotational movement is in the direction shown by the downwardly pointing arrow 58 in FIG. 4 .
[0172] It should also be observed that that rotation of the mechanical stop 36 does not open the front jaw 24 since the second latch 34 is still extending partially across the opening of the jaw 24 —it actually closes it further, as shown by the upwards arrow 60 in FIG. 4 . Upon that rotation of the mechanical stop, the first latch 26 is free to be retracted from its latching position into a non-latching position by the hydraulic ram 32 (not shown in FIG. 4 either, again for clarity). Thus, the rear jaw 22 can be opened (as shown in FIG. 4 ).
[0173] Although the basic operations of the three latches have been described above, the preferred method for attaching an accessory, such as a bucket 62 , to the coupler 10 will now be described with reference to FIGS. 3 , 4 and 5 .
[0174] Referring first to FIG. 3 , the first step in the attachment procedure is the engagement of the front jaw 24 of the coupler onto the front attachment pin 52 of the bucket 62 . That is usually done while the bucket 62 sits on the ground and is achieved by manipulation of the coupler 10 relative to the bucket 62 , while the coupler is in its normal upright orientation. However, before that can be done, the front jaw 24 needs to be open, i.e. the second latch 34 needs to have been lifted into or above the roof of the front jaw 24 .
[0175] The front jaw is likely to be open if the last operation with the coupler was the disengagement of the coupler from an accessory. However, if it is not open, to open it the second latch 34 must be lifted. That, however, can only be done while the rear jaw 22 is not accommodating an attachment pin, and only when the first latch has been driven rearwardly to a fully extended position. That can usually be done by using the hydraulic ram 32 , as shown in FIG. 3 .
[0176] Once the first latch 26 is fully extended, or while it is being fully extended, the mechanical stop 36 falls clear of the first latch 26 once it is no longer able to reach the first latch 26 to bear against it. That additional rotation of the mechanical stop is then enough to lift the attached second latch 34 clear of the front jaw 24 , i.e. fully into or above the roof of the front jaw 24 , to open that jaw 24 .
[0177] Once the front attachment pin 52 of the bucket 62 has then been engaged into the front jaw 24 of the coupler 10 , the hydraulics of the excavator arm are then powered up to curl the bucket 62 and the coupler 10 under the excavator, i.e. towards the cab, so as to invert the coupler 10 . That positions the bucket 62 roughly above the coupler 10 , as shown in FIG. 4 . During that rotation of the coupler, the mechanical stop 36 will again fall under the influence of gravity to rotate it in the direction shown by the single downward arrow 58 in FIG. 4 . Thus the end 56 of the mechanical stop passes the first latch 26 again.
[0178] Further, as that happens the weight of the bucket will keep the front attachment pin securely in the cradle of the front jaw. Thus the second latch will be able to slide back partially across the opening of the front jaw 24 to close the front jaw 24 for securing the front attachment pin 52 within that front jaw 24 .
[0179] While the above is happening, the first latch 26 remains fully extended. Thus it prevents the passage of the rear attachment pin 54 of the bucket 62 into the rear jaw 22 of the coupler 10 . However, once the above has happened, the first latch 26 can then be retracted by the hydraulic ram 32 to open the rear jaw 22 —the mechanical stop 36 is moved clear of the fist latch so it will not prevent that from happening.
[0180] Next, as the first latch 26 is retracted, the rear jaw opens and eventually the rear attachment pin 54 will fall into that jaw 22 under the weight of the bucket. Then the first latch 26 can be powered back to a latching position by the hydraulic ram. The bucket 62 and coupler 10 can then be reinverted to the position or orientation of FIG. 5 —the normal working orientation—by uncurling the arrangement with the excavator arm.
[0181] During that uncurling operation the final part of the coupling procedure occurs—the mechanical stop falls back down into an interference position, i.e. with its end 56 bearing against the first latch 26 .
[0182] From the above it will be appreciated that it is important that the front jaw is openable sufficiently by the movement/rotation of the mechanical stop to allow an attachment pin to be engaged into the front jaw, and also for it to remain sufficiently closed during normal use, i.e. while the mechanical stop is in a latching position, to prevent removal of the attachment pin from the front jaw. That balance is more readily achieved if the latch only extends partially across the front jaw when the mechanical stop is in its latched position. Thus the length of the second latch 34 is preferably chosen such that with the mechanical stop in a latching position, the second latch extends only approximately half way across the opening for the front jaw 24 . However, adjusting the relative the lengths of the arms of the mechanical stop 36 will adjust the amount of lift/movement available for the second latch 34 by the rotation of the mechanical stop 36 into its fully dropped position from its latching position. Similarly, adjusting the location of any lower rotation stop for the mechanical stop can adjust the amount of lift/movement available for the second latch 34 by the rotation of the mechanical stop 36 into its fully dropped position from its latching position.
[0183] In this preferred embodiment the first latch 26 is a hook having an attachment pin facing surface 64 and a back surface 66 . The end 56 of the mechanical stop 36 can bear against that back surface 66 when the mechanical stop 36 is in a latching position. However, to provide a more precise latching position for the mechanical stop 36 , The back surface 66 of the first latch 26 is provided with a flange 68 having at least one step. This stepped flange 68 provides a seat onto which the mechanical stop's end 56 can sit when it is in its latching position behind the first latch 26 . Further, if more than one step is provided, each step provides an alternative seat for the mechanical stop's end 56 , whereby attachments with different pin spacings can be accommodated more readily by the coupler 10 —as shown in FIG. 3 , two or even three steps are preferably provided on the flange 68 , with each step providing a corresponding latching position for the mechanical stop 36 , depending upon the amount of extension needed by the first latch 26 for its attachment pin facing surface 64 to engage the attachment pin of the respective accessory.
[0184] Instead of multiple steps on the flange, the end 56 of the mechanical stop could instead be stepped.
[0185] In the illustrated embodiment, the rear jaw is relatively narrow. Thus only a narrow range of accessory pin spacings can be accommodated by that coupler 10 . However, that rear jaw 22 could be widened slightly to widen the range of accessory pin spacings accommodatable by the coupler.
[0186] The flange 68 also serves a second purpose. It provides more control for the operation of the mechanical stop both in its latching position and between its latching position and it fully dropped position (i.e. for opening the front jaw). By having the flange with the step, the exact state of rotation of the first latch will not define whether the mechanical stop is in a latching position. That is because it is in a latching position whenever it bears onto the step. Thus the mechanical stop will only fall past that latching position when the operator wants it to do so, i.e. by fully powering forward the fist latch 26 when there isn't an attachment pin in the rear jaw 22 .
[0187] Next, with reference to FIGS. 6 , 7 and 8 , the removal of a bucket 62 from the coupler 10 will now be described.
[0188] Referring first to FIG. 6 , the first step in decoupling a bucket 62 from the coupler 10 is to invert the bucket 62 and coupler 10 so as to place the bucket 62 roughly above the coupler 10 . That in turn causes the mechanical stop 36 to rotate clear of its latching position behind the first latch 26 , as shown by arrow 58 . The hydraulic ram 32 can then be powered to retract the first latch 26 for opening the rear jaw 22 .
[0189] Once that has been done, the bucket 62 and coupler 10 are then reinverted to the normal orientation of FIG. 7 . That in turn allows the rear attachment pin 54 to swing free from the open rear jaw 22 , as shown. The front attachment pin 52 , however, is still secured within the front jaw 24 by the second latch 34 . Thus even if free swinging, the bucket 62 still will not detach from the coupler 10 . Before that can happen it is necessary to release the front attachment pin 52 from that front jaw 24 .
[0190] To release the front attachment pin 52 from the front jaw 24 , the bucket 10 would first normally be seated onto the ground to make it safe. Then the hydraulic ram 32 is again powered, but this time to drive the first latch 26 into its fully extended position, as in FIG. 3 above, but as now shown in FIG. 8 . That in turn allows the mechanical stop 36 to fully drop into the final bucket release position (as shown by arrow 72 ) in which it lifts the second latch 34 clear up into the roof of the front jaw 24 (as shown by arrow 74 ). Only then is the front attachment pin 52 also then free to be removed from the front jaw 24 .
[0191] One final safety feature is incorporated into this coupler. That is the provision of a recess 70 in the floor of the front jaw 24 (see FIG. 1 ). That recess, in this illustrated embodiment has a width of approximately the same length as the height of the jaw's opening. An attachment pin can thus locate into it. That recess 70 makes it even more unlikely that the front attachment pin will disengage from the front jaw unintentionally. That is because even if the rear attachment pin is already free and the front jaw is open, a free swinging bucket in that open front jaw will still not tend to fallout of the jaw. Instead the pin will tend to locate into the recess within that front jaw. Further, one in the recess, it will not readily come out of it due to the weight of the bucket. Thus, only when the bucket is on the ground, or shaken vigorously, will the removal of the bucket from that jaw be facilitated. That is because only then will the weight of the bucket 62 be taken off the jaw 24 of the coupler 10 . That in turn allows the coupler 10 to be more readily manipulated in a suitable manner relative to the jaw to free the front attachment pin 52 from the front jaw 24 .
[0192] Referring finally to FIG. 9 , a top plan view of the working elements of the preferred coupler is provided. From that view it is clearly visible that the second latch 34 lies between a pair of mechanical stops 36 . However, other configurations within the scope of the claims as appended hereto would be acceptable as well. The pair of mechanical stops 36 , the hydraulic ram 32 , the first latch 26 and the second latch 34 have each been shaded with different hash lines to help identify them in the figure.
[0193] It can also be noted from FIG. 9 that in this preferred embodiment has the hydraulic ram 32 sitting generally between the two mechanical stops 36 . That provides a more compact arrangement of the coupler 10 in its height dimension, whereby the bucket's digging capacity will be less compromised by the use of a coupler between the excavator arm and the bucket.
[0194] Referring next to FIG. 10 , a further embodiment of the present invention is shown. The coupler 110 comprises a top side 112 , a bottom side 114 , a front 116 and a rear 118 . The coupler also comprises sideplates 120 (see FIG. 12 ).
[0195] In the top side 112 , two holes 122 are provided for attachment of the coupler 110 to an excavator arm of an excavator in a conventional manner, i.e. with two attachment pins (not shown).
[0196] In the bottom side 114 , a front jaw 124 and a rear jaw 126 are provided for receiving two further attachment pins (not shown), this time of an accessory (also not shown) for attachment of the accessory to the coupler 110 again in a generally conventional manner. Indeed, for this embodiment, a primary coupling mechanism (not shown) for that purpose can consist of a pivoting latching hook and hydraulic cylinder as disclosed in GB2359062. However, for simplicity, those features have not been shown in the drawings. For completeness, however, the disclosures of GB2359062 are incorporated herein by way of reference, and as such, a full discussion of the primary coupling mechanism is not required herein. The drawings do, however, show three apertures 28 that pass through both of the sideplates 120 of the coupler 110 which are for receiving a locking pin (through just one pair of them) for locking the latching hook in its latched position, as disclosed in GB2359062.
[0197] The present invention, however, has an additional feature that is not disclosed in GB2359062. That is the gravity-operated member 130 , as most clearly shown in FIG. 13 . That gravity-operated member 130 is a toggle in an upper wall 132 of the front jaw 124 . The jaw is otherwise of a generally conventional configuration, having a moulded lower wall (of a pointed type, with a pointed front 133 ) and the upper wall, with the opening 131 for the jaw 124 being defined therebetween.
[0198] The toggle is mounted within a hole 134 in the upper wall 132 and is mounted for rotation about a pivot axis, as defined by a peg or bolt 136 that passes through the hole 134 in a transverse direction (i.e. transverse to the sideplates 120 of the coupler 110 ). The head 135 and nut 137 of the bolt are shown in FIG. 12 .
[0199] The toggle may pivot about the bolt 136 between an open position, as shown in FIG. 10 , in which the toggle sits fully within the hole 134 , and a closed position, as shown in FIGS. 11 to 13 , in which part of the toggle still sits within the hole 134 , but in which a second end or nose 138 of the toggle extends out of the hole 134 to partially close the opening 131 of the jaw 124 .
[0200] That toggle is mounted off-centre relative to the bolt 136 , whereby it is balanced so that in a normal orientation of the coupler 110 , i.e. in an in-use orientation in which the front and rear jaws 124 , 126 (and therefore also any attachment pins held therein) are generally level to each other, the toggle's centre of gravity will cause it to rotate under the influence of gravity into that latter closed position in which the nose 138 descends into the front jaw so as to partially close the opening 131 of the front jaw 124 .
[0201] By having this arrangement, in normal use an attachment pin 140 within that front jaw 124 will only be able to be removed from the front jaw 124 through the opening 131 of the jaw 124 if the toggle was to rotate out of its way. That is because attachment pins 140 have a size corresponding generally to the height of the front jaw 124 . However, further rotation of that toggle is not possible due to the configuration of the toggle, the bolt 136 and the hole 134 . The toggle in its closed position has a wall 148 that bears against a front wall member 142 of the hole 134 (see FIG. 13 ). Further, preferably that front wall member 142 , the bolt 136 and the toggle are all reinforced, toughened or hardened as well, whereby they should be able to resist even a significant attempt to force an attachment pin 140 out of the jaw.
[0202] Referring now to FIG. 13 , specific details of the preferred arrangement for the toggle, the hole 134 , the bolt 136 and the front wall member 142 will now be described.
[0203] The toggle preferably comprises at its first end two perpendicular walls 144 , 148 that tangentially extend from a curved section 146 . There is also a third wall 149 that extends parallel to and perpendicular to the two other walls 144 , 148 , respectively. Further, that first end has an aperture therein through which the bolt 136 passes for pivotally mounting the toggle within the hole 134 of the front jaw 124 . The aperture is between the two parallel walls 148 , 149 and runs parallel to all three walls 144 , 148 , 149 .
[0204] The hole 134 in the upper wall 132 of the front jaw 124 has a flat bottom 151 and the inside surface of the front wall member 142 extends perpendicular to that flat bottom 151 . That inside surface also is flat.
[0205] The bolt 136 is arranged through the hole 134 of the first jaw 124 in a position that is spaced from, yet parallel to, both the flat bottom 151 and the inside surface of the front wall member 142 . The distance of the bolt 136 from the inside surface is slightly greater than the radius of the curved section 146 of the toggle. The distance of the bolt 136 from the flat bottom is greater than its distance from the inside surface.
[0206] The aperture in the toggle is arranged concentrically to the curved section 146 of the toggle. As a result, the toggle will be free to rotate within the hole 134 through a full 90° range of angles, i.e. between its open and closed positions. In the open position, the first of the two perpendicular walls 144 , 148 will bear against the front wall 142 to provide a first rotation limitation for the toggle. In the closed position, the second of the two perpendicular walls 144 , 148 will bear against the front wall 142 to provide a second rotation limitation for the toggle. Changing the angle between these two perpendicular walls 144 , 148 will therefore change the available range of angles of rotation for the toggle.
[0207] In addition, the toggle comprises a second end 138 —the end that extends out of the hole 134 when the gravity-operated member 130 is in its closed position. That end 138 comprises a curved wall 150 that will face towards an attachment pin 140 within the front jaw 124 when the member 130 is in its closed position. That curved surface, although optional, provides an increased area of surface contact between the attachment pin 140 and the toggle in the event of an attempt to remove the attachment pin 140 from the front jaw 124 through the opening of the jaw 124 when the member 130 is in its closed position. As a result, forces are less concentrated on the toggle.
[0208] No biasing member is provided for the toggle, whereby it relies purely upon gravity for its orientation. However, as a result it is free to rotate within that 90° range if it is acted upon by an external force. Accordingly, although the toggle will prevent the withdrawal of an attachment pin 140 from the front jaw 124 , the toggle will rotate to allow an attachment pin 140 to be inserted into the jaw 124 (as shown in FIG. 10 ).
[0209] By positioning the aperture for the bolt 136 in the first end of the toggle, the centre of gravity of the toggle is arranged towards the second end of the toggle relative to its pivot axis. Thus the gravity-operated member 130 , which is mounted in the upper wall 132 of the front jaw 124 (which upper wall 132 extends generally parallel to the longitudinal axis of the coupler 110 ) will default to a closed position whenever the coupler is level (e.g. as shown in FIG. 11 ). However, the toggle can be opened by rotating the coupler clockwise (as seen in the drawings) through an angle of about 90°, i.e. into the crowd position.
[0210] Referring now to FIGS. 14 , 15 and 16 , an alternative embodiment of the present invention is disclosed in which an alternative gravity-operated member 130 is provided.
[0211] Instead of the coupler having a primary coupling mechanism in accordance with GB2359062, the coupler of this embodiment features a primary coupling mechanism involving a latching hook 154 and a blocking bar 152 for that latching hook 154 , similar to that disclosed in GB2330570, the disclosures of which are incorporated herein by way of reference. Yet further, the front jaw is formed from two sideplates 153 , rather than having the moulded, pointed, configuration of the first embodiment. Both configurations, however, are generally conventional and interchangeable.
[0212] In accordance with this alternative embodiment, the gravity-operated member 130 features a flap member that has a first pivot axis 136 that extends in a generally longitudinal direction of the coupler 110 . Therefore, to allow it to rotate out of the opening of the jaw 124 from its locked position (as shown in FIG. 14 ), the coupler 110 needs to be inverted to a greater degree than the first embodiment—it must be almost completely inverted in order for gravity to cause it to rotate about its pivot axis into its open position. Additionally, however, the flap member has a second pivot axis 156 —a hinge axis. That second pivot axis 156 can be free swinging between a straight and folded position or it may be spring biased to keep it closed even when the coupler is inverted. The hinge, however, will have a rotation stop (not shown) as known in the art of hinges, to prevent it from swinging in the opposite direction to that shown in FIG. 15 , whereby an attachment pin can be inserted into the jaw, but by means of which the attachment pin cannot be removed from the jaw without inverting the coupler. Thus the hinged flap can also provide a similar function to the toggle of the first embodiment.
[0213] Referring now to FIGS. 17 to 32 , another embodiment of the present invention is shown. In many ways this is similar to the embodiment disclosed in FIGS. 1 to 9 . Thus similar or corresponding features of this embodiment to that earlier embodiment have been given the same reference signs.
[0214] This further coupler design also has a pivoting latching hook 26 that is adapted for rotation about a pivot 28 for locking an attachment pin 54 in a rear jaw 22 of the coupler 10 . That pivoting latching hook 26 is also power operated under the control of a hydraulic ram 32 .
[0215] The hydraulic ram 32 is attached at the free end of its piston to the latching hook 26 at a first pivot axis 29 . The free end of the cylinder of that hydraulic ram 32 is attached to the frame 38 of the coupler 10 at a second pivot axis. That second pivot axis is centred on the bearing hole 40 of the mechanical stop 36 . Thus a single axle 41 can be provided for both the cylinder of the hydraulic ram 32 and the mechanical stop 36 .
[0216] As shown in FIG. 17 , that axle 41 extends through both sidewalls of the frame 38 of the coupler 10 .
[0217] The pivoting latching hook 26 has also again got an attachment pin facing surface 64 which engages against a rear attachment pin 54 when an accessory is coupled to the coupler 10 .
[0218] The pivoting latching hook 26 also again has a back surface 66 against which an end 56 of the mechanical stop 36 bears when it is in a latching position behind (or “in front of” when referring to its relative position in relation to the coupler as a whole) that hook 26 . That is clearly shown in FIG. 18 .
[0219] The back surface 66 of the pivoting latching hook 26 also again features a flange 68 that also serves to support the mechanical stop 36 for preventing the mechanical stop 36 from swinging into a front-jaw opening position while an attachment pin is retained within the rear jaw 22 by the latching hook 26 .
[0220] As for the second latch 34 , however, although it is similarly positioned for at least partially closing the mouth of the front jaw 24 , its interaction with the mechanical stop 36 is different—in this embodiment, the second latch 34 is not connected to the mechanical stop 36 , although the two elements can selectively engage each other under certain conditions. Instead it is mounted for pivotal movement about its own separate pivot axle 243 , much like the gravity operated member of FIGS. 10 to 16 .
[0221] The interaction between the pivoting latching hook 26 , the mechanical stop 36 and the second latch 34 will be further described below.
[0222] With reference to FIGS. 19 to 23 , a preferred method of coupling an accessory to the coupler 10 will now be described.
[0223] As can be seen, the aim is to achieve the completed attachment as shown in FIG. 19 , i.e. with the two attachment pins 52 , 54 of an accessory (not shown) safely secured within the two jaws 22 , 24 of the coupler 10 —the rear attachment pin 54 is held by the pivoting latching hook 26 in the rear jaw 22 , thus also preventing movement of the front attachment pin 52 within the front jaw 24 , but with the front jaw 24 also at least partially closed by the second latch 34 so that the front attachment pin 52 would not be free to exit the front jaw 24 in the event of an incorrect mounting of the rear attachment pin 54 within the rear jaw 22 by the pivoting latching hook 26 .
[0224] To achieve that completed attachment, the first step, with an uncoupled coupler 10 , is to power the hydraulic ram 32 to a fully extended state, for fully extending the pivoting latching hook 26 rearwardly across the rear jaw for closing that rear jaw. See FIG. 20 . By powering that latching hook 26 rearward, the flange 68 extending from the back surface 66 of the latching hook 26 clears away from of the end 56 of the mechanical stop 36 . Then, with the coupler in a normal, non-inverted orientation, i.e. preferably with the two jaws at approximately the same height with respect to each other, the mechanical stop 36 will fall past that flange into a fully rotated position—the third or predetermined non-latching position, whereat further rotation is prevented by a stop 245 provided on the frame or main body 38 of the coupler 10 . This stop 245 is illustrated schematically in FIG. 20 and is likely to be some integral component of the base of the frame 38 of the coupler 10 .
[0225] With the mechanical stop 36 in that predetermined non-latching position, the opposite end 247 of it—extending away from the pivot axle 41 in a different direction—will have lifted to move a flange 249 of it clear of a corresponding flange 251 on the second latch 34 . The second latch is therefore then free to rotate between a closed or locked condition into a non-closed position.
[0226] The interrelation between those flanges, and the rotation of the second latch 34 between a closed or locked condition and the non-closed position will be described in greater detail below.
[0227] Since the second latch 34 is now free to rotate through its full range of motion within the frame 38 of the coupler 10 , a front attachment pin 52 can be slotted through the mouth of the front jaw 24 as shown in FIG. 20 . During that process, the front attachment pin 52 will rotate the second latch 34 up into the roof of the jaw 24 so that it can pass that second latch 34 for locating into the rear of that jaw 24 . The second latch will then fall again under the influence of gravity into a closed position, thereby locking that attachment pin within that jaw 24 . That therefore is a first safety feature of the present invention—the accessory cannot now accidentally decouple itself from that front jaw 24 .
[0228] The accessory, however, is only presently half coupled to the coupler 10 . Thus it is now necessary to have the rear attachment pin 54 secured into the rear jaw. For that, as shown in FIG. 21 , and by the arrow 253 in FIG. 20 , the coupler 10 and accessory, with it two attachment pins 52 , 54 , is rotated by crowding the excavator arm so as to place the accessory generally above the coupler 10 .
[0229] During that rotation, if the front attachment pin 52 was not already fully engaged into the rear of the front jaw 22 , the weight of the accessory will pull the front attachment pin 52 tightly into the rear of the front jaw 22 . Further, the weight of the accessory will causes the rear pin 54 of the accessory to bear against the underside (or now top side since the coupler is inverted) of the pivoting latching hook 26 . Yet further, due to the inversion of the coupler, and the arrangement of the moment of inertia of the mechanical stop 36 , that mechanical stop 36 will also rotate under the influence of gravity (in a counter-rotation direction relative to the rotation of the coupler) so as to fall into a non-latching position away from the back surface 66 of the pivoting latching hook 26 .
[0230] As the mechanical stop rotates in that manner relative to the coupler, a bearing surface 255 on its flange 249 (at its opposite end of the mechanical stop) then engages a bearing surface 257 on the adjacent flange 251 of the second latch 34 for biasing that second latch 34 into its jaw-closing position, thus again ensuring a secure initial coupling of the first attachment pin 52 to the coupler 10 . Thus, even though still only one attachment pin is within a jaw of the coupler 10 (the front jaw 24 ), the accessory would still not fall out of the front jaw 22 even if the coupler was to be further rotated, despite it being inverted, due to the second latch now being biased into its closed position.
[0231] Whilst in that inverted condition, the next step is to power the hydraulic ram to draw back the pivoting latching hook 26 into a retracted, jaw-open position, as shown in FIG. 22 . This has to be done while the coupler 10 is inverted in order not to have the mechanical stop 36 blocking its path.
[0232] As a result of the retraction of the pivoting latching hook 26 , the rear attachment pin 54 will fall into the rear jaw 22 under the weight of the accessory.
[0233] Once the rear attachment pin is located in that rear jaw 22 , the hydraulic ram 32 is again powered to extend the pivoting latching hook 26 back across the rear jaw 22 for securing the pin 54 within the rear jaw 22 .
[0234] The coupler 10 can then be rotated back to a non inverted condition by uncrowding the excavator arm, as shown by arrow 259 in FIG. 22 .
[0235] Once normally oriented, the mechanical stop 36 falls back into a latching position on the flange 68 (or on one of the stepped surfaces provided on the back surface of the hook 26 if a narrower pin spacing is provided for the accessory), as shown in FIG. 23 . The accessory is thus now correctly coupled to the coupler 10 .
[0236] Referring next to FIGS. 24 and 25 , further details of the second latch, and its interaction with the mechanical stop 36 , will be described.
[0237] As shown in FIG. 24 , the coupler 10 , with an attached accessory, has been rotated to an angle of approximately 45° relative to the level orientation. The mechanical stop 36 is still in its blocking position behind the latching hook 26 . Further, the two attachment pins 52 , 54 are securely locked within the jaws 22 , 24 of the coupler 10 . Yet further, due to the orientation of the coupler, the second latch 34 has rotated under its own weight into a non fully closed position.
[0238] Referring then to FIG. 25 , which is an enlarged view of the second latch 34 and the mechanical stop 36 , while the coupler 10 is still rotated to an angle of approximately 45° relative to the level orientation, it can be seen that the second latch 34 has a pivot axle 243 , about which it rotated into the illustrated non fully closed position. Further it has a first flange 261 extending in a first direction away from that axle 243 . That flange 261 serves to at least partially close the front jaw 24 when the second latch 34 is in a closed position (such as this non fully closed position, or the fully closed position of FIG. 23 ). Yet further the second latch 34 has a second flange 251 . That flange 251 is the flange mentioned above that has the bearing surface 257 that engages with the bearing surface 255 of the mechanical stop when the coupler 10 has been inverted into a crowd position. There is also a third flange 285 which will be described in greater detail below with reference to FIGS. 31 to 33 .
[0239] It should be appreciated that the mechanical stop 36 is in a blocking position. Thus its end 56 bears down on the flange 68 of the pivoting latching hook 26 (not shown in FIG. 25 —see instead FIG. 24 ). As a result, rotation of the mechanical stop 36 in a further anti-clockwise direction (as viewed in FIG. 25 ) is not possible. As a result of that, the mechanical stop, in this blocking position serves two purposes. Firstly it serves to prevent retraction of the pivoting latching hook 26 from its latched position, as per the prior art. Secondly, however, it serves to prevent rotation of the second latch into a non jaw closing position in the roof of the front jaw 24 . That is achieved s follows:
[0240] The bearing surface 257 on the second flange 251 of the second latch 34 bears against the point 263 of the flange 249 on the mechanical stop 36 prior to the second latch 34 achieving a position in which the front attachment pin 52 can exit the front jaw 24 . Attempts to further rotate the second latch will also be in vain due to the inability for the mechanical stop to rotate further anti-clockwise due to it already bearing against the flange 68 of the pivoting latching hook (as discussed above). Thus this arrangement provides a highly secure coupling of an accessory onto the coupler in that neither jaw can be opened while the coupler is in a normal orientation.
[0241] It should also be appreciated that with narrower pin spacings, the mechanical stop would be rotated even less anti-clockwise due to it sitting on one of the stepped surfaces on the back surface 66 of the hook 26 . Thus the degree of available rotation for the second latch 34 from a fully closed condition would be even more restricted.
[0242] In view of the above arrangement, a special procedure needs to be followed for decoupling an accessory from the coupler 10 of this embodiment. This procedure will now be described with reference to FIGS. 26 to 30 .
[0243] The first action to taken is to rotate the coupler, and the accessory, into the crowd position, as shown in FIG. 26 for inverting the coupler. The mechanical stop 36 will then falls away from behind the back surface 66 of the hook 26 (and the second latch 34 will also be biased into the fully closed position as discussed above). This position is shown in FIG. 26 .
[0244] Once in that position, the rear jaw 22 can then be opened by powering the pivoting latching hook 26 into a retracted position as shown in FIG. 27 . That then unlocks the rear attachment pin 54 from its containment within the rear jaw 22 .
[0245] To then remove the rear attachment pin 54 from the now open rear jaw 22 , the coupler 10 and accessory are once again rotated from the crowd position and the accessory is then rested on the floor so as to allow the coupler 10 and the accessory to be rotate relative to one another about the front attachment pin 52 within the front jaw 24 as the excavator arm is further operated.
[0246] That relative rotation (see the arrow 265 in FIG. 28 ) then draws the rear attachment pin 54 clear of the rear jaw 22 , as shown in FIG. 28 .
[0247] Once the rear attachment pin 54 is clear of the rear jaw 22 , and while the accessory is resting on the floor (in the case of a bucket, in a tipped condition), the pivoting latching hook 26 can then again be powered into a fully extended condition across the mouth of the rear jaw 22 , as shown in FIG. 29 , for moving the flange 68 clear of the mechanical stop. The mechanical stop is then free to assume the third or predetermined position for releasing the second latch 34 —in that third or predetermined position, the point 263 of the flange 249 of the mechanical stop 36 is displaced sufficiently far away from the flange 251 of the second latch 34 that they won't engage one another. Thus the coupler can then be further manipulated by the excavator arm to orient the coupler nearly on end so as to fully open the front jaw 24 —see FIG. 30 . The accessory can then be released from the coupler 10 by lowering the coupler with respect to the front attachment pin of the accessory. The accessory will then fall to its rest position on the ground, decoupled from the coupler 10 .
[0248] To facilitate that final decoupling, the first flange 261 of the second latch 34 has a ramped nib 267 on its end, whereby even if the first flange 261 of the second latch 34 is not fully oriented into the roof of the front jaw 24 by the rotation of the coupler 10 , the passing of the attachment pin 52 out of the front jaw 24 against the nib 267 will push the second latch into that fully open position.
[0249] A beneficial result of this decoupling procedure can also be seen in that the coupler 10 is immediately ready for coupling to another accessory—the pivoting latching hook is already in its fully extended condition.
[0250] Referring finally to FIGS. 31 to 33 , further details of the second latch 34 and its interaction with the frame 38 of the coupler 10 will be described in further detail.
[0251] As previously described, the second latch 34 is mounted onto the frame via a pivot axle 243 . For that purpose, the frame 38 has two coaxial through-holes 269 in side walls 275 of a rail 277 . Further, those holes can be aligned with a through-hole 271 in the second latch 34 , and the axle 243 is then threaded through those three holes. The holes are shown in FIGS. 32 and 33 .
[0252] Once the axle 243 has been threaded through those through-holes 269 , 271 , one or more cotter pin 273 , or the like, is used to retain that pivot axle 243 within the frame 38 and the second latch 38 .
[0253] The second latch 34 is thus pivotally mounted to the frame 38 via a rail 277 that is integrally formed on the front 16 of the frame 38 of the coupler 10 .
[0254] The rail 277 has an inside surface that is adapted to be born against by the front of the first flange 261 of the second latch 34 . Preferably that front is a front-most surface 279 on the leading face of the first flange 261 when the second latch is in a fully closed condition.
[0255] The front 279 is preferably planar but may instead be curved. Preferably the inside surface 281 of the rail 277 has a corresponding shape to provide a large surface area of contact between the second latch 34 and that rail 277 when the second latch is in its fully forward or fully closed position.
[0256] As also shown in FIG. 33 (in which the second latch 34 and the pivot axle 243 have been removed for clarity), a further load bearing surface 283 is formed on the frame 38 of the coupler 10 . This additional load bearing surface 283 is spaced from the inside surface 281 of the rail 277 but is again integrally formed with the frame 38 .
[0257] It should be noted that the rail and the load bearing surface may be welded to, or otherwise connected to, the frame 38 .
[0258] The additional load bearing surface 283 is also for bearing any load carried by the frame when the second latch 34 is in a fully closed condition, further to spread the load. For that purpose, the third flange 285 (mentioned above) is provided on the second latch 34 .
[0259] That third flange is clearly shown in FIG. 32 , in which the frame has instead been removed for clarity.
[0260] That third flange 285 has a bearing surface 287 on its underside. It is positioned so that it bears against the additional load bearing surface 283 whenever the front of the second latch is bearing against the inside surface of the rail. It this provides the additional surface area against which the second latch can bear when it is in its fully closed position.
[0261] The additional area is particularly beneficial since it spreads the loading on the frame in the event of the second latch being tasked to carry the weight of an accessory on it, such as due to a failure of some other component of the coupler (such failure releasing the attachment pin in the rear jaw 22 ), or in the event of an improper mounting state for the accessory. Simply loading such a potential force onto the rail might overload the rail.
[0262] Preferably the two bearing surfaces 287 (on the first and third flanges 285 of the second latch 34 are planar and substantially perpendicular to one another.
[0263] In this embodiment it is also shown that the third flange 285 extends only part way across the width of the second latch (i.e. in the axle direction). It stops clear of the arm of the mechanical stop. Further, where it ends, the second flange 251 starts. In this manner, the mechanical stop will not interfere with the operation of the third flange.
[0264] The third flange is in a different plane to the second flange of the second latch 34 .
[0265] It is also observed that the front of the second latch 34 has two additional surfaces—the ramped nib 267 described above and an intermediate ramp 289 . Those two additional surfaces may be blended to form a curve, which curve may be blended with the front planar surface 279 . Those surfaces allow or assist the above described camming of the second latch 34 into the roof of the jaw 24 as the front attachment pin 52 exits the jaw 24 during the last stage of the decoupling procedure.
[0266] Various aspects of the present invention have been described above purely by way of example. It should be noted, however, that modifications in detail can been made within the scope of the invention as defined in the claims appended hereto, and elements of one aspect might be combined with elements of the other aspects, as would be appreciated by a skilled person. | Couplers for attaching an accessory to an excavator arm of an excavator. Couplers having a first side for attaching the coupler to the excavator arm and a second side onto which the accessory will be coupled. The coupler includes a latch for selectively securing and releasing an attachment pin of the accessory in a jaw, groove, hook or slot in the second side of the coupler. The coupler is fully controllable from within the cab of the excavator and it allows improved security in the securement of the accessory to the coupler, i.e. preventing accidental decouplings, but while still allowing intentional decoupling operations to be carried out without undue burden. | 4 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
This application claims priority to U.S. Provisional Application Ser. No. 61/715,430, filed Oct. 18, 2012, which is hereby incorporated by reference herein in its entirety.
BACKGROUND
One of the most important aspects of chip fabrication, such as complementary metal-oxide-semiconductor (CMOS) fabrication, entails the contact definitions. In a highly complex chip design, there are many contacts to interconnect a multitude of devices within the chip. Devices such as transistors and diodes specific to a particular circuit have contacts dedicated to that circuit. Parallel and series circuits are generally made by fabricating devices specific to that circuit, and a circuit requiring the connections of the devices in a particular way is separately fabricated. If a different circuit comprising the same device types but requiring a different circuit connection is needed, a new set of devices with the required connections would have to be fabricated separately. Such a process reduces real estate in a chip and gives rise to other complications, such as reliability issues during fabrication, reliability issues during operation, and increased heat buildup in the chip.
It can therefore be appreciated that it would be desirable to have an alternative system and method for forming contact definitions.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure may be better understood with reference to the following figures. Matching reference numerals designate corresponding parts throughout the figures, which are not necessarily drawn to scale.
FIG. 1 is a schematic diagram of an embodiment of a circuit comprising multiple metal-insulator-metal devices.
FIGS. 2A-2D are cross-sectional views that illustrate steps in an embodiment of fabricating the circuit of FIG. 1 .
FIGS. 3A-3C are schematic diagrams of alternative circuit embodiments comprising multiple metal-insulator-metal devices.
FIG. 4 is a partial side view of a mask set that can be used to fabricate a circuit.
FIG. 5 is a top view of two of the masks of the mask set of FIG. 4 , illustrating alignment marks provided on the masks.
FIGS. 6A-6C are illustrations of different alignments between the masks of FIG. 5 and show the results of the alignments.
FIG. 7 is a first example circuit that can be formed using the masks of FIG. 5 .
FIG. 8 is a second example circuit that can be formed using the masks of FIG. 5 .
DETAILED DESCRIPTION
As described above, current methods for forming contact definitions for devices on a chip can be disadvantageous because circuits for connecting the devices must be specifically fabricated for the desired circuit. Therefore, if a different circuit comprising the same device types is desired, a new set of devices with a new set of connections would need to be separately fabricated. As described herein, such disadvantages can be avoided. In some embodiments, a circuit comprising multiple metal-insulator-metal (MIM) devices can be formed by depositing layers of metal that both form the top electrodes of the MIM devices and provide interconnection of the MIM devices. In some embodiments, the extent to which the layers of metal overlap, and therefore the size of the active area, can be controlled to change one or both of the current density and the frequency range of the devices.
In the following disclosure, various embodiments are described. It is to be understood that those embodiments are example implementations of the disclosed inventions and that alternative embodiments are possible. All such embodiments are intended to fall within the scope of this disclosure.
The methods disclosed herein enable multiple MIM tunnel devices to be connected either serially or in parallel to form an electrical circuit. Moreover, the contact areas between devices can be altered by simply moving a photomask used to form the top electrodes of the devices by incremental distances. This enables the current densities of the devices to be altered without having to redesign the devices. In some embodiments, a plurality of MIM devices can be fabricated with the point of contact being defined in such a way that the devices can be used in series or in parallel with multiple variations, as desired for the test setup or circuit. Moreover, by varying the dielectric properties and/or thicknesses of the insulators, the devices can be altered to be used as a resistors, capacitors, or diodes.
Thin-film devices are now increasingly used in the fabrication of passive elements such as resistors and capacitors, and active devices such as diodes including transistors. MIM devices are widely-used thin-film devices. MIM devices typically are formed as quadrilateral structures that include a bottom electrode, an insulator, and a top electrode. The fabrication methods described below enable multiple MIM devices to be connected either serially or in parallel to complete an electrical circuit. Moreover, the contact areas between devices can be altered by simply moving the photomask used to form the top electrode. This enables the current densities of the devices to be altered without having to redesign the devices. Assuming a quadrilateral configuration, one, two, three, or four devices can be connected at any single circuit connection. Therefore a base of one, two, three, or four connection combinations can be achieved. By connecting the devices in such a manner, bottom electrodes and insulator stacks can be independently fabricated and the circuit can later be completed by forming top electrodes that connect two or more electrode/insulator stacks. Also, by including a switching element, single or multiple devices can be called into operation as needed without having to constantly pass power through the same devices.
FIG. 1 illustrates an example circuit 10 that can be formed using the techniques described above and FIG. 2 illustrates steps of an example fabrication method. In the example of FIG. 1 , six MIM devices 12 are formed. As is shown in FIG. 2A , the circuit 10 can be formed on a substrate 14 , such as a silicon substrate. With reference to FIG. 2B , bottom electrodes 16 of the devices 12 can be formed on the substrate 14 in a spaced configuration. In some embodiments, the electrodes 16 are made of a metal material, such as nickel, aluminum, gold, or platinum, and are deposited using a conventional microfabrication process, such as photolithography and material deposition (e.g., sputtering). In some embodiments, the electrodes 16 can be approximately 0.5 to 3 μm thick.
With reference next to FIG. 2C , each of the bottom electrodes 16 is encapsulated in a layer or film 18 of insulating material. In some embodiments the insulating material can comprise one or more of a metal oxide (e.g., nickel oxide or aluminum oxide) or a polymer (organic or inorganic) and can also be formed using a conventional microfabrication process. In some embodiments, the insulating films 18 can be approximately 0.001 to 1 μm thick. The insulating films 18 act as insulators in the MIM devices 12 .
Once the bottom electrodes 16 and insulating films 18 have been formed, a photomask can be used to define windows for the top electrodes of the MIM devices 12 . As with the bottom electrodes, the top electrodes can be made of a metal material, such as nickel, aluminum, gold, or platinum, and can also be formed by using a conventional microfabrication process. As shown in FIG. 2D , layers of metal 20 can be deposited on top of the insulating films 18 to form the MIM devices 12 shown in FIG. 1 . In some embodiments, the metal layers 20 can be approximately 0.5 to 3 μm thick.
As indicated FIG. 2D , each metal layer 20 covers portions of the insulating films 18 , and therefore overlaps bottom electrodes 16 , of multiple devices 12 (two devices in this example) so that the top electrodes of multiple MIM devices are formed by the same metal layer. In other words, the deposited metal layers 20 extend across multiple MIM devices so as to both form the top electrodes of and electrically connect the MIM devices over which they extend. As is shown in FIG. 2D , the metal layers 20 also cover portions of the sides of the insulating films 18 as well as the surface of the substrate 14 . In the illustrated embodiment, four metal/insulator stacks are covered by three metal layers 20 to form six MIM devices 12 that are electrically connected to each other. Therefore, multiple MIM devices can be simultaneously fabricated and interconnected in a single lithography step.
The method described above can be used to form devices that are serially connected or connected in parallel. FIGS. 3A-3C illustrate example circuit layouts 30 , 34 , and 38 (left) and their equivalent circuit diagrams 32 , 36 , and 40 (right). In the circuits, each of the devices can be MIM devices, which can be configured as resistors, capacitors, or diodes, depending upon the nature of the insulation films (e.g., dielectric properties, thickness) that is used in their construction. As can be appreciated from the layouts and circuit diagrams, a plurality of MIM devices can be connected either serially ( FIGS. 3A and 3B ) or in parallel ( FIG. 3C ) and the connections between the devices can be altered depending on the desired result.
As expressed above, the circuits can be formed using conventional microfabrication processes, such as photolithography. In such a process, photomasks are used to define the patterns of the features (e.g., electrodes) that are to be formed on a substrate. In the typical case, a mask set comprising one photomask for each layer of the devices to be formed is provided. FIG. 4 shows an example mask set 50 that comprises three photomasks, 52 , 54 , and 56 , which can, for example, be used to form the bottom electrodes, insulating layer, and top electrodes, respectively of multiple MIM devices. Each photomask 52 - 56 can comprise a thin transparent (e.g., glass) plate that includes a layer of opaque material (e.g., chrome) that forms a pattern that enables ultraviolet light to pass through the plate in some areas (e.g., where an electrode is to be formed) but prevents the light from passing through the plate in other areas.
The photomasks of a mask set are typically aligned with each other using alignment marks that are provided on the photomasks. Such alignment ensures that the various features that are formed on the substrate are laterally aligned with each other in the desired manner. Such alignment marks can be used to control the amount of overlap between two layers of material. Therefore, alignment marks can be used to control the amount of overlap between bottom and top electrodes of an MIM device and, therefore, control the size of the MIM device's active area.
FIG. 5 shows examples of alignment marks provided on two photomasks 52 , 54 of the mask set 50 of FIG. 4 . As shown in FIG. 5 , the first photomask 52 comprises an alignment mark 58 in the form of a series of corner markers 60 - 66 . Each corner marker 60 - 66 comprises a first line (x-direction line) that extends from a point and a second line (y-direction line) that extends from the same point in a direction 90° out of phase of the first line so as to define a 90° corner. In the illustrated example, there are four such corner markers 60 - 66 , each equally spaced from its neighbor(s) along a 45° diagonal direction.
The second photomask 54 also comprises an alignment mark 68 that comprises a corner marker 70 . Like the corner markers 60 - 66 , the corner marker 70 comprises a first line that extends from a point and a second line that extends from the same point in a direction 90° out of phase of the first line so as to define a 90° corner. If the corner markers 60 - 66 are said to have lines that extend in the x direction and the y direction, the corner marker 70 can be said to have lines that extend in the −x direction and the −y direction so as to be rotated 180° relative to the corner markers 60 - 66 .
The alignment marks 58 and 68 can be used to control the overlap between different layers of a device. FIGS. 6A-6C show an example of this. As indicated in FIG. 6A , the first and second masks have been aligned so that the corner marker 70 of the alignment mark 68 aligns with the second corner marker 62 of the alignment mark 58 . With this configuration, a relatively small amount of overlap between two layers 72 and 74 will be formed.
Referring to next FIG. 6B , the masks have been aligned so that the corner marker 70 of the alignment mark 68 aligns with the third corner marker 64 of the alignment mark 58 . With this configuration, a larger amount of overlap between two layers 72 and 74 results.
Finally, with reference to FIG. 6C , the masks have been aligned so that the corner marker 70 of the alignment mark 68 aligns with the fourth corner marker 66 of the alignment mark 58 . With this configuration, a still larger amount of overlap between two layers 72 and 74 results.
In some embodiments, the alignment between two or more photomasks can be changed for different wafers to form devices having different current densities from wafer to wafer. In other embodiments, the alignment can be changed for different dies on the same wafer to form devices having different current densities on the same wafer.
FIGS. 7 and 8 show example arrays of devices (e.g., MIM devices) that can be formed using the above-described alignment method. In FIG. 7 , an array of first layers 76 is formed on a substrate using a first photomask and an array of second layers 78 is formed over the first array using a second photomask. As indicated in the figure, the second layers 78 overlap the first layers 76 to a relatively small degree. In FIG. 8 , an array of first layers 80 is formed on a substrate using a first photomask and an array of second layers 82 are formed over the first layers using a second photomask. In this example, however, the second layers overlap the first layers to a much larger degree. In some embodiments, such arrays can be used as sensors. For example, the devices can be immersed in a fluid (gas or liquid) and the electrical properties of the device, such as resistance or capacitance, can be observed to determine the effect of the fluid on the properties as a means of detecting the presence or concentration of a substance. In such an application, different current densities resulting from different degrees of overlap can be used to adjust the sensing frequency.
Although the above discussion has focused on MIM devices, the disclosed methods can be used in conjunction with other devices, such as metal-insulator-semiconductor devices. | In one embodiment, an electrical circuit formed on a substrate includes a first multi-layer stack and a second multi-layer stack that share a top layer that comprises a continuous piece of conductive material. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to crystalline, low melting ε-caprolactone polymers bearing basic amine functionalities which are linked to the ester chain ionically or covalently to induce catalyzed hydrolysis. The ester components can be derived from ε-caprolactone with or without small amounts of glycolide, and/or similar lactones. Such polymers with accelerated absorption profiles are especially adapted for use as transient coatings for absorbable multifilament surgical sutures.
Multifilament surgical sutures such as Dexon® polyglycolide multifilament suture typically require a surface coating to improve the handling and knotting characteristics of the suture. Capitalizing on the desirable low melting temperature, crystallinity, and rheological properties of polycaprolactone as a coating material, several compositions based on this polymer were investigated as coatings for surgical sutures. Recognizing the fact that the ε-caprolactone homopolymer is essentially non-absorbable led to the development of copolymers of ε-caprolactone with variable amounts of more absorbable monomers to improve the coating absorbability. U.S. Pat. No. 4,624,256 discloses a suture coating copolymer of at least 90 percent ε-caprolactone and a biodegradable monomer and optionally a lubricating agent. Examples of monomers for biodegradable polymers disclosed include glycolic acid and glycolide, as well as well-known monomers typically used to prepare absorbable polymer fibers or coatings for multifilament sutures. U.S. Pat. No. 4,788,979 and U.S. Pat. No. 4,791,929 disclose a bioabsorbable coating of a copolymer of at least 50 percent ε-caprolactone and glycolide. Sutures coated with such polymers are reported to be less stiff than sutures coated with other materials and the physical properties of the coated suture are also reported to be acceptable. U.S. Pat. No. 4,994,074 discloses copolymers of a predominant amount of ε-caprolactone, the balance being glycolide and glycolic acid; the use of glycolic acid reportedly increasing the rate of absorption of the copolymer when used as a coating for multifilament surgical sutures.
Unfortunately, the problem of adequate bioabsorbability of ε-caprolactone-based polymers without detrimental effects on their desirable properties as coatings still remains. Specifically, the use of sufficient amounts of glycolide to achieve sufficient absorbability of the copolymeric coating can compromise its crystallinity and melting characteristics, for it may become amorphous or liquid near room temperature. On the other hand, the strategy of using glycolic acid to achieve the reported results in coating absorbability does limit the ability to produce sufficiently long chain molecules to achieve optimum frictional properties, due to glycolic acid's known properties as both a ring-opening initiator and a chain terminator. Thus, a totally new approach to modifying the absorbability of polycaprolactone and its copolymers without affecting their desirable properties as suture coatings would be a more desirable goal.
SUMMARY OF THE INVENTION
One aspect of the invention are low melting, crystalline, basic nitrogenous polyesters, or polyesteramides, where the amine functionality represents between 1 and 10 percent of the total weight, while the repeat units of the polyester chain originate predominantly from ε-caprolactone. The balance ester sequences can be derived from glycolide, lactide p-dioxanone and/or one or more of the corresponding hydroxy acids. The amine functionality can be linked to the polyester chain ionically or covalently.
In another aspect, the invention is a coating for a surgical suture which displays autocatalyzed hydrolysis and improved absorbability over polyester coatings of the prior art which are devoid of any basic amine functionality. This coating comprises a low viscosity melt or a solution in an organic solvent, of the amine-bearing polyesters described above. Surprisingly, the incorporation of 1 to 5 percent of the amine functionality increased the polyester absorbability substantially, without compromising its desirable physical properties such as those associated with crystallinity and melting profile.
Polyesters bearing the amine-functionalities subject of this invention and coating derived therefrom can be used for coating bioabsorbable multifilament surgical sutures.
DETAILED DESCRIPTION OF THE INVENTION
Polyesters comprising predominantly ε-caprolactone polymer sequences generally refers to polymers with ε-caprolactone-based sequences of greater than 90 mole percent. ε-Caprolactone is the predominant component of the polyester because of its low melting, exceptionally low glass transition temperature (Tg) and its ability to enhance the physical properties of coated multifilament sutures. Preferably, the amount of ε-caprolactone used in the synthesis of the polyester ranges from 90 to 99, more preferably 96 to 99 mole percent. For copolyesters of this invention, the remaining comonomers are preferably glycolide and/or glycolic acid. Other lactones such as lactide and p-dioxanone and/or their corresponding hydroxy acids can be used. The hydroxy acids can be used, specifically, as chain initiators to control the polyester molecular weight, as determined in terms of their inherent viscosities (I.V.) as 0.1 g/dl solutions in hexafluoroisopropyl alcohol, and/or to provide chains with a carboxylic end group. The basic nitrogenous polyesters which are the subject of this invention, are to have I.V. of 0.05 to 0.35 dl/g and, preferably, 0.05 to 0.25 and, more preferably 0.10 to 0.20 dl/g.
Two major types of amine functionalities can be introduced into the polyester chain to accelerate its absorption through autocatalyzed hydrolysis. The weight percent of the amine functionalities in the polyesters subject of this invention can be between 1 and 5 and, preferably, 1 to 3. The first type of amine-functionality comprises an ionically linked mono- or poly-functional amine which is capable of forming a carboxylate salt with an acid-terminated polyester chain. This can entail, for instance, a caprolactone/glycolide copolymer made using catalytic amounts of stannous octoate and glycolic acid as the chain initiator, and following a typical reaction scheme established for caprolactone polymerization. The resulting acid terminated polyester is then allowed to form carboxylate salts with amine-bearing molecules: lysine, potassium lysinate or an alkane diamine, as depicted by structures A and B, respectively. ##STR1##
The second type of amine functionality is covalently incorporated into the polyester chain. This can be achieved by amidation of preformed polyester with di- or poly-functional amine or using di- or poly-amine with at least one reactive hydrogen as the chain initiator, such as 1-methyl 4-aminomethyl-piperidine and 3,3'-diamino-N-methyldipropylamine. The ring opening polymerization can be achieved using catalytic amounts of stannous octoate. Typical polyesters covalently linked to the amine functionalities can be illustrated by structures C and D shown below. ##STR2##
Although this invention addresses low melting crystalline polyesters made predominantly of ε-caprolactone, those skilled in the art can foresee the use of other aliphatic polyesters as the base materials and incorporate the amine functionality to the acid terminated polyester chains by salt formation or the amidation of pre-formed polyester chains using amino compounds similar to those associated with structures C and D above.
The coating can be applied to the braided suture as a low viscosity melt at temperatures between 70° and 100° C. and, preferably 70°-90° C. Excess coating can be removed by passing through a pad of non-woven fabric, e.g., polypropylene or a sizing die. More traditional methods of coating application can entail the use of 1 to 10 percent solution and, preferably, 2 to 5 percent in an organic solvent such as toluene at room temperature or between 25° and 50° C. The solvent can then be evaporated by air-drying at room temperature of between 25° and 75° C. Other solvents or mixture of solvents can be used as substitutes for toluene. The coated suture can be further treated thermally to insure even distribution of the coating on the braid components. Typical sutures which can be coated with compositions subject of this invention include those made of polyglycolide and polyethylene terephthalate. Depending on the suture size, the percent add-on of the coating can be varied between 1 and 10 percent and, preferably, 1.5 to 4.5 percent as the suture decreases from size #1 to size #50. At such level of coating, the suture handling and tie-down characteristics are improved substantially without compromising other properties such as visibility, surface appearance, and knot strength and security.
The absorption profile of the coating is such that it will not affect that of an absorbable suture to any discernable extent. Typically, when representative coatings subject of this invention are used on polyethylene terephthalate sutures incubated in a phosphate buffer at 37° C. and pH of 7.26 lose 50-100 percent of their original mass in two to six months.
The following examples illustrate the claimed invention and are in no way intended to limit its scope.
EXAMPLE 1
Synthesis of acid-terminated polycaprolactone Polymer A
ε-Caprolactone (57.1 g, 0.5 mole) glycolic acid (7.6 g, 0.1 mole) and stannous octoate (0.5 ml of 0.1M solution in toluene, 20 mg, 5×10 -5 mole) were added to a glass reactor. The reactor was purged with dry nitrogen gas. The reactor was heated in an oil bath at 180° C., under nitrogen, for 12 hours while the contents were magnetically stirred. The resultant homopolymer has a Tg of -60° C. and Tm of 39° C. as measured by DSC. The resultant polymer inherent viscosity is 0.1 dl/g at 30° C. in hexafluoroisopropyl alcohol.
EXAMPLE 2
Preparation of potassium L-lysinate salt of Polymer A
Potassium L-lysinate (1.25 ml of 2.0M solution in methanol, 25 mmole), is slowly added with stirring to Polymer A (4.4 g, 25 mmole) in 100 ml tetrahydrofuran at room temperature. The tetrahydrofuran is then removed by vacuum. The structure of the resultant coating as an onium salt was determined by IR and NMR. The Tg and Tm were shown by DSC to be -62° and 44° C., respectively. Elemental analysis data were consistent with the proposed chemical structure:
______________________________________ % N % K______________________________________Found 1.52 2.23Calculated 1.45 2.05______________________________________
EXAMPLE 3
Synthesis of random copolymer of 98.5/1.5 caprolactone-glycolide, Copolymer B
ε-Caprolactone (57.1 g, 0.5 mole), glycolide (1.1 g, 9.5 mole), glycolic acid (7.6 g, 0.1 mole) and stannous octoate (0.5 ml of 0.1M solution in toluene, 20 mg, 5×10 -5 mole) were added to a glass reactor. The reactor was purged with dry nitrogen gas. The reactor was heated in an oil bath at 180° C. under nitrogen for 12 hours, while the contents were magnetically stirred. The final composition was determined by 1 H NMR is shown to be essentially the same as the theoretical. The Tm is -62° C., and the Tg is 37° C.
EXAMPLE 4
Preparation of potassium L-lysinate salt of Copolymer B
Potassium L-lysinate (1.25 ml of 2.0M solution in methanol, 25 mmole), is slowly added with stirring to Polymer B (4.4 g, 2.5 mmole) in 100 ml tetrahydrofuran at room temperature. The tetrahydrofuran is then removed by vacuum. The structure of the resultant coating as an onium salt was determined by IR and NMR. The Tg and Tm were shown by DSC to be -60° and 39° C., respectively. Elemental analysis data were consistent with the proposed chemical structure:
______________________________________ % N % K______________________________________Found 1.31 2.03Calculated 1.45 2.05______________________________________
EXAMPLE 5
Synthesis of random copolymer of 95/5 ε-caprolactone/glycolide, Copolymer C
Following a procedure similar to that used for the synthesis of copolymer C B, copolymer was made and shown to have an inherent viscosity of 0.1 dl/g in HFIP at 25° C. It has a Tg of -60° C., and Tm of 40° C.
EXAMPLE 6
Preparation of potassium L-lysinate salt of Copolymer C
The salt is prepared following a procedure similar to that used for the preparation of the salt of Copolymer B. The composition of the resultant coating was consistent with its elemental analysis and NMR data. The Tg and Tm were shown by DSC to be -53° and 36° C., respectively.
EXAMPLE 7
Synthesis of acid-terminated polycaprolactone, Polymer D
ε-Caprolactone (57.1 g, 0.5 mole), lactic acid (9.0 g. 0.1 mole) and stannous octoate (0.5 ml of 0.1M solution in toluene, 20 mg, 5×10 -5 mole) were added to a glass reactor. The reactor was purged with dry nitrogen gas. The reactor was heated in an oil bath at 180° C., under nitrogen, for 12 hours, while the contents were magnetically stirred. The resulting Polymer D was removed and shown to have an inherent viscosity of 0.1 dl/g in hexafluoroisopropyl alcohol.
EXAMPLE 8
Preparation of amine-terminated polycaprolactone, Polymer E
ε-Caprolactone (57.1 g, 0.5 mole), 1-methyl-4-aminomethyl piperidine (2.54 g, 0.02 mole) and stannous octoate (0.5 ml. of 0.1M solution in toluene, 20 mg, 5×10 -5 mole) were transferred to a predried glass reactor under oxygen-free dry nitrogen atmosphere. The reaction mixture was heated to 170° C. under dry nitrogen. The polymerization was continued for 12 hours while the contents were magnetically stirred. The resulting Polymer E was removed and shown to have an inherent viscosity of 0.15 dl/g in hexafluoroisopropyl alcohol.
EXAMPLE 9
Preparation of polycaprolactone with internally placed amine functionality, Polymer F
Using the same polymerization scheme as in Example 8 and all reagents except 1-methyl-4-aminomethyl piperidine, which was replaced by 3,3'-diamino-N-methyldipropylamine (2.32 g, 0.016 mole) to produce a polymer having an inherent viscosity of 0.13 dl/g.
EXAMPLE 10
Preparation of potassium L-lysinate salt of Polymer D
This is done following a procedure similar to that used for the preparation of the coating in Example 2.
EXAMPLE 11
Solution coating of size 2-0 polyglycolide braided suture
The suture is dipped 5-10 times in a 2 percent solution of the coating (from Examples 2, 4, or 6) in methylene chloride, with each coat dried in between dips. This yields a very thin homogeneous coating layer (typically 2.5 to 5 weight percent of the suture) which gives excellent knot tie-down properties both wet and dry, with no visible flaking.
EXAMPLE 12
Application of molten coating polymer to size 2-0 polyglycolide braided suture
The suture is passed through the molten coating (from Examples 2, 4, or 8) in a temperature of 5° to 50° C. above the melting temperature of the coating material, and then threaded through two non-woven Teflon® pads under slight compression to remove excess coating. This yields a thin, uniform coating layer (typically 5 weight percent of the suture). The coated suture exhibited excellent knot tie-down properties both wet and dry, with no visible flaking.
EXAMPLE 13
Absorption profiles of coatings
Depending on the composition of the polyester component, as in Examples 4 and 6, of the coating, and the level of amino groups, the mass loss ranges from 10 to 20 at three weeks, 40 to 50 at ten weeks, and 55 to 65 at thirteen weeks. To obtain accurate weight loss, a size 2-0 non-absorbable suture braid made of polyethylene terephthalate was used. | Crystalline, low melting ε-Caprolactone polymers which undergo accelerated hydrolysis for use, for example, as absorbable coatings for surgical sutures; the polymers bearing basic amine functionalities, ionically or covalently linked to the ester chain, which induce autocatalyzed hydrolysis. | 0 |
BACKGROUND OF THE INVENTION
This invention relates to party games, and more particularly, to electronic party games and components thereof.
Board-games, card games and other party games have provided entertainment for groups of people for many years. A number of party games require individual players to answer questions. These answers in turn entertain the group. One such game, known as Scruples (trade mark), tests individual players with moral dilemmas. A disadvantage associated with this game is that a player may lie, in answering the moral question, and often it is difficult or impossible for the other players to detect the lie.
There exist a number of lie-detector devices which have been considered to be suitable for entertainment purposes. U.S. Pat. No. 3,648,686 discloses an instrument for measuring the galvanic skin response, which utilizes a bridge amplifier and relies upon a change in the audible frequency to signal an untruth, but this device has poor resolution. U.S. Pat. No. 3,841,316 discloses an apparatus for measuring the psychogalvanic reflex, which also uses a resistance bridge circuit, but this device is not practical, since the transistor meter combination required to make the circuit practical does not exist. U.S. Pat. No. 4,331,160 discloses a lie-detector apparatus which is an improvement over that disclosed in the above patents, because it provides a constant baseline, but it also uses a resistance bridge circuit which does not create a linear output. Furthermore, these prior art devices are not very reliable lie-detectors, because they do not take into account the fact that a particular person may have a relatively high response to every question, or a relatively low response to every question, regardless of whether a person is telling the truth.
There also exist highly sophisticated polygraph machines which calculate scores corresponding to the certainty of deceit, based upon complex measurements of various factors, but these machines are very expensive, and can only be used by trained operators.
There is accordingly a need for a relatively simple, inexpensive lie-detector apparatus, adapted for use as a component of a party game.
SUMMARY OF THE INVENTION
The present invention is directed towards apparatus for monitoring and comparing user psycho-physiological responses to questions. The apparatus comprises a housing shaped to fit into the palm of a hand of the user, having an outside top surface shaped to receive a pair of extended adjacent fingers, and a pair of spaced electrodes extending through the top surface, each electrode being positioned to contact one of the extended fingers, and bias means coupled to the housing for selectively biasing the user's fingers against the electrodes. Current generating means located within the housing is electrically coupled to the electrodes and generates an electrical current flow from one electrode through a section of the user's body to the other electrode and a corresponding voltage signal which is proportional to the resistance of the section of the user's body. Measuring means coupled to the current generating means measures differences in the voltage signal created when the user responds to a given question. Signal generation means responsive to the measuring means generates a signal to the user correlatable with the differences in the voltage signal.
The present invention is also directed to an electronic party game comprising display means for displaying questions to be asked to a player, and monitoring means for monitoring the player's psycho-physiological responses to the questions. The monitoring means comprises a housing dimensioned to be fit into the palm of the player answering the questions, the housing having an outside top surface shaped to receive two extended fingers of the player, and a pair of electrodes extending through the top surface, each of the electrodes being positioned to contact one of the extended fingers near the tip thereof, and bias means operatively coupled to an outside portion of the housing for selectively biasing the player's fingers against the electrodes. Circuit means located within the housing generates an electric current from one electrode to the other through a section of the player's body, which creates a measurable electric signal correlatable with the change in resistance resulting from the player's response to the questions. Signalling means generates a signal to the other players indicative of the changes in resistance.
The present invention is further directed to a method and apparatus for determining which of two questions generates a greater psycho-physiological response in a user hearing the questions. The method comprises the steps of contacting adjacent fingers of the user to spaced electrodes; applying a current across the electrodes and generating a measurable voltage signal related to the resistance of a section of the user's body extending between the electrodes; signalling when the user should be asked a first question and allotting a time interval for the user's response; detecting the change in voltage signal across the electrodes when the user responds to the first question during the first time interval; filtering out components of the voltage signal outside of a preselected frequency range; storing a first filtered voltage signal for the first time interval; signalling when the player should be asked a second question and allotting a second time interval for the user's response; detecting the change in voltage signal across the electrode when the user responds to the second question during the second time interval; filtering out components of the voltage signal outside of a preselected frequency range; measuring a second filtered voltage signal for the second time interval; comparing the first filtered voltage signal with the stored filtered voltage signal and generating a comparison signal indicative of which of the two signals is greater; and displaying to the user an indication of the comparison signal.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described, by way of example only, with reference to the following drawings, in which:
FIG. 1 is a perspective top view of a player response monitor of a party game made in accordance with the preferred embodiment of the subject invention;
FIG. 2 is a schematic view of the display cards of the party game made in accordance with the preferred embodiment of the present invention;
FIG. 3 is a partially cutaway perspective bottom view of the response monitor of the subject invention;
FIG. 4 is a block diagram of the electronic circuitry for the response monitor;
FIG. 5 is an electrical schematic diagram for the response monitor; and
FIG. 6 is a top plan view of a portion of the response monitor in use.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, a party game made in accordance with a preferred embodiment of the present invention comprises player response monitor 10 and a plurality of display cards 11, 12 and 13. Response monitor 10 is a portable, battery-powered device sized to fit into the palm of a user.
Each of question display cards 11a, 11b displays a different question designed to generate an emotional response. Control display card 12 is divided into two sections 12a and 12b, and displays questions designed to determine whether a player is calm enough to be asked a response question. Section 12a preferably displays the question "Is your name ?" and section 12b preferably displays the question "Are you ready for the test?". Indicator display cards 13a and 13b, marked "1" and "2" respectively enable the players asking the questions to indicate to the player being questioned which of the two questions they indicated would generate the greater emotional response, after the response is given. The subject party game preferably includes about 200 question cards like question cards 11a, 11b, each of which displays a different question.
Referring now to FIGS. 1 and 3, response monitor 10 comprises a housing 14 shaped to be held comfortably in the palm of a user's hand, defining an interior space for accommodating printed circuit board 15 and battery 17. Housing 14 is composed of top housing portion 16 glued or otherwise joined to bottom housing portion 18 along junction line 19. Housing portions 16, 18 are preferably made of moulded plastic. Battery 17 is preferably a 9 volt transistor battery.
Top surface 20 of top housing portion 18 includes a longitudinal extending central divider ridge 21 which extends at a slight angle to the longitudinal axis A of housing 14, and divides top surface 20 roughly in half, to form index and middle finger rest areas 22, 23. Index finger rest area 22 is shaped to receive the index finger of a user's left hand and middle finger rest area 23 is shaped to receive the user's middle finger.
Spaced electrodes 26, 27 extend through and slightly above the top surface 20 in finger rest area 22, 23. Elastic band 24 protrudes outwardly from both sides of housing 14 along junction line 19, and extends over the top of spaced electrodes 26, 27 and divider ridge 21. Elastic band 24 acts as a biasing means to bias or urge the fingers of the user against electrodes 26, 27. Top surface 20 also includes openable battery compartment 25.
As shown in FIG. 3, light emitting diode (LED) 28 and speaker 29 extend through bottom surface 31 of bottom housing portion 18. LED 28 informs the question asker when to ask questions. Speaker 29 provides an audible sound, preferably either a long beep or a short beep. Bottom surface 31 is also provided with an on/off switch 32.
In the preferred embodiment, response monitor 10 compares the psycho-physiological responses of a user to two distinct questions. The first question is asked when LED 28 turns on, signalling the beginning of the first question period, and the second question is asked when LED 28 turns off after a preset time, signalling the beginning of the second question period. If the first question generates a higher response, speaker 29 will generate a short beep at the end of the second question period. If, however, response monitor 10 detects a higher response to the second question, speaker 29 will generate a long beep during the second question period. The audible beep is preferably a 400 Hz +/-100 Hz signal.
Referring now to FIG. 4, the electronic circuitry of response monitor 10 comprises constant current source 36 coupled to electrodes 26, 27, signal filter and amplifier 38, buffer 44, storage means 46, comparator 48, trigger 50, timer 52, power supply filter 54 and speaker driver 56.
Constant circuit source 36 generates a constant current through a small section of the user's hand, extending across electrodes 26, 27. The current preferably ranges from about 2 microamps to about 7 microamps, depending upon the desired sensitivity and required range of human variability. Signal filter and amplifier 38 filters out undesirable signals outside of a preselected frequency range, preferably signals below about 0.1 Hz and above about 18 Hz, amplifies the desired response by about 1,000 times, or 60 dB, and provides a voltage signal which correlates to the user's response to hearing a question. Buffer 44 provides a small buffer against electronic noise. Storage means 46 clears the stored voltage signals at the beginning of the first question period, stores the voltage signal received during the first question, and stores the voltage signal received during the second question period. Comparator 48 compares the voltage signal generated by the second question to the voltage signal generated by the first question, and provides a signal out if the second question generates a higher signal. Comparator 48 also provides a signal out at the beginning of the questioning sequence. Trigger 50 provides a signal to clear the stored value in storage means 46 at the beginning of the question sequence. Timer 52 provides the timing for the entire circuit, including providing a signal to turn LED 28 on and off to indicate the questioning sequence, and a signal to comparator 48 to synchronize the clearing signal. Timer 52 also provides timing for storage means 46. The duration of the timing signal is preferably 8-15 seconds on, and 8-15 seconds off. Power supply filter 54 filters out any power supply noise. Speaker driver 56 includes an oscillator for speaker 29, and provides a signal to determine the length of the sound generated by speaker 29.
Referring now to the circuit diagram shown in FIG. 5, resistor 70 and zener diode 71 of constant current source 36 provide a constant voltage V to the non-inverting output of Op Amp 72. The voltage is preferably 3.2 volts+/± 5%. Capacitor 73 is used to filter out noise. Resistor 75 is connected to the inverting input of Op Amp 72, and is used to determine the value of a current which will travel through the hand of the person being questioned, which is determined by the equation: Current=3.2 Volts/R, where R is the resistance of resistor 75. The value of resistor 75 is preferably 1 megohm, which results in a 3.2 microamp constant current, giving an operational range of equivalent resistance of the user's body of from about zero to about 1.5 megohms. Resistor 76 protects the circuit. The output of Op Amp 72 provides a voltage proportional to the equivalent resistance of the body of the person being monitored by response monitor 10. The output of Op Amp 72 changes with corresponding changes in the equivalent resistance of the body.
Capacitor 78 and the Thevenin resistance of signal filter and amplifier 38, combine to filter out the changes in body resistance generated by movement and the user's overall level of relaxation or anxiety, and act as a DC shift or level adjustment. Op Amp 80 and related circuitry of signal filter and amplifier 38 provide a gain to the signal generated by the user when telling a lie, which has predominately 1-3 Hz frequency components. Capacitor 84 also filters out frequency components outside this desired frequency range.
Resistors 85, 86 and 87 of buffer 44 combine to give a reference voltage for storage means 46, and resistor 85 provides a buffer against noise into comparator 48.
Capacitor 90 of storage means 46 is connected to the output of Op Amp 91 through resistor 92 and the low leakage base connector diode of transistor 93. This part of storage means 46 functions as a peak detector, which saves the peak value of the response to question 1 as a voltage on capacitor 90. Resistor 92 is used to limit current through the small base collector junction. Transistor 93 and resistor 92 combine to clear the value stored on capacitor 90 at the end of question 2. The base-collection junction of transistor 93 functions as a low leakage diode, whereas the collector-emitter junction of transistor 93 functions as a transistor. Diode 94 and resistor 92 combine to prevent capacitor 84 from sampling the response to question 2. Capacitor 90 is used to hold the value of question 1 during question 2. Diode 94 and diode 95 are used in conjunction with the control signals from trigger 50 to program the clearing function, the peak detection function, and the hold function.
Op Amp 100 of comparator 48 is used in the open loop configuration as a comparator. It compares the level stored on capacitor 90 and connected to the inverting input of Op Amp 100, with the magnitude of the response to question 2, which is connected to the non-inverting input of Op Amp 100. The output of Op Amp 100 sends a logic high to speaker driver 56 when the second response is greater than the first response, thereby indicating a lie.
Trigger 50 comprises a NAND Gate 102, acting as a Schmitt trigger, which generates a 50 millisecond pulse low to clear capacitor 90 in storage means 46. NAND Gate 102 also causes comparator 48 (through storage means 46) to generate a short logic high at the beginning of question 1. The result is a short beep, which tells the operator to begin the questioning sequence.
Capacitor 104 and resistor 105 of timer 52 combine to control the timing for the circuit. NAND Gate 106 is configured as an oscillator using the RC timing constant and the hysteresis of the NAND Gate. The value of resistor 105 and capacitor 104 depend upon the amount of time required for the questioning and manufacturers' process variations. NAND Gate 107 is used as an inverter to condition control signals. LED 28 are used to indicate to the user when to ask the questions.
Capacitors 110 and 111 of power supply filter 54 are used to filter out noise induced on the power supply. Internal factors as well as noise generated by appliances and lighting are filtered out, although these problems are drastically reduced in any event due to the low power requirements of the circuit, and the elimination of an AC/DC power supply and noise with the use of a battery.
NAND Gate 114 of speaker driver 56 is used as an oscillator to drive speaker 29, which is preferably a piezo electric speaker. Resistor 115 and capacitor 116 are used to program the frequency of the output of speaker 29. Preferably, 400 Hz square wave is output to the speaker. Pin 1 of NAND Gate 114 is used as the control for the oscillator. A logic high turns it on and logic low turns it off. Resistor 117 and capacitor 118 combine to give a 4-5 second logic high to the speaker driver, to indicate a lie. Resistor 119 with the appropriate control signal provides a 0.2-0.3 second pulse to the speaker driver, to indicate the beginning of the question sequence with a short beep. Resistor 120 and diode 121 are used to start the time sequences, and resistor 120 also reduces false triggers and switching noise induced back into the power supply.
In use, referring now to FIG. 1, response monitor 10 is preferably placed in a user's left hand, such that user's index finger 33 and middle finger 34 make good contact with electrodes 26, 27. Elastic band 24 is then placed over the two fingers, thereby pressing the fingers 33, 34 against electrodes 26, 27. The middle finger of the user may extend over the front end of housing 14, as shown. The user should then turn his left hand palm up, so that LED 28 may be seen by person asking the questions.
The party game of the present invention may be played in accordance with the following rules:
1. Divide the players into two teams and determine who will begin the first session.
2. Turn on response monitor 10 and place it in the left hand of the first person to be questioned. (See diagram 1).
3. The person being questioned will now select two question display cards 11 randomly from the deck of question cards and must read the two questions to everyone playing the game.
4. The other team must now discuss which question will cause the highest emotional response from the player being questioned and place the corresponding indicator display card 13a or 13b face down in front of them.
5. No one is allowed to speak or make any noises during the questioning sequence and the person being questioned should close their eyes sit comfortably with both feet flat on the floor and the device facing up on their lap. When the START light comes on a short beep is heard. The following sequence must be followed and the person being questioned must respond with a YES or a NO only Repeat a and b up to three time if necessary. (See hints)
a) START light ON "is your name . . . ?"
b) START light OFF "Are you ready for the test?"
c) START light ON Ask question number one.
d) START light OFF Ask question number two.
6. A LONG BEEP indicates the second question caused the highest response. A SHORT BEEP indicates the first question caused the highest response. Turn up the indicator display card. A correct match scores one point for the team asking the questions. (The players might want to discuss the results at this point.)
7. Response monitor 10 is then connected to a person on the other team following the above procedure. Every person will eventually be connected to monitor 10.
There are three methods of play:
1. The game can be played to a final point value. A typical game played to ten will last about two hours.
2. The game can also be played to a time limit. The team with the most points after two hours wins.
3. You can also play just for the fun of it, utilizing response monitor 10 as a lie-detector. Ask any questions you want, one victim at a time, as discussed in more detail hereinbelow.
Hints:
If possible, place people with a knowledge of each other (i.e. spouses or close friends) on opposing teams. Attempt to have an equal number of males and females on each team. Women tend to be three to four times better at playing the subject game than men. In general, people tend to guess which question will generate the highest response only about a third of the time, so don't be discouraged if at first you don't do well.
Try to relax if you are going to be questioned. Take several deep breaths, relax and try to get as comfortable as possible. When being questioned, breathe normally and remain still. If the person being questioned has a response (a long beep) to question b) "Are you ready for the test?", repeat questions a and b. You can decide how many times to repeat the sequence to allow the person to relax. A person who is unable to relax will continually respond and will appear to have the highest response to the second question.
Wash your hands prior to the game. If your hands are extremely dry, use a small amount of hand cream.
When determining which question will give the highest emotional response, consider the following. If the question will cause embarrassment, humour, guilt, anger, disgust, or sexually stimulate the person, a high response will be measured even if the person is not lying. The other players in the game will also affect the responses to questions. For example, a question regarding citizenship of your country is unlikely to cause much of a reaction for most people, however if you were to ask this question to an illegal alien with an immigration worker in the room the response would be quite different.
If you have knowledge of an incident which relates to a question, you can use this to your advantage. If you feel, the person will respond highly to that question you can increase the response by subtly reminding them of the incident. Attempt to determine the person's reaction when the questions are first being read.
The game includes three extra cards. The indicator two cards 13a, 13b have either the number 1 or number 2 on them and are used to secretly pick the number of the question which you think will give the highest response. The other card is a double control card 12 which has the questions "a) is your name . . . ?" and b) Are you ready for the test?" These form part of the questioning sequence. You can place them in order with the two question cards 11 to make it easier to ask the questions (i.e. a,b,c,d) See rule 5 and/or diagram 2.
The response monitor 10 of the subject invention may be used as a lie-detector for entertainment purposes, keeping in mind that the reliability of a lie-detector depends greatly on the skill and training of the person asking the questions. It should also be appreciated that the psycho-physiological response created by a lie is very similar to embarrassment, sexual arousal, anger, disgust or humour.
Therefore, when formulating the questions, the user must be very careful that the response is generated by the lie and not other emotions. The setting is important as well. The room should be quiet and free from distractions. It is recommended that the person being questioned close their eyes. The person being questioned must be familiar with the sequence of questions to follow and be prepared. When asking the questions, it is important to watch the person's breathing. The person must maintain normal breathing through the entire test or they may alter the results. A small wager on the results may improve the results.
______________________________________a) START light ON "Is your name . . . . . . . . . . . . . ?" (insert person's name)b) START light OFF "Are you ready for the test?"c) START light ON "Is your name . . . . . . . . . . . . . ?" (insert person's name)d) START light OFF Ask a relative question______________________________________
When asking questions a) and c) the person being questioned must respond NO. This is called a directed lie. The questioner knows the person's name and instructs the person to lie about it. The "Lie Detector" then compares this response to the response measured when question d) is asked. Question d) must be phrased so the response to the question is NO (i.e. Did you steal a cookie from the cookie jar today?). The questions must be specific to avoid a misunderstanding. Most of the questions supplied with the game are examples of poor "lie detector" questions. The questions in the game were designed to be open ended or have many interpretations. This is designed to increase the enjoyment of the game and illustrate how poorly people tend to understand their friends and relatives, but gives very little insight into the truthfulness of the response. This is because it is not certain what generated the response.
If the person has a response to question b) the questioner should repeat questions a) and b) until no response is registered. If the person has a response to this questions (LONG BEEP) they are not ready for the test. This could mean they already know they are going to fail or they are not sufficiently relaxed to get accurate readings. A LONG BEEP after question d) is a good indication that the person is being deceitful. Repeating the test several times can increase the reliability.
Response monitor 10 of the subject invention provides a number of advantages over known lie-detector game devices. Response monitor 10 compares the magnitude of the response to a relative question (a second question), to the magnitude of a directed lie (the first question). The subject response monitor may also function as an emotional response monitor, which compares the emotional responses to two different questions.
The subject response monitor effectively filters out signals not due to the lie or emotional response, and being hand-held without any long wires, it is less sensitive to radio frequency and other electrical noise, and less susceptible to contact variation.
Unlike sophisticated polygraph systems used by police forces, the subject response monitor can be used by lay persons not trained in polygraph operation. The subject response monitor is much smaller and more transportable than professional polygraph machines. The subject device is also more comfortable to use, and far less expensive than professional lie-detector machines, which typically sell for several thousands of dollars.
It should be understood that various modifications can be made to the preferred embodiment described and illustrated herein, without departing from the subject invention, the scope of which is defined in the appended claims. | An electronic party game, comprising display cards for displaying questions to be asked to a player, and a response monitor for monitoring the player's psycho-physiological responses to the questions. The response monitor comprises a housing dimensioned to be fit into the palm of the player answering the questions, the housing having an outside top surface shaped to receive two extended fingers of the player, and a pair of electrodes extending through the top surface, each of the electrodes being positioned to contact one of the extended fingers near the tip thereof, bias means operatively coupled to an outside portion of the housing for selectively biasing the player's fingers against the electrodes, an electronic circuit located within the housing which generates an electric current from one electrode to the other through the player's fingers and a voltage signal correlatable with the change in resistance resulting from the player's response to the questions, and an indicator which generates a signal indicative of the changes in resistance. The subject monitor is capable of monitoring a user's psycho-physiological responses to hearing a pair of questions and determining whether the user's response to the first question is greater than the user's response to the second question. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of synthetic filament production. More specifically, the present invention relates to the field of liquid finish applicators and methods whereby a liquid finish is applied onto surfaces of synthetic filaments.
BACKGROUND AND SUMMARY OF THE INVENTION
[0002] Synthetic filaments are traditionally produced by various spinning techniques. For example, synthetic filaments may be melt-spun by extruding a melt-spinnable polymer through relatively small-sized orifices in a spin pack to form a stream of filaments that is substantially immediately solidified in a quench cabinet. The filaments are thereafter continuously taken up by a high speed winder to form a generally cylindrical package. Depending on the intended end use, the filaments may be undrawn or may be subjected to a drawing step prior to being taken up to form the package.
[0003] The solidified filaments are typically passed through a metered finish applicator, which applies a liquid finish material (colloquially referred to as a “finish oil”) so as to lubricate the filaments to reduce filamentary friction and/or to achieve desired processability characteristics. Typically, a finish applicator mounting unit supports a plurality of fixed-position finish applicator nozzles that each include a slot to receive the individual filament threadlines. A portion of the slot against which the filaments are guided includes a small opening for the finish oil. Thus, as the filaments pass through the finish applicator nozzle during production, the finish oil is supplied to the slot and thereby coated onto the filaments.
[0004] The finish applicator nozzles are typically formed of a durable, low friction material, such as a ceramic material. Over time, however, the small amount of friction between the filaments moving at a relatively high speed and the stationary finish applicator nozzle causes some wear to be experienced in the latter. A greater amount of friction on the moving filaments will result as the finish applicator nozzle experiences greater wear which, in turn, is detrimental to the filaments. Too great a frictional force against the filaments can, in extreme cases, cause filament breakage requiring production down time.
[0005] Recently, U.S. Pat. No. 5,679,158 (the entire content of which is expressly incorporated hereinto by reference) suggested providing a finish applicator assembly with applicator nozzles removably received in a corresponding aperture of a mounting unit. While the applicator nozzles of this U.S. '158 patent are more easily accessible for the purpose of cleaning, repair and/or replacement, some improvements are still desired.
[0006] For example, it would especially be desirable for finish applicators and methods to be provided which would increase the wearability of the finish applicator thereby lessening the friction experienced between the applicator and the moving filaments over a significantly greater period of time than can now be accomplished. It is towards fulfilling such a need that the present invention is directed.
[0007] Broadly, the present invention is embodied in apparatus and methods whereby a finish oil may be applied onto a moving filament by a stationary, yet periodically movable finish applicator. The finish applicator is most preferably annular and is thus capable of being rotated relative to the traveling filament so as to sequentially bring at least one and another arcuate applicator surface segments into contact with the travelling filament. By continually exposing different surface segments of the finish applicator to filament contact at different times, the amount of wear experienced by a single one of the surface portions is minimized. As such, the finish applicator is capable of being kept in production for prolonged time periods and thus minimizes (if not eliminates entirely) at least some of the problems noted previously with respect to conventional finish applicators.
[0008] Thus, in one especially preferred aspect of the present invention, liquid finish is applied to a travelling filament by bringing the travelling filament into contact with an arcuate surface portion associated with a normally stationary, but rotatable, annular finish applicator, and thereafter periodically rotating the annular finish applicator to bring at least one other arcuate surface portion thereof into contact with the travelling filament. Most preferably, an actuator assembly is provided having first and second actuator fingers which are capable of relative separable rectilinear movements towards and away from one another. These actuator fingers, in an especially preferred embodiment, are each pivotally moveable and magnetically coupled to one another. As such, separable movement will in turn cause that one of the actuator fingers connected to the annular finish applicator to pivot thereby rotating the later to expose a “fresh” arcuate surface region in contact with the filament.
[0009] These and other aspects and advantages will become more apparent after careful consideration is given to the following detailed description of the preferred exemplary embodiments thereof.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[0010] Reference will hereinafter be made to the accompanying drawings, wherein like reference numerals throughout the various FIGURES denote like structural elements, and wherein;
[0011] [0011]FIG. 1 is a schematic illustration of a melt spinning system in which the finish applicator assembly of the present invention may be employed;
[0012] [0012]FIGS. 2A through 2C are perspective views of a preferred embodiment of a finish applicator assembly of the present invention at different operational stages; and
[0013] [0013]FIGS. 3A through 3B are end elevational views of the finish applicator assembly at different operational stages corresponding to FIGS. 2A through 2C, respectively.
DETAILED DESCRIPTION OF THE INVENTION
[0014] In a typical melt spinning apparatus as shown in FIG. 1, an extruder 10 extrudes a polymer melt through a spin pack 12 having a plurality of spinneret orifices that form a plurality of filament threadlines 14 . It will be understood that, depending on the intended end use, each of the threadlines may include a single filament or may include any number of filaments forming a yarn. The filament threadlines 14 are first cooled in a quench cabinet 16 and may thereafter be drawn by a drawing assembly 22 , comprised of godet rolls 22 a - 22 c . The finished filaments are then wound by a high speed winder 24 to form a package 24 a . Prior to being taken up by the winder 24 , the filament threadlines 14 may be brought into contact with a finish applicator FA according to this invention so that finish oil may be applied.
[0015] As is more clearly depicted in accompanying FIGS. 2 A- 2 C and 3 A- 3 C, the finish applicator FA includes a base frame 32 supporting opposed pairs of upright frame members 32 , 34 . Upper and lower pairs of guide rods 36 , 38 span the distance between, and are thus supported by, the upright frame members 32 , 34 . Extending transversely between these guide rods 36 , 38 are a finish applicator roll 40 and a filament guide roll 42 , each being mounted for rotational movement about its respective longitudinal axis. In this regard, cross-support members 44 , 46 extend between the opposed pairs of upper and lower guide rods 36 , 38 and are slidably coupled thereto by bushings 44 - 1 and 46 - 1 and slide blocks 44 - 2 and 44 - 2 at respective ends thereof. The rolls 40 , 42 are carried by the transverse supports 44 , 46 by means of one-way clutch bearings 40 - 1 , 42 - 1 , respectively (see FIGS. 3 A- 3 C), the purpose of which will be explained in greater detail below.
[0016] A pair of actuator fingers 40 - 2 , 42 - 2 are connected operatively to their respective clutch bearing 40 - 1 , 42 - 1 and extend radially outwardly therefrom in a generally opposed direction relative to one another. Most preferably the actuator fingers 40 - 2 and 42 - 2 are magnetically attracted to one another so as to be magnetically coupled when in contact, the purpose of which will be explained in greater detail below. The bushings 44 - 1 , 46 - 1 and slide blocks 44 - 2 , 46 - 2 allow the cross-support members 44 , 46 and the rolls 40 , 42 carried thereby, to be moved reciprocally along the guide rods 36 , 38 , respectively. The slide block 44 - 2 is most preferably positioned relative to the filament threadlines 14 during start-up and fixed in place (e.g., by clamping) to the guide rods 36 . Thereafter, in use, the slide block 44 - 2 (and thus roll 40 ) remains stationary while the slide block 46 - 2 is capable of being moved reciprocally along the guide rods 38 so as to move the roll 42 carried thereby towards and away from the roll 40 .
[0017] The rolls 40 , 42 are provided with a series of annular finish applicator and guide slots (a representative few of which are identified in FIGS. 2 A- 2 C by reference numerals 40 - 3 , 42 - 3 , respectively) which are spaced apart from one another along the longitudinal axis of the rolls 40 , 42 . Each of the annular applicator and guide slots 40 - 3 , 42 - 3 , respectively, is most preferably formed of a ceramic material so as to minimize friction against the travelling filaments in contact therewith. A series of finish applicator nozzles 48 are removably supported by the cross-support member 44 so as to be in registry with a respective one of the annular applicator slots 40 - 3 . The applicator nozzles 48 are fluid-connected to a source of liquid finish (not shown) so that the liquid finish material may be supplied to, and discharged from, the nozzles 48 onto each respective annular applicator slot 40 - 3 . Filament strands 14 in contact with the annular applicator slots 40 - 3 will thus be coated with the liquid finish supplied thereto by means of the nozzles 48 . A drain tray 50 is positioned below the annular applicator slots 40 - 3 so as to receive excess liquid finish.
[0018] In use, filament threadlines 14 will be positioned in contact around a forward surface portion of a respective annular applicator slot 40 - 3 and a rearward surface portion of a respective annular guide slot 42 - 3 . The individual filament strands 14 will thus be in contact along a selected arcuate segment (known as the “wrap angle”) of the annular and 25 applicator slots 40 - 3 , 42 - 3 . This wrap angle may, however, be changed by reversing the stop arm 52 which depends from, and is carried by, the cross-support 44 . That is, as is perhaps more clearly shown in FIGS. 3 A- 3 B, a stop 54 carried by the slide block 46 - 2 is normally in contact with the lower end of the stop arm 52 . If the stop arm 52 is reversed, the larger boss at the terminal end 52 - 1 thereof will thus be in contact with the stop 54 thereby increasing the horizontal separation distance between the rolls 40 , 42 (and thereby decreasing the wrap angle of the filaments around the annular applicator and guide slots 40 - 3 , 42 - 3 , respectively). Most preferably, the stop 54 is magnetized so as to be magnetically coupled to the stop arm 52 when in contact therewith. Magnetic coupling between the stop 52 and stop arm 54 will thus maintain the rolls 40 , 42 (and the actuator fingers 40 - 2 , 42 - 2 ) in their normal operative positions as depicted in FIGS. 2A and 3A during the filament spinning operation.
[0019] Periodically in the filament production cycle, there is a need to doff the yarn packages 24 a . During such time, the threadlines will be directed “off-line” prior to restringing onto a fresh yarn package core. At this time, an operator will separate the rolls 40 and 42 in a horizontal dimension by sliding the slide block 46 - 2 rectilinearly along the guide rods 38 in the direction of arrow A 1 (see FIGS. 3B and 3C). The roll 42 will thus move away from roll 40 thereby increasing the horizontal separation distance therebetween. Each of the actuator fingers 40 - 2 , 42 - 2 will, in response to such rectilinear movement of the slide block 46 - 2 , rotate in the directions of arrows A 2 and A 3 (see FIG. 3B), respectively, due to the magnetic coupling therebetween.
[0020] As noted previously, the actuator fingers 40 - 2 , 42 - 2 are connected operatively to one-way clutch bearings 40 - 1 , 42 - 1 , respectively. Thus, when the actuator fingers 40 - 2 , 42 - 2 are rotated in the directions of arrows A 2 and A 3 , the one-way clutch bearings 40 - 1 , 42 - 1 will responsively “free-wheel”. As a result, the rolls 40 , 42 will not rotate in response to rotation of the actuator fingers 40 - 2 , 42 - 2 in the direction of arrows A 2 and A 3 . In other words, the one-way clutch bearings 40 - 1 , 40 - 2 will cause the rolls 40 , 42 to rotate only in response to rotation of the actuator fingers 40 - 2 , 42 - 2 in a direction opposite to arrows A 2 and A 3 as will be explained in greater detail below.
[0021] Continued movement of the slide block 46 - 2 (i.e., in the direction of arrow A 1 from the state depicted in FIGS. 2B and 3B) will thus cause the actuator fingers 40 - 2 , 42 - 2 to physically separate from one another as depicted in FIGS. 2C and 3C. In such a state, the threadlines 14 may be more easily re-strung.
[0022] Following re-stringing of the filament threadlines 14 , the slide block 46 - 2 may be rectilinearly moved along guide rod 38 toward roll 40 (i.e., in a direction opposite to arrow A 1 in FIGS. 3B and 3C). The actuator fingers 40 - 2 , 42 - 2 will thus again be brought into contact with one another as shown in FIG. 3B. As a result of continued movement of the slide block 46 - 2 in a direction opposite to arrow A 1 , the actuator fingers 40 - 2 , 42 - 2 to be rotated in a direction opposite to arrows A 2 and A 3 , respectively. However, rotation of the actuator fingers 40 - 2 and 42 - 2 in directions opposite to arrows A 2 and A 3 , respectively, will cause the rolls 40 , 42 to be driven in the same rotational direction by virtue of the interconnection of the fingers 40 - 2 , 42 - 2 with their respective one-way clutch bearing 40 - 1 , 42 - 1 . The surfaces of the annular applicator and guide slots 40 - 3 , 42 - 3 which are exposed to the filament strands 14 upon subsequent re-stringing will thus be changed. As a result, fresh surfaces of the annular applicator and guide slots 40 - 3 , 42 - 3 will be presented to the threadlines 14 .
[0023] It will be understood that the description of the rotation of the rolls 40 , 42 (and hence the annular applicator and guide slots 40 - 3 , 42 - 3 carried thereby) as being rotated only when the actuator fingers 40 - 2 ,. 422 are rectilinearly advanced toward one another represents a presently preferred embodiment of the present invention. Thus, it is entirely possible in accordance with the present invention that the rolls 40 , 42 (and hence the annular applicator and guide slots 40 - 3 , 42 - 3 carried thereby) may be rotated during relative rectilinear separation of the actuator fingers 40 - 2 , 42 - 2 , depending on the operation of the one-way clutch bearings 401 and 42 - 1 , respectively. Furthermore, if desired, the magnetic coupling of the actuator fingers could be employed in the absence of a one-way clutch bearing to cause rotation of the rolls 40 , 42 (and hence the annular applicator and guide slots 40 - 3 , 42 - 3 carried thereby) in response to the actuator fingers 40 - 2 , 42 - 2 being rectilinearly advanced and retracted relative to one another. Suffice it to say here, therefore, that one skilled in this art may recognize that a variety of substantially equivalent structures may be provided to achieve substantially the same result in substantially the same way as described above.
[0024] Furthermore, although one-way clutch bearings have been described in detail above, it will be understood that they also presently represent the most preferred embodiment of the invention. Thus, a variety of equivalent arrangements to achieve one-way roll rotation can be envisioned, such as, for example, a pawl and ratchet assembly, cooperating rollers, rack and pinion systems, torsional spring systems and the like. Furthermore, it will be understood that the guide roll 42 , although presently preferred, is not absolutely necessary in order to impart a liquid finish to filament surfaces. Thus, only the roll 40 may be provided in a finish applicator in accordance with the present invention, in which case, the actuator finger 40 - 2 may be contacted by a rotational or stationary magnetic finger member associated with a slide-block actuator or by any of the equivalent means noted above.
[0025] Therefore, while the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. | Liquid finish is applied to a travelling filament by bringing the travelling filament into contact with an arcuate surface portion associated with a normally stationary, but rotatable, annular finish applicator, and thereafter periodically rotating the annular finish applicator to bring at least one other arcuate surface portion thereof into contact with the travelling filament. Most preferably, an actuator assembly is provided having first and second actuator fingers which are capable of relative separable rectilinear movements towards and away from one another. These actuator fingers, in an especially preferred embodiment, are each pivotally moveable and magnetically coupled to one another. As such, separable movement will in turn cause that one of the actuator fingers connected to the annular finish applicator to pivot thereby rotating the later to expose a “fresh” arcuate surface region in contact with the filament. | 3 |
PRIORITY
[0001] This application is a non-provisional application which claims the priority date from the provisional application entitled FlexStayK Two-Piece Damage Resistant Marking Stake filed by Scott A. Morton, Naomi Morton-Knight and Craig Knight on Jan. 27, 2005 with application Ser. No. 60/647,527, the disclosure of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to an improved marking stake and more particularly, to a two-piece damage resistant marking stake for effectively marking a location even when damaged or partially removed from the ground.
[0004] 2. Background Information
[0005] Wooden stakes ranging from 12 inches to 48 inches in length are currently used in the majority of survey and location marking applications. Some plastic stakes are available as a direct replacement for wooden stakes. The higher cost of the plastic stakes frequently prevents or limits their use. Surveys for roads, pipelines and other such facilities are frequently carried out in harsh environments with considerable effort taken to effectively mark a position. In order to be effective, the stakes must remain positioned so that the marked position and attached information may be referenced in subsequent activities.
[0006] In many cases, surveying activities are done in areas where livestock is present or where other activities are taking place. Animals such as cows and horses frequently uproot or displace the stakes by chewing on, stepping on or rubbing on them. This problem is particularly acute in areas where cattle are present. Because cattle are used to contact and interaction with humans, they regularly follow behind a survey crew, breaking and/or pulling up survey stakes almost as soon as they are placed. The cattle chew on marking stakes and ribbons, pull them from the ground and rub on the stakes, thereby breaking them and/or obliterating the survey marking. In some cases, the stakes may simply be trampled resulting in the location sensitive marker being moved, broken or otherwise rendered unreadable. When stakes, ribbons, or other markers are broken, the survey staking must be repeated multiple times for a single project, incurring considerable additional expense.
[0007] There is a need in the art for a marking stake that will continue to mark a location despite being abused, broken, displaced, removed, or otherwise damaged as described above.
[0008] Additional objects, advantages and novel features of the invention will be set forth in part in the description which follows and in part will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
SUMMARY OF THE INVENTION
[0009] One embodiment of the present invention is a device for marking a location. The device coming in two separate pieces, namely a ground stake and a marking post. The ground stake configured for insertion into a ground surface. The marking post configured for attachment to the ground stake. The post is preferably removable from the stake so that when livestock are present, if they uproot or displace the marking post portion of the device, the ground stake remains in the ground still marking the location. If a survey crew or other individual is at the marking location after the post has been removed, they can replace the post (or insert a replacement post) to return the device to its full functionality.
[0010] The preferred ground stake having an abutment collar configured for abutting the ground surface, the abutment collar configured for allowing the stake to be driven into the ground surface but remaining clearly visible. The abutment collar further having a planar surface with a hole defined there through, this hole aligned with an internal passageway into a connection body. It is preferred that that abutment collar's upper facing surface have at least one planar writing surface for allowing marking information and data to be written thereupon.
[0011] The connection body having an open end (cooperating with the hole) extending to a closed end thereby defining a passageway there-between. Within the passageway is preferably a plurality of protrusions/flanges/tabs/teeth/ridges/etc., configured for grasping the marking post (when inserted therein). It is further preferred that at least one orifice extending from the passageway to an exterior surface of the body for allowing air to escape from the passageway when a first end of a post is inserted into the passageway be provided.
[0012] The ground stake further comprising a ground engagement portion connecting to one or both of the abutment collar/connection body. This ground engagement portion comprising at least one pointed distal end for insertion into a ground surface. Preferably, the ground engagement portion comprises at least one retaining ridge extending there-from for fixing the ground engagement portion within the ground surface.
[0013] The marking post having a first end extending to a second end. The first end configured for insertion into the passageway through the passageway open end and the hole in the abutment collar. It is preferred that the post has an exterior surface configured for being grasped by the passageway's interior protrusions. It is also preferred that the post have at least one planar writing surface for allowing marking information and data to be written thereupon.
[0014] The purpose of the foregoing Abstract is to enable the United States Patent and Trademark Office and the public generally, and especially the scientists, engineers, and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection, the nature and essence of the technical disclosure of the application. The Abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.
[0015] Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description wherein we have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by carrying out our invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiment are to be regarded as illustrative in nature, and not as restrictive in nature.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an exploded, perspective (partial cut-away) view of one embodiment of the present invention.
[0017] FIG. 2 is an un-exploded, perspective (partial cut-away) view of the embodiment of FIG. 1 .
[0018] FIG. 3 is a cross-sectional view of a second embodiment of a ground stake/socket of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims.
[0020] The present invention relates to an improved marking device (marking stake) and more particularly, to a two-piece damage resistant marking stake for marking a location despite damage or partial removal from the ground. The present invention allows for a location to be effectively marked despite damage or removal as described above.
[0021] FIGS. 1 and 2 show cut-away views of a first embodiment of the present invention (marking stake 100 ). FIG. 1 showing an exploded state, whereas FIG. 2 shows an unexploded (in-use) state. In the preferred embodiment, the present invention comprises these two main components: the ground stake (“ground socket”) 102 and the marking post (“elastomeric shaft”) 104 . FIG. 3 shows a cross-sectional view of a second embodiment of a ground stake 202 of the present invention.
[0022] The first component of the present invention 100 is the ground stake 102 . The ground stake 102 having a ground engaging portion 136 configured for being driven into the ground until (preferably) the abutment collar (top flange) 115 is generally flush with the ground surface. Being flush with the ground surface, the flange 115 visually demarks the location of the ground stake 102 attached there-to. Additionally, because the flange 115 is generally flush with the ground it is not easily removed by an animal, the elements and/or passing machinery. Because the diameter or shape of the flange 115 is larger than the diameter or shape of the ground engagement portion extending there below, the flange 115 prevents the ground stake 102 from being driven into the ground so far that it is no longer visible.
[0023] The ground stake 102 would most likely be molded of an impact resistance plastic material such as acrylonitrile-butadiene-styrene copolomers (ABS) or a polycarbonate/ABS alloy and would be colored a fluorescent orange, yellow, blue, red, etc., color similar to current survey marking paint and flagging. While these are the preferred materials of manufacture, obviously other materials would likewise be suitable.
[0024] The ground stake 102 has an upper portion connecting to the aforementioned flange 115 . A pointed distal end (tip) 120 is provided at an end opposite the flange 115 of the ground stake 102 . The tip 120 is formed and/or shaped to a point to more easily allow the ground stake 102 to be inserted, screwed, vibrated, pressed and/or driven into the ground.
[0025] The ground stake 102 having a connection body 110 configured for connecting with the marking post 104 . The outer surface of the ground stake may be smooth (as shown in FIG. 3 ) if soil friction conditions are sufficient to resist extraction by livestock, or may define ground retaining ridges 140 (as shown in FIGS. 1 and 2 ) for preventing the ground stake 102 from being easily removed once inserted into the ground. The ground retaining ridges 140 are preferably one-way ridges or notches so that it is not difficult to pound, drive or otherwise insert the socket into the ground. Other such mechanisms known in the prior art could likewise be used to accomplish this same purpose including but not limited to threading, ring shanks, etc.
[0026] Installation of the ground stake 102 (insertion into the ground) may be accomplished in various manners. One installation method allows a special slide hammer designed with a pin to fit into a passageway (“socket cavity”) 130 defined within the connection body 110 . The passageway 130 having an internal passageway open end 116 and an internal passageway closed end 114 . Hammering this slide hammer resulting in the ground stake 102 being driven into the ground. When the desired depth is reached, the pin would thus be removed from the passageway. The ground stake 102 may also be inserted by manually pushing it into the ground or by hammering the flange end of the ground stake 102 .
[0027] In the preferred embodiment of the present invention, the flange 115 of the ground stake 102 is preferably large enough in shape/diameter to legibly write generally used survey marking information/data upon, for instance upon a planar surface 112 .
[0028] Other manners of applying such data could likewise be provided, from stickers, to stamps, to RFID, etc. In one example, the top surface of the flange itself comprises a planar writing surface upon which a user could write using a permanent marker. The benefit of doing so is that if the marking post (which traditionally is the location of such data) is ever removed from the ground stake, data marked upon the planar writing surface allows a subsequent user to obtain useful marking information from the ground stake 102 itself.
[0029] The second component of the present invention 100 is the marking post 104 . The marking post having an elastomeric shaft 150 that is configured for insertion into the socket cavity 130 of the ground stake 102 . The shaft 150 is preferably flexible so that it will not break if driven over, stepped on, or in the event of other abuse. The shaft 150 would most likely be molded from polyurethane or polypropylene with a durometer A rating in the 80 to 95 range.
[0030] The socket cavity (“passageway”) 130 of the ground stake 102 is preferably cylindrically shaped or tapered for allowing for increasing tightness as the shaft 150 is inserted further within the socket cavity 130 . The ground stake 102 preferably further defines one-way retaining ridges (or other protrusions, flanges, etc) 160 , 260 within the socket cavity 130 that grasps the shaft and thus prevent the shaft 150 from being easily extracted once inserted. These retaining ridges 260 may take the form of a tapered buttress screw thread as shown in FIG. 3 to facilitate removal of the molding core for the socket and to allow adjustment of the removal pull-out force for the elastomeric shaft 150 by how far the shaft 150 is screwed into the socket threads, may take the form of concentric ridges 160 as shown in FIGS. 1-2 , etc.
[0031] Threaded retaining ridges 260 effectively allow a user to select a shaft 150 removal force by screwing the shaft against the retaining ridges 260 based on elements such as soil quality, animals present, and other environmental and external conditions. In the embodiment shown in FIGS. 1 and 2 , the one-way retaining ridges 160 are ribbed ridges defining the edges of the socket cavity 130 . Other types of connections are likewise envisioned.
[0032] The ground stake 102 may also define one or more slits 180 that extend from the socket cavity 130 to the outer surface of the ground stake 102 . This allows air within the socket cavity 130 to be displaced to outside the ground stake 102 so that air is not compressed within the ground stake 102 creating a rebounding force that would tend to push the shaft 150 out of the ground stake 102 as a user inserts the shaft into the socket. Additionally, this allows the outer surface area of the ground stake 102 and the shaft 150 to be more closely matched creating a much tighter fit. The elastomeric shaft 150 may also be tapered to match the taper of the tapered buttress screw threads of the retaining ridges 160 in the socket allowing for a much tighter fit when a user determines that conditions warrant. The marking post 104 is preferably installed by pushing the end of the shaft 150 into the passageway 130 by hand and turning the shaft to engage the buttress screw thread retaining ridges.
[0033] The elastomeric shaft 150 preferably comprises or connects with a planar writing surface 170 . In the embodiment shown in FIGS. 1 and 2 , this writing surface being a paddle. The paddle having a flat shaped writing area or planar surface on which survey marking information may be written. In one embodiment, the entire elastomeric shaft 150 would be molded from the same fluorescent orange, yellow, blue, red, etc., colors as the ground stake 102 . Different colors of shafts 150 and sockets 110 could be mixed and matched for specific applications as decided by a user.
[0034] In the preferred embodiment, the extraction force needed to remove the shaft 150 of the marking post 104 from the ground stake 102 is preferably less than the extraction force of the ground stake 102 from the ground, so that if the shaft 150 is removed, the ground stake 102 remains in the ground to mark the survey point. It is preferred that the ground stake 102 be brightly colored to allow the ground stake 102 to be more easily located if the elastomeric shaft 150 is removed from the socket. Additionally, the elastomeric shaft 150 is more easily retrieved because of its bright color.
[0035] FIG. 3 showing a second embodiment of the present invention, this figure showing a second embodiment of a ground stake 202 . This embodiment having the same general features as the embodiment of FIGS. 1-2 (i.e., abutment collar (top flange) 215 , pointed distal end (tip) 220 , connection body 210 , internal passageway (“socket cavity”) 230 , internal passageway open end 216 , planar surface 212 , internal passageway closed end 214 , ground engaging portion 236 , retaining ridges 260 ). Of note in this embodiment is that the retaining ridges 260 are a screw threading style (for allowing the shaft to be screwed therein vs. the concentric flanges 160 shown in FIGS. 1-2 for grasping the shaft. Further, in this embodiment the exterior surface is smooth and does not have the retaining ridges 140 shown in FIGS. 1-2 .
[0036] Radio frequency identification (RFID) tags may be attached to the ground stake 102 and/or the marking post 104 to aid in locating these parts if they do get separated, and to store survey or other information. Additionally, a user could program information into the RFID tags while in the field or at a base location. This information could include any information relating to the survey point, name and individual assigned to the project, contact information, etc.
[0037] The invented marking stake 100 can be used for many different applications and in many different manners. In one example installation, once a user has found a specific location that he needs to mark, he selects a color of his choice. He then drives the flanged socket into the ground at the desired location. The manner the flanged socket is driven into the ground will depend on the soil type and user preference. The socket is preferably driven into the ground until the flange is flush with the ground. At this point, or later, the user may elect to write survey, location, or other information/data on the flange of the socket.
[0038] The user then selects a marking post. At this point, or later, the user may elect to write survey, location and/or other information/data upon the paddle (planar writing surface) of the marking post. The user would then decide what he would like the shaft extraction force to be. The farther the user twists the elastomeric shaft into the shaft cavity and corresponding buttress screw thread the greater the shaft extraction force will be. The user will likely elect to choose an extraction force that is less than the socket extraction force so that if an animal were to pull on the shaft, it would come free before the socket would come free from the ground. However, a user could make the shaft extraction force anything he chooses. When a user needs to remove the elastomeric shaft from the socket, he will simply twist it in the opposite direction to remove it from the socket.
[0039] Once a user has connected the socket and the elastomeric shaft, he may return at anytime to gather more information or alter or move the marking stake as needed. In some cases, animals may have tugged the elastomeric shaft from the socket. In that instance, a user may visually scan the general location to find the fluorescent shaft and flange wherever they may be. Sometimes the shaft and socket will not be readily visible because of plants, weeds, dirt, rocks and other visual obstructions. In those instances, the user can use the RFID tags to find the parts of the marking stake. Additionally, at any point during the marking process, the RFIDs of the shaft and socket can be programmed with information or used to gather the preprogrammed information as needed.
[0040] The present invention may further include an admixture treatment on at least a portion of the exterior surface of the ground stake/socket for increasing the holding power of the stake in the ground. This would be very similar to cement coated nails, where the coating “melts” under the influence of friction during insertion and “glues” the nail into the wood. A ground stake with an admixture coating would function similarly with the coating “gluing” the stake within the soil. To apply a coating to the stake, it (preferably the ground engagement portion) would be dipped, sprayed, or brushed with a coating such as rosin, shellac, or a synthetic resin, for example, vinyl or acrylic. Other types of coatings are envisioned. When the stake is driven into the ground, the heat from friction softens the thin film of resin on the stake shaft, which then adheres to soil particles and significantly increases the extraction force of the stake.
[0041] While there is shown and described the present preferred embodiment of the invention, it is to be distinctly understood that this invention is not limited thereto but may be variously embodied to practice within the scope of the following claims. From the foregoing description, it will be apparent that various changes may be made without departing from the spirit and scope of the invention as defined by the following claims. | A device for marking a location. The device coming in two separate pieces, namely a ground stake and a marking post. The ground stake configured for insertion into a ground surface. The marking post configured for attachment to the ground stake. The post is preferably removable from the stake so that when livestock are present, if they uproot or displace the marking post portion of the device, the ground stake remains in the ground still marking the location. If a survey crew or other individual is at the marking location after the post has been removed, they can replace the post (or insert a replacement post) to return the device to its full functionality. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the heating and chemical treatment of aqueous process fluids such as the aqueous mining fluid used in the Frasch process for mining sulfur. More particularly, the present invention relates to the heating and chemical treatment of such aqueous process fluids using a sulfur-containing fuel as the energy source.
2. Description of the Prior Art
The Frasch process for mining sulfur is well known to those skilled in the art, and a description of its operation may be found in the patent literature and in numerous chemistry books and encyclopedias including, for example, the Kirk-Othmer Encyclopedia of Chemical Technology, Second Edition, Vol. 19, pp. 337-348, John Wiley & Sons, Inc., 1969. In the Frasch process, a hot aqueous mining fluid, e.g., water, is used to melt the solid sulfur present in an underground sulfur-bearing formation by injecting the fluid, heated under pressure to around 325° F., through the annulus formed by two concentric pipes and using compressed air to lift the molten sulfur to the surface through the inner pipe. The air is usually forced down through a small diameter pipe located within the described concentric arrangement.
Until recent years, the source of heat for the operation of a Frasch process sulfur mine has been the relatively abundant, low-cost supply of sulfur-free gas. However, as these reserves dwindle and gas supplies, when available, soar in price, it is becoming increasingly necessary to resort to the use of other fuels.
The use of sulfur-free natural gas as the fuel and source of heat in Frasch sulfur mining operations permitted attainment of relatively high overall plant efficiencies, due in part to the fact that even the heat in the effluent combustion gases from the steam-generating boilers could be reclaimed by the incoming cold aqueous mining fluid through intimate, direct contact of the fluid and combustion gases in heat exchange units appropriately labeled "flue gas heat reclaimers".
In addition to providing low-level heat to the incoming aqueous mining fluid, a consequence of which was to reduce the oxygen content of the fluid and render it less corrosive, the combustion gases also provided carbon dioxide, a portion of which dissolved in the fluid, lowering its pH and thereby lessening its tendency to lay down alkaline scale deposits in the subsequent high-temperature heating stages.
Now that natural gas is relatively unavailable to industrial operations, it is becoming necessary to resort to the use of other fuels such as oil or coal, both of which usually contain varying amounts of sulfur. If these materials are used as fuel in the boilers and the resultant combustion gases used in the usual economical manner, i.e., by passing them through flue gas heat reclaimers to scavenge the heat, the aqueous mining fluid undergoes reduction in dissolved oxygen content, picks up scale-mitigating carbon dioxide, and dissolves large amounts of sulfur dioxide which are present in the combustion gases as the result of combustion of the sulfur in the fuel. Dissolution of this sulfur dioxide results in two problems. First, this acid gas lowers the pH of the fluid (makes it more acidic), thereby increasing the fluids corrosivity towards metals in the system. Secondly, there is an increased tendency towards deposition of calcium sulfite scale because of this material's extremely low solubility in aqueous fluids. In order to circumvent these problems it is possible to employ a system whereby the heat in the SO 2 -containing flue gases is transferred to the aqueous fluid by indirect heat exchangers ("economizers") so that a considerable proportion of the heat normally reclaimed in direct contact heat reclaimers is still attained.
Such a system has serious drawbacks, however, such as, for example:
1. In order to offset the lack of CO 2 pickup by the aqueous fluid in the indirect heat exchange system, a mineral acid has to be added, at some cost, to adjust the pH of the fluid so as to prevent the alkaline scale deposition previously described;
2. Cooling of the flue gases in the economizers results in condensation of water vapor which dissolves sulfur dioxide and carbon dioxide and produces a very serious corrosion problem with respect to the materials of construction of the economizer (unless the economizer were constructed of extremely costly acid-resistant alloys) since heat transfer tubes of normal low-cost materials of construction cannot be protected by coatings, etc., and still provide the required heat exchange rates; and
3. The incoming cold aqueous mining fluid should receive prior treatment with an oxygen-scavenging chemical to prevent extreme corrosion in the economizer as well as in the heat exchangers subsequently employed to heat the water to mining temperatures. While the chemical reactions involved in the removal of dissolved oxygen are fairly rapid at elevated temperatures, at the ambient temperatures of this system the reaction rates are very slow, unless increased by the use of a costly catalyst in addition to the oxygen-scavenging chemical, for example, by the use of cobaltous sulfate as a catalyst to promote the reaction between dissolved oxygen and an oxygen scavenger such as sodium sulfite.
SUMMARY OF THE INVENTION
It is therefore a primary object of the present invention to provide a process for economically heating and chemically treating an aqueous process fluid such as the aqueous mining fluid in the Frasch sulfur mining process.
It is another object of the present invention to provide such a process which permits the use of sulfur-containing fuels such as coal, oil, sour gas, etc., but which at the same time effectively eliminates the corrosion and scaling potential normally attendant upon the use of such fuels.
Still further objects and the entire scope of applicability of the present invention will become apparent from the accompanying drawing and detailed description given hereinafter; it should be understood, however, that the drawing and detailed description, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.
It has been found that the above objects may be attained by a process for heating and chemically treating an aqueous fluid which comprises burning a sulfur-containing fuel to produce hot combustion gases containing carbon dioxide and sulfur dioxide, adjusting the pH of the aqueous fluid to 6.7 or below with a base, directly contacting said aqueous fluid with said hot combustion gases to heat said aqueous fluid and absorb carbon dioxide and sulfur dioxide therein, and adding additional base to said aqueous fluid following said contacting whereby the heated aqueous fluid has a pH between 6.0 and 6.7.
In one preferred embodiment, the hot combustion gases are first brought into indirect contact with high-quality boiler feedwater to convert said water into high pressure steam and said steam is used to further heat said heated aqueous mining fluid. In another preferred embodiment, at least a portion of said high pressure steam is first used to generate electrical and mechanical energy and the exhaust steam from the energy-generation equipment then used to further heat said heated aqueous mining fluid. The fluid is preferably heated to a temperature suitable for the mining of sulfur and is used as the aqueous mining fluid in the Frasch sulfur mining process to provide an integrated system such as shown in the drawing.
BRIEF DESCRIPTION OF THE DRAWING
The single FIGURE is a schematic flowsheet of a preferred embodiment of the integrated system for heating and chemically treating an aqueous mining fluid for producing sulfur by the Frasch mining process.
As shown in the drawing, the subject integrated system of the present invention involves a boiler 10 which burns a sulfur-containing fuel from line 12 and produces a flue gas which is fed through line 22 to flue gas heat reclaimer 24 into which an aqueous mining fluid flows through line 28 and is distributed over packed bed 26 and heated by the rising flue gases. Prior to entering the flue gas heat reclaimer, the aqueous fluid in line 28 is treated with an injection of a solution of a base, e.g., a soda ash solution, from tank 46 via pump 48 and line 40. The partially heated aqueous fluid is then again treated in the storage zone 44 of heat reclaimer 24 with additional basic solution from tank 46 through line 42. The amount of basic solution added must be controlled to adjust the pH of the aqueous solution, before it exits reclaimer 24, to between 6.0 and 6.7. The thus treated water exits the lower portion of heat reclaimer 24 through line 54 at 120°-130° F. and a pH of 6.0-6.7, and is then pumped by mine water pump 56 to low-pressure pressure and high-pressure steam heat exchangers 36 and 38, respectively, from which it emerges with a pH of 6.0-6.7 and a temperature of approximately 325° F.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the preferred embodiment of the invention shown in the drawing, the system operates as follows:
Assuming normal on-stream, steady-state operation, boiler 10 is fired with a fuel oil fed through line 12 and containing not more than 1.0%, and preferably 0.3-0.7%, by weight sulfur to produce high-pressure steam which exits boiler 10 through line 14 and is used in turbine-driven equipment 16 and, after pressure reduction, in heaters 36 and 38 as low-pressure exhaust steam in lines 18 and 20 for heating the aqueous mining fluid as will be discussed in more detail hereinafter. Boiler 10 also produces a flue gas which, at a temperature of from 600° F. to 800° F., e.g., about 700° F., is fed through line 22 to flue gas heat reclaimer 24 wherein it flows upwardly through packed bed 26 of the reclaimer and comes into direct contact with incoming aqueous mining fluid fed through line 28. In packed bed 26 the temperature of the fluid is raised from ambient temperature, e.g., about 70° F., to from about 120° F. to about 130° F., e.g., 130° F., by transfer of heat from the hot flue gases. The thus cooled flue gases leave the top of heat reclaimer 24 at a temperature of from 80° F. to about 130° F., e.g., about 100° F., through line 30.
The preferred sulfur-containing fuels for use in the process of the present invention are oil and coal. However, any fuel containing not more than 1.0% by weight sulfur can be used. An example of another suitable fuel is sour gas. The packed bed 26 of heat reclaimer 24 may be packed with berl saddles, raschig rings, lessing rings, or other similar type of packing material constructed of ceramic, procelain or other corrosion resistant material, as is well-known in the art. The packed bed operates by increasing the interfacial area for heat transfer and mass transfer and the intimacy of contact of phases between which heat transfer and mass transfer is effected.
The aqueous fluid fed to heat reclaimer 24 through line 28 may be seawater that has been treated with a chlorine solution fed through line 32 or it may be a mixture of chlorine-treated seawater and brine fed through line 34, or it may even be brackish water, fresh river water, "bleedwater", etc. "Bleedwater" is a term used in the Frasch sulfur mining industry to denote the water that must be bled from the sulfur mine formation to control the mine pressure and which is normally treated and pumped to waste. The seawater may be treated with an aqueous chlorine solution containing from 100 to 600 parts per million chlorine for the purpose of preventing marine fouling of the equipment through which the seawater will pass in the system. Irrespective of the type of water used, when it contacts the flue gases from boiler 10 in heat reclaimer 24, the aqueous fluid will absorb heat, carbon dioxide (CO 2 ) and sulfur dioxide (SO 2 ), the latter resulting from the combustion of the sulfur in the sulfur-containing fuel.
The presence of the dissolved carbon dioxide and sulfur dioxide in the aqueous fluid has both desirable and undesirable features. The desirable features are that both the carbon dioxide and the sulfur dioxide tend to lower the pH of the fluid and, as a result, prevent or minimize the amounts of alkaline carbonate and alkaline hydroxide scale deposition that will occur when the fluid is subsequently heated in low-pressure and high-pressure heaters 36 and 38. However, of even more importance, the sulfur dioxide reacts with residual dissolved oxygen and, as a result, lessens the corrosive potential of the fluid which is due to oxygen contained therein. The presence of sulfur dioxide, then, can eliminate the cost of chemicals such as sodium sulfite which are otherwise needed in order to scavenge oxygen and control corrosion in these systems. It should be noted that no real detrimental effect results from the presence of carbon dioxide, unless it were to be present in excessively high concentrations.
The undesirable and detrimental features are that the sulfur dioxide can cause scale deposition in heaters 36 and 38 due to the relatively low solubility of the calcium sulfite that tends to form when sulfur dioxide is present, and that an excess of dissolved sulfur dioxide can lower the pH of the fluid to the point where it becomes corrosive. In order to overcome the above-mentioned undesirable and detrimental features and at the same time take advantage of the advantageous features which result from the presence of carbon dioxide and sulfur dioxide in the flue gas-heated aqueous fluid, the present invention provides for a first injection of a solution of a base, e.g., a soda ash solution, through line 40 into the aqueous fluid in line 28 prior to entering heat reclaimer 24 whereby the pH of the aqueous fluid is adjusted to between about 6.0and 6.7, e.g., to 6.3, and a second injection of the same solution of the base through line 42 into the water-storage zone 44 of heat reclaimer 24 in which the water is heated from ambient temperature, e.g., about 70° F. to about 120° -130° F. This assures that the pH lowering effect of the carbon dioxide and sulfur dioxide which are dissolved in the aqueous fluid during direct contact thereof with the flue gases in heat reclaimer 24 will be offset and that the pH of the aqueous fluid in and withdrawn from storage zone 44 will be maintained between 6.0 and 6.7. In addition, the present invention provides for the use of a sulfur-containing fuel having not more than 1.0% by weight sulfur, e.g., from 0.01% to 1.0% by weight, and preferably 0.3-0.7% by weight, sulfur. The combination of the use of a fuel having not more than 1.0% by weight sulfur and the injection of the solution of a base at the two points described above to adjust the pH of the aqueous fluid leaving heat reclaimer 24 to between 6.0 and 6.7 permits the system to be operated without any significant scale deposition and without any significant corrosion of the metallic components of the system which contact the water after it has left heat reclaimer 24. It is necessary that the amounts of soda ash added to the water be controlled so as to avoid raising the pH above 6.7. If too much base is used and the pH of the aqueous fluid rises above 6.7, insoluble calcium carbonate (CaCO 3 ) and insoluble calcium sulfite (CaSO 3 ) will begin to form in increased quantities and their precipitation will scale the tubes of heaters 36 and 38. If the pH is too low, i.e., below about 6.0, the water will be too corrosive for the materials of construction normally used in the heaters. On the other hand, if the pH of the aqueous fluid leaving heat reclaimer 24 is maintained between 6.0 and 6.7, and preferably about 6.3, soluble bisulfites and bicarbonates will be maintained in solution, and their presence in the fluid will not interfere with the heat transfer in the heat exchangers.
In a preferred embodiment of the present invention, boiler 10 is fed fuel oil having about 0.3-0.7% by weight sulfur through line 12 and boiler feedwater through line 50. High-pressure steam having a pressure of from about 575 to about 650 psig, e.g., about 600 psig, is generated in boiler 10 and passed through line 14 to drive turbine-driven equipment 16. The turbine-driven equipment may be, for example, steam turbines connected to electric generators which produce electricity for use in the treating plant or elsewhere, or may be pumps, air compressors and various other pieces of equipment needed in the operation of the integrated facility. The exhaust steam from turbine driven equipment 16 has a pressure of from about 85 to about 100 psig, e.g., about 95 psig. A portion of the exhaust steam is passed through pressure reducing valve 52 wherein the pressure is reduced to from about 45 to about 55 psig, e.g., about 50 psig, and then passes through line 18 to low-pressure heater 36. Another portion of the exhaust steam is passed through line 20 to high-pressure heater 38. The treated aqueous fluid in storage zone 44 of heat reclaimer 24, having a temperature of about 120° to about 130° F. and a pH of from 6.0 to 6.7 is withdrawn through line 54 and passed through pump 56 to low-pressure heater 36 wherein the temperature of the fluid is raised to from about 265° to about 285° F., e.g., about 275° F., and then to high-pressure heater 38 wherein the temperature of the aqueous fluid is raised to from about 300° F. to about 330° F., e.g., about 325°F., which is usually the required mining temperature range for an aqueous sulfur mining fluid. The heated mining fluid, or "booster water", is sent from high-pressure heater 38 through line 58 to the wells for melting the sulfur in the underground formation. Steam condensate 60 from the shell of high-pressure heater 38 is trapped and fed into the shell of low-pressure heater 36, wherein it is flashed to the steam pressure therein being maintained. The steam condensate 62 from the shell of low-pressure heater 36 is eventually returned to boiler 10, preferably via stream 50.
While soda ash (Na 2 CO 3 ) is the preferred base for use in the pH adjustment steps of the present invention, it is also possible to use other bases such as lime (CaO) or hydrated lime (Ca(OH) 2 )instead of soda ash. The cost of hydrated lime, for example, is only about 30% of that of soda ash and, since only about 75% by weight as much hydrated lime as soda ash is required for the treatment, the pH-adjustment steps may be carried out at about 22% of the cost of using soda ash when hydrated lime is substituted for soda ash.
The use of lime for this purpose, however, will result in an increase in the calcium content of the mine water, and hence the extent to which lime may be used in place of soda ash will depend on the calcium and sulfate concentrations in the aqueous fluid, e.g., seawater and brine, with which it is admixed in the pH-adjustment steps. The principal consideration will be the ability to maintain an arithmetic product of calcium concentration times sulfate concentration in the water that does not exceed the solubility product of the system at the elevated temperatures in the low-pressure and high-pressure heaters, so as to avoid significant amounts of calcium sulfate scaling in the tubes of these heaters. It is thus possible to use mixtures of lime or hydrated lime and soda ash, in addition to lime or hydrated lime only or soda ash only. In most cases, the solution of the base should contain from 1.0% by weight up to the saturation point of the base in the solvent, such as water, e.g., in the case of soda ash the solution should contain between 1 and 14% by weight Na 2 CO.sub. 3. Another base which may be used is sodium hydroxide (NaOH).
EXAMPLE
Using the integrated system shown in the drawing, a fuel oil containing about 0.7% by weight sulfur was burned in boiler 10 to convert boiler feedwater into steam having a pressure of 600 psig. The flue gases from boiler 10 having a temperature of 700° F. were fed into heat reclaimer 24. At the same time, a mixture of chlorine-treated seawater and brine was injected with an 8.0% by weight solution of soda ash to adjust the pH of the mixture to about 6.3 and fed into the heat reclaimer, brought into direct contact with the flue gases therein, heated thereby to a temperature of 130° F. and collected in water storage zone 44 of the heat reclaimer. Following said direct contact, additional soda ash solution was added to the heat reclaimer to maintain the pH of the heated aqueous mixture in the storage zone at about 6.3. The steam generated in boiler 10 was used to operate turbine driven equipment 16 and the exhaust steam therefrom had a pressure of 95 psig. A portion of the exhaust steam was passed through pressure reducing valve 52 wherein the pressure was reduced to 50 psig and then passed to low-pressure heater 36. Another portion of the exhaust steam was passed to high-pressure heater 38. The treated and partially heated aqueous mixture in storage zone 44 was passed through low-pressure heater 36 wherein its temperature was raised to 275° F. and through high-pressure heater 38 wherein its temperature was raised to 325° F. and was then used as an aqueous sulfur mining fluid. No substantial scaling or corrosion was observed in heaters 36 and 38. | An integrated system and process is provided to heat and chemically treat an aqueous process fluid such as the water required for producing sulfur by the Frasch process without undue scaling and corrosion of apparatus when a sulfur-containing fuel such as oil is employed as the energy source. | 4 |
FIELD OF THE DISCLOSURE
The present disclosure relates to bias circuitry for balanced amplifiers.
BACKGROUND
Balanced amplifiers are widely used in the amplification of radio frequency (RF) signals due to their exceptional performance in many practical situations. Specifically, balanced amplifiers often exhibit, good input and output return losses, and better stability when compared to single-ended amplifiers. An exemplary conventional balanced amplifier 10 is shown in FIG. 1 . The conventional balanced amplifier 10 includes an RF input node 12 , an RF output node 14 , an input termination impedance 16 , an output termination impedance 18 , a first amplifying device 20 , a second amplifying device 22 , an input quadrature coupler 24 , and an output quadrature coupler 26 . The input quadrature coupler 24 includes a first input node 28 coupled to the input termination impedance 16 , a second input node 30 coupled to the RF input node 12 , a first output node 32 coupled to an input of the first amplifying device 20 , and a second output node 34 coupled to an input of the second amplifying device 22 . The output quadrature coupler 26 includes a first input node 36 coupled to an output of the first amplifying device 20 , a second input node 38 coupled to an output of the second amplifying device 22 , a first output node 40 coupled to the RF output node 14 , and a second output node 42 coupled to the output termination impedance 18 .
In operation, the conventional balanced amplifier 10 is configured to receive an RF input signal RF_IN at the RF input node 12 and produce an amplified RF output signal RF_OUT at the RF output node 14 . Specifically, the conventional balanced amplifier 10 is configured to receive an RF input signal RF_IN with a phase angle of zero degrees at the RF input node 12 . As the RF input signal RF_IN enters the input quadrature coupler 24 , the signal is split into an in-phase portion and a quadrature portion. The in-phase portion of the RF input signal RF_IN is equal to the RF input signal RF_IN over the square root of two (0.707 multiplied by the RF input signal RF_IN) at a phase angle of zero degrees, while the quadrature portion of the RF input signal RF_IN is equal to the RF input signal RF_IN over the square root of two (0.707 multiplied by the RF input signal RF_IN) at a phase angle of −90 degrees. The in-phase portion of the RF input signal RF_IN is delivered to and amplified by the second amplifying device 22 , while the quadrature portion of the RF input signal RF_IN is delivered to and amplified by the first amplifying device 20 . The resulting amplified in-phase portion of the RF input signal RF_IN is delivered to the second input node 38 of the output quadrature coupler 26 , while the resulting amplified quadrature portion of the RF input signal RF_IN is delivered to the first input node 36 of the output quadrature coupler 26 .
The output quadrature coupler 26 shifts the amplified in-phase portion of the RF input signal RF_IN at the second input node 38 by −90 degrees and delivers both the amplified and phase-shifted in-phase portion of the RF input signal RF_IN and the amplified quadrature portion of the RF input signal RF_IN (with an unchanged phase) to the RF output node 14 . Accordingly, the amplified and phase-shifted in-phase portion of the RF input signal RF_IN and the amplified quadrature portion of the RF input signal RF_IN each have a phase equal to −90 degrees, and therefore combine to produce an RF output signal RF_OUT equal to the gain of the amplifying devices multiplied by the RF input signal RF_IN at a phase angle of −90 degrees. Further, the quadrature output coupler 28 shifts the quadrature portion of the RF input signal RF_IN by −90 degrees and delivers both the amplified and phase-shifted quadrature portion of the RF input signal RF_IN and the amplified in-phase portion of the RF input signal RF_IN (with an unchanged phase) to the output termination impedance 18 . Since the amplified and phase-shifted quadrature portion of the RF input signal RF_IN and the amplified in-phase portion of the RF input signal RF_IN are of equal magnitude and are also 180 degrees out of phase with one another, these signals effectively cancel.
As the load provided at the RF output node 14 changes to become mismatched with the output termination impedance 18 , for example, due to a change in the impedance of an antenna connected to the RF output node 14 , the balanced amplifier experiences what is known as “load pull” due to a high voltage standing wave ratio (VSWR). Specifically, the magnitude of the amplified in-phase portion of the RF input signal RF_IN and the amplified quadrature portion of the RF input signal RF_IN become mismatched, and therefore the signals no longer cancel at the output termination impedance 18 as discussed above. This results in a buildup of voltage across the output termination impedance 18 , which may eventually result in damage to the output termination impedance 18 as well as damage to the first amplifying device 20 and/or second amplifying device 22 . Further, this results in thermal stress on the first amplifying device 20 and/or the second amplifying device 22 , reduced efficiency, and higher voltage swings at the device terminals.
In an effort to protect the conventional balanced amplifier 10 from damage due to high VSWR conditions, external isolators have been used in conjunction with the output termination impedance 18 . FIG. 2 shows the conventional balanced amplifier 10 including an external isolator 44 coupled in series with an additional output termination impedance 45 between the RF output node 14 and ground. The external isolator 44 may be a circulator, which may consume a large amount of area and further add expense to the surrounding circuitry of the conventional balanced amplifier 10 . Further, the external isolator 44 may degrade the efficiency of the conventional balanced amplifier 10 . As shown in FIG. 2 , the conventional balanced amplifier 10 may be integrated onto a semiconductor die, represented by the dashed box 46 shown in FIG. 2 . However, the external isolator 44 cannot be integrated onto the semiconductor die 46 due to the size thereof. Accordingly, there is a need for a balanced amplifier that is capable of safely dealing with high VSWR conditions while simultaneously being efficient and compact.
SUMMARY
The present disclosure relates to bias circuitry for balanced amplifiers. In one embodiment, circuitry includes a balanced amplifier and bias adjustment circuitry. The bias adjustment circuitry is coupled to the balanced amplifier and is configured to measure an RF termination voltage across an output termination impedance of the balanced amplifier and adjust a bias voltage supplied to the balanced amplifier based on the RF termination voltage. Notably, the RF termination voltage is proportional to a voltage standing wave ratio (VSWR) of the balanced amplifier, and thus enables an accurate measurement thereof. By using the RF termination voltage to adjust a bias voltage supplied to the balanced amplifier, damage to the balanced amplifier as a result of high VSWR conditions may be avoided while maintaining the performance of the balanced amplifier and adding minimal additional area to the balanced amplifier.
In one embodiment, the balanced amplifier and the bias adjustment circuitry are monolithically integrated on a semiconductor die.
In one embodiment, the bias adjustment circuitry comprises termination voltage amplification circuitry configured to receive and amplify the RF termination voltage and bias adjustment voltage generation circuitry configured to generate a direct current (DC) bias adjustment voltage based on the amplified RF termination voltage.
In one embodiment, the bias adjustment voltage generation circuitry comprises a bias adjustment input node, a bias adjustment output node, a load resistor coupled between the bias adjustment input node and ground, a bias adjustment capacitor coupled between the bias adjustment input node and an intermediary bias adjustment node, a first bias adjustment diode including an anode coupled to the intermediary bias adjustment node and a cathode coupled to ground, a second bias adjustment diode including a cathode coupled to the intermediary bias adjustment node and an anode, a first bias adjustment resistor coupled between the anode of the second bias adjustment diode and the bias adjustment output node, and a second bias adjustment resistor coupled between the bias adjustment output node and a nominal bias voltage input node.
In one embodiment, the termination voltage amplification circuitry comprises a variable gain amplifier.
In one embodiment, the balanced amplifier comprises an RF input node and an RF output node, an input termination impedance and an output termination impedance, a first amplifying device, a second amplifying device, an input quadrature coupler, and an output quadrature coupler. The input quadrature coupler includes a first input node coupled to the input termination impedance, a second input node coupled to the RF input node, a first output node coupled to an input node of the first amplifying device, and a second output node coupled to an input node of the second amplifying device. The output quadrature coupler includes a first input node coupled to an output node of the first amplifying device, a second input node coupled to an output node of the second amplifying device, a first output node coupled to the RF output node, and a second output node coupled to the output termination impedance.
Those skilled in the art will appreciate the scope of the present disclosure and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.
FIG. 1 is a schematic representation of a conventional balanced amplifier.
FIG. 2 is a schematic representation of a conventional balanced amplifier including isolation circuitry.
FIG. 3 is a schematic representation of a radio frequency (RF) transmit chain according to one embodiment of the present disclosure.
FIG. 4 is a schematic representation of a balanced amplifier including bias adjustment circuitry according to one embodiment of the present disclosure.
FIG. 5 is a schematic representation of a balanced amplifier including bias adjustment circuitry according to an additional embodiment of the present disclosure.
FIG. 6 is a schematic representation of a balanced amplifier including bias adjustment circuitry according to an additional embodiment of the present disclosure.
DETAILED DESCRIPTION
The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims.
It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, without departing from the scope of the present disclosure. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
It will be understood that when an element such as a layer, region, or substrate is referred to as being “on” or extending “onto” another element, it can be directly on or extend directly onto the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” or extending “directly onto” another element, there are no intervening elements present. Likewise, it will be understood that when an element such as a layer, region, or substrate is referred to as being “over” or extending “over” another element, it can be directly over or extend directly over the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly over” or extending “directly over” another element, there are no intervening elements present. It will also be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. In contrast, when an element is referred to as being “directly connected” or “directly coupled” to another element, there are no intervening elements present.
Relative terms such as “below” or “above” or “upper” or “lower” or “horizontal” or “vertical” may be used herein to describe a relationship of one element, layer, or region to another element, layer, or region as illustrated in the Figures. It will be understood that these terms and those discussed above are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes,” and/or “including” when used herein specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.
FIG. 3 shows a radio frequency (RF) transmit chain 48 according to one embodiment of the present disclosure. The RF transmit chain 48 includes modulation circuitry 50 , a first driver stage amplifier 52 , a second driver stage amplifier 54 , a final driver stage amplifier 56 , an antenna 58 , and control circuitry 60 . The modulation circuitry 50 is coupled to an input of the first driver stage amplifier 52 . An output of the first driver stage amplifier 52 is coupled to an input of the second driver stage amplifier 54 . An output of the second driver stage amplifier 54 is coupled to an input of the final driver stage amplifier 56 , the output of which is in turn coupled to the antenna 58 . The control circuitry 60 may be connected to one or more of the first driver stage amplifier 52 , the second driver stage amplifier 54 , and the final driver stage amplifier 56 in order to control the operation thereof. Specifically, the control circuitry 60 may be configured to control the level of a bias voltage delivered to one or more of the first driver stage amplifier 52 , the second driver stage amplifier 54 , and the final driver stage amplifier 56 , and further may be configured to control the level of bias voltage adjustment accomplished by bias adjustment circuitry coupled to one or more of the first driver stage amplifier 52 , the second driver stage amplifier 54 , and the final driver stage amplifier 56 , as will be discussed in further detail below.
In operation, a baseband signal BB_IN is received at the modulation circuitry 50 of the RF transmit chain 48 , where it is modulated at a desired carrier frequency and delivered to the first driver stage amplifier 52 . The first driver stage amplifier 52 amplifies the modulated baseband signal and delivers the amplified modulated baseband signal to the second driver stage amplifier 54 . The second driver stage amplifier 54 once again amplifies the modulated baseband signal and delivers the resulting signal to the final stage amplifier 56 . The final driver stage amplifier 56 further amplifies the modulated baseband signal to a level appropriate for transmission from the antenna 58 and delivers the signal to the antenna 58 , where the signal is subsequently radiated into the surrounding environment.
Although two driver stage amplifiers and one final stage amplifier are shown in the RF transmit chain 48 , any number of driver stages may be used in the RF transmit chain 48 without departing from the principles of the present disclosure. Further, additional components may be included in the RF transmit chain, for example, input matching circuitry, output matching circuitry, etc. may be included in the RF transmit chain 48 without departing from the principles of the present disclosure. Finally, although not explicitly described, the principles of the present disclosure may be extended to additional applications such as RF receive chains including one or more cascaded low noise amplifiers (LNAs), all of which are contemplated herein.
FIG. 4 shows a balanced amplifier 62 and accompanying bias adjustment circuitry 64 according to one embodiment of the present disclosure. The balanced amplifier 62 and the bias adjustment circuitry 64 may be used as one or more of the first driver stage amplifier 52 , the second driver stage amplifier 54 , and the final driver stage amplifier 56 in the RF transmit chain 48 discussed above. The balanced amplifier 62 is substantially similar to that shown above with respect to FIG. 1 , such that the balanced amplifier 62 includes an RF input node 66 , an RF output node 68 , an input termination impedance 70 , an output termination impedance 72 , a first amplifying device 74 , a second amplifying device 76 , an input quadrature coupler 78 , and an output quadrature coupler 80 . The input quadrature coupler 78 includes a first input node 82 coupled to the input termination impedance 70 , a second input node 84 coupled to the RF input node 66 , a first output node 86 coupled to an input of the first amplifying device 74 , and a second output node 88 coupled to an input of the second amplifying device 76 . The output quadrature coupler 80 includes a first input node 90 coupled to an output of the first amplifying device 74 , a second input node 92 coupled to an output of the second amplifying device 76 , a first output node 94 coupled to the RF output node 68 , and a second output node 96 coupled to the output termination impedance 72 .
The bias adjustment circuitry 64 includes termination voltage amplification circuitry 98 and bias adjustment voltage generation circuitry 100 . The termination voltage amplification circuitry 98 is coupled to the second output node 96 of the output quadrature coupler 80 , such that the termination voltage amplification circuitry 98 is configured to receive and amplify the voltage across the output termination impedance 72 , which is herein referred to throughout as the “RF termination voltage.” The bias adjustment voltage generation circuitry 100 is coupled to an output of the termination voltage amplification circuitry 98 , such that the bias adjustment voltage generation circuitry 100 is configured to receive an amplified version of the RF termination voltage. The bias adjustment voltage generation circuitry 100 is further coupled to a nominal bias voltage input node 102 , such that the bias adjustment voltage generation circuitry 100 is configured to receive a nominal bias voltage V_NB. Finally, the bias adjustment voltage generation circuitry 100 is coupled to each one of the first amplifying device 74 and the second amplifying device 76 . Accordingly, the bias adjustment voltage generation circuitry 100 is configured to generate a direct current (DC) bias adjustment voltage based on the amplified RF termination voltage, and deliver the bias adjustment voltage to each one of the first amplifying device 74 and the second amplifying device 76 . The control circuitry 60 may be coupled to the termination voltage amplification circuitry 98 , the bias adjustment voltage generation circuitry 100 , or both, in order to control one or more parameters of the bias adjustment circuitry 64 , as discussed in further detail below.
As discussed above, as the voltage standing wave ratio (VSWR) of the balanced amplifier 62 increases, due to, for example, a changing impedance of an antenna coupled to the RF output node 68 , a proportional RF termination voltage builds across the output termination impedance 72 . Notably, the bias adjustment circuitry 64 utilizes this proportional relationship of the VSWR of the balanced amplifier 62 to that of the RF termination voltage in order to adjust a bias voltage of the first amplifying device 74 and the second amplifying device 76 and thereby protect the first amplifying device 74 and the second amplifying device 76 in the event of a high VSWR condition. Specifically, when the RF termination voltage measured across the output termination impedance 72 is above a predetermined threshold, the bias adjustment voltage generation circuitry 100 generates a bias adjustment voltage sufficient to turn the first amplifying device 74 and the second amplifying device 76 off, thereby protecting the first amplifying device 74 and the second amplifying device 76 from damage due to high VSWR conditions. Measuring the VSWR of the balanced amplifier 62 using the RF termination voltage is achieved practically for free, as it impacts the operation of the balanced amplifier 62 minimally, if at all.
In one embodiment, the balanced amplifier 62 and the bias adjustment circuitry 64 are monolithically integrated on a semiconductor die. An exemplary semiconductor die is shown as the dashed box 104 shown in FIG. 4 . As discussed in further detail below, the design of the bias adjustment circuitry 64 is such that it can be integrated onto a relatively small area of a semiconductor die at a low cost, thereby saving valuable area in a device incorporating the balanced amplifier 62 and bias adjustment circuitry 64 .
FIG. 5 shows details of the termination voltage amplification circuitry 98 and the bias adjustment voltage generation circuitry 100 according to one embodiment of the present disclosure. The termination voltage amplification circuitry 98 includes a variable gain amplifier 106 . The variable gain amplifier 106 may receive and amplify the RF termination voltage across the output termination impedance 72 such that the resulting signal is suitable for processing by the bias adjustment voltage generation circuitry 100 . Notably, the input impedance of the variable gain amplifier 106 may be exceptionally high in order to mitigate the effect of the bias adjustment circuitry 64 on the functionality of the balanced amplifier 62 . Further, the variable gain amplifier 106 may be coupled to the control circuitry 60 , such that the control circuitry 60 is capable of adjusting the gain of the variable gain amplifier 106 . Adjusting the gain of the variable gain amplifier 106 results in an increase or decrease in the predetermined threshold at which the bias adjustment circuitry 64 turns off the first amplifying device 74 and the second amplifying device 76 . Accordingly, the control circuitry 60 may adjust the sensitivity of the bias adjustment circuitry 64 to the VSWR of the balanced amplifier 62 .
The bias adjustment voltage generation circuitry 100 includes a bias adjustment input node 108 , a bias adjustment output node 110 , an intermediary bias adjustment node 112 , a load resistor R 1 , a first bias adjustment resistor R 2 , a second bias adjustment resistor R 3 , a first bias adjustment capacitor C 1 , a first bias adjustment diode D 1 , and a second bias adjustment diode D 2 . The load resistor R 1 is coupled between the bias adjustment input node 108 and ground. The first bias adjustment capacitor C 1 is coupled between the bias adjustment input node 108 and the intermediary bias adjustment node 112 . The first bias adjustment diode D 1 includes an anode coupled to the intermediary bias adjustment node 112 and a cathode coupled to ground. The second bias adjustment diode D 2 includes a cathode coupled to the intermediary bias adjustment node 112 and an anode. The first bias adjustment resistor R 2 is coupled between the anode of the second bias adjustment diode D 2 and the bias adjustment output node 110 , and the second bias adjustment resistor R 3 is coupled between the nominal bias voltage input node 102 and the bias adjustment output node 110 . Finally, the bias adjustment output node 110 is connected to the input of each one of the first amplifying device 74 and the second amplifying device 76 .
In operation, when the amplified RF termination voltage provided by the termination voltage amplification circuitry 98 is below a predetermined threshold, a voltage sampled across the first bias adjustment capacitor C 1 is insufficient to place the first bias adjustment diode D 1 into a forward conduction mode of operation. Accordingly, the compact rectification circuit formed by the first bias adjustment diode D 1 , the second bias adjustment diode D 2 , the first bias adjustment resistor R 2 , and the second bias adjustment resistor R 3 is turned off. A nominal bias voltage provided at the nominal bias voltage input node 102 is thus provided as a bias adjustment voltage through the second bias adjustment resistor R 3 to the first amplifying device 74 and the second amplifying device 76 . Notably, the first amplifying device 74 and the second amplifying device 76 are configured such that they are active (i.e., conducting) when they receive the nominal bias voltage.
When the amplified RF termination voltage is raised above the threshold voltage of the first bias adjustment diode D 1 , the compact rectification circuit formed by the first bias adjustment diode D 1 , the second bias adjustment diode D 2 , the first bias adjustment resistor R 2 and the second bias adjustment resistor R 3 is turned on, and thus produces an average or DC current (I DC ), which flows from the nominal bias voltage input node 102 to ground through the second bias adjustment resistor R 3 , the first bias adjustment resistor R 2 , the second bias adjustment diode D 2 , and the first bias adjustment diode D 1 . This in turn reduces the nominal bias voltage at each one of the first amplifying device 74 and the second amplifying device 76 and begins to turn off the first amplifying device 74 and the second amplifying device 76 .
As discussed above, the RF termination voltage is proportional to the VSWR experienced by the balanced amplifier 62 . Accordingly, the bias adjustment circuitry 64 is configured to adjust the bias voltage to the first amplifying device 74 and the second amplifying device 76 based on the VSWR of the balanced amplifier 62 , turning off the first amplifying device 74 and the second amplifying device 76 when the VSWR experienced by the balanced amplifier 62 is above a predetermined threshold. Turning off the balanced amplifier 62 during high VSWR conditions effectively protects the first amplifying device 74 and the second amplifying device 76 from high power dissipation and thus breakdown conditions, thereby increasing the reliability of the balanced amplifier 62 and reducing the risk of failure. When the high VSWR condition subsides, the RF termination voltage is reduced, thereby turning off the compact rectification circuit and restoring the bias voltage provided to the first amplifying device 74 and the second amplifying device 76 to its nominal value. Accordingly, the first amplifying device 74 and the second amplifying device 76 are placed into an active mode of operation (i.e., conducting), thereby restoring the balanced amplifier 62 to its normal state of operation.
In one embodiment, the first bias adjustment resistor R 2 and the second bias adjustment resistor R 3 are adjustable. Further, the first bias adjustment resistor R 2 and the second bias adjustment resistor R 3 may be connected to the control circuitry 60 such that the control circuitry 60 can adjust the resistance of the first bias adjustment resistor R 2 and the second bias adjustment resistor R 3 . Accordingly, an additional way for the control circuitry 60 to adjust the sensitivity of the bias adjustment circuitry 64 to the VSWR of the balanced amplifier 62 is provided. Although the control circuitry 60 is shown separately from the bias adjustment circuitry 64 and off the semiconductor die 104 , the control circuitry 60 may be part of the bias adjustment circuitry 64 and integrated onto the semiconductor die 104 in some embodiments.
FIG. 6 shows details of the first amplifying device 74 and the second amplifying device 76 according to one embodiment of the present disclosure. The first amplifying device 74 includes a first input matching network 114 , a first amplifying transistor 116 , and a first output matching network 118 . The first input matching network 114 is connected to a gate contact (G) of the first amplifying transistor 116 . The first output matching network 118 is connected to a drain contact (D) of the first amplifying transistor 116 , which is in turn connected to a supply voltage V CC . A source contact (S) of the first amplifying transistor 116 is coupled to ground. Similarly, the second amplifying device 76 includes a second input matching network 120 , a second amplifying transistor 122 , and a second output matching network 124 . The second input matching network 120 is coupled to a gate contact (G) of the second amplifying transistor 122 . The second output matching network 124 is coupled to a drain contact (D) of the second amplifying transistor 122 , which is in turn coupled to the supply voltage V CC . A source contact (S) of the second amplifying transistor 122 is coupled to ground.
The quadrature portion of the RF input signal RF_IN is delivered to the first input matching network 114 along with the bias adjustment voltage. The quadrature portion of the RF input signal RF_IN from the first output node 86 of the input quadrature coupler 78 and the bias adjustment voltage from the bias adjustment circuitry 64 are separately delivered to the first input matching network 114 and combined through one or more matching components such that the gate contact (G) of the first amplifying transistor 116 receives a combination of the two signals. Similarly, the in-phase portion of the RF input signal RF_IN from the second output node 88 of the input quadrature coupler 78 and the bias adjustment voltage from the bias adjustment circuitry 64 are separately delivered to the second input matching network 120 such that the gate contact (G) of the second amplifying transistor 122 receives a combination of the two signals.
The first amplifying transistor 116 and the second amplifying transistor 122 may be field-effect transistor (FET) devices. For example, the first amplifying transistor 116 and the second amplifying transistor 122 may be metal-oxide semiconductor field-effect transistors (MOSFETs). In other embodiments, the first amplifying transistor 116 and the second amplifying transistor 122 may be high electron mobility transistors (HEMTs), bipolar junction transistors (BJTs), insulated gate bipolar transistors (IGBTs), or the like. The particular configuration of the first input matching network 114 , the first output matching network 118 , the second input matching network 120 , and the second output matching network 124 may vary substantially between embodiments. In general, any suitable impedance matching network may be used for the first input matching network 114 , the first output matching network 118 , the second input matching network 120 , and the second output matching network 124 .
Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow. | Circuitry includes a balanced amplifier and bias adjustment circuitry. The bias adjustment circuitry is coupled to the balanced amplifier and is configured to measure an RF termination voltage across an output termination impedance of the balanced amplifier and adjust a bias voltage supplied to the balanced amplifier based on the RF termination voltage. Notably, the RF termination voltage is proportional to a voltage standing wave ratio (VSWR) of the balanced amplifier, and thus enables an accurate measurement thereof. By using the RF termination voltage to adjust a bias voltage supplied to the balanced amplifier, overvoltage and/or thermally stressing conditions of the balanced amplifier as a result of high VSWR may be avoided while simultaneously avoiding the need for large or expensive isolation circuitry. | 7 |
FIELD OF THE INVENTION
The present invention is directed to automatic identification devices and more specifically to providing a visual indication of the dynamic state of an identification device, such as an RFID device.
BACKGROUND OF THE INVENTION
The use of Electronic Article Surveillance, Radio Frequency Identification, and electronic security tag technology (hereinafter collectively referred to as ‘RFID’) is becoming increasingly prevalent in manufacturing, inventory control, and residential settings. First used in the Battle of Britain to recognize friendly fighter planes, RFID technology is now emerging as a valuable tool in our everyday lives. For example, RFID technology can be used by manufacturers or retailers to instantaneously track product inventories and thereby adjust to specific inventory needs. Similarly, RFID technology can be used by automobile commuters to pay highway tolls without interrupting their commute. RFID technology can also be used by pet owners to provide reassurance that pets are readily locatable, regardless of lost collars.
RFID technology involves the transmission of information through radio waves. A typical RFID system includes an RFID tag and an RFID reader. The RFID tag includes a circuit chip and an antenna attached to the circuit chip. The circuit chip and antenna are generally thin, flexible, and mounted to a flexible dielectric substrate. Antennas have numerous configurations and each is structured generally to broadcast electromagnetic energy to a distant reader. RFID chips can be programmed to store a variety of information. For example, RFID chips often include retail product identification such as a product serial number. In other applications, relatively more complex information may be provided such as biometric information on an employee ID badge.
RFID technology provides efficient, instantaneous communication between a reader and an RFID tag without directed near-field scanning as is commonly required in more conventional automatic identification technologies (e.g., bar-code, optical scanning, etc.). Further, the cost of RFID technology has recently dropped making it particularly useful in open supply chain applications, where disposable identification technologies are desired. However, in spite of these benefits, and perhaps because of them, RFID technology has produced discomfort, fear, and paranoia in some consumers.
Many consumers fear that RFID technology could be used in an Orwellian manner. For example, some consumers are wary that retailers may use RFID tags to covertly track consumer purchasing habits, interests, or behavior by placing hidden RFID readers throughout a retail location such as a shopping center. The readers could detect RFID tags provided in various previously purchased articles (e.g., wallets, purses, clothing, etc.) located on the consumer's person, thereby remotely tracking, logging, and analyzing the consumer's movements as they proceed through the shopping center. Although potentially benefiting retailers in terms of understanding, for example, which retail displays are effective at drawing consumer interest, many consumers view the above use of RFID technology as an unwarranted invasion of privacy. Accordingly, consumer groups have mobilized to prevent such use of RFID technology. Such groups have strongly discouraged use of RFID technology and have, in some cases, proposed legislation aimed at requiring retail stores employing RFID technology to install equipment that allows consumers to disable or de-activate RFID tags.
In view of the consumer objections referenced above, there is a need for a device associated with an RFID tag that is capable of deactivating the RFID tag in a manner that is visually apparent to a consumer. Such a device should simple, economical, efficient, and should ensure deactivation to the satisfaction of a consumer.
BRIEF SUMMARY OF THE INVENTION
The present invention addresses the above needs by providing a device for deactivating identification tags in a permanent and visually perceptive manner. The deactivation may occur manually or with the use of a deactivation device, and the visual indication occurs without use of additional equipment or electronics. Such visual indication is easy to interpret, so that a person viewing it will be able to quickly determine whether the identification tag is active or has been disabled. Identification tags capable of visually indicating this state (i.e., active or disabled) according to various embodiments of the present invention are simple, economical, efficient, and capable of wide use across many product lines.
In general, the present invention provides an identification tag for visually indicating deactivation of at least a part of an electronic circuit portion of the identification tag. The electronic circuit portion stores an identification associated with the identification tag, and a deactivation indicating portion is capable of visually indicating deactivation of at least a part of the electronic circuit portion. The visual indication may be an indicating color or an indicating indicia, and may occur under normal or alternate lighting conditions.
In other specific embodiments, the electronic circuit portion may be placed between two layers such that when the layers are separated, as when a user manipulates one of the layers or uses a tool or other mechanism to at least partially separate the layers, at least a part of the electronic circuit portion of the identification tag is deactivated. A deactivating indicating portion then visually indicates, such as through an indicating color or indicia, that at least a part of the electronic portion has been deactivated.
An identification tag of another embodiment of the present invention may be deactivated by removing a coating that is adjacent to an electronic circuit portion such that at least a part of the electronic circuit portion is deactivated. The process of removing the coating then reveals a visual indication of deactivation.
An identification tag of still another embodiment of the present invention may be deactivated using a pull-tab assembly that is designed to deactivate at least a part of an electronic circuit portion when the pull-tab assembly is removed from the identification tag. The process of removing the pull-tag triggers a deactivation indicating portion, which may be a two-part color generating system that results in visual indication of the deactivation.
Thus, the present invention provides a device for deactivating an RFID portion of an identification tag and indicating that the RFID portion is deactivated. The device for deactivating the RFID portion provides visual indication that the RFID portion is deactivated. The visual indication occurs without the use of additional equipment or electronics and it is easy to interpret, so that a viewer will be able to quickly determine whether the RFID portion of the identification tag has been deactivated.
BRIEF DESCRIPTION OF THE DRAWINGS
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
FIG. 1 is a top view of an identification tag capable of visually detectable deactivation of an RFID portion in accordance with one embodiment of the present invention;
FIG. 1A is a cross sectional view of the identification tag depicted in FIG. 1 ;
FIG. 1B is a cross sectional view of the identification tag depicted in FIG. 1A ;
FIG. 1C is a top view of the identification tag of FIG. 1 , wherein the RFID portion is visually deactivated by separating a first layer from a second layer;
FIG. 2 is a top view of an identification tag capable of visually detectable deactivation of an RFID portion in accordance with another embodiment of the present invention;
FIG. 2A is a top view of the identification tag depicted in FIG. 2 , wherein the RFID portion is deactivated;
FIG. 2B is a top view of the identification tag depicted in FIG. 2 , wherein the RFID portion is deactivated and wherein such deactivation is visually detectable;
FIG. 3 is a top view of an identification tag capable of visually detectable deactivation of an RFID portion in accordance with another embodiment of the present invention;
FIG. 4 shows a top view of an identification tag capable of visually detectable deactivation of an RFID portion in accordance with another embodiment of the present invention;
FIG. 5 shows a top view of an identification tag capable of visually detectable deactivation of an RFID portion in accordance with another embodiment of the present invention;
FIG. 6 shows a top view of an identification tag capable of visually detectable deactivation of an RFID portion in accordance with another embodiment of the present invention;
FIG. 6A shows a top view of the identification tag depicted in FIG. 6 , wherein part of a removable coating has been removed;
FIG. 6B shows a top view of the identification tag depicted in FIG. 6 , wherein the RFID portion is deactivated and wherein such deactivation is visually detectable;
FIG. 7 shows a cross sectional view of the identification tag depicted in FIG. 6 ;
FIG. 8 shows an exploded perspective view of an identification tag capable of visually detectable deactivation of an RFID portion in accordance with another embodiment of the present invention;
FIG. 9 shows a perspective view of the identification tag depicted in FIG. 8 ;
FIG. 10 shows a cross sectional view of the identification tag depicted in FIG. 9 ;
FIG. 11 shows a detail cross sectional view of a central portion of the identification tag depicted in FIG. 10 ;
FIG. 12 shows a detail cross sectional view of a central portion of an identification tag capable of visually detectable deactivation of an RFID portion in accordance with another embodiment of the present invention;
FIG. 13 shows a perspective view of the identification tag depicted in FIG. 9 , wherein the tape assembly has been removed to deactivate the RFID portion;
FIG. 14 shows a top view of the identification tag depicted in FIG. 13 , wherein the RFID portion is deactivated and wherein such deactivation is visually detectable through an indicating color;
FIG. 15 shows a top view of the identification tag depicted in FIG. 13 , wherein the RFID portion is deactivated and wherein such deactivation is visually detectable through an indicating indicia;
FIG. 16 shows an exploded perspective view of an identification tag capable of visually detectable deactivation of an RFID portion in accordance with another embodiment of the present invention;
FIG. 17 shows a perspective view of the identification tag depicted in FIG. 16 ;
FIG. 18 shows a cross sectional view of the identification tag depicted in FIG. 17 ;
FIG. 19 shows a top view of the identification tag depicted in FIG. 17 , wherein the RFID portion has been deactivated and wherein such deactivation is visually detectable through an indicating color;
FIG. 20 shows a top view of the identification tag depicted in FIG. 17 , wherein the RFID portion has been deactivated and wherein such deactivation is visually detectable through an indicating indicia;
FIG. 21 shows an exploded perspective view of an identification tag capable of visually detectable deactivation of a portion an antenna of an RFID portion in accordance with another embodiment of the present invention;
FIG. 22 shows an exploded perspective view of an identification tag capable of visually detectable deactivation an RFID portion in accordance with another embodiment of the present invention;
FIG. 23 shows a perspective view of the identification tag depicted in FIG. 22 ;
FIG. 24 shows a cross sectional view of the identification tag depicted in FIG. 23 ;
FIG. 25 shows a detail cross sectional view of a central portion of the identification tag depicted in FIG. 24 ;
FIG. 26 shows top view of the identification tag depicted in FIG. 23 , wherein the RFID portion has been deactivated and wherein such deactivation is visually detectable through an indicating color;
FIG. 27 shows a top view of the identification tag depicted in FIG. 23 , wherein the RFID portion has been deactivated and wherein such deactivation is visually detectable through another indicating color; and
FIG. 28 shows a top view of the identification tag depicted in FIG. 23 , wherein the RFID portion has been deactivated and wherein such deactivation is visually detectable through an indicating indicia.
DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
The present invention provides a device for deactivating an RFID tag. The present invention also provides a visual indication that the RFID tag has been successfully deactivated. In one embodiment, the RFID tag deactivation and accompanying visual indication occur simultaneously, such that a user may verify that the RFID tag has indeed been deactivated. In other embodiments, however, it may be appropriate to introduce a delay between RFID tag deactivation and the visual indication of such deactivation. In either case, visual indication of deactivation according to various embodiments of the invention is easy to interpret, simple, economical, and accurate as will be apparent in view of the disclosure provided below.
Referring collectively to FIG. 1-1C , one embodiment of the present invention includes an identification tag 10 having a first layer 11 adhered to a deactivation indicating portion 50 . In the depicted embodiment, the deactivation indicating portion 50 comprises a second layer 12 . For purposes of the foregoing specification and appended claims the term “identification tag” refers to any system that includes a memory or identity and mechanism for communicating remotely with a reader/encoder, such as remotely detectable tags that incorporate RFID or other similar technologies. For example, identification tags may include EAS tags, magnetic tags, RFID tags, RFID labels, smart cards, optical communication tags, capacitive tags, and the like. In the depicted embodiment, the first layer 11 includes a tab 16 typically disposed at one corner. The tab 16 is comprised of a flap of material extending from a portion of the first layer 11 such that a user, or a deactivation device may manipulate the tab 16 . In other embodiments, the tab 16 may be attached to a portion of the first layer 11 . In the depicted embodiment, the second layer 12 of the identification tag 10 includes an RFID portion 13 having an antenna 15 . The depicted antenna 15 is a single layer antenna disposed in a concentric pattern surrounding a circuit chip 14 , however, in alternate embodiments, other antenna structures may be used including multi-layered antennas and antennas of any shape. The antenna 15 may be constructed by any method as is known in the art, such as by printing, etching, or by deposition.
It should be noted that the term deactivation device as used herein is defined as any material, device, mechanism, tool, and/or combinations of the above that disrupts the operability of the electrical circuit, either mechanically or otherwise. The deactivation device may include, but is not limited to “tear tapes”, severing cords, fuses, and rudimentary tools. The deactivation device may also include attachment of a portion of the electrical circuit to one component and another portion of the electrical circuit to another component, where the other component is separable from the first component.
In various embodiments, the second layer 12 of the identification tag 10 may include an adhesive (not shown) on a bottom surface 18 for securing the identification tag 10 to a retail product or other item 19 . In one embodiment, the first layer 11 may be adhered to the second layer 12 by a second adhesive (not shown) that is less aggressive than the first adhesive such that the first layer 11 may be separated from the second layer 12 without removing the second layer 12 from the item 19 . It should be noted that in other embodiments, a patterned adhesive could be used so as to provide tamper evidencing.
FIG. 1B shows the identification label 10 having the first layer 11 peeled away from the second layer 12 . In one embodiment, a severing device, such as a cord 17 , is located adjacent to at least a part of the RFID portion 13 of the identification tag 10 . More particularly, in the depicted embodiment, the severing cord 17 is disposed beneath the circuit chip 14 and antenna 15 as shown. In alternate embodiments, however, the severing cord 17 may pass exclusively beneath either the antenna or circuit chip (not shown). Also, the severing cord 17 may be embedded in a dielectric substrate 9 that supports the RFID portion 13 as shown. In alternate embodiments, the severing cord 17 may be fixed beneath the RFID portion 13 by an adhesive or other coating.
In the depicted embodiment, the severing cord 17 is constructed of nylon similar to a fishing line; however, in alternate embodiments, the severing cord may be constructed of such materials as plastics, polymers such as polypropylene, metal wire, fiber strings, woven nylon, Mylar®, paper, or other strong materials. In other embodiments, the severing cord 17 may comprise the antenna 15 . In various embodiments, a first end 17 A of the severing cord 17 may be attached to tab 16 of first layer 11 such that when the first layer 11 is peeled from the second layer 12 , the severing cord 17 remains attached to the first layer 11 . In this regard, a user desiring to deactivate the RFID portion 13 of the identification tag 10 simply manipulates the tab 16 and at least partially peels the first layer 11 away from the second layer 12 . This could be done manually and may also be done with a deactivation device capable of manipulating the tab 16 so as to at least partially peel the first layer 11 away from the second layer 12 . The severing cord 17 is pulled upwardly with the first layer 11 , thus tearing through the RFID portion 13 and mechanically severing the circuit chip 14 and/or antenna 15 as shown in FIG. 1C . Advantageously, severing cords 17 used in accordance with the depicted embodiment permanently deactivate the RFID portion 13 of the identification tag 10 .
In another embodiment of the present invention, the second layer 12 is coated by an environmentally reactive dye 22 . Upon peeling and removal of the first layer 11 , the second layer 12 becomes exposed to the environment. The environmentally reactive dye 22 is designed to react with an environmental stimulus such as oxygen, nitrogen, carbon, moisture, temperature, light, and the like. In one embodiment, the reaction may occur approximately as the reactive dye 22 is exposed to the environmental stimulus, however in other embodiments, the reaction may occur after a delay, or in still other embodiments, the reaction may occur after exposure to a combination of environmental stimuli. In alternate embodiments, the deactivation device itself may provide the environmental condition that triggers the reaction, such as by generating heat.
In the depicted embodiment, the reaction between the dye 22 and the environmental stimulus produces a color change in the dye 22 that results in an indicating color that indicates to a user that the RFID portion 13 of the identification tag 10 has been deactivated. The indicating color may be any color, such as one that is distinguishable from the color of an exterior surface of the previously removed first layer 11 so that a user may readily identify a deactivated tag from one in which the first layer has yet to be removed. For example, in various embodiments the environmentally reactive dye 22 may produce a red, orange, or black, “deactivated” color against a pale (e.g., white, yellow, etc.) exterior first layer color. The above color scheme may of course be reversed as will be apparent to one of ordinary skill in the art in view of the above disclosure. Alternatively, the color change may be a color that is visible under alternate lighting conditions, such as under ultraviolet or infrared light.
In an alternate embodiment, the environmentally reactive dye 22 may be disposed in a pattern to form indicating indicia (not shown) such as text or figures. The indicating indicia may also include certain symbols, or any combination of colors, text, figures, and symbols. In one embodiment, the indicia may include words that clearly indicate to a viewer that the RFID portion 13 has been successfully deactivated, including but not limited to “DISABLED,” “DEACTIVATED,” and “SAFE.” Upon peeling the first layer 11 from the second layer 12 , the environmentally reactive dye 22 reacts to the environmental stimulus as referenced above thereby revealing the indicia to a user. In alternate embodiments, the text may be printed in reverse, so as to be readable using a mirror or through a bottle.
In another alternative embodiment, the second layer may include preprinted indicating colors and/or indicia such that when the first layer is removed, the preprinted colors and/or indicia are revealed.
FIGS. 2-2B depict an identification tag 110 capable of visual deactivation in accordance with another embodiment of the present invention. The depicted identification tag 110 includes an RFID portion 113 having a circuit chip 114 and an antenna 115 . In one embodiment, the RFID portion 113 may include a fuse 119 disposed between the circuit chip 114 and the antenna 115 . In other embodiments, the fuse 119 may be disposed anywhere along the antenna 115 as will be apparent in view of the disclosure provided below. The depicted identification tag 110 includes an exothermic dye 125 that coats an area proximate the fuse 119 . In one embodiment, the exothermic dye 125 may completely cover the fuse 119 as shown.
In various embodiments, the fuse 119 is structured to produce heat or light when the identification tag 110 is selected for deactivation by a user. In one embodiment, the fuse 119 may be a weakened or narrowed portion of the RFID antenna 115 that shorts out when the identification tag 110 is placed in an electromagnetic field over a certain magnitude. As the fuse 119 is shorted or otherwise activated, the fuse 119 produces heat or light as referenced above and thereby triggers an exothermal chemical reaction that changes the color of the exothermic dye 125 as shown in FIG. 2 and FIG. 2B collectively. The color change may produce any color that will indicate to a user that the RFID portion 113 of the identification tag 110 has been deactivated.
Other embodiments of the present invention are shown in FIGS. 3-6 . Common to each of these embodiments are identification tags 210 , 410 , 510 , 310 each having an RFID portion 213 , 413 , 513 , 313 . The RFID portions 213 , 413 , 513 , 313 include circuit chips 214 , 414 , 514 , 314 and antennas 215 , 415 , 515 , 315 . FIG. 3 depicts an identification tag 210 having a dye portion 226 in accordance with one embodiment of the invention. In the depicted embodiment, the dye portion 226 is comprised of an exothermic dye 225 and is structured to cover only a portion of the substrate 209 of the identification tag 210 . In one embodiment, the dye portion 226 may possess a color substantially similar to the substrate of the identification tag 210 before deactivation of the RFID portion 213 . After deactivation of the RFID portion 213 , the exothermic reaction described above causes the exothermic dye 225 to change color, thereby visibly distinguishing the dye portion 226 from the remainder of the identification tag substrate 209 . Such embodiments may be useful for products that have colors that may be confusingly similar to the color chosen to indicate deactivation, thus providing a contrasting border that surrounds a deactivated RFID portion 213 . In alternate embodiments of the present invention, it may be advantageous to choose a color change that will allow another automatic identification method to be used after visual indication of RFID deactivation has taken place. One such embodiment is depicted in FIG. 4 . In the depicted embodiment, the identification tag 410 also includes a barcode 421 . Upon deactivation of the RFID portion 413 as described above, an exothermic dye 425 causes the identification tag 410 to change color, thereby visibly indicating that the RFID portion 413 is deactivated. The color change resulting from the exothermic reaction is such that the barcode 421 can still be read by a barcode scanner (not shown) after the exothermic reaction has taken place. An example of such a color may be yellow, however the color change may be any color change that will allow a barcode scanner to read the barcode 421 after the exothermal reaction has taken place. As noted above, in other embodiments the color change may be visible under alternate lighting conditions, such as under ultraviolet or infrared light. Also, the color change may only be located in certain parts of the identification tag. Embodiments such as this may be useful in applications that may require later identification of an item using other automatic identification technologies, such as barcode scanning after the RFID circuit has been disabled.
This embodiment is of particular importance in instances where redundancy is needed. If the RFID tag becomes faulty for some reason, a user could deactivate the tag which will reveal the bar code for subsequent identification of the article to which the tag is connected.
FIG. 5 shows another embodiment of the present invention. In the depicted embodiment, upon deactivation of the RFID portion 513 by heating a fuse 519 , an exothermic reaction with an exothermic dye 525 causes indicia 522 , such as text or figures, to appear on the surface of the identification tag 510 in substitution of a color change as described above. In another embodiment, the indicia 522 may be appear in conjunction with a color change as described above. In one embodiment, the indicia may include words that clearly indicate to a viewer that the RFID portion 513 has been successfully deactivated, as described above.
FIGS. 6-7 show another embodiment of the present invention. In the depicted embodiment, RFID portion 313 is supported by substrate 309 , which is similar to that described above. Substrate 309 supports a circuit chip 314 that is connected to antenna 315 . In the depicted embodiment, antenna 315 is located in a layer above circuit chip 314 . A deactivation indication layer 351 serves as a deactivation indication portion and is located between circuit chip 314 and 315 , as shown in FIG. 7 . A removable coating 320 is also shown in FIGS. 6-7 . The removable coating 320 may be any coating that is capable of being mechanically removed by a user or deactivation device. In the depicted embodiment, for example, the removable coating 320 may be removed with the edge of a coin. Such removable coatings are known in the art and typically comprise foil or ultraviolet curable coatings. In the depicted embodiment, the removable coating 320 surrounds antenna 315 , although in other embodiments, the removable coating 320 may be in close proximity to the antenna 315 , such as covering antenna 315 or located below antenna 315 . When a user removes the removable coating 320 , antenna 315 becomes detached from circuit chip 314 , thereby deactivating the RFID portion 313 . Upon removing the removable coating 320 , an indicating indicia 322 and/or an indicating color (not shown), which has been pre-preprinted onto deactivation indicating layer 351 , is revealed. As noted above, the indicating indicia may include color, text, figures, symbols, or combinations of the above. In the depicted embodiment, the indicating indicia 322 is a universal “no” symbol characterized by a red circle and slash, overlapping a symbol referencing radio waves.
Another embodiment of the present invention is depicted in FIGS. 8-11 . In the depicted embodiment, an identification tag 610 is shown having multiple layers that together visually indicate deactivation when the identification tag 610 has been deactivated. In the depicted embodiment, the identification tag 610 generally includes an RFID portion 613 and a deactivation indicating portion 650 . As shown in FIG. 10 , the deactivation indicating portion includes a dual indicating layer 671 and a deactivation device. In the depicted embodiment, the deactivation device is a tape assembly 655 . As will be discussed in detail below, the RFID portion 613 is deactivated when the tape assembly 655 is removed from the identification tag 610 .
In general, the RFID portion 613 is located between a first layer 611 and a second layer 612 . In the depicted embodiment, the first layer 611 comprises an outer layer 616 , and the second layer 612 comprises the dual indicating layer 671 and a dielectric substrate layer 609 . The outer layer 616 is constructed of a destructible vinyl or polypropylene material that is designed to fracture upon tearing, however it may be constructed of any material capable of severing when the tape assembly 655 is removed from the identification tag 610 . A dielectric substrate layer 609 is included to support the RFID portion 613 . It should also be noted that in other embodiments, the outer layer 616 and the dielectric substrate layer 609 may be omitted without deviating from the spirit of the present invention. In the depicted embodiment, the RFID portion 613 and the tape assembly 655 are located between the outer layer 616 and the dual indicating layer 671 , and the RFID portion 613 is adhered to the dual indicating layer 671 . It should be noted that in order to simplify the figures, FIG. 10 (as well as other like figures throughout) shows the first layer 611 separated from the RFID portion 613 , however in practice, the outer layer 616 contacts and is adhered to the RFID portion 613 .
As shown in FIG. 8 , the tape assembly 655 includes a pull-tab 656 and a tape portion 657 . The tape portion 657 is made of a polypropylene material as is common in commercially available “tear tapes.” However, the tape portion may be made of any material suitable for severing the layers of the identification tag 610 , including polyester, cellophane, laminates, and other materials including those described with respect to the severing cord above. The pull-tab 656 may be integral with the tape portion 657 or it may be a separate component that is attached to the pull-tab 656 such that when the tape assembly 655 is removed from the identification tag 610 , the tape portion 657 remains attached to the pull-tab 656 . As such, the pull-tab 656 may be made of a polypropylene film or other like material, including those described with respect to the tape portion 657 , that allows for removing the tape assembly 655 from the identification tag 610 . In the depicted embodiment, at least a part of the tape assembly 655 is attached to the RFID portion 613 . The tape portion 657 may be attached in close proximity to the circuit chip 614 with an adhesive 658 . In the depicted embodiment, the tape portion 657 is attached above the circuit chip 314 . It should be noted that although the identification tag 610 is depicted as having a particular geometry, the identification tag 610 may have any shape that is suitable for supporting the RFID portion 613 , including but not limited to a triangular shape and a circular shape. Additionally, although the pull-tab 656 is depicted as having a particular geometry, it may also have any shape that is suitable for a user or deactivation device to grab in order to remove the tape assembly 655 from the identification tag 610 .
As noted above, in the depicted embodiment, the deactivation indicating portion 650 also includes a dual indicating layer 671 . The dual indicating layer 671 comprises a two-component color generating system as is commonly known in the commercial paper industry with regard to pressure sensitive copying paper and carbonless papers, as generally described in U.S. Pat. Nos. 2,730,456 and 2,730,457 to Green et al., the entire contents of which are hereby incorporated by reference. These patents describe two-component color generating systems in which an encapsulated ink reacts with a reactant coating to produce coloration. The capsules may be specifically designed to react with an associated reactant coating. When the capsules are ruptured, the ink reacts with the reactant coating to produce coloration. Along these lines, the dual indicating layer 671 of the embodiment of the present invention depicted in FIGS. 8-11 generally comprises a two-component color generating system. Referring to FIG. 11 , a layer of capsules 661 , containing indicating ink 665 , is applied to a top surface of the dual indicating layer 671 . Likewise, a reactant coating 662 is also applied to the top surface of the dual indicating layer 671 . In several embodiments, the reactant coating 662 may coat areas of the top surface of the dual indicating layer 671 that contain capsules 661 , or the reactant coating 662 may coat areas surrounding various areas containing the capsules 661 . In an another embodiment depicted in FIG. 12 , the dual indicating layer 671 may be substituted with a two-layer system comprising a top indicating layer 751 and a bottom indicating layer 752 . In this embodiment, the top indicating layer 751 includes capsules 761 containing indicating ink 765 on a bottom side of the top indicating layer 751 , and the bottom indicating layer 752 includes a reactant coating 762 on a top side of the bottom indicating layer 752 .
Referring to the embodiment depicted in FIGS. 8-11 , and as indicated above, the RFID portion 613 is located between the outer layer 616 and the dual indicating layer 671 . The tape portion 657 of the tape assembly 655 is attached to the top of the circuit chip 614 of the RFID portion 613 with an adhesive 658 . In various embodiments, the second layer 612 of the identification tag 610 may include an adhesive (not shown) on a bottom surface for securing the identification tag 610 to a retail product or other item. In various embodiments, a user desiring to deactivate the identification tag 610 manipulates the pull-tab 656 and pulls the tape assembly 655 across the identification tag 610 . The pull-tab 656 may be manipulated manually or through the use of a tool or other similar mechanism capable of manipulating the pull-tab 656 . As such, the pull-tab 656 may include various indicia 659 instructing a user regarding how to pull the tape assembly 655 in order to deactivate the identification tag 610 . Likewise, the top surface of the outer layer 616 may also include indicia (not shown) instructing a user regarding deactivation of the identification tag 610 .
In the depicted embodiment, upon pulling the tape assembly 655 across the identification tag 610 , the circuit chip 614 remains attached to the tape portion 657 such that the circuit chip 614 is detached from the antenna 615 , thereby permanently deactivating the RFID portion 613 of the identification tag 610 , as shown in FIG. 13 . As the tape assembly 655 is removed from the identification tag 610 , the circuit chip 614 ruptures the capsules 661 containing the indicating ink 665 underneath the circuit chip 614 . As the capsules 661 containing the indicating ink 665 are ruptured, the released indicating ink 665 is then exposed to the reactant coating 662 included on the dual indicating layer 671 in the area in which the capsules 661 were ruptured. The reaction between the indicating ink 665 and the reactant then produces a visual indicating color 673 , as shown in FIG. 14 . The color may be any color, and may be a color that is distinguishable from the color of an exterior surface of the identification tag such that a user may readily identify a deactivated tag from one in which the pull tag assembly 655 has not been removed from the identification tag 610 . For example, in various embodiments the indicating color 673 may be a red, orange, or black, “deactivated” color against a pale (e.g., white, yellow, etc.) exterior first layer color. The above color scheme may of course be reversed as will be apparent to one of ordinary skill in the art in view of the above disclosure.
Alternatively, the reaction between the indicating ink 665 and the reactant coating 662 may produce an indicating indicia 674 . The indicating indicia 674 may include text or figures that clearly indicate to a viewer that the RFID portion 613 of the identification tag 610 has been successfully deactivated, including but not limited to “DISABLED,” “DEACTIVATED,” and “SAFE,” as shown by example in FIG. 15 .
Another embodiment of the present invention is depicted in FIGS. 16-18 . In the depicted embodiment, an identification tag 810 is shown having multiple layers that together visually indicate deactivation when at least a part of an RFID portion 813 of the identification tag 810 has been deactivated. The depicted embodiment is generally similar to the embodiment depicted in FIGS. 8-11 , however, in this embodiment, the tape portion 857 is attached below the circuit chip 814 with an adhesive 858 . Additionally, the tape portion 857 is also adhered to a dual indicating layer 871 , which contains a similar two-part color generating system as the embodiment depicted in FIGS. 8-11 . It should be noted that in other embodiments of this invention, the dual indicating layer 871 may be substituted with a two-layer system as described above.
In various embodiments, a user desiring to deactivate the identification tag 810 manipulates the pull-tab 856 as described above and pulls the tape assembly 855 across the identification tag 810 in a similar manner as the embodiment depicted in FIGS. 8-11 . Upon pulling the tape assembly 855 across the identification tag 810 , the circuit chip 814 remains attached to the tape portion 857 such that the circuit chip 814 is detached from the antenna 815 , thereby permanently deactivating the RFID portion 813 of the identification tag 810 , in a similar manner as that shown in FIG. 13 . In the depicted embodiment, as the tape assembly 855 is removed from the identification tag 810 , the tape portion 857 ruptures the capsules 861 containing the indicating ink 865 underneath the tape portion 857 of the tape assembly 855 . As the capsules 861 containing the indicating ink 865 are ruptured, the released indicating ink 865 is then exposed to the reactant coating 862 included on the dual indicating layer 871 in the area in which the capsules 861 were ruptured. The reaction between the indicating ink 865 and the reactant coating 862 then produces a visual indicating color 873 , as shown in FIG. 19 . As noted above, the color may be any color, and may be a color that is distinguishable from the color of an exterior surface of the identification tag such that a user may readily identify a deactivated tag from one in which the tape assembly 855 has not been removed from the identification tag 810 . Alternatively, the reaction between the indicating ink 865 and the reactant coating 862 may produce an indicating indicia 874 . The indicating indicia 874 may include text or figures that clearly indicate to a viewer that the RFID portion 813 of the identification tag 810 has been successfully deactivated, as described above, and as shown by example in FIG. 20 .
Another embodiment of the present invention is depicted in FIG. 21 . In the depicted embodiment, an identification tag 910 is shown having multiple layers that together visually indicate deactivation when at least a part of an RFID portion 913 of the identification tag 910 has been deactivated. The depicted embodiment is generally similar to the embodiments depicted above, however, the tape portion 957 is attached adjacent to a portion of the antenna 915 , with the tape portion 957 also being adhered to a dual indicating layer 971 (or, in other embodiments, a two-layer two-component color generating system as described above). In various embodiments, a user desiring to deactivate the identification tag 910 simply manipulates the pull-tab 956 and pulls the tape assembly 955 across the identification tag 910 , in a similar manner as described above. Upon pulling the tape assembly 955 across the identification tag 910 , a portion of the antenna 915 located adjacent to the tape portion 951 is severed from the remaining portion of the antenna 915 , thereby changing the frequency response of the RFID portion 913 of the identification tag 910 . In the depicted embodiment, as the tape assembly 955 is removed from the identification tag 910 , the tape portion 952 ruptures the capsules 961 containing the indicating ink 965 underneath the tape portion 952 of the tape assembly 955 . As the capsules 961 containing the indicating ink 965 are ruptured, the released indicating ink 965 is then exposed to the reactant coating 962 in a similar manner as described above. Visual indication similar to that described above may then be produced to indicate that a portion of the RFID portion 913 has been deactivated.
Another embodiment of the present invention is depicted in FIGS. 22-25 . The identification tag 1010 of the depicted embodiment is similar to those embodiments described above, however the RFID portion 1013 is located between a first layer 1011 , which comprises an outer layer 1016 and a top indicating layer 1051 , and a second layer 1012 , which comprises the bottom indicating layer 1052 and a dielectric substrate layer 1009 . As described above, the outer layer 1016 and the top indicating layer 1051 may be constructed of a destructible vinyl or polypropylene material that is designed to fracture upon tearing, however each or both of the outer layer 1016 and the top indicating layer 1051 may be constructed of any material capable of severing when the tape assembly 1055 is removed from the identification tag 1010 . As noted above, in other embodiments, the outer layer 1016 and dielectric substrate layer 1009 may be omitted without deviating from the spirit of the present invention.
The deactivation indicating portion 1050 of the depicted embodiment includes the top indicating layer 1051 and the bottom indicating layer 1052 . Together the top indicating layer 1051 and the bottom indicating layer 1052 create a separated two part two-component color generating system. Referring to FIG. 25 , a layer of capsules 1061 containing indicating ink 1065 is applied to a bottom surface of the top indicating layer 1051 . Likewise, a reactant coating 1062 is applied to a top surface of the bottom indicating layer 1052 .
The RFID portion 1013 is located between the top indicating layer 1051 and the bottom indicating layer 1052 . In the depicted embodiment, the tape portion 1057 of the tape assembly 1055 is attached to the top of the circuit chip 1014 of the RFID portion, however as described above, the tape portion 1057 may alternatively be located below the RFID portion 1013 . In the depicted embodiment, upon pulling the tape assembly 1055 across the identification tag 1010 , the circuit chip 1014 remains attached to the tape portion 1057 such that the RFID portion 1013 is deactivated. As the tape assembly 1055 is removed from the identification tag 1010 , the tape portion 1057 severs the top indicating layer 1051 . As the top indicating layer 1051 is severed, capsules 1061 containing the indicating ink 1065 are ruptured along tear lines 1081 (shown in FIGS. 26-28 ). The released indicating ink 1065 is then exposed to the reactant coating 1062 included on the bottom indicating layer 1052 . In one embodiment, relatively small capsules 1061 are used on the first indicating layer 1051 such that the reaction between the indicating ink and the reactant produces a visual indicating color 1073 along the tear lines 1081 , as shown in FIG. 26 . In another embodiment, larger capsules 1061 are used on the top indicating layer 1051 such that the indicating ink is exposed to a greater area of the reactant coating 1062 on the bottom indicating layer 1052 resulting in an indicating color 1073 A covering a larger area, as shown in FIG. 27 . Alternatively, the reaction between the indicating ink 1065 and the reactant coating 1062 may produce an indicating indicia 1074 , as shown in FIG. 28 .
In response to privacy concerns with regard to the increased use of RFID technology, the present invention provides a device for deactivating an RFID portion located on an identification tag, and also provides visual indication that an RFID portion has been deactivated. Deactivation of the RFID portion triggers a visual indication that the RFID portion is deactivated, thus resulting in an accurate representation of RFID deactivation. So designed, deactivation of an RFID portion will be apparent to a viewer without the use of additional equipment or electronics.
Many modifications and other embodiments of the invention set forth herein will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. | A device for deactivating an RFID portion on an identification tag and indicating that the RFID portion is deactivated. The present invention addresses current privacy concerns regarding potential use of RFID technology after the point of sale. The device for deactivating the RFID portion of an identification tag provides visual indication that the RFID portion is deactivated. The visual indication occurs without the use of additional equipment or electronics. The visual indication component of the present invention is easy to interpret, so that a viewer will be able to quickly determine whether the RFID portion of the identification tag has been deactivated. | 6 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation application of U.S. Ser. No. 13/044,382 entitled “Integrated Vehicle Fluids” filed on Mar. 9, 2011, the entire disclosure of which is hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention generally relates to rocket propulsion systems for space launch vehicles placed and maintained in planetary orbits. More specifically, the invention relates to systems and methods for propelling and powering an upper stage of a space launch vehicle by capturing waste ullage gases vented from the main upper stage propellant tanks, and generating power by an internal combustion engine used for replacement of power, pressurization, and reaction control systems traditionally powered by separate hydrazine systems and batteries.
BACKGROUND OF THE INVENTION
[0003] Over the past decade there have been increasing demands to lower the cost of space transport to geostationary and other orbits as well as perform missions which are simply not possible with existing launchers such as manned exploration of the moon and Mars. Implicit is the demand that reliability be enhanced and certainly not degraded. Unspoken but also implicit is that commercially viable launchers must fill this broad range of demands since single-purpose launchers such as the Saturn rocket or Space Shuttle are cost prohibitive, even for governments with substantial space budgets. The commercial launchers presently being used for most missions are the result of decades of evolution and have become highly refined and proven. Each individual system on the launchers has been raised to a high level of performance which is very difficult to improve upon, even with large investments in engineering development. Since only incremental improvements can be expected by addressing individual systems, there is a need to view space vehicle systems in a more broad sense to determine if substantial improvements can be accomplished.
[0004] One example of a high performance, highly evolved upper stage is the Centaur®. The Centaur® upper stage is capable of delivering payloads to nearly any orbit from Low earth Orbit to interplanetary trajectories. The Centaur® is capable of delivering a high energy to the payload by burning liquid hydrogen (LH 2 ) and liquid oxygen (LO 2 ) in a very high efficiency, low weight engine such as the RL10. The total mass of the Centaur when empty is less than 2.5 mt, yet it can contain in excess 20 mt of propellant. Propellants are stored in lightweight stainless steel tanks whose structural rigidity is provided primarily by the pressure of the propellants within the tank. In order to keep the tanks from collapsing prior to the loading of propellant, the tanks are pressurized with gas. In the Centaur®, a common double bulkhead is used to separate the LO 2 and LH 2 tanks. The two stainless steel containers are separated by a very thin layer of insulator which is contained within a hermetic cavity. Therefore, the appearance is of a single tank, but it is divided into the separate LO 2 and LH 2 tanks with an intermediate vacuum cavity. The extreme cold of the liquid hydrogen on one side of the bulk head creates a vacuum within the intermediate cavity. The insulator prevents the two metal bulkheads from contacting thereby maintaining a low thermal conductivity, thus preventing heat transfer from the comparatively warm LO 2 to the super cold LH 2 . The exterior of the tanks are also insulated to suppress heat flows from the external environment to the propellants.
[0005] While on the ground and filled with propellants, the tank pressures are controlled by valving which maintains the tanks within a specific pressure band. The propellants within the tanks boil due to external heating and the vapor formed is passed through these regulating valves which hold the tank internal pressure within band regardless of the heating and attendant boil off vapor mass flow. By controlling the tank pressure at which the propellants boil, their saturation conditions are established. For the sake of maximizing the density of the propellants and hence reducing the size of the vehicle tanks, the pressures and temperatures are kept as low as possible within the tanks. These vent valves are thus precision cryogenic regulators that are complex, costly and heavy.
[0006] While on the ground, loads imparted to the vehicle are quite low, and the stiffening effects of the low internal pressures controlled by vent valves are sufficient to maintain structural integrity of the vehicle. However, during the ascent phase of flight and also prior to operation of the upper stage engines, the pressures within the vehicle tanks must be raised. In the case of ascent, the vehicle must be further stiffened so that it can survive the very high bending and compressive loads generated by aerodynamic, thrust and inertial effects. Pressures are raised prior to engine start to permit the proper operation of the engine pumps. These high capacity pumps must receive propellants whose pressure is substantially above their saturation pressure. This saturation pressure was effectively set prior to liftoff by the valving controlling tank pressures. Without system pressure maintained above saturation pressure, the propellants would boil within the pumps and they would cease to function properly. This margin is commonly referred to as Net Positive Suction Pressure (NPSP) and is commonly on the order of 3-10 psi.
[0007] In most modern upper stage vehicles, these pressurization demands are met by introducing gaseous helium into the ullage spaces of the propellant tanks. This helium is stored in separate vessels, typically at high pressure, and is delivered via valves to the propellant tanks at need. Helium is used since it has a low density, is chemically inert, and does not condense to a liquid at the cryogenic temperatures seen in the LO2 and LH2 tanks. Hence it can be used to pressurize both the LO2 and LH2 tanks with a tolerable mass penalty. Once the upper stage engines are operating, it is possible to perform the pressurization task by bleeding small amounts of warm H2 and O2 gases from the engine. This reduces the amount of helium required for the mission. The amount of helium required is thus dictated by the size of the propellant tanks, their pressure and the number of burns which are expected to be performed. The mass of the hardware required to contain this helium is very significant and many approaches have been taken to suppress system complexity and weight. However even the most advanced existing systems have strict limitations on their capabilities. These systems all have a limited amount of GHe and hence the number of engine burns, tank size, and other factors are all limited. Even a small leak of helium from the storage systems can result in a catastrophic loss of pressurant and hence mission failure.
[0008] During flight the upper stage propellant tanks will continue to absorb energy from the environment, albeit at a lower rate than what was present prior to launch. During engine burns, elevated tank pressures are maintained with GHe, gaseous O2 or H2 to establish and maintain sufficient NPSP and hence will end up at the end of a burn at a tank pressure above the saturation condition of the propellants. As heat is applied to the liquid propellants, they will gradually increase in temperature until their saturation pressure matches the partial pressure of H2 or O2 in the ullage gas. At this point, the propellants begin to boil. Tank pressures rise as the boil-off continues. If no action is taken prior to the next start of the engines, the system must be pressurized above this new higher pressure. The incremental increases in tank pressures therefore directly drive the peak operating pressures of the tanks, and hence their mass. Therefore, tank designs may have to account for much higher pressures, such as a 60 psia capability, which results in a substantial mass penalty.
[0009] To mitigate this pressure building effect on missions lasting more than a few minutes, it is common to vent the pressure in the ullage space to a level close to the original saturation pressure. Especially on the LH2 tank, during a mission to geostationary orbit, this venting may be performed multiple times. The energy absorbed from the environment is stored in the enthalpy of the ullage gases which therefore must be subsequently dumped overboard.
[0010] A significant limiting factor for all missions in space is accounting for the ullage losses associated with the continual boil off of cryogens. It is this propellant loss that has prevented to date the use of cryogenic propulsion systems for missions to the moon or indeed any mission with a duration that is much longer than one day. One of the most effective approaches for reducing losses is to apply a very low thrust to settle the propellants within the tanks to fixed locations, generally towards the aft end of their respective tanks. Less than a thousandth of one G is required to achieve this effect. Settling thrust segregates the liquid and gaseous phases of each propellant. Cold liquid propellant is thus physically separated from much warmer gas by the settling thrust. The quiescent gaseous ullage, in a microgravity environment without significant convection, then behaves as an excellent insulator and blocks heat from entering the liquid propellant surfaces. Heat is conducted down the side walls from the warm ullage side of the tank to the cold liquid side but this is inhibited by the relatively long conductive distances, reduced thermal conductivity due to the cryogenic operating temperatures and low wall thicknesses. Naturally the thinner these walls are the better. Thus it can be seen that a tank with a low gage and hence low allowable operating pressure is also thermally superior. All of these effects conspire to slow boil off when settling is imposed.
[0011] Settling thrust is typically provided by one or more small rockets fueled by hydrazine. On the Saturn S-IVB stage, the ullage gases were burned in a small thruster to maintain vehicle settling and some of the heat of the burning H2 and O2 was used to warm cold helium up for use in the pressurization system. Other vehicles such as the Delta Cryogenic Second Stage simply vent the boil-off gas aft to produce a small amount of settling thrust during long duration missions. Most often though, these waste ullage gases are simply dumped. Depending on vehicle design and mission duration, these wasted propellants can weigh into the hundreds of pounds. Naturally, the amount of time that a hydrazine system can support settling is strictly limited by the amount of propellant that it contains. Despite the best conservation efforts, hydrazine-based settling can at best be sustained for a handful of hours. Once settling is lost the surface tension effects within the propellants will gradually cause the interior of the propellant tanks to be fully wetted, temperature segregation will be lost and boil off rates can triple.
[0012] The vehicle must also provide a means for changing its attitude, and this function is also typically done with a hydrazine fueled thruster system. On the Centaur® vehicle, the attitude control thrusters and settling thrusters share a common supply system. While the settling function consumes the vast majority of hydrazine capacity, the attitude control task cannot be ignored. Settling thrusters can be commanded off, but the vehicle attitude must be stabilized for various reasons to include (i) maintaining radio links to the ground, (ii) providing an optimal attitude relative to the sun so that components such as avionics do not get too hot or cold, and (ii) suppressing heating of the main propellant tanks. Even if settling is eliminated, the attitude control function alone can consume hundreds of pounds of propellant over the course of a multiday mission. This propellant requirement is insupportable by most commercial upper stage launch vehicles.
[0013] Regarding the use of hydrazine as a propellant, while its application to space vehicles is widespread, there are a number of problems associated with its use. Hydrazine is a highly toxic, highly corrosive fluid that is compatible with only a handful of materials. Handling hydrazine requires hazardous procedure precautions, often requiring the use of positive-internal pressure inflatable SCAPE (Self Contained Atmospheric Protective Ensemble) suits to protect technicians loading a vehicle. Hydrazine can only be used in a narrow band of temperatures near room temperature. Hence, elaborate thermal control measures including heaters are mandatory, thus burdening the electrical storage system and exacerbating propellant heating. Hydrazine is also quite costly. Hydrazine is also a very inefficient fuel, delivering only a miserly specific impulse of 235 seconds. The advantages of Hydrazine are that as a fuel, it is simple and reliable to use assuming the appropriate environmental conditions can be maintained during its storage and delivery to a reaction chamber. Hydrazine is catalytically decomposed in a simple reaction chamber and does not require an ignition system or even an oxidizer. Nevertheless, the continued use of hydrazine sets harsh boundaries on improving overall vehicle operations and costs.
[0014] The electrical systems on the upper stage currently use large electrochemical batteries to provide power. This battery technology has evolved over decades to favor batteries of increasing power density and attendant sophistication. The desire to provide redundancy has doubled the storage demand. Even with the best modern technology, these batteries are extremely heavy, costly and can only supply enough power for less than a day's operation of a vehicle such as a Centaur®. Without a means to recharge these batteries, they set a strict limit on mission duration. Unfortunately the two common sources of power for recharge are solar panels and fuel cells, and these systems are both very costly to incorporate on a vehicle. Use of solar panels requires vehicle orientation control relative to the sun, and are physically bulky with complex deployment mechanisms. Most spacecraft that use solar panels are effectively in zero-G conditions, and hence large deployed solar panels are never exposed to high loads. A vehicle like Centaur® will generate acceleration forces in excess of 2 G's, and hence the mounting system for even a small solar array would be very heavy.
[0015] Fuel cells, while being more compact than batteries efficient and seemingly simple, are quite costly and complex to operate and support due to their intolerance of inert gases within the reactant streams and due to the necessity to dispose of the water they produce. To date, only manned vehicles such as the space shuttle can justify their cost and complexity.
[0016] While cost reduction, increased simplicity and reliability are primary goals in an improved vehicle, there is also an increasing need to expand mission capabilities beyond merely moving heavier payloads. Current missions are performed over a maximum flight duration of less than a day. However if the vehicle could efficiently fly for longer, it would be extremely valuable. Missions such as those to the moon require coast durations measured in days. The increasing amount of space junk in orbit will soon require the deliberate disposal of not only obsolete satellites but also the stages which placed them in orbit. This disposal activity at present would impose large performance penalties which would drastically increase the cost to orbit. However by performing disposal maneuvers at optimal times, this function can be accomplished with a minimum of cost. Missions such as space junk removal require a vehicle be capable of flying for days to weeks. In summary if one wishes to improve vehicle system performance and cost, yet expand the mission duration and improve reliability, a broader view of the vehicle must be taken to include a simultaneous analysis of vehicle thermodynamics, power, propellant and pressurant storage limitations, vehicle structural and thermal interactions, and the demands of widely varying missions. While it may be possible to redesign vehicle systems on a micro level, that is, to redesign selected systems based on specific mission requirements, this design approach inevitably compromises the majority of missions and can also create a proliferation of system designs that are all slightly different and likely incompatible. This micro level design solution is the origin of the present state of most space vehicle capabilities.
[0017] The use of waste ullage gas was recognized in the 1960's as a potential source of fuel for an auxiliary engine on the Saturn S-IVB. NASA recognized that these ullage gases could be captured and reused within an internal combustion engine that could be used to provide power for the upper stage vehicle. Although this recycling or reuse of the ullage gases was recognized development stalled with the proof of concept of a H2/O2 burning internal combustion engine. The concept was never flown.
[0018] There are a number of examples of improvements made to rocket propulsion systems in order to increase main engine propulsion efficiency, or to simplify the components of a launch vehicle, with one intent being increasing the available payload of the vehicle.
[0019] One example of such a reference is the U.S. Pat. No. 5,282,357 for a high-performance dual-mode integral propulsion system. This reference discloses a propulsion system in which pure hydrazine is used as the fuel for both a bi-propellant rocket engine for high thrust performance and in multiple mono-propellant thrusters for station keeping and attitude control functions. The use of the common fuel for both modes of operation significantly reduces propellant weight and inert propulsion system weight. For station keeping, the mono propellant thrusters can be augmented in performance by employing either electrothermal or additional direct chemical energy, arc jet operation, or force fuel acceleration to provide increased specific impulse values.
[0020] The U.S. Pat. No. 6,135,393 provides a spacecraft attitude and velocity control thruster system that incorporates mono-propellant RCS thrusters for attitude control and bi-propellant scat thrusters for velocity control. Both sets of thrusters are designed to use the same liquid fuel, supplied by a pressurized non-pressure regulated tank, and operate in a blow down mode. In the propulsion system, such station keeping and attitude control thrusters may function in conjunction with a large thrust apogee kick engine that uses the same propellant fuel. Hydrazine and bi-nitrogen tetroxide are preferred as the fuel and oxidizer, respectfully.
[0021] Despite improvements in general rocket technology, to include increasing the efficiencies of rocket engines and components, there is still a need to provide even greater efficiencies, and to simplify space launch vehicle systems while carrying larger payloads over longer durations.
SUMMARY OF THE INVENTION
[0022] In accordance with the present invention, a system, methods and sub-systems or sub-combinations are provided to supply all required vehicle functions including attitude control, propellant settling, tank pressurization and venting, hardware actuation and purging and power generation without the need for any fluids other than the LO2 and LH2 present in the main vehicle tanks. The system thus has a capability to perform these functions without any limits other than the mass of the primary vehicle propellants. The overall system can be referred to as an integrated vehicle fluid (IVF) module that provides these functions. The waste or ullage gases from the hydrogen and oxygen tanks that are typically vented overboard, are used as the fuel and oxidizer to run a small internal combustion engine to provide power for all of the other vehicle functions. The power output shaft from the engine can be used to drive a number of secondary devices to include one or more generators that generate electrical energy for storage in one or more small batteries. Power from the shaft is also used in other secondary devices such as one or more pumps to modulate and regulate fluid pressures in the vehicle, to include most importantly, pressures in the LO 2 and LH 2 tanks.
[0023] The internal combustion engine (ICE) can be one of many selected types of engines to include a piston engine or a Wankel engine. This engine burns the gaseous hydrogen (GH 2 ) and gaseous oxygen (GO 2 ) from the upper stage propellant tanks. The GH 2 is introduced into the engine through a flow control valve that throttles the mass flow of the GH 2 . Before the GH 2 enters the engine, the hydrogen is used to cool the exterior of the engine, maintain pressure in the crank case, and cool the internal chamber of the engine. The GO 2 is injected either into the hydrogen before or at the intake port or directly into the engine combustion chamber at an elevated pressure, similar to fuel injection in a diesel engine. In circumstances when the space vehicle requires additional power output from the engine, it is also contemplated that LH 2 can be mixed with the GH2 bled from the hydrogen tank to temporarily feed the engine. This additional cold fluid enables greater cooling capacity for the engine and increases the H2 density within the combustion chamber thus allowing more O2 to be introduced and hence more energy released. This mixing can be modulated by an intake control valve. Under most circumstances, however, the waste ullage hydrogen is all that is required to power the engine in order to provide sustained power for all upper stage systems.
[0024] In another important aspect of the invention, the exhaust from the internal combustion engine, composed primarily of high temperature hydrogen rich gas, is used to power one or more of the settling thrusters with a very high efficiency of thrust generation, as discussed further below. Therefore, the hydrogen ullage gas undergoes not only a single recycling use through the engine, but also an additional recycling use to power the settling thrusters.
[0025] The selection of a Wankel engine provides some advantages as compared to a traditional piston engine; however, either the piston engine or Wankel engine is contemplated for use in the present invention. As compared to a piston engine, a Wankel engine has no intake or exhaust valves, has fewer moving and lubricated parts, a very simple crank system, and is a very dynamically balanced engine due to its symmetrical disposition with respect to the movement of the rotor. Because of this simplicity the engine is very light. The three chamber configuration of the rotary engine has distinct hot and cold areas that can enable very simple gas cooling, yet may achieve higher exhaust gas temperatures that can be used as the exhaust gas for the settling thrusters. Regardless of the type of engine used, because of the limitations on combustion physics and materials, the engine preferably operates at a very low mixture ratio between 0.6 and 2. This range precisely matches the boil off characteristics of the vehicle which often generates more H2 than O2. Hence the engine more effectively uses the waste gases from the vehicle.
[0026] To accomplish all known vehicle functions requires a total shaft power of less than 10 kW and more commonly less than 2 kW. This allows the engine to be only moderately efficient and with a very small displacement on the order of 200 cc. High exhaust pressures can be tolerated by the engine, (such as in the range of 10-20 psia) which enables at least a 5-10 psia thruster chamber pressure in the settling thrusters by simply direct venting from the engine exhaust into the receiving chamber to the thrusters, without any further pressurization requirements. Settling thrust thereby generated is in the precise band to provide continuous low G forces. With respect to generation of electrical power, a very simple yet effective electric power generation is achieved by an electric starter/generator that is driven by the output shaft of the engine. The starter/generator generates electrical current for storage in a rechargeable battery. The starter/generator, associated electronics and the battery itself may also be cooled with hydrogen flowing through the IVF module. The battery can then provide electrical power for all the other upper stage systems, as well as power for pressurization pumps to pressurize the propellant tanks. The battery maintains a minimum charge and will discharge during peak loading conditions. The battery is easily recharged during vehicle coasts in which power loading is reduced since system duty cycle for lateral thrusters and pressurization is low during this period. By inclusion of the battery, this removes many restrictions on peak power and total available energy that were an inherent concern for prior space launch vehicles that solely relied upon battery power for many functions. The battery can be less than 5% of the capacity of present batteries with a proportional reduction in mass and volume. The drastic reduction enables the use of less exotic, lower power density battery designs without significant mass penalty but with large cost benefits.
[0027] The starter/generator permits the repeated startup and shutdown of the IC engine as required for ground testing and flight operations. If desired, the engine can be shut down for extended periods and all vehicle power provided by the vehicle battery. Settling can continue to be supported without the operation of the IC engine and hence low-boil off, settled thermodynamic conditions can be maintained for even longer periods. When the battery has been discharged to its low limit the IC engine can be restarted and the system loads transferred effectively to the generator which simultaneously recharges the battery. In its preferred embodiment the starter and generator functions are performed by a single electromechanical device.
[0028] In its preferred embodiment the IVF system performs the function of ground venting of the main propellant tanks via a ground vent valve. These valves are connected to the airborne system via disconnects which actuate once the vehicle has achieved liftoff. Because the ground valves are not restricted in mass, their regulation capability is far more precise and stable than a mass and volume restricted airborne valve. Their flow capacity is also far higher and hence higher heating rates or lower tank pressures can be readily accommodated. Since the high heating rates requiring these valves are not present during flight, the lower capacity airborne systems are used once the vehicle is placed in the vacuum of space.
[0029] One important aspect of the invention is that the launch vehicle can operate for long settled periods with thrust supplied only from the ullage gases. This sustained vehicle settling drastically reduces propellant losses in the tanks. Empirical testing has shown that boil off can be reduced to less than a third of normal losses. Unlike hydrazine based systems, this settling capability is generated by fluids that would typically have been merely dumped.
[0030] The present invention provides multiple levels and sources of settling thrust and integrates the airborne main tank vent function into the settling thrusters. Ultra-low forces can be generated by simply venting cold GH2 gases though the settling thruster. This also accomplishes the venting of the main LH2 tank during flight described in the background. Because this is accomplished with multiple axial thrusters, the vent rate can be modulated and there are redundant valves to enable this critical function. Thus a rapid tank vent can be accomplished without the need for dedicated vent valves as is the requirement with presently known vehicles. These vent events produce axial thrust which helps further settle the vehicle, and by modulating the axial thrusters, the vehicle attitude can be maintained by the guidance system. The need for precisely balanced vent systems as required in known vehicles is thus eliminated.
[0031] Although a rapid tank vent can be commanded, it may be more effective to simply burn off the excess gas in the ullage. Low thrust for sustained coast settling, (such as in the range between about 0.5. to 2 lbf) may be provided directly by the hydrogen rich ICE exhaust gas fed to the axial thrusters. Since the hydrogen fed to the ICE is supplied by the vented tank ullage, this venting gradually consumes the H2 ullage gas which would have to be vented in any event to reduce tank pressure. Combinations of direct H2 tank vent and ICE hydrogen burn off can be executed as required by mission needs, external heating requirements, or power demands. In nearly every case except direct venting of cold gas, the specific impulse of these settling thrusters are at least 50% higher than for existing hydrazine thrusters thereby providing a powerful performance enhancement.
[0032] Greater thrust and gradual LO2 tank vent down is obtained from the axial thrusters by adding GO2 to the ICE exhaust gases at the axial thrusters or in the exhaust lines leading to them thereby increasing the energy release. By adding GO2 to the ICE exhaust, a demand for GO2 is created from the accumulator which during a coast phase is replenished from the LO2 tank ullage. Thus in addition to direct venting of the LO2 tank through an axial thruster, excess GO2 is effectively burned off via the axial settler
[0033] The highest axial thrust (4-25 lbf) and simultaneous LH2 and LO2 tank vent down is obtained by adding further GH2 from the ullage to the ICE exhaust stream as well as adding GO2. This mode is effectively the highest rate of tank venting while generating peak axial thrust. This mode is used during the highest settling demand periods immediately prior to and after main engine operation.
[0034] The ability to allow tank pressures to be reduced while taking full advantage of the vented gas allows us to efficiently re-saturate the liquid propellants at lower pressures. Since tank pressures are not allowed to rise uncontrolled, design pressures can be reduced on the vehicle main tanks. As described, this design pressure reduction has a profound positive effect on vehicle tank mass and its overall thermal efficiency. Both of these factors amplify the performance benefits of the IVF system.
[0035] The lateral thrusters are supplied from small accumulators which are held by a control system at a low pressure (approximately 200-500 psia) and near-ambient temperature. These thrusters burn H2 and O2 at a moderate mixture ratio between 1 and 4. The inlet mixture ratio is bounded by the temperature and pressure limits imposed on the storage accumulators. Because of this the high performance inherent (a specific impulse in excess of 350 seconds) in a H2/O2 thruster is obtained without need to bring cryogenic liquids and maintain them in thermodynamic stasis at each thruster inlet valve. In addition the seals, seats and other soft goods are not exposed to cryogenic conditions and hence are simpler, more reliable and less prone to leakage. Regenerative cooling of the thruster combustion chamber enables the total deletion of high temperature alloys and complex assembly methods from the thruster.
[0036] The lateral thrusters can operate in two modes. The first is the standard combustion mode whereby H2 and O2 are ignited within the thruster to produce on the order of 10-35 lbf of thrust. In each axis there are twin redundant thrusters so two levels of force are immediately available. The thrusters can also be operated in cold gas mode by only commanding a H2 inlet valve open. This provides a capability to produce very small impulses using a low-temperature and non-condensable exhaust. Precision vehicle maneuver in close proximity to other vehicles becomes straightforward without the threat of high temperature plumes either damaging or contaminating sensitive radiation shielding or other elements of the vehicle being docked.
[0037] The IVF module includes two small accumulators for containing GO2 and GH2. These accumulators are periodically replenished from either the gaseous ullage or from the liquid propellants in the vehicle tanks. Whenever the main upper stage engines are operating, GH2 and/or LO2 can be bled from the main engine pumps. During coast phases when the engines are not operating low pressure fluids from the main propellant tanks (either gaseous or liquid) are pumped up to an accumulator pressure of between 200 and 500 psia with small pumps which are driven through clutches or via electric motors by the internal combustion engine. Fluids exiting the main engine bleeds or the IVF pumps may be quite cold and might require warming prior to storage in the accumulators. This is accomplished by warming them in heat exchangers which are part of the exhaust system of the internal combustion engine and the downstream axial thrusters. The temperature of these gases is controlled by either simple mechanical thermostatic devices or via sensors and active computer control. These control devices modulate the amount of heat which is added to the cold gases exiting the pumps to achieve a steady temperature of gas delivered to the accumulators. Gases stored in the accumulators are thus stabilized within a narrow pressure and temperature band which is close to room temperature.
[0038] During low duty cycle periods the accumulators are replenished via the IVF pumps using ullage gas. This is typical of coast periods of a mission when the main engines are not operating and tank pressurization events are not occurring. This enables the best use of the waste boil off gases. Compression of gases though requires a larger expenditure of energy by the IC engine due to the larger enthalpy change associated with gaseous compression. This limits the total mass flow which can be supported by ullage gas compression. When ullage gases are flowing through the pumps, the need for heat addition from the IC engine exhaust and axial thrusters is low since much heating is accomplished simply by the heat of compression added in the IVF pump.
[0039] For high duty cycle periods when rapid and simultaneous pressurization of both hydrogen and oxygen tanks is required along with high settling thrust, the pumps consume liquid cryogens which are more efficient to compress and raise to accumulator pressure. These liquid cryogens require more heat addition from the axial thrusters but far larger mass flows can be supported by the IC engine power output. The use of liquid cryogens of course debits the vehicle main propellants and decreases the amount of LH2 and LO2 available to the main engines. The amount of liquid cryogens thus consumed however is compensated by the elimination of dry mass, hydrazine and helium from the vehicle. Effectively, these liquid propellants are converted to gaseous pressurants which are then later reused to generate power, settling and axial thrust.
[0040] The stabilization of the accumulator pressure and temperature simplifies the design of downstream devices such as the thrusters and pressurization valves. The thrusters can be operated with a narrow range of mixture ratios and thrust output since the inlet conditions are bounded. Similarly the pressurization valves can be sized to address only a restricted inlet density band unlike the situation with typical existing systems where valves must be capable of throttling inlet gases with a pressure band in the thousands of psi and temperature swings in the hundreds of degrees. The near-ambient storage conditions in the accumulators also enable the use of elastomeric and other materials in the construction of downstream valves and components. The combination of low pressure and ambient temperatures enables leakage of hydrogen and oxygen to be minimized with simple and reliable seats. The necessity for specialized, low-rate and hence costly cryogenic components is thus eliminated.
[0041] The oxygen and hydrogen pumps for the IVF module are extremely small with displacements typically on the order of 1-10 cc. The pumps can either be driven with mechanical clutches off of the internal combustion engine shaft or be driven by motors supplied with electricity from the starter/generator. The pumps are commanded by the IVF controller to turn on whenever their respective accumulator reaches its low pressure limit or can be directly commanded whenever significant fluid loads are imminent.
[0042] In a fashion similar to the thrusters, each module contains valves whose function is to deliver warm GO2 and GH2 to the respective main propellant tank ullages for tank pressurization. These gases are bled from the IVF accumulators at need, typically immediately prior to upper stage engine start and during engine operation but also during booster ascent. The lines leading to the main tanks for pressurization are in one embodiment separate from the vent lines leading from those same ullage spaces to the intakes of the pumps and internal combustion engine. This prevents the ingestion of warm, high pressure gas into these devices which are optimized to induct the colder, lower pressure gas resident in the ullage spaces.
[0043] The mass of the ullage gases which remain inside the vehicle at the completion of the mission are also dramatically reduced by the IVF module. The hydrogen tank, now pressurized with warm H2 from the accumulators, will have approximately half the mass as would be encountered in prior systems. This is due to the elimination of GHe (a heavier molecule than H2), the overall warmer temperature of the ullage, plus the reduction in the peak pressure required. The GO2 ullage is also considerably lighter due to the increased temperature and decreased pressure.
[0044] The IVF system also can supply gaseous H2 and O2 to actuate valves on the main vehicle and main engines. The propellant flow control systems on the vehicle are often actuated by medium pressure gaseous helium (GHe). Typically this gas enters into a piston in cylinder arrangement and the supplied pressure forces the piston to move which then actuates a ball, butterfly or poppet valve. The GHe is trapped in a dead-headed cavity adjacent to extremely cold liquid propellants. The gradual cooling of this actuation gas can adversely affect the opening and closing characteristics of the cryogenic valve. Venting the GHe causes the valve to then close. With the elimination of GHe from the vehicle, the IVF system provides either gaseous H2 or O2 as a replacement. Unlike in a GHe supplied system where the amount of gas is strictly limited, an IVF based system enables the actuation gas to be flowed through the valve actuator so that the temperature conditions within the valve actuation cavity remain stable over extended durations. The performance of the valve can be stabilized and control improved.
[0045] The IVF system can supply either one way or recirculating purges of either GH2 or GO2 to either prevent the ingress of external atmosphere into components on the vehicle, maintain stable temperature conditions at sensors or to thermally condition components such as avionics boxes, actuators, or to provide vapor cooling of structures. Vapor cooling is a technique whereby heat is blocked from moving down a structure by intercepting it with cold gas. Such techniques can drastically reduce heating in the main vehicle tanks and further extend flight operations by suppressing boil off.
[0046] While the IVF system takes advantage of the internal combustion engine to provide electrical power for vehicle systems and for the operation of the IVF pumps, this is not the boundary of what can be done with the power produced. The nature of the IVF system is that it taps at most 25% of the total power which is available from the engine. The shaft power can used for any function in the nature of an auxiliary power unit. It can circulate fluids for cooling or hydraulic power and can drive much larger pumps than those described for the internal IVF use. Large boost pumps which raise the pressure of propellants entering the main engines can be directly driven by the IVF engine and such pumps can also be used to circulate propellants within the vehicle or between docked vehicles. Boost pumps can further minimize or eliminate the need for direct tank pressurization since they provide the main engine's required NPSP by direct application of work to the fluid. The electrical generation system can be augmented with multiple generators including those for higher voltage which supports the use of multiple or higher power electromechanical actuators for driving engine thrust vectoring or other uses. The IVF engine can be used on an intermittent basis in concert with solar power or fuel cell systems. These systems can be sized for average loads but the IVF engine can be activated when peak demands are expected such as prior to and during main engine burns. In this way these other systems can be reduced in mass and cost with an overall benefit to system performance.
[0047] Moreover, the entire IVF system can be placed in a safe condition and vented of gases if it is not needed. This is a common requirement for rendezvous and docking with crewed space stations. Unlike a hydrazine system which can at best isolate the remaining propellant with pyrotechnic valves, the IVF can dump the accumulators and render itself completely inert. The possibility of inadvertent operation of a thruster or engine is thus completely eliminated.
[0048] In a preferred embodiment, a modular design is provided for the integrated fluid system. More specifically all elements are mounted to a single common panel and share a single set of fluids and electronic interfaces to the main vehicle. The module in one embodiment would contain two opposing pairs of pitch thrusters, one pair of yaw thrusters, and a pair of axial or vehicle settling thrusters. The accumulators, being quite small, can be closely coupled to the thrusters and also the pressurization control valves with a minimum of intervening plumbing thus minimizing leak sources and component count. The internal combustion engine, starter/generator and all electronic controls can share a common radiation enclosure which enables thermal stabilization of the components in space within a band near room temperature. The combination of all these masses on a rigid, shock and vibration isolated panel suppresses the movement of vibration energy both to and from the module. The module can be completely inspected and validated prior to installation on the vehicle. In the event of a fault after installation, it can be readily removed and replaced as a unit. In the preferred embodiment, the module can be mounted on existing available space on the aft deck of the vehicle and because of its small size, no modifications are required to the existing vehicle.
[0049] In one embodiment two modules are required per vehicle to provide the requisite redundancy and performance margins. The configuration of thrusters is such that the thrusters within the two modules work in concert to achieve the proper roll, pitch and yaw maneuvers. Because the two modules are interconnected they can preserve overall system function even if a single or multiple components on one module are inoperative. For example the GO2 pump on one module can act to supply the oxygen to the thrusters on the other module and vice versa.
[0050] In accordance with methods of the invention, a number of functions are provided within an integrated fluid design. The methods provide various functions to include production of mechanical energy by an internal combustion engine that has an output shaft, and the generation of electrical power through an electrical starter/generator that communicates with the shaft of the engine. Electric current from the alternator may be stored in a battery.
[0051] Another function is sustained vehicle settling to drastically reduce propellant losses in the upper stage propellant tanks.
[0052] Another function includes a modular design for a plurality of thrusters that utilize waste ullage gas, the thrusters being arranged for both attitude and settling capabilities. The thrusters may utilize the hydrogen rich exhaust gas from the internal combustion engine or may be traditional combustion-type thrusters that burn the H2 and O2.
[0053] Another function includes propellant tank pressurization control by hydrogen and oxygen accumulators that are pressurized, and have pressurization lines routing back to the tanks to maintain the tanks at desired pressurization levels.
[0054] Another function is the replenishment of gases in the accumulators by the periodic flow of both waste gases in the ullage or by vaporizing liquid propellants via small pumps
[0055] Various other features and advantages of the system and methods will become apparent from review of the following detailed description, taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0056] FIG. 1 is a fragmentary perspective view of part of an upper stage of a space launch vehicle illustrating an IVF module mounted to the aft deck of the upper stage;
[0057] FIG. 2 is an enlarged perspective view of the IVF module;
[0058] FIG. 3 is a schematic diagram illustrating one aspect of the invention, namely, the provision of an internal combustion engine in the IVF system to produce mechanical power;
[0059] FIG. 4 is a cross-sectional schematic diagram of the ICE of the present invention, in the form of a Wankel engine;
[0060] FIG. 5 is another schematic diagram for another aspect of the invention, namely, the provision of electrical power;
[0061] FIG. 6A is another schematic diagram illustrating yet another aspect of the invention, namely, provision of a thruster assembly for sustained vehicle settling using exhaust gas from the ICE;
[0062] FIG. 6B is another schematic diagram for the aspect of FIG. 6A , but using ullage gases for powering the thruster assembly;
[0063] FIG. 7 is a simplified schematic diagram illustrating the port and starboard positioning of separate IVF modules for the upper stage of the vehicle;
[0064] FIG. 8 is a perspective view of an example construction for a thruster assembly including a panel to which the thrusters may be mounted, along with hydrogen and oxygen manifolds for delivery fluids to the thrusters;
[0065] FIG. 9 is a schematic diagram illustrating another aspect of the invention, namely, tank pressurization and vent;
[0066] FIG. 10A is a schematic diagram illustrating another aspect of the invention, namely, venting the propellant tanks directly through the thrusters;
[0067] FIG. 10B is a schematic diagram illustrating the aspect of FIG. 10A , but venting through the ICE;
[0068] FIG. 11 is schematic diagram illustrating another aspect of the invention, namely, accumulator replenishment;
[0069] FIG. 12 is a schematic diagram of one type of axial thruster, namely, exhaust gas thrusting;
[0070] FIG. 13 is a schematic diagram of another type of axial thruster, namely, one that combusts GH 2 and GO 2 ;
[0071] FIG. 14 is another schematic diagram illustrating basic functions of the IVF module; and
[0072] FIG. 15 is a system schematic illustrating the primary elements within the integrated fluid system and fluid connections between the elements in the system.
DETAILED DESCRIPTION
[0073] FIG. 1 illustrates the upper stage 10 of a space launch vehicle. The outer covering or shell 12 is broken away to view the propellant tanks 14 , which comprise the liquid hydrogen tank 60 and the liquid oxygen tank 62 with a common bulkhead separating the tanks. The aft of the vehicle includes a circumferential deck 16 that provides for mounting of various system components 20 such as avionics, fluid and mechanical devices as well as the IVF module 30 of the present invention. FIG. 1 also illustrates the main propulsion rockets 18 that are used to propel the upper stage 10 . In the Figure, the relatively small size of the IVF module 30 is shown. Preferably, there is an IVF module mounted on opposite sides of the aft deck 16 . Twin IVF modules are able to generate more than enough power to supply all of the upper stage system requirements, yet reduce overall vehicle weight by eliminating much of the wiring harness mass associated with traditional vehicles that use battery power. The elevated DC voltages that can be provided by the battery of an IVF module is also valuable for reducing EMA actuator mass. The particular vehicle 10 illustrated is a conceptual 41 ton propellant capacity upper stage. However, the IVF module of the present invention can be used with any type of upper stage vehicle that has at least some minimal space for mounting of exterior components.
[0074] Referring to FIG. 2 , an example is provided for an IVF module design. In this Figure, major structural components of the IVF module are illustrated to include a GO 2 accumulator 34 , a GH 2 accumulator 36 , and mounting straps 38 that can be used to mount the accumulators to a frame of the module. Lines 40 and 42 communicate with the accumulators 34 and 36 , and represent either vent, purge, or pressurization lines associated with the accumulators. A housing 44 is provided for the internal combustion engine (not shown), and a plurality of various other gas/liquid lines 50 are shown protruding from the frame for delivering gas or liquid throughout the system. A thruster group or assembly 46 is illustrated as another component of the module having a plurality of thrusters for settling and attitude control of the upper stage. As shown, the thruster assembly 46 includes a pair of axial thrusters 98 , two pairs of opposing pitch thrusters 94 , and a pair of yaw thrusters 96 . A vehicle battery 48 is also illustrated and is secured to the IVF module, the battery 48 being charged by a generator connected to the output shaft of the ICE as discussed below.
[0075] FIG. 3 illustrates one aspect or concept of the present invention, namely, the provision of a small internal combustion engine (ICE) 80 that is used to provide power for the upper stage systems. In a preferred embodiment, the size of the ICE 80 is approximately 200 cc, and runs at a preferred mixture ratio between 0.6 and 2.0. As shown in the Figure, ICE 80 receives its GH 2 fuel from the liquid hydrogen tank 60 by vent line 64 . The oxidizer, GO 2 , is provided by an oxygen accumulator 34 , through line 176 , and metered through valve 76 . The hydrogen vent line 64 communicates with a hydrogen intake mixture valve 72 that modulates the amount of hydrogen provided to the ICE. Depending upon demand, the ICE can also receive hydrogen through a dedicated hydrogen bleed line 66 that provides liquid hydrogen to the intake mixture valve 72 . The metered amount of hydrogen is then combusted with the oxygen within the ICE, thereby producing a mechanical output shown as shaft 82 . The exhaust gas from the ICE 80 is captured in exhaust line 84 that can be used for powering the axial thrusters as discussed below. The hydrogen vent line 64 would typically be used to dispose of waste ullage hydrogen gas. In the present invention; however, the waste ullage hydrogen is used to fuel the ICE. Optionally, the GH 2 carried by line 100 downstream of the valve 72 can be used to cool the engine exterior, maintain pressure in the crank case, and cool the internal rotor of the ICE.
[0076] Referring to FIG. 4 a particular construction is provided for the ICE 80 in the form of a Wankel engine. As illustrated, GO 2 is provided through line 176 , while the GH 2 is provided through line 100 downstream of the intake mixture valve 72 . The hydrogen is first circulated in a gap 92 between the engine block 90 and a cooling jacket 88 . As the low pressure GH 2 is circulated, it warms by heat transfer from the block 90 , and finally flows to the intake port 93 . Valve 104 can be used to meter the GH 2 flowing into the ICE. Once inside the engine, the hydrogen first enters the fuel intake chamber 108 . A solenoid injector valve 76 opens at the correct moment during the intake phase to inject the GO 2 . This injector also prevents GO 2 back flowing into the GH 2 system, and also controls the engine mixture ratio. As the rotor 114 rotates about the eccentric shaft 116 , the hydrogen and oxygen are then compressed with an area defined as the combustion chamber 110 . Spark plugs 102 provide the source of ignition for igniting the fuel within the combustion chamber 110 . The expansion of the gases in the combustion chamber provide the motive force for rotating the rotor 114 , thus moving the combusted gas to the portion of the engine defined as the exhaust chamber 112 . The high temperature, GH 2 rich and pressurized gas exits the exhaust port 118 into the exhaust line 84 . Although one will appreciate the simple, yet effective design for a Wankel engine incorporated in the IVF system of the present invention, it shall be understood that a standard piston engine (not illustrated) can also be used as the ICE 80 . The GO 2 and GH 2 are provided to the piston engine in the same manner as illustrated for the Wankel engine. More specifically, the GO 2 is provided through line 176 , while the GH 2 is provided through line 100 downstream of the intake mixture valve 72 . The hydrogen can be circulated in a gap between the engine block and cooling jacket of the piston engine. As the low pressure GH 2 is circulated, it warms by heat transfer from the block, and finally flows to a fuel intake port of the piston engine. Valve 104 can be used to meter the GH 2 flowing into the piston engine. Once inside the engine, the hydrogen is transferred to the cylinders. One or more injector valves can be used to inject the GO 2 into the cylinders for mixing with the GH 2 . Spark plugs 102 provide the source of ignition for igniting the fuel within the cylinders. The expansion of the gases upon ignition provide the motive force for rotating a crankshaft of the piston engine, and the combusted gases are evacuated from the cylinders to the portion of the engine defined as the exhaust chamber 112 . The high temperature, GH 2 rich and pressurized gas exits the exhaust port 118 into the exhaust line 84 .
[0077] Referring to FIG. 5 , in another aspect of the present invention, electrical power is provided by an electrical alternator 86 that is driven by the output shaft 82 powered by the ICE 80 . The alternator 86 in turn provides electrical current for charging a battery 48 . For IVF system pumping requirements to charge the accumulators as discussed below, power can be supplied either from the battery 48 , or power can be provided by the output shaft 82 to a clutch (not shown) connected to the accumulator pumps. The clutch can be engaged and disengaged to operate the pumps. As the vehicle operates, the battery 48 will discharge during peak loading requirements, but will recharge during vehicle coasts, i.e., those times during which power demands are low. The use of a charged battery 48 removes previous restrictions on peak power and total available energy that was a problem with prior launch vehicle systems in which power was limited to only battery power.
[0078] FIG. 6A is another schematic diagram illustrating another aspect of the invention, namely, sustained settling modes provided by the thruster assembly 46 . The thruster assembly as mentioned includes a pair of axial thrusters 98 that provide settling thrust. For long duration, low thrust settling, the high temperature, high pressure exhaust 84 can be used directly from the ICE to generate thrust 120 . However, the thrust 120 provided in this mode is limited by the peak mass flow through the engine and the allowable engine combustion temperature. Using the exhaust gas of the ICE is a very efficient method for sustained settling, since the ICE is normally operating to provide vehicle power and will rarely cease to operate for any extended period of time. Therefore, there is a constant flow of exhaust gas 84 that can be used for providing thrust. In another vehicle settling mode shown in FIG. 6B , settling thrust can be provided directly through the GH 2 ullage vent line 64 to the thruster assembly, with oxygen provided directly through the GO 2 ullage vent line 68 . These ullage gases are then combined and combusted in combustion chamber of the thrusters. The ullage gases provide more than sufficient fuel and oxidation material for running the axial thrusters.
[0079] Referring to FIG. 7 , a schematic diagram is provided showing that a pair of IVF modules 30 is used, each having the same construction, and mounted to opposite sides of the vehicle 10 when looking at the vehicle outer diameter in schematic cross section. The IVF modules 30 are generally illustrated showing the thruster assemblies 46 having the pitch thrusters 94 , yaw thrusters 96 , and axial thrusters 98 . The pair of IVF modules 30 provides redundancy without adding significant weight.
[0080] Referring to FIG. 8 , an example is provided for a specific thruster assembly construction. Specifically, a panel 140 can be used to mount the yaw thrusters 96 on one side of the panel, while the two pairs of pitch thrusters 94 can be mounted on the other side of the panel 140 . A hydrogen manifold 142 comprises a plurality of lines and fittings for carrying hydrogen to the thrusters, while an oxygen manifold 142 also comprises a plurality of lines and fittings for carrying oxygen to the thrusters. The axial thrusters 98 can also be mounted to the panel 140 , or may be mounted to a separate panel. It is noted that the particular thruster panel assembly shown in the FIG. 8 can be modified to allow the thrusters to conveniently fit within the space available on the mounting structure of the space vehicle. As compared to in the FIG. 2 , the FIG. 8 shows a different, yet functional arrangement for the thrusters.
[0081] Referring to FIG. 9 , yet another concept is illustrated with respect to the invention, namely, tank pressurization. As shown, both the LH 2 60 and LO 2 tanks 62 have respective pressurization lines. Specifically, an oxygen pressurization line 78 pressurizes the oxygen tank 62 , while the hydrogen pressurization line 79 pressurizes the hydrogen tank 60 . The accumulators 34 and 36 are maintained at an adequate pressure, and the tank pressurization controls 122 monitor and adjust pressurization. In this model, the accumulators supply all of the pressurization required for the propellant tanks to operate.
[0082] FIGS. 10 A and 10 AB illustrate yet another aspect of the invention, namely, tank venting. Referring to FIG. 10A in one tank venting mode, the propellant tanks can be directly vented through the axial thrusters 98 . The ullage gases are combined and combusted in the axial thrusters. As shown, the GH 2 vent line 64 and GO 2 vent line 68 both connect to the axial thrusters. The high thrust forces that can be generated with use of the ullage gases in this manner are very valuable to prevent vehicle shutdown caused by slosh of the LO 2 and GH 2 . This high thrust producing venting mode can be activated at any time to relieve pressure in the propellant tanks, as well as to provide on demand, additional thrust for settling and attitude control. Referring to FIG. 10B in a low flow venting mode, the GH 2 and the GO 2 demands from the ICE engine 80 are normally sufficient for relieving pressure in the propellant tanks to maintain them in optimal pressure conditions. The vent lines 64 and 68 provide the flow of GH 2 and GO2, respectively to the ICE 80 . The operation of the ICE 80 in this low venting mode provides continuous settling of the vehicle, and suppresses heating within the tanks to prevent boil off of the propellants.
[0083] Now referring to FIG. 11 , in accordance with another aspect or concept of the present invention, accumulator replenishment is illustrated. One fundamental concept of accumulator replenishment is that the accumulators 34 and 36 must be pressurized. Accordingly, pumps 134 and 135 are provided to pressurize the lines 153 and 152 that charge the accumulators 34 and 36 , respectively. Drive motors 132 and 133 drive the pumps 134 and 135 . The drive motors 132 and 133 may be powered by either the ICE 80 , or may be electrically powered by the battery 48 . A LO 2 bleed along with a GO 2 vent from tank 62 are controlled respectively by a liquid inlet valve 148 and ullage gas inlet valve 150 . In the FIG. 11 , these valves 148 / 150 are shown as a single block. These valves then meter the ullage gas or liquid oxygen through the pump 134 for ultimate delivery to the GO2 accumulator 34 . The outlet line 153 from the pump 134 carries the ullage gas/liquid oxygen in a heat exchange relationship through the thruster group 46 , functioning to extract heat as necessary from one or more of the thrusters in the assembly 46 . The line 153 then carries the gaseous oxygen to the accumulator 34 . The same arrangement is provided for hydrogen in which liquid hydrogen or GH 2 ullage are provided through the inlet control valves 149 / 151 , the pump 135 delivers the liquid/gaseous oxygen through outlet line 152 and in a heat exchanger relationship with the thruster group 46 . Line 152 then carries the gaseous hydrogen to the GH2 accumulator 36 . In summary, the motor driven pumps pressurize the ullage or liquid up to the necessary accumulator pressures. Liquid compression enables high pressure requiring only low shaft power from the drive motors 132 and 133 . Heat is selectively added as needed through the thruster group 46 to thereby deliver primarily GH2 and GO2 through the lines 152 and 153 , as most LH 2 and LO 2 will boil when coming in contact with the thruster group 46 .
[0084] Referring to FIGS. 12 and 13 , in another aspect of the invention, different types of axial thrusters are illustrated. Referring first to FIG. 12 , exhaust gas thrusting is illustrated. The exhaust 84 from the ICE 80 communicates with one or more inlet ports 160 of a thruster 98 . The GH 2 rich exhaust gas at high temperature is then routed through internal passageways 162 of the thruster to the aft or rear end 164 of the thruster. At that point, the high temperature and pressurized gas is vented through one or more openings 168 into a first smaller chamber 168 , through a nozzle or restriction 170 , and then is allowed to expand within the cowl 172 . The thrust is provided by the expanding gas as it passes through the nozzle 170 into the cowl 172 . Therefore, efficient means are provided for axial thrusting by simply utilizing the exhaust gas from the ICE 80 . Although the axial thruster 98 is illustrated, it is also contemplated that the exhaust gas 84 can be used to power any of the other thrusters.
[0085] Referring to FIG. 13 , another type of thruster is illustrated in which ullage GH 2 is combined with ullage GO 2 and then combusted to create gas expansion and production of thrust. More specifically, one or more ullage gas inlets 180 are provided for receiving ullage GH 2 , such as through vent line 64 . Similarly, oxygen can be provided through GO 2 vent line 68 . The GH 2 flows through passageways 182 to cool the thruster, and through openings 184 to join the GO 2 in the combustion chamber 188 . An ignition source (not shown) ignites the GO 2 and GH 2 , resulting in an expansion of gas through nozzle 190 into the cowl 192 . FIG. 13 also shows the heat exchange that can occur with the liquid or gaseous propellants carried in the lines 152 / 153 . As shown, a simple heat exchanger 198 is illustrated as a jacket that allows flow of the propellants over the exterior of the thruster to absorb heat from the thruster. The propellants are then carried downstream to the respective accumulators.
[0086] Referring to FIG. 14 , a system overview is provided showing the basic functions of the IVF system. In general, the IVF system provides functions to include attitude control, sustained settling, tank pressurization, and a power supply. The ICE 80 provides power for an alternator 86 to generate current to be stored by the battery 48 . The ICE 80 can also provide power to the drive motors 132 and 133 for powering the oxygen and hydrogen pumps 134 and 135 in order to pressurize the accumulators 34 and 36 . The accumulators store GO 2 and GH 2 at high pressures, and provide the source of high pressure to pressurize the propellant tanks. Tank pressurization controls 122 monitor and maintain the LH 2 tank 60 and LO 2 tank 62 at the proper pressures. The exhaust gas 84 from the ICE 80 can be used to drive the axial settling thrusters 98 . Alternatively, ullage gas, supplemented with liquid hydrogen under peak demands, provides sustained settling thrust that greatly reduces losses in the tanks. The ICE 80 as well as the settling thrusters 98 can be cooled from the waste ullage gases by first passing the gases in a heat exchange relationship prior to combustion. The ICE 80 and the battery 48 work together to share power demands. Specifically, power boosts can be easily provided by changing the fuel mixture ratio for the ICE in order to either more quickly charge the battery 48 or to provide the necessary mechanical power for other vehicle systems.
[0087] Referring to FIG. 15 , a schematic system diagram is provided with a more detailed view of a plumbing schematic showing the system components and manner in which they are interconnected. More specifically, an IVF module 30 is shown with components, and the general piping connections between the components. The additional IVF module 30 shown on the right side of the diagram within the dotted lines has the same piping configuration as the fully illustrated IV module on the left side of the figure, but for clarity, the piping configuration is not shown for the right side IVF module.
[0088] Referring to the schematic diagram of FIG. 15 , the various vent, purge, and bleed lines/elements are illustrated as they communicate with the propellant tanks. As also discussed in part with reference to the prior Figures, these vent, purge and bleed lines include hydrogen vent 64 , hydrogen pressurization 79 , GH 2 bleed 131 , H 2 purge 137 , LH 2 bleed 66 , GO 2 vent 68 , GO 2 pressurization 78 , and LO 2 bleed 70 .
[0089] For the axial thrusters 98 , the schematic diagram shows the heat exchangers 198 that receive the pressurized gas/liquid through the lines 152 / 153 that are pressurized by the pumps 134 and 135 . Bypass valves 196 allow the fluid/gas to be delivered directly to the accumulators without passing through the heat exchangers 198 . As shown, only one of the axial thrusters 98 communicates with the exhaust line 84 for receiving the GH 2 rich heated gas, while both of the axial thrusters are shown as being capable of operating as combustion type thrusters in which lines carry the ullage GO 2 and GH 2 to the axial thrusters for combustion.
[0090] For the pitch and yaw thrusters, these are preferably combustion type thrusters, each receiving GH 2 and GO 2 from the accumulators as shown. Specifically, pitch thrusters 94 and yaw thrusters 96 receive GO 2 from line 176 that connects directly to the GO 2 accumulator 34 , and thrusters 94 and 96 receive GH 2 fuel from lines 174 that connect directly to the GH 2 accumulator 36 .
[0091] As also discussed previously, the combination of vent and bleed lines from the LH 2 and LO 2 tanks provide fuel and an oxidizer to the ICE 80 that produces power for the vehicle. FIG. 15 also shows a supplemental method of providing oxidizer to the ICE 80 by inducting oxygen directly into the ICE 80 from the LO 2 tank ullage instead of from the accumulator 34 and through the injector 76 . Specifically, FIG. 15 shows the supplemental method by an extension of the LO 2 bleed line 70 that connects directly to another intake port of the ICE 80 . A throttle valve 71 connected inline can be used to meter the LO 2 into the ICE 80 at a desired rate. One advantage of this supplemental method is that the ICE 80 can be operated without having to operate any system pumps.
[0092] The attitude and settling thrusters operate with combustion of the propellants, or at least one of the thrusters can produce thrust by using the exhaust gas from the ICE. The accumulators are pressurized, and control pressures in the propellant tanks. The IVF module is small, but can produce power and thrust to service all of the vehicles needs in these requirements.
[0093] While the present invention has been explained and illustrated with respect to various functional features or aspects in one or more preferred embodiments, it shall be understood that the invention can be modified, commensurate with the scope of the claims appended hereto. Further, it should be understood that each of the different concepts or aspects of the invention can be considered as having separate utility. Accordingly, the invention comprises a number of separate sub-combinations and combinations that have utility with respect to supporting the functions of an upper stage space vehicle. | A system and methods are provided for combining systems of an upper stage space launch vehicle for enhancing the operation of the space vehicle. Hydrogen and oxygen already on board as propellant for the upper stage rockets is also used for other upper stage functions to include propellant tank pressurization, attitude control, vehicle settling, and electrical requirements. Specifically, gases from the propellant tanks, instead of being dumped overboard, are used as fuel and oxidizer to power an internal combustion engine that produces mechanical power for driving other elements including a starter/generator for generation of electrical current, mechanical power for fluid pumps, and other uses. The exhaust gas from the internal combustion engine is also used directly in one or more vehicle settling thrusters. Accumulators which store the waste ullage gases are pressurized and provide pressurization control for the propellant tanks. The system is constructed in a modular configuration in which two redundant integrated fluid modules may be mounted to the vehicle, each of the modules capable of supporting the upper stage functions. | 5 |
TECHNICAL FIELD
The invention proceeds from a procedure to operate an internal combustion engine, in whose exhaust gas section, a NO x sensor is disposed downstream after the SCR catalytic converter; and from a device to implement the procedure according to the class of the independent claims.
BACKGROUND
In the German patent DE 199 03 439 A1 a procedure and a device to operate an internal combustion engine are described, in whose exhaust gas section a SCR catalytic converter (Selective Catalytic Reduction) is disposed, which reduces the nitrogen oxides contained in the exhaust gas of the internal combustion engine to nitrogen using a reagent substance. The metering of the reagent substance is carried out preferably as a function of the operating parameters of the internal combustion engine, such as, for example, the engine rotational speed and the amount of fuel injected. Furthermore, the metering is carried out preferably as a function of the exhaust gas parameters, such as, for example, the exhaust gas temperature or the operating temperature of the SCR catalytic converter.
Provision is made, for example, for ammonia to be the reducing agent, which is derived from a urea water solution. The dosage of the reagent substance or of the source materials of the reagent substance must be carefully established. A dosage which is too small has the consequence that the nitrogen oxides in the SCR catalytic converter can no longer be completely reduced. Too large of a dosage leads to a slip of the reagent substance, which on the one hand can lead to an unnecessarily large consumption of the reagent substance, and on the other hand as a function of the composition of the reagent substance can lead to an unpleasant odor.
In the German patents DE 199 60 731 A1 and DE 199 62 912 A1, NO x , sensors are described in each case, in which provision is made for the acquisition of the NO x concentration present in an exhaust gas flow. The NO x sensors contain multiple chambers, which are connected to each other via diffusion barriers. The known multiple chamber NO x sensors have as a result of the measuring principle a cross sensitivity with regard to ammonia (NH3). For example as a reagent substance, the ammonia contained in the exhaust gas leads to a falsification of the sensor signal by way of the reactions 4 NHS+5O2→4NO+6H2O. If an increase of the reagent substance dosage thus occurs during the previously known procedural approaches, the sensor signal will increase when an excess dosage or a correct dosage of the reagent substance exists due to the reagent substance slip which arises; and when an underdosage of the reagent substance exists due to the increasing NO x conversion, the sensor signal will drop out. If on the other hand the reagent substance dosage is lowered, the sensor signal will drop out if an excess dosage of the reagent substance exists due to the decreased reagent substance slip; and the sensor signal will increase when a correct dosage or an underdosage of the reagent substance exists due to the NO x conversion, which is no longer complete.
In the German patent DE 10 2004 046 640 A1, a procedure to operate an internal combustion engine and a device to implement the procedure are described, in which a NO x sensor with a cross sensitivity with regard to a reagent substance is disposed downstream after the SCR catalytic converter. At least one SCR catalytic converter, which is impinged with a reagent substance, is disposed in the exhaust gas section. The reagent substance contributes to the NO x conversion in the SCR catalytic converter. Provision is made for the calculation of at least one measurement for the NO x concentration arising downstream after the SCR catalytic converter. This calculation makes an increase in accuracy when establishing a dosage of the reagent substance possible.
A reagent substance slip can be ascertained from the difference between the calculated measurement for the NO x concentration and the measured quantity for the sum of the NO x concentration and the reagent substance concentration. The fact is taken into account that a reagent substance slip as well as an insufficient NO x reducing reaction causes a deviation in the same direction between the calculated measurement for the NO x concentration and the measured quantity for the sum of the NO x concentration and the reagent substance concentration. According to one embodiment the dosage of the reagent substance is initially reduced when a difference as mentioned above occurs. If a reagent substance slip were present, the reduction of the dosage of the reagent substance would lead to a reduction of the reagent substance slip. The reduction of the dosage of the reagent substance proved in this case to be the correct step. If too small a dosage of the reagent substance were originally present, the difference ascertained would continue to increase due to a small NO x , conversion, so that it could be suggested from this, that the reduction of the reagent substance was false and an increase of the dosage is to be conducted instead.
In the German patent DE 10 2004 031 624 A1, a procedure is described to operate a SCR catalytic converter used to purify the exhaust gas of an internal combustion engine, in which provision is made for an open-loop or closed-loop adjustment of the reagent substance fill level in the SCR catalytic converter to a specified storage set point. The targeted specification of the storage set point secures on the one hand that during transient states of the internal combustion engine, a sufficient amount of the reagent substance is available to remove the NO x emissions of the internal combustion engine before the SCR catalytic converter as completely as possible; and that on the other hand, a reagent substance slip is avoided.
The reagent substance fill level of the SCR catalytic converter is ascertained using a catalytic converter model, which takes into account the NO x mass flow entering into the SCR catalytic converter, the NO x mass flow departing the SCR catalytic converter, the temperature of the catalytic converter as well as if need be the reagent substance slip. The maximum possible reagent substance fill level of the SCR catalytic converter depends especially on the operating temperature of the SCR catalytic converter, which is the highest at low operating temperatures and drops off to lower values with an increasing operating temperature. The efficiency of the SCR catalytic converter depends on the catalytic activity; which is small at low operating temperatures, passes through a maximum with a rising operating temperature and drops off again when the operating temperature continues to rise.
The task underlying the invention is to indicate a procedure to operate an internal combustion engine, in whose exhaust gas section a SCR catalytic converter and a NO x sensor located downstream after the SCR catalytic converter are disposed, as well as a device to implement the procedure, which allows for the most optimal as possible result for the purification of the exhaust gas simultaneously with a minimal reagent substance slip.
The task is solved in each case by the characteristics indicated in the independent claims.
SUMMARY OF THE INVENTION
The procedure according to the invention to operate an internal combustion engine assumes that at least one SCR catalytic converter is disposed in the exhaust section of the internal combustion engine. The SCR catalytic converter is impinged with a reagent substance, which contributes to the NO x conversion in the SCR catalytic converter. Downstream after the catalytic converter, a NO x catalytic converter is disposed, which provides a sensor signal, which reflects at least a measurement for the NO x concentration in the exhaust gas downstream after the catalytic converter. At least one measurement is additionally calculated for the NO x concentration arising downstream after the SCR catalytic converter. The difference is ascertained between the calculated measurement for the NO x concentration and the measured NO x concentration. A reagent substance signal, which establishes the dosage of the reagent substance, is not only affected by a correction signal as a function of the ascertained difference, but additionally as a function of a measurement for the temperature of the SCR catalytic converter.
When establishing the dosage of the reagent substance, the procedural approach according to the invention takes into account the temperature of the SCR catalytic converter, which has an affect on the storage capability of the reagent substance in the SCR catalytic converter. A change of the reagent substance signal, which is required if necessary, is thereby adapted to the temperature dependent storage capability of the reagent substance in the catalytic converter. With this step, an excess dosage of the reagent substance, which arises contingent on a change of the reagent substance and would lead to an increased reagent substance slip, as well as an underdosage of the reagent substance, which would lead to and increased NO x impact on the environment, is avoided in each case.
The procedural approach according to the invention can be implemented with simple and cost effective means so that merely a NO x sensor disposed downstream after the SCR catalytic converter is required, which if need be has an inherently undesirable cross sensitivity with regard to the reagent substance. This cross sensitivity is specifically utilized within the scope of an embodiment of the procedural approach according to the invention.
Advantageous modifications and embodiments of the procedural approach according to the invention result from the dependent claims.
Provision is made in one embodiment for the correction signals to be deposited as a function of the difference and of the measurement for the temperature of the SCR catalytic converter in a characteristic diagram, which supplies a selected correction signal.
Provision is made in one embodiment for the reagent substance signal to be established as a function of the reagent substance fill level in the SCR catalytic converter. Provision is made in a modification of this embodiment for the reagent substance signal to be indirectly affected by way of a manipulation of the reagent substance fill level in the SCR catalytic converter. Preferably the reagent substance fill level in the SCR catalytic converter is regulated in a closed-loop to a specified reagent substance set point fill stand.
Provision is made in one embodiment for the temperature of the SCR catalytic converter and the reagent substance fill level in the SCR catalytic converter and/or the space velocity of the exhaust gas in the SCR catalytic converter to be taken into account along with the NO x emissions before the SCR catalytic converter when calculating the NO x concentration arising downstream after the SCR catalytic converter. In so doing, a high degree of accuracy is achieved.
Provision is made in an additional embodiment for the specified reagent substance set point fill level to be established at least at a maximum value, which corresponds to an SCR catalytic converter completely filled with the reagent substance. This embodiment has advantages in connection with an additional embodiment, in which provision is made for the NO x sensor to have a cross sensitivity with regard to the reagent substance. The cross sensitivity can thereby specifically be taken advantage of; in that when a difference occurs, initially a manipulation of the reagent substance signal is continuously conducted for the purpose of reducing the dosage of the reagent substance. This takes place because the difference reflects a reagent substance slip with a high degree of probability.
The device according to the invention to operate an internal combustion engine concerns initially a control unit, which is designed to implement the procedure. The control unit especially contains a difference ascertainment, which ascertains the difference between the exhaust gas sensor signal provided by the NO x sensor and the NO x concentration downstream after the SCR catalytic converter, which is calculated by a NO x concentration ascertainment. Provision is additionally made for the control unit to contain a characteristic diagram, which provides a correction signal for the manipulation of the reagent substance signal and in which the correction signals are deposited at least as a function of the difference and as a function of the measurement for the temperature of the SCR catalytic converter.
The control unit preferably contains an electrical storage memory, in which the procedural steps are filed as a computer program.
Additional advantageous modifications and embodiments of the procedural approach according to the invention result from additional dependent claims and from the following description.
BRIEF DESCRIPTION OF THE DRAWING
The FIGURE shows a technical environment, in which the procedure according to the invention is operating.
DETAILED DESCRIPTION
The FIGURE shows an internal combustion engine 10 , in whose air intake section 11 , an air ascertainment 12 is disposed; and in whose exhaust gas section 13 , a reagent substance metering 14 , a first NO x sensor 15 , an SCR catalytic converter 16 , a temperature sensor 17 assigned to the SCR catalytic converter 16 as well as a second NO x sensor 18 are disposed.
An exhaust gas flow ms_abg as well as an untreated NO x concentration NO x — vK arises downstream after the internal combustion engine 10 . A NO x concentration NO x — nK as well as a reagent substance slip ms_Rea_nK arises downstream after the SCR catalytic converter 16 .
The air ascertainment 12 provides an air signal ms_L to a control unit 20 ; the internal combustion engine 10 provides an engine rotational speed signal n; the first NO x sensor 15 provides a first NO x signal NO x — vK_mess; the temperature sensor 17 provides a measurement for the temperature te_Kat of the SCR catalytic converter 16 ; and the second NO x sensor 18 makes an exhaust gas sensor signal S_nK available to the control unit 20 .
The control unit 20 provides a fuel signal m_K to a fuel metering device 25 assigned to the internal combustion engine 10 as well as a reagent substance signal S_Rea to the reagent substance metering 14 and to the fuel metering device 25 .
The control unit 20 contains a torque ascertainment 30 , which is provided with the air signal ms_L, the engine rotational speed signal n as well as a torque set point MFa and which ascertains a torque Md of the internal combustion engine 10 .
The control unit 20 additionally contains an untreated NO x concentration ascertainment 31 , which is provided with the air signal ms_L, the engine rotational speed signal n as well as the fuel signal m_K and which ascertains a calculated measurement NO x — vK_mod of the untreated NO x concentration before the SCR catalytic converter NO x — vK.
The control unit 20 further contains a NO x concentration ascertainment 32 , which is provided with the calculated measurement NO x — vK_mod for the untreated NO x concentration before the SCR catalytic converter NO x — vK, the measurement for the temperature te_Kat of the SCR catalytic converter 16 , a space velocity RG as well as a reagent substance fill level ReaSp in the SCR catalytic converter 16 , and which ascertains a calculated measurement NO x — nK_mod for the NO x concentration NO x — nK downstream after the SCR catalytic converter 16 .
The calculated measurement NO x — nK_mod for the NO x concentration NO x — NK and the exhaust gas sensor signal S_nK are provided to a first difference ascertainment 33 , which ascertains a difference D. The difference D as well as the measurement for the temperature te_Kat is provided to a characteristic diagram 34 , which provides a correction signal d_ReaSp, which is supplied to a first summing amplifier 35 .
The first summing amplifier 35 ascertains a reagent substance actual fill level ReaSp_Ist from the correction signal d_ReaSp and the reagent substance fill level ReaSp. The reagent substance actual fill level ReaSp_Ist is provided to a second difference ascertainment 36 , which ascertains a control deviation 37 from the reagent substance actual fill level ReaSp_Ist and a reagent substance set point fill level ReaSp_Soll. A closed-loop controller 38 ascertains a regulating variable 39 from the control deviation 37 . This regulating variable 39 is provided to a second summing amplifier 40 , which adds a reagent substance pilot variable S_Rea_VS to the regulating variable 39 and which provides a reagent substance signal S_Rea.
The reagent substance pilot variable S_Rea_VS is provided by a pilot value ascertainment 41 , which ascertains the reagent substance pilot variable S_Rea_VS from the torque Md and the engine rotational speed signal n.
The reagent substance signal S_Rea is provided to a catalytic converter model 42 , which continues to obtain the untreated NO x , concentration before the SCR catalytic converter NO x — vK, the NO x concentration after the SCR catalytic converter NO x — nK, the measurement for the temperature te_Kat of the SCR catalytic converter 16 and the reagent substance slip ms_Rea_nK. The catalytic converter model 42 supplies the reagent substance fill level ReaSp.
The procedure according to the invention works as follows:
The torque ascertainment 30 disposed in the control unit 20 ascertains the torque Md generated by the internal combustion engine 10 as a function of at least the specified torque set point MFa, which, for example, is provided by an unspecified accelerator pedal of a motor vehicle, in which the internal combustion engine 10 is disposed as the power source. The torque Md is at least approximately a measurement for the load of the internal combustion engine 10 . When ascertaining the torque Md, the engine rotational speed signal n and/or the air signal ms_L supplied by the air acquisition 12 can continue to be taken into account.
The control unit 20 transmits the fuel signal m_K, which is established especially on the basis of the torque, to the fuel metering device 25 . The fuel signal m_K establishes, for example, a fuel point of injection as well as an injected quantity of fuel.
The fuel combusted in the internal combustion engine 10 leads to the exhaust gas flow ms_abg, which can contain the undesirable, more or less large, untreated NO x concentrations before the SCR catalytic converter NO x — vK as a function of the operating point of the internal combustion engine 10 .
At least the SCR catalytic converter 16 is disposed in the exhaust gas section 13 of the internal combustion engine 10 for the most extensive as possible removal of the untreated NO x concentration before the SCR catalytic converter NO x — vK. Beside the SCR catalytic converter 16 , provision can be made for additional catalytic converters and/or a particle filter. The SCR catalytic converter 16 supports the reducing reaction of the NO x with a reagent substance, which is either metered into the exhaust gas section 13 with the reagent substance metering 14 and/or if need be is supplied within the motor. Provision can be made for a source material instead of the reagent substance. In the case of the reagent substance ammonia, provision can be made, for example, for a urea-water solution or, for example, for ammonium carbamate to be the source material. The dosage is established with the reagent substance signal S_Rea, which is provided to the reagent substance metering 14 . Alternatively or additionally, when the reagent substance is supplied by the engine internally, the fuel signal m_K can be modified by the reagent substance signal S_Rea in such a way that the required amount of reagent substance is generated internally.
After starting the procedure according to the invention, the establishment of the reagent substance set point fill level ReaSp_Soll occurs at the specified reagent substance fill level ReaSp_Soll, which, for example, can be established at a value, which lies under the maximum possible reagent substance fill level in the SCR catalytic converter 16 if a reagent substance slip ms_Rea_nK is to be avoided if possible in all operating states. Provision is made in contrast in an advantageous embodiment for the specified reagent substance set point fill level ReaSp_Soll to correspond to the maximum possible reagent substance fill level in the SCR catalytic converter 16 , which is dependent on the temperature te_Kat in the SCR catalytic converter 16 . The correlation is described in detail in the German patent DE 10 2004 031 624 A1 mentioned at the beginning of the application, which is hereby referred to in its entirety.
The establishment of the reagent substance set point fill level ReaSp_Soll can also be accomplished at a value higher than the maximum value, so that in this case a reagent substance slip ms_Rea_nK, which at least is very small, has to always be anticipated. The important advantage of establishing the reagent substance set point fill level ReaSp_Soll at least the maximum value or at a higher value, which can only exist as an operand, lies with the fact that the SCR catalytic converter 16 is constantly operated in the range of its maximum efficiency, at which the highest possible NO x conversion takes place. In all of the operating states of the internal combustion engine 10 as well as the SCR catalytic converter 16 and within all of the parameters of the exhaust gas in the exhaust gas section 13 , assurance is made for the NO x concentration after the SCR catalytic converter NO x — nK to have the minimum possible value. A reagent substance slip ms_Rea_nK occurring at least occasionally must be taken for granted. Provided the reagent substance set point fill level ReaSp_Soll is established at a value higher than the maximum value, a small reagent substance slip ms_Rea_nK always occurs.
The reagent substance fill level ReaSp in the SCR catalytic converter 16 can be set by an open loop control to a specified reagent substance set point fill level ReaSp_Soll. Provision is preferably made for a closed-loop controlled setting to the specified reagent substance set point fill level ReaSp_Soll. In the second difference ascertainment 36 , the reagent substance set point fill level ReaSp_Soll is compared with the reagent substance actual fill level ReaSp_Ist. The second difference ascertainment 36 develops a difference, which is fed to the closed-loop controller 38 as a control deviation 37 . The closed-loop controller 38 then ascertains the regulating variable 39 . The regulating variable 39 is added to the preferably already existing reagent substance pilot variable S_Rea_VS in the second summing amplifier 40 .
The reagent substance pilot variable S_Rea_VS can specify, for example, a base amount of the reagent substance to be metered as a function of the operating parameters of the internal combustion engine 10 . In the pilot variable ascertainment 41 , the torque Md as well as the engine rotational speed signal n is, for example, taken into account. This procedural approach allows for a comparatively easy application.
The regulating variable 39 , which if necessary is combined with the existing reagent substance pilot variable S_Rea_VS, establishes the reagent substance signal S_Rea, which is fed to the reagent substance metering 15 and/or the fuel metering device 25 . The reagent substance signal S_Rea enables, for example, a cross section of a valve to open, which corresponds to a specified reagent substance flow, which additionally depends on the reagent substance pressure.
The catalytic converter model 42 ascertains the reagent substance fill level ReaSp using the reagent substance signal S_Rea while taking into account the untreated NO x concentration before the SCR catalytic converter NO x — vK, the NO x concentration after the SCR catalytic converter NO x — nK as well as the measurement for the temperature te_Kat of the SCR catalytic converter 16 . The reagent substance slip ms_Rea_nK is if need be additionally taken into account. The catalytic converter model 42 is described in the aforementioned State of the Art, to which reference is again made at this point.
Provision is made to ascertain the calculated measurement NO x — nK_mod for the NO x concentration after the SCR catalytic converter NO x — nK. The calculation takes place in the NO x concentration ascertainment 32 on the basis of the calculated measurement NO x — vK_mod for the untreated NO x concentration before the SCR catalytic converter NO x — vK, which the untreated NO x concentration ascertainment 31 supplies on the basis of, for example, the torque Md and/or the engine rotational speed signal n. The NO x concentration ascertainment 32 ascertains a degree of efficiency for the SCR catalytic converter 16 using the measurement for the temperature te_Kat, which the temperature sensor 17 provides. The temperature sensor 17 can be disposed before, in or downstream after the SCR catalytic converter 16 , so that the sensor signal supplied by the temperature sensor 17 is at least approximately a measurement for the temperature te_Kat of the SCR catalytic converter 16 . Provision can also be made for an estimate of the temperature te_Kat of the SCR catalytic converter 16 instead of a temperature measurement.
Preferably the exhaust gas space velocity RG is additionally taken into account in the NO x concentration ascertainment 32 . The exhaust gas space velocity RG can be ascertained from the known geometric data of the SCR catalytic converter 16 and from the exhaust gas flow ms_abg. Additionally, the reagent substance fill level ReaSp in the SCR catalytic converter 16 is taken into account because the degree of efficiency also especially depends on the reagent substance fill level ReaSp.
The measurement NO x — nK_mod calculated by the NO x concentration ascertainment 32 for the NO x concentration after the SCR catalytic converter NO x — nK is subtracted from the exhaust gas sensor signal S_nK in order to obtain the difference D. A difference D, which occurs, can be taken into account in the metering strategy, and the reagent substance signal S_Rea can be manipulated accordingly.
When the correction signal d_ReaSp is being supplied, the measurement for the temperature te_Kat of the SCR catalytic converter is furthermore taken into account along with the difference D. The required correction signals d_ReaSp are deposited in the characteristic diagram 34 at least as a function of the difference D and as a function of the measurement for the temperature te_Kat of the SCR catalytic converter 16 . The characteristic diagram 34 is addressed as a function at least of both parameters and emits the correction signal d_ReaSp corresponding to the deposited value. Within the scope of the patent application, the characteristic diagram 34 is provided with at least pairs of variates; whereby when the difference D is constant at higher temperatures te_Kat, the dosage of the reagent substance is to be reduced by a slight degree lower than the dosage at lower temperatures te_Kat. Correspondingly when the difference D is constant at higher temperatures te_Kat, the reagent substance fill level ReaSp is to be increased by a slight degree than is the case at lower temperatures.
The correction signal d_ReaSp could immediately be pulled up to influence the reagent substance signal S_Rea. In the example of embodiment depicted, the reagent substance signal S_Rea is indirectly affected by an intervention into the reagent substance fill level ReaSp, whereby the correction signal d_ReaSp manipulates the reagent substance actual fill level ReaSp_Ist in the SCR catalytic converter 16 . The reagent substance fill level ReaSp calculated from the catalytic converter model 42 is acted upon by the correction signal d_ReaSp, so that the reagent substance actual fill level ReaSp is modified. Provided that a difference D corresponding to a reagent substance slip ms_Rea_nK occurs, an increase in the reagent substance actual fill level ReaSp_Ist, for example, results, which due to the closed-loop control consequently elicits a degradation of the reagent substance signal S_Rea.
It is possible in principle to acquire the NO x concentration NO x — nK after the SCR catalytic converter with a NO x sensor and to acquire the reagent substance slip ms_Rea_nk with a reagent substance sensor. The utilization of an existing cross sensibility of the second NO x sensor 18 with regard to the reagent substance is, however, particularly advantageous or a targeted development of such a cross sensibility. In this case, the exhaust gas sensor signal S_nK reflects the sum of the reagent substance slip ms_Rea_nK and the NO x concentration after the SCR catalytic converter NO x — nk. A difference D, which occurs, could mean for that reason that either a reagent substance slip ms_Rea_nK or a high NO x concentration after the SCR catalytic converter NO x nK has occurred. Discrimination between the two would not be possible in this operating state. If according to the advantageous embodiment the reagent substance set point fill level ReaSp_Soll in the SCR catalytic converter 16 is established to the maximum possible value, it can thereby be assumed that an overdosage of the reagent substance exists, which corresponds to a reagent substance slip ms_Rea_nK. Provision is made for the closed-loop control in the example of embodiment depicted, so that the reagent substance slip ms_Rea_nK either only occurs for a short time or in the case of a continuous overdosing of the reagent substance is limited to a small amount. | invention relates to a method for operating an internal combustion engine, in the exhaust gas section of which is arranged at least one SCR catalytic converter, which is hit with a reagent that contributes to NO x conversion in the SCR catalytic converter, and to a device for implementing the method. At least one measure is calculated for the NO x concentration downstream after the SCR catalytic converter. An NO x sensor, which is arranged downstream after the SCR catalytic converter, generates an exhaust gas sensor signal which corresponds to at least the NO x concentration and optionally, as a result of cross sensitivity, to a reagent slip. A reagent signal, which determines the dosage of reagent, is influenced by a correction signal as a function of the difference and as a function of a measure for the temperature of the SCR catalytic converter. | 8 |
RELATED APPLICATIONS
[0001] The present application is related to U.S. Pat. No. 4,568,901, issued Feb. 4, 1986, included by reference herein.
[0002] The present application is related to U.S. Pat. No. 4,808,306, issued Feb. 28, 1989, included by reference herein.
[0003] The present application is a continuation-in-part application of United States provisional patent application, Ser. No. 5129382, filed Jul. 14, 1992, included by reference herein and for which benefit of the priority date is hereby claimed.
[0004] The present application is related to U.S. Pat. No. 5,637,226, issued Jun. 10, 1997, included by reference herein.
[0005] The present application is related to U.S. Pat. No. 5,943,998, issued Aug. 31, 1999, included by reference herein.
[0006] The present application is related to U.S. Pat. No. 6,971,409, issued Dec. 6, 2005, included by reference herein.
[0007] The present application is related to U.S. Pat. No. 4,572,145, issued Feb. 25, 1984, included by reference herein.
[0008] The present application is related to U.S. Pat. No. 5,124,045, issued Jun. 23, 1992, included by reference herein.
[0009] The present application is related to U.S. Pat. No. 5,359,979, issued Nov. 1, 1994, included by reference herein.
[0010] The present application is related to U.S. Pat. No. 5,816,227, issued Oct. 6, 1998, included by reference herein.
[0011] The present application is related to U.S. Pat. No. 6,890,432, issued May 10, 2005, included by reference herein.
[0012] The present application is a continuation-in-part application of United States provisional patent application, Ser. No. 7,004,153, filed Feb. 28, 2006, included by reference herein and for which benefit of the priority date is hereby claimed.
FIELD OF THE INVENTION
[0013] The present invention relates to fuel treatment and enhancement devices and, more particularly, to magnetic hydrocarbon treatment devices and methods.
BACKGROUND OF THE INVENTION
[0014] Hydro carbon fuels lack stability and the variability of the stability of these hydrocarbon fuels fluctuates due to storage conditions, refining methods, transportation methods, as well as environmental conditions resulting in a clustering of molecules. As the clustering of molecules increases the burn ability of the fuels decreases. Fuel efficiency drops, maintenance issues increase and an over all lack of efficiency besets the systems using these fuels as their energy source. Some of this activity is compounded through introduced bio-organisms such as bacteria, molds, fungus and other microbial activity. But much of it is the result of a polymerization and agglomerations of the organic compounds in the hydro carbon fuels. The problem has been on how to prevent and or correct these issues and stabilize the fuels until they can be burned.
[0015] Early users of these and similar fuels were not faced with the issues of today such as very high cost and shortage of resource coupled with environmental issues concerning the emission of dangerous and harmful toxins and chemicals into the atmosphere. People were both unconcerned and unaware of the health consequences that were caused by these emissions and until recently they were unaware of the additional maintenance costs resulting from the pollution of other electronic systems and even the cleaning of buildings from the discoloration effect that these emissions caused. There are both primary and secondary negative circumstances caused by the volume of emissions created by the burning of hydrocarbon fuels.
[0016] Today's economy and environmental concerns and costs do not permit operation of hydrocarbon systems as they have in the past.
[0017] A great many methods have been tried to reduce the problems previously mentioned. They include magnetic devices of varying configurations, filters of all types, flue scrubbers that clean or collect exhaust emissions or at least part of the particulates that otherwise would be sent into the atmosphere causing pollution of various sorts. Other solutions include fuel additives, blending of various combinations of fuels and additives temperature treatments and other more novel methods.
[0018] The search for solutions is ongoing and properly so since no one perfect solution has yet been found. Improvement in this area is ongoing in the attempt to find ever better ways to improve fuel efficiency while reducing combustion emissions and their hazards.
[0019] Other systems such as flue scrubbers are very expensive to install and maintain and yet again there is the issue of the particulates they have collected and how to deal with their disposal. This creates a condition where costs rise and pollution issues have been deferred rather than reduced.
[0020] Some of the others such as catalytic converters eliminate the problems of pollution and reduce fuel costs but their installation is expensive and limited in scope. They are not suitable for most after market or retro fit situations so do not address the billions of tons of fuels currently being consumed in devices that are not fitted with them. More over none of these mechanical devices actually treats the fuel before it is burned to increase the fuels efficiency and reduce its emissions.
[0021] In conclusion these present devices do not make the treatment of hydrocarbon fuels economic, convenient or efficient and there fore are used primarily only where emission reduction is mandated by law rather than employed because of the economic advantages that a new device would impart.
[0022] It is therefore an object of the invention to increase fuel efficiency.
[0023] It is another object of the invention to decrease combustion emissions.
[0024] It is another object of the invention to reduce maintenance costs.
[0025] It is another object of the invention to reduce combustion chamber size.
[0026] It is another object of the invention to fuel storage size.
[0027] It is another object of the invention to increase burn temperatures.
[0028] It is another object of the invention to reduce burn times.
SUMMARY OF THE INVENTION
[0029] In accordance with the present invention, there is provided a magnetic treatment of hydrocarbon fuel flowing through a fuel conduit. A plurality of magnets with repelling polarity is used in affecting the fuel structure and alternating said structure by aligning the hydrocarbons in a parallel uniform manner to increase combustion efficiency thus increasing power while reducing pollutants and exhaust emissions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0030] A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description, in which:
[0031] FIG. 1 is a perspective view of a fuel line fitted with ceramic magnets arranged to affect the structure of the carbon and hydrogen molecules flowing through the fuel line;
[0032] FIG. 2 is a perspective view of a fuel line detailing the change in the hydrogen and carbon molecules after being effected by the ceramic magnets;
[0033] FIG. 3 is a perspective view of a combustion furnace retrofitted with a magnetic hydrocarbon treatment device; and
[0034] FIG. 4 is a perspective view of an oil derrick retrofitted with a magnetic hydrocarbon treatment device.
[0035] For purposes of clarity and brevity, like elements and components will bear the same designations and numbering throughout the Figures.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0036] Referring now to FIG. 1 , in accordance with a preferred embodiment of the present invention generally concerns a fuel treatment system wherein the system preferably comprises a ceramic magnet 4 mounted with its south polarity 5 directly against a fuel conduit 6 with a plurality of additional ceramic magnet 4 ( s ) fitted circularly around the same fuel conduit 6 with all conduit contact sides providing a south polarity 5 ensuring an opposing force on all sides of the fuel conduit 6 . The generally rectangular prismatic shaped ceramic magnet 4 is made of a strontium carbonate and iron oxide and sized to fit the variables of the fuel conduits dimensions. A permanently attached metal backing 14 in contact with the north polarity 7 of the magnets provides shape for placement as well as rigidity and fastenability of the opposing magnetic sections 9 . Sections are fastened by means of a standard hardware fastener 16 such as a threaded bolt passing though a formed flange at the end of each rectangular shaped metal backing 14 fitted with a fastener hole 18 in each flange opposed to a fastener hole 18 in a opposing flange.
[0037] In operation more than one set of magnets may be stacked upon the other resulting in a stronger magnetic affect upon the fuel conduit 6 . The present invention may also be applied linear to have effect over a great length of the fuel conduit 6 .
[0038] Referring now to FIG. 2 , in accordance with a preferred embodiment of the present invention it shall be understood that the carbon atoms 23 and hydrogen atoms 21 move through the fuel conduit 6 from the fuel source side 8 as clusters 20 past the mounted present invention where by the negative polarity causes the hydrogen atoms 21 and carbon atoms 23 to separate and align with like atoms. In a most preferred embodiment of the present invention ceramic magnet 4 mounted with its south polarity 5 directly against a fuel conduit 6 with a plurality of additional ceramic magnet 4 ( s ) fitted circularly around the same fuel conduit 6 with all conduit contact sides providing a south polarity 5 ensuring an opposing force on all sides of the fuel conduit 6 causing the positively charged carbon atoms 23 to travel to the outside of the fuel conduit 6 while the negatively charged hydrogen atoms 21 are pushed to the center allowing providing for separated atoms 22 for easier combining of introduced oxygen 30 with the hydrogen atoms 21 for more complete combustion as the fuel passes the magnetic hydrocarbon treatment device 26 and moves toward the fuel outlet direction 10 .
[0039] Referring now to FIG. 3 , in accordance with a preferred embodiment of the present invention the magnetic hydrocarbon treatment device 26 is mounted immediately upstream from the combustion unit on the fuel conduit 6 affecting the temperature and pollutants in the flue exhaust 28 .
[0040] In operation the effects of the present invention result in more complete combustion so increase the flue temperature while reducing the particulate matter emitted from the furnace 24 . In the case of a furnace 24 depicted the output heat 32 temperature is increase by some 10 to 20% resulting in greater fuel efficiency while at the same time reducing the amount of unburned fuels and thus reducing the amount of expelled pollutants into the atmosphere. The effect varies depending upon the device the units are attached too. For example, in a boiler the temperature may not increase because the rate of fuel consumption will be adjusted down thus saving fuel while maintaining the appropriate temperature. In others the temperature may rise so the burn time is shortened where thermostats determine burn and rest times for a device. In yet other situations the only effect may be to reduce the expelled pollutants by providing for a more efficient burn while temperature or burn time is not an issue such as in a well burn off and in yet another instance the present invention may be applied to a pipeline designed to transport raw fuel such as crude oil as a means to increase the flow rate of the crude oil with no imminent intention to combust.
[0041] Referring now to FIG. 4 , in accordance with a preferred embodiment of the present invention the magnetic hydrocarbon treatment device 26 is mounted immediately upstream from the combustion unit on the fuel conduit 6 of an oil derrick 34 with burnt gases 36 being expelled.
[0042] In operation the present invention serves to reduce pollutants being expelled into the atmosphere with no regard to burn time or specific temperature output.
[0043] It should be understood that the descriptions refer to the most preferred embodiment and it should be recognized that many minor changes in shape and mounting may be used to achieve the same results as described and that this description is not meant to limit the variability but rather to provide a reasonable understanding of the invention, its application and methods.
[0044] Since other modifications and changes varied to fit particular operating requirements and environments will be apparent to those skilled in the art, the invention is not considered limited to the example chosen for purposes of disclosure, and covers all changes and modifications which do not constitute departures from the true spirit and scope of this invention.
[0045] Having thus described the invention, what is desired to be protected by Letters Patent is presented in the subsequently appended claims. | A magnetic treatment of hydrocarbon fuel flowing through a fuel conduit. A plurality of magnets with repelling polarity is used in affecting the fuel structure and alternating said structure by aligning the hydrocarbons in a parallel uniform manner to increase combustion efficiency thus increasing power while reducing pollutants and exhaust emissions. | 1 |
This application is a continuation of application Ser. No. 07/517,405 filed May 2, 1990, now U.S. Pat. No. 5,058,035, which is a continuation of application Ser. No. 07/089,339, filed Aug. 25, 1987, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a recording apparatus for image recording on a recording medium according to information sent from a host apparatus.
2. Related Background Art
Image recording apparatus, such as a printer, is generally equipped with dip switches for enabling the operator to modify the functions to a certain extent. However such dip switches can only cope with modifications of rather limited functions, for example setting of interface conditions.
Recently there are also known apparatus allowing the operator to select functions through an intelligent operation panel, by the use of a non-volatile RAM instead of the dip switches. However, such apparatus, still requiring manipulation of the operation panel, only serves to facilitate the setting with the dip switches and allows the selection of individual functions only.
There are also known, as disclosed in the U.S. Pat. No. 4,059,833, apparatus in which the parameters such as the character size and the line pitch are instructed by a host apparatus such as a host computer to a printer. However such parameters have to be set to the printer by the operator every time the power supply is turned on. Also in certain apparatus such as word processors, the parameter settings of the printer are stored in a floppy disk or a non-volatile memory Provided in the host apparatus, but the operator is required to provide an instruction for reading the stored settings from said floppy disk or the like. Also in such apparatus a considerable load is unavoidable on the part of the host apparatus.
Recent development of non-impact printers, for printing characters in the form of a group of dots, has made it possible to print not only characters but also to form lines and pictures. For this reason, instead of the conventional printout of characters on an already printed business form sheet, the printout can be made by storing data for format pattern in advance and overlaying the thus stored format pattern with newly supplied data, as described in the U.S. Pat. No. 4,059,833. Such process is called form overlay.
The form and print data are usually designed separately, so that they often do not fit each other in the actual printout. It therefore becomes necessary, as shown in FIG. 7, to move a pattern ABCD to a position A'B'C'D'. In such case it has conventionally been necessary to redesign the form or the print data, involving cumbersome work.
Also in case of forming, as shown in FIG. 9, the same image in different positions 408 and 409, it has been necessary to send the same data repeatedly from the host apparatus, so that the efficiency in image forming time cannot be improved.
There is also known an apparatus in which an image displacement is made on a display such as a cathode ray tube and the displaced image is then printed, as disclosed in the U.S. patent application Ser. No. 914,150. However the image displacing process, conducted in the host apparatus, imposes a significant load thereon, and other processes cannot be executed during such image displacing process.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a recording apparatus not associated with the above-mentioned drawbacks.
Another object of the present invention is to provide a recording apparatus which enables setting of the initial conditions therefor from a host apparatus such as a host computer, and which stores said set conditions in a rewritable non-volatile memory to dispense with the resetting operation even when the power supply is cut off.
Still another object of the present invention is to provide a recording apparatus in which the pattern of a desired area can be moved to a desired position in response to an instruction from the host apparatus.
Still another object of the present invention is to provide a recording apparatus capable of reducing the time required for preparing a form preparation, without redesigning of the data for a form.
Still another object of the present invention is to provide a recording apparatus capable of saving time required for the transfer of the same data and enabling efficient image formation.
The foregoing and still other objects of the present invention, and the advantages thereof, will become fully apparent from the following description to be taken in conjunction with the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a printer control unit of a laser beam printer embodying the present invention;
FIG. 2 is a cross-sectional view of the laser beam printer of said embodiment;
FIG. 3 is a view showing the format of an initializing command;
FIG. 4 is a flow chart showing an initializing sequence;
FIG. 5 is a flow chart showing an input interruption sequence;
FIG. 6 is a block diagram of a recording apparatus embodying the present invention;
FIG. 7 is a view showing an image displacement in the recording apparatus of said embodiment;
FIG. 8 is a view showing the format of an image control command of the recording apparatus of said embodiment;
FIG. 9 is a view showing an image displacement or a copying in the recording apparatus of said embodiment; and
FIG. 10, consisting of FIGS. 10A, 10B and 10C, is a flow chart showing the function of the recording apparatus of said embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now the present invention will be clarified in detail by embodiments thereof shown in the attached drawings.
Laser Beam Printer (FIG. 2)
FIG. 2 is a cross-sectional view of the mechanism of a laser beam printer embodying the present invention.
In FIG. 2, a laser beam printer 100 converts character information supplied from an externally connected host computer and forms an image on a recording sheet. An operation panel 300 is provided with a power switch etc. A printer control unit 101 controls the entire printer 100, and analyzes the character information and control commands supplied from the host computer. Said printer control unit 101 controls or monitors various mechanisms of the printer and converts the input character information into corresponding character patterns for supply to a laser driver 102. Said laser driver 102 is provided for controlling a semiconductor laser 103, and turns on and off a laser beam 104 emitted from the semiconductor laser 103 according to the input video signal.
The laser beam, after being deflected in a lateral direction by a rotary polygon mirror 105, irradiates a photosensitive drum 106, thereby forming a latent image of the character pattern thereon. Said latent image is rendered visible by a developing unit 107 provided along the photosensitive drum 106 and is transferred onto a recording sheet. Cut recording sheets are stored in a sheet cassette 108 mounted in the laser beam printer 100, and are supplied therefrom toward the photosensitive drum 106 by means of a feed roller 109 and transport rollers 110, 111.
Control Unit (FIG. 1)
FIG. 1 is a block diagram of the printer control unit 101.
In FIG. 1, a central processing unit (CPU) 200 has a ROM storing control programs corresponding to flow charts shown in FIGS. 4 and 5. When a power switch 208 for the printer control unit and the entire printer is turned on, a power-on reset signal is supplied to the CPU 200 whereby the CPU 200 executes an initializing program to set the laser beam printer in an initial state. Then the CPU 200 sends a request signal RS for the initializing conditions to an interface circuit 201, thus requesting a host computer 210 to transmit an instruction signal for the initializing conditions. In response the host computer 210 sends the instruction for the initializing conditions to the laser beam printer 100 and said conditions are stored in an initial-state buffer 205. Thus the laser beam printer 100 sets initializing conditions, corresponding to the stored conditions, in various ports of the printer.
If the initializing conditions need not be changed when the request signal RS is received (whether the initializing conditions are to be changed is up to the decision of the operator and is not an automatic function of the device), the host computer 210 releases a signal indicating that the change is unnecessary. Also in case no change is required, it is also possible not to release any signal from the host computer 210. It is therefore unnecessary to set the initializing conditions by sending the instruction again.
The print information sent from the host computer 210 to the laser beam printer 100 is in the form of codes.
Upon entry of the character codes from the host computer 210, an interruption signal S01 advising of said entry and a character code signal D01 are sent from the interface 201 to the CPU 200. A buffer RAM 202 is provided for temporarily storing the character code supplied from the host computer 210 through the CPU 200, which reads said character code signal D01 and temporarily stores said code in the buffer 202, according to an input interruption program started by the interruption signal S01. A page buffer RAM 203 edits thus entered character information into the unit of a page, and stores said information together with print format control information.
A timer unit 204, giving timer interruption signals to the CPU 200 at an interval for example of 100 mS, executes required task switching control, by activating a timer interruption routine in a printer control program of multi-task process. An initial-state buffer 205, composed of a non-volatile RAM for storing instructions to be executed when the power supply is turned on, stores initializing conditions. A code address converter 206 is composed of a ROM and is provided for converting the character code data into the address of a corresponding character pattern. 207 is a character generator ROM provided in the laser beam printer 100.
At the printing operation, the character generator 207 converts the character information received from the page buffer 203 in the unit of a line at a time, into Print signals of character patterns, and sends said signals to an output interface 209, which supplies a printing unit 211 with various control signals and the video signal. In response to a print start signal S03 from the CPU 200, the printing unit 211 is activated, and a print control sequence is conducted including a sheet supply, rotation of the photosensitive drum 106, activation of the laser driver 102 etc. A memory ROM 212 is provided for storing control program, etc.
Initial State Command (FIG. 3).
FIG. 3 shows the format of an initial state command supplied from the host computer 210 for storage in the initial state buffer 205 of the laser beam printer 100.
There are provided a command code 301 indicating that following data are instructions to be stored in the initial state buffer; a command code 303 indicating the end of said instructions; and an initial state instruction 302 to be actually stored in the initial state buffer 205. The initial state command 302 may contain any of the instructions that can be executed by said laser beam printer. More specifically said instruction may be that for page layout (margin, line pitch, character pitch, page direction etc.), that for font selection, that for form overlay, that for moving the print position, etc.
Initializing Process (FIG. 4)
FIG. 4 is a flow chart of an initializing sequence when the power switch 208 is turned on.
When said switch 208 is turned on, the CPU 200 at first executes, in a step S1, an ordinary initialization. The CPU releases an initializing instruction for the printer, and creates a standard state or a default state in which the operator does not set any conditions (margin, pitch, font, etc.) in the initial state buffer. The data of said standard state are stored in the program memory 212, and the standard state is set for example at the shipment from the manufacturer. Then the initializing request signal RS is sent to the host computer 210. Then a step S2 discriminates whether any instruction is already stored in the initial state buffer 205, and, if not, the sequence is terminated. In this manner the initial state is always maintained constant if the operator has not set any conditions in the initial state buffer 205.
On the other hand, if any instruction has been stored in the initial state buffer 205, the sequence Proceeds to a step S3 to read the instruction a byte at a time from the initial state buffer 205, and said instruction is executed in succession. This operation is the same as the ordinary operation in which the CPU 200 reads the reception buffer 202 a byte at a time and forms the data for the page buffer 203 by executing thus read instruction, and is only different in that another buffer memory is used.
The initialization process is completed when all the contents of the initial state buffer 205 are executed. Thus an initial state desired by the operator can be arbitrarily generated without any burden.
Data Input Process (FIG. 5)
FIG. 5 is a flow chart of an input interruption process in response to the data reception from the host computer 210.
This process is started by the entry of the interruption signal S01 from the interface 201 in response to data reception, and a step S10 discriminates whether the received data contain the command code 301, i.e. whether said data are an initial state code. If an initial state code is identified, a step S11 stores the instruction data 302 in the initial state buffer 205 until the registration end code 303 is received. On the other hand, if no initial state code is identified in the step S10, the sequence proceeds to a step S12 for storing the received code in the reception buffer 202, and the sequence is terminated.
In the present embodiment the initial state is stored in a non-volatile RAM, but there may be employed a detachable, re-writable non-volatile memory such as a floppy disk or an IC card.
Also instead of using the power switch for starting the initializations, there may be employed another panel switch or an initialization command from the host computer.
In the present embodiment the initialization request signal is sent from the printer to the host computer, but it is also possible to dispense with said request signal and to send a signal indicating the conditions to be set from the host computer only when the initially set conditions are to be changed.
As explained in the foregoing, in the present embodiment, once the initial state is formed by a command defining the initial state, it need not be reset thereafter unless the initial condition become different at the start of power supply, and the transition to the initial state specific to each user can be automatically made in an easy manner, so that various requirements of the user can be securely met.
In the following there will be explained an example of printer operation in response to the initial state command supplied from the host computer.
FIG. 6 is a block diagram of a recording apparatus embodying the present invention, and there will be explained a case of recording, with a displacement of position, character patterns (including symbols) with a page printer such as a laser beam printer, in response to character code data and control commands sent from the host computer. In FIG. 6 there are shown a host computer 601 for generating character code data and control commands to be explained later, corresponding to the host computer 210 shown in FIG. 1; a ROM 605 storing a control program; an auxiliary memory RAM 609; an input buffer 602 for temporarily storing the character code data and control commands; a CPU 603 composed of a general-purpose microprocessor; a character generator 604 for generating character patterns in response to the character code data; an originating address register 620 indicating the originating address; a destination address register 621 indicating the destination address; an image length register 622 indicating the length of the image to be transferred; an image width register 623 indicating the width of the image to be transferred; an output page buffer 606 composed of a RAM of a capacity equal to the number of dots of a page; a printer interface 607 serving as an interface with the printer and generating a video signal in response to dot information from the output page buffer 606; a printer 608 for forming an image in response to said video signal; and a control board 610.
The input information from the host computer 601 contains character codes, image data and control commands and is temporarily stored in the input buffer 602. The CPU 603 reads said input information from the input buffer 602. In the case of a character code, the CPU 603 sends said code to the character generator 604 to generate a corresponding pattern, which is stored in the output buffer 606 under the position control by the CPU 603. Image data are stored directly in the output page buffer 606.
FIG. 8 shows the format of an image control command, and FIG. 9 shows the structure of the output page buffer 606.
The output page buffer 606 has a capacity of one page. The upper left corner of the sheet is taken as the origin (0, 0), and the lateral and vertical directions are respectively taken as the X- and Y-axis. In FIG. 8, there are shown an identification code 801 indicating that it is an image movement command; x' and Y-coordinates (X, Y) 802, 803 of the upper left corner of the pattern before movement, corresponding to a position 408 on FIG. 9; a width 804 in the X-direction of the image to be moved; a length 805 in the Y-direction of the image to be moved; an X- and Y-coordinates 806, 807 of the upper left corner of the pattern after movement, corresponding to a position 409 on FIG. 9; an identification code 808 indicating an image copy command; and following data 802-807 similar to those following the image movement command 801.
Now reference is made to a flow chart shown in FIG. 10, corresponding to a program stored in the ROM 605, for explaining the control sequence after the reception of an image movement command or an image copy command.
A step S501 reads the parameters of the image movement command or the image copy command shown in FIG. 8, and sets the X- and Y-coordinates (X, Y) 802, 803 of the upper left corner of the pattern before movement in the originating address register 620. Also the length 605 of the image and the width 804 are respectively stored in the image length register 622 and the image width register 623. A step S502 calculates the address (X2, Y2) of the lower right corner of the pattern before movement. Similarly a step S503 calculates the address (X'2, Y'2) of the lower right corner 405 of the pattern after movement. Steps S504-S506 identify the direction of movement from (X, Y) and (X', Y'). Based on the result of said identification of the direction of movement, steps S510-S519, or steps S520-S529, or steps S530-S539 are executed. In the following there will be explained the case of movement in a lower right direction (X'>X and Y'>Y).
A step S510 sets the addresses X2, Y2, X'2, Y'2, calculated in the steps S502 and S503, in work registers x, y, x' and y', which are provided in the CPU 603 but are not illustrated. A step S511 sets the content of the image length register 622 in a work register L, and step S512 sets the content of the image width register 623 in a work register W. Then a step S513 reads a byte of the lower right corner 404 of the coordinate (x, y) before movement, and writes it in the lower right corner 405 after movement indicated by the coordinate (x', y'). Then a step S514 discriminates whether a copying operation is instructed, and, if an image movement is instructed, a step S515 writes "0" in the data of the lower right corner 404 indicated by the coordinate (x, y), thus clearing the data located at the position of origin of transfer (404) before movement, i.e. the data of the original position is cleared. A step S516 then subtracts "1" from the count of the work registers x, x' and W, whereby the coordinate (x, y) indicates a position 406 adjacent, at left, to the lower right corner 404, and the coordinate (x', y') indicates a position 407 adjacent, at left, to the lower right corner 405. A step S517 then discriminates whether thus subtracted content of the image width work register W is "0". If not, steps S513-S517 are repeated.
In case said content is zero, indicating that the movement or copying in the X-direction is completed, a step S518 subtracts "1" from the count of the work registers y, y' and L, and returns the contents of the work registers x and x' to the original values x2, x'2. In this manner there are determined addresses of a position 410 immediately above the lower right corner 404 before movement and a position 411 immediately above the lower right corner 405 after movement. A step S519 discriminates whether the content of the length work register L is "0", and, if not, steps S512-S519 are repeated.
If the content of said register L is zero, indicating that the movement or copying of all the image data in the designated area is completed, the process is terminated. In such moving or copying process, the original area and moved area may partially overlap as shown in FIG. 7.
In the following there will be explained overlaying of a form and print data. In the structure shown in FIG. 6, the pattern of the form and the pattern of the data may be separately stored in the output page buffer 106. In this case the form pattern is stored at first, and is then moved so as to match the data pattern as explained before, and is recorded in overlay with the data pattern. Also if a buffer for storing the form pattern is provided in the circuit shown in FIG. 6, the overlay can be easily achieved by the movement of either the form pattern or the data pattern.
In the foregoing embodiment the address of the upper left corner of the pattern before movement is used as reference, but it is also possible to use the address of one of other three corners for the same purpose.
Also the host computer may be replaced by a reader unit for generating electric signals by reading an original image.
The present invention is not limited to the foregoing embodiment but is subject to various modifications and variations within the scope and spirit of the appended claims. | A control apparatus and method, in which a format for a particular instance of recording is designated or set, as by instructions from a host computer, or from an operator via a keyboard, and that desired format is used or not, according to whether the necessary information for that format is present in a memory (preferably non-volatile). If the necessary format information is present in the memory, the desired format is used for recording, while otherwise, a default format is used instead or the information for the desired format is supplied to the memory. | 6 |
BACKGROUND
[0001] The present invention generally relates to trailers. More specifically, the present invention relates to a trailer with an anchor system for securing large generators for transport.
[0002] Large generators are used at sites as temporary power. The generators are so large that a trailer is required to transport such a generator to and from a site, where it remains mounted. A trailer is also required to transport such a large generator that is to be installed temporarily at a site, until further decisions are made regarding utility. Typically, the generator is bolted or welded to the trailer to anchor the generator to the trailer, during transport. This increases the time and complexity to secure and remove the generator when using a trailer. When the generator is bolted to the trailer, specific wrenches are needed to secure or loosen the bolts holding the generator to the trailer. The use of bolts requires a person with enough strength to tighten and loosen the bolts, which could lead to strain type injuries to the person performing such a task.
[0003] It is an object of the present invention to provide a trailer with an anchor system for a generator which provides an easy process for securing and unsecuring the generator in relation to the trailer.
SUMMARY OF THE INVENTION
[0004] A generator trailer with anchor system adapted for transporting a large generator. The trailer has a bed with a front, rear and two sides surrounding the bed. There are at least four tightening devices. Each of the tightening devices includes a trailer component, an adjustable tension component and a generator component. The trailer component attaches to the trailer. The generator component is adapted to be attached to the generator. The adjustable tension component attaches between the attached trailer component and the attached generator component to provide tension to secure the generator to the trailer and provides a quick disconnect from the generator.
BRIEF DESCRIPTION OF DRAWINGS
[0005] FIG. 1 is a perspective view of a trailer with an anchor system according to the present invention.
[0006] FIG. 2 is a perspective view of a trailer with an anchor system according to the present invention.
[0007] FIG. 3 is a perspective exploded view of a trailer with an anchor system according to the present invention.
[0008] FIG. 4 is a perspective view of a trailer with an anchor system according to the present invention.
[0009] FIG. 5 is a perspective view of a tightening device according to the present invention.
[0010] FIG. 6 is a perspective view of a tightening device according to the present invention.
[0011] FIG. 7 is a perspective view of a tightening device according to the present invention.
[0012] FIG. 8 is a perspective view of a trailer with an anchor system according to the present invention.
[0013] FIG. 9 is a perspective view of a trailer with an anchor system according to the present invention.
DETAILED DESCRIPTION
[0014] The present invention is a trailer with an anchor system for large generators, as show in FIGS. 1-9 . The anchor system includes at least four tightening devices. FIGS. 1-2 shows the trailer 10 as a trailer 10 with a bed 12 surrounded by a front 14 , rear 16 and two sides 18 . FIG. 1 shows a generator 20 mounted on the bed 12 of the trailer 10 . FIG. 2 shows the trailer 10 without the generator 20 . The trailer 10 includes extended walls 22 extending upward from the bed 12 of the trailer 10 at the front 14 , rear 16 and sides 18 of the trailer 10 . The bed 12 of the trailer 10 within the extended walls 22 is approximately the same size as the base of the generator 20 . The trailer 10 could also be without the extended walls 22 , such that the bed 12 is even with a top surface 24 of the front 14 , rear 16 and sides 18 of the trailer 10 and the generator 20 sits on the top surfaces 24 . The tightening devices 26 can be mounted two on each side 18 or one on each of the front 14 , rear 16 and sides 18 . The tightening devices 26 are designed to have a quick release feature to simplify attachment to the generator 20 .
[0015] Two tightening devices 26 are shown mounted to each side 18 of the trailer 10 . FIGS. 1-6 show a first version of the tightening device 26 and FIGS. 7-8 show a second version of the tightening device 26 . The first version of the tightening device 26 is a ratchet 28 and ratchet strap 30 , as shown in FIGS. 3-6 . The ratchet 28 includes a ratchet body 32 and a ratchet mechanism 34 . The ratchet body 32 is mounted to the sides 18 of the trailer 10 . The ratchet body 32 is shown with a bolt hole 36 for bolting the ratchet body 32 in a permanent manner to the trailer 10 . The ratchet body 32 could also be welded or attached by other fastening means to the trailer 10 . The ratchet mechanism 34 is shown as one of many of the standard ratchet mechanisms available which receives the ratchet strap 30 . One end of the ratchet strap 30 attaches to the ratchet mechanism 34 , while the other end of the ratchet strap 30 includes attachment of a clevis 38 . The clevis 38 is shown as a U-shaped clevis which two ends 40 . Each end 40 of the clevis 38 includes a bolt hole 42 . The clevis 38 is attached to the ratchet strap 30 by looping an end of the ratchet strap 30 about the U-shape clevis and sewing the end of the ratchet strap 30 to the ratchet strap 30 , as shown in FIG. 3-6 .
[0016] The generator 20 includes attachment points 44 along the sides of the generator 20 for each tightening device 26 and which align between the bolt holes 42 of the clevis 38 . The attachment points 44 include a bolt hole 46 to receive a bolt 48 , as shown in FIG. 6 . The bolt 48 is used to attach the clevis 38 to the attachment point 44 by placing the bolt 48 through one of the bolt holes 42 of the clevis 38 , through the bolt hole 46 of the attachment point 44 and finally through the other bolt hole 42 of the clevis 38 . A nut 50 is used to secure the bolt 48 in the bolt holes 42 , 46 . The bolts 48 can be replaced by a pin. The pin shown have some locking means to retain the pin in the bolt holes 42 , 46 . The ratchet mechanism 34 is used to tighten the ratchet strap 30 when the clevis 38 is attached to the generator 20 and the generator 20 is to be secured to the trailer 10 . The ratchet mechanism 34 is used to loosen the ratchet strap 30 when the clevis 38 is attached to the generator 20 and the generator 20 is to be unsecured from the trailer 10 . The tightening and loosening of the ratchet strap 30 is performed based on the particular style of ratchet mechanism 34 employed. The end of the ratchet strap 30 attached to the ratchet mechanism 34 can be easily removed from the ratchet mechanism 34 without the use of tools, thereby making it easy to unsecure the generator 20 from the trailer 10 . Also, if pins are used instead of bolts 48 , the clevis 38 can be quickly released from the attachment point 44 of the generator 20 .
[0017] The second version of the tightening device 26 shown in FIGS. 7-8 and includes a turnbuckle 52 and two attachment hooks 54 . Each attachment hook 54 includes a hook 56 extending from an attachment plate 58 . Each attachment plate 58 is shown with two bolt holes 60 and two bolts 62 . One attachment hook 54 is bolted to the trailer 10 , while the other attachment hook 54 is bolted to the generator 20 in an aligned manner. The attachment hooks 54 could also be secured by welding them to the trailer 10 and the generator 20 . The attachment hook 54 on the generator 20 acts as the attachment point 44 . The turnbuckle 52 includes a turnbuckle body 64 and two threaded eyes 66 . The threaded eyes 66 each have an eye 68 with a threaded shaft 70 extending from the eye 68 . The threaded shafts thread in and out of ends 72 of the turnbuckle body 64 . Each threaded eye 66 screws into one of the ends 72 of the turnbuckle body 64 , which is typical of a turnbuckle 52 . To secure the generator 20 to the trailer 10 the eyes 68 of the turnbuckle 52 are placed over the aligned hooks 56 attached to the trailer 10 and the generator 20 , as shown in FIG. 8 . The turnbuckle body 64 is then turned to pull the eyes 68 toward the turnbuckle body 64 and hence tighten down the generator 20 to the trailer 10 . To unsecure the generator 20 from the trailer 10 , simply turn the turnbuckle body 64 such that the eyes 68 move away from the turnbuckle body 64 . FIG. 9 is a slightly different version of tightening device of FIGS. 7-8 . FIG. 9 shows a ring 76 attached through a hole 78 in the structure of the generator 20 . FIG. 9 shows a ring 76 attached to a ring holder 80 , where the ring holder 80 is attached to the side 18 of the trailer 10 . FIG. 9 shows the turnbuckle body 64 with two threaded hooks 82 . Whereby, the hooks 82 engage the rings 76 .
[0018] While different embodiments of the invention have been described in detail herein, it will be appreciated by those skilled in the art that various modifications and alternatives to the embodiments could be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements are illustrative only and are not limiting as to the scope of the invention that is to be given the full breadth of any and all equivalents thereof. | A generator trailer with anchor system adapted for transporting a large generator. The trailer has a bed with a front, rear and two sides surrounding the bed. There are at least four tightening devices. Each of the tightening devices includes a trailer component, an adjustable tension component and a generator component. The trailer component attaches to the trailer. The generator component is adapted to be attached to the generator. The adjustable tension component attaches between the attached trailer component and the attached generator component to provide tension to secure the generator to the trailer and provides a quick disconnect from the generator. | 1 |
CROSS-REFERENCE TO RELATED APPLICATION(S)
None.
BACKGROUND OF THE INVENTION
The present invention is directed to actuators for valves and dampers, such as used in controlled heating, ventilating and air conditioning (“HVAC”) applications. Depending upon the control system being used, such HVAC actuators typically act for a relatively short period of time (a few seconds up to a minutes or two), typically running a few times (perhaps five to ten movements) a day. In the most common applications, the HVAC actuators use a small electrically powered motor which runs at many rpms, through a gear reduction unit to increase torque and reduce the angular output of the HVAC actuator so it appropriately turns the attached valve stem or damper handle.
Some HVAC actuators operate in noisy environments (such as in an industrial plant) or in locations that are not sensitive to noise. Other HVAC actuators, however, are placed in office environments, in libraries, in residences or in other locations that are much more sensitive to sound and noise issues. When the HVAC actuator works to open or close the valve or damper, it can generate sound/noise which disturbs occupants of the building. Such sound/noise can be particularly disconcerting in that the person hearing the HVAC actuator often does not know what device created the sound/noise, or why the sound/noise occurred at that particular moment in time. Accordingly, HVAC actuators should work as quietly as possible. In general, the sound generated by a working HVAC actuator has been viewed as a necessary evil, with the only viable options being to either add a more expensive motor in the HVAC actuator design (leading to a more expensive product), or to have the installer sound insulate around the HVAC actuator or around the motor within the HVAC actuator. Both options increase the total expense of the HVAC actuator. Better solutions are needed.
BRIEF SUMMARY OF THE INVENTION
The present invention is an actuator noise reducer, a motor with an actuator noise reducer thereon, and an actuator having an actuator noise reducer therein. The actuator noise reducer has a spring arm with a sliding bearing surface which is pressed against a side of the rotating motor shaft. The spring arm introduces a generally radial force on the motor shaft, taking up bearing play and gently pressing the motor shaft into its bearing. In the preferred embodiment, the actuator noise reducer includes a cylindrical hoop mount which mates with and encircles a cylindrical portion of the electrical motor adjacent the shaft for mounting the actuator noise reducer on the motor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective assembly view of the actuator noise reducer of the present invention relative to the motor for which the actuator noise reducer was designed.
FIG. 2 is a perspective view with the actuator noise reducer on the motor.
FIG. 3 is a plan view of the actuator noise reducer of FIGS. 1 and 2 .
FIG. 4 is a side view of the actuator noise reducer of FIGS. 1-3 .
FIG. 5 is cross-sectional view of the actuator noise reducer taken along lines 5 - 5 of FIG. 3 .
FIG. 6 is a top plan view of an actuator using the actuator noise reducer of the present invention.
FIG. 7 is a bottom plan view of the actuator of FIG. 6 with the bottom plate removed to show the gear train of the actuator.
FIG. 8 is a cross-sectional view of the actuator taken along lines 8 - 8 of FIG. 6 .
FIG. 9 is a cross-sectional view of the actuator taken along lines 9 - 9 of FIG. 6 .
FIG. 10 is an enlargement of a portion of FIG. 9 .
While the above-identified drawing figures set forth a preferred embodiment, other embodiments of the present invention are also contemplated, some of which are noted in the discussion. In all cases, this disclosure presents the illustrated embodiments of the present invention by way of representation and not limitation. Numerous other minor modifications and embodiments can be devised by those skilled in the art which fall within the scope and spirit of the principles of this invention.
DETAILED DESCRIPTION
The operation of the noise reducer 10 of the present invention can be understood with reference to FIGS. 1-5 , which most clearly show the noise reducer 10 . In this case, the noise reducer 10 has been specifically designed to mate and work with a known motor 12 used in an HVAC actuator 14 . In typical HVAC actuators (and in the preferred embodiment), the motor 12 runs at speeds in excess of 100 rpms, and usually at speeds of 1000 rpms or more. This relatively fast motor output speed is then geared down to increase torque and reduce the angular output of the HVAC actuator 14 . For valve applications, the maximum stroke of the actuator is several turns (say, 1080° or less), and more commonly with a maximum stroke of about 90°. With damper applications, the maximum stroke of the actuator is commonly 180° or less. The HVAC actuators typically have a peak torque output of 10 in-lbs or more to up to about 400 in-lbs, such as low torque models rated at about 40 in-lbs and high torque models rated at about 320 in-lbs.
The depicted motor 12 is a long shaft DC motor rated at 24 VDC, commercially available from Douglas International, Inc. of Geneva, Ill. as model no. KE588. It has a rated load of 1.0 in-oz (0.06 in-lbs, or 72 g-cm), drawing about 130 mA and running at 2100±250 rpm at rated load. At no load, the preferred motor 12 draws about 15 mA and runs at 3250±350 rpm.
The housing 16 of the motor 12 is generally cylindrical, with an outer diameter of about 1.4 inches (36 mm) and a length of about 1 inch (26 mm). Positive and negative electrical terminals 18 project off one end of the housing 16 opposite a motor shaft 20 . As well known in the HVAC actuator and motor arts, application of an appropriate electric current to the two electrical terminals 18 causes rotation of the shaft 20 by a rotor/stator combination (not shown) interior to the housing 16 . The shaft 20 is rotationally supported by bearings or bushings (not shown) which are also interior to the motor housing 16 . In this particular motor 12 , an end plate 22 of the housing 16 includes a cylindrical extension 24 around the bearing/bushing, and has several threaded mounting holes 26 in the end plate 22 . The cylindrical extension 24 projects just over 0.1 inches (about 3 mm) from the rest of the end plate 22 , with an outer diameter of about 0.4 inches (10 mm). While the noise reducer 10 of the preferred embodiment is specifically designed to mate with the size and shape of this particular motor 12 , the noise reducer can be alternatively designed to mate with motors having widely varying external shapes.
The shaft could be rectangular or hexagonal or otherwise shaped with one or more flats to mate into a gear, but in the preferred motor 12 the shaft 20 is cylindrical. The shaft 20 has a thickness appropriate for the torque being transferred, such as typically with a diameter in the range of 0.05 to 0.25 inches (1 to 6 mm). The shaft 20 of the preferred motor 12 has a diameter of less than 0.1 inches (about 2 mm), extending for a length of about 0.3 inches (about 7 mm) beyond the cylindrical extension 24 .
While this motor 12 is relatively low cost and reliable for its intended use in the HVAC actuator 14 , it generates more noise than desired while running. The present invention involves the discovery that the noise output of the motor 12 can be reduced by placing a sideways force on the shaft 20 as it projects beyond the cylindrical extension 24 . In general terms, most designers using motors would try to avoid such a sideways force (i.e, a force in one radial direction) on the shaft 20 as detrimental to motor performance. Specifically, the sideways force on the shaft 20 tends to increase wear in the bearings/bushings, reduces the torque output of the motor 12 due to unnecessary drag, and tends to cause misalignment of the rotor/shaft relative to the stator within the housing 16 . For an HVAC actuator, however, these downsides are insignificant. With the HVAC actuator 14 having a total run time of only a few minutes per day, bearing or bushing wear is seldom a significant contributing cause for motor failure. Further, with a properly designed noise reducer 10 , the trade-off of lower torque is well worth the reduction in sound output of the HVAC actuator 14 while running.
The sideways force is placed onto the shaft 20 by a spring arm 28 . The spring arm 28 extends from a hoop section 30 of the noise reducer 10 which mounts the noise reducer 10 relative to the motor 12 and/or actuator 14 . The spring arm 28 has a bearing surface 32 on its free distal end which rides on the cylindrical side surface of the shaft 20 at a location just past the end of the cylindrical extension 24 . While numerous designs of spring arms could be used, the preferred spring arm 28 includes two fold locations 34 separating two relatively straight lengths 36 of the spring arm 28 . Most of the deflection of the spring arm 28 is provided by bending of the material at these two fold locations 34 . In the preferred embodiment, the spring arm 28 is molded to be about 0.02 inches (0.5 mm) thick, with the width of the spring arm 28 ranging between about 0.04 and 0.05 inches (1-1.2 mm). Numerous other geometries for the spring arm could alternatively be used.
The amount of deflection of the spring arm 28 is designed based upon the magnitude of the spring force desired and the geometrical configuration of the spring arm 28 to achieve that magnitude of spring force. For many configurations, the desired sideways spring force is achieved by a deflection of the bearing surface 32 by a distance within a range of 0.004 to 0.2 inches (0.1 to 5 mm). In the preferred design, the unbiased position of the bearing surface 32 coincides with the shaft axis. Thus, placement of the noise reducer 10 onto the motor 12 requires deflecting the bearing surface 32 of the spring arm 28 by an amount equal to the radius of the shaft 20 , which for the preferred motor 12 is about 0.04 inches (1 mm).
The spring constant for the spring arm 28 is also designed based upon the magnitude of the spring force desired and the geometrical configuration of the spring arm 28 to achieve that magnitude of spring force, and further considering the tolerances of the motor 12 and placement of the noise reducer 10 . In general, the desired spring force can be achieved with springs having a spring constant within a range of 0.5 to 500 pounds per inch.
The spring arm 28 provides a sideways force on the shaft 20 which is appropriate for the particular motor 12 to reduce the noise output of the motor 12 , and can be readily determined by placing a range of different forces on the motor 12 and seeing how noise output is reduced relative to the reduction in torque output. In HVAC actuators, the sideways force that the actuator noise reducer 10 places on the motor shaft 20 is generally within a range of 0.1 to 5 pounds to result in the desired noise reduction. With the preferred motor 12 , a sideways force within the range of 0.3 to 1.2 pounds has been found to adequately reduce motor noise. With the geometrical configuration and size of the preferred embodiment, forming the noise reducer 10 of DELRIN (Unfilled Acetal) results in a sideways force of about 0.38 lbs, forming the noise reducer 10 of LUBRICOMP (Nylon 6/6 w/10% aramid fibers & 10% PTFE) results in a sideways force of about 0.40 lbs, and forming the noise reducer 10 of ULTRAMID (35% Glass filled Nylon 6/6) results in a sideways spring force of about 1.2 lbs. That is, with a deflection of 0.04 inches (1 mm), the preferred shape results in spring constants of about 9 pounds per inch (DELRIN and LUBRICOMP) to about 30 pounds per inch (ULTRAMID). By molding the noise reducer 10 out of a polymer material, the noise reducer 10 can be easily formed at low cost, while providing the design flexibility needed to mate with various motors used in HVAC actuators and achieve desired spring forces on the motor shafts.
The amount of noise reduction achieved by the noise reducer 10 should be audibly perceptible, such as a reduction of at least 3 dB, and more preferably a reduction of at least 5 dB. The preferred embodiment reduces the noise output of the actuator 14 by about 10 to 15 dB or more. While various causes internal to the motor 12 may contribute to the sound output of the motor 12 , it is believed that the noise reducer 10 significantly takes up about 0.0002 to 0.0003 inches (0.005 to 0.008 mm) of bearing play (difference between motor shaft diameter and motor bearing diameter).
The sideways force does introduce friction and thereby reduces the efficiency of the motor 12 slightly, but not overly so. For instance, the noise reducer 10 may reduce the no-load running speed of the motor 12 by an amount within the range of 0.5 to 20%, and more preferably within the range of 1 to 10%. Measurements were taken of the reduction of no-load running speed of the motor 12 with the preferred embodiment as follows. Without the noise reducer 10 , a sampled motor 12 ran at 3113 rpm in the clockwise direction and at 3068 rpm in the counterclockwise direction. A preferred noise reducer 10 molded of DELRIN reduced these speeds to 3000 rpm (3.6% reduction) in the clockwise direction and to 2955 rpm (3.7% reduction) in the counterclockwise direction. A preferred noise reducer 10 molded of LUBRICOMP reduced these speeds to 3071 rpm (1.4% reduction) in the clockwise direction and to 3023 rpm (1.5% reduction) in the counterclockwise direction. A preferred noise reducer 10 molded of ULTRAMID reduced these speeds to 2894 rpm (7.0% reduction) in the clockwise direction and to 2839 rpm (7.5% reduction) in the counterclockwise direction.
The cylindrical extension 24 provides a convenient location for attachment of the noise reducer 10 of the present invention. The noise reducer 10 includes a peripheral hoop 30 of the same size and shape as the end plate extension 24 , and the peripheral hoop 30 of the noise reducer 10 is used to secure the noise reducer 10 into position relative to the motor 12 . In this case, because the end plate extension 24 is cylindrical, the peripheral hoop 30 is also cylindrical. The hoop 30 encircles the shaft axis, such that the force provided onto the shaft 20 by the spring arm 28 is transmitted through the hoop 30 directly to the motor housing 16 . Due to the shape of the housing 16 , the hoop 30 can be slid axially onto the cylindrical extension 24 to conveniently attach the noise reducer 10 to the motor 12 with a friction fit. The peripheral hoop 30 is tight enough and has enough surface contact with the cylindrical extension 24 that friction between the peripheral hoop 30 and the cylindrical extension 24 prevents the noise reducer 10 from rotating with the shaft 20 . A flat 38 may be provided in one side of the peripheral hoop 30 so the noise reducer 10 better mates with the housing 40 of the actuator 14 . The flat 38 can also be used to prevent rotation of the noise reducer 10 with the shaft 20 . Alternatively, the noise reducer 10 could attach to the mounting holes 26 provided in the end plate 22 of the housing 16 , or could attach to the outer cylindrical surface of the motor housing 16 , or could attach to the motor housing 16 in another way. As another alternative, the noise reducer could attach to other structure within the actuator 14 (shown in FIGS. 6-10 ) separate from the motor 12 , i.e., such that the noise reducer didn't directly attach to the motor 12 at all. For instance, the noise reducer could be formed as part of the actuator housing 40 , or be attached to the actuator housing 40 or the motor 12 with one or more fasteners such as screws (not shown) or with adhesive. By having the hoop section 30 slide axially onto the cylindrical extension 24 of the motor housing 16 , a very consistent fit is achieved for placement of the noise reducer 10 onto the motor 12 , so the designed spring force is easily achieved within tolerances during production.
FIGS. 6-10 depict an actuator 14 using the noise reducer 10 of the present invention. The actuator 14 largely consists of a housing 40 enclosing various electronic components 42 , with one or more wiring openings 44 . An output section 46 can have any of numerous shapes and designs to mate with a damper or valve, with the depicted actuator 14 having a U-bolt attachment 46 which can be tightened around a stem of a valve or a handle of a damper (not shown). The particular actuator 14 depicted is similar to a model MEP-4872 actuator commercially available from KMC Controls of New Paris, Ind., which is rated at 80 in-lb of torque. The motor 12 is one of the components mounted within the housing 40 , with a gear train 48 coupling the motor shaft 20 to the U-bolt attachment 46 . In most HVAC actuators, the gear train 48 will provide a gear ratio to 1000 to 1 or more, such that the motor 12 turns the output shaft connector 46 through its total travel in a time period within the range of 5 seconds to 5 minutes. In this instance, the gear train 48 includes 6 gears, providing a total gear ratio of about 2700 to 1. The 2700 to 1 gear ratio causes the motor 12 running at 2100 rpm to rotate the U-bolt output 46 a full stroke 90° in about 19 seconds, while at no-load the motor 12 running at 3250 rpm will rotate the U-bolt output 46 a full stroke 90° in about 12.5 seconds. If the noise reducer 10 reduces the running speed of the motor 12 by less than 10%, then the additional run time for full stroke travel introduced by the noise reducer 10 is less than 2 seconds.
If desired, the gear train 48 can be formed with all plastic gears, or alternatively a metal gear can be used on the final gear stage(s) to withstand increased torque. While different gear trains can be used to produce different torque ratings, in the preferred embodiment different torque ratings are achieved using the same gear train 48 with the use of a magnetic hysteresis clutch 50 . This clutch 50 consists of a magnet 52 pressed onto the motor shaft 20 that drives a plastic ring cup 54 containing a rotor ring (rolled strip of hysteresis metal). As the shaft 20 /magnet 52 rotates, the rotor ring/ring cup 54 rotates with the magnet 52 until a predetermined slip torque is reached. At this point the shaft 20 /magnet 52 continues to rotate and the ring cup 54 stalls out. The slip torque can be varied by changing the strength of the magnet 52 , by modifying the air gap between the magnet 52 and the rotor ring 54 , or by changing the volume of the rotor ring material. Assuming a 93% efficient gear train 48 , the rated output torque/nominal output stall torque/nominal clutch torque of the three torque ranges are as follows: 25 in-lb/45 in-lb (clutch slips at 0.018 in-lb), 45 in-lb/65 in-lb (clutch slips at 0.025 in-lb), and 90 in-lb/112 in-lb (clutch slips at 0.044 in-lb).
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | An actuator noise reducer reduces the noise output of an HVAC actuator. The noise reducer has a spring arm with a sliding bearing surface which is pressed against a side of the rotating motor shaft. The spring arm introduces a generally radial force on the motor shaft, taking up bearing play and gently pressing the motor shaft into its bearing. A cylindrical hoop mount of the noise reducer mates with and encircles a cylindrical portion of the electrical motor adjacent the shaft for mounting the actuator noise reducer on the motor by axial sliding. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
Not applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to the processing of nickel aluminide intermetallic materials. More particularly, this invention relates to a process for producing a beta-phase nickel aluminide-based ingot, such as for use as a source material in physical vapor deposition (PVD) processes.
2. Description of the Related Art
Components within the turbine, combustor and augmentor sections of gas turbine engines are susceptible to oxidation and hot corrosion attack, in addition to high temperatures that can decrease their mechanical properties. Consequently, these components are often protected by an environmental coating alone or in combination with an outer thermal barrier coating (TBC), which in the latter case is termed a TBC system.
Diffusion coatings, such as diffusion aluminides and particularly platinum aluminides (PtAl), and overlay coatings, particularly MCrAlX alloys (where M is iron, cobalt and/or nickel, and X is an active element such as yttrium or another rare earth or reactive element), are widely used as environmental coatings for gas turbine engine components. Ceramic materials such as zirconia (ZrO 2 ) partially or fully stabilized by yttria (Y 2 O 3 ), magnesia (MgO) or other oxides, are widely used as TBC materials. Used in combination with TBC, diffusion aluminide and MCrAlX overlay coatings serve as a bond coat to adhere the TBC to the underlying substrate. The aluminum content of these bond coat materials provides for the slow growth of a strong adherent continuous aluminum oxide layer (alumina scale) at elevated temperatures. This thermally grown oxide (TGO) protects the bond coat from oxidation and hot corrosion, and chemically bonds the TBC to the bond coat.
More recently, overlay coatings (i.e., not a diffusion) of beta-phase nickel aluminide (βNiAl) intermetallic have been proposed as environmental and bond coat materials. The NiAl beta phase exists for nickel-aluminum compositions of about 30 to about 60 atomic percent aluminum, the balance of the nickel-aluminum composition being nickel. Notable examples of beta-phase NiAl coating materials include commonly-assigned U.S. Pat. No. 5,975,852 to Nagaraj et al., which discloses a NiAl overlay bond coat optionally containing one or more active elements, such as yttrium, cerium, zirconium or hafnium, and commonly-assigned U.S. Pat. No. 6,291,084 to Darolia et al., which discloses a NiAl overlay coating material containing chromium and zirconium. Commonly-assigned U.S. Pat. Nos. 6,153,313 and 6,255,001 to Rigney et al. and Darolia, respectively, also disclose beta-phase NiAl bond coat and environmental coating materials. The beta-phase NiAl alloy disclosed by Rigney et al. contains chromium, hafnium and/or titanium, and optionally tantalum, silicon, gallium, zirconium, calcium, iron and/or yttrium, while Darolia's beta-phase NiAl alloy contains zirconium. The beta-phase NiAl alloys of Nagaraj, Darolia et al., Rigney et al., and Darolia have been shown to improve the adhesion of a ceramic TBC layer, thereby increasing the service life of the TBC system.
Suitable processes for depositing a beta-phase NiAl coating are thermal spraying and physical vapor deposition processes, the latter of which includes electron beam physical vapor deposition (EBPVD), magnetron sputtering, cathodic arc, ion plasma, and combinations thereof. PVD processes require the presence of a coating source material made essentially of the coating composition desired, and means for creating a vapor of the coating source material in the presence of a substrate that will accept the coating. FIG. 1 schematically represents a portion of an EBPVD coating apparatus 20 , including a coating chamber 22 in which a component 30 is suspended for coating. A beta-phase NiAl overlay coating 32 is represented as being deposited on the component 30 by melting and vaporizing an ingot 10 of the beta-phase NiAl with an electron beam 26 produced by an electron beam gun 28 . The intensity of the beam 26 is sufficient to produce a stream of vapor 34 that condenses on the component 30 to form the overlay coating 32 . As shown, the vapor 34 evaporates from a pool 14 of molten beta-phase NiAl contained within a reservoir formed by crucible 12 that surrounds the upper end of the ingot 10 . Water or another suitable cooling medium flows through cooling passages 16 defined within the crucible 12 to maintain the crucible 12 at an acceptable temperature. As it is gradually consumed by the deposition process, the ingot 10 is incrementally fed into the chamber 22 through an airlock 24 .
The preparation of beta-phase NiAl for deposition by PVD typically requires the use of a vacuum induction melting (VIM) furnace in order to promote the purity of the composition by reducing the levels of residual elements such as oxygen. Other typical requirements for the ingot 10 include full density (e.g., pore-free), chemical homogeneity, mechanical integrity (e.g., crack-free), and dimensions and dimensional tolerances suitable for the particular PVD machine used. However, the casting and finish machining of beta-phase NiAl-based compositions are difficult to control as a result of the high melting point (1640° C.), very low room temperature ductility and low ambient fracture toughness (about 6 MPa·m ½ ) of NiAl. The brittle nature of beta-phase NiAl-based materials particularly complicates the preparation of large ingots (e.g., diameters of about 2.5 inches (about 6.35 mm), lengths of about 20 to 30 inches (about 50.8 to 78.2 cm)) suitable for EBPVD processes, and machinable stock material required for cathodic arc processes. Also of concern is an exothermic reaction that takes place between nickel and aluminum when beta-phase NiAl is melted. When processing beta-phase NiAl in very small amounts, this exothermic reaction does not typically pose a significant problem. However, in the production of ingots of sufficient size for use in EBPVD processes, the exothermic reaction can be catastrophic to the processing equipment and therefore hazardous to personnel.
In view of the above, what is needed is a process for preparing, casting and processing an ingot of a beta-phase NiAl-based material that would be suitable for use in PVD coating processes, and particularly for creating relatively large cylindrical ingots for EBPVD processes and machinable stock material for cathodic arc and sputtering processes.
BRIEF SUMMARY OF THE INVENTION
The present invention is a process for preparing, casting and processing a beta-phase NiAl-based material, particularly for use in PVD coating processes. Materials produced by the process of this invention are preferably in the form of ingots that are crack-free, full density, chemically homogeneous, and capable of being machined to dimensional tolerances suitable for use in a PVD machine. In addition, the process is carried out so as to avoid the violent exothermic reaction between nickel and aluminum when beta-phase NiAl is melted.
The method entails melting a nickel-aluminum composition having an aluminum content below that required for stoichiometric beta-phase NiAl intermetallic so as to form a melt comprising nickel and Ni 3 Al. Aluminum is then added to the melt, causing an exothermic reaction between nickel and aluminum as the melt equilibrium shifts from Ni 3 Al to NiAl. However, the aluminum is added at a sufficiently low rate to avoid a violent exothermic reaction. The addition of aluminum continues until sufficient aluminum has been added to the melt to yield a beta-phase NiAl-based material, i.e., containing the NiAl beta-phase. The beta-phase NiAl-based material is then solidified to form an ingot, which is heated and pressed to close porosity and homogenize the microstructure of the ingot.
The process of this invention is capable of producing ingots of a variety of beta-phase NiAl intermetallic materials, including those that contain chromium, zirconium and/or hafnium. Importantly, the process enables the production of relatively large ingots for use in EBPVD processes and machinable stock material for use in cathodic arc and sputtering processes, while avoiding the risk of the potentially catastrophic effect of the exothermic reaction that occurs when beta-phase NiAl is melted. As a result, ingots produced by this invention are particularly well suited for use in physical vapor deposition processes used to deposit beta-phase NiAl coatings, such as overlay environmental coatings and bond coats used in TBC systems to protect components from thermally hostile environments, including components of the turbine, combustor and augmentor sections of a gas turbine engine.
Other objects and advantages of this invention will be better appreciated from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a schematic representation of a portion of an electron beam physical vapor deposition apparatus used to evaporate a beta-phase NiAl-based intermetallic material produced by the process of this invention.
DETAILED DESCRIPTION OF THE INVENTION
The EBPVD coating apparatus 20 depicted in FIG. 1 and discussed above is representative of the type of PVD apparatus that can utilize NiAl-based ingots 10 produced with the process of the present invention. Notable examples of beta-phase NiAl-based intermetallic materials disclosed in the previously-noted U.S. Pat. Nos. 5,975,852 to Nagaraj et al., 6,153,313 to Rigney et al., 6,255,001 to Darolia, and 6,291,084 to Darolia et al., which contain one or more of chromium, hafnium, titanium, tantalum, silicon, gallium, zirconium, calcium, iron, cerium and/or yttrium. It is believed that the process of this invention is also suitable for producing other beta-phase NiAl materials.
As discussed above, the NiAl alloys disclosed by Nagaraj et al., Rigney et al., Darolia and Darolia et al. are formulated as environmental coatings and bond coats for gas turbine engine applications, represented by the component 30 shown in FIG. 1 . Intense heating of the NiAl ingot 10 by the electron beam 26 causes molecules of the NiAl material to evaporate, travel upwardly, and then deposit (condense) on the surface of the component 30 , all in a manner known in the art. For deposition by a PVD process, the beta-phase NiAl ingot 10 preferably is at full density (e.g., pore-free) and chemically homogeneous to reduce spitting, which is an ejection of a particle from the molten pool that causes undesirable macroparticles to be incorporated into the coating 32 . In addition, the ingot 10 preferably has sufficient mechanical integrity to be machinable for obtaining the dimensions and dimensional tolerances required for the particular PVD machine. These and other challenges are compounded by the concern for the violent exothermic reaction that takes place between nickel and aluminum when beta-phase NiAl is melted.
The above concerns and challenges are overcome by a process that entails initially melting a composition of nickel and aluminum, in which the aluminum content is below that necessary to form beta-phase NiAl intermetallic (i.e., below about 31 atomic percent aluminum relative to the nickel content). In a preferred embodiment, an initial charge of nickel and aluminum (and potentially other alloying ingredients) containing less than the peritectic 25.5 atomic percent aluminum, such as about 20 atomic percent aluminum (relative to the nickel content of the charge), is melted in a vacuum induction melting (VIM) furnace by increasing power to the furnace until the charge is melted. Prior to introducing the initial charge, revert (previously reacted beta-NiAl, Ni 3 Al, with or without other alloying constituents), typically in an amount less than 50 wt. % of the total melt, may be melted in the crucible to reduce or buffer the exothermic reaction. At about 20 atomic percent aluminum, the melt is a mixture of nickel and the intermetallic phase Ni 3 Al (nominally 75 and 25 atomic percent nickel and aluminum, respectively), the latter having a eutectic melting point of about 1385° C. To raise the aluminum content sufficiently to obtain beta-phase NiAl (having stoichiometric aluminum content of 50 atomic percent), elemental aluminum is slowly added to the melt. When aluminum is added in an amount at and above the peritectic point (25.5 atomic percent aluminum), an equilibrium is established between NiAl (solid), liquid metal (nickel) and Ni 3 Al (solid). The addition of aluminum causes a shift in the equilibrium toward NiAl, associated with a tremendous release of energy (the exotherm) in the reaction of the molten metal and Ni 3 Al to form NiAl. As a result of this energy release, power to the VIM furnace can be reduced. Subsequent slow additions of aluminum and adjustments in power to the VIM furnace are then needed to take the melt composition toward the targeted beta-phase NiAl composition, at which point essentially all of the nickel and aluminum of the original nickel-aluminum composition and essentially all of the added aluminum has exothermically reacted to form beta-phase NiAl. Throughout the process of adding aluminum, the melt within the VIM furnace is continuously stirred as a result of induction melting and the exothermic reaction, ensuring a homogeneous melt.
In view of the above, the melting process of this invention can utilize a relative low amount of energy to create a melt of NiAl because the initial melt is molten at a temperature less than the melting temperature of NiAl (about 1640° C.), and subsequent temperature increases can be achieved without little or no increase in power to the furnace by careful additions of aluminum to control the exothermic reaction. This benefit is in addition to the basic need to control the violent exothermic reaction between nickel and aluminum that might otherwise cause operator injury and equipment damage (e.g., excessive liner deterioration, spills, etc.).
Following the melt process, additional steps may be required to produce a fully dense, crack-free ingot of beta-phase NiAl-based material. In the process of pouring the melt into a suitable crucible for solidification, a hot top or riser is preferably used by which additional melt is available to fill the porosity as it develops in the solidifying ingot. The solidification (casting) process can be carried out using known techniques to produce polycrystalline, directionally-solidified or single-crystal ingots of NiAl. The resulting ingot undergoes hot isostatic pressing (HIPping) to further close porosity and other defects, and to homogenize the microstructure of the ingot. Prior to a high temperature heat treatment, HIPping may also be necessary to improve the evaporative qualities of the ingot, and/or to put into solution any secondary phases that are present in addition to the NiAl beta-phase as a result of the particular NiAl-based composition. For example, if the NiAl-based composition is alloyed to contain titanium, zirconium and/or hafnium, beta prime (β′) Heusler phases (Ni 2 AlX where X may be Ti, Hf. Zr, Ta, Nb and/or V) will be present, namely Ni 2 AlZr and/or Ni 2 AlHf. Other Heusler phases are possible, depending on the composition of the melt. If chromium is present in the melt (e.g., the desired composition is NiAl+CrZr), alpha chromium (α-Cr) secondary phases may also be present. If these additional phases are not solutionized, the ingot will likely be very brittle, with the result that subsequent machining (e.g., centerless grinding to obtain a uniform diameter) may cause extensive cracking. In order to put these phases in solution without melting them, it is believed that very slow temperature increases must be performed prior to the HIPping process.
The following heat treatment schedule is devised for the dissolution of secondary phases prior to performing the HIPping operation. As noted above, those heat treatment steps (steps 1-6) performed before HIPping can be omitted, as can the fast cooling rate of step 8, if the NiAl-based composition does not contain titanium, zirconium, hafnium or other elements that would produce secondary phases requiring dissolution.
(1) Heat treatment at a temperature of about 2300° F. (about 1260° C.) for a duration of about twelve hours.
(2) Heat at a rate of about 200° F./hour (about 10° C./hour) to about 2375° F. (about 1300° C.) and hold for a duration of about twenty-four hours.
(3) Heat at a rate of about 200° F./hour (about 10° C./hour) to about 2425° F. (about 1330° C.) and hold for a duration of about twenty-four hours.
(4) Heat at a rate of about 200° F./hour (about 100° C./hour) to about 2500° F. (about 1370° C.) and hold for a duration of about thirty-two hours.
(5) Cool at a rate of about 100 to about 150° F./minute (about 55 to about 850° C./minute) to a temperature of less than 1800° F. (about 980° C.).
(6) Cool at any suitable rate to room temperature (about 25° C.).
(7) After heating at any suitable rate, HIP at about 2200° F. (about 1200° C.) up to near the melting temperature for a duration of about six hours at a pressure of about 15 to 30 ksi (about 100 to 200 MPa), preferably about 20 ksi (about 140 MPa);
(8) Cool at a rate of about 100 to about 150° F. minute (about 55 to about 85° C./minute) to less than 1800° F. (about 980° C.).
(9) Cool at any suitable rate to room temperature (about 25° C.).
All of the above steps are performed in an inert atmosphere, such as argon.
Following HIPping, the ingot may be machined to a final desired dimension, such as by centerless grinding (for a cylindrical bar), with the removal rate being adjusted to induce low stresses as known in the art. Alternative machining techniques include electrochemical machining (ECM) and electro-discharge machining (EDM) under low power and adequate coolant flow. If required to produce a better surface finish, the ingot can be chemically polished in a solution of about 15 volume percent HNO 3 and about 85 volume percent H 3 PO 4 for about five to thirty minutes at a temperature of about 125 to 150° F. (about 50 to about 65° C.).
In practice, the above processing steps have been shown to enable the production of NiAl-based ingots of a size and quality suitable for use in EBPVD processes to form overlay coatings. Additional benefits include the use of lower initial melt temperatures, lower power input levels to the melt furnace, and improved lives for the melting furnace liner and crucibles by avoiding excessive heating during the exothermic reaction when NiAl is melted.
While the invention has been described in terms of a preferred embodiment, it is apparent that modifications could be adopted by one skilled in the art. Accordingly, the scope of the invention is to be limited only by the following claims. | A process for casting and preparing an ingot of a beta-phase NiAl-based material, particularly for use in PVD coating processes. The method entails melting a nickel-aluminum composition having an aluminum content below that required for stoichiometric beta-phase NiAl intermetallic so as to form a melt that includes nickel and Ni 3 Al. Aluminum is then added to the melt, causing an exothermic reaction between nickel and aluminum as the melt equilibrium shifts from Ni 3 Al to NiAl. However, the aluminum is added at a rate sufficiently low to avoid a violent exothermic reaction. The addition of aluminum continues until sufficient aluminum has been added to the melt to yield a beta-phase NiAl-based material. The beta-phase NiAl-based material is then solidified to form an ingot, which is then heated and pressed to close porosity and homogenize the microstructure of the ingot. | 2 |
BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to a mounting clamp and in particular to a mounting clamp for attaching accessories such as a pick-up truck cap to the bed of a pick-up truck.
Several clamps have been developed for use in securing accessories such as a pick-up truck cap, a tonneau cover, a cab spoiler, bed rails, etc., to a pick-up truck bed. One type of truck bed clamp includes two clamping parts pivotally connected to one another and adjustable by a threaded bolt. However, depending upon the thickness of the parts being clamped together, the two clamping surfaces may not be parallel to one another in the clamped position, compromising the clamping strength. This is due to the relative rotation of the clamp parts.
The disadvantage of pivotally connected clamp parts has been overcome by another clamp that provides two parts having a pair of engaging surfaces. During adjustment of the clamp, the two parts slide relative to one another along the engaging surfaces to securely fasten items to the truck bed. The sliding motion between parts allows the clamping surfaces to remain parallel to one another over a range of material thicknesses being clamped together. However, with such a clamp having only one pair of engaging surfaces between the two parts, the bolt used to hold the clamp parts together experiences high bending loads in addition to the tensile loads necessary to produce the clamping load.
Accordingly, it is an object of the present invention to provide an improved truck bed clamp configured to avoid bending loads in the attaching bolt and to maintain the clamping surfaces parallel to each other.
It is a feature of the clamp of the present invention to provide two clamp members in which one member is formed with a pocket into which a leg of the other member is slidably received. The result is two pairs of engaging surfaces between the two members which enables the received leg to be contacted on two sides by the receiving member. Contact on both sides of the received leg enables the internal bending moment in the clamp to be carried by the clamp members themselves rather than being carried through the securing bolt.
It is a further feature of the clamp of the present invention that the contact between the engaging surfaces is in the form of point contact rather than surface to surface contact. This results in less friction between the members. To further reduce the friction, the contact points are formed by bushings made of ultra-high molecular weight polyethylene which is self lubricating. When clamping loads are applied to the clamp members, resulting in internal bending stresses, the low friction between the clamp members facilitates relative movement of the clamp members.
It is a further feature of the clamp of the present invention that one or both of the clamping surfaces are formed with rubber bushings to avoid damage to the surfaces engaged by the clamp.
The two clamp members are attached to one another by a bolt slidably carried by one member and threadably received by the other. In a preferred embodiment of the clamp, the two clamp members are made of extruded aluminum. To provide increased strength to the threaded bolt attachment, a captured nut is mounted to the member receiving the bolt and both the bolt and the nut are made of steel. Steel has greater strength than the extruded aluminum for a threaded attachment.
One or both of the clamp members can be formed with means for mounting additional accessories to the clamp itself separate from the accessory mounted to the truck bed between the two clamping surfaces of the clamp members.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a pick-up truck showing the clamp of the present invention being used to attach accessories to the truck bed;
FIG. 2 is a vertical sectional view of one embodiment of the truck bed clamp of the present invention shown in use attaching a cap to a truck bed;
FIG. 3 is a sectional view of the clamp as seen from the line 3--3 of FIG. 1; and
FIG. 4 is a sectional view of an alternative embodiment of the clamp of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The truck bed clamp 10 of the present invention is shown in FIG. 1 in use attaching accessories to the bed 6 of pick-up truck 7. The clamps 10 are used to attach a cab spoiler 8 and a rear wing 9 to the truck bed. Other accessories such as a truck cap, tonneau cover etc., can be attached to the truck bed with clamps 10.
Clamp 10 is shown in greater detail in FIGS. 2 and 3 and includes two principal components, a receiving member 12 and a received member 14. The terms "receiving" and "received" will be further described below. The clamp 10 as shown in FIG. 2 is in use securing a truck cap 16 to a truck bed 18. This is accomplished by securing a horizontal lower flange 20 of the cap to a horizontal upper flange 22 of the truck bed with a resilient gasket 24 therebetween.
The received member 14 is generally U-shaped including a base portion 36 and a pair of generally parallel legs 32 and 34 extending therefrom. Leg 32 ends in a clamping pad 56 which faces in the same direction which leg 34 extends from the base portion 36.
The receiving member 12 is generally an F-shaped member having a base portion 30 from which extends a pair of generally parallel legs 26 and 28 The distal end of base portion 30 forms a clamping pad 31 which faces in the direction of extension of the legs 26 and 28 for engagement with one of the two objects being clamped together. The two legs 26 and 28 of the receiving member 12 form a pocket 38 therebetween for receiving the leg 34 of the received member 14. Hence the labels "receiving" and "received" for the two members 12 and 14 respectively.
The two clamping pads 31 and 56 are positioned in confronting juxtaposition relative to one another by insertion of the leg 34 of member 14 into the receiving pocket 38 of the receiving member 12. As the leg 34 is inserted further into the pocket, the two clamping pads 31 and 56 are brought closer together. The spacing between the two clamping pads is determined by the amount of insertion of the leg 34 into the pocket 38. As a result, the length of the shortest leg, leg 28, determines the operating range of the clamp 10.
The received leg 34 is formed near its distal end 40 with a groove 42 into which a bushing 44 is seated. The bushing 44 engages the flat engagement surface 46 of the leg 28. Likewise, the leg 26 of the receiving member includes, at its distal end 48, a groove 50 similar to the groove 42 which mounts a bushing 52. The bushing 52 contacts the flat engagement surface 54 of the leg 34 of the received member. Surface 46 of the leg 28 is parallel to flat engagement surface 54 of the leg 34. As a result, the two clamping pad surfaces remain parallel to one another regardless of the adjusted position of the two clamp members.
The two bushings 44 and 52 are made of ultra-high molecular weight polyethylene which has a low coefficient of friction and which is self-lubricating. This provides smooth operation of the clamp as the two members are moved relative to one another while clamping loads are present. This is in contrast to clamp members engaging in surface to surface engagement where the clamp loads can produce high friction forces at the sliding engagement surfaces.
Clamping pad 56 is formed with a pair of grooves 58 for mounting resilient rubber rods 60 to provide a "no damage" clamping surface. The clamping pad 31 is shown with integral grooves forming the clamping surface but can alternatively be made identical to the clamping pad 56 with rubber rods.
The leg 34 mounts a nut 62 or other insert with a threaded bore 64. The insert is mounted in a manner which prevents rotation of the nut 62 about the axis of its threaded internal bore. The nut can be mounted to the leg 34 by a punching operation, adhesive or the like, or the nut could be free until held by the bolt 68. The receiving member 12 includes a non-threaded bore 66 through the base portion 30 at the closed end of the pocket 38 for passage of a shaft 68 of a bolt 70. The lower portion 72 of the shaft 68 is threaded to enable the bolt to be threadably received by the nut 62. The bolt 70 positions the two clamp members relative to one another to provide the clamping force at the two clamping pads 31 and 56. Clockwise rotation of the bolt 70, as viewed at the bolt head, draws the nut 62 further onto the bolt. This draws the leg 3 further into the pocket 38 and draws the clamping pad 56 of the received member toward the clamping pad 31 of the receiving member.
As the two clamping pads bear against the objects being clamped together, a load is applied to the clamp members 12 and 14 at the clamping pads. This load is carried through the clamp members and a side load is developed at the contact points of the two bushings 44 and 52 with the smooth walls they engage. The side loads balance the internal moments within the clamp members produced by the clamp loads. As the distance between the two clamping pads decreases, the bushings 44 and 52 are moved further away from one another and the magnitude of these side loads is reduced.
By sliding the leg 34 into a pocket with contact points on both sides of the leg 34, the two clamp members will remain aligned with one another upon the application of a clamping load. The side loads produced between the clamp members balance the internal moments such that the bolt 70 will not experience bending loads.
The clamp members 12 and 14 can be made of any of several materials. In a preferred embodiment, they are made from extruded aluminum bars which have been cut to a predetermined thickness. Aluminum has a high strength to weight ratio resulting in a light weight clamp. After cutting, the bore 66 is machined into the receiving member 12 and the nut 62 is secured in the received member 14. The bushings 44 and 52 and the rubber rods 60 are also installed. The use of a steel nut 62 or other threaded steel insert within the aluminum clamp member provides greater clamping strength as compared to forming the screw threads directly in the extruded aluminum. If the added strength of the steel nut is not needed, a threaded bore can be formed directly in received leg 34.
The received member 14 also includes a lateral passage 74 formed therein which can be used as a tie-down hole for securing objects within the truck bed. Additionally, other attaching features can be formed into the two clamp members for mounting other accessories to the truck bed. An alternative embodiment of the clamp 10 is shown in FIG. 4 and designated as Clamp 10a shows an accessory mount in a clamp member. In clamp 10a, similar elements to elements of clamp 10 have been given the same reference numeral with the suffix "a". The clamp 10a is functionally identical to the clamp 10 described above. The primary difference in the configuration of clamp 10a is that the leg 32 of clamp 10 has been moved from clamp member 14 to clamp member 12a forming a leg 32a. This positions the clamping pad 31a at a distance from the arm or base portion 30a of the number 12a. Conversely, the clamping pad 56a of member 14a is mounted directly to the base portion 36a.
Like the clamp 10, clamp 10a includes a tie down hole 74 to enable objects to be tied to the clamp 10a. In addition, the clamp 10 includes a second nut 78 mounted to the member 14a in a manner that prevents rotation of the nut about the axis of its internally threaded bore. The nut 78 threadably receives a threaded bolt shaft 80 used to attach the cab spoiler 8 to the clamp 10a and thereby attaching the cab spoiler to the truck bed 6. The bolt 80 passes through a horizontal mounting flange 82 on the inside of the cab spoiler 8.
As shown in FIG. 4, the clamp is only used to mount the cab spoiler 8, that is, no other accessory is mounted to the bed 6 between the clamping surfaces of the clamp. If desired, the clamp can also be used to clamp an object or other accessory to the pick-up bed 6 between the two clamping pads 31a and 56a as shown with the clamp 10 of FIGS. 2 and 3.
The clamp of the present invention thus provides numerous features as described above which improve upon previously available truck bed clamps. These features include contact of the received member on both sides of the received leg to eliminate bending stresses in the clamping bolt; low friction bushings at the contact points; a steel nut and bolt for holding the two extruded aluminum clamp members together and the addition of tie down holes or other accessary attachment means to the clamp members.
It is to be understood that the invention is not limited to the exact construction illustrated and described above, but that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the following claims. | A clamp for use in attaching a cap or other accessory to the bed of a pickup truck comprising a receiving member forming a receiving pocket and a received member having a leg insertable into the pocket of the receiving member. The received leg is contacted on both sides by the receiving pocket to maintain alignment of the two members to keep the clamping surfaces parallel to one another. Single point contact is provided between the received leg and the walls of the pocket to reduce friction. The two sided contact with the received leg eliminates bending stress in the attaching bolt. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
Applicants claim priority under 35 U.S.C. §119 of GERMAN Application No. 101 03 859.3 filed on Jan. 30, 2001. Applicants also claim priority under 35 U.S.C. §365 of PCT/EP02/00891 filed on Jan. 29, 2002. The international application under PCT article 21(2) was not published in English.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention concerns a bundle of tubes for the laying of tubes by means of a trenchless laying according to the fluid-assisted drilling method in which in a first drilling process a drilling channel is generated and during the retracting movement of the boring-flushing head this drilling channel is expanded and in this process the bundle of tubes is retracted into the drilling channel, and a procedure for the parallel laying of tubes by means of a trenchless laying according to the fluid-assisted drilling method in which in a first drilling process one drilling channel is generated and during the retracting movement of the boring-flushing head this drilling channel is expanded and in this process a bundle of tubes is retracted into the drilling channel.
2. The Prior Art
The laying of tubes according to the so-called horizontally fluid-assisted drilling method is used increasingly to be able to lay tubes or also wires with building measures as few as possible at the surface also in the inside urban area retentively built-up, for example. Particularly by the use of so-called controlled drilling proceedings the fluid-assisted drilling method offers an economic and fast alternative for the conventional laying of tubes and wires in the open trench. The application spectrum extends on many tube building measures in the context of the gas, long-distance energy supply and drinking water supply as well as the laying of sewage pressure tubes as well as cable protection tubes for TV or telecommunications, traffic conducting systems, emergency telephones or for low-, medium-, high-voltage cables and light wave conductors. Underrunning fluxes, channels, motorways, track ways or the like approximately without impediment of the operation is also possible.
At the fluid-assisted drilling method in a first pass with a boring-flushing head a small drilling channel in respect of the crosscut is bored which, controlled by probes, shows if possible the desired course below a surface. If the first drilling channel is finished then this drilling channel is enlarged to the needed crosscut dimensions in one or several passes by the use of respective expanding heads, normally this expansion is carried out during the pulling back of the boring-flushing head after the first pass. For this the original boring-flushing head is replaced by an expanding head which is milling at its periphery and expanding the drilling channel by milling in retreat direction. Therefore water is injected at high pressure into the boring zone, whereby also supplements of so-called Bentonit contribute to an improvement in the drilling behaviour and a hardening of the drilling channel. This process of the crosscut enlargement is carried out repeatedly if necessary. At the last process of this kind the tube or like to be pulled in is attached to the expanding head so that after the complete running through of the now extended drilling channel the needed arrangement of the drilling channel with the tube is readily carried out.
For the further rationalization it is increasingly tried out, to lay not only one pipe in one pass but just more tubes in the same pass if possible. This is particularly useful if different tubes shall be laid newly simultaneously with different functions in the context of rehabilitation measures, for example, furthermore it is made approximately better use of the needed building space within for example a street as if in several single drilling events the individual tubes must be laid separately with greater distances to each other respectively. It is problematically in this way of combined laying of several tubes inside such a drilling channel created by means of the fluid-assisted drilling method that the tubes are charged on torsion along the laying length because of the rotary movement of the boring-flushing head and the expanding head and therefore twist themselves to each other. On the one hand, this leads to a strong load of the material of the tubes, through what either the tubes can break or are no longer passable through by buckling, on the other hand, the location of the tubes is completely uncertain to each other or to the surface at the mounting place. This is particularly problematic by the fact that the connection of consumers gets approximately problematic in the case of combined drawing-in gas tubes, water tubes and vacant tubes for telecommunications and the like if due to the twisting the for example gas tubes and water tubes in the departure place just lie below the vacant tubes for the telecommunications. By this e.g. the attaching of T-pieces or junctions gets problematic, through what additional building measures become necessary in the respective departure places which considerably make more expensive the complete proceedings. It also can happen that the tubes don't keep a provided distance to each other so that there isn't a corresponding mounting space sufficiently for fittings etc.
SUMMARY OF THE INVENTION
It is therefore an object of the invention on hand to develop further a bundle of tubes or a procedure for the parallel laying of tubes according to a fluid-assisted drilling method so that a laying also of several tubes can be carried out without twisting of the bundle of tubes or change of the distances between the tubes so that the retracted bundle of tubes is always laid in defined spatial position relative to each other and to the surroundings.
The solution of the object according to the invention results by providing a bundle of tubes for the laying of tubes by means of a trenchless laying according to the fluid-assisted drilling method in which in a first drilling process a drilling channel is generated and during the retracting movement of the boring-flushing head this drilling channel is expanded and in this Process the bundle of tubes is retracted into the drilling channel, wherein the bundle of tubes is formed by a number of single tubes which are ordered in distance to each other by means of flanges distantly arranged at the tubes in lengthwise direction of the tubes. With regard to the Procedure, the invention provides a method for the parallel laying of tubes by means of a trenchless laying according to the fluid-assisted drilling method in which in a first drilling process one drilling channel is generated and during the retracting movement of the boring-flushing head this drilling channel is expanded and in this process a bundle of tubes is retracted into the drilling channel wherein during the retraction of the rotating boring-flushing head and expanding of the drilling channel the rotary movement of the boring-blushing head is not transmitted to the bundle of tubes by means of a device for rotary decoupling and the bundle of tubes is pulled through the drilling channel supported in constant spatial Position of the tubes to each other and to the surroundings by means of stabilizing devices inside the drilling channel. Further advantageous developments of the invention are discussed below.
The solution according to the invention in one aspect starts out from a bundle of tubes for the laying of tubes by means of a trenchless laying according to the fluid-assisted drilling method, in which in a first drilling process a drilling channel is generated and during the retracting movement of the boring-flushing head this drilling channel is expanded and in this process the bundle of tubes is retracted into the drilling channel. Such a bundle of tubes is developed further in a way according to the invention in such a manner, that the bundle of tubes is formed by a number of single tubes which are ordered in distance to each other by means of flanges distantly arranged at the tubes in lengthwise direction of the tubes. By this the tubes are fixed to each other according to the distances of the flanges to each other and therefore can move no longer or no longer inadmissibly themselves relatively to each other. By this furthermore a considerably stiffer connection of the individual tubes is formed, which is much more resistant against twisting and torsions than the individual tubes not fixed to each other in case of conventional pulling-in of several tubes simultaneously. By this the bundle of tubes twists itself not so much in case of conventional pulling-in into a drilling channel according to the fluid-assisted drilling method, as this happens during laying of single tubes not fixed to each other. This further development of the invention is of course also analogously transferable to the pulling-in of only one tube if for example torsion loads would lead to inadmissible or not desirable material loads.
A further improvement at laying of bundles of tubes is obtainable by the way, that at the rotating boring-flushing head a non co-rotating expanding cone is arranged in such a manner, that the expanding cone expands during the pulling back the drilling channel generated by the boring-flushing head to the needed crosscut dimensions for the laying of the bundle of tubes. The non co-rotating expanding cone causes therefore an exact generation of the drilling channel suitable for the pulling-in of the bundle of tubes provided with the flanges, whereby it is a special advantage, that in a further development the expanding cone presses flat against the walls of the drilling channel covered with mud and generated by the boring-flushing head and is supported by these walls and the spatial position of the expanding cone relative to the surroundings is stabilized. By this it is ensured for certain, that the bundle of tubes fixed to the expanding cone does not underlie the rotary movement generated by the boring-flushing head and is stressed not or only very little on torsion. The support of the expanding cone at the walls of the drilling channel as well as an appropriate device for the decoupling of the rotary movement of the boring-flushing head from the expanding cone capture the rotary movement of the boring-flushing head largely. At the same time the expanding cone calibrates the drilling channel so that the flanges are well drawn through the drilling channel and can support themselves at the same time to the walls of the drilling channel.
A further improvement of the stabilisation of the expanding cone in the drilling channel can be obtained thereby, that the expanding cone shows a number of, preferably symmetric, essentially axial recesses, distributed at the periphery, which stabilizes the spatial position of the expanding cone relative to the surroundings by means of the drilling mud, which penetrates here in lengthwise direction of the drilling channel. The drilling mud is compressed because of the pressure ratio between the boring-flushing head and the expanding cone and causes additionally to the surface pressure at the cone surfaces an almost form-fit support of the expanding cone.
There is a further advantage, if there is arranged at least one device for rotary decoupling between the boring-flushing head and the expanding cone, which decouples the rotary movement of the boring-flushing head from the bundle of tubes connected to the expanding cone. Such devices can for example consist of pivot bearings or the same, which are well known in the field of slings for load suspension devices and therefore shall not be described here furthermore.
A further development provides, that the flanges show dimensions, which are smaller or correspond at least in sections essentially to the cross-section of the largest diameter of the expanding cone. By this the already mentioned supporting effect also of the flanges can be obtained at the inside of the drilling channel since then the expanding cone preforms the drilling channel accordingly.
The development of the flanges provides, that the flanges are formed essentially plate-shaped and are secured to the tubes perpendicular to the lengthwise direction of the tubes. This basic construction of the flanges approximately reminding of clamps for hose pipes or the like offers a high strength for the fixation of the flanges at the tubes at simultaneously low weight of the flanges and thus only insignificant rise of the weight of the bundle of tubes in relation to the weight of the individual tubes.
A preferred embodiment provides, that the flanges show essentially at least two plate-shaped component parts, in which in the respective component parts supplementary, essentially semicircular openings are provided, in which the tubes can be inserted and which are closable by the respectively accompanying other component part sticking the tubes. By this it can be obtained, that a simple assembly of the tubes with the flanges can be carried out and the assembly is also simultaneously possible along the bundle of tubes in arbitrary places shortly before the pulling-in of the bundle of tubes into the drilling channel. So a central middle section of the flange can be inserted between the tubes forming the bundle of tubes and then the respective further component parts can be put on to the tubes and the central middle section of the flange and for example screwed together or stucked together or glued together or fixed together in an other known manner.
An embodiment provides, that the flanges are arranged in essentially regular distances at the tubes on behalf of forming the bundle of tubes. By this essentially even conditions can be achieved by the flanges with regard to the stabilization of the bundle of tubes along the complete length of the bundle of tubes.
Also it can be thought, that the flanges near to the expanding cone are arranged in a smaller distance to each other, here preferably essentially between 0.5-2 meters, as in the pull-in direction further behind the expanding cone, here preferably essentially between 3-6 meters. Particularly at the beginning of the bundle of tubes near at the boring-flushing head with his rotary movement it can be important, to provide additionally stabilization for the bundle of tubes and provide additional support areas for the flanges at the inner walls of the drilling channel.
An embodiment provides, that the flanges stay fixed to the bundle of tubes after pulling-in into the drilling channel. By the usage of so-called lost flanges it is obsolete to carry out additional building measures for the recovering of the flanges.
Also it can be thought, that the flanges can be fixed to the bundle of tubes in such a manner, that after pulling-in them into the drilling channel the flanges come to lie in stress-relieving pits driven down from the surface and can be accessibly dismantled from the bundle of tubes again.
As in the fluid-assisted drilling method often so-called unstressing pits are provided in certain distances at which the arising drilling mud is siphoned, at the same time also for example in the area of the house connection technique anyway at places apart from each other branches for the supply conducts of the houses or the like are needed, the position of the flanges at the bundle of tubes can be exactly so carried out, that the flanges come to lie approximately in these unstressing pits when the bundle of tubes is as agreed pulled-in. By this the flanges can be dismantled and reused again after pulling-in by what the costs for the production of the flanges can be apportioned on appropriately many usages.
Further stabilization of the bundle of tubes within the drilling channel can be achieved by that in the flanges openings in the region of the flanges surrounded by the tubes are provided in such a manner, that mud generated by the boring-flushing head can enter the space between two adjacent flanges and essentially body it out. Especially if to the drilling mud, as usual in the fluid-assisted drilling method, so-called Bentonit is added, then the bundle of tubes is additionally supported by means of the drilling mud entered between the two adjacent flanges against torsional strain which possibly can be guided across the expansion cone. This is caused in an advantageous way by the pressurization of the drilling mud essentially in this space which stabilizes the bundle of tubes on behalf of its spatial position to the surroundings.
Furthermore is to start out from that the outer edges of the flanges are supported by the walls of the drilling channel formed by the expanding cone in such a manner, that the flanges and the hereto fixed tubes during the pulling-in of the bundle of tubes are guided during gliding by the inner wall of the drilling channel, in which also the mud operates as antiseize agent during the movement of the flanges on the walls of the drilling channel. Easily pulling-in of the bundle of tubes is supported in addition through this and, simultaneously, further the torsion strain of the bundle of tubes is reduced due to the good support to the walls of the drilling channel.
Another improvement in the supporting effect can be achieved, if the outer profile of the flanges is formed irregular. To this contributes that the irregular profile of the flanges causes a solidification of the drilling mud adjacently to these irregular forms, by which the flanges slide along the inner wall of the drilling channel guided by the hardened drilling mud against torsion. Similar already like the arrangement of corresponding recesses at the expansion cone the drilling mud hardens also in these irregularly formed areas of the flanges and causes an additional form-fit support of the bundle of tubes in the area of the flanges.
The invention concerns furthermore a procedure for the parallel laying of tubes by means of a trenchless laying according to the fluid-assisted drilling method, in which in a first drilling process one drilling channel is generated and during the retracting movement of the boring-flushing head this drilling channel is expanded and in this process a bundle of tubes is retracted into the drilling channel. This can of course be especially a procedure for the laying of a bundle of tubes wherein the bundle of tubes is formed by a number of single tubes which are ordered in distance to each other by means of flanges distantly arranged at the tubes in lengthwise direction of the tubes. Such a generic procedure is developed further in that during the retraction of the rotating boring-flushing head and expanding of the drilling channel the rotary movement of the boring-flushing head is not transmitted to the bundle of tubes by means of a device for rotary decoupling and the bundle of tubes is pulled through the drilling channel supported in constant spatial position of the tubes to each other and to the surroundings by means of stabilizing devices inside the drilling channel. In this way in further development stabilizing devices in form of an expanding cone, especially an expanding cone wherein at the rotating head a non co-rotating expanding cone is arranged in such a manner, that the expanding cone expands during the pulling back the drilling channel generated by the boring-flushing head to the needed crosscut dimensions for the laying of the bundle of tubes, and flanges for the connection of the tubes to a bundle of tubes, especially flanges can be used that are distantly arranged at the tubes in lengthwise direction of the tubes and the bundle of tubes is pulled into the drilling channel in such a spatial position relative to the surroundings, which corresponds to the spatial position of the bundle of tubes in the pulled-in state.
There is an advantage, if tubes consisting of materials capable of bearing tensile forces are pulled in, preferably tubes made of metallic materials and/or tubes made of synthetic materials like PEHD or PEX. Such materials are usual in building pipework.
Of course it can be thought, that in a further development tubes with different diameters and/or different usage are pulled in in one common pass. So tubes can be pulled-in at the same time in a bundle of tubes for the gas supply, the electricity supply, the water supply and also the telecommunications as well as universally usable vacant tubes, for example.
Furthermore it can be thought, that the bundle of tubes is pulled off a feed roll and the flanges are pre-assembled before the pulling in.
It is also conceivable particularly at plastic tubes which can be rolled up without problems with corresponding rolling radii that the flanges are already pre-assembled on the roll and therefore only still few or no more preparations for the bundle of tubes must be made at the building site.
Another embodiment provides, that the tubes of the bundle of tubes as for example at metallic tubes are manufactured of single bar-shaped tube sections and than together with the fixing of the bar-shaped tube sections the flanges are pre-assembled before the pulling in.
BRIEF DESCRIPTION OF THE DRAWINGS
A particularly preferential embodiment of the bundle of tubes according to the invention as well as the procedure according to the invention are shown in the drawings.
It is shown in:
FIG. 1 —an arrangement of a bundle of tubes according to the invention with additional devices arranged to this,
FIG. 2 —a crosscut through a drilling channel generated by a fluid-assisted drilling method with a bundle of tubes and a flange shown in a crosscut.
In the FIG. 1 the fundamental construction of a bundle of tubes arranged according to the invention is shown in a very schematic representation, in which only the front section of the bundle 1 of tubes formed by the tubes 2 is represented with two flanges 3 ordered to this. The bundle 1 of tubes can extend in the direction contrary to the pull-in direction 15 in usual length for fluid-assisted drilling technique.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
At the left end of the bundle 1 of tubes also only schematically indicated shown is a boring-flushing head 5 in form of an expansion head, which is connected to an respective, also only partly represented drive unit by means of boring rods 18 also only represented in sections. The boring-flushing head 5 turns along the direction of rotation 19 and mills larger in an expansion proceeding a drilling channel 9 produced in a first pass. Such expansion heads 5 are in principle known and therefore shall not be further described here.
Contrary to the pull-in direction 15 of the bundle 1 of tubes into the not precisely shown drilling channel 9 behind the expansion head 5 a device 6 for the rotary decoupling is schematically shown, which for example can consist of one or a number of turning knuckled joints, by which it is guaranteed, that the rotary movement of the expansion head 5 in the turning direction 19 is transferred not or nor as much to the expanding cone 4 placed behind the device 6 . Such devices 6 for the rotary decoupling are for example variously known from the area of sling means or also the general mechanical engineering and therefore shall not here be further explained either.
Behind the device 6 for the rotary decoupling there is shown an expanding cone 4 , which here owns a similar taper angel as the boring-flushing head 5 , but simultaneously is formed with his largest diameter a little larger than the boring-flushing head 5 . The expanding cone 4 has multiple functions during the pulling-in of the bundle 1 of tubes, which will be further explained below. In the expanding cone 4 there are arranged recesses 17 , regularly distributed at the periphery of the cone area, which can for example be arranged in the form of grooves. These grooves extend essentially about the whole length of the cone area and serve for support of the expanding cone 4 at the walls 16 of the drilling channel 9 when pulling-in the bundle 1 of tubes in a manner also explained still later.
A number of tubes 2 , here of four tubes 2 , is ordered behind the expanding cone 4 at the back of the expanding cone 4 by means of coupling devices 7 also only indicated schematically. The coupling devices 7 can show for example hooked elements, this one intrude on corresponding counter-hooks or devices according to snap rings or like that. Contrary to the pull-in direction 15 one fixation each is provided at the end of the coupling devices 7 on the side of the tube at the individual tubes 2 , the coupling devices 7 is for example welded on at the tubes 2 or connected with these in another in principle known way. The forces which are transferred by the boring rods 18 to the bundle 1 of tubes when pulling-in the bundle 1 of tubes in the direction of the pulling-in direction 15 can therefore be taken by each of the tubes 2 . It has to be said that the arrangement of the tubes 2 as well as its number in the FIG. 1 of course is chosen completely arbitrarily so that the invention can refer to many different arrangements and amounts of tubes 2 with regard to the arrangement of the bundle 1 of tubes. It is also conceivable that a transfer of the invention for pulling-in only one tube 2 may be obvious, if for example this tube 2 is appropriately sensitive or other boundary conditions shall make a torsion of the tube 2 impossible.
The tubes 2 of the bundle 1 of tubes are connected to each other with two shown flanges 3 , the construction of these is indicate only roughly schematically and which are explained in an advantageous arrangement in the FIG. 2 still more precisely. The flanges 3 show corresponding openings 8 for the insertion of the tubes 2 so that the flanges 3 hold the tubes 2 of the bundle 1 of tubes. The flanges 3 are built up at least bipartitely so that at least two parts of the flanges 3 can be separated from each other for assembling at the bundle 1 of tubes or for inserting the tubes 2 into the openings 8 .
First of all it has to be mentioned between the adjacent arranged flanges 3 , that while pulling-in of the bundle 1 of tubes drilling mud which is formed at the boring-flushing head 5 presses contrary to the pulling-in direction 15 into the drilling channel 9 and is on the one hand compressed into the recesses 17 in the expansion cone 4 , while simultaneously flows through openings 14 represented still more precisely in the FIG. 2 which are provided in the flanges 3 . By this a mud storage capacity 24 is each formed between the two adjacent flanges 3 and of course in the flanges 3 arranged behind this contrary to the pulling-in direction 15 , which fundamentally contributes to the stabilization of the spatial position of the bundle 1 of tubes in still more precisely described form.
In the FIG. 2 is now once again to recognize more exactly in a cut top view the construction of a flange 3 . The flange 3 is here arranged in a drilling channel 9 which has resulted of the expansion by the expanding head 5 and pulling-in through the expansion cone 4 . The largest dimensions of every flange 3 are essentially identical with the dimensions of the walls 16 of the drilling channel 9 so that every flange 3 at least in sections fits closely to the walls 16 of the drilling channel 9 .
The flange 3 is built up essentially three-partly in which a central middle part 20 is plugged in between the great upper and the smaller below arranged tubes 2 . In the middle part 20 respectively semicircular openings 23 are provided in which the tubes 2 can be inserted. Respectively on the upper side of the upper tubes 2 and sub-sided of the lower tubes 2 further parts of the flange 3 formed like clamps are to be seen, namely a upper part 21 und a lower part 22 . In this upper part 21 und the lower part 22 corresponding also semicircular openings 23 are let in which corresponds with the semicircular openings 23 of the middle part 20 and complete these to a full circle. The diameters of these openings 23 correspond essentially to the diameter of the respective tube 2 in which the dimensions are chosen so that the tubes 2 are friction-lockedly held by means of attachment screws 10 in the now completed flange 3 after mounting of upper part 21 und lower part 22 onto the middle part 20 . It has to be taken care that the tubes 2 are not stuck too strongly to cause no damages to the tubes 2 . With this multisectional construction of the flange 3 it is possible to arrange and to fasten certainly the flange 3 in any arbitrary place of the bundle 1 of tubes also shortly before pulling-in into the drilling channel 9 . A dismantling is also relatively simply possible in ditches, for example, since the attachment screws 10 are accessible relatively well and the flange 3 therefore can easily be removed from the tubes 2 .
Also can be recognized in the FIG. 2 that the flange 3 only in sections fits closely to the walls 16 of the drilling channel 9 in which below the upper tubes 2 recesses of the outer profile of the flange 3 can be recognized which fill themselves with compressed drilling mud 13 in a manner still described and stabilizes the position of the flange 3 and with that the bundle 1 of tubes within the drilling channel 9 . A largely free crosscut 25 above the flange 3 can be recognized which serves for the removal of the superfluous drilling mud 13 . Since the bundle 1 of tubes shows of course a corresponding deadweight, the flange 3 will support himself in the area essentially sub-sided of the edges marked by the subject numbers 12 and the lateral areas next to the large tubes 2 at the inner wall 16 of the drilling channel 9 . Already alone by this a corresponding stabilization of the bundle 1 of tubes can be achieved since by means of friction between the outer profile of the flange 3 and the walls 16 a respective support on behalf of torsion loads is possible, which can be transferred to the flanges 3 or the bundle 1 of tubes as residuals of the rotary movement of the boring-flushing head along the direction 19 of rotation.
Also can be recognized in the FIG. 2 that in the flanges 3 there are provided openings 14 for penetrating drilling mud 13 from the area in pulling-in direction 15 in front of the flange 3 to the area in pulling-in direction 15 behind the flange 3 . These openings 14 which can of course be arranged differently lead to that the drilling mud 13 , which is generated under a high pressure in the area of the boring-flushing head 5 can essentially fill out the mud storage capacity 24 between adjacently arranged flanges 3 and in addition stabilizes the bundle 1 of tubes in this mud storage capacity 24 of his spatial position. One can imagine this drilling mud as a kind of stopper, which consists of the drilling mud which is quite thick and simultaneously still compressed and counteracts toughly a twist of the bundle 1 of tubes on behalf of a torsion load transferred from the boring-flushing head 5 . This drilling mud can of course leave again in the further course of the drilling process contrary to the pulling-in direction 15 by the openings 14 provided by the next flange 3 or by the free crosscut 15 and be promoted to behind.
The drilling mud which is generated in the area of the boring-flushing head 5 , will also accumulate in the area of the projections of the profile of the flange 3 below the large tubes 2 and harden in this area, by which an additional support effect is also performed on the flange 3 and with that on the bundle 1 of tubes.
Another support effect arises in that the expanding cone 4 also fits closely at the walls 16 of the drilling channel 9 at least with the area of the largest diameter, which is as a rule a little greater than the diameter of the boring-flushing head 5 , during pulling-in of the bundle 1 of tubes in pulling-in direction 15 and supports itself because of the drawing movement against these walls 16 . Because of the surface pressure arising between the walls 16 of the drilling channel 9 and the expansion cone 4 also a support of torsional moments is ensured, the drilling channel 9 is calibrated in his dimensions simultaneously and by this the passage of the flanges 3 through the drilling channel 9 is improved.
The special construction of the bundle 1 of tubes or also the sequence of operations of the proceedings according to the invention can generally be described so that by the prominently described measures for the stabilization of the bundle 1 of tubes in the drilling channel 9 it is provided that independent of the turning movement of the boring-flushing head 5 the bundle 1 of tubes keeps strictly its spatial position in between the drilling channel 9 , namely keeps that spatial position, in which the bundle 1 of tubes was fed into the drilling channel 9 initially. This has the great advantage that the spatial position of the bundle 1 of tubes along the drilling channel 9 always remains identical and by means of the effect of the flanges 3 the distance of the tubes 2 to each other remains always the same, too. On the one hand, an inadmissible load of the tubes 2 due to torsion is prevented for certain through this, on the other hand, the connection conditions are for example always the same for attaching junctions at the tubes 2 along the drilling channel 9 .
Therefore for example it cannot happen, that e.g. the large tubes 2 come to lie below the small tubes 2 by a distortion, so that a connection of a consumer or the like is not possible or only very much effort.
List of Subject Numbers
1
bundle of tubes
2
tubes
3
flange
4
expansion cone
5
boring-flushing head
6
rotary decoupling
7
coupling device
8
clamp lug
9
drilling channel
10
attachment screw
11
commissure
12
support
13
hardened drilling mud
14
passing through openings for drilling mud
15
pulling-in direction
16
walls drilling channel
17
recesses
18
boring rods
19
rotary movement boring-flushing head
20
middle part of flange
21
upperpart of flange
22
lower part of flange
23
openings for tubes
24
mud storage capacity
25
free crosscut | A bundle of tubes or pipes is arranged without trenches according to a fluid-assisted drilling method. A bore channel is made in a first boring step and the bore channel is widened when the bore/flushing head is removed therefrom, the bundle of tubes being drawn into the bore channel. The bundle is composed of individual tubes and flanges arranged lengthwise at a distance from and used as spacers for the tubes. A method is also described, wherein a rotational decoupling device prevents the rotational movement of the bore/flushing head produced during the removal process from being transmitted to the bundle of tubes. The bundle of tubes are supported by stabilizing devices inside the bore channel in the same spatial position as that of the tubes in relation to each other and the surrounding environment and are drawn through the bore channel. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims the benefit of priority to U.S. Provisional Application Ser. No. 61/196,732, filed Aug. 25, 2008, entitled “Tubule-Blocking Silica Materials for Dentifrices”, the disclosure of which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD OF THE INVENTION
[0002] This invention pertains to precipitated silica materials for utilization as abrasives or thickeners within dentifrice formulations, and more particularly to such precipitated silica materials that simultaneously effectuate tubule blocking within tooth dentin.
BACKGROUND OF THE INVENTION
[0003] Silica materials are particularly useful in dentifrice products, such as toothpastes, where they function as abrasives and thickeners. In addition to this functional versatility, silica materials, particularly amorphous precipitated silica materials, also have the advantage, when compared to other dentifrice abrasives such as alumina and calcium carbonate, of having a relatively high compatibility with active ingredients like fluoride sources including sodium fluoride, sodium monofluorophosphate, etc. Particularly relevant to their use in dentifrices is that such silica materials offer simultaneously good cleaning properties and moderate dentin abrasion levels in order to accord the user a dentifrice that effectively cleans tooth surfaces without detrimentally abrading such surfaces. The ability to provide a fluoride-compatible thickening agent for toothpaste formulations is also of great benefit to the consumer and manufacturer alike.
[0004] Tooth sensitivity has become an issue recently within the dentifrice arena, particularly in terms of the loss of enamel protection due to different eating habits and dental cleaning rituals of certain people. As such, in addition to the aforementioned abrasive and thickening benefits imparted to dentifrice products by silica materials, formulators of certain specialty dentifrice products have taken to incorporating certain materials that are useful for reducing tooth sensitivity to certain degrees. In particular, toothpastes have been designed to reduce the sensitivity of teeth to hot and cold temperatures and additional active stimuli like polysaccharide sweets and thus reduce the pain and/or discomfort associated with such undesirable sensations.
[0005] Although the causes of teeth sensitivity are not known with certainty, it is believed that sensitivity is related to exposed dentinal tubules. These tubules, which contain fluid and cellular structures, extend outward from the tooth pulp, to the surface or border of the enamel. According to some theories, age, lack of proper dental hygiene, and/or medical conditions can result in enamel loss or gum recession on the surface of teeth. Depending upon the severity of the enamel loss or gum recession, the outer portions of the dentinal tubules may become exposed to the external environment of the mouth. When these exposed tubules come into contact with certain stimuli, such as, for example, hot or cold liquids, the dentinal fluid may expand or contract causing pressure differentials within the teeth that results in discomfort and possibly pain to the subject person.
[0006] Prior efforts to address such increased sensitivity have focused on disrupting the potassium/sodium ion channel pump responsible for sending pain sensation to the brain. It is generally believed, without intending to depend on any specific scientific theory, that such a chemical mechanism has historically been imparted to a user through the inclusion of potassium nitrate within a dentifrice formulation. This alternative merely, however, prevents the ability of the body to send pain sensations; the pain still occurs, but is not actually felt by the user. This illusory effect is temporary and is lost with time, thereby requiring continued utilization of potassium nitrate-containing toothpaste for effect maintenance. Other efforts at reducing sensitivity have centered on occluding tubules within exposed dentin. In such a manner, tubule occlusion is achieved through the covering or filling of the tubule with a material such as certain types of silica materials. In preparing this “occluding material,” however, the focus has typically concerned controlling particle size to be of a size to at least partially cover the tubule opening. However, in most cases selecting occluding material based on particle size is not by itself sufficient to provide enough occlusion to obtain satisfactory sensitivity-blocking performance. Generally, the occluding material will not exhibit an affinity for the tooth surface and will thus lack proper adhesive capability to retain within, on, or around the subject tubule for a sufficient period of time to reduce the sensitivity level thereof to the necessary degree for sufficient pain and/or discomfort control, prevention, or otherwise reduction. For instance, standard precipitated silica materials will possibly occlude on a temporary basis (if provided at a suitably small particle size for such occlusion within a target tubule), but are easily removed when, for instance, the user rinses his or her mouth out with water after brushing. There is thus a need in the art for a new silica material that exhibits proper fluoride compatibility (at least with some fluoride sources), effectively small particle size for proper introduction within target dentinal tubules, proper static charge for long-term stability when introduced within a dentinal tubule, and the capability to be transferred in such a manner to a tooth and within a dentinal tubule during introduction into a user's mouth cavity and contact with the subject tooth surface during typical tooth brushing. To date, no such silica material has been provided that provides such beneficial results.
BRIEF SUMMARY OF THE INVENTION
[0007] A significant advantage of the present embodiments is the sufficient degree of affinity with target dentin surfaces exhibited by the adduct-treated precipitated silica materials to permit long-term adhesion on such dentin surfaces allowing for entry and filling of tubules therein. Another advantage of the embodiments is the ability to include such adduct-treated precipitated silica materials in dentifrice formulations as either abrasives or thickening agents and, upon brushing of the subject's teeth, such adduct-treated precipitated silica materials will transfer from the dentifrice to the tooth surfaces and occlude the target dentinal tubules.
[0008] Accordingly, in one embodiment a dentifrice comprises a precipitated silica material having a mean particle size of 1 to 5 microns and having an adduct present on at least a portion of its surface to form an adduct-treated precipitated silica material, wherein the adduct-treated precipitated silica material exhibits a zeta potential of greater than 10% of the zeta potential of a precipitated silica material of the same structure on which no adduct is present. Also encompassed is a dentifrice comprising such adduct-treated precipitated silica materials as a thickening agent, abrasive agent, or both and comprising at least one other component such as a solvent, a preservative, a surfactant, or an abrasive or thickening agent other than the adduct-treated precipitated silica materials.
[0009] Also encompassed is a method of treating a mammalian tooth comprising the steps of
[0010] a) providing a dentifrice comprising a precipitated silica material having a mean particle size of 1 to 5 microns and having an adduct present on at least a portion of its surface to form an adduct-treated precipitated silica material that exhibits a zeta potential reduction greater than 10% when compared to a precipitated silica material of the same structure on which no adduct is present;
[0011] b) applying the dentifrice to a mammalian tooth; and
[0012] c) brushing the dentifrice-applied tooth of step “b” thereby permitting occlusion of subject dentinal tubules with the adduct-treated precipitated silica material.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a series of photomicrographs showing the results of the dentifrice affinity test of a Control sample in terms of occlusion capability within dentinal tubules.
[0014] FIG. 2 is a series of photomicrographs showing the results of the dentifrice affinity test of Comparative 1 in terms of occlusion capability within dentinal tubules.
[0015] FIG. 3 is a series of photomicrographs showing the results of the dentifrice affinity test of Example 6 in terms of occlusion capability within dentinal tubules.
[0016] FIG. 4 is a series of photomicrographs showing the results of the dentifrice affinity test of Comparative 4 in terms of occlusion capability within dentinal tubules.
[0017] FIG. 5 is a series of photomicrographs showing the results of the dentifrice affinity test of Comparative 5 in terms of occlusion capability within dentinal tubules.
[0018] FIG. 6 is a series of photomicrographs showing the results of the dentifrice affinity test of Comparative 2 in terms of occlusion capability within dentinal tubules.
DETAILED DESCRIPTION OF THE INVENTION
[0019] All parts, percentages and ratios used herein are expressed by weight unless otherwise specified. All documents cited herein are incorporated by reference.
[0020] Precipitated silica materials for use in dentifrice compositions have been developed with increased affinity towards a mammalian tooth particle, thus adhering strongly to the tooth surface and providing greater occlusion over the dentinal tubules. Without being limited by theory it is believed that the increased affinity between the precipitated silica material and teeth is a consequence of the reduction of the negative charge on the surface of the precipitated silica material; this reduction is accomplished by the presence of an adduct on at least a portion of the surface of the silica.
[0021] The surface charge of silica, and manipulating that surface charge, is a much studied and explored area, if also somewhat contentious. (See e.g., Ralph K. Iler, The Chemistry of Silica: Solubility, Polymerization, Colloid and Surface Properties and Biochemistry of Silica, pp. 659-672). The use of some adducts has also been previously discussed in the patent literature, e.g., Wason, U.S. Pat. No. 3,967,563, and Wason, U.S. Pat. No. 4,122,160, although such silica materials were treated with metal adducts solely for the ability to generate transparent abrasives exhibiting large particle sizes for dentifrices.
[0022] Accordingly, in a certain embodiment a precipitated silica material has a mean particle size of 1 to 5 microns and has an adduct present on at least a portion of its surface to form an adduct-treated precipitated silica material, wherein the adduct-treated precipitated silica material exhibits a zeta potential reduction greater than 10% when compared to a precipitated silica material of the same structure on which no adduct compound is present.
[0023] In one embodiment, the adduct is a metal element. In another embodiment, the adduct is a metal element selected from the transition metals and post-transition metals. Examples of suitable metal elements include aluminum, zinc, tin, strontium, iron, copper, and mixtures thereof. The adduct-treated precipitated silica material is formed by the addition of the adduct in the form of a water-soluble metal salt during the formation of precipitated silica material. Any metal salt that is soluble in acidic conditions would be suitable, such as metal nitrates, metal chlorides, metal sulfates, and the like.
[0024] In one embodiment, the adduct-treated precipitated silica material exhibits a zeta potential reduction greater than 15% when compared to a precipitated silica material of the same structure on which no adduct is present. In another embodiment, the zeta potential reduction is greater than 20%. In still another embodiment, the zeta potential reduction is greater than 25%.
[0025] In one embodiment, the adduct-treated precipitated silica material is prepared according to the following process. An aqueous solution of an alkali silicate, such as sodium silicate, is charged into a reactor equipped with mixing means adequate to ensure a homogeneous mixture. The alkali silicate solution in the reactor is preheated to a temperature of between about 65° C. and about 100° C. The alkali silicate solution may have an alkali silicate concentration of approximately 8.0 to 35 wt %, such as from about 8.0 to about 20 wt %. The alkali silicate may be a sodium silicate with a SiO 2 :Na 2 O ratio of from about 1 to about 3.5, such as about 2.4 to about 3.4. The quantity of alkali silicate charged into the reactor is about 5 wt % to 100 wt % of the total silicate used in the batch. Optionally, an electrolyte, such as sodium sulfate solution, may be added to the reaction medium. Additionally, this mixing may be performed under high-shear conditions.
[0026] To the reactor is then simultaneously added: (1) an aqueous solution of an acidulating agent or acid, such as sulfuric acid; (2) additional amounts of an aqueous solution containing the same species of alkali silicate as is in the reactor, such aqueous solution being preheated to a temperature of about 65° C. to about 100° C. An adduct compound is added to the acidulating agent solution prior to the introduction of the acidulating agent solution into the reactor. The adduct compound is premixed with the acidulating agent solution in a concentration of mol. of adduct compound to L of acidulating agent solution of about 0.002 to about 0.185, preferably about 0.074 to about 0.150. Optionally, if higher adduct concentrations are required in the adduct-treated precipitated silica material, an aqueous solution of the adduct compound can be used in place of the acid.
[0027] The acidulating agent solution preferably has a concentration of acidulating agent of about 6 to 35 wt %, such as about 9.0 to about 20 wt %. After a period of time the inflow of the alkali silicate solution is stopped and the acidulating agent solution is allowed to flow until the desired pH is reached.
[0028] The reactor batch is allowed to age or “digest” for between 5 minutes to 30 minutes at a set digestion temperature, with the reactor batch being maintained at a constant pH. After the completion of digestion, the reaction batch is filtered and washed with water to remove excess by-product inorganic salts until the wash water from the silica filter cake obtains a conductivity of less than about 2000 μ mhos. Because the conductivity of the silica filtrate is proportional to the inorganic salt by-product concentration in the filter cake, then by maintaining the conductivity of the filtrate to be less than 2000 μ mhos, the desired low concentration of inorganic salts, such as Na 2 SO 4 in the filter cake may be obtained. The silica filter cake is slurried in water, and then dried by any conventional drying techniques, such as spray drying, to produce adduct-treated precipitated silica material containing from about 3 wt % to about 50 wt % of moisture. The adduct-treated precipitated silica material may then be milled to obtain the desired particle size of between about 1 μ m to 5 μ m. Such a particle size is imperative to provide the beneficial abrasive and/or thickening properties when in the target dentifrice formulation as well as impart the desired occlusion of dentinal tubules to reduce pain and discomfort as noted above for the subject person.
[0029] For purposes herein, a “dentifrice” has the meaning defined in Oral Hygiene Products and Practice, Morlon Pader, Consumer Science and Technology Series, Vol. 6, Marcel Dekker, NY 1988, p. 200, which is incorporated herein by reference. Namely, a “dentifrice” is “ . . . a substance used with a toothbrush to clean the accessible surfaces of the teeth. Dentifrices are primarily composed of water, detergent, humectant, binder, flavoring agents, and a finely powdered abrasive as the principal ingredient . . . a dentifrice is considered to be an abrasive-containing dosage form for delivering anti-caries agents to the teeth.” Dentifrice formulations contain ingredients which must be dissolved prior to incorporation into the dentifrice formulation (e.g. anti-caries agents such as sodium fluoride, sodium phosphates, flavoring agents such as saccharin).
[0030] When incorporated within a dentifrice formulation, the adduct-treated precipitated silica material may be present in an amount of from 0.01 to about 25% of the total weight of the entire dentifrice itself. If the adduct-treated precipitated silica material is abrasive in nature, the amount may be from 0.05 to about 15% by weight (the abrasive may act alone, or as a booster type that simultaneously provides tubule occlusion after brushing is performed). If the adduct-treated precipitated silica material is a viscosity modifiers (thickening agents), the amount may be from 0.05 to about 10% by weight. The adduct-treated precipitated silica material with the proper metal adduct present thereon for zeta potential modifications will simultaneously provide both viscosity modification and long-term tubule occlusion. If needed, however, the adduct-treated precipitated silica material does not necessarily require any characteristic other than as a tubule occluding material. As such, the amount may be within the range noted above within the dentifrice formulation, but the materials will not provide any appreciable degree of thickening or abrasivity to the dentifrice, but solely will provide tubule occlusion benefits. Such formulations may also include potassium nitrate salts, as one example, of a suitable other desensitizing materials, if desired.
[0031] The compositions and methods described above will be further understood with reference to the following non-limiting examples.
EXAMPLES
[0032] Examples were prepared to study the effect on the affinity of the silica for a mammalian tooth by adding an adduct to precipitated silica materials. In the first set of batches, prepared at pilot plant scale, several samples were prepared containing the metal adduct Al 2 O 3 , while one comparative sample used had only trace amounts of aluminum or other metals as shown in Table 1. The samples, below, were prepared as follows:
[0033] The quantities of reactants and the reactant conditions are set forth in Table 1, below. First, 67 L of an aqueous solution containing 19.5 wt % of sodium silicate (having a 3.32 molar ratio of SiO 2 :Na 2 O) and 167 L of water was charged into a 400 gallon reactor heated to 87° C. with recirculation at 30 Hz and stirring at 60 RPM. An aqueous solution of sulfuric acid (having a concentration of 17.1 wt % and containing aluminum in the concentration per acid solution specified in Table 1, below) and an aqueous solution of sodium silicate (at a concentration of 19.5 wt %, the sodium silicate having a 3.32 mole ratio, the solution heated to 85° C.) were then added simultaneously at rates of 12.8 L/min (for silicate) and 1.2 L/min (for sulfuric acid) for 47 minutes. After 47 minutes the silicate addition was stopped and the acid addition continued until the reactor batch pH dropped to 5.5. The batch temperature was then maintained at 87° C. for ten minutes to allow the batch to digest. The silica batch was then filtered and washed to form a filter cake having a conductivity of about 1500 μ mhos. The filter cake was then slurried with water, spray dried, and the spray dried product micronized by a suitable technique including jet-milling or air-milling to a particle size of about 3 μ m. A comparative precipitated silica (Comparative 2) was prepared by hammer-milling the material of Example 6 to an average particle size of approximately 10 μ m. The materials were then tested for the presence of several different metal oxides, with the concentrations listed below in Table 1.
[0000]
TABLE 1
Metal Adduct Additions
Mol
Al/L of
acid
Al 2 O 3
CaO
Fe 2 O 3
MgO
Na 2 O
TiO 2
Sample ID
solution
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
Comparative 1
—
771
26
157
60
1.29
135
Example 1
0.007
1100
31
159
68
1.15
137
Example 2
0.014
1500
38
150
72
0.96
139
Example 3
0.028
3900
30
144
74
1.03
137
Example 4
0.055
7300
40
144
77
1.70
133
Example 5
0.110
15400
44
143
89
1.29
133
Example 6
0.220
19600
37
141
79
1.48
131
Comparative 2
0.220
19600
37
141
79
1.48
131
Analysis of Inventive Materials for Tubule Occlusion and Other Characteristics
[0034] The various silica materials described herein were measured as follows, unless indicated otherwise.
[0035] The CTAB external surface area of silica was determined by adsorption of CTAB (cetyltrimethylammonium bromide) on the silica surface, the excess separated by centrifugation and determined by titration with sodium lauryl sulfate using a surfactant electrode. The external surface of the silica was determined from the quantity of CTAB adsorbed (analysis of CTAB before and after adsorption).
[0036] Specifically, about 0.5 g of silica was accurately weighed and placed in a 250-ml beaker with 100.00 ml CTAB solution (5.5 g/L, adjusted to pH 9.0±0.2), mixed on an electric stir plate for 30 minutes, then centrifuged for 15 minutes at 10,000 rpm. 1.0 ml of 10% Triton X-100 is added to 5.0 ml of the clear supernatant in a 100-ml beaker. The pH was adjusted to 3.0-3.5 with 0.1 N HCl and the specimen was titrated with 0.0100 M sodium lauryl sulfate using a surfactant electrode (Brinkmann SUR15O1-DL) to determine the endpoint.
[0037] The oil absorption values were measured using the rubout method. This method is based on a principle of mixing linseed oil with a silica by rubbing with a spatula on a smooth surface until a stiff putty-like paste is formed. By measuring the quantity of oil required to have a paste mixture which will curl when spread out, one can calculate the oil absorption value of the silica—the value which represents the volume of oil required per unit weight of silica to saturate the silica sorptive capacity. A higher oil absorption level indicates a higher structure of precipitated silica; similarly, a low value is indicative of what is considered a low-structure precipitated silica. Calculation of the oil absorption value was done as follows:
[0000]
Oil
absorption
=
ml
oil
absorbed
weight
of
silica
,
grams
×
100
=
ml
oil
/
100
gram
silica
[0038] Median particle size was determined using a Model LA-930 (or LA-300 or an equivalent) laser light scattering instrument available from Horiba Instruments, Boothwyn, Pa.
[0039] The % 325 mesh residue of silica was measured utilizing a U.S. Standard Sieve No. 325, with 44 micron or 0.0017 inch openings (stainless steel wire cloth) by weighing a 10.0 gram sample to the nearest 0.1 gram into the cup of a 1 quart Hamilton mixer Model No. 30, adding approximately 170 ml of distilled or deionized water and stirring the slurry for at least 7 min. The mixture was transferred onto the 325 mesh screen and water was sprayed directly onto the screen at a pressure of 20 psi for two minutes, with the spray head held about four to six inches distant from the screen. The remaining residue was then transferred to a watch glass and dried in an oven at 150° C. for approx. 15 min.; then cooled and weighed on an analytical balance.
[0040] The pH values of the reaction mixtures (5 weight % slurry) can be monitored by any conventional p1H sensitive electrode.
[0041] To measure brightness, samples were pressed into a smooth surfaced pellet and evaluated with a Technidyne Brightmeter S-5/BC. This instrument has a dual beam optical system where the sample is illuminated at an angle of 45°, and the reflected light viewed at 0°.
[0042] For the materials produced above, measurements of these properties were undertaken and provided in Table 2.
[0000]
TABLE 2
Properties of Prepared Precipitated Silica Materials
Mean
Median
325
Particle
Particle
Oil
H 2 O
residue
BET
CTAB
Size
Size
Absorption
5%
(%)
(%)
(m 2 /g)
(m 2 /g)
(μm)
(μm)
(cc/100 g)
pH
Brightness
Comparative 1
6.4
0.00
185
34
2.2
2.2
92
7.4
98.6
Example 1
5.7
0.01
213
31
2.5
2.5
91
7.7
98.2
Example 2
5.9
0.02
212
46
2.7
2.2
99
7.9
98.9
Example 3
6.1
0.00
210
48
2.4
2.4
102
8.1
99.4
Example 4
6.3
0.00
222
44
2.8
2.8
91
7.7
99.6
Example 5
6.2
0.00
315
53
3.1
3.0
91
8.4
98.9
Example 6
5.7
0.00
349
68
3.6
3.5
89
8.2
99.0
Comparative 2
5.7
0.10
349
68
10.9
9.5
89
8.2
99.0
[0043] Zeta potential is a measure of the charge on the external surface of a particle suspended in solution. Particles with zeta potentials of the same charge will tend to repel one another and particles with zeta potentials of the opposite charge will tend to be attracted to one another. Historically, zeta potential has been determined by microelectrophoresis, whereby an electric field is applied across a dispersion of particles and the velocity of the particles as they migrate toward an electrode of opposite charge is measured. Particles traveling at a greater velocity toward the electrode of opposite charge will tend to have an increased magnitude of charge on their surface. Alternatively, zeta potential can be determined by electrokinetic sonic amplitude (ESA) technique. ESA measures the electrokinetic properties of a particle by an electroacoustic method. A high frequency oscillating electric field is applied to a dispersion of particles. The particles will oscillate with the applied field proportional to the charge on their surface. As the particles move in one direction, the liquid they displace will move in the other. If there are density differences between the particles and the liquid medium, an acoustic wave will be generated at the interface of the electrode and the liquid dispersion as a result of the liquid that is displaced by the moving particles. The acoustic wave generated can then be measured and the intensity of the wave is then related to the magnitude of the zeta potential. Zeta potential is usually measured across a range of pH values, thus giving an indication of how the surface charge of the suspended particles varies as a function of pH (Greenwood, R. “Review of the measurement of zeta potentials in concentration aqueous suspensions using electroacoustics” Advances in Colloid and Interface Science, 2003, 106, 55-81, herein entirely incorporated by reference). The zeta potential of Comparative 1 and Example 1-6 were measured and the results are tabulated below in Table 3. As can be seen from the Table 3, the negative charge (as measured by the zeta potential) on the surface of the silica was lower for Example 6 at dentifrice pHs (i.e., between about 7 to about 9) than for Comparative 1 (the Comparatives and Examples 1-10 were sent to Colloid Measurements LLC Systems for zeta potential analysis by the ESA method).
[0000]
TABLE 3
Zeta Potentials
% Reduction in Zeta
Zeta Potential
Potential vs.
Sample
(at pH 8.0)
Comparatives
Comparative 1
−41.5
n/a
Example 1
−40.4
2.65
Example 2
−38.5
7.23
Example 3
−39.6
4.58
Example 4
−38.4
7.47
Example 5
−34.2
17.59
Example 6
−29.4
29.16
Comparative 3
−55.8
n/a
Example 7
−38.3
31.36
Example 8
−33.8
39.42
Example 9
−33.1
40.68
Example 10
−44.3
20.61
Comparative 4
−38.2
n/a
Comparative 5
−37.3
2.36
[0044] It was observed that the presence of the metal adduct had the effect of reducing the quantity of negative charge on the silica surface.
[0045] Next, the affinity between the silicas prepared above and bovine teeth (analogous to all mammalian teeth) was measured by using an atomic force microscope to measure adhesion forces. The use of atomic force microscopy (“AFM”) in this context is itself a novel procedure. Since its initial development over twenty years ago (see Binnig, G.; Quate, F. F. Phys. Rev. Lett., 56, 930 (1986)), AFM has been used in a remarkably broad array of technical fields, including such disparate fields as microelectronics (e.g., Douhéret et al., Progress in Photovoltaics: Research and Applications, 15, 713, 2007); chemistry [e.g., S. Manne et al., Science, 251, 183 (1991)] and especially the biological sciences [see especially B. Drake et al., Science 243, 1586 (1989)]. The versatility of AFM techniques are attributable to a number of factors, but among them are the fact that unlike non-optical microscope technologies such as Electron or Transmission Electron Microscopes (“EM” or “TEM”) and Scanning Electron Microscopes (“SEM”), AFMs do not require a vacuum nor special treatment of samples (e.g., sputtering or plating with a conductive layer of material). AFM is also unique in its ability to provide true three-dimensional measurements and imaging.
[0046] Sample preparation for the AFM consisted of compressing the silica to be measured into a 1.25 inch tablet using an Angstrom heavy-duty tablet press (40,000 lbs., 3 minutes hold time). The resulting tablet was then mounted onto a 15 mm AFM specimen disc using double sided adhesive tape. The prepared sample was then mounted on the X-Y stage of the AFM either on the magnetic sample holder or on the vacuum chuck directly on the stage.
[0047] Bovine teeth were obtained from the Indiana University School of Dentistry packaged in a solution of thymol. Prior to use they were sterilized in an autoclave and then stored in ethanol. Teeth were allowed to dry before any cutting or grinding was performed. AFM tips (DNP type, cantilever A, k=0.58 N/m nom.) were prepared by filing a bovine tooth with a Dremel #191 High-Speed Cutter on a Dremel 400|XPR rotary tool. A single copper filament (Hex-Wix Fine Braid solder wick, #W76-10), was used to place a small drop of epoxy (Elmers Pro Bond Super Fast Epoxy Resin) on the end of the cantilever. A separate piece of copper filament was then used to select an appropriately shaped particle of tooth (approximately spherical, roughly ˜20-30 μm in diameter) and place it into the epoxy. The AFM tip was then allowed to dry at room temperature overnight.
[0048] The AFM tip was mounted in a standard tip holder (Veeco Model #DCHNM, Cantilever Holder) or in a fluid tip holder (Veeco Model #DTFML-DD, Direct Drive Fluid Cantilever Holder) and installed on the scanning probe microscope (SPM) head of the AFM. All measurements were made following the manufacturers instructions and were carried out using a Digital Instruments Dimension 3100 AFM mounted inside an acoustic hood for vibration isolation. The instrument was controlled using NanoScope IIIa version 4.32r3 software. All raw force curve data was exported in units of V, and was converted to obtain the force in nN in a spreadsheet. The conversion was performed using the following equation provided in the Veeco Dimension 3100 users' manual:
[0000] Force (nN)=Deflection (V)×Deflection Sensitivity (nm·V −1 )× k (nN·nm −1 )
[0000] where deflection is the deflection measured on the force curve, deflection sensitivity is the slope of deflection versus Z voltage while the tip is in contact with the sample and k is the nominal spring constant of the cantilever.
[0049] Measurements were performed in both air and liquid environments. In the case of the liquid environment, a liquid tip holder was used to hold the AFM tip. In order to eliminate variation that may occur from differences in the spring constants of different AFM tips and/or differences in the size and shape of the bovine tooth fragment attached to the AFM tip, the same AFM tip was used for all measurements in a given experiment. Comparative 1 and the silica prepared in Example 6 were evaluated. For simplicity, the adhesion forces for the comparatives were set to 100 percent and the values for the examples were adjusted accordingly. The results are shown in Table 4.
[0000]
TABLE 4
Adhesion Force Measurements
Adhesion Force
In Air
In Liquid
Comparative 1
100
100
Example 6
219
135
[0050] It was observed that the inventive Example 6 containing the aluminum adduct had a greater adhesion force to the bovine tooth fragment when measured in air and liquid environments.
[0051] In order to further verify these results to confirm that these effects are indeed the result of an attractive force between the tooth particle on the cantilever tip and the silica pellet, a study was performed where commercially available AFM tips were used. A sectioned piece of bovine tooth, approximately 1mm×1 mm with the tubule openings oriented approximately 90° to the surface, was used as the substrate. Two different cantilevers, one modified with a 5 μm spherical SiO 2 bead (NovaScan PT.SiO 2 .SI.5) and the other modified with a 5 μm spherical Al 2 O 3 bead NovaScan PT.CUST.SI), were chosen and affinity measurements were performed. The results of these measurements are shown in Tables 5 and 6. It was observed that the use of the alumina particle resulted in an improvement in affinity over the use of a silica particle in both air and liquid environments. It is noted that different tips were utilized to measure the AFMs for the test subjects in each of Tables 4, 5, and 6 and thus apparent differing results were realized due to the tip differences themselves.
[0000]
TABLE 5
Adhesion Force Measurements
Adhesion Force
In Air
In Liquid
SiO 2
100
100
Al 2 O 3
232
285
[0000]
TABLE 6
Adhesion Force in Relation to Metal Adduct Amount
Adhesion Force
% Al Adduct
in Air
Comparative 1
0.077
100
Example 1
0.110
87
Example 2
0.150
113
Example 3
0.390
124
Example 4
0.730
84
Example 5
1.540
115
Example 6
1.960
156
[0052] In order to investigate the effect of the adduct loading level, a study was performed where silica samples were prepared containing increasing levels of adduct. The physical and chemical analysis of these samples is summarized in Tables 1 and 2, and the results of the AFM affinity study are shown in Table 6. It was observed that the Example 6 material exhibited the greatest affinity to the bovine tooth modified AFM tip, and that in general, the addition of the aluminum adduct increased the affinity between the silica and the tooth particle.
[0053] In order to investigate the performance of different adducts, a set of samples were prepared according to the following process. 410 mL of silicate (13.3%, 1.112 g/ml, 3.32 MR) were added to the reactor and heated to 85° C. with stirring at 300 RPM. Silicate (13.3%, 1.112 g/ml, 3.32 MR) and sulfuric acid (11.4%, 1.078 g/ml) were then simultaneously added at 82.4 mL/min and 24.8 mL/min for 47 minutes. After 47 minutes, the flow of silicate was stopped and the pH was adjusted to 5.5 with continued flow of acid. Once pH 5.5 was reached, the batch was allowed to digest for 10 minutes at 90° C. After the digestion time was complete, it was filtered, washed with approximately 6 L of deionized water and was dried at 105° C. overnight.
[0054] The silica samples were then tested for the presence of several different metal oxides, with the concentrations listed in Table 7. Several other physical properties of these materials were also measured and the results are shown in Table 8.
[0000]
TABLE 7
Metal Oxide Presence
Al 2 O 3
CaO
Fe 2 O 3
MgO
Na 2 O
TiO 2
Cu
Zn
Sn
Sample ID
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(ppm)
(%)
(%)
(%)
Comparative 3
616
37
245
81
2.36%
119
—
—
—
Example 7
604
131
191
99
1.13%
117
1.39%
—
—
Example 8
638
140
198
95
2.33%
117
—
—
3.63%
Example 9
646
35
200
70
1.17%
116
—
2.78%
—
Example 10
753
58
1.95%
99
2.55%
123
—
—
—
[0000]
TABLE 8
Physical Properties of Different Precipitated Silica Materials
Oil
BET
CTAB
Absorption
Sample ID
(m 2 /g)
(m 2 /g)
(cc/100 g)
5% pH
Comparative 3
60
40
99
9.25
Example 7
69
48
107
8.95
Example 8
54
38
93
9.40
Example 9
53
30
105
8.30
Example 10
58
47
94
9.80
[0055] The samples were pressed into pellets and were analyzed by the previously described AFM method. It was observed that silica materials containing metal adducts exhibited increased adhesion forces than the comparative silica materials prepared without metal adducts (or only trace amounts of adducts). In particular silica materials with 1.4% Cu, 3.6% Sn, and 2.0% Al all exhibited adhesion forces greater than the Comparative 3 silica containing no adducts.
[0000]
TABLE 9
Adhesion Force Measurements
Adduct
Adhesion Force in Air
Comparative 3
None
100
Example 6
2.0% Al 2 O 3
325
Example 7
1.4% Cu
325
Example 8
3.6% Sn
297
Example 9
2.8% Zn
230
Example 10
2.0% Fe 2 O 3
183
[0056] In order to gather additional data to support the observations made by the AFM affinity method, additional experiments were performed with a solution affinity test.
[0057] A bovine tooth was cut in half lengthwise with a Dremel 400|XPR equipped with a Flex Shaft and a #545 diamond wheel. The enamel was then ground off the surface of the tooth to expose the dentin with the same Dremel equipped with a #8193 aluminum oxide grinding stone. Once the dentin was exposed, the surface was smoothed by sanding with 200 and 400 grit sandpaper (McMaster-Carr Silicon Carbide sandpaper). The dentin was then polished with a 50% silica flour (US Silica) slurry. It was then rinsed with deionized water and was polished again with a 50% slurry of calcium carbonate (HUBERCAL® 950). After polishing, the tooth was sonicated for 2 minutes in a 0.5 M HCl solution and was rinsed with deionized water.
[0058] Teflon tape was cut in half lengthwise and was wrapped around the middle of the polished tooth creating, two exposed and one unexposed sections. The unexposed section was used as a control for comparison during the test. The tooth was gripped along its side with tweezers and was submerged in an aqueous slurry of silica (10.0 g silica, 150-mL beaker, 90 mL deionized H 2 O), that was stirred at a setting of 5 on a Thomas Magnematic model 15 stirplate for four minutes. During this time, the tooth was moved through the slurry with the dentin oriented into oncoming flow of silica particles. After the mixing time, the tooth was removed from the solution and was rinsed with deionized water for two seconds with a 500-mL squirt bottle. After the rinsing step, the sectioned tooth was allowed to dry at room temperature. Once dry, the Teflon tape was carefully removed and the tooth was analyzed by SEM.
[0059] For the solution affinity test, both Comparative 1 and the Example 6 sample were evaluated. The tests were repeated several times, with representative results shown in FIGS. 2 (Comparative 1) and 3 (Example 6 silica). In FIGS. 2 and 3 , the left side of the image shows the unexposed section of the tooth; the center of the image shows the boundary between the unexposed with exposed section; and the right side of the image shows the exposed section of the tooth.
[0060] It was observed that the tooth treated with the Example 6 silica (with 2% aluminum adduct) has greater surface coverage than Comparative 1 made with no adduct. These results of the solution affinity test agree with the observations of the AFM affinity test method in that the silica with adduct should be more efficient at occluding tubules in mammalian teeth.
Dentifrice Production and Analysis of Tooth Surface Contact Therewith
[0061] Selected inventive examples from above were then incorporated into dentifrice formulations in accordance with the information provided in Table 10, below.
[0000]
TABLE 10
Formulation Data for Dentifrice Samples
BATCH FORMULATION
COMPONENT
1
2
3
4
5
6
Glycerine,
11.600
11.600
11.600
11.600
11.600
11.600
99.5%
Sorbitol, 70.0%
41.320
41.320
41.320
41.320
41.320
41.320
Deionized
18.097
18.097
18.097
18.097
18.097
18.097
Water
Carbowax 600
3.000
3.000
3.000
3.000
3.000
3.000
Cekol 2000
0.600
0.600
0.600
0.600
0.600
0.600
Tetrasodium
0.440
0.440
0.440
0.440
0.440
0.440
Pyrophosphate
Sodium
0.200
0.200
0.200
0.200
0.200
0.200
Saccharin
Sodium
0.243
0.243
0.243
0.243
0.243
0.243
Fluoride
Thickener
Zeodent 165*
5.000
5.000
5.000
5.000
Comparative 4
5.000
[Zeothix 177*]
Comparative 5
5.000
[Zeothix 265*]
Abrasive
Zeodent 113*
17.000
12.000
12.000
17.000
17.000
12.000
Comparative 1
5.000
Example 6
5.000
Comparative 2
5.000
Sodium Lauryl
1.500
1.500
1.500
1.500
1.500
1.500
Sulfate
Flavor
1.000
1.000
1.000
1.000
1.000
1.000
Total
100.000
100.000
100.000
100.000
100.000
100.000
*ZEODENT ® and ZEOTHIX ® products are precipitated silica materials available from J. M. Huber Corporation
[0062] These formulations were then analyzed for thickening capability to determine if the small particle-size inventive materials provided effective viscosity modification of the target dentifrice formulation when included with a precipitated silica abrasive (Zeodent 113). The viscosity measurements were tabulated and are presented in Table 10, below. Such results show that no deficiencies in thickening capabilities exist when utilizing this inventive metal adduct-treated precipitated silica material (not all formulations were measured for viscosity at every time interval, as noted below).
[0000]
TABLE 11
Viscosity Data for Dentifrice Samples (×1000 cP)
Sample
Formulation
Number
Time
1
2
3
4
5
6
(Days)
Control
Comparative 1
Example 6
Comparative 4
Comparative 5
Comparative 2
1
—
—
—
—
—
239
3
252
272
283
306
276
—
7
275
290
314
346
300
305
21
353
353
386
388
380
—
42
406
388
468
510
419
—
[0063] To determine the effect particle size has on the ability of the inventive precipitated silica materials to occlude target dentinal tubules, as well as the ability of such materials to transfer from a dentifrice formulation to a target tooth surface (and ultimately within the tubules therein), further testing was undertaken, specifically in terms of the same solution affinity test described above, but for the results after 1 minute of brushing with 2 grams of dentifrice (from the above Table 9) applied to the subject treated bovine teeth (hereinafter the “dentifrice affinity test”). As for the same solution affinity test outlined above, a half-inch piece of TEFLON® (DuPont) tape was cut in half lengthwise and wrapped around the middle of the tooth, effectively creating three different sections, two exposed and one unexposed. The unexposed section was the internal standard during the test.
[0064] For this dentifrice affinity test, five samples were evaluated: one Control sample, Comparative 1, Example 6, Comparative 4, Comparative 5. FIGS. 1-5 show the results from the dentifrice affinity test. The tooth sections were brushed (Oral-B, soft-bristled, regular head toothbrush) with the requisite dentifrice for 1 minute. After brushing, the tooth was rinsed with deionized water until there was no visible residue left on the tooth (approximately 10 seconds).
DETAILED DESCRIPTION OF THE DRAWINGS
[0065] For each of the provided FIGS. 1-6 , the images are arranged as follows: 1) the left side of the image shows the image of the unexposed section of the tooth, 2) the center of the image shows the image of the boundary between the unexposed and exposed sections, and 3) the right side of the image shows the image of the exposed section of the tooth.
[0066] From the images shown in these FIGS. 1-6 , it can be seen that Example 6 ( FIG. 3 ) visually shows that the inventive silica materials therein exhibit a greater affinity and coverage of the dentin surface, as well as over and within the tubules, compared to the Control and Comparatives. This data correlates well with the data obtained using the AFM in that the doped silica should be better suited at occluding tubules in teeth and also with the solution affinity test which exemplifies the same phenomenon. FIGS. 1 and 2 show little to no coverage of this sort. FIGS. 4 and 5 show a larger degree of coverage than FIGS. 1 and 2 . Furthermore, the smaller particle size examples (in FIGS. 3-5 ) provide greater coverage, clearly, than that provided in FIG. 6 (larger milled silica particles treated with metal adduct). Even with the metal adduct present thereon, the size of the particles are too large to provide effective coverage within the subject tubules; only adhesion to the dentin surface is observed to any degree. In FIG. 6 , some fines present with the large particle example do make their way into some of the tubules; however, the majority of the particles are too large to have any beneficial tubule-filling effect. FIG. 6 , in particular, shows with proper particle size distribution that a result can be attained that is conducive to a large amount of silica material to adhere to, build, and fill the target tubules for sensitivity reduction to occur.
[0067] While the invention has been described in detail with respect to specific embodiments thereof, 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. Accordingly, the scope of the invention should be assessed as that of the appended claims and any equivalents thereof. | Precipitated silica materials are provided for utilization as abrasives or thickeners within dentifrice formulations that simultaneously effectuate tubule blocking within tooth dentin to reduce dentin sensitivity. Such precipitated silica materials have sufficiently small particle sizes and exhibit certain ionic charge levels by, for example, adjusting the zeta potential properties of the precipitated silica materials through treatment with certain metals to permit effective static attraction and eventual accumulation within dentin tubules when applied to teeth from a dentifrice formulation. | 0 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority from U.S. Provisional Application Ser. No. 60/710,743 filed Aug. 24, 2005, the entire contents of which are herein incorporated by reference.
FIGURE SELECTED FOR PUBLCIATION
[0002]
FIG. 1
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to a portable sanitary device. More specifically, the present invention relates to a portable sanitary device enabling washing and having at least one or more removable water supply tanks and wastewater holding tanks.
[0005] 2. Description of the Related Art
[0006] The related art involves and discloses a wide variety of portable sanitary devices. These portable sanitary devices are well-known to those traveling on the interstate or visiting job sites (e.g., “port-a-Johnny”) and in various camping type toilet apparatus.
[0007] What is not appreciated by the prior art is need to flush after using the portable sanitary device in a manner related to existing fixed-installation toilet systems, wherein a water flush is provided for waste movement. It is also not appreciated by the known travel or champing toilets to provide an optional cleansing sprits to a user or to pre-move and pre-dilute waste prior to a final flush. The present application provides a unique way to combine portability, sanitary operation, and ready flushing after use for.
[0008] Accordingly, there is a need for an improved portable sanitary device enabling rapid flushing and re-supply of water, and removal of a waste/holding tank after use for later cleaning and reuse.
OBJECTS AND SUMMARY OF THE INVENTION
[0009] An object of the present invention is to provide a portable sanitary device to facilitate and respond to the needs noted above.
[0010] Another object of the present invention is to provide a portable sanitary device having at least one or more removable water tanks that enable ready storage and refilling for easy and simple transport.
[0011] Another object of the present invention is to provide a portable sanitary device including a removable waste matter/holding tank enabling the ready removal of said tank from the portable sanitary device for ready emptying, cleaning, and sterilization.
[0012] Another object of the present invention is to provide a portable sanitary device having a compact flushing and waste transport system as well as a compact bidet system. For example, a water-receiving area proximate a seating area may be easily curved to direct and circulate water to remove and wash waste from an initial deposit zone into a waste holding tank.
[0013] Another object of the present invention is to provide a portable sanitary device enabling the use of toilet tissue following use and the transport of the used toilet tissue in a wastewater and holding tank for ready disposal and cleaning.
[0014] The present invention relates to a portable sanitary device having a removable fluid supply tank along a back upright portion of a chair and a waste fluid holding tank releasably attachable to a seat portion of a chair member for operation in relation thereto.
[0015] Another object of the present invention is to provide a water transport flange and system for receiving wash water, flushing-washing-circulating the water, and transporting the now-used wash water to waste holding tank.
[0016] The above and other objects, features and advantages of the present invention will become apparent from the following description read in conduction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 . is a perspective view of one embodiment of the present invention.
[0018] FIG. 2 is a rear-perspective view of the embodiment in FIG. 1 .
[0019] FIG. 3 is a partial sectional view along face I-I in FIG. 2 (back removed) noting internal construction in a portable use condition.
[0020] FIG. 4 is a partial sectional view along face I-I in FIG. 2 (back removed) noting an internal construction in a semi-fixed use condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Reference will now be made in detail to several embodiments of the invention that are illustrated in the accompanying drawings. Wherever possible, same or similar reference numerals are used in the drawings and the description to refer to the same or like parts or steps. The drawings are in simplified form and are not to precise scale. For purposes of convenience and clarity only, directional terms, such as top, bottom, up, down, over, above, and below may be used with respect to the drawings. These and similar directional terms should not be construed to limit the scope of the invention in any manner. The words “connect,” “couple,” and similar terms with their inflectional morphemes do not necessarily denote direct and immediate connections, but also include connections through mediate elements or devices.
[0022] Referring now to FIGS. 1 and 2 , a portable sanitary device 100 includes a seat member 4 pivotably affixed to a chair frame member 1 having opposing arm members 3 , 3 , and leg members 2 . Portable sanitary device 100 further includes a back member 31 positioned at an angle adjacent to seat 5 for slidably supporting and retaining a removable tank member 10 within sliding channels 30 , as shown.
[0023] Water tank member 10 is removably attached to a back location of back plate or back member 31 via a plurality of sliding channels 30 . At least a first waste fluid and waste matter holding tank 7 is releasably positioned below seat 4 . Slidable guides 5 engage projecting lip members 5 A on tank 7 . A handle 8 allows a user to slidably remove tank 7 for cleaning and re-use, as will be described. It is preferable that tank 7 include a waste opening 9 having a slidable/openable waste door 16 A that is actuated by a lever assembly 50 projecting from a side of seat member 4 . During a sliding installation of tank 7 along guides 5 , engagement members on a top surface of tank 7 (not shown) engage an end of lever assembly 50 so as to enable a user to operate waste door 16 A as desired.
[0024] Seat 4 defines a bounded opening 6 for receiving waste material during use of portable sanitary device 100 and is arranged to open directly over tank 7 unit opening 9 for receiving waste through a slidable waste door 16 A, as will be discussed.
[0025] As noted best in FIG. 1 , waste door 16 A is slidable along guides (not shown) in a direction A to seal opening 16 A for easy removal and transport of waste tank 7 .
[0026] An opening 16 is formed in a side wall of seat opening 6 , as shown, and includes a small spritz member (tube) directable along a direction noted by a water or spritz-guide 16 B positioned in seat opening 6 . As a consequence of this design, a user may choose to direct the spritz upwardly for self cleaning or along direction guide 16 B to aid in cleaning and flushing of waste on a top of waste door 16 A (when not opened prior to use) or downwardly into waste unit 7 as a flushing aid.
[0027] As a consequence of the present design, it is envisioned that substantial improvements over the related art is provided by the use of a sealable and removable waste unit 7 having an actuatable waste door 16 A and an engageable level 50 for operation.
[0028] Outer water unit 10 includes three reservoirs, a central reservoir 11 for initially storing flush water, a flush reservoir 22 for storing main flush water, and a spritz or cleansing cavity reservoir 15 for storing spritz water or flush water, as will be discussed.
[0029] A central filling opening 12 is formed in tank 10 for refilling water and a sealable plug (not shown) may seal opening 12 for easy transport when tank 10 is removed from back plate 31 .
[0030] One way openings 13 , 14 allow flush water to flow from main tank 11 to spritz tank 15 and flush tank 22 as will be discussed. During such motion, the water level in main tank 11 decreases along direction 21 .
[0031] Flush mechanism 23 is slidably positioned with flush tank 22 and includes a sealing plate 24 with edge seals 24 A. Sealing plate 24 and edge seals 24 A provide a wall-tight/water-tight seal with the walls of flush tank 22 .
[0032] It is envisioned, that during an initial fill process, central tank 11 is filled via opening 12 until a level 90 is reached, which in turn flows through openings 13 , 14 to reach an equilibrium pressure level within respective tanks 15 , 22 .
[0033] Due to seal 24 , 24 A and resistance plunger 23 provides, a water level is retained in flush tank 22 despite repeated spritz-uses or small flushes generated flowing from spritz tank 15 . As a consequence, while water level 21 may decrease prior to a re-filling, initial flush tank 22 retains its initial flush-full condition.
[0034] Similarly, in spritz or minor-flush tank 15 , a valve and tube assembly 19 is provided and receives an initial fluid fill to fill tube 19 A due to the water filling the initial tube and passing by a juncture with spritz valve tube assembly 18 linked with a spritz activator mechanism 17 projecting from a top of tank 10 .
[0035] During a common use, one should expect that a user will actuate spritz activator mechanism 17 multiple times to repeatedly trigger valve tube assembly 18 to release small amounts of spritz or flushing water down tube 19 A through tube 20 , to portal 16 . Due to the lower volumes released by assembly 18 , it is envisioned that tube 19 A may hold as many as 5 spritzes for each large flush provided via plunger 23 .
[0036] As also noted, a flush portal 25 is provided opposite one-way opening 14 for transporting flush water down tube 27 to a rear access portal 28 in waste tank 7 for ease of cleaning. In use, it is envisioned that a user will push downwardly on plunger 23 along the Force direction ( FIG. 3 ) to seal one-way valve 14 and force flushing water out portal 25 through one-way seal 28 . Following the force of flushing water, one-way seal 28 will close preventing back-flow up pipe 27 .
[0037] Thereafter, a user will refill tank 10 fully and will lift plunger 23 to draw water through one-way opening 14 to prepare for the next flush.
[0038] In an alternative assembly, a seal 26 may be fixed over flush port 25 , and a user may replace one-way seal 28 with an inverse one-way seal 28 A allowing waste to continuously flow down a collector pipe 29 in a manner more closely related to a long-term positioning. In this mode, it is envisioned that spritzing will be more common and that system 100 will be merely used for fluid not solid waste therefore obviating the need for a large-volume flush capacity.
[0039] Following a flush or empting use of tank 10 , a user will simply lift tank 10 along channels 30 from back support plate 31 and transport it to a filling station. Alternatively, a user may simply fill tank 10 in place via portal 12 opening.
[0040] Both said tanks are projected to be self-contained bounded regions constructed from high density poly propylene or other suitable material. It is also envisioned that the tanks may be further sub-divided into various holding regions within each tank. Access valves and drain valves are considered to be included in the tank in reasonably accessible areas and further in a manner which enable the ready sterilization of both the water tank and the waste/holding tank during a cleaning cycle.
[0041] According to one alternative in aspect of the present invention the water tank 10 includes a lever or actuating mechanism that when pulled releases water through a simple ball valve or alternative spray/bidet dispensing mechanism. According yet to another alternative embodiment there is a sliding trap similar to guide 16 B that operates to receive released water and slidably guide the water and waste into holding tank 7 in a manner similar to that of a flushing commercial toilet. Another alternative embodiment of the present invention anticipates that holding tank 7 may alternatively include a waste treatment chemical or waste disposal chemical wherein the chemical enables rapid disposal of the waste and possibly toilet tissue and similarly pacifies any organic or biologically active matter retained therein.
[0042] It is known that chemicals exist, for example, AQUA ZUME®, as an aid in decomposition and pacification of the organic matter. It is therefore considered by inventors of the present portable sanitary device that a quick dissolving and biodegradable tissue may be optionally used for this device, as well as regular tissue, and additionally that waste holding tank 7 may be preloaded with some amount of waste-fluid decomposition and pacification chemical prior to a use to mitigate smells, and other biological activity between through cleanings.
[0043] As a consequence of the above described invention for a portable sanitary device it is believed that the present invention responds to at least one of the needs noted above in a manner that is unique to the portable sanitary device arts.
[0044] In any future claims, the claims, means- or step-plus-function clauses are intended to cover the structures described or suggested herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, for example, although a nail, a screw, and a bolt may not be structural equivalents in that a nail relies on friction between a wooden part and a cylindrical surface, a screw's helical surface positively engages the wooden part, and a bolt's head and nut compress opposite sides of a wooden part, in the environment of fastening wooden parts, a nail, a screw, and a bolt may be readily understood by those skilled in the art as equivalent structures.
[0045] Having described at least one of the preferred embodiments of the present invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes, modifications, and adaptations may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. | The present invention provides a portable sanitary device comprising a sanitary device with removable water supply mechanisms and removable waste holding and removal mechanisms. The mechanisms include one or more tanks removably attached to the sanitary device and function to allow a user to wash or flush after a use and circulate waste material into a waste holding and removal tank. Alternative embodiments provide flanges and valve systems. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS (CLAIMING BENEFIT UNDER 35 U.S.C. 120)
[0001] This is a continuation of U.S. patent application Ser. No. 11/057,270, docket number AUS920010653US2, filed on Feb. 11, 2005, now under allowance, which was a divisional application of U.S. patent application Ser. No. 09/944,518, docket number AUS920010653US1, filed on Aug. 31, 2001, all by Janani Janakiraman, et al.
FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT STATEMENT
[0002] This invention was not developed in conjunction with any Federally sponsored contract.
MICROFICHE APPENDIX
[0003] Not applicable.
INCORPORATION BY REFERENCE
[0004] Related U.S. patent applications No. 11/057,270 (filed on Feb. 11, 2005) and No. 09/944,518 (filed on Aug. 31, 2001), by Janani Janakiraman, et al., are hereby incorporated by reference in their entireties including figures.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] This is a continuation application of U.S. patent application Ser. No. 11/057,270, docket number AUS920010653US2, filed on Feb. 11, 2005, now under allowance, which was a divisional application of U.S. patent application Ser. No. 09/944,518, docket number AUS920010653US1, filed on Aug. 31, 2001, all by Janani Janakiraman, et al. This invention relates to the art of dynamic configuration of server content for delivery to a client or terminal device, such as a WAP-enabled telephone or personal digital assistant, over a computer network, such as the Internet. The invention relates especially to the arts of automatically grooming or tailoring the content delivered to a microbrowser having limited resources and capabilities such that only content preferred by the user or compatible with the microbrowser is delivered.
[0007] 2. Description of the Related Art
[0008] The proliferation of e-commerce on the World Wide Web (WWW) has offered immense potential for revenue generation through advertisements. The web offers unprecedented opportunities for personalized advertisements, and there has been stunning innovations in customized advertising over the last few years.
[0009] Additionally, the “web-enablement” of various handheld terminals including wireless telephones (“cell phones” and PCS phones) as well as wirelesss-networked personal digital assistants (PDA) have added to the array of potential “browsing” devices which may interact with a web server and its content. The number of users of such devices is steadily increasing, so the demand for web site content which is targeted for these devices is also expected to continue to grow.
[0010] Turning to FIG. 1 , the well-known arrangement of client browser computers ( 1 ), web servers ( 5 ) and Advertising servers (“Ad Server”) ( 6 ) are shown. The client browser computer ( 1 ) typically is equipped with software such as a web browser and a communications protocol stack such that it may connect to and communicate via the World Wide Web ( 3 ). Client browser computers include conventional personal computers such as IBM-compatible personal computers and Apple iMac™ computers.
[0011] Other “microbrowser” devices ( 9 ), such as web-enabled wireless telephones and PDAs, WebTV terminals and Internet appliances, may also access information from the Web Server ( 5 ) and Ad Server ( 6 ).
[0012] A web server ( 5 ) is usually provided with one or more data files of web page content such that they may be delivered to a client browser computer upon request, such as by hypertext transfer protocol (HTTP). The web server is also communicably connected to the World Wide Web ( 3 ) or another suitable computer network. IBM's WebSphere™ enterprise server software combined with a suitable networking computing platform, such as a personal computer running IBM's AIX™ operating system, is an example of one such web server ( 5 ).
[0013] The microbrowser devices ( 9 ), though, typically have lower performance and considerable resource restrictions when compared to computer browsers ( 1 ), including much less memory, much smaller display area (and fewer colors in many cases), much slower microprocessor, as well as considerably slow transmission rate between the network ( 3 ) and the devices ( 8 , 2 ).
[0014] For example, a Web Server may easily deliver a component to a web page over a dial-up modem connection or cable modem ( 2 ) from a standard web browser ( 1 ) on a personal computer having a 750 MHz processor, 128 MByte or more of memory, a full 1024 by 768 pixel, 24-bit color palette display over a 56 kbit/sec or higher data link using a common protocol such as Hyper Text Transfer Protocol (HTTP). The web pages themselves may be encoded in Hyper Text Markup Language (HTML).
[0015] By contrast, the microbrowser device may only have a 100 MHz processor, 32 MByte of memory, a data link of a few kilobits per second, and may run a protocol such as Wireless Application Protocol (WAP) or i-Mode. Due to these restrictions in resources, often on the scale of one-tenth the capabilities of a standard web browser, the special protocols (WAP, i-Mode, etc.) have been developed to minimize the number of communication messages or “handshakes” which occur during a web page access. This supports effective use over the lower communications bandwidth typically available to such devices, as well as reduces the resource requirements (processing bandwidth, memory, etc.) needed on the devices to some degree.
[0016] WAP and protocols like it are intended for use by devices such as handheld digital wireless mobile phones, pagers, two-way radios, “smartphones” and communicators, although it could be applied to “higher end” devices such as personal computer or laptop computer-based web browsers. WAP itself is defined to be interoperable with most wireless networks, including cellular digital packet data (CDPD), code-division multiple access (CDMA), global system for mobile communications (GSM), time division multiple access (TDMA), and many others. These protocols are generally operating-system independent or can be used with a wide variety of operating systems which are common in such devices, including PalmOS, EPOC, Windows CE, FLEXOS, OS/9, JavaOS, and others.
[0017] To further enhance the “wireless” web browsing experience, many web servers and advertising (“ad”) servers maintain two separate sets of content: a “normal” set in HTML for normal browsers, and an “optimized” set in Wireless Markup Language (WML) for wireless browsers. HTML, HTTP, WML, WAP and i-Mode are well known in the art.
[0018] Some web pages include advertisements, such as banner ads, which include information for a user to view regarding products or services being promoted by the sponsors of the web server or web page being viewed. Many online businesses including search engines, travel services, news services, etc., have become dependent on generation of revenue through advertising as many of these companies offer their “services” at not cost to the web “visitor”.
[0019] These “ads” are typically delivered by an Ad Server ( 6 ), which is also connected to the Internet or World Wide Web ( 3 ). In FIG. 2 , the well-known process of merging ads ( 23 ) and web page contents ( 24 ) to be displayed on a portion of a client display ( 20 ) in a web browser frame ( 21 ) is shown.
[0020] The web browser frame ( 21 ) typically includes a set of navigation controls ( 22 ) such as Back and Forward buttons, as well as a Universal Resource Locator (URL) address selector. Displayed in the display frame of the web browser is the selected (“pointed to”) web page content ( 24 ), which is retrieved ( 26 ) from the web server ( 5 ) using a protocol such as HTTP.
[0021] An ad ( 23 ) located on the page is delivered typically from a separate server such as and Ad Server ( 6 ), through a common web page inclusion method in the code for the page content, such as a direct hyperlink ( 25 ) to the advertising object on the ad server ( 5 ), or through an Hyper Text Markup Language (HTML) “include” statement. These ad objects are typically graphic image files, such as Graphic Interchange Format (GIF) or Joint Photographic Experts Group (JPEG), additional web page code such as HTML, or even audio or video clips such as “WAV” or “AVI” files.
[0022] The web browser software first retrieves a base web page from the web server, and then retrieves all the data items or objects which are referred to in the web page code, such as a graphic image or additional sections of HTML. Thus, what is displayed to the user after retrieving all of the referred to objects, is a combination of all the items included in the web page source code.
[0023] As processing capabilities, memory storage availability, and communications bandwidth are severely limited when serving a microbrowser, may web server or web site operators choose to only offer a subset in WML of their full “normal” content, in order to minimize upkeep and maintenance costs of the special WML content.
[0024] However, this may still produce an undesirable wireless web browsing experience for a microbrowser user. For example, a search engine web site may decide that, due to commercial considerations, they will include a set of banner ads in their WML content. This, then, takes time to download to the microbrowser, consumer processing bandwidth and memory, and consumes valuable display area on the microbrowser. As the commercial paradigm is different in wireless web browsing (connection time is usually charged by the minute rather than a flat-rate per month in regular web browsing), an ad which takes a long time to download will cause a negative consumer reaction as it uses his or her “minutes” and results in increased cost for services for the user.
[0025] Also consider that most of these types of microbrowsers are battery-driven in order to provide mobility to the user. As each of these advertisements are downloaded, displayed and/or animated, they incrementally increase battery energy consumption through increased processor and resource (display, memory) usage. This, too, will cause a negative consumer reaction because they are aware that time “wasted” downloading and displaying such adds eventually results in an earlier “battery low” warning.
[0026] As such, the current technology allows the proprietor of a web site to customize the web site content to optimize performance for browsing by a microbrowser, but the user is left with no control or method for selecting which web content objects to download or to omit from a delivered page in order to minimize download times (and connection costs), to maximize display usefulness, and to maximize battery life.
[0027] There are methods in the art for “content negotiation”, which are well known and which could possibly be applied to this problem. However, these methods generally include more messages or “handshakes” (e.g., client-server interaction steps) to negotiate which content is available and which content to deliver, making the protocol even more resource-intensive than a nonnegotiable protocol. For example, the Internet Engineering Task Force's (IETF) 1998 Request for Comments number 2295 (RFC2295) proposes a process wherein multiple “variants” of content are stored on a server, and a list of available variants and their characteristics is delivered the client or browser device. The client or browser device may then select which variant to download. Not only does this increase the number of messages sent back and forth to communicate the list and to select the variants, it increases substantially the operating burden of the web site to include maintenance, testing, etc., of all the variants. Another IETF Request for Comments, RFC 2703, acknowledges the need for a protocol-independent content negotiation technology, but merely provides and framework of problems to be solved and does not provide a solution to the problem.
[0028] So, to employ content negotiation method to a protocol such as WAP would necessarily increase the resource requirements (processing power, communications bandwidth, memory consumption) above and beyond the requirements of the current WAP protocol. As the current WAP protocol is of marginal performance in some situations already, a proposal to increase its resource requirements to add performance negotiability would not be well-received in the industry.
[0029] Some available products for browsers allow a user to configure a “shield” from advertising objects, such as Norton's Internet Security software package. These software products typically run in the “background” on a personal computer, examining all data objects being received by the browser software. Any objects which appear to be “user deselected” object types are not fully downloaded, and are not displayed. These types of products, though, due to their very nature of their operation, require significant “extra” processor bandwidth and memory so that their “background” operation does not noticeably depreciate the performance of the normal web browser, and as such, are not suitable for use on a microbrowser.
[0030] Therefore, there is a need in the art for a system and method to allow a user to control or select which web objects are downloaded to a microbrowser without adding significant resource requirements to the microbrowser's execution or use, including it's display area, processing bandwidth, communications bandwidth, and memory consumption.
[0031] Additionally, there is a need in the art for this system and method to be easily deployable throughout an existing network to avoid the difficult or expensive retrofitting of microbrowser devices with special hardware or software.
[0032] Further, there is a need in the art for this system and method to be compatible with other technologies already present in the wireless web environment, including protocols (WAP, i-Mode, etc.) and object formats (WML, HTML, etc.).
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The following detailed description, when taken in conjunction with the figures presented herein, provides a complete disclosure of the invention.
[0034] FIG. 1 illustrates the well-known arrangement of ad servers, web servers, microbrowsers and client browser computers interconnected by the World Wide Web or similar computer network.
[0035] FIG. 2 illustrates the well-known process of delivering electronic advertisements and web page contents to a client web browser computer.
[0036] FIG. 3 graphically discloses the general arrangement and cooperation of the components of the preferred embodiment relative to a server and a microbrowser.
[0037] FIG. 4 shows the logical process of the invention as performed by a microbrowser.
[0038] FIG. 5 shows the logical process of the invention as performed by a server.
SUMMARY OF THE INVENTION
[0039] The present invention offers several improvements in the art of delivering electronic content such as advertisements for consumption, e.g., viewing and/or hearing, by a user on a microbrowser by allowing the user to configure which types of objects are not to be downloaded to by the microbrowser, including parameters and characteristics such as memory consumption, display area consumption, communications bandwidth consumption, battery conditions and other state characteristics of the microbrowser.
[0040] For example, during low battery conditions, a user may configure an enhanced microbrowser not to download advertisements, run scripts or animated objects in order to maximize remaining battery life. In another example, a user may configure an enhanced microbrowser to block the download of objects containing audio, or which will occupy more than a certain percentage of the available display area.
DETAILED DESCRIPTION OF THE INVENTION
[0041] According to the preferred embodiment, the present invention is realized as software processes executed on or by advertisement servers such as an IBM WebSphere™ e-commerce platform, running on a common web server computer such as a personal computer or and IBM AS/400 computer system. The IBM WebSphere™ product is available for many operating systems such as Linux, IBM's AIX™, or Microsoft Windows NT. However, it will be recognized by those skilled in the art that alternate e-commerce software suites and computer platforms may be adopted without departing from the spirit and scope of the present invention.
[0042] A portion of the invention may also be realized as code executable by a microbrowser device, such as inline code modifications to an existing microbrowser firmware package or a downloadable script or plug-in for such a microbrowser, compatible with popular operating systems for such devices including PalmOS, EPOC, Windows CE, FLEXOS, OS/9, JavaOS, and others.
[0043] As such, the remainder of this disclosure focuses on the logical processes to be implemented in software on a web server, ad server, and microbrowser.
[0044] Turning to FIG. 3 , the invention's logical process and component arrangement is shown. First, a microbrowser device ( 33 ) is provided with an advertisement configuration ( 34 ) data set which can be interrogated by a server. This Advertisement Configuration Data set ( 34 ) (ACD) may include a plurality of user-defined limitations, such as a maximum download time (per object and/or per page), maximum display area (per object and/or per page), number of permitted colors, amount of memory allowed, and preferences based upon states of the microbrowser such as battery condition (AC powered, battery full, battery low, etc.), wireless connection mode (digital, analog, home network, roaming, etc.), display backlight mode (on or off), etc.
[0045] Two sets of conditions are provided according to the preferred embodiment—one for normal battery conditions, and the other set for low battery conditions. A third set for AC-powered conditions may also be provided. Table 1 shows an example ad configuration data set which could be stored in a plain text file on a microbrowser.
[0000]
TABLE 1
Example Ad Configuration Data Set
when AC_powered:
max_memory_per_object = 8k
max_load_time_per_page= 30 sec
animation = allowed
colors = full
max_screen_area = 400%
scripts = allowed
when low_battery:
max_memory_per_object = 2k
max_load_time_per_page= 10 sec
animation = disallowed
colors = 2
max_screen_area = 100%
scripts = disallowed
when normal_battery:
max_memory_per_object = 4k
max_load_time_per_page= 20 sec
animation = disallowed
colors = full
max_screen_area = 100%
scripts = allowed
[0046] In this example, the user has configured the microbrowser to run scripts only when the unit is AC powered or when the battery is not low, and the user has restricted objects from downloading which use more than 2 colors when the battery is low. Anytime the unit is battery powered, the user has restricted the downloading of animated objects, and has progressively restricted the size the download time for objects based on battery conditions. However, when the unit is AC powered, the user has configured an allowance for a maximum display area to go beyond a single screen or display area, which would require scrolling to view.
[0047] In another embodiment, the ACD may be stored on the microbrowser as a cookie. In this case, the server which creates the cookie may allow the user to configure specific limitations for that site only. For example, a user who frequently visits a news service site may be provided with a series of pages in which he or she may specific web object limitations for his or her microbrowser. The news site server would then prepare a cookie containing these limitations, and would store that in the memory of the user's microbrowser. During subsequent visits to the news web site, the cookie could be retrieved in order to observe and follow the user's configured limitations.
[0048] Other microbrowser state conditions for which preferences may be set in the ACD can be type of wireless connection (digital, analog, home network, roaming, etc.), display light conditions (display backlight enabled or disabled), muting, etc. For example, advertisements and objects which require lengthy download times may be blocked when the wireless connection mode is “roaming” to avoid unnecessary connection costs.
[0049] Continuing with the discussion of FIG. 3 , the server for the microbrowser ( 30 ) is provided with two sets of conventional web objects, a first of which is a web of normal WML page content objects ( 31 ). The second set is a set of advertisement objects ( 32 ), which may also be encoded in a suitable format such as WML, graphics interchange format (GIF), joint photographics experts graphics (JPEG), audio (WAV), video (AVI), or other type of web encoding (MPEG, MP3, PDF, etc.) Each of the objects in the advertisement set ( 32 ) and preferably in the page content set ( 31 ) are also indexed as to their resource requirements such as number of colors required, animation or still, display area, transmission size/time, and whether or not they are or include a script. According to the preferred embodiment, this information is stored in a separate index or database I ( 36 ) in order to avoid the need to modify these standard objects. The index I ( 36 ) may be built and populated manually, or preferably, by an analysis tool which generates these associated characteristics.
[0050] Finally, the server ( 30 ) is provided with a Dynamic Wireless Advertisement Configurator ( 35 ) (DWAC) program, which in response to a generic page request from the microbrowser ( 33 ), receives the ad configuration data set ( 34 ) from the microbrowser, determines which, if any, of the objects within the requested page fit within the configured limitations using the index I ( 36 ), and retrieves those objects ( 31 , 32 ) for transmission to the microbrowser ( 33 ). The DWAC program is preferably realized as a Java servlet, but may alternately be realized in other programming languages and methodologies without departing from the scope of the invention.
[0051] Turning to FIG. 4 , the logical process followed by the microbrowser unit is shown in more detail. This process may be realized as an enhancement to the resident microbrowser code, or as a downloadable component such as a script or a microbrowser plug-in. First, the microbrowser is configured ( 40 ) to include an Ad Configuration Data set ( 34 ), or ACD, which is stored in memory such as non-volatile Flash or on a microdrive.
[0052] Then, while browsing the “wireless web” ( 3 ), the ACD is transmitted ( 41 ) in association with page requests ( 43 ). This may be accomplished in two ways. First, the page request may be enhanced to include the ACD information, such that it is always included with the page request. Or, it may be transmitted only upon request from a server. The second method is more easily implemented, as it does not require a modification to the WAP protocol, and only require the server's servlet to interact with the code enhancements on the microbrowser.
[0053] Further according to the preferred embodiment, the microbrowser selects which ACD or portion of its ACD to sent based upon present conditions such as the battery or AC power conditions, system clock, etc.
[0054] After the server has selected the appropriate web objects which meet the constraints of the supplied ACD, the microbrowser receives, displays and otherwise executes ( 42 ) the configured page content ( 44 ).
[0055] Turning to FIG. 5 , the corresponding and cooperating server logical process is shown in more detail. Preferably, this process is realized in a Java servlet, but may alternately be realized as a script or code change to a WML or other wireless application server software package.
[0056] When a page request is received via a wireless network ( 3 ), an ACD is also received or requested ( 51 ) (see previous description of FIG. 4 ). The index I ( 36 ) is consulted to determine which, if any, of the objects contained in the requested page meet the constraints set forth in the ACD ( 52 ), which are then transmitted as configured content ( 44 ) via the wireless web ( 3 ) to the requesting microbrowser.
[0057] As will be readily understood by those skilled in the art, the present invention may be utilized with “wired” microbrowsers, as well, such as Internet appliances and WebTV units. Anywhere and anytime browser resources are limited, the present invention may be useful in allowing the user to configure the allowed and disallowed web content to be downloaded. For example, the invention could be used to allow older personal computers which have limited resources (monochrome displays, limited memory and processor capabilities, slow modem, etc.) to continue to be useful as web browsers.
[0058] As such, the use of terms such as “wireless”, “wireless web”, specific protocols such as WAP, and specific web object formats such as WML should not be seen as limitations to the scope of the invention, but rather are facets of the preferred embodiment. Therefore, the scope of the present invention should be determined by the following claims. | A microbrowser such as web-enabled wireless telephones and personal digital assistants allows a user to configure types of objects to be blocked from download including object memory consumption, display area, download time, and restrictions on animated images and executable scripts. Microbrowser state conditions such as battery level and network connection mode are considered when providing said limitations such that more restrictions may be placed during low battery periods to maximize battery life. For example, during low battery conditions or analog connection mode, a user may configure an enhanced microbrowser not to download advertisements, run scripts or animated objects in order to maximize remaining battery life. In another example, a user may configure an enhanced microbrowser to block the download of objects containing audio, or which will occupy more than a certain percentage of the available display area. | 6 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] In the textile industry, dyeing is one of the most important finishing processes. Dyes are colored organic substances which are used to dye other objects, are soluble in acid, neutral or basic media, and possess an unsaturated molecular structure; that is, they are electronically unstable so they react with the material to be dyed, becoming fixed in the latter.
[0003] 2. Description of Related Art
[0004] The endurance or strength of a dye can vary when it is applied to different fibers. Even though the use of a given dye is properly determined, the strength thereof varies, depending on the dyeing process used. Thus, depending on the fiber to be dyed and the final use of the fabric or knitting, the suitable type of dye and the suitable dyeing process should be chosen in order to obtain the desired results. The present invention relates specifically to the dyeing of cotton and blends thereof (polyester, acrylics, Tencel® (a cellulose fabric that is obtained by an organic solvent spinning process)) in colors which are different from indigo, by means of a direct, cationic dye commonly used for paper dyeing, such that bright and clean dyes are obtained with a proper behavior to wash down, achieving the desired worn-out in fabrics used for the manufacture of so-called “jeans”. A process suitable for achieving this type of dyeing is also disclosed.
[0005] A dye known as indigo is generally used for the dyeing of the fiber or yarn used in the manufacture of fabrics for making jeans, or for the dyeing of a knitted fabric, thus obtaining satisfactory results both for the dyed fabric as well as a washed down fabric. The use of indigo is limited to blue jeans. Up to this date, and even though the existing demand so requires, it has not been possible to obtain a fabric suitable for the manufacture of colored jeans, which exhibits brightness and the proper color both before and after wash down. In the manufacture of jeans and denim garments, it is common to combine in the same garment both a washed down fabric and a non washed down fabric, thus making apparent the importance of the characteristics of the fabric both before and after the wash down.
[0006] Dyeing with sulphur-based dyes has been attempted; however, while certain washed down effects are achieved with this type of dye, the necessary brightness and the desired clean colors are not obtained in the final product.
[0007] There is a diversity of developments relating to the dyeing of cotton yarn or fabric, or blends of cotton with other types of fibers; the most common ones disclose the use of indigo on blends of the latter with other types of dyes, such as those disclosed in U.S. Pat. Nos. 3,457,002; 4,166,715; 4,536,907; and 5,295,998; as well as publications JP 02170861, EP 0 408 269 and US 20060059635, among others, which disclose various dyeing methods using indigo and blends of indigo with other types of dyes or reagents in order to achieve the desired fixation. Neither the type of dye nor the methods used are suitable for dyeing cotton or blends of cotton with other types of fibers, such that the achieved fabric has the suitable color, the brightness and the behavior to wash down both before and after the wash down, for the manufacture of colored jeans. Likewise, there are developments which point to the use of sulphur based dyes and blends of the latter with other types of dyes, as well as the dyeing method for achieving the suitable fabric for the manufacture of jeans; some of these developments are disclosed in U.S. Pat. Nos. 4,131,423 and 4,322,214, international publications WO 93/07221, WO 00/36211, WO 04/012406, and European Patent EP 0 741 168, among others. As already mentioned, the use of sulphur based dyes does not achieve neither the desired brightness nor the desired behavior to wash down.
[0008] EP 0 343 925, in the name of Mitsui Toatsu Chemicals, relates to obtaining a colored denim fabric by means of a dyeing bath containing a dye or a dye blend with an indigo, so to obtain in the final product a behavior similar to that of indigos, also exhibiting the discoloring effect similar to when indigo is bleached with a chlorine solution. With the use of the method disclosed in EP 0 342 925, it is not possible to obtain the full range of desired colors, since the dye is blended with indigo, in addition to the fact that the obtained colors are not entirely clean nor have the brightness achieved with the dyes and the process of the present invention.
[0009] Most of the dyes are organic compounds which can be positively charged (cations) or negatively charged (anions). Cationic dyes are joined to the fibers by means of forming salt bonds with the anionic groups or the acid groups of the fibers and posses a very high dyeing power. Generally, they are used to dye paper, synthetic fibers and even human hair, since a bright coloring and a deep dyeing are achieved. Direct, cationic dyes had never before been used to dye fabric, fibers or yarn for the manufacture of fabric, for the manufacture of colored jeans, since as a result of obtaining so deep colors, the fabric does not react properly to wash down. Thus, cationic dyes have been traditionally considered in industry as unsuitable for cotton fibers, yarn or fabrics, including those cases where cotton is blended with other fibers, particularly synthetic fibers. The present invention relates to the use of direct, cationic dyes to dye fabrics, fibers or yarn made of cotton or cotton blends with synthetic fibers, for the manufacture of fabric, by means of any known dyeing process, using a direct, cationic dye, so that, controlling process variables such as temperatures, pH, concentration and exposure time, fabric with clean colors and the desired brightness is achieved, which suitably reacts to wash down. A fabric of these characteristics has not been nor is currently available in the market.
[0010] Among the patents relating to the manufacture and use of cationic dyes, the most relevant patents as prior art for the present invention are U.S. Pat. No. 4,288,589, assigned to Ciba-Geigy Corporation, which discloses a greenish-yellow cationic dye, the process for making same and its use for dyeing synthetic textile materials. In addition, international publication WO 05/012437, assigned to the above-named corporation, relates to another type of cationic dyes with alkaline terminations and its use, mainly, to dye human hair; JP 09316785, in the name of Sumitomo Chemical Co., relates to a method of dyeing cellulose fiber by means of a cationic dye, to achieve a sufficiently deep and clear color; in order to achieve this purpose, cellulose is pre-treated with a sulphur containing compound. U.S. Pat. No. 5,766,269, assigned to Clariant, discloses a type of cationic dye obtained by means of cationization of a sulphur dye with a compound comprising at least an amino group of a basic nature; the dyes thus obtained are used to dye acrylic fibers, cellulosic fibers, wool, silk and, mainly, leather. None of the above-mentioned patents even contemplates the behavior of the fabric to wash down nor the suitable dyeing process to achieve a fabric having the suitable brightness, the clean nature and the behavior to wash down for the manufacture of colored jeans.
SUMMARY OF THE INVENTION
[0011] The present invention also relates to a method for dyeing fibers, yarn or fabrics made of cotton or cotton blends with synthetic fibers, by means of a direct, cationic dye which does not derive from nor contains sulphur, so to obtain a final product with a bright and clean dyeing and which can be washed down in processes or process steps after the dyeing in order to achieve the worn-out effect sought for fabrics used in the manufacture of jeans. Also described is the product obtained by means of this method.
[0012] An object of the present invention is obtaining a suitable fabric for the manufacture of colored jeans with an unsurpassable brightness and a suitable behavior to wash down.
[0013] Another object of the present invention is obtaining the range of colors not previously obtained with the described characteristics of brightness and behavior to wash down.
[0014] A further object of the present invention is the use of direct, cationic dyes for obtaining a fabric with the described brightness, color and behavior to wash down.
[0015] An additional object of the present invention is to provide a suitable method for obtaining the described fabric.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0016] There are in the market a multiplicity of dyes suitable for being used for the dyeing of textile fibers, such as cotton fibers or fibers made of blends of cotton with other fibers. Among these there are indigos, sulphur based dyes, dyeing reagents, azo dyes, as well as derivatives and blends thereof.
[0017] Likewise, many types of dyeing processes are known. Thus, it is possible to dye fibers, dye yarn of dye fabrics by means of various methods, such as dyeing by depletion, dyeing by means of a gun, dyeing by means of a brush or dyeing by immersion, among others. The variables to be considered in the dyeing process, generally, are: temperature, pH, time, volume, concentration, mechanical effect and adjuvant agents.
[0018] Dyes can be classified in several manners, according to their application, according to their chemical nature, etc. In the market, direct dyes can be found, which, as their name indicates, can be directly applied to the material to be dyed without the need of any adjuvant agent, as well as indirect dyes, which require the aid of compounds called mordants in order to be fixed to the material to be dyed. On the other hand, there exists a range of anionic dyes and cationic dyes, depending on the ionic character of its reactive group or groups.
[0019] A direct cationic dye is one the reactive groups of which are positively charged ions and which is used directly in the dyeing bath without the need of any type or vehicle or pre-treatment for the fiber for the dye to be fixed to the fiber. A direct, cationic dye is attached to the fibers by means of forming salt bonds with the anionic or acid groups of the fibers and has a very high dyeing power.
[0020] The present invention describes the dyeing of fibers, yarn or fabrics made of cotton or blends of cotton with synthetic fibers, using a direct, cationic dye.
[0021] The material to be dyed, that is fiber, yarn or fabric, is passed through a bath to remove natural impurities attached to the fibers, consisting of a water solution containing a cationic moisturizing agent in a concentration of about 2-10 g/l, the temperature of the bath varying between about 40 and 90° C., and the immersion time between about 10 and 30 seconds; the material is squeezed so that it has an absorption capacity after being squeezed, or “pick up”, of between about 60 and 80% of its own weight. Subsequently, the material is rinsed with water at a temperature of between about 40 and 80° C., passed to second rinsing step at room temperature; once it is rinsed, the material is squeezed until it achieves an absorption capacity (pick up) of about 150 to 300% of its own weight.
[0022] Subsequently, the material is passed to the dyeing process, properly speaking. The dyeing bath is prepared mixing the direct, cationic dye with water at a temperature of between about 60 and about 95° C.; the pH of the bath should be kept between about 4 and 9; in order to keep the pH within the indicated range, it is possible to use a buffer solution. The concentration of the dye varies between about 0.05 and 500 g/l, depending on the intensity of the color hue desired in the final product.
[0023] This dyeing bath can be used in any known dyeing process, such as dyeing by depletion the yarn, fiber, fabric or garment, continuous dyeing of the fabric, dyeing the yarn in width and in cord, or any type of dyeing process by immersion.
[0024] In the latter case, the material to be dyed can be passed through more than a single immersion tank, depending on the desired fixation and color. The immersion time varies between about 10 and 30 seconds.
[0025] The dyed material is rinsed with water at room temperature in order to remove the dye not fixed to the fiber and then passed to a fixation bath containing an anionic fixation agent, such as an arylsulfonate, in a concentration of about 80 to 120 g/l, with a residence time of about 30 to 60 seconds. Finally, the material is rinsed again with water at room temperature, obtaining the material—either fiber, yarn or fabric-dyed with the desired color and brightness and ready for subsequent processing.
[0026] After the dyeing, in the case of fibers, they are used to manufacture yarn and subsequently fabric; in the case of yarn, fabric is made therewith, so that the final product is a fabric with the desired color and brightness and which, in addition, can be washed down.
[0027] By means of the described process fabric can be produced in an ample range of colors. It is possible to use bi-coloring or tri-coloring, that is, mixing different colors of the same type of direct, cationic dye in order to obtain the desired color.
[0028] Many methods for wash down of fabrics are known, such as stone-wash, enzymatic wash, washing with potassium permanganate, and sand-blasting (with a sand stream), among other, and which are not an object of the present invention; however, the fabric obtained by means of the described process suitably reacts to any known method of wash down such that, in combination with the non washed down fabric obtained by means of the process of the present invention, it is used for the manufacture of garments such as jeans, coats, shirts, household textiles and the like.
[0029] Even though the invention has been described in light of its preferred embodiments, the scope of same encompass any type of change or modification which is apparent to those skilled in the art. | The present invention relates to a fabric made of cotton or cotton blends with synthetic fibers, suitable for the manufacture of colored jeans, such that the fiber(s) which form the fabric, the yarn from which the fabric is made, or the fabric itself, are dyed by means of a direct, cationic dye so to obtain a fabric with firm colors and which can be washed down. The corresponding dyeing process is also described. | 3 |
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a method for making a thin padding from stabilized fibers, for clothing articles, quilts and sleeping bags.
[0002] As is known, for making sports or winter clothing article paddings, needled waddings are conventionally used.
[0003] However, the needling process is very expensive and does not provide the clothing articles thus made with satisfactory compactness and does not prevent the fabric fibers from ragging from the fabric.
[0004] Moreover, because of the high wadding bulkiness, the clothing or garment articles made thereby have poor aesthetic characteristics.
[0005] In addition, the needled wadding does not have high thermal insulating characteristics, unless it is made with a comparatively great thickness.
[0006] Because of the above drawbacks, conventional cloth article waddings, even in a needled condition, have not been broadly used so far for making overcoats, winter sport garments and jackets, boots, shoes, quilts and the like.
[0007] Another problem related to the synthetic padding making systems is that it is necessary to use therein a comparatively large amount of synthetic raw material, with consequent great waste problems.
[0008] Furthermore, prior padding or wadding making methods are very expensive from an energy consumption standpoint.
[0009] It is also known that, at present, for making wadding materials, a lot of different machines, such as cards and lap making apparatuses, are conventionally used.
SUMMARY OF THE INVENTION
[0010] Accordingly, the aim of the present invention is to provide a novel method for making a stabilized fiber thin padding material, for use in particular in the cloth article field and for making quilts and sleeping bags, overcoming the above mentioned prior art drawbacks.
[0011] Within the scope of the above mentioned aim, a main object of the invention is to provide such a method allowing to use, as a raw or starting material, a recycled plastics material and any kind of fibers, either of natural or synthetic type.
[0012] Another object of the present invention is to provide such a method allowing to greatly reduce the resin amount coated on the article surface.
[0013] Yet another object of the present invention is to provide such a method allowing to greatly reduce the machine types for making the padding, by eliminating, for example, carding and lap making apparatuses.
[0014] Yet another object of the present invention is to provide such a method providing padding materials having simultaneously the desired thickness, lightness, washing and wearing mechanical strength features.
[0015] Yet another object of the present invention is to provide such a method for making a padding material having a high resistance against deformations, even under high mechanical or water or dry washing stress.
[0016] Yet another object of the present invention is to provide such a method allowing to make stabilized surface fibers so arranged as not to project upon use from the fabric materials.
[0017] Yet another object of the present invention is to provide such a method which, owing to its specifically designed method features, is very reliable and safe in operation.
[0018] According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a method for making a thin padding from stabilized fibers, for clothing articles, quilts and sleeping bags, characterized in that said method comprises the steps of:
providing a synthetic fiber lap; resin processing said synthetic fiber lap by thermoplastic resins spread on a surface of said lap; recovering said resins spread in said resin application step for reusing said resins in another resin processing step; heating said thermoplastic resins and said lap synthetic fibers; reducing a thickness of said lap and smoothing said lap to provide a thin padding.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Further characteristics and advantages of the present invention will become more apparent hereinafter from the following disclosure of a preferred, though not exclusive, embodiment of the invention which is illustrated, by way of an indicative but not limitative example, in the accompanying drawings, where:
[0025] FIG. 1 schematically shows a finishing system for making a stabilized fiber to thin padding according to the inventive method;
[0026] FIG. 2 is an enlarged side elevation view showing a synthetic fiber lap, being subjected to a resin coating and calendering process by a foaming machine; and
[0027] FIG. 3 is a schematic view showing a system for reducing the thickness is and smoothing the wadding surface, by adjustable steel plates.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] With reference to the number references of the above mentioned figures, the method for making a stabilized fiber thin padding according to the present invention comprises the step of providing a lap 1 , made by mixing recycled fibers and/or polyester and/or synthetic and/or natural fibers and/or thermoforming glue materials.
[0029] To reduce the amount of resin coated on the product surface, the inventive method advantageously comprises the step of mixing recycled fibers and thermobonding fibers.
[0030] The latter allow to bind the padding in its inside and reduce by 40% the amount of resin used on the padding surface, with respect to prior systems.
[0031] The resin applying step is carried out, as shown in FIG. 1 , by using spraying elements 2 .
[0032] According to the present invention, the resin 3 , spread in said spraying step, is collected in collecting basins 4 and reused in a resin recirculating circuit 5 having a specifically designed construction.
[0033] After said resin applying step, the lap 1 is conveyed through an oven 6 , heated by an IR radiation, for crosslinking said resins and actuating said thermobonding fibers.
[0034] Since said resin is sprayed only on the wadding surface, the fibers being bound by the thermobonding fibers, the drying time is shorter than that of prior methods, with a smaller power consumption.
[0035] According to another embodiment of the inventive method, a specifically designed foaming machine 7 , schematically shown in FIG. 2 , is used.
[0036] After having made the wadding, with either recycled or non recycled fibers, and containing thermobonding fibers, it is possible to further use, alternatively to the to resin applying step, the above mentioned foaming machine.
[0037] In particular, said resin foaming machine 7 deposits a thin web 8 , of about 3-5 grams, either on one or both the faces of said lap, said thin web being constituted by a finishing resin material, thereby saving about 60% of resin.
[0038] The product thus made is then cross-linked in a small cross-linking oven 6 , of about 3-5 m, being heated by an IR radiation, with a great power saving in comparison with prior systems.
[0039] In this connection, it should be pointed out that up to now the resin was mixed with water in order to be applied by spraying.
[0040] According to the invention, only a resin dispersion which may be a vinyl, acryl, polyurethane, styrene, natural or the like resin is used, with a great energy saving as to the drying thereof.
[0041] According to a further aspect of the present invention, for reducing the wadding thickness and smoothing the wadding surface, two adjustable steel plates 9 arranged in the oven 6 are used, said plates exploiting the heat emitted in a drying step for providing a calendering effect.
[0042] According to a further aspect of the present invention, to further reduce the wadding making cost, instead of conventional machines, such as carding and lap making machines, a plurality of highly ventilated modified balebreakers, operating on said fibers are herein used.
[0043] The high bulkiness and randomly arranged fibers thus opened are pneumatically transported to a silo and again stirred by highly ventilated air.
[0044] Said silo having an adjustable outlet for stabilizing the fiber material amount and thickness.
[0045] The randomized fiber carpet thus formed is deposited on a suitable conveyor belt for conveying to further processing operating steps.
[0046] Then, the finishing step is carried out by the above disclosed methods.
[0047] The wadding making method carried out by the above disclosed system provides a number of advantages.
[0048] At first, about 80% of the textile machines, in particular carding and lap making machines, are eliminated.
[0049] A further advantage is that the different type and nature fibers, either in a mixed or non-mixed condition, are not arranged parallel to one another but with a random arrangement, thereby increasing the wadding volume, which will be much larger than that of a like weight conventional wadding material, with a consequent thermal insulation improvement (as known, air is the best thermally insulating material).
[0050] It has been found that the invention fully achieves the intended aim and objects.
[0051] In fact, the invention has provided a method for making a thermally insulating material layer, having a very little thickness while including, on the two main surfaces thereof, a perspiring film or mesh construction.
[0052] The end product, in particular, is a lap including synthetic fibers covered or resin coated by a thermomelting, glue material mixture, having very satisfactory size and structural stability properties, thereby the thermoinsulating material layer has a very high wear and mechanical stress resistance, as well as a related dry or wet washing resistance.
[0053] In fact, a number of outer synthetic fibers are partially thermomelt and firmly glued with one another, thereby preventing the elementary fibers forming the fiber lap from ragging and separating from one another and projecting from the fabric material.
[0054] Thus, very stabilized non ragging fibrous material layers are achieved, which have a great resistance against high surface stresses.
[0055] In this connection it should be pointed out that the partial and surface thermomelting of the synthetic fibers constituting the target thickness lap may occur either on one or both the inventive padding material surfaces.
[0056] A further important advantage of the present invention is that it provides the possibility of making, starting from plastics waste materials, a wadding having thermally insulating, softness and washing resistance properties comparable to those of virgin fibers.
[0057] To reduce the resin amount coated on the product surface, the recycled fibers are mixed with the mentioned thermobonding fibers allowing to bind the wadding in its inside and to reduce by 40% the resin amount coated on the fiber surfaces in comparison with prior systems.
[0058] Yet another important advantage of the present invention is that the resin dispersed in the spraying step is collected in dedicated basins and reused through a recirculating circuit.
[0059] Moreover, since the resin is sprayed only on the wadding or padding surface, whereas the inside of the fibers is bound by said thermobonding fibers, the drying time will be shorter than that of prior systems.
[0060] Yet another advantage derives from the use of the above mentioned specifically designed foaming machine, as an alternative to the spraying system, allowing to deposit a thin finishing resin web, with a consequent 60% resin saving in comparison with prior systems.
[0061] Moreover, the oven cross-linking allows to achieve a great power saving in comparison with conventional systems.
[0062] In this connection, it is stressed again that up to now resin was mixed with water to be applied by spraying, whereas, according to the present invention, only a resin dispersion which may of a vinyl, acryl, polyurethane, styrene, natural or the like type is used, with a great drying power saving.
[0063] Yet another important advantage, providing a further great economic saving, is that the lap is made without using carding and lap making machines, but by a system comprising suitably modified highly ventilated balebreakers.
[0064] The advantages comprise an elimination of 80% of the textile machines, in comparison with prior systems, and the possibility of making different type and nature fibers, either mixed or not, with a non-parallel but a random arrangement, thereby providing a padding or wadding having an improved bulkiness, in comparison with a like weight prior padding, and having improved thermal insulating properties.
[0065] In practicing the invention, the used materials, as well as the contingent size and shapes can be any, according to requirements. | A method for making a thin padding from stabilized fibers, for clothing articles, quilts and sleeping bags, comprises the steps of:
providing a synthetic fiber lap; resin processing said synthetic fiber lap by thermoplastic resins spread on a surface of said lap; recovering said resins spread in said resin application step for reusing said resins in another resin processing step; heating said thermoplastic resins and said lap synthetic fibers; reducing a thickness of said lap and smoothing said lap to provide a thin padding. | 3 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] The embodiments of the present invention relate generally to methods and apparatus for subsea control systems. More particularly, the embodiments of the present invention relate to control systems for subsea chokes. More particularly, the embodiments of the present invention relate to control systems for improving the response time, controllability, uptime availability, and retrievability of the active components of subsea chokes.
[0004] In offshore oil and gas production, it is often common for more than one well to be produced through a single flowline. In a typical installation, the products from each individual well flow are combined into a common flowline, which then carries the products to the surface or combines those products with the products of other flowlines. The difficulty in managing a multiple well completion produced through a single flowline is that not all of the wells may be producing at the same pressure conditions or include the same flow constituents (liquids and gases).
[0005] For example, if one individual well is producing at a lower pressure than the pressure maintained in the flowline, fluid can backflow from the flowline into that well. Not only is the loss of production fluids undesirable, but the pressure changes and reverse flow conditions within that well may damage the well and/or reservoir. Similarly, if one well is producing at a pressure above the flowline pressure, that well may produce at an undesirable flow rate and pressure, again with the potential to damage other wells and/or the reservoir. Thus, the management of flow rates and pressures is of critical importance in maximizing the production of hydrocarbons from the reservoir.
[0006] Prior art subsea production systems, including a choke 15 , are shown in FIGS. 1-3. Referring initially to FIG. 1, control signals and a hydraulic fluid supply are transmitted along an umbilical 30 from a topside control system 20 to a subsea control module 40 , which supplies hydraulic fluid to actuators in the subsea trees, manifolds, valves, and other functions along lines 60 . As control valves within the control module 40 receive signals to open or close the choke, the control valves actuate to control the flow of hydraulic fluid to the choke actuator 17 through either hydraulic line 16 , for opening, or hydraulic line 18 , for closing. The common choke actuator 17 is a hydraulic stepping actuator, which, depending on the style of actuator and choke being used, may take 100 to 200 steps to close, although systems requiring a smaller, or larger, number of steps are possible. Each step involves the actuator 17 receiving a pulse of hydraulic pressure, which moves the actuator, and then a release of that pressure, which allows a spring to return the actuator to its initial position. In typical systems, where the SCM is located proximate (e.g., within about 30-feet) to the choke/actuator, about one second is required for the pressure pulse to travel from the control valve in module 40 to the actuator 17 and two seconds are required for the spring to return the actuator to its initial position. Thus, with a total of three seconds per step and a total of up to 200 or more steps required to fully actuate the choke, the time required to fully close or open the choke is considerable. The risk of equipment failure is also increased due to the components being actuated hundreds, thousands, or even millions, of times.
[0007] Another typical prior art subsea production system, including a choke 15 , is shown in FIG. 2. Control signals and a hydraulic fluid supply are transmitted along an umbilical 32 from a topside control system 20 directly to a subsea choke 15 , bypassing subsea control module 40 on an electro hydraulic control system. Operation of a direct hydraulic control system would also be as described above, since no subsea control module is required, and a direct electric (control) system would operate similarly, minus any hydraulic control lines. The choke 15 is opened and also closed via hydraulic signals transmitted through dedicated umbilical lines. Hydraulic signals from the surface control the flow of hydraulic fluid to the choke actuator 17 through either hydraulic line 16 , for opening, or hydraulic line 18 , for closing. The common choke actuator 17 is a hydraulic stepping actuator which, depending on the style of actuator and choke being used, may take 130-180 steps to close. Each step involves the actuator 17 receiving a pulse of hydraulic pressure, which moves the actuator, and then a release of that pressure, which allows a spring to return the actuator to its initial position. In typical systems, the time required for the pressure pulse to travel from the surface to the actuator 17 is directly related to the offset distance (umbilical length from surface to choke), water depth and actuating pressure, which can be minutes per step for long offsets. Also, an additional amount of time is required for the spring to return the actuator to its initial position. The time to actuate each step can run into minutes, thus, with a total of up to 180 steps required to fully actuate the choke, the time required to fully close or open the choke is considerable.
[0008] A third typical prior art subsea production system, including a choke 15 , is shown in FIG. 3. Electrical power and a hydraulic fluid supply are transmitted along an umbilical 34 from a topside control system 20 directly to a subsea choke actuator system 22 , bypassing subsea control module 40 on an electro hydraulic control system. Operation of a direct hydraulic control system would also be as described above, since no subsea control module is required, and a direct electric (control) system would operate similarly, minus any hydraulic control lines. A hydraulic fluid supply is stored local to the choke 15 , such as in accumulator 28 . The choke 15 is opened and also closed via electrical signals transmitted through dedicated umbilical conductors 26 and 27 to actuate the open and close functions. The electrical signals are received by a directional control valve 38 that regulates hydraulic flow to the open and close functions of choke actuator 17 . For this instance, hydraulic fluid is supplied to the local choke accumulators 28 , which are refilled by the hydraulic supply along umbilical 32 . The common choke actuator 17 is a hydraulic stepping actuator which, depending on the style of actuator and choke being used, may take 100 to 200 steps to close. Each step involves the actuator 17 receiving an electrical power pulse, followed by a pulse of hydraulic pressure, which moves the actuator, and then a release of the electrical power that releases the hydraulic pressure, which allows a spring to return the actuator to its initial position. In typical systems, roughly one second is required for the electrical power pulse to travel from the surface to the choke, and then for the pressure pulse to travel from the local choke accumulator to the actuator 17 and roughly two seconds are required for the spring to return the actuator to its initial position. Thus, with a total of three to four seconds per step and a total of up to 180 steps required to fully actuate the choke, the time required to fully close or open the choke is considerable. The power requirements for this type of system are considerable, while the umbilical must have electrical conductors 26 and 28 (one for open, one for close) for each choke.
[0009] Thus, there remains a need in the art for methods and apparatus for increasing the responsiveness and speed of choke control systems, especially subsea systems. Therefore, the embodiments of the present invention are directed to methods and apparatus for controlling choke actuation that seek to overcome the limitations of the prior art.
SUMMARY OF THE PREFERRED EMBODIMENTS
[0010] The preferred embodiments provide a choke or choke actuator having an integrated control system enabling fast closure and opening of the choke. The control system includes integral electronics, such as a valve electronic module, controlling directional control valves and/or solenoid valves, which regulate the flow of hydraulic fluid from a local hydraulic supply to the choke actuator. By locating the control system, directional control valves, and hydraulic supply proximate to the choke actuator, response times for choke actuation are greatly reduced. Additional embodiments may also include other electronic sensing and instrumentation enabling the choke control system to monitor and adjust the choke to maintain selected flow characteristics or in accordance with a predetermined production scheme. Any or all of the components of the choke, the choke control system, or the choke actuator may also be retrievable separately from the other components so as to allow maintenance and replacement.
[0011] In certain embodiments, the choke control system includes one or more valve electronic modules that receive electric signals from the surface along a single, or dual redundant, control line(s). The valve electronic module processes these signals and transmits electrical signals to a directional control valve. The directional control valve includes solenoid valves that, upon receiving a signal from the valve electronic module, actuate to allow hydraulic fluid to flow between a supply and the choke actuator. In the preferred embodiments, the hydraulic supply is located proximate to the choke, such as in an accumulator, so as to minimize the reaction time of the hydraulic signal between the supply and the choke actuator. The choke control system and actuator are preferably integrated into a single package that can be retrieved to the surface for maintenance independent of the choke. Alternatively, the choke control system and actuator can be packaged for separate and/or singular retrieval.
[0012] Incorporating a valve electronic module into the choke control system allows for gains in efficiency in actuating the choke directly from a control system located at the surface, or in actuating the choke from a subsea control module receiving commands from a control system located at the surface. Communication to the choke control system could be provided by hydraulic and electric umbilicals run between the surface control system, or the subsea control module, and the choke control system. The hydraulic and electric signals would merely be commanded by the surface control system or passed along by the subsea control module to the choke control system. Once the electric signal is received by the choke control system, the valve electronic module processes the signal and actuates the directional control valve to open or close the choke as commanded.
[0013] In an alternative embodiment, the surface control system could be in direct electrical communication with the choke control system while hydraulic supply is still received via a main umbilical through the subsea control module and any proximate accumulators. This system allows direct electrical communication with the choke control system while taking advantage of the hydraulic supply provided by the main umbilical and any proximate accumulators. The commanded electrical signal transmitted along the dedicated umbilical to the choke control system is received and analyzed by the valve electronic module to adjust the choke as desired.
[0014] In certain embodiments, the valve electronic module could also provide the choke and choke control system with additional functionality. For example, the valve electronic module may be equipped to monitor pressure transmitters attached to the directional control valve to monitor the application of hydraulic pressure to the actuator. The electronic module may also operate in conjunction with a position measurement sensor to determine the actual position of the choke at any time. The electronic module could also be used to gather data from these and other sensors, such as pressure and/or temperature sensors on the choke inlet and outlet, and transmit this data back to the surface to give the operators an indication of flow conditions at the choke. For example, the use of a venturi, or other geometry change, in conjunction with additional pressure and temperature measurement transmitted to the subsea control module and/or to the surface could enable analytical measurement and determination of flow rates and flow constituency make-up parameters.
[0015] In the preferred embodiments, the improved choke control system allows for significantly increased stepping rates leading to decreased reaction time for choke actuation. Certain embodiments may also provide for increased data acquisition and analysis of flow condition at or near the choke, which could lead to indications of flow characterization and detection of the formation of hydrates.
[0016] Thus, the present invention comprises a combination of features and advantages that enable it to improve the responsiveness and performance of a subsea, or surface, choke control system. These and various other characteristics and advantages of the present invention will be readily apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments of the invention and by referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] For a more detailed understanding of the preferred embodiments, reference is made to the accompanying Figures, wherein:
[0018] [0018]FIG. 1 is a schematic view of a prior art subsea choke system having direct hydraulic control from a subsea control module;
[0019] [0019]FIG. 2 is a schematic view of a prior art subsea choke system having direct hydraulic control from a surface control system;
[0020] [0020]FIG. 3 is a schematic view of a prior art subsea choke system having direct electric control from a surface control system;
[0021] [0021]FIG. 4 is a schematic view of a choke control system with integral electronics;
[0022] [0022]FIG. 5 is a schematic view of one embodiment of a subsea choke system including the choke control system of FIG. 4;
[0023] [0023]FIG. 6 is a schematic view of an alternative embodiment of a subsea choke system including the choke control system of FIG. 4; and
[0024] [0024]FIG. 7 is a schematic view of an alternative choke control system with integral electronics.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] In the description that follows, like parts are marked throughout the specification and drawings with the same reference numerals, respectively. The drawing figures are not necessarily to scale. Certain features of the invention may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in the interest of clarity and conciseness. The present invention is susceptible to embodiments of different forms. There are shown in the drawings, and herein will be described in detail, specific embodiments of the present invention 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 that illustrated and described herein. It is to be fully recognized that the different teachings of the embodiments discussed below may be employed separately or in any suitable combination to produce the desired results.
[0026] In particular, various embodiments of the present invention provide a number of different methods and apparatus for affecting control of a choke assembly. The concepts of the invention are discussed in the context of subsea choke assemblies but the use of the concepts of the present invention is not limited to subsea chokes specifically or choke assemblies generally. The concepts disclosed herein may find application in other choke assemblies, such as surface chokes, as well as other hydraulically actuated assemblies, both within oilfield technology and other high pressure, heavy duty applications to which the concepts of the current invention may be applied. Other embodiments of the control system may include any subsea adjustable components, for example: chokes, downhole or below the mudline/tubing hangers, control valves, etc.
[0027] In the context of the following description, the term “choke” is used to refer to the family of devices incorporating a fixed or variable orifice that is used to control fluid flow rate or downstream system pressure. These devices may also be known as pressure control valves (PCV). Chokes are available for both fixed and adjustable modes of operation and can be used for production, drilling, or injection applications. Adjustable chokes enable the fluid flow and pressure parameters to be changed to suit process or production requirements. Types of chokes may include, but are not limited to, flowline chokes (whether stepping type, or infinitely variable type); subsea or surface separator/processing unit chokes (upstream or downstream) that enable smooth flow into or out from the subsea or surface separator/processing unit; hydraulic submersible pump supply chokes; subsea or surface chemical injection “metering” chokes, etc.
[0028] [0028]FIG. 4 shows one embodiment of a subsea choke system 100 including a choke body 110 and a choke control system 120 . Choke body 110 includes an inlet 112 and an outlet 114 and controls the flow of fluid from the inlet to the outlet by varying the position of an insert (not shown) that restricts the flow through the choke body. In certain embodiments, the choke control system 120 is detachable from the choke body 110 and can be retrieved to the surface along with, or independently from, the insert for maintenance and replacement.
[0029] Control system 120 includes a choke actuator 122 , directional control valve 124 , valve electronic module 126 , signal input 128 (which may be digital, analog, optical, electrical, or any signal) (“signals,”) and hydraulic input 130 . The valve electronic module 126 receives signals from a surface control system via signal input 128 . In response to the signals received, the valve electronic module 126 transmits signals through electrical connections 132 to the solenoid valves of directional control valve 124 . A supply of hydraulic fluid is provided to the directional control valve 124 along hydraulic input 130 . The actuation of the solenoid valves opens hydraulic pathways that allow a hydraulic signal to travel from the directional control valve 124 along hydraulic conduit 134 or 136 to the choke actuator 122 .
[0030] The choke actuator 122 is preferably a hydraulic stepping actuator, of the type commonly used in choke actuation, which converts the linear motion from hydraulic actuation into rotational motion to open or close the choke insert. Hydraulic conduits 134 and 136 provide hydraulic fluid to either an open or close spring-return hydraulic cylinder. These cylinders move linearly in response to hydraulic pressure and then return to their initial positions using a biasing spring. Thus, each pressure pulse from the directional control valve 124 rotates the choke actuator a certain increment causing linear adjustment of the choke insert.
[0031] Referring now to FIG. 5, choke 100 is shown remotely controlled from a surface control system 20 via an umbilical 30 . Umbilical 30 connects, and serves as the communication link between, a subsea control module 40 and the surface control system 20 . Umbilical 30 preferably includes both conductors for relaying control signals (in digital, analog, optical, or current form), such as via wires or fiber optic cables, and one or more conduits providing a supply of hydraulic fluid to the control module 40 .
[0032] Umbilical 30 connects to module junction plate 50 which serves as the primary interface between the subsea control module 40 and the hydraulic actuators in the subsea trees, valves, and other functions via hydraulic lines 60 . Umbilical 30 could attach to a umbilical termination assembly and/or subsea distribution system, with separate or combined hydraulic and electrical flying leads connecting from the subsea distribution system to the subsea control module. In its preferred embodiments, module junction plate 50 provides an interface onto which module 40 can be coupled and de-coupled while the hydraulic plumbing 60 to the subsea functions remains intact. This allows the module 40 to be retrieved to the surface for maintenance and replacement as necessary without disturbing the subsea equipment.
[0033] In a conventional multiplexed operation, module 40 includes a plurality of electronic control valves that are actuated by signals sent from the surface control system 20 . These signals may be sent directly on electrical conductors in umbilical 30 or converted into optical signals and transmitted along fiber optic lines in umbilical 30 . The fiber optic signals are then decoded by electronic equipment integrated into the module 40 and converted into electrical signals to actuate the control valves. Once actuated, the electronic control valves open or close specific hydraulic pathways 60 accessing certain subsea functions. Module 40 receives the supply of hydraulic fluid from umbilical 30 and, in certain embodiments, provides a reservoir of pressurized hydraulic fluid for use in actuating subsea functions.
[0034] For example, if an operator wanted to close a particular subsea valve, signals would be sent from the surface control system 20 , along umbilical 30 , through a subsea distribution system, and be received by subsea control module 40 . The signals received by subsea module 40 would actuate a directional control valve, which opens to allow pressurized hydraulic fluid to flow through line 60 into a hydraulic actuator, closing the desired valve. Hydraulic fluid, which has been pumped from the surface and possibly stored in proximate accumulators, either directly supplies the hydraulic pressure and volume for actuation or is used to replenish a subsea supply of fluid used in actuating the valve.
[0035] In the preferred embodiments, module junction plate 50 includes connections 52 and 54 for subsea rigid or flying leads for signals 70 and hydraulic supply 80 to supply choke system 100 . The hydraulic supply lead 80 preferably feeds a pressurized hydraulic reservoir (e.g., proximate accumulator) 82 , which provides a source of constant pressure hydraulic fluid. The signals and hydraulic supplies are routed through module 40 , with control valves or switches in module 40 providing on/off supply of hydraulic supply and electrical power for connections 52 and 54 . Communication along signal lead 70 , utilizing electrical or optical communication signals, may provide two-way communication with choke control system 120 for relaying data concerning position, flow rate, flow constituents, et cetera back to surface control system 20 .
[0036] For the subsea case, the signal 70 and hydraulic 80 flying leads can connect directly from a local subsea control module 40 or module mounting base 50 , as shown in FIG. 5, or a dedicated signal lead cable 75 can be provided and terminate at a fixed stabplate or junction box on the choke control system 120 , as shown in FIG. 6. For the fixed stabplate case, the signal lead cable 75 is preferably equipped with either wet-mateable or dry-mateable connector(s) into which the cable terminates. This system operates substantially the same as the system described in reference to FIG. 5 but provides direct signals communication between the surface control system 20 and the subsea choke 100 . Hydraulic supply could also be provided directly to the subsea choke 100 by a hydraulic line bypassing module 40 . In other words, a system could be provided where an umbilical carrying signals and hydraulic supply can be connected directly between the surface control system and the subsea choke.
[0037] Whether using the single umbilical system of FIG. 5 or the direct umbilical system of FIG. 6, it may be preferred that the hydraulic supply 80 actually include multiple hydraulic supply lines. For systems with more than one hydraulic supply line for operating the chokes, several options are available. One option is to run multiple hydraulic supply lines from the junction plate 50 with shuttle valves (or other manifolding arrangement enabling selection of the hydraulic supply) joining the hydraulic supply lines internally within the choke control system 120 . A second option is to mount individual shuttle valves on the hydraulic supplies at or near the junction plate 50 with a single hydraulic line supplying the choke control system 120 . This ensures the supply with the highest pressure is provided to the choke control system through a single control line. Alternatively, the hydraulic supplies can be routed through the subsea control module with the control module enabling hydraulic supply selection to the choke. Other similar arrangements for hydraulic supply could be possible, including a closed loop hydraulic system. Application of the system can be similar for an all electric, or direct electric, control system, with reference to hydraulic supplies and selection changed to electric supplies.
[0038] Regardless of the system used for communicating between the surface and the subsea choke, the integration of the choke control system 120 and the choke actuator 122 allows the time required to provide a pressure pulse to the actuator to be reduced from about one second to about one-tenth of a second, providing hydraulic fluid is stored local to the choke, such as in reservoir 82 (e.g., proximate accumulators). Although time is still required for allowing the actuator to return to its initial position, the overall actuation of the choke can be greatly accelerated in comparison to previous systems, especially for direct hydraulic systems. The performance of the system is no longer a function of the subsea control module valves or the length and sizing of the connecting tubing and hydraulic couplers between the control module and the choke actuator. These embodiments also eliminate the requirement for choke control valves mounted within the control module, potentially saving space and weight and/or providing spare/extra functions for other controls as well as increasing the mean time between failures (MTBF) of the control module since less components are in the module and the choke control valves are high cycle components.
[0039] Referring now to FIG. 7, an alternative choke control system 200 is shown. Control system 200 includes a choke actuator 210 , a valve electronic module 220 , and a directional control valve 230 operating in substantially the same method as described in relation to choke control system 120 . The valve electronic module 220 receives signals from a surface control system via signal input 202 . In response to the signals received, the valve electronic module 220 transmits signals through electrical connections 222 to the solenoid valves of directional control valve 230 .
[0040] A supply of hydraulic fluid is provided to the directional control valve 230 along hydraulic input 206 . The actuation of the solenoid valves opens hydraulic pathways that allow a hydraulic signal to travel from the directional control valve 203 along hydraulic conduit 232 or 234 to the choke actuator 210 . The choke actuator 210 is preferably a hydraulic stepping actuator, of the type commonly used in choke actuation, which converts the linear motion from hydraulic actuation into rotational motion to open or close the choke insert. Other types of chokes and choke actuators, such as linear actuating chokes, fast close/open modules, ROV override, et cetera could be controlled similarly. Hydraulic conduits 232 and 234 provide hydraulic fluid to either an open or close spring-return hydraulic cylinder. These cylinders move linearly in response to hydraulic pressure and then return to their initial positions using a biasing spring. Thus, each pressure pulse from the directional control valve 230 rotates the choke actuator a certain increment causing linear adjustment of the choke insert.
[0041] Choke control system 200 also provides additional functionality in having dual pressure sensors 224 providing feedback to the valve electronic module 220 that pressure has been applied to the proper stepping piston (i.e. the solenoid valve has actuated). The choke control system 200 can also incorporate a position indication device 228 (LVDT or similar) that provides feedback as to the actual position of the choke insert and confirms that the choke actuator moves in response to control inputs. Some embodiments may also have an auxiliary instrumentation input 226 that collects data from various other sensors for analysis by either the choke or surface the control systems.
[0042] For example, pressure and/or temperature sensors could be located on the choke inlet and outlet to measure flow conditions at these points. This data could then be transmitted back to the surface to give the operators an indication of flow conditions at the choke and evaluate the performance of the choke. The system may further provide capability to yield early warning of hydrate formation and/or of choke insert failure. With a first sensor positioned upstream of the choke and a second sensor positioned downstream of the choke, and incorporating system and sensor data from previous geometry change(s) and pressure and temperature sensors, system diagnostics and analytical determination of system flow characteristics, including the determination of multiphase, flow characteristics and percentages, could be possible. The analysis and processing the information acquired by these sensors and transmitted along line 226 could be performed locally by the choke control system 200 at the subsea control module, or at the surface with the data transmitted along the electrical leads. The choke control system may also incorporate a hydraulic fluid filter (not shown) mounted internal or external to the choke control system on the hydraulic supply line 80 .
[0043] The embodiments set forth herein are merely illustrative and do not limit the scope of the invention or the details therein. It will be appreciated that many other modifications and improvements to the disclosure herein may be made without departing from the scope of the invention or the inventive concepts herein disclosed. Because many varying and different embodiments may be made within the scope of the present inventive concept, including equivalent structures or materials hereafter thought of, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirements of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in a limiting sense. | A choke actuator having an integrated choke control system enabling fast closure and opening of the choke. The choke control system includes integral electronics to receive signals from a surface or subsea control module and control directional control valves to regulate the flow of hydraulic fluid from a local hydraulic supply to the choke actuator. Response times for choke actuation are greatly reduced by locating the electronic control system and directional control valves in an integrated package with the choke actuator and providing a local hydraulic supply. Additional embodiments may also include other electronic sensing and instrumentation enabling the choke control system to monitor and adjust the choke to maintain selected flow characteristics or in accordance with a predetermined production scheme. Any or all of the components of the choke, the choke control system, or the choke actuator may also be retrievable separately from the other components so as to allow maintenance and replacement. | 4 |
BACKGROUND OF THE INVENTION
The present invention relates to a dynamic pressure bearing used for a rotational machine by which a rotational body can be rotated at high speed. In the dynamic pressure bearing, a recess for generating dynamic pressure is formed between a rotational body and an irrotational body. When the rotational body is rotated, a clearance is formed between the rotational and irrotational bodies by the pneumatic action of the recess for generating dynamic pressure, so that the rotational body can be rotated at high speed through the thus formed clearance.
In general, a rotational body having a dynamic pressure bearing is installed horizontally. By the action of the dynamic pressure bearing, the rotational body is rotated at high speed in the following manner:
A wind generated by high speed rotation of the rotational body is introduced into the recess for generating dynamic pressure formed on the irrotational body. By the action of the wind, a strong wind pressure is generated from the recess. This wind pressure is impressed upon a surface of the rotational body, so that a clearance of about several μm is formed between the surface of the rotational body and the surface of the irrotational body. Since the rotational body is rotated through the clearance, the rotational resistance is reduced. A dynamic pressure bearing is well known, which is used for a polygonal mirror rotated at a high speed of not less than 3000 rpm, wherein a clearance of several μm is formed in the radial and thrust bearings by the action of the recess for generating dynamic pressure. This technique is disclosed in Japanese Utility Model Publication Nos. 38330/1992 and 16574/1993.
When the above dynamic pressure bearing is horizontally installed, a clearance of several μm can be maintained between the rotational and irrotational bodies by the action of a wind generated from the recess for generating dynamic pressure, and the rotational body is rotated at low resistance. In the case where the above dynamic pressure bearing is used for a rotational polygonal mirror for laser beam exposure in a small printer or an image recording apparatus, in some cases, it is impossible to horizontally install the dynamic pressure bearing because the installation space and the arrangement of parts are limited. When the dynamic pressure bearing is installed being inclined together with the rotational polygonal mirror, the clearance of several μm can not be maintained and a portion of the rotational body accidentally comes into contact with an opponent surface. As described above, the polygonal mirror is rotated at high speed not lower than 3000 rpm, and the circumferential speed at the periphery is higher than that at the center. When the rotational body is diagonally arranged as described above, or when vibration is given to the rotational body from the outside of the apparatus, the rotational body can not be supported through the clearance, and a peripheral portion of the rotational body is contacted with a portion of the thrust bearing. The dynamic pressure bearing of the prior art has the above disadvantages.
SUMMARY OF THE INVENTION
An object of the present invention is described as follows:
A rotational body is supported by radial and thrust bearings of dynamic pressure type. A clearance between the rotational body and the thrust bearing is set to be larger than a clearance between the rotational body and the radial bearing. Even under the condition that the rotational body is arranged being inclined, or under the condition that the rotational body is horizontally arranged, a periphery of the rotational body, the peripheral speed of which is especially high, does not come into contact with the thrust bearing.
In order to accomplish the above object, embodiments of the present invention are composed in the following manner.
The first embodiment is to provide a dynamic pressure bearing comprising: a rotational body; a radial bearing for rotatably supporting the rotational body, the radial bearing located close to a center of the rotational body; and a thrust bearing provided to at least one end of the radial bearing, wherein the smallest clearance between the rotational body and the thrust bearing is larger than the smallest clearance between the rotational body and the radial bearing under the condition that the rotational body is stably rotating.
According to the second embodiment of the present invention, in the dynamic pressure bearing of the first embodiment, a recess for generating a dynamic pressure is provided in at least one of the radial and thrust bearings.
According to the third embodiment of the present invention, in the first embodiment, in the case of contact with the bearings, the rotational body comes into contact with at least the radial bearing, the circumferential speed of which is lower that of the thrust bearing.
According to the fourth embodiment of the present invention, in the first embodiment, the radial bearing is made of ceramics.
According to the fifth embodiment of the present invention, in the first embodiment, recesses for generating a dynamic pressure are provided in both the radial bearing and the rotational body.
According to the sixth embodiment of the present invention, in the first embodiment, thrust bearings are provided at both ends of the radial bearing.
According to the seventh embodiment of the present invention, in the first embodiment, a clearance between the thrust bearing and the rotational body is provided in such a manner that the clearance is gradually extended as it goes outside from the rotational center.
According to the eighth embodiment of the present invention, in the seventh embodiment, the clearance is extended in accordance with an inclination formed on at least one of the thrust bearing and the rotational body.
According to the ninth embodiment of the present invention, in the eighth embodiment, the clearance is extended by 2 to 5 μm in accordance with the inclination.
The tenth embodiment is composed in the following manner. The dynamic pressure bearing of the present invention comprises: a radial bearing; thrust bearings provided on both sides of the radial bearing; a rotational body rotatably supported by the radial and thrust bearings. When the rotational body is rotated being supported by the radial and thrust bearings, the minimum clearance generated between the rotational body and the thrust bearing is larger than the minimum clearance generated between the rotational body and the radial bearing.
The eleventh embodiment of the present invention is composed in the following manner. In the dynamic pressure bearing described above, in both the radial and thrust bearings, or alternatively in one of the radial and thrust bearings, a recess for generating dynamic pressure is formed.
The twelfth embodiment of the present invention is composed in the following manner. In the dynamic pressure bearing described above, when the rotational body comes into contact with the bearing, the rotational body comes into contact with at least the radial bearing, the peripheral speed of which is low.
The thirteenth embodiment of the present invention is composed in the following manner. In the dynamic pressure bearing described above, the radial bearing is made of ceramics.
The fourteenth embodiment of the present invention is composed in the following manner. The dynamic pressure bearing of the present invention comprises: a radial bearing; thrust bearings provided on both sides of the radial bearing; a rotational body rotatably supported by the radial and thrust bearings. When the rotational body is rotated being supported by the radial and thrust bearings, the minimum clearance generated between the rotational body and the thrust bearing is larger than the minimum clearance generated between the rotational body and the radial bearing. In this case, recesses for generating dynamic pressure are provided in both the radial bearing and the rotational body.
The fifteenth embodiment of the present invention is composed in the following manner. When the rotational body comes into contact with the bearing, the rotational body comes into contact with at least the radial bearing, the peripheral speed of which is low.
The sixteenth embodiment of the present invention is composed in the following manner. The radial bearing is made of ceramics.
The seventeenth embodiment of the present invention is composed in the following manner. The dynamic pressure bearing of the present invention comprises: a radial bearing; a thrust bearing provided on one side of the radial bearing; a rotational body rotatably supported by the radial and thrust bearings. When the rotational body is rotated being supported by the radial and thrust bearings, the minimum clearance generated between the rotational body and the thrust bearing is larger than the minimum clearance generated between the rotational body and the radial bearing.
The eighteenth embodiment of the present invention is composed in the following manner. In the dynamic pressure bearing described above, in both the radial and thrust bearings, or alternatively in one of the radial and thrust bearings, a recess for generating dynamic pressure is formed.
The nineteenth embodiment of the present invention is composed in the following manner. When the rotational body comes into contact with the bearing, the rotational body comes into contact with at least the radial bearing, the peripheral speed of which is low.
The twentieth embodiment of the present invention is composed in the following manner. The radial bearing is made of ceramics.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing the polygonal mirror for which the dynamic pressure bearing of the present invention is used.
FIG. 2 is a sectional view showing an example of each clearance formed in the dynamic pressure bearing of the present invention.
FIG. 3 is a sectional view showing another example of each clearance formed in the dynamic pressure bearing of the present invention.
FIG. 4 is a sectional view showing another example of each clearance formed in the dynamic pressure bearing of the present invention.
FIG. 5 is a sectional view showing the setting of each clearance formed in the dynamic pressure bearing of the present invention.
FIGS. 6(a) and 6(b)are sectional views showing another example of the dynamic pressure bearing of the present invention.
FIGS. 7(a) and 7(b) re sectional views showing another example of the dynamic pressure bearing of the present invention.
FIG. 8 s a sectional view showing another example of the dynamic pressure bearing of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a view showing the rotational support device 1 of a polygonal mirror. In the upper and lower positions of the rotational support device 1, there are provided sheet-shaped thrust bearings 2, 3. A radial bearing 4 is interposed between the thrust bearings 2, 3. The dynamic pressure bearing 11 is provided in the above manner. On the guide surfaces 21, 31 of the thrust bearings 2, 3, there are provided dynamic pressure generation recesses 22, 32, and on the guide surface 41 of the radial bearing 4, there is provided a dynamic pressure generation recess 42. There is provided a rotational body 5 on which the opposed surfaces 51, 52, 53 are rotatably formed with respect to the guide surfaces 21, 31, 41. In this case, the rotational body 5 is rotated around the center of the radial bearing 4. A polygonal mirror 7 is fixed to an outer periphery of the rotational body 5 together with the attachment members 6, 61. A magnet 6A is provided on the attachment member 6. On the rotational support device 1, there is provided a stator coil 8 opposed to the magnet 8. When the stator coil 8 is energized, the rotational body 5 is rotated by induction at high speed.
In this example, the rotational body 5 is used, the dimensions of which are described as follows. The external diameter is 22 mm, the internal diameter is 10 mm, and the thickness is 6 mm.
FIG. 2 is a view for showing the clearances formed in the thrust bearings 2, 3 and the radial bearing 4 when the rotational body 5 is rotated. The dynamic pressure generation recesses 22, 32, 42 are provided in the following manner: Under the condition that the rotational body is stably rotated, clearances are determined to be 5 to 7 μm which are provided between the guide surfaces 21, 32 on which the dynamic pressure generation recesses 22, 32 of the thrust bearings 2, 3 are formed and the surfaces 51, 52 of the rotational body 5 opposed to the guide surfaces 21, 31. Under the condition that the rotational body is stably rotated, the clearance is determined to be 1 to 3 μm which is provided between the guide surface 41 of the radial bearing 4 and the opposed surface 53 of the rotational body 5.
When the clearances are set in the above manner, the rotational motion is carried out as follows. When the rotational body 5 and the polygonal mirror 7 are rotated at high speed, even if the rotational position of the rotational body 5 is changed at little due to an inclined arrangement of the device or vibration, the opposed surfaces 51, 52 of the rotational body 5 are not contacted with the guide surfaces 21, 31 of the thrust bearings 2, 3, and only the opposed surface 53 of the rotational body 5 slightly comes into contact with the guide surface 41 of the radial bearing 4. In order to prevent the abrasion and heat generation, the radial bearing 4 may be made of ceramics.
In the same manner as that shown in FIG. 2, FIG. 3 is a view for showing the clearances formed in the thrust bearings 2, 3 and the radial bearing 4 when the rotational body 5 is rotated. The dynamic pressure generation recesses 22, 32, 42 are provided in the following manner:
Under the condition that the rotational body is stably rotated, clearances are determined to be 5 to 7 μm which are provided between the guide surfaces 21, 32 of the thrust bearings 2, 3 are formed and the opposed surfaces 51, 52 of the rotational body 5 opposed to the guide surfaces 21, 31. Under the condition that the rotational body is stably rotated, the clearance is determined to be 1 to 3 μm which is provided between the guide surface 41 of the radial bearing 4 and the opposed surface 53 of the rotational body 5.
In this example, instead of the dynamic pressure generation recesses 22, 32 provided on the guide surfaces 21, 31 of the thrust bearings 2, 3, dynamic pressure generation recesses 511, 521 are provided on the opposed surfaces 51, 52 of the rotational body 5. When the clearances are set in the above manner, the rotational motion is carried out as follows. When the rotational body 5 and the polygonal mirror 7 are rotated at high speed, even if the rotational position of the rotational body 5 is changed at little due to an inclined arrangement of the device or vibration, the opposed surfaces 51, 52 of the rotational body 5 are not contacted with the guide surfaces 21, 31 of the thrust bearings 2, 3, and only the opposed surface 53 of the rotational body 5 slightly comes into contact with the guide surface 41 of the radial bearing 4. In order to prevent the abrasion and heat generation, the radial bearing 4 may be made of ceramics.
FIG. 4 is a view showing another example of the dynamic pressure bearing illustrated in FIG. 2. In this example, only the thrust bearing 2 is provided. In this example, the dynamic pressure generation recesses 22, 42 are provided in the following manner:
Under the condition that the rotational body is stably rotated, the clearance between the guide surface 21 of the thrust bearing 2 and the opposed surface 51 of the rotational body 5 is set to be 5 to 7 μm, and under the condition that the rotational body is stably rotated, the clearance between the guide surface 41 of the radial bearing 4 and the opposed surface 53 of the rotational body 5 is set to be 1 to 3 μm. In this example, by the action of the dynamic pressure generation recess 22 provided on the guide surface 21 of the thrust bearing 2, and also by the action of the dynamic pressure generation groove 42 of the radial bearing 4, the rotational motion is carried out as follows. When the rotational body 5 and the polygonal mirror 7 are rotated at high speed, even if the rotational position of the rotational body 5 is changed at little due to an inclined arrangement of the device or vibration, the opposed surface 51 of the rotational body 5 is not contacted with the guide surface 21 of the thrust bearing 2 and only the opposed surface 53 of the rotational body 5 slightly comes into contact with the guide surface 41 of the radial bearing 4. In order to prevent the abrasion and heat generation, the radial bearing 4 may be made of ceramics.
FIG. 5 is a view showing the clearances provided in the radial bearing 4 and the thrust bearings 2, 3 of the dynamic pressure bearing 11 shown in FIG. 2 in the case where the rotational body 5 is stably rotated. In this case, the clearances between the guide surface 41 of the radial bearing 4 and the opposed surface 53 of the rotational body 5 are respectively R 1 and R 2 , and the clearances between the guide surfaces 21, 31 of the thrust bearings 2, 3 and the opposed surfaces 51, 52 are respectively t 1 and t 2 . When t 1 <t 2 and R 1 <R 2 in the stable rotation of the rotational body 5, it is set so that the inequality t 1 >R 1 can be satisfied.
Due to the foregoing, it is possible to effectively prevent the periphery of the rotational body from coming into contact with the thrust bearing. When the following approximate expression is satisfied, it is possible to more effectively prevent the periphery of the rotational body from coming into contact with the thrust bearing.
t.sub.1 >φ.sub.2 /φ.sub.1 ×R1
where the internal diameter of the rotational body 5 is φ 1 and the external diameter is φ 2 .
In FIGS. 1, 2, 3 and 5 showing the examples of the present invention, the dynamic pressure generation recesses 22, 32 are provided on the guide surfaces 21, 31 of the thrust bearing 2, 3. However, the dynamic pressure generation recesses 22, 32 may be provided only on the guide surface 21 or 31. Also, the dynamic pressure generation recesses 511, 521 of the rotational body 5 may be provided only on one of the opposed surfaces 51, 52 of the rotational body 5.
FIGS. 6(a) and 6(b) are views showing other examples. In the example illustrated in FIG. 6(a), the guide surfaces 21, 31 in the thrust bearings 2, 3 are formed into inclined surfaces 211, 311. The polygonal mirror 7 is attached to the rotational body 5. From the opposed surfaces 51, 52 of the rotational body 5, the inclined surfaces 211, 311 are successively separated outwardly as illustrated in the drawing. Therefore, the thrust bearings 2, 3 are separate from the opposed surfaces by 2 to 5 μm at the maximum. The reason why the upper limit is determined to be 5 μm is to generate a sufficiently high wind pressure. The reason why the lower limit is determined to be 2 μm is to conduct machining easily in the manufacturing process. In the same manner as that illustrated in FIG. 2, the clearance between the guide face 41 of the radial bearing 4 and the opposed face 53 of the rotational body 5 is set to be 1 to 3 μm, under the condition that the rotational body 5 is stably rotated. The outer peripheral positions of the opposed surfaces 51, 52 are separate from the inclined surfaces 211, 311 by a long distance. Next, in the device of this example illustrated in FIG. 6(b), the guide faces 21, 31 of the thrust bearings 2, 3 are formed into curved inclined surfaces 212, 312. In other words, the inclined surfaces 212, 312 are inclined being curved in such a manner that the inclined surfaces 212, 312 are gradually separated from the opposed surfaces 51, 52 outwardly, and the thrust bearings 2, 3 are separate by 2 to 5 μm at the maximum. In the same manner as that illustrated in FIG. 2, a clearance formed between the guide surface 41 of the radial bearing 4 and the opposed surface 53 of the rotational body 5 is 1 to 3 μm, under the condition that the rotational body 5 is stably rotated. Accordingly, in the same manner as that illustrated in FIG. 6(a), the outer peripheral positions on the opposed surfaces 51, 52 are separated by a long distance since the curved inclined surfaces 212, 312 are provided.
In the examples shown FIGS. 6(a) and 6(b) explained above, when the rotational body 5 provided with the polygonal mirror 7 is rotated at a speed higher than 3000 rpm, the opposed surface 53 of the rotational body 5 is rotated while it maintains a clearance of 1 to 3 μm by the action of the dynamic pressure generation recess 42. Even when the dynamic pressure bearing 11 is inclined or vibration is caused, or even when small foreign objects, the sizes of which are several μm, enter the clearance, the opposed surfaces 51, 52 of the rotational body 5 do not come into contact with the outer peripheral portions of the inclined surfaces 211, 311, 212, 312 attached to the thrust bearings 2, 3.
FIGS. 7(a) and 7(b) are other examples of the apparatus illustrated in FIG. 3. In the apparatus shown in FIG. 7(a), the opposed surfaces 51, 52 of the rotational body 5 provided with the polygonal mirror 7 are formed into inclined surfaces 511, 521. The inclined surfaces 511, 521 are inclined in such a manner that the inclined surfaces 511, 521 are gradually separated from the guide surfaces 21, 31 of the thrust bearings 2, 3 to the outside, and the maximum distance between the rotational body 5 and the guide surfaces 21, 31 of the thrust bearings 2, 3 is 2 to 5 μm. In the same manner as that shown in FIG. 2, the distance between the guide surface 41 of the radial bearing 4 and the opposed surface 53 of the rotational body 5 is 1 to 3 μm, under the condition that the rotational body 5 is stably rotated. Accordingly, the outer periphery of the rotational body 5 is greatly separated from the guide surfaces 21, 31 of the thrust bearings 2, 3 by the inclinations of the inclined surfaces 511, 521.
In the apparatus shown in FIG. 7(b), the opposed surfaces 51, 52 of the rotational body 5 provided with the polygonal mirror 7 are formed into inclined curved surfaces 511, 521. The inclined curved surfaces 511, 521 are inclined in such a manner that the inclined curved surfaces 511, 521 are gradually separated from the guide surfaces 21, 31 of the thrust bearings 2, 3 to the outside, and the maximum distance between the rotational body 5 and the guide surfaces 21, 31 of the thrust bearings 2, 3 is 2 to 5 μm. In the same manner as that shown in FIG. 2, the distance between the guide surface 41 of the radial bearing 4 and the opposed surface 53 of the rotational body 5 is 1 to 3 μm, under the condition that the rotational body 5 is stably rotated. Accordingly, the outer periphery of the rotational body 5 is greatly separated from the guide surfaces 21, 31 of the thrust bearings 2, 3 by the inclinations of the inclined curved surfaces 511, 521.
In the above examples illustrated in FIGS. 7(a) and 7(b), when the rotational body 5 provided with the polygonal mirror 7 is rotated at a speed higher than 3000 rpm, a clearance of 1 to 3 μm is formed between the guide surface 41 of the radial bearing 4 and the opposed surface 53 of the rotational body 5 by the action of the dynamic pressure generating recess 42, Even when the dynamic pressure bearing 11 is inclined or vibration is caused at this time, the inclined surfaces 511, 521, 512, 522 formed on the opposed surfaces 51, 52 of the rotational body 5 are not contacted with the outer peripheral portions of the guide surfaces 21, 31 of the thrust bearings 2, 3.
FIG. 8 is a view showing another example of the apparatus shown in FIGS. 2, 3, 4, 6(a), 6(b), 7(a) and 7(b). In this example, the guide surfaces 21, 31 of the thrust bearings 2, 3 are formed to be inclined surfaces 213, 313. The inclined surfaces 213, 313 are provided in such a manner that the inclined surfaces 213, 313 are gradually separated from the opposed surfaces 51, 52 of the rotational body 5 provided with the polygonal mirror 7. In the same manner as that illustrated in FIG. 2, the distance between the guide surface 41 of the radial bearing 4 and the opposed surface 53 of the rotational body 5 is maintained to be 1 to 3 μm, under the condition that the rotational body 5 is stably rotated. The opposed surfaces 51, 52 of the rotational body 5 provided with the polygonal mirror 7 are formed into inclined curved surfaces 513, 523. That is, the inclined curved surfaces 513, 523 are inclined in such a manner that they are gradually separated from the inclined surfaces 213, 313 of the thrust bearings 2, 3. Due to the inclinations of the inclined surfaces 213, 313 of the thrust bearings 2, 3 and also due to the inclinations of the inclined curved surfaces 513, 523 of the rotational body 5, the outer periphery of the rotational body 5 and the outer peripheries of the inclined surfaces 213, 313 are separated from each other by a long distance. The maximum distance is determined to be 4 to 10 μm. Accordingly, the peripheries of the rotational bodies are separated from each other by a long distance.
In the example illustrated in FIG. 8, when the rotational body 5 provided with the polygonal mirror 7 is rotated at a speed higher than 3000 rpm, the opposed surface 53 of the rotational body 5 maintains a clearance of 1 to 3 μm by the action of the dynamic pressure generating recess 42 provided in the radial bearing 4. Even when the dynamic pressure bearing 11 is inclined or vibration is caused at this time, the inclined curved surfaces 513, 523 formed on the rotational body 5 are not contacted with the outer peripheral portions of the inclined surfaces 213, 313 of the thrust bearings 2, 3.
As described above, the dynamic pressure bearing of the present invention is composed in the following manner. Compared with the clearance formed between the thrust bearing and the rotational body, the clearance formed between the opposed surfaces of the rotational body opposed to the radial bearing provided on the axis is small. The outer periphery of the rotational body, the rotational speed of which is increased, is prevented from coming into contact with the thrust bearing. Therefore, it is possible to prevent the rotational body having the polygonal mirror from being damaged when it comes into contact with the thrust bearing, that is, the occurrence of galling or seizing can be prevented. Accordingly, it is possible to install the rotational body provided with the polygonal mirror in an inclined condition, if necessary, and even when vibration is given from the outside, the rotational body can be stably rotated at a rotational speed not less than 3000 rpm over a long period of time.
When the polygonal mirror, the rotational speed of which is increased, is used for an image forming apparatus or printer, the image quality can be enhanced and the image can be outputted at high speed. Even in the case of contact, portions of low peripheral speed come into contact with each other. Therefore, the occurrence of galling can be reduced, and selections can be made from various materials, so that the cost can be reduced. | A dynamic pressure generating bearing includes a rotational body, a radial bearing provided adjacent to a center of the rotational body to rotatably support the rotational body around the radial bearing and at least one thrust bearing provided on one end of the radial bearing. When the rotational body is stably rotated, a minimum clearance generated between the rotational body and the thrust bearing is always greater than a minimum clearance generated between the rotational body and the radial bearing. | 5 |
BACKGROUND OF THE INVENTION
Present commercial processes for making glycols involve the hydrolysis of alkylene oxides, using a large excess of water with the application of heat with or without a catalyst. Generally, these processes obtain only about 88 percent yield of the monoglycol with the remainder going to make the higher di-, tri-, and tetraglycols. One disadvantage of the present commercial process is that there is a large excess of water which must be evaporated off in order to obtain pure glycol. This is highly energy intensive. A British patent suggests that alkylene glycols can be made from alkylene oxides using only a small amount of water in the presence of carbon dioxide under 10 to 180 atmospheres of pressure and at temperatures of 80° to 220° C. and in the presence of a catalyst, for example, an alkali metal halide such as potassium iodide or sodium iodide. It is theorized in this reference, British Pat. No. 1,177,877, that the reaction takes place through formation of the carbonate which then hydrolyzes to the glycol. Greater than 90% yields to the mono-glycol are claimed for this process. The present invention uses ethylene carbonate as a starting material together with slightly greater than stoichiometric quantities of water over an alumina catalyst to achieve 98% yields of the mono-glycol.
SUMMARY OF THE INVENTION
Ethylene carbonate, together with slightly greater than a stoichiometric amount of water, is passed over a bed of alumina catalyst at temperatures from about 80° to 200° C. to obtain about 98% mono-ethyleneglycol. Preferred temperatures are in the range of about 120° to 140° C.
DETAILED DESCRIPTION OF THE INVENTION
The lower alkylene glycols may be produced starting with the alkylene carbonates and hydrolyzing these in the presence of catalyst with only slightly greater than stoichiometric amounts of water to obtain the mono-glycols in very high yields approaching 100%. Temperatures of from about 80° to about 200° C. are operable, 120° to 140° C. being preferred. At temperatures above about 150° C., the reaction may be conducted in the absence of a catalyst, but the catalyst allows temperatures in the neighborhood of about 90° to about 110° C. to be used. Temperatures below 80° C. require excessively long residence times because of a slower reaction rate. Too high a temperature on the other hand, that is above 200° C., will cause the formation of more of the higher diethylene and triethylene glycols. The ratio of water to the alkylene carbonate is preferably at least about stoichiometric. Any less than that will slow the rate of reaction and favor the formation of the higher glycols. More than about 1.6 moles of water per mole of alkylene carbonate will work to the detriment of the process in that more energy is required to remove the excess water. Residence times of about 30 to about 120 minutes are operable, 60 to 90 minutes being preferred. Pressure is atmospheric or autogenous.
The following examples show the process performed in a batch reaction:
EXAMPLE 1 (ATMOSPHERIC)
Into a flask, fitted with a reflux condenser, was placed 100 grams of activated alumina pellets. To this was added 108 grams of ethylene carbonate and 36 grams of water (a mole ratio of 1.6 moles water per mole of ethylene carbonate). The flask was then heated to 93° C. at atmospheric pressure. Over a period of 52 minutes the temperature was slowly raised to 105° C. The yield of monoethylene glycol was 99% of theoretical.
EXAMPLE 2 (ADDED PRESSURE)
In a pressure vessel the same mole ratio of water to ethylene carbonate was introduced and temperature was raised to 191° to 193° C. The pressure was maintained at 200 psig.; the pressure was released after 106 minutes and, with a conversion of 98.7% of the ethylene carbonate, a yield of 96% monoethylene glycol and 4% diethylene glycol was obtained. No catalyst was used in this preparation.
The following example shows the use of a continuous process employing the catalyst of Example 1:
EXAMPLE 3 (CONTINUOUS)
Through a packed tube of alumina pellets, a mixture of 1.1 to 1 mole ratio of water and ethylene carbonate was passed at 130° C. at atmospheric pressure, with a flow rate of 45 ml. per hour. The effluent upon analysis showed 70% conversion of the ethylene carbonate with a 99% yield of the monoethylene glycol. In the same manner, but employing a 1.6 to 1 mole ratio of water to ethylene carbonate, the mixture was passed over alumina pellets at 130° C. at a flow rate of 13 ml. per hour, the effluent showed a 97% conversion of ethylene carbonate with a 98% yield to monoethylene glycol.
The following example shows the use of a noncatalytic process:
EXAMPLE 4
A (comparative)
In the manner of Example 1, 22 grams of ethylene carbonate and 4.5 grams of water (1/1 mole ratio of water to ethylene carbonate) were heated in the absence of catalyst for one hour at 98° C. No ethylene glycol was formed.
B (comparative)
Substantially the same mole ratio of components was then heated for two hours at a temperature of 106° to 108° C. Analysis of the contents after cooling indicated that 3.3% monoethylene glycol was formed.
C (invention)
In a third experiment employing pressure and much higher temperature, a mixture of 1.6 moles of water per mole of ethylene carbonate was heated to 191°-193° C. under 200 psig for one hour and 50 minutes. Analysis of the contents showed a 98% conversion of ethylene carbonate and a 96% yield of monoethylene glycol, 4% diethylene glycol.
Since the advantages of the present invention are primarily in the saving of energy because less water needs to be evaporated from the product, it is obvious that using the lower temperatures together with a catalyst is to be preferred over the pressure and high temperatures without the catalyst. Nevertheless, either process will work to obtain good yields of the monoglycol by the hydrolysis of ethylene carbonate. | Alkylene glycols are produced from alkylene carbonates by hydrolysis in the presence of water at temperatures of from about 80° to about 200° C. Catalysts, such as alumina, are employed at temperatures from 80° to about 150° C. and only slightly greater than the stoichiometric amount of water is employed to allow the most efficient use of the process. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to a method of and an apparatus for producing methanol.
Methods and apparatuses for conversion of methane into methanol are known. It is known to carry out a vapor-phase conversion of methane into a synthesis gas (mixture of CO and H2) with its subsequent catalytic conversion into methanol as disclosed, for example, in Karavaev M. M., Leonov B. E., et al “Technology of Synthetic Methanol”, Moscow, “Chemistry” 1984, pages 72–125. However, in order to realize this process it is necessary to provide a complicated equipment, to satisfy high requirements to purity of gas, to spend high quantities of energy for obtaining the synthesis gas and for its purification, to have a significant number of intermittent stages from the process. Also, for medium and small enterprises with the capacity less than 2000 t/day it is not efficient.
A method for producing methanol is also known which includes a separate supply of a hydrocarbon-containing gas heated to 200–500° C. under pressure 2.15 MPa and an oxygen-containing gas in a mixing chamber, subsequent stages of incomplete oxidation of methane with a concentration of oxygen 1–4 volume percent with an additional introduction of reagents (metal oxide catalyst, higher gaseous hydrocarbons or oxygen-containing compositions, a cold oxidizer) into the reaction zone of a reactor, cooling of the reaction mixture in a heat exchanger, separation of methanol from liquid reaction products in a separator, supply of gaseous waste products to an input of the reactor as disclosed in the Russian patent no. 2,049,086. However, this method requires the use of a catalyst or additional reagents and an intense heating of the reacting gasses, which leads to a decrease of methanol yield and to an increased possibility of soot formation.
A further method of producing methanol is known, which includes a separate supply into a mixer of a hydrocarbon-containing gas (natural gas typically) and an oxygen-containing gas (air or oxygen). This mixture a subsequently supplied into a non-cathalytic reactor for gas phase incomplete oxidation at pressures of 1–10 MPa during up to 1000 seconds at a temperature 300–500° C. without catalyst, return of waste reaction gasses which contain non-reacted methane for mixing with the initial hydrocarbon-containing gas into the first reactor or into the second reactor (which is connected in series with the first reactor), as disclosed in the British patent document GB 2,196,335A. This method provides a high yield of methanol. However, due to significant time of reaction and relatively low per pass conversion (5–15% of methane can reacts during each passage through the reactor) this method has a low efficiency.
A further method of producing methanol by a separate supply and oxidation of hydrocarbon-containing gas and oxygen-containing gas at temperature 370–450° C. and pressure 5–10 MPa and time of contact in the reactor 0.2–0.22 sec is also known, and includes cooling of the heated reaction mixture to 330–340° C., introduction of methanol into the reactor, as disclosed in the patent document of the Soviet Union SU 1,469,788. Cooling of the reaction mixture without intermediate condensation and separation to 380–400° C. in multi-stage heat exchangers arranged in the reactor with subsequent supply of the mixture to 2–3 successive stages of oxidation is disclosed in the patent document of the Soviet Union 1,336,471. In the first case it is necessary to have an additional consumption and a secondary separation of methanol that leads to unavoidable losses, and in the second case it is necessary to provide additional cooling loops with circulation of additional cooling agent in them.
An apparatus for producing methanol is known, which includes a plurality of units arranged after one another and connected by pipes, in particular a mixing chamber connected to separate sources of hydrocarbon-containing gas and air or oxygen, a reactor composed of an inert material with a heating element for incomplete oxidation of methane in a mixture supplied into the reactor under an excessive pressure, a condensor and a separator for separation of methanol from the products of reaction, a vessel for recirculated gaseous reaction products with a pipe for their supply into the initial hydrocarbon-containing gas or mixing chamber as disclosed in the British patent no. 2,196,335A. However, a significant time of presence of the reagents in the reactor reduces efficiency of the apparatus, and makes the process practically unacceptable in industrial conditions.
An apparatus which is close to the present invention is disclosed in Russian patent no. 2,162,460. It includes a source of hydrocarbon-containing gas, a compressor and a heater for compression and heating of gas, a source of oxygen-containing gas with a compressor. It further includes successively arranged reactors with alternating mixing and reaction zones and means to supply the hydrocarbon-containing gas into a first mixing zone of the reactor and the oxygen-containing zone into each mixing zone, a recuperative heat exchanger for cooling of the reaction mixture through a wall by a stream of cold hydrocarbon-containing gas of the heated hydrocarbon-containing gas into a heater, a cooler-condenser, a separator for separation of waste gasses and liquid products with a subsequent separation of methanol, a pipeline for supply of the waste gas into the initial hydrocarbon-containing gas, and a pipeline for supply of waste oxygen-containing products into the first mixing zone of the reactor.
In this apparatus however it is not possible to provide a fast withdrawal of heat of high-thermic volume reaction of oxidation of the hydrocarbon-containing gas, because of inherent limitations of the heat-exchanger. This leads to the necessity to reduce the quantity of supplied hydrocarbon-containing gas and, further it reduces the degree of conversion of the hydrocarbon-containing gas. Moreover, even with the use of oxygen as an oxidizer, it is not possible to provide an efficient recirculation of the hydrocarbon-containing gas due to fast increase of concentration of carbon oxides in it. A significant part of the supplied oxygen is wasted for oxidation of CO into CO2, which additionally reduces the degree of conversion of the initial hydrocarbon-containing gas and provides a further overheating of the reaction mixture. The apparatus also requires burning of an additional quantity of the initial hydrocarbon-containing gas in order to provide a stage of rectification of liquid products with vapor. Since it is necessary to cool the gas-liquid mixture after each reactor for separation of liquid products and subsequent heating before a next reactor, the apparatus is substantially complicated, the number of units is increased, and an additional energy is wasted.
A further method and apparatus for producing methanol is disclosed in the patent document RU 2,200,731, in which compressed heated hydrocarbon-containing gas and compressed oxygen-containing gas are introduced into mixing zones of successively arranged reactors, and the reaction is performed with a controlled heat pick-up by cooling of the reaction mixture with water condensate so that steam is obtained, and a degree of cooling of the reaction mixture is regulated by parameters of escaping steam, which is used in liquid product rectification stage.
Other patent documents such as U.S. Pat. Nos. 2,196,188; 2,722,553; 4,152,407; 4,243,613; 4,530,826; 5,177,279; 5,959,168 and International Publication WO 96/06901 discloses further solutions for transformation of hydrocarbons.
It is believed that the existing methods and apparatus for producing methanol can be further improved.
SUMMARY OF THE INVENTION
It is accordingly an object of the present invention to provide a method of and an apparatus for producing methanol, which is a further improvement of the existing methods and apparatuses.
It is another feature of the present invention to provide a method of and an apparatus for producing methanol which can be used directly on gas and gas-condensate deposits, and also at any gas consumer, such as power plants, gas distributing and gas reducing stations, chemical production facilities, etc.
In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a method of producing methanol, which includes the steps of supplying into a reactor a hydrocarbon-containing gas, supplying into the reactor an oxygen-containing gas; carrying out in the reactor an oxidation of said heated hydrocarbon-containing gas by oxygen of said oxygen-containing gas; and supplying into the reactor a cold hydrocarbon-containing gas to be mixed directly with a mixture of said heated hydrocarbon-containing gas and said oxygen-containing gas at a later stage of the reaction to produce methanol and also formaldehyde.
Another feature of the present invention is an apparatus for producing methanol, which has a reactor for receiving and reacting a hydrocarbon-containing gas with an oxygen-containing gas, to carry out in the reactor oxidation of said heated hydrocarbon-containing gas by oxygen of said oxygen-containing gas; and means for supplying into the reactor a cold hydrocarbon-containing gas to be mixed directly with a mixture of said heated hydrocarbon-containing gas and said oxygen-containing gas at a later stage of the reaction to produce methanol and also formaldehyde.
As can be seen, in accordance with the present invention, heated hydrocarbon-containing gas and air are supplied into a reaction zone or into a reactor, where a gas phase oxidation of the hydrocarbon-containing gas is performed at elevated temperature and pressure in the reaction zone. The reaction mixture is cooled before extraction and the cooled reaction mixture is separated into waste gas and liquid product, the liquid products are rectified with separation of methanol, the waste gas is withdrawn, and a liquid is rectified with production of formalin, wherein cold hydrocarbon-containing gas is supplied into a regulation zone of the reactor to reduce the reaction temperature for example by 70–90° and thereby to provide a production and a redistribution of the ratio of products to produce corresponding quantities of methanol and formaldehyde.
The reaction is performed in a homogenous phase by a partial combustion without presence of a hydrogenous catalyst.
The regulating zone is provided with a device for introduction of non-heated hydrocarbon-containing gas for cooling of the reaction mixture by means of its turbulent mixing with the main stream.
The device for final cooling of the reaction mixture before separation can include a gas-liquid heat exchanger connected with the reactor, a separator and a rectification unit, and a device for cooling, located one after the other.
The inner wall of the reaction zone can be coated with a material which is inert to the reaction mixture. The reactor can be provided with thermal pockets for introducing devices for control of temperature in the reaction zone and for control and regulation in the regulating zone, such as for example thermocouples.
In accordance with a preferred embodiment of the present invention, the required temperature at the inlet of the reactor is provided by heating of the hydrocarbon-containing gas to a needed temperature, for example in a tubular oven.
In accordance with a preferred embodiment of the present invention, the introduction of the cold hydrocarbon-containing gas for reduction of temperature in the regulating zone can be performed by an introducing device and a temperature regulating valve arranged in the introduction line.
In accordance with a preferred embodiment of the present invention, during cooling of the reaction mixture in the gas-liquid heat exchanger, heat is transmitted to the raw methanol supplied into a lower part of the separator, up to a desired temperature for performing rectification the input of the rectification coolant. The final cooling is carried out in the air cooling device. Then, the cooled gas is supplied into separator, in which dry gas, raw methanol and liquid are separated. The raw methanol, through the heat exchanger with temperature 100–120° C. is supplied into a rectification column. The temperature of the top of the column is 70–75° C., the pressure in the column is up to 0.2 Mpa. Methanol with the concentration up to 96% is supplied to a park, while the residue which contains formaldehyde is supplied to the rectification column with temperature at its top up to 80°. The final product is supplied to a park.
The time of presence of the reaction mixture in the reactor is 1.2 sec. The period of induction takes approximately 70% of this time, and thereafter a significant temperature increase of the mixture takes place. The content of methanol in the exiting gas, due to its high stability is 40%, while the content of the formaldehyde is 4%. In order to increase the portion of formaldehyde to 8–13% in the final product, the temperature of the reaction is reduced by 70–80° in the moment of jump after the period of induction at 0.7–1.4 sec of reaction due to the injection of the cold hydrocarbon-containing gas into the regulating zone.
When the temperature of reaction is changed from 370° C. to 450° C., the content of aldehydes is increased from 5% to 13% the content of organic acids is increased from 0.5 to 0.7%. The selectivity which is close to a maximum with respect to liquid organic products, including methanol and formaldehyde, is maintained at a concentration of oxygen in the initial gas mixture 2–2.8%.
In accordance with the present invention, the waste gasses are returned back into the process in the apparatus for gas preparation, without distorting its operation and quality of gas. Also, when the apparatus is arranged at gas power plants, the returned gas does not change its caloric content.
The apparatus is ecologically clean and does not produce hazardous wastes. In contrast, in known apparatuses, it is necessary to burn up to 3 million ton per year of formaldehyde mixture when the capacity of the apparatus 6 million ton per year.
The novel features which are considered as characteristic for the present 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 view schematically showing a reactor of an apparatus for producing methanol in accordance with the present invention;
FIG. 2 is a view showing the apparatus for producing methanol, including the reactor and other devices, in accordance with the present invention; and
FIGS. 3 and 4 are views illustrating concentrations of oxygen, formaldehyde and methanol during reactions in accordance with the prior art and in accordance with the present invention correspondingly.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An apparatus for producing methanol in accordance with the present invention has a reactor which is shown in FIG. 1 and identified as a whole with reference numeral 1 . In the reactor a gas phase oxidation of a hydrocarbon-containing gas is carried out. The reactor 1 has a reaction zone 2 which is provided with a device 3 for introducing a heated hydrocarbon-containing gas and a device 4 for introducing an oxygen-containing gas, for example air.
The reactor further has a regulation zone 5 provided with a device 6 for introducing a cold hydrocarbon-containing gas, for reducing the temperature of reaction during operation of the apparatus. In addition, the reactor 1 is provided with thermal pockets 7 for control and regulation of temperatures in corresponding zones, provided for example with thermocouples.
As can be seen from FIG. 2 , the apparatus has a device for cooling the reaction mixture before separation, which includes a gas-liquid heat exchanger 8 and an air cooling device 9 , as well as a regulator of cold gas supply 10 . The gas-liquid heat exchanger 8 is connected with a rectification unit, in particular with a rectification column 11 and a separator 12 . The rectification column 11 is connected with an air cooling device 13 , which is connected with a vessel 14 . Regenerated methanol is supplied from the vessel 14 by a pump 21 to a park.
The reactor 1 is connected with a compressor 15 for supply of compressed air, and with an oven 16 for heating of hydrocarbon-containing gas. The apparatus further has a unit for rectification of formaldehyde which includes a rectification column 17 , an air cooling device 18 and a vessel 19 , from which formaldehyde is supplied to a park.
In operation, a hydrocarbon-containing gas with a methane content for example up to 98% is supplied from an installation for preparation of gas or any other source 20 to the oven 16 , in which it is heated to temperature 430–470° C. Then the heated hydrocarbon-containing gas is supplied into the reaction zone 2 of the reactor 1 . Compressed air with pressure for example 8 MPa and with a ratio 1–2.5% of oxygen is supplied by the compressor 15 also into the reaction zone 2 of the reactor 1 . Oxidation reaction takes place in the reaction zone of the reactor 1 . A second stream of cold or in other words not heated hydrocarbon-containing gas from the same source is supplied through the introducing device 6 into the regulation zone 5 of the reactor 1 . This stream is regulated by the regulating device 10 , which can be formed as a known gas supply regulating device, regulating valve or the like.
Depending on an intended mode of operation of the apparatus, in particular the intended production of methanol or formaldehyde, the reaction mixture is subjected to the reaction in the reactor without the introduction of the cold hydrocarbon-containing gas if it is desired to produce exclusively methanol, and with the introduction of the cold hydrocarbon-containing gas when it is desired to produce also formaldehyde. By introduction of the cold hydrocarbon-containing gas, the temperature of the reaction is reduced for example by 70–90° so as to increase the content of formaldehyde into the separated mixture.
The reaction mixture is supplied into the heat exchanger 8 for transfer of heat to the raw methanol from the separator 12 , and after final cooling in the air cooling device 9 is supplied with temperature 20–30° C. to the separator 12 . Separation of the mixture into dry gas and raw methanol is performed in the separator 12 . The dry gas is returned to the source 20 , while the raw methanol through the gas-liquid heat exchanger 8 is supplied to the rectification column 11 . From the rectification column 11 vapors of methanol through the air cooling device 13 are supplied into the vessel 14 . Regenerated methanol is supplied by a pump 21 to a park. A part of methanol is supplied from the vessel 14 for spraying of the rectification column 11 .
The method in accordance with the present invention and the operation of the apparatus in accordance with the present invention are illustrated by an example of operation of the apparatus with the capacity of 6,000 t/year, with cooling of the reaction mixture by 30° C.
TABLE 1
Example 1
Example 2 with
Parameters
without cooling
cooling by 30° C.
Natural gas supply,
56800 (40570)
60208 (43004)
m 3 /hour (kg/hour)
Gas consumption in
1700 (1215)
1700 (1215)
reaction, m 3 /hour
(kg/hour)
Conversion degree, %
3
3
Oxygen concentratino in
2
2
reaction entry zones, %
Pressure in reactor, MPa
7
7
Cooling in regulation zone
no cooling
direct mixing
with cold gas
Methanol yield, kg/hour
800
800
Formaldehyde yield,
115
230
kg/hour
Total organic products
920
1040
yield, kg/hour
Initial temperature, ° C.
450
450
Reaction temperature, ° C.
530
530
Temperautre in regulation
530
500
zone, ° C.
FIGS. 3 and 4 show diagrams of concentration of oxygen, formaldehyde and methanol in reactions without cooling and with cooling.
As can be seen from FIG. 3 , approximately after 2 sec, oxygen is burnt completely. At this moment the reaction temperature reaches its maximum, and in the reaction mixture methanol and formaldehyde are produced with their proportions. Methanol as a more stable product at the end of the reaction reaches its maximum concentration and maintains it practically stable. Formaldehyde is less stable, and therefore with a temperature increase (the temperature increases until oxygen is burnt completely) its concentration somewhat reduces.
In the reaction with the cooling shown in FIG. 4 , with introduction of the cold gas when the formation of methanol and formaldehyde is completed, the temperature of a final period of the reaction is reduced, so that formaldehyde can not decompose and reduce its concentration. Since methanol remains stable, its concentration remains constant (see Table), while content of formaldehyde increases (on the account of other reaction products).
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of methods and constructions differing from the types described above.
While the invention has been illustrated and described as embodied in method of and apparatus for producing methanol, 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.
What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims. | Production of methanol includes supplying into a reactor a hydrocarbon-containing gas, supplying into the reactor an oxygen-containing as gas, carrying out in the reactor an oxidation of the heated hydrocarbon-containing gas by oxygen of the oxygen-containing gas, and supplying into the reactor a cold hydrocarbon-containing gas to be mixed directly with a mixture of the heated hydrocarbon-containing gas and the oxygen-containing gas at a later stage of the reaction to produce also formaldehyde. | 2 |
BACKGROUND OF THE INVENTION
The estimation of the lifetime of a turbine blade, whereby the remaining lifetime may be determined, is of great importance in the planning of maintenance intervals. Prior methods of estimation were based exclusively on operating time, as the lifetime of a turbine blade was set to an operating time during which it could, with reasonable certainty, be assumed that the turbine blade would exhibit satisfactory operation regardless of the loading exposed to the turbine blade during the operating time.
Obviously, such relatively simple lifetime estimation led to excessively frequent maintenance intervals, and the thus subsequent replacement of turbine blades that had been subjected to relative small loads during their operating time. Prior art now comprises lifetime estimation methods that to some extent are quite complicated, in which parameters such as power loading, failures in both the component being monitored and in nearby components, wear, and also faults in the measuring equipment used to measure the loading, are taken into account in addition to operating time.
For a turbine blade in a multi-stage axial compressor, it has been proven that rotating stall may cause overloading of the turbine blade with subsequent damage and compressor break-down, without the condition being detected by equipment and methods according to prior art. Rotating stall can occur in a turbine stage when the air approaches the turbine blade at the wrong angle. This may cause the flow to separate in the boundary layer between blade and air (boundary separation), whereby a varying flow is generated at one or more locations along the periphery of the stage. When a first turbine blade is subjected to this condition, the air flow is deflected towards a nearby turbine blade, which is then overloaded while the other nearby turbine blade is relieved. This causes the overloaded turbine blade to be subjected to stall, whereby the first turbine blade is relieved. Thus rotating stall propagates along the periphery of the stage at a speed of approximately half the speed of rotation of the turbine.
According to prior art the compressor is monitored by measuring its performance. The measured values resulting from the measurements form part of the input values in a lifetime estimation tool. The measurements are compared with anticipated values, as the anticipated lifetime of the component in question or the entire turbine is affected by whether the measured value is greater or smaller than an anticipated value. However, this form of monitoring is not designed to allow determination of which compressor stage is being subjected to stall.
SUMMARY OF THE INVENTION
In order to remedy the disadvantages of the prior art, this invention regards a method of determining the condition of a turbine blade and utilizing the collected information in an estimation of the lifetime of the turbine blade. In particular, it regards a method of determining when the turbine blade is subjected to an undesirable condition, e.g. in the form of so-called “rotating stall”, whereupon the measured and processed information is used as part of the input information into a lifetime estimation program. The invention also regards a device for implementation of the invention. In this context, the condition of a turbine blade means the type of loading to which the turbine blade is subjected. The condition (operating state) may for example be normal operation, rotating stall, etc.
These and other objects of the present invention will become more readily appreciated and understood from a consideration of the following detailed description of the exemplary embodiments of the present invention when taken together with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an axial section through a compressor; and
FIG. 2 shows a simplified diagram representing the analysis of the measured values.
DETAILED DESCRIPTION OF THE INVENTION
Trials have shown that representative and reliable measurement values that indicate the condition of the turbine blade may be obtained by means of a vibration sensitive sensor in the form of an accelerometer or other vibration sensitive instrument mounted on the turbine casing. The sensor is mounted at or in relative proximity to the compressor stage(s) to be monitored.
Mounting the sensor on the outside of the compressor casing makes it unnecessary to provide through bores in the compressor casing, such as is common in connection with pressure measurements. In a compressor casing for e.g. an air craft, it is not practicable to drill the casing after certification.
The sensor picks up acoustically generated pressure waves from the turbine blades by the pressure waves propagating through the air to the compressor casing, causing the compressor casing to vibrate.
The measurement signal from the sensor is processed e.g. by means of so-called “Fast Fourier Transform” (FFT), in which the measurement signal is converted into measured values corresponding to those frequencies at which they normally occur, and by means of other signal processing filters that are known per se.
Measured values from several compressor stages where the stages have the same number of turbine blades, may if so desired be combined into one common set of measured values/measurements.
The measured values distributed over a frequency range are then compared with anticipated values at each of the corresponding frequencies. If the measured value at a frequency exceeds or falls below a predetermined measurement interval, a signal of the measured value is transmitted to a lifetime estimation device, and the estimated lifetime is corrected in order to take into account the condition of the turbine blade in question.
In the boundary area between normal operation and rotating stall, the blade pass frequency of the compressor stage will be somewhat unstable and will fluctuate. By stating limits for the fluctuation, this condition can also be included in the lifetime estimation.
As mentioned above, rotating stall will propagate around the rotor at a speed of approximately half (50 to 70%) the speed of rotation of the turbine. The vibration energy generated by the rotating stall may be used as additional information in the lifetime estimation. However, the vibrational energy generated may be too low to be used as an indicator if rotating stall is occurring in one compressor stage only.
In the drawings, reference number 1 denotes a section of a compressor comprising several compressor stages 2 with associated stator stages 4 , compressor casing 6 and rotor 8 .
On the compressor casing 6 there is placed a vibration sensitive sensor 10 connected via an electric line 11 to a signal processing device (not shown) of a type that is known per se.
After the signals from the sensor 10 have been processed in the signal processing device (not shown), they may be presented graphically as a diagram 12 , see FIG. 2 .
The frequency range in question is distributed along the abscissa 16 of the diagram, while the ordinate 18 of the diagram 12 indicates the measured values. The processed signal is displayed as a curve 20 .
Within a frequency range defined by line 22 , the so-called “high pass” limit, and by line 24 , the so-called “low pass” limit, in the diagram 12 , a lower limit 26 and an upper limit 28 have been determined on the basis of empirical values, within which the peak level 30 of the curve 20 in said frequency range is located during normal operation.
Were a situation to occur in the compressor stage 2 in question, in which the air supply becomes too small, the value of the peak level 30 will fall below value 26 . This condition is communicated to the unit estimating the lifetime of the component. Similarly, if rotating stall were to occur, the peak value 30 would rise to a level higher than value 28 , whereby a report on this condition is communicated to the lifetime estimation device.
The abscissa 12 of the diagram may be divided into as many frequency ranges as required, with individual limit values for each range. Typically, compressor stages with different numbers of turbine blades have separate frequency ranges, as the turbine blade pass frequency, which is equal to the speed of rotation multiplied by the number of blades, is different, thereby occurring at different abscissa positions in the diagram 12 .
Accordingly, the present invention has been described with some degree of particularity directed to the exemplary embodiments of the present invention. It should be appreciated, though, that the present invention is defined by the following claims construed in light of the prior art so that modifications or changes may be made to the exemplary embodiments of the present invention without departing from the inventive concepts contained herein. | A method for determining the condition of a turbine blade ( 2, 4 ) in a compressor and utilizing the collected information in an estimation of the lifetime of the turbine blade ( 2, 4 ), whereby a measured value reflecting the condition of the turbine blade ( 2, 4 ) is generated by a vibration sensitive sensor ( 10 ) connected to the compressor's ( 1 ) casing ( 6 ). | 5 |
RIGHTS OF THE GOVERNMENT
The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty.
BACKGROUND OF THE INVENTION
This invention relates to the field of charged particle generation for high energy electronic apparatus.
Pulsed electron beam devices which operate at high power levels and high voltages (powers in the gigawatts and voltages above 100 kilovolts, for example), need electron sourcing cathodes capable of operating at high current densities (densities of 100 amperes per square centimeter and higher, for example), in order to be feasible. An inexpensive and simple cathode which is capable of operating in this environment employs materials such as graphite, carbonized felt, or other substances having the property that when suitably excited there results a high temperature plasma of positive and negative charges which can serve briefly as a source of electrons and therefore be considered to be a plasma cathode. Enhancing the operating cycle time of such a plasma cathode is a principal concern of the present invention.
The generation of a surface plasma in this manner occurs through enhancement of the electric field intensity occurring at a large number of small projections or irregularities found on the surface of the cathode material. Such electric field enhancement can accomplish the field emission of electrons. This emission can be forced to high current densities by a suitable applied voltage, a voltage which tends to thermally heat the cathode surface projections to explosively high temperatures and thereby form a plasma of positive and negative charged particles.
The explosive formation of such a plasma is accompanied by imparting a movement velocity normal to the cathode surface to the plasma. This movement velocity typically ranges from about five kilometers per second at an accelerating potential of 150 kilovolts to velocities of 20 to 30 kilometers per second with accelerating potentials of several hundred kilovolts.
This plasma surface motion is in effect a current flowing through an evacuated structure which contains the cathode and anode elements. The nature of this current is defined by the Child-Langmuir equation which may be expressed as:
J=2.34E-6 V.sup.3/2 /d.sup.2 ( 1)
where
J=current density (A/sq meter)
V=cathode to anode voltage (volts)
d=cathode to anode spacing (meters)
In using the Child-Langmuir equation the effective cathode to anode spacing, d, is the distance measured between the moving plasma surface and the anode electrode. Since the plasma is in motion, however, this spacing distance d changes with time. As the spacing d decreases, for example, the current density for the same cathode to anode voltage can be observed to increase according to the Child-Langmuir relationship. Such current change as a result of spacing decrease can be counterproductive, and may be accommodated or compensated in a particular electron device by varying the cathode to anode voltage. However, such change influences the operating power level and may also produce other changes in the operating characteristics of the device. For example, if the operating device is a virtual cathode oscillator, a VICATOR, the oscillating frequency is determined by this voltage and to an even greater extent by the cathode to anode spacing and therefore can be predicted to vary with changes in either of these parameters.
In practice, the changing of cathode to anode spacing in a plasma-dependent electronic device is referred to as "closing" of the cathode. Ultimately the plasma cathode reaches the anode and thereby closes the cathode to anode space to a final value of zero. Typically, this closing action also has the undesirable effect of limiting the usable operating time of an electronic device employing the plasma cathode to times in the 100 to 150 nanoseconds range. The overcoming of this operating time limitation is a principle feature of the present invention.
The patent art shows examples of electron apparatus of this general nature. Included in this patent art is the U.S. Patent of D. M. Goebel et al, U.S. Pat. No. 4,297,615, which is concerned with a high current density thermionic cathode structure wherein heat is used to obtain a high density plasma from a lanthanum hexaboride cathode structure. The Goebel et al lanthanum hexaboride cathode element is mounted in a plasma generating chamber and is coupled to a lower plasma density utilization chamber through one or more openings or apertures which are suitably restricted, in order to maintain the plasma density in the cathode chamber above a critical level for obtaining the desired current density from the lanthanum hexaboride material. The present invention is distinguished by the filamentary heating, the lanthanum hexaboride, the high plasma density cathode chamber and the supplying of a gas stream in order to move the plasma in the Goebel et al apparatus.
Also included in this art is the patent of Bernhard Hillenbrand et al, U.S. Pat. No. 4,634,935, and the patent of Wilhelm Huber, U.S. Pat. No. 4,659,963. Both the Hillenbrand et al and Huber patents are concerned with gas discharge display devices wherein a vacuum-tight enclosure is divided into separate spaces and wherein charged particle plasmas are used as a source of electrons for operating the display. The present invention is distinguished from the low operating power levels and other features in the Hillenbrand and Huber patents.
This art also includes the patent of George Wakalopulos et al, U.S. Pat. No. 4,749,911, which is concerned with an ion plasma electron gun housing dose rate control that is achieved by way of amplitude modulation of a plasma discharge. In the Wakalopulos invention, positive ions generated by a wire in a plasma discharge chamber are accelerated through an extraction grid into a second chamber containing a high voltage cold cathode. These positive ions bombard a surface of the cathode, causing the cathode to emit secondary electrons which form an electron beam. The present invention is distinguished over the Wakalopulos electron gun by structural and functional differences which include the secondary electron emission mechanism.
SUMMARY OF THE INVENTION
The present invention provides a high energy electron source that extends by several fold the operating cycle timewise limitation resulting from cathode closure effects. This improvement is achieved by segregating the plasma sourced generation of electrons from the electron usage portion in an electronic device and operating the closure effect susceptible plasma inclusive portion of the device at a relatively low voltage. Electrons extracted from the thus-formed plasma are communicated into a second enclosure portion of the device for utilization at higher voltages.
It is an object of the present invention therefore, to provide a high current density source of electrons that is free from the effects of cathode closure time limitations.
It is another object of the invention to provide a plasma based source of electrons that is free of closure effect time limitations.
It is another object of the invention to provide a plasma based source of high density electrons usable over an operating period of tenths to tens of microseconds.
It is another object of the invention to provide a high density source of electrons based on the field emission generation of charged particle plasma.
It is another object of the invention to provide a high density source of electrons which originates in a separate plasma chamber.
It is another object of the invention to provide a separate plasma chamber electron source which is operable at conditions favoring a long operating cycle time.
It is another object of the invention to provide a high current density source of electrons which is immune to operating conditions in a utilization chamber portion of the apparatus.
It is another object of the invention to provide a method for operating a plasma source chamber and electron utilization chamber which are in electron communication with each other.
It is another object of the invention to provide a method for achieving increased operating cycle time in a plasma sourced electron apparatus.
It is another object of the invention to provide a method for generating a quantity of electrons that is minimally influenced by electron utilization operating potentials.
It is another object of the invention to provide a plasma based source of high current density electrons wherein segregation of plasma ions and plasma electrons occurs with the aid of an electrically charged screen member.
It is another object of the invention to provide a method for operating a dual anode electron generating and electron utilizing apparatus.
It is another object of the invention to provide an energization arrangement for a dual anode electron generating and utilizing apparatus.
It is another object of the invention to provide a pulsed energy source arrangement for a dual voltage, dual chamber electron sourcing and electron utilizing apparatus.
Additional objects and features of the invention will be understood from the following description and claims and from the accompanying drawings.
These and other objects of the invention are achieved by a high current pulsed beam apparatus of tenths to tens of microseconds operating cycle duration comprising the combination of:
means including an emissive material surfaced first electrode member and electric field generating means therefor for generating a plasma of positive and negative charges in a closing velocity responsive first chamber portion of an evacuated enclosure in the apparatus;
a selected charge transparent second electrode member disposed opposite the first electrode member in the evacuated enclosure first chamber portion;
a charge collecting third electrode member disposed opposite the second electrode member in a selected change operated and closing velocity immune second chamber portion of the evacuated enclosure;
the selected charge transparent second electrode member being disposed intermediate the first and second chamber portions of the evacuated enclosure and enabling communication of vacuum and the selected charges therethrough.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a pictorial and schematic diagram of the invention.
FIG. 2 shows additional details including the preferred energization arrangement for the invention.
FIG. 3 shows current and voltage waveforms characteristic of a plasma source diode portion of the invention.
FIG. 4 shows a plurality of current and voltage waveforms describing operation of the FIG. 1 embodiment of the invention.
FIG. 5, which includes the views of FIG. 5A and FIG. 5B, shows an alternate physical arrangement of the invention.
FIG. 6 shows another alternate physical arrangement of the invention.
DETAILED DESCRIPTION
A functional arrangement of the invention is shown in diagram form in FIG. 1 of the drawings. The FIG. 1 illustrated elements consist of a vacuum enclosure 100 which is capable of sustaining a pressure of typically less than 0.0001 Torr or 0.0001 millimeters of mercury. Within the vacuum enclosure 100 are three electrically isolated elements including the electrode 102 which includes an emitting surface 104. The emitting surface 104 is comprised of material such as carbon felt, graphite, carbonized textile cloth, impregnated metallic sponge or a similar material commonly used in the art for the purpose of generating an explosive plasma when excited by high electric field stresses.
A screen electrode 106 housing a high ratio of open area to screen structure, a ratio of typically 80% or more, serves as the anode electrode of a left hand portion 114 of the FIG. 1 apparatus. This left hand portion of the FIG. 1 apparatus is also referred to as the electron source or cathode diode portion of the FIG. 1 apparatus. The source 114 in FIG. 1 is therefore comprised of the pair of electrodes consisting of a cathode 102, including the emitting surface 104, and the screen anode 106.
A second portion, the use diode or electron utilization or main diode portion 116 of the FIG. 1 apparatus, consists of the screen electrode 106, which is the cathode of this main diode, and a second anode electrode 108, which is therefore the anode of the main diode. The anode electrode 108 may be fabricated of any electrically conductive material commonly used for electrodes, such as a metal.
Two pulsed electrical energy sources are connected to the FIG. 1 apparatus: the cathode diode pulsed source 110 and the main diode pulsed source 112. The negative terminal of the cathode diode pulsed source 110 is connected to the cathode electrode 102 and the positive terminal of this source is connected to the screen electrode 106. The negative terminal of the main diode pulsed source 112 is connected to the screen electrode 106 and the positive terminal to the anode electrode 108.
The invention employs the two diodes 114 and 116 for the purpose of isolating and confining the above described closing phenomenon to one of the diodes, the cathode diode, in order that the other diode, the main diode, operate free from the deleterious effects of the closing phenomenon. The source of the electrons, 118 in the FIG. 1 apparatus, is the plasma 120 of positive and negative charged particles. The plasma 120 is comprised of the positively charged ions and negatively charged electrons which form on the surface 104 of electrode 102 when a high intensity electric field is applied by means of the cathode diode pulsed source 110 and the screen 106. The electrons which are represented at 118 leave the plasma 120 under the influence of this high intensity electric field from the cathode diode pulsed source 110 and are attracted to the screen electrode 106. Only a single electron 118 is shown in the FIG. 1 diagram, however, this single electron represents a continuance stream or current of electrons being emitted from the plasma area on the surface 104.
This plasma 120 is conductive and is actually also imparted a motion toward the screen electrode 106. In this motion, the electrons are lighter and negatively charged so as to be attracted to the anode electrode 106, and arrive at this anode first-in-time with respect to the positively charged and heavier ions. It is significant to note that movement of the plasma 120 under the influence of the anode electrode 106 causes the effective spacing between the cathode and anode of the cathode diode to decrease as the plasma 120 moves toward the screen electrode 106. The result of this change in spacing changes the electrical characteristics of the cathode diode as explained previously and as determined by equation 100.
The vast majority of the electrons 118 however, pass through the screen electrode 106 because of the high percentage of openness of the screen structure. Therefore this majority of the electrons 118 traverse the "transparent" screen 106 to enter the main diode region 116. Since the plasma 120 is confined to the cathode diode 114, the effective spacing between the screen 106 and the anode 108 in the main diode 116 remains constant. Thus, there are no closing effects present in the main diode 116. This diode may therefore be used to enable increase of the electron voltage to any arbitrarily high value during the course of extracting useful energy or signals from the main diode portion 116 of the FIG. 1 apparatus without incurring any of the undesirable cathode closing effects.
The two diodes, i.e., the cathode diode 114 and main diode 116, are therefore driven from the separate pulse sources 110 and 112. The cathode diode 114 is driven at a lower voltage (on the order of one hundred fifty kilovolts, for example), such that the closing velocity of the plasma in the diode 114 is relatively low (on the order of 5 kilometers per second, for example). The fact that the closing velocity is low in the cathode diode 114 enables it to operate for a longer period of time than has heretofore been possible. Operating periods as long as several microseconds, for example, are possible. Actually, operating times ranging between tenths and tens of microseconds are to be expected from the diode 110 before other phenomenon such as high voltage arcing or breakdown limit its operating cycle.
The pulse voltage waveform applied to the cathode diode, may be adjusted such that the diode current is constant with time over the duration of the pulse. This requires that the pulse voltage decrease with time to balance the decrease in effective cathode to anode spacing in the cathode diode 114, as is characterized by equation (1).
The anode of the cathode diode 114 consists of the conductive screen 106. The screen 106 however, has high transparency such that electrons may pass through the screen apertures and into the load diode 116 with only a few percent of depletion or attenuation. This arrangement results in the load diode 116 being supplied by a current source or electron source which is the cathode diode 114. In effect, the total cathode diode serves as the cathode of the main diode by feeding it with current. The cathode diode 114 may be driven to provide various current waveforms to the main diode, however, a constant current is the most common requirement. The behavior of the main diode 116 is determined by the voltage or energy of the electrons provided by the cathode diode 114, the current provided by the cathode diode, and the cathode to anode voltage applied to the main diode 116. The expected current density relationship in the two diodes is predicted by equation (2)
J.sub.m =2.34E-6 (V.sub.c -V.sub.m) .sup.3/2 /d.sub.m.sup.2 (2)
where:
J m =current density in the main diode, 116 in Amperes/square meter
V m =main diode voltage, in volts
V c =cathode diode voltage, in volts
d m= distance between the screen and the anode of the main diode in meters.
The current density predicted by equation (2) applies only when the current density prediction is less than or equal to the current density provided by the cathode diode 114. Within this constraint, the operating voltage of the main diode may be chosen to have any desired waveform. Typically, the main diode 116 is operated under constant voltage conditions and the cathode diode 114 is operated under constant current conditions over the pulse duration of interest. Under these conditions, the main diode 116 current will be determined by equation (2), but limited to a maximum value equal to the cathode diode current.
The diode closure effect is not observed in the main diode 116 since this diode does not receive the plasma 120, but is visited only by the electrons 118. The electrons 118 may form a space charge in the main diode 116, however, such a charge does not in fact incur the diode closure effect. The current in the main diode is therefore determined by equation (2) and is limited to a maximum value determined by the cathode diode 114 current without change in the effective spacing between the screen 106 and the main diode anode 116.
EXAMPLE 1
The following embodiment of the invention demonstrates use of a plasma cathode in an electrical diode 228 which operates for a one microsecond pulse period. Use of the invention in this arrangement eliminates the effects of explosive plasma cathode closure during the one microsecond useful operating pulse period. A comparison is made between an electrical diode employing the invention and a similar electrical diode using a conventional explosive plasma cathode.
The specifications of the electrical diode are given in Table 1.
TABLE 1______________________________________cathode area 0.1 sq meters, .357 meters diametercathode-anode spacing 0.05 metersclosing no closing effects for one microsecondcathode-anode voltage 500 kV______________________________________
The pulse source for the Table 1 electrical diode is a two section type A pulse forming network (PFN), according to the Guilliman terminology (as defined in the Massachusetts Institute of Technology Radiation Laboratory Series, Volume 5, Chapter 6), and is shown schematically in FIG. 2. The FIG. 2 circuit in fact shows two pulse forming networks 200 and 240 which may be used to energize the main diode portion 232 and the cathode diode portion 230 of the electrical diode 228. The network 240 delivers electrical energy to the cathode diode through the switch S1. The network 200 in FIG. 2 is of the type used in radar transmitters and delivers energy initially stored in the large capacitor 202 in the form of a pulse to the terminals 222 and 224 through and by means of the switch, S2. This pulse is of course, made to be of similar duration as the plasma cathode pulse of the present invention.
The nature of the pulse delivered to the terminals 222 and 224 is determined by the initial voltage and size of the capacitor 202 in combination with the size and nature of the series inductance 204 and the parallel L and C combinations of the branches 206 and 214. Such pulse waveform determinations are known in the art and may be more completely understood from the above-cited publication and other well-known references.
For completeness of disclosure, the components shown in FIG. 2 may use the values shown in the following Table 2.
______________________________________Component Value______________________________________Capacitor 202 40 microfarads at 1000 kilovoltsInductor 204 1.75 microhenryInductor 208 1.25 microhenryCapacitor 210 16 microfaradsInductor 212 250 nanohenriesCapacitor 216 20 microfaradsInductor 218 100 nanohenriesInductor 220 225 nanohenriesCapacitor 242 200 microfarads at 150 kilovoltsInductor 244 2.0 microhenries______________________________________
FIG. 3 shows the electrical performance of an electrical diode having the same dimensions as in Table 1 except that a conventional explosive plasma cathode is used therein and the present invention is not employed. The FIG. 3 electrical diode is also energized by the source 200 of FIG. 2. A plasma closing velocity of 25 kilometers per second is used to determine the performance shown in FIG. 3. The FIG. 3 diode closes by 50% of the 0.05 meter initial cathode to anode spacing in one microsecond. Due to this closure, the current waveform 306 shows a pronounced ramping up with time and the voltage waveform 304 shows a severe drop off.
To embody the FIG. 3 example in accordance with Table 1 and the present invention, a cathode diode and main diode are required. The main diode used has the same size and spacing as in Table 1 and the cathode electrode of the main diode is now of course, the anode screen of the cathode diode. The cathode diode is of the same diameter as the main diode (0.357 m), but the cathode to anode (screen) spacing is selected as 0.0136 meters. The pulse power source therefore consists of two sections, one to drive each of the two diodes. The schematic diagrams of the pulse power drivers are as shown at 200 and 240 in FIG. 2. The cathode diode for this example operates at approximately 150 kV, for example, and achieves a closing velocity of about 5 kilometers per second.
FIG. 4 shows the operational characteristics of both the cathode diode and the main diode for this example when configured according to the invention. In the FIG. 4 waveforms, the pulse 404 represents the cathode diode current and is measured against a vertical scale 400 having graduations of ten kiloamperes per division. In a similar manner, the main diode current is represented by the pulse 408. The pulses 406 and 410 in FIG. 4 represent the main diode voltage and the cathode diode voltages, respectively, and are measured against the vertical scale 400 with each division representing a voltage of one hundred twenty-five kilovolts. The repeated identification numbers shown in FIG. 4 are believed sufficient to identify the respective currents and voltages notwithstanding the overlapping of curves in the regions 412, 414, and 416.
The main diode source 200 in FIG. 2 is in fact preferably provided with a pulse delay of 0.5 microseconds in order to center the FIG. 4 main diode current pulse over the center of the current output pulse 404 of the cathode diode. This delay is achieved by synchronizing the switches S1 and S2, which are shown at 246 and 248 in the FIG. 2 circuit. It is notable that the main diode current waveform 408 is not of the same shape as the cathode diode current waveform 404 in FIG. 4. This occurs because the main diode current may be less than the cathode diode current, but may never exceed it. The main diode current 408 does not peak coincident with the cathode diode current 404 because of a space charge limitation in the main diode in this region. This space charge limitation helps shape the main diode current 408 to a more rectangular shape in this particular example.
It is significant to note that the voltage and current pulses 406 and 408 of the main diode are well formed in FIG. 4 as rectangular pulses, in sharp contrast to the waveforms in FIG. 3, which are distorted by the closing effects of the conventional explosive plasma cathode In addition to this waveform improvement, there is zero closing between the cathode and anode of the main diode when using the invention, compared to a 50% or 0.025 meter closing in the main diode not employing the invention.
EXAMPLE 2
The invention has heretofore been described in the configuration of a parallel plane diode. The described principles may however, be used to implement the invention in other diode geometries in which segregation of the explosive plasma cathode into a cathode diode compartment which provides current to the main diode compartment is used. The explosive plasma cathode and its attendant problems with closing are thereby isolated from the main diode. The main diode may then be operated to any desired high voltage level without incurring closing problems.
An example of a coaxial configuration of the invention is shown at 500 and 502 in the endwise and lateral views of FIGS. 5A and 5B in FIG. 5. The plasma material in the FIG. 5 arrangement of the invention is located at the innermost cylinder 518. The screen electrode 516 is the next cylinder in FIG. 5 and the outer cylinder 520 is the anode electrode of the main diode. The blocks 510 and 512 in FIG. 5 represent the cathode diode and main diode energy sources, respectively, and the resistor 514 represents a radio frequency load that is driven by this transmission line configuration of the invention.
The FIG. 5 configuration of the invention is suitable for implementation of devices which are based upon the concept of magnetic insulation. The simplest such device is the magnetically insulated transmission line, (MITL or MIT Line) used for transmission of very high power levels of energy. The FIG. 5 apparatus may represent, for example, a segment of a MITL device. The diode action achieved by way of the present invention provides the characteristics of magnetic insulation without the deletion limitation of closing in contrast with a normal MITL device of FIG. 5.
EXAMPLE 3
FIG. 6 in the drawings shows another coaxial arrangement of the invention, an arrangement which functions as a Magnetically Insulated Line Oscillator that is useful for generating microwave spectrum radio frequency energy. In the FIG. 6 apparatus the cathode source of plasma is shown at 600, the screen electrode at and the main diode anode is represented by the annular rings 604, 606 etc. which are disposed in the form of a slow wave structure. The radio frequency load and characteristic impedance termination are represented by the resistor 610 in the FIG. 6 apparatus. The arrow 608 represents the microwave spectrum output energy of the FIG. 6 embodiment of the invention and the blocks and 614 represent the cathode diode and main diode energy sources. These sources may also be of the FIG. 2 pulse forming network type. In the FIG. 6 arrangement of the invention, the slow wave annular rings are required for the functioning of the oscillation action and generation of the microwave power, with respect to the more basic arrangement of the invention shown in FIG. 5.
The present invention therefore extends the useful operating time of an explosive plasma cathode excited device. This extension is accomplished by recognizing that the operating time in such devices is determined by plasma closure effects. Since plasma closure velocity increases with operating voltage, attempted device operation at higher voltages also results in faster closure time and shorter device output useful pulse width. The invention, however, permits device operation at an arbitrarily high voltage without closure effects by separating the using device into source and utilization diodes wherein the closure effect is absent from the utilization diode and confined to the source diode where such provisions as moderate operating voltages can be used to limit closure effect influences.
While the apparatus nd method herein described constitute a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus or method ad that changes may be made therein without departing from the scope of the invention which is defined in the appended claims. | A high energy level electronic device is segregated into source diode and utilization diode portions, portions which may also be identified as cathode and main diode portions, respectively. The cathode diode portion is operated at a low voltage such that closure velocity effects therein although present, are minimized. A current of electrons, generated by in cathode diode plasma is fed to the second diode through an anode screen portion of the cathode diode. In this arrangement, since there are electrons, but no plasma cathode present in the main diode, no closing problem occurs therein. In this arrangement, therefore the cathode diode is effectively a source of current for the main diode and is operated at minimal voltage to enable the provision of current for a maximum length of time prior to closure effect terminations. The main diode is separated from the plasma and therefore may be operated at any arbitrarily high voltage free from closing effects, which remain isolated and controlled in the cathode diode. Separate pulse forming network energization of the cathode and main diode portions of the device are also disclosed. | 7 |
STATEMENT AS TO RIGHTS TO INVENTION MADE UNDER FEDERAL SPONSORED RESEARCH AND DEVELOPMENT
The invention described herein may be manufactured and/or used by or for the U.S. Government for govermental purposes without the payment of any royalty thereon.
BACKGROUND OF INVENTION
(1) Technical Field
This invention is concerned with improving the capability and extending the useful features of electromechanical acoustic emission detectors, for detecting acoustic emission signals that are emitted by solid objects with those signals being caused, for example, by material cracking and converting the signals obtained into electrical signals that replicate closely the actual dynamic displacements producing said detection. The transducer described herein responds to a very specific displacement, that is a displacement associated with tangential motion only. The object of this invention is to provide a broadband detector for dynamic tangential surface motion. Another object of this invention is to provide a broadband detector that acts as a point receiver for dynamic tangential surface motion. Its sensitivity has the inverse distance relationship expected of a point receiver. Another object of this invention is to provide a broadband measuring transducer that acts as a point receiver for dynamic tangential surface displacement which can be calibrated to measure absolute tangential surface displacement.
(2) Background Art
Acoustic emission, to which the present invention particularly applies, is concerned with the detection of elastic waves that are emitted from some source located within a solid object and becomes manifest at surfaces remote from the source. Several sources can be emitting at the same time. Often acoustic emission signals occur as a result of crack growth when external stresses are applied to the object that contain the crack. Examples of such stress induced acoustic emission signals can be found in pressure vessels under pressure test or in operation, in welded joints that support some force load while in service, as well as fatigue cracking that may be generated in a structure by a dynamically varying load. Chemical changes or temperature differences associated with this object may also induce acoustic emission.
Traditional acoustic emission transducers in use similar to those described in U.S. Pat. Nos. 3,855,847 and 4,011,472 do not produce voltage outputs that are related to some specified physical quantity, such as dynamic displacement. They are usually resonant in character, having sensitivities that change radically over the nominal frequency range of interest.
Besides questionable frequency response and response to unknown physical quantities, traditional acoustic emission transducers may respond to an unknown sum of different directional components of the surface motion. For instance, these transducers may have sensitivity to both normal and tangential motion, a situation that further confuses the interpretation of the transducer's voltage output. (Normal or tangential motion is motion that is in a direction that is respectively perpendicular to or parallel to the surface at the point of interest.) Another problem that most traditional acoustic emission transducers suffer from is related to the extended contact face. This contact face represents an aperture through which the stress wave energy must pass and as such gives rise to an interference problem for vibrational signals impinging on the front face of the transducer from off-axis positions. This adversely affects both the frequency bandwidth and the spacial sensitivity in a way that is both complicated difficult to assess. Thus traditional acoustic emission transducers are detectors of mechanical motion only and can not be used to obtain quantitative measurement of actual physical displacement or velocity.
Instead of being confined to doing triangulation or inerring the general size of the acoustic emission event from signals that are highly confused by transducer resonances and questionable mode of operation, there is a trend now towards trying to measure the actual valve of a specific physical quantity, for example, displacement or velocity of the surface. A few new transducers have been designed to produce voltage outputs that are faithful reproductions of the normal displacement of the surface over a very wide frequency range. But these transducers measure the normal component of the displacement, while the subject transducer measures the tangential component only.
Because acoustic emission signals come from any position in the soild object of interest, signals arriving at the receiving transducer come by various kinds of wave energy or modes of vibrations. There is a mode that travels along the surface which is known by the names Rayleigh or Lamb. There is a vibrational mode that comes by body waves in which the local displacement is parallel to the path of travel of the wave; this is known as the compressional mode. There is a vibrational mode that comes by body waves in which the local displacements are at right angles to the path of travel of the wave; this is known as the shear mode. The wave energy of each mode travels with a different and unique speed; a distinguishing feature. In the general case, at the location of the receiving transducer, the surface would experience the effects of all the impinging modes of vibration. The complex time-vibrational motion that occurs at one point on the surface contains information about the geometry of the body, about the size and kind of an acoustic emission event, and about the acoustic characteristics of the body media.
If the transducer were a perfec device it would sense the surface motion in its complex form ie. a sum of all the different modes of vibration and from all the different paths leading from the acoustic emission event to the receiving transducer position. This includes single and multi reflection paths as well as combinations of body waves where mode conversion is present. It also includes elastic energy that travels along a path that is contained in the surface. If the performance of the transducer is dominated by the unknown response characteristics alluded to in the previous paragraphs, the output becomes so complicated and clouded with the unknown character of the transducer that any interpertation of direct physical quantities such as surface displacement becomes virtually impossible. The ideal acoustic emission detection needs to faithfully measure one known physical quantity, such as displacement, over a wide frequency range that includes the frequencies of interest and it should be known to be sensitive to motion along one component only of the principal directions of the surface such as normal or tangential directions. The directional and spatial sensitivity should vary in a known and well controlled manner. To date no transducer design exists that can provide a faithful voltage representation of the tangential motion of a point on the surface of a solid. It is to this application that the present invention is directed.
SUMMARY
The disclosed broadband transducer is capable of detecting small dynamic tangential displacements of a transient nature at a point location on the surface of an elastic mechanical body. The high quality response of this transducer is achieved by the sensing element design that suppresses cross dimensional resonances and achieves a small acoustic aperture for the frequency band of interest and by a extended compound backing design that transmits stress wave energy out of the element and that also absorbs and scatters said stress wave energy in the backing. Because of the clean (free of spurious resonances) flat response and freedom from aperture interference effects, the disclosed transducer can be calibrated making it particularly useful for measuring absolute displacements of a dynamic tangential kind.
DESCRIPTION OF THE DRAWINGS
FIG. 1a is a side view and FIG. 1b bottom view of the acoustic emission transducer for tangential motion.
FIG. 2 is a perspective view of the transducer.
FIG. 3 is a schematic of the transducer mounted on the test surface and showing the measurement hookup.
FIG. 4 is a graph of the theoretically expected tangential displacement as a function of time for a point on a half space of steel as caused by a point-force step function.
FIG. 5 is a graph of the voltage output of the acoustic emission transducer of this disclosure for tangential motion as a function of time.
FIG. 6 is a graph showing the displacement response as a function of frequency in terms of volts output per unit displacement. This is obtained from the time voltage wave form of FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1a and 1b show the tangential motion sensing transducer in two views, a side sectional, and a bottom view. FIG. 2 shows a perspective view of the transducer lying on its back. The present invention consists of four main components, but may also have two or three additional minor parts. The essential components are a large, extended compound backing (1), a sensing element of low geometric symmetry (2), an electrode system (3) and (4), an attachment process (3a), and a means of leveling the transducer (5). The sensing element (2) is fabricated from some piezoelectric material selected to have similar acoustic properties to the body generating the acoustic emission. Materials suitable for use as the piezoelectric sensing element are composite piezoelectric ceramic polycrystalline materials such as barium titanate, lead zirconate, lead metaniobate, lead zirconate titanate (PZT) and mixtures thereof with each other that can be statically polarized in one direction to produce the necessary ferroelectric state. The fabricated piezoelectric sensing element (2) must be polarized in a direction which is parallel to the plane of the sensing electrodes (3) & (4). Some natural piezoelectric crystals of a single crystal nature, having the proper cut can also be used. Quartz AT,BT, or YT type are examples. The active element (2) of the disclosed device is PZT but is not necessarily limited to that material. The active element (2) must be made to or have the ability to respond only to motion which is parallel to the sensing electrodes (3) & (4). This is accomplished by the proper electrode positions and by insuring that the polarized field is exactly parallel to the sensing electrodes (4), (3). The shape of the element may take different forms which produce geometries of special lower symmetry. One characteristic that describes this said lower symmetry is that the ratio of the area of the base electrode (3) to the area of the tip electrode (4) of the active element should be a large number. The tested device has a ratio that is greater than 200. One such example of a satisfactory geometry is pyramidal in shape as is shown here; another is conical. Both the areas of the base (3) and the tip electrodes (4) are flat and parallel to each other and have very thin metal layers that are attached. Nickel electrodes of less than 0.02 mm thickness are used in the device described here for electrical contact, (3) and (4). Other metals may be used for electrode purposes. Tip contact area (4) should be small in dimension compared to the desired upper frequency cut off of the device. For this device which was designed for an upper frequency limit of 2 MHz, the tip dimensions are 0.5 mm (6) and 1.0 mm (7). The active element (2) has a square base of 12 mm on a side (8) and a height of 6 mm (9). Certain other irregular geometric shapes and sizes of transducer elements might be used with equally good results. An important feature of the geometry of transducer element (2) is that it not have a constant cross section such as that of a disk or a cylinder. This consideration helps suppress cross dimensional resonances associated with a unique constant cross component dimension.
Because of fabrication errors it is difficult but still possible to produce active elements that have a zero component of the static polarization normal to the plane of the electrodes. Such a normal component of polarization would make them show some normal sensitivity, an undesirable feature. To avoid this, before assembly, fabricated transducer elements (2) should be tested by measuring the charge output from the measuring electrodes, (3) and (4), while applying a static force that is perpendicular to the plane of the electrodes. During this test, the measured charge should be zero. Any electrical charge measured during such a test indicates the presence of some normal sensitivity and will be detrimental to the purity of the response to the tangential mode of motion.
The backing (1) is compound and is made of two segments, each serving different acoustic functions. The general characteristics of the compound backing (1) are that the backing (1) be asymetrically positioned with regard to the location of the center line of the active element (2), that the backing (1) should have dimensions that are significantly larger than the active element (2), and that the backing (1) should have a shape that causes mechanical vibrations emanating out of the active element (2) to be reflected many times within the backing (1) before these vibrations chance to intersect and re-enter the active element (2) again. The first segment of the backing (10) shall be constructed of a material with acoustic properties quite similar to that of the active element. In this case the first segment of the backing (10) is made of brass, which is a close acoustic match for the active element (2) which is PZT; but it is not necessarily limited to this material. The second segment of the backing (11) consists of a cavity filled with a material that has high absorption and scattering of ultrasonic energy in the frequency range of operation of the transducer. This filled cavity (11) should have an extensive interface (12) in contact with the first element of the backing (10). This filled cavity (11) should have a volume that is comparable to the volume of the first element of the backing (10). It should have a similar acoustic impedance to that of the first element (10). In this case the filled space (11) is filled with pure tin. The tin of (11) completely wets the brass of (10) so the interface is free of voids that could cause reflections. Other highly attenuative materials might be used as a filler for the cavity of (11).
The attachment process (3a) that adheres the active element (2) to the backing (1) at the position of the base electrode (3) should be acoustically very transparent to the stress waves that originate in the active element (2). Very little stress wave energy should be reflected back into the element at this interface of the base electrode (3). Besides matching acoustical characteristics, the attachment process (3a) should bond the backing (1) to the active element (2) producing a strong mechanical coupling. This attachment process (3a) should also provide electrical contact between the backing (1) and the active element (2). This consideration has been fulfilled by making the matching surface of the active element and the backing flat and smooth and by using a low temperature metal solder to produce the thin joint. In this case a tin-indium solder has been used to adhere the active element (2) to the brass backing (10).
A means of leveling the transducer assembly so that the tip area of the active element (4) can be made to sit flat on the surface of the test body is a necessity. In the version shown here, a three point mount is arranged using the tip of the active element (4) as one leg and two adjustable insulating screws (5) as the other two. Other means that allow the tip area to sit flat to the surface of the test body could be used.
Other additional but minor parts might be an electrical insulating case to provide electrical isolation from stray electrical fields. Such a case would have to be electrically isolated from the backing but at the same time it should provide physical support and protection for the basic transducer. It should also be built so that it does not electrically load down the voltage output of the transducer. This can be done by providing a driven voltage shield. Another minor part might be the inclusion of a very thin protective metal covering for the protruding tip of the active element. Such a protective cover is discussed in the literature by Godfrey, Mahmood, and Emmony.
FIG. 3 shows the arrangement of the transducer (13) sitting on the surface of the object (14) which is emitting mechanical vibration associated with the acoustic emission event at point (15). The voltage output of the device (13) described herein is usually measured by means of an impedance matching amplifier (16) that drives the output cables (17). Such an amplifier (16) must have a high input impedance (>5 Megohms) with a very small equivalent input capacitance (<5 pF). Such a matching amplifier (16) either can be a separate item or it can be incorporated into the structure of the transducer. FIG. 3 also shows the elements of displacement calibration as generated by a step force function at position (18) on the surface (19) of the body (14). The displacement-time function, z=f(t), describes the displacement of the surface and is known. The calibration procedure is partly described in the ASTM Standard E 1106-86 and by Breckenridge.
In order for the tip of the active element (4) to be able to follow the motion of the surface of interest, it must be cemented with a rigid cement. Phenyl salicylate is a cement that has a special property. It provides a rigid bond for acoustic coupling but is weak enough to be sheared off easily without damaging the element tip (4) when the user wishes to remove the transducer (13) from the working surface (19).
Referring to FIG. 4, this figure shows a graph of the tangential component of displacement as calculated as a function of time from elastic theory. This theoretical result is calculated for a steel body under the assumptions of a semi-infinite half space which is excited at a remote point on its surface by a point step force function and represents the tangential displacement of a point on the surface. Pekeris and others have forecast this theoretical result for this physical situation. FIG. 5 shows the voltage output from the tangential displacement transducer as described in this invention as a function of time. The equivalent experimental condition to the theory of Pekeris is simulated by the use of a large steel cylinder that has dimensions of 0.9 m in diameter and 0.45 m in thickness. Both top and bottom surfaces are flat and parallel to each other. This steel cylinder acts like an infinite half space for the first 120 microseconds after an initiating calibration event. For times longer than that the first surface reflections begin to interfere. The experimental equivalent of the point step force function is the breaking of a glass capillary. The features of the steel block and the glass capillary source is described in the literature by Breckenridge.
It is apparent from comparison of FIG. 4 and FIG. 5 that the tangential motion sensing transducer of this invention produces a voltage-time output that closely matches the calculated time function for the tangential component of the surface displacement. Using a mechanism that allows the stress on the glass capillary to be measured at the instant of fracture when the stress is released, it is possible to calibrate the voltage output against the expected displacement at the point of location of the transducer. Such a calibration is shown in FIG.6. This is a comparison of the voltage output as in FIG. 5 to the expected tangential displacement as calculated from theory, the results of that being shown in FIG. 4. This comparison is a point by point division in frequency space of the frequency response obtained from FIG. 4 and 5. This provides the expected sensitivity, ie., voltage output from the described device per the surface displacement as a function of frequency.
As a result of the particular arrangement and attachments of this invention and testing thereof, the dynamic tangential surface displacement at a point on a mechanical body can be accurately measured. This invention provides a tool by which the dynamic displacement which is directly related to a specific physical quantity, of tangential displacement, can be directly inferred from the voltage output of the invention described herein. This represents a considerable improvement over those of the prior art.
While this apparatus herein disclosed forms a preferred embodiment of this invention, this invention is not limited to the specific apparatus described. Changes can be made therein without departing from the scope of the invention which is defined in the appended claims. For example, it will be understood that the selection of the material of the active element will be made dependent on the material of which the structure of interest is made and that the selection of the material for compound backing construction will be made dependent upon the material of which the active element is constructed. The scope of the invention will not be altered by the addition of minor facets, such as self contained impedance matching preamp, an electrical shielding case, and any thin material covering faces for the purpose of protecting the active element. | A transducer is provided for measuring tangential dynamic displacement of a transient nature at a point location on the surface of a mechanical body. This broadband transducer is particularly useful for detection and measurement of acoustic emission signals. The essential components are a large, extended compound backing (1), a sensing piezoelectric element of low geometric symmetry (2) having the proper static polarization, an electrode system (3) and (4), an attachment process (3a), and a means of leveling the transducer (5). The element is characterized by two parallel plane faces of contact, the area of the rear face of attachment being much larger than the front face. The front face has a width dimension which is small in comparison to the wavelength of the highest frequency of interest. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates generally to toilet seat hinges. More particularly, this invention relates to a toilet seat hinge assembly which allows the toilet seat to automatically return to a horizontal or lowered position from a vertical or raised position via controlled hydraulic operation.
Generally, toilets are designed with a toilet seat having a hinge which allows the toilet seat to be manually pivoted between either a lowered position or a raised position for use. Many discussions and even heated arguments have arisen between the male and female population, particularly couples and family members, regarding the position the toilet seat should remain when in not in use. Specifically, many female individuals feel adamant that in residential homes the toilet seat should remain in the lowered position. This requires male individuals after use of the toilet as a urinal to be conscious of manually pivoting the toilet seat to its lowered position.
Numerous devices have been invented in an effort to try to solve the above mentioned problem. For example, U.S. Pat. No. 4,402,092, granted to Smallwood, discloses a spring mechanism wherein a spring is placed in torsion about a hinge shaft when a user manually moves the toilet seat to its use position. The spring acts either to upright a lowered toilet seat or to lower a raised toilet seat. The angular rotation of the toilet seat is slowed by the hinge shaft having a large gear engaging a small gear on an idler shaft with the rotation of the idler shaft braked by a slipping clutch.
Another example, U.S. Pat. No. 4,551,866, to Hibbs, discloses an automatic toilet seat lowering device having a lever mechanism attached to the toilet seat and to a piston which moves in an operating cylinder. Movement of the toilet seat compresses a biasing spring which urges the piston to return the toilet seat to the lowered position. The piston operates on a fluid in the cylinder to delay the lowering of the toilet seat. See also U.S. Pat. No. 454,743, to Kremelberg.
Another example, U.S. Pat. No. 4,491,989, to McGrail, discloses a closure device for toilet seats which includes a spring-biased latching lever which is activated by the flushing handle of the toilet and dampening device. The dampening device is mounted to one hinge of the toilet cover and includes a housing that rotates about a stationary hinge pin when the toilet seat or toilet seat and cover is raised or lowered. The hinge pin has a passage or bore which acts on air in the housing to delay the lowering of the toilet cover or toilet cover and toilet seat.
A further example, U.S. Pat. No. 4,995,120, to Tager, discloses a toilet seat closing device incorporating a reversible DC electric motor controlled by either an electronic circuit timer or a manual remote control device.
Other inventions for toilet seats include automatic lifting devices for lifting toilet seats from a lowered position to a raised position. For example, U.S. Pat. No. 4,951,323, to Shalom, uses a spring mechanism, whereas U.S. Pat. No. 2,092,707, to Zulkoski, uses a manual hydraulically operated foot pedal.
While satisfactory, the prior art devices all have certain significant disadvantages. Some are unreliable and cumbersome to use; others are complicated and expensive in construction and difficult to install on a standard or conventional toilet. In addition, some of these devices also require electrical power supplies, batteries or plumbing hookups, and they do not afford a variable rate descent control.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide an improved toilet seat lowering hinge assembly which automatically returns a manually raised toilet seat to a lowered position after use of the toilet as a urinal by a male individual.
It is also an object of the present invention to provide such a toilet seat lowering hinge assembly which controls the rate of pivotable descent of the toilet seat when the toilet seat is automatically lowered from a raised position to a lowered position.
It is a further object of the present invention to provide such a toilet seat lowering hinge assembly which prevents inconvenience to female individuals who prefer that the toilet seat remain in the lowered position when the toilet is not in use.
It is another object of the present invention to provide such a toilet seat lowering hinge assembly wherein the automatic lowering of the toilet seat can be overridden by a user manually applying downward pressure on the toilet seat.
It is still another object of the present invention to provide such a toilet seat lowering apparatus that is highly efficient, relatively simple in design and construction, compact, unnoticeable, economical to manufacture and readily adaptable to conventional standard toilets.
It is still yet another object of the present invention to provide such a toilet seat lowering hinge assembly that is easily installed by an individual homeowner.
Certain of the foregoing and related objected are readily attained in a toilet seat lowering hinge assembly for automatically lowering a toilet seat from a raised position to a lowered position above the toilet bowl which includes a tubular housing having an inner surface defining a chamber and a shaft sealingly disposed through the housing generally spaced from the inner surface thereof and pivotably mounted thereon for movement between the raised and lowered positions. An operating fluid is received in said chamber and means are provided for releasibly securing one of the housing and the shaft to the toilet bowl. Means are also provided for releasibly securing the shaft to the toilet seat so that the shaft and the toilet seat pivot together. A baffle is disposed in the housing extending from the inner surface of the housing to the shaft and a descent paddle is fixedly attached to the shaft which extends radially outward to sealingly engage the housing inner surface, thereby cooperating with the baffle, inner surface and shaft to partition the chamber into two compartments disposed on opposite sides of the paddle. Vent means are associated with at least one of the baffle and the paddle for allowing operating fluid to flow therethrough from one compartment to the other compartment of the chamber so as to allow the toilet seat to pivot from the raised position to the lowered position at a predetermined rate of time. Manual override means are also associated with at least one of the paddle and the baffle for permitting the toilet seat to be manually moved quickly from the raised position to the lowered position.
Preferably, the assembly further includes a one-way valve means in at least one of the baffle and the paddle for permitting the seat to be quickly pivoted from the lowered to the raised position. The one-way valve means desirably comprises a flap valve having a cover pivotally attached to one side of either the baffle or the paddle.
Most desirably, the housing is cylindrical. Most advantageously, the vent means comprises a vent hole formed in the baffle.
In a preferred embodiment of the invention, the assembly additionally includes vent hole adjustment means for adjusting the size of the vent hole.
Most desirably, the manual override means comprises a flexible sealing strip attached to the paddle which normally engages the inner surface of the housing, but which flexes and allows the operating fluid to pass from one compartment to the other when the toilet seat is manually lowered from the raised to the lowered position. Alternatively, the manual override means comprises one-way valve means associated with one of the baffle and the paddle which is normally closed but which opens and allows the operating fluid to pass from one compartment to the other when the toilet seat is manually lowered from the raised to the lowered position.
BRIEF DESCRIPTION OF THE DRAWING FIGURES
Other objects and features of the present invention will become apparent from the detailed description considered in connection with the accompanying drawings, which disclose several embodiments of the invention. It is to be understood that the drawings are to be used 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 perspective view of the automatic toilet seat lowering hinge assembly embodying the present invention installed on a conventional toilet, showing the toilet seat in its lowered position;
FIG. 2 is a perspective view of the toilet seat lowering hinge assembly installed on a toilet, showing the toilet seat in the process of automatically pivoting from a raised position to a lowered position;
FIG. 3 is an enlarged, fragmentarily-illustrated perspective view, with portions broken away, of the automatic toilet seat lowering hinge assembly, showing the toilet seat in phantom;
FIG. 4 is an enlarged, fragmentarily-illustrated, side elevational view of the toilet seat lowering hinge assembly showing the attachments to the toilet, toilet seat and toilet cover;
FIG. 5A is an enlarged, exploded perspective view, with portions broken away, of the housing and shaft;
FIG. 5B is a fragmentarily-illustrated, longitudinal sectional view, in part elevation, of the end of the housing and shaft showing the end caps and end fittings;
FIG. 6 is an enlarged, fragmentarily-illustrated perspective view of the housing showing the baffle, flow rate adjustment screw and, in phantom, movement of the paddle from the lowered to the raised position;
FIG. 7 is an enlarged, side elevational view of the one-way valve;
FIG. 8 is an enlarged, side elevational view of another embodiment of the paddle;
FIG. 9A is a fragmentarily-illustrated, side perspective view of the hinge assembly showing one embodiment of the toilet seat stop; and
FIG. 9B is a fragmentarily-illustrated, elevational end view of the hinge assembly showing another embodiment of the toilet seat stop.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now in detail to the drawing, and in particular to FIG. 1, therein illustrated is an automatic toilet seat lowering apparatus or hinge assembly 16 embodying the present invention which is installed on a conventional toilet 10 having a toilet bowl 11, water tank 12, a toilet seat cover 13 and a toilet seat 14. In residential homes it is generally preferred that the toilet seat 14 be maintained in a horizontal or lowered position when not in use. Often times the seat is raised to a vertical position, particularly by male individuals when using the toilet as a urinal, and after use not returned a lowered position. Referring to FIG. 2 there is illustrated a toilet 10 wherein the toilet seat 14 has been raised to the vertical position and is in the transition of returning in a controlled manner to a lowered position via hinge assembly 16, as described in greater detail hereinafter.
With reference to FIGS. 3 and 4, hinge assembly 16, generally includes toilet bowl mounting brackets 20, toilet cover brackets 30, toilet seat brackets 40, and a pivotable shaft 50, the middle section of which is received within a housing 60. The pair of mounting brackets 20 secures hinge assembly 16 to the toilet bowl 11. Specifically, mounting bracket 20 has a ring shaped collar or bearing section 22 (FIG. 3) and an integrally formed lug section 24 (FIG. 4) having a hole through which a standard bolt 26 can pass and attach to the conventional standardized holes in the toilet bowl 11. Ring shaped bearing section 22 has a bore 28 (FIG. 3) which supports and permits shaft 50 to freely rotate therein.
Referring again to FIGS. 3 and 4, a pair of toilet cover brackets 30 secures the toilet cover 13 to shaft 50. Each cover bracket 30 has a ring shaped collar or bearing section 32 which has a bore (not shown) similar to mounting bracket bore 28 which is mounted for free rotation on shaft 50. Integrally formed with the bearing section 32 is a lug section 34 having a hole through which a screw 36 can pass and attach to holes in the toilet seat cover 13. The toilet seat cover 13 is freely rotatable on shaft 50 allowing the seat cover 13 to act independently of the toilet seat 14.
A pair of toilet seat brackets 40 attach the toilet seat 14 to shaft 50. Specifically, each toilet seat bracket 40 has a ring shaped bearing section 42 and an integrally formed lug section 44. Lug section 44 has a hole by which a screws 46 can pass for attachment to the toilet seat 14. The ring shaped bearing 42 has a bore with number of teeth 48 for corresponding engagement with teeth 51 (FIG. 3) on the ends of shaft 50. Other conventional, well-known attachment means could equally be employed to rigidly attach the toilet seat 14 to the shaft 50, such as a set screw. The rigid attachment between toilet seat 14 and shaft 50 causes shaft 50 to pivot or rotate when toilet seat 14 is pivoted between a raised and a lowered position.
Referring now to FIGS. 5A and 5B, shaft 50 includes a rod 52, a pair of end fittings 54, and a descent paddle 56. Rod 52 extends through housing 60. End fittings 54 fixedly attach to the ends of rod 52 by a locking pin 53. The end fittings 54 each have a bearing surface 55 (shown slightly reduced in dimension in comparison to FIG. 3) which corresponds to the bearing surface in the cover bracket 30 and mounting bracket 20. The distal end 57 contains teeth 51 for corresponding engagement with teeth 48 in the toilet seat bracket 40.
Paddle 56 is attached axially along the major portion of rod 52, which is contained inside the housing 60 via a paddle sleeve 58 affixed to rod 52 (except for the ends of rod 52) and which extends axially outwardly therefrom. The distal end of the paddle 56 contains a flexible, resilient, centrally-disposed tip seal 59 which serves two functions. It forms a seal against the inner surface of the housing 60, but it is sufficiently flexible to bend under sufficient pressure to allow fluid to transfer from one side of the paddle to the other, as discussed below.
Referring once again to FIG. 5A and 5B, housing 60 includes a hollow cylindrical tube 62, a baffle 64 and a pair of end caps 66 threadably attached to the ends of the tube 62. Specifically, the radial edge of each end cap 66 has external threads 67 which correspond with internal threads 68 on the inner surface of the ends of tube 62. The end caps 66 further have a central bore 70 dimensioned so that the ends of rod 52 pass therethrough and one of the end caps 66 also has two fluid fill holes 71 normally closed via screws 73. An O-ring 72 is disposed in each end cap 66 circling bore 70 to form a tight seal which prohibits fluid transmission therethrough.
Baffle 64 acts as a barrier or wall and attaches to the inner surface of the tube 62 and extends radially to rod 52 dividing the housing into two chambers 80 and 81. The end of baffle 64 is contoured to match the outer diameter of the paddle sleeve 58, and its lower end is channeled to receive a seal strip or gasket 69 along its length. As shown in FIG. 6, a descent relief or vent hole 76 extends through the wall of baffle 64 and allows fluid communication between chambers 80 and 81. A threaded needle valve 78 is threadably received through cylinder tube 62 and baffle 64, so as to intersect vent hole 76. By adjusting needle valve 78, the amount of fluid transmission through vent hole 78 can be adjusted to, in turn, control the rate of descent of seat 14, as described in greater detail hereinafter.
Additional fluid transmission is permitted via larger vent hole 85 in one direction which corresponds to fluid moving from chamber 81 to 80 which reduces the force in raising toilet seat 14. As shown in FIG. 7, this is accomplished by a one-way flap valve 86 pivotably mounted on baffle 64 on the chamber 80 side thereof. Flap valve 86 is made from a resilient strip of material (or it could be spring-loaded) so it normally covers vent hole 85. Its operation is discussed below.
FIG. 8 illustrates a modified construction of the paddle 56, which in place of the flexible tip 59, simply has a sealing tip 59' which serves solely a sealing function. Paddle 56' is provided with a spring-loaded, one-way valve 83 for providing a manual override of the controlled descent. The one-way valve 83 includes a generally U-shaped support 98 having side vent openings 79 and a central opening which receives a pin 88 which extends through vent hole 82 and into the chamber 81. A spring-loaded valve cover plate 87 is received on pin 88 on the chamber 81 side of hole 82 so that it is normally biased against hole 82, thereby preventing fluid transmission therethrough. However, as the toilet seat 14 is lowered quickly, shaft 50 will be rotated and paddle 56' will, in turn, move downwardly (in the direction opposite to that of the arrow in FIG. 6). Due to the increasing fluid pressure in chamber 80, the spring force will be overcome, and the valve cover 87 will open and move away from vent hole 82, thereby allowing fluid into chamber 81, thereby permitting the seat to be lowered quickly.
As seen best in FIG. 5A, a pair of feet 90 are attached to the outer surface of the cylinder tube 62 adjacent the bottom for resting on the toilet bowl 11 and prohibiting the cylinder from turning with respect to the shaft 50 and toilet seat 14. Alternatively, instead of the feet 90, the mounting brackets 20 which attach to the shaft 50 could instead attach to the housing 60.
A fluid, preferably a liquid, is contained within housing 60 and acts as a biasing means allowing the toilet seat 14 to slowly fall from a raised position to a lowered position. Most advantageously, oil is used. However, air, water, or other fluid medium could also be employed. Fluid is added via fill holes 71, normally closed by screws 73, in end cap 66 for filling each compartment 80, 81 with fluid.
FIGS. 9A and 9B illustrate two embodiments of stops for preventing the toilet seat 14 from moving past its vertical upper portion. This is necessary so that the seat will tend to fall under the influence of gravity; typically, a stop angle of 3°-5° off vertical is sufficient for this purpose. As shown in FIG. 9A, a vertical stop 91 has a collar 92 fixed to shaft 50 via set screw 93, and it has a stop arm 94 preventing the toilet seat 14 from rotating past its uppermost vertical point, stop arm 94 engaging the toilet bowl 11 as shaft 50 is pivoted to an "up" or raised position. As can be appreciated, the exact orientation of the seat 14 can be adjusted by adjusting the fixed position of collar 92 relative to shaft 50 via adjustment screw 93. In FIG. 9B, an alternate embodiment is disclosed. In this case, collar 32' replaces collar 32, to which toilet seat 14 is secured. Collar 32' is provided with an extension lug 95 having a bore in which a threaded nut 96 is fixedly mounted which, in turn, receives a threaded adjustment thumbscrew 97. By adjusting the effective length of the lower end of thumbscrew 97 below lug 95, the degree to which the toilet seat 14 can be raised can be controlled, its lower end acting as a stop by abutting toilet bowl 11 to prevent further upward pivoting of toilet seat 14.
The operation of the present invention will be explained with respect to FIGS. 3 and 5A. In FIG. 3, the automatic toilet seat lowering hinge assembly 16 is shown in the lowered position. Housing 60 is positioned so that baffle 64 is slightly rearward of vertical with respect to the toilet 10. Shaft 50 is positioned so that descent paddle 56 is positioned in a generally downwardly extending orientation when the seat is in the lowered position. Adjustment of the position of the descent paddle 56 is accomplished by rotating the teeth 48 of the toilet seat brackets 40 with respect to teeth 51 of shaft 50.
When the toilet seat 14 is raised from the lowered position to a raised position the descent paddle 56 will correspondingly pivot and sweep about the inside of the tube 62 in the direction toward the baffle 64 (see arrow in FIG. 6). Fluid in the chamber 81 is forced through vent openings 76, 85 (largely through the latter and one-way flap valve 86) into chamber 80. Once the seat 14 is rotated to its uppermost raised position (slightly forward of vertical) as defined by stop 91, gravity will act on the toilet seat 14 causing it to pivot downwardly about shaft 50 as it falls to the seated position. The fluid acts to bias toilet seat 14 from pivoting too quickly by causing the fluid to pass through the descent hole 76 (hole 85 being blocked by flap valve 86). The angular speed of the toilet seat is slower while it initially starts its descent, since the torque on the toilet seat 14 is smaller due to the small moment arm, whereas the speed is greater as the toilet seat pivots downward and the moment arm increases. The threaded needle valve 78 can be threadably adjusted to, in turn, adjust the size of the vent hole 76 so as to allow the toilet seat to move from a vertical position to a seated position in about two (2) to three (3) minutes.
The toilet seat 14 can also be quickly moved to its lower position by manually applying a small pressure downward on the toilet seat 14. This will cause tip seal 59 to flex and allow fluid to pass through bypassing the vent hole 76 and allowing the toilet seat 14 to be quickly lowered. The same effect can be accompanied by the use of the one-way valve 83 shown in FIG. 8.
Various modifications can be made, as will become apparent to those skilled in the art. For example, various one-way valves of well-known design could be substituted for the one-way valves illustrated. In addition, although the various parts are preferably made from plastic materials, other materials or combinations thereof could, of course, be employed.
Accordingly, while only several embodiments of the present invention has been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention as disclosed herein. | An automatic toilet seat lowering hinge assembly for automatically lowering a toilet seat from a raised position to a lower position above the toilet seat includes a housing having a chamber through which a shaft is disposed therein. The shaft is releasibly attached to the toilet seat. The housing has a baffle extending from the inner surface of the housing to the surface of the shaft and a descent paddle extends from the shaft outwardly toward the inner surface of the housing to partition the chamber into two compartments. A vent controls the transfer of fluid between the partitioned chamber compartments so that the toilet seat pivots from the raised position to the lower position in a predetermined amount of time. | 4 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser. No. 12/386,214, filed on Apr. 15, 2009, the complete contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to compostable materials' recycling bin refrigeration devices, and more particularly, relates to compostable materials' recycling bin refrigeration devices that may be used, for example, in compost recycling programs to reduce the rate and side effects of the decomposition of compostable materials being temporarily stored in a compostable materials recycling bin.
[0004] 2. Brief Description of the Related Art
[0005] Recycling of materials has become an important part of a modern society, and it is desirable to encourage the recycling of materials where possible. The recycling of compostable materials is important to the environment. Accordingly, compostable materials may be collected from households and businesses for subsequent processing or decomposition, for example, into soil products or fertilizer. However, as it is often necessary for the households or businesses to temporarily store compostable materials for a period of time, one impediment to the recycling of compostable materials is the unpleasant reality that decomposing compostable materials may produce unpleasant odors, and may attract pests, such as insects, larvae, maggots, mold, small animals and other creatures.
[0006] It is desirable to reduce the unpleasant odors while temporarily storing compostable materials, particularly if the materials are being stored indoors, or in locations where the unpleasant odors and insects and other pests are a nuisance or hazard. While it is possible to provide an airtight container within which to temporarily store compostable materials, nevertheless, whenever the airtight container is opened, for example, to add additional compostable material to the container, or to remove the compostable material, the individual opening the container is exposed to a significant waft of odor-filled air produced by the decomposing compostable material. While it may be possible to mask some or a substantial portion of the odors produced by the decomposition of the compostable material by using, for example, a scented air freshener, scented air freshener's merely mask the odor and often produce substantially unsatisfactory results,
[0007] It is also desirable to reduce the likelihood of an infestation of the temporarily stored compostable materials with insects or other pests.
[0008] It is also desirable to improve the sanitary circumstances associated with the recycling of compostable materials.
SUMMARY OF THE INVENTION
[0009] Accordingly, one object of the present invention is to provide a device which reduces the unpleasant odors associated with the temporary storage of compostable materials.
[0010] Another object of the present invention is to provide a device which reduces the likelihood of an infestation of the temporarily stored compostable materials with insects or other pests.
[0011] Another object of the present invention is to provide a device which improves the sanitary circumstances associated with the recycling of compostable materials.
[0012] According to one aspect of the present invention, there is provided a refrigeration device for compostable materials, comprising, a recycling bin adapted to receive compostable materials, a receptacle adapted to receive the recycling bin, and refrigeration means adapted for cooling the receptacle wherein when compostable materials are positioned within the recycling bin and the recycling bin is positioned within the receptacle, the refrigeration means cools the receptacle, the recycling bin and the compostable materials positioned therein.
[0013] According to another aspect of the present invention, there is provided a refrigeration device for compostable materials, comprising, a recycling bin adapted to receive compostable materials, a liner element adapted to receive the recycling bin and refrigeration means adapted for cooling the liner element, wherein when compostable materials are positioned within the recycling bin and the recycling bin is positioned within the liner element, the refrigeration means cools the liner element, the recycling bin and the compostable materials positioned therein. An advantage of the present invention is that it provides a device which reduces the unpleasant odors associated with the temporary storage of compostable materials.
[0014] A further advantage of the present invention is that it provides a device which reduces the likelihood of an infestation of the temporarily stored compostable materials with insects or other pests.
[0015] A further advantage of the present invention is that it provides a device which improves the sanitary circumstances associated with the recycling of compostable materials.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] A preferred embodiment of the present invention is described below with reference to the accompanying drawings, in which:
[0017] FIG. 1 is an exploded view, partially in ghost, of one embodiment of the present invention;
[0018] FIG. 2 is an exploded view, partially in ghost, of an alternative embodiment of the present invention;
[0019] FIG. 3 is an exploded view, partially in ghost, of a further alternative embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] In a preferred embodiment of the present invention, as illustrated in FIGS. 1 and 2 , a removable compost bin or pail 2 , preferably made of stainless steel, aluminum, plastic or other material known to a person skilled in the art, and preferably having a handle 4 which can be rotated (as indicated by the arrow 7 ) from the vertical orientation illustrated in FIG. 1 about pivot pins or bolts 10 (or other suitable pivot devices known to a person skilled in the art) to a substantially horizontal orientation 8 , the handle when in the vertical orientation allowing the compost bin to be lowered into or lifted from the inner liner element 12 or other receptacle, which inner liner element 12 is preferably a cylindrical shape as illustrated in FIG. 1 , or alternatively, where a box-shaped bin is used, an open box-shaped inner liner element (the box preferably having four sides and a bottom) as illustrated in FIG. 2 , preferably made of stainless steel, aluminum, or other suitable material known to a person skilled in the art, which inner liner element is adapted to receive and support the compost bin or pail 2 when inserted therein, and which is adapted to transfer heat from the compost bin or pail 2 as more fully described herein.
[0021] In a preferred embodiment of the present invention, cooling coils 14 are securely positioned in contact with or in close proximity to the outside walls of the inner liner element 12 as illustrated in FIGS. 1 and 2 , the cooling coils 14 being preferably made of copper or steel or other suitable material known to a person skilled in the art and being adapted to receive and circulate a coolant gas, it being understood that many alternative gas or liquid coolants may be used as would be understood by a person skilled in the art.
[0022] In a preferred embodiment of the present invention, the coolant gas passes through and is compressed by a compressor 20 (the compressor preferably being powered by an electrical power source 18 or by such other method known to a person skilled in the art) powered by way of a power cord 19 (preferably in the manner described below), the coolant gas thereafter passing through (as indicated by the arrows 17 A) a condenser circuit 19 , preferably in the form of a length of coolant tubing or radiator (not shown) to dissipate heat from the compressed coolant gas, in one embodiment of the present invention, the condenser circuit 19 being securely attached to the outside wall of the outer casing or shell referred to below, the cooled compressed coolant gas (which may now be in the form of a liquid at this stage depending on the gas and pressures utilized) thereafter passes through an expansion valve 21 and is permitted to expand and cool, and thereafter passes (as indicated by the arrow 17 B) through the cooling coils 14 to cool the outer surface of the inner liner element 12 (and thereby cool the inner surface of the inner liner element 12 and its contents, including the compost bin 2 and any compostable materials contained therein) by absorbing heat from the inner liner element 12 and providing a cooling effect to the inside of the inner liner element 12 and the compost bin 2 and any compostable materials contained therein. The coolant gas is thereafter returned to the compressor (as indicated by the arrow 17 C) to repeat this cycle.
[0023] In the preferred embodiment of the present invention, an On/Off switch 24 is provided which is electrically or otherwise connected 23 to the compressor 20 (by way of the power supply 18 ) to allow the user to turn off the compressor when the device of the present invention is not in use (and, when placed in the “On” position, to allow the compressor to be turned on when activated by the thermostat as described hereinafter).
[0024] In a preferred embodiment of the present invention, a thermostat 22 is also provided and electrically or otherwise connected to the power supply 18 for the compressor 20 (electrically connected to the power supply 18 and the On/Off switch 24 ), the thermostat 22 being positioned such that when the On/Off switch 24 is in the “On” position, it will sense the temperature on the surface of or alternatively within the inner liner element 12 and, in the event that the temperature is above a predetermined amount (such as, for example, 10 degrees C.), the thermostat 22 , on sensing the temperature being above the predetermined amount will activate the compressor 20 in a conventional manner and circulate coolant gas as described above, until the temperature on the surface of, or alternatively within the inner liner element 12 falls to below a predetermined amount (such as, for example, 5 degrees C.), thereby maintaining the compost bin 2 and its contents within a range of between, for example, 5 degrees C. and 10 degrees C. (it being understood that different temperature ranges may be set or programmed into an appropriately settable or programmable thermostat in a manner known to a person skilled in the art).
[0025] In a preferred embodiment of the present invention, insulation 26 is positioned to substantially enclose and surround the walls and bottom of the inner liner element 12 and cooling coils 14 to reduce the amount of heat transferred from the inner liner element 12 and cooling coils 14 to the area outside of and immediately surrounding the device of the present invention.
[0026] In a further alternative embodiment of the device of the present invention, as illustrated in FIG. 3 , a Peltier device 28 or other solid state refrigerator or other refrigerating device known to a person skilled in the art, is positioned in contact with or in close proximity to the outside walls or bottom of the inner liner element 12 as illustrated in FIG. 3 , electrical power for the Peltier device or other solid state refrigerator or other refrigerating device being provided by way of an electrical power source, which may be connected to an On/Off switch and thermostat in a conventional manner. The other exposed surfaces of the inner liner element may be covered in insulation 29 .
[0027] In a preferred embodiment of the present invention, as illustrated in FIGS. 1 , 2 and 3 , a pleasantly shaped outer shell or casing 30 (preferably made of metal or rigid plastic or other material known to a person skilled in the art) is provided which preferably substantially surrounds the inner workings of the device described herein, the outer shell or casing providing the device with a pleasant overall appearance and an easy to clean outer surface. In alternative embodiments of the present invention, differently colored outer shells or casings may be provided to the user with a range of possible colors.
[0028] In a preferred embodiment of the present invention, a hinged or removable lid 13 is provided as illustrated in FIGS. 1 , 2 and 3 , which preferably provides an air-tight seal between the lid 13 and the opening 15 in the outer shell or casing (the hinged lid 13 being movable between an open and closed position as illustrated by the arrow 33 ). In an alternative embodiment of the present invention, a hinged or removable lid 13 is provided which provides an air-tight seal between the lid 13 and the opening in the inner liner element 12 .
[0029] In an alternative embodiment of the present invention, large compost bins may be used, for example, in a commercial setting that receives and temporarily stores large volumes of compostable materials, the device of the present invention being suitably scaled in size to receive, support and refrigerate such large compost bins.
[0030] In operation, a person may open the lid 13 and insert a compost bin 2 into the inner liner element 12 and thereafter rotate the handle 4 to the horizontal orientation and close the lid 13 (and turn the On/Off switch 24 to the “On” position, setting the thermostat as desired), opening the lid as needed to insert or remove compostable materials from the compost bin 2 as needed or desired. Subsequently, the bin 2 may be removed for the easy removal of the compostable materials, and for cleaning of the bin as needed.
[0031] When the compostable material is maintained at a cool temperature, the rate of decomposition of the compostable materials may be significantly reduced, resulting in a corresponding reduction in odors, and a corresponding reduction in the attractiveness of the compostable materials to pests, such as insects, larvae, maggots, mold, small animals and other creatures. Furthermore, by reducing or eliminating many of the drawbacks to recycling compostable materials, users may be more inclined to recycle compostable materials. Additionally, as the device of the present invention may reduce or substantially eliminate odors emanating from the compostable materials temporarily stored therewithin, it is possible to extend the length of time in which the compostable materials are temporarily stored by the user (thereby reducing the frequency of the need to empty the compostable materials from the device of the present invention).
[0032] The present invention has been described herein with regard to preferred embodiments. However, it will be obvious to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as described herein | A refrigeration device for compostable materials, comprising, a recycling bin adapted to receive compostable materials, a liner element adapted to receive the recycling bin; and refrigeration means adapted for cooling the liner element wherein when compostable materials are positioned within the recycling bin and the recycling bin is positioned within the liner element, the refrigeration means cools the liner element, the recycling bin and the compostable materials positioned therein. | 1 |
BACKGROUND OF THE INVENTION
1. FIELD OF THE INVENTION
The present invention relates to a control apparatus for an internal combustion engine which controls a fuel quantity to be supplied to the engine and the timing of the ignition. More particularly, it relates to how to control an engine at the time of adjusting ignition timing.
2. DISCUSSION OF BACKGROUND
FIG. 12 is a block diagram showing a construction of a conventional control apparatus for an engine. In FIG. 12, a reference numeral 1 designates a reference angle sensor which outputs a reference angle signal SG by detecting a predetermined angle before the top dead center point of the crank angle, e.g. an angle of BTDC 75°, of the engine, a numeral 2 designates an intake air pipe pressure sensor to detect a pressure in an intake air pipe in the engine, a numeral 3 designates an ignition timing adjustment signal generator which is constituted by, for instance, a switch whose one terminal is grounded and which is so operated that it is turned on at the time of adjusting the timing of ignition so that a ground potential signal is generated, a numeral 4 designates an idle switch which is turned on when it detects an idling position of a throttle valve in the intake air pipe of the engine, a numeral 5 designates an O 2 sensor which detects a concentration of oxygen in the exhaust gas, a numeral 6 designates a base advance angle value operating means which calculates a base advance angle value of ignition timing on the basis of an engine revolution number and an intake air pipe pressure, a numeral 7 designates a correction means for stabilizing idling which corrects the base advance angle value so as to eliminate the difference between an actual revolution number and an average revolution number at the time of idling operations, a numeral 8 designates a target advance angle value changing means which selects either a fixed advance angle value or a target advance angle value from the correction means for stabilizing idling 7 in accordance with a signal from the ignition timing adjustment signal generator 3 and generates an output in accordance with the selection, a numeral 9 designates an advance angle-time converting means which converts the selected target advance angle value into a time, a numeral 10 designates an ignition signal output means which outputs an ignition signal IGT immediately after a period of time converted by the converting means 9 has passed, on the basis of the reference angle signal SG, a numeral 11 designates an ignition device comprising an igniter, an ignition coil, a distributor, an ignition plug and so on, which effects ON/OFF control of a primary current of the ignition coil in response to the ignition signal IGT applied thereto, a numeral 12 designates a base fuel quantity operating means which operates a base fuel quantity on the basis of an engine revolution number and an intake air pipe pressure, a numeral 13 designates a feed-back correction means which corrects the calculated base fuel quantity upon the receipt of an output from the O 2 sensor 5, a numeral 15 designates a fuel injection signal output means which converts a fuel quantity into a time for driving a fuel injection valve so that a fuel injection valve 16 is actuated in synchronism with the reference angle signal SG during the time determined by the fuel injection signal output means, and a numeral 17A designates an electronic control unit which is constituted by the above-mentioned structural elements 6-10, 12, 13 and 15 and which generates the above-mentioned ignition signal IGT, fuel injection signal and so on.
The operation of the conventional control apparatus will be described.
The reference angle sensor 1 for detecting a crank angle position of the engine outputs a reference angle signal SG which rises at a crank angle of BDTC 75° and falls at a crank angle of BTDC 5°.
The base fuel quantity operating means 12 calculates a base fuel quantity by mapping a two-dimensional map which is prepared on the basis of an actual revolution number signal Ne which represents an actual revolution number of the engine which is obtained based on the reference angle signal SG, and a pressure signal Pb which represents an inner pressure of the intake air pipe which is detected by the intake air pipe pressure sensor 2.
The output V 02 of the O 2 sensor 5 is such as shown in FIG. 5, namely, when the air-fuel ratio exceeds a value of 14.7, the output is at a lean value which is less threshold voltage V th , and when the air-fuel ratio is less than 14.7, the output is at a rich value which exceeds V th .
The feed-back correction means 13 receives the output voltage V 02 of the O 2 sensor 5; and treats the output voltage V 02 with proportion and integration processes to thereby obtain a feed-back correction coefficient K FB (FIG. 6). Then, the correction means 13 outputs a signal indicating a fuel quantity by multiplying the base fuel quantity obtained by the base fuel quantity operating means 12 by the coefficient K FB .
The fuel injection signal output means 15 converts the fuel quantity into a time for driving a fuel injection valve and outputs a fuel injection signal having a time width corresponding to the time for driving the fuel injection valve in synchronism with the rising of the reference angle signal SG, so-that the fuel injection valve 16 is actuated. Thus, fuel is injected into the engine through the fuel injection valve 16.
On the other hand, the base advance angle value operating means 6 calculates a base advance angle value by mapping a two-dimensional map which is obtained based on an actual revolution number signal Ne which is obtained on the basis of the reference angle signal SG and a pressure signal Pb. The correction means for stabilizing idling 7 outputs the base advance angle value as a target advance angle value without any correction when the idle switch 4 is in an OFF state at the time of non-idling. The correction means for stabilizing idling 7, when the idle switch 4 is in an ON state at the time of idling, outputs the target advance angle value by correcting the base advance angle value in response to a value of difference between an average revolution number signal Na obtained on the basis of the reference angle signal SG and the actual revolution number signal Ne. The characteristic of the correction means for stabilizing idling 7 is shown in FIG. 7. Namely, when the actual revolution number is less than the average revolution number, a correction angle for stabilizing idling Δθ is shifted to a positive (+) valve, i.e., by correcting the base advance angle value to the advance angle side in an amount corresponding to Δθ to thereby increase the actual revolution number. On the other hand, when the actual revolution number is more than the average revolution number, the base advance value is corrected toward a delayed angle valve in an amount corresponding to Δθ by shifting Δθ to the negative (-) side, whereby the actual revolution number is reduced.
The target advance angle value changing means 8 selects a fixed advance value as a target advance value when it receives a ground potential signal from the ignition timing adjustment signal generator 3 and outputs a signal corresponding to the target advance angle value. On the other hand, the target advance angle value changing means 8 selects an advance angle value which is provided from the correction means for stabilizing idling 7 as the target advance angle value when it does not receive the ground potential signal, and outputs a signal corresponding thereto.
The advance angle value-time converting means 9 obtains a period T 1 corresponding to a crank angle of 180° from the reference angle signal SG, and converts the target advance angle value θ ADV selected by the target advance angle value changing means 8 into a time T a .
The ignition signal output means 10 receives a signal indicating the time T a and changes the output having an H level to an output having an L level when the time T a has passed from the rising of the reference angle signal SG, outputting the ignition signal IGT of L level to the ignition device 11. Thus, the ignition device 11 fires a gas mixture in the combustion chamber of the engine.
The reference angle signal SG and the ignition signal IGT are generated at the timings shown in FIG. 8. Namely, when the target advance angle value θ ADV is expressed by an angle of BTDC, the target advance angle value Δ ADV can be converted into T a by using the equation of ##EQU1##
In the conventional control apparatus for engine an having the construction as described above, when the ignition timing adjustment signal generator 3 generates a ground potential signal, namely, when the generator 3 is turned on, a fixed advance angle value is selected. In the case where the engine is idling, correction for stabilizing idling becomes null, whereby control to a change of revolution number is lost.
Since the feed-back control of the air-fuel ratio is conducted at the above-mentioned time, the air-fuel ratio can be converged to a point near a stoichiometric air-fuel ratio, but fluctuation in revolution number becomes large. Generally, when a timing light is irradiated to the crank shaft at the time of adjusting ignition timing, the scale of the crank shaft apparently stops, which enables the adjustment of the position of the reference angle sensor 1. However, when the fluctuation of the revolution number takes place at that moment, the scale of the crank shaft does not apparently stop, but it turns. Further, in a case of using a period estimation type ignition timing control system, it is difficult to estimate the period, and the timing of the ignition fluctuates, whereby it is difficult to adjust the ignition timing.
Further, there has been known a control apparatus for an engine as shown in FIG. 13. The conventional apparatus is the same as the apparatus as shown in FIG. 12 except that the later excludes the O 2 sensor 5 and the feed-back correction means 13. Accordingly, the same reference numerals designate the same or corresponding parts and description of these parts is omitted.
The operation of the conventional apparatus shown in FIG. 13 will be described.
The reference angle sensor 1 which detects the crank angle position of the engine generates a reference angle signal SG which rises at a crank angle of BTDC 75° and falls at a crank angle of BTDC 5°. The base fuel quantity operating means 12 calculates a base fuel quantity by mapping a two-dimensional map on the basis of an actual revolution number signal Ne representing an actual revolution number of the engine which is obtained on the basis of the reference angle signal SG, and a pressure signal Pb which represents an inner pressure of the intake air pipe which is detected by the intake air pipe pressure sensor 2. The fuel injection signal output means 15 converts the base fuel quantity into a time for driving a fuel injection valve and outputs a fuel injection signal having a time width for driving the injection valve in synchronism with the rising of the reference angle signal SG, by which the fuel injection valve 16 is actuated. Thus, the engine is supplied with fuel by the fuel injection valve 16.
The operations concerning the reference advance angle value operating means 6 through the ignition device 16 are the same as those of the apparatus as shown in FIG. 12 for which description has been made with reference to FIGS. 5 and 8, and therefore, description of these structural elements is omitted.
In the conventional control apparatus having the construction described above, since the advance angle value is fixed when the ignition timing adjustment signal generator 3 is turned on, an in particular, since correction for stabilizing idling becomes null when idling operations are effected, control against the fluctuation of revolution number in the engine is lost. In particular, since the base fuel quantity calculated by the base fuel quantity operating means 12 is such as to provide a stoichiometric air-fuel ratio (A/F=14.7), it is not easy for the gas mixture to be stably burned. Therefore, fluctuation of the revolution number in the engine tends to be large. In a case that such period estimation type ignition timing control system is used, the estimation of the period becomes difficult when the fluctuation of the revolution number is large. When the actual ignition timing fluctuates, the adjustment of ignition timing becomes difficult.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a control apparatus for an engine capable of reducing the fluctuation of the revolution number of the engine at the time of adjusting ignition timing.
In accordance with the present invention, there is provided a control apparatus for an engine comprising an air-fuel ratio sensor for detecting an air-fuel ratio on the basis of an exhaust gas component from the engine, a fuel control means which receives an output from the air-fuel ratio sensor so as to feed-back-control a fuel quantity in response to the operating conditions of the engine so that the air-fuel ratio becomes the optimum ratio, a fuel supplying means to supply fuel on the basis of a signal from the fuel control means, and a target advance angle value changing means which selects a fixed advance angle value for ignition timing independent from the operating conditions of the engine when an instruction signal for adjusting ignition timing is generated from an ignition timing adjustment signal generator, an ignition means which effects ignition in accordance with an output from the target advance angle value changing means, and a feed-back control stopping means which stops the feed-back control of the air-fuel ratio when the instruction signal is generated from the ignition timing adjustment signal generator.
Further, in accordance with the present invention, there is provided a control apparatus for an engine comprising a fuel control means which controls a fuel quantity in response to the operating conditions of an engine, a fuel supplying means to supply fuel on the basis of a signal from the fuel control means, an ignition timing adjustment signal generator, a target advance angle value changing means which selects a fixed advance angle value for ignition timing independent from the operating conditions of the engine when an instruction signal for adjusting the ignition timing is generated from the ignition timing adjustment signal generator, an ignition means which effects ignition in accordance with an output from the target advance angle value changing means, and means for increasing the fuel quantity when the instruction signal for adjusting the ignition timing is generated from the ignition timing adjustment signal generator.
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 is a block diagram showing a construction in accordance with an embodiment of the control apparatus for an engine of the present invention;
FIG. 2 is a diagram showing a concrete structural arrangement of the apparatus as shown in FIG. 1;
FIG. 3 is a flow chart showing the main routine executed by the apparatus of the embodiment according to the present invention;
FIG. 4 is a flow chart showing an interruption routine;
FIG. 5 is a characteristic diagram of an O 2 sensor;
FIG. 6 is a signal waveform diagram showing the timing of an output voltage V 02 from the O 2 sensor and a proportion·grated value;
FIG. 7 is a characteristic diagram of a correction means for stabilizing idling;
FIG. 8 is a signal waveform diagram showing the timing of a reference angle signal SG and an ignition signal IGT;
FIG. 9 is a block diagram showing a construction of another embodiment of the control apparatus for an engine according to the present invention;
FIG. 10 is a diagram showing a concrete structural arrangement of the apparatus as shown in FIG. 9;
FIG. 11 is a flow chart showing the main routine executed by the apparatus as shown in FIG. 9;
FIG. 12 is a block diagram showing a construction of a conventional control apparatus for an engine; and
FIG. 13 is a block diagram showing a construction of another conventional control apparatus for an engine.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings wherein the same reference numerals designate the same or corresponding parts throughout the several views, and more particularly to FIG. 1 thereof, there is shown a block diagram of a typical example of the control apparatus for an engine according to the present invention. In FIG. 1, description with respect to the structural elements 1-13, 15 and 16 is omitted because these elements are same as those as in FIG. 12. A numeral 14 designates a fuel quantity changing means which receives a signal corresponding to a base fuel quantity outputted from a base fuel quantity operating means 12 and a signal corresponding to a fuel quantity which is subjected to feed-back-correction, outputted from a feed-back correction means 13, and selects either of the inputted signals in response to a signal from the ignition timing adjustment signal generator 3, the selected signal being outputted to the fuel injection signal output means 15. A numeral 17B designates an electronic control unit which is constituted by structural elements 6-10 and 12-15 and outputs an ignition signal IGT and a fuel injection signal.
The operation of the control apparatus according to the above-mentioned embodiment will be described. Description concerning the same operations as already described with reference to the conventional technique is omitted and only featurized portions will be described.
The fuel quantity changing means 14 selects the base fuel quantity signal from the base fuel quantity operating means 12 when a ground potential signal is inputted from the ignition timing adjustment signal generator 3 at the time of adjusting the timing of ignition, and outputs the base fuel quantity signal. On the other hand, when the fuel quantity changing means 14 selects the fuel quantity signal of the feed-back correction means 13 when a non ground potential signal is inputted from the ignition timing adjustment signal generator 3 at the time of non-adjusting the timing of ignition and outputs the fuel quantity signal. The fuel injection signal output means 15 receives the selected signal, converts the input signal into a fuel injection signal having a time width which corresponds to a time for driving a fuel injection valve, and outputs the same.
FIG. 2 is a diagram showing the detailed construction of the electronic control unit 17B and peripheral elements shown in FIG. 1.
A CPU 100 processes various kinds of data by utilizing a memory 101 which stores operating flows in a form of program which are shown in FIGS. 3 and 4. A reference angle signal SG from the reference angle sensor 1 is inputted to an interruption control circuit 102, and transferred to the CPU 100 as an interruption command signal which is in synchronism with the rising edges (BTDC 75°). A free running counter 103 counts clock pulses CP. When the interruption command signal is generated, the counted value is read by the CPU 100 through an input port 104. A period of revolution and an actual revolution number of the engine are calculated in the CPU 100. Analogue detection signals from an intake air pipe pressure sensor 2 and an O 2 sensor 5 are inputted into an A/D transducer 105 having a multiplexing function where the detection signals are converted into digital signals to be outputted to an input/output port 106.
The ignition timing adjustment signal generator 3 and an idle switch 4 are normally in an OFF state whereby a signal having an H level is inputted to an input/output port 107. When the ignition timing is adjusted or the engine is idling, the ignition timing adjustment signal generator 3 and the idle switch 4 are in an ON state, whereby a ground potential signal is inputted to the input/output port 107.
A time for driving the fuel injection valve is set in synchronism with the interruption command signal in a down counter 109, a signal indicating the driving time being supplied from the CPU 100 through an output port 108. The down counter 109 receives clock pulses CP to start countdown and renders a transistor 110 ON by supplying a base current to the transistor 110 until the count becomes 0. When the transistor 110 is in an ON state, a current is supplied to a fuel injection valve 16 so that the valve 16 is opened.
The CPU 100 obtains calculating method data of current conduction initiating time for ignition coils in the ignition device 11 by utilizing the data of ignition timing according to a known method, and the data of current conduction initiating time is set in a down counter 112 through an output port 111. The down counter 112 counts down in accordance with the clock pulses CP. When a value to be counted becomes 0, an RS flip-flop 115 is set so that an H level signal is outputted through the Q output terminal, whereby a current is supplied to an ignition coil in the ignition device 11.
A time T a for producing the ignition signal IGT is set in a down counter 114 from the CPU 100 through an output port 113 in synchronism with the interruption command signal. When a value to be counted becomes 0 on the expiring of the time T a after the down counter 114 has been set, the RS flip-flop 115 is reset, whereby the potential at the Q output terminal of the RS flip-flop 115 is changed from an H level to an L level to thereby interrupt the current to the ignition coil.
The operation of the CPU 100 will be described with reference to FIGS. 2 through 4.
The operations according to the main routine as shown in FIG. 3 are executed. At step S1, the output voltage V 02 of the O 2 sensor 5 is converted into a digital signal to be read. At step S2, a base fuel quantity is calculated by mapping the signal indicating an actual revolution number Ne which has already been obtained and the pressure signal Pb which has also been read. At step S3, a determination is made whether the ignition timing adjustment signal generator 3 is ON or OFF. When it is ON, an operating step goes to step S5 without correcting the base fuel quantity by feed-back control. When it is OFF, a feed-back correction coefficient K FB is calculated on the basis of a value converted into a digital form of V 02 , and a corrected fuel quantity is calculated by multiplying the base fuel quantity by K FB at step S4. Then, step S5 is taken. At step S5, the fuel quantity obtained at step S2 or step S4 is converted into a time for driving the fuel injection valve. After the operation of step S5 has been finished, the operating step is returned to step S1 and the above-mentioned operations are repeated.
When the interruption command signal is generated at the rising edge (BTDC 75°) of the reference angle signal SG which is outputted from the reference angle sensor 1, the interruption routine (FIG. 4) is executed.
At step S10, a value in the free running counter 103 is read, and a period of revolution is calculated by taking a difference between the value read and a previously counted value. At step,S11, the calculated period of revolution is converted into an actual revolution number signal Ne. At step S12, a pressure signal Pb obtained by the A/D conversion of the output signal of the intake air pipe pressure sensor 2 is read. At step S13, a determination is made whether the ignition timing adjustment signal generator 3 is ON or OFF. When it is ON, a fixed advance angle value is read from the memory 101 at step S14. On the other hand, when it is OFF, step S19 is taken. At step S15, the advance angle value is converted into a count down number in the down counter 114. The count number corresponds to the time T a . At step S16, the count number corresponding to the time T a is set in the down counter 114. At step S17, information of current conduction initiating timing is set at the down counter 112. At step S18, information of fuel injection valve driving time is set at the down counter 109. Then, the operating step is returned to the main routine.
On the other hand, at step S19, a base advance angle value is calculated by mapping the actual revolution number signal Ne and the pressure signal Pb. At step S20, a determination is made whether the idle switch 4 is ON or OFF. When it is OFF, the operating step goes to step S15. On the other hand, when it is ON, the operation of the correction for stabilizing idling, which has been explained with reference to FIG. 7, is executed at step S21, and then, step S15 is taken. The operating step of step S15 and the following steps are the same as those previously described.
Thus, in accordance with the embodiment as above-mentioned, an advance angle value for ignition timing is fixed at the time of adjusting the ignition timing and feed-back control for an air-fuel ratio is stopped, whereby fluctuations of the revolution number in the engine can be reduced; the actual advance angle value becomes stable, and the adjustment of the ignition timing can be easy.
A second embodiment of the control apparatus for an engine of the present invention will be described with reference to the drawings.
FIG. 9 is a block diagram of the second embodiment of the control apparatus. In FIG. 9, the same reference numerals as in FIG. 13 designate the same or corresponding parts, and description of these parts is omitted.
A reference numeral 13 designates a fuel increment quantity correction means which corrects to increase a base fuel quantity calculated by the base fuel quantity operating means 12. A numeral 14 designates a fuel quantity changing means which selects either a base fuel quantity signal outputted from the base fuel quantity operating means 12 in response to a signal from the ignition timing adjustment signal generator 3 or a fuel quantity signal outputted from the fuel increment quantity correction means 13, and outputs the selected signal to the fuel injection signal output means 15. A numeral 17C designates an electronic control unit which is constituted by structural elements 6-10 and 12-15 and which outputs an ignition signal IGT and a fuel injection signal.
The operation of the control apparatus of the second embodiment will be described concerning only the featurized portion.
The fuel increment quantity correction means 13 corrects a fuel quantity to be increased by multiplying the base fuel quantity calculated by the base fuel quantity operating means 12 by a coefficient which is, for instance, greater than 1.0. The fuel quantity corrected to be increased is such that the air-fuel ratio assumes a value of 12.5-13. A gas mixture including fuel in an amount corresponding to the air-fuel ratio gives a stable combustion in the combustion chamber of the engine.
The fuel quantity changing means 14 selects the fuel quantity signal of the fuel increment quantity correction means 13 when a ground potential signal is received from the ignition timing adjustment signal generator 3 at the time of adjusting the ignition timing, and outputs the selected fuel quantity signal. On the other hand, the fuel quantity changing means 14 selects the base fuel quantity signal of the base fuel quantity operating means 12 when a non-ground potential signal is received from the ignition timing adjustment signal generator 3 at the non-adjusting time of the ignition timing, and outputs the selected base fuel quantity signal. The fuel injection signal output means 15 receives the selected signal; converts the fuel quantity corresponding to the input signal into a time for driving the fuel injection valve, and outputs a fuel injection signal having a time width corresponding to the driving time to a fuel injection valve 16.
FIG. 10 is a diagram showing the electronic control unit 17C and circumferential elements as in FIG. 9.
The electronic control unit 17C comprises a CPU 100 which processes various kinds of data by utilizing a memory 101 which stores operating flows as programs which are shown in FIGS. 4 and 11. A reference angle signal SG from a reference angle sensor 1 is received in an interruption control circuit 102, and the signal is transformed in an interruption command signal synchronized with the rising edges (BTDC 75°), the command signal being supplied to the CPU 100. A free running counter 103 counts clock pulses CP. When the interruption command signal is generated, a value counted by the counter 103 is read by the CPU 100 through an input port 104, whereby a period of revolution and an actual revolution number of the engine are calculated in the CPU 100. An analogue detection signal from an intake air pipe pressure sensor 2 is inputted to an A/D transducer 105 where it is transformed into a digital signal which is inputted into an input/output port 106.
An ignition timing adjustment signal generator 3 and an idle switch 4 are usually in an OFF state and they produce H level signals. When ignition timing is adjusted or the engine is in an idling operation, they are turned on, and ground potential signals are respectively inputted to an input port 107. A signal indicating a time for driving the fuel injection valve is supplied from the CPU 100 through an output port 108 to a down counter 109 by which the time for driving fuel injection valve is set at the down counter 109 in synchronism with the interruption command signal. The down counter 109 receives the clock pulses CP and maintains a transistor 110 ON by supplying a base current to the transistor 110 until a value to be counted becomes 0. When the transistor 110 is in an ON state, a fuel injection valve 16 is supplied with a current so that it is actuated.
The CPU 100 obtains by a known calculating method information of current conduction initiating time for an ignition coil in an ignition device 11 from data of ignition timing. The obtained current conduction initiation timing is set in a down counter 112 through an output port 111. The down counter 112 counts down the clock pulses CP until the value to be counted becomes 0. When the value becomes 0, an RS flip-flop 115 is set so that an H level signal is generated from the Q output terminal. The H level signal is supplied to the ignition coil of the ignition device 11. A time T a to produce an ignition signal IGT is set in a down counter 114 through an output port 113 in synchronism with the generation of the interruption command signal. The down counter 114 resets the RS flip-flop 115 when the value becomes 0 at the lapse of the time T a after the down counter 114 has been set. Accordingly, the potential at the Q output terminal of the RS flip-flop 115 is changed from an H level to an L level, whereby current to the primary side of the ignition coil is interrupted.
The operation of the CPU 100 will be described with reference to FIGS. 4 and 10.
The main routine as shown in FIG. 11 is executed.
At step S21, a base fuel quantity is calculated by mapping the signal indicating the actual revolution number Ne which has already been obtained and the pressure signal Pb which has also been read. At step S22, a determination is made whether the ignition timing adjustment signal generator 3 is ON or OFF. When it is OFF, the operating step goes to step S24 without any correction of increasing the base fuel quantity. On the other hand, when it is ON, the fuel quantity is calculated so as to increase the quantity by multiplying the base fuel quantity by a predetermined coefficient which is greater than 1.0, at step S23. Then, the operating step goes to S24. At step S24, the fuel quantity obtained at step S21 or step S23 is converted into a time for driving the fuel injection valve. After the operation of step S24 has been finished, the operating step is returned to step S21, and the above-mentioned operations are repeated.
The interruption routine as shown in FIG. 4 is executed when the interruption command signal is generated at the rising edge (BTDC 75°) of the reference angle signal SG outputted from the reference angle sensor 1. The description concerning the interruption routine is omitted since the interruption routine is the same as described with reference to the first example.
Thus, in accordance with the second embodiment of the present invention, an advance angle value for ignition timing is fixed at the time of adjusting the ignition timing and the fuel quantity is corrected so as to increase it. Accordingly, a stable combustion in the engine is obtained, and accordingly fluctuations of the revolution can be reduced, the actual advance angle value becomes stable, and the adjustment of ignition timing becomes easy.
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. | A control apparatus for an engine comprises an air-fuel ratio sensor for detecting an air-fuel ratio on the basis of an exhaust gas component from the engine, a fuel controller which receives an output from the air-fuel sensor so as to feed-back-control a fuel quantity in response to the operating conditions of the engine so that the air-fuel ratio becomes optimum, a fuel supplier to supply fuel on the basis of a signal from the fuel controller, and a target advance angle value changer which selects a fixed advance angle value for ignition timing independent from the operating conditions of the engine when an instruction signal for adjusting the ignition timing is generated from an ignition timing adjustment signal generator, an ignition device which effects ignition in accordance with an output from the target advance angle value changer, and a feed-back control stopping device which stops the feed-back control of the air-fuel ratio when the instruction signal is generated from the ignition timing adjustment signal generator. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present patent application claims priority from provisional patent application No. 60/458,115, filed on Mar. 26, 2003, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1). Field of the Invention
[0003] This invention relates to a fluid delivery system, or fluid delivery system, of the kind that may include interconnected fluid control components such as valves, regulators, mass flow controllers, filters, and pressure transducers.
[0004] 2). Discussion of Related Art
[0005] Fluid delivery systems, also known as fluid delivery systems, are used in, for example, semiconductor processing systems to provide predetermined gases or mixtures of gases at predetermined flow rates and predetermined pressures into a processing chamber. Various supply gases are connected to inlets of such a manifold, and one or more outlets of the manifold are connected to the processing chamber. Such a manifold system usually includes components such as valves, regulators, mass flow controllers, filters, and pressure transducers that are connected to one another over a two-dimensional area in a manner that will ensure delivery of the desired gases or mixtures of gases at the desired flow rates and pressures to the processing chamber.
[0006] Fluid delivery systems are frequently in the form of smaller components that can be mounted to a base mounting structure in a modular fashion to create a desired flow pattern between fluid control components. It has been found that maintenance to such systems is usually extremely cumbersome because the replacement of a single piece may require disassembly and reassembly of a large number of pieces, and usually involves the breaking of a large number of seals that are expensive to replace.
SUMMARY OF THE INVENTION
[0007] The invention provides a fluid delivery system, including a mounting structure, a plurality of rows of locator alignment components secured to the mounting structure, a plurality of rows of fluid connecting pieces, each having inlet and outlet ports and a fluid communication passage interconnecting the ports, the fluid connecting pieces being arranged in pairs, each pair including two of the fluid connecting pieces located next to one another in a respective row of fluid connecting components, the fluid connecting pieces of each pair being releasably held by and aligned relative to one another by a respective one of the locator alignment components and a plurality of manifold pieces extending transverse to the rows of fluid connecting pieces, at least one manifold piece having a manifold passage with a center line crossing over a center line interconnecting the farthest ports of one of the pairs and being removable without removing the locator alignment component by which the respective pair is held from the mounting structure.
[0008] The locator alignment components may be arranged in sets, each set including two of the locator alignment components next to one another in a respective row of locator alignment components, and each fluid connecting piece being held by both locator alignment components in a respective set.
[0009] A gap may be defined between fluid connecting pieces of a respective pair, the manifold piece being removable out of the gap without removal of the pair from the locator alignment component holding the pair.
[0010] The system may further include a plurality of locator alignment fasteners removably fastening the locator alignment pieces to the mounting structure.
[0011] The locator alignment components may, for example, be cradles. Each cradle may prevent movement of the fluid connecting pieces of a respective pair in x, y, and ⊖.
[0012] The system may further include a plurality of fluid control components placed in flow communication with one another through the fluid communication passages and the manifold passages.
[0013] One of the fluid control components may have an inlet passage connected to an outlet port of one of the connecting pieces of a pair, and an outlet passage connected to an inlet port of another one of the connecting pieces of the respective pair.
[0014] The fluid control components may include at least one of a valve, a regulator, a mass flow controller, a filter, and a pressure transducer.
[0015] The ports of each respective fluid connecting piece may be located into the same side of the respective fluid connecting piece.
[0016] The system may further include at least one fluid T-piece having at least three ports and at least one fluid communication passage interconnecting all three ports, the T-piece being releasably held and aligned relative to one of the locator alignment components, one of the ports of the fluid T-piece being connected to the manifold piece.
[0017] The system may further include at least one fluid elbow piece having at least two ports and at least one fluid communication passage interconnecting both ports, the elbow piece being releasably held and aligned relative to one of the locator alignment components, one of the ports of the fluid elbow piece being connected to the manifold piece.
[0018] A gap may be defined between the fluid connecting pieces of a respective pair, and the system may further include a purge piece between the fluid connecting pieces of the respective pair, having at least two ports, one of which is connected to the manifold piece.
[0019] The system may further include a locator end piece holding and aligning one of the fluid connecting components and being smaller than the locator alignment components.
[0020] The invention also provides a fluid delivery system, including a mounting structure, at least three locator components secured to the mounting structure, at least three pairs of fluid connecting pieces, each having inlet and outlet ports and a fluid communication passage interconnecting the ports, each respective pair being releasably held and aligned by a respective one of the locator pieces, and a plurality of manifold pieces having a manifold passage having a center line crossing over a line interconnecting the two farthest ports of the fluid connecting pieces and being removable without removing any of the three locator components.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention is further described by way of example with reference to the accompanying drawings, wherein:
[0022] FIG. 1 is a perspective view of one row of components of a fluid delivery system, according to an embodiment of the invention;
[0023] FIG. 2 is a perspective view of one of many locator alignment cradles forming part of the system;
[0024] FIG. 3 is a perspective view of one of many fluid connecting blocks forming part of the system;
[0025] FIG. 4 is a perspective view of additional components of the system that are used to interconnect rows extending in an x-direction to one another in a y-direction;
[0026] FIG. 5 is a perspective view of a fluid T-piece forming part of the system;
[0027] FIG. 6 is a perspective view of a purge piece forming part of the system;
[0028] FIG. 7 is a perspective view of a locator end piece forming part of the system;
[0029] FIG. 8 is a perspective view of a fluid T-piece that may be used instead of the T-piece of FIG. 5 ,;
[0030] FIG. 9 is a perspective view of another fluid T-piece that may be used instead of the fluid piece of FIG. 5 ;
[0031] FIG. 10 is a perspective view of a purge piece that may be used instead of the purge piece of FIG. 6 ;
[0032] FIG. 11 is a perspective view of a flange piece forming part of the system;
[0033] FIG. 12 is a perspective view of a flange component that may be used together with the flange piece of FIG. 11 ;
[0034] FIG. 13 is a perspective view of an elbow piece that can be used at an end of a row of fluid connecting blocks;
[0035] FIG. 14 is a perspective view of an elbow piece that may be used instead of the elbow piece of FIG. 13 ;
[0036] FIG. 15 is a perspective view of an elbow piece that may be used instead of the elbow piece of FIG. 13 ;
[0037] FIG. 16 is a perspective view of further components of the system, particularly illustrating the positioning of the locator end pieces of FIG. 7 ; and
[0038] FIG. 17 is a perspective view of the system as fully assembled.
DETAILED DESCRIPTION OF THE INVENTION
[0039] FIG. 1 of the accompanying drawings illustrates one row of a fluid delivery, or gas manifold system 10 according to an embodiment of the invention, including a base mounting plate 12 , three locator alignment cradles 14 , six locator fastener screws 16 , three fluid connecting blocks 18 , six seals 20 , three fluid control components 22 , and twelve component fastener screws 24 .
[0040] The base mounting plate 12 has six cradle mounting openings 26 formed therein. Six nuts 28 are welded to a bottom surface of base mounting plate 12 . Each nut 28 has a threaded hole which is aligned with a respective one of the cradle mounting openings 26 .
[0041] Referring to FIG. 2 , each locator alignment cradle 14 has a base portion 30 and four securing and alignment pillars 32 . The alignment pillars 32 extend upward from four corners of the base portion by a distance 34 , are spaced from one another in an x-direction by a distance 36 , and in a y-direction by a distance 38 . Two base plate mounting openings 40 are formed in the base portion 30 . Six connecting block alignment openings 42 are also formed in the base portion 30 . A respective threaded component mounting opening 44 is formed into an upper surface of each respective alignment pillar 32 .
[0042] Referring again to FIG. 1 , the locator alignment cradles 14 are positioned in a row extending in an x-direction on the base mounting plate 12 , with each base plate mounting opening 40 aligned with a respective one of the cradle mounting openings 26 .
[0043] A respective one of the locator fastener screws 16 is subsequently inserted into each respective one of the base plate mounting openings 40 , a cradle mounting opening 26 , and then is screwed into one of the nuts 28 . The locator alignment cradles 14 are thereby secured to the base mounting plate 12 . Although there should be little need to remove the locator alignment cradles 14 for maintenance purposes, the locator alignment cradles 14 can still be removed by undoing the locator fastener screws 16 , for example for purposes of removing some of the locator alignment cradles 14 or rearranging the locator alignment cradles 14 in a modular fashion.
[0044] Referring to FIG. 3 , one of the fluid connecting blocks 18 has a height 48 in a z-direction, a length 50 in an x-direction, and a width 52 in a y-direction. Inlet and outlet ports 54 are formed in an upper surface 56 of the fluid connecting block 18 . A passage 60 is drilled into an end surface 62 and interconnects lower portions of the ports 54 . The passage 60 is closed off at the surface 62 . A fluid connecting passage is thereby jointly defined by lower portions of openings forming the ports 54 and the passage 60 . A gas can thus flow into one of the ports 54 , through the fluid connecting block 18 , and exit through the other port 54 . Four cradle alignment pins 64 stand proud of a lower surface of the fluid connecting block 18 .
[0045] Referring again to FIG. 1 the fluid connecting blocks 18 are inserted into the locator alignment cradles 14 . The fluid connecting block 18 to the left has a left portion which is located on the locator alignment cradle 14 to the left, and a right portion which is located on the locator alignment cradle 14 in the middle. The fluid connecting block 18 in the middle is held jointly by the locator alignment cradles 14 in the middle and to the right. The width ( 52 in FIG. 3 ) of each fluid connecting block 18 matches the distance in a y-direction ( 38 in FIG. 2 ) and defined by the locator alignment cradles 14 so that the fluid connecting blocks 18 are prevented from movement in a y-direction and in ⊖ in an x-y plane about a z-axis. The cradle alignment pins ( 64 in FIG. 3 ) also engage with the connecting block alignment openings ( 42 in FIG. 2 ) to further prevent movement of the fluid connecting blocks 13 in a y-direction and in ⊖. Interengagement of the cradle alignment pins 64 with the connecting block alignment openings 42 also prevent sliding of the fluid connecting blocks 18 in an x-direction relatively toward or away from one another, so that a gap 68 is maintained between adjacent ones of the fluid connecting blocks 18 . The fluid connecting blocks 18 are thus positioned relative to one another with their ports aligned in a row 70 extending in an x-direction and with gaps 63 defined between them.
[0046] FIG. 4 illustrates additional components of the fluid delivery system 10 , including additional locator alignment cradles 14 ; and additional fluid connecting blocks 18 . The additional locator alignment cradles 14 and fluid connecting blocks 18 are mounted, as illustrated in FIG. 1 , in rows that extend in an x-direction but are located adjacent one another in a y-direction.
[0047] The fluid delivery system 10 further includes a fluid T-piece 74 , a manifold piece 76 , and a purge piece 78 .
[0048] Referring to FIG. 5 , the fluid T-piece 74 has a length 80 in an x-direction which equals the length 50 of the fluid connection block 18 in FIG. 3 plus the length of the gap 68 in FIG. 1 , in addition to inlet and outlet ports 54 , the fluid T-piece 74 also has a third port 82 extending in a y-direction. The third port 82 is in flow communication with both of the inlet and outlet ports 54 of the fluid T-piece 74 . Gases can, for example, flow in a downward z-direction into the inlet and outlet ports 54 , be combined within the fluid T-piece 74 , and flow in a y-direction out of the third port 82 .
[0049] Referring again to FIG. 4 , the manifold piece 76 is connected to the third port 82 and extends in a y-direction away from the fluid T-piece 74 . Referring to FIG. 6 , the purge piece 78 has one port 54 in an upper surface thereof, and an additional port 84 extending therefrom in a y-direction. The ports 54 and 84 of the purge piece 78 are in flow communication with one another, so that a gas can, for example, flow in a y-direction into the additional port 84 and leave in a z-direction out of the port 54 of the purge piece 78 . The purge piece 78 has a width 88 that substantially equals the gap 68 in FIG. 1 . Referring again to FIG. 4 , the additional port 84 of the purge piece 78 is connected to the manifold piece 76 .
[0050] The fluid T-piece 74 , together with the manifold piece 76 and the purge piece 78 , can be inserted downward into the locator alignment cradles 14 . The fluid T-piece 74 fits on two of the cradles 14 in the same manner as one of the fluid connecting blocks 18 , except that the fluid T-piece 74 extends further to the left over its cradle 14 than one of the fluid connecting blocks 18 . The manifold piece 76 extends through the gaps ( 68 in FIG. 1 ). The manifold piece 76 has a center line that, when viewed from the top, crosses over a center one of the rows 70 . The purge piece 78 is inserted into a gap between two of the fluid connecting blocks 18 . The inlet and outlet ports 54 of the fluid T-piece 74 are located in one of the rows 70 , and the port 54 of the purge piece 78 is located in another one of the rows 70 .
[0051] Referring again to FIG. 1 , a seal 20 is located on each one of the ports 54 , whereafter the fluid control components 22 are positioned over the fluid connecting blocks 18 . Each fluid control component 22 has a respective flange 90 with four cradle mounting openings 92 therein. The cradle mounting openings 92 of each component 22 are located over the component mounting openings 44 of a respective locator alignment cradle 14 . A respective component fastener screw 24 is inserted through a respective cradle mounting opening 92 and screwed into a component mounting opening 44 to secure the respective fluid control component 22 to the respective locator alignment cradle 14 and compress two of the seals 20 . As with the locator alignment cradles 14 , the fluid control components 22 are located in a row. Adjacent ones of the fluid control components 22 are in flow communication with one another through a respective one of the fluid connecting blocks. It can thus be seen that the fluid control components 22 located in a row extending in an x-direction can be placed in flow communication with one another utilizing the components illustrated in FIG. 1 . Referring again to FIG. 4 , the fluid T-piece 74 , the manifold piece 76 , and the purge piece 78 can be used to place fluid control components that are in different rows spaced from one another in a y-direction in flow communication with one another.
[0052] An advantage of the invention is that the fluid delivery system 10 is easily maintained. The manifold piece 76 can, for example, be replaced by simply removing any fluid control pieces located over the manifold piece 76 and then lifting the manifold piece 76 together with the fluid T-piece 74 and the purge piece 78 out of the locator alignment cradles 14 . There is thus no need to remove any of the locator alignment cradles 14 or any of the fluid connecting blocks 18 in order to replace the manifold piece 76 , even though a center line of the manifold piece 76 crosses over one of the rows 70 .
[0053] FIGS. 7 through 15 illustrate further components that may be used for constructing the fluid delivery system 10 and are presented for purposes of completeness. FIG. 7 illustrates a locator end piece 96 having only two pillars 98 . The locator end piece 96 has a length 100 in an x-direction which is less than a length 102 of the locator alignment cradle 14 in an x-direction. As illustrated in FIG. 16 , the locator end pieces 96 may, for example, be used adjacent ends of a row of locator alignment cradles 14 , but do not have the additional pillars of the locator alignment cradles 14 in order to save space in an x-direction.
[0054] FIG. 9 illustrates a fluid T-piece 106 which is the same as the fluid T-piece 74 of FIG. 5 , except that a third port 108 thereof extends in an opposite direction than the third port 82 . FIG. 8 illustrates a fluid T-piece 110 which is the same as the fluid T-piece 74 of FIG. 5 , except that the fluid T-piece 110 has third and fourth ports 112 and 114 extending in opposite directions. The combination of the fluid T-pieces of FIGS. 5, 8 and 9 allow for a modular design wherein gas can be directed up, down, or in both directions on a y-axis.
[0055] FIG. 10 illustrates a purge piece 120 which is the same as the purge piece 78 of FIG. 6 except that, in addition to the ports 54 and 84 of the purge piece 78 of FIG. 6 , an additional port 116 is provided, which extends in an opposite direction as the port 84 . The purge piece 120 thus allows for flow both upward and downward thereof on a y-axis.
[0056] FIG. 11 illustrates a flange piece 122 that can be used for changing flow between a z-direction and an x-direction, and would typically be located at an end of a row. FIG. 12 illustrates a flange connection 124 that may be used in combination with the flange connection piece 122 of FIG. 11 to direct flow in an x-direction, for example for purposes of connection to an external source of gas.
[0057] FIGS. 13 to 15 illustrate elbow pieces 130 , 132 , and 134 respectively. The elbow pieces 130 , 132 , and 134 are typically located at an end of a particular row. Each elbow piece 130 , 132 , and 134 has a single port 54 in an upper surface thereof, so that flow in an x-direction is terminated. Ports 136 allow for flow in a y-direction into or out of the elbow pieces 130 , 132 , or 134 .
[0058] FIGS. 16 and 17 illustrate final assembly of the fluid delivery system 10 . When fully assembled, as shown in FIG. 17 , the fluid delivery system 10 includes various flow fluid control components 22 connected to one another in an x- and y-array, including regulators, mass flow controllers, filters, and pressure transducers.
[0059] Other embodiments of the invention may also be used to flow fluids other than gases, such as liquids. The components of the fluid delivery system may be sized and shaped differently to accommodate different designs of fluid control components utilizing different sealing interfaces. A complete fluid delivery system need not include the manifold pieces and comprise a row of locator alignment cradles, fluid connecting pieces, and fluid control components.
[0060] While certain exemplary embodiments have been described and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative and not restrictive the of the current invention, and that this invention is not restricted to the specific constructions and arrangements shown and described since modifications may occur to those ordinarily skilled in the art. | The invention provides a fluid delivery system, including a mounting structure, a plurality of rows of locator alignment components secured to the mounting structure, a plurality of rows of fluid connecting pieces, each having inlet and outlet ports and a fluid communication passage interconnecting the ports, the fluid connecting pieces being arranged in pairs, each pair including two of the fluid connecting pieces located next to one another in a respective row of fluid connecting components, the fluid connecting pieces of each pair being releasably held by and aligned relative to one another by a respective one of the locator alignment components, and a plurality of manifold pieces extending transverse to the rows of fluid connecting pieces, at least one manifold piece having a manifold passage with a center line crossing over a center line interconnecting the farthest ports of one of the pairs and being removable without removing the locator alignment component by which the respective pair is held from the mounting structure. | 5 |
[0001] This is a U.S. original application which claims priority on French patent application No. 0108833 filed Jul. 4, 2001.
FIELD OF THE INVENTION
[0002] The present invention relates to a process for grinding a knife shaft and the control device linked to the implementation of the process. The knife shaft is used in a machine intended for cutting sheets of material into strips, for example, sheets of paper, plastic, plates of photosensitive film or any other material having the form of thin sheets.
BACKGROUND OF THE INVENTION
[0003] In the photographic industry, to obtain several strips of photosensitive film from an initial strip of large width, slitters are used comprising many rotary knives mounted in spaced apart manner on a first knife shaft, and many counter-knives mounted on a second knife shaft, with the strip to be cut running between these two rows of knives and counter-knives. In place of knife shafts, independent units can be used carrying the knives or counter-knives. It is necessary that the knives and counter-knives be sharpened regularly to maintain a good quality of cut on the edge of the cut strips.
[0004] There already exist many means that enable the taking into account of the sharpening done on the knives of various slitters, by compensating dimensionally using appropriate means, for the loss of material due to the sharpening of one or more knives. These compensation means enable sufficiently good control of the cutting process to be kept over time, following successive sharpening of the knives. This control of the cutting process produces a sufficiently good cutting quality of the cut strips and little dimensional variability of these cut strips. However, this dimensional variability remains excessive compared with the specifications of film strips used in the photographic industry.
[0005] U.S. Pat. No. 4,592,259 describes a method and means for adjusting the relative positioning of the slitter knives of a strip cutting apparatus; in order to obtain a correct relative position of the knives one with another, and between each of the cutting units taking these knives; the cutting units can move on slides. Electrical and mechanical means enable automatic compensation for the dimensional variations of thickness of the knives in time. These compensations produce adjustments of the position of the cutting units one with another on their slides. The objective is to obtain a constant and specified distance between the cutting edges of two successive knives, by comparison with a standard reference value recorded in a memory, and corresponding, for example, to the thickness of a new blade. This invention enables a constant distance between the knives to be obtained, but this concerns knives belonging to slitters or carriages that are independent one from another as to their relative movements on their respective slides. In other words, the overall geometry of the cutting means modifies according to the dimensional variations of the knives, to keep constant the distance between the cutting units and therefore between the cut edges of the knives.
[0006] U.S. Pat. No. 4,607,552 describes an apparatus enabling automatic control of the position of many slitters that cut a moving strip. Electronic control means enable, from the measurement of wear of the cutting blades of each slitter, calculation of the dimensional compensation to correctly reposition the blade, relative to the strip to be cut and to the part acting as the counter-knife. This apparatus thus enables compensation of the wear of each of the slitter's blades, independently one from another.
[0007] The object of the invention disclosed in U.S. Pat. No. 5,097,732 has certain similarities with that of U.S. Pat. No. 4,607,552. A numerical control device enables the measurement and control of the interval between the cutting units of a slitter having many cutting units. The objective of the invention is to be able to move many cutting units simultaneously to a preset position. Then after this movement of the cutting units, the respective adjustment of the contact pressures of the upper and lower knives is carried out.
[0008] U.S. Pat. No. 4,072,887 discloses an apparatus enabling the movement of mobile elements, especially a first pair of circular cutting blades working together having their axes parallel, into a new position, through a translation according to the axis of the circular cutting blades. The apparatus enables the repositioning, using appropriate measuring means, of successive pairs of blades located side by side on independent units, compared with the first pair of blades moved.
[0009] European Patent Application 0,602,655 describes a sharpening method for circular cutting blades attached to a shaft. This invention especially aims to not remove the blades from the same knife shaft to sharpen them and so avoid inducing causes of error and thus dimensional variations linked to the remounting operation of these blades on their shaft after their sharpening. The sharpening operation described in this invention especially enables, from the knife shaft comprising its blades to be sharpened and mounted between points on a grinder, to plunge one or more rotating grinding wheels towards the edges of the blades by ensuring the movement of the grinding wheel with a numerically controlled programmed device. This is in order to sharpen successively or simultaneously the cutting blades of the same shaft without removing the blades. The final objective being to improve the lateral and radial run-out of the blade cutting edges by increasing the precision obtained on the cut strips of product. However, the result obtained as to the strip widths of product cut with the knife shafts sharpened according to this sharpening method remains unsatisfactory.
[0010] French Patent Application 9912181 relates to a device and a process to position many knives mounted on a first knife shaft in relation to many counter-knives mounted on a second knife shaft of the same strip slitter. This does not enable ensuring especially the dimensional constancy or reproducibility of the pitch on a given slitter.
[0011] All the means described in the above mentioned documents are based on principles and means of control or measurement enabling the positioning or repositioning one against the other, of cutting units or slitters comprising knives, to compensate for example for the parameters of variability of the cutting process. The purpose of this is to conserve overall control of the process. In the case of slitters, an important variability parameter of the known process is the wear of the knife blades used on these machines. This phenomenon can be controlled by acting on certain physical components of the slitter, for example, by moving them one in relation to the others to compensate for example for the wear of the knives. It is possible on the same slitter to change, for example, the type of manufacture and proceed to remove the knives corresponding to a first type of manufacture to replace them by other knives corresponding to a new planned manufacture. Then later, for example, all or part of the knives corresponding to the first type of manufacture may be reused. In this case, appropriate control and measuring means enable the control and repositioning if necessary of the knives one in relation to the others; but the guarantee of the reproducibility of the axial pitch between the knives is not assured when sharpening; consequently the quality of the cut obtained by a good correspondence or good pairing of the respective knives of the two knife shafts working together to cut, for example, the same strip of material is not assured. In other words, the means used in the prior art mentioned enable control of the cutting process but without controlling the reproducibility or the variability of the cutting pitch of the knife shaft.
SUMMARY OF THE INVENTION
[0012] An object of the present invention is to control the evenness of sharpening the knife shafts of the same slitter, and more precisely pairs of knife shafts equipped with knives, so that over time and with successive sharpening or grinding, these knife shafts, for a specified cutting width, have a pitch between their respective knives that is perfectly controlled and even along with the grinding; which guarantees good pairing of the two shafts. Thus advantageously special additional adjustments of one shaft in relation to the other on the slitter taking these two shafts are prevented; all without generating dimensional drift or scatter of the various cutting pitches in time. The present invention enables a robust grinding process to be obtained and maintained, while making productivity gains, as the grinding of the knife shafts is done in concurrent time on a special grinding machine. For a given pair of knife shafts, initial adjustments of the slitter are no longer necessary, as the two paired knife shafts of the same slitter will have knives that stay well positioned one in relation to the other, during successive grinding. Thus what is obtained is not only excellent mastery of the precision of the specified cut width, but also and above all a better cut due to at least the control of the variability of the axial pitch between the various knives; this enables dimensional evenness of the knife shafts to be obtained along with the grinding. It is even possible to contemplate interchangeability between the knife shafts of different pairs of knife shafts, given the precision level and low dimensional variability obtained with the process according to the invention.
[0013] One advantage of the process according to the invention is that it is independent of the variability parameters, e.g. mechanical, due to the grinding machine.
[0014] Another advantage of the process according to the invention is that it enables keeping good geometric positioning of the knives and a constant pitch independently from variations of the physical parameters linked to the grinding machine's environment. One of these parameters is, for example, the ambient temperature.
[0015] The usefulness of this process is precisely being able to correct each knife of a knife shaft by evening up the dimensions of the individual pitches between two consecutive knives without depending on the variability of the grinding machine's mechanical components.
[0016] The present invention relates to a grinding process of many knives placed on the periphery of a knife shaft, a process characterized by the following steps:
[0017] a) define the difference of the actual position of each knife in relation to a reference position corresponding to the theoretical positions of the knives, by determining for each different pair of consecutive knives of the knife shaft the algebraic value of the difference between the actual pitch measured between two consecutive knives and the theoretical pitch;
[0018] b) calculate the average algebraic value of the algebraic values of the differences between the actual pitch and the theoretical pitch determined at step a), by dividing the sum of said algebraic values of the differences by the total number of different pairs of consecutive knives of the knife shaft;
[0019] c) determine the algebraic value corresponding to a first corrected relative position of each knife, by removing said average algebraic value of the differences calculated at step b) from each of the algebraic values of the difference between the actual pitch and the theoretical pitch determined at step a);
[0020] d) determine the algebraic value of the difference between the total actual length between the two end knives of the knife shaft, and the total theoretical length of the knife shaft calculated by multiplying the total number of different pairs of consecutive knives by the value of the theoretical pitch;
[0021] e) determine the algebraic value of the difference for the length per knife by dividing the algebraic value of the difference between the total theoretical length and the total actual length obtained at step d) by the total number of knife pairs of the knife shaft;
[0022] f) determine the algebraic value corresponding to a second corrected relative position of the knives by adding the algebraic value of the difference for the length per knife to the algebraic values corresponding to the first corrected relative position; and
[0023] g) from the sum of the algebraic values of the second corrected relative position, determine the quantities of material to be removed per knife.
[0024] Other characteristics will appear on reading the following description, with reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 represents the general view of a strip slitter;
[0026] [0026]FIGS. 2A and 2B represent diagrams of the cutting operation principle carried out by the knife shafts of a slitter;
[0027] [0027]FIG. 3A represents a schematic view of the reference positioning of the knife shafts on the slitter;
[0028] [0028]FIG. 3B represents a detail of FIG. 3A;
[0029] [0029]FIG. 4 represents a front schematic view, in the environment of the grinding machine, of the electromechanical control device according to a preferred embodiment of the invention;
[0030] [0030]FIG. 5 represents a right hand schematic view of the device of FIG. 4;
[0031] [0031]FIG. 6 represents the positioning of the position measuring sensors of the control device in relation to the knives according to a preferred embodiment of the invention; and
[0032] [0032]FIG. 7 is a graphic representation corresponding to the values of the table attached in Annex I.
DETAILED DESCRIPTION OF THE INVENTION
[0033] In the description, use of the term “knife” is taken to mean both the knives and the counter-knives.
[0034] [0034]FIG. 1 represents a slitter or cutting unit 10 that enables sheets of material to be cut into strips, like for example, photographic film plates, that have to be cut into strips with high precision. Such a slitter comprises two shafts 40 and 50 on which are mounted respectively rotary knives 20 and counter-knives 30 . The two shafts 40 and 50 are mounted so that their main axes are parallel. These elements 20 and 30 have the specialty of being circular shaped and they are placed on the periphery of the knife shaft 40 , 50 in order to enable continuous cutting, when the two shafts 40 , 50 turn together, their respective axes being parallel. To cut a sheet of material, cutting is based on the principle of scissors according to the principle represented in FIGS. 2A and 2B. The sheet of material to be cut 12 runs in direction 14 between the rotary knives 20 and the counter-knives 30 , in for example, the respective directions of rotation 15 and 16 ; after passing between the cutting elements 20 and 30 , the sheet 12 is cut and transformed into strips 18 . Generally, the knives are regularly spaced on the slitter to cut film strips of the same width 19 (FIG. 3A), or they can be spaced irregularly to obtain strips of different widths. But in all cases, the objective is to control the variability of these cutting width dimensions, to try to limit adjustments on the slitter and reduce the complexity of the knife grinding operations; while keeping correct evenness or reproducibility of the pitch between two consecutive knives, and for a set strip width 19 .
[0035] An objective of the process according to the present invention is also to be able to pair up with the minimum adjustment or even without adjustment, the knife shafts on a slitter, and to do this with maximum precision and cutting quality linked to this precision. In the manufacture of photographic film, whether for example film used in professional cinema or amateur film cartridges, the cutting operation is important. Later correct perforation directly depends on this. A simple variation in film width causes random and inaccurate perforation and thus a finished product of less quality that disappoints the customer when he/she uses, for example, the film strip in projectors or cameras. Today in the field of photographic film cutting, the precision required in terms of geometric variations on the cut strip width is in the order of a micrometer. This precision corresponds to controlling the variability of the strip width to be cut and its cut quality, these being a direct consequence of correct prior relative positioning of the respective knives 20 , 30 of the two shafts 40 , 50 of the slitter 10 . According to FIG. 3A, the process according to the invention enables this evenness or control of the reproducibility of the axial pitch P between knives to be produced, to obtain a pitch variability P between two consecutive knives practically less than two micrometers (0.002 mm), while ensuring correct pairing of the respective knives 20 , 30 of the shafts 40 , 50 of the slitter 10 . According to FIGS. 3A and 3B, the pairing corresponds to the axial play A between the faces of the knives 20 and 30 positioned in the slitter 10 . The knife shafts 40 , 50 are pre-positioned one in relation to the other with spacers so that the first respective knives 20 , 30 of each knife shaft 40 , 50 are positioned one in relation to the other according to a correct relative axial position characterized by the axial play A. The process according to the invention also enables control of this axial play for all the knives 20 , 30 with high precision, i.e. variability in the order of 0.01 mm maximum.
[0036] By experience, slitters comprising the two knife shafts are stopped and disassembled after a set number of hours of use. The knife shafts are then ground on, for example, grinding type machines. The grinding precision required, in the order of several microns, demands much more precise machining than that obtained on a conventional lathe. To check the grinding, an electromechanical control device 5 suited to the grinding machine is used. This control device 5 , of which an example is represented in FIGS. 4 and 5, is fixed on a carriage or longitudinal saddle 6 of the grinding machine, by fixing means 7 schematized by their axes. These means 7 can be, for example, fixing screws. The electromechanical control device 5 is equipped with a pair of position measuring sensors 43 , 47 , for example TESA type sensors known to those skilled in the art. Each sensor 43 and 47 comprises, for example, a diamond point type mechanical feeler 8 , 16 that contacts the knife whose position is to be determined. The sensor pair 43 , 47 is electronically linked to a set of control instruments 9 functioning together. The set of control instruments 9 comprises, for example, a galvanometer, and an electronic device that enables direct reading of the values in micrometers, their recording and the performance of calculations on the basis of preset calculation programs. The reading device is, for example, an LED display screen. The recording and calculation device can be a programmable logical controller equipped with a program and an appropriate memory. The carriage 6 of the grinding machine is generally motorized and moves in translation parallel to the axis 1 of the knife shaft to be ground. Apart from the control device 5 the carriage 6 takes a device 3 holding the grinding tool 4 for the knives 30 . The device 3 is also fixed to the carriage 6 . The grinding tool 4 of the knives can be, for example, a rotary grinding wheel 4 ; the rotation axis of this tool 4 is fixed on the tool-holder device 3 . The knife shaft to be ground is fixed for example between points or in a mandrel on the grinding machine 25 . The motorized carriage 6 allows low speed movement of the carriage comprising the tool-holder device 3 , for example, in the order of 0.1 mm/min. This set of electromechanical components constitutes a relatively simple measuring and advance system, both easy to produce with standard material and very efficient; it enables sharpening passes of a few microns on the knives to be sharpened to be performed.
[0037] The electromechanical control device 5 enables the measuring of the differences of the actual position of the knives according to, for example, a chosen theoretical value Po of the pitch corresponding to the distance between two consecutive knives. According to FIGS. 4 and 5, the device 5 comprises a main support 26 fixed by the fixing means 7 to the longitudinal carriage 6 of the grinding machine 25 . The main support 26 is solid with a mechanical arm 27 onto which is fixed a measuring assembly 60 . The measuring assembly 60 comprises a first carriage 41 and a second carriage 28 ; the assembly can be moved along two practically orthogonal axes, one being parallel to the main axis 1 of the knife shaft.
[0038] In a preferred embodiment, the measuring assembly 60 comprises the second vertical carriage 28 , solid with the arm 27 ; the second carriage 28 ensures by means of a device or upper element 51 the movement of the measuring assembly 60 in a direction practically perpendicular to the axis 1 of the knife shaft 40 , 50 fixed on the grinding machine 25 . The device 51 can be, for example, an actuator. According to the embodiment chosen, the first carriage 41 enables the movement of the measuring assembly 60 in the axis 1 of the knife shaft 40 , 50 . Movement of the first carriage 41 is ensured, for example, by a device comprising a horizontal actuator 48 and a spring 42 . According to another embodiment without the second carriage 28 , the first carriage 41 is directly solid with the arm 27 . The second carriage 28 lets the measuring assembly rise or fall to correctly position the mechanical feelers 8 , 16 on the face of the knifes to be checked. The movement of the first carriage 41 in relation to the arm 27 , is practically parallel to the axis 1 of the knife shaft 40 , 50 . The position of the movement of the first carriage 41 is measured by a first high-precision sensor 43 . In the preferred embodiment comprising the actuator 48 and the spring 42 , the actuator 48 moves the first carriage 41 parallel to the axis 1 , under the reverse action of the spring 42 . This horizontal movement of the first carriage 41 enables the first mechanical feeler 8 of a fixed support 70 to be brought into contact with the face of the first knife. The feeler 8 is linked to the sensor 43 . The feeler 8 which enables a stroke of a few millimeters in the axis 1 is linked for example to a galvanometer. After bringing the feeler 8 into contact with the first knife, the feeler 8 is made electrically zero. Then the control instrument 9 is initialized using a precision rule 22 as measurement reference. The rule 22 is itself electronically linked to the control instrument 9 , in this sense that the translation movement in the axis 1 of the control device 5 comprising the measuring sensors and feelers 8 , 16 is always done with reference to the rule. The precision rule 22 is fixed to the grinding machine 25 , and its main axis 11 is parallel to the direction of movement of the carriage 6 in the axis 1 of the shaft to be ground. Preferably a glass rule calibrated with a resolution of 0.001 mm is used. The translation movements of the carriage 6 are always recorded with reference to this rule 22 with a measuring sensor 62 . The rule remains fixed in relation to the carriage 6 which itself moves in translation. The initialization position serving as reference for the measurements to be carried out on the shaft to be ground is recorded in relation to the position of a first theoretical knife chosen as reference for the measurement of the length of the knife shaft 40 , 50 between the two end knives. The reference value is initialized using a simple digital value, for example zero, and recorded as reference in the control instrument 9 . Then the zero (reset) of the rule 22 is made to coincide with the sensor zero 8 . Then, using the carriage 6 , the sensor 8 is moved to the last knife that can be measured with the measuring assembly 60 . This last knife is generally the one before last of the shaft; i.e. if the knife shaft comprises, for example 39 knives, generally the actual distance between the first and the thirty-eighth knife is measured. Once the feeler 8 is positioned at its electrical zero when it is in contact with the thirty-eighth knife, the actual length measured between the knives is read, with reference to the rule 22 . This length is, for example, read directly on a digital display linked to the rule 22 and it is compared with the theoretical length. The theoretical length equals the total number of the theoretical pitch Po of the knife shaft 40 , 50 multiplied by the value of the theoretical pitch Po along the knife shaft. This value of the theoretical pitch Po is generally constant. In certain embodiments, this value of the theoretical pitch can be slightly variable along the knife shaft, to take account of the entire manufacturing process.
[0039] The fixed support 70 onto which is fixed the feeler or diamond point 8 is solid with the first carriage 41 ; the fixed support 70 is fixed to the first carriage 41 and this fixed support 70 takes a measuring subassembly 44 fixed on the support 70 . The subassembly 44 comprises a moving support 45 , moving in relation to the fixed support 70 . The relative position of the moving support 45 is measured by a second high-precision sensor 47 , the sensor being fixed in relation to the fixed support 70 . The sensor 47 enables measurement of the relative movement, in the axis 1 , of the second diamond point 16 in relation to the first diamond point 8 . The sensor 47 , by means of a deforming mechanical device, measures the position of the moving support 45 determined by the contact between the second mechanical feeler 16 and the face of the second knife to be checked. The deforming mechanical device is, for example, a deforming spring leaf 52 . The second mechanical feeler 16 in contact with the second knife of a first pair of checked knives, generates a second algebraic value that in relation to the first algebraic value of the first checked knife, indicates the algebraic difference of the length of the first pitch P measured in relation to the theoretical pitch Po. All these values are thus recorded knife by knife and serve as reference to determine the values for the quantities of material to be ground on the knives. Of course, the spacing or the distance between the two mechanical measuring feelers 8 , 16 is initially preset, for example with a precision gauge block.
[0040] In a preferred embodiment, generally the value of the reference pitch is taken between the sensors 8 , 16 equal to the value of the theoretical pitch Po. But it can also be contemplated in a downgraded embodiment to make the presetting of the pitch according to a reference pitch 19 on FIG. 3A; this reference pitch 19 is very close to the theoretical pitch Po and can be chosen arbitrarily on the shaft 50 .
[0041] At the end of the checking operation of the first pair of knives, the actuator 48 moves the feelers 8 , 16 slightly so that they are no longer in contact with the knives; then the feelers 8 , 16 are disengaged by means of the upper element 51 , to be far from the knives. According to a preferred embodiment of the device 5 according to the invention, a uniaxial articulation 54 equipped with a mechanical stop 55 enables the arm 27 taking the measuring assembly 60 to turn in relation to the main support 26 , around the axis 2 of the articulation 54 , and this in a direction of rotation removing the arm 27 from the mechanical stop 55 . These kinematics facilitate the retraction of the control device assembly 5 so that the operations for putting into place and removing the knife shafts on the grinding machine are easier.
[0042] The pitch P between the knives as shown in FIG. 3A must be as constant as possible at least for the same pair of knife shafts, in order to ensure the cutting quality due in particular to a good pairing of the knife shafts 40 , 50 , i.e. good control of the play between knives and counter-knives represented by the dimension A. This control of the dimension A is due essentially to the reproducibility of the pitch P when sharpening. Actually, this pitch P is not constant because of the scatter due to conventional grinding processes, even if they were managed by numerical control means. The objective of the process according to the invention is to reduce the maximum difference between two pitches, and enable throughout the life of the knife shaft to remain in the tolerances or specifications required, by keeping good control of the variability of the cutting pitch P.
[0043] When the feelers 8 , 16 of the sensors 43 , 47 giving the algebraic difference of position of the first pair of checked knives are brought into contact with the surface of the knives to be checked, this in relation to the reference position initialized in relation to the rule 22 , and recorded in the control instrument 9 , it is considered that the sensor is in the control position to measure the position of the knives. From the values measured and recorded in the control instrument 9 , values that represent the absolute position of the first pair of knives checked with reference to the rule 22 , the relative difference of the knife consecutive to the first checked knife is measured and recorded relative to the reference pitch 19 . The carriage is moved, always in relation to the reference position, itself initialized in relation to the precision rule 22 , by a distance equal to the value of a theoretical pitch Po. This value of movement is, for example, read directly on the digital display screen. Then a second value corresponding to the position of the second pair of consecutive knives is recorded, i.e. situated immediately after the first pair of knives chosen. Thus the differences of position between the checked knives of the various knife pairs is recorded successively. This difference means on the one hand the relative difference in relation to the theoretical pitch, and on the other hand the differences of position of the checked knives in relation to the theoretical positions they should have. The values thus recorded are called algebraic, i.e. they can be positive, negative, or zero. Thus these measurements and recordings of the positioning of each knife are repeated successively, in relation to the reference pitch 19 , from one knife to the next and so continuing to the last knife of the knife shaft to be checked. The process according to the invention then enables the determination of the average algebraic value of the difference per knife according to the sum of the algebraic differences thus recorded, then removing the average calculated value from each of the actual differences of positioning of the knives previously recorded. A first corrected relative position of each of the knives is thus obtained. Then, always with reference to the precision rule 22 , the actual length of the shaft to be ground is measured, by measuring for example the actual distance between the two end knives. Based on the recorded position of the first knife, and always with reference to the precision rule 22 , the position sensor is moved to the last knife of the shaft with the longitudinal carriage 6 comprising the control device 5 and the algebraic difference of the length of the shaft in relation to the theoretical length is recorded. Practically, if the feeler 8 serving as reference for the actual length measurement of the knife shaft is moved, with reference to the precision rule 22 , the sensor 8 can only be positioned on the first knife and on the next to last knife of the shaft; the place of the last knife is generally occupied by the second sensor 16 . This specified theoretical length for each knife shaft type corresponding to the strip widths of the various films is recorded, for example, in a data file of the device 9 . A knife shaft comprising, for example, 39 knives and intended to cut film strips with a width of 35 mm will have a total theoretical length LT=38×35=1330 mm.
[0044] The process according to the invention enables calculation of the algebraic difference for the length per knife, by calculating the algebraic difference between the actual length obtained by moving the corresponding measuring position sensor to the positions of the two knives placed at the ends of the shaft to be ground, and the specified total theoretical length. The process according to the invention adds the difference for the length per knife to the first corrected relative position of each of the knives, and thus a second corrected relative algebraic position of each of the knives is obtained. From the algebraic sum of the values of the second corrected relative position of each of the knives, the process according to the invention thus displays the values of the material to be removed per knife. The values of material to be removed per knife are obtained from these accumulated algebraic values of the second values corresponding to the corrected relative position of each knife. The highest positive algebraic value thus found corresponds to the knife for which there is no material to be removed, and inversely, the negative algebraic value with the greatest absolute value corresponding to the knife for which there is the most material to be removed. In practice, the difference between these two end values is a few tens of micrometers, i.e. some hundredths of millimeters. The actual values to be removed on each of the other knives is obtained, by removing from the algebraic value with the greatest absolute value found, each of the other individual calculated accumulated values of the second relative position. Generally, for reasons inherent in obtaining good grinding quality, a fixed value has to be added to each of the calculated accumulated values of the second corrected relative positions; the fixed value to be added depends on the grinding conditions and especially the dimensional characteristics of the material of the knives to be ground. In practice, this enables for example making two or three grinding passes per knife, by planning a first blank pass that can for example be zero, i.e. there is no material to be removed for part of the shaft's knives, and only representing a few micrometers for the rest of the knives. This then ensures good quality and good evenness of the following passes; the final pass for example is uniform and 20 micrometers for each of the shaft's knives. A preferred embodiment of the implementation of the process according to the invention enables making knife checks by using the two sensors 43 , 47 simultaneously to take the measurements for a given pair of knives of the knife shaft. According to FIG. 6, these sensors 43 , 47 are placed on the control device 5 on board the carriage 6 so that they are positioned preset one in relation to the other, for example, at a distance P 0 equal to the value of the theoretical pitch of the knife shaft. The value of the theoretical pitch is preset on the device 5 holding the sensors 43 , 47 and equals the distance P 0 separating the two sensors 43 , 47 . According to FIG. 6 the reference position of the sensors is the position of their initial presetting meaning the distance P 0 between these two sensors. The device 5 holding the sensors 43 , 47 moves in translation parallel to the axis 1 of the knife shaft. The device 5 holding the sensors 43 , 47 enables the sensors to be removed from the shaft, to move them from pitch to pitch along the shaft. Further, to be able to measure conveniently the measured differences, the two sensors 43 , 47 held by the device 5 can move relatively one in relation to the other in the axis 1 of the knife shaft, under the effect of a low mechanical force exerted in the direction of the axis 1 . This distance P 0 is measured according to a line parallel to the axis 1 of the shaft to be ground. The actual pitch between the two knives checked simultaneously can take the value P 0 if the actual pitch equals the theoretical pitch P 0 , the value P 1 if the actual pitch is greater than the theoretical pitch, or the value P 2 if the actual pitch is smaller than the theoretical pitch. The various positions encountered when measuring the distance differences between pairs of consecutive knifes are shown in FIG. 6. Checking the first two consecutive knives situated, for example, at the end of the knife shaft by using the pair of preset sensors enables the values of the differences in relation to the reference position previously initialized of the corresponding theoretical knives on the knife shaft to be obtained.
[0045] The example shown in the table of Annex I concerns a knife shaft 40 , 50 comprising 39 knives and 38 different pairs of consecutive knives enabling the cutting of 38 film strips. The first knife N° 0 serving as starting reference for the check is not mentioned in the table; i.e. the knife N° 1 is the second knife of the knife shaft 40 , 50 and the knife N° 38 is the thirty-ninth knife of said knife shaft.
[0046] To implement the process according to the invention, the preset sensors 8 , 16 , for example, are brought into contact with the first two consecutive knives of the shaft. The algebraic value of the difference read for example on a galvanometer is +1 (first line of Knife No column of the table). This difference +1 expresses the difference in micrometers of the first actual pitch checked on the first pair of knives 20 , 30 of the knife shaft 40 , 50 in relation to the theoretical pitch, or even to a reference pitch 19 chosen very close to the theoretical pitch. The first actual pitch checked also shows that the second knife N° 1 is offset by +1 in relation to its theoretical position on the knife shaft 40 , 50 ; this in relation to the reference knife N° 0 (not mentioned in the table).
[0047] After having moved in the axis 1 the measuring assembly 60 by a distance approximately equal to the pitch value, then for example the second pair of consecutive knives formed by the knives N° 1 and N° 2 is checked. The algebraic value of the difference read is again +1 (second line of Knife No column of the table). This difference +1 means that the difference of the second actual pitch checked on the second pair of knives is +1 in relation to the theoretical pitch. This difference +1 also means that the third knife N° 2 is offset by +2 (+1+1) in relation to its theoretical position. The example of the ninth knife N° 8 shows that the pitch checked between the seventh and eighth knife is offset by +3 in relation to the theoretical pitch and implicitly means that the knife N° 8 is offset by +14 in relation to its theoretical position; +14 is the algebraic value of the sum of all the recorded differences (Knife N° column of the table). Thus pitch by pitch, i.e. for each pair of consecutive knives, the value of the difference of the actual position of each of the knives 20 , 30 in relation to a reference position taken with regard to the first knife N° 0 of the knife shaft 40 , 50 is determined; the difference of the actual position of each of the knives is defined in relation to the theoretical position of the knives; this difference is determined for each different pair, generally each successive pair of consecutive knives, by the algebraic value of the difference between the actual pitch between the consecutive knives and the theoretical pitch P 0 or reference pitch 19 by default. The algebraic values of the differences between the actual pitches and the theoretical pitch are shown in column 1 of the table and by the curve C 1 of FIG. 7. Then the average algebraic value of the previously determined differences is determined. For this, the differences are summed and divided by the total number of different pitches or pairs of consecutive knives of the knife shaft 40 , 50 . For example, the algebraic sum of the differences of column 1 of the table is +21; the total number of knife pairs is 38; the average algebraic value of said differences is calculated by dividing +21 by 38, which gives approximately an average algebraic value of +0.6. From this value of +0.6 a first corrected relative position of each of the knives is determined by removing said average algebraic value from each of the individual values of the differences obtained in the previous step (column 1 of the table of Annex I). This operation leads to the data of column 2 of the table. For example, for the second knife N° 1, the following is obtained:
+1−0.6=+0.4; for the sixteenth knife N° 15, the following is obtained: −2−0.6=−2.6.
[0048] To refine the correction, a second corrected relative position of each of the knives is determined, by adding the algebraic value of the difference for the length per knife to the algebraic values corresponding to the first corrected relative position. The algebraic difference for the length per knife is obtained from the value of the actual length of the shaft to be ground, generally measured between the two end knives of the knife shaft 40 , 50 . Firstly the algebraic value of the difference between the total theoretical length of the knife shaft and the corresponding total actual length between the two end knives of the knife shaft is determined. The total theoretical length LT is calculated by multiplying the total number of different pairs of consecutive knives of the knife shaft by the value of the theoretical pitch P 0 . The algebraic value of the difference for the length per knife is determined by dividing the algebraic value giving the difference between the theoretical length and the corresponding actual length by the corresponding number of knife pairs. If one takes the total number of pitches or pairs of consecutive knives of a knife shaft 40 , 50 enabling 38 film strips to be cut, the number of corresponding knives will be 39. But, for reasons linked to the operating conditions of use of the measuring assembly 60 comprising the two feelers 8 , 16 , an actual length can be determined by using the feeler 8 with reference to the precision rule 22 , which is close but less than the total length between the two end knives. The theoretical length LT is, for example, calculated for 37 pitches or knife pairs; if the specified theoretical pitch is, for example 34.958 mm, the theoretical length will be 1293.446 mm (34.958×37); the number of knives corresponding to these 37 pitches will be 38.
[0049] The actual length LR measured for 37 pitches is for example 1293.442 mm. The algebraic difference for the length per knife is determined by the formula:
LR−LT
Number of Knife Pairs
[0050] In an example an approximate algebraic value of the difference for the length per knife of −0.1 micrometer is obtained.
1293.442−1293.446=−0.1
38
[0051] Then the algebraic value of a second corrected relative position of each knife is determined by adding the algebraic value of the difference for the length per knife to the algebraic values of the first corrected relative position (column 2 of the table). Thus column 3 of the table of Annex I is obtained that corresponds to the algebraic values of the second corrected relative positions of the knives. For example, the value of the second corrected relative position of the second knife N° 1 is: +0.4−0.1=+0.3; that of the thirty-first knife N° 30 is: +3.4−0.1=+3.3.
[0052] Then, based on these successive corrections, the algebraic sum of the values obtained in the column 3 is determined to obtain the actual positions of the knives along the knife shaft, in relation to their respective theoretical positions. This sum corresponds to the column 4 of the table of Annex I and the curve C 2 of FIG. 7. The positive algebraic values correspond to the knives for which there is the least material to be removed, the greatest value 13.6 for the thirteenth knife N° 12, corresponding for example, to the knife for which no material at all is removed, and the lowest value −21.2 for the knife N° 26, corresponding to the knife for which there is the most material to be removed; the value to be removed for this knife N° 26 being the difference in absolute value between the two end values of the column 4 ; in our example
+13.6−(−21.2)=34.8.
[0053] This means that if, for example, one chooses not to remove material from the knife N° 12, 34.8 micrometers is removed from the knife N° 26. For example 13.6−(3.8)=9.8 is removed from the knife N° 6. Thus the material to be removed for each of the knives is determined. The first knife N° 0 of the knife shaft not shown in the table is ground by the same value as the knife N° 1 to which the average algebraic value of the differences between the actual pitches and the theoretical pitch. The average algebraic value being obtained by dividing the algebraic sum of the differences of column 1 of the table by the total number of knife pairs.
[0054] According to a variant of this last embodiment aiming to grind all the knives 20 , 30 of the knife shaft 40 , 50 , clearly it can be contemplated to grind a finite number of knives less than the total number of knives of the knife shaft. Also according to column 5 of the table, to improve the grinding operating conditions and ensure that all the knives are sharpened, an additional value, for example, 20 micrometers can be added to the value to be removed per knife; this additional value is systematically removed during the last sharpening pass for all the knives 20 , 30 of the knife shaft 40 , 50 . This way of proceeding enables, while grinding the knives, keeping both the good geometric positioning of the knives and a constant pitch all along the shaft to be ground independently of surrounding physical phenomena and especially the temperature variations around the grinding machine.
[0055] It can be contemplated to grind in one or more passes per knife. Columns 6 to 8 of the table constitute an example where the knives are ground in three successive passes by systematically removing 20 micrometers from each knife during the third and last grinding pass. Of course, during the first grinding pass (column 6 of the table), a good number of knives where no material is removed are found.
[0056] A slightly downgraded variant of the process according to the invention, but nevertheless giving very acceptable results, does not take into account the algebraic value of the difference for the length per knife.
[0057] One implemented variant of the preferred embodiment includes applying the process according to the invention for grinding the knives 20 , 30 by taking into account the variability of the manufacturing process and the physical characteristics of the photographic film strip to be cut by choosing not a uniform value P 0 of the theoretical pitch along the axis 1 of the knife shaft 40 , 50 , but by choosing a slightly variable pitch Po+ΔPo, for example, for the knife pairs situated at each end of the knife shaft 40 , 50 . ΔPo can increase or decrease linearly or follow a non-linear function. Thus strips of widths slightly different in a range corresponding to the variations of width of the strips of about 0.05 mm could be cut using the same knife shaft. In general numeric data relative to the first shaft of the slitter 10 are used to grind the second shaft of said slitter, in order to ensure good pairing of the two knife shafts 40 , 50 working together.
[0058] Clearly any other arrangement of the elements of the control device in relation to the grinding machine and the knife shaft to be ground can be contemplated, in so far as they enable the process according to the invention to be produced.
[0059] The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.
Knife N° 1 2 3 4 5 6 7 8 1 1 0.4 0.3 0.3 33.3 0 13.3 20 2 1 0.4 0.3 0.6 33.0 0 13.0 20 3 1 0.4 0.3 0.9 32.7 0 12.7 20 4 2 1.4 1.3 2.2 31.4 0 11.4 20 5 2 1.4 1.3 3.5 30.1 0 10.1 20 6 1 0.4 0.3 3.8 29.8 0 9.8 20 7 3 2.4 2.3 6.1 27.5 0 7.5 20 8 3 2.4 2.3 8.4 25.2 0 5.2 20 9 3 2.4 2.3 10.7 22.9 0 2.9 20 10 2 1.4 1.3 12.0 21.6 0 1.6 20 11 2 1.4 1.3 13.3 20.3 0 0.3 20 12 1 0.4 0.3 13.6 20.0 0 0 20 13 −1 −1.6 −1.7 11.9 21.7 0 1.7 20 14 −1 −1.6 −1.7 10.2 23.4 0 3.4 20 15 −2 −2.6 −2.7 7.5 26.1 0 6.1 20 16 −1 −1.6 −1.7 5.8 27.8 0 7.8 20 17 −3 −3.6 −3.7 2.1 31.5 0 11.5 20 18 −3 −3.6 −3.7 −1.6 35.2 0 15.2 20 19 −3 −3.6 −3.7 −5.3 38.9 0 18.9 20 20 −1 −1.6 −1.7 −7.0 40.6 0.6 20 20 21 −1 −1.6 −1.7 −8.7 42.3 2.3 20 20 22 −1 −1.6 −1.7 −10.4 44.0 4.0 20 20 23 −1 −1.6 −1.7 −12.1 45.7 5.7 20 20 24 −1 −1.6 −1.7 −13.8 47.4 7.4 20 20 25 −3 −3.6 −3.7 −17.5 51.1 11.1 20 20 26 −3 −3.6 −3.7 −21.2 54.8 14.8 20 20 27 1 0.4 0.3 −20.9 54.5 14.5 20 20 28 3 2.4 2.3 −18.6 52.2 12.2 20 20 29 4 3.4 3.3 −15.3 48.9 8.9 20 20 30 4 3.4 3.3 −12 45.6 5.6 20 20 31 3 2.4 2.3 −9.7 43.3 3.3 20 20 32 2 1.4 1.3 −8.4 42.0 2.0 20 20 33 1 0.4 0.3 −8.1 41.7 1.7 20 20 34 2 1.4 1.3 −6.8 40.4 0.4 20 20 35 1 0.4 0.3 −6.5 40.1 0.1 20 20 36 1 0.4 0.3 −6.2 39.8 0 19.8 20 37 1 0.4 0.3 −5.9 39.5 0 19.5 20 38 1 0.4 0.3 −5.6 39.2 0 19.2 20
Annex I | The present invention relates to a process and control device to grind a knife shaft used in a machine intended for cutting sheets of materials into strips, for example, sheets of paper, plastic, plates of photosensitive film or any other material having the form of thin sheets. The process includes determining the actual differences of position of the knives of the knife shaft in relation to a theoretical position and then dividing these differences to cut the film strips by widths practically equal to one another, and determining the quantities of material to be eliminated by grinding for each knife. This process especially finds its principal application in the photographic industry, in particular on grinding machines for the knives of knife shafts equipping the film slitters. | 1 |
FIELD OF THE INVENTION
The present invention relates to micro electro-mechanical systems (MEMS) devices. More particularly, the present invention relates to a device and method for stacked multi-level uncoupled electrostatic actuators that may be used to drive optical micro-mirrors.
REFERENCES
[1] Data sheet of ADXL, at http://www.analog.com/
[2] L. J. Hornbeck U.S. Pat. Nos. 4,956,619; 5,061,049; 5,535,047
[3] See http://www.siliconlight.com/
[4] D. J. Bishop, C. R. Giles, and G. P. Austin, The Lucent LambdaRouter: MEMS technology of the future here today, IEEE Comm. Mag., Vol. 40(3), pp. 75-79, 2002.
[5] H. Toshiyoshi, W. Piyawattanametha, C. Cheng-Ta and M. C. Wu, “Linearization of electrostatically actuated surface micromachined 2-D optical scanner”, JMEMS, 10, 2, pp. 205-214, 2001.
BACKGROUND OF THE INVENTION
Electrostatic actuation is the most prevalent means of driving micro electro-mechanical systems (MEMS) devices. State-of-the-art MEMS devices utilizing electrostatic actuation include: inertial sensors such as Analog Devices ADXL™ [1]; pressure sensors; RF switches and filters; MEMS displays such as TI-DLP™ [2], Silicon Light Machines' Grating Light Valve™ (GLV™) [3], optical cross-connect, e.g., Lucent LambdaRouter™ [4] and more.
The emerging technology of scanning micro-mirrors enables the processing of relatively compact and low cost digital and analog light. Among such applications are the Texas Instruments DLP™ used for modern, state of the art displays and the Lucent double-gimbaled WaveStar™ micro-mirror used in optical communication state-of-the-art all-optics routers. Other applications include barcode scanners, scanning confocal microscope, scanning for direct display on retina and more. A gimbal is a device that permits a body to incline freely around a predetermined axis, or suspends it so that it will remain level when its support is tipped.
In many MEMS applications multi-axis drive and control of deformable elements is required. Double-gimbaled micro-mirrors have been developed in order to achieve scanning in two dimensions. In state of the art double-gimbaled micro-mirror technology, the actuation of the two degrees of rotation is coupled due to electrostatic coupling effects. For example, the Lucent LambdaRouter™ uses a double-gimbaled micro-mirror to route optical information from a source fiber into a 2D array of target fibers. The electrostatic coupling between the two axes of rotation causes distortion of the picture that requires special linearization algorithms to reconstruct the correct rectangular domain. Moreover, the calibration has to be carried out for each individual device to account for its specific electromechanical properties. This in turn, increases the cost associated with these devices.
The principle of setting an element on a multi-gimbaled frame is well known, e.g., for use in traditional rotation gyroscopes. However, the use of electrostatic actuation to drive the gimbaled devices, results in a nonlinear coupling between the axes. As a result, the scan range becomes distorted [5]. Many control techniques have been proposed to deal with this nonlinear coupling effect. However, all such prior art has further complicated the calibration and operation of the device.
Therefore, there is a need in the art to provide a simpler device and method that avoids nonlinear coupling between the axes, when using electrostatic actuation to drive dual axes devices.
SUMMARY OF THE INVENTION
Accordingly, it is a principal object of the present invention to provide a device and method that avoids nonlinear coupling between the axes, when using electrostatic actuation to drive a micro-device with multiple rotation axes.
It is a further object of the present invention to provide a simpler device and method for electrostatic actuation to drive a micro-device with multiple rotation axes.
It is another object of the present invention to provide a device and method for electrostatic actuation to drive micro-devices with multiple rotation axes devices that is applicable for a wide variety of applications.
It is yet another object of the present invention to provide a device and method for electrostatic actuation to drive micro-devices with multiple rotation axes that enable larger scanning angles, while keeping the applied voltage relatively low.
A multi-axis electromechanical actuator is described, with no electrostatic coupling between the axes. The proposed new technology eliminates the problem of coupling between axes by using multi-level stacked actuators. The decoupling between the different axes of rotation is achieved by stacking each actuator over the deformable element of the previous level. This method is used to achieve dual-axis scanning with a fixed and independent electromechanical response of each axis. Each actuator has a single degree of freedom that is separately actuated. Therefore, there is no cross talk between the multiple axes, and a rectangular scanning domain is achieved with no need for calibration or special algorithms. This technology can be extended to more than two levels of stacking, thus enabling larger scanning angles, while keeping the applied voltage relatively low.
In accordance with a preferred embodiment of the present invention, there is provided a multi-level decoupled micro-actuator device for a micro-mirror having multiple axes, using micro electro-mechanical systems (MEMS)-on-MEMS stacking technology. The device includes a first level substrate having at least one first level bottom electrode on its upper side. The device also includes a second level frame stacked on the first level substrate, the second level frame having a first deformable element rotatable about the x-axis. The first deformable element includes at least one counter electrode on its lower side corresponding to, and oppositely charged to, the at least one first level bottom electrode and at least one second level bottom electrode on its upper side. The device further includes a third level frame stacked on the first deformable element, the third level frame comprising a second deformable element rotatable about the y-axis, the second deformable element being driven by at least one second level bottom counter electrode on its lower side corresponding to, and oppositely charged to, the at least one second level bottom electrode on the first deformable element, such that there is no coupling between the rotation of the first and second deformable elements, respectively, about the x-axis and the y-axis.
Additional features and advantages of the invention will become apparent from the following drawings and description.
BRIEF DESCRIPTIONS OF THE DRAWINGS
For a better understanding of the invention in regard to the embodiments thereof, reference is made to the accompanying drawings and description, in which like numerals designate corresponding elements or sections throughout, and in which:
FIG. 1 shows a schematic view of a double-gimbaled two-axis micro-mirror device, constructed to illustrate the principles of the current art;
FIG. 2 schematically presents the electromechanical response of the double-gimbaled two-axis micro-mirror device shown in FIG. 1 , exhibiting the coupling between the two axes, constructed to illustrate the principles of the current art;
FIG. 3 shows a schematic illustration of a multi-stacked, uncoupled, two-axis micro-mirror device, constructed in accordance with the principles of the present invention; and
FIG. 4 shows the separated layers of the device of FIG. 3 , constructed in accordance with the principles of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will now be described in connection with certain preferred embodiments with reference to the following illustrative figures so that it may be more fully understood. References to like numbers indicate like components in all of the figures.
The principal aim of the proposed technology is to eliminate the coupling between the different axes for the electrostatic actuators used to drive multiple axes micro-mirrors. The principle applied involves the decoupling of each axis. This is achieved by assembling the actuators such that the moving element of one level is the reference base of the next level. Thus, each succeeding level is driven relative to the moving element of the previous level. This is in contrast to the existing technology in which all levels are driven relative to the same fixed base.
To make clear the source of the nonlinear coupling between the two axes in the double gimbaled actuator, reference is now made to the system illustrated in FIG. 1 , which shows a schematic view of a double-gimbaled two-axis micro-mirror device 100 , constructed to illustrate the principles of the current art. A micro-mirror 105 is rotated over a first angle θ 110 , about a first axis of support 115 , which is connected to a first frame 117 . First frame 117 is in turn-connected to a second frame 127 . Second frame 127 is rotated over a second angle Φ 120 , about a second axis of support 125 , which is also connected to first frame 117 .
FIG. 2 schematically presents an electromechanical response curve 200 of the double-gimbaled two-axis micro-mirror device shown in FIG. 1 , exhibiting the coupling between the two axes, constructed to illustrate the principles of the current art. The electromechanical response of the inner frame is illustrated in FIG. 2 , for various applied voltages, V 210 . The angular response θ, over first angle 110 of the inner gimbal is affected by the external gimbal rotation over second angle Φ 120 . Two curves are shown. A first curve 221 corresponds to values of first angle θ 110 for a value of second angle Φ=Φ 1 and a second curve 222 corresponds to values of first angle θ 110 for a value of second angle Φ=Φ 2 . As shown, second angle deflection, φ 120 of the external frame affects the electromechanical response of the inner frame. This is due to the fact that as the external frame is deflected, the inner frame is deflected with it, while the driving bottom electrodes remain fixed. Consequently, the relative position between the inner frame and its driving electrodes is affected by second angle deflection φ 120 of the external frame.
One means of eliminating this coupling is to deflect the driving electrodes of the inner frame such that they remain parallel to the inner frame axis. This can be achieved by fixing the driving electrodes of the inner frame to the same external frame that deflects the inner frame axis. In the present invention this is achieved by multi-level stacking of multiple actuators, one upon the other, each having a single degree of freedom. FIG. 3 gives a schematic illustration of such a stacked micro-mirror.
FIG. 3 is a schematic illustration of a multi-level stacked, uncoupled, two-axis micro-mirror device 300 , constructed in accordance with the principles of the present invention. This device is constructed from three levels, as described in greater detail hereinbelow, with reference to FIG. 4 .
FIG. 4 shows the separated layers 400 of the device of FIG. 3 , constructed in accordance with the principles of the present invention. The first level 410 contains the first level bottom electrodes 412 that drive the first deformable element 431 about the x-axis 440 . The second level 420 contains first deformable element 431 . First deformable element 431 contains the counter electrodes to the first level bottom electrodes 412 on its lower side. However, the counter electrodes are not visible in a top perspective view. Also, first deformable element 431 contains, on its upper side, the second level bottom electrodes 422 that drive the second deformable element 432 about the y-axis 445 . The third level 430 contains the second deformable element 432 , of which the frame is attached to the first deformable element 431 on second level 420 .
It is understood that in the stacked micro-mirror device there is virtually no electrostatic coupling between the two axes of rotation. Therefore, the electromechanical response of second deformable element 432 is unaffected by the tilting angle of first deformable element 431 . This is in contrast to the electromechanical coupling between the axes of rotation of double-gimbaled actuator 100 shown in FIG. 1 .
Applications for the present invention include micro electro-mechanical systems (MEMS) devices for optical cross connect, and for use in scanning and displays. Another application is multiple-axes inertial sensors.
Additional applications include inertial sensors, pressure sensors, radio frequency (RF) switches and filters, MEMS displays, as well as double-gimbaled micro-mirrors used in optical communication state of the art all-optics routers, barcode scanners, scanning confocal microscopes and scanners for direct display on retina.
Having described the present invention with regard to certain specific embodiments thereof, it is to be understood that the description is not meant as a limitation, since further modifications will now suggest themselves to those skilled in the art, and it is intended to cover such modifications as fall within the scope of the appended claims. | A multi-level decoupled micro-actuator device comprising a first level substrate ( 410 ), a second level frame ( 420 ) stacked on said first level substrate ( 410 ), a third level frame ( 430 ) stacked on said second level frame ( 420 ). | 6 |
BACKGROUND OF THE INVENTION
(i) Field of the Invention
The present invention relates to abradable gas turbine seals and, more particularly, to novel turbine seals having cellular metallic structures suitable for operation in an oxidizing and/or carburizing gas environment at high temperatures.
(ii) Description of the Related Art
Cellular structures made from thin sheet metal or metal foil are attractive for use in space and aerospace applications, in particular in jet engines, because they provide a high stiffness to weight ratio and high mechanical energy absorption capabilities and acoustic damping while being light in weight. As a direct consequence of their low density they are also readily abradable, which is a characteristic favorable for usage in jet engines, and also in stationary gas turbines used for power generation, to reduce the gap between the stationary shroud and rotating blade components, thereby improving efficiency of the gas turbine cycle. While the cellular structure used as an abradable seal must be soft enough to allow the tips or knife edges of a rotating blade to cut into it without causing damage to the blade and the structure carrying the abradable cellular structure, it must be strong enough to withstand static and high frequency vibratory loads, abrasion, cyclic thermal stresses and cyclic oxidation and/or carburization attack, all occurring at high temperatures. Furthermore, the seal must not crack under thermal shock and low cycle fatigue loading. In other words, the cellular structure used as a gas path seal must be resistant to hot gas corrosion attack and must have excellent structural integrity and long term dimensional stability to withstand the mechanical and thermal loads imposed on it for many cycles and over lengthy periods of time.
Conventional abradable cellular gas path seals are manufactured from highly alloyed, austenitic stainless steels and nickel-base alloys and are provided having regular hexagonal cells formed by corrugating ribbons of sheet or foil and welding the corrugated sheets together where abutting walls of adjacent corrugated ribbons meet to form a double wall, i.e. a node.
U.S. Pat. No. 3,867,061 issued Feb. 18, 1975 typifies a conventional prior art honeycomb shroud for rotor blades for turbines in which the honeycomb cell walls are made from nickel-base heat-resistant alloys and the honeycomb strips are brazed or resistance welded to a back-up ring.
U.S. Pat. No. 4,063,742 issued Dec. 20, 1977 discloses another embodiment of prior art abradable fluid seal for use in gas turbines consisting of a conventional honeycomb made by conventional honeycomb equipment in which abutting three-sided semi-hexagonal strips each having a pair of flat slanted sides and a flat crest of equal length standing on edge (“soe”) are resistance welded together at the crests.
Honeycomb structures typically are fabricated by building up the structure layer by layer to result in a three dimensional body having a height determined by the width to which the ribbon had been slit prior to corrugation. The length of the structure is parallel to the plane of the double walls or nodes and the width is represented by the direction of layer build up. Such a cellular body is brazed to face sheets to form a sandwich skin or brazed to backplates of a rind or ring segments to form a seal, the contacting surface of the cellular body being a “soe” surface. Such brazing does not only join the cellular structure body to the face sheet or backplate but also contributes significantly to the stiffness of the cellular structure itself. This is due to the fact that the brazing alloy, in a liquid state and due to capillary action, rises up the gap formed by the two neighbouring walls of the node, thereby wetting the abutting surfaces of said node walls and, after resolidification of the braze filler metal, forms a stiffened cellular structure. The braze flow up the nodal walls is referred to as “wicking”. Such wicking is essential to provide a brazed cellular structure with good mechanical behaviour at high temperatures to resist combined thermal and mechanical loads.
The most commonly used method to provide a turbine engine seal segment or ring is to sandwich a braze filler metal foil, tape or brazing powder between the abutting surfaces of the “soe” cellular structure and the backplate surface, and brazing this assembly together. The liquid braze metal must travel up the full depth of the nodes to impart improved structural strength. The exposed surface at which the rotor blade tip or knife edge rubs is also the surface where the most severe combination of mechanical load, wear and temperature occurs and therefore requires excellent structural integrity. If inadequate wicking success is achieved during brazing, there is a twofold drawback: not only is the cellular structure unstiffened, with the consequence of low shape stability, which may cause premature failure of the seal body in service, but also the bulk of the braze filler metal remains at the backplate surface and penetrates both the backplate material and the cellular foil alloy structure by diffusion while in the liquid state to a much larger extent than would be the case if the braze alloy flowed up the nodes. This has the effect of significantly altering the chemical and mechanical characteristics of the backplate and the foil metal alloy, at least locally at their juncture.
Because oxidation resistance and carburization resistance at high temperatures are required, sheet or foil metals having a good hot gas corrosion resistance must be used for the manufacture of turbine seals. The resistance of metals to oxidation and carburization is based on the formation of surface oxide layers which protect the underlying metal from further attack. The nickel base alloys and highly alloyed, austenitic stainless steels used in conventional abradable cellular seals rely on the formation of chromia (Cr 2 O 3 ) or mixed Cr 2 O 3 /NiO oxides to provide such protection. At very high temperatures or in combustion gas atmospheres flowing at high speeds, both found in turbine engines, this type of protection is unstable due to further oxidation of the Cr 2 O 3 to volatile CrO 3 as described by James L. Smialek and Gerald E. Meier in Superalloys II by Chester T. Sims et al. (eds.), John Wiley & Sons, Inc. (1987). The same authors, in the same handbook, describe that much better protection is achieved with alumina (Al 2 O 3 ) which is formed on metals having a high Al concentration and being further enhanced by high chromium (Cr) contents and the addition of rare earth metals, such as yttrium (Y), zirkonium (Zr), cerium (Ce), hafnium (Hf), ytterbium (Yb), praseodymium (Pr), neodymium (Nd), samarium (Sm) or lanthanum (La) leading to so called MCrAlX alloys with X representing the rare earth metal addition and M being the major alloy constituent selected from the group of Ni, Fe or Co or combinations thereof. If yttrium is chosen as the main rare earth addition, then the resulting alloys are referred to as MCrAlY alloys. MCrAlY alloys are disclosed in U.S. Pat. No. 5,116,690 by W. J. Brindley et al., issued May 26, 1992. Other patents such as U.S. Pat. No. 4,034,142 issued Jul. 5, 1977 to R. J. Hecht and U.S. Pat. No. 4,503,122 issued Mar. 5, 1985 to A. R. Nicholls describe similar MCrAlY alloys with excellent self protection against hot gas attack. All the aforementioned patents describe the use of MCrAlY alloys as overlay coatings and not as a structural material in He form of foil to provide a welded cellular structure.
It is difficult to obtain MCrAlY alloys in thin sheet or foil form because they are hard and difficult to roll which is the effect of the high aluminium concentration, typically in the range 2-6% by weight, with 6″7% representing the upper limit to retain workability. If available in thin sheet or foil form the MCrAlY materials are difficult to corrugate and to form into a cellular structure such as described above. In particular, these materials are difficult to form into a corrugated ribbon, if a portion or all of the added yttrium is present as yttria (Y 2 O 3 ) and/or part of the alloy matrix aluminium is present as matrix alumina. The insufficient formability of these alloys results in cellular structures which may deviate significantly from the optimum shape since no sharp comers, but only rounded ones with a relatively large bend radius, can be achieved by corrugations which compromises brazeablity. This is especially true for MCrAlY foil or sheet metal having thick gauges. For use at high temperatures, the foil thickness of the MCrAlY sheet or foil used must be greater than a certain minimum limit to avoid break-away oxidation. Break-away or catastrophic oxidation occurs when, due to straightforward growth of the protective alumina scale or due to repeated scale spallation and automatic rebuild of the protective scale in oxidising environments at high temperature, the bulk aluminium concentration in the foil or sheet alloy is consumed and falls below a certain critical value. This phenomenon is described by W Quadakkers and K Bongartz in Werkstoffe und Korrosion 45, 232-241 (1994). The same authors propose to use high initial Al concentrations in the MCrAlY alloy and the use of thicker foil or sheet to delay the onset of break-away oxidation. Both of these measures, however, are detrimental to formability and to brazeability of the material when formed into a cellular structure and brazed to a backing sheet metal ring, sheet metal ring segments or cast backing members.
Even if successfully formed into a cellular shape with good geometrical features, the MCrAlY materials are difficult to braze because they contain a high amount of Al and Y or Y 2 O 3 . Due to the high affinity of aluminium to oxygen, there is a strong tendency towards the formation of stable and tightly adherent alumina scales at the MCrAlY metal surface, thereby reducing the wettability and consequently braze wicking which is required to achieve structural stiffness of the cellular structure to be used as an abradable turbine engine seal. Likewise yttrium has a very strong affinity to oxygen to form very stable yttria (Y 2 O 3 ) which also acts as a braze flow stopper. Typically therefore MCrAlY alloys, typically containing 6-30% by weight Cr, 2-7% by weight Al, 0.005-0.6% by weight Y and other reactive elements from the group consisting of Zr, Ti, Hf, La, Ce, Er, Yb, Pr, Nd, Sm, balance one or more of the elements belonging to the group of Fe, Ni, Co are extremely difficult to braze and it is therefore difficult to use them in a cellular structure of an abradable seal system.
H. Bode in “Metal-Supported Automotive Catalytic Converters”, H. Bode (ed. ), Werkstoff Informationsgesellschaft mbH, Frankfurt (1997), p. 17-31, describes cellular structures made from MCrAlY foil alloys for use at high temperature as support structures for automotive catalysts. The cellular structures are built up by alternating layers of flat or microcorrugated foil and corrugated foil having sinusoidal ridges. The sinusoidal corrugated foil may be manufactured using Fe—Cr—Al—Y alloys.
PCT Application No. PCT/EP95/00885 (WO 95/26463)published Mar. 9, 1995, discloses a metallic cellular structure made from an MCrAlY alloy having an aluminium content of greater than 6% by weight for increased electrical resistivity. The cellular structure is fabricated by extrusion of metal powders or metal—ceramic powders or by making the metal foil by rapid solidification because of the difficulties in formability of MCrAlY alloys having an aluminum content of greater than 6wt %.
SUMMARY OF THE INVENTION
In accordance with the present invention there are provided novel cellular structures preferably made from MCrAlY alloy metal foil or sheet having good structural integrity and stiffness after brazing to a metal backing structure and therefore show long term dimensional stability at high temperature.
In its broadest form this is achieved through a novel, elongated cell shape of a cellular honeycomb structure. According to the present invention, the cell shape is elongated in the direction parallel to the direction of the double wall crests or nodes and, more particularly, comprises a plurality of abutting semi-hexagonal strips each having alternating flat slanted sides interconnected by a flat crest, the abutting strips joined together at the adjacent flat crests to form generally hexagonal cells having double wall crests or nodes, the slanted sides having an equal length and the crests having a length greater than slanted sides whereby the width w measured between opposed flat crests of adjacent strips relative to the distance b between the planes of opposed slanted sides has a ratio of b:w of greater than 1.15:1.0. Preferably, the ratio of b:w is 1.2 to 2.0:1.0, and snore preferably, the ratio of b:w is 1.3 to 1.6:1.0.
In a further preferred embodiment of the invention, the semi-hexagonal elongate strips are a foil metal or sheet metal alloy of a MCrAlY comprising 13 to 27% by weight Cr, 2 to 7% by weight Al, 0.005 to 0.6% by weight Y, at least one of up to 0.6% by weight Zr, up to 0.6% by weight Hf, up to 0.6% by weight Ce, up to 6% by weight La, up to 6% by weight Si, up to 0.6% by weight Mn, up to 0.6% by weight Ti and up to 0.3% by weight C, and the balance, apart from impurities, Fe or Ni or combinations thereof. More preferably, the iron content is at least 6% by weight Fe, the balance Fe or Ni or combinations thereof.
The novel honeycomb structure of the invention can be used as an abradable seal in a gas turbine such as a jet engine or stationary gas turbine comprsing a metal backplate with the honeycomb structure attached standing on edge to the metal backing plate, the honeycomb structure consisting of the metal foil or sheet metal of the MCrAlY. The metal back member preferably is a nickel-base alloy in the form of a backing sheet metal ring, sheet metal ring segments or cast backing members and the metal foil or sheet metal used to manufacture the cellular structure has a thickness of 0.100 mm to 0.400 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
The abradable gas seal of the invention will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a plan view of a prior art honeycomb cellular structure;
FIG. 2 is a plan view of the novel honeycomb cellular structure of the present invention;
FIG. 3 is a perspective view of a honeycomb cellular structure of the invention; and
FIG. 4 is a perspective view of the honeycomb structure of the invention illustrated in FIGS. 2 and 3 preparatory to attachment by brazing to a backplate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, FIG. 1 illustrates a prior art honeycomb cellular structure 10 fabricated from a plurality of strips 12 of corrugated metal foil or sheet metal having a three-sided, semi-hexagon shape consisting of a pair of flat slanted sides 14 , 16 having a length k interconnected by adjacent intermediary flat crests 18 , 19 having a length m, all of equal length wherein m=k. The adjacent strips 12 , 12 a , 12 b are joined together at their abutting crests 18 , 19 such as by resistance welding or by laser spot welding to form the three-dimensional body 10 having a height determined by the width to which the strips had been slit from a sheet, not shown.
Honeycomb cellular structure 10 has a long axis parallel to the direction depicted by L, perpendicular to the cell width w. The distance b between the planes of opposed slanted sides 14 , 14 and 16 , 16 of adjacent steps 12 , 12 a , 12 b is equal to the distance w, i.e. b:w=1.
Turning now to FIG. 2, the honeycomb cellular structure 30 of the present invention fabricated from a plurality of corrugated strips 32 of metal foil or sheet metal each having a three-sided shape consisting of a pair of flat slanted sides 34 , 36 having an equal length k interconnected by adjacent intermediary flat crests 38 , 39 having a length m wherein m is longer than k, whereby the cell width w when measured between opposed flat crests 18 , 19 of adjacent strips is shorter than the distance b between the planes of opposed slanted sides 34 , 34 and 36 , 36 , the ratio b:w being at least 1.15:1.0, preferably 1.2 to 2.0:1.0, and more preferably 1.3 to 1.6:1.0. Alternatively, with reference to the length of cell y, as viewed in FIGS. 1 and 2, relative to the width of cell w, the ratio y/w must be at least 2.30:1.0. The ratio of y:w in FIG. 1 is 1.155:1.0.
It has been found surprisingly that the honeycomb cellular structure having a ratio of b:w of greater than 1.15:1.0, preferably, 1.2:1.0 to 2.0:1.0 and more preferably 1.3:1.0 to 1.6:1.0, provides consistently good braze wicking of up to 100% for honeycomb cellular structures made from the MCrAlY's of the invention. The adjacent strips 32 , 32 a, 32 b are joined together at their abutting crests 38 , 39 such as by resistance welding or by laser spot welding 40 to form three-dimensional body 30 shown in FIGS. 3 and 4 having a height H determined by the width of the strips, a length L and width B. The honeycomb structure 30 standing on edge with surface 42 abutting surface 44 of backplate 46 of a ring shroud (not shown) is brazed to a backplate 46 of a ring shroud to form a seal structure for use as an abradable turbine seal. Backplate 46 may be a backing sheet metal ring, sheet metal ring segments or cast backing members of a nickel-base alloy forming part of the shroud of the gas turbine of a jet engine or a stationary gas turbine.
The preferred metal foil or sheet alloy of the invention consists of 6 to 30% by weight Cr, 2 to 7% by weight Al, 0.005 to 0.6% by weight Y, at least one of the elements selected from the group consisting of Zr, Hf, Ce, La, Si, Mn, Ti in the amount of at least 0.6% by weight and C in the amount of 0.3% by weight, at least 6% by weight Fe, and the balance, apart from impurities, being Fe or Ni or combinations thereof.
The honeycomb cellular structure 30 is attached to backplate 46 by resistance welding or laser spot welding. A braze filler metal in powder form then is applied by filling the vertically aligned cells with the braze powder and the assembly heated to above the melting point of the braze powder, preferably in the range of about 1190° C. to 1215° C., in a conventional vacuum furnace for a time sufficient such as about 2 to 8 minutes to melt and wet the nodal walls of the honeycomb cellular structure and to rise up the double nodal walls by capillary action to effectively join the structure to the backplate and to stiffen the honeycomb cellular structure. Suitable cobalt-base braze filler metal alloys for the MCrAlY honeycomb structure can consist of 19% by weight Cr, 17% by weight Ni, 8% by weight Si, 4% by weight W, 0.8% by weight B, 0.4% by weight C and the balance Co, or 21% by weight Cr, 4.5% by weight W, 2.4% by weight B, 1.6% by weight Si, 0.1% by weight C, and the balance Co.
The abradable turbine seal of the invention will now be described with reference to the following non-limitative examples.
EXAMPLE 1
A conventional, non MCrAlY alloy having the nominal chemical composition of 22% by weight Cr, 18% by weight Fe, 9% by weight Mo, 1.5% by weight Co, 0.6% by weight W, balance Ni was provided in the form of 125 μm (0.125 mm, 0.005″) thick foil to form a cellular structure illustrated in FIG. 1 having a length L of 55 mm, a width B of 35 mm and a nodal height H of 8 mm, by corrugating and laser spot welding the foil to form a six-sided honeycomb cell shape having a nodal cell size as measured as the minimum internal distance between the cell walls forming the nodal walls of w=1.59 mm and a cell size b, measured as the minimum internal distance between opposed single foil thickness cell walls, of 1.59 mm. Therefore the ratio of b:w is 1. Small deviations, usually less than 10%, from this value are allowable due to manufacturing tolerances. The structure, having the described cellular configuration, was brazed to a metallic backplate as typified in FIG. 4 using a braze filler metal in powder form having the chemical composition of 19% by weight Cr, 10.2% by weight Si, 0.03% by weight C, balance Ni. The braze alloy powder was applied by filling a total of 8.7 g into the cells after having resistance welded the cellular body to the backplate with the nodal height dimension H standing on edge at 90° to the backplate. This assembly was heated to 1193° C. and held at that temperature for 6 minutes in a conventional vacuum furnace causing the braze filler metal to melt and wet the nodal walls of the cellular structure and to join the cellular structure to the backplate. After brazing, the braze wicking result was determined by assessing the percentage of nodes which showed complete wetting with braze filler over the total nodal height of 8 mm, i.e. the percentage of nodes showing braze filler metal at the surface 49 (FIG. 4 ). This result was assessed to be 100% with a total of 114 nodes investigated.
EXAMPLE 2
An MCrAlY alloy foil having a thickness of 110 μm (0.110 mm, 0.004″) with an alloy composition of 20.2% by weight Cr, 5.8% by weight Al, 0.05% by weight Y, 0.04% by weight Zr, 0.04% by weight Hf; balance Fe, was formed into two cellular structures having the same outside dimensions and cell sizes as described in Example 1. The two structures were resistance welded to the same backplate material as used in Example 1 and the same type and amount of braze filler metal as used in Example 1 was filled into the cells. The assemblies were brazed in the same furnace run as the assembly of Example 1. The braze wicking results, assessed as described in Example 1, were 54 and 71% respectively. A total of 114 and 95 nodes, respectively, were investigated.
A comparison of the results of examples 1 and 2 suggests that a much better braze wicking result is achieved with conventional Ni-base alloys than with MCrAlY alloys when a conventional honeycomb cell shape is used.
EXAMPLE 3
An MCrAlY alloy having the nominal chemical composition of 19% by weight Cr, 5.5% by weight Al, 0.5% by weight Ti, 0.21% by weight Y and balance Fe was provided in the form of a foil having a thickness of 0.125 mm (0.125 mm, 0.005″). This foil material was corrugated and welded to provide a cellular structure body having outside dimensions as given in Example 1, i.e. a length L of 55 mm, a width B of 35 mm and a nodal height H of 8 mm. The cell size of the cellular structure of this body was w=2.5 mm and b=2.5 mm when assessed as described in Example 1. The cellular structure was resistance welded to a backplate material as used in Examples 1 and 2 with the nodal height dimension H standing on edge being at 90° to the backplate. Braze filler metal powder having the nominal chemical composition of 19% by weight Cr, 17% by weight Ni, 8% by weight Si, 4% by weight W, 0.8% by weight B, 0.4% by weight C and balance Co was filled into the cells of the cellular structure. The same amount of braze filler metal as in Example 1 was used. The assembly was heated to a temperature of 1204° C. and held at that temperature for 6 minutes. This treatment caused the braze filler metal to melt and wick up the nodal walls. The braze wicking success, assessed as outlined in Example 1, was only 8% with a total of 168 nodes investigated.
EXAMPLE 4
The MCrAlY alloy foil material as described in Example 2 was processed into a cellular body having dimensions of L=55 mm, B=35 mm and H=8 mm, as described above. The cellular structure had the cell dimensions as given in Example 3 when measured as in Example 1. The further processing of this cellular structure including resistance welding and powder filling and the braze filler metal powder, type and amount were exactly the same as those used in Example 3. The assembly was brazed in the same furnace run as the assembly described in Example 3. The wicking result after brazing, as assessed by the procedure described in Example 1, was 84%. A total of 114 nodes were investigated.
EXAMPLE 5
The MCrAlY alloy foil material of the composition described in Examples 2 and 4 was processed into a cellular structure body having outside dimensions as before, L=55 mm, B=35 mm and H=8 mm. The cellular structure, however, had the special six-sided honeycomb cell shape in accordance with the present invention. The cell width, as measured as the minimum internal distance w between cell walls forming the double wall crests or nodes was 1.59 mm and the cell dimension b, measured as the minimum distance between the single foil thickness cell walls, was 2.41 mm, giving a ratio of b:w=1.52 or a ratio of y/w=2.31. This honeycomb structure was resistance welded to the same backplate material as used in Examples 1 through 4 with the nodal height H being at 90° to the backplate. Braze alloy filler metal, as used in Examples 3 and 4, filled the cells. This assembly was brazed in the same furnace run as the assemblies described in Examples 3 and 4. The braze wicking result, determined in the manner as described in Example 1, was 95%. A total of 114 nodes were investigated.
EXAMPLE 6
The MCrAlY alloy foil material having the composition described in Examples 2, 4 and 5 was provided in a cellular structure body form having outside dimensions as before but with the cell shape as described in Example 5, i.e. having a ratio of b:w of 1.52. The further processing and additional materials used to provide an assembly for brazing as before were the same as described in Example 5, except the amount of braze filler metal was 9.8 g. This assembly was heated to a temperature of 1190° C. and kept at that temperature for 4 minutes. The braze wicking success, determined in the manner as described in Example 1, was 100%. A total of 220 nodes were investigated.
EXAMPLE 7
The MCrAlY alloy foil material having the composition described in Example 3 was provided as a cellular structure body having a nodal height H of 7.5 mm and a honeycomb cell shape according to the present invention with the cell dimension w, as measured as the minimum internal distance between the cell walls forming the double wall crests or nodes of the cell, being 1.45 nm and the cell dimension b, measured as the minimum internal distance between the single wall thickness cell walls, being 2.08 mm, giving a ratio of b:w of 1.43. This cellular structure body was placed standing on edge on a metal backing plate having the nominal chemical composition of 10% by weight Co, 6.6% by weight Cr, 6.5% by weight Ta, 6.4% by weight W, 5.5% by weight Al, 3.0% by weight Re, 1.0% by weight Ti, 0.6% by weight Mo, 0.09% by weight Hf, balance Ni and being provided in a cast, monocrystalline form. The cellular structure was placed on the backing metal by putting a weight on top of the cellular structure which, as before, had the direction of the nodal height H at 90° to the backplate. Braze alloy powder having the nominal chemical composition of 21% by weight Cr, 4.5% by weight W, 2.4% by weight B, 1.6% by weight Si, 0.1% by weight C, balance Co, was filled into the cells. This assembly was heated to a temperature of 1210° C. and held at that temperature for 2 minutes in a conventional vacuum furnace. This caused the braze filler metal to melt and rise up the double or nodal walls. The braze wicking result, determined as described in Example 1, was 96%.
Table 1 below gives a summary of braze wicking test results for direct comparison, the test samples having in common the same MCrAlY foil material, the same braze alloy and the same backing plate material.
TABLE I
Example No.
Cell Shape
Braze Wicking Result
4
b: w = 1; y: w = 1.16
84%
prior art
5
b: w = 1.52; y: w = 2.31
95%
as per present invention
6
b: w = 1.52; y: w = 2.31
100%
as per present invention
The ratio was measured to be 0.98 to 1.03 for the prior art structure according to Example 4 and the ratio was assessed to be 1.30 to 1.36 for the novel cellular structures according to Examples 5 and 6.
Table 2 below gives a summary of braze wicking results achieved using the same MCrAlY and using similar Co-base braze filler metals in different cell shapes.
TABLE 2
Example No.
Cell Shape
Braze Wicking Result
3
b: w = 1; y: w = 1.18
8%
prior art
7
b: w = 1.43; y: w = 2.40
96%
as per present invention
Table 3 gives an overview of all braze tests performed with the same MCrAlY alloy for direct comparison of different braze filler alloys on prior art cell shapes and tile cells of the present invention.
TABLE 3
Example
Braze Wicking
No.
Cell Shape
Braze Alloy
Braze Cycle
Result
2a
prior art
Ni—Cr—Si—C
1193° C./6 min
54%
2b
prior art
Ni—Cr—Si—C
1193° C./6 min
71%
3
prior art
Co—Cr—Ni—Si-W-B-C
1204° C./4 min
8%
4
prior art
Co—Cr—Ni—Si—W-B-C
1204° C./4 min
84%
5
per present invention
Co—Cr—Ni—Si-W-B-C
1204° C./4 min
95%
6
per present invention
Co—Cr—Ni—Si-W-B-C
1190° C./4 min
100%
7
per present invention
Co—Cr—W-B-Si—C
1210° C./2 min
96%
The above tables and examples demonstrate that good braze wicking, i.e. better than 95% when determined as described in Example 1, with good reinforcement and consequently good long term dimensional stability of the cellular structures, was achieved with the honeycomb cell shape according to the present invention. This is particularly evident by comparing the results of Example 3 to that of Example 7 and the results of Examples 2 and 4 to those of Examples 5 and 6. 100% braze wicking is achieved with conventional Ni-base alloys when prior art cell shapes are used However, with MCrAlY foil materials, braze wicking results of only 8 to 84% were achieved when using this standard cell shape.
All the cellular structures of Examples 5, 6 and 7 showed excellent shape stability and oxidation resistance when tested in air at temperatures higher than 850° C., and good resistance against carburization attack was observed when exposed to high speed burner gases also at temperatures higher than 850° C.
MCrAlY foil or sheet material having thick gauges advantageously can be formed into a honeycomb cellular structure according to the present invention as discussed in Examples 8 and 9 below with reference to FIG. 4 .
EXAMPLE 8
An MCrAlY alloy having the nominal chemical composition of 16% by weight Cr, 4.5% by weight Al, 3% by weight Fe, 0.1% maximum by weight Zr, 0.01% by weight Y, 0.7% by weight maximum Mn+Si, 0.05% by weight C, balance, apart from interstitial impurities, being Ni was provided in the form of thick foil having a thickness of s=0.254 mm (0.010″). This thick foil material was corrugated and welded to provide a cellular structure having outside dimensions of L=100 mm, B=38 mm and H=10 mm. The cell size characteristics of this cellular structure were: w=1.48 mm, b=2.44 mm, hence b/w=1.67, y=3.66 mm, m=1.46 mm and k=1.07 mm and hence m:k=1.36. The cellular structure shown in FIG. 4 could easily be manufactured in this special cell shape. All attempts to provide a cellular structure according to the prior art design, i.e. having a ratio of b:w=approx. 1, with values of b=w=1.0 to 2.0 mm, failed.
EXAMPLE 9
A conventional, non MCrAlY foil alloy, having the chemical composition of25% by weight Cr, 10% by weight Mo, 0.05% by weight C and 0.03% by weight Ce was provided in the form of thick foil having a gauge of 0.254 mm (0.010″). This foil material was corrugated and welded to provide a cellular structure body having outside dimensions as in Example 8. The cell shape characteristics were similar to those of Example 8, in particular the ratio b:w was greater than 1.15 and the ratio m:k was greater than 1. This cellular structure was fabricated. Again, all attempts to fabricate conventional hexagonal cell shape structural bodies from the aforementioned foil material failed when cell dimensions w=b=1.0 to 2.0 mm were envisaged.
It will be understood, of course. that modifications can be made in the embodiments of the invention illustrated and described herein without departing from the scope and purview of lie invention as defined by the appended claims. | An abradable turbine seal having a novel honeycomb cellular structure fabricated from metal foils or sheets showing good manufacturability, optimized brazeability and especially good structural integrity and oxidation resistance after brazing to metal support structures. MCrAlY (M=Ni, Fe, Co or combinations thereof) foil and sheet metals are particularly suitable to produce such a structure. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, in general, to fire alarms or the like for producing an alarm signal when the temperature within a house or the like rises past a certain degree.
2. Description of the Prior Art
Heretofore, various fire alarms and the like have been developed. See, for example, Guthrie, U.S. Pat. No. 598,508; De Froment, U.S. Pat. No. 643,491; Sitts, U.S. Pat. No. 662,032; Crutchfield, U.S. Pat. No. 910,118; and Edwards, U.S. Pat. No. 3,324,464. None of the above patents disclose or suggest the present invention.
SUMMARY OF THE INVENTION
The present invention is directed toward improving upon prior alarm means and the like. The concept of the present invention is to provide an alarm means in which a fusible link is utilized to cause an alarm signal to be produced when the ambient temperature at the fusible link rises above a certain degree.
The alarm means of the present invention comprises, in general, a body means including a first head portion, a second head portion, the first and second head portions being movable between open and closed positions and being electrically insulated relative to one another when in the open position, and urging means for normally urging the first and second head portions to a closed position; first electrical contact means for being positioned on the first head portion of the body means; second electrical contact means for being positioned on the second head portion of the body means and for electrically contacting the first electrical contact means when the first and second head portions are urged to the closed position; fusible means for being attached relative to the first and second head portions and for normally holding the first and second head portions in the open position to normally hold the first and second electrical contact means out of electrical contact with one another, the fusible means being rendered ineffective at a certain temperature to then allow first and second electrical contact means to electrically contact one another; and circuit means for being electrically coupled to the first and second electrical contact means and for producing an alarm signal if the first and second electrical contact means make electrical contact with one another.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a somewhat diagrammatic view of the alarm means of the present invention showing the head portions of the body means in the open position.
FIG. 2 is an enlarged sectional view of the first head portion of the body means of the alarm means of the present invention.
FIG. 3 is an enlarged sectional view substantially as taken on line III--III of FIG. 1.
FIG. 4 is a front view of the body means of the alarm means of the present invention showing the head portions in the closed position.
FIG. 5 is an enlarged sectional view substantially as taken on line V--V of FIG. 4.
FIG. 6 is an enlarged sectional view substantially as taken on line VI--VI of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The alarm means 11 of the present invention is adapted to produce an alarm signal when the temperature at a certain location rises to or above a certain degree. Thus, a preferred use of the alarm means 11 is to provide automatic fire protection to the occupants of a house, building or the like.
The alarm means 11 includes a body means 13. The body means 13 includes a first head portion 15 and a second head portion 17. The first and second head portions 15, 17 are movable between an open position as shown in FIG. 1 and a closed position as shown in FIG. 4, and are electrically insulated relative to one another when in the open position. The body means 13 additionally includes urging means 19 for normally urging the first and second head portions 15, 17 to the closed position. The body means 13 preferably includes a first body member 21 and a second body member 23. Each body member 21, 23 has a first end and a second end with the first end of the first body member 21 defining the first head portion 15 and with the first end of the second body member 23 defining the second head portion 17. The urging means 19 preferably includes a spring member 25 for pivotally joining the first and second body members 21, 23 to one another in such a manner that the first ends thereof are movable between open and closed positions and normally urged to the closed position. The first and second body members 21, 23 are preferably constructed of an electrically nonconductive material, such as wood, plastic or the like. Thus, the body means 13 may consist basically of a typical clothes pin or the like of a construction well-known to those skilled in the art.
The alarm means 13 includes a first electrical contact means 27 for being positioned on the first head portion 15 of the body means, and includes a second electrical contact means 29 for being positioned on the second head portion 17 (see FIG. 1) and for electrically contacting the first electrical contact 27 when the first and second head portions 15, 17 are urged to the closed position. The first electrical contact means 27 preferably includes first and second electrical contact members 31, 33 for being attached to the first head portion 15. Likewise, the second electrical contact means preferably includes first and second electrical contact members 35, 37 attached to the inner side of the second head portion 17. Each electrical contact member 31, 33, 35, 37 preferably consists of an electrically conductive plate member 38 constructed of any electrically conductive material, such as copper, aluminum or the like, and attached to the respective head portion 15, 17 in any manner apparent to those skilled in the art (see, in general, FIGS. 5 and 6). Additionally, each electrical contact member 31, 33, 35, 37 may include electrically conductive bolt means having a threaded rod 39 which extends through an aperture 41 in the head portions 15, 17 which is secured to the head portions 15, 17 by a nut 43 or the like for holding the respective plate member 38 to the body means 13 (see, in general, FIGS. 5 and 6). The head 44 of each bolt means may be positioned in an offset manner with respect to the head 44 of the bolt means of the opposing electrical contact member so as to insure a good electrical connection between each head 44 and the plate member 38 of the opposing electrical contact member when the head portions 15, 17 are in the closed position as clearly shown in FIGS. 5 and 6. Thus, the electrical contact members 31, 33, 35, 37 are positioned on the head portions 15, 17 of the body means 13 in such a manner that the first and second electrical contact members 31, 33 of the first electrical contact means 27 make electrical contact with respective first and second electrical contact members 35, 37 of the second electrical contact member 29 when the first and second head portions 15, 17 are in the closed position.
The alarm means 11 includes a fusible means 45 for being attached relative to the first and second head portions 15, 17 of the body means 13 and for normally holding the first and second head portions 15, 17 in the open position to normally hold the first and second electrical contact means 27, 29 out of electrical contact with one another (see FIG. 1). The fusible means 45 is adapted to be rendered ineffective at a certain temperature in holding the first and second head portions 15, 17 in the open position to then allow the first and second electrical contact means 27, 29 to electrically contact one another. The fusible means 45 preferably includes an elongated fusible link member 47 having a first end 49 and a second end 51 and having a first aperture 53 through the first end 49 and having a second aperture 55 through the second end 51 (see, in general, FIG. 3). Such fusible link members are well-known to those skilled in the art and available from various sources such as, for example. Elsie Manufacturing Co. located at Pine and Maple Streets, Waterloo, Indiana. Such fusible link members are Underwriters Laboratory approved and rated at various temperatures, such as, for example, 135 degrees, 160 degrees, 212 degrees Farenheit, etc. The specific construction and physical characteristics of such fusible link members will be apparent to those skilled in the art. Thus, it will be understood that the fusible link member 47 will be rendered ineffective in holding the head portions 15, 17 in the open position when exposed to a predetermined temperature. The fusible link member 47 may be attached relative to the head portions 15, 17 in any manner now apparent to those skilled in the art. Preferably, the alarm means 11 includes a first pin member 57 for being attached to and extending outwardly of the first head portion 15 and includes a second pin member 59 for being attached to and extending outwardly from the second head portion 17 (see, in general, FIGS. 1, 2 and 4). The fusible means 45 can then be attached between the first and second pin members 57, 59. Thus, the first and second apertures 53, 55 in the first and second ends 49, 51 of the fusible link member 47 may receive the first and second pin members 57, 59 and the force of the spring member 25 urging the head portions 15, 17 to the closed position also urges the first and second pin members 57, 59 against the sides of the first and second apertures 53, 55 respectively to hold the link member 47 relative to the head portions 15, 17. The apertures 53, 55 are spaced apart from one another a distance sufficient to hold the head portions 15, 17 in the open position when the first and second pin members 57, 59 are received in the first and second apertures 53, 55 respectively. The pin members 57, 59 may be of any construction now apparent to those skilled in the art. For example, the pin members 57, 59 may consist of standard nails, or the like, hammered or otherwise fixedly attached to the first ends of the body members 21, 23. The pin members 57, 59 may have slightly enlarged heads 57', 59' to aid in holding the fusible link member 47 thereon.
The alarm means 11 includes circuit means as shown in FIG. 1 for being electrically coupled to the first and second electrical contact means 27, 29 and for producing an alarm signal if the first and second electrical contact means 27, 29 make electrical contact with one another. Preferably, the circuit means includes a first circuit for being electrically coupled to the first electrical contact members 31, 35 of the first and second electrical contact means 27, 29 and a second circuit for being electrically coupled to the second electrical contact members 33, 37 of the first and second electrical contact means 27, 29. The alarm means 11 is preferably installed within a building having a typical light system 61 including one or more standard light members 63 for selectively lighting the interior and/or exterior of the building and the like. The first circuit of the circuit means is preferably electrically coupled to the light system 61 for producing a visible alarm signal when the first and second head portions 15, 17 of the body means 13 are in the closed position. The specific electrical pathway provided by the first circuit may vary in any manner now apparent to those skilled in the art. Thus, for example, a first electrically conductive wire 65 may extend from the electrical contact member 31 to one or more light members 63, a second electrically conductive wire member 67 may extend from light members 63 to a typical source of electrical energy 69, and a third electrically conductive wire 71 may extend from the source of electric energy 69 to the electrical contact member 35, thereby causing a closed electrical circuit to be provided between the light member 63 and source of electrical energy 69 when the first electrical contact members 31, 35 of the first and second electrical contact means 27, 29 electrically contact one another (i.e., when the head portions 15, 17 are in the closed position). The first and third electrically conductive wires 65, 71 may be electrically coupled to the electrical contact members 31, 35 in any manner now apparent to those skilled in the art. Thus, for example, the bolt means of each electrical contact member to the respective body member may act as a typical terminal in providing an electrical connection to the various electrical contact members.
The alarm means 11 is also preferably installed within a building having an audible entrance signaling system 73 including a typical doorbell mechanism 75 or the like and the second circuit of the circuit means is preferably electrically coupled to the audible entrance signaling system 73 for producing an audible alarm signal when the first and second head portions 15, 17 are in the closed position. The specific electrical pathway provided by the second circuit may vary in any manner now apparent to those skilled in the art. Thus, for example, the second circuit may include a first electrically conductive wire 77 extending between the second electrical contact member 33 of the first electrical contact means 27 and the doorbell mechanism 75, a second electrically conductive wire 79 extending between the doorbell mechanism 75 and the source of the electrical energy 69, and a third electrically conductive wire 81 extending from the source of electrical energy 69 and the second electrical contact member 37 of the second electrical contact means 29 to thereby provide a closed electrical circuit between the doorbell mechanism 75 and the source of electrical energy 69 when the second electrical contact members 33, 37 of the second electrical contact means 29 make electrical contact with one another (i.e., when the head portions 15, 17 are in the closed position). The first and third electrically conductive wires 77, 81 may be electrically coupled to the electrical contact members 33, 37 in any manner now apparent to those skilled in the art. Thus, for example, the bolt means of each electrical contact member to the respective body member may act as a typical terminal in providing an electrical connection to the various electrical contact members.
The alarm means 11 is preferably installed within the building with the first end of the first and second body members 21, 23 (i.e., the first and second head portions 15, 17) directed downwardly.
As thus constructed and used, the alarm means 11 provides an automatic fire protection and alarm to the occupants of a building. Thus, in the event of a fire or the like in a building in which the alarm means 11 is installed, once the ambient temperature adjacent the alarm means 11 reaches a certain degree, the fusible link means 47 will be rendered ineffective by melting or the like, thus allowing the head portions 15, 17 of the body means 13 to move to the closed position, thereby activating the light system 61 and audible entrance signaling system 73, or the like, thereby producing both visual and audible alarm signals and allowing the occupants of the building to safely depart the building.
Although the present invention has been directed and illustrated with respect to a preferred embodiment thereof and a preferred use therefore, the present invention is not to be so limited since changes and modifications can be made therein which are within the full intended scope of the invention. | First and second head portions are movably urged toward a closed position, a fusible link holding the head portions in an open position. Electrical contacts are mounted on the head portions for making electrical contact when the head portions are in the closed position to energize an electric circuit for producing an alarm signal (e.g., turning on the lights in the room and ringing the doorbell of the building) when the head portions are in the closed position. | 6 |
This application is based on application No.10-251995 filed in Japan on Aug. 22, 1998, the content of which incorporated hereinto by reference.
BACKGROUND OF THE INVENTION
This invention relates to a chroma key system which replaces background with a separately input image. A chroma key system is shown in FIG. 1. A chroma key system discriminates non-background, such as a human, from the background region of a picture input from a television camera 30 . The detected background is replaced by a replacement image separately input from a video tape recorder, a laser disk, or another television camera. Since background is replaced with a different image when a chroma key system is used, it finds use in various applications. For example, a superimposed image of a commentator in front of a country's weather map is possible, or the commentator's background can be made into an entirely different scenery.
Prior art chroma key systems discriminate background from non-background by establishing a specific color for the background. In these systems, regions of specified color are taken as background, and regions of color different from the background color are taken as non-background. This discriminates non-background from background. Almost without exception, prior art systems specify blue as the background color, and discriminate blue regions as background and regions that are not blue as non-background.
As described above, prior art chroma key systems which discriminate background from non-background, have the drawback that non-background regions with the same color as the background are mistakenly taken to be in the background. For example, if a non-background commentator wears a necktie with the same color as the background, the necktie will be mistakenly determined to be background. This has the drawback that the region of the commentator's necktie will be changed into the replacement image. To avoid this problem, prior art requires care that every part of the non-background is not the same color as the background. This has the drawback of putting restrictions on the color of the non-background. In actuality, it is difficult to always make every part of the non-background a different color than the background. This is because the type of subject captured by the camera as non-background is not predetermined.
Therefore, prior art chroma key systems have drawbacks such as mistaken detection of one part of non-background as background and input of another image into that part.
The present invention was developed with the object of solving these types of problems with prior art chroma key systems. Thus a primary object of the present invention is to provide a chroma key system which eliminates non-background color restrictions, and which can accurately discriminate background with the data necessary for image synthesis in the background region screen even, for example, if a map, etc. is displayed or the studio set is used in place of a screen.
The above and further objects and features of the invention will more fully be apparent from the following detailed description with accompanying drawings.
SUMMARY OF THE INVENTION
The chroma key system of the present invention discriminates background from non-background by color differences. Further, the chroma key system of the present invention does not use a background which always has the same color, but rather is characterized by changing the background color. The changing background color is determined to discriminate background from non-background. The chroma key system of the present invention does not discriminate unchanging color as background. Background is discriminated by changing color under specified conditions. Therefore, the probability of a region of non-background changing color according to the same specified conditions as the changing background color is, in actual practice, approximately equal to zero. Even in the hypothetical case where a non-background region changed color according to the same conditions as the background, background and non-background regions could be correctly discriminated by controlling color changing conditions to be different than that of the non-background.
This type of chroma key system has the characteristic that non-background color restrictions are eliminated and background can be reliably and accurately discriminated. Further, since background and non-background can be discriminated by varying or flashing light in the background region, the system is characterized by allowing information necessary for image synthesis to be displayed on a background screen. In addition, since background can be discriminated when it is varied or flashed according to specified conditions, the background region is not restricted to a screen. Therefore, the system has the characteristic that even the studio set can be used as background. This is because the chroma key system of the present invention does not specify a background color, but rather changes background color and discriminates change in color as background.
The chroma key system of the present invention changes background color by illuminating the background via background illumination equipment. The chroma key system of the present invention uses devices such as light emitting diodes (LED's), projection television, etc. either alone or in combination as background illumination equipment. Further, in the chroma key system of the present invention, the background may be a television monitor wherein background color is changed by the television monitor. An image display cathode ray tube monitor or an array of many LED's for full color image display can be used.
The chroma key system of the present invention is provided with background illumination equipment to provide light on the background, a television camera to capture non-background and background, and a background discrimination and swapping circuit to discriminate background from television camera output and replace background regions with a different replacement image. The background discrimination and swapping circuit controls the background illumination equipment to change background color, and discriminates the changing background color to distinguish background regions.
The background discrimination and swapping circuit of the chroma key system of the present invention is configured with a lighting/image control signal generation circuit, a lighting control circuit which changes background color by controlling background illumination equipment via a light control signal output from the lighting/image control signal generation circuit, and a key signal generation and image signal swapping circuit which discriminates background from a discrimination signal output from the lighting/image control signal generation circuit and from the image signal output from the television camera and replaces the background with a replacement image.
In the chroma key system of the present invention, the background illumination equipment may be a projection television. The lighting/image control signal generation circuit outputs a background image signal to the projection television as the light control signal. The key signal generation and image signal swapping circuit discriminates background from the background image signal and from the image signal output from the television camera and replaces the background with a replacement image.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a prior art chroma key system.
FIG. 2 is a block diagram showing an embodiment of the chroma key system of the present invention.
FIG. 3 is an oblique view showing an example of background illumination equipment to change background color.
FIG. 4 is an oblique view showing an example of background illumination equipment to change background color.
FIG. 5 is a graph showing a light control signal generated by the lighting/image control signal generation circuit.
FIG. 6 is a block diagram showing the key signal generation and image signal swapping circuit of the chroma key system shown in FIG. 2 .
FIG. 7 is a block diagram showing another embodiment of the key signal generation and image signal swapping circuit of the chroma key system shown in FIG. 2 .
FIG. 8 is a graph showing a comparison of the first frame and second frame image signals.
FIG. 9 is a block diagram showing another embodiment of the chroma key system of the present invention.
FIG. 10 is a block diagram showing still another embodiment of the chroma key system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The chroma key system shown in FIG. 2 is provided with background illumination equipment 2 to illuminate a white or colored screen background 1 and make the background a specified color, a television camera 3 to capture background 1 and non-background 9 subjects in front of the background, and a background discrimination and swapping circuit 4 to discriminate background 1 regions from television camera 3 output and input a different replacement image 20 into the background 1 regions.
The background illumination equipment 2 illuminates the screen 8 , which makes up the background 1 , and changes background color. The background illumination equipment 2 varies background 1 color by changing either screen 8 color hue, saturation, or brightness, or by changing these three and other elements in combination. Further, the background illumination equipment 2 can also change background color by combining a plurality of colors to make a compound color on the screen and changing that color's component color ratios. The background illumination equipment 2 may vary background color by blinking illumination on and off or by changing luminance. Background color can be changed by blinking or changing the luminance of one element of the background illumination equipment. Or, a plurality of background illumination equipment elements can be blinked or changed in luminance to change background color. Although all elements of background illumination equipment, which changes background color via a plurality of illumination elements, may be blinked on and off or changed in luminance, background color can be changed by blinking or changing the luminance of just some of the elements of the background illumination equipment.
The background illumination equipment 2 of FIG. 2 is provided with three types of LED's; red, green, and blue. Since LED's have fast response time, they are well suited for changing background color at high speeds. Further, background illumination equipment provided with red, green, and blue LED's can make the background white by simultaneous illumination by all LED's, and can change the background in full color by controlling the brightness of each LED.
Fast response time LED's are suitable variable background illumination equipment.
As shown in FIGS. 3 and 4, projection television can also be used as background illumination equipment to change background color. The projection television of FIG. 3 projects onto the front side of the background screen, and the projection television of FIG. 4 projects onto the back side of the background screen. Further, although not illustrated, the chroma key system of the present invention can also use a television monitor as the entire background and change background color via the television monitor. An image display cathode ray tube monitor or a full color LED display made up of an array of many LED's can be used as the television monitor. Projection television or a television monitor can change the entire background as a single color, change the background color with image information necessary for image synthesis, or change the background partially with different colors. In the chroma key system of the present invention, there is no requirement to make the entire background a single color. Background and non-background can be discriminated when parts of the background are made different colors. Background color can also be changed as motion images for projection television and television monitors.
The chroma key system of the present invention detects change in background color to determine the background region. A plurality of image frames are compared to determine whether or not the background color varies according to specified conditions. For example, if the television camera 3 captures 30 frames per second, the frame frequency is 30 Hz. In this case, if background color is changed with a period of {fraction (1/30)} th of a second, the background region can be determined from the changing background color by comparing adjacent frames. Consequently, the background illumination equipment ideally changes background color with a field frequency higher than the frame frequency.
In the chroma key system of the present invention, it is not always necessary to specify the frequency of background color change equal to the frame frequency. For example, images every 30 frames, or frames every one second interval can be compared to determine the background region from background color change. However, as the interval between comparison frames grows longer, cases occur where the border between background and non-background cannot be clearly determined. This occurs when non-background movement is faster than movement that can be captured in the time for variation or strobe of the background color. This drawback can be corrected for accurate discrimination of background and non-background images by performing vector detection of non-background image movement and comparison arithmetic processing of the background image changing according to specified conditions. This type of calculation is not performed for slowly moving non-background subjects, but rather background and non-background can be accurately discriminated even when the frequency of background color change is made slow similar to the non-background movement.
A variable frame frequency high speed camera or camera used in prior art chroma key systems can be used as the television camera 3 . However, the television camera is not restricted to one that directly outputs an image signal, and may be of the type that outputs an image recorded on a video tape recorder. Consequently, in this application, the term television camera has a wider meaning to include a video tape recorder which records the television camera image. The video tape recorder which records the television camera image also records along with it the signal specifying background color change.
The background discrimination and swapping circuit 4 is provided with a lighting/image control signal generation circuit 5 which generates a signal to change background color, a lighting control circuit 6 which changes background color by controlling background illumination equipment 2 via a light control signal output from the lighting/image control signal generation circuit 5 , a key signal generation and image signal swapping circuit 7 which discriminates background 1 by background color change and replaces the background 1 with a replacement image 20 , a variable delay circuit with frame synchronization 21 , and a synchronizing signal generator circuit 22 which generates a synchronizing signal to synchronize and drive the entire system.
The lighting/image control signal generation circuit 5 generates a light control signal to change background color at the frame frequency of the television camera 3 . For example, the lighting/image control signal generation circuit 5 outputs a light control signal synchronized with the vertical synchronizing signal output from the television camera 3 . Turning to FIG. 5, a light control signal is shown. The light control signal of this figure turns on LED's, which are the background illumination equipment, during the vertical retrace interval (vertical blanking interval) of the television camera 3 . Blue and red LED's, which are the background illumination equipment, turn on with a period of {fraction (1/30)} th of a second during the vertical retrace interval and turn off during periods of useful image scanning. The blue and red LED's are turned on alternately in sequence. As shown in FIG. 5, an apparatus which turns on LED's during the vertical retrace interval via a light control signal can easily discriminate background and non-background. This is because color emitted from LED's activated during the vertical retrace interval is stored and read out from the television camera's charge coupled device (CCD) or camera tube.
The television camera scans a single frame and outputs the image signal for one entire frame with a period of {fraction (1/30)} th of a second. During scanning, the output image signal does not output a color signal at a specific instant. A color signal accumulated during the period from the previous frame scan to the next frame scan is output. For example, if the background color is blue during the first frame scanning interval and red during the second frame scanning interval, an all red signal is not output as the image signal for the second frame background region. A compound color of first frame blue and second frame red is output as the background color image signal. In the image signal for the second frame, the beginning of the background is near blue and as the end of the background is approached, it becomes closer to red. The middle is a compound color of blue and red.
A chroma key system which pulses the background illumination equipment to evenly illuminate the background only during the vertical retrace interval can produce image signals with a single color for each frame. This is because color emitted by the background illumination equipment only during the vertical retrace interval is instantaneously stored as background by the television camera's CCD or camera tube. For example, when blue LED's are turned on only during the vertical retrace interval of the first frame, the background region of the first frame is stored as all blue, and successively scanned and output as a blue image signal. A chroma key system which turns on the background illumination equipment only during the vertical retrace interval does not change the background color within each frame. Therefore, background and non-background can be easily discriminated.
In the chroma key system of the present invention, the background illumination equipment may also be turned on at times other than during the vertical retrace interval, and may be turned on during the valid image scanning interval. In this case, background color is accumulated by the television camera's CCD or camera tube resulting in compound colors, and this must be considered to discriminate the background. Since the CCD or camera tube outputs a color signal accumulated during the scanning interval as the image signal, background color changes with scanning time. For example, in the case where the background illumination equipment switches between blue and red illumination at the frame rate, the time for the CCD or camera tube to accumulate the first frame background color and the second frame background color is different depending on location on the image. However, since the background color change characteristics are known, background and non-background can be discriminated accounting for those characteristics.
When the lighting/image control signal generation circuit 5 generates a light control signal to control background illumination equipment 2 LED's as shown in FIG. 5, LED color switches between blue and red. Under these conditions, images output from the television camera for each frame in succession (first frame, second frame, third frame, fourth frame . . . ) change in background color (blue, red, blue, red . . . ).
As described above, when the lighting/image control signal generation circuit 5 changes background color at the same frequency as the television camera 3 frame frequency, background 1 regions can be discriminated by the change in background color from frame to frame. However, as described in the section on background illumination equipment, the lighting/image control signal generation circuit does not necessarily have to change LED activation at the same frequency as the television camera frame frequency. Background color may also be changed at a frequency lower or higher than the television camera frame frequency.
The lighting/image control signal generation circuit 5 does not have to change background color between blue and red as shown in FIG. 5 . For example, background color may also be changed by flashing only blue LED's on and off while constantly illuminating the background with fixed background illumination equipment. Further, with the lighting control circuit 6 shown in FIG. 2, individual red, green, and blue background illumination equipment can be controlled in combination to produce any desired change in background color. A chroma key system which changes background color in this manner can store the changing background color in background memory 711 as shown in FIG. 7 . Background memory 711 stores, along with control data, a background image signal output from the television camera 73 when the television camera 73 captures background with non-background removed. The stored background image signal and signals required for lighting control are used by the calculation circuit 714 as signals for background image discrimination, and are used as well for required periodic lighting control.
The lighting control circuit 6 controls the background illumination equipment 2 to change background 1 color via the light control signal output from the lighting/image control signal generation circuit 5 . The lighting control circuit 6 contains switching elements 15 such as (bipolar) transistors or field effect transistors (FET's) and a switching circuit 16 to turn the switching elements 15 on and off according to the light control signal. As shown in FIG. 2, the lighting control circuit 6 which strobes the red, green, and blue LED's is provided with switching elements 15 for each of the red, green, and blue LED's. The switching elements 15 for the red LED's are connected in series between the LED power supply and the red LED's, and when the switching elements are turned on, red LED's in the background illumination equipment 2 are illuminated. The switching elements for the green LED's are connected in series between the power supply and the green LED's, and when they are turned on, green LED's are illuminated. Similarly, the switching elements for the blue LED's are connected in series between the power supply and the blue LED's, and when they are turned on, blue LED's are illuminated.
If the light control signal shown in FIG. 5 is input to the switching circuit 16 , blue LED switching elements are turned on by positive pulse signals and red LED switching elements are turned on by negative pulse signals. A device which controls three or more pieces of background illumination equipment determines which piece of background illumination equipment to turn on by the light control signal voltage level or pulse width. Or, the brightness of the background illumination equipment turned on may also be controlled by the light control signal voltage level.
The lighting control circuit 6 of FIG. 2 strobes the red LED's, the green LED's, and the blue LED's on and off. However, a lighting control circuit to strobe only a single color of background illumination equipment, such as blue LED's only, need only control switching elements connected to the related background illumination equipment. Therefore, a lighting control circuit, which strobes only background illumination equipment of a single color, has the characteristic that its circuit can be simple.
The key signal generation and image signal swapping circuit 7 discriminates background region with discrimination signal output from the lighting/image control signal generation circuit 5 and image signal input from the television camera 3 , and replaces the background region with a separately input replacement image 20 . The key signal generation and image signal swapping circuit 7 is provided with a transfer switch 10 to switch between the television camera 3 image signal and the replacement image signal.
As shown in FIG. 6, the transfer switch 10 has its common or output side connected to output terminal 17 , one of its two input terminals 18 connected to the television camera 3 , and the other input terminal 18 connected to a device such as a video tape recorder (VTR) 19 to replace the background. The transfer switch 10 switches between the television camera 3 image signal and the VTR 19 or other device replacement image 20 . When the television camera 3 outputs an image signal which is background signal, the transfer switch 10 is switched to the position shown by the broken line of FIG. 6, and the replacement image 20 is output. When the television camera 3 image signal is non-background signal, the transfer switch 10 is switched to the position shown by the solid line of FIG. 6, and the television camera 3 image signal is output. Consequently, the image signal from the television camera 3 is switched to output a signal with the background signal replaced by the replacement image 20 .
In FIG. 2, the transfer switch 10 is shown by an arrow symbol to allow circuit operation to be easily understood. In reality, a high speed switching element such as a transistor or FET is used as the transfer switch 10 .
The transfer switch 10 is switched by detection of the background region through color change. The key signal generation and image signal swapping circuit of FIG. 6 is provided with an analog to digital converter (A/D converter) 13 to convert the analog image signal output from the television camera 3 to a digital signal, a delay circuit 12 to delay and sequentially output frame data sequentially output from the A/D converter 13 by a delay time equivalent to one frame, a calculation circuit 14 to discriminate the background region of the image signal from the signal output from the delay circuit 12 and A/D converter 13 and from the discrimination signal input from the lighting/image control signal generation circuit 5 , and a variable delay circuit 21 to delay the image signal output from the A/D converter 13 by a time delay corresponding to the time required for the calculation circuit 14 to discriminate between background and non-background. The variable delay circuit 21 is a variable delay circuit with frame synchronization to synchronize its output with the replacement image signal.
In the following embodiments, system elements which are the same as for previously described embodiments are labeled by similar numbers, wherein a “7” has been added as a left most digit in each of the numbers for FIG. 7, wherein a “9” has been added as a left most digit for each of the numbers for FIG. 9, and wherein “10” has been added as the two left most digits for each of the numbers for FIG. 10 .
In other words, as shown in FIG. 7, the transfer switch 710 has its common or output side connected to output terminal 717 , one of its two input terminals 718 connected to the television camera 73 , and the other input terminal 718 connected to a device such a video tape recorder (VTR) 719 to replace the background. The transfer switch 710 switches between the television camera 73 image signal the VTR 719 or other device replacement image 720 .
As shown in FIG. 9, the transfer switch 910 has its common or outside connected to output terminal 917 , one of its two input terminals 918 connected to the television camera 93 , and the other input terminal 918 connected to a device such a video tape recorder (VTR) 719 to replace the background. The transfer switch 910 switches between the television camera 93 image signal the VTR 919 or other device replacement image 920 . Variable delay circuit 921 delays the image signal output from the A/C converter 913 by a time delay corresponding to the time required for the calculation circuits 914 to discriminate between background and non-background.
As shown in FIG. 10, the transfer switch 1010 has its common or output side connected to output terminal 1017 , one of its two input terminals 1018 connected to the television camera 103 , and the other input terminal 1018 connected to a device such a video tape recorder (VTR) 1019 to replace the background. The transfer switch 1010 switches between the television camera 103 image signal the VTR 1019 or other device replacement image 1020 . Variable delay circuit 1021 delays the image signal output from the A/C converter 1013 by a time delay corresponding to the time required for the calculation circuits 1014 to discriminate between background and non-background.
The key signal generation and image signal swapping circuit of FIG. 7 is provided with background memory 711 for storing background color as an image signal. The background memory 711 stores from one to a plurality of frames worth of image signal output from the A/D converter 713 , where such an image signal has no non-background. To store an image signal with no non-background in background memory 711 , the television camera 73 captures the background with the non-background removed. As a minimum, background memory 711 stores one frame of image signal with no non-background. The background memory 711 of FIG. 7 stores two frames of background image signal. Background memory 711 storage time is preferably one period of the light control signal issued from the lighting/image control signal generation circuit 75 , which corresponds to the frame rate of background and non-background that can be discriminated by the calculation circuit 714 . When the lighting/image control signal generation circuit 75 changes background color at a frequency of fHz, storage time of the background memory 711 is made 1/f second. For example, when the frame frequency for changing background color is 30 Hz and background color is switched alternately between red and blue, one period of the light control signal is {fraction (2/30)}th of a second. In this case, background memory is {fraction (2/30)}th of a second and two frames of image signal are stored as background. When the frame frequency for changing background color is 30 Hz and background color is switched alternately between the three colors, red, green, and blue, one period of the light control signal is {fraction (3/30)}th of a second, background memory is {fraction (3/30)}th of a second, and three frames of image signal are stored as background. However, it is not always necessary for the background memory to store a plurality of frames of background image signal. This is because the calculation circuit can determine background from one frame of background image signal stored in background memory and the discrimination signal.
A system, which A/D converts an image signal with no non-background from the television camera and stores it in background memory as a background image signal, inputs a background image signal into background memory from the television camera. The television camera, which inputs an image signal with no non-background into background memory, captures a scene with background only, that is with no non-background, and outputs that image signal. The image signal from the television camera is input and stored in background memory as a background image signal. The calculation circuit discriminates a signal, which is the same as the background image signal stored in background memory, as background, and thus determines the background regions of an image signal captured by the television camera that includes non-background. In this type of chroma key system, a screen does not need to be used in the background, the existing background in the studio can be used as is, and the background regions can be determined by changing background color with the background illumination equipment. This is because the existing studio background with no non-background can be input from the television camera directly into background memory as a background image signal. Consequently, this chroma key system can discriminate background from non-background for a television camera image signal taken with existing studio or other unaltered background without requiring any special conditions for the background.
Background memory 711 stores an A/D converted image signal and a synchronizing signal output from the television camera 73 as a background image signal. Background memory 711 is synchronized with the light control signal output from the lighting/image control signal generation circuit 75 and stores an image signal with no non-background input from the television camera along with required control signals. Background memory 711 is synchronized with the light control signal, and the light control signal changes background color by controlling the background illumination equipment. The changing background color is captured by the television camera 73 and stored sequentially as background image signal. The light control signal synchronized background image signals stored in background memory are read out as signals necessary for control and discrimination and are output to the lighting/image control signal generation circuit 75 and calculation circuit 714 .
A chroma key system, which has a plurality of frames of background image signal stored in background memory, can randomly output that plurality of stored frames of background image signal to the lighting/image control signal generation circuit to change the order of background color change via the background image signal stored in background memory. For example, a background memory storing three frames of background image signal does not need to output a background image signal to the calculation circuit and lighting/image control signal generation circuit with a frame order 1, 2, 3, but rather it can output a background image signal to the lighting/image control signal generation circuit with frame orders such as 1, 3, 2, or 3, 2, 1. The lighting/image control signal generation circuit controls the lighting control circuit with the background image signal input from background memory and changes background color according to the background color stored in background memory.
A chroma key system, which changes background color by randomly controlling the order of a plurality of frames of background image signal stored in background memory, has the characteristic that background and non-background can be more accurately discriminated when non-background changes in the same order as background color.
The delay circuit 12 time delays the signal output from the A/D converter 13 by a time corresponding to one frame. For example, when the television camera 3 frame frequency is 30 Hz thereby outputting 30 frames per second and background color changes every frame, the delay circuit 12 adds a time delay of {fraction (1/30)} th of a second corresponding to the time for one frame. In the case of a different television system standard, a time delay corresponding to the time for one frame in that system is implemented.
The calculation circuit 14 of FIG. 6 performs calculations on two frames of image signal from the input side and the output side of the delay circuit 12 and on the discrimination signal from the lighting/image control signal generation circuit 5 to determine whether the signal is background. The calculation circuit 714 of FIG. 7 performs calculations on two frames of image signal from the input side and the output side of the delay circuit 712 , on the discrimination signal from the lighting/image control signal generation circuit 75 , and on the background image signal from background memory 711 to determine background region. For example, when the lighting/image control signal generation circuit 5 makes the first frame background color blue, the second frame background color red, and alternately switches from blue to red as shown in FIG. 5, the key signal generation and image signal swapping circuit of FIG. 6 detects background 1 regions by color change according the following operation.
(1) The television camera 3 outputs the first frame, the second frame, and the third frame etc. of image signal in sequence. An analog image signal output from the television camera 3 is converted to a digital signal by the A/D converter 13 .
(2) The converted digital image signal for the first frame is input to the delay circuit 12 and the variable delay circuit 21 .
(3) The delay circuit 12 time delays the first frame of image signal by one frame. The variable delay circuit 21 delays the first frame of image signal by the time for the calculation circuit 14 perform calculations and switch the transfer switch 10 .
(4) Image signals from the input side and the output side of the delay circuit 12 are input to the calculation circuit 14 . When the image signal output from the delay circuit 12 into the calculation circuit 14 is the first frame image signal, the image signal, which bypasses the delay circuit 12 and is directly input into the calculation circuit 14 from the A/D converter 13 , is the second frame image signal. The first frame and second frame image signals are synchronized and input to the calculation circuit 14 .
(5) Under these circumstances, the first frame image signal and second frame image signal are synchronized and input to the calculation circuit 14 as shown in FIG. 8 . Then the first frame image signal blue regions and the second frame image signal red regions are the same as the background colors and are recognized as background regions.
(6) When the calculation circuit 14 determines the image signal to be background signal, the transfer switch 10 is switched to the broken line position and a replacement image from a VTR or other source is output in place of the background. When the calculation circuit 14 determines the image signal to be non-background signal, the transfer switch 10 is put in the solid line position and the television camera 3 image signal is output.
The key signal generation and image signal swapping circuit of FIG. 7 detects background regions by the changing background color according the following operation.
(1) The television camera 73 captures the background with no non-background in the picture and outputs the first frame, the second frame, and the third frame etc. of image signal in sequence. An analog image signal output from the television camera 73 is converted to a digital signal by the A/D converter 713 .
(2) The converted digital image signals for the first frame and second frame are stored in the background memory 711 as background image signals. Since the lighting/image control signal generation circuit 75 alternately switches background lighting from blue to red, the background image signals input to the background memory 711 from the television camera 73 are blue for the first frame and red for the second frame.
(3) After the background image signals have been stored in background memory 711 , the television camera 73 now captures both background and no non-background and outputs the first frame, the second frame, and the third frame etc. of image signal in sequence. The analog image signal output from the television camera 73 is converted to a digital signal by the A/D converter 713 and input to the delay circuit 712 and the variable delay circuit 721 .
(4) The delay circuit 712 time delays the first frame of image signal by one frame. The variable delay circuit 721 delays the first frame of image signal by the time for the calculation circuit 714 perform calculations and switch the transfer switch 710 .
(5) Image signals from the input side and the output side of the delay circuit 712 are input to the calculation circuit 714 . When the image signal output from the delay circuit 712 into the calculation circuit 714 is the first frame image signal, the image signal, which bypasses the delay circuit 712 and is directly input into the calculation circuit 714 from the A/D converter 713 , is the second frame image signal. The first frame and second frame image signals are synchronized and input to the calculation circuit 714 . The background image signal from the background memory 711 is synchronized with the light control signal and input to the calculation circuit 714 .
(6) Under these circumstances, the first frame image signal and second frame image signal are input to the calculation circuit 714 as shown in FIG. 8 . In addition, the background image signals stored in the background memory 711 and the discrimination signals from the lighting/image control signal generation circuit 75 are synchronized with the image signals and input to the calculation circuit 714 . The calculation circuit 714 determines from the background image signals that blue regions in first frame image signal and red regions in the second frame image signal are the same as the background colors and recognizes those regions as background.
(7) When the calculation circuit 714 determines the image signal to be background signal, the transfer switch 710 is switched to the broken line position and a replacement image from a VTR or other source is output in place of the background. When the calculation circuit 714 determines the image signal to be non-background signal, the transfer switch 710 is put in the solid line position and the television camera 73 image signal is output.
In the calculation circuit 714 described above, when the first and second frame image signal are compared, background 1 is discriminated when the first frame image signal is blue and the second frame image signal is red. Continuing, when the second frame image signal and third frame image signal are input, background 1 is discriminated when the second frame image signal is red and the third frame image signal is blue. To determine image signal background color, the discrimination signal is input from the lighting/image control signal generation circuit 75 or a signal is input from the background memory 711 to the calculation circuit 714 . In other words, the discrimination signal from the lighting/image control signal generation circuit 75 and the background image signal from the background memory 711 are signals input to the calculation circuit 714 to determine the background color of each frame.
The calculation circuit requires calculation time to input adjacent frames of image signal and calculate background and non-background regions of the input image signals. For example, if the time to calculate background and non-background for the first and second frames of image signal input to the calculation circuit 14 , 714 of FIGS. 6 and 7 is 10 msec, the variable delay circuit 21 , 721 delays its signal for input to the transfer switch 710 by one image signal frame plus 10 msec. The variable delay circuit 21 , 721 compensates for the calculation time of the calculation circuit 14 , 714 . Consequently, the image signal output from the variable delay circuit 21 , 721 is synchronized with the timing of the calculation circuit 714 switching the transfer switch 10 , 710 between background and non-background.
The chroma key system described above shows a specific example of a system that switches background color between blue and red at the frame frequency. This type of chroma key system has the characteristic that background can be discriminated with simple circuitry. However, the chroma key system of the present invention is not restricted to a system that changes background color between two colors. Background color can also be switched between three or more colors such as red, green, and blue, etc. A chroma key system that changes background color to three or more colors can discriminate background more accurately. This system is provided with two delay circuits 912 , 1012 as shown in FIGS. 9 and 10. Three frames of image signal, the discrimination signal, and the background image signal from background memory 1011 are input to the calculation circuit 1014 . As illustrated in FIG. 9, the calculation circuit 914 inputs the discrimination signal from the lighting/image control signal generation circuit 95 to discriminate background for the three frames of image signal and switch the transfer switch 910 . As illustrated in FIG. 10, the calculation circuit 1014 inputs the discrimination signal from the lighting/image control signal generation circuit 105 , or the background image signal from the background memory 1011 , or both to discriminate background for the three frames of image signal and switch the transfer switch 1010 .
The chroma key system described above discriminates background and non-background by the background color of each frame, where the background color of each frame is a single color. In the chroma key system of the present invention, the color of the entire background of each frame does not always have to be a single color. Background and non-background can be discriminated with different colors for different regions of the background. In a chroma key system with different colored regions of background, light sources which illuminate different regions of the background with different colors and changes those colors, a projection television, or a television monitor can be used as background illumination equipment. A projection television or television monitor uses the light control signal output from the lighting/image control signal generation circuit, which is the background image signal, for display on the background screen or monitor as changing background colors. The projection screen or television monitor displays an image which is a single color, or one with different background color in different regions. Further, the displayed background colors are colors which change. A replacement image signal may also be used as the background image signal, or it can be processed.
Since background color changes in different regions of a single image signal frame for this type of chroma key system, the lighting/image control signal generation circuit outputs a background image signal as the light control signal input to the projection television or television monitor. The projection television or television monitor, which inputs the background image signal, is captured by the television camera with no non-background, and the television camera output is stored as background image signal in the background memory. The background image signal stored in background memory is synchronized with the image signal from the television camera and input to the calculation circuit.
The calculation circuit inputs background image signal from the background memory to determine changing background color in each frame of image signal and discriminate background. When the calculation circuit determines from the frame background image signal that the input signal is background, it switches the transfer switch to replace the image signal from the television camera with a replacement image signal.
Since the chroma key system described above converts the image signal to a digital signal and switches the transfer switch, the replacement image signal is also converted to a digital signal and passed through a variable delay circuit with frame synchronization into the transfer switch. The output of the transfer switch is converted to an analog signal by a digital to analog (D/A) converter and then output. However, the output from the transfer switch may also be output directly as a digital signal.
In the chroma key system shown in FIGS. 6 and 7, the image signal which bypasses the delay circuit 12 , 712 is input to the transfer switch 10 , 710 after time delay by the variable delay circuit 21 , 721 . However, in the chroma key system of the present invention, the image signal may also be input to the transfer switch through the variable time delay circuit and after passing through the time delay circuit.
Finally, although the embodiments of the chroma key system described above change background color every frame, background color may also be changed repeatedly after a plurality of frames. A chroma key system, which changes background color repeatedly after a plurality of frames, stores image signals for changing or flashing background color, in a contiguous fashion along with lighting/image control signal generation circuit 75 control signals in T seconds worth of background memory.
As this invention may be embodied in several forms without departing from the spirit 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 the meets and bounds of the claims or equivalence of such meets and bounds thereof are therefore intended to be embraced by the claims. | The chroma key system discriminates background and non-background by color difference. Further, the chroma key system changes background color by illuminating the background via background illumination equipment, discriminates the changing background color as background, and thereby discriminates background from non-background. The chroma key system comprises a lighted control circuit operable to control the background illumination equipment so as to provide a color changeable illumination to the background, and a background discriminating and swapping circuit operable to discriminate the subject from the background using information within an image signal based on the color changeable illumination of the background. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 07/959,070 filed Oct. 9, 1992, now U.S. Pat. No. 5,316,747 entitled "Method And Apparatus For The Selective Oxidation Of Carbon Monoxide In A Hydrogen-Containing Gas Mixture." The '070 application, incorporated herein by reference in its entirety, describes the selective oxidation of carbon monoxide present in a mixture of gases, including hydrogen, to carbon dioxide by introducing oxygen or an oxygen-containing gas mixture at locations along the latter portion of the reaction chamber of an isothermal reactor.
FIELD OF THE INVENTION
The present invention relates to the treatment of the reactant gas streams of electrochemical fuel cells. More particularly, the present invention relates to a method and apparatus for oxidizing the carbon monoxide present in the incoming reactant fuel stream and/or the carbon monoxide produced by the reverse water shift reaction in the reactant stream of an electrochemical fuel cell.
BACKGROUND OF THE INVENTION
Electrochemical fuel cells convert fuel and oxidant to electricity and reaction product. In electrochemical fuel cells employing hydrogen as the fuel and oxygen as the oxidant, the reaction product is water. Such fuel cells generally employ a membrane electrode assembly ("MEA") consisting of a solid polymer electrolyte or ion exchange membrane disposed between two electrodes formed of porous, electrically conductive sheet material, typically carbon fiber paper. The MEA contains a layer of catalyst, typically in the form of finely comminuted platinum, at each membrane/electrode interface to induce the desired electrochemical reaction. The electrodes are electrically coupled to provide a path for conducting electrons between the electrodes through an external load.
At the anode, the fuel permeates the porous electrode material and reacts at the catalyst layer to form cations, which migrate through the membrane to the cathode. At the cathode, the oxygen-containing gas supply reacts at the catalyst layer to form anions. The anions formed at the cathode react with the cations to complete the electrochemical reaction and form a reaction product.
In electrochemical fuel cells employing hydrogen as the fuel and oxygen-containing air (or substantially pure oxygen) as the oxidant, the catalyzed reaction at the anode produces hydrogen cations (protons) from the fuel supply. The ion exchange membrane facilitates the migration of hydrogen ions from the anode to the cathode. In addition to conducting hydrogen ions, the membrane isolates the hydrogen-containing fuel stream from the oxygen-containing oxidant stream. At the cathode, oxygen reacts at the catalyst layer to form anions. The anions formed at the cathode react with the hydrogen ions that have crossed the membrane to complete the electrochemical reaction and form liquid water as the reaction product.
In conventional fuel cells, the MEA is interposed between two fluid-impermeable, electrically conductive plates, commonly referred to as the anode and the cathode plates, respectively. The plates are typically formed from graphite, a graphite composite such as graphite/epoxy, but can also be formed from other suitable electrically conductive materials. The plates serve as current collectors, provide structural support for the porous, electrically conductive electrodes, provide means for carrying the fuel and oxidant to the anode and cathode, respectively, and provide means for removing water formed during operation of the fuel cell. When the channels are formed in the anode and cathode plates, the plates are referred to as fluid flow field plates. When the anode and cathode plates overlay channels formed in the anode and cathode porous material, the plates are referred to as separator plates.
Reactant feed manifolds are generally formed in the anode and cathode plates, as well as in the MEA, to direct the fuel (typically a substantially pure hydrogen gas stream or hydrogen-containing reformate gas stream from the conversion of hydrocarbons such as methanol or natural gas) to the anode and the oxidant (typically substantially pure oxygen or oxygen-containing gas) to the cathode via the channels formed in either the fluid flow field plates or the electrodes themselves. Exhaust manifolds are also generally formed in the anode and cathode plates, as well as the MEA, to direct the unreacted components of the fuel and oxidant streams, as well as water accumulated at the cathode, from the fuel cell.
Multiple fuel cell assemblies comprising two or more anode plate/MEA/cathode plate combinations, referred to as a fuel cell stack, can be connected together in series (or in parallel) to increase the overall power output as required. In such stack arrangements, the cells are most often connected in series, wherein one side of a given fluid flow field or separator plate is the anode plate for one cell, the other side of the plate is the cathode plate for the adjacent cell, and so on.
Perfluorosulfonic ion exchange membranes, such as those sold by DuPont under its NAFION trade designation, have been used effectively in electrochemical fuel cells. Fuel cells employing Perfluorosulfonic cation exchange membranes require accumulated water to be removed from the cathode (oxidant) side, both as a result of the water transported across the membrane with cations and product water formed at the cathode from the electrochemical reaction of hydrogen cations with oxygen. An experimental perfluorosulfonic ion exchange membrane, sold by Dow Chemical Company under the trade designation XUS 13204.10, appears to have significantly less water transported with hydrogen cations across the membrane. Fuel cells employing the Dow experimental membrane thus tend to accumulate less on the cathode (oxidant) side, as the accumulated water at the cathode is essentially limited to product water formed from the electrochemical reaction of hydrogen and oxygen.
Recently, efforts have been devoted to identifying ways to operate electrochemical fuel cells using other than pure hydrogen as the fuel. Fuel cell systems operating on pure hydrogen are generally disadvantageous because of the expense of producing and storing pure hydrogen gas. In addition, the use of liquid fuels is preferable to pure, bottled hydrogen in mobile and vehicular applications of electrochemical fuel cells.
Recent efforts have focused on the use of an impure hydrogen fuel stream obtained from the chemical conversion of hydrocarbon fuels to hydrogen and carbon byproducts. However, to be useful for fuel cells and other similar hydrogen-based chemical applications, hydrocarbon fuels must be efficiently converted to relatively pure hydrogen with a minimal amount of undesirable chemical byproducts, such as carbon monoxide.
Conversion of hydrocarbons to hydrogen is generally accomplished through the steam reformation of a hydrocarbon such as methanol in a reactor sometimes referred to as a reformer. The hydrogen-containing stream exiting the reformer is generally referred to as the reformate stream. The steam reformation of methanol is represented by the following chemical equation:
CH.sub.3 OH+H.sub.2 O+heat⃡3H.sub.2 +CO.sub.2 ( 1)
Due to competing reactions, the initial gaseous mixture produced by steam reformation of methanol typically contains about 65% to about 75% hydrogen, about 10% to about 25% carbon dioxide, as well as from about 0.5% to about 20% by volume of CO, all on a dry basis (in addition, water vapor can be present in the gas stream). The initial gas mixture produced by the steam reformer can be further processed by a shift reactor (sometimes called a shift converter) to reduce the CO content to about 0.2%-2% by volume, on a dry basis. The catalyzed reaction occurring in the shift converter is represented by the following chemical equation:
CO+H.sub.2 O⃡CO.sub.2 +H.sub.2 ( 2)
Even after a combination of steam reformer/shift converter processing, the product gas mixture will have minor amounts of CO and various hydrocarbon species, typically about 5% or less by volume, on a dry basis, of the total product mixture.
In low-temperature, hydrogen-based fuel cell applications, the presence of CO in the inlet fuel stream, even at the 0.1% to 1% level, is generally unacceptable. In solid polymer electrolyte fuel cells, the electrochemical reaction is typically catalyzed by an active catalytic material comprising a noble metal such as platinum. Carbon monoxide adsorbs preferentially to the surface of platinum, particularly at temperatures below about 150° C., effectively poisoning the catalyst, and significantly reducing the efficiency of the desired electrochemical hydrogen oxidation reaction. A steam reformer/shift converter process can be used to reduce the amount of CO in the hydrogen-containing reformate gas stream to less than about 100 parts per million (ppm). In order to employ such a CO-containing reformate stream as the fuel stream for a fuel cell, the fuel cell must first be able to handle (i.e., the catalyst present in the MEAs cannot be poisoned by) the CO present in the reformate stream. In addition to the CO content of the reformate stream, CO can also be produced in the fuel cell by the reverse water shift reaction:
CO.sub.2 +H.sub.2 ⃡CO+H.sub.2 O (3)
In typical reformate fuel streams, the equilibrium concentration of CO from this reaction is about 100 ppm near room temperature.
The present method and apparatus oxidizes the carbon monoxide present in the incoming reactant stream of a fuel cell and/or produced by the reverse water shift reaction (reaction (3) above). The oxidation of carbon monoxide is particularly important where the electrocatalyst promotes the reverse water shift reaction, as is the case with platinum-containing catalysts.
Watkins et al. Canadian Patent No. 1,305,212 entitled "Method for Operating a Fuel Cell on Carbon Monoxide Containing Fuel Gas" discloses the oxidation of carbon monoxide present in a fuel gas introduced to a low-temperature, solid polymer electrolyte fuel cell which employs a noble metal catalyst, such as platinum, rhodium or ruthenium, in the anode. The method involves (a) reacting the fuel gas with an oxygen-containing gas, (b) contacting the resulting fuel gas mixture with a suitable catalyst to selectively convert carbon monoxide to carbon dioxide and thereby reduce carbon monoxide levels in the fuel gas to trace amounts, and (c) feeding the resulting substantially carbon monoxide-free fuel gas to the fuel cell.
Gottesfeld U.S. Pat. No. 4,910,099 entitled "Preventing CO Poisoning In Fuel Cells" discloses the injection of oxygen (O 2 ) into the fuel stream, before introducing the fuel stream to the fuel cell, in order to remove CO present in the reformate fuel stream fed to the fuel cell. The oxygen so injected is in the form of either substantially pure O 2 or oxygen-containing air.
Watkins' selective oxidation of carbon monoxide to carbon dioxide and Gottesfeld's injection of oxygen into the reformate fuel stream prior to introducing the fuel stream to the fuel cell, both effectively remove CO initially present in the fuel stream. However, the removal of CO upstream of the fuel cell will not affect the further production of CO within the reactant fuel stream of the fuel cell by the reverse water shift reaction. In this regard, the removal of CO from the fuel stream by selective oxidation and/or the initial injection of oxygen, will promote the production of CO by the reverse water shift reaction to produce CO (i.e., reaction (3) above will be driven to the right) because of the substantial presence of carbon dioxide and hydrogen in the fuel stream, as well as the presence of the platinum electrocatalyst in the fuel cell. In order to effectively remove CO produced in the reactant stream of the fuel cell, oxidant (either substantially pure oxygen or oxygen-containing air) should be introduced, preferably in a substantially uniform manner, across the active area of the fuel cell in which electrocatalyst is present. The uniform introduction of oxidant is particularly effective for fuel cell designs having large active areas and in which the residence time of the reformate stream in the fuel cell is prolonged.
Even in the absence of the reverse water shift reaction, the uniform introduction and distribution of oxygen across the active area of the fuel cell is advantageous. In this regard, the even introduction and distribution of O 2 across the active area of the fuel cell promotes the maintenance of a uniform temperature profile across the active area by preventing temperature increases from the oxidation reactions (reactions (1) and (2) above). A uniform temperature profile in turn prevents the localized heating and sintering of the catalyst. Catalyst sintering can reduce the surface area of the catalyst, inhibit the mass transport through the catalyst, and lower the porosity of the catalyst, thereby diminishing the ability of the catalyst to promote the desired electrochemical reactions in the fuel cell. Thus, the uniform introduction and distribution of oxygen into the active area of the fuel cell not only effects the oxidation of carbon monoxide, but also maintains an advantageous uniform temperature profile across the active area.
Accordingly, it is an object of the present invention to provide a method and apparatus for reducing the concentration of carbon monoxide in a hydrogen-containing gas mixture so as to render the mixture suitable for use as the fuel stream for electrochemical fuel cells, and for other applications employing catalysts that would be adversely affected by higher carbon monoxide concentrations.
It is also an object of the invention to provide a method and apparatus for the oxidation of carbon monoxide to carbon dioxide in a reactant stream within an electrochemical fuel cell.
Another object of the invention is to provide an apparatus and a method for the oxidation of carbon monoxide, produced by the reverse water-shift reaction in a hydrogen-containing reformate gas mixture, by introducing oxygen or an oxygen-containing gas mixture at locations along the reaction pathway within a fuel cell.
A further object of the invention is to provide a method and apparatus for the oxidation of carbon monoxide in a hydrogen-containing reformate gas mixture by introducing oxygen or an oxygen-containing gas mixture at various locations along the reaction pathway in the active area of a fuel cell.
A still further object of the invention is to provide a method and apparatus for the uniform introduction and distribution of oxygen or an oxygen-containing gas mixture into the active area of the fuel cell to maintain a uniform temperature profile across the active area.
SUMMARY OF THE INVENTION
The above and other objects are achieved by a method and apparatus for oxidizing carbon monoxide in the reactant stream, particularly the fuel stream, of an electrochemical fuel cell. In a first embodiment of the method, carbon monoxide is oxidized to carbon dioxide, where the carbon monoxide is present in a reactant stream of an electrochemical fuel cell. The fuel cell has a reactant stream inlet and a reactant stream outlet, and the reactant stream comprises hydrogen, carbon dioxide and, optionally, carbon monoxide. The method comprises:
introducing a first oxygen-containing gas stream into the reactant stream through a first port disposed between the reactant stream inlet and the reactant stream outlet;
contacting the reactant stream including the first oxygen-containing gas stream with catalyst present in the fuel cell, such that the catalyst promotes the oxidation of carbon monoxide to carbon dioxide;
introducing a further oxygen-containing gas stream into the reactant stream through at least one secondary port located between the first port and the reactant stream outlet; and
further contacting the reactant stream including the further oxygen-containing gas stream with the catalyst present in the fuel cell, such that the catalyst further promotes the oxidation of carbon monoxide to carbon dioxide.
The catalyst is preferably present in the electrochemically active section of the fuel cell, but can also be disposed in portions of the fuel cell other than the electrochemically active area, such as the reactant manifolds or the optional humidification section when integral with the fuel cell stack.
In a second embodiment of the method, carbon monoxide produced by the reverse water-shift reaction is oxidized to carbon dioxide in a reactant stream of an electrochemical fuel cell. The fuel cell has a reactant stream inlet, a reactant stream outlet and a membrane electrode assembly comprising an electrocatalyst. The reactant stream comprises hydrogen, carbon dioxide and, optionally, carbon monoxide. The reverse water-shift reaction converts carbon dioxide and hydrogen to water and carbon monoxide. The method comprises:
introducing a first oxygen-containing gas stream into the reactant stream through a first port disposed between the reactant stream inlet and the reactant stream outlet;
directing the reactant stream including the first oxygen-containing gas stream to at least a portion of the membrane electrode assembly;
introducing a further oxygen-containing stream through at least one secondary port located between the first port and the reactant stream outlet;
directing the reactant stream including the further oxygen-containing gas stream to at least a portion of the membrane electrode assembly.
In preferred embodiments of each method, the at least one secondary port preferably comprises a plurality of secondary ports located between the first port and the reactant stream outlet. The first port and the at least one secondary port are preferably spaced along the path of the reactant stream between the reactant stream inlet and the reactant stream outlet, such that the concentration of oxygen within the reactant stream is maintained substantially constant between the reactant stream inlet and the reactant stream outlet. The ports are most preferably uniformly spaced along the path of the reactant stream between the reactant stream inlet and the reactant stream outlet. Where the reactant stream further comprises oxygen, the oxygen-containing gas stream can be drawn from the reactant stream.
In a first embodiment of the apparatus, the oxidation of carbon monoxide to carbon dioxide is promoted, where the carbon monoxide is present in a fuel stream of an electrochemical fuel cell. The fuel stream comprises hydrogen, carbon dioxide and, optionally, carbon monoxide. The apparatus comprises:
(a) first and second fluid flow field plates, the plates formed of electrically conductive material, the first plate material substantially impermeable to the fuel stream and the second plate material substantially impermeable to an oxygen-containing oxidant stream, the first plate having an inlet for introducing the fuel stream to a major surface thereof and an outlet for discharging the fuel stream from the major surface, the major surface having formed therein means for directing the fuel stream from the fuel stream inlet to the fuel stream outlet,
(b) a membrane electrode assembly interposed between the first and second plates, the assembly comprising first and second electrode layers, the first electrode layer disposed adjacent the major surface of the first plate having the channels formed therein, each of the electrode layers formed of porous electrically conductive sheet material and having a catalyst associated therewith, and an ion exchange membrane interposed between the first and second electrode layers,
wherein the first plate has formed therein means for introducing an oxygen-containing gas stream into the fuel stream between the fuel stream inlet and the fuel stream outlet.
The means for introducing the oxygen-containing gas stream into the fuel stream comprises a plurality of pores formed within the first plate. Alternatively, the means for introducing the oxygen-containing gas stream into the fuel stream comprises a plurality of milled openings formed in the first plate. The plurality of openings are preferably formed in the first plate such that the openings are disposed substantially adjacent the at least one channel when the first plate is assembled adjacent the first electrode layer. The plurality of openings are most preferably uniformly spaced between the fuel stream inlet and fuel stream outlet, such that the concentration of the oxygen-containing gas within the fuel stream is maintained substantially constant between the fuel stream inlet and the fuel stream outlet. The oxygen-containing gas stream can be drawn from the oxygen-containing oxidant stream. In that case, the oxygen-containing gas stream is preferably drawn from the oxygen-containing oxidant stream through the ion exchange membrane. Where the fuel stream further comprises oxygen, the oxygen-containing gas stream is preferably drawn from the fuel stream.
The means for directing the fuel stream from the fuel stream inlet to the fuel stream outlet comprises at least one continuous channel interconnecting the fuel stream inlet and the fuel stream outlet. The at least one continuous channel comprises either a single continuous channel or a plurality of continuous channels. Alternatively, the means for directing the fuel stream from the fuel stream inlet to the fuel stream outlet comprises at least one inlet channel extending from the fuel stream inlet and at least one outlet channel extending from the fuel stream outlet, such that the at least one inlet channel is discontinuous with respect to the at least one outlet channel. In operation, the fuel stream flows from within the at least one inlet channel to the at least one outlet channel through the interstitial spaces of the adjacent first electrode layer. The at least one outlet channel preferably comprises at least two outlet channels and each of the at least one inlet channels is preferably interposed between adjacent outlet channels, such that the fuel stream inlet and the fuel stream outlet channels are interdigitated.
In a second embodiment of the apparatus, carbon monoxide is oxidized to carbon dioxide, where the carbon monoxide is present in a fuel stream of an electrochemical fuel cell. The fuel stream comprises hydrogen, carbon dioxide and, optionally, carbon monoxide. The apparatus comprises:
(a) first and second separator layers, the separator layers formed of electrically conductive sheet material, the first separator layer sheet material substantially impermeable to the fuel stream and the second separator layer sheet material substantially impermeable to an oxygen-containing oxidant stream;
(b) a membrane electrode assembly interposed between the first and second separator layers, the assembly comprising first and second electrode layers, the electrode layers formed of porous electrically conductive sheet material and having catalyst associated therewith, and an ion exchange membrane interposed between the first and second electrode layers, the first electrode layer comprising a fuel stream inlet, a fuel stream outlet, and means for flowing the fuel stream within the first electrode layer between the fuel stream inlet and the fuel stream outlet,
wherein the first separator layer has formed therein means for introducing an oxygen-containing gas stream into the fuel stream between the fuel stream inlet and the fuel stream outlet.
The means for introducing the oxygen-containing gas stream into the fuel stream comprises a plurality of pores formed within the first plate. Alternatively, the means for introducing the oxygen-containing gas stream into the fuel stream comprises a plurality of milled openings formed in the first plate. The plurality of openings are preferably spaced between the fuel stream inlet and the fuel stream outlet, such that the concentration of oxygen within the fuel stream is maintained substantially constant between the fuel stream inlet and the fuel stream outlet. The plurality of openings are most preferably substantially uniformly spaced between the fuel stream inlet and the fuel stream outlet. The oxygen-containing gas stream can be drawn from the oxygen-containing oxidant stream. In that case, the oxygen-containing gas stream is preferably drawn from the oxygen-containing oxidant stream through the ion exchange membrane. Where the fuel stream further comprises oxygen, the oxygen-containing gas stream is preferably drawn from the fuel stream. The flow means preferably comprises the interstitial spaces within the first electrode layer.
The first electrode layer preferably has at least one channel formed in the surface thereof facing away from the membrane, and the surface of the first separator layer facing the first electrode layer is substantially planar, whereby the surface of the first electrode layer and the adjacent surface of the first separator layer cooperate to define a passage for the flow of the fuel stream within the first electrode layer. The plurality of openings are preferably formed in the first separator layer such that the openings are disposed substantially adjacent the passage. The at least one channel preferably interconnects the fuel inlet and the fuel outlet. Alternatively, the at least one channel comprises a first channel extending from the fuel inlet and a second channel extending from the fuel output, the second channel being discontinuous with respect to the first channel, whereby the fuel stream flows from within the first channel to the second channel through the interstitial spaces of the first electrode layer. The at least one outlet channel preferably comprises at least two outlet channels, and each of the at least one inlet channels is preferably interposed between adjacent outlet channels, such that the fuel stream inlet and the fuel stream outlet channels are interdigitated.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of a fuel cell stack showing the electrochemically active and humidification sections.
FIG. 2 is an exploded side view of a fuel cell including a membrane electrode assembly interposed between two fluid flow field plates having reactant flow channels formed in the major surfaces of the plates facing the electrodes.
FIG. 3 is an exploded side view of a fuel cell including a membrane electrode assembly having integral reactant flow channels interposed between two separator layers.
FIG. 4 is a top plan view of a fluid flow field plate having a single continuous open-faced channel that traverses the central area of the plate in a plurality of passes between a fluid inlet directly connected to a fluid supply opening and a fluid outlet directly connected to a fluid exhaust opening, as described in Watkins U.S. Pat. No. 4,988,583.
FIG. 5 is an enlarged sectional view of the channels formed in the surface of the fluid flow field plate illustrated in FIG. 4.
FIG. 6 is a top plan view of a fluid flow field plate having multiple continuous open-faced channels, each of which traverses the central area of the plate in a plurality of passes between a fluid inlet directly connected to a fluid supply opening and a fluid outlet directly connected to a fluid exhaust opening, as described in Watkins U.S. Pat. No. 5,108,849.
FIG. 7 is a top plan view of a fluid flow field plate having 11 discontinuous, interdigitated fluid flow channels, 5 channels of which are inlet channels extending from a reactant inlet opening and 6 channels of which are outlet channels extending from a reactant outlet opening, each of the inlet channels being disposed between a pair of outlet channels.
FIG. 8 is a top plan view of a fluid flow field plate having an oxidant bleed channel formed therein around the perimeter of the electrochemically active area and which has uniformly spaced branches extending therefrom for introducing an oxygen-containing gas stream from the oxidant exhaust manifold to the fuel stream flowing through a serpentine flow field.
FIG. 9 is a side sectional view taken in the direction of arrows A--A in FIG. 8.
FIG. 10 is a side sectional view of a fluid flow plate, interposed between a gas impermeable separator layer and a membrane electrode assembly, in which the plate has a plurality of openings or ports formed therein for introducing an oxygen-containing reformate gas stream to the opposite fuel flow field side of the plate.
FIG. 11 is a top plan view of the fuel manifold side of a fluid flow field plate having two serpentine channels, each of which has 15 uniformly spaced ports formed therein for introducing oxygen-containing reformate gas to the opposite fuel flow field side of the plate.
FIG. 12 is a top plan view of the fuel flow field side of the fluid flow field plate illustrated in FIG. 11, having two serpentine channels, each of which has 15 uniformly spaced ports formed therein for receiving oxygen-containing reformate gas introduced from the opposite fuel manifold side of the plate.
FIG. 13 is a top plan view of the fuel manifold side of a fluid flow field plate having two serpentine channels, each of which has 30 uniformly spaced ports formed therein for introducing oxygen-containing reformate gas to opposite fuel flow field side of the plate.
FIG. 14 is a top plan view of the fuel flow field side of the fluid flow field plate illustrated in FIG. 13, having two serpentine channels, each of which has 30 uniformly spaced ports formed therein for receiving oxygen-containing reformate gas introduced from the opposite fuel manifold side of the plate.
FIG. 15 is a top plan view of the fuel manifold side of a fluid flow field plate having 5 discontinuous channels, each of which has a plurality of uniformly spaced ports formed therein for introducing oxygen-containing reformate gas to the opposite fuel flow field side of the plate.
FIG. 16 is a top plan view of the fuel flow field side of the fluid flow field plate illustrated in FIG. 15, having 11 discontinuous, interdigitated channels, 5 of which have a plurality of uniformly spaced ports formed therein for receiving oxygen-containing reformate gas introduced from the opposite fuel manifold side of the plate.
FIG. 17 is a top plan view of the fuel manifold side of a fluid flow field plate having 5 discontinuous channels, each of which has a plurality of uniformly spaced ports formed therein for introducing oxygen-containing reformate gas to the opposite fuel flow field side of the plate.
FIG. 18 is a top plan view of the fuel flow field side of the fluid flow field plate illustrated in FIG. 17, having 5 rows of uniformly spaced ports formed therein for receiving oxygen-containing reformate gas introduced from the opposite fuel manifold side of the plate and 6 discontinuous channels disposed in interdigitated relation to the rows of ports.
FIG. 19 is a top plan view of the fuel manifold side of a fluid flow field plate having 5 discontinuous inlet channels, each of which has a plurality of uniformly spaced inlet ports formed therein for introducing oxygen-containing reformate gas to the opposite fuel flow field side of the plate, and 6 discontinuous outlet channels, each of which has a plurality of uniformly spaced outlet ports formed therein for receiving oxygen-containing reformate gas from the opposite fuel flow field side of the plate, the inlet and outlet channels being disposed in interdigitated relation and separated by a gasket seal.
FIG. 20 is a top plan view of the fuel flow field side of the fluid flow field plate illustrated in FIG. 19, having 5 inlet channels formed therein, each of which has a plurality of uniformly spaced inlet ports formed therein for receiving oxygen-containing reformate gas introduced from the opposite fuel manifold side of the plate, and 6 outlet channels formed therein, each of which has a plurality of uniformly spaced outlet ports formed therein for returning reformate gas to the opposite fuel manifold side of the plate, the inlet and outlet channels being disposed in alternating relation.
FIG. 21 is a top plan view of a membrane electrode assembly having a cylindrical opening formed therein for introducing an oxygen-containing gas stream from the cathode side of the fuel cell into the reactant fuel stream on the anode side of the fuel cell through openings formed in the electrodes and the membrane.
FIG. 22 is a side sectional view taken in the direction of arrows B--B in FIG. 21.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning first to FIG. 1, a fuel cell stack assembly 10 includes an electrochemically active section 26 and optionally includes a humidification section 28. Stack assembly 10 is a modular plate and frame design, and includes a compression end plate 16 and a fluid end plate 18. An optional pneumatic piston 17, positioned within compression end plate 16, applies uniform pressure to the assembly to promote sealing. Bus plates 22 and 24 located on opposite ends of active section 26 provide the negative and positive contacts, respectively, for the electrical path directing current generated by the assembly to an external electrical load (not shown). Tie rods 20 extend between end plates 16 and 18 to retain and secure stack assembly 10 in its assembled state with fastening nuts 21.
Active section 26 includes, in addition to bus plates 22 and 24, a plurality of fuel cell repeating units 12. Each repeating unit 12 consists of a membrane electrode assembly, an anode fluid flow field plate, a cathode fluid flow field plate (or alternatively anode and cathode separator layers if the anode and cathode reactant flow channels are formed in the surfaces of the electrode material) and optionally a cooling jacket, as described in more detail below. In the assembly illustrated in FIG. 1, the repeating units 12 are electrically coupled in series by virtue of the contact between the electrically conductive layers which form the flow field plates (or the separator layers) and the cooling jackets.
Optional humidification section 28 includes a plurality of humidification assemblies 14, each assembly 14 consisting of fuel or oxidant reactant flow field plate, a water flow field plate, and a water transport membrane interposed between the reactant flow field plate and the water flow field plate. When present, humidification section 28 imparts water to the fuel and oxidant streams fed to active section 26, thereby preventing the membranes within the active section from drying out.
FIG. 2 illustrates a fuel cell 30, which includes a membrane electrode assembly 32 interposed between rigid flow field plates 34 and 36, preferably formed of graphite or a graphite composite material. Membrane electrode assembly 32 consists of an ion exchange membrane 42 interposed between two electrodes, namely, anode 44 and cathode 46. Anode 44 and cathode 46 are typically formed of porous electrically conductive sheet material, preferably carbon fiber paper, and have planar major surfaces. Electrodes 44 and 46 have a thin layer of catalyst material disposed on their major surfaces at the interface with membrane 42 to render them electrochemically active.
As shown in FIG. 2, anode flow field plate 34 has at least one open faced channel 34a engraved, milled or molded in its major surface facing membrane 42. Similarly, cathode flow field plate 36 has at least one open faced channel 36a engraved, milled or molded in its major surface facing membrane 42. When assembled against the cooperating surfaces of electrodes 44 and 46, channels 34a and 36a form the reactant flow field passages for the fuel and oxidant streams, respectively.
Turning now to FIG. 3, a fuel cell 50 employs a membrane electrode assembly 52 having integral reactant fluid flow channels. Fuel cell 50 includes membrane electrode assembly 52 interposed between lightweight separator layers 54 and 56, which are substantially impermeable to the flow of reactant fluid therethrough. Membrane electrode assembly 52 consists of an ion exchange membrane 62 interposed between two electrodes, namely, anode 64 and cathode 66. Anode 64 and cathode 66 are formed of porous electrically conductive sheet material, preferably carbon fiber paper. Electrodes 64 and 66 have a thin layer of catalyst material disposed on their major surfaces at the interface with membrane 62 to render them electrochemically active.
As shown in FIG. 3, anode 64 has at least one open faced channel 64a formed in its surface facing away from membrane 62. Similarly, cathode 66 has at least one open faced channel 66a formed in its surface facing away from membrane 62. When assembled against the cooperating surfaces of separator layers 54 and 56, channels 64a and 66a form the reactant flow field passages for the fuel and oxidant streams, respectively.
A prior art fluid flow field plate 110 having a single continuous reactant flow channel, described in Watkins U.S. Pat. No. 4,988,583, is shown in FIG. 4. Major plate surface 115 has formed therein, typically by numerically controlled machining, stamping or molding, a single continuous fluid flow channel 122. Channel 122 has a fluid inlet 124 at one end and a fluid outlet 126 at the other end. Fluid inlet 124 is directly connected to a fluid supply opening or manifold 125 formed in plate 112. Fluid outlet 126 is directly connected to a fluid exhaust opening or manifold 127 formed in plate 112. Fluid opening 126 is connected to a source of fuel (not shown) in the case of the anode flow field plate or a source of oxidant (not shown) for the cathode flow field plate. Channel 122 traverses in a plurality of passes a major central area of plate 112, which in turn generally corresponds to the electrocatalytically active region of the anode or cathode to which it is adjacent when assembled sealant or gasketing material 114 fluidly isolates the major central area of plate 112.
FIG. 5 shows a cross sectional view of the channel 122 of fluid flow field plate 110 in FIG. 4. Channel 122 has a configuration that is typical of machined open face channels, namely, it is defined by a substantially flat base 129 and opposing side walls 130 which diverge outwardly toward the open face 123 of channel 122. The illustrated cross sectional configuration of channel 122 is designed to minimize tool wear. Channel 122 is preferably of uniform depth throughout its length. A series of lands 132 is defined between the passes of channel 122. When assembled, the lands 132 between channels 122 are in contact with the electrode surface adjacent thereto, so that each flow field plate also functions as a current collector.
A prior art fluid flow field plate 140 having multiple continuous reactant flow channels, described in Watkins U.S. Pat. No. 5,108,849, is shown in FIG. 6. Major surface 142 has formed therein a plurality of flow field channels, several of which are designated by the numeral 144. Channels 144 each define a generally serpentine path between fluid supply opening or manifold 145 and fluid exhaust opening or manifold 147. Each channel 144 has an inlet end 146 and an outlet end 148 directly connected to the respective fluid supply openings or ports 145 and fluid exhaust openings or ports 147. Plate 140, which contains 10 individual serpentine channels 144, has been found to operate effectively in a fuel cell adjacent the cathode, and is sometimes referred to as a 10-pass cathode flow field plate. A greater or lesser number of channels 144 could be incorporated in the plate, such as, for example, in the case of a 2-pass flow field plate which has been found to operate effectively adjacent the anode, and is sometimes referred to as a 2-pass anode flow field plate.
FIG. 7 shows a fluid flow field plate 180 having 11 discontinuous, interdigitated fluid flow channels. Plate 180 has a fluid inlet 182 formed in the surface 181 thereof. Inlet channels 186 extend from inlet 182 toward the central region of plate, which is adjacent to the electrocatalytically active region of the electrode with which plate 180 is associated. Plate 180 also has a fluid outlet 188 formed in the surface 181 of plate 180. Outlet channels 192 extend from outlet 188 toward the central region of the plate. As illustrated in FIG. 7, inlet channels 186 and outlet channels 192 are interdigitated, so that a pressurized fluid stream entering through opening 182 will be directed to inlet channels 186. At that point, the fluid stream will be forced through the interstices of the adjacent porous electrode material (not shown) on either side of each inlet channel 186 to one of the nearby outlet channels 192. From there, the fluid stream will flow through outlet 188, where it is discharged from the flow field plate 180.
As shown in FIG. 7, plate 180 contains 11 discontinuous fluid flow channels, 5 channels of which are inlet channels extending from the inlet and 6 channels of which are outlet channels extending from the outlet. Each of the inlet channels is preferably disposed between a pair of outlet channels so that the fluid stream from the inlet channels is uniformly directed from either side of the inlet channels to one of the neighboring outlet channels.
FIG. 7 also illustrates the location of a sealant or gasketing material 194 which contacts surface 181 and circumscribes the central area of plate 180. Sealant or gasketing material 194 isolates and defines within it the electrocatalytically active region of the fuel cell adjacent plate 180. Plate 180 also has other openings 196 formed therein, which serve as the manifolds for other reactant and coolant streams within the fuel cell.
FIG. 8 illustrates a fluid flow field plate 210 having an oxidant bleed channel 212 formed therein for introducing an oxygen-containing gas stream from the humidified oxidant exhaust manifold 220, humidified oxidant manifold 224 and the dry oxidant supply manifold 222 to the fuel stream prior to feeding the fuel stream to the active section of the fuel cell. The fuel stream is introduced to the surface of plate 210 from the humidified fuel manifold 214 through a fuel inlet 228. The fuel stream then passes through a two-pass serpentine flow field formed by two channels 216a and 216b formed on the major surface of plate 210. The fuel stream flowing through channels 216a and 216b receives oxygen-containing gas from the branch channels 234 extending from the oxidant bleed channel 212. As shown in FIG. 8, the branch channels 234 are substantially uniformly spaced around the perimeter of the electrochemically active area of the plate 210, which is traversed by the serpentine channels 216a and 216b. The unreacted fuel stream components exit channels 216a and 216b via an outlet 230 to a fuel exhaust manifold 218. The area 226 between the broken lines on the surface of plate 210 represents the location of sealant or gasketing material which isolates the electrochemically active area from the manifolds, isolates the manifolds from each other, and isolates the electrochemically active area and the manifolds from the external environment.
FIG. 9 shows a cross-section of plate 210 taken in the direction of arrows A--A in FIG. 8, and illustrates in particular the configuration of oxidant bleed channel 212 formed in plate 210.
FIG. 10 shows a fluid flow plate 250 interposed between a gas impermeable separator layer 254 and a membrane electrode assembly 252. Plate 250 has a plurality of milled openings or ports 256 formed therein for introducing an oxygen-containing reformate fuel gas stream 256 to the opposite fuel flow field side of the plate. As shown in FIG. 10, the unreacted components of the fuel gas stream exit the fuel flow field as fuel exhaust gas stream 258.
Alternatively, the fluid flow plate 250 of FIG. 10 can be formed as a porous plate. In the porous plate embodiment, the oxygen-containing gas stream is introduced into the fuel stream through a plurality of pores formed within the plate 250. The pores are the interstitial spaces or passages at the interior of plate 250 which are not occupied by the solid, electrically conductive sheet material from which plate 250 is formed. The pores of the porous plate embodiment perform the function of the ports 255 in FIG. 10.
FIG. 11 shows the fuel manifold side of a fluid flow field plate 310. Plate 310 has two serpentine channels 316a and 316b formed on the surface of the fuel manifold side. Oxygen-containing reformate fuel gas enters the channels 316a and 316b via an inlet 314 from reformate fuel gas manifold 312. Each of channels 316a and 316b has 15 uniformly spaced openings or ports 318 formed therein for introducing the oxygen-containing reformate gas to the opposite fuel flow field side of plate 310 (shown in FIG. 12). FIG. 11 also illustrates the location of fuel exhaust manifold 324 into which the unreacted fuel stream components exit from the opposite fuel flow field side of plate 310.
FIG. 12 shows the fuel flow field side of plate 310 illustrated in FIG. 11. Plate 310 has two serpentine channels 320a and 320b formed on the fuel flow field side. Each of channels 320a and 320b has 15 uniformly spaced openings or ports 318 formed therein for receiving oxygen-containing reformate fuel gas introduced from the opposite fuel manifold side of plate 310. The unreacted fuel stream components exit channels 320a and 320b via an outlet 322 to a fuel exhaust manifold 324.
FIG. 13 shows the fuel manifold side of a fluid flow field plate 340. Plate 340 has two serpentine channels 346a and 346b formed on the surface of the fuel manifold side. Oxygen-containing reformate fuel gas enters the channels 346a and 346b via an inlet 344 from reformate fuel gas manifold 342. Each of channels 346a and 346b has 30 uniformly spaced openings or ports 348 formed therein for introducing the oxygen-containing reformate gas to the opposite fuel flow field side of plate 340 (shown in FIG. 14). FIG. 13 also illustrates the location of fuel exhaust manifold 354 into which the unreacted fuel stream components exit from the opposite fuel flow field side of plate 340.
FIG. 14 shows the fuel flow field side of plate 340 illustrated in FIG. 13. Plate 340 has two serpentine channels 350a and 350b formed on the fuel flow field side. Each of channels 350a and 350b has 30 uniformly spaced openings or ports 348 formed therein for receiving oxygen-containing reformate fuel gas introduced from the opposite fuel manifold side of plate 340. The unreacted fuel stream components exit channels 350a and 350b via an outlet 352 to a fuel exhaust manifold 354.
FIG. 15 shows the fuel manifold side of a fluid flow field plate 370. Plate 370 has 5 discontinuous channels, two of which are designated in FIG. 15 as channels 376a and 376b, formed on the surface of the fuel manifold side. Oxygen-containing reformate fuel gas enters the channels via an inlet 374 from reformate fuel gas manifold 372. Each channel has a plurality of uniformly spaced openings or ports 378 formed therein for introducing oxygen-containing reformate gas to the opposite fuel flow field side of plate 370 (shown in FIG. 16). FIG. 15 also illustrates the location of fuel exhaust manifold 384 into which the unreacted fuel stream components exit from the opposite fuel flow field side of plate 370.
FIG. 16 shows the fuel flow field side of plate 370 illustrated in FIG. 15. Plate 370 has 11 discontinuous, interdigitated channels. A first group of five channels, one of which is designated in FIG. 16 as channel 380a, has a plurality of uniformly spaced openings or ports 378 formed therein for receiving oxygen-containing reformate gas introduced from the opposite fuel manifold side of plate 370. A second group of 6 channels, one of which is designated in FIG. 16 as channel 380b, does not have openings or ports formed therein. Each of the second group of channels receives the fuel gas stream which flows through the porous electrode material from the first group of channels having openings or ports 378 formed therein. The unreacted fuel stream components exit the second group of channels via an outlet 382 to a fuel exhaust manifold 384.
FIG. 17 shows the fuel manifold side of a fluid flow field plate 410. Plate 410 has 5 discontinuous channels, two of which are designated in FIG. 17 as channels 416a and 416b, formed on the surface of the fuel manifold side. Oxygen-containing reformate fuel gas enters the channels via an inlet 414 from reformate fuel gas manifold 412. Each channel has a plurality of uniformly spaced openings or ports 418 formed therein for introducing oxygen-containing reformate gas to the opposite fuel flow field side of plate 410 (shown in FIG. 18). FIG. 17 also illustrates the location of fuel exhaust manifold 424 into which the unreacted fuel stream components exit from the opposite fuel flow field side of plate 410.
FIG. 18 shows the fuel flow field side of plate 410 illustrated in FIG. 17. Plate 410 has five rows of uniformly spaced openings or ports 418 formed therein for receiving oxygen-containing reformate gas introduced from the opposite fuel manifold side of plate 410. Plate 410 also has 6 discontinuous, interdigitated channels formed therein, two of which are designated in FIG. 18 as channels 420a and 420b, which do not have openings or ports formed therein. Each channel receives the fuel gas stream which flows from the openings or ports 418 through the porous electrode material. The unreacted fuel stream components exit the channels via an outlet 422 to a fuel exhaust manifold 424.
FIG. 19 shows the fuel manifold side of a fluid flow field plate 450. Plate 450 has 5 discontinuous inlet channels, one of which is designated in FIG. 19 as channel 456a. Oxygen-containing reformate fuel gas enters the inlet channels via an inlet 454 from reformate fuel gas manifold 452. Each inlet channel has a plurality of substantially uniformly spaced inlet openings or ports 458 formed therein for introducing oxygen-containing reformate gas to the opposite fuel flow field side of plate 450 (shown in FIG. 20). Plate 450 also has 6 discontinuous outlet channels, one of which is designated in FIG. 19 as channel 456b. Each outlet channel has a plurality of substantially uniformly spaced outlet openings or ports 472 formed therein for receiving the unreacted fuel stream components from the opposite fuel flow field side of plate 450 (shown in FIG. 20). The unreacted fuel stream components exit the outlet channels via an outlet 462 to a fuel exhaust manifold 464. As shown in FIG. 19, the inlet and outlet channels are disposed in interdigitated relation and are separated by a gasket seal 470. FIG. 19 also illustrates the location of fuel exhaust manifold 464 into which the unreacted fuel stream components exit from the opposite fuel flow field side of plate 450. The presence of channels 460a and 460b is optional; the reactant (fuel) stream could flow through the interstitial spaces in the adjacent porous electrode material, between the inlet openings 458 and the outlet openings 472.
FIG. 20 shows the fuel flow field side of the plate 450 illustrated in FIG. 19. The flow field side of plate 450 has 5 inlet channels, one channel of which is designated in FIG. 20 as channel 460a. Each inlet channel has a plurality of substantially uniformly spaced inlet openings or ports 458 formed therein for receiving oxygen-containing reformate gas introduced from the opposite fuel manifold side of plate 450. The flow field side of plate 450 also has 6 outlet channels formed therein, one of which is designated in FIG. 20 as channel 460b. Each outlet channel has a plurality of substantially uniformly spaced outlet openings or ports 472 formed therein for returning reformate gas to the opposite fuel manifold side of plate 450.
FIG. 21 illustrates a membrane electrode assembly 510 having a cylindrical opening 512 formed therein. As shown in more detail in FIG. 22, membrane electrode assembly 510 consists of a membrane electrolyte 514 interposed between two sheets of porous electrode material, one sheet of which forms the anode 516 and the other of which forms the cathode 518. As further shown in FIG. 22, a rigid disc 520, preferably formed of metal and having an annular orifice 522 formed at the center thereof, is disposed in the portion of the opening 512 formed by cathode 518. In operation, an oxygen-containing gas stream from the cathode side of the fuel cell is introduced into the reactant fuel stream on the anode side through orifice 522.
While particular elements, embodiments and applications of the present invention have been shown and described, it will be understood, of course, that the invention is not limited thereto since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings. It is therefore contemplated by the appended claims to cover such modifications as incorporate those features which come within the spirit and scope of the invention. | A method and apparatus oxidizes the carbon monoxide present in an incoming reactant fuel stream and/or carbon monoxide produced by the reverse water-shift reaction to carbon dioxide in a reactant stream introduced to an electrochemical fuel cell. The reactant stream comprises hydrogen, carbon dioxide and carbon monoxide. A first oxygen-containing gas stream is introduced into the reactant stream through a first port disposed between the reactant stream inlet and the reactant stream outlet. A further oxygen-containing gas stream is introduced into the reactant stream through at least one secondary port located between the first port and the reactant stream outlet. | 7 |
[0001] This application is a continuation of U.S. application Ser. No. 14/018,297, filed Sep. 4, 2013, which is a continuation of Ser. No. 13/080,764, filed Apr. 6, 2011, which is a continuation of U.S. application Ser. No. 11/701,535 filed Feb. 2, 2007, currently allowed now U.S. Pat. No. 7,928,462, issued Apr. 19, 2011, and claims the benefit of Korean Patent Application No. 10-2006-0015039, filed on Feb. 16, 2006 and Korean Patent Application No. 10-2006-0015040, filed on Feb. 16, 2006, which are all hereby incorporated by reference as if fully set forth herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a light emitting device having a vertical structure, a package thereof and a method for manufacturing the same, and more particularly, to a light emitting device having a vertical structure, a package thereof and a method for manufacturing the same which are capable of damping impact generated in a substrate separation process, and achieving an improvement in mass productivity.
[0004] 2. Discussion of the Related Art
[0005] Light emitting diodes (LEDs) are well known as a semiconductor light emitting device which converts current to light, to emit light. Since a red LED using GaAsP compound semiconductor was commercially available in 1962, it has been used, together with a GaP:N-based green LED, as a light source in electronic apparatuses, for image display.
[0006] The wavelength of light emitted from such an LED depends on the semiconductor material used to fabricate the LED. This is because the wavelength of the emitted light depends on the band gap of the semiconductor material representing energy difference between valence-band electrons and conduction-band electrons.
[0007] Gallium nitride (GaN) compound semiconductor has been highlighted. One of the reasons why GaN compound semiconductor has been highlighted is that it is possible to fabricate a semiconductor layer capable of emitting green, blue, or white light, using GaN in combination with other elements, for example, indium (In), aluminum (Al), etc.
[0008] Thus, it is possible to adjust the wavelength of light to be emitted, using GaN in combination with other appropriate elements. Accordingly, where GaN is used, it is possible to appropriately determine the materials of a desired LED in accordance with the characteristics of the apparatus to which the LED is applied. For example, it is possible to fabricate a blue LED useful for optical recording or a white LED to replace a glow lamp.
[0009] On the other hand, initially-developed green LEDs were fabricated using GaP. Since GaP is an indirect transition material causing a degradation in efficiency, the green LEDs fabricated using this material cannot practically produce light of pure green. By virtue of the recent success of growth of an InGaN thin film, however, it has been possible to fabricate a high-luminescent green LED.
[0010] By virtue of the above-mentioned advantages and other advantages of GaN-based LEDs, the GaN-based LED market has rapidly grown. Also, techniques associated with GaN-based electro-optic devices have rapidly developed since the GaN-based LEDs became commercially available in 1994.
[0011] GaN-based LEDs have been developed to exhibit light emission efficiency superior over that of glow lamps. Currently, the efficiency of GaN-based LEDs is substantially equal to that of fluorescent lamps. Thus, it is expected that the GaN-based LED market will grow significantly.
[0012] Despite the rapid advancement in technologies of GaN-based semiconductor devices, the fabrication of GaN-based devices suffers from a great disadvantage of high-production costs. This disadvantage is closely related to difficulties associated with growing of a GaN thin film (epitaxial layer) and subsequent cutting of finished GaN-based devices.
[0013] Such a GaN-based device is generally fabricated on a sapphire (Al 2 O 3 ) substrate. This is because a sapphire wafer is commercially available in a size suited for the mass production of GaN-based devices, supports GaN epitaxial growth with a relatively high quality, and exhibits a high processability in a wide range of temperatures.
[0014] Further, sapphire is chemically and thermally stable, and has a high-melting point enabling implementation of a high-temperature manufacturing process. Also, sapphire has a high bonding energy (122.4 Kcal/mole) and a high dielectric constant. In terms of a chemical structure, the sapphire is a crystalline aluminum oxide (Al 2 O 3 ).
[0015] Meanwhile, since sapphire is an insulating material, available LED devices manufactured using a sapphire substrate (or other insulating substrates) are practically limited to a lateral or vertical structure.
[0016] In the lateral structure, all metal contacts for use in injection of electric current into LEDs are positioned on the top surface of the device structure (or on the same substrate surface). On the other hand, in the vertical structure, one metal contact is positioned on the top surface, and the other contact is positioned on the bottom surface of the device structure after removal of the sapphire (insulating) substrate.
[0017] In addition, a flip chip bonding method has also been widely employed. In accordance with the flip chip bonding method, an LED chip, which has been separately prepared, is attached to a sub-mount of, for example, a silicon wafer or ceramic substrate having an excellent thermal conductivity, under the condition in which the LED chip is inverted.
[0018] However, the lateral structure or the flip chip method suffers from the problems associated with poor heat release efficiency because the sapphire substrate has a heat conductivity of about 27 W/mK, thus leading to a very high heat resistance. Furthermore, the flip chip method has also disadvantages of requiring large numbers of photolithography process steps, thus resulting in complicated manufacturing processes.
[0019] To this end, LED devices having a vertical structure have been highlighted in that the vertical structure involves removal of the sapphire substrate.
[0020] In the fabrication of such a vertical LED structure, a laser lift off (LLO) method is used to remove the sapphire substrate, and thus, to solve the problems caused by the sapphire substrate.
[0021] However, it is impossible to completely remove the sapphire substrate at once, using the LLO method, due to the size and limited uniformity of a laser beam used in the LLO method. For this reason, uniform small-size laser beams are irradiated to respective portions of the sapphire substrate, in order to the entire portion of the sapphire substrate.
[0022] In the LLO method, stress is applied to the GaN thin film upon incidence of a laser beam. In order to separate a sapphire substrate and a GaN thin film from each other, it is necessary to use a laser beam having a high energy density. The laser beam resolves GaN into a metal element, namely, Ga, and nitrogen gas (N 2 ).
[0023] The resolved nitrogen gas exhibits a high expansion force, so that it applies considerable impact not only to the GaN thin film 2, but also to a support layer for the GaN thin film 2 and metal layers required for the fabrication of the device. As a result, a degradation in bondability occurs primarily. In addition, a degradation in electrical characteristics occurs.
[0024] For example, wave patterns exhibited as having irregularities may be formed at the peripheral portion of the GaN thin film after completion of the LLO process. Also, during the LLO process, many poor bonding portions may be observed on the thin film.
[0025] Thus, the nitrogen gas generated during the LLO process damages the semiconductor layer arranged in the vicinity of the nitrogen gas. There may also be a phenomenon that cracks formed at poor-quality portions of the GaN thin film are propagated to other portions of the GaN thin film.
[0026] As apparent from the above description, a prolonged process is required in fabricating a desired device using a GaN thin film to form an LED layer. Furthermore, there are many difficulties in implementing this process. In particular, where separation of a substrate is carried out using a laser, nitrogen gas generated due to the laser may easily damage the thin films of a semiconductor layer arranged in the vicinity of the nitrogen gas. As a result, a degradation in productivity may occur.
SUMMARY OF THE INVENTION
[0027] Accordingly, the present invention is directed to a light emitting device having a vertical structure, a package thereof and a method for manufacturing the same that substantially obviate one or more problems due to limitations and disadvantages of the related art.
[0028] An object of the present invention is to provide a light emitting device having a vertical structure, a package thereof and a method for manufacturing the same which are capable of preventing damage of a semiconductor thin film during a laser lift off process, reducing the number of processes and the processing time, enabling the device to have various arrangement and various shapes.
[0029] Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
[0030] To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, a method for manufacturing a package of a light emitting device package having a vertical structure comprises: growing a semiconductor layer having a multilayer structure over a substrate; forming a first electrode on the semiconductor layer; separating the substrate including the grown semiconductor layer into unit devices; bonding each of the separated unit devices on a sub-mount; separating the substrate from the semiconductor layer; and forming a second electrode on a surface of the semiconductor layer exposed in accordance with the separation of the substrate.
[0031] In another aspect of the present invention, a package of a light emitting device having a vertical structure comprises: a sub-mount having a light emitting device chip mounting portion formed with at least one pair of electrodes; a light emitting device chip bonded to the sub-mount, the light emitting device chip comprising a support layer electrically connected to one side of each electrode of the sub-mount, a first electrode arranged on the support layer, a semiconductor layer arranged on the first electrode and formed with a light extraction pattern, the semiconductor layer having a multilayer structure, and a second electrode arranged on the semiconductor layer and electrically connected to the other side of each electrode of the sub-mount; and zener diodes formed at the sub-mount such that the zener diodes are connected to respective electrodes of the sub-mount.
[0032] In still another aspect of the present invention, a light emitting device having a vertical structure comprises: a support layer made of a metal or semiconductor; an adhesion layer arranged on the support layer, the adhesion layer having a single layer structure or a multilayer structure; a first electrode arranged on the adhesion layer; a semiconductor layer arranged on the first electrode and formed with a light extraction pattern, the semiconductor layer having a multilayer structure; and a second electrode arranged on the semiconductor layer.
[0033] It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:
[0035] FIGS. 1 to 18 are sectional view illustrating a first embodiment of the present invention, in which:
[0036] FIG. 1 is a sectional view illustrating a process for forming a semiconductor layer;
[0037] FIG. 2 is a sectional view illustrating an example of a process for forming a first electrode and a support layer;
[0038] FIG. 3 is a sectional view illustrating another example of the process for forming the first electrode and support layer;
[0039] FIG. 4 is a sectional view illustrating a laser scribing process;
[0040] FIG. 5 is a sectional view illustrating a first example of a light emitting device chip;
[0041] FIG. 6 is a sectional view illustrating a mesa etching process carried out after the formation of the semiconductor layer;
[0042] FIG. 7 is a sectional view illustrating a process for forming the first electrode and a passivation layer;
[0043] FIG. 8 is a sectional view illustrating a process for forming a metal support layer;
[0044] FIG. 9 is a sectional view illustrating a second example of the light emitting device chip;
[0045] FIG. 10 is a sectional view illustrating a trench etching process carried out after the formation of the semiconductor layer;
[0046] FIG. 11 is a sectional view illustrating a third example of the light emitting device chip;
[0047] FIG. 12 is a sectional view illustrating an example of bonding of the light emitting device chip to a sub-mount in accordance with the present invention;
[0048] FIG. 13 is a schematic view illustrating an example of the sub-mount according to the present invention;
[0049] FIG. 14 is a sectional view illustrating a circuit of the sub-mount according to the present invention;
[0050] FIG. 15 is a sectional view illustrating a state in which a chip is attached to the sub-mount in accordance with the present invention;
[0051] FIG. 16 is a sectional view illustrating a first example of the sub-mount according to the present invention;
[0052] FIG. 17 is a sectional view illustrating a second example of the sub-mount according to the present invention;
[0053] FIG. 18 is a sectional view illustrating a third example of the sub-mount according to the present invention; and
[0054] FIG. 19 is a perspective view illustrating a light emitting device package manufactured in accordance with the present invention; and
[0055] FIGS. 20 to 30 are sectional views illustrating a second embodiment of the present invention, in which:
[0056] FIG. 20 is a sectional view illustrating a process for forming a semiconductor layer;
[0057] FIG. 21 is a sectional view illustrating an example of a process for forming a first electrode;
[0058] FIG. 22 is a sectional view illustrating a laser scribing process;
[0059] FIG. 23 is a sectional view illustrating a fourth example of a light emitting device chip;
[0060] FIG. 24 is a sectional view illustrating a mesa etching process carried out after the formation of the semiconductor layer;
[0061] FIG. 25 is a sectional view illustrating a process for forming the first electrode and a passivation layer;
[0062] FIG. 26 is a sectional view illustrating a process for forming a metal plate;
[0063] FIG. 27 is a sectional view illustrating a fifth example of the light emitting device chip;
[0064] FIG. 28 is a sectional view illustrating a trench etching process carried out after the formation of the semiconductor layer;
[0065] FIG. 29 is a sectional view illustrating a sixth example of the light emitting device chip; and
[0066] FIG. 30 is a sectional view illustrating another example of the bonding of the light emitting device chip to the sub-mount in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0067] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.
[0068] The present invention may, however, be embodied in many alternate forms and should not be construed as limited to the embodiments set forth herein. Accordingly, while the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that there is no intent to limit the invention to the particular forms disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the claims.
[0069] Like numbers refer to like elements throughout the description of the figures. In the drawings, the thickness of layers and regions are exaggerated for clarity.
[0070] It will be understood that when an element such as a layer, region or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. It will also be understood that if part of an element, such as a surface, is referred to as “inner,” it is farther to the outside of the device than other parts of the element.
[0071] In addition, relative terms, such as “beneath” and “overlies”, may be used herein to describe one layer's or region's relationship to another layer or region as illustrated in the figures.
[0072] It will be understood that these terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. Finally, the term “directly” means that there are no intervening elements. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
[0073] It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms.
[0074] These terms are only used to distinguish one region, layer or section from another region, layer or section. Thus, a first region, layer or section discussed below could be termed a second region, layer or section, and similarly, a second region, layer or section may be termed a first region, layer or section without departing from the teachings of the present invention.
First Embodiment
[0075] Hereinafter, a first embodiment of the present invention will be described with reference to the accompanying drawings.
[0076] First, a method for manufacturing individual semiconductor light emitting device chips will be described.
[0077] As shown in FIG. 1 , in order to manufacture a light emitting device chip according to this embodiment, a semiconductor layer 20 having a multilayer structure is formed over a sapphire substrate 10 , using a thin film growing method such as a hydride vapor phase epitaxy (HVPE) or a metal organic chemical vapor deposition (MOCVD) method. The HVPE method is advantageous in that it is possible to grow a thin film having a low impurity concentration, namely, a high purity, at a high growth rate of 50 to 100 μm per hour.
[0078] The growth of the semiconductor layer 20 , which has a multilayer structure, can be achieved by first forming an n type GaN semiconductor layer over the substrate 10 , forming an active layer over the n type GaN semiconductor layer, and forming a p type GaN semiconductor layer over the active layer.
[0079] A first electrode 30 is then formed on the semiconductor layer 20 , as shown in FIG. 2 . The first electrode 30 is a p type electrode or an ohmic electrode. In this case, a transparent electrode may be used for the first electrode 30 . The transparent electrode may be made of a transparent conductive oxide such as indium tin oxide (ITO).
[0080] A separate support layer 40 may be formed over the first electrode 30 , in order to achieve an enhancement in light emission efficiency and an improvement in bonding structure, and to provide a function for protecting or supporting the semiconductor layer 20 . The support layer 40 may be made of a metal or a semiconductor containing silicon.
[0081] The support layer 40 may include a reflection layer adapted to reflect light emerging from the active layer of the semiconductor layer 20 , and thus, to achieve an enhancement in light emission efficiency, and an anti-diffusion layer formed over the reflection layer.
[0082] The anti-diffusion layer is also called a “under bump metallization (UBM) layer”. Where plating is carried out over a reflection electrode, or a metal support layer is attached to the reflection electrode, a solder is mainly used. In this case, the solder may be diffused into the semiconductor layer 20 in a melted state, so that it may adversely affect light emission characteristics. The anti-diffusion layer functions to avoid such a phenomenon.
[0083] In order to enable a chip to be bonded to a sub-mount, which will be described later, a plate made of a metal such as Cu, Ni, or Au may be subsequently formed on the anti-diffusion layer. For the same purpose, a semiconductor wafer or substrate made of, for example, Si, may be attached to the anti-diffusion layer.
[0084] On the other hand, after the formation of the first electrode 30 over the semiconductor layer 20 formed over the substrate 10 , an adhesion layer 41 having a single layer structure or a multilayer structure may be formed over the first electrode 30 , for formation of the support layer 40 , as shown in FIG. 3 .
[0085] In this case, the first electrode 30 may include a reflection film, or may be made of a material having a high reflectivity, to function as a reflection electrode.
[0086] The adhesion layer 41 arranged on the first electrode 30 is a metal layer for bonding the support layer 40 to the first electrode 30 . The adhesion layer 41 may have a single layer structure or a multilayer structure including two or more layers.
[0087] The adhesion layer 41 may have a thickness corresponding to 2 to 10 times the thickness of the first electrode 30 , in order to provide a sufficient bonding strength.
[0088] The support layer 40 is bonded to the adhesion layer 41 . The support layer 40 may be made of a semiconductor wafer or substrate containing Si.
[0089] For the support layer 40 , a metal plate may be used. The metal plate may be formed over the adhesion layer 41 in accordance with a plating process.
[0090] Thereafter, a process for separating the chip structure fabricated as described above into individual unit device chips is carried out. As shown in FIG. 4 , the substrate 10 is first thinned. Scribing is then carried out using a laser, to define regions corresponding to respective unit device chips. Thereafter, a cutting force is applied to the scribed portions of the chip structure in accordance with a mechanical method, thereby causing the chip structure to be separated into individual chips 100 .
[0091] On the other hand, in accordance with another method for manufacturing individual light emitting device chips, individual device chips may be fabricated using a mesa etching process carried out after the growth of the semiconductor layer 20 which has a multilayer structure, as shown in FIG. 6 .
[0092] In the mesa etching process, the semiconductor layer 20 grown over the substrate 10 is etched until the n type semiconductor layer is exposed in each device chip region.
[0093] In this case, as shown in FIG. 7 , a first electrode 30 is then formed. Subsequently, a passivation layer 50 is formed to protect the first electrode 30 and surfaces exposed in accordance with the etching process.
[0094] Thereafter, a support layer 40 is formed, as shown in FIG. 8 . The support layer 40 may include a reflection electrode, an anti-diffusion layer, and a metal plate made of a metal such as Cu, Ni, or Au.
[0095] Subsequently, a process for thinning the substrate 10 , performing laser scribing, and separating chips is carried out in the same manner as described above. Each separated chip 100 has a structure as shown in FIG. 9 .
[0096] Alternatively, device chips may be fabricated by performing, in place of the mesa etching process, a trench etching process in which the semiconductor layer 20 is etched until the substrate 10 is exposed, as shown in FIG. 10 .
[0097] The remaining processes are identical to those in the above-described case. Each chip 100 , which is finally obtained, has a structure as shown in FIG. 11 .
[0098] As shown in FIG. 12 , each chip 100 is bonded to a sub-mount 60 which is separately prepared. The bonding of the chip 100 is carried out such that the first electrode 30 or support layer 40 of the chip 100 is attached to a mounting portion 61 of the sub-mount 60 . The first electrode 30 or support layer 40 is electrically connected to electrodes 62 and 63 formed at the mounting portion 61 of the sub-mount 60 .
[0099] A reflection plate 65 may be formed on a portion of each of the electrodes 62 and 63 .
[0100] For the sub-mount 60 , a substrate made of Si, MN ceramic, AlO x , Al 2 O 3 , or BeO, or a PCB substrate may be used. Zener diodes 64 may be formed at the sub-mount 60 , to achieve an improvement in electrostatic discharge (ESD) property.
[0101] When static electricity is generated in a device, a high voltage may be applied to the device. In this case, an electrostatic breakdown occurs, so that the characteristics of the device disappear. This phenomenon is called an “ESD phenomenon”. Such an ESD phenomenon occurs frequently in a procedure of assembling or handling the device in a manual manner or using equipment. Accordingly, it is important to enhance the characteristics of the device by optimizing the structure of the device for eliminating an internal current concentration phenomenon, and thus, achieving an improvement in ESD property (namely, an increase in the electrostatic resistance of the device at a higher voltage).
[0102] In detail, such static electricity may be generated during a process for manufacturing a semiconductor, or during a process for mounting the manufactured semiconductor on a PCB.
[0103] Static electricity is not always generated. Furthermore, although static electricity is generated, its quantity (voltage and current) is not constant. For this reason, for a quantitative test for static electricity, it is necessary to produce static electricity having constant voltage and current waveforms. For an international standard (for complete products) for standardized static electricity, there is IEC 61000-4-2, EIAJ, MIL STD, -883D, E (3015). The representative standard in Korea is KN61000-4-4 (Korean version of IEC61000-4-2).
[0104] The bonding of the chip 100 to the sub-mount 60 may be achieved using the following method.
[0105] In accordance with one method, the unit device chip 100 is mounted on the sub-mount 60 using an adhesive. Thereafter, a pressure is thermally applied to the unit device chip 100 , thereby bonding the unit device chip 100 to the sub-mount 60 .
[0106] In accordance with another method, the unit device chip 100 is aligned with the sub-mount 60 , and is mounted on (brought into contact with) the sub-mount 60 . Thereafter, bonding is carried out using a frictional heat generated in accordance with ultrasonic vibrations.
[0107] In the latter case, the metal plate for the support layer 40 of the chip 100 may be made of Au, and Au balls may be arranged on an area facing the chip 100 . When ultrasonic (U/S) bonding is carried out, it is possible to improve bonding characteristics, in particular, thermal characteristics.
[0108] FIG. 13 illustrates an example of a 3D through hole interconnection (THI) sub-mount provided with zener diodes 64 to achieve an improvement in ESD property.
[0109] As shown in FIG. 13 , the sub-mount 60 includes a mount portion 61 to which a light emitting device chip is bonded. A pair of electrodes 62 and 63 are formed at the mounting portion 61 . The electrode 62 is a positive electrode to come into contact with the first electrode 30 or support layer 40 of the chip 100 , whereas the electrode 63 is a negative electrode to come into contact with a second electrode 70 of the chip 100 which will be described later. Of course, the electrodes 62 and 63 may be arranged at positions opposite to those of the above-described case. Also, the objects, to which the electrodes 62 and 63 are to be bonded, may be changed.
[0110] When the zener diodes 64 are coupled to the chip 100 in such a manner that they are coupled to the electrodes 62 and 63 in opposite directions, to exhibit opposite polarities, respectively, a circuit shown in FIG. 14 is established.
[0111] That is, in the circuit of FIG. 14 , the zener diodes 64 are connected to the chip 100 in parallel in such a manner that the zener diodes 64 are connected to the electrodes 62 and 63 connected to the chip 100 in opposite directions, to exhibit opposite polarities, respectively. When an excessive voltage higher than a breakdown voltage of the zener diodes 64 is applied to the chip 100 in the circuit of FIG. 14 , current flows through the zener diodes 64 .
[0112] As described above, it may be possible to reflect light emitted from the chip 100 , using the reflection plate 65 which is separately provided at the mount portion 61 of the sub-mount 60 , as described above.
[0113] FIG. 15 illustrates light emitting device chips 100 respectively attached to a plurality of sub-mounts 60 . The sub-mounts 60 are connected to one another, and form a planar structure. Chips 100 are then attached to the connected sub-mounts 60 . Thus, a light emitting device package structure is completely fabricated. The light emitting device package structure is finally separated into individual packages which will be used.
[0114] After completion of the bonding of the chip 100 to the sub-mount 60 , the substrate 10 is separated from the semiconductor layer 20 by irradiating a laser to the bonded structure at the side of the substrate 10 .
[0115] That is, an eximer laser is irradiated to the substrate 10 . The laser beam passes through the substrate 10 , and locally generates heat at the interface between the substrate (sapphire substrate) 10 and the semiconductor layer 20 . The generated heat resolves GaN into Ga and N 2 gas at the interface between the sapphire substrate 10 and the GaN layer of the semiconductor layer 20 . As a result, the sapphire substrate 10 is separated from the semiconductor layer 20 . This process is called a “laser lift off process”.
[0116] Since the separation of the substrate 10 is carried out under the condition in which each chip 100 has been separated from the package structure, but has been still attached to the associated sub-mount 60 , it is possible to reduce the processing time and to maintain a superior thin film quality, as compared to the case in which the laser lift off process is carried out under the condition in which the chip 100 has not been separated from the package structure.
[0117] This is because, although N 2 gas generated during the laser irradiation is spread toward the semiconductor layer 20 , thereby damaging the semiconductor layer 20 , in the latter case, such N 2 gas can be discharged out of the chip 100 at the boundary surfaces of the chip 100 under the condition in which the chip 100 has been separated from the package structure, but has been still attached to the sub-mount 60 , as in the former case.
[0118] After the separation of the substrate 10 , a second electrode 70 is formed at a surface of the semiconductor layer 20 exposed in accordance with the separation of the substrate 10 , as shown in FIGS. 16 to 18 . A wire bonding process is then carried out to connect the second electrode 70 to the negative electrode 63 formed on the sub-mount 60 by a wire 71 .
[0119] In this case, the second electrode 70 may be an n type electrode.
[0120] For the sub-mount 60 , a planar sub-mount as shown in FIG. 16 , a 3D sub-mount as shown in FIG. 17 , or a 3D THI sub-mount as shown in FIG. 18 may be used.
[0121] In the case using a planar sub-mount 60 shown in FIG. 16 , the light emitting device chip 100 is bonded to electrodes 62 and 63 formed on an upper surface of the planar sub-mount 60 . Zener diodes 64 may be formed beneath the electrodes 62 and 63 , respectively.
[0122] In the case using a 3D sub-mount shown in FIG. 17 , the light emitting device chip 100 is bonded to the sub-mount 60 , using a structure as shown in FIG. 12 .
[0123] On the other hand, in the case using a 3D THI sub-mount shown in FIG. 18 , a through hole is formed between adjacent sub-mounts. A positive electrode 62 and a negative electrode 63 are then formed to extend along upper and lower surfaces of each sub-mount through the through hole. Zener diodes 64 are formed on the portions of the electrodes 62 and 63 arranged on the lower surface of each sub-mount.
[0124] In order to achieve an enhancement in the light emission efficiency of the chip 100 , a light extraction pattern, which may have various shapes, may be formed on a light emission surface of the chip 100 .
[0125] The pattern formation may be achieved using various methods. One method is a method using a patterned sapphire substrate (PSS). In accordance with this method, a patterned structure is formed on a sapphire substrate, in order to grow thin films for fabrication of a desired device.
[0126] When the sapphire substrate 10 is separated after the fabrication of the device as described, an irregularity pattern enabling light to be effectively emitted is naturally formed at the light emission surface.
[0127] In addition, it is possible to form a micro pattern on the light emission surface, using attachment of PBC (photonic crystals) or nano particles, or nano imprint.
[0128] Meanwhile, a white light emitting device may be fabricated by coating phosphors, such as yellow phosphors, over the outer surface of the chip 100 after completion of the fabrication of the device.
[0129] In this case, blue light emitted from the GaN-based light emitting device is emitted after being partially absorbed by the yellow phosphors, so that white light is emitted.
[0130] The coating of yellow phosphors may be achieved using various methods, for example, a dispensing method, a screen printing method, or a molding method for an epoxy resin mixed with yellow phosphors.
[0131] Thereafter, a filler is formed on the sub-mount 60 . A lens 80 is then bonded to the sub-mount 60 over the chip 100 . The resulting structure, which has been obtained after completion of the above-described processes carried out for a plurality of sub-mounts 60 , is separated into individual devices. Thus, packaging of light emitting devices is completed.
Second Embodiment
[0132] Hereinafter, a second embodiment of the present invention will be described with reference to FIGS. 20 to 30 . No description may be given of the processes of the second embodiment identical to those of the first embodiment.
[0133] First, a method for manufacturing individual semiconductor light emitting device chips will be described.
[0134] As shown in FIG. 20 , in order to manufacture a light emitting device chip according to this embodiment, a semiconductor layer 20 having a multilayer structure is formed over a sapphire substrate 10 , using a thin film growing method such as a hydride vapor phase epitaxy (HVPE) or a metal organic chemical vapor deposition (MOCVD) method, after formation of a metal buffer layer 90 over the sapphire substrate 10 .
[0135] The growth of the semiconductor layer 20 , which has a multilayer structure, can be achieved by first forming an n type GaN semiconductor layer over the substrate 10 , forming an active layer over the n type GaN semiconductor layer, and forming a p type GaN semiconductor layer over the active layer.
[0136] A first electrode 30 is then formed on the semiconductor layer 20 , as shown in FIG. 21 . The first electrode 30 is a p type electrode or an ohmic electrode, and has a reflection electrode function. Accordingly, the first electrode 30 can achieve an enhancement in light emission efficiency as it reflects light emitted from the active layer of the semiconductor layer 20 . The first electrode 30 may be made of indium tin oxide (ITO).
[0137] A separate support layer 40 may be formed over the first electrode 30 . The support layer 40 may include an anti-diffusion layer 41 . Where plating is carried out over the first electrode 30 , or the support layer 40 is attached to the first electrode 30 , a solder, which may be mainly used in this case, may penetrate into the semiconductor layer 20 in a melted state, so that it may adversely affect light emission characteristics. The anti-diffusion layer 41 functions to avoid such a phenomenon.
[0138] In order to enable a chip to be bonded to a sub-mount, which will be described later, a plate 42 made of a metal such as Cu, Ni, or Au may be subsequently formed on the anti-diffusion layer 41 . For the same purpose, a semiconductor substrate made of, for example, Si, may be attached to the anti-diffusion layer 41 .
[0139] Thereafter, a process for separating the chip structure fabricated as described above into individual unit device chips is carried out. As shown in FIG. 22 , the substrate 10 is first thinned. Scribing is then carried out using a laser, to define regions corresponding to respective unit device chips. Thereafter, a cutting force is applied to the scribed portions of the chip structure in accordance with a mechanical method, thereby causing the chip structure to be separated into individual chips 100 .
[0140] On the other hand, in accordance with another method for manufacturing individual light emitting device chips, individual device chips may be fabricated using a mesa etching process carried out after the growth of the semiconductor layer 20 which has a multilayer structure, as shown in FIG. 24 .
[0141] In the mesa etching process, the semiconductor layer 20 grown over the substrate 10 is etched until the n type semiconductor layer is exposed in each device chip region.
[0142] In this case, as shown in FIG. 25 , a first electrode 30 is then formed. Subsequently, a passivation layer 50 is formed to protect the first electrode 30 and surfaces exposed in accordance with the etching process. Thereafter, a support layer 40 is formed, as shown in FIG. 26 . The support layer 40 may include a metal plate made of a metal such as Cu, Ni, or Au.
[0143] Subsequently, a process for thinning the substrate 10 , performing laser scribing, and separating chips is carried out in the same manner as described above. Each separated chip 100 has a structure as shown in FIG. 27 .
[0144] Alternatively, device chips may be fabricated by performing, in place of the mesa etching process, a trench etching process in which the semiconductor layer 20 is etched until the substrate 10 is exposed, as shown in FIG. 28 .
[0145] The remaining processes are identical to those in the above-described case. Each chip 100 , which is finally obtained, has a structure as shown in FIG. 29 .
[0146] As shown in FIG. 30 , each chip 100 is bonded to a sub-mount 60 which is separately fabricated. The bonding of the chip 100 is carried out such that the first electrode 30 of the chip 100 is attached to electrodes 62 and 63 formed on a mounting portion 61 of the sub-mount 60 .
[0147] For the sub-mount 60 , a substrate made of Si, MN ceramic, AlO x , Al 2 O 3 , or BeO, or a PCB substrate may be used. Zener diodes 64 may be formed at the sub-mount 60 , to achieve an improvement in electrostatic discharge (ESD) property. Also, a reflection plate 65 may be formed to achieve an enhancement in light emission efficiency.
[0148] After completion of the bonding of the chip 100 to the sub-mount 60 , the substrate 10 is separated from the semiconductor layer 20 by etching the metal buffer layer 90 of the chip 100 .
[0149] Thereafter, a second electrode is formed at a surface exposed in accordance with the separation of the substrate 10 . A packaging process involving a wire bonding process is then carried out. This process is identical to that of the first embodiment.
[0150] It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | A light emitting device having a vertical structure and a package thereof, which are capable of damping impact generated in a substrate separation process, and achieving an improvement in mass productivity. The device and package include a sub-mount, a first-type electrode, a second-type electrode, a light emitting device, a zener diode, and a lens on the sub-mount. | 7 |
FIELD OF THE INVENTION
This invention relates generally to raster scan cathode ray tube displays and more specifically to stroke writing during vertical retrace periods with such displays.
BACKGROUND OF THE INVENTION
Prior art television type raster scan cathode ray tube displays are used in certain applications wherein data to be displayed comes from two sources and this data is displayed during two sequential periods of time during the operation of the display. That is, during normal raster scan writing of data and then during each vertical retrace period. Typically, data written during the vertical retrace period is written using stroke writing techniques. The conventional vertical deflection amplifier is a linear amplifier that can be used for both raster and stroke writing operation. However, unlike the slow speed vertical deflection amplifier, the high speed horizontal deflection amplifier in most television raster displays is not a linear amplifier. The horizontal deflection amplifier functions as a power control or switching system which dissipates only a fraction of the large circulating wattless power required to deflect the beam in the horizontal direction. If a linear amplifier were used this large wattless power would be uselessly dissipated as heat in the deflection amplifier. Since a linear amplifier is required for stroke writing, the typical horizontal amplifier circuit cannot be used. Furthermore, in most television displays a portion of the horizontal retrace energy is used to generate the high voltage CRT anode potential and other potentials required in the display. If the horizontal deflection amplifier were to be used for stroke writing for any significant period, this power generating capability would not be possible, and a separate costly power supply would be required.
Thus, there is a need in the art for a horizontal raster deflection and stroke writing amplifier arrangement that minimizes power usage, and does not interfere with the ability to utilize the horizontal flyback energy as a D.C. power source.
SUMMARY OF THE INVENTION
The foregoing need of the prior art is satisfied by my invention. I provide a novel horizontal raster deflection and stroke writing amplifier arrangement that minimizes power usage and doesn't interfere with the use of the horizontal flyback energy to develop the high D.C. voltage required by the CRT anode. I utilize a first amplifier that is a conventional synchronous deflection amplifier having an input from a horizontal oscillator to provide a horizontal deflection signal to the horizontal coil of the deflection yoke on the neck of a cathode ray tube only during raster scan writing periods. During vertical retrace periods an electronic analog switch is used to disconnect synchronous horizontal deflection amplifier from the horizontal coil of the deflection yoke and reconnects it to a dummy yoke or coil which is an inductor having the same inductance as the horizontal coil. The analog switch reconnects the synchronous horizontal deflection amplifier to the horizontal coil of the deflection yoke at the end of the vertical retrace period. This procedure is repeated during every vertical retrace period. By this switching operation and use of a dummy yoke the operation of the synchronous horizontal deflection amplifier is not interrupted.
Because a conventional synchronous horizontal deflection amplifier and oscillator is used a conventional television type high voltage power supply basically consisting of a high voltage rectifier and step-up flyback transformer may be utilized to provide the high D.C. voltage required by the anode of the CRT.
To provide stroke writing of data on the face of the CRT during vertical retrace a linear amplifier amplifying stroke writing signals obtained from a conventional source is also provided which is connected to the horizontal coil of the deflection yoke via the analog switch only during the vertical retrace period. With the linear deflection amplifier being connected to the deflection yoke only a relatively small percentage of the time the power required by the linear amplifier is greatly reduced. In addition, an analog switch is used to connect the vertical oscillator to the linear vertical deflection amplifier during the raster scan period and to connect stroke writing signals obtained from the conventional source during the vertical retrace period.
DESCRIPTION OF THE DRAWING
My invention will be better understood on reading the following detailed description in conjunction with the drawing in which:
FIG. 1 is a simplified schematic block diagram of the invention;
FIG. 2 is a graph showing conventional raster scan horizontal and vertical deflection waveforms and waveforms output from the zero crossing detector and threshold detector in the switch control circuit;
FIG. 3 is a schematic diagram of the invention; and
FIG. 4 shows timing diagrams necessary for understanding the operation of the switch control circuit.
DETAILED DESCRIPTION
In FIG. 1 is shown a simplified block diagram of my novel invention which is a modification of the conventional horizontal and vertical raster scan sweep circuits of a television type display. The conventional deflection circuitry comprises the following. A horizontal oscillator (not shown) and synchronous horizontal deflection amplifier 11 are used which generate a periodic ramp current waveform shown in FIG. 2(A) which is the waveform of the current that normally flows in horizontal coil 27 of deflection yoke 14. A vertical oscillator (not shown) and vertical deflection amplifier 15 are used which provide a periodic ramp waveform shown in FIG. 2(C) which is normally applied to vertical coil 26 of deflection yoke 14. Deflection yoke 14 is a modified conventional yoke having lower inductance vertical and horizontal coils 26 and 27 required to be used for both raster scan deflection and stroke writing operation. Finally, a conventional deflection flyback transformer 42 and high voltage rectifier 43 are used to provide the high voltage D.C. voltage required for the CRT anode. All this conventional circuitry operates in a manner well known in the television art and is not described in detail herein.
To this conventional deflection circuitry I add linear amplifier 10, analog switches 28, 29 and 39, switch control 13, dummy horizontal deflection coil 25, and conventional circuitry for providing horizontal and vertical stroke writing signals (not shown). With this additional circuitry switch control 13 functions to control electronic analog switches 28 and 29 to connect the horizontal oscillator (not shown) and synchronous horizontal deflection amplifier 11 to horizontal coil 27 of deflection yoke 14 during the normal raster scan period on the face of a cathode ray tube (not shown). During each normal vertical retrace period, when it is desired to display other information on the face of the cathode ray tube using stroke writing techniques, switch control circuit 13 operates analog switches 28 and 29 to reconnect synchronous amplifier 11 to dummy horizontal deflection coil 25 to permit it to function without interruption, and also to connect linear amplifier 10 to horizontal coil 27 of deflection yoke 14. At all times vertical deflection amplifier 15 is connected to vertical coil 26 of deflection yoke 14 and switch control circuit 13 controls analog switch 39 to change the deflection signal applied to its input signal. Vertical deflection amplifier 15 has the vertical oscillator connected to its input during the normal raster scan period, and has the vertical stroke deflection signal applied to its input during the vertical retrace period. This can be done since vertical amplifier 15 is a linear amplifier that can handle both types of signals. In contrast, synchronous horizontal deflection amplifier 11 is not designed to handle stroke deflection signals so such deflection signals must be applied via linear amplifier 10 to horizontal coil 27. In addition, the use of a linear horizontal deflection amplifier during the vertical retrace period would preclude the use of a simple high voltage power supply in the form of a rectifier and step-up flyback transformer using the high voltage surges created during each horizontal retrace period to provide the high D.C. voltage required by the CRT anode. Accordingly, a relatively expensive high voltage power supply would have to be used to provide the CRT anode voltage. To accommodate this a dummy horizontal deflection coil 25 is connected via analog switch 29 to the output of synchronous horizontal deflection amplifier 11 during the vertical retrace period so that the oscillatory operation of synchronous amplifier 11 may continue uninterrupted and the simple conventional high voltage power supply in the form of high voltage rectifier 43 and step-up flyback transformer 42 may use the high voltage surges created during the horizontal retrace period to provide the high D.C. voltage required by the CRT anode. This precludes the requirement for a relatively expensive high voltage power supply to provide the CRT anode voltage. In analog switches 28, 29 and 39 are shown contacts 16 through 19, 40 and 41. Contacts 16, 18 and 41 are normally open and only close a path therethrough upon the operation of switches 28, 29 and 39 under control circuit 13. Contacts 17, 19 and 40 are normally closed and open the paths through these contacts when analog switches 28, 29 and 39 are operated. In reality analog switches 28, 29 and 39 do not have electromechanical switch contacts such as shown in these switches in FIG. 1. This representation is only for ease of understanding what elements are connected or disconnected during the function of my invention. An example electronic analog switch is the type AD7512D1 analog switch manufactured by Analog Devices Inc. in Norwood, Mass.
Switch control circuit 13 senses the outputs from synchronous horizontal deflection amplifier 11 and vertical deflection amplifier 15 and provides a control signal via lead 24 to operate analog switches 28, 29 and 39 during each vertical retrace period. Switch control circuit 13 releases analog switches 28, 29 and 39 during the normal raster scan period. During normal raster scan the output of synchronous amplifier 11 is connected via normally closed contact 19 and lead 20 to horizontal coil 27 of deflection yoke 14, and the output of linear deflection amplifier 10 is connected via normally closed contact 17 to a dummy load resistance R. During this same period the output of the vertical oscillator (not shown) is connected via normally closed contact 40 of analog switch 39 to the input of vertical deflection amplifier 15 which drives vertical coil 26 of deflection yoke 14. With the connections just described and the signals being applied thereby to deflection yoke 14, the electron beam of the cathode ray tube (not shown) is deflected to accomplish normal raster scanning. The electron beam is intensity modulated in a manner well known in the art to display information on the face of the cathode ray tube.
At the end of the normal raster scanning period, and just before the beginning of the vertical retrace period, switch control circuit 13 operates analog switches 28, 29 and 39 to open contacts 17, 19 and 40 and to close contacts 16, 18 and 41. Accordingly, the output of synchronous amplifier 11 is connected via contact 18 and lead 21 to dummy horizontal deflection coil 25 so that synchronous amplifier 11 along with its horizontal oscillator input, and flyback transformer 42 with high voltage rectifier 43 may all continue to operate in their conventional manner. The stroke deflection signals being amplified by linear amplifier 10 are now connected via contact 16 and lead 20 to horizontal coil 27 of deflection yoke 14. During this same period the output of the vertical oscillator (not shown) is disconnected from the input of vertical deflection amplifier 15 due to the opening of contact 40 and, instead, a vertical stroke deflection signal is input to vertical amplifier 15 via contact 41 to be amplified and applied to vertical coil 26 of deflection yoke 14. In this manner, during the vertical retrace period stroke deflection signals are applied to vertical coil 26 and horizontal coil 27 of deflection yoke 14, while the horizontal oscillator, synchronous horizontal deflection amplifier 11, flyback transformer 42 and high voltage rectifier 43 continue to function normally.
In FIG. 2 are shown four waveforms in FIGS. 2A, 2B, 2C and 2D. FIG. 2A shows a representation of the horizontal deflection current in the horizontal coil of the deflection yoke of a conventional television receiver. This is the same vaveform of the current in horizontal coil 27 of deflection yoke 14 during the normal raster scanning period. It can be seen that the horizontal deflection signal is oscillatory in nature. The time period for one cycle of the horizontal deflection signal, which is the time it takes the electron beam to sweep one horizontal sweep across the face of the cathode ray tube and return and be ready to commence sweeping another horizontal sweep is the time t 1 shown in FIG. 2A. Time t 1 is further broken down into time t 2 which is the time it takes the electron beam to sweep across the face of the CRT for a single horizontal scan. The time t 3 is the horizontal retrace time, which is the time in which the electron beam is blanked and retraces from the right hand edge of the face of the CRT back to the left hand edge of the CRT to be ready to commence the next raster scan line.
FIG. 2B shows a number of periodic pulses having the same frequency as the horizontal deflection signal shown in FIG. 2A. These pulse waveforms shown in FIG. 2B are generated by the zero crossing detector 31 in switch control circuit 13 shown in FIG. 3, and is described in detail further in the specification. In FIG. 2A it can be seen that the periodic horizontal deflection signal passes through zero once in the positive sense during horizontal sweep at time t 0 and once in the negative sense during horizontal retrace time. Zero crossing detector 31 in switch control circuit 13 in FIG. 3 responds only to a signal passing through zero in the positive sense or direction and generates a pulse which are the pulses shown in waveform 2B. An example of a commercially available zero crossing detector is the GEL300 Zero Voltage Switch available from the General Electric Company.
In FIG. 2C is shown the waveform of a single cycle of the periodic vertical deflection signal output from vertical amplifier 15 to vertical coil 26 of deflection yoke 14 during normal raster scan. The time base in FIG. 2C is not the same as the time base for FIGS. 2A and 2B. As is known in the art there are 2621/2 horizontal scan lines traced during each vertical trace on the face of the cathode ray tube to make up one scan field. Two interlaced fields make up a 525 scan line frame. The overall time for one vertical deflection waveform is t 4 , which is made up of the vertical sweep time t 5 and the vertical retrace time t 6 . It is during this vertical retrace time, that the electron beam is normally blanked and is being returned to the upper left hand corner of the cathode ray tube to commense scanning another scan field. It is during this vertical retrace time t 6 , which is equal approximately to the time it takes to horizontally scan 30 to 40 lines, that stroke writing of information is to be accomplished on the face of the CRT. Also in FIG. 2C is a Threshold Level and two times t 7 and t 8 . As will be described in detail hereinafter with reference to FIG. 3, in switch control 13 is a threshold detector 32 to which the output of the vertical deflection amplifier 15 is applied via lead 23. During the time that the amplitude of the vertical deflection signal exceeds a defined figure, herein the Threshold Level, there is an output from threshold detector 32 the waveform of which is shown in FIG. 2D. The period of time between times t 7 and t 8 is the period during which the amplitude of the vertical deflection signal exceeds the Threshold Level. A Threshold Level detector may be implemented using a differential amplifier as is well known in the art.
Turning now to FIG. 3, therein is shown a schematic diagram of my invention. Most of the elements are shown in block diagram form because they are known in the prior television receiver art or are well known elements such as linear amplifier 10, analog switches 28, 29 and 39, zero crossing detector 31 and threshold detector 32. The operation of deflection flyback transformer 42 and high voltage rectifier 43 are well known in the art and so are not described. The details of the switching functions of analog switches 28, 29 and 39 were previously described in detail with reference to FIG. 1 wherein contact configurations are shown so only the results of the operation of the switches are summarized as required hereinafter in the specification.
The operation of the circuitry within switch control circuit 13 is now described with reference to FIG. 4 in the subfigures of which are shown the timing diagrams necessary to understand the operation of the circuitry within switch control circuit 13. There are two inputs to switch control circuit 13 and one output therefrom. One of the inputs is the horizontal sweep deflection signal and is input via lead 22. The other input is the vertical sweep deflection signal which is input via lead 23. The output from switch control circuit 13 is on lead 24 and is used to operate analog switches 28, 29 and 39. As previously generally described in this specification, switch control circuit 13 operates analog switches 28, 29 and 39 such that during the normal raster scan period the periodic horizontal deflection signal generated by the combination of the horizontal oscillator, synchronous amplifier 11 and deflection flyback transformer 42 is connected through analog switch 29 and over lead 20 to horizontal coil 27 within deflection yoke 14. During this period of time in which a single field is scanned on the face of the cathode ray tube the output of the vertical oscillator is applied through analog switch 39 and vertical amplifier 15 to vertical coil 26 of deflection yoke 14. At the end of the scan field, at the beginning of the vertical retrace period switch control 13 operates analog switches 28, 29 and 39 to connect the periodic horizontal deflection signals to dummy horizontal deflection coil 25 and to connect the horizontal stroke deflection signals amplified by linear amplifier 10 to horizontal coil 27 of deflection yoke 14, and to connect the vertical stroke deflection signals amplified by vertical amplifier 15 to vertical coil 26 of deflection yoke 14. With reference to FIG. 2A, the switching action to operate or release analog switches 28, 29 and 39 is accomplished when the horizontal raster deflection signal is passing through zero at time t 0 in order to avoid transients that disrupt the operation of the circuitry. Accordingly, zero crossing detector 31 in circuit 13 monitors the horizontal raster deflection signal and provides the pulse output shown in FIG. 2B each time the horizontal raster deflection signal pass through zero in the positive sense such as at time t 0 . These pulse signals generated by zero crossing detector 31 are used to synchronize the operation of the other circuitry within switch control circuit 13 to assure that analog switches 28, 29 and 39 are operated and released only in synchronization with the occurrence of a positive sense zero crossing of the horizontal raster deflection signals to avoid transient problems.
In FIG. 4A is another representation of the pulses generated by zero crossing detector 31 responsive to each cycle of the horizontal raster deflection signal. The time base of FIG. 4A is merely different than the time base of the same pulses shown in FIG. 2B.
As described briefly heretofore threshold detector 32 monitors the vertical raster deflection signals and provides an output during the time when the amplitude of the vertical raster deflection signal exceeds a predetermined Threshold Level between times t 7 and t 8 as shown in FIG. 4B. Thus, there is an output from threshold detector 32 starting immediately before the end of the vertical raster deflection signal to indicate that the vertical retrace period is about to start. It should be noted that there are two output signals from threshold detector 32 shown in FIG. 4B indicating that there are two vertical trace periods. The breaks within the time base of each of the waveforms of FIG. 4A through 4H are necessary to accurately show the operation of the circuitry within switch control circuit 13. For example, within the actual period of time between times t 9 and t 11 shown in FIG. 4C there occur in the order of 40 pulses from zero crossing detector 31. As this would be difficult to show the dotted lines are used on the time base. Similarly, during a raster scan field there are in the order of 262 pulses from zero crossing detector 31, almost all of which are deleted by the use of the dotted lines on the time base.
Before continuing with a description of the circuitry within switch control circuit 13, I briefly mention a few of the individual circuits used therein that have not been mentioned heretofor. Gates 33, 36 and 37 are known in the art and include inverting inputs which are used as shown in FIG. 3. Flip-flop 34 is well known in the art and is a flip-flop having a set input S and a reset input R, and when a pulse is applied to the set input S the output of this flip-flop goes to a one state and remains there until a pulse is applied to the reset input R of flip-flop 34 at which time the output goes to a zero state. One-shot multivibrator 38 is also well known in the art and functions such that when a pulse is applied to its input its output goes to a one state for a given period of time at the end of which it returns to a zero state. In addition, if multiple pulses are applied to the input of one-shot multivibrator 38 before the time out period for this multivibrator the timing period will be restarted by each pulse.
Upon threshold detector 32 detecting that the vertical raster deflection signal is near its peak, indicating the end of the vertical deflection period, there is the output from detector 32 commencing at time t 7 as shown in FIG. 4B. The output from detector 32 ends at time t 8 very shortly after the beginning of the vertical retrace period. Within the time period between times t 7 and t 8 approximately three horizontal scan lines occur as represented by the pulses in FIG. 4A starting at time t 9 . There is no information displayed on the face of the cathode ray tube during these last few scan lines. The output from threshold detector 32, which is at a one state between times t 7 and t 8 , is connected to one of the two inputs of AND gate 33. The other input of AND gate 33 is connected to the output of zero crossing detector 31 which provides an output for each cycle of the horizontal deflection signal as shown in FIG. 4A. The result is that there is an output from AND gate 33 only when both inputs are at a one state. This occurs for the three zero crossing pulses output from zero crossing detector 31 starting at time t 9 as shown in FIG. 4A. The first output pulse occurring at time t 9 is applied to the set input S of flip-flop 34 and sets this flip-flop so that its output goes to a one state. This output from flip-flop 34 is applied via lead 24 to operate analog switches 28, 29 and 39. The operation of flip-flop 34 is represented by the waveform in FIG. 4C. It can be seen in FIG. 4C that the operation of flip-flop 34 is synchronized with the zero crossing pulses and goes to its one state starting at time t 9 . Flip-flop 34 remains in its one state until a time t 11 that is also synchronized with a zero crossing and occurs shortly after the end of the vertical retrace period.
The output of flip-flop 34 is also connected to the inverting input of AND gate 37. Due to the operation of the inverting input of AND gate 37 the waveform of the signal actually applied to this input is inverted as shown in FIG. 4D. It is merely an inversion of the waveform shown in FIG. 4C. The second uninverted input of AND gate 37 is connected to the output of zero crossing detector 31 and therefore has the zero crossing pulses shown in FIG. 4A applied thereto. Before the operation of flip-flop 34, which is prior to time t 9 , due to the inverting action of the inverting input of AND gate 37, the inverting input is at a one state. Thus, upon the occurrence of each pulse output from zero crossing detector 31 there is a pulse output from AND gate 37 as shown in FIG. 4E which pulses are applied to the triggering input of one-shot multivibrator 38. As the time between each of the pulses applied to the triggering input of multivibrator 38 is shorter than its time out period, the multivibrator starts its timing period with each pulse but does not finish timing out so its output remains in its one state. Each subsequent pulse restarts the timing period of one-shot multivibrator 38 until flip-flop 34 is operated causing the inverting input of AND gate 37, after inversion, to go to its zero state which blocks further pulses from being output from AND gate 37. This operation is shown in FIG. 4E. Thus, the last pulse output from AND gate 37 at time t 9 restarts the timing sequence of one-shot multivibrator 38 which now finishes timing out at time t 10 and the output of multivibrator 38 then goes to its zero state as shown in FIG. 4F. The output of one-shot multivibrator 38 is connected to the inverting input of the two inputs and AND gate 36. Due to the inverting action, when the output of one-shot multivibrator 38 is in its one state up time t 10 , as shown in FIG. 4F, the inverted input of AND gate 36 is at its zero state as shown in FIG. 4G. This prevents any signal from passing through AND gate 36. The second input of AND gate 36 is uninverted and is connected to the output of zero crossing detector 31 to have the zero crossing pulses input thereto. Thus, after one-shot multivibrator 38 times out at time t 10 the inverted input of AND gate 36 goes to its one state and the next occurring zero crossing pulse output from zero crossing detector 31 passes through AND gate 36 as shown in FIG. 4H. This pulse passed through AND gate 36 is applied to the reset input R of flip-flop 34 causing the flip-flop to be reset and its output goes back to its zero state. This results in the release of analog switches 28, 29 and 39. The time out period of multivibrator 38 is designed such that it times out at time t 10 which occurs immediately after the end of the vertical retrace period as shown in FIG. 4F. Thus, with the operation of the circuitry within switch control circuit 13 as just described analog switches 28, 29 and 39 are operated immediately prior to the occurrence of the vertical retrace period and are released immediately after the end of the vertical retrace period. Both the operation and release of analog switches 28, 29 and 39 occur on the appearance of a positive sense zero crossing of the horizontal deflection signals.
Due to inherent propogation delays in the operation of switch control circuit 13 analog switches may be operated and released a moment after the actual horizontal raster deflection signals zero crossing. To compensate for this delay an offset bias may be applied to zero crossing detector 31 which causes it to trigger and provide a pulse output immediately before each zero crossing. Thus, even with the propogation delays analog switches 28, 29 and 39 are operated upon the actual occurrence of zero crossings.
While what has been described hereinabove is a preferred embodiment of the invention those skilled in the art will realize that many changes may be made without departing from the spirit and scope of the invention. For instance timing circuitry may be utilized in switch control circuit 13 rather than the circuitry shown. | A Raster and Stroke Writing Deflection Amplifier Arrangement for a cathode ray tube (CRT) is disclosed which uses a conventional vertical oscillator and vertical deflection amplifier and a conventional horizontal oscillator and synchronous horizontal deflection amplifier, both driving deflection coils for providing vertical and low power horizontal scan operation for raster scan writing of data, and a flyback transformer and rectifier for providing the high D.C. voltage required by the CRT anode by rectification of high surge voltages created during horizontal retrace periods. During each vertical retrace period a switch connects the synchronous horizontal deflection amplifier to a dummy yoke at a zero crossing of the horizontal deflection signal for uninterrupted operation, connects a source of horizontal stroke writing signals amplified by a linear amplifier to the deflection coil, and also connects a source of vertical stroke writing signals to the vertical deflection amplifier to drive the deflection coil to accomplish stroke writing of information during each vertical retrace period. | 6 |
DEDICATORY CLAUSE
The invention described herein may be manufactured or used by or for the Government for governmental purposes without the payment to us of any royalties thereon.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 288,455, filed Sept. 12, 1972, which was in turn a continuation of application Ser. No. 871,746, filed Oct. 9, 1969, which was in turn a continuation of application Ser. No. 516,160, filed Dec. 23, 1965 all abandoned.
BACKGROUND OF THE INVENTION
The use of semi-active homing guidance for a missile, of itself, is known. A radar beam is usually employed as the target illuminator and the missile homes on the reflected illumination from said radar beam. A radar illuminator suffers from weight and complexity disadvantages and is not readily adaptable to being carried and operated by a single man. The present invention uses a compact, portable laser illuminator which could be carried and operated by a single man.
There are known missile guidance systems which can be carried by a single man such as the Redeye missile, which uses a man carried optical target tracking telescope with an infrared homing-all-the-way guidance system on the missile. Another type of guidance system that can be man carried is that used by Entac, which uses a missile command-guided over trailing wires by means of a manually operated "joy-stick" control box. The missile, itself, can be transported separately from the control box.
The Redeye missile is used against aircraft and could not effectively track land targets because of the infrared radiation clutter from the ground. The Entac missile has the disadvantage of using trailing wires and could not be used effectively against aircraft.
The invention does not rely upon radiation from the target and does not employ trailing wires or other command links and can be effective against air or ground targets.
Another object of the invention is to provide a system for intercepting a target by using a missile homing on reflected laser illumination of the target.
BRIEF DESCRIPTION OF THE DRAWING
The invention may be best understood by reference to the drawing, which shows the missile system according to this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In the drawing, numeral 1 designates a tank whose destruction is desired. An operator 2 has a laser generator 3, which provides a coherent light beam, with a telescope 4 mounted thereon. Optics 5 focus the laser illumination into a narrow collimated, coherent light beam 6, with which the operator illuminates the target tank (by sighting through telescope 4). A missile 7 is fired from a launcher (not shown) and, through a detector in its forward portion 8, receives reflected illumination 9 from target 1. The missile homes on such reflected illumination intercepts and destroys the target. Narrow collimated beam 6 has a small cross sectional area with respect to the area of the target to discretely illuminate the target.
While the invention has thus far shown interception and destruction of a land vehicle, other types of targets may be destroyed in accord with the invention. The operator 2 could direct the beam of his laser illuminator on targets such as gun emplacement 10, aircraft 11, ship 12, or men 13 and the missile would home on such targets.
The laser illumination could either be visible or infrared radiation, as desired. Obviously, missile 7 would need the proper detector in accord with the illuminating radiation used. Said missile could be of any desired configuration, such as high explosive, antipersonnel, armor piercing, etc., with a contact, magnetic proximity, or any desired fusing. The launcher for missile 7 could be adjacent operator 2 or could be located away from the operator but so located that missile 7 would be able to detect the reflected target illumination after launching. An example of a form that missile 7 could take is the missile as shown in U.S. Pat. No. 2,969,018 of Jan. 24, 1961, to S. J. Erst et al. Laser illuminator 3 could take any one of various forms, such as those forms shown in British Patent Specification No. 957,235 of May 6, 1964 and in Sperry Engineering Review, Winter 1962 (pp. 44-53).
While a specific embodiment of the invention has been described, other embodiments may be obvious to one skilled in the art in light of this description. The laser illuminator could obviously be vehicle carried, if desired, and would find use in helicopters or other aircrafts, land vehicles including ground effect machines, and watercraft. | A system for intercepting a target with a missile having semi-active homing guidance. The target is discretely illuminated by a laser beam and the missile homes on the reflected illumination from the target. | 5 |
TECHNICAL FIELD
This disclosure relates to a compression ignition, internal combustion engine. More specifically this disclosure relates to a piston with improved performance.
BACKGROUND
Design of internal combustion engines requires delicately balancing competing requirements of low emissions and low fuel consumption. Governments generally limit the production of various emissions including NOx, smoke, soot, and unburned hydrocarbons. Reducing NOx emissions may be accomplished through various techniques. Many of these techniques require lowering combustion temperatures and in turn increasing fuel consumption.
Users of the engines in industrial environments such as work machines require that they operate over a wide range of speeds and loads while still meeting the emission requirements and while achieving reasonable fuel consumption. In particular, high speed (up to 2500 rpm), medium-bore (cylinder bores between 100 mm and 175 mm), compression ignition engines used in work machines may repeatedly cycle between a high speed, high load condition and an idle condition. Meeting emissions requirements through these transients requires a flexible combustion system. Additionally, compared with light duty operation seen in automotive engines, these engines operate a larger portion of their life in conditions that may contribute to fouling of fuel injectors.
To meet these challenges, designers must work with various tools to achieve a combustion cycle that meets the above needs. These tools include fuel injection equipment, air flow control, and design of the combustion chamber. In small bore (bore diameters of less than 100 mm) engines, air system geometries may be used to introduce air into the combustion chamber in a manner that generates swirling motion within the combustion chamber. The smaller bore engines may operate at higher speeds (in excess of 2500 rpm) and require faster mixing of fuel and air. The air system creates a swirling motion to increase mixing of fuel and air. Combustion chambers with swirl tend to have a narrower throat area compared with the overall piston diameter as shown in U.S. Pat. No. 5,000,144 issued to Schweinzer et al. on 19 Mar. 1991 and European Patent Application No. 0 911 500 published on 28 Apr. 1999. The narrow throat area creates a greater squish area between a top of the piston and cylinder head. Fuel injected into these combustion chambers is intended to enter a torroidal portion without contacting a floor portion. Schweinzer also shows a recess that allows the piston to approach a top dead center position in the cylinder without hitting a fuel injector tip. However, Schweinzer does not discuss interaction of air in the recess with performance of the injector.
Large-bore (180 mm diameter or greater), medium speed (between 900 and 1500 rpm), compression ignition engines tend to use quiescent or semi-quiescent open combustion chamber designs. These designs introduce air into the combustion chamber in a manner that generates little or no swirling motion of the gases about a central axis of the combustion chamber. Higher fuel injection pressures in these types of combustion chambers create motion to promote mixing of fuel and air. Also, finer drop sizes increase surface area exposed to air. These combustion chamber designs also have less squish area available to provide air to the torroidal section. U.S. Pat. No. 7,438,039 issued to Poola et al. on 21 Oct. 2008 discloses using an acute angle reentrant on a large bore, medium speed diesel to improve air flow in a quiescent or semiquiescent combustion chamber. Poola also teaches placing a recess near a tip of the fuel injector. The recess in Poola generally is thought of as an aid in removal of the piston from the engine for servicing. Again, Poola does not explain the interaction of air in the recess with fuel injector tip.
None of these references discuss the importance of improved air flow around the tip of the fuel injector. Without appropriate air flow, combustion characteristics of the engine may change over the its life or during certain conditions. For instance, high temperatures about the tip of the injector may cause increased fouling of the fuel injector tip over time. These changes may reduce the ability of the engine to meet both the customer requirements of low fuel consumption and the regulatory requirement of low emissions.
The current piston disclosed in this application addresses one or more aspects set out above to improve combustion in a medium-bore, high speed, compression ignition engine.
SUMMARY OF INVENTION
In a first aspect a piston for an engine is disclosed having a crown portion with an outer diameter and an inner diameter wherein a ratio the inner diameter to outer diameter is greater than 0.65. The piston is a reentrant design bowl including a reentrant portion, torroidal portion, and floor portion leading to a recess portion about a central axis of the piston. The floor portion has a floor angle of about 65 to 70 degrees. The recess portion has a recess depth that is less than a maximum bowl depth.
In a further aspect, a piston for an internal combustion engine is disclosed having a crown portion having an outer diameter and an inner diameter wherein a ratio of the inner diameter to the outer diameter is greater than 0.65. The reentrant bowl design includes a reentrant portion, torroidal portion, and a floor portion. A recess portion is connected to the floor portion by a recess transition portion. The recess portion has a recess depth that is less than the bowl depth.
In yet another aspect, a piston for an internal combustion engine is disclosed having a crown positioned about a central axis. An outer diameter of the crown is about 105 mm and the ratio of the inner diameter to the outer diameter is between about 0.65 and 0.75. The reentrant bowl design includes a reentrant portion with a reentrant angle of about 63 to 68 degrees. A torroidal portion defines a maximum bowl depth. A recess portion has a ratio of a recess diameter to the inner diameter being about 0.09.
These and additional features will become clearer from the following specification of a preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a partial cross-sectional view of a compression ignition engine;
FIG. 2 shows a cross-sectional view of the piston of FIG. 1 ;
FIG. 3 shows a top view of the piston of FIG. 2 .
FIG. 4 shows an enlarged cross-sectional detail of “A” in FIG. 2 ; and
DETAILED DESCRIPTION
Reference will now be made in detail to specific embodiments or features, examples of which are illustrated in the accompanying drawings. Generally, the same or corresponding reference numbers will be used throughout the drawings to refer to the same or corresponding parts. It should be appreciated that the terms “upper,” “lower,” “top,” “bottom,” “up,” “down,” and other terms related to orientation are being used solely to facilitate the description of the objects as they are depicted in the figures and should not be viewed as limiting the scope of this description to the orientations associated with each of these terms. All dimensions provided should be understood to include conventional tolerances associated with manufacturing processes such as machining, casting, or the like.
As best shown in FIG. 1 , an engine 10 is made up of a block 20 defining a cylinder 30 . A piston 40 is positioned in the cylinder in a slideable manner. The cylinder 30 may also be formed by a cylinder liner (not shown) positioned in the block 20 wherein the cylinder liner defines the cylinder 30 . A cylinder head 50 connects to the block 20 . The cylinder head 50 has a cylinder facing portion 60 . The cylinder facing portion 60 , the piston 40 , and the cylinder 30 define a combustion chamber 70 . A fuel injector 80 is positioned in the cylinder head 50 and has a tip portion 90 with a plurality of nozzles (not shown) adapted to direct fuel into the combustion chamber 70 . The cylinder head 50 also defines at least one inlet port 100 and at least one exhaust port 110 . An inlet valve 120 moves within the cylinder head 50 to at least partially block the inlet port 100 . Similarly, an exhaust valve 130 is positioned in the cylinder head 50 to at least partially block the exhaust port 130 . The tip portion 90 of the fuel injector 80 has an injection angle IA where the injection angle IA is defined as angle between a piston central axis 140 and a nozzle central axis 150 .
The piston as shown in FIG. 2 has a land 160 , a skirt 170 , a crown 180 , and a bowl 190 . The land 160 has a first end portion 200 and a second end portion 210 . The second end portion contains a ring groove 220 . The crown portion 180 is proximate the second end portion 210 of the land portion 160 . The skirt 170 is adjacent the first end portion 200 of the land 160 . The bowl 190 has a bowl volume Vb defined by a crown transition portion 250 , a reentrant portion 260 , a torroidal portion 270 , a floor portion 280 , and a recess portion 290 . In the present embodiment, the bowl volume Vb is about 57 cc. The crown transition portion 250 is preferably a radius of 1.5 mm that transitions from the crown 180 to the reentrant portion 260 . However, a smaller radius or edge may also be used for the crown transition portion 250 . The reentrant portion 260 is a partial conical surface connecting the crown transition portion 250 with the torroidal portion 270 and has a reentrant angle RA of between 63 and 68 degrees with the crown 180 . The recess portion 290 is a partial spherical surface formed by a radius of about 9 mm with a recess depth 295 of about 9.4 mm from the crown 180 . The recess portion 290 in the present embodiment has a volume Vr of about 0.1 cc. The volume of the recess may also be described by the equation Vr≧KVb where K is a constant of about 0.002.
The crown 180 as best shown in FIG. 3 is ring shaped and has an inner diameter 230 measured from the intersection of the crown transition portion with the crown 180 . An outer diameter of the crown 240 is measured from the land 160 . The recess portion 290 has a recess diameter 297 measured at a location where a line tangent to the recess portion is perpendicular with the piston central axis. In the present embodiment, the outer diameter is about 105 mm. The ratio of the inner diameter 230 to outer diameter 240 is between 0.65 and 0.75. The ratio of the recess diameter 297 to the inner diameter 240 is about 0.09.
Greater detail of the floor portion in FIG. 4 shows a floor angle FA of between 65 and 70 degrees defined in reference to the piston central axis 140 . The recess transition portion 300 connects the floor portion 280 with the recess portion 290 . A floor transition portion 310 connects the floor portion 280 with the torroidal portion 270 . Both the recess transition portion 300 and the floor transition portion 310 may be formed by radiuses of 3 mm or less. The torroidal portion 270 is formed by a radius 320 and connects the floor transition portion 310 with the reentrant portion 260 . In this embodiment, the radius 320 is about 9 mm with maximum bowl depth 330 of about 16.8 mm.
Industrial Applicability
During operation, the piston 40 moves downward drawing an oxidant like air through the inlet port 100 past the intake valve 120 (intake stroke). The inlet port 100 closes at some time prior to operation of the fuel injector 80 introducing fuel into the combustion chamber 70 . As the piston 40 moves toward the cylinder head 50 and the both the inlet port 100 and exhaust port 110 are blocked by the respective inlet valve 120 and exhaust valve 130 , the piston 40 compresses the oxidant within the combustion chamber 70 (compression stroke) including the recess portion 290 . The piston 40 eventually begins to slow and changes direction such that the piston 40 travels away from the cylinder head 50 (working stroke). The fuel injector 80 will supply at least some fuel as the piston 40 nears the transition from the compression stroke to the working stroke (also known as the top dead center position).
In the present embodiment, the fuel injector 80 directs a fuel jet portion 340 toward the torroidal portion without contacting the floor portion 280 . However, a fuel plume portion 350 will vaporize and come in contact with the floor portion 280 . The fuel plume portion 350 contacting the floor portion 280 slows the combustion process and reduces the rate of temperature rise thus reducing NOx formation. The plume portion 350 moves along the floor portion 280 into the torroidal portion 270 where the floor transition portion 310 allows additional air from the torroidal portion 270 to further mix with un-combusted fuel (not shown). This further mixing increases combustion of the un-combusted fuel and reduces formation of soot. Similarly, the reentrant angle RA of the reentrant portion 260 promotes additional mixing of air into un-combusted fuel and oxidation of soot
Air retained in the recess portion 290 during the compression stroke provides additional air for mixing with fuel exiting the fuel injector 80 . In particular, the recess portion 290 reduces surface temperatures of the fuel injector 80 by increasing both motion and volume of air near the tip portion 90 at a start of fuel injection. The current embodiment reduces combustion temperatures by about 100 K (180 R) and allows timing of fuel injection to be advanced in order to improve fuel consumption while still meeting emissions requirements. Reducing combustion temperatures near the fuel the tip portion 90 limits fouling of the tip portion 90 and may improve the injector 80 operational life.
Although the preferred embodiments of this disclosure have been described herein, improvements and modifications may be incorporated without departing from the scope from the following claims. | A piston for a compression ignition internal combustion engine includes a crown portion, torroidal portion, and a reentrant portion. The piston further has a recess portion about a central axis of the piston designed to reduce temperatures near a tip portion of the fuel injector. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for controlling ignition in an internal combustion engine. The apparatus according to the present invention is used in an AC continuous-discharge type ignition apparatus for restricting the primary coil current of an ignition coil.
2. Description of the Related Art
In a conventional AC continuous-discharge type ignition apparatus for a spark ignition type internal combustion engine, the discharge duration of a spark plug can be prolonged during a single combustion cycle of the engine, as needed. The apparatus has a high average discharging current, e.g., 50 mA or higher, and allows easy ignition of a fuel-air mixture.
However, the conventional ignition apparatus generates only one ignition instruction signal. When this signal is at H level, there is a delay time of 0.5 to 1 msec from when the apparatus is rendered conductive until ignition start time. Therefore, spark timings cannot be controlled accurately. In addition, since ignition energy for the first discharge is insufficient, a sufficiently high voltage cannot be generated.
The conventional ignition apparatus is disclosed in, for example, U.S. Pat. No. 4,356,807.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved ignition control apparatus which is free from the above problem and in which a second ignition instruction signal for indicating an ignition timing is generated to control the ignition timing and to increase ignition energy for the first discharge, so that an optimal ignition can be carried out in an internal combustion engine, thereby improving the fuel consumption ratio and reducing harmful components in the exhaust gas.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of an ignition control apparatus for an internal combustion engine according to an embodiment of the present invention;
FIG. 2 is a detailed circuit diagram of an ignition instruction signal generator in the apparatus of FIG. 1;
FIGS. 3 and 4 are flow charts for explaining the operation of the ignition instruction signal generator;
FIGS. 5 and 6 are signal waveform charts of the apparatus of FIG. 1;
FIG. 7 shows enlarged waveforms of the waveforms in FIG. 6;
FIG. 8 shows a graph of the relationship between a delay time and a battery voltage; and
FIGS. 9 and 10 are circuit diagrams of other embodiments of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows an ignition control apparatus for an internal combustion engine according to an embodiment of the present invention. Referring to FIG. 1, reference numeral 11 denotes an ignition instruction signal generator as an ignition instruction signal generating means for generating an ignition instruction signal; 12, a reference voltage generator as a preset value generating circuit; 13, a discriminator; and 14, a logic circuit. An AND gate 141 in the circuit 14 produces an AND product of a first ignition instruction signal generated from a terminal 1141 of the generator 11 and the output signal from the discriminator 13. When the first ignition instruction signal is "1" level, the AND gate 141 passes the output pulse signal from the discriminator 13 therethrough. When this signal is "0" level, the AND gate 141 generates a "0" level signal.
An AND gate 142 produces an AND product of the first ignition instruction signal and the output signal from a NOT gate 143, which is the inverted output signal from the discriminator 13. When the first ignition instruction signal is "1" level, the AND gate 142 passes the output pulse signal from the NOT gate 143 therethrough. When this signal is "0" level, the AND gate 142 generates a "0" level signal.
Reference numerals 23 and 24 denote power transistors acting as first and second switching elements. The bases of the power transistors 23 and 24 are connected to the output terminals of the AND gates 141 and 142, respectively. The collectors of the power transistors 23 and 24 are respectively connected to primary terminals 35 and 36 of primary coils 31 and 32 in an ignition coil 3 through diodes 25 and 26, which prevent reverse current flow. In this case, the collectors of the transistors 23 and 24 are connected to the cathodes of the diodes 25 and 26, respectively. The emitters of the power transistors 23 and 24 are connected to the ground potential through current detection resistors 21 and 22, which have a small resistance and act as current detection elements.
The ignition coil 3 comprises the primary coils 31 and 32 having a turn ratio of about 300, a secondary coil 33, and an iron core 34. The primary coils 31 and 32 are magnetically coupled to the secondary coil 33 through the iron core 34. The coil 3 transforms a voltage generated at the primary coils 31 and 32 and generates it from the secondary coil 33. The terminals 35 and 36 of the primary coils 31 and 32 are connected to the anodes of the diodes 25 and 26, and an intermediate terminal 37 thereof is connected to the positive terminal of a battery 6. The negative terminal of the battery 6 is connected to the ground potential.
An output terminal 38 of the secondary coil 33 of the ignition coil 3 is connected to a center electrode 41 of a distributor 4. The center electrode 41 is rotated in synchronization with the rotation of the engine so as to distribute high voltages over side electrodes 421 to 424. Spark plugs 51 to 54 arranged in respective cylinders of the engine are connected to the side electrodes 421 to 424 of the distributor 4 through high voltage cables 431 to 434, respectively.
The discriminator 13 detects voltage drops across the resistors 21 and 22, thus discriminating the level of primary coil currents Ia and Ib from the ignition coil 3. In the discriminator 13, the voltage across the resistor 21 is applied to the non-inverting input terminal of a comparator 131. A reference voltage V(REF) corresponding to a preset current value from a terminal 127 of the generator 12 is applied to the inverting input terminal of the comparator 131. The comparator 131 then compares both voltages. If the terminal voltage is higher than the reference voltage V(REF), the comparator 131 generates a "1" level signal; otherwise, it generates a "0" level voltage. A comparator 132 receives the terminal voltage from the resistor 22 at its non-inverting input terminal, and also receives the reference voltage V(REF) from the terminal 127 of the generator 12 at its inverting input terminal. If the terminal voltage is higher than the reference voltage V(REF), the comparator 132 generates a "1" level signal; otherwise, it generates a "0" level signal. An RS flip-flop 133 has a terminal S as a set terminal, a terminal R as a reset input terminal, and a terminal Q as an output terminal. The terminals S and R of the flip-flop 133 are connected to the output terminals of the comparators 132 and 131, respectively. If the comparator 131 generates a "1" level signal, the terminal Q generates a "0" level signal. If the comparator 132 generates a "1" level signal, the terminal Q generates a "1" level signal.
In the generator 12, output terminals O of two analog switches 123 and 124 are commonly connected to the terminal 127. Reference voltage V(r1) and V(r2) are respectively applied to the input terminals of the switches 123 and 124. A terminal 126 of the generator 12 is connected to a control terminal C of one analog switch 123, and is connected to a control terminal C of the other analog switch 124 through a NOT gate 125. When the terminal 126 is "1" level, the switches 123 and 124 are ON and OFF, respectively, and the reference voltage V(REF) generated from the terminal 127 becomes equal to one reference voltage V(r1). In contrast, when the terminal 126 is "0" level, the analog switches 123 and 124 are respectively OFF and ON, and the reference voltage V(REF) becomes equal to the other reference voltage V(r2). Therefore, the generator 12 can selectively set the reference voltage V(REF) at V(r1) and V(r2) in accordance with the level of the second ignition instruction signal applied to the terminal 126.
A reference position sensor 101 and a rotational angle sensor 102 are of a known magnet pickup type and can generate pulse signals in synchronism with the engine. The sensor 101 generates a pulse every 180° CA (crank angle), and the sensor 102 generates a pulse every 30° CA. The pulses from sensors 101 and 102 are respectively supplied to terminals 1151 and 1152 of generator 11.
A vacuum sensor 103 is a known semiconductor diaphragm type pressure sensor, and generates an analog voltage which is proportional to the intake pipe vacuum of the engine (not shown) and is supplied to a terminal 1161 of the generator 11. A terminal 1162 of the generator 11 is connected to the positive terminal of the battery 6.
The generator 11 carries out calculations in accordance with the output signals from the sensors 101, 102, and 103, and the battery voltage, and generates the first and second ignition instruction signals from the terminals 1141 and 1142, respectively.
FIG. 2 shows the arrangement of the ignition instruction signal generator 11. The generator 11 is a computer system comprising a central processing unit (CPU) 111, a RAM 112, and a ROM 113, and the like. A digital input port 115 of the generator 11 fetches the pulse signals generated by the sensors 101 and 102 from the terminals 1151 and 1152.
A digital output port 114 generates the first and second ignition instruction signals from the terminals 1141 and 1142, respectively. An A/D converter 116 receives the voltage signal from the negative pressure sensor 103 and the voltage of the battery 6 from the terminal 1162, and converts them to digital signals.
The operation of the apparatus in FIG. 1 will now be described with reference to FIGS. 3 to 7. FIG. 3 is a flow chart showing the calculation processing of the generator 11. The operation of the generator 11 will first be described with reference to the waveform chart in FIG. 5. During the operation of the engine, reference signals at every 180° CA and angle signals at every 30° CA are supplied to the generator 11, as shown in FIGS. 5(1) and 5(2). As shown in FIG. 3, a 180° interruption step S101 starts in response to the 180° CA reference signal generated at time t0. In step S102, a rotational speed N(E) is calculated by a reciprocal operation from the time required for rotating the crank shaft through 180°. In step S103, a signal corresponding to an intake pipe negative pressure P(M) is fetched, and is converted to a digital signal. In step S104, an optimal ignition timing θ(SPK) is searched from a two-dimensional map based on a rotational speed N(E) and the intake pipe negative pressure P(M). In step S105, a battery voltage V(S) is fetched and is converted to a digital signal. In the primary coil 3, there is a delay time t(DLY) from when the primary coils begin to be energized until a high voltage appears at the secondary coil. The delay time t(DLY) changes with changes in a battery voltage V(B), as shown in FIG. 8. Therefore, a current start timing θ(STA) of the primary coils of the ignition coil 3 must be shifted earlier than the ignition timing θ(SPK) by a delay angle θ(DLY) corresponding to the delay time t(DLY). For this purpose, in step S106, the optimal delay angle θ(DLY), which is searched from the two-dimensional map based on the rotational speed N(E) and the battery voltage V(B), is subtracted from the ignition timing θ(SPK), thus obtaining the current start timing θ(STA). In step S108, it is discriminated if the crank angle of the engine coincides with the current start timing θ(STA). If YES in step S108, the flow advances to step S109. In step S109, the second ignition instruction signal for generating a "1" level signal during a period from timing t1 which is a current start timing θ(STA) to timing t2 which is an ignition timing θ(SPK) and the first ignition instruction signal for generating a "1" level signal during a period from timing t1 to timing t3 which is discharge termination timing θ(STP) are delivered from the terminals 1141 and 1142, respectively. Then, the flow returns to step S110.
A 30° interrupt routine shown in FIG. 4 starts from step S201 every 30° CA in response to the signal from the rotational angle sensor 102, as shown in FIG. 5(2). In step S202, the rotational angle is calculated to provide the angle necessary for calculation of the crank angle in step S108 of the main routine. The flow then returns to step S203.
The operation of the ignition apparatus will now be described with reference to the waveform charts in FIGS. 6 and 7. FIG. 7 is an enlargement of a part of FIG. 6.
The first and second ignition instruction signals shown in FIGS. 6(1) and 6(2) are generated from the terminals 1141 and 1142 of the generator 11 in synchronism with the engine rotation. More specifically, the generator 11 generates a "1" level signal during an interval corresponding to the delay time t(DLY) from the terminal 1142. In summary, the discriminator 13 generates a rectangular-wave pulse signal shown in FIG. 6(7) at a frequency of 1 to 5 kHz, determined by the design of the circuit containing the ignition coil 3, during an interval from t2 to t3, and an inverter 143 generates an inverted signal of this pulse signal. These signals are applied to the bases of the transistors 23 and 24 through the AND gates 141 and 142, so that the transistors 23 and 24 are alternatively turned ON and OFF during the interval from t1 to t3, thus enabling the push-pull operation. Thereby, the currents shown in FIGS. 6(3) and 6(4) flow through the primary coils 31 and 32 of the ignition coil 3, and a high voltage is generated from the secondary coil 33, as shown in FIG. 6(5), thus causing the spark plugs 51 to 54 discharge.
FIG. 7 is an enlargement of a part of FIG. 6 during the period from t1 to t3. When the first ignition instruction signal shown in FIG. 7(1) goes to "1" level at time t1, the transistor 23 is turned ON, and the current Ia flowing through the primary coil 31 increases with time, as shown in FIG. 7(3). During the interval from t1 to t3 (i.e., the delay time t(DLY)), since the second ignition instruction signal is at "1" level, as shown in FIG. 7(2), the reference voltage V(REF) becomes equal to the voltage V(r1) higher than V(r2), as shown in FIG. 7(9). When the primary coil current Ia is 16 A, the reference voltage V(r1) is set high enough to compensate for the voltage drop, corresponding to the voltage V(r2), across the resistor 21. Therefore, before time t2, even if the current Ia reaches 18 A, the output from the comparator 131 is kept at the "0" level, as shown in FIG. 7(3).
The reference voltage V(REF) is switched from the voltage V(r1) to V(r2) at timing t2, as shown in FIG. 7(9). The reference voltage V(r2) is set to be equal to the voltage drop across the resistor 21 when the current Ia is 16 A. Therefore, since the voltage drop across the resistor 21 corresponding to the current Ia becomes larger than the reference voltage V(REF) which is equal to V(r2) after timing t2, the comparator 131 generates a pulse signal at timing t2, as shown in FIG. 7(4). Since the pulse signal is supplied to the terminal R of the flip-flop 133, the output from the terminal Q thereof goes to the "0" level at timing t2, as shown in FIG. 7(8), thus turning OFF the transistor 23. Therefore, the current Ia abruptly decreases immediately after it reaches the maximum value 18 A, as shown in FIG. 7(3). As a result, a counterelectomotive force is generated in the primary coil 31 in the direction indicated by arrow X in FIG. 1, and a high trigger voltage of about -30 kV appears across the terminal 38 of secondary coil 33, as shown in FIG. 7(7). This high voltage causes the spark plug 51 in the first cylinder to start discharging through the distributor 4 and the high voltage cable 431. Thereafter, a constant voltage of about -2 kV is generated. In this way, since the current Ia of the primary coil 31 is set at the maximum value 20 A, a sufficiently high energy accumulates in the ignition coil 3 to generate a high trigger voltage and obtain enough energy for the first discharge. After the discharging, the transistor 24 is electrically connected to the diode 26, and the current Ib from the primary coil 32 increases with time as shown in FIG. 7(5).
The resistance of the resistor 22 is set such that the voltage drop across the resistor 22 becomes equal to the reference voltage V(REF) which is equal to V(r2) when the current Ib has reached 16 A at timing t21. Therefore, since the voltage drop across the resistor 22 corresponding to the current Ib becomes higher than the reference voltage V(REF) which is equal to V(r2) after timing t21, the comparator 132 generates a pulse signal at timing t21, as shown in FIG. 7(6). When the pulse signal is supplied to the terminal S of the flip-flop 133, the output from the terminal Q goes to the "1" level, thus turning OFF the transistor 24. Therefore, the current Ib of the primary coil 32 abruptly decreases immediately after it reaches the maximum value 16 A, as shown in FIG. 7(5). As a result, a counterelectromotive force is generated from the primary coil 32 in the direction indicated by arrow Y in FIG. 1. If discharging of the spark plug 51 is interrupted at timing t21, the terminal 38 of the primary coil 33 generates a high positive trigger voltage, thus resuming the discharging operation of the plug 51. However, if the discharging operation is maintained at timing t21, no trigger voltage is generated from the terminal 38 of the primary coil 33, and the voltage from the coil 33 is switched from a negative voltage of about -2 kV to a positive voltage of about +2 kV, as indicated by the solid lines in FIG. 7(7).
After timing t21, the current Ia of the primary coil 31 flows as shown in FIG. 7(3), and the discharging operation of the spark plug 51 can be thereby maintained. After time 21, the current Ia of the primary coil 31 increases with time, as shown in FIG. 7(3).
When the current Ia of the primary coil 31 reaches 16 A at time t22, the comparator 131 generates the pulse signal shown in FIG. 7(4), and the output from the terminal Q of the flip-flop 133 goes to the "0" level. In contrast to this, the output voltage from the secondary coil 33 is switched from +2 kV to -2 kV, as shown in FIG. 7(7), thus maintaining the discharging operation of the spark plug 51. The above-mentioned operation is also repeated after timing t22, as shown in FIG. 7. In this way, the spark plug 51 can carry out a continuous AC discharge while the first ignition instruction signal is kept at the "1" level.
The diode 26 is connected between the primary coil 32 and the collector of the transistor 24. Since this diode 26 interrupts the electrical connection between the base and collector of the transistor 24, to prevent the absorption of a high negative pulse voltage, a counterelectromotive force in the direction X can be stably generated from the primary coil 31, and a high negative trigger voltage is generated from the secondary coil 33. The diode 25 is connected between the primary coil 31 and the collector of the transistor 23. Since the diode 25 similarly interrupts the electrical connection between the base and collector of the transistor 23 to prevent the absorption of a high positive pulse voltage, a counterelectromotive force in the direction Y can be stably generated from the primary coil 32 at time t21. When the discharging operation of the spark plug 51 is stopped, a high positive trigger voltage is generated from the secondary coil 33; when not stopped, the polarity of the voltage is switched to maintain the discharging operation of the plug 51. In this way, a high trigger voltage can be generated stably and continuous discharging is possible, due to the presence of the diodes 25 and 26.
From the above descriptions, the spark plug 51 performs a capacitive discharging operation by the high trigger voltage of -30 kV from the secondary coil 33, and thereafter maintains the operation with a 2 kV constant voltage. It should be noted that a sufficiently high trigger voltage and spark energy for the first discharge operation can be obtained, and that the trigger voltage and the continuous discharging voltage are repeatedly generated. Thus, even if the discharging operation of the spark plug 51 is temporarily interrupted by an irregular airflow in a combustion chamber of the engine, a high trigger voltage is generated by the switching operation performed slightly thereafter, thus immediately resuming the discharging operation. The above descriptions are related to the discharging operation of the first cylinder during timing t1 to t3. Similarly, the operations are repeated for the third, fourth, and second cylinders in that order after time t5, thus driving all four cylinders.
In general, since a conventional apparatus only generates the first ignition indication signal, time t2 as the ignition timing cannot be determined accurately. In contrast to this, the apparatus in FIG. 1 generates a second ignition instruction signal in addition to the first signal, thus allowing precise control of the ignition timing. In addition, since the primary coil current of the conventional apparatus has a constant maximum value, the spark energy and trigger voltage are low. However, the apparatus in FIG. 1 is free from the above problem. Thus, a high spark energy can be obtained at an ignition timing optimal for the engine, thus improving fuel consumption and reducing harmful components in the exhaust gas.
FIG. 9 shows an ignition control apparatus for an internal combustion engine according to another embodiment of the present invention. In the apparatus shown in FIG. 9, the emitters of power transistors 23 and 24 are commonly connected to a single current detection resistor 27. The terminal voltage across the resistor 27 is supplied to the non-inverting input terminal of a single comparator 134, whose output is applied to a clock input terminal Cp of a data flip-flop 135. The Q output from the flip-flop 135 is supplied to a data input terminal D thereof, and the Q output therefrom is supplied to a logic circuit 14 as an output from a discriminator 13.
In the apparatus in FIG. 9, the primary currents of primary coils 31 and 32 are detected by the single resistor 27. When the primary currents exceed s preset level, a comparator 134 generates a "1" level pulse output, thus inverting the Q output from the data flip-flop 135 from "0" to "1" level. In this manner, the power transistors 23 and 24 are alternatively switched through the logic circuit 14.
FIG. 10 shows an ignition control apparatus for an internal combustion engine according to another embodiment of the present invention. In the apparatus shown in FIG. 10, a reference voltage generator 12 always generates a single reference voltage V(r2), which is equal to the voltage drop generated across current detection resistors 21 and 22 shown the primary coil current is 16 A. The output from an AND gate 141 of a logic circuit 14 is connected to one input of an OR gate 144, the other input of which receives a second ignition instruction signal from an ignition instruction signal generator 11. The output from the OR gate 144 is connected to the base of the power transistor 23. In this embodiment, a first ignition instruction signal from the generator 11 is kept at the "1" level during the interval from a spark timing t2 to an AC discharge termination timing t3, i.e., during the interval corresponding to the "1" level interval of the first ignition instruction signal shown in FIG. 6(1) from which the "1" level interval of the second ignition instruction signal shown in FIG. 6(2) is omitted.
In the apparatus in FIG. 10, the power transistor 23 is enabled through the OR gate 144 in response to the second ignition instruction signal generated at timing t1, and is disabled at the ignition timing t2. Since the "1" level interval of the second ignition instruction signal is set long enough to increase the primary coil current from the ignition coil 3 to a given level, e.g., 18 A, the voltage across the resistor 21 becomes higher than the reference voltage from the generator 12, corresponding to the 16 A primary current. Thus, the output signal from the comparator 131 goes to "1" level, thereby resetting the flip-flop 133. When the first ignition instruction signal goes to "1" level at the ignition timing t2, the currents from the primary coils 31 and 32 alternatively switch the power transistors 23 and 24 every time they reach a given level (16 A) during the "1" level in interval of the first ignition instruction signal. | The apparatus includes an ignition instruction signal generating unit for repeatedly generating a first ignition instruction signal instructing an AC discharging duration and a second ignition instruction signal instructing the current flow time of a first primary coil at each ignition timing; and an ignition control circuit unit for causing the first and second switching elements to perform a push-pull operation for a predetermined period of time upon reception of a given ignition instruction signal. When it is detected from a current detection signal from the current detection element upon reception of the first ignition instruction signal that the current of one of the first and second closed circuits has reached a predetermined value, a signal for turning OFF the one of the first and second closed circuits is supplied to one of the first and second switching elements and a signal for turning ON the other closed circuit is supplied to the other switching element so as to enable the push-pull operation of the switching elements. Accordingly, one of the switching elements is turned ON in response to the second ignition instruction signal for the current flow time of the primary thereby, and is then turned OFF. Thus, an ignition timing can be determined precisely, and a sufficiently high voltage can be obtained. | 5 |
PRIORITY CLAIM
The present application claims priority to European Patent Application 03104118.9 filed Nov 7,2003.
FIELD OF THE INVENTION
The invention relates to a bubble breaker assembly for dispersing gas bubbles in a multiphase fluid transportation conduit, such as a production tubing in a crude oil production well into which lift gas is injected to decrease the density of the produced fluid.
More particularly, the invention relates to a method and system for dispersing gas bubbles in a multiphase fluid transportation conduit, wherein the gaseous and liquid fluid fractions are intensively mixed to produce a low density froth or foam comprising small and uniformly distributed gas bubbles in a liquid matrix.
BACKGROUND OF THE INVENTION
Such a method and system are known from International patent application WO00/05485.
In the known method and system one or more bubble breaker assemblies are arranged in the conduit to create alternating flow zones of small and large cross-sectional areas with abrupt transition from the small cross-sectional areas to the large cross-sectional areas to produce a turbulent flow in which swirls and eddies are generated. The known bubble breaker assemblies consist either of venturi-like orifices that are concentric to the central axis of the conduit or of annular flow passages which are formed between the inner wall of the conduit and a central mandrel which is arranged in a concentric position.
U.S. Pat. No. 4,544,207 discloses a method for the uniform distribution of a two phase mixture by one or more orifice containing turbulence promoters which may comprise plates containing orifices of various shapes.
It is an object of the present invention to provide a method and bubble breaker assembly, which further enhance the mixing of gaseous and liquid fractions in the conduit such that the size of the gas bubbles is further decreased and the gas bubbles are distributed as a finely dispersed froth in the multiphase fluid stream.
SUMMARY OF THE INVENTION
The method according to preferred embodiments of the invention for dispersing gas bubbles in a multiphase fluid transportation conduit comprises inserting at least one bubble breaker assembly in the conduit, which assembly comprises a plurality of orifices that are located in a substantially eccentric position relative to a central axis of the tubing, characterised in that lift gas is injected at one or more downhole gas injection points spaced along the length of the production tubing to enhance oil production from the well, and that one or more bubble breaker assemblies with eccentric orifices are arranged at selected distances downstream of the lift gas injection points.
The present invention includes a method of producing crude oil, wherein large gas slugs, that are known as are Taylor bubbles, are broken up into finely dispersed smaller gas bubbles by means of one or more bubble breaker assemblies with eccentric orifices in accordance with the method for dispersing gas bubbles in a production tubing in an oil production well, the method comprising inserting at least one bubble breaker assembly in the tubing, which assembly comprises a plurality of orifices that are located in a substantially eccentric position relative to a central axis of the tubing, wherein lift gas is injected at one or more downhole gas injection points spaced along the length of the production tubing to enhance oil production from the well, and that one or more bubble breaker assemblies with eccentric orifices are arranged at selected distances downstream of the lift gas injection points.
It has been found that the use of a bubble breaker assembly in which a plurality of eccentric orifices are arranged significantly enhances the dispersion of relatively large gas bubbles into a large amount of small gas bubbles, which are uniformly distributed in the multiphase fluid stream.
In an embodiment a flow restriction may comprise a disk-shaped plate in which at least two eccentric orifices are arranged, and which disk may be removably secured to the inner wall of the conduit, for example by a clamping assembly which can be contracted if the plate needs to be removed.
Preferably a plurality of flow restrictions are arranged at selected distances along the length of the conduit, wherein at least two of said flow restrictions comprise disk-shaped plates in which different patterns of eccentric orifices are arranged
In an embodiment at least one flow restriction may comprise a pair of eccentric orifices that are located substantially symmetrically relative to a plane of symmetry in which the central axis of the conduit lies.
Alternatively at least one flow restriction may comprise three or more equidistant eccentric orifices that are arranged at regular angular intervals relative to a longitudinal axis of the conduit.
In the fluid stream downstream of the gas-injection point(s) the gas bubbles will tend to coalesce into steadily growing larger gas bubbles, known as gas slugs or Taylor bubbles, and by arranging a series of bubble breakers according to the invention, each with eccentric orifices, an intensively mixed low density multiphase stream of crude oil and uniformly distributed small gas bubbles is created throughout the length of the production tubing.
The invention also relates to a system for dispersing gas bubbles in a multiphase fluid transportation conduit, which system comprises at least one bubble breaker assembly which is arranged within the tubing, which assembly comprises a plurality of orifices that are located in a substantially eccentric position relative to a central axis of the tubing characterised in that one or more downhole lift gas injection points are arranged along the length of the production tubing to enhance oil production from the well, and that one or more bubble breaker assemblies with eccentric orifices are arranged at selected distances downstream of the lift gas injection points.
Further features, advantages and embodiments of the method and system according to the present invention are detailed in the following detailed description of preferred embodiments and in the appended claims, abstract and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Some preferred embodiment of the method and system according to the present invention will be described by way of example with reference to the accompanying drawings, in which:
FIG. 1 is a schematic three-dimensional view of a production tubing in a well into which lift gas is injected and which comprises downstream of the gas injection point a bubble breaker assembly with eccentric orifices according to the present invention which serve to break up coalesced large gas bubbles into a large amount of finely dispersed small gas bubbles;
FIG. 2 is a schematic three-dimensional view of a production tubing in a well in which an alternative embodiment of a bubble breaker with four eccentric orifices is arranged;
FIG. 3 is a longitudinal sectional view of a bubble breaker which is clamped between a pair of retrievable well tubulars;
FIG. 4A is a side view of the bubble breaker plate shown in FIG. 3 ;
FIG. 4B is a cross sectional view of the bubble breaker plate shown in FIG. 4A , taken along line B-B and seen in the direction of the arrows;
FIG. 5 is a diagram which provides a comparison of the oil production rate in a 3000 m deep well with and without a bubble breaker according to the invention;
FIG. 6 is a diagram which illustrates the improvement of oil production in the well of FIG. 5 ; and
FIG. 7 is a plotted diagram in which the improvement in mean gas hold up of a conventional bubble breaker with a central orifice is compared with that of a bubble breaker with eccentric orifices according to the invention.
FIG. 8 is a schematic drawing of a well in which a plurality of bubble breaker assemblies are arranged at selected distances along the tubing.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an underground oil production well 1 passing through an underground formation 2 .
The well 1 comprises a well casing 3 and a production tubing 4 into which lift gas bubbles 5 are injected through an assembly of lift gas injection nozzles 6 that are arranged in a lift gas injection mandrel 7 which is retrievably inserted into a side pocket 8 in the production tubing 4 . The lift gas may be natural gas which is separated from the produced hydrocarbon stream and which is reinjected via the wellhead (not shown) into the annular space 9 between the production tubing 4 and surrounding well casing 3 . The lift gas flows from the annular space 9 via an orifice 11 in the production tubing 4 into the interior of the side pocket 8 and via openings 12 through the interior of the gas lift injection mandrel towards the orifices 6 as illustrated by arrows 13 . The orifices 6 may be surrounded by a porous membrane (not shown) as disclosed in European patent application EP 1278938.
The injected gas bubbles 5 may gradually coalesce into large gas slugs or Taylor bubbles 15 and in the region where such coalescence may take place a bubble breaker assembly 16 according to the invention is arranged, which comprises at least one disk shaped plate 17 in which twelve eccentric orifices 18 is arranged.
The twelve orifices 18 are arranged at regular angular intervals relative to the central longitudinal axis of the production tubing 4 .
The bubble breaker assembly 16 further comprises a tubular carrier body 19 which is retrievably clamped and sealed within the production tubing 4 by an expandable clamping mechanism 20 and inflatable seals 21 . The bubble breaker assembly 16 further comprises a pulling nose 22 which can be coupled to a wireline tool or well robot (not shown) which is configured to expand the clamping mechanism 20 and inflate the seals 21 during installation of the bubble breaker assembly 16 and to contract the clamping mechanism 20 and deflate the seals 21 if the bubble breaker assembly 16 is retrieved for maintenance of the assembly itself or of well components, such as the gas lift injection mandrel 7 , that are located below the bubble breaker assembly 16 .
FIG. 2 depicts an alternative embodiment of a bubble breaker assembly 26 according to the invention, wherein the assembly 26 comprises a disk shaped plate 27 in which four eccentric orifices 28 are arranged at regular angular intervals relative to a longitudinal axis of the production tubing 34 . The tubing 34 is suspended within a well casing 33 of a crude oil production well 31 , which passes through a subsurface earth formation 32 . Natural gas may be injected into the tubing 34 via the annular space 29 between the tubing 34 and well casing 33 and one or more orifices (not shown) in the wall of production tubing 34 below the bubble breaker assembly 26 . Alternatively or additionally natural gas which is dissolved in the crude oil at reservoir pressure may be released and form gas bubbles 35 in the stream of crude oil within the production tubing 34 . The injected and/or released gas bubbles 35 may coalesce in to large gas slugs that are known as Taylor bubbles 36 , which are broken up into a large number of finely dispersed small gas bubbles by the bubble breaker assembly 26 according to the invention.
In the configuration shown in FIG. 2 the disk shaped plate 27 is inserted in an annular recess between two tubular sections 37 and 38 . The upper tubular section 38 is screwed below a tubular carrier body 39 which is suspended and sealed within the production tubing 34 by sealing rings 40 and an expandable locking mechanism 41 that fits within a recess 42 in the inner wall of the production tubing 34 . The bubble breaker assembly 26 shown in FIG. 2 is inserted into the production tubing 34 by a wireline tool or well robot which is configured to release the locking mechanism 41 when it is located adjacent to the annular recess 42 and expand the sealing rings 40 during installation of the assembly 26 and which contracts the locking mechanism 41 and sealing rings 40 when the assembly 26 is to be retrieved from the well 31 .
The eccentric orifices 18 , 28 break up the gas slugs of Taylor bubbles 15 , 36 into a large amount of finely dispersed smaller gas bubbles 25 , 37 that only re-coalesce slowly into larger bubbles. Preferably the gas bubbles formed have a diameter less than about 1 millimeter, so that microbubbles are formed which are highly resistant to re-coalescence into large Taylor bubbles 15 , 36 .
A benefit of creating small bubbles is that residence time of the gas in a bubbly flow is higher than in a slug flow, resulting in less slip between the gas and crude oil stream and a corresponding higher gas hold-up in the tubing downstream of the bubble breaker assembly 16 , 26 . The higher gas hold-up results in a lower average fluid density and therefore a lower pressure drop in the tubing 4 , 34 . The lower pressure drop in the tubing 4 , 34 leads to a lower flowing bottom hole pressure and an increase of the crude oil production rate.
Experiments revealed that the pressure loss associated with the bubble breaker assembly 16 , 26 with eccentric orifices 18 , 28 according to some embodiments of the invention is small compared to the beneficial pressure effect of the low density bubbly flow it creates, often only one-tenth the magnitude. Therefore there is a net reduction in the bottom hole pressure in the crude oil inflow region of the well 1 , 31 and an increase in the crude oil production rate of the well 1 , 31 .
FIG. 3 illustrates how a bubble breaker plate 50 can be installed using a specially designed carrier, consisting of two tubular sections 51 and 52 screwed together with the plate 50 in between. The inner surface 51 A of the top part of the upper tubular section 51 can be threaded to match a standard lock mandrel or other installation device. The bubble breaker plate 50 can easily be interchanged when loosening the lower tubular section 52 , the installation tool will not be damaged.
FIG. 4A and FIG. 4B show that the bubble breaker plate 50 has eight circumferentially spaced eccentric orifices 53 and is weakened around the periphery by milling a ring-shaped groove 53 into the upper surface of the plate 50 such that the groove 53 intersects the orifices 53 .
This enables an operator to punch out the inner part of the plate 50 in case of emergency. The groove 54 is not milled all the way through the plate 50 so that the fluids can still only pass through the eccentric orifices 53 .
Computer simulations of the method according to some embodiments of the invention indicate that crude oil production increase of as much as 20% can result.
FIG. 5 shows the gas-lift performance curve for a typical 3000 m deep gas lifted oil well with and without bubble breakers according to the invention. The lower curve 55 shows the gas lift performance of a gas lifted oil well without bubble breakers and the upper curve 56 shows the gas lift performance of a gas lifted well with a bubble breaker assembly 16 , 26 , or 50 according to some embodiments of the invention as illustrated in FIGS. 1-4 .
In the simulated crude oil production well lift gas is injected at the bottom of a 3000 m deep production tubing, with a tubing head pressure of 10 bar. The tubing diameter is 76 mm. The crude oil API is 30° and crude oil density is 850 kg/m 3 . The specific density of the lift gas is 0.65 and the reservoir pressure is 220 bar.
In FIG. 5 the horizontal axis represents the gas injection rate Qg (sm 3 /day) and it can be seen that for gas injection rates less than 80.000 sm 3 /day the amount of crude oil Ql (m 3 /day) produced by a gas-lifted oil production well equipped with a bubble breaker assembly 16 , 26 according to some embodiments of the invention is significantly higher than of the same gas lifted well without bubble breakers according to the invention. It is observed that the unit sm 3 refers to standard cubic meters, which is the volume of the injected gas at atmospheric pressure.
FIG. 6 is a diagram, which depicts the improvement in production resulting from application of the bubble breaker assembly 16 , 26 in the oil well production diagram of FIG. 5 . In FIG. 6 the horizontal axis represents the gas lift injection rate Qg (sm 3 /day), and the vertical axis represents the percentage of improvement Δ (%) in oil production for the curve 56 with bubble breaker, when compared with the curve 55 without bubble breaker. FIG. 6 indicates that at a lift gas injection rate of about 15.000 sm 3 /day a production improvement Δ of about 18% is generated by application of the bubble breaker with eccentric orifices according to the invention.
Experiments were done with bubble breaker assemblies with various patterns of orifices in an 18 m high transparent perspex test conduit having an internal diameter of 72 mm and through which a water-ethanol mixture was pumped in an upward direction at a flow rate of 15-70 l/minute. Air was injected at the bottom of the conduit and a disk shaped plate in which one or more orifices were made was inserted in the conduit at about 5 m above the bottom.
Several experiments were carried out with a bubble breaker assembly with a single central orifice and with a number of eccentric orifices.
The experiments revealed that a bubble breaker plate with eccentric orifices breaks up gas bubbles more efficiently into finely dispersed small bubbles than a conventional bubble breaker plate with a central orifice.
FIG. 7 shows the results of an experiment where the improvement in mean gas hold up of a bubble breaker with a single central orifice is plotted and represented by dotted curve 70 and that of a bubble breaker with a series of eight eccentric orifices as shown in FIG. 4 is plotted and represented by dotted curve 71 . FIG. 7 illustrates the improvement in gas hold up downstream of the bubble breaker as a function of gas flow rate for a constant liquid flow rate of 54 l/minute. The dotted curve 71 for the device with eccentric orifices is higher than the curve 70 for the device with a single central orifice. The cross-sectional area and local pressure loss is the same for the device with eccentric orifices and for the device with a single central orifice.
FIG. 7 indicates that the increase in gas hold up was higher for the experiments with the number of eccentric orifice keeping the pressure drop over the device constant. On the horizontal axis of FIG. 7 the difference in gas hold up downstream of the bubble breaker is plotted against the gas injection rate. FIG. 7 shows that the improvement in mean gas hold up is larger for a bubble breaker with several eccentric orifices around the periphery, while keeping the pressure drop over the device constant.
Observations with a high speed camera revealed that the eccentric orifices according to some embodiments of the invention generated a large amount of turbulent eddies in the fluid stream and that the air bubbles were broken over and over again by these eddies in the region of the bubble breaker until they had a diameter of one or a few millimeters. | A method and system are disclosed for dispersing gas bubbles in a multiphase mixture in a production tubing in an crude oil production well or in a riser connected to such a well, by means of one or more bubble breaker assemblies in which a plurality of orifices are arranged that are located in a substantially eccentric position relative to a central axis of the tubing. The use of eccentric orifices promotes the breaking up of large gas bubbles into a large amount of smaller gas bubbles, which are finely dispersed in the fluid stream and only re-coalesce slowly into larger bubbles. | 8 |
PARENT CASE TEXT
This application is a continuation of U.S. application Ser. No. 11/741,282, filed Apr. 27, 2007, which is a continuation-in-part of U.S. application Ser. No. 10/675,936 filed Sep. 30, 2003, which application draws priority of U.S. Provisional Application No. 60/455,032, filed Mar. 14, 2003.
GOVERNMENT SUPPORT
This invention was made with Government support under contract number DE-AC02-98CH10886, awarded by the U.S. Department of Energy. The Government has certain rights in the invention.
BACKGROUND OF THE INVENTION
DNA sequencing projects have provided coding sequences for hundreds of thousands of proteins from organisms across the evolutionary spectrum. Recombinant DNA technology makes it possible to clone these coding sequences into expression vectors that can direct the production of the corresponding proteins in suitable host cells. The resulting proteins are widely useful, as objects of biochemical, biophysical, structural and functional studies for understanding basic biological processes, as enzymes to serve as research tools or produce valuable chemicals, as diagnostics, vaccines, therapeutics or targets for developing medically useful drugs, or for protein chips, to mention a few.
The T7 expression system comprises in vivo inducible expression, in T7 expression system host strains, of T7 RNA polymerase from a chromosomal copy of a cloned gene for the T7 RNA polymerase enzyme (gene 1 of bacteriophage T7), followed in turn by recognition and binding of a T7 promoter sequence contained in T7 expression vectors carried in the host strain, followed by intense transcription of any gene(s) cloned downstream of the T7 promoter sequence, and, where the cloned sequence is a protein coding sequence, subsequent translation of the transcripts. This recombinant gene expression system, originally developed in Escherichia coli and which has become the standard by which other prokaryotic expression systems are judged, has been adapted for use in other bacterial species including Salmonella enteric serovar Typhimurium (McKinney, J., et al. (2002) J. Bacteriology 184:6056-6059), Pseudomonads (Schweizer, H P (2001) Curr. Opin. Biotechnol. 12:439-445), Rhodobacter capsulatus (Drepper, T., et al. (2005) Biochem. Soc. Trans. 33:56-58), Ralstonia eutropha (Barnard, G. C., et al. (2004) Prot. Exp. & Purif. 38:264-271) and Bacillus subtilis (Conrad, B., et al. (1996) Mol. Gen. Genet. 250:230-236).
The inducible T7 expression system is highly effective and widely used to produce RNAs and proteins from cloned coding sequences in the bacterium Escherichia coli (Studier and Moffatt, J. Mol. Biol. 189: 113-130 (1986); Studier et al., Methods in Enzymology 185: 60-89 (1990); Novagen). The coding sequence for T7 RNA polymerase is typically present in the chromosome under control of the inducible lac or lacUV5 promoter in the chromosome of host cells such as BL21(DE3), B834(DE3) and HMS174(DE3), and derivatives of such cells such as ER2566 and ER 2833 (New England Biolabs). In another derivative strain, designated “BL21-AI” (Invitrogen), gene 1 is under the control of the arabinose-inducible araBAD promoter. In the absence of inducing compounds, transcription by the host cell RNA polymerase is blocked by the natural endogenous repressor. In the case of the lac promoter, it is the lac repressor and for the araBAD promoter, the product of the araC gene is the repressor.
The coding sequence for the desired RNA or protein (referred to as the target RNA or protein) is typically placed in a plasmid under control of a T7 promoter, that is, a promoter recognized specifically by T7 RNA polymerase. In the absence of an inducer for the lacUV5 promoter, little T7 RNA polymerase or target protein should be present and the cells should grow well. However, upon addition of an inducer, typically IPTG (isopropyl-β-D-thiogalactoside), T7 RNA polymerase will be made and will transcribe almost any DNA controlled by the T7 promoter. T7 RNA polymerase is so specific, active and processive that the amount of target RNA produced can be comparable to the amount of ribosomal RNA in a cell. Thus, large amounts of RNAs that are useful in themselves, such as ribozymes, can be produced. If the target RNA contains the coding sequence for a protein and appropriate translation initiation signals (such as the sequence upstream of the start codon for the T7 major capsid protein), target protein can be produced, often accumulating to become a substantial fraction of total cell protein. See also U.S. Pat. Nos. 4,952,496; 5,693,489; and 5,869,320, the contents of which are incorporated herein by reference.
In strains in which the T7 gene 1 (T7 RNA polymerase gene) is under control of the lac or lacUV5, IPTG has typically been used to induce expression of target proteins. Lactose will also cause induction and, being much cheaper than IPTG, may be preferable for large-scale production. Neubauer et al., Appl. Microbiol. Biotechnol. 36: 739-744 (1992) obtained induction by lactose with the same efficiency as with IPTG by careful monitoring of the glucose level in fermentation and by addition of lactose when the glucose was nearly depleted. Hoffman et al., Protein Expression and Purification 6: 646-654 (1995) used similar procedures to obtain comparable levels of protein synthesis with lactose or IPTG induction in a fermentor process.
A problem in using inducible T7 expression systems is that T7 RNA polymerase is so active that a small basal level can lead to a substantial expression of target protein even in the absence of added inducer. If the target protein is sufficiently toxic to the host cell, establishment of the target plasmid in the expression host may be difficult or impossible, or the expression strain may be unstable or accumulate mutations (Kelley et al., Gene 156: 33-36 (1995)). An effective means to reduce basal expression (and thereby increase the range and stability of target proteins that can be established and expressed) is to place the lac operator sequence (the binding site for lac repressor) just downstream of the start site of a T7 promoter, creating a T7lac promoter (Dubendorff and Studier, J. Mol. Biol. 219: 45-59 (1991)). Lac repressor bound at the operator sequence interferes with establishment of an elongation complex by T7 RNA polymerase at a T7lac promoter and substantially reduces the level of target mRNA produced. If sufficient lac repressor is present to saturate all of its binding sites in the cell, the basal level of target protein in uninduced cells is substantially reduced, but induction unblocks both the lacUV5 and T7lac promoters and leads to the typical high levels of expression. Thus, the T7lac promoter increases the convenience and applicability of the T7 system for expressing a wide range of proteins.
It was early noticed that growth of T7 expression cultures to saturation could cause problems, and Grossman et al., Gene 209: 95-103 (1998) showed that cultures growing in certain complex media induce the target protein to high levels upon approach to saturation even when the T7lac promoter was used. They pointed out that such unintended induction could be a problem in isolating and using strains that express proteins that are toxic to E. coli . They concluded that the known inducer lactose was not responsible for this effect, but that cyclic AMP is required, and they recommended using a mutant unable to make cyclic AMP as an expression host.
Although such basal level of expression from T7 expression vectors can be suppressed through use of the T7lac promoter in such vectors, this does not solve problems resulting from unintended induction of T7 expression strains when they are grown to saturation, which was noted by Grossman et al. ( Gene 209: 95-103 (1998)). Grossman et al. showed that cultures growing in certain complex media induce the target protein to high levels upon approach to saturation even when the T7lac promoter was used. They pointed out that such unintended induction could be a problem in isolating and using strains that express proteins that are toxic to E. coli . In their work, they concluded that lactose had not been responsible for this effect, but that cyclic AMP was required, and they recommended using a mutant host strain that is unable to make cyclic AMP. They also found that addition of 1% glucose to late log phase cells prevented the unintended induction, and the Novagen web site references their paper and recommends adding 1% glucose to the medium to manage this problem.
Structural genomics is an area where multi-milligram amounts of many different proteins over a wide evolutionary range are required for determination of protein structures by X-ray crystallography or nuclear magnetic resonance (NMR). Fabrication of protein chips is another application where many different proteins are needed. Expressing cloned coding sequences in the T7 system is an efficient, widely used method for obtaining these proteins. Screening large numbers of clones for protein expression level and solubility makes it desirable to have procedures that can be applied to many clones in parallel, preferably using automation. The need to process many cultures in parallel dictates batchwise growth of cultures in small vessels such as culture tubes or multi-well plates such as the 24-, 96- or 384-well plates commonly available. A high level of protein production per volume of culture is also desirable. The needed multi-milligram amounts of pure protein could be produced in fermentors, but cultures grown batchwise in vessels aerated by shaking (a baffled flask on a rotary shaker, for example), bubbling air, or oxygen can typically produce this amount of protein in the T7 expression system in a liter or less of culture, allowing several cultures, each producing a different protein, to be grown and induced in parallel.
In trying to develop reliable procedures for growing and inducing protein synthesis in many cultures in parallel, a significant difficulty was to obtain all of the cultures in a comparable state of growth so that they could be induced simultaneously in parallel. Substantial effort was required to measure the cell density of each culture and add inducer at the proper time, even using a plate reader that could measure the densities of cultures in all of the different wells of a plate in a single reading. Even if comparable amounts of culture could be inoculated in each well, differences in lag time or growth rate typically generated situations where cultures in different wells would be ready for induction at substantially different times. If the entire plate was to be collected at once, cultures would also vary in the length of time in which they had been producing target protein, possibly making it difficult to choose a time when all had been induced to optimal levels without substantial overgrowth of some cultures by cells that had lost plasmid.
An obvious strategy was to grow the entire plate to saturation in a small volume of medium in each well, dilute by adding fresh medium, grow for an appropriate time (determined by previous testing or by direct measurement of cell densities), and add inducer to all wells at the same time. The hope was that all cultures in a plate would saturate at near enough to the same density and grow after dilution with similar enough kinetics that the culture-to-culture variation in density at the time of induction would be tolerable. However, in trying to implement this strategy, when certain lots of complex growth media were used, the problem described by Grossman et al. (1998) was encountered, namely, induction during the growth to saturation. Indeed, it was found that media made with a particular lot of N-Z-amine showed this induction behavior, whereas otherwise identical media made with a second lot from the same supplier did not. Unwanted induction at saturation would make it extremely difficult to obtain sufficient uniformity of growth to permit parallel manipulation of cultures expressing target proteins of different, usually unknown degrees of toxicity. Although addition of glucose could suppress this induction (Novagen), the saturated cultures could become very acid, which would limit the saturation density and again make it difficult to get uniform growth upon dilution. Screening different lots of N-Z-amine for those without the inducing behavior did not seem to be an attractive solution, as there was no guarantee that such lots would always be available. Thus, the approaches taken, leading to the present invention, were to determine causes of and ways to prevent unwanted induction and to develop means to promote desirable auto-induction of expression strains.
The ability to control the problem of sporadic, unwanted induction in complex media would represent a significant advance in the art. A systematic analysis of the components of both complex and defined media was undertaken. The goal was to define requirements for batchwise growth of T7 expression strains to high density under conditions suitable for growth and induction of many cultures in parallel, and, complementarily, to develop formulations that would reliably grow cultures of expression strains to saturation with little or no induction.
SUMMARY OF THE INVENTION
The present invention relates, in one aspect, to a method and growth media for promoting auto-induction of transcription of cloned DNA in cultures of bacterial cells grown batchwise, the transcription being under the control of a promoter whose activity can be induced by an exogenous inducer whose ability to induce said promoter is dependent on the metabolic state of said bacterial cells. Initially, a culture media is provided which includes: i) an inducer capable of inducing transcription from said promoter in said bacterial cells; and ii) a metabolite that prevents induction by said inducer, the concentration of said metabolite being adjusted so as to substantially preclude induction by said inducer in the early stages (early to mid-log phase) of growth of the bacterial culture, but such that said metabolite is depleted to a level that allows induction by said inducer at a later stage of growth (mid to late-log phase and prior to saturation). The culture medium is inoculated with a bacterial inoculum, the inoculum comprising bacterial cells containing cloned DNA, the transcription of which is induced by said inducer. The culture is then incubated under conditions appropriate for growth of the bacterial cells until such growth sufficiently depletes the metabolite such that auto-induction of transcription occurs, and where applicable the transcripts have been translated.
In a preferred embodiment, the present invention relates to promoting auto-induction of transcription of cloned gene 1 of bacteriophage T7 in batchwise-grown bacterial cells, which cloned gene is under the control of an inducible promoter and is stably propagated in the bacterial cells. A culture medium comprising an exogenous inducer which is capable of inducing transcription from the inducible promoter and one or more constituents that prevents induction by said inducer until such time as growth and division of the bacterial cells has depleted the one or more constituents of the culture medium to a level that permits induction by the inducer. The provided culture medium is inoculated with the bacterial cells, the culture is incubated under conditions for growth of the bacterial cells until the level of the one or more constituents has been depleted to a level permitting auto-induction of transcription of the cloned gene 1.
This embodiment of the present invention further includes incubating the culture to permit translation of the gene 1 transcripts into T7 RNA polymerase enzyme. The present invention also includes bacterial cells which are T7 expression strains, i.e., the cells contain a T7 expression plasmid in which a target gene is under the control of a T7 promoter (e.g., pET vectors (Novagen); Variflex vectors (Stratagene) and pRSET vectors (Invitrogen), etc.). The present invention further includes incubating the culture until such time as the T7 RNA polymerase enzyme has transcribed target genes under the control of a T7 promoter, and, further includes incubating the culture until such time as the latter transcripts are translated into protein. In general the preferred embodiment includes incubating the inoculated cultures until a saturating cell density is achieved.
In another aspect, the present invention relates to a method for improving the production of a selenomethionine-containing protein or polypeptide in a bacterial cell, the protein or polypeptide being produced by recombinant DNA techniques, the bacterial cell encoding a vitamin B12-dependent homocysteine methylase. The method for improving the production of this protein or polypeptide includes culturing the bacterial cell in a culture medium containing vitamin B12.
In another aspect, the invention relates to a method for suppressing transcription of cloned DNA in cultures of bacterial cells grown batchwise, said transcription being under the control of a promoter whose activity can be induced by an exogenous inducer whose ability to induce said promoter is dependent on the metabolic state of said bacterial cells. This aspect includes the steps of: a) providing a culture medium comprising a carbon source whose uptake and metabolism by said bacterial cells suppresses induction of transcription from said promoter; b) inoculating the culture medium with a bacterial inoculum, the inoculum comprising bacterial cells containing cloned DNA, the transcription of which is suppressed by the carbon source; and c) incubating the culture of step b), with shaking, under conditions appropriate for growth of the bacterial cells while suppressing transcription of the cloned DNA.
DETAILED DESCRIPTION OF THE INVENTION
1. Development of Non-Inducing Media
Well known media for growth of E. coli and production of target proteins with the T7 expression system include ZB, ZY (equivalent to LB), M9 or M9ZB, which contain various combinations of 1% of a tryptic digest of casein (such as tryptone or N-Z-amine AS), 0.5% yeast extract, 0.5% NaCl, or the components of M9 medium (Studier and Moffatt, J. Mol. Biol. 189: 113-130 (1986)). These were the starting components in the search for formulations that would allow batchwise growth to high cell densities with reproducible and reliable behavior relative to induction of protein expression in the T7 system. The E. coli strains used for testing growth and expression were primarily BL21 (DE3) or B834(DE3), alone or containing plasmids containing coding sequences under control of the T7lac promoter and the upstream translation initiation signals of the T7 major capsid protein.
The standard measure of growth was optical density at 600 nm (A600) after dilution in water to concentrations that gave readings below 0.25. Viability and stability of cultures grown under different conditions were tested by plating, usually on agar plates containing ZB. A standard configuration for testing different media formulations in parallel was growth of 0.5 ml cultures in 13×100 mm glass culture tubes vertically in a plastic rack in a gyratory incubator at 300-350 rpm. The usual incubation temperature was 37° C., although 20° C. or even lower temperatures were also tested. Time courses of more than a few points were measured in 125-ml Erlenmeyer flasks, usually containing 5 ml or less of medium. These configurations provided sufficient aeration to sustain logarithmic growth to an A600 approaching 10 in the appropriate media. Higher levels of aeration could be achieved with smaller volumes of culture in larger vessels, but the above configurations were used because results obtained with them seemed to translate well to 500 ml culture volumes in 1.8- or 2.8-liter baffled Fernbach flasks, convenient for producing multi-milligram amounts of as many as six proteins at once in a gyratory incubator.
Although they support good growth and protein expression, the usual media are far from optimal. In a typical experiment, saturation density (A600) in ZB was 1.2, in ZY was 2.8, in M9ZB without glucose was 2.6, and in M9ZB containing 2% glucose was 5.8. The usual glucose content of M9ZB is 0.4%, and metabolism of the higher concentration overwhelmed the buffering capacity of M9ZB, producing a final pH of 4.6. Increasing the concentration of N-Z-amine in ZB increased the saturation density approximately in proportion to concentration up to at least 8%, which saturated at A600 of about 8. Adding 1% glucose to 8×ZB or ZY gave little change in saturation density, but greatly reduced the final pH. Increasing the buffering capacity of the medium allowed saturation in glucose-containing media at densities greater than 10. Clearly, even complex media are limited for components needed for growth, and maintenance of a pH near neutral is important for obtaining growth to high density.
To test induction of T7 RNA polymerase in expression hosts in the absence of a target plasmid, the T7 deletion mutant 4107 was used (Studier and Moffatt, J. Mol. Biol. 189: 113-130 (1986)). This mutant T7 phage lacks the entire coding sequence for T7 RNA polymerase and is unable to form a plaque on a lawn of cells unless the host cell supplies T7 RNA polymerase. The basal level of T7 RNA polymerase in uninduced BL21 (DE3) is low enough that only small plaques develop at low efficiency, and they typically begin to appear only after about 3 hours. In contrast, induced BL21 (DE3) supports large plaques that become apparent in less than 2 hours, typical of wild-type T7. This 4107 plaque assay was used to test whether T7 polymerase was induced in cultures of BL21(DE3) grown in different media. Cultures grown in media made with the lot of N-Z-amine that did not give induction of target proteins at saturation also appeared uninduced in the plaque assay, giving only small plaques that took a long incubation time develop. Cultures grown in media made with the lot of N-Z-amine that did give induction of target proteins at saturation rapidly gave the large plaques indicative of induction, unless the growth medium also contained glucose, which appeared to prevent induction, as others had reported previously.
Fully defined media were formulated with simple salts and with glucose as the sole carbon source, both to test the requirements for different nutrients and to develop non-inducing media that would support growth of T7 expression strains to saturation at reasonable densities with the lowest possible basal levels of T7 RNA polymerase. When all nutritional requirements are satisfied, the main limitation in achieving high cell densities appears to be maintaining the pH of the culture near neutral, since metabolism of glucose can produce substantial amounts of acid. One solution to this problem is to buffer the medium with phosphate, a required nutrient that buffers in the neutral range. Increasing concentrations of phosphate can buffer the acid generated by higher concentrations of glucose, allowing higher cell densities to be attained while maintaining a pH near neutral (typically greater than pH 6) all the way to saturation. However, too much phosphate can be inhibitory, presumably because of high ionic strength or osmotic pressure. A phosphate concentration of 100 mM seems a reasonable compromise, providing enough buffering capacity to allow growth to saturation in 0.5% glucose while maintaining a pH close to neutrality. Such cultures grow with a doubling time of about 60-70 minutes at 37° C. and saturate at A600 of approximately 5 to 6 and a pH around 6.5. One such growth medium is P0.5G (Table 1).
Several other compounds besides phosphate were tested for ability to help manage the acid produced by the metabolism of glucose or glycerol during growth to saturation. Succinate proved to be particularly useful. Growth of BL21(DE3) on a simple salts medium containing 75 mM succinate (0.23%) as sole carbon source was relatively slow (about a 2 hour doubling time), but the pH of the culture increased with growth (to a pH of 8.7 at an A600 of 0.9). In glucose-succinate mixtures, cultures appear to metabolize glucose preferentially, doubling at about the same rate as in cultures where glucose is the sole carbon source. At appropriate succinate and glucose concentrations, the pH of the growing culture initially decreases and then reverses, presumably as glucose is depleted and succinate is metabolized. For a given medium and culture condition, the range of succinate concentrations that balance the acid generation by glucose, glycerol, or other carbon sources whose metabolism generates acid is easily determined empirically. With too little succinate, the pH at saturation may fall well below 5; with too much succinate the pH at saturation may increase beyond pH 9. In the preferred range of succinate concentrations, the pH at saturation lies between 6.5 and 7.5. A culture grown in a simple salts medium containing 0.5% glucose and 20 mM succinate as sole carbon sources (NIMS medium, Table 1), typically saturates at A600 of approximately 5 to 6, and pH between 6.5 and 7.5. Growth of BL21 (DE3) in simple salts with succinate as sole carbon source did not appear to induce T7 RNA polymerase, as determined by the 4107 plaque assay.
Fumarate and DL-malate are cheap and readily available carbon sources that behave like succinate in their ability to balance acid generation. Citrate and acetate are also effective, but somewhat less so. Growth of BL21 (DE3) in simple salts with succinate as sole carbon source did not appear to induce T7 RNA polymerase, as determined by the 4107 plaque assay. Neither succinate nor any of these other carbon sources, in mixtures with glucose in simple salts media, appear to cause induction of target protein synthesis in T7 expression strains.
Considerable testing of growth of BL21(DE3) or B834(DE3), with and without target plasmids, showed that all expression strains tested, even strains that express highly toxic target proteins such as the gene 7.7 protein of bacteriophage T7, grow to saturation in P0.5G or NIMS medium with little or no expression of target protein, loss of plasmid, or loss of ability to express plasmid. These media can provide a substantial advantage over typical lots of ZY (or LB) in obtaining expression strains for target proteins that are deleterious to the host. In the case of T7 gene 7.7, transformants in BL21 (DE3) readily gave colonies on P0.5G plates, but no colonies on ZY plates made with the lot of N-Z-amine that caused induction upon approach to saturation.
The ability to balance acid generation with succinate or other carbon sources allows complete flexibility in testing the minimum concentrations of all components (including phosphate) needed for growth of T7 expression strains (or any bacteria) and good expression of target proteins. Tests with P0.5G, NIMS, and media with other combinations of carbon sources (Table 1) showed that minimum concentrations to assure growth to an A600 of at least 5 and good expression of target proteins include approximately 0.5 mM Mg, 5 mM PO 4 , 25 mM NH 4 , 0.5 mM SO 4 , 5-10 μM Fe, and lower concentrations of other metal ions. At least 10 mM Mg, 150 mM PO 4 , 100 mM NH 4 , 25 mM SO 4 , and 500 μM Fe can be tolerated with little or no effect on growth to high density and expression of target proteins. Concentrations in the media that have been tested most extensively have been 1 or 2 mM Mg, 25-100 mM PO 4 , 25-100 μM NH 4 , 1-25 mM SO 4 , and 5-100 μM Fe (Table 1).
Since a significant fraction of proteins bind metals for stability or function, and in structural genomics or other projects the metal-binding properties of target proteins may be unknown, the mixture of trace metal ions given in Table 2 was designed to provide most metal ions that are known to be specifically bound by proteins. A target protein of 50,000 Da produced at a level of 100 mg/liter would have a concentration of 2 μM and a protein of 10,000 Da would have a concentration of 10 μM. The 1× concentration of metal mix provides 2-50 μM of each of 10 different trace ions, probably sufficient to saturate most metal-binding proteins that would be produced. If the metal content of a target protein is known, a saturating amount of that metal can be added specifically. In cultures where target protein is not to be expressed, 0.1× concentration of metal mix should be sufficient for high-density growth, or 50 μM Fe plus 0.02-0.05× metal mix. In cultures whose growth was limited by lack of trace metals, the most dramatic stimulations of growth upon the addition of 1, 10 or 100 μM of individual metal ions of the metal mix were provided by 10-100 μM Fe, 1-100 μM Mn and 1-10 μM Co. Evidence of toxicity up to 100 μM concentration was seen only for Co, which caused a lag before growing well at 10 μM and almost completely prevented growth at 100 μM, and Se, which supported growth normally at 10 μM, but only poorly at 100 μM. At least 5× concentration of metal mix had no apparent deleterious effect on growth to high densities and expression of target proteins in a simple salts medium, and at least 10× metals was tolerated in a simple salts medium plus 200 μg/ml each of 18 of the natural amino acids (no cysteine or tyrosine).
BL21 (DE3) has no nutritional requirements for growth. B834(DE3) was known to require methionine for growth, and 200 μg/ml is sufficient for high density growth and expression of target proteins. In the course of this work, it was discovered that the methionine requirement of B834 could be satisfied instead by vitamin B12 (as little as 1 nM). This demonstrated that B834 is a metE mutant, defective in the vitamin B12-independent homocysteine methylase that would normally synthesize methionine, the last step in methionine biosynthesis. Vitamin B12 is known to activate a second homocysteine methylase of E. coli , the product of metH. Since E. coli is unable to synthesize vitamin B12, this second enzyme is active only when this vitamin is added to the growth medium. Ability to grow on either methionine or vitamin B12 is the defining characteristic of metE mutants.
To make the media described here generally useful for the growth of expression hosts or other bacteria that may have additional, sometimes multiple nutritional requirements, specific growth factors, mixtures of growth factors such as amino acids, vitamins or nucleosides, or complex media components such as N-Z-amine and yeast extract may be added to the minimal media. Some such media are given in Table 1. A useful stock solution is the mixture of 17 of the 20 natural amino acids, each at 10 mg/ml. Left out of this mixture are cysteine, which slowly forms the essentially insoluble cystine and precipitates; tyrosine, which is only slightly soluble; and methionine, which is often used for radioactive labeling or is replaced by selenomethionine (Se-Met) to label proteins for phasing X-ray crystallographic data. Addition of 18 amino acids (no C or Y) substantially increases the growth rate over that of simple salts media, giving a doubling time of 30-35 minutes as opposed to 60-70 minutes. A concentration of 200 μg/ml of each amino acid seems sufficient for most purposes, although higher concentrations may be better for very high density growths. The omission of cysteine and tyrosine seemed to have little effect on growth rate or saturation density compared to a mixture containing all 20 amino acids. In contrast to amino acids, addition of mixtures of vitamins or nucleosides seemed to give little if any stimulation of the growth rate or increase in saturation density of BL21 (DE3), which has no specific requirement for them. Addition of the complex ZY components to the minimal salts media seemed to provide slightly higher growth rates and saturation densities than the addition of 18 amino acids in most experiments. To minimize the possibility of induction near saturation in complex media, glucose should be added at a high enough concentration that it will not be depleted (as indicated by a decrease in pH and no subsequent increase), typically 0.8% in ZYP medium.
Extensive experience with growing and storing cultures of BL21(DE3) and B834(DE3), alone or containing expression plasmids, in NIMS and in P0.5G indicates that these are excellent media for stable storage of freezer stocks in 8% glycerol at −70° C. or working stocks stored in the refrigerator and used for inoculating subcultures. In contrast to previous experiences with other media, cultures grown to saturation in these media remain viable for periods of weeks to months of storage in the refrigerator, retaining their titer (typically greater than 10 10 /ml) and ability to grow subcultures with little or no lag.
2. Development of Auto-Inducing Media
Hoffman et al., Protein Expression and Purification 6: 646-654 (1995) reported that fed-batch techniques in a well controlled fermentor allowed induction of target protein synthesis in the T7 system by addition of lactose or glucose-lactose mixtures after depletion of glucose. They proposed that these techniques may slow induction rate and allow more time for proper folding and solubility while producing amounts of protein comparable to those obtained by IPTG induction and culture densities with A600 in the range of 25-40.
It was of interest to determine whether such techniques, when applied to batchwise production of proteins in the T7 expression system in these new media, could increase the solubility of target proteins that were expressed well, but were largely insoluble, of which several were in a structural genomics project. Also, studies of the ClpP protein of E. coli had revealed considerable variability in the fraction of soluble ClpP produced, suggesting that lower rates of induction might produce a larger fraction of soluble protein.
The 4107 plaque assay confirmed that growth of BL21 (DE3) to saturation in minimal medium containing 2% α-lactose (and no glucose), with or without added ZY, caused induction of T7 RNA polymerase. However, adding 0.1% or 0.5% lactose to complex medium containing 2% glucose gave only a slight indication of a possible increase in T7 RNA polymerase in the 4107 plaque assay.
Target protein P35 of a structural genomics project (yeast protein coproporphyrinogen III oxidase) under control of a T7lac promoter in a pET vector in B834(DE3) was expressed to substantial levels when grown to saturation in ZYP medium made with the lot of N-Z-amine that showed inducing activity. The protein is apparently not very toxic to the expression host, because the plating efficiency of cells from the saturated culture appeared to be normal. Addition of 1% lactose to the medium produced about a 50% increase in saturation density, but little increase in the level of target protein. However, almost all of the cells capable of forming a colony had lost plasmid. (It was soon discovered that even cells without plasmid can grow quite well in ZYP medium in the presence of 25 μg/ml of kanamycin, the concentration used in this experiment.) Apparently, 1% lactose caused induction to such a high level that cells that contained plasmid were killed. Addition of 0.05% or 0.1% glucose substantially increased the level of target protein produced, apparently by allowing growth to higher density before the level of induction caused by 1% lactose became high enough to kill the cells. Almost all of these surviving cells had also lost plasmid.
These results suggested that perhaps the induction in certain lots of ZYP medium was in fact due to the presence of a small amount of lactose, contrary to what Grossman et al., Gene 209: 95-103 (1998) concluded. Their conclusion was based on their finding that β-galactosidase treatment of the medium did not eliminate the induction phenomenon and their inability to detect lactose in the medium (<0.002%). It was tested whether adding lactose to ZYP medium made with the lot of N-Z-amine that showed no inducing activity could reproduce the observed behavior of the lot with inducing activity, namely induction of the target protein to levels readily apparent by gel electrophoresis upon growth to saturation with retention of a typical plating efficiency of cells that essentially all retained plasmid. Indeed, expression was detected by SDS gel electrophoresis with Coomassie blue staining with as little as 0.001% added lactose in the non-inducing medium, and substantial induction was observed at 0.003% lactose or higher. Loss of titer in the saturated cultures started to become significant at 0.01% to 0.02% lactose and was severe by 0.05%. Thus, the lactose concentrations that can cause detectable induction without significant loss of titer are near or below the levels detectable by Grossman et al., Gene 209: 95-103 (1998).
It was concluded that, contrary to the belief in the previous art, the presence of small amounts of lactose in some commercial lots of complex media is an important factor, and perhaps the determining factor, in the spontaneous induction of target protein synthesis sometimes observed in the T7 expression system near the onset of stationary phase. The conclusion seems quite reasonable given that the complex media contain tryptic digests of casein (a milk protein), milk contains substantial amounts of lactose, and only very small amounts of lactose are needed to cause induction. Although the casein used in the tryptic digests was purified in its preparation from milk, it seems almost certain that small amounts of lactose contaminating certain lots of purified casein are responsible for the inducing activity observed.
The realization that the inducing activity was due to lactose, together with the results of experiments exploring the effects of different mixtures of glucose and lactose on induction behavior, caused rethinking of the results and conclusions of Hoffman et al., Protein Expression and Purification 6: 646-654 (1995) on the induction of target protein by batch-fed lactose or glucose-lactose mixtures under controlled conditions in a fermentor.
It seemed from initial results that cultures grown in different mixtures of glucose and lactose were not inducing production of target protein at intermediate rates, as proposed by Hoffman et al., Protein Expression and Purification 6: 646-654 (1995), but were in fact growing with little or no induction until the glucose was depleted, and only then being induced by the lactose present in the medium. A comprehensive series of tests, including time courses of growth and induction under different conditions, were consistent with this interpretation. The term auto-induction is used to refer to the growth pattern of inducible expression strains in inducer-containing media, where growth is essentially normal in the early stages, with little or no induction, and expression of the target protein is turned on automatically at a later stage of growth, with no intervention. Much of the testing to define the auto-induction behavior and the factors affecting it was done with target protein P21 of a structural genomics project, a well induced, not particularly toxic protein (yeast peptide chain release factor subunit 1) expressed under control of a T7lac promoter in a pET vector in B834(DE3) which also contained a compatible plasmid expressing tRNAs for rare arginine, isoleucine and leucine codons. The results may be summarized as follows.
Little growth was apparent in simple salts media containing lactose as sole carbon source, presumably because the level of induction was too high to allow growth. Addition of increasing concentrations of glucose to media containing 0.1% to 1.5% lactose allowed growth to increasing saturation densities, with expression of target protein occurring in cultures that had low glucose concentrations, but decreasing to undetectable levels at about 0.5% glucose or higher. In somewhat of a surprise, ZY-containing media with no added glucose suppressed induction by even high concentrations of lactose (1.5%) to undetectable levels during early log phase growth, followed by high-level induction of target protein, typically occurring at an A600 between about 1 and 2. This suppression of induction by lactose in early log phase in the absence of added glucose is apparently due, at least partly, to the presence of amino acids rather than, for example, contaminating glucose in the complex ZY media, because purified amino acids also have this suppressive effect in simple salts media containing lactose and glycerol. Serine seems to be particularly effective in suppressing lactose induction in early log phase, and can itself allow growth and induction in a lactose-glycerol mixture about as well as a mixture of all 20 amino acids. Serine is not required, however, as a mixture of 17 amino acids lacking serine, cysteine and tyrosine was also effective.
Lactose itself appears not to be a very good carbon source for growth of auto-induced cultures to high cell densities. Addition of glycerol to simple or complex media allows growth to much higher densities and does not seem to interfere with auto-induction. Mixtures containing from 0.5% to 2.5% glycerol with 0.05% glucose and 0.2% lactose have been very effective at promoting growth to high culture densities and auto-induction of many different target proteins in both simple and complex media. A short-hand notation for these particular mixtures has been 5052 to designate the mixture 0.5% glycerol, 0.05% glucose, 0.2% lactose, 10052 to designate 1% glycerol, 0.05% glucose, 0.2% lactose, and so on, where the last three digits, 052, denote the 0.05% glucose, 0.2% lactose and the first one or two digits refer to the concentration of glycerol. Other economical and readily available carbon sources that have been effective in promoting high-density growth and auto-induction in combination with glucose and lactose include maltose and sorbitol.
Saturation densities of auto-induced cultures can vary considerably depending on the effect of the expressed target protein on the host cell. Auto-induced cultures which express target proteins that directly affect growth may saturate with high levels of target protein at an A600 of around 5. More typical are saturation densities in an A600 range of 10-20, and densities as high as 30-50 have been observed. Auto-induction with production of large amounts of target protein has been effective with many different target proteins at temperatures between 18° C. and 37° C.
One factor that significantly affects the saturation density is level of aeration. This was varied in experiments by changing the volume of culture relative to the volume of the vessel. Lower relative volumes of culture provide higher levels of aeration. Both saturation and induction occurred at lower cell density, the lower the level of aeration, but the level of target protein produced per cell seemed to remain fairly constant over a range of saturation densities. Extremely high aeration occasionally seemed to delay or reduce induction to the point where it hardly occurred, perhaps because an extremely high cell density depleted an essential nutrient, or because some general stress response involved in high-level induction was muted. Growth of 0.5-ml cultures in 13×100 mm glass culture tubes or 500-ml cultures in 2- or 2.8-liter baffled Fernbach flasks seem to provide an appropriate level of aeration for effective auto-induction with media formulations comparable to those given in Table 1.
The auto-induction phenomenon is consistent with a large body of previous work showing that the presence of glucose in the growth medium excludes the use of lactose both by preventing the uptake of lactose from the medium by the lac permease, and through catabolite repression, which operates through the effect of glucose metabolism on cAMP levels. However, the lacUV5 promoter, which directs the expression of T7 RNA polymerase, does not require cAMP-mediated activation and can be induced by IPTG in the presence of glucose. IPTG acts directly as an inducer and does not require the lac permease to enter the cell. Induction by lactose, on the other hand, requires both uptake by the lac permease, and conversion to the true inducer by the transgalactosidation activity of P-galactosidase. Thus, one would not expect auto-induction to work in T7 expression strains that carry mutations in the lac permease because such cells cannot take up lactose, nor in cells that carry mutations in β-galactosidase that prevent the transgalactosidation reaction which generates the true repressor.
Grossman et al., Gene 209: 95-103 (1998) found that unintended induction was reduced in a cAMP-deficient mutant of BL21 (DE3), and proposed that cAMP, rather than acting directly on the lac promoter, may trigger a general stress response occurring during the approach to saturation. It seems quite possible that some such response may be involved in the auto-induction phenomenon.
Catabolite repression and inducer exclusion by the presence of glucose in the growth medium is a general phenomenon in E. coli and is known to affect other carbon sources besides lactose, including galactose, maltose, arabinose, and many others. Expression systems that use promoters regulated by any of the compounds subject to catabolite repression and inducer exclusion would also be suitable for application of the auto-induction methods disclosed here.
3. Applications
The current understanding of auto-induction of target protein production in the T7 system, and the development of reliable media and protocols for batchwise growth of expression strains to saturation either with essentially no induction or with auto-induction of high levels of target protein at high culture densities, has great utility for producing proteins from cloned coding sequences. Both non-inducing and auto-inducing cultures are simply inoculated and grown to saturation. Non-inducing media produce cultures that are viable for weeks at refrigerator temperature for making subcultures for screening expression and solubility or production of substantial amounts of target protein. Agar plates made with non-inducing media also allow expression strains to be obtained for some target proteins that are too toxic to be obtained in typical commercial media.
In contrast to conventional inductions by addition of either IPTG or lactose, where growth of each culture must be monitored and inducer (IPTG or lactose) added at the proper time, auto-inducing cultures are simply inoculated and grown to saturation. At 37° C., high-level auto-induction is usually achieved in 14 hours in minimal salts media, or 8-10 hours in media supplemented with ZY or amino-acid mixtures, convenient lengths of time for overnight inductions. Continued incubation for several hours after saturation appears not to be deleterious. In fact, where high levels (typically 2% or more) of glycerol or other neutral carbon source such as maltose are present and the pH remains near neutral, cell density can continue increasing slowly for 24 hours or longer and can lead to substantial further increases in culture density and yield of target protein. (A potential problem with using high concentrations of maltose is that most lots have significant contamination with glucose, which, if high enough, could interfere with induction.) Auto-induction at lower temperatures, such as 20° C. requires substantially longer incubations, often 24-36 hours. The incubation time can be shortened without reducing the desired solubility of the induced target protein by incubating the cultures at 37° C. for a few hours and then transferring them to the lower temperature before they become more than lightly turbid.
The densities of induced cells obtained by auto-induction in the disclosed media are much higher than those typically produced by conventional induction. The densities of batchwise auto-induced cultures are typically high enough that screening for expression and solubility is accomplished with 5-50 μl of culture, readily obtainable in 96-well plates. The simplicity and reliability of obtaining non-induced and auto-induced cultures makes highly parallel screening of many target proteins readily automatable.
Larger-scale growth of auto-induced cultures to obtain protein for purification is readily accomplished in baffled flasks on a rotory incubator at 300-350 rpm. A single 1.8- or 2.8-liter baffled Fernbach flask with 500 ml of auto-induced culture can yield tens to hundreds of milligrams of target proteins from well expressed clones, sufficient for structure determination and many other purposes. It is not unusual for auto-induced cultures to yield ten times the amount of purified target protein as obtained from the same volume of culture induced with IPTG in the conventional way.
The disclosed fully defined auto-inducing media also make it possible to develop media for efficiently labeling proteins. Useful examples are Se-Met labeling for protein structure determination by X-ray crystallography, or isotopic labeling for structure determination by NMR. An efficient auto-inducing medium for Se-Met labeling is the PASM-5052 medium given in Table 1.
To label target proteins with Se-Met, PASM-5052 medium is inoculated with a fresh overnight culture grown in PA-0.5G. Growth at 37° C. from a thousand-fold dilution into PASM-5052 typically reaches saturation in 14-16 hours. Growth at 20° C. is much slower and a culture can take 3 days or longer to become induced and reach saturation.
Auto-induction in PASM-5052 medium will produce target proteins essentially fully labeled with Se-Met when expressed in either the methionine auxotroph B834(DE3) or the prototroph BL21 (DE3). The presence of Se-Met reduces the growth rate of the two strains comparably, presumably because both strains incorporate Se-Met into their proteins in place of methionine (but possibly due to other toxic effects as well). Enzymes of the methionine synthesizing pathway are apparently repressed by the presence of Se-Met in the medium, as they would be by methionine, preventing endogenous production of methionine.
The small amount of methionine present in PASM-5052 medium allows significantly faster growth in the presence of Se-Met, and the concentration of Se-Met is sufficient to support the growth of the methionine-requiring B834 to saturation (in the absence of vitamin B12). The presence of vitamin B12 in PASM-5052 medium significantly increases the yield of target protein and largely prevents the appearance of a brown-orange color that can appear in cells upon continued incubation at saturation in the presence of a slight excess of Se-Met. Vitamin B12 is known to activate an enzyme (the product of metH) that methylates homocysteine to produce methionine. Perhaps a significant fraction of Se-Met is converted to Se-homocysteine during growth or induction in this medium, and the B12-dependent methylase stimulates production of target protein by regenerating Se-Met.
TABLE 1
Compositions of representative non-inducing and auto-inducing media
Na 2 HPO 4
KH 2 PO 4
NH 4 Cl
(NH 4 ) 2 SO 4
Na 2 SO 4
MgSO 4
FeCl 3
18aa
mM
mM
mM
mM
mM
mM
μM
metl
ZY
μg/ml
Glyc %
Gluc %
Lact %
Succ mM
Non-inducing media:
P-0.5G
50
50
25
1
0.1x
0.5
PA-0.5G
50
50
25
1
0.1x
100
0.5
ZYP-0.8G
50
50
25
1
1x
0.8
NIMS
12.5
12.5
50
5
1
0.1x
0.5
20
Auto-inducing media:
ZYP-5052
50
50
25
1
1x
1x
0.5
0.05
0.2
PA-5052
50
50
25
1
1x
200
0.5
0.05
0.2
P-5052
50
50
25
1
1x
0.5
0.05
0.2
PASM-5052
50
50
25
1
1x
**
0.5
0.05
0.2
MS-15052
12.5
12.5
50
5
2
50
1x
1.5
0.05
0.2
35
MAS-15052
12.5
12.5
50
5
2
50
1x
200
1.5
0.05
0.2
15
ZYM-15052
12.5
12.5
50
5
2
50
1x
1x
1.5
0.05
0.2
** PASM-5052 contains 200 μg/ml each of 17 amino acids (no M, C, Y), 10 μg/ml methionine, and 125 μg/ml selenomethionine plus 100 nM of vitamin B12
ZY is 1% N-Z-Amine AS + 0.5% yeast extract
metl is the metals mix shown in Table 2
Metals may be omitted from media containing ZY if high concentrations are not required
Metals may be reduced to 0.1x in simple salts media if high concentrations are not required
18aa gives the concentration of each of 18 of the natural amino acids (no cysteine or tyrosine)
Glyc is glycerol
Gluc is glucose
Lact is alpha lactose
Succ is Na 2 succinate
TABLE 2
Composition of a Trace Metals Mix (1x)
50 μM FeCl 3
20 μM CaCl 2
10 μM MnCl 2
10 μM ZnSO 4
2 μM CoCl 2
2 μM CuCl 2
2 μM NiCl 2
2 μM Na 2 MoO 4
2 μM Na 2 SeO 3
2 μM H 3 BO 3
Dilute from a 1000x stock solution in ~50 mM HCl | A bacterial growth medium for promoting auto-induction of transcription of cloned DNA in cultures of bacterial cells grown batchwise is disclosed. The transcription is under the control of a lac repressor. Also disclosed is a bacterial growth medium for improving the production of a selenomethionine-containing protein or polypeptide in a bacterial cell, the protein or polypeptide being produced by recombinant DNA techniques from a lac or T7lac promoter, the bacterial cell encoding a vitamin B12-dependent homocysteine methylase. Finally, disclosed is a bacterial growth medium for suppressing auto-induction of expression in cultures of bacterial cells grown batchwise, said transcription being under the control of lac repressor. | 2 |
RELATED APPLICATIONS
[0001] This application, pursuant to 37 C.F.R. 1.78(c), claims priority based on provisional application Ser. No. 60/408,932, filed Sep. 7, 2002, U.S. Provisional Application Ser. No. 60/408,925, filed Sep. 7, 2002 and U.S. Provisional Application Ser. No. 60/408,933, filed Sep. 7, 2002
BACKGROUND OF THE INVENTION
[0002] This invention relates to the separation of unwanted constituents from a slurry produced during operation of the Armstrong Process and method to produce a product as disclosed in U.S. Pat. Nos. 5,779,761, 5,958,106 and 6,409,797 patents, the disclosures of which are herein incorporated by reference. As indicated in the above-identified and incorporated patents, the continuous process there disclosed, produces, for instance, titanium or a titanium alloy by the reduction of titanium tetrachloride with excess sodium. The product stream that exits the reactor is a slurry of liquid metal, salt particles or powder and titanium metal or metal alloy as particulates or powder. It should be understood that this invention relates to any material which can be made according to the Armstrong Process. When the slurry produced by the Armstrong Process is filtered, a gel or gel-like material is formed of the metal powder or particulates, the salt powder or particulates and the excess liquid reducing metal. This slurry has to be treated to separate the unwanted constituents, such as excess liquid metal, salt particulates from the desired end product which is the metal particulates or powder.
SUMMARY OF THE INVENTION
[0003] In developing the Armstrong Process with respect to titanium and its alloys, it has been found that the method of producing the slurry above referenced is very rapid and separation of the product from the slurry is the most difficult aspect in engineering of the continuous process. The description will be in terms of the exothermic reduction of titanium tetrachloride with sodium to produce titanium particles, sodium chloride particles and excess sodium; however, this is not to be construed as a limitation of the invention but for convenience, only.
[0004] Accordingly, it is an object of the present invention to provide a method for separating metal powder or particulates from a slurry of liquid metal and metal powder or particulates and salt powder or particulates.
[0005] Yet another object of the present invention is to provide a method of separating metal particulates from a slurry of the type set forth in which one of the unwanted constituents is used to separate both constituents from the slurry.
[0006] A still further object of the present invention is to provide a method of separating metal particulates from a slurry of original constituents of liquid metal and metal particulates and salt particulates, comprising concentrating the metal and salt particulates by removing at least some of the liquid metal, passing the liquid metal or a liquid of the original salt constituent or a mixture thereof at a temperature greater than the melting point of the original salt constituent or mixture thereof through the concentrated metal and the particulates to further concentrate the metal particulates, and thereafter separating the metal particulates from the remaining original constituents or a mixture of the salt constituent.
[0007] A final object of the present invention is to provide a method of separating metal particulates from a slurry of original constituents of liquid metal and metal particulates and salt particulates, comprising introducing the slurry of original constituents into a vessel having a liquid salt therein wherein layers form due to density differences with the liquid metal being the lightest and the metal particulates being the heaviest increasing the concentration of the metal particulates toward the bottom of the vessel, removing liquid metal from the vessel, separating the concentrated metal particulates with some liquid salt from the vessel, filtering the salt from the metal particulates, and thereafter cooling and water washing the salt from the metal particulates.
[0008] Additional advantage, objects and novel feature of the invention will become apparent to those skilled in the art upon examination of the following and by practice of the invention.
[0009] The invention consists of certain novel features and a combination of parts hereinafter fully described, illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For the purpose of facilitating an understanding of the invention, there is illustrated in the accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the invention, its construction and operation, and many of its advantages should be readily understood and appreciated.
[0011] FIG. 1 is a schematic illustration of a first embodiment of the invention;
[0012] FIG. 2 is a schematic illustration of another embodiment of the present invention; and
[0013] FIG. 3 is a schematic illustration of another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0014] Referring now to the drawings and more particularly to FIG. 1 , there is shown a separation system 10 in which a vessel 15 has a generally cylindrical portion 16 with a dome shaped top 17 and a frustoconical shaped bottom 18 and exit pipe 19 extending from the bottom of the vessel 15 . A reactor 20 of the type disclosed in the above-referenced patents has a outer liquid metal or sodium tube 21 and an inner halide vapor or titanium tetrachloride tube 22 . A liquid metal or sodium supply tank 25 feeds sodium to the sodium or other liquid metal to the reactor 20 and a halide boiler 26 feeds the appropriate halide vapor to the reactor 20 , all as previously described.
[0015] Internally of the vessel 15 is a downwardly sloping baffle 28 having a distal end 28 a extending at a more acute angle and generally opposite to a sodium or liquid metal outlet 29 . The liquid metal outlet 29 is in fluid communication with a metal or sodium pump 31 which leads to a heat exchanger 33 having a fluid inlet 34 and a fluid outlet 35 . A liquid metal make-up line 37 is in communication with the supply tank or reservoir 25 . A vent line 38 is provided in the tank or reservoir 25 , as is well known in the engineering art.
[0016] A valve 40 with an actuator 41 is positioned in the exit 19 of the vessel 15 which is in communication with two exit lines 42 and 43 , each of which being provided with a valve such as a valve 44 illustrated in line 42 .
[0017] A filter assembly 45 includes a container 46 and a sloping filtered plate 47 for a purpose hereinafter set forth. A passivating gas inlet 50 has a valve 51 intermediate the source of passivating gas (not shown) and the container 46 . A vacuum drying line 52 exits the container 46 and is provided with a valve 53 . A slurry outlet line 56 at the bottom of the container 46 is provided with a valve 57 and a salt outlet line 61 is provided with a valve 62 . Finally, a water wash inlet pipe 66 is provided with a valve 57 .
[0018] The separation system 10 operates in following manner wherein material such as a metal or metal alloy is produced in the reactor 20 by the method previously described in the aforementioned and incorporated Armstrong patents. By way of illustration only, titanium or a titanium alloy may be made by the reduction of titanium tetrachloride vapor or a plurality of halide vapors for an alloy by an alkali or alkaline earth metal such as sodium or magnesium. Alloys are easily made with the Armstrong Process by mixing the halide vapors in the appropriate quantities and reducing them in the exact same manner as hereinbefore described. In any event, using a large excess of the reducing metal to control the reaction produces a slurry of excess reducing metal, such as sodium, the metal particulates such as titanium and another reaction product such as salt particles, sodium chloride. The slurry leaving the reactor 20 may be at a variety of temperatures controlled, in one instance, by the amount of excess reducing metal present.
[0019] In an actual example, the slurry may typically have up to about 10% by weight particulates, and the particulates may be salt having diameters on average of from about 10 to about 50 microns and titanium having diameters on average in the range of from about 0.1 micron to about 500 microns, the titanium particulates or powder may be more likely to be in the range of from about 1-10 microns and the agglomerated ligaments (lumps) of the titanium in the range of between about 50 and about 1000 microns. This combination of liquid metal, salt particulates and titanium particulates leave the nozzle 20 and enter the vessel 15 . The salt in the vessel 15 is indicated to be at a level of which may be arbitrarily chosen so long as it is below the sodium outlet 29 . The salt may be the reaction product salt, for instance sodium chloride, or a salt mixture which has a melting point lower than the reaction product salt. Although the salt may be as stated any salt, preferably the salt is the product of reaction or a mixture thereof, for instance an eutectic such as the calcium chloride-sodium chloride eutectic which melts at about 600° C.
[0020] The entire system 10 then may be operated at a lower temperature. For instance, sodium chloride melts at about 850° C. so if the salt in the vessel 15 is sodium chloride, then the vessel 15 must be operated above the melting point thereof, but as the eutectic melts at 600° C., this reduces the operating temperature. In any event, irrespective of what salt is present at the level 30 in the vessel 15 , the liquid metal will float due to density differences and be extracted through the outlet 29 by means of the sodium or liquid metal pump 31 . A heat exchanger 33 having suitable inlet and outlet lines 34 , 35 serves to reduce the temperature of the sodium out from the 600° in the vessel 15 (by way of example only) so that the recycled sodium enters the reactor 20 at a preselected temperature (for instance about 400° C.). The baffle 28 and 28 a prevents particulates entering the vessel 15 from the reactor 20 from being sucked into the sodium outlet 29 .
[0021] As particulates settle in the lower portion 18 of the vessel 15 , the particulate concentration is increased due to the removal of sodium through the line 29 . Upon actuation of the valve 40 , concentrated slurry will drain through the outlet or exit 19 through line 42 into the filter assembly 45 . In the filter assembly 45 , which is maintained by temperatures sufficient to keep the molten salt in a liquid phase, metal particles collect on the filter plate 37 while salt passing through the filter plate exits through line 61 to be returned, for instance, to an electrolytic cell (not shown). The valve 62 opens the line 61 to permit the salt to drain while valve 57 is closed to prevent material from exiting the filter assembly 45 . After a sufficient filter cake has been built up, the valve 62 is closed, the valve 44 is closed and the vacuum drying line 53 is opened after the filter cake has cooled to less than about 100° C. so that the passivating gas which may be argon and a small percentage of oxygen may be introduced into the container 46 by actuation of the valve 51 . After the filter cake which may be principally titanium powder with some salt is passivated, then the valve 51 is closed and the water wash valve 67 opened thereby allowing water to enter into the container 46 which both dissolves salt and moves the filter cake through line 56 to a finish wash and classification, it being understood that valve 67 will be opened prior to the water wash. The salt coming out of the filter assembly 45 through line 61 can be recirculated to the vessel 15 as indicated by the line 61 a.
[0022] As seen therefore, the separation system 10 depends on the difference in gravity between the unwanted liquid metal constituent of the slurry and the salt and metal particulates produced during the reaction of the dried vapor and the reducing metal. Although this separation system 10 is a batch system, it can be rapidly cycled from one filter assembly 45 to other filter assemblies as needed through a simple valve distribution system, as is well known in the art.
[0023] Although the above example was illustrated with sodium and titanium tetrachloride, it should be understood that any material made by the Armstrong Process may be separated in the aforesaid manner.
[0024] FIG. 2 shows an alternate embodiment separation system 80 in which a vessel 85 is similar to the vessel 15 and has a cylindrical portion 86 , a dome top 87 and a frustoconical bottom 88 having an exit 89 extending therefrom. A reactor 90 of the same type as hereinbefore described is in communication with the vessel 85 and has a halide inlet 91 and a reducing metal inlet 92 . A slurry outlet 93 which is in communication with the top 87 of the vessel 85 . The filter 95 is any suitable filter, well known in the art, but preferably, for purposes of illustration only, is a “wedge screen filter” of a size to pass up to 125 micron particles. The material that flows through the filter 95 exits the vessel 85 through an output line 96 and flows into a gravity separator 97 . The gravity separator 97 is frustoconical in shape and has an outlet 99 through which the heavier of the materials flows, in this particular case sodium chloride. An outlet 98 takes the lighter of the material, in this case sodium and recycles same through appropriate filters and other mechanisms, not shown, to the reactor 90 . In this embodiment, the vessel 85 is maintained at an elevated temperature of about 850° C. with either internal or external heaters, as is well known in the art, in order that the salt in this case, sodium chloride, is liquid or molten. The molten sodium in large excess displaces the sodium chloride around the particulates and therefore the sodium and the salt flows through the filter plate 95 into the gravity separator 97 and is recycled as previously described. After a suitable filter cake is built up on the filter plate 95 , the valves are closed and the filter cake is thereafter removed for further processing. The advantage of the embodiment disclosed herein is that one of the unwanted constituents, that is the sodium liquid metal is used to displace the other unwanted constituent which in this case is the molten salt. Suitable heat exchangers are required to reduce the temperature of the exiting sodium in line 98 before it is recycled and to heat and maintain the temperature of the salt in the molten state in both the vessel 85 and in the vessel 97 .
[0025] Referring now to FIG. 3 , there is another embodiment of the present invention illustrated as the separation system 100 . The separation system 100 is provided with similar equipment as illustrated in embodiments 10 and 80 . In the system 100 , there is a vessel 105 having a cylindrical portion 106 , a dome shaped top portion 107 and a frustoconical shaped bottom portion 108 having an exit 109 at the bottom thereof. A reactor 110 of the type described in the previously described for practicing the Armstrong process has, as for example only, a titanium tetrachloride inlet 111 and a sodium inlet 112 which serves to produce the reaction previously described with the outlet 113 carrying the slurry produced from the reaction.
[0026] A gravity separator 117 is frustoconical in shape and has an outlet 118 for the lighter weight liquid metal such as sodium and a bottom outlet 119 through which the heavier unwanted constituent, in the present case sodium chloride, exits. Suitable valves are provided between the exit line 116 and the gravity separator 117 as indicated by the valve 121 and a valve 122 is in the exit line 116 between the vessel 105 and the sodium inlet 112 . Another valve 123 is intermediate the vessel 105 and the sodium chloride outlet from the gravity separator 117 and finally a valve 124 is intermediate the reactor 110 and the vessel 105 .
[0027] In the present system 100 , the filter plate 115 collects the metal particulates as the salt which is molten and at a suitable temperature such as greater than the melting points, such as 850° C. for sodium chloride flows through the filter plate 115 carrying with it excess molten sodium which is displaced from the filter cake as it builds on the filter 115 . The combination of liquid sodium and liquid salt flows out of the vessel 105 . Closing valve 122 and opening the valve 121 results in the material being moved by a suitable pump (not shown) to the gravity separator 117 . In the gravity separator 117 , the liquid metal sodium floats and the liquid salt forms the heavier layer at the bottom of the separator 117 and is separated as indicated with the sodium being drawn off at the top of the separator through line 118 to be recycled (after cooling if required) to the sodium inlet to the reactor 110 . The salt is recycled through valve 123 to the vessel 105 . The reactor 110 can be isolated from the system by the valve 124 so that after a predetermined amount of time, the reactor can be disconnected from the system and shunted to a different separation module while liquid salt is used to displace liquid sodium present in the vessel 105 and in the titanium particulates forming the cake on the filter 115 .
[0028] Although the separation systems disclosed herein are batch operations, the valving is such that continuous separations can occur while the reactor is running. A simple system of two or more of the separation systems 10 , 80 or 100 permits a reactor continuously to produce the product of the Armstrong reaction.
[0029] Although described herein with reference to titanium and sodium, any alkali metal or alkaline earth metal or various combinations thereof may be used as the reductant metal. Any halide may be useful or any combinations of halides may be useful as the vapor which is injected into the liquid metal to cause the exothermic reaction to occur. For reasons of economics, sodium or magnesium are preferred with sodium being mostly preferred. For other reasons, titanium tetrachloride along with the chlorides of vanadium and aluminum are also preferred in order to make titanium powder or various titanium alloys, the titanium 6:4 alloy being the most preferred titanium alloy presently in use. The 6:4 titanium alloy is 6% aluminum and 4% vanadium with the remainder titanium, as is well known in the art.
[0030] While there has been disclosed what is considered to be the preferred embodiment of the present intention, it is understood that various changes in the details may be made without departing from the spirit, or sacrificing any of the advantages of the present invention. | A method of separating metal particulates from a slurry of original constituents of liquid metal and metal particulates and salt particulates is disclosed. The metal and salt particulates are concentrated by removing at least some of the liquid metal, and then, liquid metal or a liquid of the original salt constituent or a mixture thereof is passed through the particulates at a temperature greater than the melting point of the original salt constituent to further concentrate the metal particulates. The metal particulates are then separated from the remaining original constituents or a mixture of the salt constituent. Density differences between the liquid metal and salt are also used to facilitate separation. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a §371 national stage entry of International Application No. PCT/EP2010/059568 filed Jul. 5, 2010, which claims priority from BE 2009/0412 filed Jul. 6, 2009, both of which are hereby incorporated by reference in their entirety, for all purposes herein.
FIELD OF THE INVENTION
[0002] The invention relates to a cutter head for dredging ground under the water surface, this cutter head being suitable for attachment to the ladder of a cutter suction dredger and for being moved over the ground therewith in a lateral sweeping movement. The invention also relates to a cutter suction dredger provided with such a cutter head, and to the use of the cutter head for dredging ground, in particular relatively hard ground.
[0003] A cutter head of the type described in the preamble is for instance known from NL-1031253. The known cutter head is a revolving body which is rotatable around a central axis and formed by a base ring and a hub placed at a distance therefrom and concentrically thereto, between which extend a number of support arms provided with cutting tools. The known cutting tools are bit-like, which means that they comprise a flattened part at their free outer end, with the end surface of which they make contact with the ground over a determined linear distance. For a good cutting action the cutting tools must be first to come into contact with the ground during rotation of the known cutter head. The cutting tools are therefore situated on a leading part of the support arms as seen in the direction of rotation of the cutter head.
[0004] The cutter head is applied in combination with a cutter suction dredger (also referred to as cutter dredger). A cutter suction dredger comprises a vessel anchored in the ground by means of so-called spud posts. Owing to this anchoring the reaction forces occurring during dredging can be absorbed and transmitted to the ground. Attached to the ladder of the cutter suction dredger is a suction conduit which is connected to the cutter head and along which the dredged ground is removed. During dredging the cutter head is set into rotation and with ladder and suction conduit lowered into the water at a generally oblique angle until it touches the ground. The cutter head is dragged through the ground by hauling the ladder alternately from port side to starboard side using winches. Because the cutter head rotates about the axis of the cutter head—the line connecting the centres of rotation of the base ring and the hub—the end surfaces of the cutting tools strike the ground with great force under the weight of the cutter head, ladder and suction conduit. Via passage openings between the support arms the hereby formed fragments are suctioned up and discharged by the suction conduit. A whole ground surface can be dredged by moving the cutter suction dredger over a determined distance at a time and repeating the above stated sweeping movement.
BACKGROUND OF THE INVENTION
[0005] U.S. Pat. No. 4,319,415 discloses a cutter head for a cutter. The cutter head comprises a revolving body that is rotatable around an axis of revolution and which is formed by a base ring and a hub located at a distance thereof, between which a number of support arms extend. The support arms are provided with teeth holders for cutting teeth. The teeth holders have a T-shaped profile with which they can be releasably attached to the support arms.
[0006] WO 2005/035884 A describes a robotic manipulator for removing a worn tooth from a dredger cutter head, and for replacing the removed tooth with a new tooth. The manipulator is installed on a dredger vessel. The disclosed cutter heads are of the usual type including about 5 support arms carrying about 8 teeth each.
[0007] GB-A-2 032 492 discloses a cutter head comprising a central hub onto which at least one spiral-helical web is mounted. The web is provided with an array of cutter bits spaced along the web and projecting therefrom such that in use successive bits on the same web cut deeper than a previous bit.
[0008] NL-A-8 104 969 discloses a conventional cutter head for a cutter suction dredger, the cutter head comprising the usual amount of 5 support arms with about 8 teeth attached to it.
[0009] U.S. Pat. No. 4,470,210 discloses an adapter for a cutter head. The adapter is rotatable around a longitudinal and a transverse axis, such that the optimum cutting angle of the cutting teeth can be adjusted.
[0010] U.S. Pat. No. 4,986,011 discloses a cutting tooth for a cutter dredger that may be attached to a support arm of a cutter head by clamping part of it in an adapter, making use of an intermittent flexible element.
[0011] The known cutter head has the drawback that relatively hard ground, such as for instance rock, defined in the context of the present application as ground with an Unconfined Compressive Strength (UCS) of at least 50 MPa, either cannot be dredged or can only be dredged with limited efficiency. The UCS is a concept known to the skilled person and represents the compressive strength of a ground mass, the side walls of which are not supported during compression. Efficiency is understood in the context of this application to mean the volume of ground dredged per unit of time and unit of power.
[0012] The present invention has for its object to provide a cutter head for a cutter suction dredger which, in addition to other advantages, can dredge ground surfaces more efficiently and which makes it particularly possible to dredge relatively hard types of ground with an increased efficiency relative to the known cutter head.
[0013] According to the invention there is provided for this purpose a cutter head which comprises a revolving body which is rotatable around a central axis and which is formed by a base ring and a hub placed at a distance therefrom, between which extend a number of support arms provided with cutting tools, wherein the cutter head comprises at least 50 cutting tools, which cutting tools are axisymmetrical at least at their free outer end, and preferably along their entire length, thereby allowing free rotation around their longitudinal axis. It has been found that, by providing inter alia the support arms of the cutter head with cutting tools that are axisymmetrical at the soil contact side thereof, relatively hard ground in particular, such as for instance rock, can be dredged with an increased efficiency relative to the known cutter head. The axisymmetry of the cutting tools has been found to have a favourable effect on the breaking of the ground, and particularly relatively hard ground.
[0014] The known cutting tools are relatively wide at their free outer end to be able to withstand the great forces to which they are subjected during the dredging. The weight of the underwater components of the cutter suction dredger is after all distributed over the contact surface area between the cutting tools and the ground. By giving the known cutting tool a relatively wide free outer end this contact surface area is relatively large, whereby the force transmitted to the ground is distributed over a relatively large surface area. The average pressure on the contact surface is thus kept limited, whereby breaking of the cutting tools is prevented.
[0015] Because the cutting tools according to the invention are axisymmetrical at least at their free outer end, and come into contact with the ground with this part, the cutting tools already penetrate the ground at relatively low forces. The pressure exerted locally on the ground is moreover relatively high, whereby the ground, and particularly relatively hard ground, is crushed effectively.
[0016] It should be mentioned that US-A-4 488 608 describes a rotary stone-cutting head for cutting dry rock and the like, the cutting head carrying conical cutting tools, a part of which comprise a hardened (Tungsten carbide) insert. The tools having the inserts are placed in a somewhat retracted position vis-a-vis the other cutter tools to avoid early breakage when coming in contact with an irregular rock surface.
[0017] DE 10 2005 051450 A1 discloses an axisymmetrical cutting tool that can be rotated freely around its axis of rotation symmetry in a case, whereas U.S. Pat. No. 4,575,156 relates to a similar axisymmetrical cutting tool for use in coal mining Both documents do not suggest using such tools in underwater dredging.
[0018] A preferred embodiment of the cutter head has the feature that the cutting tools are rotation-symmetrical, and are more preferably of conical form. Such a geometry allows higher average pressures to be transmitted to the ground than is possible with the known cutting tool. A further advantage of the cutting tool according to the invention, and particularly the conical preferred variant, is that, owing to its shape, it takes up less space than the known cutting tool. It hereby becomes possible to provide the cutter head with a large number of cutting tools, and this has been found advantageous for the dredging efficiency of the cutter head. For the same reason the passage openings which are present between the support arms of the cutter head and along which the dredged ground is discharged can likewise be smaller than is the case in the known cutter head. This is because the cutting tools according to the invention obstruct the passage less. The number of support arms can hereby also increase.
[0019] According to another preferred embodiment of the invention, the cutting tools comprise a substantially cylindrical shank part with a reduced diameter with respect to a conical top part. The cutting tool according to this embodiment is arranged with its cylindrical shank part in coupling means, provided on the arms of the cutter head. The coupling means preferably comprise a block socket with a central bore in which the cylindrical shank part is inserted for ready rotation. In this embodiment, the conical part will protrude outside the block socket over an active length, which is relatively short in comparison with the total length of the cutting tool. This has the advantage that much larger forces can be withstood than with the state of the art cutting teeth. The block socket moreover effectively supports the cutting tool against bending deformations. In a preferred embodiment the cutting tools have a length protruding outside its holder lying between 10 and 500 mm, more preferably between 20 and 250 mm, and most preferably between 50 and 150 mm.
[0020] In a particularly preferred embodiment, the cutting tool is arranged, preferably in its socket, such that it can be rotated freely or at least readily around its axis of rotation-symmetry. This is possible due to the fact that the cutting tools are rotation-symmetric. Allowing free or ready rotation of the tools during operation reduces the risk for breakage and also self-sharpens the soil-contacting tip of the cutting tools by friction with the soil. The useful life of the cutting tools is hereby extended and precious time is saved in not having to replace broken or blunt cutting tools frequently.
[0021] The conical part of the cutting tool is preferably provided with a hardened tip at the outer end which comes into contact with the soil. The tip may for instance be made of carbide.
[0022] In another preferred embodiment the cutter head according to the invention is characterized in that the top part of the conical cutting tools has a radius of curvature of a maximum of 500 mm, more preferably of a maximum of 350 mm, still more preferably of a maximum of 100 mm, and most preferably of a maximum of 50 mm. Yet another preferred variant comprises conical cutting tools, the top part of which has a radius of curvature lying between 1 and 100 mm, and more preferably between 5 and 80 mm. In yet another preferred variant the cutting tools comprise a holder in which a conical hard metal insert is received.
[0023] A preferred embodiment of the cutter head according to the invention has the feature that the cutter head comprises at least 5 support arms, more preferably at least 10 support arms, and most preferably at least 15 support arms. It is even possible for the cutter head to comprise a revolving surface provided with passage openings between the base ring and the hub. The part of the revolving surface lying between the openings then forms the ‘support arms’ of the cutter head. Another option is to provide the cutter head with axially running support arms on which are mounted transverse arms running in the peripheral direction.
[0024] The number of cutting tools can be varied within broad limits, wherein it is advantageous if the number of cutting tools is as high as possible. In a preferred embodiment the cutter head according to the invention comprises at least 100 cutting tools, still more preferably at least 140 cutting tools, and most preferably at least 180 cutting tools. The cutting tools can here be distributed regularly, but also irregularly, over the revolving surface of the cutter head. The number of cutting tools per support arm preferably comprises at least 10 cutting tools, more preferably at least 15 cutting tools, still more preferably at least 20 cutting tools, and most preferably at least 25 cutting tools.
[0025] The cutter head according to the invention cuts the ground in a fundamentally different manner than the known cutter head. Where the known cutter head strikes large fragments out of the ground with great force, the cutter head according to the invention will break off much smaller pieces of ground. Owing to the greater number of cutting tools in the direction of rotation of the cutter head the ground is moreover cut in more rapid succession. This operation is found to result in a higher efficiency, particularly in harder grounds.
[0026] It has further been found advantageous for the support arms to comprise a first series of cutting tools on a leading part as seen in the direction of rotation of the cutter head, and at least one support arm comprises a second series of cutting tools on a part facing away from the central axis. Although it is unusual to provide a part of a support arm facing away from the central axis with cutting tools, an improved efficiency is obtained. It has been found, surprisingly, that the connection of the cutting tools to the part of the support arm facing away from the central axis is sufficiently strong to transmit to the support arm the forces resulting from the cutting tools striking against particularly hard ground such as rock. More cutting tools can in this way be placed on a single support arm than according to the prior art. This provides advantages, particularly in the dredging of relatively hard ground.
[0027] In an advantageous embodiment the cutting tools of the first series on a support arm are offset relative to the cutting tools of the second series. This further increases the efficiency of the dredging process. Because the cutting tools are offset, an increased working area of the cutting tools is obtained. This is because cutting tools of the second series are not obstructed by cutting tools of the first series.
[0028] In yet another embodiment the support arms have a length and the cutting tools are located on either side of the middle of the support arms along a maximum of 80% of the length of the support arm. The absence of cutting tools close to the outer ends of the support arms is not found to adversely affect the efficiency of the cutter head, while owing to this measure the construction of the cutter becomes simpler and therefore cheaper. On the other hand, the presence of cutting tools close to the hub of the cutter head is advantageous for the progression of the cutter head.
[0029] The cutting tools can be formed integrally with the support arms of the cutter head. Another method is to connect them directly to the support arms, for instance by welding cutting tools embodied substantially in steel to support arms manufactured substantially from steel, this resulting in a strong connection. The cutting tools can particularly be connected to the support arms via coupling means. Cutting tools can hereby be replaced easily, which may be necessary as a result of wear or damage. It is advantageous here to connect the coupling means themselves integrally with the support arms, such as by making use of a welded connection.
[0030] In a preferred embodiment of the cutter head according to the invention the support arms of the cutter head are provided with guides on which the coupling means and/or the cutting tools are displaceably mounted. A suitable guide comprises for instance a guide rail over which the coupling means and/or the cutting tools can slide. The present preferred variant has the advantage that the coupling means and/or the cutting tools can be displaced easily. The intermediate distance between the cutting tools can thus be adjusted in simple manner depending on the properties, and in particular the hardness, of the ground.
[0031] The invention also relates to the use of a cutter head according to the present invention for cutting into ground parts a ground with an Unconfined Compressive Strength (UCS) of between 50-200 MPa, preferably between 60-150 MPa and most preferably 80-100 MPa. For the advantages of the use of the cutter head reference is made to the advantages already stated above of the cutter head according to the present invention.
[0032] The invention also relates to a cutter suction dredger provided with a cutter head according to the present invention. With a cutter suction dredger provided with a cutter head according to the present invention ground, and in particular relatively hard ground, i.e. a ground with a UCS of more than 50 MPa, can be dredged with an improved efficiency.
SUMMARY OF THE INVENTION
[0033] The invention will now be further elucidated with reference to the following figures and description of preferred embodiments, without the invention otherwise being limited thereto. The figures are not necessarily drawn to scale. In the figures:
[0034] FIG. 1 is a schematic side view of a part of a cutter suction dredger with a ladder attached thereto and provided with a cutter head according to the invention;
[0035] FIG. 2 is a perspective view of a cutter head according to the invention;
[0036] FIG. 3 is a side view of a detail of a cutting tool according to the invention;
[0037] FIG. 4 is a side view of a detail of a cutting tool according to another embodiment of the invention; and
[0038] FIG. 5 is a side view of a detail of a cutting tool according to still another embodiment of the invention.
DETAILED DESCRIPTION
[0039] FIG. 1 shows a cutter suction dredger 1 on which a ladder 2 is mounted pivotally around a horizontal shaft 3 . Ladder 2 is provided with a suction pipe 4 which can suction up the loosened ground parts to a level above water surface 100 , after which they are discharged. Ladder 2 is hauled over the ground surface 9 for dredging or breaking by means of a winch 5 which is arranged on the deck of cutter suction dredger 1 and is provided with a number of swing winches (not shown) and ladder winch 8 . Ladder 2 is provided on the outer end thereof with a cutter head 10 according to the invention. Cutter head 10 can be lowered under water by means of the ladder winch cables 8 and moved during use over ground surface 9 in a reciprocating, sweeping movement from the port side to the starboard side of cutter suction dredger 1 and back. In order to be able to absorb the forces generated here on the ground surface, cutter suction dredger 1 is anchored in the ground by means of a spud post 101 . FIG. 1 shows the left-hand (starboard) spud post in unanchored position and the right-hand (port side) spud post in anchored position.
[0040] Referring to FIG. 2 , cutter head 10 according to the invention comprises a revolving body 11 which can be set into rotation around its rotation axis 12 by means of drive means (not shown). Rotation axis 12 herein coincides with the central axis of cutter head 10 . In the shown embodiment revolving body 11 is set into rotation in clockwise direction R as seen from the bridge. Support arms 15 extend spirally between a base ring 13 and a hub 14 located at a distance from base ring 13 , these support arms 15 being connected to base ring 13 and hub 14 . Support arms 15 are here arcuate, wherein the convex sides are directed in the rotation direction R. Base ring 13 , hub 14 and support arms 15 are manufactured substantially from steel. This not only makes cutter head 10 strong but also gives cutter head 10 a great weight, whereby during dredging the cutter head 10 is urged in the direction of the ground for dredging under the influence of the gravitational force. Support arms 15 are herein placed regularly round the periphery of cutter head 10 . Passage openings 16 are located between support arms 15 . Coupling means 17 manufactured substantially from steel are welded to a leading edge 15 a of support arms 15 relative to the rotation direction of cutter head 10 for the purpose of coupling a first series of cutting tools to support arms 15 . Coupling means 17 likewise manufactured substantially from steel are welded to the edge 15 b of support arms 15 facing away from the central axis of cutter head 10 for the purpose of coupling a second series of cutting tools 20 to support arms 15 . Coupling means 17 are oriented such that the front side or striking side of cutting tools 20 of the first and second series are directed in rotation direction R.
[0041] Referring to FIG. 3 , an embodiment of a cutting tool 20 is shown. The shown cutting tool 20 with overall length 27 comprises a substantially cylindrical part 22 with diameter 25 , and a conical second part 23 . Cutting tool 20 can be arranged with cylindrical part 22 in an above described coupling means 17 of cutter head 1 , for instance by means of a snap connection 220 . A permanent connection is also possible, or other form of releasable connection. In the situation where cutting tool 20 is arranged in coupling means 17 , conical part 23 will protrude outside the coupling means or holder 17 over an active length 26 . Conical part 23 of cutting tool 20 is provided with a hardened tip 28 at the outer end which comes into contact with the soil. The appropriate radius of curvature of the tops of cutting tools 20 depends on, among other factors, the properties of the ground and on the specific design of the cutter head, but preferably lies between 1 and 100 mm. A suitable overall length 27 of a cutting tool 20 preferably amounts to between 20 and 400 mm. Suitable transverse dimensions 25 preferably amount to between 10 and 100 mm. In a preferred embodiment the cutting tools 20 have a length 26 protruding outside holder 17 lying between 10 and 500 mm, more preferably between 20 and 250 mm, and most preferably between 50 and 150 mm.
[0042] As shown in FIGS. 4 and 5 , the cutting tool 20 is preferably coupled to the support arms 15 through coupling means 17 in the form of a block socket with a central bore 170 in which the cylindrical shank part 22 of a cutting tool 20 is inserted for ready rotation. In the embodiment of FIG. 4 , the conical part 23 with the carbide tip 28 protrudes outside the block socket over an active length that is relatively short in comparison with the total length of the cutting tool 20 . The block socket 17 supports the cutting tool 20 against bending deformations and allows to transfer large compressive forces in the axial direction 171 of the cutting tool 20 . The cutting tool 20 is inserted into the central bore 170 from the left until the snap connection 220 engages a corresponding annular groove 221 in the socket. In the engaged state, the cutting tool 20 is free to rotate around the axis 171 in the central bore 170 , due to the fact that the cutting tool 20 is rotation-symmetric. This rotation may be hindered somewhat by frictional forces between the outer surface of the shank part 22 and the inner surface of the central bore 170 , or between the contact surfaces of socket and conical part 23 , but is essential a free rotation.
[0043] Another embodiment shown in FIG. 5 , uses a separate holding ring 172 with a slot 173 such that it may be made smaller by compressing it. Once engaged with a corresponding annular groove 221 (as in the embodiment shown in FIG. 4 ) it expands and leaves the outer surface of the shank part 22 free to rotate. Locking of the cutting tool 20 in the axial direction 171 is accomplished by engagement of the rear part 222 of cutting tool 20 against the annular ring 172 . | A cutter head according to the invention is particularly suitable for breaking relatively hard ground, is self-sharpening and has an extended service life. | 4 |
This application is related to Japanese Patent Application No. H11-237277, filed Aug. 24, 1999, the disclosure of which is hereby incorporated by reference in its entirety.
FIELD OF INVENTION
The present invention generally relates to components onto which a resin is molded, and more specifically, molding a resin body onto seat belt components such as a shoulder anchor, a tongue, and the like to lessen or eliminate burrs.
BACKGROUND OF THE INVENTION
The outer surfaces of seat belt components that are touched by a person's hand are typically molded out of a synthetic resin. At least a portion of the metal components may be covered by the resin.
FIGS. 6 ( a ) and ( b ) are schematic sectional views illustrating the molding of a synthetic resin onto the outer surfaces of a metal plate by a conventional mold processing method. As shown in FIG. 6 ( a ), a metal plate 3 is inserted into a cavity 4 . Cavity 4 is created by the joining of metal molds 1 and 2 . A synthetic resin is charged into the cavity 4 by an injection machine or the like. After the resin hardens and the metal molds are removed, a component composed of the metal plate 3 whose outer surfaces are covered with a synthetic resin molded body 5 is obtained, as shown in FIG. 6 ( b ).
According to the above-mentioned conventional mold processing method, a relatively large burr 6 can be made because the synthetic resin flows along the outer surfaces of the plate 3 . The burr is created along at least a partial length of the defining edge or outer boundary of the molded resin body. The burr 6 not only lessens the aesthetics of the component but also possibility generates a friction force when coming into contact with a seat belt and thereby at least partially obstructing the smooth motion of the seat belt.
SUMMARY OF THE INVENTION
An object of the present invention is to overcome the drawback caused by a burr formed by the molding process. The burr is lessened in size or eliminated by forming an externally standing step surface or surfaces on the metal portion, preferably near the end of the molded resin body.
In such a molded component, the stepped surfaces would prevent the flow of synthetic resin. However, the occurrence of a large burr and/or the occurrence of a burr that obstructs the smooth sliding of a seat belt can be prevented. Specifically, when the metal component is inserted into the metal molds and a resin is injected, the injection is carried out by abutting the stepped surfaces of the metal component against the inner surfaces of the metal molds, and the stepped surfaces are pressed against the metal molds by the pressure of the injected resin. Accordingly, no or a smaller gap is formed between the stepped surfaces and the inner surfaces of the metal molds and consequently no or a smaller burr is made.
The present invention is directed to overcoming or at least reducing some of the problems set forth above and at least is directed to accomplishing at least some of the objectives set forth above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of an shoulder anchor according to an embodiment of the invention.
FIG. 2 is a transverse sectional view taken along the line II—II of FIG. 1 .
FIG. 3 is partial enlarged view of the rear portion of the shoulder anchor shown by III of FIG. 1 .
FIG. 4 is a sectional view taken along the line IV—IV of FIG. 3 .
FIG. 5 is a partial enlarged view of the portion V of FIG. 2 .
FIG. 6 is a sectional view showing a conventional example.
FIG. 7 is a sectional view showing an embodiment of the present invention, with
FIG. 7 ( a ) showing the injection molding set-up and FIG. 7 ( b ) showing the finished product.
FIG. 8 is a sectional view showing an embodiment of the present invention.
FIG. 9 is a sectional view showing an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An embodiment of the present invention will be described below with reference to drawings. FIG. 7 is a sectional view showing a component according to an embodiment of the present invention and also illustrates a method of manufacturing the component.
As shown in FIG. 7 ( a ), a metal plate 3 A is inserted into a cavity 4 A formed by metal molds 1 A and 1 B and a synthetic resin is charged into the cavity 4 A by an injection machine or the like. A component having a synthetic resin molded body 5 A molded on the outer surfaces thereof is obtained after hardening the resin and removing the molds, as shown in FIG. 7 ( b ). The metal plate 3 A includes externally standing stepped surfaces 7 at portions near, and preferably very near, to an end of the synthetic resin molded body 5 A. The provision of the stepped surfaces 7 prevents the flow of the synthetic resin any further down the length of the metal plate 3 A and no burr spreads in an excessively wide range. Further, even if a burr is made, because it is at least concealed by the stepped surfaces 7 , there is not a possibility that a seat belt is abutted against the burr so that the seat belt smoothly slides on the component at all times.
In another embodiment of the present invention, stepped surfaces 8 may be formed by defining grooves or indentations as in a metal plate 3 B of FIG. 8 . Alternatively, in yet another embodiment, stepped surfaces 9 may be formed by providing projections as in a metal plate 3 C of FIG. 9 .
FIGS. 1 to 5 show the arrangement of a shoulder anchor according to the first embodiment of the present invention. The shoulder anchor 10 includes a metal plate 11 , a seat belt guide 12 fitted on the plate 11 and having a C-shaped cross section, and synthetic resin molded bodies 13 molded so as to adhere to the plate 11 and the seat belt guide 12 .
A bolt insertion hole 14 is defined through the front portion 11 A of the plate 11 to fasten the shoulder anchor 10 to the pillar or the like of an automobile. Further, an opening (slot) 15 is defined at the rear portion 11 B of the plate 11 to pass a seat belt 20 therethrough. A seat belt guide 12 is mounted on the rear edge portion (right edge of FIG. 2) of the inner peripheral edge of the opening 15 .
One of the synthetic resin molded bodies 13 is molded on the rear portion of the plate 11 using metal molds. The synthetic resin molded body 13 is formed so as to expose the curved surface of tie seat belt guide 12 on the opening 15 side thereof. Further, the synthetic resin molded body 13 covers the rear end surface (right end surface of FIG. 2) of the seat belt guide 12 . As shown explicitly in FIGS. 3, 4 and 5 , a recessed stepped portion 16 having a stepped surface 17 is formed on the projecting square portion of the seat belt guide 12 . The synthetic resin molded body 13 is formed so as to come into the recessed stepped portion 16 .
The seat belt 20 is inserted through the opening 15 of the shoulder anchor 10 arranged as described above and extended along the seat belt guide 12 . In the shoulder anchor 10 , because the stepped surface 17 is defined on the projecting square portion of the seat belt guide 12 , the synthetic resin molded body 13 does not protrude to the outer peripheral surface (surface for guiding the seat belt) of the seat belt guide 12 . As a result, a burr, which at least partially obstructs the smooth sliding of the seat belt 20 , is not made or is made of a smaller size. Accordingly, the seat belt 20 smoothly slides through the seat belt guide 12 at all times.
As described above, when a seat belt component of the present invention is made, the burr of the synthetic resin molded body is less conspicuous and has better aesthetics qualities. Further, the seat belt can slide more smoothly at all times through the component because no burr or a smaller burr is created, thereby allowing for decreased obstruction of its travel.
While preferred embodiments have been shown and described, it should be understood that the changes and modifications can be made therein without departing significantly from the invention in its broader aspects. For example, while reference number 10 in FIGS. 1-5 refers to a shoulder anchor, the reference number 10 could also refer to a tongue for a seat belt buckle or other similar component. Various features of the invention are recited in the following claims. Furthermore, the figures are provided for the purpose of illustration and are not necessarily drawn to scale. | To provide a seat belt component having a molded resin surface in which the burr formed by the resin is less conspicuous or eliminated. The seat belt component could be a shoulder anchor and have the added benefit of allowing the seat belt to slide smoothly therethrough. An externally formed structural element is formed on the metal surface to prevent further flow of the synthetic resin. | 0 |
FIELD OF THE INVENTION
This invention relates to the treatment of material by use of an electric arc. The invention is particularly but not exclusively concerned with the treatment of waste products so as to enable or assist their safe disposal. It will be convenient to hereinafter describe the invention with particular reference to that example application of the invention.
BACKGROUND OF THE INVENTION
Efficient and effective disposal of waste products is a matter of major concern. Various methods have been proposed and adopted, but none has proven to be entirely satisfactory. The use of an electric arc to treat waste product has a number of attractions, but a major problem with such a method is the difficulty of ensuring that all material passing by the arc is uniformly treated. The relatively small cross-sectional size of the arc is a major factor in that difficulty.
OBJECTS OF THE INVENTION
It is an object of the present invention to provide an improved method and apparatus for treating materials. It is a further object of the invention to provide such a method and apparatus which involves the use of an electric arc and which is such that there is substantially uniform treatment of material passing by the arc. It is an object of the invention in a preferred form to provide such a method and apparatus for treating waste products.
SUMMARY OF THE INVENTION
According to one aspect of the invention, there is provided a method of treating material, including the steps of generating an arc between two electrodes, causing movement of the arc such that the arc attachment at each said electrode moves across a surface of the respective said electrode to thereby form a substantially uninterrupted curtain of plasma between the two electrodes, and passing material to be treated through said curtain.
According to a further aspect of the invention, there is provided apparatus for treating material including first and second electrodes, means operative to cause an electric arc to be generated between said electrodes, arc influencing means operative to cause the arc attachment at each said electrode to move across a surface of the respective said electrode so as to thereby form a substantially continuous curtain of plasma between said electrodes, and means operative to direct a stream of material to pass through said curtain.
It is preferred that an annular space exists between the two electrodes and that the plasma curtain is formed around that space as a result of rotating the arc about the axis of the annular space. The material to be treated may be fed through the curtain in a direction away from or towards the axis of the annular space, but the former is generally preferred. It is further preferred that one of the electrodes is in the form of a cylindrical tube which is substantially coaxial with the annular space, and that material is fed longitudinally through the interior of that electrode towards the treatment zone, which is the zone of the plasma curtain.
In one particularly satisfactory form of the method, the direction in which the arc extends between the two electrodes is transverse to the direction in which the arc is moved to create the plasma curtain. The material is moved through the curtain in a direction which is transverse to both the direction in which the arc extends and the direction in which the arc is moved. By way of example, in the case where the arc is moved about a circular path to create an annular curtain of plasma, that path is transverse to the direction in which the arc extends between its attachments to the two electrodes. Material which is caused to flow through the curtain on the other hand, has a direction of movement which is transverse to both the direction in which the arc extends and the direction in which the arc is moved.
The annular curtain and the space surrounded by that curtain, constitutes a material treatment zone. It is preferred that material to be treated is fed towards that zone along one path, and that the product of the treatment 13 moved away from the treatment zone along another path which extends in the substantially opposite direction to the direction of the first path. It is further preferred that the two paths are separated by a wall of heat conductive material.
In circumstances where one of the electrodes is of tubular form, the material to be treated and the product that treatment may flow in opposite directions along the inner and outer surfaces respectively of the tubular electrode. Preferably, the material to be treated is subjected to the direct influence of the electric arc at or near an end of the tubular electrode, and the material flow changes direction at that end so as to move towards and through the plasma curtain. The flow along each of the two paths is substantially parallel to the axial direction of the tubular electrode. In a preferred arrangement, the flow is from the inside to the outside of the tubular electrode, but the reverse could apply.
Several benefits arise out of use of such a method, and they will emerge in subsequent passages of this specification. It is particularly relevant however, that the thermal efficiency of the process is enhanced because the material being treated flows in opposite directions along the inner and outer surfaces respectively of the tubular electrode.
In one form of the method, the material to be treated is fed to the region of the arc in a stream which contains a quantity of water. Water at a suitable temperature (e.g., above 650° C.) is a potent agent for the conversion of complex organic materials to simple more benign substances. The carbon in such substances is oxidised to carbon monoxide while hydrogen is released, and the hydrogen may react with other substances such as chlorine.
It is preferred that the arc is struck between adjacent ends of the tubular electrode and another electrode having a cylindrical well or cavity formed in its respective adjacent end and arranged substantially coaxial with the tubular electrode. The outer diameter of the tubular electrode is no greater than, but preferably less than, the diameter of the cavity. In one possible arrangement, the tubular electrode protrudes into the cavity of the other electrode, and the material being treated flows through a clearance space formed between the outer surface of the tubular electrode and the surrounding cylindrical surface of the cavity.
It is further preferred that the tubular electrode extends upwardly from the other electrode and is disposed with its longitudinal axis substantially vertical. In that form of construction, the other electrode will be arranged so that the axis of its cavity will be similarly disposed.
The electrode having the cavity, which is the lower electrode in the above arrangement, may also be of tubular form. At least, the end portion adjacent the smaller diameter tubular electrode may be tubular. In such an arrangement, the base of that cavity may be formed in any appropriate manner, and it may be formed by either a solid or a liquid barrier. In the event that a solid barrier is used to form the base, a drain may be provided within that base through which slag or metal residue may escape as hereinafter explained. Preferably, material escaping through that drain falls into a body of liquid such as water which quenches the deposited material and also acts as a gas seal for the apparatus.
According to yet another possible arrangement, the lower or cavity forming electrode is rotatable about the axis of the cavity. As hereinafter explained, such an arrangement assists in separating heavy residue from the gas stream which moves through the region of the arc.
Rotation of the arc as previously referred to, can be achieved in any of a variety of ways. For example, the arc may be driven to rotate by magnetic means or by a flow of gas, or a combination of both. The configuration of the electrodes particularly described above however, may be such as to naturally impart a radial component in the movement of the material stream through the region of the arc. That radial component may cause or at least encourage rotation of the arc, and in some circumstances may be the sole means for driving the arc into rotary motion.
Also, the geometry of the two electrodes may be such that gas flow through the arc zone is relatively unhindered. As a result, it is possible to achieve a relatively high residence time for the material in the arc zone.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are described in detail in the following passages of the specification which refer to the accompanying drawings. The drawings, however, are merely illustrative of how the invention might be put into effect, so that the specific form and arrangement of the various features as shown is not to be understood as limiting on the invention.
In the drawings:
FIG. 1 is a cross-sectional diagrammatic view of one form of apparatus in accordance with the invention.
FIG. 2 is a perspective view of part of the apparatus shown in FIG. 1.
FIG. 3 is a diagrammatic representation of the directions in which the arc extends and is moved, and the direction in which material is passed through the plasma curtain formed by the arc.
FIG. 4 is view similar to FIG. 1 but showing another embodiment of the invention.
FIG. 5 shows yet another embodiment of the invention.
DETAILED DESCRIPTION
FIG. 1 shows, in diagrammatic form, one possible form of apparatus for carrying out the method of the invention. That apparatus includes two tubular electrodes 1 and 2, which are arranged in substantially coaxial relationship and with axes extending substantially vertical. The outer diameter of the electrode 1 is at least no greater than, and is preferably smaller than, the inner diameter of the electrode 2. Also, as shown, the two electrodes 1 and 2 are arranged with their adjacent ends 3 and 4 relatively close, and the electrode 1 extends upwardly from the electrode 2.
Any suitable material may be used to form the electrodes, but they are preferably formed from a refractory carbide such as silicon carbide or tantalum carbide.
As will be evident from FIG. 1, an annular space 5 is provided between the electrode ends 3 and 4. Means (not shown) is provided to generate an electric arc 6 between the electrode ends 3 and 4 so as to extend across the space 5 as shown in FIG. 2. Opposite ends of that arc 6 attach to surfaces of the electrodes 1 and 2 respectively as is well known in the art. Further means as hereinafter described, is provided to induce movement of each of the two arc attachments across the respective electrode surface so that the arc 6 rotates about the longitudinal axis of the electrodes 1 and 2. As a result of that rotation, a substantially uninterrupted curtain of plasma can be formed across the space 5.
Means is provided in the arrangement shown to induce reverse travel of material to and from the treatment zone 7 (FIG. 1) which is in the region of the arc 6 and the plasma curtain formed by rotation of that arc. The arrangement is such that the material to be treated travels along a first path which is at one surface of the tubular electrode 1, and the product of the treatment travels along a second path which is at another surface of that electrode. In the arrangement shown, the first path is through the interior of the electrode 1, and the second path is along the outside of that electrode. Any suitable means could be provided to induce the desired flow reversal, but in the particular arrangement shown, that means includes a cavity 8 formed in the end 4 of the electrode 2. The base 9 of the cavity 8 can be formed in any appropriate manner. It may be integral with or formed separate from the electrode 2, and is preferably formed of the same material as the electrode 2.
In the particular arrangement shown, the base 9 of the cavity 8 is formed by a member 10 located within the lower electrode 2 and arranged to form a barrier across the axial bore of that electrode. A hollow space 11 is provided below the base 9, and a drain passage 12 is formed through the base 9 to allow material to fall from the cavity 8 into a body 13 of liquid such as water. That space 11 and drain passage 12 are not necessary in all forms of the apparatus.
The electrodes 1 and 2 are contained within a housing 14, preferably made of or lined with a suitable refractory material, and an annular chamber 15 is provided within that housing 14 around the end portion 16 of the electrode 1. A discharge passage 17 formed through the housing 14 communicates with the chamber 15. Other arrangements are clearly possible.
Material to be treated, hereinafter called feed material, may be introduced into the apparatus in any appropriate way. In the particular construction shown, the feed material is introduced by way of a feed tube 18 disposed substantially coaxial within the upper electrode 1. The feed material may be of a heterogeneous nature, including, by way of example, gases, solids and liquids. In a preferred arrangement, the feed material includes a quantity of water for reasons previously stated.
Any suitable means may be provided to cause rotation of the arc 6 struck between the electrodes 1 and 2, and in the arrangement shown such means includes a magnetic field core 19 located around the housing 41 near the region of the arc 6.
When apparatus according to FIG. 1 is in use, an arc 6 is struck between the electrode ends 3 and 4, and feed material is introduced into the treatment zone 7 through the tube 18. In particular, that material travels axially through the inside of the electrode 1 towards the cavity 8 as indicated by the arrows in FIG. 1. Material entering the cavity 8 encounters the barrier formed by the base 9 and is thereby deflected radially outwards and upwards towards the annular space 5 formed between the electrode ends 3 and 4, as shown by the arrows in FIG. 1. As previously indicated, a plasma curtain effectively extends across and around the space 5 because of the rapid rotation imparted to the arc 6 by the magnetic field induced by the coil 19. The continuity of that curtain will depend upon the speed of rotation of the arc 6, and the curtain will generally be of frusto-conical form because of the relative arrangement of the electrode ends 3 and 4. If the arc current and the speed of rotation of the arc 6 are both sufficiently high, the curtain will in effect become a conical plasma sheet.
Material entering the space 5 is thereby subjected to the direct influence of the arc, and substantially uniform treatment of the material stream results. Because of exposure to the arc 6, the material constitents will be destroyed or will undergo change or reaction such as to, for example, become environmentally safe.
The electrical power input to the arc 6 is divided between the electrodes 1 and 2 and the column of the arc 6. Since the arc column is relatively remote from cool parts of the apparatus, a relatively high level of the power dissipated in the arc column will be transferred to the feed material. The higher the arc voltage (i.e. by increasing the electrode gap) the higher the efficiency of transfer of input power to the feed material.
One consequence of the magnetically driven rapid translation of the arc 6 is that a higher arc voltage is required for a given current as compared with an arc carrying the same current but stationary in the absence of a magnetic field. Another consequence is that electrode wear is substantially reduced.
The product of the treated material, which is primarily gas, which passes beyond the arc curtain, will have a very high temperature. Consequently, as that material travels over the outside of the electrode 1 towards the discharge passage 17, there will be a transfer of heat to the tubular wall of the electrode 1. Heat is thereby transferred through that wall to the colder material stream exiting from the tube 18, thereby enhancing the thermal efficiency of the process.
Reversal of flow through the region of the arc 6 has the further benefit of minimising the possibility of liquid droplets and solid particles being carried in the exit stream of material product flowing from the arc zone to the discharge passage 17. Because of their inertia, such droplets and particles will tend to fall towards the base 9 of the cavity 8. It is therefore very difficult for untreated material to reach the discharge passage 17.
Any liquid such as slag or molten metal residue which separates from the material stream passing through the cavity 8, will tend to collect on the cavity base 9 and then drain through the passage 12. The upper surface 20 of the base 6 may be appropriately shaped for that purpose. The slag and molten metal will then fall into the water body 13 with consequent rapid quenching. That water body 13 also serves to form a seal against escape of gas from the apparatus.
In a variation of the apparatus described above, the solid base 9 may be omitted and the water body 13 may form the lower end of the cavity 5 so that it in effect substitutes for the base 9.
A feature of the arrangement described is that material passes through the plasma curtain in a direction which is generally transverse to both the direction in which the arc 6 extends and the direction in which the arc 6 is moved or rotated. Furthermore, the last two mentioned directions are transverse to one another.
In FIG. 2, the direction in which the arc 6 extends is represented by the arrow 21, the direction of rotation of the arc 6 is represented by the arrow 22, and the direction of movement of material through the plasma curtain is represented by the arrow 23. FIG. 3 diagrammatically shows the mutually transverse arrangement of those three directions.
FIG. 4 shows another possible form of apparatus for carrying out a method according to the invention. Components of the FIG. 4 embodiment which correspond to components of the FIG. 1 embodiment, will be identified by like reference numerals except that they will be in the number series 100 to 199.
A significant difference between the FIG. 1 and FIG. 4 embodiments is that in the latter the end portion 116 of the electrode 101 extends well into the cavity 108 of the electrode 102. Also, the diameter of the cavity 108 is enlarged towards the electrode end 104 so that an annular chamber 115 of reasonable cross-sectional size is created between the outer surface of the electrode 101 and the surrounding surface of the cavity 108. That annular space 115 is the functional equivalent of the space 15 of the FIG. 1 embodiment even though it is formed between different surfaces.
In the preferred arrangement shown, the housing 114 includes a lining part 124 and an outer wall 125. A space 126 may be provided between the lining 124 and the wall 125 for a reason explained below. The stream of feed material gas which flows upwards along the outer surface of the electrode 101 may travel through the space 127 above the electrode 102 to an appropriate discharge.
Escape passages 128 are formed through the wall of the cavity 105 adjacent the electrode end 104, for a reason explained below. Those passages 128 communicate with a continuous slot 129 or other form of separation, which may be continuous or non continuous, between upper and lower sections of the housing lining 124.
The electrode 102 is mounted for rotation about its axis, and any suitable means may be adopted to cause it to rotate about that axis. The speed of rotation can be selected according to requirements.
Feed material may be introduced into the apparatus as described in connection with the FIG. 1 embodiment, or in accordance with any other arrangement as may be desired.
When the FIG. 4 embodiment is in use, an arc is struck between the electrode end 103 and the adjacent surface of the cavity 108. As in the previously described embodiment, the arc column is driven by a magnetic field, or other appropriate means, so as to sweep out a conical path having its centre at the axis of the electrodes 101 and 102.
Rotation of the electrode 102 relative the electrode 101 results in liquid metal and other heavy constituents of the feed material stream being flung radially outwards to accumulate on the inside surface of the cavity 108. As that precipitated material accumulates on the surface of the cavity 105, it will tend to develop into a body 130 of precipitate having a deeply paraboidal free surface 131. The internal configuration of the cavity 108 may assist in that regard, and particularly the frusto-conical form of the lower part of that cavity as shown in the particular embodiment described.
As the precipitate continues to accumulate on the surface of the cavity 108, it will tend to move up that surface towards the escape passages 128. Again the shape of the lower part of the cavity 108 may assist in that regard. Precipitate will thereby escape from the electrode 102 to enter the slot 129, from which it will pass into the space 126 formed between the lining part 124 and the outer wall 125 of the housing 114.
If desired, means 132 may be provided to maintain a stream of water or other coolant within the space 126 so as to quench the precipitate entering that space.
In all other respects, the embodiment of FIG. 4 may operate generally in the same manner as the FIG. 1 embodiment.
The embodiment shown by FIG. 5 has been successfully used in practice using argon as a plasma gas. Components of that embodiment which correspond to components of the FIG. 1 embodiment will be given like reference numerals except that they are in the number series 200 to 299.
Electrodes 201 and 202, which may be composed of graphite, are contained within a water cooled cylindrical housing 214. The conduits 233 and and 234 represent the water inlet and water outlet respectively which connect with the hollow interior 235 of the housing wall 236. The wall 236 may be composed of austenitic stainless steel or other suitable material. End walls 237 and 238 of the housing 214 may be made of any suitable heat resistant material, which is preferably electrically non-conductive.
An axial magnetic field is produced at the annular space 205 by means of a suitable coil 219. The coil 219 could be connected in series with one of the electrodes 201 and 202, but such an arrangement may not be satisfactory in all circumstances.
Material to be treated is introduced into the treatment zone 207 through the axial bore 239 of the electrode 201. The product of the material treatment is removed through the discharge conduit 240, which may have a connected branch line 241 for gas sampling purposes.
It will be apparent from the foregoing description that a method and apparatus as described provides substantially benefits in the treatment of waste products and other materials. The use of water as an oxidant in a preferred form of the method as described, is a matter of some significance. It is essential in conventional plasma torches to use an inert gas such as argon or a non-oxidising gas such as hydrogen, to form the plasma stream. When such a plasma torch is used to treat waste or other materials with significant carbon content, it is often necessary to inject air or oxygen to prevent carbon deposits from accumulating and thereby adversely effecting operation of the torch. In the apparatus according to the present invention, the use of suitable electrode materials and arrangement of electrodes, enables water to be used for both purposes because carbides, such as silicon carbides can tolerate high temperatures in an oxidising environment.
At temperatures above 1000° C. water reacts with carbon
C+H.sub.2 O→CO+H.sub.2
This is the reaction which is exploited in gas producers as used to make fuel gas from coke. The reaction is endothermic. For more chemically complicated substances, the effect, in general, of exposure to water vapour at temperatures greater than 1000° C. is to decompose the substances to produces CO, H 2 and other simple substances such as acidic anhydrides, e.g., HCl.
Other advantages of the method and apparatus described are as follows. The system is tolerant in that it can treat gases, liquids, solids or heterogeneous inputs. There is no cold zones between the input and exit sides of the feed material stream, and the possibility of material escaping destruction by a surface diffusion or boundary layer mechanism is minimised if not prevented. There is also the advantage of achieving relatively high residence time of feed material within the region of the arc. Other advantages are:
A. The use of water as an oxidant provides a cheap, universally available and safe means of effectively inhibiting carbon deposit.
B. The electrode geometry is relatively simple, and enables convenient incorporation of devices for mechanical removal of deposits.
C. The geometry of the electrodes is such that there is relatively little restriction to gas flow in the region of the arc. The rate of gas flow is relatively low, and as a consequence the residence time of the gas within the arc region is relatively high.
D. The use of carbides for the electrodes enhances the useful life of the electrodes.
E. The arc geometry and the absence of water cooling of surfaces close to the arc column, result in a much higher power efficiency as compared with conventional plasma torches.
F. There is no need for an argon shield for the electrodes as in conventional arrangements.
G. The apparatus is relatively simple and relatively inexpensive to manufacture.
Various alterations, modifications and/or additions may be introduced into the constructions and arrangements of parts previously described without departing from the spirit or ambit of the invention as defined by the appended claims. | A method of treating waste material which involves creating a substantially continuous curtain of plasma and directing the material to be treated through that curtain. An electric arc is generated between two electrodes which are separated by an annular space, and the arc column is caused to rotate about the axis of that annular space so that a substantially uninterrupted curtain of plasma bridges the space and extends around the circumferential extent of the space. The direction of rotation of the arc column is generally transverse to the direction in which that column extends between the two electrodes, and material to be treated is fed through the curtain in a direction which is transverse to both the rotational direction and the direction of longitudinal extent of the arc column. One of the electrodes may be of cylindrical tubular form, in which event material to be treated is fed into the region of the arc through the axial bore of that electrode. The other electrode may have a cavity in alignment with the adjacent end of the tubular electrode which serves to direct material in a direction such as to pass through the plasma curtain. | 1 |
This appln. is a 371 of PCT/US97/04389 filed Mar. 19, 1997 and also claims the benefit of Provisional No. 60/014,032 filed Mar. 25, 1996.
BACKGROUND OF THE INVENTION
Refuse vehicles are typically used by municipalities and waste-removal contractors to collect refuse material from widely dispersed sources such as residences or commercial establishments and to transport the collected refuse to a central dump site such as a landfill, recycling center, or transfer point where it can be ejected. Since the dump site may be located a long distance from the collection area, it is desirable to "pack" (i.e, compress or compact), the refuse material as it is collected so as to maximize the number of sources which can be serviced by a vehicle of a given storage capacity before another trip to the dump site is necessary. A refuse vehicle typically comprises a conventional truck chassis or trailer chassis upon which is mounted a refuse body having apparatus for collection, packing, storage, and ejection of the refuse.
Three general classes of refuse vehicles are commonly encountered. A "rear-loader" type refuse vehicle is typically provided with a hopper, i.e., receiving compartment, which is accessible from the rear of the vehicle and a movable blade for packing the refuse forward from the hopper into a storage area for storage. A "front-loader" type vehicle is typically provided with a hopper which is accessible from the top, a power-actuated loading mechanism for elevating and dumping refuse containers from the front of the vehicle into the hopper, and a movable blade for packing the refuse rearward from the hopper into a storage area for storage. A "side-loader" type vehicle is typically provided with a hopper which is accessible from the side. Some side-loaders have a power-actuated loading mechanism adapted for gripping, elevating and dumping refuse containers from the side of the vehicle into the hopper, however, other side-loaders utilize manual feeding of the hopper. A movable blade is also provided for packing the refuse rearward from the hopper into a storage area for storage.
It is generally desirable to maximize the number of sources served by a refuse vehicle during a given time period. In many situations the vehicle's crew can access refuse containers for loading into the hopper faster that the packing blade can complete its packing cycle, i.e., extending the packing blade to pack material from the hopper into the storage compartment, then retracting the packing blade to its original position. Many refuse body designs, however, cannot accommodate loading of the hopper until the packing blade has finished its packing cycle since refuse material may otherwise fall behind the extended blade and jam the mechanism. In these cases, the crew must wait for the packing blade to complete its cycle before loading the hopper, thus increasing the time required for the crew to complete their route. A need therefore exists, for a refuse body apparatus which allows dumping of refuse material into the loading compartment at any time during the packing operation.
After the storage area of the refuse body has been filled with packed refuse material, the material must be transported to the dump site and ejected. In some vehicles, this ejection is accomplished by opening a rear door on the body and tilting the entire body at an angle so that the packed "bale" of refuse slides out of the opened rear door. However, tilting the refuse body during the ejection operation raises the center of gravity of the entire vehicle, making it more susceptible to overturning, a very dangerous condition. This danger is especially high when the ejecting operation takes place at a dump site having soft or non-level ground, such as a landfill. A need therefore exists, for a refuse body apparatus having full ejection of refuse without tilting of the body.
In other vehicles, ejection of the packed refuse bale is accomplished by opening a rear door and extending an ejecting blade from the front of the storage compartment to the rear doorway, thereby pushing the refuse bale out the opened rear door without tipping the body. This is termed "full ejection." While this full ejection method avoids the dangers inherent in the tipping of the body, it typically requires an ejecting blade actuator which can extend the entire length of the storage compartment. Refuse bodies having full ejection, especially front-loader and side-loader type bodies having long storage areas, typically utilize one or more multi-stage hydraulic cylinders (i.e., units well known in the art comprising a barrel, one or more telescoping, fluid actuated sleeves and a telescoping, fluid actuated plunger which allows the extended unit to "telescope" to several times its retracted length) to achieve the required length of movement required. Although these multi-stage cylinders may provide a compact actuator unit with long extension length, they are generally significantly more expensive to purchase initially, significantly more expensive and complicated to maintain, and generally have a significantly shorter life than single-stage cylinders (i.e., units having only a single movable fluid actuated rod) used under the same conditions.
In some refuse bodies using full ejection to eject the packed bale, especially front-loader and side-loader type bodies having long storage areas, the same multi-stage hydraulic cylinders used for the ejecting operation are also used for the refuse packing operation. In such cases, the multi-stage cylinders are partially extended (i.e., extended only a portion of their full length) to perform the packing operation and are fully extended only to perform the ejecting operation. Such a design thus requires only one type of actuator to accomplish two functions. However, these designs subject the multi-stage cylinders to relatively high-frequency use since the packing operation is typically performed hundreds of times per day while the ejecting operation is typically performed only several times per day. Although the multi-stage cylinder is only partially extended most of the time, this nonetheless results in increased wear on the multi-stage cylinders and increases the need for expensive and time-consuming maintenance on them.
In rear-loader type bodies, single-stage cylinders are generally used for the packing operation (which packs from the rear) and multi-stage cylinders are generally used for the full eject operation (which ejects from the front). It is known from experience with these rear-loader type bodies that using only the single-stage cylinders for the relatively frequent packing operation and using the multi-stage cylinders only for the relatively infrequent full ejection operation results in long life and reduced maintenance on the expensive multi-stage cylinders. A need therefore exists, for an apparatus for use in front-loader and side-loader type refuse bodies in which both packing and ejecting are accomplished from the front of the storage area which utilizes only single-stage hydraulic cylinders for the packing operation.
SUMMARY OF THE INVENTION
For purposes of clarity and consistency some of the terms used in the specification and the claims hereof will now be defined. Directional terms such as "up," "down," "upper," "lower," "top," "bottom," "forward," "rearward," "front," "back," "side," "floor," "horizontal" and "vertical" refer to refuse bodies and refuse vehicles as though they were disposed in an upright, level position with the front of the body facing the normal direction of vehicle travel.
It is an object of the current invention to provide a refuse body which allows refuse to be loaded into the loading compartment at any point in the packing cycle. It is a further object of the current invention to provide a refuse body which does not require tipping the body to eject the refuse from the storage compartment. It is yet another object of the current invention to provide a refuse body in which all packing operations are accomplished through the use of single-stage hydraulic cylinders.
These and other objects of the invention are realized by providing a refuse body apparatus adapted to be mounted upon a vehicle chassis for loading, packing, and ejecting refuse. The refuse body apparatus comprises a body shell including a storage compartment and a loading compartment, a carrier member mounted for movement longitudinally in the body shell, a packing actuator connected between the body shell and the carrier member comprising only single-stage hydraulic cylinders, a packing-and-ejecting blade mounted for movement longitudinally in the body shell, an ejecting actuator connected between the packing-and-ejecting blade and the carrier member, a scraper member pivotally connected to a front wall of the loading compartment and having a free end in sliding contact with the packing-and-ejecting blade when the blade is below adjacent, and a scraper lifting actuator disposed below the scraper member to position the free end at a predetermined position when the packing-and-ejecting blade is not below adjacent.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages will become apparent from the following and more particular description of the preferred embodiment of the invention, as illustrated in the accompanying drawings in which like reference characters generally refer to the same parts or elements throughout the views, and in which:
FIG. 1 is a side elevation view with parts broken away of a refuse body according to one embodiment of the current invention shown mounted upon the chassis of a vehicle of conventional design of a type generally known as a side loader illustrating the various elements of the refuse packing and ejecting apparatus in loading position.
FIG. 2 is a fragmentary plan view taken along lines 2--2 of FIG. 1 showing the various elements of the refuse packing and ejecting apparatus in loading position.
FIG. 3 is a simplified side elevation view similar to FIG. 1 but illustrating the packing and ejecting apparatus in packing position.
FIG. 4 is a fragmentary plan view similar to FIG. 2 but taken along lines 4--4 of FIG. 3 illustrating the packing and ejecting apparatus in packing position.
FIG. 5 is a simplified side elevation view similar to FIGS. 1 and 3 but illustrating the packing and ejecting apparatus in ejecting position and the rear door open to allow ejection of a refuse bale.
FIG. 6 is a fragmentary plan view with parts broken away similar to FIGS. 2 and 4 but taken along lines 6--6 of FIG. 5 illustrating the packing and ejecting apparatus in ejecting position.
DETAILED DESCRIPTION OF THE INVENTION
Referring generally to FIGS. 1-6, a preferred embodiment of a refuse body in accordance with the current invention is shown. Referring specifically to FIGS. 1 and 2 refuse body apparatus 20 is adapted to be mounted upon a vehicle chassis 22 for loading, packing and injecting refuse. In the preferred embodiment, vehicle chassis 22 is a conventional refuse truck chassis which can be configured as either a side-loader type vehicle or a front-loader type vehicle according to the selection of container retrieval mechanism 23 (shown generally in phantom) or chassis 22 could be a trailer chassis designed to be towed by a tractor type truck.
Refuse body 20 includes a body shell 24 having a storage compartment 26 and a loading compartment 28.
Storage compartment 26 is defined by a top 30, side walls 32, a floor 34, an openable door 36 normally closing the rear of the storage compartment, and loading compartment 28 disposed at the front of storage compartment 26. Loading compartment 28 is defined by a front wall 38, side walls 40 lying generally in the plane as side walls 32 of the storage compartment, a floor 42 lying generally in the same plane as floor 34 of the storage compartment, and a rear wall 44 that is common with storage compartment 26 and extends downwardly to a level above said floors 34, 42 for defining an opening 46 from loading compartment 28 into storage compartment 26.
Referring still to FIGS. 1 and 2, refuse body apparatus 20 also includes a carrier member 48 mounted for movement longitudinally in body shell 24. In the preferred embodiment, carrier member 48 includes guides 50 which extend from the sides of carrier member 48 and engage a corresponding longitudinal channel 52 formed along the side walls 32 and 40 of body shell 24. A packing actuator 54 is connected between body shell 24 and carrier member 48. Packing actuator 54 comprises at least one double-acting (i.e., powered during both extension and retraction) single-stage hydraulic cylinder. In the preferred embodiment, packing actuator 54 comprises two double-acting single-stage hydraulic cylinders, each having a barrel portion 56 connected to carrier member 48 by trunnion 58 and rod portions 60 connected to lugs on body shell 24 by pins 62. The extension and retraction of packing actuator 54 causes longitudinal relative movement between carrier member 48 and body shell 24 since carrier member 48 is constrained to move longitudinally by the interaction of guides 50 and channel 52.
Refuse body apparatus 20 further comprises a packing-and-ejecting blade 64 mounted for longitudinal movement in body shell 24. In the preferred embodiment, packing-and-ejecting blade 64 is constrained to move longitudinally by guides 66 which extend from the side of blade 64 and engage longitudinal channel 52 formed along side walls 32 and 40 of body shell 24. Blade 64 includes a generally vertical packing face 68 and a generally horizontal top face 70. An ejecting actuator 72 is connected between packing-and-ejecting blade 64 and carrier member 48. In the preferred embodiment of the current invention, ejecting actuator 72 comprises a double-acting multi-stage hydraulic cylinder comprising a barrel portion 74 connected to packing-and-ejecting blade 64 by trunnion 76, extendable sleeves 78a and 78b, and extendable plunger portion 79 which is connected to lugs on carrier member 48 by pin 80. The extension and retraction of ejecting actuator 72 causes relative longitudinal movement between packing-and-ejecting blade 64 and carrier member 48 since both blade 64 and carrier member 48 are constrained to move in longitudinal channel 52 by guides 66 and 50, respectively.
Refuse body apparatus 20 also includes a scraper member 82 pivotally connected to front wall 38 of loading compartment 28. In the preferred embodiment shown, scraper member 82 is connected to front wall 38 by hinge 84. Scraper member 82 has a free end 86 in sliding contact with top face 70 of packing-and-ejecting blade 64 when blade 64 is below adjacent to free end 86. In the preferred embodiment shown, free end 86 of scraper member 82 is comprised of a high density plastic material designed to resist abrasion caused by the movement of top surface 70. A scraper lifting actuator 88 is disposed below scraper member 82 to position free end 86 of scraper member 82 at a predetermined position 90 when packing and ejector blade 64 is not below adjacent to free end 86.
Normal operation of a refuse body according to the current invention can now be described. FIGS. 1 and 2 depict a refuse body 20 according to the current invention with packing-and-ejecting blade 64 in the loading position, i.e., with both packing actuator 54 and ejecting actuator 72 retracted. Refuse material 100 (shown in phantom) is dumped into loading compartment 28 where it either falls directly to floor 42 or falls on scraper member 82 and is deflected to the floor.
Referring now to FIGS. 3 and 4, extension of packing actuator 54 causes carrier member 48, ejecting actuator 72, and packing-and-ejecting blade 64 to move longitudinally rearward as a unit into the packing position shown in FIGS. 3 and 4. This movement causes packing face 68 of blade 64 to push any refuse 100 (shown in phantom) on floor 42 of loading compartment 28 through opening 46 and into storage compartment 26. As refuse 100 accumulates in storage compartment 26, additional cycling of packing actuator 54 will cause the refuse to be packed into a dense bale (not shown). Additional refuse 102 (shown in phantom) may be dumped into loading compartment 28 at any time during the packing operation because scraper member 82 and blade top face 70 will prevent the material from falling beneath packing-and-ejecting blade 64 where it could jam the mechanism.
When packing actuator 54 is retracted, carrier member 48, ejecting actuator 72, and packing-and-ejecting blade 64 move longitudinally forward as a unit, returning to the loading position of FIGS. 1 and 2 and completing the packing cycle. During retraction, scraper member 82 will remove refuse 102 from top face 70 of the blade and dump it onto floor 42 so that it can be packed in the next packing cycle. Note that in this preferred embodiment, the packing operation is accomplished solely through the actuation of the single acting hydraulic cylinders of packing actuator 54. Actuation of ejecting actuator 72 is not required for the packing operation. This prevents unnecessary wear on the expensive, multi-stage hydraulic cylinder of ejecting actuator 72.
Referring now to FIGS. 5 and 6, extension of packing actuator 54 causes carrier member 48 to move longitudinally rearward a distance A relative to body shell 24 and the cooperative extension of ejecting actuator 72 causes packing-and-ejecting blade 64 to move longitudinally rearward a distance B relative to carrier member 48 so that blade 64 assumes the ejecting position shown in FIGS. 5 and 6. This rearward movement of blade 64 causes a bale 104 (shown in phantom) of compacted refuse to be pushed out the rear end of storage compartment 26 through door 36 which has been previously opened. In the preferred embodiment, side walls 32 of the storage compartment 26 are not precisely parallel, rather they diverge slightly, i.e., the width of storage compartment 26 is slightly larger at the rear end than at the front end. These diverging side walls 32 prevent refuse bale 104 from binding as it is being ejected by blade 64. Any residual refuse material 106 (shown in phantom) that falls from compacted bale 104 as it is being ejected will fall onto top face 70 of packing-and-ejecting blade 64 and will be removed when blade 64 is retracted.
As previously discussed, since packing actuator 54 has moved carrier member 48 a distance A from the front end of body shell 24, ejecting actuator 72 must only extend rearward a distance B in order to accomplish ejecting of the refuse bale rather than moving the entire distance C which would have been required to eject bale 104 without the cooperative use of packing actuator 54 to assist in ejection. In this manner, the requirements for ejecting actuator 72 may be met through the use of a multi-stage hydraulic cylinder having at least one fewer stages than would be required without the cooperative use of packing actuator 54.
When packing actuator 54 and ejecting actuator 72 are retracted, packing-and-ejecting blade 64 and carrier member 48 are returned to the loading position shown in FIGS. 1 and 2. As blade 64 approaches free end 86 of scraper member 82, scraper lifting actuator 88 will lift free end 86 to predetermined position 90 so that it will not interfere with the return motion of blade 64. After top face 70 has become below adjacent to scraper free end 86, actuator 88 will allow free end 86 to resume sliding contact with top face 70 so that any residual refuse 106 can be pushed onto loading compartment floor 42. Since this ejection cycle operation is only performed a few times each day, the current invention minimizes wear on ejecting actuator 72. This is especially important in cases where the ejecting actuator is a multi-stage hydraulic cylinder.
While the preferred embodiment of the invention has been disclosed with reference to a particular refuse body and the method of operation thereof, it is to be understood that many changes in detail may be made as a matter of engineering choices without departing from the spirit and scope of the invention, as defined by the appended claims. | This invention relates generally to refuse collecting and disposal vehicles. In one aspect, it relates to a refuse body adapted to be mounted on a conventional refuse vehicle chassis for loading, compacting and ejecting refuse without tilting of the body. | 1 |
GOVERNMENT RIGHTS
Work leading to this invention was funded in part through the Office of Naval Research Grant #N00014-91-J-1828. Accordingly, the United States government may own certain rights in this invention.
BACKGROUND OF THE INVENTION
Cemented carbide articles such as cutting tools, mining tools, and wear parts are routinely manufactured from carbide powders and metal powders by the powder metallurgy techniques of liquid phase sintering or hot pressing. Cemented carbides are made by "cementing" hard tungsten carbide (WC) grains in a softer fully-dense metal matrix such as cobalt (Co) or nickel (Ni).
The requisite composite powder can be made in two ways. Traditionally, WC powder is physically mixed with Co powder in a ball or attritor mill to form composite powder in which WC particles are coated with Co metal. A newer way is to use spray conversion processing, in which composite powder particles are produced directly by chemical means. In this case, a precursor salt in which W and Co have been mixed at the atomic level, is reduced and carbonized to form the composite powder. This method produces powder particles in which many WC grains are imbedded in a cobalt matrix. Each individual powder particle with a diameter of 50 micrometers contains WC grains a thousand times smaller.
The next step in making a cemented carbide article is to form a green part. This is accomplished by pressing or extruding WC-Co powder. The pressed or extruded part is soft and full of porosity. Sometimes further shaping is needed, which can be conveniently done at this stage by machining. Once the desired shape is achieved, the green part is liquid phase sintered to produce a fully dense part. Alternatively, a fully-dense part is sometimes produced directly by hot pressing the powder. In a final manufacturing step, the part is finished to required tolerances by diamond grinding.
Cemented carbides enjoy wide applicability because the process described above allows one to control the hardness and strength of a tool or part. High hardness is needed to achieve high wear resistance. High strength is needed if the part is to be subjected to high stresses without breaking. Generally, cemented carbide grades with low binder levels possess high hardness, but have lower strength than higher binder grades. High binder levels produce stronger parts with lower hardness. Hardness and strength are also related to carbide grain size, the contiguity of the carbide grains and the binder distribution. At a given binder level, smaller grained carbide has a higher hardness. Trade-off tactics are often adopted to tailor properties to a particular application. Thus, the performance of a tool or part may be optimized by controlling amount, size and distribution of both binder and WC.
The average WC grain size in a sintered article will not, generally, be smaller than the average WC grain size in the powder from which the article was made. Usually, however, it is larger because of grain growth that takes place, primarily, during liquid phase sintering of the powder compact or extrudate. For example, one can start with 50 nanometer WC grains in a green part and end up with WC grains larger than 1 micrometer.
A major technical challenge in the art of sintering is to limit such grain growth so that finer microstructures can be attained. Thus, it is typical to add a grain growth inhibitor to WC-Co powder before it is compacted or extruded. The two most commonly used grain growth inhibitors are vanadium carbide (VC) and chromium carbide (Cr 3 C 2 ). However, the use of these additives presents some problems. First, both are particularly oxygen sensitive, and when combined with WC and binder metal in a mill, both tend to take up oxygen, forming surface oxides. Later, during the liquid phase sintering step, these oxides react with carbon in the mixture to form carbon monoxide (CO) gas. If extra carbon has not been added to the powder to allow for this consumption of carbon, the oxides react with WC and Co to form brittle η-phases, which ruin the article. If too much carbon has been added, so-called carbon porosity results, again ruining the article. Even if just the right amount of carbon has been added, the evolution of CO gas itself can lead to unacceptable levels of porosity. High oxygen levels in powder compacts or extrudates lead to major problems during their sintering.
Of these two grain growth inhibitors, VC is most effective at limiting growth of WC grains. However, VC itself is harder and more brittle than WC. If more than about 0.5 weight per cent is added to the powder, the sintered article becomes too brittle for many applications. Higher levels of Cr 3 C 2 are tolerable. It does not alter strength nearly as drastically as VC, but also it is not nearly as effective at inhibiting WC grain growth. Furthermore, higher levels of Cr 3 C 2 mean higher levels of oxygen and consequently difficulties in sintering. The best compromise seems to be the use of a suitably small amount of Cr 3 C 2 in combination with a somewhat lesser amount of VC. The addition of Cr 3 C 2 to the powder has the added benefit of increasing the corrosion resistance of the tool or part.
During liquid phase sintering the binder metal melts. In the case of WC-Co materials the sintering temperature is chosen in the range 1350°-1500° C. The liquid metal wets the WC grains and capillary forces cause the grains to reposition, packing closer together as porosity is reduced. Any remaining porosity can be eliminated by raising the sintering temperature, thereby increasing the amount of liquid that is present, which permits further rearrangement of WC grains. Alternatively, the temperature can be held constant and the sintering time increased, allowing larger WC grains to grow at the expense of smaller WC grains. In this way, the remaining WC grains can rearrange so that their center of masses are closer together. The latter grain growth process is called Oswald ripening. It is an activated process, which means that the rate of grain growth is higher at higher temperatures. Thus if one wants to maintain small grains, it is clear that the lowest possible sintering temperature is to be favored. Generally, compositions with a low binder level require higher sintering temperature to produce enough liquid to totally eliminate porosity. Low binder level compositions are the most difficult compositions to sinter to full density. In such cases, it is often necessary to liquid phase sinter the part at increased pressure (sinter-HIP) or to post-HIP the sintered part to completely close all porosity.
The carbide industry, in the past, has balanced and offset the problems and advantages associated with using grain growth inhibitors, higher temperatures, higher pressures and so on, attempting to maximize tool or part performance by adjusting composition and WC grain size while working within the natural constraints inherent in WC-Co material system.
SUMMARY OF THE INVENTION
The present invention is premised upon the realization that a low-melting-point binding alloy, referred to as a "master alloy" or a "sintering aid", can be formed from one or more binder metals, such as iron, cobalt or nickel, in combination with a minor portion of one or more grain growth inhibitor metals (so called because carbides of these metals are commonly used as grain growth inhibitors), such as vanadium, chromium, tantalum or niobium, and carbon. This binding alloy can be formed as a single constituent incorporating the binding metal(s), inhibitor metal(s), and carbon or, alternatively, as several constituents, each one of which is a different low-melting-alloy. An example of the former type of alloy is a powder consisting of particles comprised of cobalt, chromium, vanadium and carbon. An example of the latter type of alloy is a powder mixture of particles comprising cobalt, chromium and carbon; and particles comprising cobalt, vanadium and carbon. The former has the advantage that only one powder need be produced and handled. The latter has the advantage of increased manufacturing flexibility in that various proportions of the separate alloys can be milled together to change the composition of the sintering aid. In any case the formed alloys melt at a temperature sufficiently low to permit excellent sintering at temperatures significantly lower than 1350° C., and as low as 1200° C. -150° to 200° C. below normal sintering temperatures used to manufacture WC-Co tools and parts.
In particular, the present invention incorporates a particle forming method in combination with a carbonization process to form X-Y-C alloy powders for use as grain growth inhibitors and/or sintering aids, wherein X is one or more binder metal(s) chosen from the group Co, Ni or Fe, and Y is one or more inhibitor metal(s) chosen from the group Cr, V, Ta or Nb. Low-melting Co-Cr-C, Co-V-C, and Co-Cr-V-C alloys, for example, are prepared by spray drying homogeneous mixtures of a metal salt such as cobalt nitrate, a chromium salt such as (CH 3 CO 2 ) 7 Cr 3 (OH) 2 and/or a vanadium salt such as ammonium vanadate. The spray dried salt mixture is carbonized in a dilute stream of methane, ethane or ethylene and hydrogen to remove oxygen and add carbon to the system when forming the alloy. Alternatively, the alloys may be formed by milling one or more binder metal(s) with one or more carbides of grain growth inhibitor metal(s). These compositions melt at a temperature significantly below 1320° C.
In turn, these alloys permit the low temperature, liquid phase sintering of ceramic powders, cermet powders and mixtures thereof to density of 95% thereby preferably 98% to 99%. Preferably the ceramic powder will be tungsten carbide, molybdenum carbide, chromium carbide, tantalum carbide, niobium carbide, vanadium carbide, titanium carbide or mixtures thereof. This is especially useful in sintering powders that contain nano-size WC grains. The cermets would be combinations of ceramic powders with iron, cobalt or nickel. Generally, these alloys permit the low temperature sintering of any ceramic-metal (cermet) composite powders, ceramic powders or mixtures of ceramic powders and cermet powders.
It is important, for reasons cited above, to limit the amount of grain growth inhibitor in a sintered tool or wear part. If low-melting binder alloy powder(s) are used to sinter pure WC powder, the resulting article will, for most useful amounts of binder, contain too much inhibitor. The process of the present invention circumvents this problem, for example, by using WC-Co composite powder in combination with low-melting Co-Cr-C and Co-V-C binder alloys to form green parts. The cobalt solid solution in the WC-Co composite powder particles melts at about 1320° C., while low-melting binder alloy particles melt below about 1200° C. When the alloy particles melt, some of the WC-Co particles dissolve thereby increasing the volume of liquid phase and further lowering the melting temperature of the liquid phase. In any case, the amount of Co in the WC-Co particles is adjusted to dilute the amount of chromium carbide and vanadium carbide in the final product to an acceptable low level. This procedure succeeds because the amounts of low-melting binder alloy(s) needed to produce useful compositions for tools and parts, provide enough liquid at low temperature for complete densification to take place.
In a preferred embodiment, the present invention can be used to produce ceramic particles bonded by a cobalt-chromium-vanadium-carbon alloy having a size less than 500 nanometers and preferably tungsten carbide with 120 nanometer mean tungsten carbide grain size having low A-type porosity, excellent density, high hardness and high magnetic coercivity.
The objects and advantages of the present invention will be further appreciated in light of the following detailed descriptions and drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphic depiction of the sintering temperature/pressure used in Example G.
FIG. 2 is a graphic depiction of the sintering temperature used in Example I.
FIG. 3 is a graphic depiction of the sintering temperature used in Example K.
FIG. 4 is a graphic depiction of the sintering temperature used in Example M.
DETAILED DESCRIPTION
According to the present invention, abrasive carbide containing particles will be sintered together, singly or in combination, using a binding alloy comprising binding metal(s), such as cobalt, nickel and/or iron, in combination with a lesser amount of grain growth inhibitor metal(s), such as vanadium, chromium, tantalum and/or niobium, in combination with carbon.
The abrasive carbide can be any typical abrasive metal carbide, alone or in combination, such as tungsten carbide, molybdenum carbide, chromium carbide, tantalum carbide, titanium carbide, niobium carbide or vanadium carbide. These can be comprised of individual particles of the carbide, or are generally comprised of composite particles which are carbide grains embedded in a matrix of binding metal, particularly cobalt, nickel or iron. While the abrasive carbide content can be adjusted to from 50% to 97%, the preferred amount will be from about 70% to about 95%. All percents used herein are by weight, unless otherwise specified.
These particles can be purchased from various sources. A preferred method of manufacturing, particularly small submicron grains is disclosed, for example, in Polizotti U.S. Pat. No. 5,338,330 entitled "Multiphase Composite Particle Containing A Distribution of Nonmetallic Compound Particles," McCandlish U.S. Pat. No. 5,230,729 entitled "Carbothermic Reaction Process for Making Nanophase WC-Co Powders" and McCandlish U.S. Pat. No. 5,352,269 entitled "Spray Conversion Process for the Production of Nanophase Composite Powders."
Any or any combination of cobalt, nickel and iron can be employed as the binding metal in the present invention. However, cobalt is preferred because of its ability to wet the carbide-containing particles. Preferably, the total amount of binding alloy will be 5% to 30%. The total amount of binder is the sum of the amount added as pure binder powder, the amount added as part of composite carbide/binder powder and the amount added as part of the low-melting alloy(s).
The low-melting binding alloy can be formed in one of two manners. In the simplest method, a binding metal can be mixed and/or milled with the desired amount of grain growth inhibitor metal (see Table) in the form of a metal carbide, e.g., vanadium carbide and/or chromium carbide. The milled powder can then be melted at a temperature of 1200° C. to 1300° C., after treatment to remove surface oxide. Surface oxide removal can be accomplished by heating the powder to between 900° C. and 1000° C. in a flowing stream of hydrogen gas that contains 0.5 to 5 vol % of a carbonizing gas such as methane or ethane for a time effective to remove the oxide. The low-melting binding alloy may undergo either eutectic-type melting, as is the case for chromium, or peritectic-type melting, as is the case for vanadium.
The amount by weight of binding metal, carbon, vanadium chromium, tantalum or niobium can be adjusted to achieve a melting temperature of less than 1300° C. Specifically the amount of chromium vanadium, tantalum and niobium are adjusted to achieve this low melting point. Generally the alloy will contain less than 60% iron.
The alloy will have at least about 3% of vanadium, chromium, tantalum or niobium. The amount of chromium will be from 0-25%. The amount of vanadium, tantalum or niobium will be from 0-20%. Preferably the vanadium content is minimized to improve performance. Generally the alloy will include 5-25% chromium, tantalum or niobium and 3 to 20% vanadium.
The carbon present will be about equal to the amount present if all of the vanadium, chromium, niobium or tantalum were present as VC, Cr 3 C 2 , NbC or TaC, respectfully. Thus the carbon content is largely dependent on the combined amount of vanadium, chromium and niobium and tantalum.
The following table shows the approximate liquidus temperature for alloys having cobalt carbon and either vanadium or chromium. Chromium and vanadium can also be used in combination.
______________________________________Co (%) Cr.sub.3 C.sub.2 (%) Approximate Liquidus (°C.)______________________________________95 5 130090 10 126080 20 1230Co (%) VC (%) Approximate Liquidus (°C.)95 5 126090 10 126080 20 1260______________________________________
An alloy formed from 80% Co and 20% NbC should have a temperature of about 1237° C. An alloy of 80% Co and 20% TaC should have a liquidus temperature of about 1280° C.
The low-melting binding alloy can also be made by dissolving a binding-metal-containing composition and a melt-suppressant-metal-containing composition in a solvent, again in the desired weight percentages. Suitable binding material compositions would include cobalt, nickel, and iron nitrates, acetates, citrates, oxides, carbonates, hydroxides, oxalates and various amine complexes. Preferably, these will be compositions containing only the binding metal and elements from the group carbon, nitrogen, oxygen and hydrogen. To form the chromium containing or vanadium containing alloy, a composition containing the binding metal and a chromium containing composition or a vanadium containing composition are dissolved in an appropriate solvent. Suitable chromium compositions can include acetates, carbonates, formates, citrates, hydroxides, nitrates, oxides, formates, and oxalates. Suitable vanadium compositions include vanadates and oxides. It is important, of course, to select a binding metal composition in combination with a chromium containing composition or vanadium containing composition, both of which are soluble in the same solvent. The preferred solvent is water, although organic solvents can be employed, depending on the solubility of the various compositions.
The solution is then spray dried to form homogeneous discrete powder particles. This powder can, in turn, be carbonized by heating in a flowing stream of hydrocarbon/hydrogen gas mixture, as described hereinafter for a time effective to cause the reaction of the powder to form the low-melting binding alloy. Generally, the temperature will be about 800° C. to about 1100° C., the time 1 hour to about 24 hours. Various types of furnaces can be used, such as a fluidized bed reactor, a rotating bed reactor, a stationary bed reactor such as a tubular reactor or a belt furnace, or the like. The carbonizing gas should be introduced at a flow rate sufficient to purge reaction products from the furnace. The optimum flow rate will depend on such factors as type and size of furnace and size of powder load. Suitable carbonizing gases include the lower molecular weight hydrocarbons such as methane, ethane, ethylene and acetylene. The formation of the low melting alloy is further described in the Examples below.
In the practice of this invention, the ceramic, cermet or mixture of ceramic and cermet is combined with binder powder and low-melting alloy powder(s) in proportions to give the desired final composition. The mixture is milled until a powder of about 1 micron-size particles is achieved. Next, the powder is formed into a green part and finally sintered to make a dense desired article, i.e., 95 to 99% theoretically.
The proportions of low-melting alloy powder(s), binder powder(s), and/or composite binder-containing powder(s) are adjusted so that after sintering, the grain growth inhibitor concentrations are sufficiently diluted from what they were in the low-melting alloy powder(s), so as not to excessively impair mechanical properties of the final product. It is preferable, again for example, to have a combination of vanadium and at least one other grain growth inhibitor selected from the group consisting of chromium, tantalum and/or niobium in combination with carbon to maximize grain growth inhibition and, at the same time, minimize the decrease in toughness brought on by the use of vanadium. Accordingly, in the final sintered product it is generally preferred to have an amount of chromium, tantalum or niobium equivalent to 0.1%-3% Cr 3 C 2 NbC or TaC in combination with an amount of vanadium equivalent to 0.1%-0.5% VC in the final sintered article.
In these sintered compositions a preferred range is carbide particles (ceramic), 5-30% binder metal, 0 to 10% V, Cr, Ta or Nb and carbon. For a WC-Co combination a preferred ratio is WC, 5-30% Co, 0-10% Cr, 0-10% V and C wherein at least 0.3% of V and/or Cr are present.
Preferably the ceramic particles will have a particle size prior to sintering of less than 1.0 micron and preferably less than 0.5 micron and most preferably less than 120 nanometers. In one embodiment when a combination of ceramic and cermet particles are combined, the grain size of the ceramic particles can be 1 to 20 microns and the cermet particles has a ceramic phase mean grain size of less than 1 micron. Although not essential, the preferred method of sintering is liquid phase sintering. The sintering temperature will be less than 1,300° C. preferably less than 1,280° C., i.e., the liquid forming temperature of the master alloy.
The practice of this invention is further described in the following Examples.
EXAMPLE A
Co-Cr-C Low Melting Point Chromium Alloy Grain Growth Inhibitor for Sintering WC-Co Compositions
A precursor solution for the chromium alloy was prepared by dissolving 111.2 g of cobalt acetate tetrahydrate, Co(CH 3 CO 2 ) 3 .4H 2 O, and 19.2 g of chromium acetate hydroxide, (CH 3 CO 2 ) 7 Cr 3 (OH) 2 , in 750 ml deionized water. These proportions of salts are appropriate for producing a Cr 3 C 2 -82Co alloy upon reduction of Co and carburization of Cr.
A precursor powder for the master alloy was prepared by spray drying the precursor solution in a Yamato laboratory-scale spray dryer. A Spray Systems bi-fluid nozzle (2850 SS Nozzle and 64-5 SS Cap) was used to atomize the solution. Atomizing air pressure was 2 Kgf/mm 2 and the solution flow rate was 20 cm 3 /min. The drying-air flow was 0.6 standard m 3 /min. The inlet air temperature was set at 325° C. and the outlet air temperature was maintained between 90° C. and 100° C. The soluble precursor powder, so obtained, was a light violet color.
Three hundred milligrams of precursor powder was placed in a platinum boat for reaction with a gas mixture of hydrogen and ethylene in a controlled atmosphere thermogravimetric analyzer (TGA). The reactor was first evacuated to a pressure of 3.6 Torr and then back-filled with argon. The argon atmosphere in the reactor was then displaced by a flowing (180 cm 3 /min) mixture of one percent ethylene in hydrogen. The temperature of the reactor was ramped to 900° C. in 60 minutes, held at 900° C. for 37 minutes and cooled to room temperature in 60 minutes. The change in sample weight during the reaction cycle was recorded. X-ray diffraction analysis showed a small diffraction peak for Co metal, but was otherwise featureless. The master alloy powder was placed in an alumina crucible and melted at 1200° C. in vacuum.
A larger batch of master alloy was prepared in an alumina boat in a horizontal tube furnace by reductive carburization of 12 g of master alloy precursor powder. Again, one percent ethylene in hydrogen was used as a carbon source gas. The reactor was evacuated and back filled with argon before starting the temperature ramp (15° C./min). The reactor temperature was held at 900° C. for 8 hours. The sample was cooled in a hydrogen atmosphere to 150° C. and then in an argon purge to 50° C.
EXAMPLE B
A double batch of chromium alloy powder was made in tandem boats at 900° C. according to the preparation reported in Example A. 12.54 g of precursor powder was placed in the upstream boat and 15.81 g of precursor powder was placed in the down-stream boat.
EXAMPLE C
A new batch of chromium alloy powder was produced from 13.441 g of precursor powder. The sample was heated to 400° C. at 3° C./min in hydrogen flowing at 180 cm 3 /min. At 400° C. the heating rate was increased to 15° C./min and 3.8 cm 3 /min of C 2 H 2 was added to the flowing hydrogen. The sample was heated to 900° C. and held there for 8 hours. The sample was cooled to room temperature under hydrogen. 4.1818 g of Master Alloy were produced. We recovered 3.8541 g after discarding the end of the cake which was near the carbon deposition zone. This modified preparation developed a finer porosity inside the Master Alloy cake than was previously obtained.
The low melting vanadium containing alloy can be formed by a method similar to that used in the formation of the low melting chromium containing alloy described above. Generally, it is preferable to have somewhat less vanadium. Generally, the vanadium content will be less than 20 percent down to about 5 percent, relative to the amount of cobalt present. As with the chromium alloy, a precursor powder is formed preferably by spray drying a solution containing the desired concentration of vanadium composition and a binding metal composition. Suitable vanadium compositions include ammonium vanadate and vanadium oxide. The formed spray dried precursor powder is heated in a reactor with a flowing stream of carbon-containing gas at a temperature of about 800° C. to about 1100° C. for a period of time sufficient to form the vanadium alloy. This is further described in the following example.
EXAMPLE D
Co-V-C Low Melting Point Vanadium Alloy Grain Growth Inhibitor for Sintering WC-Co Compositions
4.7948 g of spray dried Co(NO 3 ) 2 /NH 4 VO 3 (12.06% V by ICP) was converted in a tube furnace at 1100° C. for 8 hours in H 2 -1% C 2 H 4 flowing at 180 cc/min. The procedure yielded 2.7264 g of Co-V-C master alloy. The x-ray diffraction pattern showed a minor amount of VC, Co metal, and major unidentifiable peaks.
It is interesting to note that when the low melting alloy containing cobalt, chromium and carbon is formed by reaction of a precursor powder with a carbonizing gas, the product, when tested by x-ray diffraction, does not show peaks that are characteristic of chromium carbide. Likewise, when the low melting alloy containing cobalt, vanadium and carbon is formed by reaction of a precursor powder with a carbonizing gas, the x-ray diffraction pattern of the product shows only minor peaks attributable to vanadium carbide and major peaks due to unidentified phase(s). In other words, under reaction conditions such that one might expect the formation of Cr 3 C 2 or VC, one finds that these carbides are not formed. Rather, the presence of Co inhibits their formation, and an unexpected product is obtained. Nevertheless, as described above, low melting chromium and vanadium alloys can be made by milling together appropriate amounts of chromium carbide and/or vanadium carbide and cobalt. Low melting alloys, formed either by chemical reaction or milling, function equivalently in the cementing of abrasive carbides in the practice of this invention.
EXAMPLE E
Preparation of Co-Cr 3 C 2 and Co-VC Master Alloy Powders by Mechanical Mixing
0.6586 g of Cr 3 C 2 powder was mixed with 3,0004 g of Co powder to produce a mixed powder of the desired composition. The mixed powder was annealed in a tube furnace in hydrogen at 900° C. for 8 hours.
0.5089 g of VC powder was mixed with 3.001 g of Co powder to produce a mixed powder of the desired composition. The mixed powder was annealed in a tube furnace in hydrogen at 900° C. for 8 hours.
The chromium and vanadium alloys of the present invention can be used either alone or in combination to form cemented carbide tools or wear parts.
The use of these alloys in the formation of cemented carbide is further illustrated in the following examples.
EXAMPLE F
Preparation of WC-8Co-0.8Cr 3 C 2 -0.4VC Powder from WC-2.1Co+Co-Cr-C Master Alloy Powder+Co-V-C Master Alloy Powder
1.4372 gm of Co-Cr-C master alloy powder, prepared as in Example A, 0.8922 gm of Co-V-C master alloy powder, prepared as in Example D, and 30.0007 gm of WC-2.1 Co powder were mixed by shaking in a capped test tube. The master alloy powders were added along with the WC-2.1Co powder, in small amounts, until the master alloy powders were consumed. Increasing amounts of WC-2.1Co powder were added to the mixed powders until all of the WC-2.1Co powder was consumed. The mixed powders were charged into a Union Process Attritor Mill (Model 01) with 200 cm 3 of milling media (0.25" diameter WC-Co balls). Milling was done under hexane (160 ml). The agitator was rotated to 250 rpm. The milling time was 2 hours 50 minutes. The final powder composition was WC-8Co-0.8Cr 3 C 2 -0.4VC. Approximately 31.8 gms of powder was recovered from the mill.
EXAMPLE G
Sintering of WC-8Co-0.8Cr 3 C 2 -0.4VC Powder from WC-2.1Co+Co-Cr-C Master Alloy Powder+Co-V-C Master Alloy Powder
3.0248 g of powder, prepared in Example F, was die compacted into a 2.54 mm high disk of 15.18 mm diameter using a pressure of 256 MPa. After heating at 900° C. in a flowing mixture of 1% ethylene/hydrogen for 1 hour, the disk was pressureless sintered in a vacuum induction furnace according to the temperature schedule shown in FIG. 1. After sintering the disk was 1.76 mm high with a diameter of 11.8 mm. The final measured density was 14.47 g/cm 3 . The measured hardness of the material was Hv30=1875. The measured magnetic coercivity was Hc=560 Oe.
EXAMPLE H
Preparation of WC-9.4Co-0.8Cr 3 C 2 -0.4VC Powder from WC-3.7Co+Co-Cr-C Master Alloy Powder+Co-V-C Master Alloy Powder
1.2447 gm of Co-Cr-C master alloy powder, prepared as in Example A, 0.7731 gm of Co-V-C master alloy powder, prepared as in Example D, and 26.0006 gm of WC-3.7Co powder were mixed by shaking in a capped test tube. The master alloy powders were added along with the WC-3.7Co powder, in small amounts, until the master alloy powders were consumed. Increasing amounts of WC-3.7Co powder were added to the mixed powders until all of the WC-3.7Co powder was consumed. The mixed powders were charged into a Union Process Attritor Mill (Model 01) with 200 cm 3 of milling media (0.25" diameter WC-Co balls). Milling was done under hexane (160 ml). The agitator was rotated at 250 rpm. The milling time was 2 hours 50 minutes. The final powder composition was WC-9.4Co-0.8Cr 3 C 2 -0.4VC. Approximately 31.8 gms of powder was recovered from the mill.
EXAMPLE I
Sintering of WC-9.4Co-0.8Cr 3 C 2 -0.4VC Powder from WC-3.7Co+Co-Cr-C Master Alloy Powder+Co-V-C Master Alloy Powder
4.57 g of powder, prepared in Example H, was die compacted into a 3.15 mm high disk of 15.2 mm diameter using a pressure of 256 MPa. After heating at 900° C. in a flowing mixture of 1% ethylene/hydrogen for 1 hour, the disk was pressureless sintered in a vacuum induction furnace according to the temperature schedule shown in FIG. 2. After sintering the disk was 2.45 mm high with a diameter of 11.87 mm. The final measured density was 14.3 g/cm 3 . The measured hardness of the material was Hv30=2026. The measured magnetic coercivity was Hc=593 Oe.
EXAMPLE J
Preparation of WC-11.6Co-1.3Cr 3 C 2 -0.4VC Powder from WC-3.7Co+Co-Cr-C Master Alloy Powder+Co-V-C Master Alloy Powder
2.4075 gm of Co-Cr-C master alloy powder, prepared as in Example A, 0.9204 gm of Co-V-C master alloy powder, prepared as in Example D, and 30.0008 gm of WC-3.7Co powder were mixed by shaking in a capped test tube. The master alloy powders were added along with the WC-3.7Co powder, in small amounts, until the master alloy powders were consumed. Increasing amounts of WC-3.7Co powder were added to the mixed powders until all of the WC-3.7Co powder was consumed. The mixed powders were charged into a Union Process Attritor Mill (Model 01) with 200 cm 3 of milling media (0.25" diameter WC-Co balls). Milling was done under hexane (160 ml). The agitator was rotated at 250 rpm. The milling time was 2 hours 50 minutes. The final powder composition was WC-11.6Co-1.3Cr 3 C 2 -0.4VC. Approximately 31 gms of powder was recovered from the mill.
EXAMPLE K
Sintering of WC-11.6Co-1.3CrC 2 -0.4VC Powder from WC-3.7Co+Co-Cr-C Master Alloy Powder+Co-V-C Master Alloy Powder
3.98 g of powder, prepared in Example J, was die compacted into a 3.22 mm high disk of 15.11 mm diameter using a pressure of 256 MPa. After heating at 900° C. in a flowing mixture of 1% ethylene/hydrogen for 1 hour, the disk was pressureless sintered in a vacuum induction furnace according to the temperature schedule shown in FIG. 3. After sintering the disk was 2.57 mm high was a diameter of 11.94 mm. The final measured density was 13.98 g/cm 3 . The measured hardness of the material was Hv30=1809. The measured magnetic coercivity was Hc=488 Oe.
EXAMPLE L
Preparation of WC-9.4Co-0.8CrC 2 -0.4VC Powder from Co-Cr 3 C 2 and Co-VC Mechanically Mixed Master Alloy Powders
1.4381 gm of Co-Cr 3 C 2 master alloy powder and 0.8928 gm of Co-VC master alloy powder, prepared as in Example E, and 30.0021 gm of WC-3.7Co powder were mixed by shaking in a capped test tube. The master alloy powders were added along with the WC-3.7Co powder, in small amounts, until the master alloy powders were consumed. Increasing amounts of WC-3.7Co powder were added to the mixed powders until all of the WC-3.7Co powder was consumed. The mixed powders were charged into a Union Process Attritor Mill (Model 01) with 200 cm 3 of milling media (0.25" diameter WC-Co balls). Milling was done under hexane (160 ml). The agitator was rotated at 250 rpm. The milling time was 2 hours 50 minutes. The final powder composition was WC-9.4Co-0.8Cr 3 C 2 -0.4VC. Approximately 30 gms of powder was recovered from the mill.
EXAMPLE M
Sintering of WC-9.4Co-0.8CrC 2 -0.4VC Powder from Co-Cr 3 C 2 and Co-VC Mechanically Mixed Master Alloy Powders
4.04 g of powder, prepared in Example L, was die compacted into a 3.15 mm high disk of 15.07 mm diameter using a pressure of 256 MPa. After heating at 900° C. in a flowing mixture of 1% ethylene/hydrogen for 1 hour, the disk was pressureless sintered in a vacuum induction furnace according to the temperature schedule shown in FIG. 4. After sintering the disk was 2.58 mm high with a diameter of 11.92 mm. The final measured density was 14.26 g/cm 3 . The measured hardness of the material was Hv30=2040. The measured magnetic coercivity was Hc=571 Oe. | A low melting point alloy is used to sinter metal carbide particles. The alloy is a eutectic-like alloy formed from a binding metal such as iron, cobalt or nickel, in combination with vanadium and chromium. The alloy is preferably formed by forming two separate alloys and blending these together. The first alloy is formed by spray drying together a solution of a binding metal salt such as a cobalt salt with a solution of a chromium salt. The formed particles are then carburized to form a cobalt-chromium-carbon alloy. A separate vanadium alloy is formed in the same manner. The two are combined to establish the amount of chromium and vanadium desired, and this, in turn, is used to sinter metal carbide parts. This permits sintering of the metal carbide parts at temperatures less than 1250° C. and in turn significantly inhibits grain grown without a significant decrease in toughness. It is particularly adapted to form carbide products wherein the carbide grain size is as low as 120 nanometers. | 2 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a division of U.S. Ser. No. 08/877,689, filed Jun. 17, 1997 which issued on May 18, 1999 as U.S. Pat. No. 5,903,962.
FIELD OF THE INVENTION
The present invention relates generally to carpets yarns, and more particularly to a method and device for pretreating staple-fiber carpet yarns and other carpet yarns having tiny fine hairs on their surface.
RELATED TECHNOLOGY
In addition to natural fibers, staple-fiber yarns (spun yarns) made of polyamide fibers (PA6, perlon; PA6.6 nylon), polypropylene, polyester or other man-made fibers, as well as of blends of such fibers, are being used to manufacture tufted, woven or knitted carpets. The staple-fiber carpet yarns are spun from staple fibers, i.e. from fibers of a defined length.
Staple-fiber yarns have the advantage, inter alia, that they are able to be dyed well and uniformly, and that the dyed carpets produced from them have a uniform appearance. However, a disadvantage of these carpet yarns, whether made of natural or synthetic fibers, is that they are very hairy, i.e., the ends of the individual fibers forming the yarn are not merged into the yarn, but rather stick out from the yarn, so that under mechanical action, they can be separated or pulled out from the yarn. Such staple-fiber yarns are strongly inclined to fuzz.
This leads to heavy deposits of fuzz in the machines and installations processing these yarns, which then must be cleaned accordingly. The necessary cleaning either requires a substantial outlay from the standpoint of machine technology (filter systems, brushes, suction installations) if the cleaning is to be performed continuously or else results in costly equipment downtime.
Such an accumulation of fuzz and wearing-away of fibers occurs not only when manufacturing and finishing such carpets, but also during their use, especially during the initial phase after installation.
The result of these problems with staple-fiber carpet yarns is that, despite their economic and dyeability advantages, in recent years the world-wide market share of staple-fiber carpet yarns has been decreasing and shifting toward an increased use of filament yarns, which represent an alternative to staple-fiber carpet yarns. Filament yarns are not spun from individual, thin staple fibers, but rather are made of individual, continuous synthetic-material fibers extruded from fine dies, the fibers in themselves being compact and several of them being intertwined to form the yarn to be processed. If desired, several such yarn hanks are twisted to form a thicker carpet yarn.
The shift to filament yarns has occurred even though they have disadvantages compared to the staple-fiber yarns. While filament yarns, because of their construction, may not have the fuzzing problem associated with staple-fiber yarns, they still cannot be dyed as efficiently. Filament yarns also do not have very good mechanical properties. For example, they exhibit a poorer "retractive force" in response to intermittent loading over time. Mechanical stresses such as foot prints or pressure points from objects or furniture feet placed on the carpets continue to be visible for a long time after the pressure action has ceased. Dyed carpets produced from filament yarns also often have an unequal, unlevel, often streaky appearance.
These circumstances were the reason for varying efforts over the years to promote spun yarns, the aim of these efforts being to reduce fiber hairiness, and, consequently, the accumulation of fuzz. Thus, for example, fiber blends were produced which had other fibers having a lower melting point blended into the core fibers, to try to enable the fine, projecting, individual, small hairs to be subsequently bonded to the yarn by means of a thermal treatment.
Attempts also were made to use different chemical applications to, as it were, glue to the yarn the individual small hairs which are not securely merged into the yarn and which cause the fuzz formation.
All the methods tried heretofore have not led to the desired result, namely, the production of a usable, clean yarn made from spun staple fibers that is able to be economically produced.
Other carpet yarns may have similar problems to staple carpet yarns described above, for example, carpet yarns produced from natural fibers, as well as mixtures of natural and synthetic fibers, and the present invention is applicable to these hairy carpet yarns as well. In the same way, it makes no difference whether the carpet yarn is intended for the pile or for the back of the carpet.
SUMMARY OF THE INVENTION
An object of the present invention is to pretreat a hairy carpet yarn in a way that will enable the fuzz accumulation to be reduced without entailing substantial outlay and without having a disadvantageous effect on the mechanical yarn properties and the dyeing behavior.
The present invention therefore provides a method for pretreating a carpet yarn having fine, tiny hairs on its surface before it is processed to make a carpet, characterized in that the surface of the carpet yarn is exposed for a brief duration to the action of a temperature that is very high relative to the characteristic temperatures of the carpet yarn material.
Surprisingly, it has turned out that, by means of the temperature treatment, the individual tiny hairs sticking out from the carpet yarn, in so far as they are synthetic yarns, disappear nearly without residue, in that they vaporize or sublime, and specifically, in a manner that the yarn itself does not undergo any thermal fiber damage. In the case of natural fibers, the projecting, individual, small hairs burn. In this manner, a clean yarn is formed, whose surface is almost completely free of projecting tiny hairs. Of course, the method requires exact control, with due consideration of the operating speed, the temperature acting on the yarn surface, and the yarn material. In this connection, the expression "on its surface during a brief exposure time" means that a sharp temperature gradient with respect to the yarn is produced from the outside to the inside, so that a high temperature acting outside affects the tiny hairs sticking out from the surface, while the inner volume of the yarn hank still experiences no substantial increase in temperature during the brief exposure time and remains unchanged.
"Characteristic temperatures" are understood as the values such as glass point, melting point and ignition temperature. The very high temperatures should lie markedly, e.g. at least 500° C., above these, temperatures, to enable thorough removal of the tiny hairs in the brief exposure times and to allow adequate operating speeds, at the same time, the heat not yet penetrating substantially into the interior of the carpet yarn and fiber damage thus being prevented.
It is also possible, in another regard, to selectively and reproducibly influence the carpet yarn in different ways by way of the mentioned control. Thus, in addition to the degree of cleanliness, the surface hardness or the flexural strength of the carpet yarn can be increased as desired, depending on the application case. By this means, the hand or the crush resilience of the carpets produced from such carpet yarns can be influenced.
An important point is also that the staple-fiber carpet yarns subjected to the thermal treatment are able to be better dyed, and a more uniform, level appearance results.
A further advantage of the method according to the present invention is attained when the thus treated fibers are used to manufacture carpets to be imprinted. A drawback of the hairy and fuzz-afflicted staple-fiber carpet yarns used under known methods heretofore was that they were only able to be to imprinted very poorly or not at all. First of all, the hairiness and the fuzz accumulation quickly clogged the printing screens, and secondly, a sharply-contoured, level print image is difficult or almost impossible to produce on such carpets.
Great disadvantages exist in processing unclean yarns, both in the pile and back areas, when weaving carpets, as well. The heavy fuzz accumulation necessitates frequent cleaning resulting, accordingly, in shutdowns of the weaving machines, and involves costly suction and cleaning devices. Cleaning the yarns by means of a thermal treatment according to the present invention eliminates these problems to the greatest extent possible.
Finally, the thermal treatment of the present invention greatly aids in fixing the mechanically produced twisting of the individual fibers to form a carpet yarn. To bulk the carpet yarns and to fix the yarn twist (bulking and heat-setting), special machines and processes are used, representing a costly part of the installation, in which the carpet yarn is exposed to the action of overheated steam or saturated steam under excessive pressure. Inserting the thermal treatment of the present invention into the yarn-production process can reduce the expenditure for fixing aggregates. This leads to cost reductions in the yarn production.
The thermal treatment method of the present invention can be easily integrated into existing installations. For the most part, the location where the treatment is carried out within the installation is able to be selected. If a part of the installation is available for the heat-setting, then it may be that, in principle, the treatment can be carried out after the fixing process and before the winding-up operation, but implementation of the thermal treatment between the warp creel and the heat-setting apparatus is preferred. The temperature treatment can also be applied as a completely separate operation.
As already mentioned, the material primarily coming into consideration for the present invention is staple-fiber carpet yarn, especially made of fully synthetic material such as polyamide, polypropylene, polyester or the like.
In the preferred specific embodiment, the carpet yarn is moved lengthwise through a zone where the high temperature prevails and which is traversed in the moving direction in a time of 3 to 50 milliseconds.
Thus, the staple-fiber carpet yarn is passed quickly through a high-temperature treatment zone, so that, because of their small diameter and low thermal capacity, the projecting tiny hairs do, in fact, reach a high temperature virtually instantaneously and burn, vaporize or sublime, but the inner volume of the yarn, because of the poor thermal conductivity of the material, has no time to heat up substantially.
The treatment can especially be effected in such a way that a flat carpet warp-yarn sheet is moved through at least one elongated, narrow zone that extends transversely to the carpet warp-yarn sheet and has the high temperature.
To promote the evenness of the temperature action, this can be carried out from both sides of the flat carpet warp-yarn sheet.
The expression "transversely" is supposed to refer both to an arrangement perpendicular to the carpet warp yarn sheet, as well as to an oblique arrangement, by means of which the extent of the exposure zone can be increased in the moving direction of the carpet yarn threads, if desired, without having to make adjustments on the treatment device.
Another possibility is to pass the individual carpet-yarn threads through a heat source of any form surrounding them, e.g. a nozzle or a ring burner.
The preferred temperature range of the treatment according to the invention for the carpet yarns that come under consideration in the manufacture of carpets lies at 800 to 1700° C., in which case the exposure time should not be more than a few milliseconds, for instance three to 50 milliseconds. However, even higher temperatures can come into consideration.
With the temperatures and times mentioned, the interior of the carpet yarn is not yet substantially affected by the temperature rise and, moreover, substantial carpet-yarn feed rates of 300-800 m per minute are still rendered possible.
The preferred specific embodiment for creating a high-temperature defined zone, through which the carpet yarn is guided, is a singe device in which, therefore, the high temperature is produced by burning gases.
Suited for this purpose are high-efficiency singe burners, which are adapted to the treatment of carpet yarns, and have a sharp, narrow, high-energy and very hot flame, as are used in a similar design in singeing machines for textile fabrics. The flame gases have the "very high temperatures". Many individual threads or, as is customary in the case of heat-setting because of the better manipulability, only four or six individual threads can be processed simultaneously side-by-side in a flat warp-yarn sheet.
Although singeing has been known for decades in the field of textile fabrics and has been continually further developed (German Patent No. 500 153; German Laid Open Document 20 23 782; EP-A1 274 649), and in special cases has already even been used for yarns, especially sewing yarn (M. Peter and H. K. Rouette "Grundlagen der Textilveredlung" [Fundamentals of Textile Finishing], 13th edition, (1989) Deutscher Fachverlag, Frankfurt am Main, p. 400), thermally treating hairy carpet yarns, in particular staple-fiber carpet yarns made of synthetic material, has not been considered in known methods heretofore. The technical world had to "live" with the problems of hairiness and fuzz accumulation described herein, and tried--unsuccessfully--to reduce them using other methods.
As an alternative, the staple-fiber carpet yarn can also be exposed to the short-term action of a high temperature in another manner, for example, by means of a laser.
To concentrate the effect of the high temperature even more on protruding, tiny hairs, or to protect the main volume of the carpet yarn from a disadvantageous temperature rise, the carpet yarn can be moistened before the temperature treatment. Methods suitable for this, e.g. spraying on atomized moisture, condensation of vapor or the like, are found in related art.
After the temperature treatment, i.e., when the carpet yarn has left the singe burner but still has an elevated temperature, it is advisable to cool it by blowing on it a fluid medium to allow quick, problem-free further processing of the treated carpet yarn.
An air-water mixture has proven to be particularly effective for this purpose.
Should moisture still remain on the carpet yarn, then it can be removed by a drying process.
As already mentioned, one important aspect of the present invention is that the temperature treatment not only rectifies the fuzz problem in the manufacturing and finishing of the carpets and also at least in the initial phase of their use, but also that this action is associated with further advantageous effects. First, the temperature treatment has the effect of supporting the fixing of the yarn twist, which improves the mechanical properties of the yarn, such as bulk and crush resilience and possibly, in certain cases, permits at least partially dispensing with the fixing aggregates otherwise especially provided for that purpose. Second, the temperature treatment is associated with an improvement in the dye affinity of the staple-fiber carpet yarn, so that the color yield is higher. In this manner, cost savings are achieved which, in and of themselves, already justify the treatment operation of the present invention
Notwithstanding the possible contribution that the pretreatment method according to the present invention, taken by itself, makes to the fixation of the carpet yarn, one important use lies in combining the temperature treatment with the yarn fixation process so that the pretreatment of the carpet yarn under the action of the very high temperature is combined with a yarn treatment according to the heat-setting process. Such a combination, with the temperature treatment preferably being carried out before the heat-setting process, yields a carpet yarn with improved properties, which are evident both in the carpet fabrication processing and in the finishing of the carpet, as well as when the carpet is used.
The present invention further provides for the utilization of the yarn-singeing method for pretreating staple-fiber carpet yarns prior to their processing to make a carpet.
The present invention also provides a device for implementing the method, characterized in that the device comprises a singe burner (100,100') having a singe channel (10) which is formed in a housing (7,7'), has a straight axis, is open at both ends (10,10"), and through which at least one yarn thread (5), stretched in its lengthwise direction, is able to be passed with a conveying direction (6) running parallel to the axis of singe channel (10), and that, provided in the area of entrance (10') of singe channel (10) at either side of yarn thread (5) are mutually opposed burner nozzles (15,15') whose gas-mixture jets (19,19') can heat or contact the tiny hairs protruding from the carpet yarn surface.
In doing this, one important aspect is that the burner flames and the conveyance of the yarn threads have meaningful parallel components, so that a type of tangential singeing is achieved which stresses the core thread only a little, and which is concentrated predominantly on the protruding tiny hairs.
The expression "having a parallel component" should be generously interpreted. Coming under this expression is an actually parallel alignment, but also an alignment at an acute angle, which can be 20° to 600°. An alignment in the same direction as the conveying direction is preferred, but an alignment in the opposite direction is not ruled out.
The conveying velocity of the carpet-yarn threads through the very high temperature zone is considerable, namely, 300 to 800 m/min. Devices for conveying carpet-yarn threads at these speeds are found in the related art.
In the preferred specific embodiment of the invention, an individual carpet-yarn thread is not treated, but rather a warp-yarn sheet of a plurality of carpet-yarn threads is treated. For this, it is expedient to design the singe channel so that singe channel (10) has an elongated cross-section, transversely to conveying direction (6), with a plane of symmetry (4), and wherein a plurality of yarn threads (5,5, . . . ) are able to be conveyed, with transverse clearance from one another, in plane of symmetry (4), through singe channel (10). The height of the singe channel transversely to the plane of symmetry may, e.g., be 8 to 20 mm and the length of the singe channel from the point of impact of the gas-mixture jets to the end of the singe channel situated in the conveying direction may be 100 to 300 mm, for example.
To strongly intermix the gas-mixture jets emerging from the burner nozzles, turbulence-producing grooves in inner walls (2,2') bordering singe channel (10) on its flat sides, the grooves running transversely to conveying direction (6), are recommended, as they improve the uniformity of the gas distribution, especially transversely to the conveying direction.
The burner nozzles expediently have small-diameter openings allowing sufficiently high velocities of the gas-mixture jets. "Openings" are understood to be both bore holes and narrow slits, whereby the "diameter" of the slits should be their cross-sectional dimension. The openings are arranged in a straight line, in the case of slits, they being situated with their longitudinal direction parallel to the line. The openings advantageously conform in width to the warp-yarn sheet.
At entrance (10') of singe channel (10), means (24), such as wall extensions, may be provided for restricting the channel cross-section to the size needed to only just allow yarn thread (5) to pass through unimpeded. This minimizes the ingress of infiltrated air at the entry of the singe channel. This infiltrated air, possibly pulled along by the rapidly running yarn threads, can make the burning process, which the stoichiometrically composed gas mixture is geared to, uneven.
For structural and handling reasons, it is preferable for the singe burner to be divided in the plane of symmetry, in particular, that it be able to swivel about an axis running parallel to the conveying direction, outside of the singe burner, or the two halves are detachable from one another transversely to the plane of symmetry.
In this manner, the singe burner can be opened and put into operation laterally adjacent to the warp-yarn sheet. This is expedient, in order to attain a uniform singeing result from the beginning of the yarn run and to avoid greater starting losses of the yarn. The singe burner is preheated in the closed state without yarn. After reaching the operating temperature, the yarn run is started and the singe burner is brought together with the running warp yarn sheet when in operation. In so doing, the singe burner can be guided into the warp-yarn sheet, or else the warp-yarn sheet can be guided into the singe burner. However, in principle, it is also possible to ignite the singe burner with the warp-yarn sheet in the singe channel at the start of the yarn run.
When the yarn run stops, it is possible to open the singe burner and guide the warp-yarn sheet out of the hot zone.
Dividing the singe burner also renders possible a design which is structurally simple and prevents the outer burner parts from heating up too much during operation, namely that singe burner (100,100') is formed by two refractory plates (1,1') that are provided with shallow depressions (3,3'), and are joined together with the open sides of depressions (3,3') facing one another, the depressions (3,3') together forming singe channel (10). The refractory plates (1,1') may be arranged in sheet-metal housings (7,7') and separated from the inner walls of sheet-metal housing (7,7') by an insulating back lining (8).
For operation of the burner, a pressure control is advised for supplying the gas mixture to burner nozzles (15,15') under such a pressure that the burning first starts at a short distance beyond burner nozzles (15,15'), viewed in conveying direction (6), so that the front of the flame is prevented from receding into the burner nozzles. The efficiency of the singe burner, and thus the temperature or the singe intensity, can also be adjusted or controlled through the pressure of the burnable gas mixture in the singe burner.
It is frequently necessary to cool the carpet yarn after leaving the singe burner, which can be carried out by nozzles (26) arranged downstream of singe burner (100,100') whose jets (27) strike carpet-yarn threads (5), cool them and free them of adhering material. The jets (27) may strike the carpet-yarn threads at a distance (25) of up to approximately 500 mm in conveying direction (6) beyond singe burner (100). Moreover, jets (27) may strike the carpet-yarn threads at an acute angle (β). Jets (27) also may be oppositely directed to conveying direction (6).
One important refinement of the invention as far as the apparatus aspect is concerned, as well, is the combination with a carpet-yarn fixing installation (heat-setting unit). The carpet-yarn fixing installation (heat-setting installation) (200) may be arranged downstream of singe burner (100).
BRIEF DESCRIPTION OF THE DRAWINGS
One exemplary embodiment of the device is illustrated schematically in the drawing, whose Figures show:
FIG. 1: a longitudinal section through the singe burner;
FIG. 2: a cross-section along the Line II--II in FIG. 1;
FIG. 3: a longitudinal section through a singe burner with air jets arranged downstream;
FIG. 4: a longitudinal section, corresponding to FIG. 1, through a modified singe burner;
FIG. 5: a diagram of a relevant pretreatment installation.
DETAILED DESCRIPTION
The singe burner, denoted as a whole by 100 in FIG. 1, comprises two identical ceramic plates 1,1', which are placed back-to-back with planar delimiting surfaces 2,2' facing one another (FIG. 2). Formed in delimiting surfaces 2,2', over the length of the refractory plates 1,1', are mutually opposed through-depressions 3,3' which together form a traversing singe channel 10 that is open at the ends, has a straight axis, and which, in a transverse plane, has the elongated cross-section, apparent from FIG. 2, with a plane of symmetry 4 situated parallel to the longitudinal direction of the cross-section and containing the axis. The height 21 of singe channel 10, transversely to the plane of symmetry 4 (FIG. 2), is approximately 8 to 20 mm; in the exemplary embodiment more or less 12 mm. The length 22 of singe channel 10 from location 17, where the nozzle jets strike plane of symmetry 4 and where the very high temperature zone 18 begins, to end 10" of singe channel 10 is 100 to 300 mm; in the exemplary embodiment 200 mm. The described embodiment of the device reveals a treatment zone that extends in conveying direction 6 of yarn threads 5 and has the very high temperatures only in the leading area, but an after-effect is still present because the carpet-yarn threads 5 and the hot gases produced by the burning pass through singe channel 10 together. In the area of very high temperature zone 18, grooves 23 running in the transverse direction are provided in delimiting planes 2,2', the grooves promoting turbulence in the burning gas-mixture stream and evening out 5 the temperature distribution in the transverse direction of singe channel 10. Planar delimiting surfaces 2,2' lie in plane of symmetry 4 in which a warp-yarn sheet of parallel, side-by-side carpet-yarn threads 5 is able to be conveyed in their longitudinal direction through singe channel 10 in a conveying direction 6 parallel to the channel direction. In the exemplary embodiment, there are six carpet-yarn threads 5 lying side-by-side with transverse clearance. The means of conveyance, provided outside of singe burner 100 for carpet-yarn threads 5 permit a high conveying speed of 300 to 800 m/min; in the exemplary embodiment, approximately 500 m/min.
The refractory ceramic plates 1, 1' are each accommodated in sheet-metal housings 7,7' which surround them and whose inner walls have clearance from the periphery of refractory ceramic plates 1,1', the intervening space being filled with insulating mineral wool 8.
Ceramic plates 1,1' are retained in their housings 7,7' on holders 9,9' which extend outside of housing 7,7' to both sides of plane of symmetry 4 and which are supported on one another on one side outside of housing 7,7' about an articulated axle 11 extending parallel to conveying direction 6, about which housings 7,7' are able to swivel in the direction of arrow 12.
Formed at the entrance 10' of singe channel 10 and extending across its width are inclined gas ducts 13,13', whose median plane forms an angle α with plane of symmetry 4 or carpet-yarn threads 5, the angle being 30° in the exemplary embodiment. Provided at the entrance-side front end 14,14' of refractory ceramic plates 1,1' are gas-mixture nozzles 15,15', which are compactly distributed over the width of singe channel 10, have openings in the form of small-diameter bore holes, and are able to be supplied with a burnable gas mixture via supply chambers 16,16' made of sheet metal and extending across the width of refractory ceramic plates 1,1'. The gas-mixture jets 19, indicated in FIG. 1 only by emerging from burner nozzles 15,15' pass through gas-mixture ducts 13,13' and strike at a location 17 on plane of symmetry 4 in,which carpet-yarn threads 5 run. The gas mixture is ignited in a suitable manner giving rise to a very high temperature zone 18 in which the burnable gas mixture burns from the end of gas-mixture ducts 13 in conveying direction 6. Carpet-yarn threads 5 are conveyed in synchronism with the gas flow according to FIG. 1 from right to left through singe channel 10. On the entry side, carpet-yarn thread 5 still has tiny hairs 28 as indicated in FIG. 1. The projecting tiny hairs 28 are burned or vaporized in zone 18, or are partly fused onto the core threads, so that at the outlet 10" of singe channel 10, there are no longer any tiny hairs on carpet-yarn threads 5 which could easily loosen during further processing or use of the carpet and lead to fuzz formation.
To prevent yarn threads 5 that feed in conveying direction 6 at a high velocity from bringing too much infiltrated air into singe channel 10, the inner cross-section of singe channel 10 is restricted at entrance 10' by means of transversely mounted restrictors 24 to the extent that yarn threads 5 are only just able to pass through without making contact.
After leaving singe channel 10, carpet-yarn threads 5 are cleaned of clinging residues from combustion and simultaneously cooled by means of strongly acting air jets, as shown in FIG. 3. For this purpose, preferably fan jets 26 are arranged above and below carpet-yarn threads 5, at a distance 25 from end 10" of singe channel 10 of up to approximately 500 mm. In each case, air jet 27 is directed at acute angle β toward conveying direction 6 of carpet-yarn threads 5. Instead of air, a water-air mixture can also be used. Round slotted nozzles encircling each individual carpet-yarn thread 5 are possible, as well.
FIG. 4 shows a modified specific embodiment of a singe burner 100', in which parts corresponding functionally to singe burner 100 are characterized with the same reference numerals. The difference consists only in the fact that supply chambers 16,16' are incorporated into housing 7,7' and, in particular, gas-mixture nozzles 15,15' are so arranged that gas-mixture jets 19' are directed parallel to and in synchronism with conveying direction 6.
FIG. 5 schematically represents a relevant pretreatment installation where the singe burner of the present invention (whether 100 according to FIG. 1 or 100' according to FIG. 4) is combined with a yarn-fixing installation (heat-setting installation). The single carpet-yarn thread 5 is reeled off from a supply spool 30, several times the number of supply spools being provided in an appropriate support stand as there are carpet-yarn threads 5 treated side-by-side in singe burner 100 in question, in order to assure a transition without stoppage.
In the preferred specific embodiment of the invention, carpet-yarn thread 5 runs, as shown by solid lines, into a singe burner 100 or 100', and then into a heat-setting apparatus 200, which is generally known and, therefore, is not described further, in which the yarn twist is fixed and the carpet yarn is bulked. Carpet-yarn thread 5 is subsequently wound in each case onto a supply spool 31.
In an alternative, possible embodiment, after being reeled off from supply spool 30, carpet-yarn thread 5 first runs through heat-setting apparatus 200 and only then passes through singe burner 100 or 100' of the type according to the invention indicated with a dotted line in FIG. 5, to then be wound onto supply spool 31. The singeing process can also be conducted separately, i.e., without a heat-setting apparatus. In this context, carpet-yarn thread 5 or the thread warp runs from a warp creel through singe burner 100,100' to the winding machine. In this case, it is advantageously possible to work with a greater number of carpet-yarn threads 5. | A method for pretreating a staple-fiber carpet yarn (5) before it is processed to make a carpet, in order to reduce the hairiness and fuzz accumulation associated with such yarns. The surface of the carpet yarn (5) is exposed for a brief time to the action of a temperature which is very high relative to the characteristic temperatures of the carpet yarn material. This can be carried out in a singe burner (100) through which the carpet-yarn threads (5) are guided in their lengthwise direction. | 3 |
BACKGROUND OF THE INVENTION
There are many advantages of using laser light sources to illuminate digital projection systems, but the high coherence of laser light tends to produce undesirable speckle in the viewed image. Known despeckling methods generally fall into the categories of polarization diversity, angle diversion, and wavelength diversity. In the laser projection industry, there has been a long-felt need for more effective despeckling methods.
SUMMARY OF THE INVENTION
In general, in one aspect, an optical apparatus that includes a pulsed green laser, a Raman-shifting device, and a digital projector. The pulsed green laser generates a green light with a light pulse that illuminates the Raman-shifting device. The light pulse is shaped in time to generate a desired spectrum from the Raman-shifting device, and the desired spectrum illuminates the digital projector.
Implementations may include one or more of the following features. The desired spectrum from the Raman-shifting device may have lower speckle than the pump green light. The desired spectrum may have a higher luminous efficacy than the pump green light. The light pulse may have a square-wave shape. The desired spectrum may be red. The light pulse may be shaped in time to alternate between a square shape of two different amplitudes. The desired spectrum may alternate between green light and red light. The digital projector may have a single light valve. The single light valve may form a full color digital image by synchronizing with a source of blue light and with the spectrum that alternates between green and red light. The desired spectrum may include a green band and a red band. The desired spectrum may have a gap between the green band and the red band. The gap may match a low transmission band of the digital projector.
In general, in one aspect, a method of despeckling that includes generating a pulsed green laser light, Raman-shifting the pulsed green laser light to generate a Raman-shifted laser light, using the Raman-shifted light to illuminate a digital projector, and projecting a digital image with the digital projector. The pulsed green laser light has a light pulse that is shaped in time to Raman-shift the laser light to a desired spectrum.
Implementations may include one or more of the following features. The desired spectrum from the Raman-shifting device may have lower speckle than the pump green light. The desired spectrum may have a higher luminous efficacy than the pump green light. The light pulse may have a square-wave shape. The desired spectrum may be red. The light pulse may be shaped in time to alternate between a square shape of a first amplitude and a square shape of two different amplitudes. The desired spectrum may alternate between green light and red light. The digital projector may have a single light valve. The single light valve may form a full color digital image by synchronizing with a source of blue light and with the spectrum that alternates between green and red light. The desired spectrum may include a green band and a red band. The desired spectrum may have a gap between the green band and the red band. The gap may match a low transmission band of the digital projector.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
FIG. 1 is a top view of a laser projection system with spectral control of Raman despeckling;
FIG. 2 is a computer-simulated time graph of stimulated Raman scattering from a Gaussian pulse in a KGW crystal;
FIG. 3 is a computer-simulated spectral graph of stimulated Raman scattering from a Gaussian pulse in a KGW crystal;
FIG. 4 is a computer-simulated time graph of stimulated Raman scattering from an exponential-decay pulse in a KGW crystal;
FIG. 5 is a computer-simulated spectral graph of stimulated Raman scattering from an exponential-decay pulse in a KGW crystal;
FIG. 6 is a computer-simulated time graph of stimulated Raman scattering from a square pulse generating green stimulated-Raman-scattering light in a KGW crystal;
FIG. 7 is a computer-simulated spectral graph of stimulated Raman scattering from a square pulse generating green stimulated-Raman-scattering light in a KGW crystal;
FIG. 8 is a computer-simulated time graph of stimulated Raman scattering from a square pulse generating red stimulated-Raman-scattering light in a KGW crystal;
FIG. 9 is a computer-simulated spectral graph of stimulated Raman scattering from a square pulse generating red stimulated-Raman-scattering light in a KGW crystal;
FIG. 10 is a computer-simulated time graph of stimulated Raman scattering from a square pulse in a multimode fiber;
FIG. 11 is a computer-simulated spectral graph of stimulated Raman scattering from a square pulse in a multimode fiber;
FIG. 12 is a spectral graph of transmission through a projector;
FIG. 13 is a flowchart of a method of laser projection with spectral control of Raman despeckling;
FIG. 14 is a flowchart of a method of laser projection with spectral control of Raman despeckling that alternates between green and red; and
FIG. 15 is a flowchart of a method of laser projection with spectral control of Raman despeckling that generates a low level of yellow light.
DETAILED DESCRIPTION
Conventional laser projection systems are typically constructed with narrow-band laser sources. The narrow bands of light tend to produce speckle patterns in the projected images. Spectral broadening of the laser sources may be used to add wavelength diversity that reduces the speckle characteristic. By using stimulated Raman scattering (SRS) in a potassium gadolinium tungstate (KGW) crystal, optical fiber, or other Raman-shifting device, additional Stokes-shifted peaks may be added to help reduce laser speckle with wavelength diversity.
Raman despeckling may be defined as the general method of adding Raman scattering light to increase the spectral diversity and therefore lower speckle. Raman scattered light is generated in peaks that typically have much larger bandwidth than the original laser light used to generate the Raman scattered light. Both additional peaks and larger bandwidth of each peak contribute to increased spectral diversity that reduces speckle. Control of the Raman spectrum is useful to achieve desired spectrums that enable specific system configurations for laser projectors or other goals such as improving performance by increasing brightness or meeting color points that are required for industry-specified color gamuts. The luminous efficacy (lumens per watt) of the light can also be increased in a controlled way by changing the spectrum with controlled Raman shifting.
FIG. 1 shows a top view of a laser projection system with spectral control of Raman despeckling. Green laser 100 generates first light beam 102 . First light beam 102 illuminates first lens assembly 104 . First lens assembly 104 produces second light beam 106 . Second light beam 106 illuminates KGW crystal 108 and generates third light beam 110 which includes SRS light. Third light beam 110 illuminates second lens assembly 112 . Second lens assembly 112 produces fourth light beam 114 . Fourth light beam 114 transmits through beamsplitter 116 to form fifth light beam 118 . Fifth light beam 118 illuminates third lens assembly 120 . Third lens assembly 120 produces sixth light beam 122 . Sixth light beam 122 illuminates digital projector 124 . Blue laser 126 generates seventh light beam 128 . Seventh light beam 128 illuminates fourth lens assembly 130 . Fourth lens assembly 130 produces eighth light beam 132 . Eighth light beam 132 reflects from beamsplitter 116 to combine with fifth light beam 118 . The number of passes through KGW crystal 108 may be modified to attain a longer or shorter path length as desired to convert more of less of the green laser light to SRS light. One pass through KGW crystal 108 is shown in FIG. 1 , but any number of passes may be utilized. The lens assemblies may be any combination of lens or other optical elements that are designed to collect and shape the beam for optimal effect in each part of the system. KGW crystal 108 may alternately generate green and red light depending on the peak energy from green laser 100 . If KGW crystal 108 is not used to generate red light, as separate red laser may be used with an additional beamsplitter. Digital projector 124 may be a projector based on digital micromirror (DMD), liquid crystal device (LCD), liquid crystal on silicon (LCOS), or other digital light valves. Additional elements may be included to further guide or despeckle the light such as additional lenses, diffusers, vibrators, or optical fibers.
FIG. 2 shows a computer-simulated time graph of SRS from a Gaussian pulse in a KGW crystal. A computer model was utilized to calculate the conversion properties of the KGW crystal with a pulsed laser beam pump that creates Raman gain in the crystal to produce Stokes-shifted peaks of SRS light. The model utilizes several parameters of the crystal and laser source to determine the Stokes-shifted peaks. For the example shown in FIG. 2 , the Stokes shift was 768 cm −1 , the Raman gain cross section was 1.4×10 −12 mm/W, the average laser spot size in the crystal was 250 micrometers in diameter, the laser pulse energy was 1.8×10 −3 joules, the input pulse full-width half-maximum was 70 ns, the crystal physical length was 50 mm with 5 passes (total effective length of 250 mm), the spontaneous Raman seed power was 1×10 −7 W, the quantum defect level was 0.95, and the crystal transmission was 99.9% cm −1 . The input pulse to the KGW crystal was based on the output pulse from a green laser that has a Gaussian pulse shape. The x-axis represents time in nanoseconds, and the y-axis represents intensity in arbitrary units. First curve 200 shows the input pulse with Gaussian shape. Second curve 202 shows the residual energy that is not Stokes shifted. Third curve 204 shows the first Stokes-shifted peak. Fourth curve 206 shows the second Stokes-shifted peak. Fifth curve 208 shows the third Stokes-shifted peak. Sixth curve 210 shows the fourth Stokes-shifted peak. Seventh curve 212 shows the fifth Stokes-shifted peak. Overall, FIG. 2 describes the evolution in time of the SRS process.
The model used to generate FIG. 2 was used with the same parameters to generate FIG. 3 which shows a computer-simulated spectral graph of SRS from a Gaussian pulse in a KGW crystal. The horizontal axis represents wavelength in nanometers and the vertical axis represents normalized light intensity. First peak 300 shows an unshifted peak used to pump the crystal at 520 nm. Second peak 302 shows the first Stokes-shifted peak at 542 nm. Third peak 304 shows the second Stokes-shifted peak at 565 nm. Fourth peak 306 shows the third Stokes-shifted peak at 591 nm. Fifth peak 308 shows the fourth Stokes-shifted peak at 619 nm. Sixth peak 310 shows the fifth Stokes-shifted peak at 650 nm. Although not shown to scale in FIG. 3 , first peak 300 is typically a very narrow peak that has a width of much less than one nanometer, whereas the other peaks typically have bandwidths in the range of 1 to 5 nm each because they are broadened by the SRS process. The overall envelope of the spectrum is gradually rising from the green to the red, so the Gaussian input pulse tends to generate more red than green.
FIG. 4 shows a computer-simulated time graph of SRS from an exponential-decay pulse in a KGW crystal. The same computer model was utilized with the same parameters as for FIG. 2 except that the pulse shape was changed, the input pulse full-width half-maximum was 93 ns, and the laser pulse energy was 2×10 −3 joules. The x-axis represents time in nanoseconds, and the y-axis represents intensity in arbitrary units. First curve 400 shows the input pulse with a rapidly rising edge and exponential decay on the trailing edge. Second curve 402 shows the residual energy that is not Stokes shifted. Third curve 404 shows the first Stokes-shifted peak. Fourth curve 406 shows the second Stokes-shifted peak. Fifth curve 408 shows the third Stokes-shifted peak. Sixth curve 410 shows the fourth Stokes-shifted peak. Seventh curve 412 shows the fifth Stokes-shifted peak. Overall, FIG. 4 describes the evolution in time of the SRS process.
The model used to generate FIG. 4 was used with the same parameters to generate FIG. 5 which shows a computer-simulated spectral graph of SRS from an exponential-decay pulse in a KGW crystal. The horizontal axis represents wavelength in nanometers and the vertical axis represents normalized light intensity. First peak 500 shows an unshifted peak used to pump the crystal at 520 nm. Second peak 502 shows the first Stokes-shifted peak at 542 nm. Third peak 504 shows the second Stokes-shifted peak at 565 nm. Fourth peak 506 shows the third Stokes-shifted peak at 591 nm. Fifth peak 508 shows the fourth Stokes-shifted peak at 619 nm. Sixth peak 510 shows the fifth Stokes-shifted peak at 650 nm. Although not shown to scale in FIG. 3 , first peak 500 is typically a very narrow peak that has a width of much less than one nanometer, whereas the other peaks typically have bandwidths in the range of 1 to 5 nm each because they are broadened by the SRS process. The overall envelope of the spectrum is flat in the middle of the spectrum, so the exponential-decay input pulse can be used to generate approximately equal amounts of green and red.
FIG. 6 shows a computer-simulated time graph of SRS from a square pulse generating green SRS light in a KGW crystal. The same computer model was utilized with the same parameters as for FIG. 2 except that the pulse shape was changed, the input pulse full-width was 325 ns, and the laser pulse energy was 3.1×10 −3 joules. The x-axis represents time in nanoseconds, and the y-axis represents intensity in arbitrary units. First curve 600 shows the input pulse that has a square-wave shape. Second curve 602 shows a very small amount of residual energy that is not Stokes shifted. Third curve 604 shows the first Stokes-shifted peak. Overall, FIG. 6 describes the evolution in time of the SRS process.
The model used to generate FIG. 6 was used with the same parameters to generate FIG. 7 which shows a computer-simulated spectral graph of SRS from a square pulse generating green SRS light in a KGW crystal. The horizontal axis represents wavelength in nanometers and the vertical axis represents normalized light intensity. First peak 700 shows the spectral position of the pump light used to pump the crystal at 520 nm. Because the pump light is efficiently converted by the Raman process, the residual pump light is not visible as a peak in FIG. 7 . Second peak 702 shows the first Stokes-shifted peak at 542 nm. Although not shown to scale in FIG. 7 , first peak 700 is typically a very narrow peak that has a width of much less than one nanometer, whereas the other peaks typically have bandwidths in the range of 1 to 5 nm each because they are broadened by the SRS process. Overall, FIG. 7 shows that a square input pulse can be used to generate only green when it is at a specific pulse intensity.
FIG. 8 shows a computer-simulated time graph of SRS from a square pulse generating red SRS light in a KGW crystal. The same computer model was utilized with the same parameters as for FIG. 2 except that the pulse shape was changed, the input pulse full-width was 70 ns, and the laser pulse energy was 2×10 −3 joules. The x-axis represents time in nanoseconds, and the y-axis represents intensity in arbitrary units. First curve 800 shows the input pulse that has a square-wave shape. Second curve 802 shows a very small amount of energy that is not Stokes shifted or is shifted into the first, second, and third Stokes peaks. Third curve 804 shows the fourth Stokes-shifted peak. Overall, FIG. 8 describes the evolution in time of the SRS process.
The model used to generate FIG. 8 was used with the same parameters to generate FIG. 9 which shows a computer-simulated spectral graph of SRS from a square pulse generating red SRS light in a KGW crystal. The horizontal axis represents wavelength in nanometers and the vertical axis represents normalized light intensity. First peak 900 shows the spectral position of the pump light used to pump the crystal at 520 nm. Because the pump light is efficiently converted by the Raman process, the residual pump light is not visible as a significant peak in FIG. 9 . Second peak 902 shows a very small first Stokes-shifted peak at 542 nm. Third peak 904 shows a very small second Stokes-shifted peak at 565 nm. Fourth peak 906 shows a very small third Stokes-shifted peak at 591 nm. Fifth peak 908 shows a large fourth Stokes-shifted peak at 619 nm. Although not shown to scale in FIG. 9 , first peak 900 is typically a very narrow peak that has a width of much less than one nanometer, whereas the other peaks typically have bandwidths in the range of 1 to 5 nm each because they are broadened by the SRS process. Overall, FIG. 9 shows that a square input pulse can be used to generate only red when it is at a specific pulse intensity.
By utilizing alternating pulses between the case shown in FIG. 6 and FIG. 8 , alternating green and red light may be generated as shown in FIG. 7 and FIG. 9 and the alternating green and red light can be efficiently synchronized with a digital projector to generate full-color images as shown in FIG. 1 . The pulse intensities in FIG. 6 and FIG. 8 have been selected to achieve a green-to-red intensity ratio of approximately 1.2. This ratio approximately meets the white point requirements of the Digital Cinema Initiative (DCI) after the appropriate amount of blue light at 462 nm. The projector transmission was assumed to be spectrally flat in this example, but the green-to-red ratio may be adjusted to compensate for the actual projector transmission if desired.
FIG. 10 shows a computer-simulated time graph of SRS from a square pulse in a multimode fiber. The same computer model was utilized as for FIG. 8 except that the Raman shifting device was a multimode optical fiber rather than a KGW crystal, and the input pulse full-width was 60 ns. The x-axis represents time in nanoseconds, and the y-axis represents intensity in arbitrary units. First curve 1000 shows the input pulse that has a square-wave shape. Second curve 1002 shows a very small amount of energy that is not Stokes shifted or is shifted into the third, fourth, fifth, and sixth Stokes peaks. Third curve 1004 shows the first Stokes-shifted peak. Fourth curve 1006 shows the second Stokes-shifted peak. Fifth curve 1008 shows the seventh Stokes-shifted peak. Overall, FIG. 10 describes the evolution in time of the SRS process.
The model used to generate FIG. 10 was used with the same parameters to generate FIG. 11 which shows a computer-simulated spectral graph of SRS from a square pulse in a multimode fused-silica optical fiber. The horizontal axis represents wavelength in nanometers and the vertical axis represents normalized light intensity. First peak 1100 shows the spectral position of the pump light used to pump the crystal at 515 nm. Because the pump light is efficiently converted by the Raman process, the residual pump light is not visible as a significant peak in FIG. 11 . Second peak 1102 shows a first Stokes-shifted peak at 527 nm. Third peak 1104 shows a second Stokes-shifted peak at 540 nm. Fourth peak 1106 shows a very small third Stokes-shifted peak at 554 nm. Fifth peak 1108 shows a very small fourth Stokes-shifted peak at 568 nm. Sixth peak 1110 shows a very small fifth Stokes-shifted peak at 583 nm. Seventh peak 1112 shows a seventh Stokes-shifted peak at 599 nm. Eighth peak 1114 shows a very small sixth Stokes-shifted peak at 616 nm. Although not shown to scale in FIG. 11 , first peak 1100 is typically a very narrow peak that has a width of much less than one nanometer, whereas the other peaks typically have bandwidths in the range of 1 to 5 nm each because they are broadened by the SRS process. Overall, FIG. 11 shows that a square input pulse in a fused silica optical fiber can be used to generate green and red light that meet the color requirements of the DCI standard while not generating light in the gap between the two colors. The light in the gap is yellow light that generally does not have high transmission through a digital projector.
FIG. 12 shows a spectral graph of transmission through a projector. The horizontal axis represents wavelength in nanometers and the vertical axis represents light transmission through a typical digital cinema projector. Curve 1200 shows the variation of light transmission through the projector with wavelength. First region 1202 shows the transmission for blue light. Second region 1204 shows the transmission for green light. Third region 1208 shows the transmission for red light. Fourth region 1206 shows the transmission for yellow light. The transmission of blue, green, and red light is much higher than the transmission of yellow light. The reduction in yellow light is generally necessary to meet the DCI color requirements for the green and red primary colors. By generating a despeckled laser spectrum that avoids or reduces the amount of yellow light, the transmission of laser light through the projector is improved.
FIG. 13 shows a flowchart of a method of laser projection with spectral control of Raman despeckling. In step 1300 , pulsed green laser light is generated. In step 1302 , SRS is used to achieve a desired spectrum based on the shape of the pulses. In step 1304 , the SRS light is used to illuminate a digital projector.
FIG. 14 shows a flowchart of a method of laser projection with spectral control of Raman despeckling that alternates between green and red. In step 1400 , pulsed green laser light is generated that alternates between square pulses of different amplitudes. In step 1402 , SRS is used to alternately generate green light and red light. In step 1404 , the SRS light is used to illuminate a digital projector. In step 1404 , a single-light-valve digital projector is synchronized with the alternating green and red light.
FIG. 15 shows a flowchart of a method of laser projection with spectral control of Raman despeckling that generates a low level of yellow light. In step 1500 , pulsed green laser light is generated. In step 1502 , SRS is used to generate green and red light with a gap between that has a low level of yellow light. In step 1504 , the SRS light is used to illuminate a digital projector that has a low transmission of yellow light.
The computer model utilized to calculate the SRS light in a KGW crystal or multimode optical fiber can be used to optimize the Raman conversion process and transfer of power in the series of cascaded Raman shifts to longer wavelengths. This enables design of a system that efficiently converts power to higher-order Stokes peaks. It also enables the calculation of the spectral output behavior of the system. This can be utilized to provide a spectrum that is controlled to meet the requirements specific applications such as the DCI specification. This model is a simplification of the general problem of nonlinear processes in crystals. It does not account for four wave mixing effects for example. However the results of the model are in general agreement with experimentally determined results.
KGW is a biaxial crystal with Raman shifts that are dependent on polarization orientation. The Raman shift is either 768 cm −1 or 901 cm −1 . The 768 cm −1 shift is advantageous for despeckling because minimal peak spacing enables the maximum number of peaks to fit into the visible bands in order to achieve maximum despeckling. The crystal is typically cut to allow propagation along the b-axis. The output wavelength from the Raman crystal may be controlled by an optical waveplate that controls the polarization orientation of the pump laser beam. Other crystals may be used instead of KGW for the Raman conversion process.
Pulsed green laser sources with high peak power may be used to pump the KGW crystal, multimode fiber, or other material that makes SRS light. The pulsed green laser source may be constructed by utilizing a solid-state laser that includes a neodymium or ytterbium-doped crystal (such as yttrium aluminum garnet, vanadate or yttrium lithium fluoride) to provide an infrared (IR) laser beam at a wavelength of approximately one micron and a nonlinear crystal (such as lithium triborate) to convert the laser energy from IR to green. Green light is generally accepted to be in the wavelength range of 510 nm to 560 nm. Red light is generally accepted to be in the wavelength range of 600 nm to 700 nm.
For multimode optical fibers, the Raman-shifting KGW computer model discussed above may be utilized after adding modifications to include the effects of multiple fiber modes. The model simulates the Raman conversion properties of a multimode optical fiber with a pulsed laser beam pump that creates Raman gain in the crystal to produce first, second and up to seventh Stokes-shifted light peaks. It incorporates several parameters of the fused-silica material and the laser source to calculate the Stokes-shifted beams. These parameters include: Raman gain cross section, fiber core diameter, fiber length, fiber optical loss, laser input power, pump-laser-pulse temporal profile, spontaneous Raman signal level, and quantum defect level.
The distribution of power in the fiber waveguide modes is important to modeling the Raman processes in multimode fiber. The key issue is the coupling of power from a launched mode to higher order modes as the input pulse propagates through the fiber. The overlap integrals for several higher order modes can be calculated using a Bessel function analysis. These were calculated for a circular, step-index profile. The input laser pump launch power is predominantly in the LP01 mode. This power is then distributed to higher order modes as the laser pulse propagates along the fiber. The coupling in the higher order modes can be treated as a series of groups of coupled modes. The power ratio between modes can be calculated and the Raman gain for a specific fiber mode or group of modes can be calculated. The evolution of several Raman spectra from multiple modes can then be computed.
The parameters used for the multimode-fiber computer simulation in FIG. 10 and FIG. 11 are as follows: the Stokes shift was 455 cm −1 , the Raman gain cross section was 1.4×10 −13 m/W, the fiber core diameter was 50 micrometers, the laser pulse energy was 2×10 −3 joules, the fiber length was 50 m, the spontaneous Raman seed power was 1×10 −7 W, the quantum defect level was 0.97, and the fiber transmission was 99.9% m −1 . The computer model can be used to study the trade space of fiber length, pump pulse laser energy, pulse profile in time, and pulse duration. This can be used to optimize the SRS conversion process and transfer of power in a series of cascaded Raman shifts to longer wavelengths. This enables design of a system that efficiently converts power to higher Stokes orders. It also enables a study of the spectral output behavior of the system, and can be utilized to provide a resultant color condition that is controlled to meet the requirements for DCI specifications. The multimode-fiber computer model is in general agreement with experimentally determined results.
In addition to Gaussian, exponential decay, and square pulses discussed above, other pulse shapes may be utilized to make a variety of SRS spectrums. For example, exponential rise, stairstep, triangle, and other shapes may be useful in various projection system designs.
Other implementations are also within the scope of the following claims. | An apparatus and method for controlling the spectrum of stimulated Raman scattering that is used for despeckling of digitally projected images. The stimulated Raman scattering is utilized to add wavelength diversity for reduced speckle and to change the color of the light to a more desirable combination of wavelengths. Digital projection with color-sequential projectors may be enabled by alternately switching the Raman spectrum between green and red. Improved projector transmission may be achieved by minimizing the amount of yellow light generated in the Raman spectrum. | 6 |
CLAIM TO PRIORITY
[0001] This application claims priority to provisional application 12/263,455 filed on Nov. 1, 2008which is incorporated herein by this reference for all that it discloses.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to an apparatus and method for conditioning materials for processing with replaceable teeth. The invention is particularly useful for conditioning used material to prepare such material for recycling.
BACKGROUND
[0003] It is often necessary to condition materials for transport to a facility that uses such material in a commercial process such as power generation, manufacturing, and recycling. Often times such materials contain impurities making it necessary to chop up or pulverize to separate the wanted material from the impurities. In some situations such materials are used plastic containers that need to be conditioned into a more condense form.
[0004] One area in particular where a device is often needed to “condition” materials relates to the recycling industry. Recyclable materials include many kinds of glass, paper, metal, plastics, textiles, and electronics. For example, plastic containers are often recycled. Unfortunately, such plastic containers are often more bulky than necessary and may contain unwanted material (such as fluid, dirt, etc.). To assist in making the process of recycling plastic containers more economically feasible, the plastic containers need to be preconditioned to extract the wanted material from the unwanted material. The present invention is a pulverizing/shredding machine well suited for such a purpose.
[0005] Prior art pulverizing devices are known such as the machines manufactured by Remcon Equipment, Inc. While such a device works well for its intended purposes, it has its issues. First, Remcon's fingers are curved and spring loaded which allows large pieces of material to pass thereby compromising the effectiveness of the preconditioning process. Second, Remcon's device uses a drum with flat ends that allow material to get trapped between the drum end and the drum housing. Third, such prior art devices need a second row of substantially stationary teeth to better shred the material to be recycled in to smaller pieces than can be easily achieved with only one row of teeth. Forth, such second row of substantially stationary teeth should be easily taken out of the system to allow for bigger pieces of recycled material as required by the recycler.
[0006] The invention address all the above described deficiencies in the prior art.
SUMMARY
[0007] Objects and advantages of the invention will be set forth in the following description, or may be obvious from the description, or may be learned through practice of the invention.
[0008] Broadly speaking, a principal object of the present invention is to provide a material conditioner with configurable replaceable teeth wherein said apparatus is configured to reduce the size of materials and separate impurities from the wanted material where the occurrences of materials becoming lodged inside the machine are minimized or eliminated.
[0009] Another general object of the present invention is to provide a tooth replacement kit for a material conditioning apparatus.
[0010] Additional objects and advantages of the present invention are set forth in, or will be apparent to those skilled in the art from, the detailed description herein. Also, it should be further appreciated that modifications and variations to the specifically illustrated, referenced, and discussed steps, or features hereof may be practiced in various uses and embodiments of this invention without departing from the spirit and scope thereof, by virtue of the present reference thereto. Such variations may include, but are not limited to, substitution of equivalent steps, referenced or discussed, and the functional, operational, or positional reversal of various features, steps, parts, or the like. Still further, it is to be understood that different embodiments, as well as different presently preferred embodiments, of this invention may include various combinations or configurations of presently disclosed features or elements, or their equivalents (including combinations of features or parts or configurations thereof not expressly shown in the figures or stated in the detailed description).
[0011] Those of ordinary skill in the art will better appreciate the features and aspects of such embodiments, and others, upon review of the remainder of the specification.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] A full and enabling description 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 figures, in which:
[0013] FIG. 1 is an elevated side perspective view of one exemplary embodiment of the invention;
[0014] FIG. 1 b is an elevated side perspective view of one exemplary embodiment of the invention;
[0015] FIG. 1 c is a side view of conditioner housing walls;
[0016] FIG. 1 d is a side view of hopper housing walls;
[0017] FIG. 2 is a side view of one exemplary embodiment of a mobile-tooth-carrier comprising a drum and a shaft;
[0018] FIG. 3 is a side view of the exemplary shaft depicted in FIG. 2 ;
[0019] FIG. 4 is a side view of one exemplary embodiment of a mobile-tooth support bar;
[0020] FIG. 5 is a close up view of one exemplary embodiment of an end-tooth associated with one end of a mobile-tooth support bar;
[0021] FIG. 6 is a side view of one exemplary embodiment of a mobile-tooth;
[0022] FIG. 7 is a front view of the exemplary mobile-tooth depicted in FIG. 6 ;
[0023] FIG. 8 is a side view of one exemplary embodiment of a finger-tooth;
[0024] FIG. 9 is a top view of the exemplary finger-tooth depicted in FIG. 8 ;
[0025] FIG. 10 is a top view of one exemplary embodiment of a finger-plate;
[0026] FIG. 11 is a top view of one exemplary embodiment of the invention without housing walls;
[0027] FIG. 12 is an elevated perspective view of the embodiment depicted in FIG. 11 ;
[0028] FIG. 13 is a side view of one exemplary embodiment of the invention depicting one possible hopper plate, conditioner section, and output bin configuration;
[0029] FIG. 14 is a view of the drum assembly of FIG. 11 with a replaceable tooth kit; and
[0030] FIG. 15 is a perspective view of a tooth kit.
[0031] Repeat use of reference characters throughout the present specification and appended drawings is intended to represent the same or analogous features or elements of the present technology.
DETAILED DESCRIPTION
[0032] Reference now will be made in detail to the embodiments of the invention, one or more examples of which are set forth below. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used on another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents. Other objects, features, and aspects of the present invention are disclosed in or may be determined from the following detailed description. Repeat use of reference characters is intended to represent same or analogous features, elements or steps. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.
[0033] It should be appreciated that this document contains headings. Such headings are simply place markers used for ease of reference to assist a reader and do not form part of this document or affect its construction.
[0034] For the purposes of this document two or more items are “mechanically associated” by bringing them together or into relationship with each other in any number of ways including a direct or indirect physical connection that may be releasable (snaps, rivets, screws, bolts, etc.) and/or movable (rotating, pivoting, oscillating, etc.)
[0035] Similarly, for the purposes of this document, two items are “electrically associated” by bringing them together or into relationship with each other in any number of ways. For example, methods of electrically associating two electronic items/components include: (a) a direct, indirect or inductive communication connection, and (b) a direct/indirect or inductive power connection. Additionally, while the drawings illustrate various components of the system connected by a single line, it will be appreciated that such lines represent one or more connections or cables as required for the embodiment of interest.
[0036] While the particulars of the present invention may be adapted for use in any process for conditioning materials, the examples discussed herein are primarily in the context conditioning plastic to be used in a recycling process.
[0037] Referring now to FIG. 1 and FIG. 1 b , side perspective views of a material conditioner ( 10 ) according to exemplary embodiments of the present invention are considered. Material conditioner ( 10 ) comprises a conditioner section ( 12 ) disposed between a hopper ( 16 ) and an output bin ( 22 ). A frame ( 14 ) surrounds the various sections and provides structural support. As depicted in FIG. 1 b , housing wall ( 12 a ) has been removed to expose a portion of the inside of conditioner section ( 12 ) thereby revealing one exemplary embodiment of a mobile-tooth-carrier, drum ( 30 ). Similarly, side guard ( 18 , FIG. 1 ) has been removed to expose one exemplary embodiment of a shaft support, bearing housing ( 82 , FIG. 1 b ). For the embodiments depicted in FIG. 1 and FIG. 1 b , conditioner housing ( 12 h ) comprises two sets of opposing walls; ( 12 a opposed by 12 b ) and ( 12 c opposed by 12 d ). Such walls are associated with each other so as to define a four wall housing having a housing input positioned at interface ( 15 ) ( FIG. 1 b ), located at a point of association between hopper ( 16 ) and conditioner section ( 12 ). For the presently preferred embodiment of the invention, the hopper ( 16 ) comprises two sets of opposing walls; ( 16 a opposed by 16 b ) and ( 16 c opposed by 16 d ) configured to form a hopper enclosure. The distance between opposing walls ( 16 a ) and ( 16 b ) is substantially the same as the distance between opposing walls ( 12 a ) and ( 12 b ). The distance between opposing walls ( 16 c ) and ( 16 d ) is substantially the same as the distance between opposing walls ( 12 c ) and ( 12 d ). One of ordinary skill in the art will appreciate that for such a configuration, the output of hopper ( 16 ) will better associate with the input of conditioner housing ( 12 h ), at interface ( 15 ). Thus, material dropped into hopper input ( 24 ) will travel through the hopper enclosure, exit the hopper output and fall into the conditioner housing ( 12 h ) input.
[0038] Referring now to FIG. 1 c , the opposing walls ( 12 a, 12 b, 12 c, 12 d ) defining conditioner housing ( 12 h ) are steel plates with a thickness of about one-forth inches. Opposing walls ( 16 a ) and ( 16 b ) are rectangular having dimensions (l 2 ab -H× 12 ab -L) of about twenty and three-forth inches high by thirty and three-forth inches Long (wide, looking at front). The opposing walls ( 16 c ) and ( 16 d ) are rectangular having dimensions ( 12 cd -H× 12 cd -L) of about twenty and three-forth inches high by twenty-five inches long (deep, looking at front). Opposing walls ( 16 c ) and ( 16 d ) further define a cutout ( 13 ) having a cutout width ( 13 w ) of about two and three-forth inches and a cutout length ( 13 L) of about eleven and three-forth inches. Cutout ( 13 ) is positioned about nine inches from side ( 12 s ) as shown in FIG. 1 c . As will be discussed later in this document, cutout ( 13 ) allows the ends of a mobile-tooth carrier to extend through opposing walls ( 12 c ) and ( 12 d ) thereby defining a movable association between the two. A six inch by seven inch cover plate is used to cover the unused portion of cutout ( 13 ).
[0039] Referring now to FIG. 1 d , for one preferred embodiment, the opposing walls ( 16 a, 16 b , 16 c, 16 d ) defining the hopper housing are plate steel with a thickness of about one-eight inches. One will notice that the hopper plate steel (⅛ in thick) is thinner than the conditioner housing plate steel ( 2/8 in thick). Such allows for some production tolerance as the hopper housing rests on top of the conditioner housing. The opposing walls ( 16 a ) and ( 16 b ) are rectangular having dimensions ( 16 ab -H× 16 ab -L) of about twenty-two inches High by thirty and three-forth inches Long (wide, looking at unit from front). Opposing walls ( 16 c ) and ( 16 d ) are rectangular having dimensions ( 16 cd -H× 16 cd -L) of about twenty-two inches High by twenty-five and one-forth inches Long (deep, looking at unit from front).
[0040] Referring now to FIG. 1 b , hopper ( 16 ) may further include diverter plates. For the presently preferred embodiment, a first diverter plate ( 102 ) extends out from about a top edge of hopper wall ( 16 a ), at a first diverter plate angle ( 104 ), to a point about 30% of the way across and about 30% of the way down said hopper wall ( 16 a ). For this embodiment, the sides of diverter plate ( 102 ) adjacent to hopper walls ( 16 a, 16 c, and 16 d ) are secured to such walls by any suitable means such as wielding. A second diverter plate ( 100 ) extends from about the top of hopper wall ( 16 b ), at a second diverter plate angle ( 106 ), to a point about 70% across and 80% down said hopper wall ( 16 b ). Alternatively, the second diverter plate ( 100 ) may extend from other points including half-way down said second hopper wall ( 16 b ), at a second diverter plate angle ( 106 ), to a point about 50% across and 50% of the way down said hopper wall ( 16 b ). It should be appreciated that any suitable diverter plate configurations may be used. Preferably, the second diverter plate ( 100 ) endpoint ( 110 ) extends beyond the first diverter plate ( 102 ) endpoint ( 108 ) to prevent substantially all occurrences of items traveling in the reverse direction (i.e. to prevent items from coming out the hopper input).
[0041] Referring now to FIG. 3 , one exemplary embodiment of a mobile-tooth-carrier is presented. A mobile-tooth-carrier is simply a device that is configured to be associated with teeth and wherein a second device is associated with the mobile-tooth-carrier, said second device configured to generate mobile-tooth-carrier motion. Consequently, as the mobile-tooth-carrier moves, the teeth associated the mobile-tooth-carrier will also movie; hence the name “mobile-teeth”. Any suitable device may be used such as frames, wheels, drums, shafts, etc.
[0042] For the presently preferred embodiment, the mobile-tooth-carrier is drum assembly ( 31 ) comprising a cylindrical drum ( 30 ) having a length ( 37 ) of about nineteen and three-forth inches and a diameter of about twelve and three-forth inches. Cylindrical drum ( 30 ) is further associated with end caps ( 32 ) and ( 33 ). Such end caps ( 32 ) define a rounded, dome shaped end point for cylindrical drum ( 30 ). Referring now to FIG. 3 , drum assembly ( 32 ) further comprises a drive-shaft ( 36 ) with a length ( 36 L) of about forty inches and having a diameter of about two and three-sixteenth inches. One end of draft-shaft ( 36 ) defines a key ( 38 ) with dimensions of about one-half inch wide, one-fourth inch deep, and seven inches long ( 38 L). Draft-shaft ( 36 ) further defines a first-shaft-end ( 34 ) and an opposing second-shaft-end ( 35 ). When assembled, the first-shaft-end ( 34 ) is positioned outside said drum ( 30 ) with said drive-shaft ( 36 ) extending through the approximate center of said first-drum-end ( 32 ), through said drum and out the approximate center of said second-drum-end ( 33 ) to said second-shaft-end ( 35 ) about seven and one-half inches from the second-drum-end. It should be appreciated that one piece “drum assemblies” fall with the scope of the invention. Such drum-assemblies ( 31 ), after being associated with the desired mobile-tooth configuration, are typically balanced to minimize vibrations.
[0043] Referring now to FIG. 11 , various embodiments of the mobile-tooth-sets are considered. For one exemplary embodiment of the invention, the mobile-tooth-carrier is configured for being associating with at least two mobile-tooth-sets ( 41 ). For the embodiment depicted in FIG. 11 , there are five mobile-tooth-sets (three shown in FIG. 11 ). The mobile-tooth-carrier's first end ( 34 ) is movably associated with said first housing wall ( 12 c ) and said second end is movably associated with said second housing wall ( 12 d ). For this embodiment of the invention, such movable association is provided by cutout ( 13 ) that allows drive-shaft ( 36 ) to extend through the walls and rotate relative to the wall as described later.
[0044] Mobile-tooth-sets ( 42 ) comprise a plurality of mobile-tooths ( 48 ) (“tooths” is used instead of “teeth” in an attempt to reduce confusion). For the presently preferred embodiment, cylindrical drum ( 30 ) is associated with five mobile-tooth-sets ( 42 ) with three sets being shown in FIG. 11 . Mobile-tooth-set ( 41 ) comprises eight mobile-tooths ( 48 ) spaced along the surface of drum ( 30 ). For such embodiment, mobile-tooths ( 48 ) are in alignment along said cylindrical drum and drive-shaft ( 36 ) where the distance between the center points of any two adjacent mobile-tooths are substantially equal. It should be appreciated that some embodiments may have unequally spaced mobile-tooths ( 48 ).
[0045] Referring now to FIG. 6 , FIG. 7 , and FIG. 11 , each mobile-tooth ( 48 ) comprises a first mobile-tooth end ( 48 a ) and a second mobile-tooth end ( 48 b ), wherein the first mobile-tooth end ( 48 a ) of each mobile-tooth is associated with the surface of drum ( 30 ) so that each mobile-tooth ( 48 ) extends outward from drum ( 30 ) there by defining a tooth. For the presently preferred embodiment, each mobile-tooth ( 48 ) is substantially the same size which is about three-eights of an inch thick ( 52 ), about three inches long ( 54 ), and about one and one-half inches wide ( 50 ). Consequently, the first end of each mobile-tooth ( 48 ) will be associated with the surface of drum ( 30 ) and each mobile tooth extends perpendicularly outward from the drum a distance of about three inches. It should be appreciated that embodiments where mobile-tooth-sets comprise mobile-tooths having a plurality of different sizes that extend out for the mobile-tooth-carrier at the same or different angles fall within the scope of the invention.
[0046] As shown in FIG. 6 , the first end ( 48 a ) may be cut at an angle thereby defining a predefined mobile-tooth-angle ( 49 ) selected based on the shape of the cylindrical drum at the mobile-tooth to drum interface point. For the presently preferred embodiment, mobile-tooth-angle ( 49 ) is about 10 degrees. Such a mobile-tooth-angle improves the mechanical association between the cylindrical drum ( 30 ) surface and the first end of the mobile-tooth. The front edge of each mobile-tooth ( 48 ) may be further shaped to define a cutting edge. For such a feature, about one-sixteenth of an inch (about 15%) is removed from both sides of the front edge ( 56 ) of each tooth.
[0047] Referring now to FIG. 4 , FIG. 5 , and FIG. 11 , exemplary embodiments of the invention comprising a mobile-tooth support bar ( 40 ) are considered. For such embodiments, each mobile-tooth-set comprises a mobile-tooth support bar ( 40 ). Support bar ( 40 ) defines a first support end ( 44 a ) and an opposing second support end ( 44 b ). Support bar ( 40 ) is preferably a one inch square bar having a length ( 43 ) of about twenty-eight inches.
[0048] As shown in FIG. 4 , FIG. 5 , and FIG. 11 , support-bar-surface ( 44 , FIG. 4 ) of support bar ( 40 ) is mechanically associated (welding is one example) with the surface of cylindrical drum ( 30 ) so that the first support bar end is positioned a predefined distance from the first cylindrical drum end and so that the second support bar end is positioned a predefined distance from the second cylindrical drum end. In addition, the position of support bar ( 40 ) is selected so that a side surface ( 44 c ) of support bar ( 40 ) may be associated with the back side of each mobile-tooth in the mobile tooth set thereby providing support to such mobile-tooths. For example, support bar ( 40 ) may be welded to the drum surface and to the back side of each mobile-tooth as shown in FIG. 11 . For the present embodiment, there are five support bars ( 40 ) positioned around the drum about seven inches apart.
[0049] As shown in FIG. 5 , for some embodiments, the ends of support bar ( 40 ) may be cut to define a support-bar-angle ( 46 b ). Such allows each end of support ( 40 ) to be associated with an end-tooth ( 48 e ). For the preferred embodiment, support-bar-angle ( 46 b ) is between about 20 degree and 50 degrees. More specifically, for the current embodiment, support-bar-angle ( 46 b ) is around 35 degrees.
[0050] It will be appreciated by those skilled in the art that by minimizing the distance between the rounded ends of drum ( 30 ) [and thereby the support bar ( 40 ) end points] and the adjacent conditioner housing walls, the occurrences of materials becoming lodged between the conditioner housing walls and the ends of drum ( 30 ) will be minimized. Such a feature is further enhanced by associating an end-tooth with the support bar as described.
[0051] Referring now to FIG. 10 , one exemplary embodiment of a finger plate is considered. Finger plate ( 80 ) comprises a plurality of fingers ( 81 ), wherein each finger ( 81 ) extends horizontally out from said finger plate ( 80 ), in the Z direction, a predefined distance to a finger-end-point ( 83 ) where each finger-end-point ( 83 ) defines a finger-interface. One or more sides ( 81 s ) of fingers ( 81 ) may be configured to enhance the material conditioning process. For example, sides ( 81 s ) may be serrated. Adjacent fingers are separated by a gap thereby defining an adjacent-finger-gap ( 91 ). For the presently preferred embodiment, the distance between adjacent adjacent-finger-gaps ( 91 ) is about two inches and are substantially equal. Other embodiments included a plurality of adjacent-finger-gaps ( 91 ) values.
[0052] The distance between each finger-plate-interface ( 83 ) and the mobile-tooth-carrier (in this case, drum assembly 31 ) is selected to define a finger-carrier-gap. The finger-carrier-gap is one parameter that determines the size of the material that exits the material conditioner ( 10 ). The finger-carrier-gap is determined by the position selected for the finger-plate ( 80 ) relative to the mobile-finger-carrier. For the embodiment depicted in FIG. 11 , all fingers are part of an integral finger plate with all fingers defining a substantially equal finger-carrier-gap. Alternative embodiments include fingers ( 81 ) of different lengths and different finger-carrier-gaps distances. Another alternative embodiment includes a finger plate design comprising movable fingers associated with a motor to allow remote adjustment of the finger-carrier-gaps. For such configurations, the position of each finger-end-point ( 83 ), or groups of finger-end-points may be independently selected.
[0053] As depicted in FIG. 1 , FIG. 1 b , and FIG. 11 , the mobile-tooth-carrier is associated with a motor configured to generate mobile-tooth-carrier motion, and thereby mobile-tooth motion relative to finger plate ( 80 ). For the presently preferred embodiment, an electric motor ( 20 ) is associated with one end of drive-shaft ( 36 ) via a pulley system ( 86 , 88 , and 90 ). For such embodiment, pulleys ( 88 ) associated with motor ( 20 ) are seven inches in diameter. Pulley's ( 86 ) associated with drive-shaft ( 36 ) are nine inches in diameter. Both pulleys ( 86 ) and pulleys ( 88 ) are v-belt pulleys. One of ordinary skill will appreciated that such a pulley system ( 86 , 88 , and 90 ) allow the power (torque) and speed of drum ( 30 ) to be configured by simply changing pulley diameters. For the configuration described above, Motor ( 20 ) is a fifteen horse power motor that turns drive-shaft ( 36 ) at about 1,750 rotations per minute. Lower horse power motors may be used if the pulley configuration is changed accordingly.
[0054] As drive-shaft ( 36 ) rotates thereby turning drum assembly ( 31 ), mobile-tooths ( 48 ) move in a circular path thereby defining a mobile-tooth-motion-path (clockwise for the present embodiment). The relative position of drum-assembly ( 31 ) to finger-plate ( 80 ), and the configuration of the finger-plate ( 80 ) and mobile-tooth-sets ( 41 ) are selected so that the mobile-tooth-motion-path for each mobile-tooth goes through an adjacent-finger-gap ( 91 ).
[0055] Referring now to FIG. 8 , FIG. 9 , and FIG. 11 , exemplary embodiments of finger-tooth ( 60 ) are considered. As shown in FIG. 11 , a finger-tooth ( 60 ) is associated with each finger ( 81 ). For the preferred embodiment, finger-tooth ( 60 ) has a length ( 62 ) of about four inches, a width ( 66 ) of about one and one-half inches, and a height ( 64 ) of about one-forth inches (although any suitable size may be used). The top surface ( 68 ) of finger-tooth ( 60 ) may be serrated to enhance the conditioning process. As shown in FIG. 11 , the finger-tooth ( 60 ) and finger ( 81 ) association is a fixed association such as a welded joint. For one alternative embodiment of the invention, fingers ( 81 ) are configured with a finger-tooth opening though which finger-tooths protrude. For such a configuration, the finger tooth ( 60 ) may be associated with a motor to allow remote lowering and rising of a finger-tooth. A motor may be associated with each finger tooth ( 60 ), a motor may be associated with groups of finger-tooths ( 60 ), and a single motor may be associated with all finger-tooths ( 60 ). Using such a configuration, the material conditioning process can be altered by independently selecting the finger-tooth height.
[0056] Referring now to FIG. 13 , one exemplary embodiment of the invention is presented with ghost images for components of interest. Hopper ( 16 ) presents a slightly different diverter-plate configuration to the one previously described and depicted in FIG. 1 . For this embodiment, diverter-plate ( 100 ) starts about half-way down and along a hopper wall ( 16 c ) to a distance ( 120 a ) beyond the end point of diverter-plate ( 102 ) and a distance ( 122 ) beyond an endpoint of the drum-assembly ( 31 ).
[0057] Large pieces of material ( 113 ) are dropped into the hopper input, hit diverter-plate ( 102 ) and then diverter-plate ( 100 ) and then past through the input of conditioner section ( 12 ). The rotating drum-assembly ( 31 ) crushes, rips, pulverizes, and/or cuts, (etc.) the material ( 113 ) into small pieces of material ( 114 ) and smaller pieces of material ( 116 ), depending on the material conditioner ( 10 ) configuration. When material conditioner ( 10 ) is configured to only output one size material, output bin ( 22 ) is simply a “conduit” of sorts to a transportation apparatus or storage area. When material conditioner ( 10 ) configuration includes mobile-teeth of different sizes, adjustable carrier-finger-gap, and adjustable finger-teeth, providing for different sized output pieces, output bin ( 22 ) may further be configured to act as a sorter. For this configuration, output bin plate ( 112 ) is a grate having openings of a first size so that items too large to fall through such opening will pass to output bin section ( 110 ).
[0058] Referring now to FIG. 14 and FIG. 15 , one exemplary alternative embodiment of the invention is presented comprising a mobile-tooth-carrier assembly configured with a replaceable tooth kit. One suitable mobile-tooth-carrier is drum ( 30 ). For such embodiment, a replaceable tooth kit ( 200 ) comprises support bar ( 202 ) mechanically associated with a plurality of bar teeth ( 48 ). Alternatively, support bar ( 202 ) may define integral teeth ( 48 ). Additionally, tooth kit ( 200 ) may further comprise support bar interface ( 204 ).
[0059] For the presently preferred embodiment, support bar ( 202 ) defines a plurality of bar-tooth-attachment-points ( 48 bs ), each configured for being mechanically associated with a bar tooth ( 48 ). Similarly, support bar ( 202 ) defines a plurality of bar-attachment-points ( 206 a ) suitably configured to align with a plurality of interface-attachment-points ( 206 b ). For the present embodiment, each bar tooth ( 48 ) is welded to support bar ( 202 ) although any method of removably mechanically associating tooth ( 48 ) to support bar ( 202 ) may be used. It should be noted that the tooth kit ( 200 ) comprises eight teeth. One of ordinary skill in the art will appreciate however, that tooth kit ( 200 ) may comprise any number of teeth as required for a particular material conditioner configuration.
[0060] As depicted in FIG. 14 , support bar interface ( 204 ) is mechanically associated with the outer surface of drum ( 30 ). Support bar interface ( 204 ) defines a plurality of drum-attachment-points ( 208 a ) configured for associating a support bar interface ( 204 ) with a drum ( 30 ) via attachment mechanism ( 208 ). For the currently preferred embodiment, the support bar interface width ( 204 w ) is about 2.5 inches and the support bar interface thickness ( 204 t ) is about 0.25 inches. Support bar interface ( 204 ) is preferably formed/shaped to match the curved surface of drum ( 30 ). Support bar interface ( 204 ) further defines a plurality of interface-attachment-points ( 206 b ) configured for being associated with bar-attachment-points ( 206 a ) via attachment mechanisms ( 206 ) thereby removably associating support bar ( 202 ) with support bar interface ( 204 ). Support bar interface ( 204 ) further defines a plurality of drum-attachment-points ( 208 a ) configured for securing support bar interface ( 204 ) to drum ( 30 ).
[0061] For this presently preferred embodiment, the drum assembly comprises five support bar interfaces ( 204 ) mechanically associated to drum ( 30 ) at equal intervals around drum ( 30 ). Each support bar interface ( 204 ) is preferably milled to the approximate length of drum ( 30 ) and is constructed from flat bar steel. Each support bar interface ( 204 ) is removably associated with drum ( 30 ) with nine attachment mechanisms ( 208 ). Suitable attachment mechanisms ( 208 ) include ⅜ to ¾ inch fine thread Allen Head Bolts counter sunk into support bar interface ( 204 ).
[0062] Similarly support bar interface ( 204 ) is configured to removably receive support bar ( 202 ) via eight support bar attachment mechanisms ( 206 ). Suitable attachment mechanisms ( 206 ) include ⅜ to 1½ inch fine thread Allen Head Bolts configured to associate with counter sunk hole ( 206 a ) into support bar ( 202 ) and threaded into support bar interface ( 204 ).
[0063] Support bar ( 202 ) is preferably “square stock” having a bar width ( 202 w ) and a bar height ( 202 h ) of about 1 inch with a length of about the approximate length of drum ( 30 ) and support bar interface ( 204 ) as depicted in FIG. 14 . It should be appreciated that support bar ( 202 ) may not have equal width and high dimensions.
[0064] As noted above, support bar ( 202 ) is one of (a) mechanically associated with a plurality of teeth ( 48 ) or (b) defines a plurality of teeth ( 48 ). Preferably, teeth ( 48 ) are equally spaced along support bar ( 202 ) although unequal teeth ( 48 ) spacing may be used are required for the material conditioner configuration of interest. Similarly, tooth kit ( 200 ) may be configured with any number of teeth ( 48 ) and such would typically be determined by the material conditioner configuration of interest.
[0065] Grouser Bar is one suitable embodiment of teeth ( 48 ) having dimensions of about 2¾ inches long and 1½ inches wide. As noted above, the back edge of a tooth ( 48 ) is preferably suitable for being mechanically associated with a bar-tooth-attachment-point defined by support bar ( 202 ). Tooth-slot ( 48 bs ) is one embodiment of a suitable bar-tooth-attachment-point. Support bar ( 202 ) may define a plurality of teeth-slots ( 48 bs ); one at each tooth attachment point. It should be further noted that the tooth replacement kit ( 200 ) depicted in FIG. 15 is not angled at end point ( 210 ) and is not associated with an end-tooth ( 48 e ) as show for the configuration depicted in FIG. 5 . That said, embodiments comprising a support bar ( 202 ) defining a support-bar-angle ( 46 b ) (preferably between about 20 and 50 degrees) configured to receive an end-tooth ( 48 e ) all within the scope of the present embodiment.
[0066] While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily adapt the present technology for alterations to, variations of, and equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations, and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art. | The invention relates to an apparatus and method for conditioning materials for processing wherein such conditioned materials are used in a recycling process. The invention includes a conditioning section comprising a drum associated with a tooth kit. The tooth kit is easily removable from said drum and replaced. The invention also covers the tooth kit. | 1 |
BACKGROUND
[0001] 1. Technical Field
[0002] The present disclosure relates to rack assemblies and, particularly, to a rack assembly for housing electronic components of a server.
[0003] 2. Description of Related Art
[0004] Servers usually include a server rack assembly and a number of rack-mount computers. The rack assembly generally includes a rack and a number of removable chassis for receiving the rack-mount computers. In assembly, the chassis is housed in the rack and is fixed to the rack with a locking device. However, electrical connections between the rack-mount computers received in the chassis and connection ports of the rack may not be properly established due to improper assembly or vibrations after the assembly. As a result, the server may not work properly.
[0005] Therefore, it is desirable to provide a new server rack assembly, which can overcome the above-mentioned limitations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Many aspects of the present disclosure should be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
[0007] FIG. 1 is an isometric, assembled view of a server rack assembly, according to an exemplary embodiment.
[0008] FIG. 2 is an exploded view of the server rack assembly of FIG. 1 .
[0009] FIG. 3 is an exploded view of a locking device of the server rack assembly of FIG. 1 .
[0010] FIG. 4 is a top, cross-sectional view of the server rack assembly of FIG. 1 .
[0011] FIG. 5 is similar to FIG. 1 , but showing another state of the server rack assembly.
DETAILED DESCRIPTION
[0012] Embodiments of the present disclosure will now be described in detail with reference to the drawings.
[0013] Referring to FIGS. 1 and 2 , a server rack assembly 100 , according to an exemplary embodiment, is for housing a computer 40 . The rack assembly 100 includes a rack 10 , a chassis 20 , and a locking device 30 .
[0014] The rack 10 includes a bottom plate 113 , two side plates 114 , a top plate 111 , and a back plate 112 . In the present embodiment, the bottom plate 113 , two side plates 114 , and the back plate 112 is one-piece or integrally formed. The two side plates 114 each extend upwards from two opposite ends of the bottom plate 113 and define a receiving slot 115 at an end thereof. The top plate 111 is connected to the two side plates 114 with screws (not shown), opposing the bottom plate 113 . The back plate 112 contacts an end of each of the side plates 114 that is distant from the receiving slot 115 and forms a number of first connection ports 121 thereon. The rack 10 defines a first cavity 14 for receiving the chassis 20 . The first connection ports 121 are located between the two side plates 114 , received in the first cavity 14 .
[0015] The chassis 20 includes a bottom wall 215 , two side walls 216 extending upwards from two opposite ends of the bottom wall 215 , a top wall 213 , and a back wall 214 extending downwards from an end of the top wall 213 . In the present embodiment, the bottom wall 215 and two side walls 216 are one-piece or integrally formed, the top wall 213 and the back wall 214 is also one-piece or integrally formed. The back wall 214 defines a number of connection slots 2141 corresponding to the first connection parts 121 of the rack 10 . The top wall 213 is connected to two side walls 216 , opposing the bottom wall 215 , with the back wall 214 connected to an end of each side wall 216 . The chassis 20 defines a second cavity 217 for housing the computer 40 .
[0016] Referring to FIGS. 2 to 4 , the locking device 30 is connected to the end of the chassis 20 that is opposite to the back wall 214 . The lock device 30 includes a bracket 221 , a locker 227 fixed to the center of the bracket 221 , and two elastic members 228 , each of which is fixed at the corresponding opposite ends of the bracket 221 .
[0017] The bracket 221 includes a first plate 225 for sealing the second cavity 217 and a second plate 226 substantially perpendicularly connected to an edge of the first plate 225 . The first plate 225 defines two first slots 2251 , two second slots 2252 , and two third slots 2253 . The first slots 2251 , the second slots 2252 , and the third slots 2253 are substantially symmetrical with respect to the center of the first plate 225 . The first slots 2251 are positioned between the second slots 2252 . The second slots 2252 are positioned between the third slots 2253 . The third slots 2253 are formed at an edge of the first plate 225 , adjacent to the second plate 226 . The second plate 226 forms two strip slots 2263 whose lengthwise direction is substantially perpendicular to the first plate 225 .
[0018] The locker 227 is fixed to the center of the first plate 225 and includes two shafts 2273 , a helical spring 2271 interconnecting the two shafts 2273 , and a shell 2272 receiving the shafts 2273 and the helical spring 2271 . In detail, the shaft 2273 includes a main body 2274 , two positioning portions 2275 substantially parallel to each other, an operating portion 2276 , a locking portion 2277 , and a connecting portion 2278 . The positioning portion 2275 and the operating portion 2276 extend outwards from two opposite sides of the main body 2274 . The locking portion 2277 and the connecting portion 2278 extend from two opposite ends of the main body 2274 . The helical spring 2271 engages with both connecting portions 2278 . The shell 2272 includes a rectangular bottom plate 2279 and four side plates 2280 surrounding the bottom plate 2279 . The bottom plate 2279 defines four positioning slots 2281 along the lengthwise direction thereof, corresponding to the positioning portions 2275 .
[0019] In assembly, the positioning portions 2275 are inserted through the corresponding positioning slots 2281 of the shell 2272 , while the operating portion 2276 protrudes out of the first slot 2251 of the first plate 225 . The two shafts 2273 and the helical spring 2271 are received in the shell 2272 . The shell 2272 is fixed to the first plate 225 with screws (not labled). In this situation, the shaft 2273 is capable of moving along the positioning slot 2281 when the operating portion 2276 is operated. In a normal state (no external force is applied to the operating portion), the locking portion 2277 seals the second hole 2252 .
[0020] The elastic member 228 includes a hook 222 , an elastic piece 223 , a first rivet 2241 , and a second rivet 2242 . The hook 222 includes a substantially rectangular rotating board 2221 , a protrusion 2222 , a block 2223 , a resisting portion 2224 , and a locking piece 2225 . The protrusion 2222 extends from a first end (not labeled) of the rotating board 2221 . The block 2223 protrudes from the first end of the rotating board 2221 , and is adjacent to the protrusion 2222 . The resisting portion 2224 extends upwards from an edge of the rotating board 2221 . The locking piece 2225 includes an operating plate 2226 and a locking plate 2227 . The operating plate 2226 extends upwards from a second end (not labeled) opposite to the first end of the rotating board 2221 . The locking plate 2227 substantially perpendicularly extends from the edge of the operating plate 2226 that is away from the protrusion 2222 . The locking plate 2227 defines a locking slot 2228 therethrough, corresponding to the locking portion 2277 of the shaft 2273 . The rotating board 2221 forms a fixing hole 2229 between the protrusion 2222 and the resisting portion 2224 .
[0021] The elastic piece 223 includes a fixing portion 2231 and an elastic portion 2232 . The fixing portion 2231 is substantially “FIG. 8 ” shaped. The elastic portion 2232 is substantially “L” shaped, slanting outward from the middle of the fixing portion 2231 . In assembly, the first rivet 2241 is mounted on the second plate 226 , near the strip slot 2263 . The second rivet 2242 runs through the strip slot 2263 and is mounted to the fixing hole 2229 , with the fixing portion 2231 of the elastic piece 223 intervened between the first and second rivets 2241 and 2242 . In this case, the elastic portion 2232 of the elastic piece 223 is resisted at the third slot 2253 of the first plate 225 , and partially protrudes out of the third slot 2253 . Meanwhile, guided by the second rivet 2242 , the hook 222 can move along the strip slot 2263 . The locking device 30 is connected to the chassis 20 by screws (not labeled).
[0022] Referring to FIGS. 1 to 4 , in operation, the computer 40 is received in the second cavity 217 of the chassis 20 . Then the top wall 213 and the back wall 214 cover the computer 40 , with a number of second connection parts 41 of the computer 40 extending out of the connection slots 2141 . The chassis 20 is then arranged in the first cavity 14 of the rack 10 , thereby the second connection parts 41 are connected to the first connection ports 121 of the rack 10 . After that, an external force pushes the operating plate 2226 , so that the hook 222 rotates about the second rivet 2242 . The locking plate 2227 then passes through the second slot 2252 , and is locked in the locker 227 by the engagement of the locking portion 2277 and the locking slot 2228 . Meanwhile, the resisting portion 2224 seals the third slot 2253 , the protrusion 2222 is then engaged with the receiving slot 115 of the rack 10 . Thereby, the computer 40 , the lock device 30 and the chassis 20 is locked in the rack 10 .
[0023] In this situation, the elastic portion 2232 of the elastic piece 223 resists the resisting portion 2224 of the hook 222 , generating a force between the elastic piece 223 and the resisting portion 2224 . As the hook 222 engages with the receiving slot 115 , which makes it unable to move along the direction shown as the arrow 50 , and the second rivet 2242 can move along the strip slot 2263 , the force generated by the elastic piece 223 then forces the locking device 30 and the chassis 20 to move along the strip slot 2263 , opposite to the arrow 50 . Therefore, when vibration or inaccuracy in the process of fixing the chassis 20 into the rack 10 occurs, the chassis 20 will move towards the first connection ports 121 automatically, which ensures a reliable connection between the first and the second connection ports 121 and 41 .
[0024] Also referring to FIG. 5 , when taking out the chassis 20 , the two operating portions 2276 of the two shafts 2273 are pushed towards each other. Then the locking portion 2277 slides out of the locking slot 2228 of the hook 222 . Resisted by the elastic portion 2232 of the elastic piece 223 , the resisting portion 2224 bounces off the third slot 2253 , which makes the locking plate 2227 come out of the second slot 2252 automatically. During the locking plate 2227 coming out of the second slot 2252 , the block 2223 of the hook 222 resists the end of the receiving slot 115 away from the locking device 30 . Under the counterforce of the side wall 216 , the chassis 20 can be easily taken out of the rack 10 .
[0025] It should be understood that the chassis 20 could also be used for housing other electronic components, not limited to computers 40 .
[0026] It will be understood that the above particular embodiments is shown and described by way of illustration only. The principles and the features of the present disclosure may be employed in various and numerous embodiment thereof without departing from the scope of the disclosure as claimed. The above-described embodiments illustrate the scope of the disclosure but do not restrict the scope of the disclosure. | A server rack assembly includes a rack, a chassis, and a locking device. The rack has two side plates each defining a receiving slot. The chassis receives an electronic component, and is received between the side walls. The locking device includes a bracket, a locker, and two elastic members. The bracket is positioned at an end of the chassis and adjacent to the receiving slot. The locker is fixed to the center of the bracket. The two elastic members are fixed to two opposite ends of the bracket. Each elastic member includes a protrusion and a locking piece at two opposite ends thereof. The elastic member is capable of rotating between a first position where the locker locks the locking piece and the protrusion is received in the receiving slot, and a second position where the locker unlocks the locking piece and the protrusion is released from the receiving slot. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 10/669,103, filed on Sep. 23, 2003, which was a continuation of U.S. patent application Ser. No. 09/998,098 filed Nov. 30, 2001, which was a continuation of U.S. application Ser. No. 09/465,277, filed Dec. 16, 1999 which was a continuation-in-part of U.S. patent application Ser. No. 09/327,590 filed on Jun. 8, 1999, now U.S. Pat. No. 6,277,037 which was a continuation-in-part of U.S. patent application Ser. No. 09/146,476 filed Sep. 3, 1998, now U.S. Pat. No. 5,938,544 which was a continuation of 08/943,584 filed on Oct. 3, 1997, now U.S. Pat. No. 5,823,891.
BACKGROUND OF THE INVENTION
[0002] As indicated in the September, 1996 issue of “Golf Digest”, hitting golf balls into the water occurs with a great degree of frequency. As a result, an entire industry has developed in the recovery of golf balls which are then resold despite the fact that the ball has spent a fair amount of time in the water. While the golf ball cover seems to be fairly impervious, the question has become as to the effect of the immersion of the ball over a number of days at the bottom of a pond laying in the mud.
[0003] As will be appreciated, golf balls come in two varieties, a three-piece ball and a two-piece ball. According to the above article, when such balls were tested using a robotic hitting machine and a standard length metal driver with a 9.53 degree loft and an extra stiff shaft, with a club head speed 93.7 miles per hour and a launch angle of 9.0 degrees and with a spin rate of 2,800 rpm, the result for a three-piece ball was a difference in carry of 6 yards after an eight day immersion, a 12 yard loss after three months and a 15 yard loss after six months.
[0004] For a two-piece ball, the amount of carry was 6 yards shorter and after having been immersed for eight days was a total of 9.1 yards shorter. While for two-piece balls being in the water typically makes the ball harder in terms of compression, it also shows down the coefficient of restitution or the ability of the ball to regain its roundness after impact. The above factors make the ball fly shorter. Three-piece balls have been found to get softer in terms of compression, but they also fly shorter according to the above-mentioned article.
[0005] Whatever the results of the immersion of a golf ball in a pond, the characteristics of the ball in flight are altered by the immersion. The problem therefore becomes one of being able to determine when a golf ball has been immersed so that it may be reflected in favor of a new golf ball.
[0006] Note that golf ball construction is shown in the following U.S. Pat. Nos. 5,609,953; 5,586,950; 5,538,794; 5,496,035; 5,480,155; 5,415,937; 5,314,187; 5,096,201; 5,006,297; 5,002,281; 4,690,981; 4,984,803; 4,979,746; 4,955,966; 4,931,376; 4,919,434; 4,911,451; 4,884,814; 4,863,167; 4,848,770; 4,792,141; 4,715,607; 4,714,253; 4,688,801; 4,683,257; 4,625,964; 4,483,537; 4,436,276; 4,431,193; 4,266,772; 4,065,537; 3,704,209; 3,572,722; 3,264,272.
SUMMARY OF INVENTION
[0007] In order to alleviate the problem of having to deal with balls which may have been immersed and recovered, in the subject invention a golf ball is provided which changes color, has imprinted writing which disappears or has some other indicia which changes after immersion to indicate that the ball has been immersed.
[0008] In the present invention, in one embodiment, imprints on the ball are made with water-activated ink which vanishes when it is exposed to water for long periods of time. In another embodiment, imprints on the ball are made with water-activated transparent ink which appears when it is exposed to water for long periods of time. The invention is thus used as an indicator of balls previously exposed to water to for one to several days in the bottom of a lake, pond, pool or other body of water. Such an indicator is used to alert golfers to potential changes in ball properties due to long water exposure times.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] These and other features of the subject invention will be better understood when taken in conjunction with the Detailed Description the Drawings of which;
[0010] FIG. 1 is a diagrammatic illustration of a golfer hitting a golf ball into a water hazard;
[0011] FIG. 2 is a diagrammatic illustration of the ball of FIG. 1 after immersion in water, showing a visual indicator that the ball has been immersed in water for an extended period of time;
[0012] FIG. 3 is a diagrammatic illustration of a two piece ball which provides a visual indicator of elongated water immersion in which the ball includes a solid rubber core and a hard molded shell of an ionomer or ionomer blend such as Surlyn or a similar appropriate polymer resin, with the ball being provided with a conformal overcoat polymer dispersion containing encapsulated dye particles that goes over the shell or mantle of the ball, and with this overcoat then being covered with a final gloss coat containing no dye particles to maintain high gloss finish and provide an additional diffusion barrier on the ball to prevent dye release in humid or moist environments;
[0013] FIG. 4 is a diagrammatic illustration of a three piece ball which provides a visual indication of elongated water immersion in which the ball includes a solid, liquid or gel, a wound rubber band or molded rubber outer core and a shell of a glossy rubbery material such as balata rubber, polybutadiene blends or low shore hardness ionomer and an additional overcoat layer of polymer/encapsulated dye underneath the gloss final coat;
[0014] FIG. 5 is a schematic diagram depicting diffusion of water into the ball when it is immersed in a body of water for long time periods;
[0015] FIG. 6 is a diagrammatic representation of an encapsulated dye particle;
[0016] FIG. 7 is a diagrammatic illustration of another type two piece of golf ball;
[0017] FIG. 8 is a diagrammatic representation of dye pellets used in the subject system;
[0018] FIG. 9 is a perspective view of a golf ball with a water activated vanishing ink; and
[0019] FIG. 10 is a perspective view of a golf ball with a water activated ink which appears when the ball is immersed.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] Referring now to FIG. 1 , in a typical situation, a ball 10 has been hit by a golfer 12 into a water hazard 13 , where it resides until it is plucked out either by the golfer or by a company which retrieves golf balls from water hazards. It will be appreciated that, as mentioned before, such balls when immersed for a long period of time lose their flight characteristics, and regardless of their being washed and resold, will not regain these characteristics due to the immersion.
[0021] In order to provide an indicator of golf balls that have been immersed in water for some time, and referring now to FIG. 2 , it can be seen that golf ball 10 is provided with a mottled appearance 15 , which serves as an indicator that the ball has been immersed in water.
[0022] It is this or some other indicator which is water activated that provides a convenient method for the purchaser of a golf ball to ascertain that the ball is in fact a used ball and one which has been immersed in water for some time or has been subjected to some other predetermined condition.
[0023] As will be described, in one embodiment this distinctive discoloration or indication is provided through the utilization of water soluble inks or dyes which are activated through the infusion of water into encapsulated dye particles in one embodiment. The result of the infusion of water is that the dye particles emit their dyes to mark the golf ball in some distinctive manner. Whether it is with dyes or inks which are water soluble or are released upon water activation, it is immaterial as to what type of indication is given so long as the golfer purchasing the golf ball can ascertain that it is in fact one that has been immersed in water or is otherwise unsuitable for play.
[0024] It is noted that controlled release technology is a well-proven means of slowly delivering a small amount of a compound over a given time period or at a specific time based on a desired stimulus. In the subject invention controlled release technology is used as an approach to the slow color change of a golf ball in water. The subject invention, in one embodiment, involves the use of inks or dyes which are micro-encapsulated with a thin polymer coating to form small particles or beads. These micro-capsules, which may vary in size from tens of microns to millimeters, can be incorporated into a hard, glassy polymer coating material such as polymethyl methacrylate or polyvinyl acrylate ester, which can act as a gloss coat for the ball, or the encapsulant can be incorporated into the rubber or ionomer cover of the ball itself.
[0025] A microencapsulant is a polymer coating used to enclose a liquid or solid material within a small particle. Micro-encapsultants are generally in the range of tens to hundred of microns in diameter. Encapsulation approaches have been used for a number of applications in which a compound must be slowly but systematically released to an environment under the desired conditions. Examples include microcapsules in drug delivery, vitalizing nutrients or proteins in time release cosmetic products and fertilizers or pesticides for agricultural products.
[0026] The polymer coating may consist of a broad range of potential polymeric materials and polymer blends. The basis for most controlled release technology is the slow diffusion of the encapsulated product through the polymer coating or matrix and into the surrounding environs. The driving force for diffusion is mass transfer from the highly concentrated interior to the dilute exterior regions. The diffusion process is often accelerated or activated by the presence of a solvent that swells or partially solvates the polymer film, thus plasticizing the polymer film and increasing the effective diffusivity of the polymer matrix. The result is a faster rate of transport of the encapsulated material out of the microcapsule.
[0027] A second route to controlled release systems is the slow dissolution of an uncrosslinked or linear polymer coating in a good solvent, resulting in the release of the encapsulated compound as the coating walls become thinner and ultimately dissolve completely. In this case, the dissolution rate of the polymer, rather than the diffusion rate alone, is the rate determining step in the release of the encapsulant.
[0028] A third approach to the controlled release of a material is macro-encapsulation. In this case, the material is slowly released from a continuous polymer matrix, which may be molded into any number of shapes or objects. The primary difference between this approach and that of microencapsulation is that in the latter, the material is enclosed in well defined microspheres on the order of magnitude of several microns, whereas in macroencapsulation, the material of interest is directly enclosed in an object of the order of magnitude of centimeters and greater. Both of these approaches involve the slow diffusion of the material out of the matrix or the encapsulant shell.
[0029] Referring now to FIG. 3 , in one embodiment of the subject invention a conventional two piece ball 10 with a solid rubber core 12 illustrated having a hard molded shell 14 of an ionomer blend such as Surlyn, or a similar polymer resin. As can be seen, a conformal overcoat polymer dispersion 16 contains encapsulated dye particles 10 , with the dispersion going over the shell or mantle of the ball.
[0030] This overcoat is then covered with a final gloss coat 20 containing no dye particles to maintain a high gloss finish and provides an additional diffusion barrier on the ball to prevent dye release in humid or moist environments.
[0031] Likewise, for a three piece ball as illustrated in FIG. 4 , the three piece ball 30 is provided with a solid, liquid or gel inner core 32 , a wound rubber band or molded rubber outer core 34 and a shell 36 of glossy rubber material such as balata rubber, polybutadiene blends or low shore hardness ionomer.
[0032] Note that an additional overcoat layer 36 of polymer/encapsulated dye is formed underneath the final gloss coat 38 .
[0033] Referring to FIG. 5 and as will be described, a schematic diagram depicts the diffusion of water 50 into ball 10 when it is immersed in a body of water for a long period of time. Water molecules slowly diffuse as illustrated at 51 into the ball through gloss overcoat 52 . In some cases, dye capsules 54 in layer 56 will exist close to the gloss overcoat and away from the shell here illustrated at 58 . Water will permeate these capsules first and will then take longer to diffuse to capsules in the bulk of the layer 56 . The water will slowly seep into or solvate the microencapsulant allowing controlled diffusion of a water soluble dye out of the polymer microcapsule and gloss overcoat 52 , staining the overcoat. Over time, water will diffuse across the layer into the ionomer shell 58 where the ionomer resin will permanently absorb the dye resulting in a deep color change.
[0034] A number of different polymers and blends of polymers may be used for microencapsulation coating, including polymethyl methacrylate, polymethacrylic acid, polyacrylic acid, polyacrylates, polvacrylamide, polyacryldextran, polyalkyl cyanoacrylate, cellulose acetate, cellulos acetate butyrate, cellulos nitrate, methyl cellulose and other cellulose derivatives, nylon 6,10, nylon 6,6, nylon 6, polyterephthalamide and other polyamides, polycaprolactones, polydimethylsiloxanes and other siloxanets, aliphatic and aromatic polyesters, polyethylene oxide, polyethylene-vinyl acetate, polyglycolic acid, polylactic acid and copolymers, poly(methyl vinyl ether/maleic anhydride), polystyrene, polyvinyl acetate phthalate, polyvinyl alcohol) polyvinylpyrollidone, shellac, starch and waxes such as paraffin, beeswax, carnauba wax. Polymers used should have a near zero diffusivity of the ink through the polymer matrix in the absence of water. Upon the introduction of water in the surrounding matrix and the subsequent diffusion of water through the polymer film, the diffusivity of the polymer coating for the dye molecules increases, allowing transport of the dye across the polymer film. The ideal polymer systems for this application are those which have a limited permeability to water and thus provide a longer range of diffusion times before releasing the water soluble dye. Such polymers could be crosslinked or uncrosslinked blends of a hydrophobic and a hydrophilic polymer, segmented or block copolymer films with a hydrophilic block or polymers which are not soluble in water, but have a small but finite affinity for water. Such polymers include nylons such as nylon 6,10 or nylon 6, polyacrylonitrile, polyethylene terephthalate (PET), polyvinyl chloride. More water permeable polymers which may be blended with hydrophobic polymers to adjust the dye and water permeability coefficients of the film include cellulose derivatives, polyacrylates, polyethylene oxides, polydimethyl siloxane and polyvinylalcohol.
[0035] Dyes that may be used should be water-soluble and may vary from a broad range of industrial dye materials. Ideally, the dye should be compatible with the polymer used for the shell or mantle underneath the dye-encapsulant coating. Ionic and a number of water soluble dyes would be particularly compatible with ionomer materials commonly used in such mantles due to the presence of carboxylate and carboxylic acid groups in the polymer. Some dye systems change color in the presence of more polar solvents. This effect may be useful if the dye has very little color until exposed to water. Some potential dyes for this application might include merocyanine dyes and pyridinium-N-phenoxide dyes. Examples may include Napthalene Orange G, Crystal Violet, CI Disperse Red and a number of other common industrial dyes. Dyes of larger molecular weight may be desirable, as higher molecular weight dyes diffuse more slowly through a polymer matrix.
[0036] Prior to water exposure, the water-soluble dye is enclosed by a rigid solid polymer film, which is immersed in a nonaqueous medium, with a very low driving force and a high resistance to diffusion through the coating. As shown in FIG. 5 , on exposure to water for long time periods, water will slowly diffuse into polymer layer 56 and thence, through microcapsule 60 to dye particle 62 as shown in FIG. 6 . The diffusion of the dye out of layer 56 can be modeled using basic mass transfer laws. Note, the rate at which dye diffuses out of the capsule is shown in FIG. 6 to be related to R out and R in for a dye capsule 60 which encapsulates a dye particle 62 . Fick's first law is commonly used to model the diffusion process. At steady state, the mass transfer of dye from the microcapsule can be modeled using the equation below:
ⅆ M ⅆ t 4 T T D K Δ C RoRi ( Ro - Ri )
where dM/dt is the rate of transfer of dye with time, D is the diffusivity of the dye in the polymer layer, K is the solubility of the dye in the layer, C is the concentration difference of the dye in the microcapsule versus the exterior capsule, Ro is the outer diameter and Ri is the inner diameter of the capsule. For a microcapsule that is 50 microns in diameter, with an inner diameter of 45 microns, and thus a wall thickness of 5 microns, the time for diffusion of half of the dye through a polymer film such as nylon could range from ten to one hundred hours, depending on the relative solubility of the dye in the matrix. The diffusion times can be tailored using various polymers or polymers or polymer blends, as well as different materials. Processing the techniques, including the use of a thin secondary top coating layer of pure polymer containing no particles, can control the distribution of ink microparticles to prevent the immediate release of ink from microparticles that may be located at the surface of the ball.
[0037] The formation of microcapsules may be done using a number of technologies. These technologies include polymer coacervation/phase separation using the agitation of colloidal suspensions of insoluble polymer and subsequent isolation of microparticles in a nonaqueous medium. Polyamide and some polyester and polyurethane coatings may be formed using interfacial polymerization, using stabilizers to form stabilized microemulsions. Bead suspension polymerization techniques, again using nonaqueous nonsolvent medium, may be used for a number of polymers achieved through free radical polymerization of vinyl polymers such as polyacrylates or acetates, or copolymers. It may be necessary to “hide” the color of the dye, in the microencapsulant if the polymer coating is very transparent. In this case, the incorporation of white pigment in the polymer coating wall can be introduced during the encapsulation process.
[0038] After the dye microcapsules are prepared at the desired size and film thickness, the particles may be stored under a desicator, and dried under a vacuum with desiccant at least 24 hours prior to formulation with a polymer film to form an overcoat. The polymer medium for the overcoat can be a traditional gloss coating material such as a polyurethane or polyacrylate. Diffusion limitations of water to the particles will vary with the choice of polymer medium for both the overcoat and gloss coat. Preferred materials may include polyurethanes, polymethyl methacrylate, polyethlyl methacrylate, polybutadiene and various polyvinyls. The particles must be blended in the polymer overcoat film under dry conditions with a humidity of 50% or lower, at loadings of 1 to 30%. The conditions of dispersion may be at temperatures below the flow temperature of microsphere polymer coating, or in an overcoat polymer-solvent mixture with a solvent that cannot dissolve the microsphere polymer coating. Alternatives include the use of crosslinked microspheres, which cannot dissolve or flow under heat, or the use of a crosslinkable liquid monomer or prepolymer. The overcoating can be dip coated or spraycoated onto the ball and cured. A second gloss coating containing no particles may then be applied to the ball. The coating thicknesses of the overcoat and gloss should approximate the thickness of traditional gloss coatings used on conventional golf balls.
EXAMPLE 1
[0039] In one configuration, the golf ball can be a two piece golf ball consisting of a wound rubber core and a thick Surlyn ionomer cover containing TiO 2 , powder and blue as a brightener. Then a translucent coating containing dye particles can be applied. This coating will consist of a soluble nylon, polyester, PET or other barrier coating blended with 5% of dye encapsulant material. If the encapsulated form of the dye is colored, some TiO 2 may be added to this layer to ensure whiteness is preserved. Finally, a final gloss coating will be added to the outer layer. The layers important to color change in the ball are the two outermost layers, which should be approximately 100 microns, or 0.1 mm, in thickness.
[0040] In the first embodiment, the dye used is a common water soluble dye, Nile Blue. This dye is a crystalline material at room temperature and is available as a granular powder containing crystals that are 20 to 40 microns in size. These solid crystals are hard and non-porous and small enough that when dispersed in a matrix at low concentrations, there will be no detected color change. The individual dye particles would be encapsulated with a gelatin coating using gelatin coacervation in an organic solvent to prevent water solubilization of the dye molecules; procedures for coacervation are well-known, and have been used in drug encapsulation and in the cosmetics and agricultural industries for many years. The encapsulated dye would then be isolated and added in a 1% by mass concentration to a polymeric gloss coating such as a polyurethane or polyester gloss coat. The two piece Surlyn coated ball would be dip-coated with the gloss coat resin which would then be dried during a solvent removal process using heat and/or air flow; the overcoat layer should be approximately 100-200 microns thick. A second layer of gloss coating such as polyurethane could then be added using a spray-coating method. This second layer would be added to provide one additional barrier to moisture and to ensure an even gloss coating. The thickness of the gloss coating should be approximately 100 microns thick.
[0041] The resulting ball would thus contain a water-soluble dye encapsulated in thin film barrier. Permeation of water through a 100 micron thick polymer film, such as a polyurethane with a DK or diffusivity times solubility of 60 m2/sec-Pa would result in a diffusion half time for water of approximately 10 to 12 hours. The water would then be able to access the dye particles in the second layer containing dye encapsulant. The time for permeation of water through the gel encapsulant, assuming an inner radius of 40 microns and an outer radius of 50 microns, for a typical gelatin encapsulant, would be on the order of 5 to 6 hours, resulting in a color change after exposure to water of 16 to 18 hours, or essentially overnight. The time for permeation may be increased by using encapsulants or gloss barrier coatings with lower permeabilities. A nylon based overcoating would result in diffusion half-times approximately 100 times longer and the color change would then take place over the period of 100 to 160 hours or several days.
EXAMPLE 2
[0042] A second embodiment involves the use of a dye particle encapsulated in a water-soluble polymer such as polyethylene oxide or poly acrylic acid, by formation of a mixture of hard dye particles in a fluid prepolymer. The prepolymer could be, for example, a water soluble polyacrylamide resin with a temperature activated initiator and bisacrylamide crosslinker agent. The mixture would be added dropwise to an incompatible organic solvent such as toluene with an emulsifying agent such as polyvinyl alcohol with stirring at high speeds. The emulsified drops are polymerized when the emulsion is heated, and the resulting beads contain dye particles. This process can be adjusted to produce dye beads in varying sizes. 100 micron size beads would be produced for this application. The resulting beads should not be colored because the bead formation process is done in the absence of water under controlled conditions. The resulting beads are then isolated, and added in 1% by weight to a polyurethane gloss coating followed by a second barrier gloss coating. In this case, dye diffusion, would be dependent solely on the thickness of the outer barrier coating. Once, water reaches the dye particles, the polyacrylamide beads would swell, and dye diffusion through the polyacrylamide beads would be very rapid, resulting in the release of a very strong dye in the golf ball overcoating. As described in the first embodiment, diffusion through a barrier gloss coat could range from 10 to 100 hours depending on the polymer chosen for the coating. Polymers of choice include polyurethanes and nylons such as Nylon 6,6, Nylon 6 and Nylon 6,10.
[0043] EXAMPLE 3
[0044] In a third embodiment, a colorless compound called a color former is used. Color formers are converted to strong dyes when exposed to a developer. The developer is a slightly acidic clay or resin which absorbs or dissolves the color former and results in a colored dye.
[0045] This technology is extremely well developed and has been used for thermal printing, electrochromic printing, and pressure sensitive (carbonless copy paper) industries. Colors achieved with these dyes include very deep black and blue shades that would be easily recognized against a white golf ball.
[0046] In this invention, the developer would be mixed in the gloss resin along with encapsulated particles containing the color former. Water diffusion would activate the developer, and water and developer would diffuse into the microparticle containing the color former. The resulting dye would then be released from the microparticle. In this example, a common color former known as Crystal Violet Lactone, which goes from colorless to blue in the presence of the developer, is encapsulated in a nylon microcapsule using interfacial polymerization.
[0047] In the polymerization process, the color former, which is organic and non-water soluble, is contained in an organic phase with a diacid chloride which is then contacted with a diamine in aqueous solution containing a weak base. The resulting emulsified droplets become microparticles for the carbonless copy paper industry and is well documented. A gloss resin can often be formulated to contain a commercially available color developer. A common developer is bisphenol A, which is cheap and fairly easy to process. A second choice, which is more effective developer and thus requires smaller quantities, but is more expensive, is zinc salicylate. Both compounds can be added to the encapsulant containing inner coating in small quantities—1 to 5 wgt. %.
[0048] The water diffusion process will involve the solubuilization of the water soluble developer. The water then acts as a carrier of the developer and delivers it via diffusion to the color former in the microparticles. The dye is then converted to a colored water soluble dye, which can diffuse out of the microparticle to produce a colored ball. For this example, the diffusion rates are dependent on the thickness of a second, barrier coating of polyurethane or nylon, which regulates the speed with which water reaches the first color former microparticles which again can be adjusted from 10 to 100 hours. The intensity or effectiveness of the system may be improved by putting the developer in, this outer coating, while the encapsulated color former remains in the inner coating.
[0049] All of the above examples involve the formation of a two layer gloss coating on the golf ball. The resulting release of dye from the inner layer will result in the coloration of the gloss coat and the underlying golf ball cover. The described invention may be used for detection of water absorption in two or three piece golf balls.
[0050] The processing steps required to manufacture golf balls are varied depending on the manufacturer and the final properties of this ball desired. This invention involves modification of the final finishing process steps in the manufacture of the golf ball. The application of the primer, label and the gloss coat are replaced by:
1. Application of primer on the golf ball cover 2. Application of company logo or label 3. dip-coating of gloss coat with encapsulant particles onto ball 4. drying/solvent removal and/or cure of encapsulant containing gloss coat 5. spray coating of second gloss coat 6. drying or cure of second gloss coat
[0057] Spinning or air flow may be used to dry the first coat and ensure a uniform coating. The thickness of the second coat should be fairly well controlled to ensure the appropriate amount of time before color change is activated.
[0058] A golf ball has thus been described which contains dye particles which are activated by the presence of water, resulting in a color change marker which effectively destroys the appearance of the ball, alerting the consumer to balls which have been exposed to water for inordinate amounts of time, and the potential for poor ball performance.
[0059] EXAMPLE 4
[0060] The above describes the incorporation of dyes into an intermediate coating between the gloss coat and the golf ball cover. A different approach would involve the incorporation of dye into the golf ball cover itself. In this embodiment, illustrated in FIG. 7 , dye 60 may be incorporated into the ionomer ball cover of a two piece golf ball 62 as a solid particle or as an encapsulated dye. Here the ball has a core 64 and a shell 66 which acts as a cover. Dyes are used which exist as solid, crystalline dye particles that are 10 to 40 microns in diameter. If such dyes can be compounded with the ionomer at temperatures below the dye melt point, the dye particles should main suspended in the polymer matrix without adversely coloring the ball. Upon absorption of water into the ionomer cover, the dye would immediately begin to dissolve, producing a splotchy, colored appearance in the ball cover. In this case, the golf ball gloss coating 68 is the primary barrier to water, and as water permeates the gloss coating and begins to diffuse into the ball shell or cover 66 , color change will occur. The use of an encapsulated dye could be used to obtain better control of the discoloration process. The dye encapsulant used would have to be chosen to withstand the compounding conditions of the ionomer ball.
[0061] In a further embodiment, as shown in FIG. 8 , the dye or ink as the case may be can be provided in pelletized form as illustrated by pellets 70 for ease of manufacture. For instance, the dye can be compounded with polybutadiene or an ionomer resin respectively for a golf ball core or mantle/cover. The dye is compounded with surfactants or other additives to produce pellets which are then provided to the golf ball manufacturer to alleviate the need to handle otherwise volatile materials. The use of pellets also assures mixing in correct proportions for reliable dye release.
[0062] One skilled in the art is aware of the fact that there are various hues of the color white. Whereas, some embodiments include a noticeable change in that hue or color, other embodiments result in isolated changes in the appearance of the surface of the golf ball, such as to specific markings on the ball.
Over the years, golf balls have been marked with a wide variety of marking compounds. Most commonly, markings made to golf balls, such as the imprint of the manufacturer and/or brand names, are generally accomplished through a pad printing ink process. In another embodiment of the present invention, water-activated inks are used to effectuate a change in appearance to the golf ball in one of two ways: (i) a marking 80 that is transparent but appears after exposure to water as shown in FIG. 10 , or (ii) a marking 82 that is noticeable but vanishes upon exposure to water, as shown in FIG. 9 . A suitable water-activated ink that is initially transparent and then appears when immersed in water is available from United BioTechnology, Inc. of Akron, Ohio under the trademark AquaClear. A suitable ink that is noticeable on the ball but that disappears upon immersion is sold under the trademark Aqua-Destruct by Sun Chemical of Cincinnati, Ohio. Such inks may be combined with resins in order to establish precise controlled degradation or release of the components that result in visual changes in appearance. Additionally, colors may be adapted to suit manufacturing preferences.
[0064] In other embodiments, oxidation-reduction chemistry can be used to generate reactions involving a change in the oxidation state of atoms or ions which results from the “loss” or “gain” (or partial transfer) of electrons, and as a result one can compound an ink or dye-like material that vanishes after being submerged in water for a period of time. The transfer of electrons between the atoms of these elements result in drastic changes to the elements involved. Due to the formation of ionic compounds, the changes that occur in the oxidation state of certain elements can be predicted quickly and accurately by the use of simple guidelines. The result of a combination reaction can also be reversed; in other words, a compound can be decomposed into the components from which it was formed. This type of reaction is called a decomposition reaction. Several known chemical structures are susceptible to oxidation and reduction by water. By utilizing these structures within the composition of an ink, the appearance of the ink can be manipulated upon exposure to water. The net effect of these reactions is that the ink becomes transparent or vanishes as the composite atoms are converted to their original oxidized and reduced states.
[0065] Having now described a few embodiments of the present invention, and some modifications and variations thereto, it should be apparent to those skilled in the art that the foregoing is merely illustrative and not limiting, having been presented by the way of example only. Numerous modifications and other embodiments are within the scope of one of ordinary skill in the art and are contemplated as falling within the scope of the invention as limited only by the appended claims and equivalents thereto. | A golf ball is provided which changes color or other indicia after exposure to moisture to indicate that the ball may not have predictable flight characteristics which may result in loss of carry and roll. In one embodiment, a microencapsulated dye layer is formed immediately below the final gloss coat, with controlled dye release causing a stained look to the ball after significant exposure to moisture. In another embodiment, the dye or ink is provided in pelletized form for ease of manufacture. In other embodiments, a dye, ink, or chemical is compounded with other materials and introduced into or applied onto the golf balls composite materials in a solid, liquid, or gaseous form. In still other embodiments imprints on the ball are made with a water activated ink which either appears or disappears upon the exposure of the golf ball to moisture. | 0 |
TECHNICAL FIELD
This invention is related to the field of photography and more particularly to the recording of scene parameters magnetically on film on a frame-by-frame basis.
BACKGROUND OF THE INVENTION
The advantages of recording scene parameters on film contemporaneously with each exposure are well understood. For example, U.S. Pat. No. 4,702,580 teaches the recording on film of an indication that a group of frames thereon are related to the same scene. Such an indicator is readily used by the photofinisher to justify applying the same print exposure conditions to all of the film frames in the group, thereby keeping the scenes uniform in the prints returned back to the customer.
One disadvantage of the foregoing technique is that the series scene indication thus recorded on the film may not necessarily be reliable enough for a photofinisher to rely upon. For example, if it is the camera user himself who is to manually activate the means for recording the series scene indication on the film, the reliability of such an indication is limited by the skill of the camera user. Another disadvantage is that this type of technique is typically taught in connection with an optical recording technique using bar codes and the like. Thus, while the film itself serves as a memory in which to store the series scene indication, the film is merely a read-only memory following its development, when the series scene indication becomes readable. Accordingly, if any related information is to be stored by the photofinisher, he cannot use the film to do so.
Therefore, a problem which needs to be solved is how to record a series scene indication on film in the camera in a reliable manner such that a photofinisher can rely on such an indication in nearly all instances for selecting the scenes bearing such a series scene indication for printing with uniform print exposure conditions. Another problem is how to record series scene indications using the film as a memory in such a manner that the film remains useful as a memory in which further information related to the series scene indication may be stored as well as retrieved on the film by the photofinisher following development of the film. A third problem to be solved is how to record on the film a series scene indication for each frame wherever appropriate in such a manner that the indication is unambiguously associated with the corresponding film frame and readily acccessible to a photofinisher.
SUMMARY OF THE INVENTION
The foregoing problems are solved in the present invention, which is a system including a film having a magnetic layer, a camera having a magnetic recording device and a photofinishing system having a magnetic record and playback device. The camera recording device includes a processor connected to the camera shutter button and to a circuit which synchronizes the camera shutter and the autowind motor. The magnetic recording and Playback device in the photofinishing system includes a processor connected to a film scanner and to an exposure adjustable print exposure source.
In the camera, the synchronization circuit synchronizes the actuation of the camera shutter and the film autowind motor, so that each time the shutter is opened and then closed, the autowind motor rotates the take-up spool in the camera so that the film is transported until the next frame is adjacent the camera shutter. The shutter release button controls the operation of the synchronization circuit.
In operation, the processor intelligently senses whether the camera is in rapid fire mode. In this mode, the shutter button is held down continuously so that the synchronization circuit causes the shutter to open and close a number of times in quick sequence as the autowind motor rapidly moves successive frames past the shutter, stopping the film briefly during each exposure for the time required. For each frame in which the processor senses this to be the case, the processor instructs recording electronics to energize the camera's magnetic head each time the film is transported by the take-up reel by one frame, so that a predetermined code indicating a series scene is recorded by the magnetic head in a magnetic track lying within or adjacent the current film frame. The magnetic track preferably extends longitudinally along one edge of the film adjacent the individual frame, the track starting and stopping within a length spanned by the frame. The magnetic track in which the series scene indication code is recorded may be particularly dedicated to the recording of scene indications such as the series scene indication discussed here.
In the photofinishing system, a processor is connected to receive data from an automatic film scanner and to transmit commands to an exposure adjustable print exposure source. As each frame in the developed film is positioned adjacent the film scanner, the film scanner determines the pixel density for each one of three primary colors (e.g., red, green and blue) as well as the pixel density for luminance or gray.
Using techniques well-known in the art, the photofinishing system processor computes from the color density data the optimum exposure values for gray and the three primary colors which are optimum for that particular frame. The processor then sends color adjustment commands to the color adjustable print exposure source. A frame on a photosensitive print paper is then exposed to the current film frame by the color adjustable print exposure source in accordance with the color adjustment signals transmitted by the processor.
In the invention, the photofinishing processor is also connected to magnetic record and playback electronics controlling a magnetic head positioned to read and record in previously recorded tracks on the film, such as the magnetic tracks recorded by the camera described above. The processor monitors the magnetic data read out by the magnetic head to determine whether a series scene indication was recorded for any particular frame on the film. If it was, the processor at first does not compute the optimum primary color exposure values for that frame. Instead, the processor postpones this step and instead compares the data obtained from the film scanner with the same type of data obtained for previous frames on the film. Unless there is a large deviation between such data, the processor then assumes that the series scene indication is valid with respect to the present frame and that the print exposure primary color values previously computed for a given one of the earlier frames in the series may be validly applied to the current frame. Accordingly, the processor, which has stored the previously computed exposure values, retrieves these values from storage and transmits them to the print exposure source for exposing of the current frame. On the other hand, if the scanning data obtained for the current frame deviates from the scanning data obtained for previous frames in the current series scene group of frames, the processor then assumes that this particular frame deviates from the series scene group, so that its optimum exposure values need to be computed individually instead of using the exposure values stored for the group of series scenes of which the current frame is a member. An example of this might be a group of series scenes shot in rapid fire sequence by the camera, during one frame of which a lightning strike occurs.
In one embodiment of the invention, the processor always stores the latest set of film scanning data and print color exposure values computed therefrom for use in subsequent frames in the event a series scene indicator code is sensed by the magnetic head. In one embodiment, this memory is simply a semiconductor memory connected to the processor. In another embodiment of the invention, this memory is the magnetic layer in the film, the data otherwise recorded a memory being recorded instead by the photofinisher magnetic head in a dedicated magnetic track on the film. In this embodiment, as the photofinisher inspects each frame, it magnetically records the scanning data as well as the print exposure values computed therefrom, so that in any given frame the magnetic track may include the following data: a series scene indication, film scanning data, and optimum print exposure values for the primary colors and gray. In accordance with the foregoing description, only the first frame in a group of frames bearing successive series scene indications will have print exposure values recorded in its magnetic track(s).
DESCRIPTION OF THE DRAWINGS
The invention is best understood by reference to the accompanying drawings, of which:
FIG. 1 is a simplified schematic block diagram illustrating a camera embodying one aspect of the invention;
FIG. 2 is a plan view indicating the location of the parallel dedicated magnetic tracks with respect to the image frames on the film for use in the camera of FIG. 1;
FIG. 3 is a simplified schematic block diagram illustrating a photofinishing system embodying another aspect of the invention;
FIG. 4 is a flow chart illustrating the operation of the Processor in the camera of FIG. 1; and
FIG. 5 is a flow chart illustrating the operation of the processor in the photofinishing system of FIG. 3.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a camera embodying the invention includes a take-up reel 10 around which a length of film 12 is wound so as to be transported past a camera shutter 14. The take-up reel is actuated by an auto wind motor 16. Shutter and auto wind motor synchronization circuit 18 responds to a shutter release button 20 so that, whenever the camera user pushes the shutter button 20 down, the shutter 14 opens to a predetermined aperture size for a predetermined exposure time, and immediately at the end of the exposure, the auto wind motor 16 rotates the take-up reel 10 so that the film 12 is transported Past the shutter by the pitch of one film frame. The invention includes a magnetic head 22 connected to recording electronics 24 controlled by a processor 26. The processor 26 responds to the activation of the shutter release button 20 and to the activation of the synchronization circuit 18.
The magnetic head 22 is controlled by the processor 26 through the recording electronics 24 so as to record in a magnetic track adjacent each frame on the film a series scene indication whenever the shutter button 20 is held down so that the synchronization circuit 18 operates the shutter 14 and the auto wind motor 16 in a rapidfire mode. The rapidfire mode occurs whenever the shutter button 20 is held down continuously over a number of frames or by the shutter button 20 being pushed rapidly up and down several times in rapid succession. FIG. 2 illustrates the magnetic tracks 30 adjacent each frame 32 of the strip of film 12. Each track 30 is longitudinal and parallel with the direction of the length of the film 12. There may be more than one track, FIG. 2 illustrating plural dedicated magnetic parallel tracks adjacent each frame 32. One of the tracks 30 is dedicated to the recording of a series scene indication.
The operation of the camera processor 26 is illustrated in FIG. 4. The algorithm illustrated in FIG. 4 is executed automatically by the processor 26 in accordance with instructions stored therein. First, the processor senses the shutter button 20 being pushed down or "on" and also senses the synchronization circuit actuating the shutter 14 and then actuating the auto wind motor 16. During the sequence, as soon as the shutter button 20 is released up or "off" for a minimum amount of time, the processor 26 sets an internal flag. This internal flag signifies that a rapidfire mode is not in effect with respect to the next picture frame. The processor 26 then senses the next time that the synchronization circuit 18 actuates the shutter 14 and then starts the onset of the auto winding of the film by the auto wind motor 16. At this point the processor 26 inquires whether the flag is set. If the flag is set, processor 26 returns to the initial state it was in at step 40 (the YES branch of block 46). On the other hand, if the flag is not set at this point (NO branch of block 46), the processor 26 concludes that the camera auto wind motor 16 and shutter 14 are operating in the rapidfire mode under the control of the synchronization circuit 18. Therefore, the processor 26 records a series scene indication as a coded symbol in a predetermined one of the dedicated magnetic tracks 30 on the film 12 as the film begins its movement to bring the next frame adjacent the shutter 14. A series scene indication signal is transmitted from the processor 26 to the recording electronics 24 where it is transformed to a channel encoded signal, transmitted to the magnetic heads 22 and recorded on the film 12. This being accomplished, the processor 26 returns to its original state at the beginning of step 40.
Referring to FIG. 3, the photofinishing system of the invention includes a processor 50 which receives sensiometric data regarding each frame of the film 12 from a film scanner 52. The processor 50 also transmits exposure values for various predetermined colors to a print exposure source 54. In addition, the processor 50 is connected through a record/playback electronics 56 to a magnetic head 58 positioned to read and write data to or from magnetic tracks 30 in the film 12 as it is transported through the photofinishing system of FIG. 3. Each frame 32 on the film 12 is first positioned adjacent the film scanner 52. The film scanner 52 measures the light intensity, and by inference the film pixel density, for each of three primary colors and gray in the film frame using a known light source transmitting light from the other side of the film. The processor 50 receives this photosensiometric data and, using well-known techniques computes the desired exposure values for a print to be made from that frame for the three primary colors and gray. Processor 50 then transmits commands to the exposure source 54, the commands signifying the amount: of red, green, blue and gray exposure values for light to be transmitted through the current frame to a frame on a roll of photosensitive paper 61. The processor continually monitors the signals read by the magnetic head from the magnetic tracks 30 on the film 12 so as to be alerted whenever a series scene indication is present in the magnetic tracks adjacent one of the frames 32. If the processor 50 senses a series scene indication it immediately postpones computation of the optimum exposure values from the photosensiometric data sensed by the film scanner 50 in the current frame. Instead, the processor 50 compares the photosensiometric data sensed by the scanner 52 with the photosensiometric scanner data recorded measured from a previous frame and stored in a memory 60. If the processor 50 determines that there is no significant deviation between the current and previous photosensiometric scanning data the processor 50 retrieves from the memory 60 the print exposure values already computed from the previous photosensiometric scanning data stored in the memory 60, translates these values to commands which are then transmitted to the exposure source 54 and used to expose the next print on the paper 61 from the current frame on the film 12. For this purpose, the processor 50, in the absence of a series scene indication, always computes the optimum print exposure values from the photosensiometric data received from the film scanner 52 and automatically stores both the photosensiometric data and the optimum print exposure values in the memory 60 for possible use in printing subsequent frames. In the absence of a series scene indication recorded in the next frame, the current contents of the memory 60 is erased and replaced by the same type of information corresponding to the next frame in the film 12. This record and erase process is suspended as soon as a successive group of frames is encountered bearing the series scene indication code in their magnetic tracks. Then, the most recent print exposure value stored in the memory 60 is used to expose all of the frames in the series. The exception is individual frames in the series whose photosensiometric scanning data deviates significantly from that of the group in the series. For such a deviant frame, an individual set of print exposure values is computed from the photosensiometric data sensed for that frame, the print exposure values thus computed being used to print that frame only, the data stored in the memory 60 being used to print the rest of the frames in the series which do not deviate from the photosensiometric values of the group.
This operation is best illustrated in FIG. 5. The film 12 is transported so that the next film frame therein is adjacent the scanner 52 (step 500). As the film is thus transported, the magnetic head 58 reads the magnetic tracks in that frame, the data being transmitted to the processor 50 (step 502). Then, the processor 50 receives the photosensiometric data for the current frame from the film scanner 52 (step 504). The processor 50 then determines whether a series scene code is present in the magnetic track or tracks of the present frame (block 506). If not, the processor 50 in step 508 determines the optimum print exposure values in the primary colors from the photosensiometric data sensed by the scanner 52 from the current film frame. The photosensiometric data and the optimum exposure values are stored by the processor 50 in the memory 60 and a previous such exposure values, photosensiometric data for previous frames being erased or flagged as no longer applicable. The exposure values thus determined in step 508 are used by the exposure source 54 to expose the current film frame (step 512). If, on the other hand, in step 506 the processor 50 determined that a series scene code was present in the magnetic tracks of the magnetic frame (YES branch of block 506), then the processor 50 determines whether the photosensiometric data of the current frame is consistent with the photosensiometric data for a previous frame last recorded in the memory 60. If so (YES branch of block 514), the processor retrieves the exposure values previously stored in the memory 60 and sends these as commands to the exposure source 54 so that the current frame is exposed using the exposure values previously stored in the memory 60 (block 516). Presumably, these values correspond to the first frame in a series of frames exposed in rapidfire sequence by the camera.
If the processor 50 determines that a significant deviation between the photosensiometric data stored in the memory 60 and the photosensiometric data sensed by the scanner 52 from the current film frame exists, then (taking the NO branch of block 514), the processor 50 determines the exposure values from the photosensiometric data of the current frame (block 520), notwithstanding that it has a series scene indication recorded on it. It then uses these currently computed exposure values to expose the current frame (block 512), as if no series scene indication had been recorded for that frame. However, the exposure values and photosensiometric data previously recorded in the memory 60 for an earlier frame are retained therein in case subsequent frames are members of the same series scene group and may be exposed using the exposure value of the first frame in the group.
Therefore, the processor 50 returns to its original state at the beginning of step 500 in preparation for the next film frame.
Of course, it is not necessary to use just the exposure value of the first frame in a group of series scene frames. Instead, one could use the first several frames in the series scene frame group to construct an average set of exposure values used for the entire group. Other alternative embodiments may be readily apparent to those skilled in the art. Accordingly, while the invention has been described in detail with specific reference to preferred embodiments thereof, it is understood that variations and modifications of the invention may be made without departing from the true spirit and scope of the invention. | A series scene indication magnetically recorded adjacent appropriate frames in a strip of film by an autowind camera whenever it is in rapidfire mode are employed by a photofinishing station for using same print exposure value for one of the frames in the series to expose and print all of the frames in the same series. However, the photofinisher computes individual print exposure values for those frames in a series having photosensiometric data significantly different from the photosensiometric data of the rest of the frames in the series. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to a filler-fiber composite, a process for its production, the use of such in the manufacture of paper or paperboard products and to paper produced therefrom. More particularly the invention relates to a filler-fiber composite in which the morphology and particle size of the mineral filler are established prior to the development of the bond to the fiber. Even more particularly, the present invention relates to a PCC filler-fiber composite, wherein the desired optical and physical properties of the paper produced therefrom are realized.
[0002] 1. Background of the Invention
[0003] Loading particulate fillers such as calcium carbonate, talc and clay on fibers for the subsequent manufacture of paper and paper products continues to be a challenge. A number of methods, having some degree of success, have been used to address this issue. To insure that fillers remain with or within the fiber web, retention aids have been used, direct precipitation onto the fibers have been used, a method to attach the filler directly to the surface of the fiber have been used, mixing the fiber and the filler have been used, precipitation within never dried pulp have been used, a method for filling the cellulosic fiber have been used, high shear mixing have been used, fiberous material and calcium carbonate have been reacted with carbon dioxide in a closed pressurized container, fillers have been trapped by mechanical bonding, cationically charged polymers have been used and pulp fiber lumen loaded with calcium carbonate have all been used to retain filler in fiber for subsequent use in paper. Most of the methods for fiber retention are both expensive and ineffective.
[0004] Therefore, what is needed is a filler fiber composite and a method for producing the same that is both effective in retaining the filler and inexpensive for the paper maker to utilize.
[0005] Therefore, an object of the present invention is to produce a filler-fiber composite. Another object of the present invention is to provide a method for producing a filler-fiber composite. While another object of the present invention is to produce a filler-fiber composite that maintains physical properties such as tensile strength, breaking length and internal bond strength. Still a further object of the present invention is to produce a filler-fiber composite that maintains optical properties such as ISO opacity and pigment scatter. While still a further object of the present invention is to provide a filler-fiber composite that is particularly useful in paper and paperboard products.
[0006] 2. Related Art
[0007] U.S. Pat. No. 6,156,118 teaches mixing a calcium carbonate filler with noil fibers in a size of P50 or finer.
[0008] U.S. Pat. No. 5,096,539 teaches in-situ precipitation of an inorganic filler with never dried pulp.
[0009] U.S. Pat. No. 5,223,090 teaches a method for loading cellulosic fiber using high shear mixing of crumb pulp during carbon dioxide reaction.
[0010] U.S. Pat. No. 5,665,205 teaches a method for combining a fiber pulp slurry and an alkaline salt slurry in the contact zone of a reactor and immediately contacting the slurry with carbon dioxide and mixing so as to precipitate filler onto secondary pulp fibers.
[0011] U.S. Pat. No. 5,679,220 teaches a continuous process for in-situ deposition of fillers in papermaking fibers in a flow stream in which shear is applied to the gaseous phase to complete the conversion of calcium hydroxide to calcium carbonate immediately.
[0012] U.S. Pat. No. 5,122,230 teaches process for modifying hydrophilic fibers with a substantially water insoluble inorganic substance in-situ precipitation.
[0013] U.S. Pat. No. 5,733,461 teaches a method for recovery and use of fines present in a waste water stream produced in a paper manufacturing process.
[0014] U.S. Pat. No. 5,731,080 teaches in-situ precipitation wherein the majority of a calcium carbonate trap the microfiber by reliable and non-reliable mechanical bonding without binders or retention aids.
[0015] U.S. Pat. No. 5,928,470 teaches method of making metal oxide or metal hydroxide-modified cellulosic pulp.
[0016] U.S. Pat. No. 6,235,150 teaches a method of producing a pulp fiber lumen loaded with calcium carbonate having a particle size of 0.4 microns to 1.5 microns.
[0017] The problem of insuring that filler materials, such as calcium carbonate, ground calcium carbonate, clay and talc, remain within fibers that are ultimately to be used in paper has been subjected to a number of proofs. However, none of the prior related art discloses a filler fiber composite where the morphology of the filler is predetermined prior to introducing fibers, a method for its production nor its use in paper or paper products.
SUMMARY OF THE INVENTION
[0018] The present invention relates to a filler-fiber composite including feeding slake containing seed to a first stage reactor, reacting the slake containing seed in the first stage reactor in the presence of carbon dioxide to produce a first partially converted calcium hydroxide calcium carbonate slurry, reacting the first partially converted calcium hydroxide calcium carbonate slurry in a second stage reactor in the presence of carbon dioxide to produce a second partially converted calcium hydroxide calcium carbonate slurry and reacting the second partially converted calcium hydroxide calcium carbonate slurry in a third stage reactor in the presence of carbon dioxide and fibers to produce a filler-fiber composite.
[0019] In another aspect, the present invention relates to a filler-fiber composite including feeding slake containing seed to a first stage reactor, reacting the slake containing seed in the first stage reactor in the presence of carbon dioxide to produce a first partially converted calcium hydroxide calcium carbonate slurry and reacting the first partially converted calcium carbonate slurry in a second stage reactor in the presence of carbon dioxide and fibers to produce a filler-fiber composite.
[0020] In a further aspect, the present invention relates to a filler-fiber composite including feeding slake containing citric acid to a first stage reactor, reacting the slake containing citric acid in the first stage reactor in the presence of carbon dioxide to produce a first partially converted calcium hydroxide calcium carbonate slurry, reacting the first partially converted calcium hydroxide calcium carbonate slurry in a second stage reactor in the presence of carbon dioxide to produce a second partially converted calcium hydroxide calcium carbonate slurry, and reacting the second partially converted calcium hydroxide calcium carbonate slurry in a third stage reactor in the presence of carbon dioxide and fibers to produce a filler-fiber composite.
[0021] In yet a further aspect, the present invention relates to a filler-fiber composite Including feeding slake containing citric acid to a first stage reactor, reacting the slake containing citric acid in the first stage reactor in the presence of carbon dioxide to produce a first partially converted calcium hydroxide calcium carbonate slurry, taking a first portion of the partially converted calcium hydroxide calcium carbonate slurry adding fibers and reacting such in a second stage reactor in the presence of carbon dioxide to produce a calcium carbonate fiber composite to serve as a heel and taking a second portion of the partially converted calcium hydroxide calcium carbonate slurry adding fibers and surfactant and reacting in the presence of CO 2 to produce a second partially converted Ca(OH) 2 /CaCO 3 /fiber material and reacting the second partially converted Ca(OH) 2 /CaCO 3 /fiber material in the presence of CO 2 in a third stage reactor to produce a filler-fiber composite.
[0022] In still a further aspect, the present invention relates to a filler-fiber composite including feeding slake containing citric acid to a first stage reactor, reacting the slake containing citric acid in the first stage reactor in the presence of carbon dioxide to produce a first partially converted calcium hydroxide calcium carbonate slurry, taking a first portion of the partially converted calcium hydroxide calcium carbonate slurry adding fibers and reacting such in a second stage reactor in the presence of carbon dioxide to produce a calcium carbonate/fiber composite to serve as a heel and taking a second portion of the partially converted calcium hydroxide calcium carbonate slurry adding fibers and polyacrylamide and reacting in the presence of CO 2 to produce a second partially converted Ca(OH) 2 /CaCO 3 /fiber material and reacting the second partially converted Ca(OH) 2 /CaCO 3 /fiber material in the presence of CO 2 in a third stage reactor to produce a filler-fiber composite.
[0023] In a final aspect, the present invention relates to a filler-fiber composite including feeding slake containing citric acid to a first stage reactor, reacting the slake containing citric acid in the first stage reactor in the presence of carbon dioxide to produce a CaCO 3 heel and adding slake containing sodium carbonate to the heel material of the first stage reactor in the presence of CO 2 to produce a partially converted calcium hydroxide calcium carbonate slurry and reacting the partially converted calcium hydroxide calcium carbonate slurry in a second stage reactor in the presence of carbon dioxide and fibers to produce a filler-fiber composite.
[0024] Fiber as used in the present invention is defined as fiber produced by refining (any pulp refiner
[0025] known in the pulp processing industry) cellulose and/or mechanical pulp fiber. The fibers are typically 0.1 to 2 microns in thickness and 10 to 400 microns in length and are additionally prepared according to U.S. Pat. No. 6,251,222, which is by this reference incorporated herein.
DETAILED DESCRIPTION OF THE INVENTION
[0026] Precipitation of PCC with Varying Morphologies
[0027] Continuous Flow Stir Tank Reactor (CFSTR)
[0028] Scalenohedral Morpholog
[0029] The first step in this process involves making a high reactive Ca(OH) 2 milk-of-lime slake and screening it at −325 mesh. This slake is then added to an agitated reactor, brought to a desired reaction temperature, 0.1 percent citric acid is added to the slake to inhibit aragonite formation, and reacted with CO 2 gas. The reaction proceeds 10 percent to 40 percent of the way through at which point the reaction is stopped. This produces a partially converted Ca(OH) 2 /CaCO 3 slurry (approximately 20 percent solids by weight) which is then fed into a reaction vessel at a rate that matches CO 2 gassing to maintain a given conductivity (ionic saturation) to produce a scalenohedral crystal. This reaction proceeds until stabilization of the process is achieved. The product made once stabilization is achieved (approximately 95 percent converted) is then mixed with diluted fibers (approximately 1.5 percent concentration) and water. This mixture is then reacted with CO 2 gas to endpoint pH 7.0. The product manufactured using this method can contain from about 0.2 percent to about 99.8 percent scalenohedral PCC with respect to fibers at 3 percent to 5 percent total solids.
[0030] The product has a specific surface area from about 5 meters squared per gram to about 11 meters squared per gram; product solids from about 3 percent to about 5 percent and a PCC content from about 0.2 percent to about 99.8 percent, and is predominantly scalenohedral in morphology.
[0031] Aragonitic Morpholog
[0032] The first step in this process involves making a high reactive Ca (OH) 2 milk-of-lime slake and screened at −325 mesh. The concentration of this slake is approximately 15 percent by weight. This slake is then added to an agitated reactor, brought to a desired reaction temperature, from about 0.05 percent to about 0.04 percent additive is added to direct morphology and size, and reacted with CO 2 gas. The reaction proceeds 10 percent to 40 percent of the way through at which point the reaction is stopped. This produces a partially converted Ca (OH) 2 /CaCO 3 slurry which is then fed into a reaction vessel at a rate that matches CO 2 gassing to maintain a given conductivity (ionic saturation) to produce an acicular, aragonitic crystal. The reaction continues until process stabilization is achieved. The product made once stabilization is achieved, (approximately 95 percent calcium carbonate) is mixed with diluted fibers (approximately 1.5 percent concentration) and water. The calcium carbonate and fibers are then reacted with CO 2 gas to an endpoint of pH 7.0. The product manufactured using this method contains from about 0.2 percent to about 99.8 percent aragonitic PCC with respect to the fibers at about 3 percent to about 5 percent total solids.
[0033] The product has a specific surface area of about 5 meters squared per gram to about 8 meters squared per gram; product solids from about 3 percent to about 5 percent by weight and a PCC content from about 0.2 percent to about 99.8 percent with respect to fibers and has a predominantly aragonitic morphology.
[0034] Rhombohedral Morphology
[0035] The first step in this process involves making a high reactive Ca (OH) 2 milk-of-lime slake which is screened at −325 mesh and has a concentration of approximately 20 percent by weight. 0.1 percent citric acid is added to inhibit aragonite formation. A portion of this slake is added to an agitated reactor, brought to a desired reaction temperature and carbonated with CO 2 gas. The reaction proceeds to conductivity minimum producing a “heel”. A “heel” is defined as a fully converted calcium carbonate crystal with average particle size typically in the range of about 1 micron to about 2.5 micron with any crystal morphology. Sodium carbonate is added to the remainder of the slake not used in the manufacture of the “heel” material. This slake and CO 2 is added to the “heel” material at a CO 2 gassing rate to maintain a given conductivity (ionic saturation) to produce a rhombohedral crystal. The reaction is continued until process stabilization is achieved. Once stabilization is achieved, this product (approximately 90 percent to 95 percent converted) is mixed with diluted fibers (approximately 1.5 percent concentration) and water. Additional CO 2 is added to an endpoint of pH 7.0. The product manufactured using this method contains from about 0.2 percent to about 99.8 percent rhombohedral PCC with respect to fibers and is about 3 percent to about 5 percent total solids.
[0036] The product has a specific surface area from about 5 meters squared per gram to about 8 meters squared per gram; product solids from about 3 percent to about 5 percent; and PCC content from about 0.2 percent to about 99.8 percent and has a predominantly rhombohedral morphology:
EXAMPLES
[0037] The following examples are intended to exemplify the invention and are not intended to limit the scope of the invention.
Example 1
[0038] Scalenohedral PCC
[0039] Reacted 15 liters of water with 3 kilogram CaO at 50 degrees Celsius producing a 20 percent by weight Ca(OH) 2 slake. The Ca(OH) 2 slake was then screened at −325 mesh producing a screened slake that was transferred to a first 30-liter double jacketed stainless steel reaction vessel with an agitation of 615 revolutions per minute (rpm). 0.1 percent citric acid, by weight of total theoretical CaCO 3 to be produced, was added to the screened slake in a 30-liter reaction vessel and the temperature of the contents brought to 40 degrees Celsius. Began addition of 20 percent CO 2 gas in air (14.83 standard liter minute CO 2 /59.30 standard liter minute air) to the 30-liter reaction vessel to produce a 2:1 Ca (OH) 2 /CaCO 3 slurry. At this point, CO 2 gassing was stopped and the slurry was transferred to an agitated 20-liter storage vessel. 2 liters of the 2:1 Ca(OH) 2 /CaCO 3 slurry was transferred to a first 4-liter agitated (1250 rpm) stainless steel, double jacketed reaction vessel. The temperature was brought to 51 degrees Celsius and 20 percent CO 2 gas in air (1.41 standard liter minute CO 2 /5.64 standard liter minute air) was added to the first 4-liter reaction vessel until a pH of 7.0 was achieved producing a CaCO 3 slurry. Once a pH 7.0 was achieved began addition of the 2:1 Ca(OH) 2 /CaCO 3 slurry of the 20-liter storage vessel to the first 4-liter reaction vessel while continuing to add 20 percent CO 2 gas in air (1.41 standard liter minute CO 2 /5.64 standard liter minute air) to the first 4-liter reaction vessel to maintain a conductivity of approximately 90 percent ionic saturation. The addition of Ca(OH) 2 /CaCO 3 slurry and CO 2 to the first 4-liter reaction vessel was continued for approximately 12 hours until product physical properties remained essentially unchanged, producing a CaCO 3 slurry that was approximately 98 percent converted. Transferred 0.18 liters of the 98 percent CaCO 3 slurry to a second 4-liter agitated (1250 rpm), stainless steel, double jacketed reaction vessel, added 0.66 liters of 3.8 percent by dry weight cellulosic fibers and diluted to 1.5 percent consistency. This mixture of CaCO 3 slurry and fiber was reacted with 20 percent CO 2 in air (1.41 standard liter minute CO 2 /5.64 standard liter minute air) to produce a CaCO 3 filler-fiber composite. The calcium carbonate filler had a predominantly scalenohedral morphology.
Example 2
[0040] Aragonitic PCC
[0041] Reacted 10.5 liters of water with 2.1 kilograms CaO at 50 degrees Celsius producing a 15 percent by weight Ca(OH) 2 slake. The Ca(OH) 2 slake was then screened at −325 mesh producing a screened slake that was transferred to a 30-liter double jacketed stainless steel reaction vessel with an agitation of 615rpm. Added 0.1 percent by weight of a high surface area (HSSA) aragonitic seed (surface area ˜40 meters squared per gram, approximately 25 percent solids) to the 30-liter reaction vessel and brought the temperature of the contents to 51 degrees Celsius. A “seed” is defined as a fully converted aragonitic crystal that has been endpointed and milled to a high specific surface area (i.e. greater than 30 meters squared per gram and typically a particle size of 0.1 to 0.4 microns). Began addition of 10 percent CO 2 gas in air (5.24 standard liter minute CO 2 /47.12 standard liter minute air) to the 30-liter stainless steel, double jacketed reaction vessel for a 15-minute period after which the CO 2 concentration was increased to 20 percent in air (10.47 standard liter minute CO 2 /41.89 standard liter minute air) for an additional 15 minutes producing a 2.3:1 Ca (OH) 2 /CaCO 3 slurry. At which time CO 2 gassing was stopped. The 2.3:1 Ca(OH) 2 /CaCO 3 slurry was transferred to an agitated 20-liter storage vessel. Transferred 2 liters of the 2.3:1 Ca(OH) 2 /CaCO 3 slurry to a first 4-liter agitated, double jacketed stainless steel reaction vessel with agitation set at 1250rpm and the temperature was brought to 52 degrees Celsius. Began addition of 20 percent CO 2 gas in air (1.00 standard liter minute CO 2 /3.99 standard liter minute air) to the first 4-liter reaction vessel and the reaction was continued until a pH of 7.0 was achieved producing a 100 percent CaCO 3 slurry. The temperature of the 100 percent CaCO 3 slurry of the first 4-liter reaction vessel was brought to 63 degrees Celsius. Began addition of the 2.3:1 Ca(OH) 2 /CaCO 3 slurry of the 20-liter storage vessel to the first 4-liter reaction vessel while continuing to add 20 percent CO 2 in air (1.00 standard liter minute CO 2 /3.99 standard liter minute air) to the first 4-liter reaction vessel maintaining a conductivity of approximately 90 percent ionic saturation. Continued the reaction for approximately 9 hours until the physical properties of the resultant product remained essentially unchanged, producing a 98 percent by wt. CaCO 3 slurry.
[0042] Transferred 0.35 liters of the 98 percent CaCO 3 slurry to a second 4-liter agitated (1250 rpm), stainless steel, double jacketed reaction vessel, added 0.66 liters of 3.8 percent by wt. cellulosic fiber and 1.0 liters water to the second 4-liter reactor producing a 1.5 percent by wt. CaCO 3 /fiber mixture. Added an additional 20 percent CO 2 in air (1.00 standard liter minute CO 2 /3.99 standard liter minute air) to the second 4-liter reaction vessel until a pH of 7.0 was reached at which time the reaction was completed producing a CaCO 3 /fiber composite. The composite consisted of approximately 75 percent aragonitic PCC to fiber.
Example 3
[0043] Rhombohedral PCC
[0044] Reacted 15 liters of water with 3 kilograms CaO at 50 degrees Celsius producing a 20 percent by weight Ca(OH) 2 slake. The Ca(OH) 2 slake was screened at −325 mesh producing a screened slake that was transferred to an agitated 20-liter storage vessel. Transferred 2-liters of the screened slake from the 20-liter storage vessel to a first 4-liter agitated, stainless steel, double jacketed reaction vessel and began agitation at 1250 rpm. Added 0.03 percent citric acid by weight of theoretical CaCO 3 to the first 4-liter reaction vessel and raised the temperature of the contents to 50 degrees Celsius. Added 20 percent CO 2 gas in air (1.44 standard liter minute CO 2 /5.77 standard liter minute air) to the first 4-liter reaction vessel until a pH of 7.0 was achieved producing a 100 percent CaCO 3 slurry. To the screened slake in the 20-liter storage vessel, added a solution of 1.3 percent by weight of Na 2 CO 3 , based on theoretical yield of CaCO 3 , producing a Ca(OH) 2 /Na 2 CO 3 slake. Increased the temperature of the contents of the first 4-liter reaction vessel to approximately 68 degrees Celsius and began addition of the Ca(OH) 2 /Na 2 CO 3 slake of the 20-liter storage vessel to the first 4-liter reaction vessel while continuing to add 20 percent CO 2 in air (1.44 standard liter minute CO 2 /5.77 standard liter minute air) to the first 4-liter reaction vessel maintaining a conductivity of approximately 50 percent ionic saturation. Addition of the Ca(OH) 2 /Na 2 CO 3 slake and CO 2 was continued for approximately 12 hours until physical properties of the resultant product remained essentially unchanged producing an approximate 98 percent by wt. CaCO 3 slurry.
[0045] Transferred 0.22 liters of the 98 percent CaCO 3 slurry to a second 4-liter agitated (1250 rpm) dual jacketed, stainless steel reaction vessel and added 0.66 liters of 3.8 percent by weight cellulosic fiber and 1.0 liters water to the second 4-liter reactor producing a 1.5 percent by weight CaCO 3 /fiber mixture. Added an additional 20 percent CO 2 in air (1.44 standard liter minute CO 2 /5.77 standard liter minute air) to the second 4-liter reaction vessel until a pH of 7.0 was reached at which time the reaction was completed producing an approximate 3.4 percent by wt CaCO 3 /fiber composite. The calcium carbonate had a predominantly rhombohedral morphology.
Example 4
[0046] Scalenohedral—CFSTR
[0047] Reacted 15 liters of water with 3 kilograms CaO at 48 degrees Celsius to produce a Ca(OH) 2 slake, added an additional 6 liters of water producing a 20 percent by weight Ca(OH) 2 slake. The 20 percent Ca(OH) 2 slake was screened at −325 mesh and transferred to a 30-liter double jacketed, stainless steel reaction vessel with an agitation of 615 rpm. Added 0.015 percent citric acid, by weight of total theoretical CaCO 3 to be produced, to the 30-liter reaction vessel and the temperature of the contents brought to 36 degrees Celsius. Began addition of 20 percent CO 2 gas in air (13.72 standard liter minute CO 2 /54.89 standard liter minute air) to the 30-liter reaction vessel to produce a 5:1 Ca(OH) 2 /CaCO 3 slurry. CO 2 gassing was stopped and the Ca(OH) 2 /CaCO 3 slurry was transferred to an agitated 20-liter storage vessel.
[0048] In a 4-liter agitated storage vessel, combined 0.25 liters of the Ca(OH) 2 /CaCO 3 slurry with 0.66 liters of 3.8 percent by weight fibers and with 1.09 liters of water making a Ca(OH) 2 /CaCO 3 /fiber material. Transferred 2 liters of the Ca(OH) 2 /CaCO 3 /fiber material to a 4-liter agitated (1250 revolutions per minute) reaction vessel and the temperature brought to 55 degrees Celsius and carbonated with 20 percent CO 2 in air (1.30 standard liter minute CO 2 /5.23 standard liter minute air) to a pH of 7.0 producing a CaCO 3 /fiber composite. Prepared 16-liters of 1.5 percent by weight fibers and a separate 10-liter vessel of water. To the 4-liter reaction vessel began addition of the Ca(OH) 2 /CaCO 3 slurry of the 20-liter agitated storage vessel, along with the 1.5 percent consistency fiber mixture at 172.05 ml per minute, along with 31.21 ml per minute of additional water while maintaining the flow of CO 2 gas (1.30 standard liter minute CO 2 /5.23 standard liter minute air) at a rate to maintain conductivity of approximately 90 percent ionic saturation, while maintaining mass balance of approximately 4 percent to 5 percent total solids.
[0049] This reaction was continued until product physical properties remained essentially unchanged. Addition of material from the storage vessel was stopped while CO 2 addition was continued and the material in the 4-liter agitated reaction vessel was brought to a pH of 7.0 at which time CO 2 addition was stopped producing a 2.2:1 CaCO 3 /fiber composite with the CaCO 3 having a well defined scalenohedral morphology.
Example 5
[0050] Scalenohedral CFSTR/Surfactant
[0051] Reacted 15 liters of water with 3 kilograms CaO at 48 degrees Celsius to produce a Ca(OH) 2 slake, added an additional 6 liters of water producing a 20 percent by weight Ca(OH) 2 slake. The 20 percent Ca(OH) 2 slake was screened at −325 mesh and transferred to a 30-liter reaction vessel (615revolutions per minute). Added 0.015 percent citric acid, by weight of total theoretical CaCO3 to be produced, to the 30-liter reaction vessel and the temperature of the contents brought to 35 degrees Celsius. Began addition of 20 percent CO 2 gas in air (14.08 standard liter minute CO 2 /56.30 standard liter minute air) to the 30-liter reaction vessel producing a 5:1 Ca(OH) 2 /CaCO 3 slurry. At this point, CO 2 gassing was stopped and the Ca(OH) 2 /CaCO 3 slurry was transferred to a 20-liter agitated storage vessel.
[0052] In a 4-liter agitated storage vessel, combined 0.25 liters of the Ca(OH) 2 /CaCO 3 slurry with 0.66 liters of 3.8 percent by weight fibers and with 1.09 liters of water making 2 liters of Ca(OH) 2 /CaCO 3 /fiber material.
[0053] Transferred 2 liters of the Ca(OH) 2 /CaCO 3 /fiber material to a 4-liter stainless steel, double jacketed, agitated (1250 revolutions per minute) reaction vessel and the temperature was brought to 58 degrees Celsius. Reacted the Ca(OH) 2 /CaCO 3 /fiber material with 20 percent CO 2 in air (1.30 standard liter minute CO 2 /5.23 standard liter minute air) to a pH of 7.0.
[0054] At this point, prepared 16-liters of 1.5 percent by weight fibers (6.32 liters of fibers at 3.8 percent consistency and 9.68 liters of water) and a separate 10-liter vessel of water. Added 0.04 percent surfactant based on the volume of fibers at 1.5 percent consistency. The surfactant is Tergitol™ MIN-FOAM 2× which is available commercially from Union Carbide, 39 Old Ridgebury Road, Danbury, Conn. 06817.
[0055] Once a pH of 7.0 was achieved in the 4-liter reaction vessel, began addition of the remaining 5:1 Ca(OH) 2 /CaCO 3 slurry from the 20-liter agitated storage vessel, with a flow of the 1.5 percent fiber mixture at 176.48 ml per minute and with 32.00 ml per minute water from the 10-liter vessel to the 4-liter reaction vessel while maintaining the flow of CO 2 gas (1.30 standard liter minute CO 2 /5.23 standard liter minute air) at a rate to maintain conductivity of approximately 90 percent ionic saturation, while maintaining mass balance of approximately 4 percent to 5 percent total solids. Continued addition of the material from the agitated storage vessel to the reaction vessel until product physical properties remained essentially unchanged. At which point, addition of material from the storage vessel was stopped while CO 2 addition was continued to a pH of 7.0 at which time CO 2 addition was stopped. This produced a 2.33:1 CaCO 3 /fiber composite with the calcium carbonate having a well defined scalenohedral morphology.
Example 6
[0056] Scalenohedral CFSTR/Polyacrylamide
[0057] Reacted 15 liters of water with 3 kilograms CaO at 48 degrees Celsius producing a Ca(OH) 2 slake, added an additional 6 liters of water producing a 20 percent by weight Ca(OH) 2 slake. The 20 percent Ca(OH) 2 slake was then screened at −325 mesh producing a screened slake that was transferred to a 30-liter agitated (615 rpm) reaction vessel. Added 0.1 percent citric acid, by weight of total theoretical CaCO 3 to be produced, to the 30-liter reaction vessel and the temperature of the contents brought to 50 degrees Celsius. Began addition of 20 percent CO 2 gas in air (15.01 standard liter minute CO 2 /60.06 standard liter minute air) to the 30-liter reaction vessel producing a 5:1 Ca(OH) 2 /CaCO 3 slurry. CO 2 gassing was stopped and the slurry was transferred to a 20-liter agitated storage vessel. To a 4-liter agitated vessel added 0.31 liters of the Ca(OH) 2 /CaCO 3 slurry, 0.60 liters of fibers at 3.8 percent consistency and 1.09 liters of water to produce a Ca(OH) 2 /CaCO 3 /fiber material. 2 liters of the Ca(OH) 2 /CaCO 3 /fiber material was transferred to a 4-liter agitated (1250 revolutions per minute) reaction vessel and the temperature was brought to 51 degrees Celsius. Began addition of 20 percent CO 2 in air (1.34 standard liter minute CO 2 /5.34 standard liter minute air) until a pH of 7.0 was reached producing a CaCO 3 /fiber composite.
[0058] At this point, prepared 16-liters of 1.5 percent by weight fibers (6.32 liters of fibers at 3.8 percent consistency and 9.68 liters of water) and a separate 10-liter vessel of water. Added 0.05 percent cationic polyacrylamide (Percol 292) based on the volume of fibers at 1.5 per cent consistency. Percol 292 is commercially available from Allied Colloids, 2301 Wikroy Road, Suffolk, Va. 23434.
[0059] Once a pH of 7.0 was achieved in the 4-liter reaction vessel, began addition of the remaining 5:1 Ca(OH) 2 /CaCO 3 slurry from the 20-liter agitated storage vessel, with a flow of the 1.5 percent fiber mixture at 90 ml per minute, along with 48.5 ml per minute of additional water to the 4-liter agitated, double jacketed reaction vessel while maintaining the flow of CO 2 gas (1.30 standard liter minute CO 2 /5.23 standard liter minute air) at a rate to maintain conductivity level of approximately 90 percent ionic saturation, and maintain mass balance of the reaction to maintain product concentration at approximately 4 percent to 5 percent solids. Continued addition of the material from the agitated storage vessel to the reaction vessel until product physical properties remained essentially unchanged. Addition of material from the 20-liter storage vessel was stopped while CO 2 addition was continued until a pH of 7.0 was reached at which time CO 2 addition was stopped producing a 3.34:1 CaCO 3 /fiber composite with the PCC having a well defined scalenohedral morphology.
[0060] The control fiber of the present invention was refined at the Empire State Paper Research Institute (ESPRI) using an Escher-Wyss (conical) refiner to an 80° SR (freeness). Measured by a fiber quality analyzer (using arithmatic means) the control fiber measured 200-400 microns
[0061] How Control Filler-Fiber was Made
[0062] Produce a 15% solids slake and mix with fibers (˜1.5% consistency) React in the presence of CO 2 to endpoint of pH of 7.0 producing a filler-fiber composite with a surface area of 6-11 m2/g (˜60 to 80% PCC but can have more or less in composite)
TABLE 1 Breaking Length Physical Properties in Meters Filler Loading Scalenohedral Aragonitic Rhombohedral Control Levels Filler-fiber Filler-fiber Filler-fiber Filler-fiber 20 4,021 4,599 4,312 4,245 25 3,799 4,358 3,813 3,715 30 3,280 3,674 3,871 2,998
[0063] [0063] TABLE 2 Tensile Strength Physical Properties in kN/m Filler Loading Scalenohedral Aragonitic Rhombohedral Control Levels Filler-fiber Filler-fiber Filler-fiber Filler-fiber 20 3.062 3.555 3.397 3.382 25 3.124 3.324 2.999 3.021 30 2.658 2.785 3.005 2.448
[0064] [0064] TABLE 3 Internal Bond Strength Physical Properties in ft-lb Filler Loading Scalenohedral Aragonitic Rhombohedral Control Levels Filler-fiber Filler-fiber Filler-fiber Filler-fiber 20 237.70 264.07 283.13 255.67 25 263.20 285.95 251.65 256.95 30 242.63 248.60 273.65 249.53
[0065] The morphology controlled filler-fiber composite showed equivalent or greater physical properties (i.e. tensil strength, breaking length, and internal bond strength) as compared with the control filler-fiber.
TABLE 4 ISO Opacity Optical Properties Filler Loading Scalenohedral Aragonitic Rhombohedral Control Levels Filler-fiber Filler-fiber Filler-fiber Filler-fiber 20 89.20 88.20 87.38 88.18 25 89.93 89.15 88.78 89.55 30 90.95 90.40 89.68 90.83
[0066] [0066] TABLE 5 Pigment Scatter Optical Properties Filler Loading Scalenohedral Aragonitic Rhombohedral Control Levels Filler-fiber Filler-fiber Filler-fiber Filler-fiber 20 60.15 55.47 55.08 58.55 25 64.90 62.40 61.10 65.40 30 70.55 69.55 65.80 73.13
[0067] The morphology controlled filler-fiber composite showed equivalent optical properties (i.e. ISO Opacity and Pigment Scatter) as compared with the control filler-fiber. | The present invention relates to a filler-fiber composite, a process for its production, the use of such in the manufacture of paper or paperboard products and to paper produced therefrom. More particularly the invention relates to a filler-fiber composite in which the morphology and particle size of the mineral filler are established prior to the development of the bond to the fiber. Even more particularly, the present invention relates to a PCC filler-fiber composite, wherein the desired optical and physical properties of the paper produced therefrom are realized. | 3 |
REFERENCE TO RELATED APPLICATION
The present application is based on provisional application Serial No. 60/128,948 filed Apr. 13, 1999 entitled METAL CORE SUBSTRATE ENABLING THERMALLY ENHANCED BALL GRID ARRAY PACKAGES.
DESCRIPTION OF THE PRIOR ART
Prolinx C 2 BGA
The C 2 BGAs are fabricated using a complicated etching donut isolation method, resulting in copper islands on the core that are suspended by some isolation material, and then followed by surface processing and photo via steps. The incurred cost for the complex steps and the resulting complex structure is significant.
SUMMARY OF THE INVENTION
The Ball Grid Array (BGA) is an advanced array package for fine pitch, high pin count semiconductor packaging, which is used normally in a multiple-layer chip-up printed wiring board (PWB) substrate for housing the integrated circuit structure in today's IC industry. However, the heat dissipation is a major concern with the arrival of high speed CPUs such as the Pentium II & III, as well as high speed graphics, networking, DSP, and programmable logic chips. Better thermal BGA packaging solutions are required to fulfill the need of IC products in the 21 century.
The object of this invention is to provide a new and simpler PWB structure and method with comparable or better thermal performance, resulting in lower cost and better reliability. High degree of flexibility in choice of material and layer counts and layer thickness allows for a wide range of applications in packaging and high density printed circuit board or PWB. The plated copper vias also allow for better thermal performance and result in better overall thermal performance for the resulting package.
The processing steps are also ones that have proven to be practical for implementing high density interconnect for packaging applications.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, advantages and features of the invention will become more apparent when considered with the following description when taken in conjunction with the accompanying drawings in which like reference characters identify corresponding components or elements and wherein:
FIG. 1A shows, in section the initial metal core structure incorporating the invention,
FIG. 1B shows the metal core structure after the addition of two additional functional layers on respective glass fiber layers, incorporating the invention,
FIG. 1C shows a five-layer structure incorporating the invention,
FIG. 1D shows the use of a solder mask coating on the structure of FIG. 1C,
FIG. 2 illustrates a type 1 via according to the invention,
FIG. 3 illustrates a type 2 via according to the invention,
FIG. 4 illustrates a type 3 via according to the invention,
FIG. 5 illustrates a sectional view of an overall structure incorporating the invention, and
FIG. 6 is a perspective view of a finished BGA IC package with a substrate incorporating the invention, mounted on a PWB which can either be of a conventional laminated board or one that incorporates the invention.
DETAILED DESCRIPTION OF THE INVENTION
Structure
FIG. 1A shows the structure during the initial metal core 110 forming stage. FIG. 1B shows the structure after the first two build up layers 120 are fabricated. FIG. 1B shows two drilled Plated Through Holes (PTH) 220 in the structure. It can be the complete PWB structure if a 3-layer structure 210 - 110 - 210 is desired, which is simpler and less costly. Please note that the ⅓ oz copper foil 210 and the 5-10 oz copper core 110 are separated with insulating glass fiber prepreg layers 230 . Also the blind or laser drilled & plated via 240 is used for connecting to the core 110 as ground. The five-layer structure in FIG. 1C is intended for more complex and high density applications. FIG. 1C shows two extra build-up layers 310 , with build-up vias 320 , and a PTH 220 . In the following discussion, we will focus on the five-layer structure depicted in FIG. 1C, which includes three distinct types of vias implemented in the invention.
Type 1 via 220 as illustrated in FIG. 2, is for implementing the majority of the vias in the structure also shown in FIG. 1B, FIG. 1 C. It is isolated from the core and is connected to the outer layers through build-up vias 320 that are either laser drilled or controlled depth mechanically drilled.
Type 2 via, as illustrated in FIG. 3, is a via that is connected with the core, which is typically used as a ground plane. It is implemented by a through hole drill 330 directly on the core 110 and followed by plating, which results in side-wall connection with the core.
The advantage of the type 2 via is that it provides a direct thermal transfer path from the top layer 310 to the core 110 and then to the bottom layer 350 , ideal for implementing thermal vias in packaging applications.
The only drawback with type 2 via is that the side-wall plating has interface with various layers including the core 110 and the prepreg 230 , as well as with the interface between the conductive layers 210 , 310 and the prepreg, which if not properly processed, will contain micro-cracks that allow moisture to penetrate through. The micro-cracks may result in delamination of the interface between the core 110 and the prepreg 230 .
Type 3 via, as illustrated in FIG. 4, is also a via that connects to the ground plane on the core 110 , and also provides good thermal path to the core 110 . It is implemented by build-up core vias 240 and 320 through laser or controlled depth drill, also shown in FIG. 1 B and FIG. 1 C. It is good for thermal performance and does not have the reliability drawback as does the type 2 via.
Materials
The preferred choice of the metal core 110 is copper C 194 foil of 5-10 oz, or 5-15 mils thickness, as shown in FIG. 1 A. The liquid to plug the metal core holes 120 can be PHP 900 or equivalent materials.
The inner prepreg 230 is either BT (bismaleimide triazine) or 47 N with glass fiber, of 1.5 to 3 mil thickness. The glass fiber ingredient allows for structural enhancement against thermal expansion coefficient mismatch between the metal core 110 and the prepreg material 230 .
The outer prepreg 340 can be either B.T. or R.C.C. (Resin-Coated-Copper) material, typically used for laser-drilled build-up. The thickness of the outer preg 340 is also within the range of 1.5 to 3 mils. The copper foil 210 used in the non-core layers can be of ⅓ oz thickness, though a wide thickness range is appropriate (⅛, {fraction (1/4 )}, or {fraction (1/2 )} oz) for various applications.
Process
The following describes a preferred process step sequence, though variations can be adopted by those familiar with the art of printed circuit board and HDI (high density interconnect) fabrication.
1. Starting with the metal core 110 , drill or etch holes at the through-core vias sites, as shown in FIG. 1 B and FIG. 1C, with hole sizes around 25 mils (15 mil to 40 mils is the allowable range for BGA applications). Note that typical panel sizes are 12″×18″, or 18″×24″, or variations hereof. Black oxide processing is performed on the metal surface for better adhesion to the laminated prepreg layer 210 , 230 310 , 250 and 340 .
Singulation lines at the border of each substrate unit can be pre-drilled or pre-etched, during the first via drill-etch step, for easy singulation in strip or singulated delivery format.
2. Liquid (PHP 900 ) plug the holes 120 (as the hatched areas shown in FIG. 1 A). In the case of a thinner core 110 , such as around 5 mils, the liquid plugging 120 may not be necessary, as the inner prepreg 230 will naturally flow and fill the holes during lamination. For thick cores, it is better to plug the holes first.
3. Prepreg laminations 230 and 340 .
For example, 3-mil prepregs with ⅓ oz copper foil is used in FIG. 1 C. Note that for the reason of maintaining symmetry, one prepreg layer for each of the top and the bottom side is laminated at the same time.
4. Drill holes for the through vias isolated from the core. The diameter of the drill is about 10 mils laser drill or controlled-depth mechanical drill for vias that are to be connected to the core, with the diameter in the range of 2 mils to 6 mils, as shown in FIG. 1 B. Note that the liquid plugging material 120 which is the prepreg that flows into the first drill hole in step 2 , isolates the plated vias 220 from the core 110 .
5. Transfer inner layers 210 and 250 images to form pads and trace circuitry.
6. Laminate outer prepreg layers 310 and 340 with BT or R.C.C. material. If a 3-layer only structure is desired, the outer prepreg layers 310 and 340 are not needed. With the same principle, if a 4-layer only structure is desired, then the bottom BT or R.C.C. layer is not required.
7. Form build-up via holes 320 by Laser hole drill or controlled-depth mechanical drill.
8. Mechanical through hole drill for type 2 via 330 if desired.
9. Plating copper 310 and 350 for through hole vias and panel plating.
10. The rest of the steps depend on Ni/Au plating technology and application needs. This includes imaging transfer for outer layers and Ni/Au plating 420 .
11. Solder mask 410 coating, as shown in FIG. D.
12. Finishing: Singulating the panel into individual units or into strips for packaging assembly.
Advantages
1. Efficient symmetric layer and via structures for high thermal conductance.
2. Achieving same or better thermal performance comparing to prior art, with mature processing technology and proven materials.
3. Requires only incremental cost increase for offering better performance than Plastic Ball Grid Array (PBGA).
FEATURES OF THE INVENTION
1. New copper-core based structure for chip-up high thermal performance package using 3-layer (core+1-top+1-bottom), 4-layer (core+2-top+1-bottom), and 5-layer (core+2-top+2-bottom). Moreover, 5 or more layers can be built easily. The 3-and 5-layer options are symmetric, with better warpage prevention.
2. The use of drilling/etching, optional liquid-filled, laminating, drilling, and plating process steps for forming the through core via holes.
3. The combination of laser blind vias build-up on top of the metal core structure, enabling additional build-up layers for high density applications.
4. Efficient thermal vias by plating build-up and connecting to the core from both the top and bottom sides.
5. Singulation lines at the border of each substrate unit can be pre-drilled or pre-etched, during the first via drill-etch step, for easy singulation in strip or singulated delivery format.
6. Applications: a) Metal core based substrates for thermally enhanced fine-pitch BGAS, and b) Metal core based high density boards such as for high thermal output SDRAM DIMM modules.
While the invention has been described in relation to preferred embodiments of the invention, it will be appreciated that other embodiments, adaptations and modifications of the invention will be apparent to those skilled in the art. | A method of making a thermally enhanced BGA substrate in which a metal (copper) core, has dielectric layers applied to each side thereof and conductive through-core build-up vias are provided. Rigidifying non-conductive dielectric sheets are laminated to the oppositely facing surfaces and then conductive layers are applied to at least one of the rigidifying non-conductive sheets and via connections are made through the dielectric layer(s) to the core conductive layer. | 8 |
[0001] The present application is a continuation of U.S. patent application Ser. No. 09/629,017, filed Jul. 31, 2000, now U.S. Pat. No. 6,518,780. The present application is based on and claims priority from this, the disclosure of which is hereby incorporated herein by reference.
BACKGROUND OF INVENTION
[0002] The present invention relates to an electrical test probe tip for use with testing instruments, and more particularly a wedge-shaped electrical test probe tip.
[0003] Integrated circuit devices (hereinafter referred to as “ICs”) come in a wide variety of shapes and sizes depending on the function of the particular device. ICs have a set of pins, leads, or legs (hereinafter referred to as “pins”) that function as a conductive path between the internal circuitry of the IC and the external circuit to which the IC is interfaced. ICs have evolved from devices with relatively large and widely spaced pins to devices with small, closely spaced pins. Pins on modern ICs may be spaced less than a millimeter apart.
[0004] To measure an electrical signal of an IC, a test probe is connected to an oscilloscope, digital multimeter, or other measuring, monitoring, diagnostic, or signal processing instrument (herein referred to as a “testing instrument”). At one end of a test probe is a probe tip. The probe tip may be integral or replaceable. Typically, the probe tip is an elongate conductive member that terminates in a conical, blunt, or rounded point. FIG. 1 shows one example of a traditional probe tip.
[0005] When a probe tip contacts a pin, it forms an electrical connection therewith. The electrical signal on the pin may then be measured. It is difficult to form a contact with a single pin on a modern IC using a traditional probe tip because of the small geometry and close spacing of the pins. If the probe tip contacts two adjacent pins simultaneously, a short circuit between the two adjacent pins results. A short circuit prevents measurement of the desired signal, and in some situations, may result in damage to the internal circuitry of the IC. A traditional probe tip provides no means of preventing the occurrence of a short circuit.
[0006] U.S. Pat. No. 4,943,768 to Niki, et al. sets forth a description of a testing device (hereinafter referred to as the “Niki device”) for electrical circuit boards. The Niki device is designed to make simultaneous electrical connections with multiple horizontal test terminals on a circuit board and is, therefore, relatively wide. Strips of conductive material appear on the surface of the body and are arranged in conformity with the parallel test terminals on the circuit board. The Niki device has a tapered, sharp edge at its lower end that is suitable only for measurement of signals appearing on the multiple horizontal test terminals. The Niki device is unsuitable for insertion between the pins of an IC because its relatively wide body would likely contact other components on a circuit board. If the Niki device were to be inserted between adjacent pins of an IC, the result would depend on the particular arrangement of the strips of conductive material on the surface of the body. One possibility is that a strip would contact both adjacent pins causing a short circuit. A second possibility is that only the probe body would contact the pins resulting in an open circuit between the conductive strip and the testing instrument. For this reason, proper measurement of the desired signal is unlikely.
[0007] U.S. Pat. No. 4,987,364 to Watts sets forth a description of a device (hereinafter referred to as the “Watts device”) for use in testing printed circuit boards. The Watts device is designed to measure signals from two types of test pads on the surface of a circuit board. The first type of test pad has a small geometry, while the second type has a large geometry with a hole in its center. The Watts device consists of a probe body that is generally thin and sheet-like (described in the specification as “laminar”). The preferred embodiment of the Watts device has a probe body that includes a bottom edge that tapers downward in a stair-step fashion to provide a contact portion. The Watts device relies on the thin geometry of its probe body to avoid simultaneous contact with more than a single test pad. For its stated purpose, insulated surfaces on the body perpendicular to the plane of the circuit are unnecessary. Without insulated surfaces, however, insertion of the Watts device between adjacent pins of an IC would likely result in a short circuit.
[0008] U.S. Pat. No. 5,923,177 to Wardell sets forth a description of a device (hereinafter referred to as the “Wardell device”) for use in testing ICs. The Wardell device consists of a plurality of probe tips arranged in a row, and attached to a housing. The stated purpose of the device is to sample a plurality of pins simultaneously. Each probe tip is an elongate, relatively narrow member that is approximately the same thickness as the horizontal distance between adjacent pins of an IC. Each probe tip tapers in both thickness and width, and terminates in a flat surface perpendicular to its length. On the side of each probe tip is a conductive surface. The conductive surfaces on either side of a probe tip are not connected electrically, and are separated by alternating layers of filler material and adhesive. In contrast, the exterior conductive surfaces of two adjacent probe tips that face each other are electrically connected. The two conductive surfaces that face each other contact and sample the signal on the solitary pin that fills the space between the two probe tips. Because the Wardell device has two relatively large conductive surfaces, it is likely that the inductance of the device will be significantly larger than that of a probe tip with a single, relatively small surface. In addition, the Wardell device is not intended to directly sample the signal on a single pin. To sample the signal on a single pin the Wardell device requires that signals on the remaining pins be disregarded. Because of its laminar structure and multiplicity of probe heads, the Wardell device would be relatively expensive and complex to produce.
BRIEF SUMMARY OF THE INVENTION
[0009] An electrical test probe wedge tip according to the present invention includes an electrically conductive interior optionally surrounded, at least partially, by an electrically insulated exterior surface. A longitudinal axis extends the length of the electrical test probe tip. In one preferred embodiment the top tip end has a single planar surface at an angle to the longitudinal axis.
[0010] A method of fabricating an electrical test probe tip includes providing an elongate electrically conductive blank coated with insulation. An angled surface is exposed by removing a portion of the first end along a plane at an angle to the longitudinal axis of the blank.
[0011] The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0012] [0012]FIG. 1 is a perspective view of a prior art probe tip with a non-insulated, conical, pointed tip.
[0013] [0013]FIG. 2 is a perspective view of an exemplary embodiment of the electrical test probe wedge tip of the present invention.
[0014] [0014]FIG. 3 is a front view of the embodiment of FIG. 2.
[0015] [0015]FIG. 4 is a side view of the embodiment of FIG. 2.
[0016] [0016]FIG. 5 is a back view of the embodiment of FIG. 2.
[0017] [0017]FIG. 6 is the embodiment of FIG. 2, viewed from the top looking directly into the tip.
[0018] [0018]FIG. 7 is the embodiment of FIG. 2, viewed from the bottom looking directly into the base.
[0019] [0019]FIG. 8 is an enlarged perspective view of an elongate electrically conductive metal blank.
[0020] [0020]FIG. 9 is a perspective view of FIG. 8, shown coated with insulation, in partial cutaway and with a graphical representation of the modification to be made to create one preferred embodiment of the present invention.
[0021] [0021]FIG. 10 is a cross-sectional view of one embodiment of an electrical test probe wedge tip inserted between the pins of an IC, this embodiment having an insulated angled surface, and an electrically conductive exterior annular surface.
[0022] [0022]FIG. 11 is a cross-sectional view of an alternate embodiment of an electrical test probe wedge tip inserted between the pins of an IC, this embodiment having an electrically conductive angled surface, and an insulated exterior annular surface.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The present invention is directed to an electrical test probe wedge tip (hereinafter the “wedge tip”) indicated generally as 20 . As shown in FIGS. 2 - 7 , an exemplary embodiment of the wedge tip 20 preferably includes a top tip end 22 (or first end) with an angled surface 24 , 24 a, 24 b capable of insertion between narrowly spaced adjacent pins of an IC, and a bottom base end 26 (or second end). Alternative embodiments may include a connector base 28 , a shielding head 30 , and a surface coated with insulation 46 (FIG. 9). The present invention also includes methods for making and using the wedge tip 20 .
[0024] The wedge tip 20 has a longitudinal axis 34 (FIG. 2) extending from the top tip end 22 to the bottom base end 26 . As shown in FIG. 5, the maximum length 36 of the wedge tip is measured from the top tip end to the bottom base end along back side 38 . FIG. 3 shows that the minimum length 40 of the wedge tip is measured from the top tip end to the bottom base end along the front side 42 . The maximum and minimum lengths 36 and 40 are not equal. The slope of angled surface 24 is defined by the difference between the maximum and minimum lengths. In one preferred embodiment, the length of the wedge tip decreases linearly from the maximum length to the minimum length forming the planar angled surface 24 . The difference between the maximum and minimum lengths may be varied to adjust the angle of the angled surface to best suit an intended use. Further, alternate embodiments of the angled surface 24 may be used. For example, the angled surface could descend from the maximum length to the minimum in a curved manner, forming a concave or convex surface. The angled surface could also descend from the maximum length to the minimum in equally spaced, discrete distances, forming a stair-step surface. In addition, the angled surface could descend from the maximum length to the minimum in one step at the midpoint of the cross-section of the wedge tip. In this embodiment, the back one-half of the cross-section would be the maximum length, and the front one-half would be the minimum length. In another alternative embodiment, the angled surface could be constructed so that the edges of the angled surface are beveled. It should be noted that, in addition to a smooth, regular surface, the angled surface could include irregularities such as one or more dimples, bumps, or grooves. In addition, one or more cavities, pits, or openings could be defined on the angled surface 24 .
[0025] In one preferred embodiment, the wedge tip 20 may have a circular cross-section with a diameter 44 as shown in FIG. 6. In an alternative preferred embodiment, the cross-section may be square. In addition, the cross-section may assume a variety of geometries in various other alternative embodiments.
[0026] In one preferred embodiment of the present invention suitable for probing pins set apart by a distance of approximately 0.279 mm or less, the length of wedge tip 20 would be between 1.27 and 3.81 mm, and the angle of angled surface 24 would be between 30 and 45 degrees. The diameter 44 of the cross-section of the wedge tip should be approximately 30-60 percent greater than the distance between adjacent pins. In this exemplary embodiment, the length of the wedge tip would be 0.300 inches, the distance between the top tip end 22 and the bottom base end 26 would be 0.130 inches or 3.3 mm, and the distance between the bottom base end and the bottom 45 of the connector base 28 would be 4.3 mm. In this preferred embodiment, the angle of the angled surface 24 would be 33 degrees. The diameter of the cross-section of the wedge tip would be 0.508 mm. This example is meant to be exemplary and different dimensions could be adopted for other intended purposes.
[0027] The wedge tip 20 is preferably made from electrically conductive material, except that the angled surface 24 a, as shown in FIG. 10, may be coated with a nonconductive material 46 (herein “insulation”). FIG. 11 shows an alternative preferred embodiment of this invention in which the exterior surface of the wedge tip is at least partially coated with insulation, except that the insulation is removed from the angled surface 24 b. In one preferred embodiment, the wedge tip is made from brass and the insulation is made from dip spin hard coat. It should be noted that other materials such as steel, aluminum, or any conductive metal may be used to form the conductive interior of the wedge tip. Similarly, other materials such as plastic, enamel, ceramic, or paint may be used as insulation.
[0028] In the exemplary embodiment shown in FIG. 2, the bottom base end 26 of the wedge tip 20 is attached to a connector base 28 , which may be coupled to a test probe 29 , or otherwise directly or indirectly to a testing instrument. The shown connector base is an elongate member having a circular cross-section. In alternative preferred embodiments, the connector base may have a square cross-section or other cross sectional geometries. The connector base may be integral to the wedge tip, or it may be fastened to the bottom base end. In embodiments where the connector base is fastened to the bottom base end the connector base may be fastened by screwing it into a threaded receptacle in the bottom base end, the connector base may be fastened with glue or cement, or other methods for fastening the bottom base end to the connector base may be used. The shown connector base 28 is meant to be exemplary and may be replaced by any type of connection adapted to mate with an electrical test probe 29 .
[0029] In an alternative preferred embodiment, the wedge tip 20 may be connected directly to a test probe 29 without the connector base 28 . In a further alternative embodiment, the wedge tip may be an integral part of an electrical test probe 29 .
[0030] As shown in FIGS. 2 - 5 , the wedge tip 20 may flare to a shielding head 30 at the bottom base end 26 . In an alternative embodiment, the shielding head 30 may be a symmetrical washer shaped disk. In an additional alternative embodiment, the bottom base end 26 of the wedge tip 20 may connect directly to the connector base 28 without a shielding head.
[0031] A general method for making the wedge tip 20 of the present invention begins with an elongate electrically conductive blank 48 (hereinafter a “blank”) as shown in FIG. 8. Material may be removed from one end, according to the graphical representation shown in FIG. 9, to form the planar angled surface 24 b.
[0032] Specifically, FIG. 9 shows a planar cut or other removal being made at an angle to the longitudinal axis. This creates a blank with an angled surface. A blank with an angled surface may be made by alternate methods including, but not limited to machining, casting, or forging.
[0033] Material may be removed using a variety of methods. In one preferred method, material may be removed by cutting it away. Alternatively, the material may be removed by machining, grinding, filing, or chemical etching. In addition, other methods may be used to remove the material.
[0034] The angled surface insulated wedge tip 50 shown in FIG. 10 may be made using several methods. For example, using the blank with an angled surface, the angled surface 24 a can be coated with insulation 46 .
[0035] The exterior surface insulated wedge tip 52 shown in FIG. 11 may be made using several methods. For example, the exterior surface of the blank with an angled surface may be coated with insulation 46 . Excess insulation may then be removed from the angled surface 24 b, if necessary. Alternately, the blank 48 of FIG. 8 is pre-coated with insulation 46 . Material may then be removed at an angle to the longitudinal axis (as shown in FIG. 9) to form the angled surface 24 b and expose the electrically conductive material of the blank 48 .
[0036] Referring to the embodiment shown in FIG. 10, the signal on an IC pin (herein referred to as the “target pin”) may be measured by inserting the wedge tip 50 so that the back side 38 faces the target pin 54 , and the angled surface 24 faces the adjacent pin. In this manner, if the wedge tip should simultaneously contact both the target pin and the adjacent pin, a short circuit is prevented because the insulated angled surface 24 prevents electric current from flowing between the adjacent pins. Further, the lateral pressure that results when the wedge tip is inserted snugly between the adjacent and target pins results in good electrical contact with the target pin.
[0037] To measure the signal on an IC pin using the embodiment shown in FIG. 11, the wedge tip 52 is inserted so that the angled surface 24 faces the target pin 56 and the back side 38 faces the adjacent pin. The advantages of short circuit protection and good electrical contact described above are similarly present with this embodiment.
[0038] The terms and expressions that have been employed in the foregoing specification are used as terms of description and not of limitation, and are not intended to exclude equivalents of the features shown and described or portions of them. The scope of the invention is defined and limited only by the claims that follow. | An electrical test probe wedge tip according to the present invention includes an electrically conductive interior optionally surrounded, at least partially, by an electrically insulated exterior surface. A longitudinal axis extends the length of the electrical test probe tip. In one preferred embodiment the top tip end has a single planar surface at an angle to the longitudinal axis. A method of fabricating an electrical test probe tip includes providing an elongate electrically conductive blank coated with insulation. An angled surface is exposed by removing a portion of the first end along a plane at an angle to the longitudinal axis of the blank. | 6 |
BACKGROUND
[0001] A. Technical Field
[0002] The present invention relates to inductive switching converters and, more particularly, to systems, devices, and methods of utilizing zero-current and zero-voltage switching to reduce transition losses in DC/DC converters.
[0003] B. Background of the Invention
[0004] The electronics industry has continually demanded higher switching regulator efficiencies. Switching regulators transfer energy from a given input voltage level to a higher or lower output voltage level for delivery to a load. Inductive switching converters take advantage of in important physical property of inductors, the resistance to any changes to the current the inductor carries, in order to transform an input voltage to a desired output voltage. The level of the output voltage is adjusted by controlling the operation of active switching elements within the switching regulator.
[0005] Typical efficiencies of DC/DC converters have reached about 96%, such that a reduction of power losses by an additional one or two percent can reduce existing power losses by as much as 50%. Aside from conduction losses in the turned on active devices, which are typically transistor power switches, one major source of power dissipation in switching regulators are transition losses. There are two types of transition losses that occur during the switching process, the first type is capacitive loss resulting from charging and discharging a parasitic capacitance at the switching node of the converter. The second type of transition loss is conduction loss associated with turning on a power switch having a large voltage and non-zero inductor current present at the same time. This second type of transition loss is exacerbated by reverse recovery current in the power switch due to the body diode in the switch being forward biased.
[0006] Some existing approaches reduce switching power losses by avoiding transitions from a low voltage to a high voltage by applying zero voltage switching (ZVS) or zero current switching (ZCS) methods. In order to perform ZVS, by definition, the voltage across a switch needs to be at a near zero value at the time the switch is being turned on. However, existing ZVS or ZCS topologies have major drawbacks. For example, ZVS or ZCS buck converter topologies require (lossy) discontinuous current mode operation with average inductor current values that have to be approximately two times larger than the output current, as the inductor needs to reach zero for the switching regulator to actually perform ZVS or ZCS. A 10 A output current, for example, typically requires a 20 A peak current. Existing ZVS or ZCS topologies, by definition, require an inductor current that approaches zero, thus, conduction losses are typically more than twice as high as in continuous current buck converters that have very low ripple content. Alternative approaches address this problem by either employing resonant or critical conduction topologies. However, these approaches create more problems than they solve and do not result in higher system efficiency at higher ripple currents due to increased conduction losses associated with resonant or critical conduction topologies. What is needed are tools for switching regulator designers to overcome the above-described limitations.
SUMMARY OF THE INVENTION
[0007] Embodiments of the invention effectively eliminate losses associated with hard switching of power MOSFETs in various switching regulator topologies utilizing continuous current converter switching. Certain embodiments of the invention provide for reduced transition losses by employing a novel ZVS method that allows either voltage transitions to occur without activating the power MOSFET switch; a novel type of ZCS switching that allows current in a power MOSFET switch to be near zero prior to activating the switch, thereby, removing the loss factor of current in the switch while transitioning when voltage is present across the switch; and a novel type of switching that, herein, is referred to as Negative Current Switching (NCS), which terminology is not common to those skilled in the art. NCS allows for further reduction of switching losses by switching at a time when the current is flowing in the same direction that the switch is trying to move a voltage node coupled to the switch.
[0008] Certain embodiments of the invention allow to eliminate losses associated with body diode reverse recovery current in power MOSFET body diodes, thereby, eliminating the need for additional, fairly complex circuitry to minimize body diode reverse recovery currents.
[0009] In particular, in certain embodiments, zero volt switching and zero current switching is accomplished by adding a relatively low value inductor in series with a higher value inductor within a switching regulator; adding two switching devices to the output path; and timing all switching devices in a manner such as to cause the stored energy in the low value inductor to enable ZCS, NCS or transition the output node from one voltage to another voltage without power losses otherwise associated with resistive switches. In some embodiments, one high-side switch is operated to perform ZVS, while a second high-side switch is operated to selectively perform one of ZVS, NCS, or ZCS.
[0010] Certain features and advantages of the present invention have been generally described here; however, additional features, advantages, and embodiments presented herein will be apparent to one of ordinary skill in the art in view of the drawings, specification, and claims hereof. Accordingly, it should be understood that the scope of the invention is not limited by the particular embodiments disclosed in this summary section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Reference will be made to embodiments of the invention, examples of which may be illustrated in the accompanying figures. These figures are intended to be illustrative, not limiting. Although the invention is generally described in the context of these embodiments, it should be understood that it is not intended to limit the scope of the invention to these particular embodiments.
[0012] FIG. 1A is a schematic of a prior art buck converter.
[0013] FIG. 1B illustrates a typical prior art timing diagram for the prior art buck converter of FIG. 1A .
[0014] FIG. 2 is a schematic of an illustrative buck converter circuit utilizing, zero current switching, or negative current switching, according to various embodiments of the invention.
[0015] FIG. 3 illustrates an idealized version of a typical timing diagram for the buck converter circuit in FIG. 2 , according to various embodiments of the invention.
[0016] FIG. 4A through FIG. 4E illustrate exemplary current distributions between two series inductors of the buck converter circuit in FIG. 2 , according to various embodiments of the invention.
[0017] FIG. 5 shows a partial view of timing diagram in FIG. 3 .
[0018] FIG. 6 is a flowchart of an illustrative process for zero volt switching, zero current switching, or negative current switching, in accordance with various embodiments of the invention.
[0019] FIG. 7 is a schematic of an illustrative boost converter circuit utilizing zero volt switching, zero current switching, or negative current switching, according to various embodiments of the invention.
[0020] FIG. 8 illustrates a typical timing diagram for the boost converter circuit in FIG. 7 , according to various embodiments of the invention.
[0021] FIG. 9 is a schematic of an illustrative buck-boost converter circuit utilizing zero volt switching, zero current switching, or negative current switching, according to various embodiments of the invention.
[0022] FIG. 10 illustrates a typical timing diagram for the buck-boost circuit in FIG. 9 , according to various embodiments of the invention.
[0023] FIG. 11 illustrates a typical timing diagram for the buck circuit in FIG. 2 , utilizing zero voltage switching and zero current switching, according to various embodiments of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0024] In the following description, for the purpose of explanation, specific details are set forth in order to provide an understanding of the invention. It will be apparent, however, to one skilled in the art that the invention may be practiced without these details. One skilled in the art will recognize that embodiments of the present invention, described below, may be performed in a variety of ways and using a variety of means. Those skilled in the art will also recognize that additional modifications, applications, and embodiments are within the scope thereof, as are additional fields in which the invention may provide utility. Accordingly, the embodiments described below are illustrative of specific embodiments of the invention and are meant to avoid obscuring the invention.
[0025] Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearance of the phrase “in one embodiment,” “in an embodiment,” or the like in various places in the specification are not necessarily referring to the same embodiment.
[0026] Furthermore, connections between components or between method steps in the figures are not restricted to connections that are affected directly. Instead, connections illustrated in the figures between components or method steps may be modified or otherwise changed through the addition thereto of intermediary components or method steps, without departing from the teachings of the present invention.
[0027] In this document the term “inductor” refers to any inductive element capable of storing magnetic energy, the term “capacitor” refers to any capacitive element capable of storing electric energy recognized by one of skilled in the art, and the term “switch” refers to any type of switching device recognized by one of skilled in the art. It is noted that timing diagrams herein are not drawn to scale and gate voltages are drawn relative to gate to source voltages and represent merely qualitative transitions between on and off states. Switches and their gate potentials are sometimes referred to interchangeably. Although only a selected number of circuit designs are shown and discussed, it is envisioned that the invention applies equally to other switching regulator topologies, such as forward converters, two-switch H-bridges, four-switch forward converters, etc. It is further noted that all references to ZCS equally applicable to NCS.
[0028] FIG. 1A is a schematic of a prior art buck converter. Buck converter 100 is a step-down converter that is commonly used whenever the input voltage is greater than a desired load voltage. Buck converter 100 comprises voltage input terminal 102 , high-side switch DH 104 , low-side switch DL 106 , inductor 110 , and output capacitor C OUT 114 . High-side switch DH 104 , low-side switch DL 106 , and inductor 110 , are coupled to each other via voltage node LX 108 . Since switching processes in buck converter 100 generate unwanted AC ripple noise, output capacitor C OUT 114 is placed at the output, such that output capacitor C OUT 114 and inductor 110 form a low-pass filter that functions to remove the noise from the output terminal V OUT 112 of buck converter 100 in order to obtain a DC voltage at the load that is coupled to the output terminal V OUT 112 . The inductance value of inductor L 110 and capacitance value C OUT of output capacitor C OUT 114 are chosen to limit the ripple on V OUT 112 to an acceptable range that is determined by the requirements of the load and the feedback of buck regulator 100 .
[0029] Control circuitry (not shown) controls the current flowing through inductor 110 by controlling the on time and off times of switches 104 , 106 , for example, via a PWM controller. The signal at output terminal V OUT 112 is typically fed back to an input of the PWM controller to adjust the V OUT accordingly.
[0030] As will be explained next, during switching events, switch 104 dissipates power due to the presence of current and voltage across it during the entire time the voltage at node LX 108 rises from a ground potential to the supply voltage V IN 102 . In addition, a low-side body diode reverse recovery current causes losses within an intrinsic diode in switch 104 and large supply current spikes due to the sequence in which switches 104 and 106 are turned on and off in continuous mode. Therefore, in addition to dissipating heat caused by switching, buck converter 100 dissipates heat in the diode itself.
[0031] FIG. 1B illustrates a typical prior art timing diagram for the prior art buck converter of FIG. 1A . In such conventional buck converters, high-side switch 156 turns off at time t1 160 , which causes the voltage at node LX 154 to decrease toward zero, and inductor current I L 152 to decrease relatively slowly. A short time after the voltage at node LX 154 reaches zero, at time t2 170 , low-side switch 158 is turned on. Since the voltage at node LX 154 is already near zero, low-side switch 158 switches with zero voltage due to the nature of the buck converter.
[0032] However, at the end of the “off time” of high-side switch 156 , at time t4 190 , when the output node of the switching regulator switches from a low state to a high state, high-side switch 156 turns on with a positive current I DH 151 that is equal to inductor current I L 152 , while node LX 154 is still at ground potential. During this transition that high-side switch 156 turns on, current I DH 151 (typically the average output current) flows through the inductor and high-side switch 156 between t4 190 and time t5 192 . As a result, switch 156 dissipates power due to the presence of current and voltage across it at the same time. This unnecessarily causes power dissipation in switch 156 . Therefore, in order to increase efficiency and avoid switching losses associated with hard switching of high-side power MOSFETs, it would be desirable to have transitions occur without having voltage and current applied to power MOSFET switches at the same time.
[0033] FIG. 2 is a schematic of an illustrative buck converter circuit utilizing zero volt switching, zero current switching, or negative current switching, according to various embodiments of the invention. Buck converter 200 comprises high-side switches DHA 202 and DHB 206 , low-side switches DLA 204 and DLB 208 , inductor 210 , inductor 232 , voltage input terminal 216 , and output capacitor C OUT 234 . High-side switch DHA 202 and low-side switch DLA 204 are coupled to each other at voltage node LXA 230 , while high-side switch DHB 206 and low-side switch DLB 208 are coupled to each other at voltage node LXB 220 . Inductor L1 232 and inductor L2 210 are coupled in a series configuration and comprise a common voltage node, here, LXA 230 . Output capacitor C OUT 234 is coupled to output terminal 240 and inductor L1 232 .
[0034] In one embodiment, inductor 210 is an inductive element that has an inductance value that is sufficiently low so as to be implemented into the lead-frame or a PCB trace coupled to buck converter 200 . This reduces complexity of the inductor design as well as cost. The inductance of inductor 210 may be 20 nH or, for example, 10% of the inductance value of inductor 232 . Switches DHA 202 and DLA 204 may be designed 1/10th of the size of switching devices DHB 206 and DLB 208 , respectively. In one embodiment, low-side switches DLA 204 and DLB 208 may be implemented as Schottky diodes. Next, it will be explained how buck converter 200 is operated in such a manner that the energy stored in inductor 210 can be used to enable zero current switching or zero voltage switching of LXA 230 and LXB 220 .
[0035] FIG. 3 illustrates an idealized version of a typical timing diagram for the buck converter circuit shown in FIG. 2 . Timing diagram 300 shows exemplary inductor currents I L1 302 , I L2 304 and node voltages LXB 306 and LXA 308 as well as logic levels of gates 310 - 316 . In one embodiment, as shown in example in FIG. 3 , at time t1 320 , currents I L1 302 and I L2 304 through inductors L1 and L2 (not shown), respectively, are about equal (e.g., 15 A). High-side switch DHB 312 on node LXB 306 is turned off first and then low-side switches DLA 314 and DLB 316 are turned on, and high-side switch DHA 310 on node LXA 308 remains turned off. As a result, switches DLA 314 and DLB 316 short to ground both terminals of the inductor carrying I L2 304 and cause significantly constant circulating currents to flow in inductor L2 as the voltage though inductor L2 and, thus, di/dt equals zero. In other words, during the off time of high-side switch DHA 314 , the shorting to ground both sides of the smaller inductor causes the current in the smaller inductor to reduce only relatively slightly (e.g., from 15 A to 14.5 A) while the voltage across the inductor is approximately zero.
[0036] In contrast, since only one node of the inductor L1 is grounded, this allows current I L1 302 to continuously decrease by an amount representative of the system ripple (e.g., from 15 A to 12 A), such that toward the end of the off time of high-side switch DHA 310 , at time t2 330 , the smaller inductor L2 carries a greater current I L2 304 (e.g., 14.5 A) than the larger inductor L1 (e.g., 12 A). Once common node LXA 308 between the two inductors is released by turning off low-side switch DLA 314 , due to the energy stored in the smaller inductor, the voltage at node LXA 308 automatically rises, for example, to a top rail voltage, i.e., to the supply voltage applied to the buck converter. In other words, by opening switch DLA 314 , current I L2 304 in the inductor L2 forces the voltage on node LXA 308 to rise.
[0037] When the voltage at voltage node LXA 308 reaches the top rail voltage, here V IN , high-side switch DHA 310 is turned on without any voltage across it, i.e., with zero volt switching. Since the voltage on node LXA 308 reaches the top rail voltage without turning on any switch that has voltage and current present at the same time, zero voltage switching is achieved and switching losses are avoided. After time t2 330 , current I L2 304 in the inductor L2 rapidly diminishes to 0 A or below.
[0038] In one embodiment, once current I L2 304 reaches zero at time t4 350 , the status of switch DLB 316 changes from closed to open. This couples the input voltage to output voltage via the inductor L1 232 , which allows node LXB 306 to rise and reach a value equal to the top rail voltage at time t5 360 . Since the voltage on node LXB 306 rises before switch DHB 312 is turned on at time t5 360 , the transition of switch DHB 312 occurs without any voltage drop or current present. As a result, zero-volt switching is achieved also on switch DHB 312 and switching losses are successfully avoided. After switch DHB 312 is turned on, switch DHA 310 is turned off allowing node LXA 308 to fall due to the imbalance of the currents in the two inductors. In one embodiment, prior to LXB 306 rising another method of implementing this invention would be to turn on DHB 312 while LXB is near ground and force ZCS or NCS.
[0039] At time t6 370 , once current I L2 304 reaches the same value as current I L1 302 (e.g., 12.5 A), the voltage at node LXA 308 increases to a value that is slightly lower than the voltage at node LXB 306 . At this time the two inductors are in series with the output and the current flowing through both inductors ramps up while delivering increasing current to the output. At time t7 380 , switch DHB 312 turns off, opening the direct current path from the input of the buck converter through the series inductors to the output. Turning on low-side switches DLA 314 and DLB 316 allows both node voltages LXA 308 and LXB 306 to fall to ground. After LXB 306 falls below ground and then forward biases the body diode of switch DLB 316 , DLB 316 and DLA 314 turn on shorting out the inductor L2. Current I L2 304 remains relatively constant while current I L1 302 starts to decrease, such that both currents begin to drift apart again and being the cycle anew.
[0040] In one embodiment, not shown in FIG. 3 , LXB 306 transitions high when DHB 312 turns on and employs ZCS instead of ZVS. At time t4 340 , switch DHB 312 is turned on and the switching of node LXB 306 employs ZCS as the sum of the currents in both inductors is greater than or equal to zero. In this ZCS example, switching is NCS since the sum of the currents is negative (e.g., 12 A-14.5 A=−2.5 A). NCS does provide the benefits of ZCS even if switching does not occur exactly at zero current. Switch DHB 312 charges an intrinsic parasitic capacitance with a parasitic current and carries load current I L1 302 during the transition. The negative current I L2 304 subtracts from the parasitic current associated with charging and discharging parasitic capacitances. However, overall system losses are not necessarily reduced by the additional reduction of losses in the switch using NCS since current I L2 304 and the parasitic current do not entirely cancel each other because the amount of energy required to enable negative current switching to turn the parasitic current negative is equal to the reduction of losses gained from charging or discharging of the parasitic capacitance. Therefore, the reduction in losses employing NCS and ZCS are substantially equal.
[0041] It is noted that any level shifting voltages have been excluded from FIG. 3 and other timing diagrams herein. Gate voltages 310 - 316 represent qualitative transitions between the on and off state of each switch. Since the timing diagram is not drawn to scale, currents I L1 302 and I L2 304 appear different in the between times t6 370 and t8 390 but in fact are equal. In practice, current I L2 304 may transition to a relatively large negative value. For example, current 304 may reach a negative value that has an amplitude equal to its positive amplitude. Current I L2 304 may assume any value that is suitable to cause voltage node LXB 306 to rise.
[0042] One of ordinary skill in the art will appreciate that absolute values can be manipulated, for example, via level shifting devices. It is understood that additional circuit components, such as noise suppression elements or controllers, such as a duty cycle controller, are employed to aid in the operation of the invention. One skilled in the art will also appreciate that a controller may control the output voltage with various methods, including duty cycle control and frequency control of high-side switches and low-side switches.
[0043] FIG. 4A through FIG. 4E illustrate exemplary current distributions between two series inductors of the buck converter circuit in FIG. 2 , according to various embodiments of the invention. The schematics show various conditions that buck converter 402 assumes. Arrows 410 indicate how the conditions align with the timing diagram in FIG. 5 . FIG. 5 shows a partial view of timing diagram in FIG. 3 . For purposes of clarity, only the timing events for the currents and gate voltages are shown in FIG. 5 .
[0044] FIG. 6 is a flowchart of an illustrative process to perform zero volt switching, zero current switching, or negative current switching, in accordance with various embodiments of the invention. The process starts at step 601 when two inductors L1 and L2 that are coupled in a series configuration are provided. Each inductor comprises an inductance value that is typically different from the other.
[0045] At step 602 , a second high-side switch is turned on to establish a relatively equal current in both inductors.
[0046] At step 603 , the second high-side switch is turned off, for example, in response to a control loop that regulates the output voltage.
[0047] At step 604 , both low side switches are turned on this in affect inductor L2 is short circuited, for example, via ground in order to maintain a relatively constant current flow through inductor L2.
[0048] At step 606 , a first low-side switch is turned off, for example, in response to a control loop that regulates an output voltage.
[0049] At step 608 , a first high-side switch is turned on, for example, in response to a voltage at one terminal of the first high-side switch reaching an input voltage, thereby, making the switching event a zero-voltage switching.
[0050] Finally, at step 610 , a second low-side switch is turned off enabling zero current or zero voltage switching, and then the loop continues by going back to step 602
[0051] It will be appreciated by those skilled in the art that fewer or additional steps may be incorporated with the steps illustrated herein without departing from the scope of the invention. No particular order is implied by the arrangement of blocks within the flowchart or the description herein.
[0052] FIG. 7 is a schematic of an illustrative boost converter circuit utilizing zero volt switching, zero current switching, or negative current switching, according to various embodiments of the invention. Boost converter 700 is a step-up converter that is commonly used whenever the input voltage is lower than the desired load voltage. Boost converter 700 comprises high-side switches DHA 706 and DHB 702 , low-side switches DLA 708 and DLB 704 , inductor 710 , input terminal 716 , output terminal 740 , and output capacitor C OUT 734 . High-side switch DHA 706 and low-side switch DLA 708 are coupled to each other at voltage node LXA 720 , while high-side switch DHB 702 and low-side switch DLB 704 are coupled to each other at voltage node LXB 730 . Inductor L1 732 is coupled to input terminal 716 . Output capacitor C OUT 734 is coupled to output terminal 740 . Inductor L1 732 and inductor L2 710 are coupled in a series configuration and comprise common voltage node LXA 230 . In one embodiment, high-side switches DHA 706 and DHB 702 may be implemented as Schottky diodes. One of ordinary skill in the art will appreciate that in boost converter 700 voltages on nodes LXA 720 and LXB 730 are higher than the voltage at input terminal 716 .
[0053] FIG. 8 illustrates a typical timing diagram for the boost converter circuit in FIG. 7 , according to various embodiments of the invention. FIG. 8 illustrates a more realistic timing diagram than the timing diagram in FIG. 3 . Timing diagram 800 shows exemplary inductor currents I L1 802 , I L2 804 , LXB 806 , and LXA 808 , and gate voltages 810 - 816 . Various glitches, such as glitch 818 that occurs on LXA 808 and LXB 806 just before time t1 820 result from the effect of turning off a current flowing in an inductor with a switch. Since the body diodes stop the current in the inductor from continuing to flow, the current can only reach one body diode voltage above the input voltage V IN or one body diode voltage below ground potential (typically 0 V).
[0054] Prior to the transition at time t1 820 , the only switch active between the input voltage V IN and ground potential is switch DLB 816 , such that the only connection between V IN and ground is switch DLB 816 and inductors L1 and L2 (not shown). Currents I L1 802 and I L2 804 through inductors L1 and L2 are substantially equal when at time t1 820 low-side switch DLB 816 on node LXB 806 is turned off, both high-side switches DHA 810 and DHB 812 are turned on simultaneously, and high-side switch DHA 810 on node LXA 808 remains turned off. As a result, switches DHA 810 and DHB 812 short the inductor carrying I L2 804 and cause significantly constant circulating currents to flow in inductor L2, while I L1 802 decreases relatively rapidly. Note that as before, I L1 802 is only a ripple current and is not drawn to the same scale as I L2 804 .
[0055] Next, at time t2 830 , switch DHA 810 is turned off, i.e., node LXA 808 between the two inductors L1 and L2 is turned off. Since current I L2 804 in the smaller inductor is larger than current I L1 802 in the larger inductor L1, inductor L2 transitions the energy stored in the smaller inductor to the parasitic capacitance on node LXB and forces the voltage at node LXA 808 below ground. When the voltage at voltage node LXA 808 reaches zero, low-side switch DLA 814 is turned on at time t3 840 without any voltage across it, i.e., with zero volt switching. Since the voltage on node LXA 808 reaches the fall to zero without turning on any switch that has either a voltage or a current present at the same time, zero voltage switching is achieved and switching losses are successfully avoided.
[0056] In one embodiment, when switch DHA 810 is turned on at time t5 860 , ZCS or NCS is employed since the current in the two inductors cause I L2 804 to be equal or less than zero. ZCS and NCS provide comparable efficiency savings when compared to ZVS, because the power loss in inductor L1 resulting from NCS is similar to the power loss resulting from the transition with ZCS.
[0057] As in the buck configuration, after time t2 830 , current I L2 804 in the inductor L2 rapidly diminishes to 0 A or below. Once current I L2 804 reaches zero, at time t4 850 , the status of switch DHB 812 is allowed to change from closed to open after which time the voltage on LXB 806 decays relatively little, until, at time t5 860 , switch DLB 816 turns on and connects LXB 808 to ground potential. At that point the voltage on LXB 806 rapidly drops toward zero and employs ZCS or NCS on DHA 810 due to current I L2 804 being equal or less than zero.
[0058] Between t6 870 and t7 880 , DLA 814 is turned on. Once DLA 814 is turned off at time t7 880 , currents in I L1 1002 and I L2 1004 are allowed to equalize. Stray capacitances present in the inductors may cause a temporary ringing effect 872 that decays relatively rapidly as shown in FIG. 8 , until node voltage LXA 808 settles to a common voltage 874 that is slightly lower than voltage 862 due to the fact that node voltage LXA 808 is not tied to either switch DHA 1010 or DLA 1014 , but floating between two series inductors L1 and L2. The amplitude of voltage 874 , i.e., the value below the supply voltage V IN to which voltage node LXA 808 adjusts is determined by the ratio of the inductances of L1 and L2. For example, if the ratio is 10:1, node voltage LXA 808 would increase by 10% relative to ground. If inductors L1 and L2 had equal inductances, the increase would be 50%, etc. Then, at time t8 890 when currents I L1 802 and I L2 804 are substantially equal again, the cycle repeats.
[0059] FIG. 9 is a schematic of an illustrative buck-boost converter circuit utilizing zero volt switching, zero current switching, or negative current switching, according to various embodiments of the invention. Buck-Boost converter 900 comprises high-side switches DHA 902 and DHB 906 , low-side switches DLA 904 and DLB 908 , inductor 910 , voltage input terminal 916 , and output capacitor C OUT 934 . High-side switch DHA 902 and low-side switch DLA 904 are coupled to each other at voltage node LXA 930 , while high-side switch DHB 906 and low-side switch DLB 908 are coupled to each other at voltage node LXB 920 . Inductor L1 932 and inductor L2 910 are coupled in a series configuration and comprise a common voltage node LXA 930 . Output capacitor C OUT 934 is coupled to output terminal 940 of output capacitor 934 . In example in FIG. 9 , buck-boost converter 900 operates as an inverting converter.
[0060] FIG. 10 illustrates a typical timing diagram for the buck-boost circuit in FIG. 9 , according to various embodiments of the invention. Similar to the buck converter timing diagram in FIG. 3 , timing diagram 1000 in FIG. 10 shows exemplary inductor currents I L1 1002 , I L2 1004 and gate voltages 1006 - 1016 . In example in FIG. 10 , prior to time t1 1020 , the only switch that is active is switch DHB 1012 , such that the only connection between V IN and ground is switch DHB 1012 in series with inductors L2 and L1. As a result, the current flows from V IN through both inductors, such that the current through both inductors are equal.
[0061] At time t1 1020 , currents I L1 1002 and I L2 1004 through inductors L1 and L2 are about equal. Following glitch 1018 of about one diode voltage below ground in both LXA 1006 and LXB 1008 , high-side switch DHB 1012 is turned off and low-side switches DLA 1014 and DLB 1016 are turned on. As a result, current I L2 1004 is shorted out and circulates through inductor L2 with relatively constant amplitude, as shown in FIG. 10 . As in the buck converter configuration in FIG. 2 , since only one node of inductor L1 is grounded, current I L1 1002 continuously decays at a relatively faster rate than I L2 1004 , such that by time t2 1030 , inductor L2 carries a greater current I L2 1004 than the inductor L1.
[0062] When common node LXA 1008 between the two inductors is released by opening low-side switch DLA 1014 , at time t2 1030 , the energy stored in the smaller inductor L2 causes the voltage at node LXA 1008 to rise to V IN , while current I L2 1004 in the inductor L2 rapidly diminishes to 0 A or below. Transitioning the energy from inductor L2 allows node LXA 1008 to rise toward the top rail voltage. As a result, at time t3 1040 , after another short glitch to about one diode voltage above V IN , switch DHA 1010 turns on with zero voltage switching without experiencing switching losses. In one embodiment, DHA 1010 is turned on shortly after time t2 1030 to employ NCS since node LXA 1008 has negative current at time t2 1030 .
[0063] Next, at time t4 1040 , when current I L2 1004 reaches zero, switch DLB 1030 is turned off. This allows voltage node LXB 1006 to rise to V IN , which allows DHB 1012 to transition with zero voltage switching shortly after t5 1060 when LXA 1008 falls below ground potential. In other words, each high-side switch DHA 1010 and DHB 1012 transitions with zero voltage switching at its respective voltage node.
[0064] When DHA 1010 is turned off at t7 1080 , currents 1002 and I L2 1004 in L1 and L2 can equalize. Stray capacitances associated with inductors L1 and L2 can cause a temporary ringing 1074 , until the voltage at node LXA 1008 settles to common voltage 1074 . Common voltage 1074 is slightly lower than before time t7 1080 since node voltage LXA 1008 is not tied to either switch DHA 1010 or DLA 1014 , but floating between two series inductors L1 and L2. Similar to the boost converter in FIG. 7 , the value below the supply voltage V IN to which voltage node LXA 1008 adjusts is determined by the ratio of the inductances of L1 and L2. Finally, at time t8 1090 when currents I L1 1002 and I L2 1004 are substantially equal again, the cycle repeats.
[0065] FIG. 11 illustrates a typical timing diagram for the buck circuit in FIG. 2 , utilizing zero voltage switching and zero current switching, according to various embodiments of the invention. The switching period form t1 1118 to time t6 1123 employs ZVS. During this phase, switches DHA 1110 and DHB 1112 transition to a high state at time t2 1130 and t4 1121 , respectively, when the voltage across the respective switch is near or equal to zero. The switching period form time t7 1124 to time t10 1127 employs NCS and ZCS. During this phase, switch DHA 1110 transitions high when the current flowing through the switch is negative due to the difference in inductor currents I L1 1102 and I L2 1104 . As illustrated in FIG. 11 , DHB 1112 transitions high with ZCS at time t8 1125 when current I L2 1104 in the switch crosses zero. The system efficiency of these two different types of switching have similar efficiencies that exceed existing switching schemes.
[0066] It will be appreciated that the preceding examples and embodiments are exemplary and are for the purposes of clarity and understanding and not limiting to the scope of the present invention. It is intended that all permutations, enhancements, equivalents, combinations, and improvements thereto that are apparent to those skilled in the art, upon a reading of the specification and a study of the drawings, are included within the scope of the present invention. It is therefore intended that the claims include all such modifications, permutations, and equivalents as fall within the true spirit and scope of the present invention. | Various embodiments of the invention reduce switching losses associated with existing non-zero volt switching and non-zero current switching in DC/DC converters without the need for a resonant design. Certain embodiments of the invention provide for improved efficiency by reducing switching losses related to the simultaneous presence of current and voltage across high power switching devices. In certain embodiments, this is accomplished by adding a relatively small inductor and two switching elements to various switching regulator topologies. Energy stored in the inductor is used to transition the output of the switching converter to achieve zero volt switching and zero current switching. | 7 |
BACKGROUND
[0001] In the hydrocarbon recovery industry boreholes are drilled to access hydrocarbon bearing formations for the purpose of extracting target fluids be the fluid gas, oil or a combination of fluids. While traditionally boreholes were drilled substantially vertically and therefore orientation of a bottom hole assembly could be relatively accurately tracked by tracking the orientation of the string at the surface, orientation in highly deviated or horizontal wells that are more common today is difficult and accuracy is limited. This is due in part to the frictional factors encountered as a string of several thousand feet is driven into the low side borehole wall. Because it is difficult to measure the friction all the way up the string, it is difficult to resolve the forces that act on the string and affect actual orientation downhole relative to apparent orientation at the surface.
[0002] Being able to accurately determine orientation in the downhole environment facilitates many operational interests. Therefore, the art is always receptive to new methods and apparatus that improve or enable orientation in the downhole environment.
SUMMARY
[0003] A pressure orienting swivel arrangement including a weight assembly and a pin adapter reactably interengagable with the weight assembly to orient the pin adapter to the weight assembly.
[0004] A pressure orienting swivel arrangement including a housing, a spring compression mandrel within the housing, a spring disposed about the spring compression mandrel, a weight assembly rotatably supported in the housing, and a pin adaptor rotatably supported within the housing and reactably interengagable with the weight assembly to accept a torque from the weight assembly.
[0005] A method for orienting a downhole tool including gravitationally orienting a weight assembly, interengaging a pin adapter and inducing rotation in the pin adapter with the weight assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Referring now to the drawings wherein like elements are numbered alike in the several Figures:
[0007] FIG. 1 is a cross section view of one embodiment of a pressure orienting swivel arrangement in a non-actuated position;
[0008] FIG. 2 is a cross section view of one embodiment of a pressure orienting swivel arrangement in an actuated position;
[0009] FIG. 3 is a perspective view of a weight assembly of the arrangement;
[0010] FIG. 4 is a perspective view of a gear ring of the arrangement;
[0011] FIG. 5 is a perspective view of a pin adaptor of the arrangement.
DETAILED DESCRIPTION
[0012] Referring to FIGS. 1 and 2 , a non-actuated position and an actuated position, respectively, of one embodiment of a Pressure Orienting Swivel arrangement 10 is illustrated. A comparison of the locations of various component of the arrangement in the two figures will provide an overview for the following description of the individual components and their interactions.
[0013] Referring to FIG. 1 , and beginning at an uphole end of the arrangement (left side of the figure as per convention) a top sub 12 can be seen. Top sub 12 is fixedly attached to a spring housing 14 at a threaded connection 16 . The top sub 12 includes an inside surface 18 that defines the outer most region of a fluid pathway 20 through which pressurization fluid is applied to the arrangement 10 when actuation thereof is desired. Further the top sub 12 includes a seal recess 22 receptive to a seal such as an o-ring (not specifically depicted due to scale, and not needed due to knowledge in the art). Slidably disposed within the inside surface 18 is a seal sleeve 24 .
[0014] The seal sleeve 24 is attached at a downhole end thereof to a spring compression mandrel 26 at an interconnection point 28 . The seal sleeve 24 provides a spring shoulder 30 upon which an uphole end 32 of a spring 34 bears during actuation of the arrangement 10 . A downhole end 36 of the spring 34 bears against a bushing 38 or other surface capable of supporting the spring 34 when under compression during actuation of the arrangement.
[0015] Adjacent the bushing 38 and through the spring housing 14 is one or more fluid displacement pathway(s) 40 (two shown) within each of which is a filter material 42 in one embodiment of the arrangement 10 . This provision allows for fluid to move into or out of the arrangement while the arrangement is being actuated or released from the actuated position to avoid the potential for hydraulic locking or inhibition of movement of the components of the arrangement 10 due to hydraulic forces created by fluid in the arrangement.
[0016] Downhole of the spring housing 14 and fixedly attached thereto is an extension sleeve 44 . The extension sleeve supports a pin 48 fitted to rotationally constrain a gear ring 72 . Within the extension sleeve 44 , a weight assembly 50 is supported on the spring compression mandrel 26 at bearing 46 and bearing 52 . Between the bearings 46 and 52 , the weight assembly is balanced axially to promote a relatively frictionless rotational movement within the arrangement 10 . This is a useful attribute for the arrangement because it facilitates the self-orientation of the weight assembly 50 . Orientation of the weight assembly 50 is important to the function of the arrangement 10 . Further the construction of the weight assembly 50 facilitates operation of the arrangement 10 . Referring to FIG. 3 , an enlarged view of the weight assembly 50 is provided for clarity of its construction. The weight assembly comprises a cage 52 , a weight 54 , a key 56 and an orientation torque producer 58 . It will be appreciated from the figure that the weight 54 extends, in this embodiment, about one half of the cage 52 . The purpose of the weight is to cause that the weight assembly 50 orient itself to gravity. In a horizontal or highly deviated well, this ensures that an operator can count on a correct orientation of at least one component in the wellbore. Because the orientation of the weight assembly 50 is known, a desired orientation of another component of the arrangement 10 can be set using the weight assembly 50 as the known. The weight assembly rotates itself only and therefore does not suffer from the drawbacks of prior art devices that have attempted to use an offset weight to orient target tools. Rather the weight assembly as disclosed herein has an overall mass that is substantially concentrated in the weight 54 and therefore only a very small percentage in the cage 52 and key 56 .
[0017] Importantly then the weight assembly also features an orientation torque producer 58 that functions to orient another component of the arrangement 10 to the weight assembly 50 . It is this function that allows an operator to set a desired orientation of this separate component. The component is a pin adapter 70 identified in FIGS. 1 , 2 and 5 . Because the weight assembly will find gravity and the pin adapter will orient to the weight assembly, a specifically positioned tool attached to the pin adapter 70 will have a known orientation when the arrangement is actuated.
[0018] Referring for a moment back to FIGS. 1 and 2 , further components of the arrangement 10 are identified to improve clarity of the discussion regarding the actuation of the arrangement. A gear ring 72 is positioned at a downhole end of extension sleeve 44 and is pinned in place rotationally by pin 48 . Reference to FIG. 4 makes clear the construction of gear ring 72 including a plurality of gear teeth 74 and lead in ramps 76 to help facilitate engagement therewith by the key 56 to prevent rotational movement of the weight assembly when that assembly is engaged with the gear ring 72 . Prevention of rotational movement of the weight assembly means that all of the torque production capability of the orientation torque producer 58 , in this embodiment a helical profile, is available to turn the pin adapter 70 . The pin adapter rotates within a pin adapter housing 78 which itself is joined to the extension sleeve 44 by a stop sleeve 80 . The pin adapter 70 , in this embodiment is supported within the housing 78 by a radial type bearing 82 and a thrust bearing 84 . A seal 86 is provided between the pin adapter 70 and the spring compression mandrel 26 to seal the arrangement and working with seal 22 for pressure based operation.
[0019] At a downhole end of the arrangement 10 ( FIGS. 1 , 2 and 5 ) is a pin adapter tail 88 that features an orientation indicator such as a groove 90 that will always be in a position opposed to gravity when the arrangement is actuated because of the interaction between pin adapter 70 and weight assembly 50 , which occurs at torque producer 58 of assembly 50 and a complementary profile 92 in this embodiment. The groove thus allows an operator to connect a tool at a specific desired orientation in the wellbore. One such tool is, as illustrated here, a perforation nozzle sub 94 having nozzle receptacles 96 . It will of course be understood that any tool could be attached to the pin adapter as desired or required for a particular application.
[0020] In operation, the arrangement 10 is assembled at surface with a tool 94 oriented to the groove 90 so that the tool will have the ultimate desired orientation in the wellbore when the arrangement reaches a target depth and achieves the actuated position. The arrangement is then run in the hole until it reaches the target location. Pressure supplied to the pathway 20 acts upon the arrangement to urge a number of its components in the downhole direction. These are the seal sleeve 24 , the spring compression mandrel 26 and the weight assembly 50 . The spring 34 is compressed by spring shoulder 30 of the seal sleeve 24 during this operation. Since gravity based orientation of the weight assembly 50 has already occurred, since it is continuous until engagement of the key 56 with the gear ring 72 , downhole movement of the weight assembly causes the engagement of the key 56 between a pair of teeth of the gear ring 72 . Since the gear ring itself is restricted in rotational movement by the pin 48 , the weight assembly will now also be prevented from moving rotationally. It is noted that a reduction in pressure on the arrangement 10 will allow the key 56 to disengage from the gear ring and thereby restore rotational movement to the weight assembly under action of the spring 34 but too, a repressurization will reengage the key 56 with the gear ring. This can be repeated as desired. Importantly, and as noted above, the gear ring maintaining the weight assembly rotationless means that upon further pressure based downhole movement of the weight assembly and engagement of the torque producer 58 with the pin adapter 70 , all of the torque generated is transferred to the pin adapter 70 . Torque on the order of about 70 ft lbs can be generated in one embodiment hereof upon the application of 5,000 psi.
[0021] While preferred embodiments have been shown and described, modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustrations and not limitation. | A pressure orienting swivel arrangement including a weight assembly and a pin adapter reactably interengagable with the weight assembly to orient the pin adapter to the weight assembly. A pressure orienting swivel arrangement including a housing, a spring compression mandrel within the housing, a spring disposed about the spring compression mandrel, a weight assembly rotatably supported in the housing, and a pin adaptor rotatably supported within the housing and reactably interengagable with the weight assembly to accept a torque from the weight assembly. A method for orienting a downhole tool. | 4 |
RELATED APPLICATION
This application claims priority of U.S. Provisional Patent Application Ser. No. 60/642,318 filed Jan. 7, 2005, which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention in general relates to a dispersible granule for use in plant culture or for de-icing and anti-icing of paved surfaces and equipment, and, in particular, to a granule that foams upon contact with water.
BACKGROUND OF THE INVENTION
In the course of a growing season, modern plant culture dictates multiple treatments with fertilizer and pesticide, and in winter, where snow and ice are present for periods of time, proper property and equipment (e.g. aviation) maintenance requires the application of de-icing and anti-icing materials. A practitioner of plant culture must decide whether a particular treatment is best performed with a granular product or a liquid spray application. Crops as diverse as turf, grain crops, tubers, ground fruits and vegetables, and horticultural plantings are routinely treated with either granular or sprayed substances. Facility and equipment maintenance operations likewise employ either granular de-icers or liquid compositions, so a similar choice must be made by that practitioner. Each application method has limitations. Specifically, while granule broadcast tends to provide a simple broadcast, generally long-term release and safe handling, granules are difficult to adhere to plant and equipment surfaces, create concentration gradients about each granule, and represent an ongoing potential toxin or physical entity that can be inadvertently contacted or ingested by humans or fauna, or pose mechanical problems for equipment such as maintenance and aviation equipment. In contrast, spray treatment generally requires considerable skill for application, contacts only exposed foliage and equipment and surfaces receiving indirect drainage from other surfaces, and tends to dissipate, or “run off,” quickly. Some sprays such as anti-icers require the use of expensive polymers and additives in order to prolong the “holdover time,” or length of time the equipment may be allowed to stand ice free before it is put into service. Based on these treatment characteristics, pesticides targeting weed leaves or foliage-feeding pests and de-icers and anti-icers targeting equipment surfaces tend to be applied as a liquid spray, while fertilizers and pesticides targeting weed seeds, grubs and other soil-dwelling pests and de-icers and anti-icers targeting paved surfaces often are delivered as granules. Regardless of whether spray or granule broadcast is used, the application method is not completely satisfactory. For instance, spray application fails to reach pests dwelling on the underside of foliage and is quickly dissipated and leached into soil by rain, and liquid de-icers and anti-icers can cause environmental wastewater management problems because a significant excess amount of product must be used in order to allow for adequate contact time.
Granular pesticide formulations often require the use of additional pesticide due to inefficiencies in the timely release, or efficient environmental extraction, of the pesticide from the associated granular substrate materials.
Thus, there exists a need for a granule that, through foaming upon contact with water, has desirable attributes of both granule, broadcast and spray treatment for use in plant culture and/or in de-icing and anti-icing.
Additionally, the use of a foaming mechanism offers another tool for pest control, which may augment or replace the traditional pesticide material in certain cases. By generating a gas, along with a temporary containment for the gas, which may be directly toxic to, or which may alter the behavior of certain animal pests, the invention may serve as a pesticide or synergist in its own right.
The foaming mechanism as applied to de-icers can significantly enhance product distribution, adhesion, penetration of ice/snow cover, and separation of ice/snow from the treated surfaces due to the chemical and kinetic energy it provides. Likewise, the mechanism may enhance the use of exothermic energy (from dissolution of certain salts, e.g. calcium chloride).
SUMMARY OF THE INVENTION
A foaming granule is provided that includes an acid, a gas-evolving acid neutralizing agent, a surfactant foaming agent, and an active agent that is a plant growth enhancer, pest control agent, de-icer or anti-icer. Upon wetting a granule, the acid and neutralizing agent are brought into contact releasing gas that is trapped in the surfactant to form a foam that disperses the active agent to a greater area and more uniformly than a conventional nonfoaming granule containing a like amount of active agent. Dispersal of granules followed by sufficient time for foaming to occur represents a typical use methodology.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention has utility as a granule to deliver a substance beneficial to plant culture. An inventive granule, upon contact with water, releases gas to create a foam that spreads the granule contents beyond the dimensions of the granule. The use of an inventive granule achieves superior handling and active ingredient usage as compared to the conventional art.
The present invention incorporates a solid acid-neutralizing agent and an acid that are not completely reactive until solvated with water. Neutralization of the acid component by a carbonate, peroxide, or azide liberates a gas that functions as a propellant to expand a foaming agent present within a composition according to the present invention. A gas-evolving neutralizing agent according to the present invention generates a gas such as carbon dioxide, nitrogen or oxygen upon reaction with the acid in the presence of water. A carbonate, peroxide, or azide operative in the present invention as a neutralizing agent is one capable of neutralizing acid. Carbonates operative herein include carbonates where the cation is an alkali metal, alkali earth, hydrogen, ammonium, tetraorganal ammonium, transition metals, alone, or in combination with hydrogen. Peroxides operative herein illustratively include sodium perborate and sodium percarbonate. Sodium azide is an exemplary azide operative herein. It is appreciated that in selecting a carbonate, peroxide, or azide, the tolerance of a target plant and the healthy soil ecosystem surrounding the plant towards the carbonate chitin are important considerations. Specific examples of carbonates operative herein illustratively include sodium carbonate, sodium bicarbonate, magnesium carbonate, calcium carbonate, aluminum carbonate, and ammonium carbonate. It is appreciated that inventive carbonate is typically in the form of a mineral particulate. Additionally, it is appreciated that the ability of a carbonate to neutralize acid, and in the process deliver a carbon dioxide, is largely independent of the nature of the cation and as such, the choice of a particular carbonate is dictated by factors illustratively including cost, ease of processing, and secondary soil conditioning properties. By way of example, a soil deficient in a particular element such as calcium or magnesium derives a secondary soil conditioning benefit from the use of these respective carbonates. Likewise, ammonium carbonate, after acid neutralization, provides a bioavailable nitrogen source. The gas-evolving neutralizing agent is present from 1 to 80 wt. %; preferably the gas-evolving neutralizing agent is present in a stoichiometric amount relative to the acid equivalents of the acid component.
The only requirements as to the identity of an acid operative in the present invention are that the acid have a pKa value sufficient to generate a high enough proton ion concentration to induce active carbon dioxide generation and that the acid salt be compatible with plant culture. Preferably, the acid is in a solid and dry form. An important component of an inventive granule is the acidic material. Suitable for this purpose are any acids present in dry solid form. Acids operative herein include C 2 -C 20 organic mono- and poly-carboxylic acids and especially alpha- and beta-hydroxycarboxylic acids; C 2 -C 20 organophosphorus acids such as phytic acid; and C 2 -C 20 organosulfur acids such as toluene sulfonic acid. Typical hydroxycarboxylic acids include gluconic, glucoheptonic, 2-hydroxyisovaleric, tartaric, lactic, salicylic and citric acids as well as acid forming lactones such as gluconolactone and glucarolactone. Still other specific acids operative herein illustratively include formic, acetic, propionic, butyric, valeric, caproic, caprylic, capric, lauric, myristic, palmitic, stearic, oleic, linoleic, linolenic, propionic, benzoic, toluic, anthranilic, and acrylic, as well as dicarboxylic acids such as oxalic, adipic, glutaric, succinic, malonic, succinic, glutaric, adipic, maleic, fumaric, malic, maleic, and phthalic acids. Most preferred is citric acid. Also suitable as acid material may be encapsulated acids. Typical encapsulating material may include water soluble synthetic or natural polymers such as polyacrylates (e.g. encapsulating polyacrylic acid), cellulosic gums, polyurethane and polyoxyalkylene polymers.
Optionally, an acid salt of the acid used is present as a pH buffer and to provide storage stability to the resulting composition.
A surfactant foaming agent is present to entrain carbon dioxide emitted upon neutralization reaction between the acid and the gas-evolving neutralizing agent. A surfactant foaming agent is typically present from 0.01 to 10 per weight percent. Surfactant foaming agents operative herein illustratively include sopinin; anionic surfactants, such as fatty acid esters, alkyl sulfates, alkylarylsulfonates, such as alkylbenzene sulfonates; alkyl sulfonates; isocyanates, such as methylenedisocyanate and tolylene diisocyanate, and nonionic surfactants, such as polyoxyethylene alkyl phenols, polyoxyethylene fatty acids esters, polyoxyethylene alcohols, polyoxyethylene mercaptans, polyoxyethylene alkylamines, polyol esters, phosphate esters, alkyl mono- or poly glycosides, sorbitan esters, polymers of ethylene oxide, propylene oxide, and/or butylene oxide, vegetable oil glycerides, glycerol esters, silicones, and various compounds containing amide groups.
An inventive granule includes an active ingredient such as a plant growth enhancer, a de-icer, an anti-icer, a pest control agent fertilizer, and a combination thereof. An active ingredient is typically present in an amount ranging from 0.05% to 50% by weight of the total dry weight of the particle. In a more preferred embodiment, the active ingredient is present in an amount ranging from 0.1% to 30% by weight of the total dry weight of the granule. In a still more preferred embodiment, the active ingredient is present in an amount ranging from 0.5% to 10% by weight of the total dry weight of the particle. Optionally, a foam stabilizing agent is included in order to maintain the presence of the foam over time. Compounds such as glycerin, hydrolyzed protein, synthetic polymers, or any of a number of long chain polar compounds with straight chain hydrocarbon groups of about the same length as the surfactant, may serve this purpose.
As used herein, a plant growth enhancer is defined as a substance that enhances the growing medium in which a plant resides. A plant growth enhancer specifically includes a bioavailable source of nitrogen, potassium, or phosphorus; a soil nutrient; a soil amendment material; and a biostimulant. Exemplary fertilizers and de-icers include urea, sulfur-coated urea, isobutylidene diurea, ammonium nitrate, ammonium sulfate, ammonium phosphate, triple super phosphate, phosphoric acid, potassium sulfate, potassium nitrate, potassium metaphosphate, potassium, dipotassium carbonate, potassium oxide and a combination thereof.
Exemplary soil nutrients include calcium, magnesium, sulfur, iron, manganese, copper, zinc; oxides thereof; salts thereof, and a combination thereof.
Exemplary amendment materials include humic acid, blood meal, bone meal, seed meal, feather meal, soy meal, meat meal, animal waste, activated sludge, hydrolyzed animal hair, a fish byproduct, chitin, composts and a combination thereof. In addition, a fertilizer particle optionally includes an additive to aid in particle formation illustratively including an anti-dust agent, an anti-caking agent, a filler, a preservative, and a combination thereof.
Biostimulants are substances that promote plant survival and health and illustratively include plant growth hormones and plant growth regulators such as cytokinins, auxins, gibberellins, ethylene, absisic acid and a combination of these. A biostimulant is optionally included as a secondary active ingredient in an amount ranging from 0.05% to 10% by weight of the total dry weight of the particle. In a more preferred embodiment, the biological factor or biostimulant active ingredient is present in an amount ranging from 0.1% to 5% by weight of the total dry weight of the particle. In a still more preferred embodiment, the biological factor or biostimulant active ingredient is present in an amount ranging from 0.25% to 1% by weight of the total dry weight of the particle.
Exemplary de-icers include glycols, salts of carboxylic acids, sodium-, magnesium-, and calcium-chlorides. Exemplary anti-icers illustratively include thickened aqueous alcohols as detailed in U.S. Pat. No. 5,772,912; or a deicer that affects the colligative properties of water to depress the freezing temperature below −10° C.
In another embodiment, an inventive granule includes as an active substance a pest control agent for killing or inhibiting infestation by a target pest organism includes an arachnid; a bacterium; a bird; a fungus; an insect; a mammal, such as a rodent; a mollusk, such as a snail or a slug; a virus; and a worm. The pest control agent is appreciated to be operative not only in being lethal to the pest but also by being repellant or lessen the reproductive fitness of the pest.
A pesticide control agent includes agents such as an acaracide, an antimicrobial, a bactericide, an entomopathogen, a fungicide, a synthetic plant growth regulator such as a gibberlic acid synthesis inhibitor or promoter, an herbicide, an insecticide, a molluskicide, a nemacide, a rodenticide, a pheromone, a chemosterilant, a viricide, an imagocide, a larvicide, an ovicide, a formicide, an aphidicide, a muscacide, a culicicide, an anophelicide, an arachnidcide, and a vespacide. Preferably, an inventive bait particle containing a toxic invertebrate pesticide also contains a mammalian and/or avian ingestion repellant. More preferably, it also contains both mammalian and avian ingestion repellants to lessen the likelihood of incidental ingestion by bystander higher species. Mammalian ingestion repellants illustratively include cadaverine, butyric acid, and capsaicin. Avian repellants include artificial grape flavorant.
A pest reproductive control agent operative herein includes a pheromone, molting signaling compound or steroid that upon contact with the target pest decreases the reproductive capacity of the pest. A pest reproductive control agent is preferred over a pesticide since a reproductive control agent is specific to a species or narrower group of organisms, does not bioaccumulate, and is less detrimental to predatory or bystander organisms in the pest habitat. Additionally, a reproductive control agent is unlikely to avoid the bait due to ill health effects associated with sampling, as is often the case with a lethal pesticide.
In addition to the acid, gas-liberating neutralizing agent, surfactant foaming agent, and active ingredient, an inventive granule optionally contains a filler and/or binder. A filler operative herein is intended to provide a low-cost volume enhancement. Fillers operative herein illustratively include cereal or grain hulls, peanut hulls, plant pulp, other plant-based cellulose materials, and clays. A filler is typically present from 0.1 to 99.9 total weight percent and preferably from 5 to 98 total weight percent.
Optionally, an inventive granule has a binder component present in an amount ranging from 5% to 75% by weight of the total dry weight of the granule. In a further embodiment, the binder component is present in an amount ranging from 1% to 25% by weight of the total dry weight of the granule. A binder component is included in a granule as necessary to produce or promote cohesion in forming a particle capable of retaining a specified form during transport and/or distribution. A binder component may be bentonite clay, carbohydrate, protein, lipid, synthetic polymer, glycolipid, glycoprotein, lipoprotein, lignin, a lignin derivative, a carbohydrate-based composition, and a combination thereof. In a preferred embodiment the binder component is a lignin derivative and is optionally calcium lignosulfonate. Alternatively, the binder component is selected from the group consisting of: a monosaccharide, a disaccharide, an oligosaccharide, a polysaccharide and combinations thereof. Specific carbohydrate binders illustratively include glucose, mannose, fructose, galactose, sucrose, lactose, maltose, xylose, arabinose, trehalose and mixtures thereof such as corn syrup; celluloses such as carboxymethylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxy-methylethylcellulose, hydroxyethylpropylcellulose, methylhydroxyethyl-cellulose, methylcellulose; starches such as amylose, seagel, starch acetates, starch hydroxyethyl ethers, ionic starches, long-chain alkyl starches, dextrins, amine starches, phosphates starches, and dialdehyde starches; plant starches such as corn starch and potato starch; other carbohydrates such as pectin, amylopectin, xylan, glycogen, agar, alginic acid, phycocolloids, chitin, gum arabic, guar gum, gum karaya, gum tragacanth and locust bean gum; vegetable oils such as corn, soybean, peanut, canola, olive and cotton seed; complex organic substances such as lignin and nitrolignin; derivatives of lignin such as lignosulfonate salts illustratively including calcium lignosulfonate and sodium lignosulfonate and complex carbohydrate-based compositions containing organic and inorganic ingredients such as molasses. Suitable protein binders illustratively include soy extract, zein, protamine, collagen, and casein. Binders operative herein also include synthetic organic polymers capable of promoting or producing cohesion of particle components and such binders illustratively include ethylene oxide polymers, polyacrylamides, polyacrylates, polyvinyl pyrrolidone, polyethylene glycol, polyvinyl alcohol, polyvinylmethyl ether, polyvinyl acrylates, polylactic acid, and latex. In a preferred embodiment, the binder is calcium lignosulfonate, molasses, a liquid corn starch, a liquid corn syrup or a combination thereof.
An inventive granule is produced by a number of processes. In the preferred process, the granule components, with the exclusion of either the acid or gas-emitting neutralizing agent, are wet granulated through a process of steps, including mixing of various dry components, wet massing the dry powder mixture with liquid surfactants, binders or the like, alone or with the addition of a solvent to arrive at a suitable consistency for granulating. Upon forming a granule, the excluded acid or gas-evolving neutralizing agent is either powder coated onto the surface of the granule, alone, or with a binder as detailed herein, to adhere a predetermined and preferably stoichiometrically-balanced amount of the omitted acid or neutralizing agent to complete acid neutralization. Of the binders detailed herein, methylene urea is particularly preferred. Alternatively, a granule is coated with a polymeric acid, such as a polyacrylate, thereby affording a free-flowing granule with a passivating surface coat. Alternatively, a granule omitting either an acid or neutralizing agent is impregnated with the omitted ingredient through solvent impregnation. The solvent means are selected to carry the omitted ingredient into the interior of the granule without complete activation of the acid neutralization reaction. As such, aqueous solvent is an unacceptable solvent, whereas anhydrous alcohols, ethers, tetrahydrofuran, and alkanes are generally suitable. It is appreciated that solvent impregnation is enhanced by allowing some gas formation, so as to open pores within the granule, thereby enhancing impregnation. Alternatively, welling of a granule, a solvent carrying the omitted ingredient, followed by increasing the temperature, so as to volatize the solvent, is also operative herein.
An alternative embodiment from the inventive granule involves compressing a powder mixture into a large form that is subsequently ground to a desired size. It is appreciated that dry granulation is facilitated by the addition of a pressing agent, such as a stearate salt.
In instances where the acid component exists as a hydrated powder, a fusion method is available in which to form an inventive granule. Heating of the mixed powder dissociates water from the acid, thereby causing some gas evolution, resulting in a pliable mass that is amenable to pass through a sizing screen. As heating temperatures typically are required in the range of 80-150° C., it is appreciated that the inclusion of the active ingredient subsequent to granule formation and drying is preferred. Subsequent addition of an active ingredient occurs through coating of the granule so formed with a binder solution containing the active ingredient. The resulting granule includes the desired amount of the active ingredient and has a sealant coat that impedes atmospheric degradation of the inventive granule.
In a de-icing or anti-icing use environment, inventive granules are dispersed onto a surface such as a road surface or piece of equipment to react, creating a foam that melts ice or prevents ice formation. It is appreciated that a resultant surfactant film inhibits ice nucleation.
It is appreciated that an inventive granule is operative alone, or as an additive with conventional pelletized substances, such as fertilizer, de-icer, or pest attractant bait.
The present invention is further detailed with respect to the non-limiting examples.
Example 1
13.7 lbs of citric acid is combined with slightly more than 3 mole equivalents of potassium bicarbonate (21.4 lbs as dry powders) in a stainless steel vessel, together with 500 grams of sodium dodecyl sulfate and 10 kilograms of −40 mesh corncob grind. The resulting mixture is heated to 100° C. with constant turning. Upon softening to a paste consistency, the material is urged through a No. 6 sieve and cooled. The resulting granules are then coated with an alcoholic solution of methylene urea containing 0.3% by weight methylparathyon and allowed to dry to a hard-dry coating.
The resulting granules are broadcast onto a wet turf crop field. The granules are observed to adhere to leaf and plant surfaces with acid neutralization-based foaming observed immediately thereafter.
Example 2
21.4 kilograms of potassium bicarbonate is mixed with corncob grind, and sodium dodecyl sulfate in the amounts provided in Example 1, together with 100 grams of methylparathyon. 5 liters of water is added and the resulting slurry is screen granulated through a U.S. No. 4 mesh screen and dried. The resulting granule is coated with a concentrated aqueous solution of polyacrylic acid and flash dried to yield an inventive granule.
Patent documents and publications mentioned in the specification are indicative of the levels of those skilled in the art to which the invention pertains. These documents and publications are incorporated herein by reference to the same extent as if each individual document or publication was specifically and individually incorporated herein by reference.
The foregoing description is illustrative of particular embodiments of the invention, but is not meant to be a limitation upon the practice thereof. The following claims, including all equivalents thereof, are intended to define the scope of the invention. | A foaming granule is provided that includes an acid, a gas-evolving acid neutralizing agent, a surfactant foaming agent, and an active agent that is a plant growth enhancer, pest control agent, de-icer or anti-icer. Upon wetting a granule, the acid and neutralizing agent are brought into contact releasing gas that is trapped in the surfactant to form a foam that disperses the active agent to a greater area and more uniformly than a conventional nonfoaming granule containing a like amount of active agent. Dispersal of granules followed by sufficient time for foaming to occur represents a typical use methodology. | 0 |
BACKGROUND
Software developers use various persistent data structures or database implementations to store and organize data. Within these databases, individual data values are often grouped into data blocks, which are used as units of transfer to and from persistent storage such as disk, flash, or network storage. Each data block has a data type called a pointer associated with it that contains the data block's memory address. Specific data values can be obtained from the database by: (1) dereferencing pointers to find referenced data blocks, (2) retrieving the data blocks from persistent storage, and (3) parsing the data blocks to find the data values.
FIG. 1 illustrates a conventional database structure as discussed above. Individual data values ( 109 ) in the database are often grouped into data blocks ( 111 ) containing key→value pairs. As shown in FIG. 1 , the data blocks can include key→value pairs where the keys are people's names and the values are the people's dates of birth. Each data block has a pointer ( 101 a , 101 b ) associated with it that contains the data block's memory address for retrieving the data block. A conventional data retrieval would include: (1) dereferencing the pointer; (2) loading the associated data block into memory; and (3) parsing the loaded data block to find the desired key→value pair(s).
For example, a conventional search to find “all the people born in 1966” in the database structure of FIG. 1 requires that each pointer ( 101 a , 101 b ) to a data block ( 111 a , 111 b ) in the database be dereferenced to find each pointer's data block. Each data block ( 111 a , 111 b ) is then retrieved from persistent storage and parsed to find the key→value pairs having “1966” as the birth year of their date of birth value. This process continues until all of the data blocks are retrieved and parsed. In FIG. 1 , the first data block ( 111 a ) contains key→value pairs with birth years of 1954, 1964, 1977, 1978, and 1985. However, the conventional retrieval process requires the retrieving and parsing this data block even though the birth year “1966” will not be in the data block. Accessing persistent storage is time-consuming and expensive for computer applications.
SUMMARY
This specification describes technologies relating to data storage, data querying, data retrieval, and database management in general, and specifically to computer-implemented methods for managing a database that reduce the number of times data blocks must be retrieved from persistent storage such as disk, flash, or network storage when a search is performed for specific data values in a database.
In general, one aspect of the subject matter described in this specification can be embodied in a computer-implemented method for managing a database comprising: receiving a data set to be stored in a database; organizing and storing the data set into data blocks; obtaining a pointer to each data block; for at least one data block, obtaining a summary of a property of the data values stored in the data block; associating the obtained summary with the data block's pointer; and storing the data block's summary with the data block's pointer. Another aspect of the subject matter described in this specification can be embodied in a computer-implemented method for managing a database comprising:
receiving a data structure query; loading a data block pointer and an associated summary into memory; comparing a criteria of the received query to information from the loaded summary responsive to a match between the query criteria and information from the summary, dereferencing the data block pointer to find the referenced data block, retrieving the referenced data block from persistent storage, and parsing the retrieved data block to obtain values that are responsive to the query criteria before returning the query results; and responsive to no match between the query criteria and the information from the summary, skipping the data block pointer traversal, the retrieval of the referenced data block from persistent storage, and the parsing of the retrieved data block; and returning the query results.
These and other embodiments can optionally include one or more of the following features: the summary can be a Bloom Filter or a bit-vector; the summary can store range information; and the data structure can be a B-tree or an sstable.
The details of one or more embodiments of the invention are set forth in the accompanying drawings which are given by way of illustration only, and the description below. Other features, aspects, and advantages of the invention will become apparent from the description, the drawings, and the claims. Like reference numbers and designations in the various drawings indicate like elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating an example of conventional database storage and organization.
FIG. 2 is a block diagram illustrating the association of a pointer and a summary with a data block according to aspects of the invention.
FIG. 3 is a block diagram illustrating the association of a pointer and multiple summaries with a data block according to aspects of the invention.
FIG. 4 is a flow diagram illustrating a method for organizing and storing data values in a persistent database according to aspects of the invention.
FIG. 5 a is a block diagram illustrating an example of storing pointers and summaries in a pointer block according to aspects of the invention.
FIG. 5 b is a block diagram illustrating an example of storing pointers and summaries in a pointer block according to aspects of the invention.
FIG. 6 is a flow diagram illustrating a method for querying and retrieving data values in a persistent database according to aspects of the invention.
FIG. 7 is a block diagram illustrating an example computing device that may be used to implement various aspects of the invention.
FIG. 8 is a block diagram illustrating an example computing network that may be used to implement various aspects of the invention.
DETAILED DESCRIPTION
According to an exemplary embodiment as illustrated in FIG. 2 , each data block ( 206 a , 206 b ) also has at least one summary ( 204 a , 204 b ) associated with it, which is stored adjacent to the pointer ( 202 a , 202 b ).
This summary ( 204 a , 204 b ) is a concise representation or approximation of a property of the data values stored in the data block. As an example, represented by FIG. 2 , each data block ( 206 a , 206 b ) in the database can contain key→value pairs where the keys are people's names and the values are people's dates of birth. Each data block summary ( 204 a , 204 b ) can contain, for example, a set of years that represents the dates of birth in the values of the key→value pairs in the associated data block. As illustrated in FIG. 2 , one data block ( 206 a ) can contain nine key→value pairs with the following respective birthdate years: 1985, 1985, 1978, 1977, 1977, 1954, 1964, 1954, and 1964. An exemplary summary for this data block could be “the set of years extracted from all the dates of birth in the block: {1954, 1964, 1977, 1978, 1985}.”
Likewise, another data block ( 206 b ) can contain nine key→value pairs with the following respective birthdate years: 1987, 1987, 1957, 1987, 1957, 1972, 1966, 1966, and 1943. A summary ( 204 b ) for this data block ( 206 b ) could be “the set of years extracted from all the dates of birth in the block: {1943, 1957, 1966, 1972, 1987}.”
Although the summaries illustrated in FIG. 2 are sets, a summary can be any data type that can be used to test whether a block could contain a data value that satisfies a particular query. Some examples are: a bit-vector, a data range, and a Bloom Filter. Furthermore, although only two data blocks are shown in FIG. 2 , the database could include hundreds, thousands, or many more such data blocks.
The data value property summarized in the summary can be selected based on various criteria. For example, historical query data can be used to determine a commonly-queried property and a summary can represent or approximate the data values for the commonly-queried property. In other instances, summaries can be determined by a database administrator who specifies the properties that should be summarized when setting up the database based on knowledge of how the database will be used, such as which applications will be accessing or querying the database. In still other instances, the database system itself can determine summaries by keeping a log of the recent queries and using periodic analysis to find the most common types of queries. The system can then use the properties examined in those queries to determine which properties should be stored in the summary.
Although a summary can produce false positive results, it should not produce false negative results. If the summary asserts that data values in a given block are not a match for the search criteria, this assertion must be true. However, if the summary asserts that the data values in the given block are a match for the search criteria, this assertion may or may not be true.
There can also be multiple summaries per data block if the database system needs to support multiple types of queries as depicted in FIG. 3 . For example, if the database depicted in FIG. 3 needed to be searchable by both birth year and first name, each data block could have one summary that is a Bloom Filter of birth years and another summary that is a Bloom Filter of first names. All summaries will be loaded into memory when the pointer associated with them is loaded into memory.
Summaries can be automatically generated and managed by the database. Summaries can be added to immutable and mutable databases. For immutable data structures, the summary is computed per-block when the data set is being partitioned into data blocks and the blocks are being saved to persistent storage. For mutable data structures, the summary is computed the same way as for immutable data structures. However, the summaries stored with the pointers need to be updated when corresponding data block is updated or a copy-on-write implementation should be used.
Although FIG. 2 and FIG. 3 depict the summaries stored right next to pointers, this configuration is not the only way summaries and pointers can be stored. (See FIG. 5 a , 5 b , and description below)
FIG. 4 illustrates an exemplary method for managing a database according to aspects of the inventive concepts. The method begins with receipt of a data set to be stored in the database ( 401 ). The dataset is organized into data blocks ( 403 ). A pointer and a summary are generated for each block ( 405 , 407 ). The pointer and the summary are then associated with one another and stored in close proximity to each other in both persistent storage and in memory ( 411 ). Although the exemplary databases shown in FIGS. 3 and 4 illustrate summaries associated with each data blocks, there can be instances where some data blocks have associated summaries and others do not.
It is advantageous when a summary is less time-consuming to access than the data block associated with the summary. A typical way to implement the summary so that it is less time-consuming to access is to place both the pointer ( 502 a ) and the summary ( 504 a ) adjacent to each other in persistent storage and also adjacent to each other when stored in memory as depicted by FIG. 5 a . However, another implementation with the same advantage is to separate the pointers and their associated summaries into two distinct regions of the same pointer block ( 500 b ), depicted by FIG. 5 b . Since reads from persistent storage will retrieve an entire pointer block at one time, both the pointer and its associated summary will be available in memory at the same time.
According to another embodiment, the summaries can be used to more efficiently respond to a query. As shown in FIG. 6 , the process begins when a database query is received. ( 602 ) A pointer and its associated summary are loaded into memory. ( 604 ) This load retrieves an entire pointer block which includes multiple pointers and summaries. The query's criteria are compared with information in the loaded summary. ( 606 ) If there is a positive match when comparing the information in the summary and the query criteria, data values matching the query criteria are obtained by: (1) dereferencing the pointer to find its referenced data block ( 608 ), (2) retrieving the data block from persistent storage ( 610 ), and (3) parsing the data block to find the matching data values ( 612 ). If there is not a positive match, the pointer is not dereferenced and the data block is not retrieved from persistent storage. ( 608 ) When querying for specific data values in a database, expensive and time-consuming retrieval calls to persistent storage can be reduced by associating a data block with a summary that is stored adjacent to the data block's pointer and represents a property of the data values stored in the data block. This summary can be relatively quickly compared with query criteria. If there is no positive match between the query criteria and the summary, there is no need to retrieve the summary's associated data block from persistent storage.
For example, if the database depicted in FIG. 2 were queried to find all the people born in 1966, the query criteria, “year of birth=1966” would be compared with the summary of each data block ( 206 a , 206 b ). As discussed above, in this example there is one data block ( 206 a ) that contains a summary with the value, “the set of years extracted from all the dates of birth in the block: {1954, 1964, 1977, 1978, 1985}” ( 204 a ). Another data block ( 206 b ) contains a summary with the value, “the set of years extracted from all the dates of birth in the block: {1943, 1957, 1966, 1972, 1987}.” ( 204 b ) When the query criteria is compared to the first data block's summary ( 204 a ), there is no match because the query criteria, “year of birth=1966”, has the year of birth as 1966 and is not in the set of years {1954, 1964, 1977, 1978, 1985} extracted from all the dates of birth in the block. By using the summary, the first data block ( 206 a ) can quickly be eliminated as a data block that can contain the data any user entry with a birth year of 1966 without retrieving the data block from persistent storage.
When the query criteria is compared to the other data block's ( 206 b ) summary, there is a match because the query criteria has “1966” as the year of birth which is in the set of years {1943, 1957, 1966, 1972, 1987} extracted from all the dates of birth in the block. Accordingly, the data block's pointer will be traversed to find the data block ( 206 b ). Then, the data block ( 206 b ) will be retrieved from persistent storage and parsed to find data values containing the birth year “1966.”
FIG. 7 is a block diagram illustrating an example computing device ( 700 ) that is arranged for managing a database. In a very basic configuration ( 701 ), the computing device ( 700 ) typically includes one or more processors ( 710 ) and system memory ( 720 ). A memory bus ( 730 ) can be used for communicating between the processor ( 710 ) and the system memory ( 720 ).
Depending on the desired configuration, the processor ( 710 ) can be of any type including but not limited to a microprocessor (μP), a microcontroller (μC), a digital signal processor (DSP), or any combination thereof. The processor ( 710 ) can include one more levels of caching, such as a level one cache ( 711 ) and a level two cache ( 712 ), a processor core ( 713 ), and registers ( 714 ). The processor core ( 713 ) can include an arithmetic logic unit (ALU), a floating point unit (FPU), a digital signal processing core (DSP Core), or any combination thereof. A memory controller ( 715 ) can also be used with the processor ( 710 ), or in some implementations the memory controller ( 715 ) can be an internal part of the processor ( 710 ).
Depending on the desired configuration, the system memory ( 720 ) can be of any type including but not limited to volatile memory ( 704 ) (such as RAM), non-volatile memory ( 703 ) (such as ROM, flash memory, etc.) or any combination thereof. System memory ( 720 ) typically includes an operating system ( 721 ), one or more applications ( 722 ), and program data ( 724 ).
The computing device ( 700 ) can have additional features or functionality, and additional interfaces to facilitate communications between the basic configuration ( 701 ) and any required devices and interfaces. For example, a bus/interface controller ( 740 ) can be used to facilitate communications between the basic configuration ( 701 ) and one or more data storage devices ( 750 ) via a storage interface bus ( 741 ). The data storage devices ( 750 ) can be removable storage devices ( 751 ), non-removable storage devices ( 752 ), or a combination thereof. Examples of removable storage and non-removable storage devices include magnetic disk devices such as flexible disk drives and hard-disk drives (HDD), optical disk drives such as compact disk (CD) drives or digital versatile disk (DVD) drives, solid state drives (SSD), and tape drives to name a few. Example computer storage media can include 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.
Non-volatile memory ( 703 ), removable storage ( 751 ), non-removable storage ( 752 ), and network storage as depicted in FIG. 8 are all examples of persistent storage for storing the database as described by aspects of the invention. The microprocessor implements the exemplary methods for managing a database. The exemplary process depicted in FIG. 6 runs in volatile memory ( 704 ) and pointer blocks, including pointers and their associated summaries are loaded into volatile memory ( 704 ) as the process runs. Computer readable medium stores the program that implements the inventive methods.
System memory ( 720 ), removable storage ( 751 ), and non-removable storage ( 752 ) 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 computing device 700 . Any such computer storage media can be part of the device ( 700 ).
The computing device ( 700 ) can be implemented as a portion of a small-form factor portable (or mobile) electronic device such as a cell phone, a personal data assistant (PDA), a personal media player device, a wireless web-watch device, a personal headset device, an application specific device, or a hybrid device that include any of the above functions. The computing device ( 700 ) can also be implemented as a personal computer including both laptop computer and non-laptop computer configurations.
Non-volatile memory ( 703 ), removable storage ( 751 ), and non-removable storage ( 752 ) are all examples of persistent storage for storing the database as described by aspects of the invention. A processor ( 710 ) may be used to implement the exemplary methods for managing a database. The exemplary process depicted in FIG. 6 runs in volatile memory ( 704 ) and pointer blocks, including pointers and their associated summaries are loaded into volatile memory ( 704 ) as the process runs. Data blocks are loaded into volatile memory as necessary depending on the results of the comparison between query criteria and a data block's summary (or summaries). Computer readable medium stores the program that contains the inventive methods.
FIG. 8 shows various computing devices each of which may be constructed in a manner similar to the computing device ( 700 ) depicted in FIG. 7 . Each of these devices is connected to a network. Managing a database in a networked environment is very similar the above description for managing the database in a single computing device. However, in a network, persistent storage can be network storage as depicted in FIG. 8 .
The foregoing detailed description has set forth various embodiments of the devices and/or processes via the use of block diagrams, flowcharts, and/or examples. Insofar as such block diagrams, flowcharts, and/or examples contain one or more functions and/or operations, it will be understood by those within the art that each function and/or operation within such block diagrams, flowcharts, or examples can be implemented, individually and/or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In one embodiment, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, can be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and/or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subject matter described herein are capable of being distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of the particular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive, a Compact Disc (CD), a Digital Video Disk (DVD), a digital tape, a computer memory, etc.; and a transmission type medium such as a digital and/or an analog communication medium. (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.)
With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity.
Thus, particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results. In addition, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous. | Methods for organizing and retrieving data values in a persistent data structure are provided. Data values are grouped into data blocks and pointers are obtained for each data block. In addition, one or more summaries, related to a properties of the data block, are created and associated with the data block's pointer. The summaries allow for a more efficient retrieval of data values from the data structure by preventing unnecessary retrieval calls to persistent storage when the summaries do not match query criteria. | 6 |
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a completion of the Provisional Application No. 62/041,636 filed on Aug. 25, 2014 and claims priority based on that application.
BACKGROUND
[0002] The subject invention is directed to a self-service automated coupon kiosk system which may be located at entrances to malls or other commercial establishment It may be used at the entrance to specific retailers in the mall to draw attention to offers of the specific retailer.
[0003] The system is ideally designed to be employed in high traffic areas or zones. For example, the unit The kiosk is designed to continuously deliver fresh, rotating coupons, special offers and video and messages to attract shoppers as the enter the mall, such coupons being specifically directed to retailers in the mall.
[0004] In addition, the system may also be used as an ATM location. The unit can also serve as a marketing channel for the mall itself or for specific retailers. A high capacity plastic gift card printer may also be incorporated into the unit. Any combination from one to all of these features may be used depending upon the application.
[0005] The kiosk system of the subject invention provides mall marketers and advertisers with new and useful marketing tools. Coupons, ad messages and video presentations are delivered in an integrated kiosk directed specifically toward visitors of the mall at the specific time they enter the mall to shop.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a perspective view of a kiosk with a coupon delivery system in accordance with the invention.
[0007] FIG. 2 is a flow diagram of the management software for the system.
[0008] FIG. 3 is a perspective view of a kiosk with additional advertising functions and/or an integrated ATM machine and gift card delivery system.
DESCRIPTION
[0009] As shown in FIG. 1 the kiosk is a stand alone unit 10 having a display screen 12 for displaying video messages and ads. A dispenser slot 14 is provided for dispensing coupons. A second dispenser slot may be used for dispensing written or graphic information relating to the ads or messages.
[0010] FIG. 2 shows the functions of the management interface 16 , the client (retailer) interface 18 and the shopper of user interface 20 . As indicated at management interface 16 , remote management of the kiosk permits: client input and editing, including deletion; input, editing and deletion of coupons, messages and video. Recognition software may also be provided, including, but not limited to facial recognition. The system is designed to produce and deliver monthly billing to the client/retailer.
[0011] FIG. 3 shows a kiosk with additional advertising modules such as the video screen 22 , the ATM module 24 , which can also be configured as a gift card dispenser. This may also include audio, as is typical.
[0012] The client interface 18 permits input or loading of coupons and/or video, including editing and deletion functions. Individual coupons and/or videos may be activated or deactivated.
[0013] The kiosk provides the shopper interface 20 . The number of coupons to be printed may viewed and selected from the database.
[0014] The technology supports the delivery of both paper and electronic coupons and is compatible with smart phones for loading the coupons directly on the cell phone device. This permits seamless delivery of almost instantaneous offers from a retailer to a shopper on a continuous basis.
[0015] The coupon delivery system is the main product of invention, as indicated at 14 and 16 . This is a multi-platform media console designed specifically to accommodate a 3-way partnership in profit between a major mall, its resident mall merchant advertisers.
[0016] In the most basic terms, The unit allows mall merchants to distribute their coupon offers to their most qualified market segment (those consumers physically walking into the mall) in a fast, efficient and economical way. The unit is strategically located in high traffic choke points in mall entrances with a large video display 22 that attracts consumers and distributes coupons from retailers inside the mall.
[0017] In addition, can also double as an ATM location as indicated at 24 . Due to the design of the unit, an ATM module can be attached to add an additional service to consumers as they enter the mall.
Benefits and Features
[0018] EASE OF USE—Coupons are submitted by the merchant through a simple online account interface 18 , see FIG. 2 , to the system with user-driven and user-friendly software where advertisers can enter their existing in-store coupons into available coupon slots, or they can choose from coupon templates offered in the software.
[0019] EFFICIENT—Merchants have flexibility to remotely control amount, terms or expiration dates, run daily or hourly specials or blowouts, immediately cancel coupons on sold-out merchandise, instantly sweeten the offer if the coupon is not performing and quickly turn overstocks or closeouts into cash. The merchant receives fast marketing feedback to quickly test offers or campaigns.
[0020] ECONOMICAL—Merchants pay only for actual coupons-in-hand and actual counted impressions disseminated to their best prospective customers. With the system of the subject invention, 100% of coupon ads are delivered “in hand” every time, guaranteeing that merchant advertisers get what they pay for with video proof available.
[0021] Most ad media charge impression rates based on the number of people who could “potentially” see your ad, not by the actual number that were within a measured distance from the screen when their video ad plays.
Operating System
[0022] Shoppers pull coupons from delivery slot(s) 14 , 16 as they enter the mall and are also counted as impressions for the advertiser whose video ad is playing on the screen 22 as they are present in the viewing cone of the screen. Their presence in the mall defines them as being in a buying frame of mind and makes them more likely to act on a store's offer.
[0023] Shoppers will also be attracted to the unit's ATM machine 24 for cash and other banking services.
[0024] The unit is fully self-sufficient outside of minor regular maintenance and requires no retail employees. The consumer experiences a seamless transition from parking their car outside the mall, seeing the retailer's ad pulling coupon sheets from delivery slots 14 , 16 , and entering the mall to shop. Specialized software allows the advertisers to easily upload their video impressions and coupons.
Advantages Over Existing Ad Options
[0025] The unit neutralizes the disadvantages of common coupon delivery vehicles/systems, which are:
Distance from merchant when delivered Unchangeable offers with long lead times to test and change the terms or the offer Exposure to numerous distractions on the way to buying coupon item Coupons get stale quickly Coupons “die” in handbags and pockets and eventually get thrown away
[0031] Merchant tenants get the ability to micro-target their advertising allowing them to increase the effectiveness of their advertising dollar and more efficiently raise their sales. With the model, merchants can deliver offers when:
Shopper is no further than a few hundred feet from the store Shopper, by definition by being at the mall, are in a shopping frame of mind.
[0034] Advertisers can create urgency with close-in expiration dates (fear of loss will tend to make it difficult for some shoppers to leave the mall knowing that a valuable coupon in their possession will expire in a few hours), Instantly sweeten the offer if the coupon is not performing, offer the retailer prompt measurability and feedback, provide “fresh” coupons which has not been in the possession of the consumer in the mall long enough to be forgotten, lost or thrown away.
[0035] The system capitalizes on the principal of instant gratification. Discounts “cost” the retailer nothing as the only out-of-pocket expense is coupon distribution cost.
[0036] In the preferred embodiment of the invention the unit doubles as an ATM location to help in attracting consumers to the unit.
[0037] Coupons are guaranteed to be “eyeballs-on-ads” or “ads-in-hand” and impressions are guaranteed making for efficient use of an advertiser's marketing dollars. The Company's systems will allow advertisers to more clearly see their actual cost, compelling other in-mall media to abandon ambiguous pricing and vague traffic estimates. This should lead to more in-mall media competition leading to lower prices for advertisers.
[0038] The system creates a broader, timelier, more convenient and simple way distributing money-saving coupons, ad messages and impressions allowing consumers to be exposed to many more savings opportunities.
[0039] The system may include video cameras 26 ( FIG. 3 ) that verify the delivery of a coupon to a shopper. This gives coupon advertisers video verification that the sheet that contains their coupon was actually delivered. This also permits the advertiser to count people to satisfy and fulfill the impressions side of the units:
[0040] Most malls use “ESTIMATES” to determine their annual traffic number. Our system will count all of the people who walk by our unit(s) within a pre-defined cone of detection. This information based on actual count can be invaluable to both the private and the public sector in determining shopping behavior and effectiveness of advertising.
[0041] A number of coupon slots may be set aside for public service announcements, security announcements, amber alerts, etc. Similarly, a number of video ad time slots may also be set aside for public announcements, security announcements, amber alerts. In an emergency (lost child, fire, etc.) both the outputs in all units in a mall can immediately be switched to address the emergency and disburse information about it to shoppers in the mall.
[0042] Physically, the unit includes two output components, 1) printers to issue coupons at slots 14 , 16 , and 2) monitors to accommodate coupon search. The monitors can deliver ad messages to shoppers within 6-8 feet of the audio visual message playing on the screen. This builds revenue from the impressions that are created, priced and sold in much the same way as cable TV does, with one major difference.
[0043] The units also have a video camera on both sides which, with the addition of an off-the-shelf software module for each camera, can be made to accurately count every person that walks by the unit on either side, coming or going.
[0044] If a merchant's ad of any length plays to a steady but erratic flow of foot traffic, the unit can accurately count the number of people walking by while it was playing (creating impressions) and charge accordingly. The technology in certain software also has an anonymity feature that can block faces for usage in those states where videotaping laws require it.
[0045] The combination of harvesting millions of impressions from mall visitors and offering advertisers an accurate count as to exactly how many impressions they are getting while the screen plays their ad is a unique, one-of-a-kind ad medium that could easily make other media in the mall relatively less attractive.
[0046] In addition, combination packages permits an advertiser to use a broadcast on the monitor to promote taking a coupon that they have in the coupon rotation or in their library by simply pushing a button on the touch screen while it is playing. This creates a unique and very attractive 1-2 punch marketing method.
[0047] The third revenue stream comes from the modular nature of the unit. By adding an ATM 24 to the unit.
[0048] The revenue stream also comes from the modularity of the unit and allows us to add gift a gift card exchange in combination with or at the opposite end of the ATM module and similarly shaped. A selection of off-the-shelf software is available in the gift card exchange category and we are in the process of evaluating them now. The way these work is that remaining balances on old cards are exchanged, at varying rates of discount depending on the brand, for a new card of a brand of their choice with a balance equal to the credit accrued from their exchanging the old gift cards.
[0049] These systems require a CPU, a touch-screen monitor, a card value reader and a printer (pictured as a printer slot on the face of the end cap), all off-the-shelf. The gift card can be an e-card, similar to an airline e-ticket, where the confirmation of value is represented by a bar code, either printed or stored on a smart phone. The system is designed to deliver both. By paper, we will print out a bar code for the new card and offer an electronic transfer of the code to a phone as well, consumer's choice.
[0050] Not all ad impressions will always be sold, leaving the unit with extra available ad run times. These may be offered to the mall partner free of charge or at a reduced rate as a unique value proposition that will help secure the partnership.
[0051] The target market is major retailer's regional marketing managers. This audience is a small, identifiable group of prospects which should prove to be relatively simple to reach. Media that is suited for drawing broad audiences can deliver “waste” —diluting marketing efforts and ultimately delivering a less cost-efficient plan.
[0052] While certain advantages and features of the invention have been described in detail herein, is should be understood that the invention includes all modifications and enhancements within the scope and spirit of the following claims. | A self-service automated coupon kiosk system may be located at entrances to malls or other commercial establishments. It may be used at the entrance to specific retailers in the mall to draw attention to offers of the specific retailer. The system is ideally designed to be employed in high traffic areas or zones. The kiosk is designed to continuously deliver fresh, rotating coupons, special offers and video and messages to attract shoppers as the enter the mall, such coupons being specifically directed to retailers in the mall. In addition, the system may also be used as an ATM location. The unit can also serve as a marketing channel for the mall itself or for specific retailers. A high capacity plastic gift card printer may also be incorporated into the unit. Any combination from one to all of these features may be used depending upon the application. | 6 |
This application is a continuation of application Ser. No. 030,124, filed Mar. 26, 1987, now abandoned.
FIELD OF THE INVENTION
This invention relates to adhesive systems. More particularly, this invention relates to an adhesion promoter capable of bonding diverse elastomers to substrate materials, and to methods for making that promoter; to the use of that promoter in adhesive compositions; to methods of making those adhesive compositions; to bonding methods which employ those compositions; and to bonded articles produced by those bonding methods.
DESCRIPTION OF BACKGROUND AND RELEVANT MATERIALS
Adhesive compositions are used extensively in bonding natural and synthetic elastomers to themselves, and to other substrates to form laminates and bonded articles. The industrial need for adhesives with the capability to bond such materials is sufficiently great, and the difficulties of achieving such a capability are sufficiently complex, that commercial acceptance of prior art adhesives has frequently represented no more than selection of the least unsatisfactory product.
Quite often, these prior art products have proven useful only for bonding a few specific elastomers to a few specific substrates, and thus are sadly lacking in versatility. Moreover, while many of these products were adequate for use with the elastomers and manufacturing processes in prevailing use at the time of their development, they have become increasingly unsatisfactory as the varieties of new and different synthetic elastomers have multiplied; as the areas in which both natural and synthetic elastomers can be advantageously used have expanded; and as the conditions of use, including temperature, flexibility, load carrying, environmental conditions and the like, have become more severe.
Adhesive compositions which have been employed in the past have included admixtures of chlorinated rubber and at least one polyalkylene polyamine adhesion promoter; mixtures of halogenated ethylene-propylene copolymer and sulfur; mixtures of chlorosulfonated polyethylene, orthoalkoxy aryl diisocyanates and dinitrosobenzene; chlorinated rubber-expoxylated novolak-epoxy resin curing agent admixture; and mixtures including chlorine-containing polymers, polyisocyanates, epoxylated novolaks, gammamethacryloxypropylthimethoxysilane, and dinitrosobenzene.
BRADLEY et al., U.S. Pat. No. 2,459,742, discloses that chlorinated rubber adhesive compositions containing at least one polyalkylene polyamine adhesion promoter can be employed for bonding natural rubber, polychloroprene, polybutadiene, butadiene-styrene copolymer, and butadiene-acrylonitrile copolymer elastomers to substrates such as metals, plastics, textiles and paper.
COLEMAN et al., U.S. Pat. No. 3,258,388, discusses the incorporation of poly-C-nitroso aromatic compounds into conventional rubber-to-metal adhesives to improve bonding. The conventional adhesives into which these compounds may be incorporated include compositions containing thermo-setting condensation polymers; polymers and copolymers of polar, ethylenically unsaturated materials; halogenated rubbers; and polyisocyanates.
DeCREASE et al. U.S. Pat. No. 3,282,883, discloses a class of adhesive compositions for bonding natural and synthetic rubbers, such as ethylene-propylene-nonconjugated diene terpolymers, neoprene, styrene-butadiene rubber, butyl rubber, halobutyl rubber, butadiene-acrylonitrile, halosulfonated polyethylene rubber, polyurethane rubber, and polyacrylate rubber. The rubbers may be bonded to themselves or to other substrates, such as metals. The adhesive compositions disclosed by DeCREASE et al. include chlorosulfonated polyethylene, orthoalkoxy aryl diisocyanates, and dinitrosobenzene.
BARKER, U.S. Pat. No. 3,824,217, discloses combining an oxime compound with an excess of a polyisocyanate compound, so that all oxime groups are reacted with isocyanate. The resulting compound may be used in compositions for bonding rubbers to primed metal substrates.
MANINO, U.S. Pat. No. 3,859,258, discloses employing the oxime-isocyanate reaction product of BARKER in a nonsulfur vulcanization system. The elastomers to which the MANINO vulcanization system may be applied can be bonded to various substrates, including metals, by curing the elastomer in situ on the substrate; priming of the substrate with a polyisocyanate is generally necessary.
WESTLEY, U.S. Pat. No. 4,581,092, discloses a cold-vulcanizable adhesive system for bonding vulcanized rubbers. The system is of particular use in creating durable seams between rubber strips or sheets. The adhesive compositions disclosed in WESTLEY include butyl rubber, a polyisocyanate compound, and at least one of a nitroso compound and an oxime compound, with the oxime compound requiring the additional presence of an oxidizing agent.
GLADDING et al., Canadian Pat. No. 729,596, discloses bonding elastomeric materials to substrates such as metals by utilizing a first adhesive layer of chlorosulfonated polyethylene; a second layer of cured rubber, such as polyisochloroprene, as an interlayer; and a third adhesive composition, including polyisocyanates and/or a polychlorinated natural rubber, to provide an interlayer of rubber-to-metal bond. This system is obviously rather cumbersome.
Russian Pat. No. 717,085 discloses a compound for modifying adhesives based on butyl rubber, which may be used in bonding rubber to metal. The patent teaches that the compound may be produced by reacting quinone dioxime with a polyisocyanate compound, in such a proportion that the ratio of oxime groups to isocyanate groups ranges from just over 1:1 up to 2:1, but does not appear to specifically teach how the compound may be used.
Experience with prior art adhesive systems in this field has revealed that, while they may be useful in bonding vulcanizable elastomers which have a low amount of residual olefinic unsaturation, they suffer from one or more drawbacks when used with more highly unsaturated elastomers; at relatively high cure temperatures; or in lengthy precure heat cycles. In many instances, reactive ingredients such as curing agents and accelerators can prematurely cure the elastomer prior to its contact with the metal substrate, causing mold fouling and, particularly at higher mold temperatures, premature curing of the adhesive. These problems become more severe as the degree of unsaturation of the elastomer increases.
Moreover, prior art systems almost universally require one or more of a dinitroso compound, an oxime compound, a polyisocyanate compound, and an oxidizing agent. The high toxicity of these ingredients poses serious handling and safety problems, and the dinitroso compounds, particularly dinitrosobenzene (DNB), exhibit fuming at relatively high cure temperatures which aggravates the problem of mold fouling. It is also impractical to incorporate an unsaturated film-forming agent into an adhesive compound which includes dinitroso compounds, or an oxime compound used in combination with an oxidizing agent, because these compounds will proceed to react with the unsaturation sites of the film-forming agent, rendering the adhesive composition unusable after a relatively short shelf life.
Thus, there remains a need for new adhesive compositions that are simple, safe, stable, and effective for bonding elastomers with a relatively high degree of unsaturation to themselves and to other substrates, especially at high vulcanization temperatures and in extended precure heat cycles.
SUMMARY OF THE INVENTION
The present invention is directed to a method for reacting an oxime compound with a polyisocyanate compound, such a proportion that the ratio of oxime groups to isocyanate groups exceeds 2:1, with a ratio of about 2.5:1 being most preferred, and is also directed to the adduct produced thereby. The method involves combining an isocyanate compound with a slurry of an aromatic dioxime compound in an inert organic solvent, such as toluene, trichloroethylene, and methylethylketone. Depending on the precise selection and concentration of reactants, the reaction may proceed at room temperature without a catalyst, or may require a catalyst, such as triethylenediamine, and may proceed at slightly elevated temperatures, such as up to about 70° C.
While a wide range of oxime compounds and polyisocyanate compounds may be used in the practice of the present invention, para-benzoquinone dioxime (QDO) and toluene diisocyanate (TDI), respectively, are preferred.
The present invention is further directed to an adhesive composition, which is activatable by heat, incorporating the above-described reaction product in combination with an unsaturated elastomer. In addition, when incorporated into the adhesive composition of the present invention, the oxime compound and polyisocyanate compound may be reacted in such a proportion that the ratio of oxime groups to isocyanate groups equals or exceeds 2:1.
The elastomer used in the adhesive composition should have greater than two mole percent residual olefinic unsaturation, with an unsaturation of at least four mole percent being preferred. Ethylene-propylene-nonconjugated diene terpolymer (EPDM) is most preferred as the elastomer component, with the diene monomer component preferably being 1,4-hexadiene; dicyclopentadiene; 5-ethylidene-2-norbornene; or 5-isopropylidene-2-norbornene. Such EPDM elastomers are common materials of commerce available from several suppliers under a variety of trade names, including Epsyn, from Copolymer Corporation; Nordel, from DuPont; Vistalon, from Exxon; and Royalene, from Uniroyal.
The adhesive composition is particularly noteworthy in that it does not require the presence of an oxidizing agent in order to be effective, and it is free from low-molecular weight, toxic compounds which are likely to be volatile at cure temperatures, thereby presenting a health hazard as well as causing mold fouling.
The present invention further encompasses methods for bonding rubber to metal using the above-described heat-activatable adhesive composition, as well as the bonded articles produced thereby. The methods involve coating the relevant surface of at least one of the substrates to be bonded with the adhesive composition, such as by dipping, spraying, or brushing, and bringing the surfaces into contact under sufficient conditions of time, temperature, and pressure to activate the adhesive composition and effect bonding. Depending on whether the rubber being bonded is cured or uncured, the time for bonding may range from about five minutes to one-hundred and twenty minutes, and the temperature may range from about 90° C. to 200° C.
DESCRIPTION OF PREFERRED EMBODIMENTS
In accordance with the present invention, it has been discovered that compositions comprising at least one ethylene-propylene-nonconjugated diene terpolymer, and at least one adduct of an aromatic dioxime compound and a monomeric isocyanate compound having at least one but preferably two reactive isocyanate groups, are unexpectedly effective in bonding vulcanizable elastomers, particularly elastomers having a relatively low degree of residual olefinic unsaturation, to themselves or to other solid structural substrates. If desired, conventional additives such as fillers, dies, pigments, extenders, and the like can be incorporated into the adhesive compositions of the present invention in amounts conventionally used for such additives, ranging generally from about 0 to 100 parts by weight of the adhesive composition.
The EPDM terpolymer is more particularly characterized by a residual olefinic unsaturation of greater than two mole percent, preferably greater than four mole percent, and the degree of unsaturation may even substantially exceed five mole percent. Most of the ethylene-propylene copolymers (EPM) and terpolymers of ethylene, propylene, and a nonconjugated diene, known in the art as EPDM elastomers, can be employed in forming the novel adhesive compositions of the present invention. The types of EPDM elastomers currently available commercially differ principally with respect to the non-conjugated diene. The dienes most used commercially are 1,4-hexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, and 5-isopropylidene-2-norbornene. These elastomers are well known in the art and no detailed discussion of their properties or preparation is needed for an understanding of their use in accordance with the invention.
Any aromatic dioxime may be employed to produce the adducts of the invention, including, but not limited to, p-benzoquinone dioxime (QDO), naphthoquinone dioxime, toluquinone dioxime, diphenylquinone dioxime, and diquinoyl dioxime, with QDO being preferred.
Any suitable organic isocyanate can be employed which contains at least one, and preferably at least two, reactive isocyanate groups. Suitable isocyanates include, without limitation, monoisocyanates such as phenylisocyanate; diisocyanates such as toluene diisocyanate (either the 2,4or 2,6-isomer or a mixture of both) and benzene diisocyanate, as well as dimers and trimers of these diisocyanates; methylene/bis(4-phenylisocyanate) and the corresponding saturated compound methylene/bis(4-cyclohexylisocyanate); and higher polyisocyanates, including the polyisocyanate of hexamethylenediamine urea condensate and polymethylenepoly(phenylisocyanate). Toluene diisocyanate (TDI) is preferred.
The dioxime-isocyanate adduct is more particularly characterized by the presence of at least one, and preferably two or more, oxime functional groups and by the substantial absence of a reactive isocyanate group. This follows from the fact that, during formation of the adduct, all of the isocyanate groups of the isocyanate moiety are reacted with the oxime, which is accomplished by defining the molar ratio of the dioxime moiety to the polyisocyanate moiety in the reaction mix as greater than 2:1, with a ratio of about 2.5:1 being preferred. When the adduct is to be employed in the adhesive compositions of the present invention, the ratio of oxime groups to isocyanate groups in the reaction mix may equal or exceed 2:1, with a ratio of about 2.5:1 being preferred.
Generally, the dioxime-isocyanate adduct will be present in the adhesive composition in an amount of from about 2 to about 50 parts by weight per 100 parts by weight of the terpolymer, and preferably in the range of from about 10 to about 40 parts by weight per 100 parts by weight of the terpolymer.
The dioxime-isocyanate adducts can be produced by adding the aromatic dioxime and polyisocyanate together in the presence of a reaction medium such as an inert organic liquid; toluene, trichloroethylene, or methyl ethyl ketone are preferred because of their ready commercial availability. This may be done, for example, by rapidly adding the isocyanate compound to a slurry of the aromatic dioxime in inert organic liquid. Alternatively, a slurry of the aromatic dioxime in inert organic liquid may be added slowly to a solution of the isocyanate compound in inert organic solvent. Typically, the solid reactants are present in the reaction mixture in an amount of from about 5-60% by weight, with a range of from about 10-20% by weight being most preferred.
In order to achieve complete reaction of the oxime groups of the dioxime with the isocyanate, an excess of aromatic dioxime is employed. In general, the molar ratio of the dioxime reactant to the isocyanate reactant should be greater than 2:1, and is preferably about 2.5:1. In this way, the essential stoichiometric proportion of oxime group to isocyanate is always obtained.
While not essential, a suitable catalyst, such as triethylenediamine, dibutyltin dilaurate, stannous octoate, or other catalysts may be employed in the reaction at a suitable concentration, such as approximately one percent.
The solid reaction product may be separated from the liquid reaction medium by any suitable means such as filtration; washed with a suitable inert organic solvent, such as toluene, trichloroethylene, or methyl ethyl ketone, to remove any unreacted polyisocyanate; and dried by conventional means, such as in a vacuum oven. It will be obvious to those skilled in the art that the reactants, reaction medium, reaction vessel, and washing liquid should be free from water, since the isocyanate group reacts with water.
Alternatively, a fine suspension of the reaction product may be produced by grinding the reaction mixture in a sand mill, Kady mill, ball mill, or other suitable grinding instrument. In this way, the solid adduct does not have to be isolated.
The reaction conditions will vary somewhat, as would be expected, depending upon the relative reactivity of the reactants, whether or not a catalyst is employed, the concentration of the reactants and catalyst, and so forth. With some reactants the reaction will proceed at room temperature and go to completion in a short time without a catalyst, whereas with other reactants it may be necessary to employ a catalyst and conduct the reaction at somewhat elevated temperatures, up to about 70° C., in order to complete the reaction in a convenient time period. Selection of the precise conditions for a reaction using a given set of reactants will not present difficulties to one of ordinary skill in the art.
Preferably, the composition will be compounded with an appropriate inert solvent or diluent to provide an adhesive lacquer. Toluene, trichloroethylene, or methyl ethyl ketone are preferred because of their availability. The lacquer will have a viscosity of from about 25 to about 5,000 centipoises, and preferably from about 50 to 250 centipoises, at a total solids content of from about 3 to about 90 percent, preferably of from about 3 to about 70 percent, and most preferably of from about 5 to 30 percent.
Any suitable anhydrous inert organic liquid may be employed as the reaction medium, solvent, or washing liquid. As previously stated, toluene, trichloroethylene, and methyl ethyl ketone are preferred because of their ready availability.
If desired, conventional additives such as are normally used in adhesive compositions, e.g., fillers, colorants, extenders, and the like, can be included in the adhesive compositions of the present invention in amounts conventionally used for such additives. Optionally, the adhesive compositions of the invention can include from about 0.5 to about 200 percent by weight, per 100 parts by weight of terpolymer, of at least one halogenated compound such as chlorinated rubber or chlorosulfonated polyethylene.
The adhesive compositions are applied to substrate materials in any conventional manner, such as by dipping, spraying, brushing, and the like. Preferably, after being coated the substrate surfaces are allowed to dry before being brought together. After the surfaces have been pressed together with the adhesive layer between, the assembly is heated in accordance with conventional practices. The exact condition selected will depend upon the particular elastomer being bonded and on whether or not it is cured. If the rubber is uncured and curing is to be effected during bonding, the conditions will be dictated by the rubber composition and will generally be at a temperature of from about 140° C. to about 200° C., for from about five to about sixty minutes. If the rubber is already cured the bonding temperature may range from about 90° C. to about 180° C., for from about fifteen minutes to about one hundred and twenty minutes.
The pressure employed in contacting the substrate surfaces is not critical, and in general may be simply that amount of pressure necessary to keep the substrate surfaces in firm contact while bonding takes place. The pressures typically encountered in compression, transfer, or injection molding operations are quite suitable to the practice of the present invention, and a pressure of anywhere from 0 to 3,000 psi is acceptable.
The compositions of the present invention are characterized by an unexpected ability to provide exceptionally strong rubber-to-metal bonds without the necessity of first priming the metal surface; however, the use of conventional substrate primer compositions does enhance the strength of the adhesive bond. Thus, the compositions of this invention are effective as one-coat adhesive materials, particularly for elastomers such as EPDM, EPR (ethylene-propylene rubber), IIR (isobutyleneisopropylene rubber), NR (natural rubber), Cl-IIR (chlorobutyl rubber), SBR (styrene-butadiene rubber), and blends thereof; and, as two-coat adhesive materials when used with conventional substrate primers, with the preferred primer being Chemlok 205, manufactured by Lord Corporation.
A wide range of metal substrates may be used for rubber-to-metal bonding using the adhesive compositions of the present invention, including grit blasted steel, cold-rolled steel, aluminum, and zinc-phosphatized steel.
Besides providing excellent primary adhesion, the compositions of the present invention exhibit an exceptionally long shelf life, excellent resistance to sweeping during transfer-type molding operations, and outstanding stability at environmental conditions of use. The compositions are particularly noteworthy in that they do not require any oxidizing agent because they do not function through the formation of dinitrosobenzene, thereby eliminating the fuming and mold fouling problems caused by dinitrosobenzene or low-molecular weight free oxime compounds at curing temperatures.
The present invention may be more fully understood and appreciated by reference to the following examples, which are provided for purposes of illustration only. It is to be understood that the invention is not limited to the examples nor to the specific details therein enumerated. In the examples, amounts are parts by weight, unless otherwise specified.
The dioxime-polyisocyanate adducts of the present invention may be prepared as follows:
EXAMPLE A
TDI/QDO ADDUCT
3,700 ml of methyl ethyl ketone (MEK) are charged to a 5 liter reactor. After distilling off 50 ml of the MEK, 368 grams (2.67 moles) of QDO are added. The mixture is heated to 75° C., and 232 grams (1.33 moles) of TDI are slowly added, over a one-half hour period. The reaction mixture is next heated at 75°-80° C. for about three hours, until the percent of NCO groups present in the reaction mix is equal to or less than 0.1. An equal volume, of about 3,700 ml, of toluene is added to this reaction mixture. The solid product which then precipitates is filtered and dried to yield 410 grams of a brown-green powder, for a yield of 68 percent.
EXAMPLE B
TDI/QDO ADDUCT SLURRY
To a 5 liter reactor was charged 3,700 ml of methyl ethyl ketone (MEK) and 368 grams (2.67 moles) of QDO. Approximately 100 ml of MEK was removed by distillation, and 232 grams (1.33 moles) of TDI was then added in four equal portions over a period of 1.5-2.0 hours. The reaction mixture was then heated at 75°-80° C. for an additional hour, and the remaining isocyanate content (less than 0.1 percent) was measured by standard titration. The reaction mixture was removed and ground into a fine dispersion by a standard sand mill process. Solids totalled twenty percent.
The following examples relate to specific formulations of the adhesive compositions of the present invention, and further describe the effectiveness of those adhesive compositions when tested as shown. In the following examples, commercial butyl compounds A and B, which were the rubbers used to test the effectiveness of the adhesive compositions of the present invention, are proprietary, customer-supplied butyl rubber samples, whose precise compositions are not critical for purposes of the examples. The QDO/TDI adduct used in Examples C and D is the adduct prepared by either of the procedures given in Examples A and B.
EXAMPLE C
Adhesive Formulation A Tested With Commercial Butyl Compounds A and B
______________________________________Formulation ADry Weight(parts, per hundred) Ingredient Wet Weight______________________________________52.0 FEF Carbon Black 52.011.6 QDO/TDI adduct 58.0 @ 20% in toluene36.4 Epsyn 55 EPDM @ 16% in 277.5 naphtha Naphtha/toluene 1:1 376.8100.0______________________________________
Formulation A is prepared as follows: the solution of Epsyn 55 EPDM in naphtha-toluene blend is added to a fine dispersion of QDO-TDI adduct prepared by processing on a Kady mill, ball mill, or sand mill. This mixture is further dispersed by milling to a grind of approximately 1-2 mil on a grind gauge.
The following bonding results were obtained:
______________________________________Commercial Butyl Compound ACure Conditions: Precure heating 4 minutes @ 320° F. Cure 20 mins. @ 320° F. to zinc phosphatized substrateTest Method: ASTM D-429A, 1-in./min., room temperatureSample Peak Stress at break, psi % Rubber Retention*1 614 982 689 993 661 100Avg. 654 99Commercial Butyl Compound BCure Conditions: Precure heating 4 minutes @ 320° F. Cure 28 mins. @ 320° F. to zinc phosphatized substrateTest Method: ASTM D-429A, 1-in./min., room temperatureSample Peak Stress at break, psi % Rubber Retention*1 637 952 596 903 666 95Avg. 633 93______________________________________ *Percent rubber retention refers to the percent of the adhered substrate area which retains rubber after the bonded substrate assembly has been tested on an Instron test instrument.
EXAMPLE D
Adhesive Formulation B Tested With Commercial Butyl Compounds A and B
______________________________________Formulation BDry Weight(parts per hundred) Ingredient Wet Weight______________________________________45.0 FEF Carbon Black 45.010.0 QDO/TDI adduct 50.0 @ 20% in toluene13.5 Hypalon 40 @ 20% in 67.5 toluene31.5 Epsyn 55 EPDM 196.9 Naphtha/toluene 1:1 363.0100.0______________________________________
Formulation B is prepared similarly to Formulation A in Example C, except that Formulation B includes, as an additional ingredient, a toluene solution of Hypalon 40 (chlorosulfonated polyethylene).
Formulation B gives slightly inferior performance compared to Formulation A, but affords a harder, tougher film than Formulation A. The following bonding results were obtained.
______________________________________Commercial Butyl Compound ACure Conditions: Precure heating 4 minutes @ 320° F. Cure 20 mins. @ 320° F. to zinc phosphatized substrateTest Method: ASTM D-429A, 1-in./min., room temperatureSample Peak Stress at break, psi % Rubber Retention*1 663 992 614 853 642 100Avg. 640 95Commercial Butyl Compound BCure Conditions: Precure heating 4 minutes @ 320° F. Cure 28 mins. @ 320° F. to zinc phosphatized substrateTest Method: ASTM D-429A, 1-in./min., room temperatureSample Peak Stress at break, psi % Rubber Retention*1 407 502 583 853 463 50Avg. 484 62______________________________________ *Percent rubber retention refers to the percent of adhered substrate are retaining rubber after testing the bonded substrate assembly on an Instro test instrument. | Compositions of matter based on the reaction product of a dioxime compound and a polyisocyanate compound, made by reacting the compounds in an inert organic liquid in such a proportion that the ratio of oxime groups to isocyanate groups in the reaction is greater than 2:1, and is preferably about 2.5:1. The reaction product may be used in an adhesive composition which further includes an elastomer with a degree of unsaturation of greater than two mole percent, which is preferably an ethylene-propylene-diene terpolymer, and which may further include a film-forming adjunct, an inert filler material, and an inert solvent. The adhesive composition, which does not require an oxidizing agent, may be made into a liquid adhesive composition by mixing with an inert organic liquid. The liquid adhesive composition may be used to bond rubber to metal, producing useful bonded and laminated articles, by coating at least one of the substrate surfaces to be bonded with the composition; bringing both substrate surfaces into contact with the composition layered therebetween; and maintaining contact under sufficient conditions of time, temperature, and pressure to effect bonding. Both cured and uncured rubbers may be bonded. | 2 |
BACKGROUND OF THE INVENTION
This invention is directed toward the field of colorimeters, and more specifically to colorimeters sealed in environmentally tight enclosures.
Colorimeters are well known devices used to characterize the color of an object and compare it to the color of other objects. The colorimeter provides illumination which is reflected or transmitted by the object and is transmitted optically to a dispersing element which disperses the coherent light spectrally. A detector array converts the spectra of the light into discrete signals which provide a color signature of the object. The signal is then sent to an A/D converter and then input into a microprocessor for processing. After the color signature has been generated by the detector array it may then be compared to signatures stored in memory.
There was a desire among some users of colorimeters to use the devices in industrial environments. Such use would expose a colorimeter to airborne dust and moisture, and occasionally to hose directed water. However, due to the nature of the colorimeter's components, such an environment would cause colorimeters to fail.
Yet, merely enclosing a colorimeter in an environmentally tight enclosure is not a complete solution to the problem. Both the National Electrical Manufacturers Association (NEMA) and Underwriter's Laboratory (UL) have issued standards which require that the external surface temperature of such a device be no greater than 70 degrees C., with an external ambient of 40 degrees C. Both the lighting means and the processing electronics radiate heat, at least some of which must be dispersed to meet the NEMA and UL standards.
Further, halogen lamps, which were often used as the source of illumination, have a regenerative cycle which is dependent upon the temperature of the surrounding air. Such a halogen lamp must be kept at a constant preselected temperature in order to maximize lamp life.
Thus, it is an object of the present invention to provide a colorimeter which is environmentally sealed from the surrounding environment while still allowing for cooling of the processing electronics and lighting means.
SUMMARY OF THE INVENTION
The present invention is an environmentally sealed colorimeter which provides heat dissipation path for internal heat sources. The colorimeter includes an enclosure with an access hole and light entry and exit ports, a cover for sealing the access hole, processing electronics mounted in the enclosure, a lighting means for illuminating an object being scanned and a heat shield for shielding the lighting means from the processing electronics and to provide a heat dissipation path for heat generated by the lighting means.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a perspective view of the external housing of the inventive colorimeter.
FIG. 2 is a cutaway view taken along line 2--2, of the colorimeter of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The following description, which corresponds with FIGS. 1 and 2, will allow one of ordinary skill in the art to build and use the inventive colorimeter.
Referring to FIG. 1, thereshown is the colorimeter 5 of the present invention. Housing or enclosure 10 is constructed of a material with good heat transfer characteristics. One material particularly well suited to such a use based on heat transfer, extrudability and cost is type 6061-T6 aluminum. Enclosure 10 includes an internal cavity 200, shown in FIG. 2. Internal cavity 200 is adapted to hold internal circuit parts (see FIG. 2).
Light exit port 15, is formed in enclosure 10 so that light from an internal lighting means (see FIG. 2) can be directed at an object (not shown) to be scanned. Light entry port 18, is formed in enclosure 10 so that light transmitted or reflected by the object can be presented to a processing means (see FIG. 2) for analysis.
Internal cavity 200 can be sealed from the environment surrounding the colorimeter 5 through the use of covers 20, 40. Screws 30 are used to hold the covers 20, 40 in place. Elastomer seals 35, 45 are interposed between covers 20, 40 and enclosure 10 to insure that an environmental seal is created.
In order to allow for external cable connections to the internal circuit parts, a cable connector 25 is mounts on and penetrates cover 20. An elastomer seal (not shown) is interposed between the cable connector and the cover 20 to ensure an environmentally tight seal.
Turning now to FIG. 2, thereshown is a cutaway view of the colorimeter 5 of FIG. 1. As can be seen, enclosure 10 defines an internal cavity 200. Internal cavity 200 holds a data processing means 202 including power supply 205 and processor 210, lighting means 228 including lamp extractor 230, concave mirror 235, lamp 240, heat shield 220, and detector optics means 215.
At this point, a brief description of the operation of the colorimeter is in order. Light from lamp 240 travels through a hole 242 in heat shield 220 into light exit port 15. Light exit port 15 will be attached to an optical fiber (not shown) in actual use. The end of the optical fiber not inserted into light exit port 15 will be placed near an object to be scanned. A second optical fiber will have one end positioned near the object being scanned, the other end of the optical fiber being inserted in light entry port 18. Light from lamp 240 travels to the object along the first optical fiber, is reflected or transmitted by the object onto the second optical fiber and returned to the detector optics means 215. The detector optics means 215 breaks the coherent light received from the object into an array of signals representative of the intensity of groups of wavelengths present in the coherent light. The processor 210 then compares the sensed array of signals with one or more stored arrays of signals to determine the color signature of the scanned object.
When energized, both the processing means 202 and the lighting means 228 produce enough heat that damage may result to the internal circuitry if some cooling means is not provided. Because of the desirability of having the colorimeter sealed from its environment and due to the cost of using forced air, the colorimeter cannot be cooled by forcing air through the internal cavity. Thus, only natural convection cooling is available as a cooling method. Here, the enclosure is designed to have sufficient surface area to disperse the internally produced heat. The surface area is increased by adding one or more fins 50 to the exterior of enclosure 10. The amount of surface area required to disperse a known quantity of internally generated heat is calculated using a method well known in the art.
To further aid in protecting the processing means from excessive heat, a heat shield 220 is interposed between lamp 240 and processing means 202. In the present embodiment, heat shield 220 takes the shape of a rectangular parallelepiped having a hollow internal cavity and one missing side. The missing side is arranged so that when cover 40 is in place on enclosure 10, lamp 240 is substantially isolated from the internal circuitry. Heat shield 220 is adapted to provide a heat conduction path from the lamp 240 to the external environment. In the present embodiment, heat shield 240 is constructed of a highly heat conductive material such as aluminum type 2024-T6, and the heat shield is arranged so that a portion of the heat shield contacts an inner wall of internal cavity 200.
In order to reduce the heat produced by the colorimeter, the present lighting means was created. Concave mirror 235 collects and focuses light which would otherwise be wasted, onto an optical fiber inserted into the light exit port to increase the light presented to the object to be scanned. Use of the mirror in turn allows for a smaller lamp to be used to illuminate an object with a desired amount of light, thus reducing the heat produced over a colorimeter not using a mirror as shown.
By using the above arrangement, the NEMA and UL standards may be maintained. Further, the air temperature of the air surrounding the lamp may be maintained at a level which allows the regenerative cycle of the lamp to operate. Note that the amount of surface area of the enclosure will vary with, among other things, lamp heat output and the amount of internal circuitry.
It should be noted that many access holes may be made in enclosure 10, but that there should be a cover for each hole, each cover providing for some means for sealing the internal cavity 200 from the external environment during operation of the colorimeter. Further, in order to seal the light exit and entry ports 15, 18 from the environment, threaded couplings 250 are inserted into the ports, with elastomer seals 245 being interposed between the couplings and enclosure 10. In order to operably seal the light exit and entry ports, optical fibers are inserted into the threaded couplings, and a packing nut is tightened onto the threads. An elastomer O ring is contained inside each of the threaded couplings, and surrounds an optical fiber inserted therein to provide sealing around the optical fibers.
The foregoing has been a description of a novel and non-obvious environmentally sealed colorimeter. The applicant does not intend to limit the invention by the foregoing description, but instead defines the limit of the invention in the claims appended hereto. | A colorimeter for characterizing the color of an object is placed in an environmentally sealed enclosure for use in industrial environments. In order to maintain an acceptable operating temperature for the colorimeter's electronics and lamp, a heat shield is placed around the lamp to substantially isolate it from the electronics. The heat shield and the environmentally sealed enclosure are made of a highly heat conductive material such as aluminum. The heat shield is thermally coupled to the environmentally sealed enclosure. | 6 |
This application is being filed as a non-provisional patent application under 37 C.F.R. 1.53(b).
FIELD OF THE INVENTION
This invention relates generally removable disc drives, also referred to as disc drive cartridges, and in particular to a disc drive cartridge configured to provide an improved combination of shock protection and electrical interface alignment (registration) to other computer hardware.
BACKGROUND OF THE INVENTION
A removable disc drive cartridge is a type of removable media that is employed to store and to physically transport data between two different locations. Typically, a disc drive cartridge transports data between two different computers that are each located at different locations. Other types of removable media, such as a compact disc (CD), a digital video disc (DVD), a tape cartridge or a flash memory key can also be used to physically transport data between two different computers.
Patents and patent publications that relate to the general subject matter of removable disc drive cartridges include U.S. Pat. No. 4,941,841 to Darden, U.S. Pat. No. 5,837,934 to Valavanis, U.S. Pat. No. 6,154,360 to Kaczeus, and U.S. 2005/0257949 to Lalouette. Differences between the subject invention and these patents and patent publications will be described in the following invention description.
SUMMARY OF THE INVENTION
The invention provides an improved combination of shock protection and electrical interface alignment (registration) for a removable disc drive cartridge.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of the invention can be better understood with reference to the claims and drawings described below. The drawings are not necessarily drawn to scale, and the emphasis is instead generally being placed upon illustrating the principles of the invention. Within the drawings, like reference numbers are used to indicate like parts throughout the various views. Differences between like parts may cause those parts to be indicated by different reference numbers. Unlike parts are indicated by different reference numbers.
For a further understanding of these and objects of the invention, reference will be made to the following detailed description of the invention which is to be read in connection with the accompanying drawing, wherein:
FIG. 1A illustrates an exploded view of a removable disc drive cartridge.
FIG. 1B illustrates the bottom side of the disc drive that includes (4) mounting holes that are provided with the disc drive.
FIG. 2A illustrates a top-down view of a plurality of mounting and shock absorbing components residing within an embodiment of the bottom portion of the disc drive cartridge enclosure, in accordance with the invention.
FIG. 2B illustrates a side view of an embodiment of individual mounting and shock absorbing strut of FIG. 1A .
FIG. 2C illustrates a perspective view of the embodiment of individual mounting and shock absorbing strut of FIGS. 2A-2B .
FIG. 3 illustrates an exploded view of a removable disc drive cartridge enclosure including an elastomeric outer rear mounting and shock absorbing component.
FIG. 4 illustrates an exploded view of a removable disc drive cartridge enclosure including a rear mounting and shock absorbing component that is overmolded around a rear side of the bottom portion and the top portion of the enclosure.
FIG. 5A illustrates a close up view of holes located along the left side and the right side (not shown) of the disc drive that are configured to engage snap hooks.
FIG. 5B illustrates a close up view of hooks located within the top portion of the enclosure that are configured to snap assemble and engage the holes of FIG. 5A .
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1A illustrates an exploded view of an embodiment of a removable disc drive cartridge 100 . As shown, the removable disc drive cartridge 100 , also referred to as a cartridge 100 , is comprised of an enclosure 150 that includes a top portion 130 and a bottom portion 110 . The top 130 portion and the bottom 110 portion are shaped and sized to fit together to form the enclosure 150 that encloses a cavity within which a disc drive is located and protected. The enclosure 150 is configured to substantially surround and to protect a disc drive 120 from sudden movements (shocks), such as for example, caused by an impact between the enclosure and another object.
The disc drive 120 has a front side 122 a , left side 122 b , a right side 122 c , rear side 122 d , top side 122 e and bottom side 122 f (Shown in FIG. 1B ) A plurality of electronic connectors 124 protrude from the front side 122 a of the disc drive 120 . The electronic connectors 124 are configured to electronically connect to a complementary set of electronic connectors provided within a receiving bay (not shown) of a host computer or a peripheral of a host computer (not shown).
The enclosure 150 is configured to provide an opening 116 within its front side 112 a to allow passage of electronic connectors 124 protruding from the front side 122 a of the disc drive 120 . In the embodiment shown, the front side 112 a of the bottom portion 110 of the enclosure 150 provides the opening 116 within the enclosure 150 . In other embodiments, the opening 116 can be provided within the top portion 130 of the enclosure 150 .
Four screws 114 a - 114 d can be each inserted through a separate opening, each proximate to a mounting and shock absorbing component (See FIG. 2A ), and located in the bottom surface of the bottom portion 110 of the enclosure 150 . The screws 114 a - 114 d are configured to mate with screw holes located on the bottom surface of the bottom portion 110 of the enclosure 150 (Shown in FIG. 1B )
FIG. 1B illustrates the bottom side (surface) 122 f of the disc drive 120 that includes (4) mounting locations 126 a - 126 d that are manufactured as part of the disc drive 120 . In this embodiment, each mounting location 126 a - 126 d is implemented as a screw hole configured to receive a screw 114 a - 114 d (Shown in FIG. 1A ). As shown, each mounting location 126 a - 126 d is configured provide a physical (mounting) attachment between the disc drive 120 and the bottom portion 110 of the enclosure 110 (Shown in FIG. 1A ).
FIG. 2A illustrates a top-down view of a plurality of mounting and shock absorbing components 212 a - 212 d manufactured as part of an embodiment 210 of the bottom portion 110 of the disc drive cartridge enclosure 150 , in accordance with the invention. As shown, (4) mounting and shock absorbing components 212 a - 212 d , also referred to as mounting and shock absorbing struts 212 a - 212 d or struts 212 a - 212 d , are configured to attach to the bottom side 122 f of the disc drive 120 .
Each strut 212 a - 212 d includes an opening 214 a - 214 d configured to allow access to each of the mounting locations 126 a - 126 d residing on the bottom side 122 f of the disc drive 120 . In some embodiments, a screw is configured to be inserted upwards and rotated through each of the openings 214 a - 214 d and respectively into and engaging each of the screw holes (mounting locations) 126 a - 126 d of the bottom side 122 f of the disc drive 120 in order to form an attachment between each strut 212 a - 212 d and the disc drive 120 .
In accordance with the invention, the struts 212 a - 212 b , also referred to as the front struts 212 a - 212 b that are located along the front side of the bottom portion 110 of the enclosure 150 , are configured to provide rigid support to the front side of the disc drive 120 and rigid support to the position of the electronic connectors 124 within the enclosure 150 . In some embodiments, the struts 212 c - 212 d , also referred to as the rear struts 212 c - 212 d , also provide the same rigid support as the front struts 212 a - 212 b . In other embodiments, the rear struts 212 c - 212 d provide less rigid and more flexible support, by being configured for more deflection in response to a shock (force), than any deflection provided by the front struts 212 a - 212 b in response to a shock (force).
Rigid support of the position of the electronic connectors 124 within the enclosure 150 enables proper alignment (registration) of the electronic connectors 124 in order for the electronic connectors 124 to connect with complementary electronic connectors located and positioned within a bay of a computer or peripheral within which the cartridge 100 is to be installed (not shown).
In some embodiments, the rigid forward struts 212 a - 212 b are made from, Acrylonitrile Butadiene Styrene (ABS) plastic or some other metallic material such as aluminum or magnesium, for example. In accordance with the invention, the forward struts 212 a - 212 b are not made from elastomeric materials, such as rubber or materials having deflection properties of rubber. Elastomeric materials do not provide sufficient rigid support for the electronic components 124 .
Some prior art removable disc cartridges require use of an intermediate electronic connector, also referred to as an interposer, to connect the electronic connectors 124 with the complementary electronic connectors located and positioned within a bay of a computer or peripheral within which the cartridge 100 is to be installed. Interposers create additional cost, interfere with signal integrity and can cause reliability issues.
Like embodiments of the invention, other prior art removable disc cartridges do not require use an interposer and provide an opening through which the electronic connectors 124 may pass through and protrude from the enclosure 150 in order to connect to the complementary electronic connectors located and positioned within a bay of a computer or peripheral within which the cartridge 100 is to be installed.
Unlike the embodiments of the invention, the aforementioned other prior art does not provide sufficiently rigid support to the front end 122 a of the disc drive 120 and consequently, the front end 122 a and the electronic connectors 124 can become misaligned within the enclosure 150 of the cartridge 100 . As a result, the electronic connectors will often not properly connect with the complementary electronic connectors when installing the cartridge 100 within a bay of a computer or peripheral. This type of circumstance is inconvenient for users of the removable disc cartridge 100 . Embodiments of the invention are designed to avoid this type of circumstance.
FIG. 2B illustrates a side view of an embodiment of an individual mounting and shock absorbing strut 212 of FIG. 1A . This side view shows a near longitudinal side 220 a of the strut 212 . The strut 212 includes a lower portion 216 and an upper portion 218 . A lower portion of the strut 212 rises above a wall of the bottom portion 110 of the enclosure 150 at approximately a 45 degree angle. The upper portion 218 of the strut 212 is oriented approximately parallel to the wall of the bottom portion 110 of the enclosure 150 . Both the lower 216 and upper 218 portions are approximately 3 mm in thickness. A top surface of the lower portion 216 is approximately 12 mm in length and a top surface of the upper portion is approximately 6 mm in length (as shown). The top surface of the upper portion 218 is approximately 8.5 mm above the top surface of the wall of the bottom portion 110 of the enclosure 150 .
FIG. 2C illustrates a perspective view of the embodiment of individual mounting and shock absorbing strut 212 of FIGS. 2A-2B . The width of the lower 216 and upper 218 portions is approximately 6 mm. The opening 214 is circular in shape and has a diameter of approximately 1 mm. The opening 214 is centered between the near longitudinal edge 220 a and a far longitudinal edge 220 b of the top surface of the strut 212 .
Each strut 212 a - 212 d is configured to deflect vertically and/or horizontally to counteract potential forces applied to the enclosure 150 from vertical and/or horizontal directions. A particular deflection of a strut in a direction can be quantified in terms of an amount of energy required to cause that particular deflection, also referred to as a strain energy.
Each strut 212 a - 212 d is configured for a vertical (Y axis) down deflection caused from dropping the cartridge 150 (oriented top side up and bottom side down), including a disc drive 120 , from a height of one meter onto a rigid floor. Impact between a bottom side of the bottom portion 110 of the enclosure 150 with the floor creates an upward force causing a downward deflection of the struts 212 a - 212 d . For this type of drop, the bottom side (not shown) of the cartridge 150 physically impacts the floor while being oriented parallel to the floor.
Each strut 212 a - 212 d is also configured for deflection towards the front side 122 a or the rear side 122 d (Z axis) or towards the left side 122 b or the right side 122 c (X axis) of the enclosure 150 in response to a force (shock) applied to the enclosure 150 .
In one embodiment, the cartridge 150 has dimensions of 24.5 mm (height)×85.7 mm (width)×111.9 mm (length). In some embodiments, removable disc drive cartridges can be dimensioned to comply with standards associated with a Standard Form Factor (SFF). Under a first variation of the SFF standard, a disc drive has a height of 9.5 cm and under a second variation of the SFF standard, a disc drive has a height of 12.5 cm.
For example, under the first variation of the SFF standard, a disc drive has dimensions of 9.5 mm (height)×69.85 mm (width)×100.2 mm (length). When enclosed within the enclosure 150 having a 2 mm wall thickness, there remains (24.5−9.5) mm−(2 walls)(2 mm/wall)=11 mm of vacant height (Y axis) space within the enclosure 150 , (85.7−69.85) mm−(2 walls)(2 mm/wall) mm=11.85 mm vacant width (X axis) space within the enclosure 150 , and (111.9−100.2)−(2 walls)(2 mm/wall)=7.7 mm vacant length (Z axis) space within the enclosure 150 .
When the disc drive 120 is centered within the enclosure 150 , the vacant space in any dimension (height, width or length) is divided into two separate portions that are each located on opposite sides of the disc drive 120 . Each separate portion is referred to as sway space. For the example described above, the dimensions of the sway space is 11 mm/2=5.5 mm of sway space in the height dimension (Y axis), 11.85 mm/2=5.925 mm sway space in the width dimension (X axis) and 7.7 mm/2=3.85 mm of sway space in the length dimension (Z axis), when the disc drive 120 is centered within the enclosure 150 .
Preferably, for a force (shock) applied in a given direction, the strut should not deflect so far that the disc drive 120 physically impacts a wall of the enclosure 150 . For example, considering that the struts 212 a - 212 d each have a height dimension of approximately 8.5 mm above the bottom wall of the enclosure 150 , when deflecting in the vertical down direction, a deflection of greater than 8.5 mm would cause the disc drive 120 to physically impact the bottom wall of the enclosure 150 . Hence, each strut 212 a - 212 d should vertically deflect less than 8.5 mm from the force (shock) of the bottom side (wall) of the enclosure impacting a rigid floor from a fall of the enclosure 150 and the enclosed disc drive 120 from a height of one meter.
Like wise, if the disc drive 120 is centered within the enclosure 150 , the (X axis) deflection of the struts 212 a - 212 d should be limited to 5.925 mm in a direction along the (X axis) and limited to 3.85 mm in a direction along the (Z axis).
Notice that the disc drive 120 , when supported by the struts of FIGS. 2A-2C , is located approximately 8.5 mm, minus a small deflection to support the weight of the disc drive 120 , above the wall of the bottom portion 110 of the enclosure 150 . This location is not exactly centered within the cavity formed by the enclosure given that the vertical (Y axis) vacant space is 11.85 mm. If centered, the disc drive 120 would be located approximately 11/2=5.5 mm above the wall of the bottom portion 110 of the enclosure 150 .
In other embodiments, the configuration of the struts 212 a - 212 d , specifically the shape and size of the struts 212 a - 212 d , is altered to support the disc drive 120 at other heights above the top surface of the wall of the bottom portion 110 . For example, the struts 212 a - 212 d can be configured to have a height of 5.5 mm instead of 8.5 mm. In one embodiment, the angle of the strut 212 a - 212 b can be altered to be less than 45 degrees, instead of equaling 45 degrees, as shown in FIG. 2B . This would enable the disc drive 120 to be centered within the cavity.
The mass of the disc drive 120 is typically between 80-140 grams. The mass of an enclosure made from ABS plastic is approximately 15 grams. A disc drive 120 is typically designed to withstand an impact of 800 G without sustaining serious damage. The energy of a fall of a combined mass of 155 grams (0.155 kilograms) equals 0.155 kilograms×9.81 Newtons/kilogram×1 meter=1.5 Newton Meters (Joules)
The energy required to cause a specified deflection, also referred to as the strain energy, is a function of the amount of deflection squared times one-half of a spring constant. Hence, a spring constant equal to approximately 111000 Newtons/kg would correspond to strain energy of 1.5 joules for a deflection amount of approximately 5.2 mm ((0.0052 m)**2) (111,000)/2=1.5 joules
For example, a spring constant equal to approximately 195,000 Newtons/meter would correspond to strain energy of 1.5 joules when deflecting approximately 3.9 mm. In order to limit the impact force to below 800 G, the struts 212 a - 212 d must collectively absorb the strain energy of a 1 meter drop without imposing an acceleration on the disc drive greater than 800 G. The acceptable spring constant for the combined supporting struts employed lies within the range of approximately 111,000 newtons per meter to 195,000 newtons per meter.
In many embodiments, each strut 212 a - 212 d , as designed and manufactured, is likely to have a unique and different spring constant of deflection for a direction along each of the X, Y and Z axes. For example, a strut 212 a - 212 d may have a spring constant of deflection of 120,000 in the Y axis direction, by have a spring constant of 200,000 in the X axis direction and 250,000 in the Z axis direction.
In accordance with the invention, a substantially rigid strut 212 a - 212 b is not intended to include an entirely rigid strut, such as a strut made from a little deflecting or non-deflecting material. A substantially rigid strut 212 a - 212 d is configured to provide at least a minimum (greater than zero) amount of deflection. In accordance with this objective, in some embodiments, the struts 212 a - 212 d are configured to deflect in accordance with a spring constant of less than or equal to 200,000 Newtons per Meter.
Likewise, in accordance with the same objective, in some embodiments, the struts 212 a - 212 d configured to deflect at least 20 percent relative to a range of deflection between the strut 212 a - 212 d at rest (undeflected except for miniscule deflection required to support a disc drive) and at maximum permitted deflection without making physical contact with a wall of the encloaure.
With respect to FIG. 2B , the deflection of the strut 212 a - 212 d at rest, is a miniscule deflection (less than 0.1 mm) of the strut when supporting a 140 gram disc drive 120 . The maximum permitted deflection of the strut 212 a - 212 d is approximately 8.5 mm. Hence, a 20 percent deflection within the above described range would equal approximately (0.2)(8.5 mm)=1.7 mm.
In accordance with the invention, a substantially rigid strut 212 a - 212 b is not intended to include a substantially flexible strut, such as a strut made from elastomeric material. In some embodiments, the struts 212 a - 212 d are configured to deflect in accordance with a spring constant of greater than or equal to 100,000 Newtons per Meter.
FIG. 3 illustrates an exploded view of a removable disc drive cartridge enclosure including an elastomeric outer rear mounting and shock absorbing component 340 . The outer rear mounting and shock absorbing component 340 , also referred to as a rear mount 340 , is made of an elastomeric material. An elastomeric material is a material that has properties of rubber and that generally provides less rigid support than ABS or other plastics or metals, for example. In accordance with the invention, an elastomeric material is not employed for manufacturing the front struts 212 a - 212 b.
As shown, the rear mount 340 is shaped and sized to surround and enclose the rear side 122 d of the disc drive 120 . Preferably, the rear mount 340 is shaped and sized to form a friction fit over the rear side 122 d of the disc drive 120 .
As shown, the rear mount 340 is configured to provide substantially less rigid support for the rear side 122 d of the disc drive 120 than the rigid support provided for the front side 122 a of the disc drive 120 by the front struts 122 a - 122 b , as previously described. As a result, the rear mount 340 can permit the rear side 122 d of the disc drive 120 to deflect a farther distance in response to a force applied to the cartridge 100 than any deflection permitted for the front side of the disc drive 120 by the front struts 122 a - 122 b.
Preferably, the no portion of the disc drive 120 , including its rear side 122 d , should be permitted to deflect so far as to make physical contact in any of the X, Y or Z axis directions, with a wall of the enclosure 150 , as a result of forces applied to the enclosure 150 that are within a pre-determined range of force (shock) applied to the cartridge 100 .
FIG. 4 illustrates an exploded view of a removable disc drive cartridge enclosure 150 including a rear mounting and shock absorbing component 440 a - 440 b , also referred to as a rear mount 440 a - 440 b , that is over molded around a rear side of the bottom portion 110 and the top portion 130 of the enclosure 150 . Like the rear mount 340 of FIG. 3 , this embodiment of the rear mount 440 a - 440 b is made of an elastomeric material and is configured to provide substantially less rigid support for the rear side 122 d of the disc drive 120 than the rigid support provided for the front side 122 a of the disc drive 120 by the front struts 122 a - 122 b , as previously described.
As a result, the rear mount 440 a - 440 b can permit the rear side 122 d of the disc drive 120 to deflect a farther distance in response to a force applied to the cartridge 100 than any deflection permitted for the front side of the disc drive 120 by the front struts 122 a - 122 b. In effect, in accordance with the embodiments of FIGS. 3-4 , the disc drive 120 deflects in hinge like fashion when dropped onto a rigid floor as previously described where the front struts 122 - a - 122 b can appear to act like a hinge while the rear side 122 d acts like a plane, such as a door, tilting (rotating) around from a hinge over a small angle of rotation.
FIG. 5 illustrates a close up view of holes located along the left side and the right side of the disc drive 120 that are configured to engage snap hooks. The snap hooks (not shown) can be attached to the top portion 130 or the bottom portion 110 of the enclosure 150 . In this embodiment, the snap hooks enable snap together assembly between the disc drive and the upper portion, or between the disc drive and the lower portion or between the upper portion and the lower portion, or any combination thereof.
FIG. 5B illustrates a close up view of hooks 552 a - 552 d that protrude from the top portion 130 of the enclosure 150 and that are configured to snap assemble and engage the holes 550 a - 550 d of FIG. 5A . In other embodiments, the hooks are configured to engage holes (not shown) manufactured as part of the bottom portion 110 of the enclosure 150
While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims. | A removable disc drive cartridge providing an improved combination of shock protection and electrical alignment (registration) of a enclosed removable disc drive. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to Chinese Patent Application No. 201510154312.2 filed Mar. 26, 2015.
BACKGROUND
[0002] 1. Technical Field
[0003] The present utility model relates to a cup holder, and in particular to a cooling cup holder that is suitable for chairs including massage armchairs, sofas and seats in coaches, airplanes, ships, theaters and cinemas.
[0004] 2. Related Art
[0005] The patent for utility model with Patent No. 201020541343.6 discloses a “MULTI-FUNCTIONAL TOUCH COOLING CUP HOLDER”. The cup holder can be equipped in seats, including massage armchairs, sofas and seats in coaches, airplanes, ships, theaters and cinemas. It can cool drinks to provide cool drinks for people in hot weather. However, the cooling cup holder is open, and it is easy for dust and other sundry crumbs to drop into the cup holder, thus bringing about trouble to cleaners.
SUMMARY
[0006] An objective of the present utility model is to provide a cooling cup holder with a rotary flip so as to overcome the defects in the prior art, so that the cooling cup holder can be covered when it is unnecessary to cool a drink, and the cooling cup holder can be open when it is necessary to cool a drink, thus keeping hygiene of the cooling cup holder.
[0007] Another objective of the present utility model is that, in addition to the above objective, various functions in a seat can be controlled through the cooling cup holder, including motor variation, the ON/OFF of headlight or footlight, heating and push rod expansion and contraction.
[0008] In order to achieve the first objective, the following technical solution can be adopted: the cooling cup holder with a rotary flip in the solution, like the prior art, includes a cup holder, wherein the cup holder includes a circular socket that can accommodate a beverage can or a beverage bottle or a water cup, a lower end of the circular socket is provided with an annular bottom cap, and a lower portion of an inner bore of the bottom cap has an annular shallow slot which is slightly larger than the inner bore; further includes a thermal conductive plate, wherein the thermal conductive plate is in a shape of a shallow plate turned upside down, and a plate edge thereof is embedded in the annular shallow slot of the lower portion of the inner bore of the bottom cap; further includes a thermoelectric cooler, wherein the thermoelectric cooler is installed between a thermal radiator described below and the thermal conductive plate and is electrically connected with a control circuit in a control circuit board, a side of a thermoelectric cooler can face toward the thermal conductive plate; and further includes a thermal radiator, wherein the thermal radiator includes a plurality of radiation fins which are in parallel and a cooling fan, and is installed under the bottom cap; and improvements thereof are as follows:
[0009] middle portions of left and right side faces of the circular socket in the cup holder each are provided with a raised large cylinder with a blind hole in the center, the two large cylinders being symmetric with each other, and each of the two blind holes is provided with a metal nut; upper and lower positions of a rear portion of each of the large cylinders each are provided with a raised middle cylinder with a female threaded hole in the center, the middle cylinders being symmetric with each other; towards the top of a front portion of each of the large cylinders is a raised small cylinder I with a female threaded hole in the center, the small cylinders being symmetric with each other; a top plate I which has a large round hole in the center is further fixedly connected around the top portion of the circular socket, the periphery of the top plate being rectangular; on a bottom surface of the rectangular top plate I, near a rear side edge thereof is a row of female threaded holes where a rear side frame described below is assembled; on the bottom surface of the rectangular top plate I, left and right sides near a front side edge thereof each are provided with a pair of downwardly raised small cylinders II with female threaded holes in the centers respectively; a pair of rib plates with vertical slots are further disposed in the middle of the two pairs of small cylinders II, and the two vertical slots are opposite and notched inwardly; and an upper surface of the rectangular top plate I is fixedly connected with a frame, the frame including:
[0010] a left side plate and a right side plate vertically fixedly connected with left and right side edges of the rectangular top plate I respectively, wherein top surfaces of the left side plate and the right side plate each are further fixedly connected with a rectangular ring plate extending outwardly, and projection of front and rear side edges of rectangular holes in the rectangular ring plate in a vertical direction is an appropriate distance longer than projection of the front and rear side edges of the rectangular top plate I in the vertical direction; and four sides of the rectangular ring plate each are fixedly connected with a short bent edge extending downwardly;
[0011] a rear side frame, wherein the rear side frame includes a bottom slat, and a row of screw holes corresponding to the row of female threaded holes in the rectangular top plate I are disposed near a front side edge of the bottom slat; left and right side edges of the bottom slat each are fixedly connected with a left side slat and a right side slat vertically upward, a rear side edge of the bottom slat is fixedly connected with a rear wallboard vertically upward, and the rear wallboard is fixedly connected with and is as high as the left side slat and the right side slat;
[0012] wherein left and right sides of the bottom cap near the front of a transverse center line thereof each are provided with a notch, and a limiting step is disposed in each notch; left and right sides directly in front of an outer circle of the bottom cap each are provided with a raised small cylinder VII with a female thread hole in the center; further including:
[0013] a rotary flip, the rotary flip including:
[0014] a rotary face shell, wherein the rotary face shell includes a rectangular top plate II, and four sides of the rectangular top plate II each are provided with a downward bent edge, wherein the height of the bent edge of the rear side edge is properly greater than the height of the bent edge of the front side edge and the height of the bent edges of the left and right side edges, and the height of a rear portion of each of the bent edges of the left and right side edges is equal to the height of the bent edge of the rear side edge; left and right sides of an inner surface of the bent edge of the rear side edge are provided with a pair of raised small cylinders III where a touch circuit board A bracket described below is assembled, the small cylinders having female threaded holes in the centers; an outer surface of the bent edge of the rear side edge is provided with a cooling key icon fitting in with a touch circuit board A described below; a rear portion of a bottom surface of the rectangular top plate II is provided with a row of three raised small cylinders mutually bolted with a flip bottom shell described below and having female threaded holes in the centers, and left and right sides near a front end of the bottom surface of the rectangular top plate II each are provided with a small cylinder IV mutually bolted with a flip bottom shell described below and having a female threaded hole in the center; and further including a flip panel, wherein the flip panel is a thin plastic plate which is as big as the rectangular top plate II, a cooling key icon fitting in with a touch circuit board B described below is disposed near a front edge of the flip panel, and a row of English words “PUSH TO OPEN” are written near a rear edge of the flip panel; and the flip panel is stuck to a top surface of the rectangular top plate II of the rotary face shell;
[0015] a flip bottom shell that can be mutually buckled with the rotary face shell, wherein the flip bottom shell includes a left side plate and a right side plate, the left side plate and the right side plate respectively include a bar-like vertical plate, a front end of the bar-like vertical plate is fixedly connected with a small rectangular vertical plate which slightly protrudes downwardly, and a rear end of the bar-like vertical plate is fixedly connected with a large rectangular vertical plate which protrudes downwardly; front ends, rear ends and lower ends of the two small rectangular vertical plates on left and right sides are fixedly connected into a small rectangular box respectively by using a transverse slat; at front ends of the two large rectangular vertical plates on the left and right sides, front end faces thereof are fixedly connected by using a transverse slat, lower ends of the two large rectangular vertical plates are fixedly connected by using a rectangular flat plate, and the rectangular flat plate extends backwardly an appropriate distance longer than rear end faces of the large rectangular vertical plates; and further including a top plate, wherein the top plate fixedly connects upper end faces of the bar-like vertical plates on the left and right sides together; left and right sides of a front end face near a bottom surface of the small rectangular box each are provided with a screw hole corresponding to the small cylinder IV; on a top surface of the rectangular flat plate, near a front end thereof are a row of raised small cylinders V with female threaded holes in the centers, the small cylinders corresponding to the three small cylinders in the rotary face shell; middle positions between the three small cylinders V each are provided with a small cylinder VIII with a female threaded hole in the center; and left and right sides near a front portion of the top plate each are provided with at least two raised small cylinders VI with female threaded holes in the centers, a left rotating arm and a right rotating arm being assembled at the small cylinders;
[0016] a touch circuit board A bracket, wherein the touch circuit board A bracket includes a cross bar, two ends of the cross bar each are fixedly connected with a small round socket, and a center distance of the two small round sockets is equal to a center distance of the two small cylinders III with female threaded holes in the centers in the rotary face shell; and two ejecting blocks are disposed in the middle of the cross bar;
[0017] an elongated touch circuit board A, wherein the touch circuit board A uses two screws to pass through inner bores of the small round sockets in the touch circuit board A bracket, to be tightened into the female threaded holes in the centers of the two small cylinders III in the rotary face shell, and front ends of the ejecting blocks tightly abut against the back of the touch circuit board A;
[0018] a touch circuit board B, wherein the touch circuit board B is assembled onto a bottom plate in the small rectangular box in the flip bottom shell;
[0019] a backlight pressing block, wherein the backlight pressing block includes a small round socket, the front of the small round socket is fixedly connected with a vertical arm, and a lower side of the vertical arm is fixedly connected with a pressing block; further including:
[0020] a backlight, wherein the backlight is placed at a rear portion of the top surface of the rectangular flat plate in the flip bottom shell, and uses two screws to pass through inner bores of the small round sockets in the backlight pressing blocks, to be tightened into the female threaded holes in the centers of the small cylinders VIII in the flip bottom shell, and the pressing block in the backlight pressing block compresses the backlight tightly;
[0021] a left rotating arm, wherein the left rotating arm includes a rectangular mounting substrate, and at least two screw holes are disposed on the mounting substrate; a bending arm similar to a “C” shape is fixedly connected to a bottom surface of the mounting substrate, and a touch block is disposed in the middle of a right side of the bending arm; a lower end of the bending arm is fixedly connected with a circular ring, and an aperture of an inner bore of the circular ring fits in with an outer diameter of the large cylinder in the circular socket in the cup holder; a left side of the circular ring is provided with a circular recess, a small notch is further disposed in the middle of a junction between the recess and the bending arm, and a circular arc notch is cut in a front portion of an outer wall of the recess; and a lower-middle portion of an outer circle of the circular ring is further fixedly connected with a quadrant;
[0022] a right rotating arm, wherein the structure of the right rotating arm is symmetric with that of the left rotating arm, and the right rotating arm and the left rotating arm are of the same size;
[0023] wherein at least four screws are used to respectively pass through screw holes on substrates of the left rotating arm and the right rotating arm, and are tightened into the female threaded holes in the centers of the small cylinders VI in the flip bottom shell, to assemble the left rotating arm and the right rotating arm on a lower surface of the top plate in the flip bottom shell;
[0024] the rotary face shell is buckled on the flip bottom shell, wherein rear end faces of the large rectangular vertical plates on the left side and the right side of the flip bottom shell are connected to front end faces of rear portions of the bent edges of the left and right side edges in the rotary face shell, and a rear end face of the rectangular flat plate in the flip bottom shell is aligned with the bent edge of the rear side edge in the rotary face shell; a front end face of the small box in the flip bottom shell is aligned with a front end face of the bent edge of the front side edge of the rectangular top plate II in the rotary face shell; three screws are used to pass through the screw holes in the centers of the small cylinders in the rotary face shell from top to bottom to be respectively tightened into the female threaded holes in the centers of the three small cylinders V in the flip bottom shell; two screws are used to pass through, from the bottom up, the screw holes on the left and right sides of the front end face near the bottom surface of the small rectangular box in the flip bottom shell to be respectively tightened into the female threaded holes in the centers of the two small cylinders IV in the rotary face shell, so as to assemble the rotary face shell and the flip bottom shell together, to form the rotary flip;
[0025] a left-handed torsion spring, wherein the left-handed torsion spring is assembled into the circular recess of the left rotating arm;
[0026] a right-handed torsion spring, wherein the right-handed torsion spring is assembled into the circular recess of the right rotating arm;
[0027] two damper brackets, wherein each damper bracket includes a circular ring, upper and lower sides of the circular ring each are fixedly connected with an ear plate, the right side of the circular ring is further provided with a circular step recessed inwardly, upper and lower sides of the circular step each are fixed with a rectangular shallow recess, the two recesses being symmetric with each other, the middle of each of the two rectangular shallow recesses is provided with a female threaded hole, the two female threaded holes being symmetric with each other, on reverse sides of the two ear plates, upper and lower sides of the two female threaded holes 44 each are provided with a raised small circular ring, the small circular rings being symmetric with each other, an inner diameter of each of the small circular rings fits in with an outer diameter of each of the middle cylinders of the circular socket in the cup holder, and the center of each of the small circular rings is provided with a screw hole;
[0028] two dampers, wherein each damper includes a small circular plate, outer diameters of the small circular plates fit in with inner bores of the circular rings in the damper brackets; upper and lower sides near the right sides of the small circular plates each are fixedly connected with a small ear plate, shapes and thicknesses of the small ear plates fit in with the rectangular shallow recesses in the damper brackets, the small ear plates each are provided thereon with a screw hole, and positions of the screw holes correspond to the female threaded holes in the rectangular shallow recesses in the damper brackets; the center of each of the small circular plates is fixedly provided with a small mandrel which protrudes backwardly, a pinion is fixedly installed on the small mandrel, and the modulus of the pinion is the same as that of teeth of the quadrant in the flip bottom shell of the rotary flip;
[0029] two spring pressing plates, wherein each spring pressing plate includes a small disk, the center of the right side of the small disk has a countersunk screw hole, a raised circular ring is disposed on the back of the small disk and outside the countersunk screw hole, and an inner circle diameter of the raised circular ring fits in with an outer diameter of the large cylinder in the circular socket of the cup holder; an upper end of the small disk is fixedly connected with a short arm, an upper end of the short arm is fixedly connected with a small cylinder, and the center of the small cylinder has a screw hole; a raised small circular ring is disposed on the back of the small disk and outside the screw hole, and an inner circle diameter of the small circular ring fits in with an outer diameter of the small cylinder I in the circular socket of the cup holder; and the middle of the back of the short arm is further provided with a vertical slot;
[0030] two self-locking switch brackets, wherein each self-locking switch bracket includes a block, left and right sides of the block each are fixedly connected with an ear plate, the middle of each ear plate has a screw hole, and a center distance of the two screw holes is equal to a center distance of each pair of small cylinders II in the circular socket of the cup holder; a front side and a rear side between the ear plate on the right side and the block each are provided with a right-angled trapezoid vertical plate which extends downwardly, and the two right-angled trapezoid vertical plates are connected through a rib plate; and the two self-locking switch brackets use two pairs of screws to pass through the screw holes on the ear plates respectively to be tightened into the female threaded holes in the centers of each pair of small cylinders II in the circular socket of the cup holder;
[0031] two self-locking switches, wherein the two self-locking switches are respectively installed onto the two self-locking switch brackets, and during assembly, bottom surfaces thereof are adhered to lower end faces of the blocks of the self-locking switch brackets, and one side thereof is adhered to a vertical end face of the right-angled trapezoid vertical plates;
[0032] a rectangular control circuit board, wherein a control circuit in the control circuit board includes a main control MCU, an input end of the main control MCU is in signaling connections with the touch circuit board A and the touch circuit board B respectively, and an output end thereof is respectively in signaling connections with the backlight and a cooler control module of a control circuit in a control circuit board of a seat; a power module supplies power for the main control MCU, the backlight and the cooler control module respectively; two sides of the control circuit board near a lower end thereof each are provided with a screw hole; an upper end of the control circuit board is inserted into the vertical slots of a pair of rib plates with vertical slots in the front of the circular socket in the cup holder, and then uses two screws to pass through the screw holes on the two sides near the lower end thereof, to be tightened into the female threaded holes in the centers of the two small cylinders VII directly in front of the bottom cap;
[0033] the rotary flip penetrates from the rectangular holes of the rectangular ring plate in the frame of the cup holder, and the inner bores of the circular rings in the left rotating arm and the right rotating arm each are sheathed outside the large cylinders on the left and right sides of the circular socket in the cup holder; the left-handed torsion spring and the right-handed torsion spring are respectively nested in the circular recesses on the left side faces of the circular rings in the left rotating arm and the right rotating arm, and one ends thereof extend out of the notches of the recesses; the small disks in the two spring pressing plates are buckled outside the large cylinders, the other ends of the left-handed torsion spring and the right-handed torsion spring respectively extend into the vertical slot on the back of the short arms in the spring pressing plates, two screws are used to respectively pass through the countersunk screw holes in the centers of the small disks in the spring pressing plates on the left and right sides, to be tightened into the metal nuts in the blind holes in the centers of the large cylinders on the left and right sides of the circular socket in the cup holder, to respectively hold the left-handed torsion spring and the right-handed torsion spring down; inner circles of the raised small circular rings on the backs of the small cylinders in the two spring pressing plates are buckled outside the small cylinders I in the circular socket in the cup holder, and two screws are used to respectively pass through the screw holes in the centers of the small cylinders, to be tightened into the female threaded holes in the centers of the small cylinders I on the left and right sides of the circular socket in the cup holder; the two dampers each are inserted from the right sides of the two damper brackets, wherein the pinions are engaged with the teeth of the quadrant in the flip bottom shell, two pairs of small screws are used to respectively pass through the screw holes in the small ear plates of the two dampers, to be tightened into the female threaded holes in the rectangular recesses on the right sides of the ear plates of the damper brackets, so as to assemble the dampers and the damper brackets together, at the same time, the small circular rings on the backs of the ear plates in the damper brackets are sheathed outside the middle cylinders on the left and right sides of the circular socket in the cup holder, and then two pairs of screws are used to pass through the screw holes on the ear plates, to be tightened into the female threaded holes in the centers of the middle cylinders, so as to well assemble the dampers and the damper brackets together; and
[0034] the rotary flip can rotate at an appropriate angle around central axes of the large cylinders on the left and right sides of the circular socket in the cup holder, when the rotary slip rotates to the flip panel therein to be flush with the top surface of the rectangular ring plate in the cup holder, and when the position of “PUSH TO OPEN” in the rear edge of the flip panel is slightly pressed down, touch blocks on the bending arms in the left rotating arm and the right rotating arm touch the self-locking switches, the self-locking switches control the main control MCU to be disconnected from the backlight, at this time, the rotary flip seals the rectangular holes of the rectangular ring plate in the frame of the cup holder and the position of the rotary flip is stabilized, when the position of “PUSH TO OPEN” in the rear edge of the flip panel is slightly pressed down once again, elastic forces of the left-handed torsion spring and the right-handed torsion spring overturn the rotary flip by 90°, when the touch blocks touch the limiting steps in the notches on the left and right sides of the bottom cap, the touch blocks no longer rotate, at this time, the self-locking switches control the main control MCU to be connected with the backlight, the backlight emits light, the circular socket in the cup holder is exposed, and the key icon on the outer surface of the bent edge of the rear side edge in the rotary face shell is just located thereon.
[0035] In order to achieve the second objective, the following improvements can be made on the basis of the aforementioned technical solution:
[0036] The output end of the main control MCU in the control circuit of the control circuit board is further in signaling connections with various functional control modules in a total control circuit in a seat respectively, and the functional control modules include a motor vibration control module, a headlight or footlight control module, a heating control module and a push rod expansion and contraction control module; and
[0037] touch key icons with various functions which are in the same row as the cooling key icon and control a seat are disposed near the front edge of the flip panel in the flip face shell and on the outer surface of the bent edge of the rear side edge of the flip face shell, the touch key icons including icons of motor vibration, the ON/OFF of headlight or footlight, heating and push rod expansion and contraction.
[0038] Various functions in the seat can be controlled by pressing the touch key icons on the outer surface of the bent edge of the rear side edge of the flip face shell.
[0039] Beneficial effects of the present utility model are as follows:
[0040] 1. The cooling cup holder can be covered when it is unnecessary to cool a drink, and the cooling cup holder can be open when it is necessary to cool a drink, thus keeping hygiene of the cooling cup holder.
[0041] 2. When the backlight in the cooling cup holder emits light, the circular socket in the cup holder can be lit up, which facilitates a consumer to find his/her position and also increases the sense of beauty.
[0042] 3. Various functions in the seat can be controlled by pressing the touch key icons in the cooling cup holder, and thus it is unnecessary to otherwise assemble control keys on the seat.
[0043] In order to make the present utility model easy to understand and much clearer, the present utility model is further described below with reference to the accompanying drawings and embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] FIG. 1 is a first three-dimensional schematic view of a contour according to an embodiment of the present utility model;
[0045] FIG. 2 is a second three-dimensional schematic view of a contour according to an embodiment of the present utility model;
[0046] FIG. 3 is a third three-dimensional schematic view of a contour according to an embodiment of the present utility model;
[0047] FIG. 4 is an exploded schematic view of various parts in FIG. 3 ;
[0048] FIG. 5 is an enlarged three-dimensional schematic view of the rotary flip in FIG. 4 ;
[0049] FIG. 6 is an exploded schematic view of various parts in FIG. 5 ;
[0050] FIG. 7 is a schematic sectional view of A-A in FIG. 1 ;
[0051] FIG. 8 is a schematic sectional view of B-B in FIG. 1 ;
[0052] FIG. 9 a is a first three-dimensional schematic view of a contour of the cup holder in FIG. 3 ; FIG. 9 b is a second three-dimensional schematic view of a contour of components of the cup holder in FIG. 3 ; FIG. 9 c is a schematic front view of the cup holder; FIG. 9 d is a schematic left view of FIG. 9 c ; FIG. 9 e is a schematic rear view of FIG. 9 c ; FIG. 9 f is a schematic sectional view of B-B in FIG. 9 c ; and FIG. 9 g is a schematic sectional view of an A 00 A step in FIG. 9 c;
[0053] FIG. 10 a is a three-dimensional schematic view of the damper bracket in FIG. 3 ; and FIG. 10 b is a schematic view of the C direction in FIG. 10 a;
[0054] FIG. 11 is a three-dimensional schematic view of the damper in FIG. 3 ;
[0055] FIG. 12 a is a three-dimensional schematic view of the spring pressing plate in FIG. 3 ; FIG. 12 b is a schematic front view of FIG. 12 a ; FIG. 12 c is a schematic right view of FIG. 12 b ; and FIG. 12 d is a schematic left view of FIG. 12 b;
[0056] FIG. 13 a is a three-dimensional schematic view of the self-locking switch bracket in FIG. 3 ; FIG. 13 b is a schematic front view of FIG. 13 a ; FIG. 13 c is a schematic top view of FIG. 13 b ; and FIG. 13 d is a schematic bottom view of FIG. 13 b;
[0057] FIG. 14 is a three-dimensional schematic view of the self-locking switch in FIG. 3 ;
[0058] FIG. 15 is a schematic sectional view of the thermal conductive plate in FIG. 3 ;
[0059] FIG. 16 a is a three-dimensional schematic view of the bottom cap in FIG. 3 ; and
[0060] FIG. 16 b is a schematic top view of FIG. 16 a;
[0061] FIG. 17 is a three-dimensional schematic view of the thermal radiator in FIG. 3 ;
[0062] FIG. 18 is a three-dimensional schematic view of the rear side frame in FIG. 3 ;
[0063] FIG. 19 a is a three-dimensional schematic view of the rectangular socket in FIG. 3 ; FIG. 19 b is a schematic top view of FIG. 19 a ; and FIG. 19 c is a schematic rear view of FIG. 19 b;
[0064] FIG. 20 a is a three-dimensional schematic view of the rotary face shell in the rotary flip in FIG. 3 ; FIG. 20 b is a schematic bottom view of FIG. 20 a ; FIG. 20 c is a schematic left view of FIG. 20 b ; and FIG. 20 d is a schematic top view of FIG. 20 b;
[0065] FIG. 21 a is a schematic front view of the flip bottom shell in the rotary flip in FIG. 3 ; FIG. 21 b is a schematic right view of FIG. 21 a ; FIG. 21 c is a schematic left view of FIG. 21 b ; and FIG. 21 d is a three-dimensional schematic view of FIG. 21 b;
[0066] FIG. 22 is a three-dimensional schematic view of the backlight pressing block in FIG. 5 ;
[0067] FIG. 23 is a three-dimensional schematic view of the touch circuit board A bracket in FIG. 5 ;
[0068] FIG. 24 is a schematic front view of the flip panel in FIG. 3 ;
[0069] FIG. 25 a is a three-dimensional schematic view of the left rotating arm in the rotary flip in FIG. 3 ; FIG. 25 b is a schematic front view of the left rotating arm; FIG. 25 c is a schematic right view of FIG. 25 b ; and FIG. 25 d is a schematic left view of FIG. 25 b;
[0070] FIG. 26 a is a three-dimensional schematic view of the right rotating arm in the rotary flip in FIG. 3 ; FIG. 26 b is a schematic front view of the right rotating arm; FIG. 26 c is a schematic right view of FIG. 26 b ; and FIG. 26 d is a schematic left view of FIG. 26 b;
[0071] FIG. 27 is a block diagram of circuitry of the control circuit board in FIG. 3 ;
[0072] FIG. 28 shows a first view of an exemplary wireless charging station for use with the disclosed device;
[0073] FIG. 29 shows a second view of an exemplary wireless charging station for use with the disclosed device;
[0074] FIG. 30 shows an exemplary wireless charging station on the disclosed device;
[0075] FIG. 31 shows an exemplary wireless charging area of the disclosed device;
[0076] FIG. 32 shows a mobile electronic device on an exemplary wireless charging area of the disclosed device;
[0077] FIG. 33 shows an exemplary wireless modular power receiver for use with the disclosed device; and,
[0078] FIG. 34 shows an exemplary wireless modular power receiver on a mobile electronic device for use with the disclosed device.
DETAILED DESCRIPTION
Embodiment 1
[0079] please refer to FIG. 1 to FIG. 27 . In this embodiment, the cooling cup holder with a rotary flip includes a cup holder 11 (refer to FIG. 1 , FIG. 2 and FIG. 3 ), wherein the cup holder 11 includes a circular socket 115 that can accommodate a beverage can or a beverage bottle or a water cup (refer to FIG. 9 a to FIG. 9 g ), a lower end of the circular socket 115 is provided with an annular bottom cap 21 by using three screws 22 (refer to FIG. 16 a and FIG. 16 b and FIG. 7 , FIG. 4 ), and a lower portion of an inner bore 217 of the bottom cap 21 has an annular shallow slot 218 which is slightly larger than the inner bore; further including a thermal conductive plate 24 (refer to FIG. 15 and FIG. 7 ), wherein the thermal conductive plate 24 is in a shape of a shallow plate turned upside down, and a plate edge 241 thereof is embedded in the annular shallow slot 218 of the lower portion of the inner bore 217 of the bottom cap by using four screws 20 ; further including a thermoelectric cooler 25 (refer to FIG. 4 and FIG. 7 ), wherein the thermoelectric cooler 25 is installed between a thermal radiator 1 described below and the thermal conductive plate 24 and is electrically connected with a control circuit in a control circuit board 18 , a side of the thermoelectric cooler 25 faces up and is adhered to a bottom side 242 of the thermal conductive plate 24 , and another side faces down and is adhered to a top side 112 of the thermal radiator 1 ; and further including a thermal radiator 1 (refer to FIG. 17 and FIG. 7 ), wherein the thermal radiator 1 includes a plurality of radiation fins 11 which are in parallel and a cooling fan 12 , and is installed under the bottom cap 21 ; wherein:
[0080] middle portions of left and right side faces of the circular socket 115 in the cup holder 11 each are provided with a raised large cylinder 117 with a blind hole 1171 in the center, the two large cylinders being symmetric with each other, and each of the two blind holes 1171 is provided with a metal nut 28 (refer to FIG. 8 ); upper and lower positions of a rear portion of each of the large cylinders 117 each are provided with a raised middle cylinder 116 with a female threaded hole in the center, the middle cylinders being symmetric with each other; towards the top of a front portion of each of the large cylinders 117 is a raised small cylinder I 118 with a female threaded hole in the center, the small cylinders being symmetric with each other; a top plate I 113 which has a large round hole 1131 in the center is further fixedly connected around the top portion of the circular socket 115 , the periphery of the top plate being rectangular; on a bottom surface of the rectangular top plate I 113 , near a rear side edge thereof is a row of female threaded holes 1113 where a rear side frame 12 described below is assembled; on the bottom surface of the rectangular top plate I 113 , left and right sides near a front side edge thereof each are provided with a pair of downwardly raised small cylinders II 119 with female threaded holes in the centers respectively; a pair of rib plates 1111 with vertical slots are further disposed in the middle of the two pairs of small cylinders II 119 , and the two vertical slots are opposite and notched inwardly; and an upper surface of the rectangular top plate I 113 is fixedly connected with a frame, the frame including:
[0081] a left side plate 112 and a right side plate 114 vertically fixedly connected with left and right side edges of the rectangular top plate I 113 respectively, wherein top surfaces of the left side plate 112 and the right side plate 114 each are further fixedly connected with a rectangular ring plate 111 extending outwardly, and projection of front and rear side edges of rectangular holes 1112 in the rectangular ring plate 111 in a vertical direction is an appropriate distance longer than projection of the front and rear side edges of the rectangular top plate I 113 in the vertical direction; and four sides of the rectangular ring plate 111 each are fixedly connected with a short bent edge 1114 extending downwardly;
[0082] a rear side frame 12 (refer to FIG. 4 and FIG. 18 ), wherein the rear side frame 12 includes a bottom slat 123 , and a row of screw holes 124 corresponding to the row of female threaded holes 1113 in the rectangular top plate I are disposed near a front side edge of the bottom slat 123 ; left and right side edges of the bottom slat 123 each are fixedly connected with a left side slat 122 and a right side slat 125 vertically upward, a rear side edge of the bottom slat 123 is fixedly connected with a rear wallboard 121 vertically upward, and the rear wallboard 121 is fixedly connected with and is as high as the left side slat 122 and the right side slat 125 ;
[0083] wherein left and right sides of the bottom cap 21 near the front of a transverse center line thereof each are provided with a notch 216 , and a limiting step 212 is disposed in each notch 216 ; left and right sides directly in front of an outer circle of the bottom cap 21 each are provided with a raised small cylinder VII 213 with a female thread hole in the center; further including:
[0084] a rotary flip 14 , the rotary flip 14 including (refer to FIG. 1 to FIG. 8 and FIG. 20 a to FIG. 26 d ):
[0085] a rotary face shell 143 (refer to FIG. 20 a to FIG. 20 d ), wherein the rotary face shell 143 includes a rectangular top plate II 14311 , and four sides of the rectangular top plate II 14311 each are provided with a downward bent edge, wherein the height of the bent edge 1433 of the rear side edge is properly greater than the height of the bent edge 1431 of the front side edge and the height of the bent edges of the left and right side edges, and the height of a rear portion 1432 of each of the bent edges of the left and right side edges is equal to the height of the bent edge 1433 of the rear side edge; left and right sides of an inner surface of the bent edge 1433 of the rear side edge are provided with a pair of raised small cylinders III 1434 where a touch circuit board A bracket 145 described below is assembled, the small cylinders having female threaded holes in the centers; an outer surface of the bent edge 1433 of the rear side edge is provided with a cooling key icon 14312 fitting in with a touch circuit board A 146 described below; a rear portion of a bottom surface of the rectangular top plate II 14311 is provided with a row of three raised small cylinders 1435 mutually bolted with a flip bottom shell 1416 described below and having female threaded holes in the centers, and left and right sides near a front end of the bottom surface of the rectangular top plate II 14311 each are provided with a small cylinder IV 1439 mutually bolted with a flip bottom shell 1416 described below and having a female threaded hole in the center; and further including a flip panel 141 (refer to FIG. 24 ), wherein the flip panel 141 is a thin plastic plate 1411 which is as big as the rectangular top plate II 14311 , a cooling key icon 1412 fitting in with a touch circuit board B 1418 described below is disposed near a front edge of the flip panel 141 , and a row of English words “PUSH TO OPEN” 1413 are written near a rear edge of the flip panel 141 ; and the flip panel 141 is stuck to a top surface of the rectangular top plate II 14311 of the rotary face shell 143 ;
[0086] a flip bottom shell 1416 that can be mutually buckled with the rotary face shell 143 , wherein the flip bottom shell 1416 (refer to FIG. 21 a to FIG. 21 d ) includes a left side plate and a right side plate, the left side plate and the right side plate respectively include a bar-like vertical plate 14161 , a front end of the bar-like vertical plate 14161 is fixedly connected with a small rectangular vertical plate 141610 which slightly protrudes downwardly, and a rear end of the bar-like vertical plate 14161 is fixedly connected with a large rectangular vertical plate 14162 which protrudes downwardly; front ends, rear ends and lower ends of the two small rectangular vertical plates 141610 on left and right sides are fixedly connected into a small rectangular box 14169 respectively by using a transverse slat; at front ends of the two large rectangular vertical plates 14162 on the left and right sides, front end faces thereof are fixedly connected by using a transverse slat, lower ends of the two large rectangular vertical plates 14162 are fixedly connected by using a rectangular flat plate 14163 , and the rectangular flat plate 14163 extends backwardly an appropriate distance longer than rear end faces of the large rectangular vertical plates 14162 ; and further including a top plate 14165 , wherein the top plate 14165 fixedly connects upper end faces of the bar-like vertical plates 14161 on the left and right sides together; left and right sides of a front end face near a bottom surface 14162 of the small rectangular box 14169 each are provided with a screw hole 14167 corresponding to the small cylinder IV 1439 ; on a top surface of the rectangular flat plate 14163 , near a front end thereof are a row of raised small cylinders V 141615 with female threaded holes in the centers thereof, the small cylinders corresponding to the three small cylinders 1435 in the rotary face shell 143 ; middle positions between the three small cylinders V 141615 each are provided with a small cylinder VIII 141614 with a female threaded hole in the center; and left and right sides near a front portion of the top plate 14165 each are provided with at least two raised small cylinders VI 14166 with female threaded holes in the centers, a left rotating arm 1412 and a right rotating arm 1411 being assembled at the small cylinders;
[0087] a touch circuit board A bracket 145 , wherein the touch circuit board A bracket 145 includes a cross bar 1453 , two ends of the cross bar 1453 each are fixedly connected with a small round socket 1452 , and a center distance of the two small round sockets 1452 is equal to a center distance of the two small cylinders III 1434 with female threaded holes in the centers in the rotary face shell 143 ; and two ejecting blocks 1453 are disposed in the middle of the cross bar 1451 ;
[0088] an elongated touch circuit board A 146 (refer to FIG. 6 ), wherein the touch circuit board A 146 uses two screws 144 to pass through inner bores of the small round sockets 1452 in the touch circuit board A bracket, to be tightened into the female threaded holes in the centers of the two small cylinders III 1434 in the rotary face shell 143 , and front ends of the ejecting blocks 1453 tightly abut against the back of the touch circuit board A 146 ;
[0089] a touch circuit board B 1418 (refer to FIG. 6 ), wherein the touch circuit board B 1418 is assembled onto a bottom plate 141612 in the small rectangular box 14169 in the flip bottom shell 1416 ;
[0090] a backlight pressing block 148 (refer to FIG. 22 ), wherein the backlight pressing block 148 includes a small round socket 1481 , the front of the small round socket 1481 is fixedly connected with a vertical arm 1482 , and a lower side of the vertical arm 1482 is fixedly connected with a pressing block 1483 ; further including:
[0091] a backlight 147 (refer to FIG. 6 ), wherein the backlight 147 is placed at a rear portion of the top surface of the rectangular flat plate 14163 in the flip bottom shell 1416 , and uses two screws to pass through inner bores 1484 of the small round sockets in the backlight pressing blocks 148 , to be tightened into the female threaded holes in the centers of the small cylinders VIII 141614 in the flip bottom shell 1416 , and the pressing block 1483 in the backlight pressing block 148 compresses the backlight 147 tightly;
[0092] a left rotating arm 1412 (refer to FIG. 25 a to FIG. 25 d ), wherein the left rotating arm 1412 includes a rectangular mounting substrate 14121 , and at least two screw holes 14127 are disposed on the mounting substrate 14121 ; a bending arm 14122 similar to a “C” shape is fixedly connected to a bottom surface of the mounting substrate 14121 , and a touch block 14123 is disposed in the middle of a right side of the bending arm 14122 ; a lower end of the bending arm 14122 is fixedly connected with a circular ring 14125 , and an aperture of an inner bore of the circular ring 14125 fits in with an outer diameter of the large cylinder 117 in the circular socket 115 in the cup holder 11 ; a left side of the circular ring 14125 is provided with a circular recess 14126 , a small notch 14127 is further disposed in the middle of a junction between the recess 14126 and the bending arm 14122 , and a circular arc notch 14128 is cut in a front portion of an outer wall of the recess 14126 ; and a lower-middle portion of an outer circle of the circular ring 14125 is further fixedly connected with a quadrant 14124 ;
[0093] a right rotating arm 1411 , wherein the structure of the right rotating arm 1411 is symmetric with that of the left rotating arm 1412 , and the right rotating arm and the left rotating arm are of the same size;
[0094] wherein at least four screws 1415 (the number of the screws is not limited to four) are used to respectively pass through screw holes on substrates 14127 of the left rotating arm 1412 and the right rotating arm 1411 , and are tightened into the female threaded holes in the centers of the small cylinders VI 14166 in the flip bottom shell 1416 , to assemble the left rotating arm and the right rotating arm on a lower surface of the top plate 14165 in the flip bottom shell 1416 ;
[0095] the rotary face shell 143 is buckled on the flip bottom shell 1416 , wherein rear end faces of the large rectangular vertical plates 14162 on the left side and the right side of the flip bottom shell 1416 are connected to front end faces of rear portions 1432 of the bent edges of the left and right side edges in the rotary face shell 143 , and a rear end face of the rectangular flat plate 14163 in the flip bottom shell 1416 is aligned with the bent edge 1433 of the rear side edge in the rotary face shell 143 ; a front end face 14168 of the small box 14169 in the flip bottom shell 1416 is aligned with a front end face of the bent edge of the front side edge of the rectangular top plate II 14311 in the rotary face shell 143 ; three screws 142 are used to pass through the screw holes in the centers of the small cylinders 1435 in the rotary face shell 143 from top to bottom to be respectively tightened into the female threaded holes in the centers of the three small cylinders V 141615 in the flip bottom shell 1416 ; two screws are used to pass through, from the bottom up, the screw holes 14167 on the left and right sides of the front end face near the bottom surface of the small rectangular box 14169 in the flip bottom shell 1416 to be respectively tightened into the female threaded holes in the centers of the two small cylinders IV 1439 in the rotary face shell 143 , so as to assemble the rotary face shell 143 and the flip bottom shell 1416 together, to form the rotary flip 14 ;
[0096] a left-handed torsion spring 1410 (refer to FIG. 6 ), wherein the left-handed torsion spring 1410 is assembled into the circular recess 14126 of the left rotating arm 1412 ;
[0097] a right-handed torsion spring 1413 , wherein the right-handed torsion spring 1413 is assembled into the circular recess of the right rotating arm 1411 ;
[0098] two damper brackets 4 (refer to FIG. 10 a and FIG. 10 b ), wherein each damper bracket 4 includes a circular ring 41 , upper and lower sides of the circular ring 41 each are fixedly connected with an ear plate 42 , the right side of the circular ring 41 is further provided with a circular step 46 recessed inwardly, upper and lower sides of the circular step 46 each are fixed with a rectangular shallow recess 45 , the two recesses being symmetric with each other, the middle of each of the two rectangular shallow recesses 45 is provided with a female threaded hole 44 , the two female threaded holes being symmetric with each other, on reverse sides of the two ear plates, upper and lower sides of the two female threaded holes 44 each are provided with a raised small circular ring 43 , the small circular rings being symmetric with each other, an inner diameter of each of the small circular rings 43 fits in with an outer diameter of each of the middle cylinders 116 of the circular socket 115 in the cup holder 11 , and the center of each of the small circular rings 43 is provided with a screw hole 47 ;
[0099] two dampers 3 (refer to FIG. 11 ), wherein each damper 3 includes a small circular plate 31 , outer diameters of the small circular plates 31 fit in with inner bores of the circular rings 41 in the damper brackets 4 ; upper and lower sides near the right sides of the small circular plates 31 each are fixedly connected with a small ear plate 32 , shapes and thicknesses of the small ear plates 32 fit in with the rectangular shallow recesses 45 in the damper brackets 4 , the small ear plates 32 each are provided thereon with a screw hole 33 , and positions of the screw holes 33 correspond to the female threaded holes 44 in the rectangular shallow recesses 45 in the damper brackets 4 ; the center of each of the small circular plates 31 is fixedly provided with a small mandrel 34 which protrudes backwardly, a pinion 35 is fixedly installed on the small mandrel 34 , and the modulus of the pinion 35 is the same as that of teeth of the quadrant 14124 in the flip bottom shell 1416 of the rotary flip 14 ;
[0100] two spring pressing plates 6 (refer to FIG. 12 a to FIG. 12 d ), wherein each spring pressing plate 6 includes a small disk 61 , the center of the right side of the small disk 61 has a countersunk screw hole 62 , a raised circular ring 68 is disposed on the back of the small disk and outside the countersunk screw hole 62 , and an inner circle diameter of the raised circular ring 68 fits in with an outer diameter of the corresponding large cylinder 117 in the circular socket 115 of the cup holder 11 ; an upper end of the small disk 61 is fixedly connected with a short arm 63 , an upper end of the short arm 63 is fixedly connected with a small cylinder 64 , and the center of the small cylinder 64 has a screw hole 65 ; a raised small circular ring 66 is disposed on the back of the small disk 61 and outside the screw hole 65 , and an inner circle diameter of the small circular ring 66 fits in with an outer diameter of the corresponding small cylinder I 118 in the circular socket 115 of the cup holder 11 ; and the middle of the back of the short arm 63 is further provided with a vertical slot 67 ;
[0101] two self-locking switch brackets 10 (refer to FIG. 13 a to FIG. 13 d ), wherein each self-locking switch bracket 10 includes a block 102 , left and right sides of the block 102 each are fixedly connected with an ear plate 101 , the middle of each ear plate 101 has a screw hole 104 , and a center distance of the two screw holes 104 is equal to a center distance of each pair of small cylinders II 119 in the circular socket 115 of the cup holder 11 ; a front side and a rear side between the ear plate on the right side and the block 102 each are provided with a right-angled trapezoid vertical plate 105 which extends downwardly, and the two right-angled trapezoid vertical plates 105 are connected through a rib plate 106 ; and the two self-locking switch brackets 10 use two pairs of screws 8 to pass through the screw holes 104 on the ear plates respectively to be tightened into the female threaded holes in the centers of each pair of small cylinders II 119 in the circular socket 115 of the cup holder 11 ;
[0102] two self-locking switches 9 (refer to FIG. 14 ), wherein the two self-locking switches 9 are respectively installed onto the two self-locking switch brackets 10 , and during assembly, bottom surfaces thereof are adhered to lower end faces of the blocks of the self-locking switch brackets, and one side thereof is adhered to a vertical end face of the right-angled trapezoid vertical plates; the self-locking switches are preferably self-locking switches whose model is PR-07 produced by Dongguan Xi Bang Electronic Co., Ltd., and certainly, self-locking switches of other manufacturers are also feasible;
[0103] a rectangular control circuit board 18 (refer to FIG. 4 ), wherein a control circuit in the control circuit board 18 includes a main control MCU 182 , an input end of the main control MCU 182 is in signaling connections with the touch circuit board A 146 and the touch circuit board B 1418 respectively, and an output end thereof is respectively in signaling connections with the backlight 147 and a cooler control module 186 of a control circuit in a control circuit board of a seat; a power module 181 supplies power for the main control MCU 182 , the backlight 147 and the temperature control module 185 respectively; two sides of the control circuit board 18 near a lower end thereof each are provided with a screw hole; an upper end of the control circuit board 18 is inserted into the vertical slots of a pair of rib plates 1111 with vertical slots in the front of the circular socket 115 in the cup holder 11 , and then uses two screws 19 to pass through the screw holes on the two sides near the lower end thereof, to be tightened into the female threaded holes in the centers of the two small cylinders VII 213 directly in front of the bottom cap 21 ;
[0104] the rotary flip 14 penetrates from the rectangular holes of the rectangular ring plate 111 in the frame of the cup holder 11 , and the inner bores 14125 of the circular rings in the left rotating arm 1412 and the right rotating arm 1411 each are sheathed outside the large cylinders 117 on the left and right sides of the circular socket 115 in the cup holder 11 ; the left-handed torsion spring 1410 and the right-handed torsion spring 1413 are respectively nested in the circular recesses 14126 on the left side faces of the circular rings 14125 in the left rotating arm 1412 and the right rotating arm 1411 , and one ends thereof extend out of the notches 14127 of the recesses; the small disks 61 in the two spring pressing plates 6 are buckled outside the large cylinders 117 , the other ends of the left-handed torsion spring 1410 and the right-handed torsion spring 1413 respectively extend into the vertical slot 67 on the back of the short arms 63 in the spring pressing plates 6 , two screws 7 are used to respectively pass through the countersunk screw holes 62 in the centers of the small disks in the spring pressing plates 6 on the left and right sides, to be tightened into the metal nuts 28 (refer to FIG. 8 ) in the blind holes in the centers of the large cylinders 117 on the left and right sides of the circular socket in the cup holder, to respectively hold the left-handed torsion spring and the right-handed torsion spring down; inner circles of the raised small circular rings 66 on the backs of the small cylinders 64 in the two spring pressing plates 6 are buckled outside the small cylinders I 118 in the circular socket in the cup holder, and two screws are used to respectively pass through the screw holes 65 in the centers of the small cylinders, to be tightened into the female threaded holes in the centers of the small cylinders I 118 on the left and right sides of the circular socket in the cup holder; the two dampers 3 each are inserted from the right sides of the two damper brackets 4 , wherein the pinions 35 are engaged with the teeth of the quadrant 14124 in the flip bottom shell 1416 , two pairs of small screws 2 are used to respectively pass through the screw holes 33 in the small ear plates of the two dampers 3 , to be tightened into the female threaded holes 44 in the rectangular recesses on the right sides of the ear plates of the damper brackets 4 , so as to assemble the dampers 3 and the damper brackets 4 together, at the same time, the small circular rings 43 on the backs of the ear plates in the damper brackets 4 are sheathed outside the middle cylinders 116 on the left and right sides of the circular socket in the cup holder, and then two pairs of screws 5 are used to pass through the screw holes 47 on the ear plates 42 , to be tightened into the female threaded holes in the centers of the middle cylinders 116 , so as to well assemble the dampers 3 and the damper brackets 4 together; and
[0105] the rotary flip 14 can rotate at an appropriate angle around central axes of the large cylinders 117 on the left and right sides of the circular socket in the cup holder, when the rotary slip rotates to the flip panel 141 therein to be flush with the top surface of the rectangular ring plate 111 in the cup holder 11 , and when the position of “PUSH TO OPEN” in the rear edge of the flip panel 141 is slightly pressed down, touch blocks 14123 on the bending arms in the left rotating arm 1412 and the right rotating arm 1411 touch the self-locking switches 9 , the self-locking switches 9 control the main control MCU 182 to be disconnected from the backlight 147 , at this time, the rotary flip 14 seals the rectangular holes of the rectangular ring plate 111 in the frame of the cup holder 11 and the position of the rotary flip is stabilized, when the position of “PUSH TO OPEN” in the rear edge of the flip panel is slightly pressed down once again, elastic forces of the left-handed torsion spring 10 and the right-handed torsion spring 13 overturn the rotary flip 14 by 90°, when the touch blocks 14123 touch the limiting steps 212 in the notches 216 on the left and right sides of the bottom cap 21 , the touch blocks no longer rotate, at this time, the self-locking switches 9 control the main control MCU 182 to be connected with the backlight 147 , the backlight 147 emits light, the circular socket 115 in the cup holder 11 is exposed, and the key icon 1433 on the outer surface of the bent edge of the rear side edge in the rotary face shell 143 is just located thereon.
[0106] The thermoelectric cooler 26 in FIG. 4 and FIG. 7 is used to double as cooling or heating.
Embodiment 2
[0107] please refer to FIG. 27 , FIG. 20 d and FIG. 24 . This embodiment has made the following improvements on the basis of the aforementioned technical solution:
[0108] the output end of the main control MCU 182 in the control circuit of the control circuit board 18 is further in signaling connections with various functional control modules in a total control circuit in a seat respectively, and the functional control modules include a motor vibration control module 183 , a headlight or footlight control module 187 , a heating control module 186 and a push rod expansion and contraction control module 184 ; and
[0109] touch key icons with various functions which are in the same row as the cooling key icon and control a seat are disposed near the front edge of the flip panel 1411 in the flip face shell 143 and on the outer surface of the bent edge 1433 of the rear side edge of the flip face shell 143 , the touch key icons including icons of motor vibration, the ON/OFF of headlight or footlight, heating and push rod expansion and contraction.
[0110] Various functions in the seat can be controlled by pressing the touch key icons at the front edge of the flip panel 1411 in the flip face shell and on the outer surface of the bent edge 1433 of the rear side edge thereof.
[0111] Further, a decorative ring 17 (refer to FIG. 4 and FIG. 7 ) is further disposed in the aforementioned two embodiments, wherein an outer surface of the decorative ring 17 is an electroplated glossy surface, which is assembled on the top surface of the circular socket 115 in the cup holder 11 .
[0112] Furthermore, a rectangular socket 16 (refer to FIG. 4 and FIG. 19 a to FIG. 19 c ) is further disposed, wherein the rectangular socket 16 includes a small rectangular ring plate 161 that can be nested in the bent edge 1114 , which extends downwardly, of the rectangular ring plate 111 in the frame of the cup holder 11 , and bottom surfaces of four corners of the small rectangular ring plate 161 each are provided thereon with a female threaded hole 165 ; a rectangular cover that extends downwardly is further fixedly connected inside the four female threaded holes 165 , the rectangular cover includes a left side plate 162 , a right side plate 164 , a rear side plate 163 which are as high as each other and a shorter front side slat 166 and can be just sheathed outside the left side plate 112 , the right side plate 114 and the rear side frame 12 in the frame of the cup holder 11 where the rear side frame 12 has been assembled, and an appropriate large notch is disposed below a front panel of the rectangular cover. The four screw holes 165 in the rectangular socket 16 are prepared for installing the cooling cup holder to the seat, and as shown in FIG. 4 , four screws can be used to pass through the four screw holes 165 respectively, to install the cooling cup holder into the seat.
[0113] Further, a frame panel 13 (refer to FIG. 4 ) is further disposed, wherein the frame panel 13 is a rectangular annular plastic sheet, and is stuck to the upper surface of the rectangular ring plate 111 in the frame of the cup holder 11 , used for increasing the sense of beauty of the product.
[0114] Further, an “O”-shaped seal ring 23 (refer to FIG. 4 and FIG. 8 ) is further disposed, wherein the “O”-shaped seal ring 23 is assembled between an upper surface of the plate edge 241 of the thermal conductive plate 24 and a lower surface of the annular shallow slot 218 of the inner bore 217 of the bottom cap 21 , used for preventing the beverage in the beverage cup to leak downwardly.
[0115] Further, outer side faces of the “C”-shaped bending arms in the left rotating arm 1412 and the right rotating arm 1411 each are provided thereon with a reinforcing plate 1414 .
[0116] The middle of the bottom surface of the rectangular top plate II 14311 in the rotary face shell 143 is further provided with an elongated reinforcing plate 1436 .
[0117] In other exemplary embodiments the disclosed device includes a wireless charging station 2000 as shown in FIGS. 28-34 , for recharging, e.g., a rechargeable battery of a mobile electronic device. Wireless charging station 2000 can incorporate any suitable wireless charger as known in the art, for example and without limitation, an electromagnetic induction wireless charger according to the Qi wireless charging standard. In other embodiments wireless charging station 2000 may be a wireless charger such as according to the Power Matters Alliance (PMA) standard, Alliance for Wireless Power (A4WP) standard, iNPOFi technology, or any other wireless charger within the spirit and scope of this disclosure. The wireless charging station 2000 may also operate using, e.g., radio waves and/or magnetic resonance.
[0118] The exemplary embodiment shown by FIGS. 28-34 includes a Qi wireless charging station 2000 which structure is incorporated into any or all of rotary flip 14 , flip panel 141 , rotary face shell 143 , and/or flip bottom shell 1416 . FIGS. 28-29 show an exemplary Qi wireless charging station. Wireless charging station includes, among other things, induction coil 2001 , and transmitting module 2002 .
[0119] FIG. 30 shows the wireless charging station 2000 incorporated onto a bottom surface 2006 of the flip panel 141 , as in an exemplary embodiment.
[0120] In the exemplary embodiment, power module 181 provides power to the wireless charging station 2000 by way of the transmitting module 2002 . Transmitting module 2002 may use a known component or components, such as an inverter (not shown), to convert a direct current to an alternating current. Induction coil 2001 generates pulses of electromotive force which may be received by certain electronic devices 2005 having a receiving coil (not shown) for wireless charging. Principles of induction and electromotive applications are generally known including for wireless charging products.
[0121] In the exemplary embodiment of FIGS. 28-34 , induction coil 2001 is located in sufficient proximity to flip panel 141 and an electronic device 2005 with wireless charging capability such that electromotive transmissions from the induction coil 2001 are received by the electronic device 2005 for recharging at least one power source of the electronic device. Electronic device 2005 may be placed, for example and without limitation, on a top surface 2007 of the flip panel 141 .
[0122] As shown in the exemplary embodiment of FIGS. 31-32 , wireless charging area 2004 is identified by the Qi wireless charging logo. In other embodiments the wireless charging area 2004 may be located in any suitable position consistent with this disclosure. As further shown in the exemplary embodiment of FIGS. 31-32 , touch key array 2010 is provided on the flip panel 141 .
[0123] In addition to the touch key array 2010 and functions previously described, wireless charging indicator light 2003 may be provided on the touch key array 2010 . Wireless charging indicator light 2003 may illuminate or change colors when wireless charging is initiated between the wireless charging station 2000 and an electronic device 2005 . In one embodiment, wireless charging may automatically initiate when a compatible electronic device 2005 is placed on wireless charging area 2004 . In other embodiments, a manual control (not shown) may be used to initiate wireless charging or turn the feature on and off.
[0124] A modular wireless power receiver 2007 , shown in FIGS. 33-34 , may also be included in an exemplary embodiment of the disclosed device. Modular wireless power receiver 2007 provides wireless charging capability to an electronic device that does not have an integral receiving module for wireless charging. Modular wireless power receiver 2007 includes, among other things, a receiving module for, e.g., receiving, rectifying, and filtering wireless energy transmissions, and a charging port connector 2008 for directing the current to the rechargeable device power source.
[0125] As used herein a “wireless device” may be, for example, a smartphone, tablet computer, smart watch, PDA, or other mobile or non-mobile electronic device with a rechargeable power source.
[0126] The above are merely preferred embodiments of the present utility model, but do not limit the implementation scope of the present utility model. Therefore, equivalent variation and modification without departing from the claims of the present utility model should still fall within the protection scope of the present utility model. | The present utility model relates to a cup holder, and in particular to a cooling cup holder that is suitable for chairs including massage armchairs, sofas and seats in coaches, airplanes, ships, theaters and cinemas. The cooling cup holder includes a rotary flip so that the cooling cup holder can be covered when it is unnecessary to cool a drink, and the cooling cup holder can be open when it is necessary to cool a drink, thus keeping hygiene of the cooling cup holder. The cooling cup holder may further include a wireless charging station for wirelessly charging a mobile electronic device, for example. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to the art of fluid phase separation, and, more in particular, to a centrifugal, pitot separator that separates solids and liquids and produces a fluid with acceptably low solids content to be used elsewhere and to be used for concentrating the solids so that solids and a liquid carrier discharge at an acceptably low flow rate.
It is not uncommon for a fluid to be contaminated with solid materials and for this reason to be unusable. Solids can cause abrasion damage to seals, bearings, blades and the like of machinery with which the fluid is used, either as a power fluid or as a fluid undergoing an increase in head.
There are many ways of separating solids from a fluid. One way is by centrifugal cleaners. Pitot cleaners are a type of centrifugal cleaner. A pitot cleaner has a hollow rotor driven by a motor. The rotor rotates within a casing or housing. A stationary pitot tube at a predetermined radial zone within the rotor intercepts fluid and draws the fluid out of the rotor. This cleansed fluid may then become a process fluid for some activity, say, a power fluid for hydraulic machinery. Solids that are heavier than the rest of the phases of the fluid go into the casing or housing surrounding the rotor as "underflow" through nozzles in the outside of the rotor and at the maximum radius of the rotor. The solids are entrained in liquid. There the material is discharged, but the discharge can be a nuisance.
It is also known that jet pumps that employ a pressurized fluid to aspirate another fluid are good at handling abrasive streams. A jet pump and pitot pump combination is shown in U.S. Pat. No. 3,817,659.
It is also known that cyclone separators effectively remove solids from a stream by reducing the kinetic energy of the stream and the solids, resulting in the solids coming out of suspension.
Especially in particularly dirty streams a problem of disposal of the underflow from a separator presents itself. The dirty effluent includes a carrier liquid and the quantity of the effluent creates the problem. In some locations it becomes difficult to conveniently store and dispose of the waste effluent.
It would be desirable to provide a means for concentrating the solids in order to reduce the quantity of waste resulting from separation. At the same time, it would be desirable to provide a cleansed stream with at least some of the head it had before cleaning.
SUMMARY OF THE INVENTION
The present invention provides a means for concentrating solid waste from a fluid to produce a cleansed output fluid having an acceptably low solids content.
In general, the invention contemplates the use of a centrifugal separator that separates solids from an input fluid by the action of a centrifugal force field. The waste effluent from this process is further concentrated in downstream separators to produce a cleansed stream. The cleansed stream, preferably is reintroduced into the centrifugal separator with the input fluid stream. Alternatively, the cleansed stream is a product stream. A second cleansed product fluid stream emanates from the first stage of separation.
In preferred form, the present invention contemplates a centrifugal separator that produces a solid waste effluent. A stream is taken from the separator after its head has been increased and used as the carrier stream in a a jet pump. This jet pump aspirates the solid waste from the centrifugal separator. The discharge from the jet pump passes into one or more additional separators to concentrate the solid waste. The clean discharge from these additional separators is then reintroduced into the first stage, centrifugal separator, or leaves as a cleansed stream. A cleansed stream takes off from the first stage of separation.
Preferably, the first of the centrifugal separators is of the pitot type and has at least one pitot tap located in a zone where pressure is moderate. The tap draws energized working fluid from the rotor. A branch of this stream becomes the aspirating fluid in the jet pump. Solid waste in a liquid carrier discharges from the rotor through nozzles into the casing of the separator. An agitator can keep the nozzle from clogging. The solid material aspirates into the jet pump and the discharge from the jet pump feeds into one or more cyclone separators. These latter separators concentrate the solid waste and the concentrate discharges into mud pots or the like. The cleansed fluid stream from the cyclones passes back into the inlet of the centrifugal, pitot separator.
The present invention provides a convenient and simple means for concentrating solid waste effluent to reduce the volume of storage necessary for such effluent.
These and other features, aspects and advantages of the present invention will become more apparent from the following description, appended claims and drawings.
BRIEF DESCRIPTION OF THE FIGURE
The single FIGURE is a view partly in half section and partly broken away of a pitot separator and jet pump together with schematic depictions of the balance of a solid waste concentrator circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the FIGURE, a centrifugal separator 10 has a casing 12 and a rotor 14. A drive, such as a motor 16, rotates the rotor within the casing. A pitot tap 18 within the casing has a radial passage 20 that opens into a cavity 22 that is within the rotor. The opening into the tap faces rotating fluid at a predetermined radial zone and draws fluid from within the rotor. A feed line 24 feeds dirty fluid from a source 26 into a chamber 28. From there, the fluid enters an annulus 30 that is concentric with the rotational axis of the rotor. Fluid leaving annulus 30 moves radially outward of the axis of rotation of the rotor in a plurality of radial passages 32. These passages empty into chamber 22 of the rotor slightly inward of the extreme radial periphery of the chamber.
Radial passage 20 of pitot tap 18 opens into an annular passage 34 that is concentric with the axis of rotation of the rotor. This passage leads to a discharge line 36.
Pitot tap 18 opens into chamber 22 at a radial zone determined by the pressure requirements of downstream concentrators. Pitot cleaners have the capability of increasing the static head of fluid substantially when the tap opens at a large radius. In the case of cyclone separators this can be too much pressure and represents a loss of valuable energy because the pressure would have to be dissipated.
A line 42 takes off from discharge line 36 and empties into a fore-chamber of a jet pump 46. The fore-chamber leads to a nozzle 50 through a converging passage. An aspirating chamber 54 of the jet pump sees the pressure of a fluid stream emanating from nozzle 50. Fluid in aspirating chamber 54 is aspirated into a passage 56. Passage 56 opens into a diffuser 58 to reduce the velocity of the stream and increase the static pressure of the stream. The diffuser opens into a line 59.
Rotor 14 has a plurality of radial nozzles 60 between rotor chamber 22 and an external chamber 62 between rotor 14 and casing 12. Solids and fluid pass through these nozzles into chamber 62. A line 64 from the chamber to aspirating chamber 54 provides as the aspirated fluid of pump 46 the solids and fluid from chamber 62. The fluid and solid material in chamber 62 is sometimes referred to as underflow.
To summarize the description to this point, fluid from a source enters centrifugal separator 10 and passes into rotor chamber 22. Rotor 14, driven in rotation, stratifies the phases of the fluid in accordance with their density. The stratification will find a fluid and solids at the extreme radial periphery of the rotor chamber, a lighter phase fluid inside this zone, and any gas radially inside of this intermediate zone. Solids and fluid leave the rotor through nozzles 60 and enter chamber 62. Jet pump 46, using as an aspirating fluid the fluid drawn by pitot tap 38, aspirates these solids and water through line 64 and into line 59. The aspirating fluid is energized by the rotor and leaves chamber 22 through pitot tap 38. The stream in line 59, rich in solids, then proceeds for concentration of the solids and solids disposal.
Concentration of the solids in stream 59 takes place in a bank of cyclone separators 66, 67 and 68. Line 59 branches into lines 70 and 72. Line 72 feeds cyclone 66. Line 70 supplies cyclones 67 and 68. Line 70 branches into lines 71 and 72 which directly feed cyclones 67 and 68, respectively. As is known, the cyclones receive a stream tangentially at a large diameter section of an inverted cone. The stream suffers a drop in velocity in the cyclone. Solid materials drop out of suspension because of the loss of velocity of the stream and solid materials. Concentrated solid materials in liquid fall by gravity to the bottom of the cyclones, and liquid, freed of much of the solids it formerly carried, leaves the cyclones. The liquid leaving cyclones 66, 67 and 68 does so through lines 74, 75 and 76, respectively. These lines join in a line 78. Line 78 in turn tees into feed line 24 that goes back into the centrifugal separator. Alternatively, line 78 can go off as a low pressure, clean fluid line 79, as shown in dashed lines. Solid effluent from cyclones 66, 67 and 68 leaves the cyclones as streams 80, 81 and 82, respectively, for accumulation in a mud pot 83.
The flow rate to jet pump 46 is determined by a flow control valve 84 upstream from the pump and in line 42. Since valve 84 controls the flow rate of the aspirating stream of the jet pump, it also controls the flow rate of the aspirated stream in line 64.
Back pressure control for the cyclones is by a valve 86 in line 78. This valve permits the establishment of the correct pressure differential across the cyclones for their proper functioning.
Thus, pitot separator 10 receives a stream of contaminated fluid and separates the fluid into phases. A denser phase, typically solids in a liquid although it need not be, leaves chamber 22 through nozzles 60 and enters external chamber 62. A clean phase leaves chamber 22 through pitot tap 18 and line 36. This clean phase is at comparably high pressure and thus the separation process has saved some of the energy required by it. The phase in external chamber 62, which includes waste material, is concentrated in the bank of cyclones 66, 67 and 68. The concentrated waste accumulates in mud pot 83. Without concentration, the volume of waste could be several times the volume of waste with concentration. Stream 78 usually is sufficiently clean so as not to require further cleansing. When this is the case, the stream leaves as stream 79. When further cleansing is required, stream 78 reenters pitot separator 10 for treatment.
The jet pump that feeds the cyclones feeds them with fluid under sufficient pressure to drive the cyclones. This pressure results from the pitot tap picking up an aspirating fluid with a head augmented by the pumping action of the rotor.
Separator 10 further includes a drive shaft 120. The drive shaft is driven by motor 16. A seal and bearing 122 around shaft 120 prevents leakage out of chamber 62 along the shaft. A flange 124 of shaft 120 attaches to rotor 14 as by threaded fasteners 126.
Rotor 14 has a deeply dished casing member 130 and a cover 132 secured to casing member 130 as by threaded fasteners 134. Casing 130 and cover 132 bound chamber 22. Passage 34 lies within a stationary tube 136. Tube 136 extends out into a hub 138 of housing 12 at the anterior end of the separator. A hub 139 of tube 136 is received in and supported by hub 138. Ring seals 140 on tube 136 isolate chamber 22 from the outside of tube 136 externally of the chamber. The seals cooperate with a bore 141 of cover 132 in the sealing function. Passage 34 empties into line 36 downstream of hub 139.
Cover 132 has a hub 142. A second hub 144 extends from hub 142 away from rotor 14. A web 146 at the junction of the two hubs extends radially inward and defines an inner wall of chamber 28. Annulus 30 passes through hubs 142 and 144 to meet radial passages 32.
A stirrer vane 148 attached to tube 136 and extending radially from the axis of rotation of rotor 14 in chamber 22 approaches the radius of the inlet of nozzle 60. The stirrer vane agitates the fluid and solids at the entrance to the nozzles and prevents clogging.
A tube 150 on the axis of rotation of rotor 14 opens into chamber 22 along the axis to collect any light phase material, such as gas, and the material passes through the tube to some place outside the separator.
Casing 12 includes a primary drum 154 and a cover 156. The cover secures to the drum by threaded fasteners 158. Cover 156 is integral with hub 138. Baffles 159 in the wall of drum 154 direct fluid and solids away from seal 122. The separator can mount on a stand 160.
Except where modified here, U.S. Pat. No. 4,036,427 describes a suitable pitot separator. The disclosure of this patent is incorporated herein by reference. U.S. Pat. No. 3,817,659 shows the use of a pitot separator and jet pump. The disclosure of the latter patent is incorporated herein by reference.
By way of example to illustrate the efficacy of the present invention, assume a flow rate of 80 gallons per minute of feed into the centrifugal separator. Assume an underflow rate out line 64 of about 4 gallons per minute. Aspirating stream 42 for jet pump 46 has a flow rate of also 4 gallons per minute. Each of the three cyclones 66, 67 and 68 then receives 22/3 gallons per minute. The waste effluent from the cyclones passing into mud pot 83 will have a flow rate of about one gallon per minute. Thus in practical effect the underflow has been reduced from 4 gallons per minute to one gallon per minute.
The present invention has been described with reference to a preferred embodiment. The spirit and scope of the appended claims should not, however, necessarily be limited to the foregoing embodiment. | A pitot pump separates a two-phase fluid from a source into a clean, lighter phase and a dirty, heavier phase by subjecting them to a centrifugal force field in a rotating chamber. A small radius pitot tap of the pump draws some of the lightest phase from the chamber to provide the power fluid that drives a jet pump. The jet pump aspirates dirty fluid of the heavier phase that has accumulated in the casing of the pitot pump. Cyclones separate solids of the heavier phase from liquid in the discharge of the jet pump. Concentrated solids from the cyclones in a liquid carrier discharge into mud pots. A cleansed liquid stream leaving the cyclones recycles back into the inlet of the pitot pump, or, is taken off as a clean low pressure stream. | 5 |
BACKGROUND OF THE INVENTION
The present invention relates to a rotary screening machine for pulp suspension that is contaminated with impurities. In particular, the invention relates to means in the machine, and particularly the sorting and conveying vanes, for causing the suspension and particles therein to pulsatingly move across the screen, preventing particle build-up on the screen.
A rotary screening machine of the type with which the invention is employed comprises a rotating drum, an annular basket like screen around the drum, an annular screen slot or space defined between the drum and the screen and sorting means in the screen slot, e.g. supported on the drum, for moving the suspension axially along the screen slot and for also sorting out the desirable particles and the rejected impurities, so that the former and latter materials may pass to respective collection areas.
One such rotary screening machine is known from West German Provisional Patent (Auslegeschrift) No. 27 12 715. In that machine, projections are provided on the rotating drum, and the projections rotate at a slight distance from a perforated screen basket. A vacuum is produced on the edges of the projections which are located toward the rear in the direction of flow (the trailing or run-off edges). This helps pieces of fiber and similarly shaped components of the suspension being screened to pass through the holes of the screen to be thereafter fed to one pulp outlet. The vacuum produced at the trailing edge of a projection is not very great. Furthermore, in this screening machine, the drum and the projections arranged thereon contribute minimally to conveying the suspension axially through the machine, i.e. axially of the rotating drum. Thus, a pump, or the like, must be provided to separately produce pressure for moving the pulp suspension.
SUMMARY OF THE INVENTION
The object of the present invention is to obtain good separation of the components of a fiber suspension in a screening machine with the use of as little power as possible.
Another object of the invention is to cause pulsation of the suspension and its components radially across the screen, for reducing screen clogging.
A further object is to improve axial conveyance of the suspension.
The objects are realized according to the invention. The projections on the drum are sorting vanes projecting radially outwardly from the drum. Starting at what is the leading edge of each vane during rotation, the top and bottom surfaces of the vane taper wider in the direction of the axis of the drum in a generally wedge shape.
This development of the sorting vanes alternately produces pressure and relatively large vacuum at the screening slot. As the vanes rotate past the screen basket, with the pulp suspension containing impurities in the screen slot, wherein the fibers in suspension and the impurities in suspension possibly adhere to the screen, the vanes cause the fibers and impurities to be constantly detached from the screen basket. This detachment effect may be reinforced by the eddy produced at the trailing ends of the vanes. In this way, the parts which are to be sorted out, namely the fibers in the fiber suspension, are given an increased opportunity to reach and to pass out through holes in the screen basket, and in this way to be removed from the suspension.
The vane profile is of wedge shape and thus has only a low coefficient of resistance so that the acceleration of the suspension by the vanes, particularly in the circumferential direction, is rather small. As a result, the screening machine operates with relatively low consumption of power. Spinning of the components of the suspension of the vanes can also easily be avoided in that the leading edge of the vanes (as seen in the direction of rotation) are slightly beveled rearwardly.
The screening machine is of simple construction and is easy to manufacture. By simply turning of the vanes on a lathe, the screen slot which is to be maintained between the radially outer edge of the vanes and the screen basket can be produced relatively simply.
The development and arrangement of the sorting vanes in accordance with the invention is also favorable in that it substantially eliminates the detrimental effects that might be caused by pulsations through the use of a relatively large number of vanes, since the pulsations are then of only slight amplitude.
In a preferred further development of the invention, at least one of the wedge surfaces that defines the sorting vane is inclined from the horizontal, i.e. from a plane perpendicular to the axis of the drum, along the radial direction of extension of the vane to produce additional conveyance momentum components of the fiber suspension with respect to the screen basket.
The wedge surfaces that define each vane may cooperate to give the vane a generally "V" shaped profile, widening from the leading to the trailing ends of the vane. An open space is defined between the wedge surfaces of a vane and a vacuum develops there as the drum rotates. An additional lateral wall may be positioned in that open space, extending between the upper and lower wedge surfaces and also extending rearwardly from the leading edge of the vane, to control the size and shape of that space between the wedge surfaces that faces radially outwardly toward the screen basket. The orientation and position of this wall will cooperate in determining the direction of pulsation of the fiber suspension as each vane rotates past. In a preferred embodiment, that wall is shaped, oriented and positioned so that both the radial and axial length of the space between the wedge surfaces gradually increases from the leading edge of the vane to the trailing edge thereof. Various other orientations of the limiting wall are possible, including an orientation where it is radially closer to the screen basket near the leading edge than at the trailing edge of the vane, or vice versa. The wall orientation selected depends upon the particular pressure-vacuum condition that is sought to be established there.
Along the length of the sorting drum, and preferably generally at is axially central region, the drum has diluting liquid spray holes, i.e. water spray holes, defined in it. Opposed to the spray holes, the generally porous screen basket has no openings through it, thereby confining the sprayed diluting water within the screen slot.
The drum may have different axial zones, with the sorting vanes being nearer the lower zone and the upper zone not having vanes of the type described above. By appropriate arrangement of the vanes, preferably as described just above, the accepted fiber material is conveyed toward one axial end of the machine while the rejected impurities are conveyed to the other end. The sorting vanes are configured to axially move the suspension in a manner calculated to cause the above described separation.
Other objects and features of the invention will now be described with reference to a few illustrative embodiments of the invention which are shown in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial sectional view showing a first embodiment of a rotary screening machine in accordance with the invention, which is of open, unpressurized construction;
FIG. 1a is a partial axial sectional view through the sorting drum like that of FIG. 1, shown on a large scale;
FIGS. 2 and 3 are the same type of view as FIG. 1 respectively showing further embodiments of screening machines;
FIG. 4 is a partial radial sectional view through one modified embodiment of a sorting drum, on a larger scale;
FIG. 5 is a partial axial sectional view through an embodiment of a sorting drum, on a larger scale but also showing features of the embodiment of FIG. 4;
FIG. 6 is a similar sectional view to FIG. 5 showing yet another embodiment of a sorting drum;
FIGS. 7a to 7c are views corresponding respectively to FIGS. 4-6 showing still another embodiment of a sorting drum; and
FIG. 8 shows a screening machine according to the invention with a different embodiment of a drum.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a rotary screening machine according to the invention includes an outer housing 20. An annular, cylindrical drum 1 is rotatably supported in the housing 20 and rotates about is axis with a constant radius annular screen slot 3 within an annular screen basket 2. The constant radius of the slot 3 is defined between the periphery of the drum 1 and the screen basket 2. The drum has end walls 41 and 42 at its respective axial ends. The shaft 39 supports the drum 1 for rotation. The shaft 39 is supported horizontally in the lower part of the housing 20 in a bearing (not shown). The shaft 39 is driven to rotate by the belt 38, via drive pulleys 36 and 37. The pulley 36 may be fastened to the shaft, for instance, of an electric motor (not shown).
Fiber suspension to be sorted is fed from below, through the feed connection 6, directly into the screen slot 3 between the drum 1 and the screen basket 2. The suspension is picked up in the slot 3 by the rotating vanes 4 which are fastened to the shell of the rotatable drum 1. The suspension is conveyed along the screen slot 3 in the axial direction to the rejects outlet 12 located at the upper end of the drum. The properly divided, cleaned pulp passes through the holes or pores along the length of the screen basket 2, and the pulp piles up in the housing 20 to a certain height and then discharges radially through an accepted pulp outlet 17. The rejected material passes tangentially out of the sorter at the upper end of the screen slot 3, through a chute 12.
The rotor, or drum 1, carries sorting vanes 4 and 40 projecting from its surface. Vanes 40 are described below. Each sorting vane 4 on the drum 1 is generally of wedge shape, tapering gradually wider, measured axially of the drum, rearwardly from the narrow leading edge 11 of the vane. Each vane 4 has an upper, upwardly inclined, wedge surface 10 and a lower, downwardly inclined, wedge surface 9. The direction of the inclines just mentioned is rearwardly with respect to the direction of rotation of the drum. Each vane 4 is defined by thin plates defining wedge surfaces 9 and 10, which thereby defines an open volume between the wedge surfaces 9 and 10. Upon rotation of the drum, a vacuum can build up between the surfaces 9 and 10, starting from the leading end 11 of each vane and increasing to the trailing or run-off end. At the trailing end of the vane, practically at its burble edge, eddies are produced which, upon the passage of the vanes along the inside of the screen basket 2, cooperate with the vacuum produced by the vanes to detach the mat of suspension fibers, which have deposited on the screen basket. This prevents the openings in the basket from becoming clogged. Also, constant remixing of the suspension is obtained.
Both the sorting vanes 4 and the vanes 40 are arranged somewhat in a helical array around the drum 1. But, the sorting vanes 4 are helically arranged to an extent that they do not cause an excessive axial conveyance component of the fiber suspension along the screen slot 3 to the rejects outlet 12. In practice, the vanes 4 are staggered somewhat with respect to each other, so that their lower wedge surfaces 9 also strike a part of the suspension upon the rotation of the drum 1.
In this embodiment, the lower wedge surfaces 9 of the vanes are inclined downwardly with increasing distance rearwardly from the leading edges 11 of the vanes. At the same time, in the embodiment of FIG. 1a, the lower wedge surfaces incline upwardly from the horizontal (or from a plane perpendicular to the axis of the drum 1), moving radially outwardly of the drum 1. This inclination of the surfaces 9 of the vanes causes a component of motion of the particles impinging upon the vanes which is directed toward the screen 2. In this way, the particles that were initially drawn away from the screen 2 by the vacuum produced by the rotating vanes are again conveyed against the screen, which increases the possibility that particles of acceptable quality pulp can be sorted through the holes in the screen 2. Of course, the upper wedge surfaces 10 of the vanes 4 may also be developed in the same manner as shown in FIG. 1a. These surfaces 10 are inclined upwardly from the leading edges 11 of the vanes but downwardly with respect to the horizontal, moving radially outwardly of the drum 1.
In this way, the two essential features of the sorting process in this screen slot, namely the detachment of the fibers of the suspension from the screen 2, which is caused by the vacuum and eddying, and the conveying of the fibers to the screen, continuously alternate, i.e. a pulsating movement of the fiber suspension is produced in the screen slot 3, and specifically in its lower zone where the sorting vanes 4 are present on the drum 1.
A ring of impurities 15 that forms in the uppermost zone of the screen slot 3 should consist predominantly of rejects or impurities.
A different development of the lower wedge surfaces 9 of the sorting vanes 4 over at least a selected region of the surface of the rotary drum prevents rapid passage of the suspension, particularly of suspension enriched with rejects, directly along the surface of the rotor drum, and also prevents stagnation of the flow and possibly a clogging, with the poorer sorting effect inherent therein, from occurring directly on the screen basket.
On the shell of the rotor drum 1, there are three different regions. The lowermost region is provided with above described sorting vanes 4. Adjoining the lower region is a more central axial region of the rotor drum on which other sorting vanes 40 are present. In contrast to the sorting vanes 4 present in the lower region of the drum, the vanes 40 may either be so inclined on their lower wedge surfaces 9 that their suspension conveying action away from the rejects outlet 12 is less than in the case of the other vanes 4, or the lower wedge surfaces 9 of these vanes 40 are to be narrower in the radial direction starting from the surface of the drum, as can be noted from FIG. 1, than the upper wedge surfaces 10 of either of the sorting vanes 4 or 40. In this way, a stronger deceleration of the pulp upon the passage thereof to the rejects outlet 12 is produced directly on the drum surface than on the screen surface. As a result, no build-up can develop on the screen basket 2, due to the better conveying action, or on the other hand, a better conveying action in the direction toward the rejects outlet 12 is obtained.
Furthermore, the sorting vanes 40 are also developed differently from the other vanes 4, in that their lower wedge surfaces 9 are not inclined from the horizontal measured along the radial direction, in the same way as their upper surfaces 10 are inclined.
The upper, third region 30 of the rotor drum is smooth, i.e it is developed substantially without sorting vanes 4 or 40, and it lies predominantly above the screening zone, or screen slot 3. This is necessary to permit concentrating of the rejects 15. This produces reject consistencies of 20 to 25% and more, by volume of solid to liquid materials, at the rejects outlet. For better removal of rejects, the rotor drum 1 is provided with reaming vanes 45 at its upper end.
Spray holes 8 for pulp diluent, i.e. water, are arranged in the vicinity of the smooth region 30 of the drum and are located below the top edges of the uppermost sorting blades 40. In this way, too great dilution of the rejects is avoided and rubbing of the rejects is also increased. The other spray holes for dilution water 8 lie in an axially central region along the rotor drum 1, opposite a nonporous section of the screen basket 2 where there are no sorting holes or slots. With relatively little spray water, the screen 2 is kept suitably free of fibers by dilution of the suspension. It is also preferred to provide the region of the screen basket 2 lying below the spray holes 8 with relatively large screen perforations of, for instance, 6 mm diameter as compared with screen perforations in the upper region of about 4 mm diameter.
Spray water is fed via the connection head 14 into the hollow space 44 of the double jacket, which extends at least partially down along the rotor drum. A support 46 for the drum and a seal 47 are also provided there.
The inclination, with respect to the horizontal planes through the respective leading edges 11 of the sorting vane 40, of the upper wedge surfaces 10 of those sorting vanes 40 adjacent the smooth region 30 of the rotor drum is about 10° and the inclination of the lower wedge surfaces 9 from the same planes is only about 5°, or even less inclination, if the vanes 40 are not made narrower in the radial direction. Where the selected alternative is a difference in radial width between the upper and lower wedge surfaces of the sorting vanes 40, this is selected to be a maximum of about half the width of the screen slot 3. The difference can amount, for instance, to about 20 mm when the screen slot is about 50 mm wide.
The lower region of the drum 1, which has normal sorting vanes 4, occupies about one-half the height of the screen basket 2, and the upper, smooth region of the drum also occupies about one-third of that height. The latter could, however, also be made shorter for instance, down to one-quarter of the height of the screen.
It is also advisable to prevent too strong rotation of the suspension in the screen slot 3. Weir strips (not shown), which extend parallel to the axis of rotation of the drum, are formed on the inside of the screen basket. Only about four of the strips are necessary for this purpose. This produces a better separating effect.
FIG. 8 shows a screening machine construction having a different division of zones. The drum and screen slot 3 are developed with three zones in this embodiment. In the lowermost zone, the drum 1 carries the sorting vanes 4. In the adjoining zone above, the drum carries vanes 5, which serve predominantly for the transport of the rejects toward the upper, outlet end of the sorter. In the top zone 30, the rotor 1 is smooth, being without projections, vanes or the like. In this zone, the rejects residue is to be held back, so that too rapid a passage thereof through the rotor, with too low a separating effect of the acceptable quality pulp, is avoided.
A spray-water feed with a spray-water connection head 14 is provided in the inside of the drum 1 for diluting the suspension, again by means of spray water flowing through the spray openings 8. The openings are arranged predominatly in the axially central part of the rotor. But, these openings may extend into the second, central zone and even to the third upper zone, in order to still make it possible to separate the acceptable pulp even in the upper region of the apparatus.
The open or unpressurized construction of a screening machine described above is suitable particularly as a final stage screener for the various screening residue which collect in a paper mill, including waste paper. A high consistency of rejects is obtainable, particularly with the embodiment in accordance with FIG. 1.
In the radial, sectional view through the drum embodiment, shown in FIG. 4, the leading edges 11 of the vanes are beveled or inclined somewhat rearwardly with respect to the radial direction, in order to avoid spinning of pulp on the vanes.
A wall 19, shown in dashed lines, extends between the upper and lower surfaces 10 and 9 of the vane 4, and is developed such that the volume of the free space 7 between the surfaces 10 and 9 increases continuously from the leading end 11 of the vane. By suitably arranging the wall 19, particularly the angle of the wall with respect to a tangent to the shell of the drum, production of the vacuum and thus the manner of operation of the vanes can be controlled. The wall 19 can be oriented to increase or decrease the volume of the space 7 between the surfaces 10 moving rearwardly from the leading end 11, or vice versa. It can be oriented to increase both the axial height of the space 7 (inherent in wedge surfaces) and the radial width of the space, or alternatively to decrease the radial width of the space, moving rearwardly from the leading end. The wall 19 between the upper and lower surfaces of the vanes 4 also stiffens the vanes so that the wall thickness supporting surfaces 9 and 10 can be reduced. The wall extends from the leading end 11 to the trailing end. Although the wall may simply terminate at the trailing end, it instead turns radially inwardly along the trailing edge of the vane 4 at 19a, so that the volume radially inward of the wall 19 is enclosed and does not directly provide a force component to the suspension.
Another possible way to control the vacuum is by adjusting the inclination of the rear edges of the surfaces 9 and 10 with respect to the horizontal. This, of course, depends on the extent of the spiral or helix arrangement of the vanes in the direction for producing a greater or lesser component of conveyance for suspension in the direction toward the rejects outlet.
In the unpressurized screening machine of open construction shown in FIG. 1, the conveying component of the sorting vanes in the direction toward the rejects outlet is important since this also serves for the passage of the good quality pulp.
The factors which influence the conveyance of the fiber suspension, and particularly of the rejects, in the axial direction along the screen slot toward the rejects outlet and the movement of the fiber suspension which leads to good sorting of the good pulp, i.e. of the fibers to be collected, can be adapted to each other. By simple experiment, it is possible to determine the best arrangement in each case for the pulp suspension and type of screening machine on hand.
In the screening machine of the invention, the screen slot 3 can be made relatively narrow so that a relatively low conveying energy is required. A narrow radius annular screen slot 3 is also helpful for assuring that sorting takes place essentially only in the immediate vicinity of the screen 2, while an unnecessarily large screening slot 3, i.e. one with a large radial size can only be disadvantageous.
Although it is not shown in this Figure, substantially vertically extending ledges may be fastened to the inner wall of the screen 2 for producing despecking, in that the vanes which pass closely along the screen (or the ledges) break down the specks present in the fiber suspension.
The vanes 4, particularly in the sorting machines of open unpressurized construction, may be arranged so that upon one revolution of the drum 1, the entire height of the first, lower zone of the screen slot 3, which is provided with sorting vanes 4, is traversed by the vanes. The vanes can, however, also be provided in a denser arrangement on the drum.
FIG. 5 shows a partial axial section through a drum 1 with vanes 4 having features like those in FIG. 4. In this case, the upper wedge surface 10 and the lower wedge surface 9 of a vane 4 are inclined oppositely to the example of FIG. 1a described above. First, as before, the surfaces 9, 10 diverge axially, measured from the vane front end 11, giving the vane a wedge shape. Then, with respect to the horizontal or radial direction, i.e. in a plane perpendicular to the axis, the wedge surfaces are inclined to also diverge as measured axially. In this way, the surfaces produce a conveying component of the fiber suspension that is normally away from the screen 2. Finally, as in FIG. 4, the wall 19 gradually curves radially inwardly moving rearwardly. The radially inwardly turned wall portion 19a closes off the space radially inwardly of the wall 19.
With this form of vane, separation of the fiber suspension from the screen is naturally produced to a greater extent than in the previous embodiment. This form of a vane is predominantly used in a closed or pressurized construction of the screening machine. Therefore, pressurized screening machines with sorting of the good pulp is effected from the inside to the outside, i.e. out of the screen slot 3 and accordingly the feeding of the fiber suspension is from the outside into the screen slot 3. The drum 1 is then developed without division into zones, i.e. similar to the embodiment of FIG. 2. The force for feeding the pulp through the sorting machine is supplied in the so-called pressurized screening machines predominantly by the conveyor pump for the fiber suspension.
It is finally also possible to combine the two above described inclinations of the surfaces 9 and 10, as viewed along the radial direction, as shown in FIG. 6. Here, the upper surface 10 inclines upwardly or diverges from the horizontal, moving radially outwardly. In this case, eddying is produced to an increased extent at the trailing end of the vanes 4. This loosens the fiber suspension on the screen 2 so that the particles to be sorted are more easily passed through the holes of the screen.
Feeding of the fiber suspension in this embodiment operates as with the embodiment of FIG. 5. This embodiment is used predominantly for the closed, pressurized construction, with the type of drum in accordance with FIG. 2, and also without the division thereof into zones.
The closed construction as illustrated in FIG. 2 closes the housing by a bottom plate. The lower part of the housing includes a socket for the discharge of the rejects, corresponding to the socket 17 provided for the discharge of the accepted suspension.
In FIG. 2, the screening machine provides passage of the rejects from the top to the bottom with respect to the axial component of their movement. The sorting residue, which collects in the screen slot 3 and which would already be relatively strongly concentrated, can be diluted with spray water coming from spray holes 8 in the shell of the drum, and this helps achieve a further sorting out of accepts. The spray water is fed into the interior of the drum 1 via a spray water connecting head 14 which is sealed against the stationary housing of the screening machine, generally at a housing lid, and the hollow drum shaft or a shaft-like connection of the drum, similar to FIGS. 1 to 3.
FIG. 3 shows a rotary screening machine of open unpressurized construction. Here the drum 1 and screen slot 3 are also not subdivided into zones. Instead, the drum carries the sorting vanes 4 over its whole surface. Spray-water holes 8 feed spray water via a spray head 14, as in the embodiment of FIG. 1. The inlet for the fiber suspension is in this case located on top at the socket 6 and the discharge of the acceptable quality pulp is at the bottom at the socket 17. Thus, transport of the fiber suspension, and particularly of the rejects, is along the axial direction from the top to the bottom, so that gravity promotes the passage of the heavy rejects. In order to prevent too rapid passage of the fiber suspension, a weir or damming wall 23 is provided, through the lower part 1a of the drum being made of a larger diameter than the upper part 1b of the drum. An overflow is provided for the upper part 1b of the drum, and the purified suspension is dammed up by a weir wall 22. Through a socket 18, the good pulp then emerges after the first or upper zone.
In place of or in addition to this, and as already explained with reference to FIG. 1, the sorting vanes 4 can be shifted with respect to each other so that the upper wedge surfaces thereof impinge to a strong extent on the fiber suspension and thus repeatedly provide the fiber particles with a component of motion in the direction toward the inlet. For this purpose, the angle of inclination of the upper wedge surfaces 10 can be relatively steep, and be steeper than that angle for the lower wedge surfaces 9, because gravity aids the passage of the fiber suspension through the screening machine.
Still another embodiment of a pressure screening machine of closed pressurized construction is possible with, however, the screening of the good quality pulp taking place radially inwarly into the screen slot 3. Here the feeding of the fiber suspension would be radially inward from the outside of the screen basket 2 toward the screen slot.
For the last mentioned embodiment, the vanes 4 are developed in accordance with FIG. 7a and either FIG. 7b or 7c. The wall 19 which extends between the upper wedge surface 10 and the lower wedge surface 9 of vane 4 is arranged so that the free space between the surface of the wall 19 facing toward the screen slot 3 and the screen 2 is continuously reduced from the leading edge 11 to the trailing end of the rotating sorting vane 4. The radial divergence of wall 19 can be seen in FIGS. 7b and 7c. The covering rear wall portion 19a can also be seen. Pressure is built up in front of the vane, on top and on bottom, and particularly to the side of the vane. Thus, with the selected inward direction of flow of the fibers (see arrows) through the screen basket 2, and with the flow being in a pulsating manner, separation of the solid particles which collect and deposit on the screen basket 2 is effected.
For this construction of the screening machine, the wedge surfaces 9 and 10 of the sorting vanes are radially outwardly inclined in accordance with FIG. 5. This is shown in FIG. 7b. In this case, the relatively large lateral surface which produces the pressure pulses on the screen basket, i.e., the surface of the side limiting wall 19, is also present. However, an embodiment of vane 4 with noninclined wedge surfaces, as shown in FIG. 7c, can also be suitably used. The radially converging inclination in accordance with FIG. 1a may also possibly be used in this case, but it is not as good as that inclination illustrated in FIG. 7b.
Since pressure screening machines are used more for fine screening and are generally arranged directly in front of the entrance of the pulp into the paper machine, it is desirable to have the narrowest possible screen slot a at the run-off or trailing end of the sorting vanes in FIG. 7a, and this slot should amount at most to about 1.5 mm. However, this depends on the size of the screen holes and thus on the degree of fineness of the screening stage, i.e. also on the fiber suspension itself. For best results, the screen slot gradually decreases in radial width from b at the leading edge 11 to the trailing end at a.
The inclination of the limiting wall 19 with respect to a tangent to the circumference of the screen basket will be selected, for instance, at 10°.
The various embodiments of the rotary screening machine produce extremely favorable action, since the development and attachment of a mat of fibers on the screen basket 2 is prevented by the pulsating movement of the pulp across the screen basket. Clogging of the screen holes, starting from the attachment of particles of pulp at one point, namely from the side of the holes facing the direction of rotation, to an ever-increasing extent by the continuous addition of further particles which deposit there, is prevented by the pulsating movement, which repeatedly changes the direction of attack of the particles and the suspension against the screen and its holes. This makes it possible, to an increased extent, for very long fibers of the good pulp to be able to pass through the screen holes. The tendency of these fibers is to align themselves in the circumferential direction, which would substantially prevent passage through the screen holes. The invention avoids this. Due to the low coefficient of resistance of the sorting vanes and in the case of the open unpressurized construction of screening machine, the good conveying action within a relatively narrow screening slot, furthermore only little drive power is required for the conveying of the fiber suspension.
Although the present invention has been described in connection with the preferred embodiments thereof, many variations and modifications will now 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. | The disclosure concerns a rotary screening machine for moving pulp suspension through a screening slot and for separating impurities from the pulp suspension. An annular rotatable drum is surrounded by an annular porous screen basket that is spaced away to define a screening slot. Pulp suspension is delivered to one axial end of the slot and is discharged from the other axial end of the slot. Generally wedged shaped vanes, widening in the axial direction between the leading and trailing ends of the vane, are provided around the drum. The wedge defining surfaces may also be inclined with respect to a respective plane perpendicular to the axis. The space between the wedge surfaces is an open volume. A wall in that space is oriented to help create appropriate vacuum and eddy conditions behind the vane. The drum may have different zones, with the lower zone being provided with vanes and the upper zone being generally smooth. Other types of vanes or projections may be provided in the intermediate zone. Water sprayed into the slot dilutes the suspension. The configuration of the vane causes conveyance of the pulp suspension generally toward the impurities outlet and conveys the impurities to that outlet. The configuration of the vanes also causes the suspension to pulsate across the screen basket which dislodges pulp suspension fibers that otherwise might become matted on the screen. | 3 |
This is a continuation of application Ser. No. 582,784, filed Feb. 23, 1984 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The field of the present invention is woven fabrics of synthetic yarns as may be used in papermaking and other industrial processes.
With the advent of flat woven papermakers fabrics, the need to join or seam the fabric into an endless belt became a major concern in the production of papermaker's fabrics. Many seams such as the coil seam were developed to join the fabric ends. With the increased speed, heat, and chemical deterioration associated with the use of newer papermaking equipment and higher production temperatures, the prior art coil seam materials and joining wires are proving insufficient to meet the demands of the industry.
2. Description of the Prior Art
Originally papermaking fabrics were woven endless and were placed on the machine as a single fabric without the need for seaming or any other method of joining the ends. However, over time, as the papermaking equipment grew in size and the fabrics grew in response thereto, it became desirable to weave the fabrics in what is known as a flat woven condition and to join the fabrics into an endless belt by means of seaming the fabrics. Over the years many methods have been developed to take flat woven fabrics and join them into an endless belt.
One early attempt at joining the fabrics was the use of lacing methods which entailed great work and difficulty in addition to producing seams of questionable reliability. Such a method is exemplified in U.S. Pat. No. 340,335.
Another prior art method for joining together flat woven belts in order to make them continuous is shown in U.S. Pat. No. 1,841,303. In this method a plurality of metallic elements were secured onto each end of the fabric to form a plurality of loops which were then interlaced and joined by a single pintle or hinge wire. Over the years this method was developed and refined and was frequently referred to in the industry as a clipper hook seam.
Another method for joining flat woven felts into an endless unit was through the use of a zipper or closure member. Such a method is disclosed in U.S. Pat. No. 1,852,732 and U.S. Pat. No. 1,948,411 and U.S. Pat. No. 1,986,785.
Another method of doing this is what is known in the art as the Pintle seam which is exemplified by U.S. Pat. No. 2,629,909.
Another prior art attempt to join the flat woven fabric into an endless belt was the use of interwoven formed warps which are formed and rewoven into the fabric to produce a plurality of loops through which the joining wire may be located. One example of this technique is U.S. Pat. No. 2,883,734.
Another prior art attempt at joining the belts was comprised of folded over end portions which were stitched to form loops which were interlaced and through which a flat key or joining means could be located. An example of this construction is U.S. Pat. No. 3,309,790.
Additional attempts to join the ends of fabric belts are shown in U.S. Pat. Nos. 3,316,599, 3,324,516, 3,335,844, 3,581,348, 3,664,907, 4,006,760, 4,026,331, 3,281,905, and 4,250,882.
With reference to U.S. Pat. No. 4,250,882, entitled LOW BULK PIN TYPE SEAM FOR USE IN PAPERMAKER'S EQUIPMENT FABRICS SUCH AS DRYER FELTS, the pin seam construction set forth therein is one which is compatible with the use of the joining wire and coil material in accordance with the instant invention. Additionally, U.S. Pat. No. 4,351,049, entitled STITCHLESS LOW BULK PIN TYPE SEAM FOR USE IN PAPERMAKING EQUIPMENT FABRICS, SUCH AS DRYER FELTS also sets forth a procedure which is compatible with the instant invention.
While most of the prior art constructions for joining fabric ends have proven successful as to the methodology employed, many of the fabric seams have been unsatisfactory because of the materials used in forming the seam. For instance, difficulty has been experienced with the metallic hooks used in making the fabric seam in addition to the associated problems which arise from the wear generated by the metallic members. Likewise, those seams which have attempted to employ yarns or strands actually taken from the body of the fabric and back woven thereto have met with limited success due to the stresses put on the materials. In addition, many of the prior art constructions which have employed independently constructed coils and joining wires have experienced difficulties due to the harsh environment in which the fabric must operate.
Woven fabrics fashioned into endless belts for conveying and guiding products under manufacture are used in various industrial processes. Both metallic and synthetic materials have been used for these flat woven belts as well as the seams joining the ends. As the industry and manufacturing equipment have advanced, the use of high speed and/or high temperature conditions have become more common. The more demanding conditions likewise are more destructive of the seam. Two synthetic materials which have found some use in high temperature applications are polymers known by the Trademarks Nomex and Kevlar, as reported in U.S. Pat. No. 4,159,618 and available from the Du Pont Company. These materials are twisted from multifilaments, or staple fibers into yarns, and are not available for applications where monofilament threads are preferred. Having a relatively rough, porous surface a multifilament can be difficult to keep clean in applications where contaminants are a problem. In addition to problems with contaminants, multifilaments often fail to retain their form or shape and can be difficult to join. For the foregoing reasons, Nomex and Kevlar yarns are sometimes coated with suitable resins to simulate monofilaments. These composite coated yarns can be used in fabrics where elevated temperatures are frequently encountered: however, under extended high temperature exposure, dry or moist, there can be a severe loss in tensile strength, as further reported in the above cited patent. An additional difficulty with composite yarns is that they do not withstand the physical abuse of abrasion during their operation.
Another synthetic material monofilament used with industrial conveying and guiding belts is polyester. It has gained widely accepted usage in the forming, press and dryer sections of papermaking machines because of its abrasion resistance, ability to flex, dimensional stability after being thermoset, chemical inertness, and ease of handling. Over the years techniques have been developed for weaving, thermosetting and seaming, polyester yarns and fabrics so that this material can be readily handled in the manufacture of endless belts. Polyester consequently enjoys wide acceptance; however, this material has poor high temperature hydrolytic stability, and cannot be satisfactorily used under moist conditions at continuous elevated temperatures. In papermaking applications, for example, it can be a limiting factor for the temperatures under which drying procsses can be carried out, and where high temperatures are desired some other material must be resorted to.
As can be seem from the above, the prior art has recognized that the currently available materials do not provide a seam of sufficient temperature, abrasion or hydrolysis resistance.
SUMMARY OF THE INVENTION
As a result of my investigation, I have discovered that the prior art limitations on the seam area may be overcome by the use of seaming coils and joining wires which are fabricated from monofilaments extruded from one of the family of polyaryletherketones. A preferred polyaryletherketone is polyetheretherketone or PEEK.
It is an object of my invention to provide a coil seam constructed of elements which are performed from synthetic monofilament yarns having increased temperature, abrasion and/or hydrolysis resistance.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a coil winding apparatus suitable for producing the coils according to the invention.
FIG. 2 depicts joining elements according to the invention; (A) is a monofilament joining element and (B) depicts an embodiment having more than a single monofilament joining wire.
FIG. 3 depicts a coil element according to the invention prior to its application in the fabric seam.
FIG. 4 is a table depicting the results of testing conducted in connection with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
All of the monofilament of the coil and joining wire as depicted in FIG. 2 were extruded monofilaments of polyetheretherketones. Seaming elements fabricated from polyaryletherketones polymers could be utilized in fabrics using various synthetic materials alone or in combination with other threads of other synthetic materials. However, due to the different weaving and heat setting characteristics of the various materials, it will be necessary to design the fabric with final finishing in mind.
Since the class of materials polyaryletherketones have higher heat characteristics, they have associated higher heat settings or thermal plastic characteristics. In addition, polyaryletherketones are generally more costly than the prior art materials used for coils and joining wires and accordingly, are most useful in those applications where the additional cost of heat setting and the raw materials are justified by the environment and the long life provided by the polyaryletherketone materials. As noted, the heat setting characteristics of the polyarlyetherketones will be somewhat different than the characteristics of the synthetic materials which make up the fabric body. As will be explained hereinafter, it is necessary to heat set the coils of the instant invention separately from those of the fabric body because of the elevated temperatures necessary for working the coil material.
The polyaryletherketone material becomes economically practical when the application calls for a high temperature, high moisture, high speed environment. Under these conditions, the added seam life combined with increased production time justify the additional cost associated with the polyaryletherketone polymers.
Polyaryletherketone polymers suitable as the monofilaments in the practice of this invention are polyetherketones having the repeating unit ##STR1## identified in the claims as --φ--O--φ--CO--φ--O such as polyetheretherketone prepared by nucleophilic polycondensation of bis-difluorobenzophenone and the potassium salt of hydroquinone. A detailed explanation of preparation of polyetherketones having the above identified repeat unit may be found in EPO application No. 78300314.8 filed on Aug. 22, 1978 and published on July 16, 1979.
Other polyaryletherketones polymers which appear suitable for monofilament threads in fabrics according to the invention are those having either of the following repeat units: ##STR2## identified in the claims as --φ--O--φ--CO-- -and ##STR3## identified in the claims as --φ--φ--O--φ--CO-- which are described in more detail in U.S. Pat. No. 3,751,398 and ICI Research Disclosure of May, 1979, No. 18127 at page 242. According to the above referenced ICI disclosure, there were problems encountered lubricant with the polyetherketone. Thus, before processing, the polyetherketone is dusted with the calcium stearate e.g. by dry tumbling. The best level of calcium stearate to use may be found by experiment but we have found 0.1-0.2% particularly about 0.15% (based on the weight of the polyetherketone) to be satisfactory. While calcium stearate is a well-known lubricant for many polymers, its successful use under the present circumstances is somewhat surprising in view of the very high processing temperatures employed; one might have expected calcium stearate to decompose or degrad at such temperatures or at any rate be rendered inactive.
Polyaryletherketone resins of the foregoing types are commercially available from several companies, including Raychem Corporation and Imperial Chemical Industries Limited. Suitable techniques for their preparation are described in Attwood et al, Synthesis and Properties of Polyaryletherketones, Polymer, Vol. 22, Aug. 1981, pp. 1096-1103; Attwood et al, Synthesis and Properties of Polyaryletherketones, ACS Polymer Preprints, Vol. 20, No. 1, April 1979, ppg. 191-194; and EPO published application S.N. 78300314.8, Thermoplastic aromatic Polyetherketones etc. See also U.S. Pat. Nos. 3,751,398 and 4,186,262 and British Pat. Nos. 1,383,393, 1,387,303 and 1,388,013. Some data with respect to extruding high temperature polyaryletherketones may be found in ICI research Disclosure of May, 1979, No. 18127 at page 242. The disclosures of the foregoing are incorporated herein by reference. Briefly, the resins may be prepared by Friedel-Crafts condensation polymerization of appropriate monomers using a suitable catalyst such as boron trifluoride. The polyaryletherketone resins suitable for the practice of this invention are to be melt extrudable, i.e. they should have appropriate molecular weights and intrinsic viscosities so as to be capable of extrusion into monofilament form.
In extruding the polyetheretherketone (PEEK) monofilaments useful in the invention, it was found that a lubricant, as previously suggested, was not necessary for proper extrusion. In extruding, the temperature profile of the several extruder zones have been heated to approximately 390° C. (734° F.) for the initial extruding, and as flow begins temperatures were reduced to 350° C. (662° F.) in the feed zone, and 380° C. (716° F.) in the transition zone and metering zone, and 370° C. (698° F.) in the die zone. Spinerettes have been used like those for other extrusions, to produce a monofilament of the desired final diameter, such as 16 mils. Various filament sizes can be obtained by adjusting screw, pump and pull roll speeds, and final thread sizing is made in a subsequent drawing operation. ICI Provisional Data Sheet of November, 1979, Ref. No. PK PD9, in providing some drawing data indicates a draw ratio of 2.8:1.
The polyaryletherketones exhibit excellent retention of tensile strength at temperatures up to at least 500° F. (260° C.). The polyetheretherketones and the polyetherketones have similar characteristics. For example, the melting point of a typical polyethertherketone of 334° C. (633° F.) compares with 365° C. (689° F.) for a typical polyetherketone, and the glass transition temperatures are respectively 143° C. (289° F.) and 165° C. (329° F.).
The polyaryletherketones also have a modulus of elasticity higher than PET polyester and a greater retention of tensile strength with increase in temperature. Such characteristics indicate good finishing qualities and these materials also exhibit adequate flexibility.
I have discovered that it is necessary to wind the PEEK coil material at lower speeds and under greater tension than that normally associated with the prior art coil materials. Likewise, the heat setting conditions and temperatures used in manufacturing the coils must be adjusted to reflect the high temperature and rigidity characteristics of the PEEK material.
With reference to FIG. 1, there is shown a suitable coil winding apparatus. The first effort to produce coil materials was with a 44 mil diameter PEEK monofilament. The coil materials were produced on a two section mandrel at 24 loops per inch for the desired distance. The length of the seam coil is a matter of design choice and does not form part of the invention. The fly wheel revolved about the mandrel at approximately 30 revolutions per minute and the mandrel advanced approximately 1/8" per revolution. The successfully wound PEEK coils, while still on the mandrel, were placed in a hot air oven and subjected to 450° F. temperature for approximately 10 minutes. The coils, see FIG. 3, were permitted to cool before being removed from the mandrels.
It will be appreciated by those skilled in the art that the maximum diameter of the monofilament may exceed 44 mils and that the fabric design will determine the maximum diameter compatible with the fabric and its end use. From the current fabric design trends, it is expected that a maximum monofilament diameter would be about 50 mils.
There were some attempts to produce PEEK monofilament coils using monofilament material having a diameter as small as 24 mils. However, due to difficulty in obtaining monofilament having sufficiently uniform diameters and as a result of the technique used with the particular test mandrel, the 24 mil monofilaments were not actually used as seaming coil materials. However, as a result of the initial work which has been done with the production of PEEK monofilament coil materials and the expected improvement in the extruding techniques, it is believed that the PEEK monofilament materials will be useful in diameters as low as 16 mils. As the technique for producing the monofilament and for producing the coils is improved, it is possible that even smaller diameter monofilament material will be useful. The limitation on the diameter is related to the technical properties of the material and its ability to resist abrasion and hydrolysis in the seam area. In addition, it will be recognized that better control of the production of the PEEK monofilament will make it possible to obtain the benefit of PEEK monofilament with even smaller diameters.
The use of PEEK material as coil material and joining wires should prove superior on papermaking machines. The PEEK monofilament has substantially better abrasion resistance and hydrolytic chemical deterioration resistance not available with prior art seaming monofilaments. Since paper machines have inherent risk of heat and chemical attack, the PEEK monofilament will improve the life cycle of the fabric seam.
With reference to FIG. 2, there is shown PEEK monofilament which has been developed into joining wires for use with the coil in making the fabric seam. It will be appreciated by those skilled in the art that the technique(s) for producing such as a joining wire, whether it be a single FIG. 2(A) or double FIG. 2(B) joining wire, is known to those skilled in the art and that the technique does not form part of the instant invention.
The end uses for these new joining wires fit well into the chemical and abrasion resistance necessary in modern papermaking equipment. The shear forces generated in the seams, which are perpendicular to the longitudinal axis, appear to have no adverse effects on the superior wear (abrasion) properties of this monofilament. It is noted that with prior art use of polyester and polyamide monofilament strands, these same forces produce adverse effect on similar sized joining wires.
With reference to FIG. 3, there is shown a single coil element according to the invention. As will be appreciated by those skilled in the art the coil element, after it has been wound on the mantle and subjected to the hot air oven heat set, will have a generally eliptical shape. The coil 10 will be continuous in length and will be sized so as to extend uninterupted for the entire width of the fabric. As will be appreciated by those skilled in the art, the coil element will be extended slightly during its application to the fabric and will become expanded so that there will be a space between each of the successive elipses of the coil element. Likewise, it will be understood by those skilled in the art that a similar element is placed on each end of the fabric to be joined. After the coil elements have been placed on each end of the fabric, the fabric ends are drawn together and the coil elements are interleafed such that one element fills the spaces between the elipses of the other element and a channel is formed for receiving the joining wire.
With reference to FIG. 4, there is shown in table form the test results of the PEEK joining wires according to the invention versus a typical braided joining wire. The tests were designed to compare a PEEK monofilament joining wire to a braided type number 16 joining wire, currently available from Asten-Hill Company of Devon, Pa., in a standard seam design. Suitable samples were obtained in sufficient quantities for the trial. The diameter of the sample varied greatly, from 0.073" to 0.089" in diameter, as compared to a desired 0.079" finished diameter; however, despite the variation in diameter, the tests were conducted in order to confirm initial observation on the improved seam elements. Sample seams were prepared and placed on a test apparatus. Samples were run at 1720 FPM at 16.0 PLI tension. The samples were run in a test chamber with a 50% relative humidity and an air temperature of about 220° F. As can be seen from FIG. 4, the results indicate that the PEEK joining wire was substantially better than the typical prior art braided joining wire. The braided type joining wire exhibited a performance level slightly lower than normally expected, however, it was within the range of typically expected performance.
As will be appreciated by those skilled in the art, the higher heat setting characteristics of the PEEK material will produce a coil or seam which is less likely to be modified by the temperatures associated with the heat setting of the remaining fabric. However, it should be understood that the PEEK material will experience some plasticity due to elevated temperatures and pressures associated with the normal heat setting process. Thus, the coil materials will be set as a result of their being wrapped on the mandrel and then will be inserted into the fabric to create the interlooping portions of the seam. The fabric will then be placed on the heat setting apparatus with the interlooped coiled ends secured by means of a joining wire. The fabric will then be subjected to the temperature and pressure necessary for the heat setting consistent with the fabric materials and end use of the fabric and will be heat set in the normal course. As a result of the increased resistance to heat setting of the PEEK coil materials versus the fabric, it will be appreciated that care must be taken in producing the coil elements so that the coil will be consistent with the weave and end use of the fabric. | An improved fabric seam for flat woven fabric is disclosed. The improved seam utilizes polyaryetherketones and preferably polyetheretherketones in forming the seaming elements, comprising coil elements and a joining element. | 3 |
This is a continuation of application Ser. No. 736,058, filed May 20, 1985, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to a system for selectively inhibiting the viewing by unauthorized subscribers of designated channels in a CATV system. More particularly, the invention pertains to such a system which is usable in CATV systems employing different transmission techniques.
In most CATV systems, certain channels are designated as "pay" channels for which the subscriber must pay a special fee to be able to watch. Thus, if a subscriber is not authorized to view a particular channel, the CATV system must be provided with a viewing control system having the capability of inhibiting viewing of that channel.
Conventionally, several different viewing control systems have been known, each employing a different technique to achieve the channel inhibiting function.
In one system, known as the jamming system, a carrier having a level about the same or greater than the level of the video carrier level and at a frequency about 2.5 MHz above the center frequency of the video carrier is injected at the CATV control center into the video band of each "pay" channel. For each authorized subscriber, a notch filter is provided for each channel to be unjammed to remove the carrier. This system, however, suffers from the drawback that one filter must be provided for each unjammed channel for each subscriber. Also, the filter must have excellent characteristics since, for instance, if the center frequency of the filter is even slightly different than the frequency of the jamming carrier, a beat will occur in the viewed picture. Thus, the filters are unavoidably expensive.
In another conventional system, known as the trap system, traps to block unauthorized reception are provided at the tap-off point to the subscriber's terminal. The disadvantages of this system are that the traps must be located in a difficult to access area, usually up a utility pole. Besides being difficult to install, the traps take up a great deal of space, which is usually at a premium at the location at which the traps must be installed. Moreover, if a large number of traps are employed in the tap circuit of a subscriber, the overall quality of the subscriber's reception is degraded.
In a further conventional system, known as the addressable terminal system, a digital signal is transmitted from the CATV control center to a terminal unit in each subscriber's home or office, the digital signal indicating which channels are authorized to be viewed. In the subscriber's terminal unit, the digital signal is decoded and unauthorized channels are jammed. This system though is disadvantageous in that a costly terminal unit must be provided each television set connected to the system, even if many different televisions are connected at a single subscriber's location. Also, it is possible for a subscriber to alter the terminal unit to receive unauthorized channels without paying the required fee. Moreover, access to the subscriber's premises must be had to service the terminal unit.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a viewing control system for a CATV system in which the above-mentioned problems have been eliminated.
In accordance with this and other objects, the invention provides a viewing control system comprising a plurality of viewing control devices, one for each subscriber located at the tap-off point from the main cable to the subscriber's home, office, etc. Each viewing control device contains a digitally controlled oscillator circuit driven to produce, in time sequence, jamming carrier signals in the video band of each of the channels to be jammed. The jamming control signals are added to the signal sent to the subscriber's television set or sets. A digital signal for instructing which channels are unauthorized is transmitted to each viewing control device from the CATV control center. The digitally controlled oscillator circuit is preferably implemented with a voltage-controlled oscillator circuit connected in a digitally controlled phase-locked loop circuit. The output of the phase-locked loop circuit is mixed with the output of a local oscillator, the oscillation frequency of which is set in accordance with the particular transmission system in use.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of a portion of a CATV system in which the viewing control system of the invention is employed;
FIG. 2 is a block diagram of a jamming signal generator circuit employed in the viewing control system of FIG. 1;
FIG. 3 is a diagram showing a frequency distribution of video and jamming signals employed in the viewing control system of FIG. 2; and
FIG. 4 is a waveform diagram used to explain the operation of the viewing control system of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, there is shown therein a portion of a CATV system employing a viewing control system of the invention. The CATV system has a branch cable 1 feeding signals from a CATV control center via a main cable and the like. The signals sent from the CATV control center include unjammed video and audio signals for all channels carried by the system and digital signals for instructing which channels are unauthorized for which subscribers. The digital signals may be FSK (Frequency-Shift Keyed) signals using a technique commonly employed in the known addressable terminal systems. A DC voltage is also imposed on the branch line to provide operating power for the various viewing control devices and other components.
At the tap-off point for a particular subscriber, a power source separating circuit 2 is employed to provide operating power. The output of the power source separating circuit 2 is filtered and regulated by a power source circuit 5 for use in the various circuits of the viewing control device and other circuits.
The video and digital signals pass from the branch line 1 via a tap 3 to a filter 4, the outputs of which are applied to a composer 11 and a second tap 3. One output of the tap 3 is applied through an attenuator to a distributor 7, while the other output of the tap 3 is applied to an FSK demodulator employed to demodulate the digital signal transmitted from the CATV control center to the viewing control device.
This much of the system illustrated in FIG. 1 is known conventionally, and is used, for instance, in the above-mentioned addressable terminal system.
A logic circuit 9 receives the output of the FSK demodulator 8, the output of the FSK demodulator being in the form of a set of digital numbers identifying channels to be jammed. In response to these numbers, the logic circuit 9 produces a repeating time sequence of numbers indicative of which channels are to be jammed. For this purpose, the logic circuit 9 can be implemented with a microprocessor or, for example, as a memory storing the values received from the FSK demodulator and a counter for repetitively reading out the contents of the memory in sequence. The output of the logic circuit 9 is applied as a PLL (Phase-Locked Loop) control signal to a jamming signal generator 10, the details of which are shown in FIG. 2.
Basically, the jamming signal generator produces, in time sequence, jamming signals falling in the video band of each of the channels to be jammed. The output of the jamming signal generator is applied through a switch 14 in a module 16 to one input of a signal adder, the other input of which is the unjammed television signal outputted by the distributor 7, boosted if necessary by a broad-band RF amplifier 12. The output of the signal adder is applied through a filter 17 to the drop line 17 to the subscriber's television set or sets.
The reason for the provision of the switch 14 is that it is of course impossible for any practical digitally controlled oscillator circuit to switch output frequency instantaneously. Therefore, the switch 14 is turned off by the logic circuit 8 for a guard-band period of time around the times at which the output frequency from the jamming signal generator is being changed to protect against interference.
The jamming signal generator is constructed as shown in FIG. 2. The PLL control signal from the logic circuit 9 is applied as a digital control signal to a programmable divider 25. The output of the programmable divider 25 is phase-compared with the output of a reference oscillator 23 by a phase comparator 26, the output of which is applied through a low-pass filter 27 to the control input of a voltage-controlled oscillator. The output of the voltage-controlled oscillator is applied to the input of the programmable divider 25 through a prescaler circuit 24. These components form a phase-locked loop circuit.
The output of the voltage-controlled oscillator is applied to one input of a mixer 19, the other input of which receives the output of a local oscillator 20. The output frequency of the local oscillator is set in accordance with the transmission system employed in the particular CATV system, as will be explained in more detail below. The output of the mixer is amplified by an RF amplifier before being applied through a distributor as the jamming signal.
The operation of the circuit of FIG. 2 will be explained with reference to FIG. 4. Each time a switching pulse is received, a different PLL control signal value is received, and hence the output of the phase-locked loop circuit changes. The changes occur in steps (waveform Vt), each step corresponding to a different channel to be jammed. The output of the phase-blocked loop circuit is thus a sequence of bursts, assumed here to be at frequencies fφ1, Fφ2, . . . , fφn, as shown in FIG. 3. Mixed with the output of the local oscillator 20 at a frequency f1, bursts at frequencies fj0, fj1, . . . , fjn are produced, which act as the jamming signal.
By the use of the local oscillator 20, the time-shared oscillation frequencies fφ1, fφ2, . . . , fφn in the frequency band of the voltage controlled oscillator are shifted down to the jamming signal frequencies fj1, fj2, . . . , fjn in the TV signal frequency band.
The intervals D1, etc., indicated in FIG. 4 correspond to the intervals where the switch 14 is turned off to prevent interference.
By proper choice of the output frequency of the local oscillator 20, the frequency interval of the bursts fj0, . . . , fjn can be made equal to the channel spacing, namely, 6 MHz as is standard in the United States. More particularly, as mentioned above, there are different transmission systems currently in use. One of these employs as transmission frequencies the ordinary over-the-air frequencies, while another employs a constant 6 MHz channel spacing throughout the transmission band. If the local oscillator were not set in accordance with the transmission system at hand, it would be necessary to use a frequency interval of about 250 kHz. This would greatly complicate the circuit construction since it is very difficult to switch the output frequency of a phase-locked loop circuit at the rate required in such a case. However, by proper choice of the output frequency of the local oscillator, this difficulty is avoided and a 6 MHz frequency interval can be employed.
This completes the description of the preferred embodiments. Although preferred embodiments have been described, it is believed that numerous modifications and alterations thereto would be apparent to one of ordinary skill in the art without departing from the spirit and scope of the invention. | A selective viewing control system for controlling viewing access to designated channels in a CATV system. A CATV control center sends to viewing control units a digital signal indicating which channels are to be jammed. In response, the viewing control unit produces a jamming signal, added with the unjammed television signal, containing frequency bursts at timed intervals. Each frequency burst corresponds to a single channel to be jammed. A digitally controlled phase-locked loop circuit is employed to generate the jamming signal. | 7 |
BACKGROUND OF THE INVENTION
The present invention relates to compressors. More particularly, the present invention relates to compressors that have shaft seals for preventing leakage of refrigerant from the internal space,of the compressor about the drive shaft.
In compressors that perform compression and intake by rotation of a drive shaft, a seal is typically provided for preventing leakage of refrigerant from the inner space about the drive shaft. Generally, this kind of seal is positioned to seal between the intake pressure area, which has a lower pressure than the discharge pressure area, and the atmosphere. Or, in a variable displacement compressor having an inclining swash plate, the seal device is positioned to seal between the operating chamber, which accommodates the swash plate, and the atmosphere.
However, as described in Japanese Unexamined Patent Publication No. 8-110104, the seal must withstand a great burden when carbon dioxide (CO 2 ), the refrigerant pressure of which is ten times greater than that of fluorocarbon-based refrigerant, is used as refrigerant. The great burden shortens the life of the seal. In a variable displacement compressor that controls the inclination of the swash plate by varying the pressure of the operating chamber, the pressure of the operating chamber is higher than the intake pressure of a fixed displacement compressor, thus increasing the burden on the seal.
SUMMARY OF THE INVENTION
The objective of the present invention is to improve the reliability of the seal device of a compressor that uses a high-pressure refrigerant like CO 2 by decreasing the burden on the seal device.
To achieve the above objective, the present invention provides a compressor having a shaft seal. The compressor includes a housing, an intake chamber located within the housing, a discharge chamber located within the housing, an operating chamber located within the housing, and a gas compressing mechanism located within the housing. At least a portion of the compressing mechanism is located within the operating chamber. The compressing mechanism draws refrigerant gas from the intake chamber and discharges the refrigerant gas to the discharge chamber. The compressor further includes a drive shaft extending between the interior of the housing and the exterior of the housing. The drive shaft drives the compressing mechanism. The compressor further includes a seal for preventing leakage of refrigerant gas from the interior of the housing to the atmosphere. The seal seals a gap between the drive shaft and the housing. One side of the seal is exposed to the atmosphere. The compressor further includes an isolation chamber formed in the housing to surround a portion of the drive shaft. One side of the seal is exposed to the interior of the isolation chamber. A pressure difference is applied to the seal by the difference between the pressures of the isolation chamber and the atmosphere. The compressor further includes a pressure reducing device for reducing the pressure in the isolation chamber when the compressor is operating. The pressure reducing device reduces the pressure difference applied to the seal and lowers the pressure in the isolating chamber with respect to that of the operating chamber.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with objects and advantages thereof, may best be understood: by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
FIG. 1 is a cross-sectional view of a compressor according to a first embodiment of the present invention;
FIG. 2 is a cross-sectional view taken on line 2 — 2 of FIG. 1;
FIG. 3 is a cross-sectional view taken on line 3 — 3 of FIG.
FIG. 4 is a partial cross-sectional view showing a second embodiment;
FIG. 5 is a partial cross-sectional view showing a third embodiment;
FIG. 6 is a partial cross-sectional view showing a fourth embodiment;
FIG. 7 is a cross-sectional view of a compressor according to a fifth embodiment;
FIG. 8 is a cross-sectional view of a compressor according to a sixth embodiment;
FIG. 9 ( a ) is a partial cross-sectional view of the compressor of FIG. 8 when the intake stroke starts and the pressure of the isolation chamber 123 is being reduced;
FIG. 9 ( b ) is a partial cross-sectional view of the compressor of FIG. 8 when the pressure of the isolation chamber 123 is not being reduced; and
FIG. 10 is a cross-sectional view of a compressor according to a seventh embodiment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A first embodiment of the present invention will now be described with reference to FIGS. 1-3.
As shown in FIG. 1, a front housing 12 and a rear housing 13 are respectively secured to the front part and the rear part of a cylinder block 11 by bolts 30 . An operating chamber 121 as an internal space is defined between the cylinder block 11 and the front housing 12 . A drive shaft 14 is rotatably supported by the cylinder block 11 and the front housing 12 through radial bearings 15 , 16 . The radial bearing 15 supports the drive shaft 14 in a bore 122 of the front housing 12 . The radial bearing 16 supports the drive shaft 14 in a through hole 116 of the cylinder 11 . A disk-shaped rotor 17 is fixed to the drive shaft 14 in the operating chamber 121 . A support arm 171 , which is formed on the periphery of the rotor 17 , includes a guide hole 172 . A thrust bearing 34 is located between the rotor 17 and the front housing 12 .
In the operating chamber 121 , a swash plate 18 is supported by the drive shaft 14 so that the swash plate slides axially and inclines with respect to the drive shaft 14 . A connecting piece 181 is fixed to the swash plate 18 . Guide pins 19 are attached to the distal end of the connecting piece 181 . The guide pins 19 engage with guide holes 172 . Each guide hole 172 guides the inclination of the swash plate 18 through engagement with the associated guide pin 19 . The guide pins and the drive shaft 14 enable the swash plate 18 to move axially along the drive shaft 14 and to integrally rotate with the drive shaft 14 .
As shown in FIGS. 1 and 3, cylinder bores 111 of the cylinder block 11 accommodate pistons 20 . Each piston defines a compression chamber 112 . A pair of shoes 21 is located between a neck 201 of each piston and the swash plate 18 . The rotation of the swash plate 18 is converted to reciprocal movement of each piston 20 through the shoes 21 and each piston moves back and forth in the corresponding cylinder bore 111 .
In the rear housing 13 , an intake chamber 131 and a discharge chamber 132 are defined. A partition plate 22 and valve plates 23 , 24 are, located between the cylinder block 11 and the rear housing 13 . Intake ports 221 and discharge ports 222 are provided on the partition plate 22 . Each intake port 221 is opened and closed by a flexible intake valve 231 of the valve plate 23 . Each discharge port 222 is opened and closed by a flexible discharge valve 241 of the valve plate 24 . A retainer 31 limits the opening degree of each discharge valve 241 . When each piston moves to its top dead center position, refrigerant in the compression chamber 112 presses open the discharge valve 241 and is discharged through the discharge port 22 into the discharge chamber 132 . When each piston moves to the bottom dead center position, refrigerant in the intake chamber 131 presses open the intake valve 231 and is drawn into the compression chamber 112 through the intake port 221 .
The stroke of each piston 20 and the inclination of the swash plate 18 vary in accordance with the difference between the pressure in the operating chamber 121 and that of the compression chamber 112 (intake pressure). Thus, the inclination of the swash plate 18 varies the displacement. When the pressure of the operating chamber 121 increases, the inclination angle of the swash plate decreases. This decreases the displacement. When the pressure of the operating chamber 121 decreases, the inclination angle of the swash plate 18 increases. This increases the displacement.
An electromagnetic displacement control valve 25 in the rear housing 13 controls the refrigerant supply from the discharge chamber 132 to the operating chamber 121 . The refrigerant in the operating chamber 121 flows to the intake chamber 131 through a pressure release passage 113 , which is restricted. The pressure of the operating chamber 121 is controlled by the refrigerant flow from the operating chamber 121 to the intake chamber 131 through the pressure release passage 113 and by the refrigerant supply through the displacement control valve 25 .
A first seal device 26 and a second seal device 27 are located between the front housing 12 and the drive shaft 14 . The second seal device is a lip seal. The first seal device 26 includes a seal ring 261 that contacts the wall of the bore 122 . The seal ring 261 is supported in a support ring 262 . The second seal device 27 contacts one end of the support ring 262 and the periphery of the drive shaft 14 . In the bore 122 , which accommodates the first and the second seal devices 26 , 27 , an isolation chamber 123 is formed. The isolation chamber 123 is isolated from the operating chamber 121 by the radial bearing 15 and the first and the second seal devices 26 , 27 .
As shown in FIGS. 1 and 2, a pressure reducing passage 28 is formed in the drive shaft 14 . An entrance 281 of the reducing passage 28 is open to the isolation chamber 123 , and an exit 282 of the reducing passage 28 is open to the through hole 116 . A fan 29 for moving refrigerant is secured to the end (on the side of the exit 282 ) of the drive shaft 14 . As shown in FIG. 3, the fan 29 rotates in the direction of the arrow R, thus moving refrigerant from the reducing passage 28 to the through hole 116 . Then, the refrigerant flows to the operating chamber 121 through gaps in the radial bearing 16 .
The isolation chamber 123 is connected to the operating chamber 121 through gaps in the radial bearing 15 and the thrust bearing 34 . The gaps in the radial bearing 15 and the thrust bearing 34 also function as oil supply passage.
The fan 29 , which, together with the pressure reducing passage 28 , serves as a pressure reducer driven by the rotation of the drive shaft 14 when the compressor operates. The fan 29 removes refrigerant from the isolation chamber 123 and delivers it to the through hole 116 through the reducing passage 28 . Accordingly, the pressure of the isolation chamber 123 is lower than that of the operating chamber 121 . Without such pressure reducing action, the pressure difference that applies to the first and second seal devices 26 , 27 between the atmosphere and the isolation chamber 123 would be equal to the pressure difference between the atmosphere and the operating chamber 121 . In the present embodiment, due to the pressure reducer, the pressure in the isolation chamber 123 is lower than that of the Operating chamber 121 . Thus, the pressure difference between the isolation chamber 123 and the atmosphere is lower than that between the atmosphere and the operating chamber 121 . This reduces the burden on the first and second seal devices 26 , 27 and improves their durability. Reducing the burden on the seals by reducing the pressure of the isolation chamber 123 is especially effective with regard to the second seal device 27 , which slidably contacts the drive shaft 14 .
Using the drive shaft 14 and the fan 29 as a refrigerant mover requires only a simple construction. There is no need for any special drive mechanism for driving the fan 29 .
The refrigerant from the operating chamber 121 flows little by little into the isolation chamber 123 through the gaps in the radial bearing 15 and the thrust bearing 34 . At the same time, lubricant mixed in the refrigerant lubricates the radial bearing 15 and the second seal device 27 . That is, the reduction of pressure in the isolation chamber 123 by the fan 29 helps lubricate the radial bearing 15 , the thrust bearing 34 , and the second seal device 27 .
The pressure reducing passage 28 is connected to the operating chamber 121 through the gaps in the radial bearing 16 . That is, a refrigerant circulation passage is formed through the operating chamber 121 , the isolation chamber 123 , and the pressure reducing passage 28 and the through hole 116 . The refrigerant circulation passage returns lubricant to the operating chamber 121 where it is needed.
The pressure of the operating chamber 121 is lower than that of the discharge chamber 132 . Though the pressure of the operating chamber 121 varies, the pressure of the operating chamber 121 is maintained higher than that of the intake chamber 131 . The pressure reduction in the isolation chamber 123 is especially suitable for reducing the burden on seal devices 26 , 27 that seal between the operating chamber 121 and the atmosphere.
In a compressor using CO 2 refrigerant, the pressure of which is ten times higher than that of the fluorocarbon-based refrigerant, the pressure reduction of the isolation chamber 123 is especially suitable for reducing the burden on the seal devices 26 , 27 .
A second embodiment of FIG. 4, a third embodiment of FIG. 5, and a fourth embodiment of FIG. 6 will now be described. The construction of each embodiment is similar to that of the first embodiment, and like numerals are used to refer to like members.
In the second embodiment, an oil supply passage 124 , which is formed in the front housing 12 , connects the operating chamber 121 to the isolation chamber 123 . When the pressure of the isolation chamber 123 is reduced, refrigerant from the operating chamber 121 flows to the isolation chamber 123 . The oil mixed in the refrigerant is effectively supplied to the isolation chamber 123 through the oil supply passage 124 . Accordingly, lubrication of the second seal device 27 is more effective.
In the third embodiment of FIG. 5, a bolt hole 127 for the bolt 30 in the front housing 12 and the isolation chamber 123 are connected by an oil supply passage 125 . The bolt hole 127 is located at the bottom of the operating chamber 121 . Lubricant oil that settles at the bottom of the operating chamber 121 flows to the isolation chamber 123 through the oil supply passage 125 when the pressure of the isolation chamber 123 is reduced. In this way, the second seal device 27 is more effectively lubricated.
In the fourth embodiment shown in FIG. 6, the bolt hole 127 and the top of the isolation chamber 123 are connected by an oil supply passage 126 . The lubricant oil accumulated at the bottom of the operating chamber 121 flows to the upper portion of the isolation chamber 123 through the oil supply passage 126 when the pressure of the isolation chamber 123 is reduced. The oil temporarily remains in the isolation chamber 123 . Accordingly, the second seal device 27 is more effectively lubricated.
A fifth embodiment of FIG. 7 will now be described. Like numerals are used to refer to like members of the first embodiment.
In the fifth embodiment, a spiral groove 283 is formed on the inner surface of the pressure reducing passage 28 in the drive shaft 14 . The spiral groove 283 moves refrigerant of the reducing passage 28 from the isolation chamber 123 to the through hole 116 when the drive shaft 14 rotates, thus reducing the pressure of the isolation chamber 123 . Employing the spiral groove 283 in the drive shaft 14 makes it unnecessary to provide a special space for a fan.
A sixth embodiment of FIGS. 8, 9 ( a ) and 9 ( b ) will now be described. Like numerals are used to refer to members similar to those of the first embodiment.
A pressure reducing auxiliary chamber 134 is formed in the rear housing 13 . The auxiliary chamber 134 is connected to the through hole 116 by a connecting port 223 , which is formed to pass through the partition plate 22 , the valve plates 22 , 24 and the retainer 31 . Also, the auxiliary chamber 134 is connected to the compression chamber 112 by a pressure reducing port 224 , which is formed to pass through the partition plate 22 , the valve plates 23 , 24 and the retainer 31 . The pressure reducing port 224 is opened and closed by the valve 232 of the valve plate 23 . The pressure reducing passage 28 , the through hole 116 , the connecting port 223 , the auxiliary chamber 134 and the pressure reducing port 224 form a passage for delivering refrigerant from the isolation chamber 123 to the compression chamber 112 .
A third seal device 32 and a lip seal type fourth seal device 33 are located between the inner surface of the through hole 116 and the drive shaft 14 . The third seal device 32 includes a seal ring 321 . The seal ring contacts the inner surface of the through hole 116 and is supported by a support ring 322 . The fourth seal device 33 contacts an end surface of the support ring 322 and the outer surface of the drive shaft 14 . The seal devices 32 , 33 close off communication between the through hole 116 and the operating chamber 121 along the outer surface of the drive shaft 14 . That is, the seal devices 32 , 33 form a seal between the drive shaft 14 and the cylinder block 11 .
An intake passage 114 is formed to connect the intake chamber 131 with the cylinder bore 111 in the cylinder block 11 . As shown in FIG. 8, the head of the piston 20 , at its top dead center position, is located closer to the partition plate 22 than the opening 115 . The intake port 221 is connected to the cylinder bore 111 by the intake passage 114 .
FIG. 8 shows a state when the discharge stroke of the piston 20 is completed, that is, when the piston is at the top dead center position. In this state, the piston 20 closes the opening 115 of the intake passage 114 and the valve 232 is closed. In the state of FIG. 9 ( a ), the piston 20 is about to start the intake stroke and the opening 115 is closed by the piston 20 . In this state, the refrigerant of the auxiliary chamber 134 presses open the valve 232 and flows into the compression chamber 112 by the vacuum action of the intake stroke of the piston 20 . Accordingly, the pressure of the isolation chamber 123 , which is connected to the auxiliary chamber 134 by the pressure reducing passage 28 , is reduced. In the state of FIG. 9 ( b ), the piston 20 opens the opening 115 and the refrigerant of the intake chamber 131 presses open the intake valve 231 and flows into the compression chamber 112 . The pressure of the compression chamber increases above the pressure of the auxiliary chamber 134 , therefore the valve 232 closes the pressure reducing port 224 .
The sixth embodiment has the following advantages.
At the beginning of the intake stroke, the valve 232 opens the pressure reducing port 224 , connecting the isolation chamber 123 to the compression chamber 112 . Accordingly, the pressure of the isolation chamber 123 is lowered below the intake pressure of the intake chamber 131 . The pressure of the isolation chamber 123 is reduced for a certain period, which extends into the discharge stroke. This relieves the burden on the seal devices 26 , 27 . Further, since the valve 232 closes, the compressed refrigerant of the compression chamber 112 cannot flow into the auxiliary chamber 134 . Therefore, the output of the compressor is not reduced by leakage from the port 224 .
Forming part of the refrigerant delivering passage in the drive shaft 14 for connecting the compression chamber 112 to the isolation chamber 123 simplifies the structure.
A seventh embodiment of FIG. 10 will now be described. Like numerals are used to refer to members that are similar to those of the first embodiment.
In this embodiment, a passage 35 is formed in the drive shaft 14 . A restricting passage 36 , which restricts a flow rate of the refrigerant, opens at the outer surface of the drive shaft 14 in the vicinity of the radial bearing 15 . The restricting passage 36 is connected to the passage 35 . A fan 37 is attached to the drive shaft 14 in the vicinity of the restricting passage 36 . The fan 37 integrally rotates with the drive shaft 14 . The refrigerant of the isolation chamber 123 is moved by the fan 37 , and the pressure of the isolation chamber 123 is reduced accordingly. As in the first embodiment, the burden on the first and second seal devices 26 , 27 is reduced.
Refrigerant from the isolation chamber 123 is sent to the operating chamber 121 through the gaps, or clearances, in the thrust bearing 34 . The lubricant oil mixed in the refrigerant lubricates the thrust bearing 34 . Refrigerant from the operating chamber 121 flows little by little to the isolation chamber 123 through the passage 35 and the restricting passage 36 . The oil mixed in the refrigerant lubricates the radial bearing 15 and the second seal device 27 . That is, the action of the fan 37 helps lubricate the radial bearing 15 , the thrust bearing 34 and the second seal device 27 .
In the present invention, the following embodiments are also possible.
The pressure reducing passage 28 of the drive shaft 14 may be connected to the intake chamber 131 . Refrigerant from the isolation chamber 123 would then be sent to the intake chamber 131 .
The operating chamber 121 may be completely shut off from the isolation chamber 123 .
The present invention may be applied to double-headed piston compressors.
The present invention may be applied to compressors that have seal devices in the intake chamber and in the discharge chamber in addition to the operating chamber.
The present invention may be applied to compressors other than piston type compressors, such as, scroll type compressors, and vane type compressors.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalence of the appended claims. | A compressor including a compressing mechanism accommodated in a housing. The mechanism draws refrigerant from an intake chamber into a compression chamber and discharges the refrigerant from the compression chamber to the discharge chamber. A seal device prevents leakage of refrigerant from the internal space to the atmosphere between the drive shaft and the housing. An isolation chamber, which is separately formed in the housing, accommodates the seal device. A pressure reducing passage reduces the pressure of the isolation chamber to reduce the pressure difference applied to the seal device. | 5 |
This application claims the benefit of U.S. Provisional application No. 60/249,042, filed Nov. 14, 2000.
The present invention relates generally to electrical circuits.
BACKGROUND
Motor vehicles include warning systems for providing audible, visible or other warning indications to a motor vehicle operator of a problem condition related to the performance of the motor vehicle. Often, the warning system include s a display panel that has indicators for signaling of fault conditions. Each indicator traditionally has a single function, warning against a particular condition that has been detected by the warning system.
A conventional display panel is limited in size. As a practical matter, the number of faults that can be detected in the complex motor vehicles of today far exceed the amount of space available in a conventional display panel. In some motor vehicles, such as motorcycles, the size of the display panel is severely restricted. Accordingly, conventional warning systems group similar faults creating generalized system level warning indicators (e.g., oil pressure, temperature, battery etc.) Users are alerted to the system level event and respond in accordance with operator instructions. In general, the warning system provides rudimentary information that must be investigated further as to its ultimate cause and correction. While the information is rudimentary, the value is often quite significant. If the motor vehicle operator chooses to disregard the detected fault, permanent damage to the motor vehicle and/or its systems can result.
SUMMARY
In one aspect, the invention provides a fault detector for determining a charge system fault in a motor vehicle charging system using an existing warning indicator on a display panel of the motor vehicle. The fault detector includes a charge isolator receiving as an input a signal indicative of the charge voltage provided from an alternator of the motor vehicle to the battery, a charge power loss detector operable to determine when a voltage level of the input signal is less than a predetermined threshold, a flasher operable to generate a pulsed signal if the voltage level of the in put signal is less than the predetermined threshold and signaling logic operable to transmit the pulsed signal to an existing warning indicator on a display panel of the motor vehicle, detect a fault associated with the existing warning signal and prioritize between the fault and the charge system fault including selecting a higher priority fault to drive the existing warning indicator.
Aspects of the invention can include one or more of the following features. The fault detector can include a flasher timer for controlling a duty cycle of the pulsed signal. The fault detector can include motor vehicle shut-off logic for detecting when the motor vehicle is not operating, and flasher power shut-off logic for shutting down the flasher when the motor vehicle is not operating. The fault detector can include a flasher amplifier operable to receive the pulsed signal and drive the existing warning indictor at a steady rate. The flasher can be an integrated circuit. The fault detector can be a CMOS integrated circuit operating as a monolithic timer in an a stable configuration. The motor vehicle can be a motorcycle, snowmobile, Altra-lite aircraft, or motorboat. The existing warning indicator can be a low oil pressure indicator. The charge isolator can be a rectifier isolation diode. The signaling logic can be operable to transmit the pulsed signal to an existing warning indicator on a display panel of the motor vehicle if a charge system fault is detected and disable the transmission of the pulsed signal to the existing warning signal if the fault associated with the existing warning indicator is detected. The fault associated with the existing warning indicator can be a low oil pressure fault. The oil pressure fault can have a higher priority than a charging system fault. The charger isolator can be operable to isolate the charging system from the motor vehicle's load and a battery. The charger isolator can be operable to current limit received signals. The existing warning indicator can be selected from the group of a low oil pressure indicator, a high oil temperature indicator, a high water temperature indicator and a low fuel indicator.
In another aspect, the invention provides a method for detecting a charging system fault in a motor vehicle. The motor vehicle includes a low oil pressure warning indicator for indicating when oil pressure for the motor vehicle is too low. The method includes detecting a charge system fault, determining if the oil pressure is too low, and if so, driving the low oil pressure warning indicator with a first signal. If the oil pressure is within an acceptable range, and if a charging system fault is detected, the method includes driving the low oil pressure warning indicator with a second signal that is distinct from the first signal used to drive the low oil pressure warning indicator when oil pressure is too low.
In another aspect, the invention provides a method for detecting a charging system fault in a motor vehicle. The motor vehicle includes an existing warning indicator driven by a first signal for indicating when one aspect of the motor vehicle performance is faulty. The method includes detecting a charge system fault, determining if the one aspect of the motor vehicle's performance is faulty and, if so, driving the existing warning indicator with the first signal. If the one aspect is not faulty and a charge system fault has been detected, the method includes driving the existing warning indicator with a second signal corresponding to the detected charge system fault. The second signal provides a different visual indication than the first signal.
Aspects of the invention can include one or more of the following advantages. A self-contained, hermetically sealed, alternator-charging system fault detector for any battery charging system is proposed. The battery charging system can be included on a motorcycle snowmobile, motorboat, Altra-lite aircraft and the like. The alternator-charging system utilizes existing vehicle wiring and fault displays. A fault detector uses a single, instrument panel mounted, indicator (e.g., low oil pressure light) for two operational meanings. In a first operational mode, the fault detector operates to detect an alternator low voltage output condition. Upon detecting the alternator low voltage output, the fault detector operates to cause the flashing of the (low oil pressure) indicator. In a second operational mode, when a loss of oil pressure is detected, the oil pressure indicator is illuminated steadily. Both of the fault modes indicate a very serious condition, however, the engine having low oil pressure is generally deemed to be of a more critical nature. A system is provided for prioritizing among the plurality of faults associated with a single fault indicator, and includes a priority indication to distinguish the higher priority fault in the event of a dual system failure.
SUMMARY OF FIGURES
FIG. 1 shows a charging system including alternator-charging system fault detector.
FIG. 2 shows a schematic block diagram of a fault detector.
FIG. 3 shows a detailed electrical schematic for one implementation of a fault detector.
DETAILED DESCRIPTION
Referring now to FIG. 1, a charging system 50 that includes an alternator-charging system fault detector (i.e., “fault detector”) 100 is shown. The charging system 50 can be part of a conventional motor vehicle charging system included, for example on a Harley Davidson Motorcycle (not shown). The charging system 50 includes a battery 52 , switch 54 , main circuit breaker 56 and an alternator (portions of which are shown including voltage regulator 60 and stator windings 62 ). Portions of a warning system for the motor vehicle are shown including an oil pressure switch 70 and display panel 72 including oil pressure indicator 74 .
Referring now to FIG. 2, a schematic block diagram of the fault detector 100 is shown. Fault detector 100 includes a charger isolator 200 , charger power loss detector 202 , oscillator power filter 206 and flasher (e.g., oscillator) 210 . Associated with power loss detector 202 are a power detector filter 203 and flasher shut off logic 204 . Associated with flasher 210 are power filter 206 , voltage controller 208 , timer 212 , amplifier coupling timer 214 , amplifier 216 , and fault indicator block 218 .
Fault detector 100 isolates the charging system 50 from the vehicle's electrical load 80 and battery 52 through charger isolation 200 . Charger isolation 200 also provides a half wave rectifier filter and current limiter to protect and prevent against alternator or vehicle electrical system damage.
Charger power loss detector 202 receives an input from the motor vehicle's alternator. Charger power loss detector 202 detects a low voltage condition from the output of the alternator (i.e., the alternator output voltage drops below the minimum battery charging level). Upon detection of a low output voltage condition, charger power loss detector 202 powers flasher 210 through flasher power filter 206 and flasher voltage control 208 . Associated with charger power loss detector 202 are one or more power detector filters 203 for filtering the alternator output voltage. In one implementation, the power detector filters 203 are low pass network filters.
Flasher power shutoff detector 204 determines the vehicle operating status as to whether the vehicle is running with no charger output (i.e., an alternator fault) or the vehicle is not running (i.e., turned off with no charger output). Flasher power shutoff detector 204 prevents battery discharge through the fault detector 100 by the operation of flasher 210 while the vehicle is not running (i.e., with no alternator output, the normal engine shutoff condition).
Flasher 210 can be a CMOS (complementary metal-oxide semiconductor type) integrated circuit (IC) operating as a monolithic timer in an astable configuration. Flasher control timing is controlled by the flasher on/off timer 212 . In one implementation, the flasher on/off timer 212 causes flasher 210 to oscillate at a rate of approximately 2.18 cycles per second. Flasher amplifier coupling timer 214 controls the timing of turning on and off of flasher amplifier 216 . In one implementation, flasher amplifier coupling timer 214 controls the flasher amplifier 216 at a duty cycle of approximately 0.3 seconds on, and 0.15 seconds off.
Flasher amplifier 216 provides an output signal to fault indicator block 218 , which in turn provides a fault indication to an indicator on a display panel on the motor vehicle (e.g., the vehicle's low oil pressure indicator).
Operation
Fault detector 100 operates on the prioritizing fault principal by alerting the operator of a charging system malfunction. Fault detector 100 detects a charging system failure using a power loss detector 202 and alerts the operator of the motor vehicle (e.g., rider of the motor cycle) that the motor vehicle is operating on limited battery power only. The flashing oil pressure indicator driven by flasher 210 (resulting in a flashing oil pressure indicator on the display panel of the motor vehicle) alerts the operator that the vehicle is operating on limited battery power. The limited battery power warning can provide the motor vehicle operator with sufficient notice to have the motor vehicle serviced without the added inconvenience of a breakdown. For example, with a nominal battery and load, a motorcycle rider can expect as much as 10 hours of motorcycle running, or nearly 600 miles of highway riding after a charge system malfunction has been detected. Results will vary depending on the condition of the battery and the amount of added electrical load on the system.
If the engine oil pressure should drop below the manufacture's preset limit, fault detector 100 will illuminate the low oil pressure indicator steadily (irrespective of a charging system malfunction). The steady illumination of the low-pressure indicator alerts the rider of an engine oil system failure (opposed to flashing, which indicates charging system malfunction). Since the oil system is more important (or a higher priority) than battery charging, fault detector 100 prioritizes the faults and provides an indication of the higher priority system failure. If at any time the oil pressure should come back within limits, then fault detector 100 will provide a charging system failure indication (with a flashing low oil pressure light) again.
Referring now to FIGS. 2 and 3, a more detailed view of one implementation of fault detector 100 is shown. In the implementation shown, fault detector 100 includes a plurality of components including a pair of transistors (Q 2 and Q 3 ), a pair of diodes (D 1 and D 2 ), six capacitors (C 1 -C 6 ), five resistors (R 1 -R 5 ) and an integrated circuit (IC).
Fault detector 100 isolates the charging system 50 from the vehicle's battery 52 and electrical load 80 through a rectifier and isolation diode 102 (D 1 ). In one implementation, rectifier and isolation diode 102 (D 1 ) is a 32-ampere rectifier and isolation diode. A first terminal (A 1 - 2 ) of rectifier and isolation diode 102 is coupled to the output of the voltage regulator 60 . A second terminal (A 1 - 1 ) of rectifier and isolation diode 102 is coupled with to one terminal of the main circuit breaker 56 , the second terminal of which is coupled to battery 52 . Rectifier and isolation diode 102 provides charger system isolation and is used as a half wave rectifier filter and current limiter to protect and prevent against alternator or vehicle electrical system damage.
Integrated circuit (IC) 126 is a flasher circuit that includes a plurality of inputs. The integrated circuit can be a CMOS (complementary metal-oxide semiconductor) type device operating as a monolithic timer in an astable configuration.
First terminal A 1 - 2 of rectifier and isolation diode 102 is coupled to the base of a transistor 104 (Q 2 ), a first terminal of first capacitor 106 (C 5 ), a first terminal of a second capacitor 108 (C 6 ) and first terminal of a first resistor 110 (R 4 ). The collector of transistor 104 (Q 2 ) is coupled to a second terminal of first resistor 110 (R 4 ). The emitter of transistor 104 (Q 2 ) is coupled to a first terminal of diode 112 (D 2 ) and to the first terminal of a third capacitor 114 (C 4 ). The second terminal of the second diode 112 (D 2 ) is coupled to the collector of a second transistor 124 (Q 3 ) and to the low oil pressure indicator 74 via a signaling port 150 of fault detector 100 . The collector of the first transistor 104 (Q 2 ) is also coupled to the first terminal of a fourth capacitor 116 (C 3 ) and the first terminal of a second resistor 122 (R 3 ). The base of second transistor 124 (Q 3 ) is coupled to a first terminal of a third resistor 128 (R 5 ), the first terminal of a fifth capacitor 118 (C 2 ) and the third input to integrated circuit 126 .
The second terminals of the second and third resistors 122 and 128 (R 3 and R 5 ) are coupled to the fourth input of integrated circuit 126 . A first terminal of each of a fourth and fifth resistor 130 and 132 (R 1 and R 2 ) are coupled to the seventh input of integrated circuit 126 . The second input to the integrated circuit 126 is coupled to the first terminal of sixth capacitor 120 (C 1 ), the sixth input to the integrated circuit 126 and a second terminal of fourth resistor 130 (R 1 ). The second terminal of fifth resistor 132 (R 2 ) is coupled to the eighth input of integrated circuit 126 .
The second terminal of third capacitor 114 (C 4 ), the first terminal of fourth and fifth capacitors 116 and 118 (C 3 and C 2 ), the second terminals of first and second capacitors 106 and 108 (C 5 and C 6 ), the second terminal of sixth capacitor 120 (C 1 ), the emitter of second transistor 124 (Q 3 ) and the first input to integrated circuit 126 are all coupled via a ground port 140 to ground.
Operation
When the alternator output voltage drops below the minimum battery charging level, tap A 1 - 2 , on the anode side of diode D 1 (first diode 102 ) goes low driving the base side of transistor Q 2 (first transistor 104 ) into the forward bias state, allowing current flow from the battery 52 , through the vehicle's ignition switch (i.e., switch 54 ), the low oil pressure indicator 74 and diode D 2 (second diode 112 ), to turn on the power loss detector Q 2 (first transistor 104 ).
The power loss detector transistor Q 2 (first transistor 104 ), being forward biased in a common emitter circuit by resistor R 4 (first resistor 110 ), supplies system operating voltage to the flasher (IC 126 ). Diode D 2 (second diode 112 ), the flasher power shutoff detector, determines the vehicle operating status as to whether it is running with no charger output (i.e., an alternator fault), or not running (i.e., turned off, with no charger output) to prevent battery discharge through fault detector 100 from the flasher (IC 126 ) operating while the motor vehicle is not running (i.e., with no alternator output, the normal engine shutoff condition).
Filtering of the alternator output voltage for transistor Q 2 (first transistor 104 ) is provided by capacitors C 5 , C 6 (first capacitor 106 , and second capacitor 108 ) in the form of a low pass network filter. Flasher supply voltage is controlled and filtered through the oscillator power filters C 3 , C 4 (fourth capacitor 116 and third capacitor 114 ), and the flasher voltage controllers R 3 , R 5 (second resistor 122 and third resistor 128 ).
Flasher control timing is provided by the flasher on/off timing circuit R 1 , R 2 , C 1 (fourth resistor 130 , fifth resistor 132 and sixth capacitor 120 ). In one implementation, the flasher on/off timer controls the flasher (IC 126 ) at a rate of approximately 2.18 cycles per second, and controls the flasher amplifier Q 3 (second transistor 124 ) at a duty cycle of approximately 0.3 seconds on, and 0.15 seconds off.
The output of the flasher (IC 126 ) is connected to the base of the flasher amplifier Q 3 (second transistor 124 ) through a coupling timer capacitor C 2 (fifth capacitor 118 ) that keeps the flashing rate steady.
A number of embodiments of the invention have been described. Nevertheless, it may be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. | A method and system is provided for detecting a charging system fault in a motor vehicle. The motor vehicle includes an existing warning indicator driven by a first signal for indicating when one aspect of the motor vehicle performance is faulty. The method includes detecting a charge system fault, determining if the one aspect of the motor vehicle's performance is faulty and, if so, driving the existing warning indicator with the first signal. If the one aspect is not faulty and a charge system fault has been detected, the method includes driving the existing warning indicator with a second signal corresponding to the detected charge system fault. The second signal provides a different visual indication than the first signal. | 7 |
BACKGROUND, FEATURES OF INVENTION
This invention relates to magnetic recording structures and more particularly to methods and fixtures for fabrication thereof.
Workers in the art of making magnetic means will recognize the rather schematically shown magnetic recording slider SL in FIG. 1 as of a type adapted for high performance digital recording, e.g., with floppy disks. Workers understand that slider SL is made up of three magnetic core pieces, #2, 3 and 4 flanked by a pair of block elements #1, 5, these elements all being very carefully aligned with high precision and bonded together as known in the art; the bond lines b being indicated. The so formed slider will present a "top" transducing face as indicated and a "base" face from which project the well known coil tabs such as core leg 3-l. is also filled with vitreous gap material as known in the art.
Workers have heretofore resorted to assembling and aligning such core pieces and then bonding them individually and using rather crude "holder means" if any. This invention is directed towards methods and associated fixtures for assembling and holding such slider elements as a batch (e.g., a group of 20 identical assemblies) and maintaining this alignment precisely while glass bonding all of the assemblies in a single sequence. Also the invention teaches a convenient fixture for effecting such batch-assembly, alignment and bonding, in a fixture allowing workers to so-handle any number of assemblies up to a maximum (e.g., 1 to 20 units in the embodiment illustrated).
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other features and advantages of the present invention will be appreciated by workers as they become better understood through reference to the following detailed description of preferred embodiments which should be considered in conjunction with the accompanying drawings, wherein like reference symbols denote like elements.
FIG. 1 is a schematic perspective of a slider workpiece for use with the invention;
FIG. 2 is a plan view of a glass bonding fixture embodiment of the invention shown relatively schematically, with some parts omitted for clarity; while FIG. 3 is a partial plan view of a related fixture with some elements indicated in phantom for a "first bonding mode", portions thereof being indicated (with minor modifications) in FIG. 4 in a "second bonding mode", with the retaining spring mechanism thereof being indicated functionally in FIG. 5; FIGS. 6 and 7 illustrating this mechanism in upper part elevation and elevation respectively; and
FIG. 8 is a plan view, of another fixture embodiment; while FIGS. 9 and 10 are respective elevation and perspective schematic views of the associated retainer spring mechanism.
DESCRIPTION OF PREFERRED EMBODIMENTS
The following description of methods and associated fixtures is given by way of example to indicate preferred embodiment according to the invention. Except as otherwise specified, workers should assume that conventional related methods, conditions, materials, etc., obtain throughout, conforming to present good practice in the art.
Workers in the art of making magnetic recording slider devices are familiar with the slider subassembly SL shown schematically in FIG. 1. Assembly SL will be understood as comprising three relatively magnetic core slices 2, 3 and 4 shaped as indicated and adapted to be bonded to one another and to flanking block elements 1, 5 along prescribed precise bond lines indicated as b.
Novel glass bonding method:
Step #1: The slider subassembly will be understood as preassembled with its parts (e.g., the five parts indicated for SL in FIG. 1, for instance) prealigned and bonded temporarily as aligned. For instance, such a slider may be understood as including manganese-zinc-ferrite elements to be formed into a tunnel erase head such as used for high technology floppy disk recording as known in the art.
Such assemblies SL are preferably gathered together in a batch, e.g., 20 in a batch, with the top (recording) face pressed against a registration surface and the sides (5-S, 1-S) being compressed resiliently to hold the parts together in alignment during the glass bonding (heating) steps [which presumably may well release the temporary adhesive--it is very important that the parts be held in intimate contact and in very precise alignment with the bond lines b kept a prescribed uniform gap distance on the order of 0.10 of a mil].
Step #2: With the batch of units SL so registered against a reference surface and resiliently clamped in place at their sides, their base surfaces will be exposed upward; accordingly the glass bond material (frit) intended to comprise the bond lines b may be painted or otherwise applied to this base surface (unless the material has been previously applied along the bonding surfaces).
Step #3: The batch is now ready for heating to form the glass bonds at b, e.g., the batch of assemblies SL so fixed in a single glass bonding fixture may be inserted in a conventional glass bonding furnace, such as a belt furnace. This will act to loosen (and preferably remove) all temporary adhesive holding a unit aligned and to heat it sufficient to liquify and distribute the (glass frit) material along the bond lines b--each unit being held in prescise critical alignment, preferably by individual spring or other resilient means to assure that uniform thickness bond b will result.
Step #4: The batch of units SL may now be cooled to harden the bonds along bond-lines b for a permanent bond, these bond lines may, according to this method be made very, very thin and thus of low mass so as to be relatively insensitive to terminal shock, according to a feature hereof. This allows the cooling period to be relatively brief, thus accelerating the overall bonding process.
Step #5: A second, "plug bonding" sequence is next invoked, with the batch of units being flipped upside down with their core legs hanging down so that the plug gap gp (FIG. 1) may be filled with bonding material as is well known in the art.
Step #6: Thus the batch of assemblies SL are reheated sufficient to melt in a glass cane (or otherwise liquify plug material) for the plug gp in a conventional known manner. This is usually done by "sagging" a glass cane into the indicated slot on the air bearing (or "top" side) of assembly SL. This slot gp exists to accommodate step grinding of the erase cores to an appropriate track width.
Novel glass bonding fixture; FIGS. 2-7:
Glass bonding methods like the foregoing are preferably implemented using a novel glass bonding fixture such as fixture F xx shown in FIG. 2 and described as follows (or alternatively with fixture F' xx in FIGS. 8-10 mentioned below).
Fixture F xx comprises a block into which a channel ch is cut to have a flat, precisely oriented planar reference base cc and a reference edge ch-c orthogonal to cc (see related embodiment FIG. 3). Thus, as indicated in FIG. 2 a batch of identical assemblies SL (such as SL-1 to SL-20) may be inserted in channel ch with their top or recording faces contacting the registration base cc of channel ch, and with one side thereof referenced against registration edge ch-c, being urged thereagainst by resilient lockable spring means sp as indicated functionally in FIGS. 5-7 (alternative embodiment in FIGS. 9, 10). With assemblies SL aligned in a row in this condition and their bases exposed upward it will be seen as relatively simple to paint on or otherwise apply the glass (frit) bonding material intended to comprise the bond lines b.
According to a feature of novelty, each mentioned spring means comprises a forked plate P urged resiliently, and selectively, against its respective slider SL by an associated biased leaf spring loop sp (see FIGS. 4-7). The "released" condition thereof is indicated functionally in FIG. 6 (compare "retained" condition in FIG. 4) whereby, with lever Lv thrown downward an eccentric cam-axle ec is so rotated as to leave the spring/plate combination "release " and in contact with a slider SL (e.g., via interposer-rod-see Lp in FIG. 9) to retain its parts carefully compressed in precise alignment. This spring pressure is very carefully metered and pre adjusted (see nut n) to apply sufficient pressure to retain the slider with its parts kept aligned together, yet not so much as to risk cracking or damaging it (as an operator is conventionally prone to do using "guesswork").
By comparison, in FIG. 4, level Lv is thrown toward the horizontal to rotate cam ec 90+° to the "parting condition" whereat it pushes the plate/spring unit away from its slider SL, allowing it to be removed, etc. To best accommodate this, plate P is pivoted from its base on ball bearing bb, also being free to swivel a bit so its two tines b may be rotated to better align with the adjacent side (5-s, etc.) of its slider SL.
As best shown in FIGS. 6, 7, axle ec is seated in a receiving pocket cut across plate P with its lever Lv attached midway along ec to be swung in the space between the plates tines b. Spring sp preferably comprises a leaf-spring (e.g., preferably of Inconel X-750) folded into a re-entrant loop and captured and pressed against plate P by a nut n or like means for adjusting spring tension. Leaf spring sp is adapted to thrust plate P and slider SL toward registration edge ch-c (normally--except where "released" by urging of eccentric cam ec rotated by rotation of associated lever Lv), thereby securing the associated head SL against registration edge ch-c.
Once the first glass bonding sequence is completed as indicated in the above described method the assemblies may be inverted (flipped over) with their core legs CL depending. For this reason, and in order to use channel ch for the second glass bonding step as well, a pair of spacers or shoulder bars sb, sb' approximating the height of core legs CL are laid along registration surface cc on opposite sides of channel ch as indicated in FIG. 4. During this glass bonding step the springs sp will similarly urge the assembly SL against reference edge ch-e (but this may not be necessary since they are already bonded together).
Results:
Workers will perceive that this fixture, and any like it, is an advantageous implementation of the novel method previously described. For instance, one can co-bond a number (e.g., here up to 20) of slider assemblies simultaneously, whereas prior art techniques bond only one or two at a time. Similarly, the retaining spring means sp, etc., is adapted to maintain the parts in intimate contact along bond lines b during the glass bond heating when the temporary adhesive is released--whereas in the prior art no such spring means are used but only weights or a like slight, non adjustable gravitational urging.
Also, such a structure including springs sp is designed to survive the harsh glass bonding environment (including the extremes of heat, atmosphere and corrosive glass chemistry and the like)--especially when Inconel X-750 springs are used. Further, it will be recognized as quite advantageous to use such a fixture wherein one can turn from the first glass bonding step to the second merely by inserting spacers such as shoulder bars sb, sb'.
Second fixture embodiment; FIGS. 8-10:
Workers will visualize alternative fixtures to F xx above described implementing some or all of its novel features. One such is fixture F' xx in FIGS. 8-10, understood as essentially the same (at least functionally) as F xx above except as otherwise specified.
In FIG. 8 (a plan view like FIG. 2, in plan view) fixture F' xx will be understood like F xx to include a slider-receiving channel ch' plus retainer means for individually securing each slider unit in channel ch' with its pieces held firmly aligned. This retainer means comprises a slotted leaf spring SP' deflectable by a rotatable 2-position cam axle c-a' and biased against an interposer rod ip, which is to selectively pin its respective slider resiliently against opposing reference edge ch-r' when cam c-a' is rotated to "rest" condition (FIG. 9) but to release it when c-a' is rotated (FIG. 10). A lever Lv' is provided to so rotate c-a' and spring SP' will be understood as centrally-slotted to allow lever connection and movement--the spring being attached to a sidewall ff of fixture F xx' . Interposer rods Lp are depressed loosely in receiving bores in the fixture body to contact a respective slider in its exact center (of height and of length) to urge it against channel wall ch-r' with minimal "tilt" and are long enough to extend from a respective spring SP' to very slightly protrude into channel ch' in "rest" condition (FIG. 9). This allows them to be urged very slightly away from a slider as the slider is inserted, biasing spring SP' in the process. The fixture body may be made of "micronite" or like machinable refractory. As before all parts are designed to survive glass bonding. As before, the fixture will be recognized as inherently "safer and gentler" for delicate slider assemblies, providing a constant, fairly precise retaining pressure to hold them firmly yet not crack them. The provision of such a two position "cam leaf spring" system assures this.
It will be understood that the preferred embodiments described herein are only exemplary, and that the invention is capable of many modifications and variations in construction, arrangement and use without departing from the spirit of the invention.
Further modifications of the invention are also possible. For example, the means and methods disclosed herein are also applicable to other forms of slider and like tiny assemblies destined for glass bonding or a like treatment--especially where each unit must be held resiliently in place with a prescribed constant, fairly-precise pressure. Also, the present invention is applicable for providing like fixtures for similar treatments of other unit-groups requiring delicate handling.
The above examples of possible variations of the present invention are merely illustrative. Accordingly, the present invention is to be considered as including all possible modifications and variations coming within the scope of the invention as defined by the appended claims. | Described is a fixture for glass-bonding a digital magnetic recording slider workpiece (the component parts thereof), while holding them carefully aligned. In one preferred embodiment this fixture includes a slot for receiving a number of such work pieces in pre-assembled form registering and aligning them together and providing retainer means individually for each work piece adapted to resiliently and selectively engage each work piece and hold it positively in careful precise alignment while glass bonding and related operations carried out on the array of multiple work pieces so-aligned and retained. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. National Phase of PCT Appln. No. PCT/EP2012/075208 filed Dec. 12, 2012, which claims priority to German Application No. 10 2011 089 449.7 filed Dec. 21, 2011, the disclosures of which are incorporated in their entirety by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to the preparation of polycrystalline silicon by chemical vapor deposition, e.g. by the Siemens process.
[0004] 2. Description of the Related Art
[0005] Polycrystalline silicon (polysilicon for short) serves as a starting material for production of monocrystalline silicon for semiconductors by the Czochralski (CZ) or zone melting (FZ) process, and for production of mono- or polycrystalline silicon by various pulling and casting processes for production of solar cells for photovoltaics.
[0006] Polycrystalline silicon is generally produced by means of the Siemens process. In this process, in a bell jar-shaped reactor (“Siemens reactor”), support bodies, typically thin filament rods of silicon, are heated by direct passage of current and a reaction gas comprising hydrogen and one or more silicon-containing components is introduced. Typically, the silicon-containing component used is trichlorosilane (SiHCl 3 , TCS) or a mixture of trichlorosilane with dichlorosilane (SiH 2 Cl 2 , DCS) and/or with tetrachlorosilane (SiCl 4 , STC). Less commonly, but also on the industrial scale, silane (SiH 4 ) is used. The amount and composition of the reaction gas are set as a function of the time or rod diameter.
[0007] The filament rods are inserted vertically into electrodes at the reactor base, through which they are connected to the power supply. High-purity polysilicon is deposited on the heated filament rods and the horizontal bridge, as a result of which the diameter thereof grows with time.
[0008] The deposition process is typically controlled by the setting of rod temperature and reaction gas flow rate and composition. The rod temperature is measured with radiation pyrometers, usually on the surfaces of the rods facing the reactor wall. The rod temperature is set either in a fixed manner or as a function of rod diameter, by control or regulation of the electrical output.
[0009] After the attainment of a desired diameter, the deposition is ended and the polysilicon rods formed in this way are cooled to room temperature. After the rods have been cooled, the reactor bell jar is opened and the rods are removed manually or with the aid of specific devices, called deinstallation aids (see, for example, EP 2 157 051 A2), for further processing or for intermediate storage.
[0010] Both the storage and the further processing, particularly comminution of the rods, and classification and packaging of broken pieces, are generally effected under special environmental conditions in climate-controlled rooms, which prevents contamination of the product. Between the time of reactor opening and until introduction into storage or further processing, the material deposited, however, is exposed to environmental influences, particularly dust particles.
[0011] The morphology and microstructure of the growing rod are determined by the parameters of the deposition process. Deposition with TCS or a mixture thereof with DCS and/or STC is typically effected at rod temperatures between 900 and 1100° C., with supply of silicon-containing component(s) (in total) of 0.5 to 10 kmol/h per 1 m 2 of rod surface area, where the molar proportion of this/these component(s) in the input gas stream (in total) is between 10% and 50% (the remaining 90% to 50% is typically hydrogen).
[0012] The figures given for rod temperature here and elsewhere relate (unless stated explicitly) to values which are measured in the vertical rod region at least 50 cm above the electrode and at least 50 cm below the bridge. In other regions, the temperature may differ distinctly therefrom. For example, significantly higher values are measured in the inner arc of the bridge, since the current flow is distributed differently in this region.
[0013] Polycrystalline silicon rods deposited under these conditions are matt gray and consist of crystallites having a mean size of 1 to about 20 μm. The crystallite size can be estimated, for example, by means of optical microscopy. Electron microscopy (SEM) allows three-dimensional scanning of almost every individual Si grain, which enables a more exact measurement of the mean crystallite size via a statistical evaluation.
[0014] Because of the very different shapes of the Si grains, the size thereof is typically determined by calculation from the area (for the conversion, the idealized round shape of the cross section is assumed).
[0015] Because of the significant surface curvature, particularly in the case of porous and fissured material, the measurement of roughness is generally not conducted over a traversing length Lt of 15 mm (as stipulated by DIN EN ISO 4288), but over the traversing length of 1.5 mm. This adapted method was employed in all the roughness measurements in the context of the invention.
[0016] In the case of deposition with silane, which is conducted at much lower temperatures (400-900° C.), flow rates (0.01 to 0.2 kmol/h of silane per 1 m 2 of rod surface area) and concentrations (0.5-2% silane in hydrogen), polysilicon rods consist of much smaller crystallites (0.01-0.5 μm). The surface of the rods is likewise matt gray and has roughness values Ra of 2.5-3.5 μm.
[0017] The morphology of the deposited rods may vary from compact and smooth (as described, for example, in U.S. Pat. No. 6,350,313 B2) up to very porous and fissured material (as described, for example, in US2010/219380 A1). The compact rods are more costly to produce, but often lead to better yields in subsequent crystallization steps.
[0018] Increasing the base parameters described above (temperature of the rods, specific flow rate, concentration) generally leads to an increase in the deposition rate and hence to an improvement in the economic viability for the deposition process. Each of these parameters, however, is subject to natural limits, exceedance of which disrupts the production process (according to the configuration of the reactor used, the limits are somewhat different).
[0019] If, for example, the concentration of the Si-containing component(s) selected is too high, there may be homogeneous gas phase deposition.
[0020] The effect of an excessively high rod temperature may be that the morphology of the silicon rods to be deposited does not become compact enough to provide a sufficient cross-sectional area for the current flow which rises with the growing rod diameter. If the current density becomes too high, this can cause silicon to melt.
[0021] In the case of rods of high diameter (from 120 mm upward), the choice of temperature is even more critical, since silicon in the rod interior, even in the case of compact morphology, can become liquid (because of the high temperature differentials between the surface and the rod center).
[0022] Customer demands on the product from the semiconductor and solar industries are also distinctly restricting the ranges for the process parameters. For example, for FZ applications, silicon rods that are very substantially free of cracks, pores, gaps, fissures, etc., and hence are homogeneous, dense and firm, are required. Moreover, these rods should preferably display an exceptional microstructure for a better yield in FZ pulling. A material of this kind and the process for production thereof are described, for example, in US2008/286550 A1.
[0023] For the production of recharging rods and what are called cut rods, which are used principally in the CZ process to increase the crucible fill level, likewise crack-free and low-tension raw polycrystalline silicon rods are required.
[0024] In the prior art, it is assumed that the microstructure of the polysilicon used is of no importance in CZ processes. In the mechanical manufacture of cut rods, FZ rods and recharging rods by means of sawing, the surface thereof is contaminated significantly. For this reason, these products generally then go through a cleaning step.
[0025] For most applications, polycrystalline silicon rods, however, are broken into small pieces, which are typically then classified by size. A process and a device for comminution and sorting of polysilicon are described, for example, in US 2007/235574 A1. In the processing to chunks, rods with cracks and further material defects are accepted as starting material. The microstructure of the polycrystalline rods is also not regarded as relevant in the prior art. The morphology of polycrystalline rods and of chunks formed therefrom, however, has a significant influence on the performance of the product.
[0026] Typically, a porous and fissured morphology has an adverse effect on the crystallization characteristics. This particularly affects the demanding CZ process, in which porous and fissured chunks were not usable because of the economically unacceptable yields.
[0027] Other crystallization processes (for example block casting, which is the most frequently used method for production of solar cells) are less sensitive to morphology. Here, the adverse effect of the porous and fissured material can be compensated for economically by the lower production costs thereof.
[0028] To improve the performance in downstream crystallization steps, silicon chunks formed in the comminution of silicon rods can be aftertreated. For example, the product quality can be increased by means of a cleaning step.
[0029] The cleaning, which is normally effected by wet-chemical means with one or more acids or acid mixtures (see, for example, U.S. Pat. No. 6,309,467 B1), is very inconvenient and costly, but generally improves the product properties. In the case of silicon chunks having porous or fissured morphology, the wet-chemical cleaning, however, cannot bring about any improvement in performance.
SUMMARY OF THE INVENTION
[0030] A problem addressed by the present invention was that of providing a novel inexpensive process for producing polycrystalline silicon, which alters the properties thereof such that a good pulling performance is enabled in downstream crystallization steps, especially in monocrystalline CZ applications. It would be particularly advantageous if the pulling performance of porous and fissured silicon rods or Si chunks formed therefrom is improved, because this material is the least expensive to produce. These and other problems addressed by the invention is solved by a polycrystalline silicon rod comprising an outer layer of polycrystalline silicon having a thickness of 0.01 to 20 mm, wherein said outer layer comprises crystallites having a mean size of more than 20 μm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 shows the microstructure of an inventive rod (at right angles to the rod axis).
[0032] FIG. 2 shows a comparison of the surface of inventive rods (left, shiny) and rods according to the prior art (right, matt).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] Preferably, the mean size of the crystallites of the outer layer is not more than 80 μm.
[0034] Preferably, the mean size of the crystallites of the outer layer is 25-60 μm, more preferably 30-60 μm, most preferably 35-55 μm.
[0035] Preferably, the polycrystalline silicon rod has a porous or fissured structure beneath the outer layer.
[0036] Preferably, the structure in the interior of the polycrystalline silicon rod is similar (thus, it has the same crystal structure, crystallite size etc. in the interior), comprising pores, gaps, clefts, cracks and fissures.
[0037] Preferably, the outer layer consists of crystallites having a mean size greater than the mean size of the crystallites beneath the outer layer. Preferably, the mean size of the crystallites beneath the outer layer is 1 μm to not more than 20 μm, more preferably 2-18 μm, and most preferably, 10-17 μm.
[0038] Preferably, the mean size of the crystallites of the outer layer is 25-80 μm and the mean size of the crystallites beneath the outer layer is 1-20 μm. More preferably, the mean size of the crystallites of the outer layer is 30-60 μm and the mean size of the crystallites beneath the outer layer is 1-25 μm.
[0039] Most preferably, the mean size of the crystallites of the outer layer is 35-55 μm and the mean size of the crystallites beneath the outer layer is 1-30 μm.
[0040] Preferably, the surface roughness is 4-10 μm, more preferably 5-8 μm.
[0041] The inventors have surprisingly and unexpectedly discovered that a change in the process parameters during a second step of the deposition leads to an improved product. The production of such a polycrystalline silicon rod envisages conducting the concluding part of the deposition process in the Siemens process, i.e. the second part of the deposition, under particular conditions.
[0042] Therefore, the problem addressed by the invention is also solved by a process for producing polysilicon by introducing a reaction gas comprising a silicon-containing component and hydrogen into a reactor, which results in deposition of polycrystalline silicon in the form of rods, characterized in that a temperature of the rods in a second step of the deposition is increased by at least 50° C. compared to a first step, where a concentration of the silicon-containing component in the reaction gas in the second step of the deposition is 5 mol % or less and a feed of the silicon-containing component is 0.25 mol per 1 m 2 of rod surface area or less.
[0043] Thus, the inventors have recognized that silicon rods and—after the comminution thereof—silicon chunks having advantageous properties for subsequent crystallization steps are the result when, in the last 0.1 to 50 hours, preferably 0.5 to 10 hours, of the deposition, which is effected with TCS or a mixture thereof with DCS and/or with STC, the process parameters in the second step are altered as follows:
the rod temperature is raised to preferably more than 1100° C., preferably to more than 1150° C., and by at least 50° C. as compared with the first step of the deposition, and the concentration of the silicon-containing component(s) (in total) is reduced to 5 mol % or less, preferably to 3 mol % or less, and the feed of the silicon-containing component(s) into the deposition reactor (in total) is reduced to 0.25 kmol/h per 1 m 2 of rod surface area or less, preferably to 0.1 kmol/h per 1 m 2 of rod surface area or less.
[0047] An outer layer which is formed under these conditions in the rods differs distinctly from the material in the rod interior and endows the product with favorable properties which have a positive effect on performance in subsequent crystallization steps.
[0048] This was surprising because it has been assumed to date in the prior art that the microstructure of the polycrystalline rods in the CZ process is unimportant. It was particularly surprising that even a thin surface layer of 0.01 to 20 mm with altered crystallite structure led to a distinctly better pulling performance.
[0049] The specific advantage of the invention is that the last layer having exceptional properties can also be applied to silicon rods having porous and fissured morphology, which have much lower production costs compared to the compact and smooth material. As a result, it is possible to use these rods, or silicon chunks which form in the breaking of inventive rods, in the subsequent crystallization without losses in yield and productivity.
[0050] This process according to the invention gives rise to polycrystalline silicon rods that are unknown as yet in the prior art. Their features include—as described above—an outer polycrystalline layer of thickness between 0.01 and 20 mm, preferably between 0.1 and 10 mm, most preferably between 0.1 and 5 mm, and a coarser microstructure compared to the inner deposited layers.
[0051] The polycrystalline silicon is preferably deposited onto filament rods of silicon heated by direct passage of current. A filament rod is formed from two vertical rods and one horizontal rod, the horizontal rod forming a connecting bridge between the vertical rods (=u-shaped support body).
[0052] The silicon-containing component used in the reaction gas is preferably TCS or a mixture of TCS and DCS or a mixture of TCS and STC.
[0053] Preferably, during the first step of the deposition, the passage of current through the filament rod is regulated such that the rod temperature is between 1000 and 1100° C. (at the same time, the temperature measured on the underside of the bridge is between 1300 and 1413° C.). The temperature of the reaction gases in the reactor is measured and adjusted such that it is at most 650° C., and the flow rate of the chlorosilane mixture is set to its maximum value within less than 30 hours, preferably within less than 5 hours, from commencement of the supply of the chlorosilane mixture.
[0054] FIG. 1 shows the microstructure of the outer region of the inventive polycrystalline silicon rod. In the right-hand part of FIG. 1 , a distinctly coarser microstructure of the outer layer is visible compared to the rod interior (left). The thickness of the outer layer is about 0.8 mm. The outer layer is formed by microcrystallites having a mean size of 30 μm or more, preferably 50 μm or more. The roughness of the surface Ra (measured to DIN EN ISO 4288, but over the shorter traversing length of 1.5 mm) is 5 mm or more.
[0055] In addition, the inventive rods preferably differ from those from the prior art in that they are shiny. FIG. 2 shows the inventive shiny rods A as compared with the matt gray rods B from the prior art.
[0056] A further feature that distinguishes the inventive polycrystalline silicon rods from the rods known in the prior art is their behavior toward acids.
[0057] When a known silicon rod (or a chunk formed therefrom, containing the outer surface of the original rod) is immersed into a 1:1 mixture of 20 to 30% HNO 3 and 2 to 3% HF, the formation of hydrogen bubbles is observed (in the case of the chunk, at the surface that originates from the surface of the original rod, i.e. not at the fracture surface) after just 160 seconds, whereas it only commences in the case of the inventive rod after 180 seconds.
[0058] The novel process has no effect on the fracture characteristics. The inventive polysilicon rod containing an outer coarsely crystalline layer can be comminuted like a known rod lacking this layer, providing the same chunk size distribution, the same sphericity and the same width/length ratio of the chunks as a known polysilicon rod.
[0059] A deposition process in which the coarsely crystalline layer is obtained repeatedly by the above-described readjustment of the process parameters, and polysilicon rods having a kind of onion-peel structure are thus produced, is also possible. It was found, however, that this process can only improve the pulling performance in a subsequent crystallization step slightly as compared with rods having an outer layer.
[0060] Preferably, the “deinstallation” or “harvesting” of silicon rods from the reactor is effected after the deposition has ended while a stream of a contamination-free gas is passed around the rods. This prevents contact of the ambient air with the rods. The contamination-free gas used is preferably nitrogen or a noble gas. Preference is given to using nitrogen or argon. With regard to the procedure in the purging of the reactor or of the rods with inert gas and the detailed technical configuration, U.S. Pat. No. 7,927,571 is fully incorporated by reference.
[0061] Preferably, deposited silicon rod pairs or support bodies are covered with sacks prior to deinstallation. The sacks consist preferably of a polymer film, more preferably a polyethylene film. This particular procedure in the deinstallation of the rods from the deposition reactor can further improve the performance of the polysilicon rods or chunks formed therefrom in downstream crystallization steps.
[0062] Preferably, the silicon rods, after being harvested from the reactor, are comminuted into chunks, dedusted and optionally cleaned. The dedusting is preferably effected as described in applications having application reference numbers EP11178284.3 and U.S. Ser. No. 13/197,977, U.S. published application 2012/0052297, which were yet to be published at the priority date of the present application, and are fully incorporated here by reference.
[0063] The invention also relates to a process for producing polysilicon by introducing a reaction gas comprising a silicon-containing component and hydrogen into a reactor, which results in deposition of polycrystalline silicon in the form of rods, characterized in that, after the deposition has ended, a stream of a contamination-free gas is passed around the polycrystalline silicon rods, and they are covered with a plastic sack and removed from the reactor.
[0064] The deposition of the polysilicon is preferably effected on a U-shaped support body composed of silicon. During the deposition, the reactor is sealed airtight. The U-shaped support body is heated up by direct passage of current. The reaction gas is introduced into the reactor through a feed line, as a result of which silicon is deposited from the reaction gas on the u-shaped support body and the diameter thereof increases. The result is a polycrystalline u-shaped rod pair.
[0065] Offgas formed in the deposition is removed from the reactor by means of a removal line. When the deposition has ended—if the desired diameter has been attained—the support body or the rod pair is cooled to room temperature. The reactor is opened and the support body is removed from the reactor.
[0066] Commencing with the opening of the reactor until the removal of the support body or of the rod pair from the reactor, a contamination-free gas is conducted through the feed line and the removal line into the opened reactor. Preferably, the contamination-free gas used is nitrogen or a noble gas. Preference is given to using nitrogen or argon. This prevents contact of the ambient air with the rods. With regard to the procedure in the purging of the reactor or of the rods with inert gas and the detailed technical configuration, U.S. Pat. No. 7,927,571 is fully incorporated by reference.
[0067] In addition, the support body or the rod pair is covered with a sack made from a plastic before the deinstallation. Preferably, the sacks used consist of a polymer film or of a polyethylene film. This special procedure in the harvesting of the rods from the reactor can improve the performance of the polysilicon rods or chunks produced therefrom in subsequent crystallization steps, as shown by Example 5.
EXAMPLES
[0068] The invention is illustrated hereinafter by examples and comparative examples. For this purpose, polycrystalline silicon rods were produced by various deposition processes. Subsequently, the silicon rods produced were comminuted into chunks. These were ultimately used in a CZ pulling process. The pulling performance was assessed with reference to the yield, which shows what percentage by weight of the polycrystalline material used was convertible to a usable dislocation-free single crystal.
[0069] In all the tests listed below, single silicon crystals were pulled by the same CZ pulling process (crucible weight 90 kg, crystal diameter 8 inches, crystal orientation <100>, pulling speed 1 mm/h). When other pulling processes are employed, these different materials behave similarly relative to one another, although the absolute yield numbers may be different according to the difficulty of the pulling process.
Example 1 (Comparative Example)
[0070] Compact polycrystalline silicon rods were deposited according to the prior art. The corresponding process is known from US 2010/219380 A1. The conditions corresponded to those disclosed in Comparative example 1. The mean crystallite size in the material deposited was about 11 μm. The roughness of the surface Ra was 3.6 μm. Finally, the rods—as described in US2007/235574 A1—were broken into chunks. This was followed by a wet-chemical treatment of the chunks, as disclosed in US2010/001106 A1. When this material was used in the above-described pulling process, it was possible to achieve a mean yield of 95.4%.
Example 2 (Comparative Example)
[0071] Here too, compact polycrystalline silicon rods were deposited according to the prior art (cf. US 2010/219380 A1, Comparative example 1).
[0072] As in Example 1, the mean crystallite size in the material deposited was 11 μm and the roughness of the surface Ra was 3.6 μm. Subsequently, the rods were broken into silicon chunks by a low-contamination method and dedusted. There was no wet-chemical treatment. With this material, it was possible to achieve a yield of 90.8% in the pulling operation.
Example 3 (Comparative Example)
[0073] Here, porous and fissured polycrystalline silicon rods were deposited according to the prior art (cf. US 2010/219380 A1, Example 1). The mean crystallite size in the material deposited was about 16 μm and the roughness of the surface Ra was 4.1 μm. Subsequently, the rods were broken into silicon chunks by a low-contamination method and dedusted. With this material, it was possible to achieve a yield of only 67.3%.
Example 4 (Comparative Example)
[0074] In this example, porous and fissured polycrystalline silicon rods were deposited according to the prior art (as described in US 2010/219380 A1, Example 1). As in Example 3, the mean crystallite size in the deposited material was 16 μm and the roughness of the surface Ra was 4.1 μm. Subsequently, the rods, according to US2007/235574 A1, were broken into silicon chunks, which were cleaned by wet-chemical means according to DE102008040231 A1. In the pulling of this material, the mean yield was 68.1%.
Example 5
[0075] In this example, the procedure was as in Example 2, with the difference that, after the deposition, polysilicon rods were covered with polyethylene sacks and deinstalled from the deposition reactor under a nitrogen atmosphere. This alteration surprisingly increased the yield in the single-crystal pulling operation by 2.1% to 92.9%.
Example 6
[0076] In this example, compact polysilicon rods were deposited. The deposition proceeded up to the diameter of 149 mm as described in US 2010/219380 A1 Comparative example 1. Then the process parameters were altered as follows: the rod temperature was raised by 120° C. to 1150° C., the TCS feed was lowered to 0.05 kmol/h per 1 m 2 of rod surface area and the TCS concentration to 4 mol %. These process parameters were maintained until the rods had attained the diameter of 150 mm.
[0077] The inventive rods obtained were shiny and had an outer layer of thickness 0.5 mm with a distinctly coarser microstructure. The mean crystallite size in the rod interior was 11 μm, and in the outer layer was 37 μm. The roughness of the rod surface had an Ra value of 5.1 μm.
[0078] Subsequently, the rods were broken into silicon chunks by a low-contamination method and dedusted. With this inventive material, it was possible to achieve a yield of 95.2% in the pulling operation.
Example 7
[0079] In this example, porous and fissured polycrystalline silicon rods were deposited. The deposition proceeded as far as 148 mm essentially as described in US 2010/219380 A1, Example 1. The rod temperature was 1075° C. At the same time, the temperature measured on the underside of the bridge as described therein was 1300 to 1413° C.
[0080] Then, the process parameters were altered as follows: the rod temperature was raised by 125° C. to 1200° C., the feed of the TCS/DCS mixture was lowered to 0.03 kmol/h per 1 m 2 of rod surface area and the TCS/DCS concentration to 3 mol %. These process parameters were maintained until the rods had attained the diameter of 150 mm.
[0081] The inventive rods obtained were shiny gray and had an outer layer of thickness 1.0 mm having a distinctly coarser microstructure. The mean crystallite size in the rod interior was 16 μm, and in the outer layer was 52 μm.
[0082] The roughness of the rod surface had an Ra value of 5.6 μm.
[0083] Subsequently, the rods were broken into silicon chunks by a low-contamination method and dedusted. With this inventive material, it was possible to achieve a yield of 93.2% in the pulling operation. | Polycrystalline silicon rods produced by the Siemens process produce a higher yield of CZ crystals when the process parameters are modified in a second stage of deposition such that an outer layer of larger crystallites having a mean swize>20 μm is produced. Harvesting of these polycrystalline rods and conventional rods by enclosing them in a plastic bag or sheath prior to removal from the reactor also surprisingly increase the yield of CZ crystals grown from a melt containing the sheathed rods. | 8 |
BACKGROUND OF THE INVENTION
The present invention refers to a ballistic ankle appliance for soccer-style kicking. For example, in the game of soccer, players and fans know that the number of goals in a match has always since the game, began been low or even zero. For example, in the game of soccer, discrepancy was again confirmed in the World Cup in Spain in 1982.
The modern game with new tactics has led to substantial modifications to the schemes for improved penetration of the opponent's defense. However, these expedients do not resolve the problem of low scoring. The spectators would prefer to see many goals, and are unsatisfied by matches with final scores of 0-0.
Of course, many shots miss due to reasons still not clearly understood. These reasons include causes other than the shooters inability, since even the most famous players commit errors as well.
The missing of shots due to causes other than a player's inability is a problem of prime importance which must be solved. It is insufficient for millions of paying customers to watch a soccer match with a good center field game and rousing rushes to goal, only to see the shots go off target.
The need to score more goals in order to have a more attractive game requires means to overcome this problem, arising from natural causes, with simple and effective devices.
SUMMARY OF THE INVENTION
One of the prime causes of the imprecision of the goal shots is due to the anatomic conformation of the human locomotion apparatus, precisely the part which essentially effects the shot.
An object of the present invention is thus to provide an ankle appliance capable of lessening the risk of deviations in the ball's trajectory due to the particular anatomic conformation of the foot-leg complex in making the shot.
A further object of this invention is to provide an ankle appliance which allows shots to be made with less physical force, but with improved effectiveness.
These and other objects are achieved by the present invention, which is a support member of web material adapted to be wrapped about an ankle and secured under the sole of the foot attached to said ankle, the support member, when wrapped and secured, being continuous band wrapped about the ankle, with a downwardly arched section extending across opposing portions of said band and secured under the sole of the foot, a flexible, elongated-rounded member portion, having two free ends, each end having a downwardly depending hook portion, the elongated rounded member being fixed to the outer periphery of the band and encircling the front part of said ankle just above a malleoli on each side of the ankle on the top of the instep of the foot and surrounding the back side of the malleoli when the support member is secured wrapped and, the elongated-rounded member being 15-25 mm in diameter.
The support member may be made of any material which may be put on the ankle, such as socks, spats or harness.
The elongated rounded member may be made of plastic or strands, preferably with a rounded cross section and shaped like a protruding arch on the ankle.
The elongated rounded member may be fixed to the support by means of strong stitching or gluing or by means of textile or mechanical type anchoring, as long as the device is safe both for the player who wears the device and for an opponent with whom he comes into contact during the game.
According to a preferred embodiment, the support member comprises an upper strip of flexible web material having two free ends and is adapted to surround the front side of the malleoli just above the ankle area and is provided with closure means at each of the free ends of the upper strip, two side strips of fabric material each extending downwardly fixed at an upper end thereof to the upper strip and depending downwardly therefrom and each of the strips having closure means at a lower end thereof, the closure means being adapted to join under the foot, said elongated-rounded member being fixed at a central portion thereof to the upper strip so that the free ends of the elongated-rounded member are each located approximately at a point along the upper strip where the upper end of one of the side strip is fixed, each of the free ends of the elongated rounded member being fixed to the upper strip at a different point thereon, so that the hook portions surround the malleoli when said support member is wrapped and secured. A preferred type of closing device is so-called "Velcro", consisting of two complementary elements of plastic material, one consisting of very fine hooks and the other of very fine eyelets.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be illustrated below in the description of one of its preferred embodiments, shown in an exemplificative and nonlimiting way, with reference to the attached drawing, in which:
FIG. 1 is a flat view of the object;
FIG. 2 is a side view of the device in FIG. 1 applied to the ankle of a soccer player;
FIGS. 3 to 7 show the ballistic functioning to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
To better understand the functioning of the present invention, the anatomical parts involved in shooting the ball and the consequent ballistic effects will be briefly described, referring first to FIGS. 3 to 7.
There are many causes of the imprecision of shots to the goal and it is impossible to describe them completely here, since it would require a long discussion of anatomy, static, barrycentric dynamic, as well as of emotional and psycho-physical conditions, not to mention the impediment of the opponent's defense.
Thus, the following is only a brief illustration.
The present analysis established that a principal cause of the shot's imprecision is due to the natural anatomic conformation of the areas known in football as the instep, which corresponds to the area including the lower quarter of the leg and the metatarsal, generally called the back of the foot.
In fact, the most famous players are those who can hit the ball with precision and power, using this particular area of the foot. The ballistic ankle appliance of the present invention assists in the proper striking of the ball with this area of the foot.
The back of the foot, in a more or less horizontal position with two arched surfaces at an angle to one another and with an inclination which rises from the front part to the rear, the leg with the front surface curved above the articulation, in a more or less vertical position, and the malleoli which protrude from the sides of the articulation form planes and reliefs differentiated from one another, which can cause the trajectory of the ball deviate many meters simply by shifting the striking point by only a few millimeters.
The discussion below is a technical analysis of a standing still shot, which is more demonstrative and simpler than a moving shot.
As a function of the angle of the striking parts of the foot and of the surface sector of the ball struck, different ballistic results are obtained.
With reference to FIG. 3, a ball is labelled with its cardinal point N, S, E, W, where N indicates the top. The relative position of the foot-leg is indicated in FIGS. 4-7 in three positions: 80° indicates an acute angle, 90° a right angle, and 100° an obtuse angle. This angling is approximate considering that the ball is lifted off the ground at the moment of the shot by the front part of the shoe and the back of the foot to reach the instep. For each of these positions, the ball can be struck at the height of a "parallel". FIG. 3 shows points A, B, C corresponding to three different parallels proceeding from N to S.
FIG. 4 shows the combined effect of the angle of the foot-leg complex and of the point of the ball struck; references A, B, C in FIG. 4 and the successive figures correspond to points A, B, C struck on the ball.
A central, corner and curve shots can vary in ballistic direction vertically and horizontally, depending on the foot-leg angle and the distance from the goal.
The goal shot is off when the ball, hitting the back of the foot with more or less force, is not counter-hit with equal intensity by the area just above the articulation. These anatomic parts, described above, being non-level, often cause the ball to slide on its axis, with consequent involuntary deviation in all directions.
The meridians SW, SSW, SSE, SE are also shown in FIG. 3, indicating the subequatorial areas of the ball which, when hit, cause a determined ballistic trajectory. When the ball is struck in the central meridian area NS, the shot is central and "clean", that is with no curve (FIG. 5). When it is hit in the SSW and SSE meridian area, the shot in "clean", but corner (FIG. 6). When the ball is struck in the SW and SE meridian area, the shot is curved (FIG. 7). As shown in the figures, the angling of the foot-leg complex determines the elevation.
From this description, in fairly simple terms, showing only some principal factors, one can understand how difficult a goal shot is.
A preferred embodiment of the present invention is described herein, with reference to FIGS. 1 and 2. The device according to the invention includes an elongated rounded member approximately 2 cm in diameter, indicated generically with 1, consisting of a single piece with one central part 2 arched to fit the curvature of the front and side part of the ankle and the two terminal parts 3 curved down and forward, so that it partially encircles the back side of the malleoli.
The member 1 is preferably made of a plastic material with a covering of suitably resistant material, preferably synthetic cloth, able to withstand, without lacerations and excessive wear and tear, the impact of the ball.
The member 1 is mounted fixed on a support element indicated generically with 4, to keep it in the desired position on the player's leg.
The support element 4 includes three strips of strong material, preferably synthetic, and more precisely a horizontal band indicated with 5, on which the cordon 1 is fixed, and two vertical side strips indicated with 6, parallel and set a predetermined distance apart, the upper ends of which are fixed to the horizontal band 5, for example by means of metal rivets 7, placed so as extend down to cover the respective malleoli when the ankle appliance is put on the ankle.
Both ends of the horizontal band 5 and the free ends of the two vertical side strips 6 have respective areas equipped with Velcro material, or fine hooks and eyelets 8. The horizontal band 5 is fixed by means of the Velcro material 8 in correspondence with the rear part of the ankle, while the free ends of the vertical strips 6 are fixed to one another below the sole of the foot.
The placement of the appliance according to the invention on one or both legs of a player is shown clearly in FIG. 2. The appliance is applied over sock 9 by joining the Velcro strips 8 in the manner described above, before the shoe 10 in put on.
The appliance according to the present invention does not injure the opponents during play, interfere with articulation or impede running. It affords considerable advantages both from a practical and functional point of view.
The cordon 1 assists in the making of a shot in all directions, since its protuberance gives a counter-shot to the ball already hit by the back of the foot.
The two curved ends 3 of the cordon 1 allow curved shots with to be achieved with a only alight torsion of the limb. The effect is an advantage for the ligaments for articulating the foot, knee and leg, since it restricts the need rotate the trunk and leg. Rotation leads, in relation to the power of the shot, to continuous micro-traumas in the articulation area, which in the long term become pathological lesions.
The two vertical strips 6 of the support member 4, as well as the above-mentioned curved ends 3 of the member 1, also provide protection for the two malleoli in case of any collisions.
This invention is not limited to the embodiment described, but includes all variants. | An appliance to be applied to the ankle of one or both legs of a soccer-style kicker to improve the trajectory of the kicked ball, involving a relatively rigid cordon-like member, with an arched shape so as to surround the front part of the ankle and with the ends curved down and forward so as to partially surround the back side of the malleoli (FIG. 2). | 8 |
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Patent Application No. 61/614,794 filed Mar. 23, 2012 and U.S. Provisional Patent Application No. 61/495,100 on Jun. 9, 2011, the entireties of which applications are hereby incorporated by reference into this application.
BACKGROUND OF THE INVENTION
Conventional supports provide a polyester filled or foam boot for support of a lower leg. Other conventional supports include an ankle foot orthotic (AFO) or foot wrap. Another conventional support includes an air chamber in a boot configuration. The air chamber supports a leg and heel above a surface of a bed patient when lying in a supine and side lying position, such as in a hospital bed.
The conventional supports have the disadvantage that pressure is applied to the heel or leg for maintaining the heel above the surface of the bed. In addition, the leg can be raised too high such that joints can lock, nerves can be potentially entrapped and the circulation to the leg can be compromised. In addition, the intraluminal pressure of conventional supports minimizes its ability to contour to the object applying the force.
Sequential or intermittent compression devices have been described which include inflatable sleeves. The sleeve is placed over the leg or foot. Pressure modulation is used in order to reduce risk of clot formation in the leg or foot.
It is desirable to provide a sequential or intermittent compression device in combination with a lower leg protection system for supporting the leg and heel when a patient is recumbent while maintaining neutral leg alignment without lifting the leg and heel from the resting surface.
SUMMARY OF THE INVENTION
The present invention relates to a support for a body part including a compression device in combination with a lower leg protection system. The compression device can be inflated sequentially or intermittently. The compression device can be inlaid into a support boot and attached to the boot with a flexible material. A valve is combined with the compression device for increasing and reducing pressure within the compression device in a sequential or intermittent manner. It is optimal to barely elevate the heel from the surface of the bed. This helps to minimize leg rotation and locking of the knee.
In one embodiment, the compression device is combined with a fluidized lower protection system including an inner positioner and an outer support. The inner positioner includes a bladder, preferably filled with a fluidized particulate material, to provide three-dimensional contouring to the lower leg and heel. The inner positioner has low pressure and is not sufficient alone to support the leg. The inner positioner has little or no flow characteristics unless an outside force is applied other than gravity. The inner positioner can displace and contour three-dimensionally as though it was fluid to the sides and top of the leg while not having flow characteristics that would result in migration of the medium under the force of gravity. The inner positioner can provide three-dimensional contouring to the Achilles tendon. The inner positioner can include a temperature regulating material for keeping the leg in an optimal range of skin temperature to keep the leg comfortable longer. The inner positioner can be shaped as a pad to mold to the underside portion of the lower leg and heel. Alternatively, the inner positioner can include various shapes to support the lower leg and heel. In one embodiment, the inner positioner also includes a portion which extends over a top portion of the leg, such as the shin.
The outer support is received over the inner positioner. The outer support can be in the shape of an open boot. In one embodiment, the compression device can be integral with the outer support at a position received over the lower leg. One or more valves can extend from a compression bladder for attachment to a pneumatic device. Inflation of the compression bladder positioner adjacent the lower leg also displaces air in the outer support toward the foot which causes simultaneous massaging of the foot. The pneumatic device can be adjusted to provide either sequential or intermittent therapies.
The outer support can include an ultra low pressure plenum. The ultra low pressure plenum is filled at a predetermined low pressure for distributing pressure along the length of the outer support, but not providing significant elevation of the lower leg and heel by itself. In this embodiment, the inner positioner is partially filled with the fluidized particulate material so it cannot support a leg on its own. For example, the inner positioner can be filled up to ⅔ of its capacity. The outer portion of the inner positioner contours to the inner portion of the ultra low pressure plenum for providing more air displacement of the outer support than if the inner positioner was not present.
In one embodiment the system is strapless. In an alternate embodiment, the system includes a strap for attachment of the outer support to the leg. The strap can be sufficiently wide and cushioned to protect the skin. In one embodiment, the strap is air bearing. In one embodiment, a rear end of the outer support includes a gate, which can be opened to allow access to the foot and heel from the rear of the boot.
The inner positioner or outer support can include a fluidized thermal regulating medium. In one embodiment, a phase change material can be used for adjusting the temperature of the system.
The system of the present invention can be a one size fits all and adapts to the size and shape of a patient's leg. The system maintains neutral alignment and helps prevent foot drop. The system gently but securely wraps the leg, helping to maintain constant heel position. The system promotes proper dorsiflexion without causing undue pressure on the lower limb.
The combination of the inner positioner including a fluidized medium along with the outer support including a ultra low pressure plenum creates sufficient support of the lower leg while responding to normal patient movement. The combination of the inner positioner and the outer support provides three-dimensional contouring to the lower leg and heel for micro adjustment while the outer support or boot is closed for minimizing friction and shear. This is not possible in conventional devices where the inner chamber is not free to communicate with the leg without negatively affecting the functionality of the outer chamber. In general, the custom fitting protection can be used in such a way as to elevate the foot without “locking out the knee” due to three-dimensional molding and provide comfort to the skin. The natural contour of the leg can be maintained while eliminating harmful pressure to the heel, ankle, Achilles and foot. The system of the present invention can respond to the twisting of the leg without causing movement of the outer support. The system of the present invention can minimize shear forces that would be associated with a non-fluidized medium.
The invention will be more fully described by reference to the following drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a side schematic diagram of an embodiment of a compression device in combination with a fluidized lower leg protection and support system including an outer support.
FIG. 1B is a rear schematic diagram of the compression device in combination with a fluidized lower leg protection and support system including an outer support, as shown in FIG. 1A .
FIG. 2 is a schematic diagram of the embodiment of the compression device in combination with a fluidized lower leg protection and support system shown in FIG. 1A from an opposite side.
FIG. 3 is a schematic diagram of the embodiment of the compression device in combination with a fluidized lower leg protection and support system shown in FIG. 1A from a rear side.
FIG. 4 is a schematic diagram of the embodiment of the compression device in combination with a fluidized lower leg protection and support system shown in FIG. 1A from a rear side in an open position.
FIG. 5 is a schematic plan view of the embodiment of the compression device in combination with a fluidized lower leg protection and support system shown in FIG. 1A .
FIG. 6 is a schematic diagram of an alternate embodiment of the compression device in combination with a fluidized lower leg protection and support system including an outer support and support strap.
FIG. 7 is a schematic diagram of an alternate embodiment of the compression device in combination with a fluidized lower leg protection and support system including an outer support, support strap and ankle strap.
FIG. 8 is a schematic diagram of the embodiment of the compression device in combination with a fluidized lower leg protection and support system shown in FIG. 7 from an opposite side.
FIG. 9 is a schematic diagram of an alternate embodiment of the compression device in combination with a fluidized lower leg protection and support system including an opening between side portions of the outer support.
FIG. 10A is a top perspective view of an alternate embodiment of the compression device in combination with a fluidized lower leg protection and support system in a fully open position.
FIG. 10B is a bottom perspective view of the embodiment shown in FIG. 10A .
FIG. 11 is a top perspective view of the embodiment of FIG. 10A including an inner positioner.
FIG. 12 is a top perspective view of the embodiment of FIG. 11 in which the rear end of the compression device in combination with a fluidized lower leg protection and support system is closed.
FIG. 13 is a top perspective view of the embodiment of FIG. 12 in which a lower leg is placed adjacent the rear end of the compression device in combination with a fluidized lower leg protection and support system.
FIG. 14 is a top perspective view of the embodiment of FIG. 13 in which a flap of the compression device in combination with a fluidized lower leg protection and support system is closed over the received lower leg.
FIG. 15 is a top plan view of a valve extending through the compression device in combination with a fluidized lower leg protection and support system for attachment to the compression device.
FIG. 16 is a schematic diagram of the compression device including a plenum providing low air loss.
DETAILED DESCRIPTION
Reference will now be made in greater detail to a preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.
FIGS. 1-5 illustrate an embodiment of a compression device in combination with a lower leg protection and support system 30 .
Compression system 40 is combined with fluidized lower leg support system 50 . In one embodiment, compression system 40 can be inlaid into lower leg protection and support system 50 and attached thereto with coupling member 42 . Lower leg protection and support system 50 can be a conventional support boot. In one embodiment, lower leg protection and support system 50 includes outer support 52 and inner positioner 14 . Compression system 40 can include bladder 44 attached with coupling member 42 to outer support 52 . Valve 46 can be associated with compression system 40 for inflating and deflating compression system 40 in a sequential or intermittent manner.
Outer support 52 can include a plurality of rows of parallel ultra low pressure plenums 53 . For example, ultra low pressure plenums 53 can be positioned within outer support 52 along the length L 1 of outer support 52 . Flap 54 can extend over front of lower leg 16 . Flap 54 can include ultra low pressure air plenums 55 , which protect lower leg 16 from strap 56 . Flap 54 can also provide anti-rotation of fluidized lower leg protection and support system 50 . Strap 56 can be adjustable for closing flap 54 for different sizes of legs. Strap 54 can include a coupling portion 57 at one end thereof for attaching to attachment section 58 . Strap 56 can include a cushioning material. In one embodiment, strap 56 is air bearing. Coupling portion 57 can be formed of a hook and loop material. Attachment section 58 can be formed of a hook and loop material. Attachment section 58 can be positioned along length L 1 of outer support 52 . Outer support 52 can be received under U-shaped base 59 , as shown in FIG. 3 . U-shaped base 59 provides anti-rotation of outer support 52 . Air pressure within ultra low pressure plenum 53 is reduced sufficiently to provide reduced pressure for conforming outer support 52 to the shape of lower leg 16 and optionally heel 17 for distributing pressure along the length of outer support 52 , but is not providing support of lower leg 16 and heel 17 .
Inner positioner 14 is formed of bladder 13 including fluidized material 15 therein which can retain its shape after sculpting. Fluidized material 15 can be a particulate material including interstitial spaces between the particles. A lubricant can be present in the interstitial spaces. For example, the lubricant can be a particulate material having a lower coefficient of friction, such as a powder. The volume of the particulate material can be controlled for controlling the interstitial air within the fluidized medium.
Bladder 13 is filled with fluidized material 15 which can retain its shape after sculpting. The flowability or lubricity of fluidized material 15 can be increased by adding a lubricant or by the removal of air from the interstitial spaces or both. The preferred medium of fluidized material 15 is a particulate material that has been modified in such a way that it acts like a fluid Fluidized material 15 refers to a compound or composition which can be sculpted and retain its shape and has no memory or substantially no memory. The no memory or substantially no memory feature enables bladder 13 to increase in height and maintain support of a body part. Fluidized material 15 is made of a viscosity that will allow it to contour but not collapse under the weight of the body part.
At sea level, the normal interstitial air pressure would exceed about 760 millibars of mercury. This increases or decreases marginally as altitude varies. Depending on the nature of the particulate fluidized material 15 , the pressure can be lowered below about 500 millibars, preferably, about 350 millibars to about 5 millibars, while still maintaining the necessary flow characteristics of the product. The amount the pressure is lowered is dependent on the interstitial spaces needed to provide desired flow characteristics of the product.
Fluidized material 15 can include beads, such as polyethylene or polystyrene (PS) beads, expanded polyethylene (PE), crosslinked expanded polyethylene (PE), polypropylene (PP) pellets, closed cell foams, microspheres, encapsulated phase changing materials (PCM). The beads can be hard shelled or flexible. In one embodiment, the beads are flexible and air can be evacuated from the beads. In one embodiment, hard beads can be mixed with flexible beads in which air can be evacuated from the flexible beads. In an alternative embodiment, fluidized material 15 can a porous foam substance including pockets of interstitial air. In one embodiment, fluidized material 15 can be a polyurethane foam. The polyurethane foam can be open or closed cell and cut into small shapes such as spheres or blocks. For example, a sphere of polyurethane foam can have a size of 2 inches in diameter. For example, a block of polyurethane foam can be a 1×1×1 inch block.
Suitable examples of fluidized material 15 can be formed of a mixture of microspheres and lubricant. The microspheres can include hollow or gas-filled structural bubbles (typically of glass or plastic) with an average diameter of less than 200 microns. The composition flows and stresses in response to a deforming pressure exerted on it and the composition ceases to flow and stresses when the deforming pressure is terminated. For example, fluidized material 15 can be formed of a product referenced to as Floam™. A flowable compound comprising lubricated microspheres, including the compound itself, formulations for making the compound, methods for making the compound, products made from the compound and methods for making products from the compound as defined by U.S. Pat. Nos. 5,421,874, 5,549,743, 5,626,657, 6,020,055, 6,197,099, and 8,171,585, each of which is hereby incorporated by reference into this application. Bladder 13 provides micro-contouring because fluidized material 15 can respond three-dimensionally.
For example, bladder 13 can be formed of a flexible plastic, such as urethane. Upon removal of residual air from fluidized material 15 bladder 13 flows concurrent with the flow of fluidized material 15 such that bladder 13 moves with movement of fluidized material 15 . Bladder 13 can have a size and shape to support lower leg 16 and heel 17 of a user. Bladder 13 can include portion 18 which extends over top portion 19 of lower leg 16 . Optionally, air can communicate throughout the whole bladder 13 for allowing maximum contouring and functional displacement of both the air and the fluidized chamber thereby providing maximum contouring to a desired body part.
Inner positioner 14 or outer support 52 can include thermo-regulating medium. Thermo-regulating medium can be a phase change material for adjusting the temperature to adapt support system 10 to temperature changes of a body part of a user. Thermo-regulating material can be associated with fluidized material 15 or cover (not shown) placed over inner positioner 14 . An example material for thermo-regulating material is manufactured by Outlast Technologies as fibers, fabrics, and foams comprising micro-encapsulated phase changing materials referred to as Thermocules, which store and release heat as further described in U.S. Pat. Nos. 7,790,283, 7,666,502 and 7,579,078, hereby incorporated by reference into this application.
For example, the pressure in ultra low pressure plenum 53 can be below 20 mm of water. It will be appreciated that all equivalents such as mm Hg and PSI can be used for measuring the pressure within ultra low pressure plenum 53 .
The pressure within ultra low pressure plenum 53 can be below about 20 mm of water if no inner positioner is used or if an area of less than about 30% of outer support 52 is covered by inner positioner 14 . The pressure within ultra low pressure plenum 54 can be below about 10 mm of water if an area of between about 30% to about 60% of outer support 52 is covered by inner positioner 14 . The pressure within ultra low pressure plenum 53 can be below about 5 mm of water if an area of greater than about 60% of outer support 52 is covered by inner positioner 14 .
Rear end 60 of outer support 52 can include overlapping flap members 62 and 63 for forming a gate to allow access to foot 19 including heel 17 , as shown in FIGS. 3A-3B . Flap members 62 and 63 can include respective coupling portions 64 and 65 for attaching flap members 62 and 63 to one another. For example, coupling portions 64 and 65 can be formed of a hook and loop material. Flap members 62 and 63 can be opened to allow access to foot 19 , as shown in FIG. 4 .
FIG. 6 illustrates an alternate embodiment of a fluidized lower leg protection support system 70 , including support strap 72 . Support strap 72 can extend around rear end 60 for providing support, for example, in supporting a patient with foot drop. Support strap 72 can include coupling portion 77 at one end thereof. Coupling portion 77 can be formed of a hook and loop material. Coupling portion 77 can attach to attachment section 58 .
FIGS. 7 and 8 illustrate an alternate embodiment of a fluidized lower leg protection and support system 80 . Support strap 82 can include coupling portion 87 at one end thereof. Coupling portion 87 can be formed of a hook and loop material. Coupling portion 87 can attach to attachment section 88 . Attachment section 88 can be positioned circumferentially around top portion 89 . Coupling portion 87 can be coupled at various locations on attachment section 88 . Ankle strap 92 can attach to attachment section 94 . Ankle strap 92 can include coupling portion 93 at one end thereof. Coupling portion 93 can be formed of a hook and loop material. Attachment section 94 can be formed of a hook and loop material. Ankle strap 92 can be positioned above ankle 95 . Attachment section 94 can be positioned adjacent or below ankle 95 .
FIG. 9 illustrates an alternate embodiment of a fluidized lower leg protection and support system 100 which includes opening 102 between side portions 103 and 104 for allowing air to contact lower leg 16 and allowing cooling of lower leg 16 while providing support. Straps 105 and 106 can attach to respective attachment sections 107 and 108 . Straps 105 and 106 can include coupling portion 109 at one end thereof. Coupling portion 109 can be formed of a hook and loop material. Attachment section 107 and 108 can be formed of a hook and loop material.
Inner positioner 14 described above can be used with each of the fluidized lower leg protection and support systems 50 , 70 , 80 and 100 . In one embodiment, inner positioner 14 is positioned horizontally at ankle 19 and wraps around the Achilles to protect the ankle.
FIGS. 10-15 illustrate leg protection and support system having compression 200 . Outer support 202 includes one or more of parallel rows of ultra low pressure plenums 203 forming outer support bladder 201 . For example, ultra low pressure plenums 203 can be positioned within outer support 202 along the length L 1 of outer support 202 . Flap 204 can include ultra low pressure air plenums 205 .
Compression bladder 214 can be positioned on inner surface 215 of outer support 202 , as shown in FIG. 10A . Compression bladder 214 can be integral with outer support 202 in which compression bladder is joined at edges 216 of outer support bladder 201 . Support bladder 214 can extend into flap 204 .
Valve 210 extends through outer support 202 to provide access to end 211 of valve 210 , as shown in FIG. 10B and FIG. 11 . End 212 of valve 210 extends into compression bladder 214 . Valve 220 extends through flap 204 of outer support 202 to provide access to end 221 of valve 220 . End 222 of valve 220 extends into flap 204 .
Rear end 230 of outer support 202 can include flap members 232 and 233 , as shown in FIGS. 10A-10B . Flap members 232 and 233 can include respective coupling portions 234 and 235 for attaching flap members 232 and 233 to one another. In one embodiment, coupling portion 234 is attached to inner surface 237 of flap member 232 and coupling portion 235 is attached to outer surface 238 of flap member 233 , as shown in FIG. 12 . For example, coupling portions 234 and 235 can be formed of a hook and loop material.
During use, inner positioner 14 can be placed over outer support 202 , as shown in FIG. 12 . Flap members 232 and 233 are attached to one another for closing leg protection and support system having compression 200 and forming foot and heel support portion 240 of outer support 202 , as shown in FIG. 13 . Lower leg 16 is received in leg protection and support system having compression 200 adjacent to heel support 240 , as shown in FIG. 14 . Inner positioner 14 provides three dimensional contouring to the received lower leg 16 and heel 17 . Flap 204 can be closed over lower leg 16 , as shown in FIG. 15 . Strap 206 can be adjusted for closing flap 204 . End 221 of valve 220 can be connected to compression device 250 . Compression device 250 can provide pneumatic pressure for inflating and deflating compression bladder 214 in a sequential or intermittent manner.
FIG. 16 illustrates an alternate embodiment of compression device in combination with lower leg support system 1000 . Outer support 1001 of system 1000 has a three layer construction. Top layer 1020 , intermediate layer 1030 and bottom layer 1040 are sealed to one another along outside edge 1050 . For example, top layer 1020 , intermediate layer 1030 and bottom layer 1040 can be formed of urethane.
Plenum 1100 formed between top layer 1020 and intermediate layer 1030 can include dynamic air. Air 1150 is pumped into plenum 1100 through valve 1110 by pump 1120 . Air 1150 is pumped beneath top layer 1020 . Top layer 1020 is perforated with apertures 1180 . Plenum 1100 provides a dynamic amount of air to system 1000 for adjusting the amount of air in plenum 1140 and providing low air loss.
Plenum 1140 formed between bottom layer 1040 and intermediate layer 1030 can include a fixed amount of static air. In one embodiment, plenum 1140 is filled with an ultra low pressure of a pressure of about 500 millibars through about 10 millibars or in some cases even lower pressures can be used. Valve 1160 can be used to adjust the pressure in plenum 1140 .
It is to be understood that the above-described embodiments are illustrative of only a few of the many possible specific embodiments, which can represent applications of the principles of the invention. Numerous and varied other arrangements can be readily devised in accordance with these principles by those skilled in the art without departing from the spirit and scope of the invention. | The present invention relates to a support for a body part including a compression device in combination with a lower leg protection system. The compression device can be integral with the outer support at a position received over the lower leg. One or more valves can extend from a compression bladder for attachment to a pneumatic device. Inflation of the compression bladder positioner adjacent the lower leg also displaces air in the outer support toward the foot which causes simultaneous massaging of the foot. The pneumatic device can be adjusted to provide either sequential or intermittent therapies. | 0 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention generally relates to an apparatus and methods for drilling, completion and rework of wells. More particularly, the invention relates to an apparatus and methods for activating and releasing downhole tools. More particularly still, the invention provides a hydraulically activated downhole tool.
2. Description of the Related Art
In the drilling of oil and gas wells, a wellbore is formed using a drill bit that is urged downwardly at a lower end of a drill string. After drilling a predetermined depth, the drill string and bit are removed, and the wellbore is lined with a string of steel pipe called casing. The casing provides support to the wellbore and facilitates the isolation of certain areas of the wellbore adjacent hydrocarbon bearing formations. The casing typically extends down the wellbore from the surface of the well to a designated depth. An annular area is thus defined between the outside of the casing and the earth formation. This annular area is filled with cement to permanently set the casing in the wellbore and to facilitate the isolation of production zones and fluids at different depths within the wellbore.
It is common to employ more than one string of casing in a wellbore. In this respect, a first string of casing is set in the wellbore when the well is drilled to a first designated depth. The well is then drilled to a second designated depth, and a second string of casing, or liner, is run into the well to a depth, whereby the upper portion of the second liner is overlapping the lower portion of the first string of casing. This process is typically repeated with additional casing strings until the well has been drilled to total depth. To properly place the additional casing strings within the wellbore, the end of the existing casing must be determined. A downhole tool, such as a tubing end locator, is typically employed to accurately locate the end of the existing casing.
Typically, a conventional tubing end locator is run downhole on a tubing string. The end of the tubing is indicated when the tubing end locator runs out the end of the tubing and is then brought back uphole, thus shearing the finger and indicating the depth of the tubing. Therefore, conventional tubing end locators employing calipers, fingers or other protrusions are capable of only reading the end of the tubing once, and thus yield a low level of accuracy as to the depth of the tubing. Consequently, when a conventional tubing end locator is run downhole and brought back uphole at the tubing end, the caliper or finger is sheared completely off thus indicating the end of the tubing and destroying the caliper or finger and requiring the tubing end locator to be brought back uphole to be re-worked or retooled.
A conventional tubing end locator may also be used to locate a preformed inner diameter profile, a collar or a nipple in an existing downhole casing. Conventional tubing end locators implement calipers or fingers which extend vertically upward and outwardly from the tubing end locator such that each caliper or finger is spring loaded and exerts an external pressure against the internal diameter and circumference of the tubing. Each caliper or finger deflects at each inner diameter profile juncture, thus indicating the location of the preformed profile, collar or nipple is located.
Another form of a conventional tubing locator employs the use of bow springs to locate a preformed inner diameter profile, a collar or a nipple in an existing downhole casing. The locator tool includes high compressive springs and a set of bow springs extending radially from a mandrel on the tool. The bow springs extend vertically, longitudinally and radially outward from the mandrel thus contacting the internal circumference and surface of the casing or tubing, and establishing a constant internal resistance detected uphole at the surface. When the bow springs contact a preformed inner diameter profile, a collar, a nipple or tubing end, the bow springs will move either upwardly towards the surface at each collar indication, or downwardly towards the end of the tubing at each tubing end indication.
Several problems may occur using a conventional tubing locator during a locator operation. One problem occurs when an excessive overpull is applied at the surface of the well during the location of the preformed inner diameter profile, collar, nipple or tubing end. In this case, the conventional tubing locator does not provide a failsafe mechanism that allows the locator tool to release and reset after applying the excessive overpull. Another problem occurs during the indication phase of the locator operation. After the conventional tubing locator has located the profile or tubing end, an overpull indication must be detectable at the surface of the well. However, the conventional tubing locator tool is unable to withstand an overpull that is easily detectable at the surface, therefore unable to accurately to determine the location of the profile.
Other downhole tools are used throughout the well completion process. One such downhole tool is a conventional under-reamer. Generally, the conventional under-reamer is used to enlarge the diameter of wellbore by cutting away a portion of the inner diameter of the existing wellbore. A conventional under-reamer is typically run down hole on a tubing string to a predetermined location with the under-reamer blades in a closed position. Subsequently, fluid is pumped into the conventional under-reamer and the blades extend outward into contact with the surrounding wellbore. Thereafter, the blades are rotated through hydraulic means and the front blades enlarge the diameter of the existing wellbore as the conventional under-reamer is urged further into the wellbore.
The conventional under reamer may also be used in a back-reaming operation. In the same manner as the under-reaming operation, the fluid is pumped into the under-reamer and the blades extend outward into contact with the surrounding wellbore. Thereafter, the blades are rotated through hydraulic means and the back blades enlarge the diameter of the existing wellbore as the under-reamer is urged toward the surface of the wellbore.
Several problems may occur using a conventional under-reamer during an under-reaming or back-reaming operation. One problem occurs when an unmovable obstruction is encountered during the under-reaming or back-reaming operation. In this situation, the front or the back blades on the conventional under-reamer may be damaged as the under-reamer is urged furthered toward the unmovable obstruction. Another problem is particularly associated with the back-reaming operation. During the back-reaming operation, the blades must remain open and the under-reamer must be able to withstand a strong pulling force to effectively remove a portion of the existing wellbore diameter. However, the conventional under-reamer typically is unable to remain open during a back-reaming operation to effectively enlarge the wellbore diameter.
A need therefore exists for apparatus with a hydraulic valving system that provides a failsafe mechanism that allows the apparatus to withstand a sufficient overpull while permitting the apparatus to release and reset after applying an excessive overpull. There is yet a further need for an apparatus with a hydraulic valving system that will provide a failsafe mechanism that allows the apparatus to close when an unmovable obstruction is encountered. There is a final need for an apparatus with a hydraulic valving system that ensures the apparatus will remain open during a back-reaming operation.
SUMMARY OF THE INVENTION
The present invention provides a method and an apparatus for use in a wellbore tool. The apparatus includes a body having a center bore and at least one side port permitting fluid communication between the bore and an annular area between the tool and the wellbore. The apparatus further includes a sliding member, wherein the sliding member moves between a first position and a second position and a valve assembly that causes the sliding member to shift to its second position at a predetermined flow rate of fluid through the body. The apparatus also includes a mechanical portion movable with the sliding member between the first and second positions.
In another embodiment, the invention provides for an apparatus for a downhole tool that includes a mandrel, a plurality of ramped sections radially disposed around the mandrel and a plurality of longitudinal grooves radially disposed between the plurality of ramped sections. The invention further includes a sliding member disposed on the mandrel, the sliding member movable between a first and second position the sliding member including a plurality of fingers and a plurality of heads, wherein the plurality of fingers are slideably recessed within the plurality of longitudinal grooves.
In another embodiment, the invention provides a collet assembly for use in a wellbore, the collet assembly includes a body and at least two extendable members movable independent of the body, the members are extendable outwards. The collet assembly further includes a sliding member attached to each member, the sliding member remotely movable between a first and second position. The collet assembly also includes a ramp formed on the body whereby, the members are urged along the surface to extend outwards and as the members are extended outwards, the members are rotated.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 illustrates a cross-sectional view of one embodiment of an apparatus in accordance with the present invention.
FIG. 1A is a side view of the collet fingers and the collet head.
FIG. 1B is a section view of FIG. 1A illustrating the collet fingers disposed in the grooves.
FIG. 2 is an enlarged cross-sectional view of apparatus illustrating the flow of fluid though the apparatus prior to the actuation of the collet.
FIG. 3 is a cross-sectional view of the apparatus after the collet head has expanded outward into contact with a tubular.
FIG. 3A is a side view of the collet fingers and the collet head illustrating the collet head expanded outward.
FIG. 4 is an enlarged cross-sectional view of the apparatus illustrating the activation of a relief valve.
FIG. 5 is a cross sectional view of an alternative embodiment of the collet for use with the apparatus.
FIG. 5A is a bottom view of the embodiment shown on FIG. 5 .
FIG. 6 is a cross sectional view illustrating the radial expansion of the collet.
FIG. 6A is a bottom view of the embodiment shown on FIG. 6 .
FIG. 7 is a cross sectional view of another embodiment of the apparatus in accordance with the present invention.
FIG. 8 illustrates a cross sectional view of the apparatus after the blades have expanded outward.
FIG. 9 is an enlarged cross-sectional view of apparatus illustrating the activation of the relief valve.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 illustrates a cross-sectional view of one embodiment of the invention used with a locator tool 100 . Typically, the locator tool is run into the wellbore on tubing string to a predetermined point. Thereafter, the locator tool is activated causing fingers to expand radially outward and then locator tool is slowly pulled upward in the wellbore to find a preformed profile within an existing tubular. When a weight gage shows an increase in overpull, the locator tool will be located in the profile.
As shown in FIG. 1, the tool 100 includes a top sub 105 . The top sub 105 includes an internal threaded section 130 to accept a tubing string (not shown). The top sub 105 further includes a shoulder 110 at a lower end to be used as a stop during operation of the tool 100 . The top sub 105 is connected to an upper portion of a mandrel 115 or body via another threaded connection. As illustrated, the mandrel 115 runs the entire length of tool 100 . The mandrel 115 includes a bore 295 to act as a fluid conduit through the tool 100 .
A spring housing 120 is disposed at the upper end of the mandrel 115 . The spring housing 120 includes a spring housing shoulder 125 to abut shoulder 110 during operation of the apparatus 100 . The spring housing 120 encloses a relief valve 330 . In this embodiment, the relief valve 330 includes a first biasing member 145 , an upper piston 135 , and a ball 140 . However, other forms of relief valves may be employed, so long as they are capable of selectively controlling fluid flow. The main function of the relief valve 330 is to provide a means of releasing fluid from a chamber 325 when fluid pressure within the chamber 325 reaches a predetermined level. As shown, the first biasing member 145 is disposed between the spring housing 120 and the mandrel 115 and biases the movement of the upper piston 135 . Upon a fluid force the ball 140 acts against the upper piston 135 , thereby urging the upper piston 135 axially in the spring housing 120 . The spring housing 120 further includes a spring housing passageway 305 to allow fluid to exit apparatus 100 .
FIG. 1 further illustrates a housing 155 or sliding member disposed around mandrel 115 . The housing 155 is movable between a first and a second position. The housing 155 includes a housing passageway 255 that acts a conduit for fluid to activate the relief valve 330 . An upper seal 150 is disposed between the mandrel 115 and the housing 155 and creates a fluid tight seal between the mandrel 115 and the housing 155 , thereby preventing fluid from traveling out the mandrel 115 . Additionally, a chamber shoulder 165 is formed in the housing 155 to be later used to urge the housing 155 axially upward.
An upper dog 170 is disposed around mandrel 115 below the chamber 325 . The upper dog 170 secures a lower piston housing 180 to the mandrel 115 . The lower piston housing 180 is disposed beneath a portion of housing 155 and encloses a one-way check valve 160 . In the preferred embodiment, the check valve 160 is a unidirectional pressure energized seal. However, other forms of the check valves may be employed, so long as they are capable of selectively controlling fluid flow. The primary function of the one way check valve 160 is to permit fluid flow from a port 185 into an inner passageway 260 while preventing fluid exiting the inner passageway 260 to the port 185 .
As shown on FIG. 1, the port 185 in the mandrel 115 permits fluid from the mandrel passageway 295 to pass through the check valve 160 and subsequently in to the inner passageway 260 that is formed between the lower piston housing 180 in the mandrel 115 . The inner passageway 260 connects the check valve 160 to the chamber 325 and then to an outer passageway 175 . The outer passageway 175 is formed between the lower piston housing 180 and the housing 155 . The lower piston housing 180 further includes an aperture 205 that connects to the outer passageway 175 to an inner portion of the lower piston housing 180 .
The inner portion of the lower piston housing 180 contains a low flow valve 210 . The primary function of the low flow valve 210 is to permit fluid to exit the apparatus 100 at a low pressure differential in the mandrel passageway 295 while preventing fluid from exiting the apparatus 100 at a high pressure differential. In the preferred embodiment, the low flow valve 210 includes a lower piston 195 , a second biasing member 240 and a plurality of seals. However, other forms of low flow valves may be employed, so long as they are capable of selectively controlling fluid flow at predetermined pressures.
The lower piston 195 is movable between a first and a second position. As illustrated on FIG. 1, the lower piston 195 is biased upward by the second biasing member 240 in the first position, thereby allowing fluid flow from the aperture 205 . As depicted, the second biasing member 240 consists of wave springs. However, other forms of biasing members, such as coil springs, wave washers or combinations thereof may be employed.
The low flow valve 210 includes a plurality of seals to prevent fluid leakage. In this respect, a first piston seal 215 is disposed on the inner portion of the lower piston 195 to create a fluid tight seal between the lower piston 195 and the mandrel 115 . Furthermore, a second and a third piston seal 190 , 220 are disposed between the lower piston housing 180 and an outer portion of the lower piston 195 . The second and third piston seal 190 , 220 are used to create a fluid tight seal around aperture 205 after the lower piston 195 moves axially downward to the second position. In addition, a lower seal 230 is disposed around the lower piston housing 180 to create a fluid tight seal between the lower piston housing 180 and the housing 155 .
A dog housing 235 is disposed at the lower end of the piston housing 180 . The dog housing 235 is held at a predetermined location on the mandrel 115 by a lower dog 225 . The second biasing member 240 abuts against the dog housing 235 . In this respect, the dog housing 235 acts as a support member for the second biasing member 240 . In the same manner, the dog housing 235 acts as a support member for a third biasing member 245 .
The third biasing member 245 is disposed around mandrel 115 and captured between the dog housing 235 and a collet 250 or mechanical portion. The third biasing member 245 is constructing and arranged to permit axial movement of the collet 250 upon at predetermined force. In the preferred embodiment, the third biasing member 245 is a coiled spring. However it is within the scope of the present invention to use other forms of a biasing member, so long as they are capable of providing the necessary force to bias the collet 250 .
As depicted on FIG. 1, the collet 250 is in a first position. The collet 250 is an annular member disposed of around mandrel 115 and connected to the housing 155 . The collet 250 moves between the first position and a second position along an axial path on mandrel 115 . In the preferred embodiment, the collet 250 includes a plurality of equally spaced collet fingers 285 . Each of the fingers 285 includes a collet head 275 . As shown, the collet 250 in the first position permits the collet fingers 285 and the collet head 275 to rest against the lower portion of the mandrel 115 .
As shown on FIG. 1, the lower portion of mandrel 115 includes a plurality of equally spaced ramp sections 290 . In the preferred embodiment, the numbers of ramp sections 290 correspond to number of collet fingers 285 . Each ramp section includes a tapered surface 310 and a substantially flat surface 315 . The ramp sections 290 are constructed to interface with the collet heads 275 during operation of the apparatus 100 . It should be noted that the outer portion of the collet 275 is a radial distance equal to or less than the radial distance of the outer portion of the ramp sections 290 , thereby allowing the apparatus 100 to obtain the location of a tubular 265 with a small inside diameter as shown on FIG. 1 .
FIG. 1A is a side view of the collet fingers 285 and the collet heads 275 . Visible specifically are heads 275 formed at an end of fingers 285 that are attached to the housing 155 at an upper end. The heads 275 are constructed and arranged to act on the tapered surfaces 310 of the mandrel 115 as the heads 275 are moved upwards relative to the tapered surfaces 310 . The mandrel 115 includes grooves 335 for housing the collet fingers 285 , the grooves 335 are formed longitudinally between the ramped sections 290 . In this manner, the fingers 285 are recessed in the mandrel 115 . FIG. 1B is a section view of FIG. 1A illustrating the fingers 285 disposed in the grooves 335 .
FIG. 2 is an enlarged cross-sectional view of the apparatus 100 illustrating the flow of fluid though the apparatus 100 prior to actuation of the collet 250 . During operation, fluid from the surface of the wellbore is pumped through the mandrel passageway 295 typically to some other downhole tool (not shown) such as a nozzle or mud motor. A pressure differential causes the fluid to pass through port 185 , as illustrated by arrow 320 . From port 185 , the fluid flows through check valve 160 and into the inner passageway 260 . Fluid continues through the inner passageway 260 around the upper dog 170 and into the chamber 325 and then into the outer passageway 175 . Next, fluid in the outer passageway 175 flows inwardly through aperture 205 . From aperture 205 , fluid flows through the second biasing member 240 , around the lower dog 225 , and third biasing member 245 exiting the tool 100 through a collet passageway 340 . In this manner, a portion of the fluid within the mandrel bore 295 exits the tool 100 into the surrounding wellbore.
FIG. 3 is a cross-sectional view of the apparatus 100 after the collet head 275 has expanded outward into contact with the tubular 265 . As the fluid flow is increases the differential pressure within the mandrel passageway 295 increases, thereby causing pressurized fluid to enter port 185 . The pressurized fluid entering the port 185 creates a force that acts against the upper portion of piston 195 in the low flow valve 210 . At a predetermined point, the force against the upper portion of piston 195 becomes greater then the biasing force on the lower portion of the piston 195 created by the second biasing member 240 . At that point, the lower piston 195 starts to move axially downward compressing the second biasing member 240 . The piston 195 continues to move axially downward until the third piston seal 220 passes aperture 205 as shown on FIG. 3 . In this manner, the movement of the piston 195 to the second position closes off the fluid pathway through the aperture 205 .
Thereafter, fluid entering the port 185 flows through the one-way check valve 160 into the inner passageway 260 and around the upper dog 170 . The fluid is prevented from flowing through the aperture 205 because the aperture 205 is closed. Therefore, fluid pressure builds within the chamber 325 and creates a force that acts against the chamber shoulder 165 . At a predetermined point, the force on the chamber shoulder 165 becomes greater than the biasing force created by the third biasing member 245 . At that point, the chamber 325 fills with fluid, thereby urging the housing 155 axially upward and compressing the third biasing member 245 . The housing 155 continues to move axially upward until the spring housing shoulder 120 contacts the sub shoulder 110 . At that point, the housing 155 reaches the second position.
The movement of the housing 155 to the second position causes the collet 250 to move axially upward to the second position since the collet 250 is connected to the housing 155 . As the collet 250 starts to move axially upward, the collet head 275 slides along the tapered surface 310 toward the flat surface 315 of the ramped section 290 . The movement of the collet head 275 along the tapered surface 310 causes the collet head 275 to move radially outward into contact with a surrounding tubular 265 . As shown, the collet head 275 is in full contact with a groove 270 formed in the tubular 265 .
The collet 250 and housing 155 may be shifted from the second position to the first position by reducing the flow of fluid through the mandrel passageway 295 . As the fluid flow is reduced, the differential pressure within mandrel passageway 295 is also reduced, thereby allowing the lower piston 195 to move axially upward exposing the aperture 205 . Thereafter, fluid from the chamber 325 and the mandrel passageway 295 may flow into the aperture 205 and through the second biasing member 240 exiting out the collet passageway 340 as discussed in a previous paragraph. In this manner, the fluid in the chamber 325 is removed allowing the third biasing member 245 to urge the collet 250 and the housing 155 from the second position to the first position, thereby disengaging the collet head 275 from the tubular 265 .
FIG. 3A is a side view of the collet fingers 285 and the collet heads 275 illustrating the collet heads 275 expanded outward. As shown, the collet fingers 285 have moved axially upward within the grooves 335 . As further shown, the collet heads 275 have traveled up a portion of the tapered surface 310 , thereby causing the collet heads 275 to extend radially outward.
FIG. 4 is an enlarged cross-sectional view of apparatus 100 illustrating the activation of the relief valve 330 . The main function of the relief valve 330 is to provide a means of releasing fluid from chamber 325 when the pressure within the chamber 325 reaches a predetermined amount. After the collet head 275 is fully engaged with the tubular 265 as shown in FIG. 3, the tubing string and apparatus 100 is pulled upward to verify location of the tubular 265 . A sensing device (not shown) connected to the tubing string indicates the upward force. If the force indicated on the sensing device is within a specific range then there is full engagement of the collet head 275 and the tubular 265 . However, the upward force may break the collet fingers 285 if the force is not maintained within a predetermined range. To prevent damage to the collet fingers 285 , the relief valve 330 senses the pressure build up in chamber 325 and releases fluid out of the chamber 325 , thereby causing the housing 155 and the collet 250 to move from the second position to the first position. The movement to the first position causes the collet head 275 to release the tubular 265 , thereby preventing damage to the collet fingers 285 . In this manner, the relief valve 330 acts as a backup to the hydraulic system, thereby preventing damage to the apparatus 100 .
The increased pressure in the chamber 325 creates a force in the fluid located in housing passageway 255 . The fluid force acts against the ball 140 . At a predetermined point, the force on the ball 140 becomes greater than the biasing force created by the first biasing member 145 . At that point, the ball 140 urges the upper piston 135 axially upward, thereby compressing the first biasing member 145 . The upward movement of the ball 140 and the upper piston 135 exposes the spring housing passageway 305 . Therefore, fluid in the chamber 325 is permitted to travel up the housing passageway 255 and exit out the apparatus 100 through the spring housing passageway 305 . In this respect, the housing 155 and the collet 250 is permitted to return to the first position.
FIG. 5 is a cross sectional view of an alternative embodiment of the collet 250 for use with the apparatus 100 . In this embodiment, rotational movement is used to engage the collet head 275 with the surrounding tubular (not shown). The collet 250 is moveable between the first and second position in the same manner as described in the previous paragraphs. FIG. 5 illustrates the collet 250 in the first position, wherein the collet head 275 is in contact with the mandrel 115 . The collet head 275 is constructed and arranged to act on the tapered surface 310 of the mandrel 115 as the head 275 is moved upward relative to the tapered surface 310 . The mandrel 115 includes grooves 335 formed longitudinally between the ramped sections 290 for housing the collet fingers 285 . In this manner, the fingers 285 are recessed in the mandrel 115 . FIG. 5A is a bottom view of the embodiment shown on FIG. 5 .
FIG. 6 is a cross sectional view illustrating the radial expansion of the collet 250 . As shown, the collet fingers 285 have moved axially upward in the grooves 335 . As further shown, the collet heads 275 have traveled up a portion of the tapered surface 310 , thereby causing the collet heads 275 to rotate outward. The rotation of the collet heads 275 causes a rotational force to act against the collet fingers 285 . The collet fingers 285 are constructed and arranged of a material that permits a predetermined rotational force to be applied to the collet fingers 285 when the collet 250 is in the second position while allowing the collet fingers 285 to return to the original shape when the collet 250 is in the first position. In this manner, the collet heads 275 are rotated outward allowing collet heads 275 to radially expand into contact with a profile (not shown). FIG. 6A is a bottom view of the embodiment shown on FIG. 6 .
FIG. 7 is a cross sectional view of another embodiment of the apparatus 400 in accordance with the present invention. As shown, apparatus 400 is downhole tool called an under-reamer. Typically, an under-reamer is run down hole with the blades in a closed position to a predetermined location. Subsequently, fluid is pumped into the under-reamer and the blades extend outward into contact with the surrounding wellbore. Thereafter, the blades are rotated through hydraulic means and the under reamer is urged downward enlarging the diameter of wellbore. The under reamer may also be used in a back reaming operation. During a back reaming operation, the under reamer is pulled toward the surface of the well while the blades enlarge the wellbore diameter.
As shown on FIG. 7, the apparatus 400 includes many of the same components of the apparatus 100 . For example, a mandrel 115 , 415 , a mandrel passageway 295 , 595 , a check valve 160 , 460 , a first biasing member 145 , 445 , upper piston 135 , 435 , a relief valve 330 , 630 , a chamber 325 , 625 , an outer passageway 175 , 475 , an aperture 205 , 505 , a shoulder 165 , 465 , an inner passageway 260 , 560 , a port 185 , 485 , a low flow valve 210 , 510 , a first piston seal 215 , 515 a second piston seal 190 , 490 , a third piston seal 220 , 520 , a lower piston 195 , 495 , a second biasing member 240 , 540 , and a third biasing member 245 , 545 . Each of the components listed function in the same manner as previously discussed for the apparatus 100 .
Additional components used in the apparatus 400 include an exit aperture 440 to allow fluid to exit the relief valve 630 and a seal member 425 to seal the relief valve 630 . The apparatus 400 further includes a bottom port 455 to allow fluid to exit the apparatus 400 . Additionally, apparatus 400 includes a piston 450 that moves between a first position and a second position due to fluid pressure in the chamber 625 . The lower end of the piston 450 abuts against rods 470 . The rods 470 are used to open and close a blade mechanism 420 that controls a pair of blades 480 . As shown on FIG. 7, the blades 480 in a closed position.
FIG. 8 illustrates a cross sectional view of the apparatus 400 after the blades 480 has expanded outward. During operation of apparatus 400 , fluid is pumped through the mandrel passageway 595 exiting out the bottom port 455 . As fluid flows through the bottom port 455 , a pressure differential created in the passageway 595 . The pressure differential causes fluid to enter the check valve 490 and exit through aperture 505 .
As the fluid flow is increased the differential pressure increases within the mandrel passageway 595 causing fluid to enter the outer passageway 475 . As the fluid fills the outer passageway 475 , a force is created that acts against the upper portion of piston 495 in the low flow valve 510 . At a predetermined point, the force against the upper portion of piston 495 becomes greater then the biasing force on the lower portion of the piston 495 created by the second biasing member 540 . At that point, the lower piston 495 starts to move axially downward compressing the second biasing member 540 . The piston 495 continues to move axially downward until the third piston seal 520 passes aperture 485 as shown on FIG. 8 . In this manner, the movement of the piston 495 to the second position closes off the fluid pathway through the aperture 485 .
Thereafter, fluid entering the check valve 460 flows into the inner passageway 560 toward the chamber 625 . As fluid collects, a pressure builds within the chamber 625 that creates a force that acts against the chamber shoulder 465 . At a predetermined point, the force on the chamber shoulder 465 becomes greater than the biasing force created by the third biasing member 545 . At that point, the chamber 625 fills with fluid, thereby urging the piston 450 to start moving axially downward and compressing the third biasing member 545 . Furthermore, the piston 450 urges the rods 470 against the blade mechanism 420 , thereby opening the blades 480 . The piston 450 continues to move axially until the blades 480 are fully opened. At that point, the piston 450 reaches the second position, thereby allowing the apparatus 400 to conduct a under reaming operation or a back reaming operation.
The piston 450 may be shifted from the second position to the first position by reducing the flow of fluid through the mandrel passageway 595 . As the fluid flow is reduced, the differential pressure within mandrel passageway 595 is also reduced, thereby allowing the lower piston 495 to move axially upward exposing the aperture 485 . Thereafter, fluid from the chamber 625 may flow down the inner passageway through the aperture 485 and into the aperture 505 exiting the apparatus 400 . In this manner, the fluid in the chamber 625 is removed allowing the third biasing member 545 to urge the piston 450 from the second position to the first position, thereby releasing the pressure on the rods 470 and allowing the blade mechanism 420 to close the blades 480 .
FIG. 9 is an enlarged cross-sectional view of apparatus 400 illustrating the activation of the relief valve 630 . The main function of the relief valve 630 is to provide a means of releasing fluid from chamber 625 when the pressure within the chamber 625 reaches a predetermined amount. After the blades 480 are fully extended as shown in FIG. 8, the apparatus 400 is urged downhole to conduct an under-reaming operation or is urged toward the surface to conduct a back-reaming operation. During the operation, an obstruction may be encountered that may damage the blades 480 if they remain open. Therefore, to prevent damage to blades 480 , the relief valve 630 senses the pressure build up in chamber 625 and allows the fluid to exit the chamber 625 .
The increased pressure in the chamber 625 creates a force that acts against the upper piston 435 . At a predetermined point, the force on the upper piston 435 becomes greater than the biasing force created by the first biasing member 445 . At that point, the upper piston 435 moves axially upward, thereby compressing the first biasing member 445 . The upward movement of the upper piston 435 causes the seal member 425 to move pass the exit aperture 440 , thereby allowing fluid to flow out of the apparatus 400 . As the fluid exits out of the chamber 625 , the piston 450 moves from the second position to the first position, thereby causing the blade mechanism 420 to close, therefore preventing damage to the blades 480 .
The hydraulic components consisting of a check valve, low flow valve, and a relief valve as constructed and arranged in apparatus 100 and apparatus 400 may also be used in the following list of down hole tools: mechanical packers, a valve system for inflatable elements, logging tools/gauging tools, orienting device/kick subs, expandable bits, whipstock setting tools, hammers, inside tubing cutters, accelerators, indexing tools, centralizers, anchors, tool for shifting sleeves, packers, wireline tools, overshots, spears, tractors and others.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | The present invention provides a method and an apparatus for use in a wellbore tool. The apparatus includes a body and a sliding member, wherein the sliding member and a mechanical portion moves between a first position and a second position. A valve assembly causes the sliding member and mechanical portion to shift to its second position at a predetermined flow rate of fluid through the body. The invention also provides an apparatus for a downhole tool that includes a mandrel and a sliding member disposed on the mandrel. The sliding member including a plurality of fingers and a plurality of heads, wherein the plurality of fingers are slideably recessed within a plurality of longitudinal grooves. The invention further provides a collet assembly that includes a body and at least two extendable members, whereby as the members extend outward, the members are rotated. | 4 |
BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to an improvement to and/or in the encoder-equipped sealing device or sealing device that has a magnet-based encoder incorporated therein. More particularly, the present invention relates to such encoder-equipped sealing device that provides the capabilities for preventing the physical cohesion by the magnetic attraction from occurring between two or more units of the encoder-based sealing devices that are adjacent to each other, when those units are placed one over another so that those units are oriented in one particular direction.
[0003] 2. Description of the Prior Art
[0004] The encoder (pulse coder) that is incorporated in the encoder-equipped sealing device that has been described above takes the form of a pulse generator ring that may be mounted on an automotive-vehicle in order to flexibly control the device that ensures that the vehicle can be running with safety and stability, such as the anti-lock braking system (ABS), traction control system (TCS) and stability control system (SCS). This encoder may be mounted on the hub flange in the suspension system together with a sensor, and is used to detect the number of revolutions for each of the vehicle wheels. The encoder is mounted on each of the four wheels, such as front, rear, right and left wheels, together with the sensor, and may be used to detect any difference in the number of revolutions between each of the wheels. In response to such difference, the encoder may turn the drive system or brake system on and off, thereby controlling the behavior of the vehicle to ensure that the vehicle can be running with stability and safety in case some emergency situations should occur.
[0005] Lubrication oils may leak from the bearing units on the automotive vehicle on which the safety running devices are install d as described above, and seals are required to avoid such leaks. Most of the sealing devices include integrated sealing and rotations detecting capabilities, and may be mounted on the gap or space that is available on the bearing units to meet such needs.
[0006] Typically, the sealing device that has been proposed for those recent years provides the rotations detecting function as well as encoder function, and has been used widely for the practical purposes.
[0007] The typical encoder-equipped sealing device that has been proposed and practically used will be described below by referring to FIG. 8.
[0008] Two units 41 , 42 of the encoder-equipped sealing device are shown in FIG. 8, in which each of the units includes two seal elements 3 , 2 combined together.
[0009] Specifically, the seal elements 3 includes a metal core 31 having a substantially L-shaped cross section wherein the metal core 31 has a cylindrical portion 31 a and a flange portion 31 b extending from one end of the cylindrical portion 31 a in the direction perpendicular to the direction in which the cylindrical portion 31 a extends. The seal element 3 further includes an elastic seal portion 6 on the flange portion 31 b that is arranged in the space defined by the cylindrical portion 31 a and flange portion 31 b.
[0010] Similarly to the seal element 3 , the seal element 2 also includes a metal core 21 having a substantially L-shaped cross section wherein the metal core 21 has a cylindrical portion 21 a and a flange portion 21 b extending from one end of the cylindrical portion 21 a in the direction perpendicular to the direction in which the cylindrical portion 21 a extends. The seal element 2 further includes a magnet-based encoder 1 that is arranged on the flange portion 21 b.
[0011] It may be seen from FIG. 8 that the seal element 3 and seal element 2 are combined such that the space defined by the cylindrical portion 31 a and flange portion 31 b of the seal element 3 and the space defined by the cylindrical portion 21 a and flange portion 21 b of the seal element 2 face opposite each other.
[0012] The encoder-equipped sealing device that includes the combined seal elements 3 and 2 may be mounted on any area that need to be sealed, such as the appropriate area in the bearing unit on the automotive vehicle, and a sensor 11 shown by dot-dash lines in FIG. 2 may be mounted adjacently to the encoder 1 so that it can face opposite the encoder 1 . It may be seen from FIG. 8 that in the unit 41 , for example, the seal element 2 including the encoder 1 may be mounted on the rotational element, such as the inner or outer race of the bearing unit, wherein the pulses that are magnetically generated by the encoder 1 may be detected by the sensor 11 .
[0013] All of the encoder-equipped sealing devices that have been described above may be maintained in storage before they are actually used, such as being mounted on the areas of the bearing units on the automotive vehicle that need to be sealed and each of the devices has the seal elements 2 , 3 completely assembled together. In storage, the individual devices are maintained like a stack in which the devices are placed one over another such that they can be oriented in one particular direction, for the convenience of the easy handing by the appropriate handling tools. It may be seen from FIG. 8 that two units 41 , 42 of the encoder-equipped sealing device, for example, are placed one over the other in the horizontal direction such that each encoder 1 is located on the right side, and is oriented in one particular direction.
[0014] The plural units of the encoder-equipped sealing device that are placed one over the other such that they are oriented in one particular direction, as shown in FIG. 8, are loaded in a magazine, and they are transported or storaged with being placed one over another such that they are oriented in one particular direction in the magazine. When they are actually used, they are removed from the respective magazines, and are mounted on the areas of the bearing unit that need to be sealed.
[0015] In the plural units of the encoder-equipped sealing device that are placed-one over the other so that they are oriented in one particular direction as shown in FIG. 8, the encoder 1 in the unit 41 , for example, produces a strong magnetic force that attracts the metal core 31 on the seal element 3 in the other unit 42 magnetically. This may cause the cohesion by the magnetic attraction to occur between the seal element 2 in the unit 41 and the seal element 3 in the other unit 42 .
[0016] When such cohesion occurs, the two units may attract each other magnetically within the magazine, from which it is difficult to remove the units by using ally appropriate fitting device that mounts the units on the area that needs to be sealed, such as the appropriate area in the bearing unit. This may cause the fitting device to become non-operational or may affect the working efficiency of the fitting device remarkably.
[0017] In another encoder-equipped sealing device that is proposed to address the problem described above, which is disclosed in Japanese patent application as published under No. 2001-141069, the seal portion is extended to provide a projection thereon. The object to provide this projection is to keep the two units of the encoder-equipped sealing device that are located adjacently to each other spaced away from each other. As this projection is formed as part of the elastic seal portion, the projection thus obtained is not sufficient to prevent the cohesion by the magnetic attraction that occurs between the two units.
SUMMARY OF THE INVENTION
[0018] In order to eliminate the serious disadvantages and problems associated with the prior art encoder-equipped sealing devices described above, it is an object of the present invention to provide an encoder-equipped sealing device that has a simple construction and prevents the cohesion by the magnetic attraction that might otherwise occur between the two units of the encoder-equipped sealing device that are located adjacently to each other. That is to say, the object of the present invention is to provide encoder-equipped sealing devices by which the encoder-equipped sealing device can be removed from the magazine without being caught by each other, and then may be mounted securely on the area that needs to be sealed, such as the appropriate area in the bearing unit, even if the plural units of the encoder-equipped sealing device are placed one over the other such that they are oriented in one particular direction, as shown in FIG. 8, and loaded in a magazine.
[0019] The problems mentioned above may be solved by providing the encoder-equipped sealing device in accordance with the present invention that is constructed as described below.
[0020] The encoder-equipped sealing device that is proposed by the present invention comprises two seal elements 3 , 2 combined together, wherein each of the elements 3 , 2 includes a metal core 31 , 32 having a substantially L-shaped cross section, each of the metal cores 31 , 32 having a cylindrical portion 31 a, 21 a and a flange portion 31 b, 21 b provided on one end of the cylndical portion 31 a, 21 a and extending in the direction perpendicular to the direction in which the cylindrical portion 31 a, 21 a extends.
[0021] One seal element 3 and the other seal element 2 are combined together such that the space defined by the cylindrical portion 31 a and flange portion 31 b of the one seal element 3 and the space defined by the cylindrical portion 21 a and flange portion 21 b of the other seal element 2 face opposite each other.
[0022] The one seal element 3 further includes an elastic seal portion 6 on the flange portion 31 b that is arranged in the space defined by its cylindrical portion 31 a and flange portion 31 b, and the other seal element 2 further includes a magnet-based encoder 1 on the flange portion 21 b.
[0023] In the before described encoder-equipped sealing device, the present invention proposes the following seven embodiments.
[0024] In an encoder-equipped sealing device according to a first embodiment of the present invention, that is shown in FIG. 1, one seal element 3 further includes a projecting portion 4 a on the end of the cylindrical portion 31 a on the side on which the flange portion 31 b is located, wherein the projecting portion 4 a extends beyond the side of the flange portion 31 b opposite the side on which the seal portion 6 is located and in the direction in which the cylindrical portion 31 a extends.
[0025] In an encoder-equipped sealing device according to a second embodiment of the present invention, that is shown in FIG. 2 and a variation of the encoder-equipped sealing device according to the first embodiment, one seal element 3 includes an end 4 b at the end of the cylindrical portion 31 a on which the flange portion 31 b is located, and wherein the said end 4 b forming a projecting portion is formed by folding the base end of the flange portion 31 b and the end of the cylindrical portion 31 a thereby overlapping each other in the direction in which the cylindrical portion 31 a extends.
[0026] In an encoder-equipped sealing device according to a third embodiment of the present invention, that is shown in FIG. 3, one seal element 3 further includes a projecting portion 4 c extending beyond the side of the flange portion 31 b opposite the side on which the seal portion 6 is located and extending in the direction in which the cylindrical portion 31 a extends.
[0027] In an encoder-equipped sealing device according to a fourth embodiment of the present invention, that is shown in FIG. 5, the end portion 4 d of the cylindrical portion 31 a of the one seal element 3 extending toward the other seal element 2 is extending in the direction in which the cylindrical portion 31 a extends and beyond the side of the other seal element 2 opposite the side on which the other seal element 2 faces opposite the one seal element 3 .
[0028] In an encoder-equipped sealing device according to a fifth embodiment of the present invention, that is shown in FIG. 4, one seal element 3 further includes a recess 4 f that is formed on the side of the flange portion 31 b opposite the side on which the seal portion 6 is located, wherein the said recess 4 f extends toward the side on which the seal portion 6 is located
[0029] In an encoder-equipped sealing device according to a sixth embodiment of the present invention, that is shown in FIG. 6, the encoder 1 is arranged on the side of the flange portion 21 b of the other seal element 2 opposite the side on which the flange portion 21 b faces opposite the one seal element 3 , and wherein the flange portion 21 b includes a projecting portion 4 e that extends beyond the surface of the encoder 1 and in the direction in which the cylindrical portion 21 a extends.
[0030] In an encoder-equipped sealing device according to a seventh embodiment of the present invention, that is shown in FIG. 7, one seal element 3 further includes an elastic lateral side portion 5 formed on the side of the flange portion 31 b opposite the side on which the seal portion 6 is located, and wherein the elastic lateral side portion 5 has undulations 4 g formed thereon
[0031] In any of the before described embodiments, the seal portion 6 may be formed from any elastic materials such as synthetic rubber, synthetic resin and the like, and the annular metal core 21 , 31 may be formed from iron or stainless steel materials. The encoder 1 is a multi-pole magnet that may be formed like an annular magnet from a mixture composed of any elastic material such as synthetic rubber, synthetic resin or like and any ferromagnetic material such as ferrite, rare earth or like in powdery forms. The annular magnet has N polarities and S polarities magnetized alternately around the circumference. The before described seal portion, annular metal core, and encoder are known and used in the conventional encoder-equipped sealing device comprised by incorporating encoder and sealing elements combined together, and mounted on the bearing unit on the automotive vehicle's wheel.
[0032] The encoder-equipped sealing devices that have been described in connection with the before described embodiments are used together with a sensor that may be disposed adjacently to and opposite the encoder 1 so that it can detect the pulses that are generated magnetically by the encoder 1 . The magnet-based encoder 1 that is located on the seal element mounted on the rotational element on the automotive vehicle are rotated as the rotational element rotates, and the pulses from the encoder 1 rotating as the before described are detected by the sensor. Thereby, the number of revolutions are detected by the sensor. It may be understood from the foregoing description that the encoder-equipped sealing device of the present invention has the encoder 1 incorporated therein.
[0033] In any of the first, second, third, fourth and sixth embodiments of the present invention, when the plural units of the encoder-equipped sealing device of the present invention are placed one over the other adjacently to each other so that they are oriented in one particular direction, for example, when two units 51 , 52 of the encoder-equipped sealing device are placed one over the other adjacently to each other so that they are oriented in one particular direction as shown in FIG. 1, the two adjacent units 51 and 52 can be kept spaced away from each other by the cylindrical portion or flange portion of the metal core. This can keep the gap between the two adjacent units 51 and 52 constant, and the physical cohesion by the magnetic attraction that would occur between the two units 51 and 52 can thus be prevented effectively.
[0034] In the fifth embodiment, when the plural units of the encoder-equipped sealing device of the present invention are placed one over the other adjacently to each other so that they are oriented in one particular direction, for example, when two units 51 , 52 of the encoder-equipped sealing device are placed one over the other adjacently to each other so that they are oriented in one particular direction as shown in FIG. 1, the area of contact between the encoder and the flange portion of the metal core can be kept as small as possible, and the physical cohesion by the magnetic attraction that would occur between the two units can thus be prevented effectively.
[0035] In the seventh embodiment, when the plural units of the encoder-equipped sealing device of the present invention are placed one over the other adjacently to each other so that they are oriented in one particular direction, for example, when two units 51 , 52 of the encoder-equipped sealing device are placed one over the other adjacently to each other so that they are oriented ii one particular direction as shown in FIG. 1, the gap between the two adjacent units can be kept constant by the elastic lateral side portion 5 having the undulations 4 g formed thereon, and the physical cohesion by the magnetic attraction that would occur between the two units can thus be prevented effectively.
[0036] It may be understood from the above description that when plural units of the encoder-equipped sealing device of the present invention are placed one over the other so that they are oriented in one particular direction as show in FIG. 1, the cohesion by the magnetic attraction that might otherwise occur between the adjacent units can be prevented effectively. So that, even if the plural units of the encoder-equipped sealing device are loaded in the magazine, with the units being placed one over the other so that they are oriented in one particular direction, the encoder-equipped sealing device can be removed from the magazine without being caught by each other, and can then be mounted securely onto the area that needs to be sealed, such as the appropriate area in the bearing unit.
[0037] That is to say, even if the plural units of the encoder-equipped sealing device are placed one over the other so that they are oriented in one particular direction, the encoder-equipped sealing device can be slided relative to the other without causing any problems. Also, either of the two units that are located adjacently can be moved away from the other without causing any problems, so that each of the encoder-equipped sealing devices can be handled after detaching each other. Thus, the encoder-equipped sealing device of the present invention can be slid smoothly out of the magazine equipped in the fitting tool, without causing any problems such as being caught or stuck. Thus, the encoder-equipped sealing device can be mounted-on the area that needs to be sealed, such as the appropriate area in the bearing unit, with the highest reliability.
BRIEF DESCRIPTION OF DRAWINGS
[0038] [0038]FIG. 1 is a cross sectional view of the encoder-equipped sealing device in accordance with a first embodiment of the present invention, showing that two units; of the encoder-equipped sealing device, for example, are placed adjacently to each other in the horizontal direction so that they are oriented in one particular direction although some non-critical parts are not shown;
[0039] [0039]FIG. 2 is a cross sectional view of the encoder-equipped sealing device in accordance with a second embodiment of the present invention, with some non-critical parts not being shown;
[0040] [0040]FIG. 3 is a cross sectional view of the encoder-equipped sealing device in accordance with a third embodiment of the present invention, with some non-critical parts not being shown;
[0041] [0041]FIG. 4 is a cross sectional view of the encoder-equipped sealing device in accordance with a fifth embodiment of the present invention, with some non-critical parts not being shown;
[0042] [0042]FIG. 5 is a cross sectional view of the encoder-equipped sealing device in accordance with a fourth embodiment of the present invention, with some non-critical parts not being shown;
[0043] [0043]FIG. 6 is a cross sectional view of the encoder-equipped sealing device in accordance with a sixth embodiment of the present invention, with some non-critical parts not being shown;
[0044] [0044]FIG. 7 is a side elevation of the encoder-equipped sealing device in accordance with a seventh embodiment of the present invention, with some parts being shown in cross section; and
[0045] [0045]FIG. 8 is a cross sectional view of the encoder-equipped sealing device in accordance with the prior art, showing that two units of the encoder-equipped sealing device are placed adjacently to each other in the horizontal, direction so that they are oriented in one particular direction although some non-critical parts are not shown;
DETAILED DESCRIPTION OF THE INVENTION
[0046] Several preferred embodiments of the present invention are now described below by referring to the accompanying drawings.
[0047] It should be noted that the encoder-equipped sealing device according to the prior art that has been described so far by referring to FIG. 8 and the encoder-equipped sealing device according to the various embodiments of the present invention that will be described below by referring to FIGS. 1 through 7 contain some common parts, elements or members. In the following description, those common parts, elements or members are given same reference numerals, and are not described to avoid the duplication.
[0048] Referring first to FIG. 1, the encoder-equipped sealing device according to a first embodiment of the present invention is described. In the encoder-equipped sealing devices 51 and 52 , the seal element 3 includes a projecting portion 4 a on the end of the cylindrical portion 31 a on the side on which the flange portion 31 b is located. The projecting portion 4 a extends beyond the side of the flange portion 31 b opposite the side on which the seal portion 6 is located and in the direction in which the cylindrical portion 31 a extends. That is to say, the projecting portion 4 a extends beyond the left side of the flange portion 31 b in FIG. 1.
[0049] In the embodiment shown in FIG. 1, the end of the cylindrical portion 31 a that is located on the left side and the base end of the flange portion 31 b are formed in such a manner as to extend toward the left side. The before described portion extends toward the left side in FIG. 1 forms the projecting portion 4 a.
[0050] Referring next to FIG. 2, the encoder-equipped sealing device according to a second embodiment of the present invention is described. This second embodiment is based on the inventive concept on which the first embodiment is based.
[0051] In the encoder-equipped sealing device shown in FIG. 2, the seal element 3 includes an end 4 b at the end of the cylindrical portion 31 a on which the flange portion 31 b is located The end 4 b forms a projecting portion as shown in FIG. 2. The end 4 b is formed by folding the base end of the flange portion 31 b and the end of the cylindrical portion 31 a thereby overlapping each other in the direction in which the cylindrical portion 31 a extends as shown in FIG. 2.
[0052] Referring next to FIG. 3, the encoder-equipped sealing device according to a third embodiment of the present invention is described.
[0053] In the encoder-equipped sealing device shown in FIG. 3, the seal element 3 includes a projecting portion 4 c extending beyond the side of the flange portion 31 b opposite the side on which the seal portion 6 is located and extending in the direction in which the cylindrical portion 31 a extends. That is to say, the projecting portion 4 c extending beyond the left side of the flange portion 31 b in FIG. 3.
[0054] In the third embodiment shown in FIG. 3, the projecting portion 4 c is formed by bending the end of the flange portion 31 b toward the left side in FIG. 3. It should be noted that this embodiment may be varied such that the projecting portion 4 c can be located on the middle portion of the flange portion 31 b.
[0055] Referring next to FIG. 5, the encoder-equipped sealing device according to a fourth embodiment of the present invention is described.
[0056] In the encoder-equipped sealing device shown in FIG. 5, the end portion 4 d of the cylindrical portion 31 a of the seal element 3 extending toward the& other seal element 2 extends in the direction in which the cylindrical portion 31 a extends. And the said end portion 4 d further extends beyond the side of the other seal element 2 opposite the side on which the other seal element 2 faces opposite the seal element 3 . That is to say, the end portion 4 d of the cylindrical portion 31 a of the seal element 3 extends beyond the right side of the seal element 2 in the direction in which the cylindrical portion 31 a extends.
[0057] In the fourth embodiment shown in FIG. 5, an encoder 1 is arranged on the side (right side in FIG. 5) of the flange portion 21 b opposite the side on which the flange portion 21 b faces the seal element 3 . As the end 4 d of the cylindrical portion 31 a of the seal element 3 extends beyond the side (right side in FIG. 5) of the seal element 2 opposite the side on which the seal element 2 faces the seal element 3 , the end 4 d extends beyond the right side of the encoder 1 in FIG. 5 and in the direction in which the cylindrical portion 31 a extends.
[0058] Referring next to FIG. 6, the encoder-equipped sealing device according to a sixth embodiment of the present invention is described.
[0059] In the encoder-equipped sealing device shown in FIG. 6, the encoder 1 is arranged on the side of the flange portion 21 b of the seal element 2 opposite the side on which the flange portion 21 b faces opposite the seal element 3 . That is to say, the encoder 1 is disposed on the right side of the flange portion 21 b of the seal element 2 . And the flange portion 21 b includes a projecting portion 4 e that extends beyond the surface of the encoder 1 and in the direction in which the cylindrical portion 21 a extends.
[0060] In the sixth embodiment shown in FIG. 6, the projecting portion 4 e is formed by bending the end of the flange portion 21 b, and the projecting portion 4 e extends beyond the right side of the encoder 1 and in the direction in which the cylindrical portion 21 a extends.
[0061] In any of the embodiments described above by referring to FIGS. 1, 2, 3 , 5 and 6 , when two units of the encoder-equipped sealing device as designated by 51 , 52 are placed one over the other adjacently to each other in particular direction as shown in FIG. 1 so that those units are oriented in one particular direction, the projecting portion 4 a, the end 4 b forming the projecting portion, the projecting portion 4 c, the end 4 d and the projecting portion 4 e can exist between the two adjacent units 51 and 52 .
[0062] Those projecting portions and ends that exist between the two adjacent units 51 and 52 can prevent the encoder 1 in one unit and the flange portion 31 b in the other unit from contacting each other over the wide area, as opposed to the case shown in FIG. 8.
[0063] Thus, the magnetic force produced from the encoder 1 in the unit 51 against the flange portion 31 b in the unit 52 can be reduced greatly.
[0064] This can prevent the cohesion by the magnetic attraction from occurring between two adjacent units 51 and 52 .
[0065] In particular, in each of the embodiments shown in FIGS. 5 and 6, the end 4 d or projecting portion 4 e in one unit can abut against the flange portion 31 b in the other adjacent unit, which can prevent the encoder 1 in the unit 51 from contacting the flange portion 31 b in the unit 52 . Thus, those embodiments are very advantageous in that the cohesion by the magnetic attraction between the two adjacent units 51 and 52 can be prevented.
[0066] It should be noted that in each of the embodiments shown in FIGS. 1, 2 and 3 , the area of contact between the encoder 1 in the unit 51 and the flange portion 31 b in the unit 52 can be made as small as possible by modifying the size of the flange portions 21 b, 31 b as viewed vertically in the respective figures, the size of the encoder 1 , the size of the projecting portion 4 a, and the size of the end 4 b forming the projecting portion, respectively.
[0067] In each of the embodiments shown in FIGS. 5 and 6, the respective end 4 d and projecting portion 4 e may be extended further toward the right side in FIGS. 5 and 6, respectively. In this way, the gap between the encoder 1 and the sensor 11 located adjacently to and opposite the encoder 1 can be covered like an umbrella by the end 4 d and projecting portion 4 e. Thus, the gap between the encoder 1 and sensor 11 can be protected from any foreign matter that might otherwise enter the gap.
[0068] In each of the embodiments described so far by referring to FIGS. 1, 2, 3 , 5 and 6 the gap between the units 51 and 52 that are located adjacently to each other are determined by the presence of the projecting portion 4 a, the end 4 b forming the projecting portion, the projecting portion 4 c, the end 4 d, and the projecting portion 4 e. Thus, those projecting portion 4 a, etc., which are made of metal, can keep the gap between the adjacent units 51 and 52 as constant as it is originally designed.
[0069] Referring to FIG. 4, the encoder-equipped sealing device according to a fifth embodiment of the present invention is now described.
[0070] In the encoder-equipped sealing device shown in FIG. 5, the seal element 3 includes a recess 4 f that is formed on the side of the flange portion 31 b opposite the side on which the seal portion 6 is located. The said recess 4 f extends toward the side on which the seal portion 6 is located. That is to say, the recess 4 f is formed at the left side of flange portion 31 b in FIG. 4. And the recess 4 f extends toward the right side in FIG. 4.
[0071] When two units 51 , 52 of the encoder-equipped sealing device are placed one over the other adjacently to each other so that they are oriented in one particular direction, as shown in FIG. 1, the presence of the recess 4 f can keep the area of contact between the encoder 1 in one unit 51 and the flange portion 31 b in the other unit 52 as small as possible. This can reduce the magnetic force attracting two units 51 and 52 , and can thus prevent the two units from attracting each other magnetically. This recess 4 f may be formed by using the knurling process, for example.
[0072] Referring next to FIG. 7, the encoder-equipped sealing device according to a seventh embodiment of the present invention is described.
[0073] In the encoder-equipped sealing device shown in FIG. 7, the seal element 3 includes an elastic lateral side portion 5 formed on the side of the flange portion 31 b opposite the side on which the seal portion 6 is located. The elastic lateral side portion 5 has undulations 4 g formed thereon. This elastic lateral side portion 5 may be made of any elastic materials, such as synthetic rubber, and synthetic resin and the like.
[0074] When two units 51 , 52 of the encoder-equipped sealing device are placed one over the other adjacently to each other so that they are oriented in one particular direction, as shown in FIG. 1, the elastic lateral side portion 5 having the undulations 4 g thereon can keep the gap between the two units 51 and 52 constant, thereby preventing the cohesion by the magnetic attraction that might occur between the two units 51 and 52 .
[0075] In the embodiment shown in FIG. 7, it should be noted that the elastic lateral side portion 5 having the undulations 4 g thereon exists between the encoder 1 in one unit 51 and the metal flange portion 31 b in the other unit 52 that is located adjacently to the unit 51 . The elastic lateral side portion 5 can keep the encoder 1 in the one unit 51 in soft contact with the metal flange portion 31 b in the other unit 52 , which will prevent the encoder 1 from being deformed or having the high molecular cohesion with the metal flange portion 31 b.
[0076] In each of the embodiments shown in FIGS. 1 through 7, it should be noted that the seal portion 6 includes radial lips 6 a, 6 b extending from the side, at which cylindrical portion 31 a exists, toward the forward end of the flange portion 31 b and in the direction in which the cylindrical portion 31 a extends, so that extending obliquely, and a side lip 6 c extending from the forward end of the flange portion 31 b toward the cylindrical portion 31 a and in the direction in which the cylindrical portion 31 a extends, so that extending obliquely.
[0077] It should also be noted that when the seal element 3 and seal element 2 are combined such that the space defined by the cylindrical portion 31 a and flange portion 31 b of the seal element 3 and the space defined by the cylindrical portion 21 a and flange portion 21 b of the seal element 2 can face opposite each other, the radial lips 6 a, 6 b can abut the circumferential surface of the cylindrical portion 21 a, and the side lip 6 c can abut the inner surface of the flange portion 21 b.
[0078] The seal portion 6 may be made of any elastic materials such as synthetic rubber, synthetic resin and the like, as it is known to the art. It should be understood that the present invention is not limited to the embodiments of the seal portion 6 described above by referring to FIGS. 1 through 7.
[0079] The encoder-equipped sealing device of the present invention are used by mounting it on the bearing unit of an automotive vehicle, which comprises an inner race and outer race relatively rotating each other, for example.
[0080] In, each of the embodiments described so far by referring to FIGS. 1 through 7, it is assumed that the seal element 2 in the encoder-equipped sealing device 51 is mounted on the rotational element on an automotive vehicle. For example, the encoder-equipped sealing device according to each of those embodiments has been described, assuming that the encoder-equipped sealing device is mounted on the bearing unit with mounting the seal element 2 in the encoder-equipped sealing device 51 on the rotational element, such as inner race. It should be understood, however, the encoder-equipped sealing device according to each of the embodiments described and shown can be mounted on the bearing unit, comprising an inner race and outer race relatively rotating each other, with mounting the seal element 2 in the encoder-equipped sealing device 51 on the outer race, which is a rotational element, although this is not shown.
[0081] Although the present invention has been described with reference to several particular preferred embodiments thereof by referring to the accompanying drawings, it should be understood that the present invention is not limited to those embodiments, and various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. | An encoder-equipped sealing device, that is, the sewing device that has the encoder incorporated therein is disclosed, which comprises a combination of seal elements ( 3, 2 ), each of which includes an annular metal core ( 31, 21 ) having a substantially L-shaped cross section and including a cylindrical portion ( 31 a, 21 a ) and a flange portion ( 31 b, 21 b ) provided on one end of the cylindrical portion ( 31 a, 21 a ) and extending in the direction perpendicular to the direction in which the cylindrical portion ( 31 a, 21 a ) extends. One seal element ( 3 ) of the two seal elements ( 3, 2 ) and the other seal element ( 2 ) are combined such that the space defined by the cylindrical portion ( 31 a ) and flange portion ( 31 b ) of the one seal element ( 3 ) and the space defined by the cylindrical portion ( 21 a ) and flange portion ( 21 b ) of the other seal element ( 2 ) face opposite each other, wherein the one seal element ( 3 ) further includes an elastic seal portion ( 6 ) provided on the flange portion ( 3 b ) and arranged in the space defined by the cylindrical portion ( 31 a ) and flange portion ( 31 b ), and the other seal element ( 2 ) further includes a magnet-based encoder ( 1 ) provided on the flange portion ( 21 b ). The one seal element ( 3 ) further includes a projecting portion ( 4 a, 4 b ) on the end of the cylindrical portion ( 31 a ) on the side on which the flange portion ( 31 b ) is located and extending beyond the side of the flange portion ( 31 b ) opposite the side on which the seal portion ( 6 ) is located and in the direction in which the cylindrical portion ( 31 a ) extends. | 5 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to systems and methods for the collection of market research data from a plurality of cooperating retail stores.
2. Description of the Prior Art
Various arrangements have been employed for the collection, summarization and forwarding of Point-Of-Sale purchasing information from retail stores for purposes of market research since the advent of Point-Of-Sale (POS) optical scanners and the widespread use of the Universal Product Code (UPC) to identify retail products. Typically, retail purchase data is summarized by an in-store POS controller or by a separate store computer attached to the POS controller in the store or, if the store is part of a large retail store chain, by a central or host computer at the headquarters of the retail store chain. The summarized retail purchase data is then typically forwarded to the users of the data by any one of a number of different data storage and transmission techniques, for example, by magnetic tape or disk or diskette or by telephonic data transmission or by over-the-air data transmission.
For example Daniel Jr., et al., U.S. Pat. No. 4,972,504 issued Nov. 20, 1990 and assigned to the present assignee, discloses a marketing research system and method for obtaining retail data on a real time basis.
The identification of frequent shoppers and analysis of their purchases can be important to retailers since frequent shoppers may be the most valuable of customers. In order to determine what steps might increase the loyalty of frequent shoppers, a retailer may wish to study the distribution of times between visits of frequent shoppers and average purchase amount for frequent shoppers as compared to infrequent shoppers. Market research studies of frequent shopper behavior may also be of interest to packaged goods manufacturers and advertising agencies.
To date technological limitations on identifying people for in-store market research studies have dictated the use of identification methods that both require a high degree of cooperation and that incidentally provide unique identification, such as identification cards that are issued to cooperating panelists and that can be read by barcode-reading equipment installed in a grocery store checkout counter. For example, a panelist study is disclosed by Eskin et al., U.S. Pat. No. 4,331,973. Other studies have used panels of cooperating shoppers who paid for their purchases with personal checks and automatic check-reading equipment, of the sort commonly used in banking, was used at the point of sale to read the panelist's bank account number and to identify the panelist.
Another method and apparatus for identifying individual members of a marketing and viewing audience are taught by David A. Kiewit U.S. Pat. No. 4,930,011, issued May 29, 1990 and assigned to the present assignee. The disclosure of U.S. Pat. No. 4,930,011 is incorporated herein by reference. Kiewit's disclosed system includes small radio transmitters that broadcast uniquely coded identification signals to be detected by data collection equipment at monitored locations within retail establishments and homes.
The use of special physical identification devices, such as cards, limits a market researcher's ability to accurately measure a panelist's shopping behavior. In the first and third cases described above, a shopper will not be counted if he or she forgets to carry the identification card or radio transmitter. In the second example a shopper will not be identified if payment is made in cash rather than by personal check. An automatic identification system that could recognize people who had previously shopped at the store and that could log the frequency and temporal distribution of their shopping trips would be valuable for retail market research studies.
Identification methods that provide an input to a retail store's computer system or that can be used to correlate the panelist and with his or her purchases are particularly advantageous to market researchers.
A number of known prior art methods of partially automatic individual identification require active cooperation on the part of the person to be identified. Some of these, such as the measurement of characteristic features of the hand, as taught by Kondo in U.S. Pat. No. 4,206,441, or of the retina, as taught by Flom and Safin in U.S. Pat. No. 4,641,349, have proven to be useful for regulating access to secure areas. Partially automatic facial image recognition systems have been taught by Felix et al, in U.S. Pat. No. 4,449,189, who describe a personal access control system using a combination of speech recognition and an analysis of characteristic shapes of the speaker's mouth. Goldman, in U.S. Pat. No. 4,811,408, teaches the use of identification cards bearing at least one portion of the image indicia. Gotanda, in U.S. Pat. No. 4,712,103, teaches an identification card or key with a password, and requires a human operator to perform the face recognition portion of the identification work.
Daozheng Lu, in U.S. Pat. No. 5,031,228, issued Jul. 9, 1991 and assigned to the present assignee, discloses an image recognition system and method for identifying a pattern of a plurality of predetermined patterns in a video image. A plurality of feature image signatures are stored corresponding to each of the plurality of predetermined patterns. A universal feature image signature is stored that includes each of the stored feature image signatures. A predefined series of portions of a captured video image is sequentially compared with the universal feature image signature to identify matching portions. Each of the identified matching video image portions is compared with the stored feature image signatures to identify the predetermined pattern.
Daozheng Lu, in U.S. Pat. No. 4,858,000, issued Aug. 15, 1989 and assigned to the present assignee, discloses an image recognition method and system for identifying predetermined individual members of a viewing audience in a monitored area. A pattern image signature is stored corresponding to each predetermined individual member of the viewing audience to be identified. An audience scanner includes audience locating circuitry for locating individual audience members in the monitored area. A video image is captured for each of the located individual audience members in the monitored area. A pattern image signature is extracted from the captured image. The extracted pattern image signature is compared with each of the stored pattern image signatures to identify a particular one of the predetermined audience members. These steps are repeated to identify all of the located individual audience members in the monitored area. The disclosures of U.S. Pat. Nos. 4,858,000 and 5,031,228 are incorporated herein by reference.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a substantially automated system and method for collecting market research data that includes retail customer data together with retail sales transactional data.
It is another object of the present invention to provide a market research system and method that overcomes many of the disadvantages of prior art arrangements.
It is another object of the invention to provide an automatic face recognition system and method to identify a retail customer.
It is a more specific object of the invention to provide an automatic face recognition system and method that is capable of identifying a market research panelist in one of a plurality of monitored stores and to associate that panelist with the purchases made in that store.
It is a further object of the invention to provide an automatic face recognition system and method capable of identifying a retail customer with sufficient accuracy to be able to measure the shopping frequency at a given store, and that overcomes many of the disadvantages of prior art methods for identifying frequent shoppers in a retail store.
It is a further object of the invention to provide an automatic face recognition system and method capable of identifying a retail customer and of associating that customer's identification with identification provided by other means.
It is an additional object of the invention to provide an automatic face recognition system that can make a first identification of a shopper who is viewing a display or advertisement within a store and subsequently make a second identification of that shopper at the checkout counter, whereby a shopper's attentiveness to a display or advertisement may be correlated with purchases of products and with other demographic purchase-related variables.
It is yet a further object of the invention to provide an automatic face recognition system that can automatically update a set of stored recognition features whenever the system's attempt at recognizing a retail shopper is either confirmed or denied by some other standard identification method, such as manually matching the customer's signature on a check with the customer's signature on a check cashing identification card.
It is yet a further object of the invention to provide an automatic face recognition system that can track its own accuracy by comparing identifications made by the automatic system with those provided by other identification means.
In brief, the objects and advantages of the present invention are achieved by a market research system and method. A plurality of cooperating establishments are included in a market research test area. Each cooperating establishment is adapted for collecting and storing market research data. A computer system remotely located from the plurality of cooperating establishments stores market research data collected from the cooperating establishments. The collected market research data includes monitored retail sales transactions and captured video images of retail customers.
BRIEF DESCRIPTION OF THE DRAWING
The present invention together with the above and other objects and advantages may best be understood from the following detailed description of the embodiment of the invention illustrated in the drawing, wherein:
FIG. 1 is a block diagram of a market research system according to the present invention;
FIG. 2 is an electrical schematic and block diagram representation of a monitoring unit of the market research system of FIG. 1 to perform the method of the present invention;
FIG. 3 is a perspective view of an illuminator and video camera module of the market research system of FIG. 1;
FIG. 4 is an electrical schematic and block diagram representation of an automatic face recognition system of the marketing research system of FIG. 1; and
FIGS. 5-9 are flow charts illustrating logical steps performed by the monitoring unit of the marketing research system of FIG. 1 in accordance with the method of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, in FIG. 1 there is illustrated a marketing research system generally designated by the reference character 10. Marketresearch system 10 includes a plurality of monitoring units generally designated by the reference character 12 coupled to a central computer 14 via communications links generally designated by the reference character 16. Each monitoring unit 12 monitors and stores selected market research data. Various conventional arrangements can be used for the communicationslinks 16, for example, such as, via telephone lines connected to the publicswitched telephone network. Central computer 14 collects market research data from the cooperating establishment monitoring units 12.
Referring to FIG. 2, a retail store includes a point of sale (POS) terminal17 typically connected to a store controller computer 18 which looks up theidentity and price of each scanned item in a price lookup table (PLU) and then causes the scanned item identity and price to be displayed on a display module 20 visible to the shopper or retail customer. Alternately the price lookup function may be performed at the point of sale terminal 17 or by a remote store controller 18 depending on the particular point ofsale system.
Each monitoring unit 12 includes at least one illuminator and camera module22, preferably located adjacent the point of sale display 20, used to acquire images of the customer's face for recognition by a computer systemwhile the customer's purchases are scanned and totalled. The preferred location of the illuminator and camera module 22 ensures that shopper is likely to occasionally look directly toward the camera in order to follow the course of the purchase transaction. A relatively featureless sheet 24 is used to provide a uniform background against which the image of the shopper's face can be more easily framed and identified. A local computer module 26 is attached by a cable 28 to the illuminator and video camera module 22.
In FIG. 2, a block 30 illustrates a small store having a single POS terminal 17 and a block 32 is illustrative of a larger store having a plurality of checkout POS terminals 17. In addition, an illuminator and camera module 22 and a local computer module 26 may be placed at other locations such as at a selected product display 34, for example, located at the end of an aisle where data can be collected to ascertain which shoppers and what fraction of shoppers were attracted to that display.
A store data collection computer 40 including a Frequent Shopper Database 80 is coupled to each of the local computer modules 26 at a line 40A and to the store controller computer 18 at a line 40B in block 32. Market research data including the identification of frequent shoppers and the collection of marketing research data associated with their purchase activities is coupled to the central office computer 14 from the store data collection computer 40. In block 30, market research data collected from the single POS terminal 17 is coupled to the central office data collection computer 14 from the local computer module 26. Retail sales transactional data can be collected by the market research system 10 of the invention by known data collection systems, such as disclosed by Daniel Jr., et al. in U.S. Pat. No. 4,972,504. The disclosure of U.S. Pat.No. 4,972,504 is incorporated herein by reference.
Referring to FIG. 3, the illuminator and video camera module 22 is shown ingreater detail. The illuminator and video camera module 22 includes a housing 50 that contains a small video camera 52 such as the Hitachi ModelVK- M10, which provides a CCD imager with a 324×246 pixel resolution.Video camera 52 is optimized for use in the near infrared portion of the spectrum or at wavelengths of 800-1000 nM, and is concealed from the shoppers' view by a plastic infrared filter 54. A covert infrared illuminator, preferentially comprised of an array of infrared light emitting diodes 56, is also mounted in the housing 50. Various wires in the cable 28 provide the module with electrical power and input commands from the local computer module 26, as well as conveying video images from the video camera 52 to a video frame grabber and buffers module 64 shown in the local computer module 26 in FIG. 4.
Since the location of the shopper near a checkout POS terminal 17 is fairlywell constrained, it should be understood that the illuminator and video camera module 22 of the present invention can be simpler than the audiencescanners taught by Lu in U.S. Pat. Nos. 4,858,000 and 5,031,228.
In order to provide adequate illumination while minimizing heat generated by the illuminator and camera module 22, the illuminator is controlled by the local computer module 26 and is used to illuminate the scene periodically when a transaction is in progress. If the ambient illumination at the checkout counter is sufficiently well controlled the use of the covert illuminators 56 may be avoided and the apparatus therebysimplified.
Referring to FIG. 4, the local computer module 26 used for image acquisition and operational control of the illumination and video camera module 22 is illustrated. Inputs and outputs of the local computer module 26 include a parallel port 60 that is used to send ON and OFF commands to the illuminator 56; a video input 62 that passes video signals from the video camera 52 to a video frame grabber and buffers block 64 of the module 26; and a serial port 66 that communicates with other computer modules 18, 40 within the store. Other inputs, such as a keyboard (not shown) and outputs, such as a display (not shown) may also be used with the local computer module 26 during installation or maintenance of the system as is known in the art.
A Model DT2853, made by Data Translation of Marlboro, Mass. can be employedfor the frame grabber 64 used in the local computer module 26. The use of frame grabbers in similar systems is described by Lu in U.S. Pat. Nos. 4,858,000 and 5,031,228.
A central processing unit (CPU) 68 controls portions of the local computer module 26 by issuing appropriate commands via a bus 70, which preferably adheres to the ISA industry standard. A memory system 72 for storing program and market research operational data coupled to the bus 70 of the local computer module 26 includes two or more megabytes of RkM, a fixed disk drive used for program and data storage and a floppy disk drive used for installation and diagnostic functions. Various commercially available microprocessor devices having standard capabilities can be used for the CPU 68, for example, such as a 80386 high-performance 32-bit microprocessor device and an associated 80387 arithmetic co-processor manufactured and sold by Intel Corporation of Santa Clara, Calif.
In normal operation, the local computer module 26 commands the illuminator 56 to flash and subsequently commands the frame grabber 64 to acquire a frame of video taken during the flash, digitize the acquired video frame, and load the digitized video frame into RAM within the memory system 72. The length of ON time for the infrared illuminator 56 is preferentially set by the illuminator hardware, rather than by the computer 26. Once a frame or a set of frames of video is stored in RAM, the local computer module 26 proceeds with attempts to find and identify a shopper's face. Communication with the other computers 18, 40 in the store via the serial port 66 is commonly employed, for example, to access the Frequent Shopper Database 80 of feature sets corresponding to frequent shoppers for the store that is being monitored. In block 30 with market research data collected from the'single POS terminal 17, the Frequent Shopper Database 80 is provided with the single local computer module 26.
Collected shopper data stored in the memory 72 is combined with the collected POS retail sales transactional data. A modem (not shown) can be provided for communications with the central computer 14 via a corresponding communications link 16.
Referring to FIG. 5, there is shown a flow chart illustrating six major functional modules of logical operations performed by the monitoring unit 12 of the marketing research system 10. The sequential operations begin with image acquisition and maintenance as indicated at a block 82. The image acquisition and maintenance functional module 82 is illustrated and described with reference to FIG. 6. Next face framing sequential operations are performed as indicated at a block 84 and illustrated and described with reference to FIG. 7. Then face recognition sequential operations are performed as indicated at a block 86 and illustrated and described with reference to FIG. 8. Next data base updating and adaptive learning sequential operations are performed as indicated at blocks 88 and90 and illustrated and described with reference to FIG. 9. A communication module as indicated at a block 92 is employed both to send data, for example, such as, a list of all frequent shoppers identified during a given day and the time of day corresponding to each identification, to other devices, such as an in-store data collection master computer 40 or acentral office computer 14; as well as to receive operating and maintenancedata and commands, for example, to have the local computer clock accuratelyset. Communication with a central office data collection computer 14 is described in greater detail in Daniel et al., U.S. Pat. No. 4,972,504.
FIG. 6 provides a detailed presentation of the image acquisition and maintenance block 82 of FIG. 5. Attempts to obtain a facial image, for example, at the beginning of a checkout or retail sales transaction are conducted by first controlling the intensity and timing of the illumination, as shown in blocks 94 and 96 labelled ILLUMINATION CONTROL and TIMING CONTROL, respectively. Then a sequence of video frames is grabbed as indicated in a block 98 labelled FRAME GRABBER CONTROL. An image grabbed in block 98 is subtracted from the previous image to determine if motion has occurred as shown in a block 100 labelled MOTION DETECTION. When no motion is detected, for example, when the subtraction operation results in an image that has an intensity of less than some threshold value everywhere in the image plane, then the new image may be used to update the value of the background, as indicated at a block 102 labelled BACKGROUND UPDATING. Note that a background image may be initially defined and periodically rechecked during times when no face is expected to be in the camera scene, for example, when the checkout lane isclosed, as is indicated by the point of sale terminal being turned off. If motion is detected in block 100, the background is subtracted from the input image to form a difference image, as shown in block 104 labelled BACKGROUND ELIMINATION. The difference image is then subjected to lowpass filtering as shown in block 106 labelled IMAGE FILTERING to remove much ofthe image noise, as is known in the art of image processing. Then the sequential steps continue with attempts to locate and identify the shopper's face.
Referring now to FIG. 7, once motion has been detected by the image acquisition and maintenance module 82, an attempt to locate a face to be identified is made by the face framing module 84. Shape analysis is used in block 108 labelled SHAPE ANALYSIS and then to approximately locate an image of a shopper's head as indicated at a block 110 labelled HEAD LOCATION. Shape analysis is taught by R. C. Gonzales and P. Wintz in "Digital Image Processing" 2nd ed., Addison and Wesley Publishing Company,1987. since a shopper may not always have his or her head in a vertical position, the head tilt is determined as indicated at a block 112 labelledHEAD 2-D ORIENTATION. Then the head image is amplitude-averaged, sized, andoriented into a standard format as shown in block 114 labelled FACE IMAGE SIZE & INTENSITY NORMALIZATION.
Referring now to FIG. 8, there is illustrated the face recognition functional module block 86 of FIG. 5. First the three-dimensional orientation of the face is determined by the use of Eigenface analysis andface space theory as indicated at a block 116 labelled 3-D ORIENTATION DETECTION. The algorithms employed at block 16 may be better understood byreference to a number of published papers, such as: a) L. Strovich and M. Kirby, "Low Dimensional Procedure for the Characterization of no. 3, pp. 519-524, 1987; b) M. Kirby and L. Sirovich, "Application of the Karhuen-Loeve Procedure for the Characterization of the Human Face", Transactions on Pattern Analysis and Machine Intelligence, vol. 12, no. 1,1990; and c) M. Turk and A. Pentland, "Eigenfaces for Recognition", Journalof Cognitive Neuroscience, vol 3, no. 1, pp. 71-86, 1991. Once the orientation of the facial image is established at block 116, features of the facial image may be extracted as indicated at a block 118 labelled FACE FEATURE EXTRACTION. The extracted features at block 118 are classified into a specific group according to the hierarchical representation of facial image features used to defined the Frequent Shopper Database 80 as indicated at a block 120 labelled FACE CLASSIFICATION. The input facial feature set is then compared with the relevant subset of all the facial feature sets in database 80 by using theEigenface parameters to arrive at a quantitative estimate of the degree to which the newly acquired facial image matches an image already present in the database 80 as indicated at a block 122 labelled EIGENFACE RECOGNITION.
As is understood by those skilled in the data processing arts, the FrequentShopper Database 80 may be physically resident on any one of a number of computers in the data collection system 10. In FIG. 2, for example, it is shown as being located in the in-store data collection computer 40. In a smaller store, shown schematically as 30 in FIG. 2, the Frequent Shopper Database 80 resides on the local computer module 26.
The database 80 may be initially defined or built by obtaining images of panel members in a standard setting, automatically extracting digital feature sets from those images by the same processes that are subsequentlyused for panelist identification as depicted in FIGS. 5-8, and storing those digital feature identification, for example, name, membership numberin the database 80 at block 88 in FIG. 5. Alternately, the database 80 may be formed without providing individual retail customer identification by collecting shoppers' feature sets and using the collected feature sets to determine when one of those previously recognized shoppers buys something at the monitored store. The collected feature sets are then retained as long as the shopper continues to be re-recognized within some predetermined time period. In either event, the database 80 is updated with a record noting each recognition occurrence, as noted in block 88 in FIG. 5.
The frequent shopper database 80 is also preferentially updated by an adaptive learning process, shown at block 90 in FIG. 5, at each recognition. In this process, the results of the current recognition are combined with information in the database 80 to define a new standard feature set corresponding to the shopper who has just been identified. Theadaptive learning process of block 90 thus accommodates the system to smallchanges in the appearance of the shopper, for example, as may occur from a change of hair style.
Referring to FIG. 9 in some cases, for example where a customer provides independent evidence of identity, the system 10 of the present invention provides both an increased level of certainty as to the customer's true identity, and a way of monitoring the performance of the automatic face recognition operations described above. A customer presents separate identification which is entered into the logical operations of the system 10 as indicated at a block 140 labelled INPUT SECOND IDENTIFICATION OPTION. For example, suppose a shopper presents a barcoded identification card bearing a signature to verify that he or she is allowed by the store to pay for purchases with a personal bank check. A clerk scans the identity card with the optical scanner associated with the POS terminal 17, so that the store computer system 18 can look up the particular customer in a Customer Identification Database 130 as indicated at a block141 labelled LOOK UP IN CUSTOMER IDENTIFICATION DATABASE. Since the customer has now been identified twice, once by recourse to the Frequent Shopper Database 80 as indicated at a block 142 labelled FORMAT FREQUENT SHOPPER DATABASE, and once by recourse to the Customer Identification Database 130 at block 141, the two identifications can be compared as indicated at a block 143 labelled DOES IMAGE IDENTIFICATION .MATCH OTHER IDENTIFICATION? The logical comparison operation at block 143 can be performed in the system 10 as shown in FIG. 2 by passing results from the Frequent Shopper Database 80 to the store controller 18 via a suitable connection 40B between the two computers and then using software resident on the store controller 18.
If both identifications agree at block 143, this agreement can be noted, and taken as an indication of the accuracy of the automatic identificationsystem. Also, as discussed above, then the new feature set can be used in adaptive learning module 88 to modify the standard recognition feature setin the frequent shopper database 80. If the two identification subsystems disagree in block 143, the store computer system 18 may alert the clerk ofa need to verify the identity of customer as indicated at a block 144 labelled VERIFY OTHER IDENTIFICATION, for example, by comparing the signature on the scannable identity card with the signature on a tendered personal check. If the identity of the customer is thus verified, the clerk can input this datum to the computer system 18, which will interpretthis as a failure of the automatic image recognition system. Then the new image feature set from the customer's face can be used in the adaptive learning process at a block 149 to improve the Frequent Shopper there previously with the new feature set. Alternately, if the clerk's verification of the customer's identification indicates that the automaticsystem was right, for example, if the shopper presented a stolen identification card this datum can also be entered into the computer system 40 as a measure of the accuracy of the image analysis system. Also,the system can provide an additional benefit of being able to prevent financial loss to the store that could occur if a stolen check cashing identification card were to be used.
Although it is expected that the greatest value of the present invention will arise from the ability to associate a frequent shopper's purchases with his or her identity in an unobtrusive manner, it should be noted thatthe system 10 also provides for a measurement of the degree of attention that a product display attracts in a store. This may be understood with reference to FIG. 2 of the drawing, where an image acquisition and recognition unit 22 is covertly placed at a product display 34. The unit 22 will acquire images of all shoppers who are deemed to pay at least a minimum amount of attention to the display, for example, all those who approach within a predetermined distance and look at the display for at least a predetermined time.
It should be noted that the product display portion of the system may operate in a slightly different way than the checkout counter portion of the system. Since shoppers can be visible from a product display at a great range of angles and distances, the image acquisition subsystem used for this application may be more sophisticated than that described in FIG.3, and may be more similar to that taught by Lu in U.S. Pat. Nos. 4,858,000and 5,031,228. Moreover, since frequent shopper identification is also doneat checkout, it is not necessary to perform the entire identification process at the product display. Instead, facial images can then be acquired and translated into standard recognition feature sets as described above, and the standard feature sets can be temporarily retainedin memory, for example, by the store data collection computer 40 for a period of one half hour for subsequent comparison with feature sets of shoppers who are identified during checkout at the POS terminal 17.
While the invention has been described with reference to details of the illustrated embodiments, these details are not intended to limit the scopeof the invention as defined in the appended claims. | A market research system and method are provided. A plurality of cooperating establishments are included in a market research test area. Each cooperating establishment is adapted for collecting and storing market research data. A computer system remotely located from the plurality of cooperating establishments stores market research data collected from the cooperating establishments. The collected market research data includes monitored retail sales transactions and captured video images of retail customers. | 6 |
PRIOR APPLICATIONS
This is a continuation of application Ser. No. 11/031,930 filed on Jan. 10, 2005 now U.S. Pat. No. 7,292,437.
TECHNICAL FIELD OF INVENTION
Computing devices, including laptop computers, desk top computers, servers and video game terminals employ microprocessors which generate considerable heat. In fact, the heat generated from microprocessors is generally considered the limiting factor in computing speed. A heat sink is provided in thermal contact with a microprocessor in cooperation with a water barrier applied to and proximate a socket configured within the computing device's motherboard for preventing water of condensation from contacting areas covered by the water barrier. Efficient refrigeration protocols are suggested to maximize heat dissipation.
BACKGROUND OF THE INVENTION
As computing devices have become more powerful, microprocessor integrated circuits have become more sophisticated having increased clock speeds and computing power. As speeds increase, microprocessors operate at higher temperatures and, in fact, the single most important limiting factor in inhibiting computing speed is the thermal energy generated from such devices.
Recognizing that heat generated from microprocessors limits the speed and resulting power of the computing device, efforts have been made to dissipate thermal energy. Most personal computers employ cooling fans integrated within the computer's chassis. However, cooling fans tend to be noisy and thus can represent a significant distraction to a user. Further, the mere passage of air over a microprocessor contained within the small confines of a personal computer is not a particularly efficient method of dispersing heat energy. Unless sufficient cooling is carried out, the heat generated by the microprocessor can cause it to overheat and damage the device.
Recognizing that conventional fan-cooled computers represent a distraction and can cause a significant annoyance to a user affecting productivity, there have been attempts to deal with heat dissipation by means other than a fan. For example, in published application 2004/0156180, a large heat sink is employed as part of the computer chassis that contains the motherboard and hard drive. The heat sink is exposed to the external ambient air for heat dissipation while the motherboard and hard drive of the device are positioned within the chassis such that they are held tightly against the heat sink to allow the heat generated by the microprocessor and hard drive to be conducted to and dissipated by the heat sink. A further example can be found in U.S. Pat. No. 6,367,543 disclosing a housing which includes a lid having liquid flowing through ports located therein. A plurality of pins project outwardly from the bottom wall of the chamber, housing the active components of the device, in a staggered pattern whereby a thermal jacket is positioned over a liquid-held heat sink that does not directly engage the semiconductor package. The rather inefficient configuration taught by this reference is intended to reduce condensation that may form when operating at sub-ambient temperatures to reduce the risk of water damage to the interior of the cooled chamber. It is further taught that the outer surface of the thermal jacket is exposed to a sealant engaging the semiconductor element that remains at or near ambient temperature to minimize condensation on the surface of the thermal jacket.
U.S. Pat. No. 6,725,682 shows a desk top type personal computer employing a cooling apparatus composed of three modules, namely, a heat exchanger, a chiller and a pump. The heat exchanger is mounted so as to be thermally coupled to a CPU microprocessor. In operation, fluid is pumped from a pump module through a chiller module and through a heat exchanger and is finally recirculated to the pump. When the cooling apparatus is operating, chilled fluid passes through the heat exchanger so as to extract heat produced by the microprocessor. It is taught that the body of the electronic device has protrusions that may be thermally coupled to the hot portion of the device to maintain it at a sufficient distance from the surface of the microprocessor so that sufficient ambient air may circulate therebetween so as to substantially prevent condensation from forming on the surface of the electronic device and from forming on and dripping from the heat exchanger when fluid is cooled to at least the dew point of the ambient air. Clearly, such a configuration reduces the effectiveness of the heat sink for direct contact between it and the electronic device to be cooled is avoided so as to prevent water of condensation from being created at or around the microprocessor.
In light of the above discussion, it appears that several matters are well recognized in the prior art. Firstly, it is universally accepted that microprocessors, hard disk drives and other active components in a computing device must be cooled for limitations as to speed and computing power are limited by failure to dissipate heat, particularly from a microprocessor. Secondly, the prior art, although suggesting alternatives to traditional fan-based cooling devices, has suggested either non-optimal heat transfer configurations or limitations in cooling in order to minimize or entirely prevent water of condensation from adversely impacting the microprocessor and its surrounding topology.
It is thus an object of the present invention to provide an efficient heat transfer assembly which eliminates the need for noise generating components such as air moving fans.
It is a further object of the present invention to provide an effective heat transfer assembly which is not limited to a specific geometry or cooling temperature and which can be employed without damaging the microprocessor, its surrounding socket assembly and other components of the supporting motherboard.
These and further objects will be more readily apparent when considering the following disclosure and appended claims.
SUMMARY OF THE INVENTION
The present invention involves an assembly for use in a computing device such as a personal laptop computer, desk top computer, server or video game terminal. Each of these devices includes a microprocessor which generates heat during its operation. The invention includes the use of a heat sink in thermal contact with the microprocessor which is capable of providing a heat dissipating sink for removing thermal energy from the microprocessor much more effectively than devices of the prior art. The present invention includes applying a water barrier proximate the socket employed for making electrical connection to the microprocessor preventing water of condensation from contacting areas covered by the water barrier. Alternatively, the microprocessor can be encased within a shell having a fluid inlet and fluid outlet for recirculating coolant proximate the microprocessor and, if properly configured, the need for a water barrier applied to the socket and surrounding regions can be effectively eliminated. In either case, efficient refrigeration protocols are suggested to maximize heat dissipation.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 (prior art) is a cross-sectional plan view of a microprocessor installed on a motherboard being cooled by fan generating circulating air; and
FIGS. 2 , 4 and 5 are cross-sectional plan views of various embodiments of the present invention; and
FIG. 3 is a top plan view of a socket and supporting motherboard for accepting a microprocessor for use in practicing the present invention.
FIG. 6 is a schematic diagram of an efficient heat transfer protocol for use in practicing the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Turning first to FIG. 1 (prior art), a cross-sectional view of a relevant area of a device 10 is shown. Specifically, motherboard 11 is depicted in partial cross-computing section supporting a microprocessor CPU 13 consisting of substrate 14 and die 15 . Microprocessor CPU 13 can be applied to supporting motherboard 11 either through a pin connection or by a flush connection over indented region 12 . That portion of motherboard 11 supporting microprocessor CPU 13 is shown in top plan view in FIG. 3 . In this embodiment, pin receiving socket 31 having openings 32 for receiving the pins of substrate 14 (not shown) surrounds indented region 12 .
Turning back to FIG. 1 , a schematic depiction of a current cooling method commonly employed in laptop and desk top computers is shown. Specifically, fan 80 is caused to rotate by connecting a shaft to a motor (not shown) which can either be constantly engaged or periodically engaged through activation prompted by a thermo-couple or other thermal sensor located in the region of microprocessor CPU 13 . As the temperature of this device reaches a threshold value, fan 80 is engaged causing air flow schematically shown by arrows 81 . However, as noted previously, the activation of fan 80 is not only noisy and distracting to a user of the computing device but the mere passage of air in the directions of arrows 81 does not represent a particularly efficient means of cooling microprocessor CPU 13 .
A first embodiment of the present invention can be readily visualized by reference to FIG. 2 . As in the configuration depicted in FIG. 1 , computing device 20 again consists of motherboard 11 supporting microprocessor CPU 13 which, in turn, consists of support 14 and die 15 . However, instead of employing fan 80 , a heat sink consisting of heat sink shell 16 having fluid inlet port 17 and fluid exit port 18 to facilitate the passage of a coolant such as water, alcohol, antifreeze or mixtures thereof to the interior of heat sink shell 16 is used. Heat sink shell 16 is in direct thermal contact with die 15 , directly, or through the use of a heat conductive film 25 of, for example, a silver based thermal grease.
As noted previously, the prior art strongly suggests either refraining from adopting a configuration such as shown in FIG. 2 or, if such a configuration is adopted, to limit the temperature of coolant passing within heat sink shell 16 so that the exterior surface of the heat sink shell does not drop below the surrounding dew point of the air within the computing device in order to avoid water of condensation from adversely affecting socket 31 and, perhaps, other active components on motherboard 11 .
In practicing the present invention, the limitations suggested by the prior art limiting the temperature of heat sink shell 16 can be ignored. Specifically, applicant proposes, as a first embodiment, applying a water barrier proximate socket 31 in the areas where water of condensation is likely to appear and where such water of condensation, if not dealt with effectively, would compromise the computing device.
It is suggested that several water barrier implementations can be employed in carrying out the present invention. For example, the water barrier can comprise a layer of dielectric grease which can be spread over the socket in areas 23 and within indented region 12 as shown as area 22 and over substrate 14 shown as area 24 . A suitable dielectric grease for use in carrying out the present invention is Luberex Dielectric Grease. Alternatively, a low viscosity liquid can be sprayed onto the socket and surrounding regions such as a silicone spray sold by Amsoil. As yet a further alternative, the entire motherboard 11 can be dipped within a fluid which can either remain in its fluid state or dried so long as its dielectric water barrier properties are maintained and electrical connections are not filled or otherwise blocked through the dipping process. Suitable fluids for dipping include latex and oil base paints which can also be brushed or sprayed in the socket region of computing device 20 . Further, commonly available household consumer products such as fingernail polish could be applied to socket region 31 and portions of substrate 14 as shown in FIG. 2 in order to create the desired water barrier. In doing so, a user of the present invention need not be concerned with relative humidity or dew point temperature of the air within computing device 20 or the relative temperature of heat sink shell 16 in terms of water of condensation. Instead, heat shell 16 can be reduced to any desired temperature and thus provide an extremely effective expedient for drawing thermal energy from die 15 thus removing heat as a barrier to increased clock speeds and computing power.
FIG. 4 represents yet another embodiment of the present invention. Specifically, computing device 40 again consists of motherboard 11 supporting microprocessor CPU 41 having substrate 14 and die 15 as shown. However, microprocessor CPU 41 can be encased within shell 42 either directly at the manufacturing facility where microprocessor CPU 41 is manufactured or as an aftermarket add on component. In this instance, inlet port 43 and outlet port 44 can again be employed to receive and circulate cooling fluid in the direction of arrows 19 and 21 . In employing this embodiment, thermal grease is no longer required as there is direct physical contact between the cooling fluid within space 45 and the heat generating die 15 . In practicing the embodiment shown in FIG. 4 , a water barrier in terms of a dielectric grease or other expedient can be applied in the region proximate socket 31 including indented region 12 in the form of barrier 22 , substrate surface in the form of barrier 24 and the contact region between the substrate 14 and socket 31 in the form of barrier 23 .
FIG. 5 depicts yet a further embodiment of the present invention. In this instance, computing device 50 again includes the depiction, in partial cross-section, of motherboard 11 focusing upon its socket region 31 . Microprocessor CPU 51 again is shown as consisting of substrate 14 which can include pin connections to pin openings 32 or could represent a flush mounted connection to socket region 31 which further supports die 15 . As in FIG. 4 , a shell 54 is placed about microprocessor CPU 51 for receiving coolant through opening 52 and circulating coolant in area 45 to be expelled through opening and absorbent 53 in the direction of arrows 19 and 21 . Thus, coolant fills region 45 thus acting as an effective heat sink for heat generating die 15 .
The FIG. 5 embodiment further includes outer shell 55 creating a space between it and shell 54 . In order to minimize the flow of water of condensation, an absorbent and opening 53 , such as a cotton cloth, can be applied in this region thus absorbing water of condensation formed at the surface of shell 54 and thus preventing moisture from compromising socket 31 and its surrounding area. Although not shown, the embodiment of FIG. 5 can also employ, as an additional expedient, the various water barriers discussed previously and applied to the socket and its proximity again, as shown and described with relation to FIGS. 2 and 4 .
As noted previously, the present invention can effectively reduce the temperature of a microprocessor CPU without the need to use conventional noise generating devices such as cooling fans. Further, because the heat sink and microprocessor can be positioned to abut one another, heat transfer from the die of the microprocessor CPU through the heat sink can be much more effective than competing devices taught in the prior art. Thus, the limitations placed upon computing devices through over heating of the microprocessor CPU can effectively be eliminated.
Although there are a number of protocols useful in providing coolant to the recited heat sink, a preferred arrangement is shown schematically in FIG. 6 . Specifically a continuous fluid path is shown feeding a coolant to a heat sink strategically located proximate CPU 106 . This fluid is maintained at the desired (low) temperature within reservoir 125 and circulated by means of pump 110 . Fluid within reservoir 125 is maintained at a predetermined temperature through the use of refrigeration unit 120 that circulates a refrigerant such as Freon through evaporator 115 consisting of heat transfer coils and an expansion valve (not shown).
The present invention has been described fundamentally in terms of a computing device suggesting its application principally in the areas of laptop and desk top personal computers. However, applicant's invention can be used in such diverse areas as servers temperature of the facility well below that which would otherwise be necessary for human comfort. In other words, the active components within the server generating heat are dealt with by reducing the entire ambient surrounding temperature of the servers which represents an exceedingly inefficient use of energy. By employing the present invention, however, a server facility need not be air conditioned and suitable heat sinks such as those described above, can be employed only in those areas within each server requiring the dissipation of thermal energy.
In view of the various embodiments to which the present invention may be applied, it is noted that the embodiments described herein are meant to be illustrative only and should not be taken as limiting the scope of the invention. | Computing devices, including laptop computers, desk top computers, servers and video game terminals employ microprocessors which generate considerable heat. In fact, the heat generated from microprocessors is generally considered the limiting factor in computing speed. A heat sink is provided in thermal contact with a microprocessor whereby a water barrier is applied to and proximate a socket configured within the computing device's motherboard for preventing water of condensation from contacting areas covered by the water barrier. | 7 |
FIELD OF THE INVENTION
[0001] The present invention relates to educational systems and “hands-on” methods for teaching that utilize samples to reinforce concepts. More specifically, some embodiments of the present invention are directed to simulating the discovery and preparation of fossils.
BACKGROUND OF THE INVENTION
[0002] There is a great deal of interest in prehistoric life and the study of fossils. Television shows, movies and books about prehistoric animals and prehistoric life enjoy almost continual popularity. Rather than merely be entertained, a large percentage of those interested in prehistoric life seek to be educated about their interests. Information concerning paleontology, biology, archeology and related disciplines is widely available for those interested. Fossils and reproductions of fossils are popular items for education and display. The process of obtaining and preparing a fossil for research or display is an experience that many would like to have.
[0003] Fossils, like other geologic specimens, typically occur in certain formations. The ages and types of fossils vary with the different compositions of fossil-bearing formations. Since fossils are only found in certain formations, those wishing to collect fossils must travel to those locations. Not only is this inconvenient for those living at a distance from any fossil beds, but even those who live in relatively fossil-rich areas may have to travel hundreds of miles to collect fossils from different eras. For example, in the western U.S. where fossils are considered relatively common, limestone strata-bearing aquatic fossils from an ancient lake with an age of 40 to 60 million years may be found in the area around Fossil Lake National Monument in Wyoming. Older fossils, such as dinosaur bones from the Mesozoic Era (150 to 165 million years ago) are several hundred miles away in the area around Vernal in Eastern Utah, and even older Paleozoic Era (245-300 million years ago) marine fossils, such as trilobites, may be found in shale strata area around the town of Delta in western Utah. Often these fossil bearing formations are in areas that are dedicated for scientific research, are National Parks or National Monuments, or are otherwise closed to the general public.
[0004] Reproductions of fossils are available for those interested in fossils. For example, U.S. Pat. No. 3,769,114, issued Oct. 30, 1973 and U.S. Pat. No. 3,917,786 issued Nov. 4, 1975 are directed to the manufacture of such reproductions. A photograph of a fossil is printed on paperboard, which is then embossed to copy the three dimensional aspects of the fossil. The paperboard is then mounted on a stone to mimic the original fossil. While this method allows those interested to own a reproduction, it fails to provide them with the experience of owning an actual fossil, of collecting that fossil and of preparing that fossil.
[0005] U.S. Pat. No. 6,216,896 issued on Apr. 17, 2001 represents one attempt to provide an enhanced fossil-owning experience. A reproduction of a fossil integrated into a reproduced rock is prepared from clay and fired in a kiln to harden. A second layer of a softer clay is then layered over the reproduction and fired. The softer clay may be scraped off by a purchaser, somewhat simulating the experience of cleaning a fossil. U.S. Pat. No. 5,94,712 is directed to an educational kit that also attempts to provide an enhanced fossil-owning experience. A miniaturized reproduction of a dinosaur skeleton and a miniature reproduction of a paleontologist's tool kit are provided. An adult hides the miniature skeleton and supervises a child in finding it. While these products provide a child with the experience of obtaining a fossil reproduction, they do not provide a realistic experience of either collecting or preparing a fossil for use. Further, they fail to provide the user with an actual fossil.
[0006] Kits that provide a user with an actual fossil are known. These kits consist of a segment of fossil-bearing rock, known to contain a fossil, such as a limestone slab known to contain a fossil fish. Appropriate tools for cleaning the fossil and cleaning instructions are also provided. The purchaser is thus provided with a fossil and the equipment needed to prepare and display that fossil. These kits have proven very popular as they provide an enjoyable and educational experience. However, like the reproductions, these kits fail to provide the user with the experience of collecting a fossil from its natural surroundings. Similarly, the preparation experience is limited to cleaning the fossil for display following a set of instructions. A system or method that provides a user with the experience of collecting an actual fossil in the field and preparing that fossil for use, without requiring the user to travel to the naturally-occurring fossil bed, would be advantageous. Such a system or method that includes fossils from different eras and locations to be collected and investigated would be further advantageous.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to systems and methods for teaching subjects related to the collection and preparation of samples, such as fossils. In one exemplary embodiment, a quarry, or “dig” is provided where students may collect samples, recreating the experience of fieldwork. Instruction on the collection of samples may be given during collection. A student may take a collected sample to a learning center or preparation laboratory that is provided to prepare the sample for study or display. Instruction on the preparation of the sample and what may be learned from the sample may be provided at the same time.
DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 illustrates one possible embodiment of a sample collection area for use with one illustrative embodiment of a system in accordance with the present invention;
[0009] [0009]FIG. 2 illustrates one possible embodiment of a sample preparation area for use with one illustrative embodiment of a system in accordance with the present invention; and
[0010] [0010]FIG. 3 is a flowchart illustrating one possible embodiment of a process for providing an educational sample collection and preparation experience, in accordance with one aspect of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0011] The present invention relates to educational systems and “hands-on” methods for teaching that utilize samples to reinforce concepts. More specifically, some embodiments of the present invention are directed to simulating the discovery and preparation of fossils.
[0012] It will be appreciated by those skilled in the art that the embodiments herein described, while illustrating certain embodiments, are not intended to so limit the invention or the scope of the appended claims. Those skilled in the art will also understand that various combinations or modifications of the embodiments presented herein can be made without departing from the scope of the invention. For example, it will be appreciated that the methods and systems discussed herein, while particularly suited for education and entertainment concerning fossils and paleontology, may easily be adapted for educating about other types of fieldwork involved in other scientific disciplines. Exemplary alternative embodiments directed to teaching archeology, geology, field biology, and so forth are possible and will also be discussed further herein. All such alternate embodiments are within the scope of the present invention.
[0013] In drawing FIG. 1, a box diagram representation of a simulated collection area 10 , useful in practicing some embodiments of the present invention, is shown. An area 12 is configured to simulate a location where an item of interest naturally occurs, such as a “dig” at a fossil bed or archeological site, or a quarry where geologic samples are collected. Area 12 maybe an indoor area, such as a room, hall, pavilion or other structure; alternatively, area 12 may be an outdoor area where appropriate. The configuration of area 12 to simulate the location where the item of interest naturally occurs may be accomplished in any desired manner. For example, where area 12 is an indoor area, the room may be painted to resemble the appropriate outdoor surroundings.
[0014] A number of simulation items 20 may be disposed in the area 12 to further enhance the simulation. Simulation items 20 may include any item that can be used to simulate the appearance of a location where an item of interest 16 naturally occurs. Plants and geologic formations from the naturally occurring location, rock strata that lie above and below the bulk collection material 16 in the natural location, a recreation of a gorge or stream, dioramas and constructions that mimic the appearance of a dig or exploration site are all examples of some potential simulation items. Where area 12 is an indoor area, environmental conditioning, such as heating, air conditioning, sun lamps, humidifiers or dehumidifiers may be used to further enhance the simulation. The recreation of appropriate naturally occurring sounds, such as animal noises, wind sound and so forth may also be used, as may the appearance of naturally occurring animals.
[0015] A bulk collection material 16 is placed into area 12 . The bulk collection material 16 contains collectible items, samples, or items of interest 18 . Bulk collection material 16 may be any material in which an item of interest 18 naturally occurs. For example, where items of interest 18 are aquatic fossils, the bulk collection material 16 may be a strata of stone containing those fossils. Alternatively, the bulk collection material 16 may be a simulated material with the items of interest 18 placed therein. For example, where items of interest 18 are archeological items, such as coins or tools, the bulk collection material 16 may be appropriately appearing layers of earth from which the archeological items (i.e. items of interest 18 ) may be retrieved. It will be appreciated that, where appropriate and desired, the items of interest 18 may similarly be reproductions, such as reproductions of certain fossils, archeological specimens, or gemstones, in order to provide a thorough educational experience where the scarcity or expense of using the actual items would be prohibitive.
[0016] Bulk collection material 16 may be integrated into the appearance of the area 12 to further simulate the naturally-occurring location. For example, where the bulk collection material 16 is fossil-containing rock, it may be placed in a geologic diorama including surrounding strata and other simulation items 20 that may be found at a location where the bulk collection material 16 naturally occurs.
[0017] Collecting tools 14 for extracting the items of interest 18 from the bulk collection material 16 may also be provided in area 12 . These may include shovels, brushes, chisels, picks trowels, screens and any other tool commonly used for such a purpose. The specific collecting tools 14 provided may vary depending on the type of items of interest 18 and bulk collection material 16 provided. Workbenches, supply cabinets and any other necessary items may also be supplied in the area 12 . Where such items are supplied, they may be integrated into the simulated appearance of the naturally occurring location, such as a fossil dig. A space for instruction, including all necessary elements, such as seats, tables, and audiovisual components may be provided in area 12 to facilitate instructions in extracting the items of interest 18 .
[0018] A user entering the area 12 may thus be provided with collecting tools 14 and appropriate instruction to extract an item of interest 18 from the bulk collection material 16 , furnishing that user with the experience of collecting an item of interest 18 in its naturally-occurring location. Any number of simulated collection areas 10 may be provided at a location, such as a store or museum, each containing different items of interest and allowing a user to experience collecting different items of interest at one central location. At a single location for example, a first collection area 10 may contain aquatic fossils from and simulate the area of Fossil Lake, Wyo. and a second collection area 10 may contain older dinosaur bone fossils (or reproductions) and simulate an appropriate area, such as Dinosaur Cove of Victoria, Australia. It will be appreciated that a simulated collection area 10 made in accordance with the principles of the present invention thus provides a location where instruction in proper collection techniques, or the experience of collecting item of interest from its naturally occurring location can be provided, without requiring users to travel to the naturally occurring location or interfering with ongoing work at such location.
[0019] A single simulated collection area 10 may be constructed to include a number of stations 15 where items of interest 18 can be extracted from the bulk collection material 16 . It will be appreciated that each station may contain different items of interest and/or different bulk collection materials 16 as desired. In one exemplary embodiment, one station 15 may hold items of interest in a bulk collection material that is easily extracted from, allowing the items of interest 18 to be easily collected, as by a small child. A second station 15 would contain the items of interest 18 in a more realistic bulk collection material 16 that requires more effort to successfully extract an item of interest 18 , providing a more realistic collection experience to an older user.
[0020] Referring to drawing FIG. 2, a block diagram of one possible embodiment of a learning center 40 , in accordance with an embodiment of the present invention is shown. Learning center 40 is set up in an area 42 that is designed to simulate the appearance of a facility where items of interest 18 would normally be processed when extracted from their naturally occurring location. For example, area 42 may be designed to appear as a preparation laboratory, where fossils are extracted and cleaned of surrounding material and studied to elucidate information therefrom. Alternatively, area 42 may simulate a field laboratory where initial work is done on samples allowing them to be transported to a larger facility. In such a “field lab” embodiment, area 42 for learning center 40 may be continuous with area 12 of FIG. 1 or may alternatively consist of an area 42 separate and apart from area 12 .
[0021] It will be appreciated that where the items of interest 18 are items other than fossils, area 42 may be configured to simulate the appropriate processing facility, such as, for example, an assaying laboratory or a gemstone processing facility. All such alternative embodiments are within the scope of the present invention.
[0022] One or more workstations 44 , such as lab benches, are disposed in area 42 where items of interest 18 may be prepared. A workstation 44 will preferably contain all the tools 48 and supplies 46 necessary for preparation of an item of interest 18 . It will be appreciated that the workstations may take any desired appearance and that tools 48 and supplies 46 may merely be made available in area 42 .
[0023] Preparing the items of interest 18 may take many forms, depending on the item of interest 18 , and may result in the item of interest 18 being ready for use or study or ready to be displayed. For example, where the items of interest are fossils, the preparation may include removing part or all of the bulk collection material 16 adhering to the extracted fossil and measuring aspects of the fossil to make determinations, such as species, age, cause of death, and so forth. Preparation could further include preparing the fossil to be displayed as a museum piece or for decoration. Where the item of interest 18 differs, the preparation may accordingly differ. For example, if the item of interest 18 is a gemstone extracted from an appropriate bulk collection material 16 , preparation may include cleaning the gemstone and preparing it for industrial use or for use as jewelry, determining the classification and weight of the gemstone, polishing and cutting the gemstone, or even mounting the otherwise prepared gemstone in a jewelry setting. As another example, where the items of interest 18 are archeological specimens, preparation may include cleaning the specimens using appropriate techniques, identifying and characterizing the specimens, and preparing the specimens for proper storage and/or display.
[0024] The tools 48 and supplies 46 needed for preparation of the items of interest 18 may vary in accordance with the requirements for differing items of interest 18 and different methods and techniques for preparation thereof. Tools 48 may include any needed brushes, probes, forceps, measuring instruments, vats, cameras, hammers, saws, cutting tools, polishing cloths, stone polishing machines, heating torches, or any other required or desired tool. Supplies 46 may include solvents, cleansers, reference books, reference tables, charts and graphs, film or any other supply required or desired for a preparation process.
[0025] Area 42 may also include an instructional area 50 set off from the workstations 44 , where users may be provided with instructions away from the preparation process. It will be appreciated that a learning center 40 , such as that depicted in FIG. 2, made in accordance with the principles of the present invention provides an area whereby instruction in proper preparation techniques or the experience of preparing a extracted item of interest can be provided without tying up the resources of a working facility or requiring users to travel to a facility.
[0026] Drawing FIG. 3 depicts a flowchart of a process for providing an educational sample collection and preparation experience to a user that is in accordance with the principles of the present invention. For clarity, the process will be explained in connection with the embodiments of FIGS. 1 and 2. It will, of course, be appreciated that the flowchart is illustrative only and depicts only one possible embodiment of a process, other processes in accordance with the teachings of the present invention are possible, and any such suitable process may be used, all such processes are within the scope of the present invention.
[0027] As shown in box P 1 , a simulated collection area 10 , discussed previously herein, is provided to mimic the appearance of a naturally occurring location of items of interest 18 . A bulk collection material 16 , containing items of interest 18 is provided in the simulated collection area 10 , as shown in box P 2 . This may occur by importing a bulk collection material 16 that naturally contains the items of interest 18 , such as a fossil containing strata of rock, or by placing items of interest, such as reproductions of fossils or antique coins into an appropriate bulk collection material 16 . By the latter method, the level of difficulty in extracting the items of interest 18 can be varied. For example, reproductions of fossils can be placed into an easy bulk extraction material 16 , such as sand, in order to provide younger children with the opportunity to extract a “fossil” and learn about paleontology.
[0028] Instruction to the users on extracting the items of interest 18 from the bulk collection material 16 may then be provided, as shown in box P 3 . For example, a lecture on proper collection technique maybe given, a video presentation on proper collection technique may be given, and/or hands on instruction may be given as items of interest 18 are extracted. Users are allowed to extract items of interest 18 from the bulk collection material 16 , as shown in box P 4 , either with assistance or on their own. Further instruction may then be given.
[0029] A simulated preparation area, such as learning center 40 is provided, as shown in box P 5 , where users may take extracted items of interest 18 for preparation. Instruction on preparing the item of interest 18 for use or display are provided, as shown in box P 6 . Instruction may be given in any suitable manner, ranging from lecture, to video or multimedia presentation, to direct instruction during “hands on” preparation of the item of interest. It will be appreciated that preparation may take any form discussed herein.
[0030] Accordingly, the present invention includes methods of teaching. In a simple form, these methods may be practiced by providing an amount of bulk collection material containing a number of samples in a designated area, instructing users in proper collection technique, and directing the users to obtain a sample the bulk collection material. The designated area may be configured to mimic the appearance of a location where the bulk collection material is naturally found. The bulk collection material may be any suitable substance, as discussed previously herein, including geologic formations bearing fossils, gemstones or other items of interest as samples. Instruction in proper collection techniques may be given as desired, including lectures and direct demonstrations in the designated area, and hands-on instruction.
[0031] These methods may further include providing a preparation area for processing collected samples and instructing users in processing the samples. This may include providing the necessary equipment for processing the collected samples. Processing may refer to any preparation discussed previously herein, such as preparing a collected sample for display or preparing the sample for use by identifying particular aspects of the sample.
[0032] The present invention further includes processes for simulating fieldwork. In a basic form, this processes may be practiced by obtaining a sample from a number of samples in a bulk collection material located in a simulated fieldwork area and processing the sample for use. The sample may be any item of interest as discussed herein, and processing the sample for use may be performed as discussed herein. Processing the sample for use may include taking the sample to a simulated preparation laboratory.
[0033] It will be appreciated by those skilled in the art that illustrated embodiments herein described are not intended to limit the invention or the scope of the appended claims. Various combinations and modifications of the preferred embodiments could be made without departing from the scope of the present invention and all such modifications are within the scope of the present invention.
[0034] Thus, 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 in the invention disclosed herein may be made without departing from the scope of the invention, which is defined in the appended claims. | Systems and methods for teaching subjects related to the collection and preparation of collectible samples, such as fossils. In one exemplary embodiment, a quarry, or “dig” is provided where students may collect samples, recreating the experience of fieldwork. Instruction on the collection of samples may be given during collection. A student may take a collected sample to a provided learning center, or preparation laboratory, is provided to prepare the sample for study or display. Instruction on the preparation of the sample and what may be learned from the sample may be provided at the same time. | 6 |
TECHNICAL FIELD
[0001] Embodiments of the invention relate to non-volatile memory devices, and, more particularly, to non-volatile memory device bit line drivers.
BACKGROUND OF THE INVENTION
[0002] Memory read, erase or program operations are conventionally executed in response to external signals provided to the memory by a controller (not shown) or other memory access device (also not shown). A bit line coupled to a selected memory cell to be read, erased or programmed must be pre-charged or prepared for executing a particular memory operation. FIG. 1 shows a block diagram of a prior art bit line driver 101 coupled to a bit line of a memory array. The bit line driver 101 is designed to meet a number of operating requirements during a memory operation. For example, during a programming operation, the bit line driver 101 receives data to be programmed to a selected memory cell, and applies the programming data signal to the bit line. Memory having multi-level cells require multiple programming voltages and/or programming pulse widths corresponding to combinations of the multiple data bits that can be stored in the memory cell.
[0003] An input data bit received by the memory device are applied to an inverter 105 through an NMOS transistor 103 that is continuously turned ON by a supply voltage Vcc coupled to its gate. The output signal of the inverter 105 is applied to a node 115 through an NMOS bias transistor 110 that receives a predetermined bias voltage. A number of components are coupled to the node 115 to allow the bit line driver 101 to perform several functions. The node 115 is coupled to the corresponding bit line by an NMOS transistor 119 , and also through an NMOS transistor 117 to an output of an inverter 125 , which precharges the node 115 to a voltage Vcc or Vss depending on a voltage applied to the input of the inverter 125 . The respective gates of the transistors 117 , 119 are coupled to an output of an inverter 123 so that both transistors 117 , 119 are turned ON responsive to a low applied to the input of the inverter 123 . The output node 115 is also coupled to a state machine through an inverter 121 that communicates signals to the state machine during programming operations. For example, the state machine may receive an instruction set to program a particular block of memory. In response, the state machine signals the bit line driver 101 to precharge the bit line or it may cause a predetermined programming voltage to be applied to the selected bit line during a programming operation.
[0004] In operation, the manner in which the bit line driver 101 responds to the input data bit depends upon the initial state of the output node 115 . For example, the state machine may interpret a low at the output of the inverter 121 as indicating that a program operation is needed to change the state of a memory cell being programmed. Thus, if the output node 115 is initially at V CC , an active operation occurs in which the input data bit applied to the inverter 105 controls the state of the output node 115 . Therefore, if the input data bit is high, the output node 115 will be pulled to the low (V SS ) at the output of the inverter 105 through the transistor 110 , which is turned ON by the bias voltage. If the input data bit is low, the output of the inverter 105 will by high. In such case, the transistor 110 will be turned OFF. Although the inverter 105 will be unable to drive the output node 115 high, the output node 115 will nevertheless remain high because of the charge on a capacitor 107 that is coupled to the output node 115 .
[0005] If the state machine interprets a low at the output of the inverter 121 as calling for an active operation, it may interpret a high at the output of the inverter 121 as calling for a null operation in which the input data applied to the inverter 105 does not control the state of the output node 115 . In the case of a null operation, the output node 115 will initially be discharged to V SS . If the input data bit is high, the output of inverter 105 will be low, and the output node 115 will therefore remain at V SS . Finally, if the input data bit is low, the output of the inverter 105 will be high. The transistor 110 will be turned ON by the bias voltage to allow the output of the inverter 105 to charge the output node 115 . However, the voltage of the output node 115 will increase only until it reaches the bias voltage less the threshold voltage of the transistor 110 , at which point the transistor 110 will turn OFF. By choosing the magnitude of the bias voltage so that it is substantially equal to V T -V SS , where V T is the threshold voltage of the transistor 110 , the output node 115 will remain at V SS , thereby continuing to indicate a null operation to the state machine. Thus, by keeping the magnitude of the bias voltage at substantially equal to V T -V SS , the bit line driver 101 can maintain the proper voltage on the output node 115 for all values of the input data bit in both the active operation and the null operation. The operation of the bit line driver 101 for both values of input data bits in the active operation and the null operation are summarized in Table 1, below:
[0000]
TABLE 1
Initial State of
Final State of
Node 115
Input Data
Node 115
Case #1
Vcc
1
Vss
Case #2
Vcc
0
Vcc
Case #3
Vss
1
Vss
Case #4
Vss
0
Vss
[0006] Unfortunately, it is difficult to maintain the bias voltage at the correct magnitude since the bias voltage can vary significantly with different process variations and as the temperature of the integrated circuit substrate varies. As a result, the voltage of the output node 115 can rise to unacceptable levels in the null operation when the input data bit is low. More specifically, if the voltage of the output node 115 increases above the threshold voltage of an NMOS transistor (not shown) in the inverter 121 , the NMOS transistor and a complementary PMOS transistor (not shown) connected in series with the NMOS transistor will both be ON at the same time. Insofar as a bit line driver 101 is provided for each column of a memory device, the amount of power consumed by the transistors in the inverter 121 can be considerable. Also, in some cases, the inverter 121 may apply a signal to the state machine that incorrectly calls for an active operation.
[0007] There is, therefore, a need for a bit line driver in a non-volatile memory device and method for generating a bias voltage that ensures the correct operation of the bit line driver for all operating conditions despite process and temperature variations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a block diagram showing a bit line driver coupled to a respective bit line in an array of memory cells.
[0009] FIG. 2 is a block diagram showing a bias voltage circuit coupled to a bit line driver of FIG. 1 , according to an embodiment of the invention.
[0010] FIG. 3 is a schematic diagram of a bias voltage circuit coupled to a bit line driver, according to an embodiment of the invention.
[0011] FIG. 4 is a block diagram showing a flash memory device having a bias voltage circuit coupled to a plurality of bit line drivers respectively coupled to a plurality of bit lines, according to an embodiment of the invention.
[0012] FIG. 5 is a simplified block diagram of a processor-based system including the flash memory device of FIG. 4 .
DETAILED DESCRIPTION
[0013] Embodiments of the invention are directed to non-volatile memory devices whose bit lines of a memory array are coupled to bit line drivers that includes a bias voltage generator. Certain details are set forth below to provide a sufficient understanding of the invention. However, it will be clear to one skilled in the art that the invention may be practiced without these particular details. In other instances, well-known circuits, control signals, and timing protocols have not been shown in detail in order to avoid unnecessarily obscuring the invention.
[0014] FIG. 2 shows a bit line driver system 300 that includes a bit line driver 301 coupled to receive a BIAS signal from a bias voltage circuit 350 according to an embodiment of the invention. The bit line driver 301 receives an input data signal and controls the voltage level applied to a respective bit line, as previously described. The bit line driver 301 is the same as the bit line driver 101 shown in FIG. 1 , except that the BIAS voltage signal is generated by the bias voltage circuit 350 . The bias voltage circuit 350 includes a bias voltage generator 354 that generates the appropriate bias voltage applied to the bit line driver 301 . Because of the time required for coupling the BIAS voltage signal to each of the bit line drivers 301 , which will be described further, the bias voltage circuit 350 also includes a pre-charging circuit 352 that expedites the time for applying the BIAS signal to the gate of the transistor 110 ( FIG. 1 ) in the bit line driver circuit 101 . The combined functionality of the bias voltage generator 354 and the pre-charging circuit 352 provides advantageous operating capabilities for both values of input data bits in both active operation and null operation, as described further below.
[0015] FIG. 3 is a schematic drawing of a bit line driver system 400 that illustrates in more detail the bit line driver system 300 of FIG. 2 . The bit line driver 401 is the same as the bit line driver 101 of FIG. 1 , except that the gate of an NMOS bias transistor 410 is coupled to the output of a bias voltage circuit 450 . Several of the components in the bit line driver 401 are the same as components in the bit line driver 101 in FIG. 1 , and are identified by the same reference numbers. In the interest of brevity, an explanation of the structure and operation of these same components will not be repeated. As described, a bias voltage circuit 450 utilizes the combination of a bias voltage generator 454 and a pre-charging circuit 452 to generate a BIAS signal that is applied to the transistor 410 . The outputs of the bias voltage circuit 450 and the pre-charging circuit 452 are coupled to a bias node 440 that provides a bias signal to control the bias transistor 410 of the bit line driver 401 . In such manner, the bias voltage circuit 450 is coupled to each of the bit line drivers 401 that are in turn coupled to each of the bit lines in the memory array. The bias node 440 is additionally coupled to a low pass filter that is formed by a series resistor 442 and a capacitor 444 coupled to ground. This low pass filter attenuates noise and other interference before the generated bias signal is applied to the bias transistor 410 .
[0016] The bias voltage generator 454 includes a current mirror circuit 473 having a pair of NMOS transistors 478 a, b coupled between two voltage supplies Vcc and Vss. The current mirror circuit 473 may be the current mirror circuit 473 in the bias voltage generator 454 or any other embodiment as known in the art. The transistors 478 a, b are coupled together in a manner such that a current is generated through the drain-to-source channel of the transistor 478 b that mirrors a current through the drain-to-source channel of the transistor 478 a , which is generated by a current source 475 coupled to the drain of the transistor 478 a . Similarly, a pair of NMOS transistors 482 a, b are coupled together (also between two voltage supplies Vcc and Vss) and the source of the transistor 482 a is biased to the drain of the transistor 478 b . As a result, a current generated through the drain-to-source channels of the respective transistors 482 a, b is also the current through the transistor 478 a . The source of the transistor 482 b is additionally coupled to the drain and gate of an NMOS bias transistor 411 whose gate is also coupled to a first input of a comparator 474 .
[0017] In operation, the bias transistor 411 provides to the comparator 474 a bias voltage V BIAS that is generated by the mirrored current through the transistor 411 . The output of the comparator 474 is coupled to the inverting input of the comparator so that it operates as a voltage follower. Therefore, the comparator 474 outputs the bias voltage V BIAS with a low output impedance, which is applied to the gate of the bias transistor 410 . The bias transistor 411 and the bias transistor 410 have the exact same characteristics such that the bias voltage V BIAS will vary with process and temperature variations in the same manner as the bias transistor 410 . Therefore, the bias voltage V BIAS will track variations of the threshold voltage V T of the transistor 410 due to process and temperature variations.
[0018] Although only one bias transistor 410 is shown in the embodiment of FIG. 3 to illustrate the operation of the single bit line driver 401 , it should be noted that a bias transistor 410 is provided for each of a large number of bit lines in a memory device. Due to the heavy load of the large number of bias transistors 410 , the bias voltage can take a very long time to build up at the bias node 440 . Therefore, the pre-charging circuit 452 is used to quickly charge up the bias voltage at the bias node 440 . The pre-charging circuit 452 includes a comparator 472 having a first input coupled to the gate of an NMOS bias transistor 413 . The gate and drain of the bias transistor 413 is additionally coupled to an NMOS transistor 482 c , that is biased by coupling its gate to the gates of the transistors 482 a, b of the mirror circuit 473 . The transistors 413 , 482 c are additionally coupled between two voltage supplies Vcc and Vss. Therefore, the transistor 482 c has a drain-to-source current that is mirrored to the currents generated by the current mirror circuit 473 . This current is coupled through an NMOS transistor 413 , which provides a bias voltage (“Vbias-Δ”) to the first input of the comparator 472 . The transistor 413 is designed with a drain-to-source impedance that is slightly less than the drain-to-source impedance of the transistor 411 . As a result, the voltage Vbias-Δ is slightly less than the voltage V BIAS .
[0019] A second input of the comparator 472 is coupled to the output signal of the comparator 474 such that the Vbias-Δvoltage is compared to the bias voltage V BIAS generated at the output for the comparator 474 . The output of the comparator 472 is coupled to the gate of another NMOS transistor 476 , whose drain is coupled to a high voltage supply V CC and the source is coupled to the output of the comparator 474 .
[0020] In operation, if the Vbias-Δ voltage is greater than the bias voltage V BIAS , the comparator 472 turns ON the transistor 476 thereby applying V CC to the bias node 440 . As a result, the bias node 440 is quickly charged towards the supply voltage Vcc until the bias node 440 is charged to the Vbias-Δ voltage. At that point, the comparator 472 turns OFF the transistor 476 . The comparator 474 then completes charging the bias node 440 to the bias voltage.
[0021] A flash memory device 600 that includes the bit line driver system according to one embodiment of the invention is shown in FIG. 4 . The flash memory device 600 includes an array 630 of flash memory cells arranged in banks of rows and columns. Command signals, address signals and write data signals are applied to the memory device 600 as sets of sequential input/output (“I/O”) signals applied to respective input terminals 632 . Read data signals are output from the flash memory device 600 through respective output terminals 634 . In practice, the same terminals can be for some of the input terminals 632 and output terminals 634 , such as data terminals that receive write data and output read data.
[0022] Address signals applied to the input terminals 632 are coupled to a bit line decoder 640 and to a word line decoder 644 . The word line decoder 644 applies signals to word lines (not shown) in the array 630 based on a row address corresponding to the address signals. Similarly, the bit line decoder 640 selects one or more bit lines based on respective column addresses corresponding to the address signals. The signals generated by the bit line decoder 640 are applied to a set of bit line drivers 650 , which may be the bit line drivers 301 or 401 shown in FIGS. 2 and 3 , respectively, or a bit line driver according to some other embodiment of the invention. The bit line decoder 640 may, for example, apply signals to the inverter 123 ( FIG. 3 ) in the bit line drivers 401 . As explained above, each of the bit line drivers 650 applies signals to respective state machines 660 indicative of the state of the respective bit line. As also explained above, the bit line drivers 650 are coupled to the array 630 through respective bit lines.
[0023] Write data signals applied to the input terminals 632 are applied to an input data drivers 670 , and from the drivers 670 to the input data terminals of the bit line drivers 650 , as explained above with reference to FIG. 3 . Read data signals applied to bit lines in the array 630 are detected by sense amplifiers 680 , which apply corresponding write data signals to the output terminals 634 .
[0024] FIG. 5 is a block diagram of a processor-based system 700 including processor circuitry 702 having a volatile memory 710 . The processor circuitry 702 is coupled through address, data, and control buses to the volatile memory 710 to provide for writing data to and reading data from the volatile memory 710 . The processor circuitry 702 includes circuitry for performing various processing functions, such as executing specific software to perform specific calculations or tasks. The processor-based system 700 also includes one or more input devices 704 coupled to the processor circuitry 702 to allow an operator to interface with the processor-based system 700 . Examples of input devices 704 include keypads, touch screens, and scroll wheels. The processor-based system 700 also includes one or more output devices 706 coupled to the processor circuitry 702 to provide output information to the operator. In one example, the output device 706 is a visual display providing visual information to the operator. Data storage 708 is also coupled to the processor circuitry 702 to store data that is to be retained even when power is not supplied to the processor-based system 700 or to the data storage 708 . The flash memory device 600 , or a flash memory device according to some other example of the invention, can be used for the data storage 708 .
[0025] Although the present invention has been described with reference to the disclosed embodiments, persons skilled in the art will recognize that changes may be made in form and detail without departing from the invention. Such modifications are well within the skill of those ordinarily skilled in the art. Accordingly, the invention is not limited except as by the appended claims. | An integrated circuit bit line driver system includes a plurality of bit line drivers coupled to respective bit lines of an array of non-volatile memory cells. Each of the bit line drivers includes a bias transistor through which an input signal is coupled to the respective bit line. The bit line driver system includes a bias voltage circuit that generates a bias voltage that is coupled to the respective gates of the bias transistors. The bias voltage circuit initially accelerates the charging of the transistor gates, and subsequently completes charging the gates at a slower rate. The bias voltage is generated using a diode-coupled transistor having electrical characteristics the match those of the bias transistors so that the bias voltage varies with process or temperature variations of the integrated circuit in the same manner as the threshold voltage of the bias transistors vary with process or temperature variations. | 6 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to means for sealing within a flow conduit for controlling fluid flow therein. In particular, the invention comprises a packer for sealing against a surrounding well conduit. The invention is particularly, though not exclusively, adapted to hydraulic set packers operated by fluid pressure applied via the tool mandrel and its supporting tubing string.
2. Description of the Prior Art
One of the problems associated with many conventional packers is that of leakage due to high pressures within the well conduit being sealed. For example, in a typical hydraulic set packer, if the pressure within the well exceeds the effective hydraulic setting pressure, leakage past the packer seal may occur. There is need for a relatively simple and economical packer which will effectively seal against such leakage without the application of excessive internal setting pressure and, in particular, one in which the seal will be tightened in its set position upon the presence of well pressure differentials across the seal in either longitudinal direction.
Another problem associated with the use of conventional packers is that the seal, being generally in an exposed and vulnerable position on the exterior of the tool, is subject to damage. For example, when the tool is being run into the well, it may be damaged by contact with internal obstructions or irregularities in the well conduit. Rapid lowering of the packer increases the likelihood of such damage and may also create a swabbing effect which can itself damage the seal and/or cause premature setting of the packer. Another occasion for seal damage may occur after the tool has been lowered into the desired position, but before it has been set, due to the abrading effects of sand and other material in the well fluid which may be circulated about the seal. Thus, in the past it has frequently been necessary to lower the packer into the well slowly to avoid such damage.
Another disadvantage of many conventional hydraulic set packers is that, in order to provide an adequate stroke for the piston of the seal actuator, the packer must be made relatively long and is consequently difficult and sometimes impossible to maneuver in tortuous well conduits. Attempts to shorten the overall packer length made at the expense of the size of the seal may result in reduced sealing effectiveness.
There is therefore a need for an improved packer, and in particular for a hydraulic set packer, which will alleviate these and other problems in conventional prior art tools.
SUMMARY OF THE INVENTION
The present invention addresses the above problems and provides a fluid pressure operated packer which includes means associated with the seal and responsive to well pressure differentials across the seal in either longitudinal direction to tighten the seal in its set position. This is accomplished through the provision of a fluid pressure reaction area adjacent one end of the seal which exceeds the transverse cross-sectional area of the other end of the seal in its unset position. Thus the packer will not leak even if the pressure on the high pressure side of the seal exceeds the effective setting pressure. Furthermore, the seal actuator defines primary and auxiliary piston areas which together exceed the transverse seal area in the unset position. This permits the use of an actual setting pressure less than the effective setting pressure.
The packer of the invention also includes a guard which overlies the seal in its unset position. Thus the packer may be lowered into the well conduit relatively rapidly, abrasive fluids may be circulated about the packer, etc. without damage to the seal. The seal and guard are selectively relatively longitudinally movable to at least partially expose the seal for movement to its set position. Preferably, the guard is formed by the cylinder for the piston of the seal actuator. Since the unset seal thus occupies part of the cylinder space, rather than resting thereabove (as in conventional hydraulic set packers) the total length of the tool is shortened without sacrificing sealing effectiveness.
The packer preferably also includes an anchor assembly comprising radially extendable gripping elements such as slips. The anchor assembly has a respective hydraulic actuator whose piston moves in a direction opposite that of the seal actuator during setting. Accordingly, the seal guard may be attached to the anchor actuator piston for movement therewith so that the guard is automatically longitudinally displaced to expose the seal during setting. Furthermore, means such as shear members are provided to prevent premature setting of the seal and/or anchor assembly. Whereas in conventional packers, having a common actuator for the seal and anchor assemblies, it was necessary to design such shear members to sever in a predetermined specific order, the shear members of the instant tool may be designed to shear at random or simultaneously due to the aforementioned actuator design.
The present packer also preferably includes a retainer adjacent the end of the seal distal its actuator piston and extending radially outwardly from the mandrel. The retainer restricts movement of only the inner portion of the adjacent end of the seal, the outer portion being longitudinally movable. Thus, as the actuator piston moves toward the retainer, the seal is extruded both longitudinally and radially outwardly over the retainer. This provides several advantages. In the first place, the retainer displaces the inner extremity of the adjacent portion of the seal radially outwardly. Thus the total volume of elastomeric seal material needed to bridge the annulus to be sealed is reduced. Furthermore, the stretching of the elastomer up and over the retainer eliminates the possibility of buckling and consequent leakage along the inner extremity of the seal. Finally, the retainer contributes to the seal tightening effect mentioned above by reducing the seal area distal the seal actuator.
Accordingly, it is a principal object of the present invention to provide an improved fluid pressure set packer.
Another object of the invention is to provide a packer having means for tightening the seal in its set position upon the presence of fluid pressure differentials thereacross in either longitudinal direction in the sealed conduit.
Still another object of the invention is to provide a fluid pressure set packer having guard means for overlying and protecting the seal in its unset position.
A further object of the invention is to provide a hydraulic set packer in which the seal in its unset position occupies a portion of the actuator cylinder for the seal.
Yet another object of the invention is to provide a well tool having a seal longitudinally and radially outwardly extrudable over a retainer extending radially outwardly from the tool mandrel.
Still other objects, features, and advantages of the present invention will be made apparent by the following description of the preferred embodiments, the drawings, and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal quarter-sectional view of a packer according to the present invention just prior to setting.
FIG. 2 is a view similar to that of FIG. 1 showing the packer in set condition.
FIG. 3 is a view similar to those of FIGS. 1 and 2 showing the packer released for removal from the well conduit.
FIG. 4 is a transverse cross-sectional view taken along line 4--4 of FIG. 1.
FIG. 5 is a transverse cross-sectional view taken along line 5--5 of FIG. 1.
FIG. 6 is a transverse cross-sectional view taken along line 6--6 of FIG. 1.
FIG. 7 is a transverse cross-sectional view taken along line 7--7 of FIG. 2.
FIG. 8 is a transverse cross-sectional view taken along line 8--8 of FIG. 2.
FIG. 9 is a longitudinal quarter-sectional view of a second embodiment of a packer in accord with the present invention just prior to setting.
FIG. 10 is a view similar to that of FIG. 9 showing the packer in set condition.
FIG. 11 is a view similar to those of FIGS. 9 and 10 showing the packer in released condition.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIGS. 1 and 4-6, there is shown a packer according to a first embodiment of the invention designed for use in anchoring and sealing against the interior of a well casing 10. While the invention will be described in relation to hydraulic set packers, it is applicable to any fluid pressure operated sealing tool, and certain features of the invention are also applicable to mechanically set tools. The packer includes a tubular mandrel assembly comprised of a main body portion 12 and a collar 14 used to connect the main body 12 to the lower end of an operating string 16. The lower end of the main body 12 forms a threaded pin by which other sections of pipe or tubing, other tools, or the like may be connected below the packer.
A seal assembly 18 is slidably carried about the main body 12. Seal assembly 18 comprises a plurality of elastomeric seal rings positioned end-to-end and encircling the body 12. The seal assembly has opposite axial ends 20 and 22. Upper end 20 of the seal assembly 18 has a radially inner portion which abuts a retainer sleeve 24 slidably disposed on the body 12. Upward movement of sleeve 24 on the body 12 is limited by the lower end of the collar 14. Downward movement of sleeve 24 on the body 12 is limited by an upwardly facing external annular shoulder 26 on the body 12 and an opposing downwardly facing internal annular shoulder 28 on the sleeve 24. The radially outer portion of the upper end 20 of seal assembly 18 abuts the lower end of a restraining collar 30 releaseably secured to the sleeve 24 by a plurality of shear pins 31.
An anchor assembly is carried by the body 12 below the seal 18. The anchor assembly comprises a generally cylindrical slip cage 32 coaxially surrounding the body 12. A plurality of gripping elements in the form of slips 34 is carried by the cage 32. The slips 34 may be radially extended and retracted through radial openings 36 in the cage 32. A compression spring 38 is interposed between each of the slips 34 and the interior of the cage 32 to bias the slips 34 radially inwardly. However, the slips 34 may be urged outwardly against the bias of springs 38, in a manner to be described more fully below, and are equipped with teeth on their radially outer surfaces for gripping the casing 10 to hold the packer in a fixed position relative thereto. A lower expander cone 40 is threadedly secured to the body 12 and has an upper portion extending into the lower end of the slip cage 32. Cage 32 is releaseably secured to the expander 40 by a plurality of shear pins 42. The cage 32 extends upwardly from the locus of the slips 34 to form a guard sleeve 32a which, in the running-in position shown in FIG. 1, completely covers the unset seal assembly 18 and abuts the outer portion of the lower end of restraining collar 30.
A pair of actuator assemblies are carried generally between the seal assembly 18 and the anchor slips 34. The first or seal actuator assembly comprises an annular abutment member 44 abutting the lower end 22 of the seal assembly 18. The lower portion of the abutment member 44 is counterbored and internally threaded to receive the upper end of a lock sleeve 46 which extends downwardly along the body 12 and into the lower expander cone 40 as shown. The member 44 is sealed with respect to the sleeve 32a and the body 12 by O-ring seals disposed in its radially outer and inner surfaces respectively. The upper portion of sleeve 32a serves as a cylinder surrounding members 44 and 46 which themselves form the piston means of the seal actuator.
The second or anchor actuator assembly comprises an upper expander cone 48 and a holder ring 50 disposed coaxially therein. Upward movement of the ring 50 in the expander cone 48 is limited by a snap ring 52 disposed in an internal annular groove in the expander 48. Downward movement of ring 50 is limited by a lock ring 54, to be described more fully hereafter, located below ring 50 and trapped between the sleeve 46 and the expander cone 48. Expander cone 48 is sealed with respect to sleeve 32a by an O-ring carried in an external groove in the expander 48. Ring 50 is sealed against the exterior of sleeve 46 and against the interior of expander 48 by respective O-rings 51 and 53 carried on the interior and exterior, respectively, of holder ring 50. Thus expander 48 and holder ring 50 are enabled to act together as a piston for the anchor actuator assembly.
FIG. 1 shows the packer in an initial condition as it would appear during running-in and also just prior to setting with the seal and anchor assemblies in their unset positions. All parts of the seal assembly, anchor assembly, and the two actuator assemblies are held in substantially fixed position with respect to the mandrel 12, 14 by the cooperative relation between these parts and, ultimately, by three sets of shear pins 31, 42 and 52 along with the lower expander 40. Expander 40 is fixed to body 12 by the threaded connection therebetween. The anchor assembly 32, 34, as well as the sleeve 32a and integral slip cage 32, are held fixed with respect to the expander 40 by the set of shear pins 42. Pins 42 fix the anchor assembly, and prevent premature setting which might otherwise occur upon relative downward movement of the anchor assembly over the lower expander 40. The inner diameter of the upper portion of expander 40 is enlarged to receive the lower end of lock sleeve 46 and to form an upwardly facing shoulder 58 which abuts the lower end of sleeve 46 thereby supporting the seal actuator piston means 44, 46. Upward movement of the piston means 44, 46, is prevented by the seal assembly 18 which is constrained against radial deformation by the sleeve 32a and against longitudinal movement by the retainer sleeve 24, which abuts collar 14, and by the restraining collar 30 connected to sleeve 24 by shear pins 31. Finally, shear pins 56 interconnect the anchor actuator piston means 48, 50 with the sleeve 32a to fix the anchor actuator assembly and prevent premature setting of the anchor assembly by downward movement of the expander 48 with respect thereto.
The packer, in the initial condition of FIG. 1, may be run into the casing 10 relatively quickly as compared with conventional packers since the sleeve 32a covers and protects the seal assembly 18 from damage due to contact with the wellhead apparatus, casing, or other subsurface apparatus. The sleeve 32a also prevents the seal elments from extending radially due to the pressure differential which is developed as the packer is moved through a wet casing string. Once in place, sandy fluids, mud, or other abrasive fluids may be circulated around the packer without danger of erosion or other damage to the elastomeric seal elements, which are protected by sleeve 32a.
The pins 42 and collar 40, which fix the guard sleeve 32a to the body 12, and the collar 30, pins 31 and sleeve 24, which interconnect the body 12 with the upper end of sleeve 32a, serve as control means to prevent relative longitudinal movement between seal 18 and sleeve 32a during running-in and thereby releasably retain sleeve 32a in overlying relation to seal 18.
As mentioned above, sleeve 32a forms a cylinder in which piston 44, 46 of the seal actuator assembly can reciprocate. Because the seal assembly 18 is disposed within, rather than wholly above, this cylinder, the overall length of the packer may be relatively small without any substantial sacrifice of seal length and effectiveness. Accordingly, the packer of the invention provides the advantages of a longer conventional hydraulic set packer but is short enough to be easily manipulated in tortuous wells having "dog legs" and like deviations from a straight path.
When the desired depth has been reached, the packer is hydraulically set by pumping a ball plug 60 downwardly through the string 16 and mandrel assembly 12, 14 until it lands on a seat sleeve 62 secured within body 12 by shear pin 64. The application of fluid pressure to the body 12 via the string 16 causes the packer to set. FIGS. 2, 7 and 8 show the packer in set condition, and an understanding of the setting process may best be had by a comparison of those figures with FIGS. 1 and 4-6 in conjunction with the following discussion. A plurality of ports 66 extend radially through the body 12. Similar ports 68 extend through the lock sleeve 46. The portion of sleeve 32a disposed generally between the anchor slips 34 and the seal assembly 18 serves as a common cylinder surrounding both the piston 44, 46 of the seal actuator assembly and the piston 48, 50 of the anchor actuator assembly. Fluid supplied through the body 12 enters this cylinder through the ports 66 and 68 and urges piston 44, 46 upwardly and piston 48, 50 downwardly with respect to the body 12 and well casing 10.
As best shown in FIG. 1, the transverse cross-sectional primary piston area defined by the O-rings of member 44 available for reaction to the fluid pressure is substantially equal to the transverse cross-sectional area of the seal assembly 18 in its unextended position. Fluid pressure from ports 66 not only flows into the cylinder formed by sleeve 32a, but also flows downwardly along the sleeve 46 to the lower end thereof. The lower end of sleeve 46 is upset on its exterior surface and is sealed against the interior of expander 40 by an O-ring 70. The transverse cross-sectional area defined within the outer diameter of O-ring 70 is slightly greater than the transverse cross-sectional area defined within the inner diameter of the O-ring 51 which seals the sleeve 46 against the holder ring 50. Thus the portion of the lower end of sleeve 46 between these two O-rings defines an auxiliary piston area to increase the total piston area of the piston 44, 46 with respect to the transverse cross-sectional area of the seal assembly 18 in its unset position. This provides a starting boost to the upward force on the actuator assembly to initially overcome the resistive force of the resilient seal assembly 18 constrained between mandrel 12, sleeve 32a, piston 44 and members 24 and 30.
Even more importantly, the relationship between the transverse cross-sectional areas of the unset seal and the seal actuator piston permits operation of the tool by an actual setting pressure less than the effective setting pressure. For example, let us assume that, with only the piston area defined by the O-rings of member 44 available for setting, a pressure of 3000 p.s.i. would be required to set the seal 18. Assume also that, once set, the seal 18 would prevent leakage upon the presence of well pressures up to 3000 p.s.i. (ignoring for the time being the seal tightening effect to be described below). With the addition of the piston area defined by the lower end of sleeve 46, the seal 18 may be set by application of an actual setting pressure less than 3000 p.s.i. However, (again ignoring the seal tightening effect) the seal will still hold in the presence of well pressures up to 3000 p.s.i. Thus the latter will be termed the effective setting pressure of the tool.
When sufficient upward force is exerted on the seal 18 via the piston 44, 46, the pins 31 will shear. The lower end 22 of seal assembly 18 will then begin to move upwardly. With the restraining collar 30 thus released, the outer portion of the upper end 20 of the seal assembly will also be permitted to move upwardly until the collar 30 strikes the lower end of collar 14. The initial upward movement of the seal assembly 18 causes the upper end of the seal assembly to move out from under sleeve 32a, the elastomer being extruded radially outwardly and upwardly over the retainer sleeve 24. Continued upward movement of the piston 44, 46 urges the seal assembly against the end of the collar 30 thereby compressing the elastomer radially outwardly into sealing engagement with the interior of casing 10. As will be described below, the setting action of the tool also moves the sleeve 32a downwardly relative to the body 12 thereby further exposing the seal 18 for engagement with the casing 10. Setting of the seal assembly 18 isolates the areas above and below the packer so that all fluid flow is forced through the body 12.
Several advantages are afforded by the provision of the retainer sleeve 24. Since the sleeve 24 extends radially outwardly from the mandrel body 12, and the upper end of the seal assembly is forced not only upwardly but also radially outwardly over the sleeve 24, less volume of elastomeric material is required to fill and seal off the annular space between the body 12 and the casing 10 than would be necessary if the seal were simply axially compressed. Furthermore, the stretching of the inner extremity of the seal material over sleeve 24 prevents buckling of the seal along its inner diameter and the leakage which could result therefrom.
The fluid pressure introduced into the cylinder formed by sleeve 32a to set the seal also urges the piston 48, 50 of the anchor actuator assembly in a downward direction with respect to the casing 10 to set the slips 34. When the downward force becomes great enough, the pins 42 and 56 will shear. The upper expander 48 may then move downwardly with respect to the slips 34. The upper and radially inner surface of each slip 34 is upwardly and radially outwardly inclined. The expander 48 has a correpondingly inclined conical surface engageable with the upper inclined surfaces of the slips 34. Thus the downward movement of the expander 48 with respect to the slips 34 urges the upper halves of the slips radially outwardly by a wedging action. The force on the piston 48, 50 will also cause the piston 48, 50 to move further downwardly toward the lower expander 40 carrying the slip cage 32 and slips 34 with it. The lower inner surfaces of the slips 34 are inclined downwardly and radially outwardly, and the lower expander 40 has a correspondingly inclined conical surface whereby the lower halves of the slips are urged radially outwardly as they move down over the expander 40.
In actual practice, the two sets of shear pins 42 and 56 shear virtually simultaneously and the various movements described above in connection with setting of the anchor assembly occur almost in unison. However, it should be noted that if either set of pins shears before the other, the anchor will still be properly set. Thus, if pins 56 shear first, the upper expander 48 with the ring 50 will move downwardly with respect to the slips 34 until stopped by being wedged between the slips and the sleeve 46. Meanwhile, the upward force exerted on mandrel body 12 via piston 44, 46, seal assembly 18, sleeve 24 and collar 14 will cause the connected lower expander 40 to shear pins 42 and move upwardly behind slips 34 completing the setting thereof. If, on the other hand, pins 42 shear first, members 48, 50, 32 and 34 can move downwardly until the slips 34 are wedged between the expander 40 and the casing 10. Then further exertion of fluid pressure will cause pins 56 to shear so that expander 48 can move further downwardly to set the upper halves of the slips 34. The downward movement of the slip cage 32 during setting of the anchor assembly moves the integral sleeve 32a away from the upper end of the seal assembly 18 to expose additional seal area for contact with the casing 10.
It can be seen that, since the pistons 44, 46 and 48, 50 move independently of each other with respect to the casing 10 and in opposite directions, setting of the seal assembly 18 by its actuator will not impede the setting movement of the other actuator or interfere with the setting of the anchor assembly. Likewise, setting of the anchor assembly will not interfere with the proper setting function of the seal assembly or its actuator. Thus there is no need for the pins 31 to shear in any particular sequential order with respect to the aforementioned pins 42 or 56. The various sets of shear pins which must be secured to set the tool may be permitted to shear at random, or more practically, simultaneously. Shear pin 64 holding seat 62 in place is designed to remain intact until pins 31, 42 and 56 have sheared. After the packer is set, the continued application of increased fluid pressure through the string 16 and mandrel assembly 12, 14 will cause the pin 64 to shear permitting the seat 62 and ball 60 to be pumped out of the bottom of string 16 leaving a free passage therethrough.
The packer is held in set condition after release of the fluid setting pressure by a locking mechanism including the lower end of lock sleeve 46, lock ring 54, and anchor actuator piston 48, 50. The radially outer surface of lock ring 54 is inclined upwardly and radially outwardly. The abutting portion of the inner surface of expander 48 is correspondingly inclined. Thus lock ring 54 is trapped between this inclined surface on the expander 48 and the lower end of holder ring 50 and constrained to move generally with the actuator assembly 48, 50. Nevertheless, some longitudinal play between ring 54 and expander 48 is permitted by virtue of the spacing between the inclined interior surface of the expander and the snap ring 52. Radial play is provided for by the fact that the ring 54 is a split ring as shown in FIG. 4.
The inner surface of lock ring 54 is equipped with ratchet teeth. Opposable mating teeth are formed in the exterior of lock sleeve 46 at 72. As the packer is set, the teeth 72 are brought into alignment with the mating teeth on the lock ring 54. The inclination of the teeth is such as to allow upward movement of the seal actuator piston 44, 46 with respect to the anchor actuator piston 48, 50 and entrapped ring 54 and/or downward movement of piston 48, 50 and ring 54 with respect to piston 44, 46. During such movements the ring 54 and sleeve 46 can ratchet past each other by virtue of the play permitted in ring 54. However, if the piston 44, 46 begins to move downwardly, or if the piston 48, 50 begins to move upwardly, the teeth 72 will catch the mating teeth of the ring 54 wedging the latter against the interior inclined surface of the expander 48 whereby such relative movements of the two actuators will be prevented.
With the packer in the set position of FIG. 2, the seal assembly 18 will be tightened in response to a well pressure differential across the seal in either direction. It is of particular significance that the seal will be tightened where the well pressure on the high pressure side of the seal exceeds the effective setting pressure, since many conventional packers will leak under such circumstances.
Recalling the above example, assume that the packer has an effective setting pressure of 3000 p.s.i., although the actual pressure which has been applied to set the packer for this value is less than 3000 p.s.i. due to the auxiliary piston area defined between O-rings 51 and 70. If a pressure in excess of 3000 p.s.i. exists in the annular space A above seal 18 and between the mandrel 12, 14 and the casing 10, and if this pressure is greater than the pressure in annulus B between the mandrel and casing below seal 18, there is a pressure differential across the seal in the downward direction. The fluid pressure in annulus A will act on a reaction area defined by the radially inner and outer extremities of the seal 18, i.e. on an area extending from mandrel body 12 to casing 10. The anchor assembly 32, 34 resists downward movement of the lower end of the seal 18, the force being transmitted to the anchor assembly via sleeve 32a and also by sleeve 46 and ring 54. Thus the lower end of seal assembly 18 is prevented from moving downwardly, and the effect of the pressure differential is to move the upper end of seal assembly 18 downwardly toward the lower end thereof. Accordingly, seal assembly 18 is further axially compressed and thereby radially tightened in its set position. In this connection, it is noted that some downward movement of the mandrel body 12 may also take place. This will effect a wedging action on the seal 18 via the retainer sleeve 24 which enhances the seal tightening effect. If such downward movement of the mandrel body 12 should displace the lower expander 40 from tight engagement with slips 34, the packer will still remain anchored since only the upper halves of the slips 34 need be firmly engaged to anchor the packer in the presence of a downward pressure differential as described.
Let us now assume that the fluid pressure in annulus B exceeds that in annulus A so that there is a pressure differential acting upwardly across the seal 18, and further that the pressure in annulus B exceeds 3000 p.s.i., the effective setting pressure. The fluid in annulus B can flow into mandrel body 12 through the open lower end thereof (or the lower end of the attached tubing) and thence through ports 66 and 68. This fluid can act in the upward direction on the piston 44, 46 over the primary piston area defined between the O-rings of abutment member 44, i.e. between the outer diameter of mandrel 12 and the inner diameter of sleeve 32a. Fluid pressure in annulus B also acts upwardly on sleeve 32a and directly on the portion of seal 18 disposed radially outwardly thereof. The effect of the auxiliary piston area defined between O-rings 51 and 70 is offset by the fact that fluid flowing upwardly over the outer diameter of the expander 40 and then downwardly therein exerts a downward force on an equal but opposite area defined by the upset at the lower end of sleeve 46.
There is thus a pressure reaction area adjacent the lower end of seal 18 equal to the full transverse cross-sectional area between body 12 and casing 10 available for reaction to fluid pressure acting upwardly. However, the upper end of seal 18, which is restrained against upward movement by sleeve 24 and collar 30, has a lesser transverse cross-sectional area, namely the annular area defined between sleeve 24 and casing 10. If the pressure reaction area adjacent the lower end of seal 18 were equal to the transverse cross-sectional area of the upper end of seal 18, the seal would hold at pressures up to the effective setting pressure, e.g. 3000 p.s.i. Since the pressure reaction area exceeds the area of the upper end of the seal, however, a downhole pressure in excess of the effective setting pressure will act on said pressure reaction area to further compress and tighten the seal 18 and leakage will not occur.
To release the packer, the mandrel 12, 14 is rotated via the operating string 16 to release the threaded connection between the body 12 and the lower expander 40. The connection between the expander 40 and the body 12 is threaded oppositely to the connections between the various parts of the drill string so that the expander can be released without disconnecting any of the parts of the operating string. FIG. 3 shows the packer in released condition. After the aforementioned threaded connection is released, the expander 40 and those parts supported thereby will tend to drop downwardly with respect to the mandrel. However, it is preferable, and in many cases necessary, to exert an upward pull on the mandrel via the operating string to force this relative movement.
The expander 40 has a number of support pins 74 extending radially outwardly therefrom into axially elongated slots 76 formed in the slip cage 32. These slots permit the necessary relative movements of the expander 40 and slip cage 32 to effect setting and release of the packer but limit such movement so that the expander 40 may be supported by the slip cage 32 after the expander is released as shown in FIG. 3.
As the body 12 moves upwardly, an external upwardly facing shoulder 82 thereon is brought into engagement with an internal downwardly facing shoulder 84 on the lock sleeve 46 so that the lock sleeve may continue to move upwardly with the body 12. This brings an external upwardly facing shoulder 86 into engagement with the lower end of the upper expander 48. Thus the expander 48 may be moved upwardly with respect to slips 34. During such movement an external upwardly facing shoulder 80 on expander 48 engages an internal downwardly facing shoulder 78 on the slip cage 32. With both expanders 48 and 40 thus removed from setting relation to the slips 34, the latter are returned to their radially inner positions by the springs 38. The various parts of the anchor assembly and actuator assemblies are suspended from the body 12 for removal from the casing 10. In particular, lock sleeve 46 is supported on shoulder 82 of body 12. Upper expander 48 and the rings 50, 52, and 54 carried thereby are supported on shoulder 86 of lock sleeve 46. Slip cage 32, including the integral sleeve 32a, is supported on shoulder 80 of the upper expander 48 and in turn supports the slips 34 and the lower expander 40 via pins 74.
The relative upward movement of the mandrel 12, 14 also releases the seal assembly 18. In particular, during such upward movement, the upwardly facing external shoulder 26 on body 12 is brought into engagement with the internal downwardly facing shoulder 28 on the retainer sleeve 28 whereby the latter will begin to move upwardly with the body 12. This in turn brings an external upwardly facing shoulder 88 on sleeve 24 into engagement with an opposed internal shoulder 90 on the collar 30.As sleeve 24 and collar 30 are thus moved upwardly with the body 12, the seal assembly 18 is permitted to retract radially by virtue of its own resiliency.
It can be seen that when the packer is in released condition, the ports 66 are covered by the seal assembly 18. Therefore, in order to provide for pressure equalization across the packer during retrieval, another set of radial ports 92 is provided in the body 12. As seen by comparison with FIGS. 1 and 2, ports 92 are covered by the retainer sleeve 24 in the running-in and set conditions of the packer and are sealed off by O-rings 94 and 96 carried by the sleeve 24 to seal against the body 12 above and below the ports 92. When the packer is released, ports 92 are exposed by the longitudinal movement of the body 12 with respect to sleeve 24.
Referring now to FIGS. 9-11, there is shown a second embodiment of the packer according to the invention. With the exception of the anchor assembly, upper expander, and seal guard sleeve, the packer of FIGS. 9-11 is substantially identical to that of FIGS. 1-8, and accordingly like parts have been given like reference characters. The primary difference between the two tools is that in the tool illustrated in FIGS. 9-11, the slip cage 100 and seal guard sleeve 102 are not integral but are formed as two separate members which, in the running-in condition of the tool, are longitudinally spaced apart as shown in FIG. 9. The upper expander for the anchor assembly is formed in two parts 104a and 104b threadedly connected together. The upper part 104b of the upper expander is connected to the guard sleeve 102 by a threaded joint rather than by releasable shear pins as in the other embodiment.
When the tool is being run into the well, the expander 104a, 104b and attached guard sleeve 102 are supported by the slips 34 which in turn are held in their radially inner positions by springs 38. As in the first embodiment, the packer is set by pumping a ball 60 through the operating string to land on the seat 62 and applying the resulting fluid pressure to the cylinder formed by sleeve 102 via ports 66 in body 12 and ports 68 in lock sleeve 46. Piston 44, 46 is thus driven upwardly to release the restraining collar 30 and set the seal assembly 18. Likewise a downward force is exerted on the piston formed by expander 104a, 104b and ring 50. Expander 104a, 104b thus urges the slips 34 radially outwardly, and they and the slip cage 100 will begin to move downwardly with the upper expander shearing pins 32 and permitting the lower portions of the slips 34 to be extended by the expander 40.
It can thus be seen that the sleeve 102 will move downwardly a distance equal to the full amount of travel of expander 104a, 104b relative to body 12 rather than just the amount of like relative travel of the slip cage 100. The required travel is permitted by the initial spacing between the sleeve 102 and slip cage 100. This allows a greater portion of the seal assembly 18 to be exposed during setting whereby a more effective seal is achieved without an increase in the length of the packer or the size of the seal assembly 18.
FIG. 11 shows the packer after it has been released by rotating the body 12 to disconnect the expander 40 therefrom and then raising the mandrel. As in the first embodiment, the lock sleeve 46 is supported on a shoulder 106 on the body 12 via its own mating internal shoulder 108 (see FIG. 10) and in turn supports the expander 104a, 104b. Sleeve 102 remains threaded to expander part 104b while slip cage 100 is suspended from an external shoulder on expander part 104a. Expander 40 is in turn suspended from slip cage 100 by pins 74.
It can be seen that, aside from the modifications mentioned above, the embodiment of FIGS. 9-11 also includes all the structural features of the embodiment of FIGS. 1-8, and in particular, that it is adapted to provide the various salient functional advantages of the preceding embodiment including the seal tightening effect, the reduction in actual setting pressure required to set the tool for a given effective pressure, the seal guard, and the retainer sleeve 24 and related longitudinally and radially extrudable seal.
It will also be apparent that numerous modifications of the preferred embodiments may be made without departing from the spirit of the invention. For example, the invention may be applied to packers for sealing against a bare well bore as well as against numerous other types of conduits. The means of releasing the packer may be modified in various ways and, in particular, need not be operated by rotation of the mandrel. The invention may also be applied to other types of packers in which the setting is not achieved solely through the application of fluid pressure.
It is thus intended that the scope of the invention be limited only to the claims which follow. | The invention comprises a packer which seals against a surrounding well conduit. The packer comprises a mandrel which carries a radially extendable seal for engaging the well conduit. A hydraulic actuator is provided for urging the seal to its set position against the well conduit. Once set, the tool is responsive to fluid pressure differentials in the well conduit across the seal in either longitudinal direction to tighten the seal means. The cylinder of the actuator also serves as a guard to overlie and protect the seal in its unset position, while the piston is designed to define auxiliary piston area to reduce the required setting pressure. The seal is set by being extruded both longitudinally and radially over a retainer extending radially outwardly from the mandrel. | 4 |
FIELD OF THE INVENTION
[0001] The invention relates to the use of wind turbines or wind turbine parks for controlling a power system frequency.
BACKGROUND OF THE INVENTION
[0002] As is commonly known, electricity generation and demand must be kept in balance at to maintain system reliability and power quality. When the electric demand drops, it is necessary to throttle back some generators and/or take certain generators off line. When the demand increases, additional generator capacity must be brought on-line or the output of on-line generators increased.
[0003] Power system frequency stability is desired and is a function of a balance between generation and consumption. If there is too much generation, residual power is transformed into generator shaft kinetic energy and the line frequency increases. If there is inadequate generation relative to the amount of power consumed, generators take shaft kinetic energy and convert it to electric power, reducing the system frequency. Power system operators try to maintain a constant frequency by matching generation to load.
[0004] In a typical power system certain generators are considered frequency-responsive or frequency support generators and other generators are not able to provide frequency stabilization. Examples of the latter may include generators coupled to nuclear generating stations, base load coal plants, and peaking units. Nuclear units and base load coal plants respond too slowly to an event that creates an under frequency or an over frequency condition. Thus these units are usually exempt from participating frequency control.
[0005] Generating units reserved for duty during peak power demands are normally brought to full-load generating capacity immediately upon start-up and thus are already in service during capacity shortages. These units may or may not have control algorithms associated with frequency response. However, since they are operated at maximum load they generally cannot respond to under-frequency events. Also, when peaking units are brought on line, the power system must have sufficient online capacity to respond to over-frequency events. Thus peaking units seldom participate in frequency control.
[0006] Synchronous generators respond to grid frequency changes according to either an inertial response or a governor response (i.e., a droop response).
[0007] Synchronous generators driven by a steam or gas turbine have an inherent inertial response as a consequence of the physical characteristics of the rotating turbine mass. This inertial response is initiated by an incident such as a change in the electrical torque caused by grid frequency changes. This inertial response is fast, inherent, uncontrolled and transient. Duration of a typical inertial response is about 5 to 20 seconds. After the inertial response ends, the generator output returns to its pre-incident condition because of the energy extracted during the response period.
[0008] Synchronous generators are also controlled to a new operating condition according to a governor response during which the amount of mechanical power supplied to the generator is controlled (increased or decreased) by altering the fuel flow to a gas turbine or the steam flow to a steam turbine. The fuel flow or steam flow remains at this new level until the next governor response to another incident.
[0009] There are conventionally two governor response modes, the droop mode and the isochronous mode, to match generation to load demand and thereby maintain a grid frequency of 60.00 Hz in North America. If neither of these control schemes are sufficient to maintain that balance, generating units can be manually brought on-line or taken off-line as needed.
[0010] Generating units that follow load and are therefore designated as frequency-responsive generators, (these units typically include, for example, combined cycle generators and non-base-load steam generators) are controlled according to a speed droop setting. A typical droop setting in the United States is 4% or 5%. Droop-mode generators are controlled to decrease their power output if the frequency goes above a predetermined dead band, which is typically either +0.0166 or +0.036 Hz from a nominal frequency (60 Hz in North America). These generators are also controlled to increase their power output (if they have sufficient generation headroom) when the frequency drops below a dead band, e.g., 0.0166 or 0.036 Hz below the nominal frequency of 60 Hz or 50 Hz.
[0011] All droop mode turbine controllers on the power system work in concert to share load demand changes among all operating turbines-generators. The load demand change is shared in proportion to a ratio of the base load rating of each generator to the overall grid generating capacity. A typical droop characteristic for a generator is 5%. If the frequency changes by 5% or more, there will be a 100% change in generator output.
[0012] In practice, most frequency variations are considerably less than this 5% value. A large frequency excursion is generally considered on the order of 0.25% or 0.15 Hz for a 60 Hz grid frequency. Any frequency deviation larger than this is considered an emergency condition that initiates an under-frequency load shedding incident.
[0013] If a unit operates according to a 5% droop, in response to a 5% frequency change the unit responds with a 100% change in output (based on the nameplate rating of the generator). A 1% frequency change corresponds to a 20% change in output power; a 2% frequency change corresponds to 40% change in output power, etc.
[0014] For example if a unit rated at 100 MW is operating at an output power of 50 MW and the frequency suddenly drops to 59.4 Hz (a 1% reduction), the turbine controller detects this change and the generator is expected to increase its output by 20 MW (20% of its rated output) to 70 MW. The output is controlled to increase in a very short period of time. Time requirements vary but a typical requirement is one minute or less.
[0015] If the frequency rises to 61.2 Hz (a 2% increase), the unit is expected to reduce its output by 40 MW (40% of 100 MW) to 10 MW or to its minimum load, whichever is greater.
[0016] As those skilled in the art are aware, there are a few nuances in the application of these rules. For example, instead of an absolute threshold value for increasing or decreasing generator output, a dead-band frequency range can be implemented. If the frequency change is within this dead band range the generator output does not change. System operators may utilize a relatively wide or a relatively narrow dead-band width or dead-band range. Further, the frequency deviation may be measured from an edge of a dead band or from a center of the dead-band.
[0017] The actual system frequency threshold or dead band range (and the other variables set forth in the immediately preceding paragraph) that cause the frequency responsive reserves to be activated are determined by the independent system operator.
[0018] This threshold may be greater than 59.5 Hz, since there are some older operating turbines that have under-speed trip points at 3570 rpm, which corresponds to 59.5 Hz. Thus the 59.5 Hz value is significantly below the dead band imposed by system operators. In North America the dead band threshold is typically either 59.983 Hz or 58.964 Hz. When the line frequency drops below this value the frequency-responsive generators increase their output as explained above.
[0019] The formula for determining the increase or decrease of a generator's output (A MW) is:
[0000] Δ MW= ( fo−freq )× Pnom /( fo×pu droop )
[0020] Where, ΔMW is the desired change in MW output,
fo is the nominal system or line frequency (60 Hz in North America), freq is the actual frequency measured, Pnom is the nominal output of the generator, and pu droop is the percent droop rating divided by 100.
[0025] For the second example set forth above,
[0026] fo=60
[0027] freq=61.2
[0028] Pnom=100
[0029] pu droop=0.05 and therefore
[0030] and therefore,
[0031] ΔMW=(60−61.2)×100/(60×0.05)
[0032] ΔMW=−40
[0033] Calculations such as those set forth above that estimate a desired change in system output may be inaccurate because real turbines and generators have operating limits that are not explicitly considered in the governing equation. For example, a unit that is already generating its maximum or minimum load (i.e., its nameplate capacity) cannot respond, respectively, to an under-frequency or an over-frequency event.
[0034] Often the operating limits of a turbine or generator are dictated by pollution emissions, which can vary from site to site and even from season to season.
[0035] For example, if the system load or system demand is 10,000 MW and an incident occurs that causes a 1% frequency drop (thus requiring a 20% increase in system output), there may not be an output change of 2000 MW. Although there may be 12000 MW on-line and therefore the output can theoretically increase to 12000 MW, a substantial portion of the 12000 MW may not be able to fully respond to the demand increase either because turbines are already operating at their capacity limit or because the turbines are not equipped for frequency response operation. Thus the actual system response may be much smaller than as calculated according to the formula above.
[0036] Very large under-frequency deviations usually invoke an automatic under-frequency load shedding event to prevent generators from tripping off line. Generators typically trip when subjected to large frequency excursions for an extended period (which, in some cases, may be more than only a few seconds). These load shedding events are typically mass customer disconnections. In some cases entire towns may be disconnected.
[0037] Over-frequency incidents are usually much easier to solve by simply reducing system generation.
[0038] When electric demand drops significantly, for example during the overnight hours, the droop and isochronous control schemes may not be sufficient to balance the generation and load. Instead, it may be necessary to throttle back some generators and/or take certain generators off line. But it is desired, if not required in some circumstances, that certain generators must be kept operating at a minimum level, e.g., base load generators especially including base load generators coupled to nuclear generating stations. Thus the power system operator may “curtail” certain generators (i.e., reducing generation supplied to the grid below 100% of the power available (where power available is determined by present wind conditions), even to 0% power output) or taking the generating unit off-line during such periods.
[0039] Combustion generators (whether using oil, diesel or biofuel as the fuel source) can be throttled back to a certain degree. Peak generating units are turned off when the peak demand, usually from about 5 to 9 PM on weekdays, is over. Cycling generating units are also turned down or off as demand drops in the late evening. Base-loaded generating units, usually the largest, steam turbine units on the grid, are only infrequently turned down and then only to their minimum required generation level.
[0040] If more energy reductions are needed to balance generation and load, most transmission system operators curtail wind turbine generators (and wind turbine parks comprising several wind turbine generators proximately situated in a geographic region) to less than 100% of available output. In a curtailed operating mode the wind turbine generator or the wind turbine park is operating at less than the total power available from current wind conditions. Thus such curtailments occur even when the wind is blowing and additional energy can be extracted from the wind (i.e., additional generation is available). Transmission system operators prefer to curtail the wind turbine generators (WTGs) during these off-peak periods in lieu of curtailing a base load unit or taking it off line. The ability of a transmission system operator to curtail WTGs makes these units more challenging to operate efficiently and profitably.
[0041] There are two forms of WTGs: fixed speed WTGs and variable speed WTGs.
[0042] In a fixed-speed WTG wind-driven blades drive a blade rotor that in turn operates through a gear box (i.e., a transmission) to turn a gearbox output shaft at a fixed speed. The gearbox output shaft is connected to an induction (asynchronous) generator for generating real power.
[0043] In the induction generator the rotor and its associated conductors rotate faster than the rotating flux applied to the stator from the grid (i.e., higher than the synchronous field frequency). The difference in these two values is referred to as “slip.” At this higher speed, the direction of the induced rotor current is reversed, in turn reversing the counter EMF (electromotive force) generated in the rotor windings, and by generator action (induction) causing current (and real power) to be generated in and flow from the stator windings. The frequency of the voltage generated in the stator is the same as the frequency of the voltage applied to the stator to develop the stator excitation.
[0044] The fixed-speed wind turbine is simple, reliable, low-cost and proven. But its disadvantages include uncontrollable reactive power consumption (as required to generate the stator rotating flux), mechanical stresses, limited control of power quality and relatively inefficient operation. In fact, wind speed fluctuations result in mechanical torque fluctuations that can result in fluctuations in the electrical power on the grid.
[0045] Variable speed WTG operation can be achieved only by decoupling the electrical grid frequency and the mechanical rotor frequency. The rotational blade speed of a variable speed WTG can be controlled to continuously adapt to the wind speed and maximize the power generated by the wind turbine. Since an electric generator is usually coupled to a variable speed WTG rotor through a fixed-ratio gear transmission, the electrical power produced by the generator has a variable frequency.
[0046] An electronic power converter is interposed between the generator output and a power system or grid to which the WTG supplies power. Generally, the power converter imparts characteristics to the generated electricity that match the electricity flowing on the grid, including controllable active power flow, voltage magnitude and frequency. Thus the converter converts the variable electrical frequency voltage output from the generator stator to the grid frequency and voltage. The power converter also electrically and mechanically decouples the grid from the WTG.
[0047] Although variable-speed WTGs are advantageous from the perspective of increased energy conversion and reduced mechanical stresses, the electrical generation system is more complicated than that of a constant speed wind turbine due primarily to the need for a power converter.
[0048] Both fixed speed and variable speed WTGs are designed to operate in parallel with a synchronous generator, both supplying power to the grid. The WTG's synchronize to the grid frequency to produce a constant frequency electrical output.
[0049] FIG. 1 illustrates a prior art wind turbine generator park 1 comprising variable speed wind turbine generators 2 , 3 .
[0050] The WTGs 2 , 3 generate electrical power that is supplied to a utility grid or power system 37 . Preferably, the WTGs 2 , 3 are variable speed wind turbines, i.e., the rotational speed of their respective generator rotors is variable depending on wind conditions.
[0051] Each WTG 2 , 3 comprises turbine blades 4 , 5 attached to a rotor shaft 6 , 7 for transmitting the torque of the wind-driven blades 4 , 5 to a gearbox 8 , 9 . An output shaft of the gearbox 8 , 9 drives an AC generator 17 , 19 for transforming the mechanical power provided by rotation of the rotor shaft 6 , 7 to electrical power. The gearbox 8 , 9 provides a transmission ratio that allows the gearbox output shaft to turn at a different speed than the rotor shaft 6 , 7 . Preferably the gearbox output shaft turns at a speed that optimizes the electricity generated by the AC generators 17 , 19 .
[0052] The AC generator 17 , 19 can comprise either a synchronous generator or an asynchronous (induction) generator and further each comprises power electronics components. Generally, in a synchronous generator, a generator rotor rotates at the same rotational frequency as the rotating magnetic field produced by a generator stator (or with an integer relationship to the frequency of the rotating magnetic field, where that integer relationship depends on the number of rotor pole pairs).
[0053] In contrast thereto, in an asynchronous generator (induction generator) the rotational frequency of the stator's magnetic field (conventionally 60 Hz when the stator magnetizing current is supplied from the electrical grid) is independent from the rotational frequency of the rotor. The difference in rotational frequency of the rotor and the stator is numerically described by a slip value.
[0054] If the generators 17 , 19 of FIG. 1 comprise synchronous generators, the frequency of the output power therefrom depends on wind velocity. But that output frequency must be converted to the frequency of the power system 37 to which the generators 17 , 19 supply electricity.
[0055] The frequency conversion process is accomplished by action of power electronics frequency converters 21 , 23 . Each frequency converter converts the frequency of the electrical power delivered by generators 17 , 19 into an electrical power having a fixed frequency corresponding to the frequency of the power system 37 . Each frequency converter 21 , 23 comprise a respective generator-side converter (rectifier) 25 , 27 for converting the AC current produced by the generator 17 , 19 into a DC current. A network-side converter (an inverter) 29 , 31 converts the DC current back to an AC current at the frequency of the power system 37 . The AC output of the network-side converter 29 , 31 is supplied to the power system 37 from the node 35 through a transformer 33 .
BRIEF DESCRIPTION OF THE DRAWINGS
[0056] The invention is explained in the following description in view of the drawings that show:
[0057] FIG. 1 is a prior art wind turbine generator park.
[0058] FIG. 2 is a block diagram illustrating the control components of the present invention.
[0059] FIG. 3 is a flow chart depicting the method steps associated with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0060] According to the prior art, on-line wind turbine parks can be designated to participate in grid frequency droop control and are thereby controlled to adjust their power output in real time in response to grid frequency changes according to their assigned droop characteristic.
[0061] When the system frequency increases above a given dead band or threshold, the WTGs in the park are controlled to reduce their power output according to an assigned droop-type governor control characteristic.
[0062] Similarly, when the grid frequency drops below a given dead band or threshold, the WTGs can increase their power output, again according to their assigned droop characteristic provided, of course, that the WTGs power output is below the total power available to be extracted from current wind conditions.
[0063] According to one embodiment of the present invention, when a wind turbine park is operating in a curtailed mode (i.e., operating a WTG or a WTG park at less than the total power available from current wind conditions) and an under-frequency condition is detected and that condition exceeds a predetermined threshold or dead band, the wind turbine park is brought to a full or 100% of available output power. This full or 100% output power condition obviously exceeds any droop condition assigned to the park according to the prior art. According to this invention the full output power of the wind turbine park assists in relieving the under-frequency condition and the park can be brought to available full power output (as that “available full power” output is determined by current wind conditions) in one or two minutes, which is considerably faster than prior art modes of under-frequency control.
[0064] According to another embodiment, in lieu of bringing the wind park to 100% output power, a different value can be selected as determined by market or other factors. But in any case this “different value” is in excess of the droop characteristic assigned to the wind park.
[0065] According to yet another embodiment, the wind park output power can be increased in discrete steps, with each step associated with a certain under-frequency value. Generally, greater under-frequency values (e.g. a frequency that is 0.5% below its nominal value) result in greater increases in power output than smaller under frequency values (e.g., a frequency that is 0.1% below its nominal value). This scheme differs from a conventional droop characteristic in that the latter is a smooth or linear function, while discrete power output steps are invoked according to the present invention.
[0066] According to another embodiment, the wind park output can be increased according to an linear or non-linear trajectory (e.g., exponential) bringing the wind park output to 100% of available power or to a value less than 100%. The trajectory can also extend over any time interval and at any ramp rate the wind turbine generator park can accommodate.
[0067] The various WTG response scenarios set forth above are referred to as under-frequency response characteristics assigned to the WTG when an under frequency incident is detected. Such an under frequency response characteristic can involve the WTG supplying more power to the power system than according to a conventional droop characteristic and/or supplying the additional power at a faster rate. As described above, since the WTG is operating in a curtailed mode it can respond faster to such under frequency events than other frequency-responsive generators.
[0068] Wind parks are sometimes curtailed and in certain jurisdictions they are required to provide frequency support while in a curtailed condition. However, according to the prior art that frequency support is provided according to a droop characteristic (typically 5% as described above) assigned to the wind park. This prior art control scheme fails to use most of the available wind power. In regions that regularly experience wind speeds suitable for generating electrical power, this scheme results in an under-utilization of wind power.
[0069] According to the present invention, it is desired to operate WTGs to provide frequency-responsive reserves (i.e., to control the system frequency) beyond their assigned droop characteristics.
[0070] ERCOT (Electric Reliability Council of Texas, an ISO or power system operator) defines a generating unit that can provide frequency-responsive reserves as one that:
[0071] A. Can arrest frequency decay within the first few seconds of a significant frequency deviation using primary frequency response and interruptible loads.
[0072] B. After the first few seconds of a significant frequency deviation, can help restore the system frequency to its scheduled value, returning the power system to normal operation.
[0073] C. Can provide energy or continued load interruption during implementation of the EEA and
[0074] D. Can provide back-up frequency regulation.
[0075] Other independent system operators have similar definitions for operating their transmission system.
[0076] Typically, frequency-responsive generating reserves are expected to provide power to the grid as quickly as possible to avoid under-frequency load tripping.
[0077] But a curtailed WTG can be controlled from zero output to full output power (as taught by the present invention) in a few seconds, e.g., about 10 seconds. Unfortunately, in the prior art the wind turbine parks are either not expected to respond to frequency deviation events (because they are not considered “firm” power because when needed in response to an under-frequency event sufficient wind energy may not be available) or they are controlled to respond to such events only on a droop characteristic (e.g., 5%) as described above.
[0078] Those skilled in the art have failed to recognize that power system frequency drops are typically significantly below the typical droop characteristic of 5%. According to the prior art, a 5% frequency drop causes the WTG to provide its full power output to the power system. And in the prior art a frequency drop of less than 5% causes the WTG to provide only a proportional share of its full output power to the grid to prop up the frequency.
[0079] For example, according to the prior art, a frequency drop of 0.5% causes a wind turbine park operating according to a 5% droop characteristic to come on-line and supply 10% of its rated capability. This 10% value is determined from the ratios:
[0000] 5%/100%=0.5%/ X
[0000] X=10%
[0080] If the frequency drops 0.25% (to 59.85 Hz) for a 5% droop characteristic then:
[0000] 5%/100%=0.25%/ X
[0000] p X=5%
[0000] Thus a 100 MW WTG park, according to the prior art, is controlled to increase its output power to 5% of 100 MW or 5 MW. The WTG operator is expected to provide the additional 5 MW of power at no charge if sufficient wind energy is available.
[0081] According to the present invention, the WTGs are not operated according to the droop characteristic (or the WTGs implement the control scheme of the present invention in addition to the conventional droop control characteristic). If a WTG or wind turbine park is operating in a curtailed mode and an under-frequency condition occurs, in one embodiment the wind park or the WTGs are controlled to provide 100% of the available power (as determined by the then-current wind conditions) to the power system as quickly as possible.
[0082] With reference to FIG. 2 according to the present invention, a wind turbine park comparator 100 is responsive to a signal representing the actual grid frequency and reference signal, e.g., a predetermined frequency threshold or a dead band. The comparator 100 detects an under-frequency condition beyond the reference or outside the dead band and supplies a representative signal at a terminal 102 .
[0083] A comparator 108 is responsive to a signal representing the actual output power from the wind turbine park and to a signal representing the output power capacity of the park based on current wind conditions. Thus a signal at a terminal 110 of the comparator 108 indicates whether the park is operating in a curtailed condition, i.e., actual output power less than available output power capacity.
[0084] The signals at the terminals 102 and 110 are input to a wind park controller 114 to control a power electronics frequency converter 118 to bring the wind park up to full output power as quickly as possible when operating from a curtailed condition. This action relieves the under-frequency condition very quickly while utilizing the maximum power generating resources of the wind park.
[0085] The wind park remains in the full-power mode (a steady state condition) for an unlimited duration, until the next under-frequency or over-frequency incident occurs or as controlled by the system operator. The park does not automatically return to a pre-incident output power level.
[0086] While other power generating resources (photovoltaic and hydroelectric) can also employ such a control scheme, the WTGs can respond to control signals increasing (or decreasing) their output faster than these other power generating devices.
[0087] If the grid frequency stabilizes at 60.00 Hz responsive to the control action of the wind turbine park, it should be unnecessary for other power generating devices to also respond to the under-frequency condition. In practice, because the WTGs can emerge from their curtailed condition quickly, the power generated by the wind turbine park may relieve the under-frequency condition before any other power generating resources have had sufficient time to initiate control actions to relieve the under frequency condition.
[0088] Typically, in certain wind-rich regions the wind-generated power made available according to the teachings of the present invention is available during both on and off-peak periods. If a nuclear plant or a large base load coal plant trips in a system like
[0089] ERCOT (Texas) or a Canadian province the grid frequency can plummet. Frequency responsive WTG reserves controlled according to the teachings of the present invention can be quickly brought on line at full power to maintain a stable grid frequency.
[0090] Since WTG curtailments may, and frequently are, concurrent with conditions of available wind power. Operation of the WTGs or wind park according to the prior art control schemes wastes available wind power as the WTGs are not contributing their full available output capacity to the power system. Additionally, from a business perspective, a wind park owner can be compensated for a frequency responsive reserve of the wind turbine park.
[0091] According to another embodiment, the invention teaches two or more different frequency threshold or dead bands. A first is operative when the wind turbine park is in a curtailed state as described herein. The second is operative when the wind turbine park is operating at 100% capacity but additional energy can be extracted from the wind (i.e., additional energy headroom is available).
[0092] The invention also provides a profit-making opportunity for a WTG wind park for the park owner. It is possible to sell frequency responsive reserves so that if the frequency extends outside of the dead band or threshold, the entire 100% WTG capacity can be provided. Such frequency reserves are typically sold for about $20/MWH. The frequency responsive reserves for a 100 MW WTG park would cost about $2000 an hour.
[0093] Presently, this arrangement is not permitted in most jurisdictions because wind power is not considered “firm” power. It is also not considered reserve capacity for the power system. Instead, the wind energy is considered just “energy.” On a cumulative or annual basis that conclusion might be true, but it is not true at any given point in time. Thus again there is ample support for implementing the teachings of the present invention in a power system that includes one or more wind turbine parks.
[0094] According to another embodiment, WTGs or a wind turbine park can also be employed to detect over-frequency conditions. During these conditions the WTGs that are on-line can quickly drop their output power. Wind turbine plants can respond very fast to abnormal frequency incidents, e.g., an order of magnitude faster than other generating units. For example, a WTG can respond at a rate of about 10% per second (increase or decrease) vs. 10% per minute for a fast gas turbine and a few percent per hour for a base load steam plant.
[0095] FIG. 3 depicts a flow chart 200 setting forth certain principle steps associated with the present invention. Execution begins at a step 201 and proceeds to a decision step 204 for determining whether the WTG or the WTG park is operating in a curtailed mode. A negative response returns processing to the start step 201 . An affirmative answer at the decision step 204 directs processing to a decision step 206 where it is determined whether the change in the power system frequency is greater than a predetermined threshold.
[0096] A negative response returns processing to the start step 201 . An affirmative answer controls processing to a step 210 where the WTG or the WTG park is controlled according to a response characteristic that is different from the known droop response characteristic. From the step 210 processing returns to the start step 201 and continues cycling through the identified steps for controlling the WTG or the WTG park.
[0097] Although the present invention has been described in the context of wind turbine generators, its teachings are also applicable to solar or photovoltaic generators or any other electricity generating devices that supply frequency responsive reserves.
[0098] While various embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous variations, changes and substitutions may be made without departing from the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims. | A wind turbine generator park ( 1 ) for supplying power to a power system ( 37 ), the park having an assigned first droop response characteristic for use in responding to an under-frequency occurrence on the power system ( 37 ). The park comprises a first comparator ( 108 ) for generating a first signal when the park is operating according to a curtailed condition, a second comparator ( 100 ) for indicating that a change in a frequency of a voltage or current on the power system ( 37 ) is greater than a first threshold value, and a controller ( 114 ) responsive to the first and second signals for controlling the park according to a second response characteristic causing the park ( 1 ) to supply an amount of power to the power system ( 37 ) greater than the power supplied according to the first droop response characteristic. | 8 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to electron beam lithography (EBL), and more particularly to an EBL method for writing a curvilinear pattern over a large area with minimal accumulation of errors.
2. Description of the Related Art
EBL is a specialized technique for creating extremely fine patterns on a workpiece or specimen, such as a semiconductor wafer. In EBL, the specimen is covered with a resist film that is sensitive to the electrons and is moved across the electron beam (e-beam). The primary advantage of EBL is that it overcomes the diffraction limit of light and enables the patterning of features in the nanometer range. EBL has has yet to become a standard manufacturing technique because of its slow speed. Because the e-beam must be scanned across the surface to be patterned, typically raster-scanned in an x-y Cartesian coordinate system, the pattern generation is serial. This makes for very slow pattern generation compared with a parallel technique like conventional photolithography in which the entire surface of the specimen is patterned at once. As a result, EBL is used mainly to generate exposure masks to be used with conventional photolithography. For commercial applications, EBL is usually produced using dedicated e-beam tools or writing systems, such as those available from Leica Microsystems and Hitachi, Ltd.
Commercial e-beam writing systems use an x-y stage that moves the specimen in a Cartesian coordinate system in a plane orthogonal to the incident e-beam. The stage is divided into square fields in the x-y coordinate system and is moved in a raster technique from field to field in the x and y directions so that fields of the specimen are successively positioned under the e-beam. After a specific field has been positioned, the e-beam is scanned across subfields within that field to write the portion of the pattern within that field. These e-beam writing systems work well for their primary application, the patterning of semiconductor masks, wherein the entire specimen contains a large number of relatively small identical patterns corresponding to the individual semiconductor chips and the patterns contain a large number of straight lines. However, it becomes difficult to use these systems to write closed curvilinear patterns such as circles, and particularly circular patterns that extend over a large area of the entire specimen. This is because errors in movement of the stage from field to field accumulate so that the last portion of the circular pattern does not correlate with the first portion.
One application for e-beam writing of large-area circular patterns is for patterned magnetic recording disks. Magnetic recording hard disk drives with patterned magnetic recording disks have been proposed to increase data density. In a patterned disk, the magnetic recording layer on the disk is patterned into small isolated data islands arranged in concentric circular data tracks. Patterned disks also have nondata regions that are used for servo positioning of the read/write heads in the data tracks. To achieve patterned disks with areal data densities greater than about 300 Gbit/in 2 , the pattern period is typically below about 50 nm along-the-track and the diameter of the data islands is below about 30 nm. One proposed method for fabricating patterned disks with such extremely small features is by nanoimprinting with a master disk or “stamper” having a topographic surface pattern. In this method the magnetic recording disk substrate with a polymer film on its surface is pressed against the master disk. The polymer film receives the image of the master disk pattern and then becomes a mask for subsequent etching of the disk substrate. The magnetic layer and other layers needed for the magnetic recording disk are then deposited onto the etched disk substrate to form the patterned-media disk. The master disk for nanoimprinting can be fabricated by EBL provided the circular patterns can be written with high precision.
What is needed is an e-beam writing method for commercial Cartesian-type EBL systems that enables closed curvilinear patterns, in particular concentric circular patterns, to be written over relatively large areas without accumulation of errors caused by movement of the x-y stage from field to field.
SUMMARY OF THE INVENTION
The invention is a method for operating a Cartesian-type EBL tool to efficiently and precisely write a closed curvilinear pattern, such as a circle, over a wide area of a workpiece. The curvilinear pattern overlies a plurality of contiguous fields of the x-y stage, and the stage is moved along a path defined by the contiguous fields. Alignment marks associated with the first and next-to-last fields are formed on the specimen. The alignment marks are used to adjust the shape of the last field so that when the e-beam is scanned in the last field there is a substantially continuous connection of the pattern between the next-to-last field and the first field. The alignment marks for the first and next-to-last fields may each be the vertices of square. The shape of the last field is adjusted by calculating the x and y offsets between the vertices of the two squares. The calculated offsets are used to correct the scanning of the e-beam in the last field so that the continuous pattern connection is achieved. The invention is particularly applicable to making a master disk with concentric circular tracks for nanoimprinting patterned magnetic recording disks.
For a fuller understanding of the nature and advantages of the present invention, reference should be made to the following detailed description taken together with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a schematic of a conventional EBL system.
FIG. 2 is a portion of a conventional EBL system x-y stage showing several fields and the raster technique for movement from field to field, with one field enlarged to show its subfields.
FIG. 3 is a view of a pattern defining a circular path overlying the fields of the x-y stage.
FIG. 4A is a schematic showing the first, next-to-last, and last fields (fields 1 , m−1, and m, respectively) of a circular pattern to illustrate the effect of the accumulation of errors when writing to the last field.
FIG. 4B shows the method of this invention for calculating the transformed shape of the last field.
FIG. 4C shows a variation of the method for calculating the transformed shape of the last field wherein there is no calculated offset in the x direction.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a high-level block diagram of a typical EBL tool or writing system. The column forms and controls the e-beam. Below the column is the chamber containing the stage that supports and moves the specimen in an x-y plane orthogonal to the e-beam. A vacuum system maintains an appropriate vacuum level in the chamber. The system is controlled by the EBL computer that controls functions such as loading and unloading the specimen, focusing the e-beam, blanking (turning the e-beam on and off), aligning the e-beam with the specimen, and sending pattern data to the pattern generator. The EBL computer drives a set of control electronics that supplies power and signals to the various parts of the system.
The user first lays out the pattern with commercially available computer-aided-design (CAD) software. The CAD software converts the pattern to a standard exchange intermediate file format, such as GDSII. The EBL computer converts the intermediate format to a format specific to the EBL tool so that the stage and e-beam are controlled to write the pattern on the specimen. In the conventional writing approach the stage is raster scanned in the x and y directions beneath the e-beam and the e-beam is blanked as necessary to write the pattern. The EBL tool uses alignment marks that are formed on the specimen before writing the pattern. Global alignment marks are used to correct for placement and rotation of the specimen on the stage. Pattern-specific alignment marks are used to precisely locate specific portions of the pattern, such as individual chips on a semiconductor wafer. The alignment marks are detected by the system and the EBL computer then calculates the adjustment required when moving the stage and scanning the e-beam.
FIG. 2 shows a portion 50 of a conventional EBL system x-y stage with several square fields numbered 1 through 9 . The stage is moved in a raster fashion, as shown by path 52 , along the +x direction to successive square-shaped fields 1 , 2 , 3 , then in the +y direction to field 4 , then in the −x direction to fields 5 , 6 , then in the +y direction to field 7 , and then in the +x direction to fields 8 and 9 . If there is no portion of the pattern within a field, the e-beam is “blanked” when that field is beneath the e-beam. An actual system may typically contain up to several tens of thousands of fields, with each field having typical dimensions of up to 1200×1200 microns. As shown by the gap between fields 2 , 3 and 4 , there may be an error in positioning from one field to the next successive field, which would cause an error in “stitching” the pattern from one field to the next field. Typically this error may be very small, e.g., with the standard deviation σ of error being in the 6-8 nm range, but the errors can accumulate to an unacceptable level as the stage is moved across a large area of the specimen. FIG. 2 also illustrates an enlargement of typical field 4 . Each field contains a number of square subfields, typically 64×64 (or 4096) subfields. Once the specimen has been mechanically positioned so that the e-beam is aligned with the center of a field, like field 4 , the e-beam is then electronically scanned across the subfields within that field. The stitching error in scanning between subfields is much less than the error between fields, e.g., with the standard deviation σ of error being in the 2-3 nm range.
FIG. 3 shows a circular pattern 60 that may extend over a large area of the specimen. As shown in FIG. 3 , a closed curvilinear pattern (circular pattern 60 ) and the fields it overlies are not to scale so that the invention and the problem it addresses can be better illustrated. The pattern 60 defines a circular path that overlies a plurality of m contiguous fields. These fields include the first field 1 and successive contiguous fields 2 - 8 near the beginning of the circular pattern 60 , and contiguous fields m−3, m−2, m−1 and last field m at the end of the pattern 60 . In this invention the pattern 60 is written not by conventional raster type movement of the x-y stage but by movement of the stage to successive contiguous fields in the circular pattern 60 . This reduces the writing time as well as reducing the accumulation of stitching errors that would occur if the stage were moved across all of the fields in the rastering method as described with respect to FIG. 2 .
However, even with this contiguous-field movement of the stage, errors will accumulate from the very first field 1 to the last field m of the circular pattern 60 so that the portion of the pattern in the last field m will not close perfectly with the portion of the pattern in the first field. This is depicted schematically in FIG. 4 by pattern portions 80 , 82 . The first field (field 1 ) in the circular pattern 60 is shown with its alignment marks, located at or generally near the field 1 vertices 61 , 62 , 63 , 64 . The next-to-last field (field m−1) is shown with its alignment marks located at or generally near the field m−1 vertices 71 , 72 , 73 , 74 . The alignment marks are typically pre-written on the specimen. When the stage has completed its movement along the contiguous fields of the circular pattern 60 and reached field m−1, the accumulation of positioning errors has resulted in a shifting of field 1 relative to field m−1. This relative shifting or offset, indicated by Δx 1 , Δx 2 , Δy 1 , and Δy 2 , will result in the portion 80 of the pattern in the last field (field m) not being perfectly stitched to the portion 82 of the pattern in field 1 .
In this invention alignment marks are written into a first field and also into a second that is spaced along the contiguous path from the first field by an intermediate field. The shape of the intermediate field is transformed from square to non-rectangular by measuring the offset of the alignment marks. In the example to be described the first field is field 1 (the very first field of the pattern) of m fields, the second field is field m−1 (the next-to-last field of the pattern), and the intermediate field is field m (the last field of the pattern). The shape-transformed field m will then have vertices corresponding generally to vertices 72 , 61 , 64 , 73 , so that there is generally a continuous connection between field m−1 and field 1 , as shown by dashed lines 84 , 86 . The e-beam is then scanned in the shape-transformed field using the calculated offset. This calculated offset is shown in the box of FIG. 4A . Thus when the e-beam scans the subfields in field m, it scans to a corrected location x′, y′ according to the transformation calculation of FIG. 4B . This will cause pattern portion 80 to connect with pattern portion 82 in a continuous fashion.
In an alternative transformation only the y coordinates are transformed, resulting in an intentional gap between field m and field 1 . The calculations for this variation are shown in the box of FIG. 4C . This variation may be desirable for forming circular tracks in a master disk for patterned magnetic recording disks to avoid a change in frequency along the track. Thus there is no calculated offset in the along-the-track or x direction.
The invention is applicable to e-beam writing of any curvilinear pattern, especially a closed curvilinear pattern that extends over a relatively large area of the specimen. The invention is particularly applicable to making a master disk for nanoimprinting patterned magnetic recording disks. The master disk has a circularly symmetric pattern of concentric tracks that can be arranged into radial groups of tracks. A group or annulus of concentric tracks is individually mastered, and between the e-beam writing of any two consecutive groups the e-beam may be automatically re-calibrated for accuracy using alignment marks. The center of symmetry for the group of concentric tracks is accurately determined using the alignment marks. This ensures that all groups are accurately positioned and centered with respect to each other. Additionally, by moving the stage around the contiguous fields of the circular path rather than by conventional rastering the stage in Cartesian coordinates, stitching errors between fields are minimized. With this method the circular pattern will accumulate errors primarily in the radial direction, which is more suitable for disk servo patterns. The method of transforming the shape of the last field in the each circular pattern and e-beam scanning of the last field minimizes the stitching error between the patterns in the next-to-last field and the first field.
The invention has been described above for transforming the last field to provide a smooth continuous pattern between the next-to-last field and the first field. However, the invention is also fully applicable to providing a continuous pattern across more fields in addition to the last field. If the misalignment between the next-to-last field and the first field is too large, and the field size is not that large, the corrected pattern may show significant distortion in the last field. If the patterns are circular tracks in a patterned magnetic recording disk, this could make it difficult or impossible for the disk drive servo system to follow the curves in the tracks where the two ends meet. To prevent this the pattern can be smoothed over more than one field when the end of the pattern is reached. Thus alignment marks can be written in each of several fields near the end of the pattern, e.g., fields m−4, m−3 and m−2, in addition to field m−1. The shape of a field, such as field m−3, would be transformed by measuring the offset of the alignment marks between fields m−4 and field m−2. The e-beam would then be scanned in the shape-transformed m−3 field using the calculated offset, in the manner as described above. This process can continue until the shape of last field m is transformed, resulting in the pattern having a continuous shape over multiple contiguous fields near the end of the pattern. This would allow the distortions within the final fields to be smaller, and increases the chance that a usable pattern can be created.
The pattern can also be smoothed over other fields along the path of contiguous fields, such as at fields distributed along a full circular track. For example if m=100, these could be fields 25 , 50 , 75 and 100 . Alignment marks would be written in fields 24 and 26 , 49 and 51 , 74 and 76 , and 99 and 1 . These alignment marks are used to measure distortions and calculate offsets for subsequent writing of fields 25 , 50 , 75 and 100 , respectively. The advantage of this method is that accumulation of errors will occur only on part of the full circular track (in this example only over about 90 degrees or one-fourth of the pattern), which limits the total error accumulation.
While the present invention has been particularly shown and described with reference to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the spirit and scope of the invention. Accordingly, the disclosed invention is to be considered merely as illustrative and limited in scope only as specified in the appended claims. | A method for operating a Cartesian-type electron beam (e-beam) lithography (EBL) tool enables the efficient and precise writing of a closed curvilinear pattern, such as a circle, over a wide area of a workpiece. The curvilinear pattern overlies a plurality of contiguous fields of the EBL tool's x-y positioning stage, and the stage is moved along a path defined by the contiguous fields. Alignment marks associated with the first and next-to-last fields are formed on the specimen. The alignment marks are used to adjust the shape of the last field so that when the e-beam is scanned in the last field there is a substantially continuous connection of the pattern between the next-to-last field and the first field. The invention is particularly applicable to making a master disk with concentric circular tracks for nanoimprinting patterned magnetic recording disks. | 6 |
PRIOR APPLICATION
[0001] This is a US national phase application that claims priority from Swedish patent application no. SE 1451445-9, filed 27 Nov. 2014.
FIELD OF THE INVENTION
[0002] The present invention relates to a method for producing pulp. More particularly, it concerns a displacement batch cooking process comprising a displacement phase using a temperature gradient in the displacement liquor used.
BACKGROUND OF THE INVENTION
[0003] The prehydrolysis-sulfate (Kraft) cooking for the production of special pulps having a high content of alpha cellulose was developed in the 1930's, see e.g. Rydholm, S. E., Pulping Processes, pp. 649 to 672, Interscience Publishers, New York, 1968. The basic idea is to remove as much hemicellulose as possible from cellulose fibers in connection with delignification, so as to obtain a high content of alpha cellulose. This is essential because the various end uses of such pulps, dissolving pulp for instance, do not tolerate short-chained hemicellulose molecules with a randomly grafted molecular structure.
[0004] A separate prehydrolysis step permits the desired adjustment of the hydrolysis of hemicelluloses by varying the hydrolysis conditions. In the prehydrolysis-kraft cooking process the necessary delignification is not carried out until a separate second cooking step. The prehydrolysis is carried out either as a steam or water phase prehydrolysis, or in the presence of a catalyst. In the former “steam” processes, organic acids liberated from wood during the process establish the necessary pH conditions and perform a major part of the hydrolysis, whereas in the latter “water” process, small amounts of mineral acid or sulfur dioxide may be added to “assist” the prehydrolysis. In the prehydrolysis stage carried out in a steam phase, often called autohydrolysis, direct steam is introduced to the chip column in the digester. Conventionally, autohydrolysis is established at some 30-40° C. higher temperature than in liquid filled hydrolysis.
[0005] Conventionally after prehydrolyzing the cellulosic material in a reactor, the hydrolysate and the prehydrolyzed cellulosic material are neutralized in the reactor with alkaline neutralizing liquor so as to produce neutralized hydrolysate and neutralized prehydrolyzed cellulosic material. There is hydrolysate both in the free liquid outside the chips and also trapped and immobilized inside the chips. In Bio Pulping, as much as possible of the hydrolysate can be recovered before the neutralization step in order to be able to utilize the carbohydrates released in the prehydrolysis as an additional product from the mill. A separate washing stage, in which the digester is first filled up with a washing liquid and then the liquid containing the carbohydrates is removed from the digester, can be used between the prehydrolysis and cooking stages. Conventionally, both the liquid filling of the digester as well as removal of the dissolved carbohydrates are done by a displacement process using heated wash liquors, all in order to maintain the temperature of the cellulose material.
[0006] EP 2430233 discloses another method to recover the hydrolysate from a steam phase prehydrolysis. In EP 2430233 hot water is introduced into the digester after prehydrolysis at top and bottom and subjected to internal circulation while filling the digester. The water filling may be continued until the entire chip volume inside digester is drenched in water. The hot water is heated to the intended temperature and stored in hot water accumulator before usage. The heating is done up to a temperature close to the temperature of the hydrolysis.
[0007] Also, a sequence of multiple displacement liquors may be used in a sequence during displacement, and one such sequence is shown in EP796367. After a prehydrolysis at some 170° C. is the hydrolysate neutralized by displacing a hot white liquor pad through the digester at some 155° C., and thereafter is kraft cooking commenced using spent cooking liquor at some 148° C. in a first phase. A problem here is that the very first portion of the hot white liquor pad that meets the hot acidic chips both is heated by the chips and due to exothermic reactions further elevate the temperature in the white liquor pad, and this while the alkali content is consumed. Thus, the last upper volume of the digester content will be exposed to a hot and alkali depleted white liquor pad that is not able to end the prehydrolysis. This will cause an extended prehydrolysis in upper part of digester in comparison to lower part, and the difference in prehydrolysis effect between upper and lower part of digester could be some 17-150%.
[0008] Similar displacement using a white liquor pad, added in volume at some 30 m 3 in a digester with a total volume about 300 m 3 , is also disclosed in EP2567023, but ahead of a CCE-filtrate added in volume at some 130 m 3 . Sequential displacement from bottom is also disclosed for hot black liquor filling as well as final liquor displacement. All displacement liquors used having an isothermal temperature when adding them to the digester.
[0009] While the processes hereto has been optimized for maintaining the established heat value in the digester, i.e. avoiding losses of heat value in the process, most implementations has used excessive heating of process liquors added after a hot treatment stage. The objective in this excessive heating has been to maintain the temperature of the content of the digester high, avoiding the losses that may be at hand if the digester is first elevated to a high process temperature, then lowered in temperature, followed by heating again to establish a higher temperature. Each such swing in temperature leads to heat losses per default, even if heat recovery is implemented after each phase.
[0010] The system has thus been designed with large accumulators for storing the heated process liquors, which accumulators are equipped with circulation systems and heat exchangers in order to heat the liquors to this elevated temperature before use at the specific treatment phase.
[0011] What is also seen in the prior art is that even if these high temperature liquors are used to end a treatment phase, the digester content is subjected to different H-factor exposure as of content close to bottom VS content close to top, and especially if the temperatures differ between phases. Using an isothermal displacement liquor after a hot treatment phase, and a somewhat colder displacement liquor to the bottom of the digester, will impose a larger cooling effect on the digester material contained in the bottom VS the digester material contained in the upper part. This due to that the displacement liquor will be heated by the digester material during displacement and in some cases due to exothermic reactions. At the instant where the displacement front reach the top is the temperature of the free displacement liquor often more than 20-40° C. higher than the temperature of the displacement liquor last added to the bottom. Now, the temperature profile may be even out afterwards by circulation, but the harm has already been done at the moment this temperature profile is obtained.
OBJECT OF THE INVENTION
[0012] The object of the present invention is to improve a displacement following a general heated treatment stage which will result in better uniformity in the pulp produced. It is especially the uniformity of pulp, as seen in over the extension of the digester between top and bottom that is improved as the P- or H-factor will be more similar over the entire content of the digester.
[0013] H-factor is a kinetic model for the rate of delignification in kraft pulping. It is a single variable model combining temperature (T) and time (t) and assuming that the delignification is one single reaction (see Herbert Sixta, Handbook of Pulp, Volume 1, Wiley-VCH Verlag 2006, pages 343-345), and P-factor is the equivalent factor for hydrolysis processes also taking the temperature and time into account.
[0014] For H-factor the delignification process doubles the reaction rate for each 8-10° C. increase starting from a temperature of about 90-100° C. where the delignification rate is almost 0 at all practical retention times and at single H-factor digits even at a retention time of 400 minutes at 100° C.
[0015] For the hydrolysis process the P-factor during 10 minutes is about 100 units at 170° C., only 20 units at 150° C. and practically neglect able at 130° C. Hence, for controlling the appropriate ending of a prehydrolysis sufficient low temperature should be established.
[0016] For ending a prehydrolysis stage it is necessary to change the conditions favoring the prehydrolysis reactions, i.e. a low pH and high temperature. In the prior art has hot white liquor been charged that at end of displacement may be heated to full prehydrolysis temperature or even higher, and this requires excessive charges of white liquor. With the invention the alkali charge may be reduced as an effective lowering of the temperature is established.
[0017] As process liquors may be used at start of displacement, not requiring heating before use, could saving in heating (less use of steam) be obtained in first phases. The necessary heating accumulators may also be smaller (less investment) as the necessary volumes of heated liquors decrease.
[0018] The present invention may be applied after any kind of heated treatment phase, where the treatment result on the material content in the digester is a result of exposure of time and temperature, i.e. H-factor or P-factor.
[0019] The present invention may preferably be applied after hydrolysis, both after steam hydrolysis, as well as liquid filled hydrolysis. The present invention is preferably applied in a prehydrolysis kraft process, where first prehydrolysis is performed at high temperatures in the order of 170° C., while subsequent black liquor impregnation is implemented at quite lower temperature below 155° C., even as low as down to 100° C., which impregnation is followed by cooking at some 135-170° C.
[0020] However, any displacement phase after impregnation or cooking liquor establishment as well as final wash may benefit from the invention, as more total equal H-factor may be obtained for the entire digester content. Equal impregnation effect is also a necessity ahead of cooking in order to obtain same pulp quality of the digester content.
SUMMARY OF THE INVENTION
[0021] The present invention is related to a method for ending a heated treatment phase in a displacement batch pulping process in a digester vessel, where the treatment phase has been done at a treatment temperature above 130° C., preferably above 150° C. The digester has at least a bottom, a mid-point and a top liquid exchange position. The method is initiated after the heated treatment phase and has the following steps;
adding a first displacement liquor to the bottom liquid exchange position while having a first lower temperature more than 20° C. below the treatment temperature in the first displacement liquor at start of the displacement filling a part of the digester with a first volume of an first displacement liquor, continuing to add the same first displacement liquor to the bottom liquid exchange position while having a higher second temperature in the first displacement liquor in a later phase of the displacement filling at least a part of the digester with a total second volume of the first displacement liquor larger than the first volume, and optionally continuing the displacement with a final displacement liquor.
[0025] By this principle could the temperature profiling of the displacement liquor reduce the residual H-factor exposure on the digester content of cellulosic material from the preceding heat treatment, obtaining less difference in pulp quality between the pulp blown first and last from digester. The final displacement liquor may be a different liquor than that used for the initial displacement liquor, but they may also be the same.
[0026] A typical state of the art batch digester with a digester volume in excess of 300 m 3 , may require some 20-30 minutes for a full displacement cycle. Hence, the P- or H-factor exposure on the digester content may differ quite a lot for the digester content, as the bottom content is effectively ending the heat treatment sooner than is obtained in the top content of the digester. Thus using a colder liquor in the first part of displacement will prevent this liquor from reaching excessive temperature at end of displacement.
[0027] According to a preferred embodiment the displacement process is improved such that the final displacement liquor is supplied and displaced until the content of the digester vessel is completely submerged under the total volume of the final displacement liquor added and wherein the first displacement liquor has been displaced from the digester via the top liquid exchange position. In this embodiment the first displacement liquor may be used entirely as a neutralization liquor with the sole objective to swing the digester content towards alkaline conditions during alkali consumption that may consume most of the alkali content.
[0028] According to yet a preferred embodiment the displacement process is improved such that after adding the first displacement liquor with the higher second temperature and before the content of the digester vessel is completely submerged is the displacement continuing by adding the same first displacement liquor to the bottom liquid exchange position while having a third temperature higher than the second temperature in the displacement liquor in a later phase of the displacement filling a part of the digester with a total third volume of first displacement liquor larger than the total second volume. In some applications more than 2 stages in the temperature profiling may be beneficial, depending on size of digester and the necessary time for starting and ending the displacement, which may take up to 10-20 minutes or more.
[0029] This may also be further improved by that the temperature in the first displacement liquor increase is done in incremental steps in at least 3 and up to 10 steps during the displacement. Alternatively, the temperature increase in the first displacement liquor may be done continuously during the displacement.
[0030] In a preferred embodiment the displacement may be succeeded with initiation of a circulation of the liquor is after the digester vessel has been filled by the final displacement liquor. This may improve further equalization of residual heat in the digester content.
[0031] In a preferred embodiment of the inventive method that is especially advantageous when using a white liquor pad as neutralization liquor after a prehydrolysis and using only 2 temperatures in a first cold and a second hot white liquor pad is the proportion of the first volume of the first displacement liquor in relation to the total volume of the first displacement liquor in the range 20-50%. This part volume of the total white liquor pad establish a sufficient part volume that could absorb most if not all of the exothermic heat release during displacement, but also most of the residual heat value of the digester content.
[0032] Also preferable when implementing the inventive method after prehydrolysis is that the total volume of the first displacement liquor is in the range 50-75% of the free digester volume, i.e. not filling the entire digester with this neutralization liquor which may reduce total alkali consumption.
[0033] In order to absorb most of the exothermic heat release and the residual heat in the digester content but still not reaching high temperatures close to those high temperatures supporting hydrolysis reactions, is preferably the first lower temperature in the first displacement liquor in the range 70-110° C., preferably 90-100° C.
[0034] As indicated before, the inventive method is preferably applied after prehydrolysis wherein the heated treatment phase is a prehydrolysis phase wherein the digester content is hydrolyzed at a temperature above 150° C. In such high temperature hydrolysis process is the residual heat value in the digester content quite high and even further heated by reaction heat formed in neutralization, so a hydrolysis effect is maintained to a large extent in final digester content volumes displaced by the displacement liquor, while first digester content volumes displaced are sooner to lower the temperature and end the hydrolysis, whereby a forced temperature profiling may reduce difference in P-factor exposure. Typically the reaction heat formation in neutralization is estimated to 0.1-0.2 GJ/tBD wood resulting in up to 10° C. temperature increase in on average for the liquor filled digester.
BRIEF DESCRIPTION OF THE FIGURES
[0035] FIG. 1 is a schematic layout of a batch digester system with the components necessary to implement the invention in a white liquor displacement phase;
[0036] FIG. 2 a is showing the a principle effect from exothermic reaction during a conventional displacement front through the digester using a hot white liquor pad WLP at a temperature of 150° C. displaced trough the digester;
[0037] FIG. 2 b is showing a conventional circulation phase after FIG. 2 a in order to establish same temperature throughout the digester after the displacement;
[0038] FIG. 3 a is showing a principle effect heating from digester content during a conventional displacement front through the digester using a first white liquor pad WLP at a temperature of 150° C. displaced by hot black liquor at a temperature of 130° C.;
[0039] FIG. 3 b is showing a conventional circulation phase after FIG. 3 a in order to establish same temperature throughout the digester after the displacement;
[0040] FIG. 4 is showing the principle effect of the inventive displacement front through the digester using a hot white liquor pad at successively higher temperature charged at 90° C. in first phase and up to 150° C. in a second phase;
[0041] FIG. 5 a is showing the principle effect of the inventive displacement front through the digester using a displacement liquor at successively higher temperature in 7 stages during complete filling of the digester; and
[0042] FIG. 5 b is showing an optional circulation phase that may be implemented after FIG. 4 a in order to absorb some of heat value still contained in the digester content.
DETAILED DESCRIPTION OF THE INVENTION
[0043] The description will be made using the schematic layout shown in FIG. 1 which only discloses the essential components for the system used necessary to implement the present invention in a white liquor displacement phase. In a full commercial plant is also additional equipment added for performing the kraft cook and heat recovery after cook, for example using warm and hot black liquor accumulators.
[0044] Only one digester is shown but typically a number of digesters are used that operate in sequence and thus in different phases of the cook. If for example 5 digesters are operated the first digester is started and then the remaining digesters are started at some time interval which time interval may correspond to ⅕ of the total cooking cycle time for one digester. Cooked pulp may then be blow to a blow tank at regular intervals, and the process liquids stored in accumulators and atmospheric tanks may be used in another digester minimizing inactive dwell time for the liquids used. The piping system is simplified showing only one liquid addition point for WL, Wash filtrate, LP_ and MP-steam but in a real system are individual piping connected to the inlet point of the digester.
[0045] During the white liquor displacement phase is white liquor used that typically is obtained from the caustization. This white liquor conventionally has a temperature of about 90° C. as it has been stored in atmospheric tanks. The white liquor is heated before supply to the hot white liquor accumulator in at least one heat exchanger HE 2P , using hotter process liquors or steam as heating medium. The content of the hot white liquor accumulator is also heated in a circulation containing an additional heat exchanger HE 2c , using hotter process liquors or steam as heating medium. The heating is performed until the entire accumulator content has reached the intended temperature which in the figure may lie at some 150° C. lif the total digester volume is about 300 m 3 , the total free volume inside a digester filled with comminuted chips is about 200 m 3 , so the accumulator needs a size of 200 m 3 to store this volume for a full displacement phase.
[0046] In FIG. 2 a is shown the principle heating effect from exothermic reactions during a conventional displacement front through the digester using a hot white liquor pad at a temperature of 150° C. In this example a drained digester is shown with a digester content of comminuted chips after a heated treatment in form of a prehydrolysis conducted at 170° C. In a first stage, first left hand figure, of the displacement phase is the inlet cone part filled with a volume of white liquor holding 150° C. when added. In a second stage, second figure from left, of the displacement phase is the inlet cone part filled with a volume of hot black liquor holding 130° C. when added, pushing the hot white liquor pad WLP upwardly. During this displacement will exothermic heat be released as alkali is consumed when the upper level of the white liquor pad neutralizes the acidic digester content but now heated to a higher temperature due to exothermic reactions. The heating effect due to exothermic reactions is in the range 0.138-0.206 GJ/odt of wood.
[0047] This continues in stages until the entire digester is filled with displacement liquor, and as a result of the heating from the exothermic reaction is a temperature profile established over the height of the digester, with a temperature of the free liquor close to the hydrolysis temperature, i.e. close to 170° C. in top but close to 130° C. in bottom. Now, the digester content in bottom has been flushed by 130° C. wash liquor during the entire displacement and is very close to 130° C. But the digester content in top has only been drenched by heated white liquor with most of the alkali content consumed during neutralization. As a result the hydrolysis is ended much sooner in bottom of digester, as the temperature has been lowered to 130° C. at an early stage and alkali has been present, while the digester content in the top is subjected to extended hydrolysis, as the criteria's for ending the hydrolysis, lowering of temperature and change to alkaline conditions has not been fulfilled.
[0048] This temperature profile may be even out by a circulation as shown in FIG. 2 b , which starts from a condition corresponding to the rightmost hand figure in FIG. 2 a , where a pump starts to withdraw liquor from mid-point liquid exchange position and return this liquor to both top and bottom. This will result in some heating in bottom and cooling in top and ideally the entire content of the digester assumes a temperature lying in-between the hot black liquor temperature and the hydrolysis temperature at end of circulation, as disclosed in the right hand figure.
[0049] In FIG. 3 a is shown the additional principle heating effect from the residual heat content of the digester during a conventional displacement front through the digester using a hot white liquor pad at a temperature of 150° C. In this example is a drained digester shown with a digester content of comminuted chips after a heated treatment in form of a prehydrolysis conducted at 170° C. In a first stage, first left hand figure, of the displacement phase is the inlet cone part filled with a volume of hot white liquor holding 150° C. when added. In a second stage, second figure from left, of the displacement phase is the inlet cone part filled with a volume of hot black liquor holding 130° C. when added, pushing the first volume upwardly but now heated to a higher temperature by the digester content. This continues in stages until the entire digester is filled with displacement liquor, and as a result of the heating from the digester content is a temperature profile established over the height of the digester, with a temperature of the free liquor elevated some 10° C. in top but close to 130° C. in bottom. Now, the digester content in bottom has been flushed by 130° C. hot black liquor during the entire displacement and is very close to 130° C. But the digester content in top has only been drenched for a short time by heated white liquor that now holds a temperature of about 150+10° C., and has thus most of the heat value from hydrolysis left also in the digester content.
[0050] This temperature profile may be even out by a circulation as shown in FIG. 3 b , which starts from a condition corresponding to the rightmost hand figure in FIG. 3 a , where a pump starts to withdraw liquor from mid-point liquid exchange position and return this liquor to both top and bottom. This will result in some heating in bottom and cooling in top and ideally the entire content of the digester assumes a temperature lying in-between the hot black liquor temperature, about 130° C., and the added heating from the digester material release, about 140° C., at end of circulation, as disclosed in the right hand figure.
[0051] These two examples in FIGS. 3 a and 4 a show the two independent heating effects from exothermic reactions and heating from digester material respectively, and that the usage of an isothermal displacement liquor results in a temperature profile in the digester, and hence is the digester content in top and bottom of digester subjected to quite a difference in H- or P-factor exposure resulting a variance in the pulp quality.
[0052] According to the invention a deliberate temperature profiling is instead implemented in the displacement liquor used, either as a part of a displacement pad or throughout a complete filling of the digester.
Embodiment in White Liquor Pad
[0053] In FIG. 4 is a first embodiment of the inventive displacement through the digester shown using displacement liquor, i.e. the one and same displacement liquor as of chemical content, which in at least 2 incremental steps, at temperatures of 90° C. and finally 150° C. is used. In this example a drained digester is shown with a digester content of comminuted chips after a heated treatment in form of a prehydrolysis conducted at 170° C. In a first stage, first left hand figure, of the displacement phase is the inlet cone part filled with a first volume of white liquor holding 90° C. when added. In a second stage, second figure from left, of the displacement phase is the inlet cone part filled with a second volume of hot white liquor holding 150° C. when added, pushing the first volume upwardly. The first and second volumes establish a white liquor pad (WLP) that is thereafter displaced trough the digester content by adding hot black liquor holding a temperature of about 150° C. With this temperature profiling of the white liquor, using an unheated white liquor in first phase, will this low temperature part of the WLP absorb the exothermic heat release as well has residual heat in the digester content, avoiding the temperature to become excessive. As indicated an upper layer of the first volume will be heated during displacement and this heated layer HL will increase during the displacement. Due to the initial low temperature at some 90° C., the heating from both exothermic reactions and residual heat in digester content will not be able to raise the temperature close to full hydrolysis temperature which will guarantee that the hydrolysis will be ended. This even if the alkali content has been depleted by the consumption during neutralization. The total volume of the White Liquor Pad WLP is 50-70% of the free volume inside digester and the first colder volume of the WLP is 20-50% of the WLP.
Embodiment in Digester Filling Phase
[0054] In FIG. 5 a is an alternative embodiment of the invention shown during a complete filling of the digester with one and the same liquor, but with a forced temperature profile. This temperature profiling may be implemented after the White Liquor Pad displacement as shown in FIG. 4 .
[0055] The principle effect of the inventive displacement front through the digester shown using a displacement liquor, i.e. the one and same displacement liquor as of chemical content, that in at least 2 or 3 incremental steps, which in FIG. 5 a are 7 incremental steps, at temperatures of 90-92.5-95-97.5-100-102.5 and finally 105° C. is used. In this example a drained digester is shown with a digester content of comminuted chips after a heated treatment in form of a prehydrolysis conducted at 170° C. In a first stage, first left hand figure, of the displacement phase is the inlet cone part filled with a volume of wash liquid holding 90° C. when added. In a second stage, second figure from left, of the displacement phase is the inlet cone part filled with a volume of wash liquid holding 92.5° C. when added, pushing the first volume upwardly but now heated to a higher temperature by the digester content to about 92.5° C. This continues in stages until the entire digester is filled with displacement liquor, and as a result of the heating from the digester content is an ISO temperature profile established over the height of the digester, with a temperature of the free liquor close to about 105° C. in the entire digester. The total heating effect is about 10° C. from exothermic reactions and about 10° C. from heat value in digester content. Now, the digester content in bottom has been flushed by liquor during the entire displacement and most of the heat value in the digester content has been absorbed in the liquor, while the digester content in top has only been drenched by heated liquor and has thus most of the heat value from hydrolysis left in the digester content.
[0056] This temperature profile may be even out by a circulation as shown in FIG. 5 b , which starts from a condition corresponding to the rightmost hand figure in FIG. 4 a , with an isothermal temperature profile of the free liquor, where a pump starts to withdraw liquor from mid-point liquid exchange position and return this liquor to both top and bottom. This will result in some heating of the free liquor by the excess residual heat in the digester content in top throughout the digester. Ideally, the entire content of the digester, both the chips and the free liquor, assumes a temperature lying somewhat above the temperature of the free liquor at end of displacement, as disclosed in the right hand figure.
Alternative Embodiments
[0057] Alternatively, the forced temperature profiling of the displacement liquor may even be modified so that the temperature of the free liquor in the final phase of displacement is not isothermal throughout the digester, but could still have a slight temperature profile with either colder or warmer temperature in final 7 th displacement phase. Hence, the digester content in bottom that is displaced by largest amount of displacement liquor may have the lowest residual heat value in the digester content, and therefore could the temperature increase be larger in the steps disclosed in FIG. 5 a.
[0058] As the objective is to expose the digester content of iso-H factor exposure, could the forced temperature profiling be controlled exponentially so that the digester content may be exposed to less total cooling effect in latter stages of displacement, i.e. using less temperature increase in first 1-3 phases and then successively higher temperature increases in last 4-7 phases.
[0059] The effect of the temperature profiling could be controlled in the pulp finally blown from the digester, taking a sample of the first blow pulp and then a sample from the last blown pulp from the digester and compare pulp quality between these samples as of viscosity, tear strength or other pulp characteristics that may be effected by the specific displacement process.
[0060] If the inventive displacement process is implemented after a prehydrolysis, could for example differences in first and last blow pulp be compared as to residual content of hemicellulose that is supposed to dissolve during the prehydrolysis. If the first blown pulp, i.e. the digester content in bottom during treatment, has a higher content of hemicellulose, one may assume that the hydrolysis has not been obtained to the same extent as the last blown pulp thus suggesting an alteration of the temperature profiling towards a higher temperature in the lower part during the displacement phase.
[0061] The temperature profiling during the displacement could easily be implemented in a principal system as that disclosed in FIG. 1 by using only unheated liquor (90° C.) in first phase, i.e. opening valve V 2A while having valve V 2B closed. Then as disclosed in figures could a change be implemented in several stages, gradually opening the valve V 2B in steps as functionally disclosed in figures, or alternatively opening the valve gradually over the entire control process. The total volume of the liquor accumulator could thus be reduced considerably, as the total heated liquor volume is reduced in proportion to usage. The opening of the valve V 2B may be controlled by a temperature sensor located after mixing of the unheated and heated wash liquors, as disclosed in FIG. 1 .
[0062] While the temperature profiling has been disclosed after a prehydrolysis, the very same temperature profiling may be forced to any displacement liquor added to batch digester to end a preceding heated phase where temperature and time exposure on the digester content of cellulosic material play a role in that treatment phase. Thus, the Hot White Liquor accumulator shown in FIG. 1 may alternatively be a Wash Liquor or Hot Black Liquor accumulator.
[0063] While the present invention has been described in accordance with preferred compositions and embodiments, it is to be understood that certain substitutions and alterations may be made thereto without departing from the spirit and scope of the following claims. | The method is for producing pulp in batch digesters. More particularly, the method is for ending a treatment phase of the digester content. In order to obtain a more uniform pulp quality from the process is the treatment phase ended by displacing a liquor volume (WLP) through the digester vessel with an imposed increasing temperature in the displacement liquor added to digester. | 3 |
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application No. 61/551,669, filed on Oct. 26, 2011, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] There is a need in the welding industry for faster preventative maintenance down-time stops during production hours. More particularly, there is a need to reduce the time required to perform preventative maintenance such as, for example, replacement of consumable welding tips which typically wear out or otherwise degrade during normal use thereof.
[0003] Metal inert gas (MIG) welding involves the sealing and joining of non-ferrous metals such as for example aluminum. Inherent in all MIG Metal Inert Gas automation and robotic processes is the desire of maximizing utilization of the investment producing product(s) so that a reasonable return on investment may be attained. In the case of production robotic MIG welding, the investment is the purchase of automated equipment or robots. During the MIG welding process, consumables must be replaced and/or cleaned periodically during operating hours. During these times, the robot or equipment remains idle waiting for the items to be removed manually by operators. Reducing this time is critical in running an efficient production facility.
BRIEF SUMMARY OF EXAMPLE EMBODIMENT
[0004] A rapid change nozzle apparatus is provided including a nozzle member and a seat or base member wherein the nozzle member may be quickly and easily manually connected with and/or detached from the seat or base member in order for maintenance personnel or operators of an associated welding system to conveniently replace the nozzle as necessary or desired without significant down-time impact relative to the underlying welding processes.
[0005] In an example embodiment, the nozzle member is supported relative to the base or seat member by a set of pin members extending from the base member and by the biasing influence of a spring member disposed between the nozzle member and the base member whereby the spring urges the nozzle member into relative separation from the base member and into contact with the locating pin members.
[0006] In the example embodiment, the nozzle member includes a set of elongate grooves configured to receive the locating pins. A longitudinally extending portion of the grooves is provided for helping to co-locate the central longitudinal axes of the nozzle and base members and to help guide the nozzle member onto the base member. A circumferentially extending portion of the grooves is provided for helping to locate the members in an attached relative position following initial relative rotation of the members whereby the pin members become seated in shoulder regions provided in the grooves whereat the pins may contact the nozzle member after the rotation thereby holding the nozzle member in the grooves and in place relative to the base member. The circumferential groove may be a spiral groove in an alternative embodiment. In another embodiment, both the longitudinally extending portion as well as the circumferentially extending portion of the set of elongate grooves provided on the nozzle member can be replaced with a single groove having a general spiral conformation. In any case, the spiral nature or shoulder region of the circumferential groove assists in selectively coupling the nozzle tip member body with the base or seat member body and in resisting decoupling by inadvertent associated forces.
[0007] The subject rapid change nozzle apparatus addresses nozzle change-out time as well as product longevity. It is typical for an operator to take up to 40 seconds to remove and replace a standard threaded nozzle. During 3 separate tests, this time may be reduced using the subject apparatus of the example embodiment to an average of 6 seconds. Additionally, where thread forms wear out on typically threaded designed products, the rapid change nozzle apparatus allows for all friction points and retaining force to be directed in a static axial relationship against a harder fixed material. The simple act of removing and installing the items has little to no wear on the product. The life of the rapid change nozzle apparatus due to normal use is expected at 4-6 times that of a standard nozzle.
[0008] For purposes of summarizing the disclosure, certain aspects, advantages and novel features of the example embodiment have been described herein. It is to be understood that not necessarily all such advantages may be achieved in accordance with any particular embodiment of the claimed invention. Thus, the claimed invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The example embodiment of the invention is further described in the detailed description which follows, in reference to the noted drawings by way of non-limiting examples of the example embodiment of the present invention, in which like reference numerals represent similar parts throughout the several views of the drawings, and wherein:
[0010] FIG. 1 is a perspective view of a rapid change nozzle apparatus for use with an associated welding system in accordance with an example embodiment;
[0011] FIG. 2 is a perspective view of a base member portion of the a rapid change nozzle apparatus of FIG. 1 in accordance with the example embodiment and with the set of locating pins members removed ease of understanding and illustration;
[0012] FIG. 3 is a top elevational view of the base member portion of the example embodiment shown in FIG. 2 ;
[0013] FIG. 4 is a side elevational view of the base member portion of the example embodiment shown in FIG. 2 ;
[0014] FIG. 5 is a cross-sectional view of the base member portion of the example embodiment shown in FIG. 2 and taken along line 5 - 5 of FIG. 4 ;
[0015] FIG. 6 is an enlarged view of the portion of the base member portion of the example embodiment within the circle marked 6 in FIG. 3 ;
[0016] FIG. 7 is a top elevational view of a tip member portion of the a rapid change nozzle apparatus of FIG. 1 in accordance with the example embodiment;
[0017] FIG. 8 is a side elevational view of a tip member portion of the a rapid change nozzle apparatus of FIG. 1 in accordance with the example embodiment;
[0018] FIG. 9 is a cross-sectional view of the tip member portion of the example embodiment shown in FIGS. 1 , 7 , and 8 and taken along line 9 - 9 of FIG. 7 ;
[0019] FIG. 10 is a cross-sectional view of the tip member portion of the example embodiment shown in FIGS. 1 , 7 , and 8 and taken along line 10 - 10 of FIG. 8 ;
[0020] FIG. 11 is a perspective view of a locating pin member of the rapid change nozzle apparatus in accordance with the example embodiment;
[0021] FIG. 12 a shows a side elevational view of the subject rapid change nozzle apparatus in accordance with the example embodiment in an initial pre-aligned stage of mutual interconnection;
[0022] FIG. 12 b shows a side elevational view of the subject rapid change nozzle apparatus in accordance with the example embodiment in an initial aligned stage of mutual interconnection;
[0023] FIG. 12 c shows a side elevational view of the subject rapid change nozzle apparatus in accordance with the example embodiment in an aligned pre-latched stage of mutual interconnection and at a position between longitudinal and circumferential groove portions; and,
[0024] FIG. 12 d shows a side elevational view of the subject rapid change nozzle apparatus in accordance with the example embodiment in a completed latched stage of mutual interconnection wherein the nozzle apparatus is ready for use with the associated welding system.
DETAILED DESCRIPTION
[0025] With reference now to the drawing Figures wherein purposed are for illustrating the example embodiment only and no for purposes of limiting the invention, FIG. 1 is a perspective view of a rapid change nozzle apparatus 10 in accordance with an example embodiment for use with an associated welding system A shown schematically in the drawing. The rapid change nozzle apparatus 10 of the example embodiment includes, in general, a base member 20 comprising a base member body 22 and a tip member 30 comprising a tip member body 32 . In accordance with the example embodiment, the base member body 22 is configured to selectively receive with the tip member body 32 along mutually coextensive central longitudinal axes and couple with the tip member body 32 in relative opposite rotational directions about mutually coextensive central longitudinal axes in a manner to be described in greater detail below. Advantageously, in accordance with the example embodiment, the tip member body 32 is easily removable from the base member body 22 by hand making its replacement, such as in a welding applications and in other work environments, quick and easy.
[0026] FIG. 2 is a perspective view of a base member portion 20 of the rapid change nozzle apparatus of FIG. 1 in accordance with the example embodiment and with the set of locating pin members 60 ( FIG. 11 ) removed for ease of understanding and illustration of the base member portion. The base member 20 comprises a base member body 22 having on opposite first 24 and second 26 ends and defining a first hollow passageway 28 extending therethrough. The first end 24 of the base member body 22 comprises a connection portion 40 being configured for selective connecting of the base member 20 with the associated welding system A. The second end 26 of the base member body 22 comprises a coupling portion 50 forming a substantially planar front face surface 52 , wherein the first hollow passageway 28 opens in the planar front face surface 52 and is configured for communicating an associated fluid (not shown) from the associated welding system A ( FIG. 1 ) between the first 24 and second 26 ends and through the hollow passageway 28 of the base member body 22 .
[0027] FIGS. 1 and 11 illustrate a set of locating pin members 60 carried on the base member body 22 in accordance with the example embodiment. For reasons to be described below, preferably, the set of locating pin members 60 are disposed in a fixed position relative to the base member 20 and extend radially relative to a longitudinal axis L extending in a direction perpendicular to the planar front face surface 52 of the base member body 22 .
[0028] With reference next to FIGS. 1 and 7 - 10 , the tip member 30 comprises a tip member body 32 having opposite first 34 and second 36 ends and defining a second hollow passageway 38 extending therethrough. The first end 34 of the tip member body 32 comprises an attachment portion 70 being configured for selective attaching of the tip member 30 with the coupling portion 50 of the base member body 22 for receiving the associated fluid from the first hollow passageway 28 into the second hollow passageway 38 . The second end 36 of the tip member body 32 comprises a nozzle portion 80 configured to direct the associated fluid towards an associated workpiece (not shown) adjacent the nozzle portion 80 during use of the subject rapid change nozzle apparatus 10 . In its preferred form, the attachment portion 70 defines a set of locating openings 90 corresponding to the set of locating pin members 60 wherein the set of locating openings 90 are configured to selectively receive the set of locating pin members 60 therein such as by threaded engagement or the like whereby the attached pins provide for rapidly and easily manually coupling and decoupling the tip member 30 relative to the base member 20 . Further, as shown, the attachment portion 70 defines a substantially planar annular coupling surface 100 on the first end 34 of the tip member body 32 .
[0029] As best shown in FIGS. 2-6 , the subject rapid change nozzle apparatus 10 further includes a biasing member 110 disposed between the base and tip members 20 , 30 . Functionally, the biasing member 110 is configured to contact and urge the base and tip member bodies 22 , 32 into relative separation whereby the tip member 30 is held relative to the base member 20 substantially exclusively by contact of the biasing member 110 with the planar front face surface 52 of the base member body 22 and the planar annular coupling surface 100 of the tip member body 32 , together with contact of the set of locating pin members 60 with the set of locating openings 90 . Preferably, the biasing member 110 is a spring washer 112 retained in a groove 114 defined on the base member body 22 and having suitable properties for accomplishing the function identified above and in accordance with the desired welding application.
[0030] In accordance with one example embodiment, the base member 20 is in the form of a nozzle seat manufactured from 360 brass. However, in practice, any material can be used as long as it resists temperatures up to 700 degrees F., which is typical in a front-end welding environment. Furthermore, the material preferably has good machining characteristics so that the retaining pins can be easily installed. It is also helpful that the material forming the base member 20 in the form of a nozzle seat be an efficient thermal conductor, but this characteristic not necessary in all applications. Other materials which can be used include bronze, tool steels, stainless steels, aluminum and certain classes of copper. It is important, however, that the machining tolerances are maintained or otherwise followed on the outer diameter of the nozzle seat where the nozzle installs so that shielding in MIG welding application of the example embodiment gas does not escape between the base and tip portions. Studies show a tolerance of 0.002-0.004 below nozzle inner diameter is highly desirable. In addition, tightening this fit may reduce or eliminate aspirating atmosphere into the gas blanket within the nozzle through a Venturi effect.
[0031] With continued reference to the drawing Figures, a groove 114 cut at the base of the nozzle seat to allow a free float for the spring washer 112 . The spring washer will be sized such that it is a press fit onto the seat until it reaches this groove, then it will more freely. This fit will also restrict the spring washer from falling back down onto the retaining pins when removing the nozzle in the vertical down position. The back side of the nozzle seat can be machined to fit onto various MIG gun configurations. Different thread forms can be identified and machined into the unit to allow for seamless installations. Further machining of components provides the undercut 116 where the groove 114 meets the base or face 52 of the nozzle seat. This allows the retaining spring to sit flush against the wall which will provide a uniform force against the nozzle while held by the retaining pins.
[0032] It is to be appreciated that, preferably, the spring type washer 112 is installed over the outer diameter of the nozzle seat prior to installing retaining pins. This is a press fit over the outer diameter of the nozzle seat, but will free float when reaching a machined groove on the back shoulder of the nozzle seat. The nozzle seat is machined such that the spring sits flush against the larger diameter of the nozzle seat. This advantageously provides a uniform force onto the nozzle when restricted by the retaining pins. This force is uniformly spread against the entire base of the nozzle and is axially directed into the nozzle which in turn transmits the force onto a set of static harder pins 60 . Different configurations of spring washers have been used depending on the desired force to restrict movement of the nozzle. Materials range from hardened steels, stainless steels and brass. Additionally the thickness of the unit combined with the material is dictated by the desired force. Thickness ranges have been from 0.009″-0.025″.
[0033] It is to be further appreciated that, preferably, the set of locating pins 60 are affixed onto the nozzle seat after the wave washer 112 has been installed. In the example embodiment, the pins are provided with male threads 62 which thread into mating holes 64 strategically located into the seat. However, the pins may also be soldered, brazed or glued in place if a more permanent assembly is desired. The outer free ends of the pins 60 are configured to slide into the vertical nozzle grooves on the nozzle for alignment. Additionally, they bear the entire axial force of the wave washer, tension against the wave washer. When the washer 112 is compressed and the pins have cleared the centerline of the horizontal nozzle groove, the nozzle is selectively manually rotated clockwise approximately 23 degrees until the pins seat themselves into retaining slots machines into the nozzle. The pins bear the entire stress of the wave washer while stabilizing the nozzle from additional stresses during the welding process. A relevant aspect is that the material has a harder tensile strength than the nozzle material being utilized. In this way, any wear from installing and removing the nozzle if not done correctly will only wear the nozzle itself, which is treated within the industry as a consumable. Further benefits of the treaded installation of the pins allow for replacement of the pins themselves in the event of a failure due to robotic crash or similar, saving the cost of an entire unit. In addition, this modular set-up also allows for replacement or change of the wave washer in the event it fails or the customer desires a different set-up. The pins are also machined so that after installation they are only slightly larger across their outer diameter than the nozzle outer diameter. In addition, the outside edge may be smooth and the corners broken so that no sharp edges remain that would hinder manual install of the nozzle, especially where the operator has heavy welding gloves.
[0034] In practice, the nozzle 22 can be machined from various material suitable for MIG welding nozzles. The material should handle temperatures up to 700 degrees F. without any sufficient breakdown. Some suitable materials are 260 and 360 brass. C145 copper, steels and some metalized carbons. Additionally, the features and benefits of each material should be weighed as to which would benefit the process itself. This design does not affect material choice as it pertains to how the nozzle performs during the welding process itself. It is also beneficial that the material be an adequate thermal conductor. Furthermore, the nozzle can be machined with or without a permanent insulator affixed to the inner diameter. For shielding gas flow, the through hole or I.D. bore size should be straight if possible. A taper is acceptable for any inner diameter under 9/16″. The finish of all surfaces machines with a maximum 32 micro to aid in gas delivery and resist spatter adhesion and cleaning.
[0035] In embodiments, the inner diameter of the nozzle in the region where it slides over the nozzle seat preferably does not exceed 0.007″ over the nominal outer diameter of the nozzle seat to restrain nozzle from lateral movement in the event of spring wear and to negate any gas leakage between the mating surfaces.
[0036] In embodiments, when assembled, the distance between the back of the nozzle (closest to the nozzle seat) and the nozzle seat edge where the spring rests is preferably not more than the spring diameter plus 0.020″-0.025″. This allows for good compression of the spring creating an axial stabilizing force sufficient enough to resist an unsuspected impact as well as creating a thermal pathway for heat to work its way back toward the outer tube of the assembly where the ambient air can better cool the unit.
[0037] In embodiments, the groove paths preferably does not exceed 0.010″-0.020″ over the nominal pin diameter to allow for clearance but restrict any “play” within the assembly during installation.
[0038] In embodiments, the horizontal groove may be located so that there is a minimum of 0.015″-0.020″ overlap of material between the nozzle and nozzle seat, again restricting gas leakage through the horizontal grooves.
[0039] Other features of the example embodiment include an outer diameter knurling region 120 to aid in installation while wearing heavy welding gloves.
[0040] As shown in the drawings such as in FIG. 2 the base member body 22 is substantially cylindrical and defines a base member body longitudinal axis L. As noted above, preferably, the planar front face surface 52 of the base member body 22 is substantially perpendicular to the a longitudinal axis L. Also as noted an above, the set of locating pin members 60 not shown in FIG. 2 for clarity and ease of discussion, are disposed in a fixed position relative to the base member 20 and extend radially outwardly to the longitudinal axis L. In the example embodiment, the set of locating pin members 60 form an angle of about 0° relative to the longitudinal axis L.
[0041] It is to be appreciated that although the set of locating pin members 60 in the example embodiment extend radially outwardly to the longitudinal axis L and that a portion of the tip member body 32 surrounds a portion of the base member body 22 , other embodiments may equivalently include the set of locating pin members 60 in the example embodiment extend radially inwardly from the base member body 22 and towards the longitudinal axis L and that a portion of the base member body 22 surrounds a portion of the tip member body 22 .
[0042] In addition to the above, in the example embodiment, the set of locating pins 60 are carried on the base member body and are spaced apart circumferentially equidistant on the base member body. In the example embodiment, a set of two (2) locating pins are used and they are circumferentially spaced apart by 180°. However, three (3) locating pins may be used and they may be circumferentially spaced apart by 120°. Four (4) locating pins would be circumferentially spaced apart by 90°, etc.
[0043] In the example rapid change nozzle apparatus 10 , the tip member body 32 is substantially cylindrical and defines a tip member body longitudinal axis M. It is to be appreciated that in the assembled or coupled orientation of the tip member 30 relative to the base member 20 such as shown in FIG. 12 c , the tip member body longitudinal axis M is co-extensive with the base member body longitudinal axis L.
[0044] To ensure interoperability, the set of locating openings 90 matches in number the set of locating pins 60 . Accordingly, the set of locating openings 90 defined by the attachment portion 70 of the tip member body 32 are spaced apart circumferentially equidistant on the tip member body 32 . In the example embodiment, a set of two (2) locating openings are used and they are circumferentially spaced apart by 180°. However, three (3) locating openings may be used and they may be circumferentially spaced apart by 120°. Four (4) locating openings would be circumferentially spaced apart by 90°, etc.
[0045] As shown best in FIG. 9 , each locating opening of the set of locating openings comprises a longitudinal alignment slot portion 92 extending in a direction substantially parallel to the tip member body longitudinal axis M, and a circumferential locking slot portion 94 contiguous with the longitudinal alignment slot portion 92 . However, the circumferential locking slot portion 94 extends circumferentially along the tip member body around the tip member body longitudinal axis M. In this way, following rotation of the tip member body relative to the base member body, the locking pins become received in the circumferential locking slot portion 94 causing mutual coupling of the tip with the base.
[0046] In accordance with the construction of the example embodiment as set out above, each alignment slot portion 92 is configured to slidably receive a corresponding a corresponding locking pin member 60 to constrain relative movement between the tip and base members to relative linear movement substantially parallel to the tip and base member body longitudinal axes M, L while the tip and base member are brought into initial mutual alignment whereat the tip and base member body longitudinal axes are coextensive. In addition, each locking slot portion 94 is configured to slidably receive a corresponding locking pin member 60 to constrain relative movement between the tip and base members to relative rotational movement substantially about the tip and base member body longitudinal axes while the tip and base member are brought into mutual relative connection.
[0047] In the example embodiment as shown best in FIG. 9 , each locking slot portion 94 defines a recess shoulder region 96 having a recess shoulder surface 98 extending on the nozzle member body in a direction parallel to the tip member body longitudinal axis M and configured to slidably engage a corresponding locking pin member 60 . In this way, the biasing member 110 urges each locking pin member 60 against a corresponding recess shoulder surface 98 thereby selectively coupling the tip member body 32 with the base member body 22 and resisting decoupling by inadvertent associated forces.
[0048] As noted and given the construction described immediately above, the pin members 60 bear the entire axial force of the wave washer 112 and thereby provide an opposing or tension against the wave washer compressing it biased between the planar front face surface 52 and the planar annular coupling surface 100 on the first end 34 of the tip member body 32 . When the washer is compressed and the pins have cleared the centerline of the horizontal nozzle groove, the nozzle is rotated clockwise approximately 23 degrees until the pins seat themselves into retaining slots machines into the nozzle. The pins bear the entire stress of the wave washer while stabilizing the nozzle from additional stresses during the welding process. A relevant aspect is that the material has a harder tensile strength than the nozzle material being utilized. In this way, any wear from installing and removing the nozzle if not done correctly will only wear the nozzle itself, which is treated within the industry as a consumable.
[0049] FIGS. 12 a - 12 c illustrate stages of relative mutual connection between the b, and 12 c the tip and body members 20 , 30 . FIG. 12 a shows a side elevational view of the subject rapid change nozzle apparatus in accordance with the example embodiment in an initial pre-aligned stage of mutual interconnection. With the tip member body 22 spaced from the base member body 32 , the bodies are initially aligned so that the longitudinal axis M of the tip member body 32 becomes co-extensive with the longitudinal axis L of the base member body 22 .
[0050] FIG. 12 b shows a side elevational view of the subject rapid change nozzle apparatus in accordance with the example embodiment in an initial aligned stage of mutual interconnection. More particularly, with the tip member body longitudinal axis M co-extensive with the base member body longitudinal axis L and while maintaining that relationship, the nozzle body 32 is manually rotated about its axis M so that the longitudinal alignment slot portion 92 of the longitudinal alignment slots are aligned with the set of pin members 60 as shown in the Figure. After establishing the desired alignment, the base body member 22 may be moved linearly in a direction x 1 and/or the tip member body may be moved linearly in a direction x 2 . This would place the members in the relative position shown in FIG. 12 c described below.
[0051] FIG. 12 c shows a side elevational view of the subject rapid change nozzle apparatus in accordance with the example embodiment in an aligned pre-latched stage of mutual interconnection and wherein the set of positioning pins 60 are located at a position between longitudinal 92 and circumferential 94 groove portions. Compression of the biasing member (not shown in the Figure for clarity) is at its maximum extent with the base and tip member bodies in the position illustrated in the Figure. After establishing the desired pre-latched stage alignment illustrated, the base body member 22 may be rotated about its longitudinal axis L a direction R 1 and/or the tip member body may be rotated about its longitudinal axis M a direction R 2 . This would place the members in the relative position shown in FIG. 12 d described below.
[0052] FIG. 12 d shows a side elevational view of the subject rapid change nozzle apparatus in accordance with the example embodiment in a completed latched stage of mutual interconnection wherein the nozzle apparatus is ready for use with the associated welding system. In this position, each of the locking pin members 60 are received in the As described above, each locking slot portion 94 is configured to slidably receive a corresponding locking pin member 60 to constrain relative movement between the tip and base members to relative rotational movement substantially about the tip and base member body longitudinal axes while the tip and base member held in their mutual relative connection. Mutual relative alignment is assisted by the slidable engagement between the inner surface of the tip portion as it is received on the outer surface of the base member in the region of mutual overlap of the member bodies 22 , 32 . In the example embodiment and as shown, each locking slot portion 94 defines a recess shoulder region 96 having a recess shoulder surface 98 extending on the nozzle member body in a direction parallel to the tip member body longitudinal axis M and configured to slidably engage a corresponding locking pin member 60 . In this way, the biasing member 110 urges each locking pin member 60 against a corresponding recess shoulder surface 98 thereby selectively coupling the tip member body 32 with the base member body 22 and resisting decoupling by inadvertent associated forces. After establishing the desired completed latched stage of mutual interconnection illustrated, the base body member 22 may be rotated about its longitudinal axis L a direction R 3 and/or the tip member body may be rotated about its longitudinal axis M a direction R 4 . This would place the members in the relative position shown in FIG. 12 c described below. However, prior to this relative rotational movement, the spring member is slightly compressed between the body members 22 , 32 owing to the lip surface 97 at the outer extent of the passageway 94 . As can be seen in the Figure, the lip surface 97 is spaced a greater distance from the end surface of the attachment portion 70 than the recess shoulder region 96 , thereby requiring overcoming the spring force before relative rotation. This is beneficial because, in this way, the biasing member 110 urges each locking pin member 60 against a corresponding pocket region defined by the corresponding recess shoulder surface 98 thereby resisting decoupling by inadvertent associated forces.
[0053] It is noted that the foregoing examples have been provided merely for the purpose of explanation and are in no way to be construed as limiting of the present invention. While the present invention has been described with reference to an exemplary embodiment, it is understood that the words which have been used herein are words of description and illustration, rather than words of limitation. Changes may be made, within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the present invention in its aspects. Although the present invention has been described herein with reference to particular means, materials and embodiments, the present invention is not intended to be limited to the particulars disclosed herein; rather, the present invention extends to all functionally equivalent structures, methods and uses, such as are within the scope of the appended claims. | A rapid change nozzle apparatus includes a nozzle member and a seat or base member wherein the nozzle member may be quickly and easily manually selectively connected with and/or detached from the seat or base member in order for maintenance personnel or operators of an associated welding system to conveniently replace the nozzle as necessary or desired without significant down-time impact relative to the underlying welding processes. The nozzle member is supported relative to the base or seat member by a set of pin members extending from the base member and received in longitudinal and circumferential grooved in the nozzle member body, and by the biasing influence of a spring member disposed between the nozzle member and the base member whereby the spring urges the nozzle member into relative separation from the base member and into contact with the locating pin members. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
This claims the benefits of the Provisional Application No. 61/579,450, filed on Dec. 22, 2011, the disclosure of which is incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention relates to methods for preparing bispecific or multi-specific biomolecules, such as bispecific antibodies, and products thereof. Particularly, the invention relates to novel cross-linkers for cross-linking molecules and methods of using the same.
BACKGROUND OF THE INVENTION
Combining biological molecules having different functions may lead to new molecules with desired or improved properties. For example, the combined molecules may have dual functions and may have improved stabilities. A common approach to combining biomolecules is to cross-link these molecules with chemical linking agents. However, the biological activities of combined molecules are not always preserved when chemically cross-linked. Therefore, there remains a need for better methods for cross-linking biomolecules.
SUMMARY OF THE INVENTION
This invention relates to methods for preparing bispecific or multi-specific biomolecules, such as bispecific antibodies (BsAbs), and products thus made. Particularly, the invention relates to novel linker-hinge domain for linking biomolecules and methods of using the same.
One aspect of the invention relates to protein domains that are referred to as “linker-hinge domains” (LHDs). An LHD in accordance with one embodiment of the invention includes a linker sequence and a hinge sequence, wherein the linker sequence comprises glycine-glycine-glycine-glycine-serine (GGGGS; SEQ ID NO: 9), and the hinge sequence comprises cysteine-proline-proline-cysteine-proline (CPPCP; SEQ ID NO: 8). The LHD may include two or more linker sequences. Examples of the LHD domain may include the sequences of SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, or SEQ ID NO: 6
One aspect of the invention relates to proteins having the above-described LHD domains. A protein in accordance with one embodiment of the invention may further include an N-terminal moiety fused to the N-terminus of the protein domain via a peptide bond and/or a C-terminal moiety fused to the C-terminus to the protein domain via a peptide bond. The N-terminal moiety and the C-terminal moiety each may be independently a peptide, a full-length immunoglobulin, or a single-chain variable region fragment (ScFv) of an antibody. For example, one of the N-terminal moiety and the C-terminal moiety may include a T-lymphocyte activating domain that comprises an anti-CD3 antibody or a single-chain variable region fragment (ScFv) of the anti-CD3 antibody, while the other of the N-terminal moiety and the C-terminal moiety may include a tumor recognition domain that comprises an anti-CD20 antibody or a single-chain variable region fragment (ScFv) of the anti-CD20 antibody. Alternatively, the N-terminal moiety comprises comprising an anti-tumor specific marker, an inflammatory disease marker, an autoimmune disease marker, or an allergy-related marker.
One aspect of the invention relates to biomolecules, each of which comprises a dimer of the above-described protein having disulfide linkages between the hinge sequences of the dimer. The biomolecule maintains a T-lymphocyte activation capability, or the biomolecule maintains an antibody to antigen binding capability. The biomolecules may have improved solubilities, stabilities, and pharmacokinetics.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A-1E show schematics illustrating constructs of various bispecific antibodies (BsAbs) in accordance with embodiments of the invention.
FIGS. 2A and 2B show results of electrophoresis, illustrating aggregation of IgG-FLΔH BsAb.
FIG. 3 shows stabilities of various BsAbs after long term storage.
FIG. 4 shows binding affinities of a BsAb without a hinge in the LHD and BsAbs having various linker lengths in accordance with embodiments of the invention.
FIGS. 5A-5C show cytotoxicities of various BsAbs according to embodiments of the invention.
FIG. 6 shows BsAbs induce PBMC proliferation in accordance with embodiments of the invention.
FIG. 7 shows pharmacokinetic (PK) analysis of LHD fused BsAb according to one embodiment of the invention.
DETAILED DESCRIPTION
Embodiments of the invention relate to methods for preparing bispecific or multi-specific biomolecules, such as bispecific antibodies, and products thereof. Some embodiments of the invention relate to novel cross-linkers for cross-linking molecules and methods of using the same. A cross-linker of the invention may comprise a linker domain and a hinge domain. Therefore, these cross-linkers may be referred to as “linker-hinge domains” or LHDs.
In accordance with embodiments of the invention, a linker domain may have a sequence of glycine-glycine-glycine-glycine-serine (GGGS; SEQ ID NO:9), and a hinge domain may have a sequence of cysteine-proline-proline-cysteine-proline (CPPCP; SEQ ID NO:8). Some cross-linkers may comprise one or more linker sequences. The hinge sequences allow for disulfide bridge formations between dimers of molecules containing such sequences
In accordance with embodiments of the invention, these LHDs may be used to construct bispecific or multi-specific biomolecules. The biomolecules may be antibodies, i.e., bispecific or multi-specific antibodies. A bispecific antibody may be referred to as “BsAb” in this description.
A bispecific antibody in accordance with embodiments of the invention may comprise an LHD linked to a constant region fragment (Fe) of an immunoglobulin (IgG) via a peptide bond—i.e., a fused protein of IgG-Fc-LHD. At the N-terminus and the C-terminus of this fusion protein, two specific ligand binding moieties may be attached to produce a bispecific biomolecule. A specific ligand binding moiety on the N-terminus or C-terminus of LHD-IgG Fc may be a protein or a peptide. Examples of such moieties may include a single-chain variable region of an antibody (referred to as “ScFv”) or a peptide that binds a specific ligand (including an antigen).
Bispecific biomolecules of the invention may have an antibody-like structure and will be referred to as “bispecific antibodies” or BsAbs. The following will describe some examples to illustrate embodiments of the invention. While only a limited number of examples are described, one skilled in the art would appreciate that other modifications or variations of these examples are possible without departing from the scope of the invention.
Examples
Constructing CD20-Targeting, Bispecific Antibodies (BsAb with LHD)
To improve the biological functionalities of multi-specific molecules, bispecific antibodies (BsAb) comprising a linker-hinge interface domain (LHD) are constructed and tested for their functions. As used herein, a “linker-hinge” interface domain (“LHD”) includes one or more glycine-glycine-glycine-glycine-serine (GGGGS or G 4 S linker; SEQ ID NO:9) linker sequences and a single cysteine-proline-proline-cysteine-proline (CPPCP; SEQ ID NO:8 hinge) hinge sequence, were constructed. (Table 1)
TABLE 1
List of Linker-Hinge Domain Sequences
Codes
LHD Sequences
SEQ ID No.
15H
GGGGSGGGGSGGGGSCPPCP
1
10H
GGGGSGGGGSCPPCP
2
5H
GGGGSCPPCP
3
10H5
GGGGSGGGGSCPPCPGGGGS
4
5H10
GGGGSCPPCPGGGGSGGGGS
5
5H5
GGGGSCPPCPGGGGS
6
ΔH
GGGGSGGGGSGGGGSGGGGS
7
ΔL
CPPCP
8
Embodiments of the invention use such LHDs to physically connect multiple functional biological molecules, including peptides and proteins. These linked biomolecules have one or more advantages, including maintaining the biological activities of linked molecules/domains, stabilizing the biological characteristics of new molecule, maintaining the chemical, biochemical and physical properties, modulating the biological characteristics, and etc.
To illustrate the beneficial roles of LHD in the construction of multi-specific molecules, several BsAb with LHD formats that recognize CD20 and CD3 as tumor marker and T-lymphocyte activating molecule, respectively, were constructed. These BsAb constructs, including anti-CD20/Sav-IgG/Fc-CH2-CH3-LHD-anti-CD3/ScFv (ScFv-IgG BsAb), anti-CD20 (Full mAb)-LHD-anti-CD3/ScFv (IgG-FL BsAb), and anti-CD20 (Full mAb)-LHD/ΔCPPCP-anti-CD3/ScFv (IgG-FLΔH), were constructed ( FIGS. 1A-1E ).
FIG. 1A illustrates an example of generating a bispecific antibody (BsAb) containing a tumor recognition domain (TRD), which comprises a single-chain variable fragment (ScFv) of an anti-CD20 monoclonal antibody (mAb), and a T-cell activating domain (TAD), which comprises a single-chain variable fragment (ScFv) of an anti-CD3 mAb. In this example, a tumor recognition molecule (TRM), abbreviated as ScFv-IgG, is constructed that comprises two parts: a tumor recognition domain (TRD) and an IgG constant heavy chain domain. The tumor recognition domain (TRD) comprises the ScFv of the anti-CD20 mAb. The IgG constant heavy chain domain comprises the CH2 and CH3 domains of an immunoglobulin G1 constant fragment (IgG1 Fe).
Then, the TRM is linked to an LHD (linker hinge domain), which comprises an LHD sequence of any of the LHD sequences listed in Table 1 (except SEQ No. 7). The LHD is covalently fused to the C-terminus of the CH3 domain of TRM. Finally, the T-lymphocyte activating domain (TAD), a.k.a. single chain anti-CD3 monoclonal antibody domain, is fused to the C-terminus of LHD. In other words, this recombinant protein comprises (from the N-terminus to the C-terminus): TRD (anti-CD20 ScFv), IgG1 Fc, LHD, and TAD (anti-CD3 ScFv).
As in a regular antibody, the biologically active form of this ScFv-IgG bispecific antibody (BsAb) will form a homodimer. The CPPCP sequence (SEQ ID NO:8) in the LHD domain of a monomeric ScFv-IgG BsAb could form disulfide linkages with the CPPCP sequence (SEQ ID NO:8) in the other LHD domain of the other monomeric ScFv-IgG following dimerization, as shown in FIG. 1A . The resultant molecule is an antibody-like molecule having two different variable domains on both ends (the C-terminal end and the N-terminal end) of the constant chain (i.e., IgG1 Fc). Thus, the resultant molecule may be referred to as a bispecific antibody (BsAb).
FIG. 1B illustrates another approach to forming a bispecific antibody (BsAb), having the same bi-specificities (i.e., anti-CD20 and anti-CD3) as those shown in FIG. 1A . This BsAb is similar to the one shown in FIG. 1A , except that a full-length anti-CD20 mAb is used, instead of a single-chain anti-CD20 antibody, for the TRM. The full length mAb includes a full length IgG1 constant heavy chain (IgG1 Fc), i.e., the heavy chain constant domain includes CH1, CH2, and CH3 domains.
As in the ScFv-IgG BsAb described above ( FIG. 1A ), an LHD is fused to the C-terminus of the TRM (i.e., the full-length anti-CD20 mAb)—i.e., fused to the C terminus of CH3 domain of the TRM. The LHD sequences may be any sequence in Table 1 except SEQ No. 7. Then, the TAD (i.e., anti-CD3 ScFv) is fused to the C terminus of the LHD sequence. As in the ScFv-IgG BsAb shown in FIG. IA, this construct will form a dimer. The CPPCP sequence in the LHD of a monomeric IgG-FL BsAb could form disulfide linkages to the LHD of another monomeric IgG-FL upon dimerization, as shown in 1 B. The bi-specificities of this molecule would be the same as those of the one shown in FIG. 1A .
FIG. 1C illustrates a variant of the bispecific antibody (BsAb) shown in FIG. IA. They have the identical TRM and TAD. However, the LHD domain in this variant has the sequence of SEQ ID NO: 8 (Table 1), i.e., without the GGGGS linker sequence SEQ ID NO:9). This variant is referred to as ScFv-IgGΔL BsAb. Like the parental format, disulfide links within the LHD of ScFv-IgGΔL BsAb are generated following dimerization of monomeric ScFv-IgGΔL BsAb, as shown in FIG. 1C .
FIG. 1D shows another variant of the bispecific antibody shown in FIG. 1A . In this variant, the LHD has the sequence of SEQ ID NO: 7 (Table 1), which lacks the CPPCP hinge sequence (SEQ ID NO:8). This variant is referred to as IgG-FLΔH BsAb. Because the LHD lacks the cysteine residues for disulfide bond formation, IgG-FLΔH BsAb is free of disulfide linkage between the two LHDs.
FIG. 1E shows an analog of the BsAb of FIG. 1A . In this analog, the TRD and TAD domains are swapped—i.e., the TAD is at the N-terminus of the IgG1 Fc, while the TRD is at the C-terminus of the LHD. This analog, referred to as “N-terminal TAD BsAb,” has the identical bi-specificities as those of the BsAb shown in FIG. 1A .
The BsAbs described above have improved properties, such as production yields and stabilities, while at the same time retain their binding specificities and potencies, as illustrated below.
The BsAbs described above have improved properties production yields and stabilities, while at the same time retain their binding specificities and potencies, as illustrated below.
BsAb with LHD Delivered Improved Productions
Production plays a key role in commercialization of protein-based therapeutic agents. In accordance with embodiments of the invention, the inclusion of LHD in proteins could improve the yields of multi-specific molecules. To demonstrate the utility of LHD according to embodiments of the invention, ScFv-IgG, IgG-FL and IgG-FLΔH BsAbs were cloned, expressed, and tested on FS293 mammalian cells to evaluate their productions and stabilities.
Results from these tests showed that regardless the repeats of the linker sequence in the LHD, all BsAb formats share similar production rates (≧1 μg/ml) under transient transfection productions. Although IgG-FLΔH BsAb has a crude yield comparable to those of the IgG-FL or ScFv-IgG BsAb formats, a poor recovery rate was noticed for the IgG-FLΔH BsAb following purification (Table 2).
TABLE 2
The Recovery Rates of BsAb with LHD Constructs Following Purification
SEQ ID NO
Label
Recovery Rates
1
15H
≧90%
2
10H
≧90%
3
5H
≧90%
4
10H5
≧90%
5
5H10
≧90%
6
5H5
≧90%
7
ΔH
≦45%
8
ΔL
≧90%
Further analysis revealed that significant amounts of aggregate formation that was pelleted down at the bottom of purification apparatus for the IgG-FLΔH BsAb. Subsequent SDS analysis showed that BsAb was the major component of these pellets ( FIG. 3 ).
Stability of protein drugs at liquid storage under 4° C. has been an issue in protein engineering, particularly linker-containing proteins (see U.S. Patent Application Publication N. 2009/0175867 A1). The examples described herein showed that mild proteolytic cleavages were observed on BsAbs with one to two linker-repeats, but rarely on other LHD constructs ( FIG. 4 ).
The Antigen-Binding Capability is not Compromised for BsAb with LHD
The binding to CD3 on T-cell surface is essential for BsAb to acquire T-cell mediated cytotoxicity. The CD3 molecule is a co-receptor of the T-cell receptor (TCR) and is responsible for the signaling following stimulations of the MHC and antigen complexes. Fusion of anti-CD3 ScFv directly to the C-terminus of ScFv-IgG, IgG-FL and IgG-FLΔH BsAbs produced some negative impacts to the CD3 binding capacities of these molecules, as shown in Table 3.
TABLE 3
Binding Constant Analysis of LHD Fusion BsAb to CD20 and CD3
SEQ
Binding to CD20
Binding to CD3
No.
Label
(IgG-FL BsAb) M
(IgG-FL BsAb) M
1
15H
2-4 × 10 −8
2.7 × 10 −8
2
10H
2-4 × 10 −8
3.3 × 10 −7
3
5H
2-4 × 10 −8
6 × 10 −8
4
10H5
2-4 × 10 −8
5.2 × 10 −8
5
5H10
2-4 × 10 −8
—
6
5H5
2-4 × 10 −8
1.5 × 10 −7
7
ΔH
2-4 × 10 −8
—
8
ΔL
Anti-CD3
—
1 × 10 −9
mAb
ScFv-IgG
8-9 × 10 −8
5 × 10 −8
(15H)
Chemically
2-4 × 10 −8
1 × 10 −9
Conjugated
BsAb
Among these BsAbs, IgG-FLΔH BsAb suffered the most significant reduction in CD3 binding (Table 3 and FIG. 2A ). Such unpredicted outcome highlights the necessity of LHD for a biologically effective BsAb. However, changes in the length of linker sequences within LHD are insufficient to fully restoreCD3 bindings to BsAbs (Table 3). Compared to the parent, full-length anti-CD3 antibody, decreased affinities to the ligand (CD3) by both ScFv-IgG and IgG-FL BsAbs were observed (Table 3). On the other hand, the binding constants to CD20-expressing lymphoma by three BsAbs (ScFv-IgG, IgG-FL and IgG-FLΔH) were not affected (Table 3).
The T-cell mediated cytotoxicity against tumor is the Holy Grail of BsAb therapy. The following examples show that an LHD helps BsAbs to perform enhanced T-lymphocyte-mediated tumor-eradication. Like chemically conjugated BsAb, both IgG-FL and ScFv-IgG BsAbs were capable of eliminating CD20 + B-cell lymphoma at low concentrations ( FIG. 5A ). Removing linker sequence (GGGGS; SEQ ID NO:9) from the LHD (i.e., ScFv-IgGΔL BsAb) also eliminates the T-lymphocyte mediated cytotoxicity ( FIG. 5A ).
IgG-FLΔH BsAb shares high degree of structural similarity with IgG-FL BsAb, except that IgG-FLΔH BsAb lacks the CPPCP sequence (SEQ ID NO:8) and, therefore, cannot form LHD-associated disulfide linkages following dimerization. The lack of LHD-associated disulfide linkage resulted in significant reductions in T-lymphocyte mediated cytotoxicity ( FIG. 5C ).
Although, BsAb with an LHD between TRM and TAD delivered improved tumor-specific cytotoxicity, the level of improvement is not universal to the LHD sequences listed in Table 1. It was found that the optimal cytotoxicity for ScFv-IgG BsAb was associated to SEQ ID 4, 5 or 6 (Table 1, FIG. 5A ). Such variations in tumor-specific cytotoxicity, however, became indistinguishable when full set of anti-CD20 mAb was used as TRM in IgG-FL format ( FIG. 5B ). Rituxan®, an anti-CD20 mAb has been shown to mediate B-cell depletion via antibody dependent cell mediated cytotoxicity (ADCC). Our experiments demonstrated that LHD comprised BsAbs, such as IgG-FL and ScFv-IgG formats, are more efficient in eradicating B-lymphoma via ADCC than Rituxan® ( FIGS. 5A , 5 B and Table 4). Prior results showed that Rituxan®-induced ADCC requires a higher effecter:target ratio (E:T ratio, 40:1 or higher) and higher Rituxan® titer (μg/ml) to keep maximal cytotoxicity at 30-50%. The IgG-FL BsAb format of selected LHD, however, delivered not only improved tumor eradication capability (up to 80%), but also reduce the E:T ratio to 10:1 (Table 4).
TABLE 4
LHD Fusion BsAb Mediate Cytotoxicity Against Tumor Cells
Cytotoxicity (BsAb)
ScFv-IgG with LHD BsAb
IgG-FL with LHD BsAb
Construct; E:T = 10:1
Construct; E:T = 10:1
Fold of
Fold of
Maximal
Maximal
Cytotoxicity
Cytotoxicity
Improved vs.
Improved vs.
SEQ
anti-CD20
anti-CD20
No.
Label
EC50 (pM)
mAb
EC50 (pM)
mAb
1
15H
14.2
2.55
4.0
2.78
2
10H
9.5
2.55
2.0
2.82
3
5H
41.7
2.55
4.6
2.82
4
10H5
3.9
2.55
3.5
2.82
5
5H10
6
5H5
4.3
2.55
2.8
2.82
7
ΔH
15.6
1
8
ΔL
≦1
ScFv-IgG BsAb with LHD and IgG-FL BsAb With LHD Induced Mild Proliferation on PBMC, as Compared to Parent Anti-CD3 Monoclonal Antibody
The full-length monoclonal anti-CD3 antibody is a well-known mitogenic inducer for non-specific T-cell activation. It has been proposed that this mitogenicity is a major contributor to the adverse effects, such as flu-like symptoms and cytokine release syndrome (CRS), following monoclonal anti-CD3 antibody therapy. We showed that parent anti-CD3 mAb induces significant proliferation on freshly-cultured peripheral blood mononuclear cells (PBMC) ( FIG. 6 ), same as N-terminal TAD BsAb ( FIG. 1E ). BsAb prepared by chemical conjugation of anti-CD20 mAb and anti-CD3 mAb showed a slightly decreased mitogenic potential, as compared to anti-CD3 mAb alone. IgG-FL/15H BsAb, however, only exhibited mitogenic effects at high concentrations ( FIG. 6 ).
T-Cell Activation Markers were Enhanced by BsAb with LHD
The proliferation assay is a “standard” in measuring the activation of T-lymphocytes, regardless of the heterogeneous cellular outcomes following activation. We showed that IgG-FL BsAbs deliver enhanced cytotoxic effects to B-lymphoma, regardless of its reduced proliferation profile ( FIGS. 5 and 6 ). To rationalize such observations, T-lymphocyte activation markers, both CD69 and CD25, were stained and revealed by FACS following various stimulations (Table 5). The examples showed that LHD-containing IgG-FL BsAb is more effective than anti-CD3 mAb in enhancing the expression of both CD69 and CD25. N-terminal TAD BsAb also share activation profiles similar to those of the LHD-containing IgG-FL BsAb. ScFv-IgG fused with LHD/ΔL is ineffective in tumor cell eradication ( FIG. 5A ), such loss in biological function is also reflected by loss of the capability in activating T-lymphocytes (Table 5).
TABLE 5
IgG-FL BsAb with LHD Enhances the Expression of CD69 and CD25
Mean Fluorescence Index (MFI)
α-CD3
α-CD69
α-CD25
Day 0
Blank
189.62
10.16
22.2
Day 4
Blank
223.62
21.75
44.01
IL-2
240.74
148.76
108.7
Anti-CD3 mAb
214.22
45.53
612.89
IgG-FL
310.45
48.92
828.58
(LHD/15H) BsAb
N-terminal Anti-
314.97
49.09
697.62
CD3 BsAb
Chemically
308.12
40.39
716.17
Conjugated BsAb
ScFv-IgG-
244.09
23.35
51.86
LHD/ΔL BsAb
Such results further indicate that the requirement of both linker and hinge for a functional LHD domain. These examples demonstrated that the inventive LHDs (Table 1) can maintain the biological activities of the linked molecules/domains and modulate the desirable biological characteristics.
IgG-FLBsAb with LHD Showed Improved Pharmacokinetic Property
The PK (pharmacokinetics) is an essential indicator for a successful drug because extended PK not only translates into a better stability, but also a less frequent dosing and better acceptance to patients and clinicians. The PK of IgG-FLon mice showed a T 1/2 of almost 96 hours ( FIG. 7 ).
Constructing Bispecific Antibodies
Restriction enzymes were purchased from various venders, DNA polymerase, T4 DNA ligase Klenow enzyme and T4 DNA polymerase were from Invitrogen (Grand Island, N.Y.). All enzymes were used as recommended by the manufactures.
All primers for PCR amplifications were purchased from various venders. DNA amplifications were performed in a PCR machine from manufacturer using a predenaturing step, followed by pre-determined cycles, containing a denaturing step, an annealing step, and an extension step, each for 30 minutes.
All expression modules are schematically represented in FIGS. 1A-1E .
The anti-CD20 light chain and truncated heavy chain were cloned into vector vector A and vector B. A single-chain fragment of anti-CD20 VH and VL was cloned into vector C and used for subsequent anti-CD20 ScFv.
Cell Lines Preparation
The Raji cell used in this invention is a B-lymphoma tumor cell line obtained from Biorescouce Collection and Research Center (BCRC), which is a division of Food Industry Research and Development Institute (FIRDI) in Taiwan, R.O.C. The Jurkat cell is a T-lymphoma cell line from ATCC. Both Raji and Jurkat cells are cultured in RPMI 1640 medium (GibcoBRL Life Technologies, Paisly, UK) supplemented with 10% Fetal bovine serum (Hyclone), 0.03% L-glutamine and 0.4 mM of sodium pyruvate. After incubation at 37° C. humidified incubator containing 5% of CO 2 , cells were subcultured or washed in sterilized buffer for testing.
Preparation of Peripheral Blood Mononuclear Cells (PBMC)
Peripheral blood mononuclear cells (PBMC) were isolated from whole blood of normal healthy adult donors with Ficoll-Paque PLUS by density centrifugation. Following the isolation, PBMC were cultured and activated for 6-14 days in RPMI-1640 medium supplemented with 10 ng/ml of anti-CD3 mAb, 75 IU/ml of interlekine-2 (IL-2) and 10% FBS.
Cytotoxicity Assays (Calcein AM Cytotoxicity)
The target cells (Raji) were labeled with 10 μM of Calcein for 30 min at 37° C. in phenol red free RPMI 1640 medium supplemented with 5% FBS. At the end of Calcein incubation, cells were washed twice with phenol red free RPMI 1640 medium with 5% FBS and the cell density was adjusted to 3×10 5 cells/ml with phenol red free RPMI 1640 with 5% FBS. For the reaction mixture, 100 μl of medium containing 3×10 4 cell were placed in each well of a 96-well culture plate. The cell density of effecter cells (PBMC) culture was calculated and adjusted to 3×10 6 cells/ml by phenol red free RPMI 1640 medium with 5% of FBS. For cytotoxic reactions, different quantities of different BsAb and 100 μl (3×10 5 cells) of effecter cells were added into Raji preload, 96 well culture plate and incubated in 37° C., 5% CO 2 enriched incubator for 4 hours. At the end of the incubation, culture plate was centrifuged at 700 g for 5 minutes, then 130 μl of supernatant from each reaction well was transferred, individually, to a new plate and the dye released was quantitated in Fusion alpha micro-plate reader. The percent of cytotoxicity was calculated according to the formula:
[fluorescence(sample)−fluorescence(control)]/[fluorescence(total-lysis)−fluorescence(control)]*100.
The total-lysis was defined as target cells treated with 0.9% of Triton for 10 minutes.
Flow Cytometry Assays
Biding Affinity to Tumor Target (B-Lymphoma)
Raji cells (1×10 6 cells/reaction) were treated with different BsAbs at different concentrations at room temperature for 30 minutes. At the end of the incubation, all reactions were washed twice with PBS supplemented with 2% of FBS. After wash, cells were re-incubated with 1 μl of FITC conjugated, affinity purified F(ab′)2 fragment, goat anti-human IgG (Fab′)2 fragment-specific antibody for 30 minutes at room temperature. Following the incubation, cells were washed twice with ice cold PBS supplemented with 2% FBS and monitored by FACS apparatus.
Jurkat cells (1×10 6 cells/reaction) were treated with different BsAbs at different concentrations at room temperature for 30 minutes. At the end of the incubation, all reactions were washed twice with PBS supplemented with 2% of FBS. After wash, cells were re-incubated with 1 μl of FITC conjugated, affinity purified F(ab′)2 fragment, goat anti-human IgG (Fab′)2 fragment-specific antibody for 30 minutes at room temperature. Following the incubation, cells were washed twice with ice cold PBS supplemented with 2% FBS and monitored by FACS apparatus.
The T-Lymphocyte Activation Markers Analysis
Peripheral blood mononuclear cells (PBMC) were isolated as described in the “Preparation of peripheral blood mononuclear cells (PBMC)” section, except that the isolated PMBC were activated for 2 or 4 days. The immune fluorescence staining of PMBC with anti-human CD25 and CD69 markers was performed as described in the “Biding affinity to tumor target” section, except that the target cells used were activated PBMC. Briefly, 1×10 6 cells/reaction were treated with either fluorescent conjugated anti-human CD25 or CD69 monoclonal antibodies at different concentrations at room temperature for 30 minutes. At the end of the incubation, all reactions were washed twice with PBS supplemented with 2% of FBS. After wash, cells were monitored by FACS apparatus.
The PK Analysis on Fusion Proteins Comprising LHD Fused Bispecific Antibody
Balb/c mice (n=4) were injected with 3 mg/kg of anti-CD20 IgG-LHD-anti-CD3/ScFcBsAb and blood samples were collected at various time points. Sera from collected animals were collected via centrifugation and the concentrations of BsAb were measured via ELISA. Briefly, serial diluted mouse sera were incubated in ELISA plate precoated with anti-human Fab antibody (Jackson Lab) for an hour. Following the incubation, microtiter plates were washed with PBST buffer several times and blocked by 5% skim milk for an hour. At the end of blocking, microtiter plates were wash again by PBST and re-incubated with HRP conjugated anti-human Fe antibody for an hour. Following this incubation, microtiter plates were washed again and color was developed and detected as manufacture suggested.
While bispecific biomolecules are illustrated, one skilled in the art would appreciate that multi-specific biomolecules may also be prepared with this approach. Similarly, the linker sequence is illustrated using GGGGS (SEQ ID NO:9) and the hinge sequence is illustrates using CPPCP (SEQ ID NO:8). However, one skilled in the art would appreciate that other similar sequences may be used. The linker sequence is to provide a proper spacing for the different domains, while the hinge domain is to provide residues for disulfide linkage formation in homodimers.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims. | This invention relates to bispecific antibodies having combinations of linker and hinge sequences to create linker-hinge interface domains with biological significance. Such linker-hinge interface domains covalently join two molecules, maintain the biological activities of linked molecules (target binding), stabilize the biological characteristics of new molecule (solubility and 4° C. stability), maintain the chemical, biochemical and physical properties (cytotoxicity) of the linked molecules, and modulate the biological characteristics of the linked molecules (activating T-lymphocytes without significant sign of proliferations). Both linker (GGGGS) and hinge (CPPCP) sequences are required to establish functional linker-hinge interface domains as deletion of any of the component resulted in significant lost of T-lymphocyte mediated activity. | 2 |
BACKGROUND OF THE INVENTION
The present invention relates to improvements in a method for constructing a tunnel.
The inventor of this invention proposed, in Japanese Patent Publication No. 54-33656, a method for constructing a tunnel consisting of the steps of assembling an inner form within a tunnel bore that has been successively dug by means of a shield tunnelling machine, placing concrete in a space delimited by the form, a shield tail and a front surface of an already placed concrete lining, and thereafter shoving the shield tunnelling machine by means of a concrete lining jack and a shield jack equipped on the shield tunnelling machine with shoving reaction forces received by the placed concrete and the inner form.
In soft ground to which a shield tunnelling method is applied for constructing a tunnel, it is necessary to employ a reinforced concrete structure to assure safety of the tunnel body structure. Accordingly, upon practicing the above-mentioned constructing method in the prior art, it is necessary to set a reinforcing steel cage within the shield tail of the shield tunnelling machine and to dispose it at a predetermined position.
However, in the shield tail section, working space is very narrow, so the work for assembling the reinforcing steel cage becomes complex, and moreover it is difficult to dispose the set reinforcing steel cage at a predetermined position. Furthermore, upon compressing the placed concrete, there is a fear that the reinforcing steel cage may be moved or deformed. Therefore, it becomes impossible to realize the function of a desired reinforced concrete structure.
SUMMARY OF THE INVENTION
It is therefore one object of the present invention to provide an improved method for constructing a tunnel in which a main tunnel body can be constructed easily and correctly as a reinforced concrete structure through a shield tunnelling method of a field-placed concrete lining type.
According to one feature of the present invention, there is provided a method for constructing a tunnel, in which a reinforcing steel cage is mounted to a combined spreader and end form of a concrete lining jack via metal mounts, placed concrete for lining is compressed while the reinforcing steel cage is moved, and thereby the reinforcing steel cage is disposed at a predetermined position within the concrete for lining.
Upon practicing the present invention as featured above, a spreader of a concrete lining jack equipped to a shield tunnelling machine is commonly used as an end form of concrete lining, a preliminarily assembled reinforcing steel cage is mounted to the combined spreader and end form via mount metals, and by extending the concrete lining jack the reinforcing steel cage is moved to the side of concrete for lining which has been placed in the spaced delimited by an inner form assembled within a tunnel bore that has been successively dug by means of a shield tunnelling machine, a shield tail and an already placed concrete lining, the same concrete is compressed by the combined spreader and end form, and the reinforcing steel cage is disposed at a predetermined position within the concrete for lining by adjusting the stroke of the concrete lining jack, whereby a main tunnel body can be constructed as a reinforced concrete structure through a shield tunnelling method of field-placed concrete lining type.
The above-mentioned and other objects, features and advantages of the present invention will become more apparent by reference to the following description of preferred embodiments of the invention taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIGS. 1 through 5 are longitudinal cross-section side views showing successive steps in a method for constructing a tunnel according to one preferred embodiment of the present invention;
FIGS. 6 through 12 are detailed partial views showing the same respective steps;
FIGS. 13 to 16 are partial perspective views showing the steps of mounting and moving a reinforcing steel cage;
FIGS. 17 and 18 are perspective views respectively showing a mount portion of a reinforcing steel cage to a concrete lining jack;
FIG. 19 is a transverse cross-section front view showing a state of arrangement of isolated reinforcing steels; and
FIGS. 20 through 25 are longitudinal cross-section side views showing successive steps in a method for constructing a tunnel according to another preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now description will be made of the illustrated embodiments of the present invention.
In FIG. 1, reference numeral (1) designates a shield shell in a shield tunnelling machine, numeral (2) designates a cutter, numeral (3) designates a motor for driving the cutter (2), numeral (4) designates a bulkhead, numeral (5) designates a cutter chamber formed between the bulkhead (4) and the cutter (2), numeral (6) designates a ring girder, numerals (7) and (8) respectively designate a shield jack and a concrete lining jack mounted to the ring girder (6), numeral (9) designates a shield tail section, and numeral (10) designates a concrete lining that was placed between a form assembled within a tunnel bore successively dug by the shield tunnelling machine (1) and the ground. FIG. 1 shows the state where shoving of the shield tunnelling machine has been completed by means of the shield jack (7) and the concrete lining jack (8) with the shoving reaction forces received by an inner form (11) and the concrete lining (10).
FIGS. 2 to 4 show the states where the respective jacks (7) and (8) are retracted, and in this state, hook bolts (12) disposed as penetrating through a combined spreader and end form (8a) of the concrete lining jack (8) are left on the side of the concrete lining (10).
Subsequently, as shown in FIG. 3, a reinforcing steel cage (13) is mounted to the combined spreader and end form (8a) via the hook bolts (12), then the reinforcing steel cage (13) is moved up to a predetermined position by extending the concrete lining jack (8), and the inner form (11) is assembled inside of the reinforcing steel cage (13) FIGS. 4 and 5 show the states where the concrete is placed in the tail section (10), and the shield tunnelling machine is shoved by jacks (7) and (8) respectively.
FIGS. 6 to 10 show the steps of mounting and moving the above-mentioned reinforcing steel cage (13), in which hook bolts (12) are inserted into through-holes (14) in the combined spreader and end form (8a) (See FIG. 7), the nuts (15) are threadedly engaged with the hook bolts (12) and fastened fixedly to secure the hook bolts (12) to the combined spreader and end form (8a), and the reinforcing steel cage (13) is engaged with hook portions at the tip ends of the hook bolts (12) (See FIG. 8). Subsequently the reinforcing steel cage (13) is moved by extending the above-described concrete lining jack (8), then the tip end of the moved reinforcing steel cage (13) is engaged with hook bolts (12) projecting from a reinforcing steel cage (13) disposed in the already placed concrete lining (See FIG. 9), and thereafter an inner form (11) is assembled (See FIG. 10).
Next, as shown in FIGS. 4 and 11, a concrete lining (10) is placed around the outer circumference of the newly assembled inner form (11).
Subsequently, as shown in FIGS. 5 and 12, the shield jack (7) and the concrete lining jack (8) are extended with the reaction forces received respectively by the inner form (11) and the placed concrete lining (10), and thereby the shield tunnelling machine is shoved until the state shown in FIG. 1 is again established.
At this time, a cavity portion (16) formed by the advance of the shield shell (1) is filled with concrete for lining (10), and the reinforcing steel cage moves rightwards as shown at (13') in FIG. 12 simultaneously with extension of the concrete lining jack (8). During this movement, the reinforcing steel cage (13') would not be displaced in the lateral position because it moves as guided by the hook bolts (12). In addition, as the reinforcing steel cage (13') is fixedly secured to the combined spreader and end form (8a) via the hook bolts (12), it would not be subjected to a thrust of the concrete lining jack (8), and hence stress or deformation would not be generated in the reinforcing steel cage (13').
When the shoving of the shield tunnelling machine has been completed in the above-described manner, the nuts (15) are removed and the combined spreader and end form (8a) is retracted, the hook bolts (12) would remain on the side of the concrete lining (10) and the state shown in FIG. 6 is realized.
Thereafter, similar steps to the above-described ones are repeated and the reinforcing steel cage is buried in the concrete lining.
FIGS. 13 to 16 show details of the steps of mounting a reinforcing steel cage (13) to the above-described combined spreader and end form (8a) and shoving the same. In the combined spreader and end form (8a) formed in an arcuated shape and having a large number of through-holes (14) as shown in FIG. 13, hook bolts (12) are inserted into the respective through-holes (14) (See FIG. 14), then a reinforcing steel cage (13) is engaged with the hook bolts (12) as shown in FIG. 15, and as shown in FIG. 16 the reinforcing steel cage (13) is supported by hook bolts (12) projecting from a concrete lining (10) by extending the concrete lining jack (8).
FIG. 17 shows details of the mount portion of the reinforcing steel cage (13) to the hook bolts (12), a combined spacer and packing (17) is fitted around each hook bolt (12), and thereby leakage of cement paste can be prevented.
FIG. 18 shows another example of the mount portion in which a packing (18) is fitted around the hook bolt (12) and a spacer (19) is interposed between the combined spreader and end form (8a) and the reinforcing steel cage (13).
FIG. 19 shows the state of arrangement of reinforcing steel cages (13) each consisting of a single reinforcing bar as arranged so as to conform to the state of stresses in a transverse cross-section. More particularly, in the top and bottom portions of a main tunnel body tensile stresses would occur in an inside portion of a transverse cross-section of the concrete lining (10), whereas in the left and right portions of the main tunnel body tensile stresses would occur in an outside portion of the transverse cross-section, and therefore, the reinforcing bars are arranged so as to effectively reinforce the concrete lining against the respective stresses.
FIGS. 20 to 25 illustrate another preferred embodiment of the present invention, in which a shield shell 1 includes a front shield drum (1A) and a rear shield drum (1B), and component parts equivalent to those of the above-described first preferred embodiment are given like reference numerals.
FIG. 20 shows the state where shoving of the shield tunnelling machine has been completed, and starting from this state a shield jack (7) is extended with a reaction force received by an inner form (11) to make the front shield drum (1A) advance resulting in the state shown in FIG. 21. During this period, a concrete lining jack (8) extend in synchronism with the shield jack (7) and thereby holds a predetermined compressing force to a concrete lining (10).
Subsequently, the respective jacks (7) and (8) are retracted, and the hook bolts (12) take the state of projecting from the reinforcing steel cage (13) within the concrete lining (10) into the space in front of the concrete surface of the concrete lining (10) (See FIG. 22).
Then, a reinforcing steel cage (13) is mounted to a combined spreader and end form (8a) of the concrete lining jack (8) via hook bolts (12) and an additional inner form (11) is assembled (See FIG. 23), and further, as shown in FIG. 24, concrete for lining (10) is placed.
Thereafter, as shown in FIG. 25, while the concrete for lining (10) is being compressed by the concrete lining jack (8), the rear shield drum (1B) is shoved by the reaction force of the concrete lining jack (8), and thus shoving of the tunnelling machine is completed, resulting in the state shown in FIG. 20.
Subsequently, by repeating the same steps as those described above, the reinforcing steel cage is buried in the concrete lining.
According to the present invention, in a shield tunnelling method of field placed concrete lining type, a main tunnel body can be constructed as a reinforced concrete structure that is structurally reliable as described above, and in this method since it is only necessary to mount a preliminarily assembled reinforcing steel cage to a combined spreader and end form of a concrete lining jack via mount metals, the work of disposing a reinforcing steel cage can be achieved easily even in a narrow space within a shield tail, and if the working space is yet insufficient, it is only necessary to retract the concrete lining jack by a desired length.
Furthermore, upon disposing the reinforcing steel cage within the concrete for lining, the reinforcing steel cage can be disposed at a predetermined position in the axial direction of the tunnel by adjusting the stroke of the concrete lining jack.
Still further, since the reinforcing steel cage can be assembled independently of the inner form as guided by the combined spreader and end form of the concrete lining jack within the shield tail, the form of the reinforcing steel cage is restricted by the method of assembling the inner form.
While a principle of the present invention has been described above in connection to preferred embodiments of the invention, it is a matter of course that many apparently widely different embodiments thereof can be made without departing from the spirit of the present invention. | The known method for constructing a tunnel of the type in which a shield tunnelling machine is shoved by means of a concrete lining jack and a shield jack equipped on the shield tunnelling machine with reaction forces received by concrete for lining placed in a space delimited by an inner form assembled within a tunnel bore successively dug by the shield tunnelling machine, a shield tail and an already placed concrete lining, as well as by the inner form, is improved in order to construct a main tunnel body as a reinforced concrete structure. The improvements include in that a reinforcing steel cage is mounted to a combined spreader and end form of the concrete lining jack via metal mounts, the placed concrete for lining is compressed while the reinforcing steel cage is moved, and thereby the reinforcing steel cage is disposed at a predetermined position within the concrete for lining by adjusting the stroke of the concrete lining jack. | 4 |
FIELD OF THE INVENTION
The present invention generally relates to a method and device for generating a set of graphical objects to be displayed by using OPC UA specification.
BACKGROUND OF THE INVENTION
OPC Unified Architecture (OPC UA) is a platform independent protocol which specifies how to exchange data between different systems, software applications and hardware devices. OPC UA enables exchange of data between software applications independently of the application's vendor, supported operating system, and used programming language.
In the process industry today, process graphics are typically built using a graphic builder, for example the ABB system 800xA includes a graphic builder, and so do most systems in this particular field. These graphic builders facilitate building of process graphics as they assist the users in building the graphic representation of a real object using predetermined graphic building blocks. A graphic builder also assists the user connecting graphic objects to the process' real time data, often provided via OPC. A graphic object does not need to be dynamic; it can be static to serve as a generic building block to be used in other graphics. The generated graphic objects can also contain built in functionality for process control, navigation and indication of invalid data. The graphic objects may also visualize for example if data exceeds specified high or low limits.
A problem with conventional graphic builders is that a great deal of programming effort is required from a developer in order to create graphical objects, and in particular when trying define a complete environment of graphical objects for a certain industrial process. Further, a set of graphical objects created for a particular industrial process cannot necessarily be reused in a different industrial process when targeting different industries, which has the drawback that a great deal of engineering is required.
“OPC Unified Architecture” by Wolfgang Mahnke et al published on Springer-Verlag generally discloses the platform independent OPC UA protocol.
WO 2009/046095 generally discloses systems and methods for gathering, analyzing, formatting and presenting information related to monitored processes and environments, where graphical representations of operational process control data received from servers is displayed within the context of geographical locations at which the processes operate.
SUMMARY OF THE INVENTION
A general object of the present invention is to solve or at least mitigate the above described problems in the art.
In a first aspect of the present invention this object is achieved by a method of generating a set of graphical objects to be displayed by using OPC UA specification. The method comprises indicating, by means of using OPC UA nodes, graphical objects to be displayed, said graphical objects representing physical components of a monitored process. Further, the method comprises indicating, by means of using OPC UA references, how an indicated graphical object should be interconnected to another indicated graphical object when displayed. Next, the respective OPC UA node is associated with a corresponding predetermined graphical object, the set of graphical objects is generated from said associations and the individual graphical objects of the set is interconnected in accordance with the indicated interconnections. Finally, the generated set of graphical objects is displayed.
In a second aspect of the present invention this object is achieved by a device for generating a set of graphical objects to be displayed by using OPC UA specification. The device is arranged to receive source code indicating, by means of using OPC UA nodes, graphical objects to be displayed. The graphical objects represent physical components of a monitored process. The source code further indicates, by means of using OPC UA references, how an indicated graphical object should be interconnected to another indicated graphical object when displayed. The device is further arranged to associate the respective OPC UA node with a corresponding predetermined graphical object, generate the set of graphical objects from said associations, interconnecting the individual graphical objects in the set in accordance with the indicated interconnections and providing the generated set of graphical objects for display.
Thus, capabilities of OPC UA are used to generate graphical objects from combinations of established and predefined OPC UA terminology. The need for prior art graphic builders is thus reduced.
OPC UA presents an object oriented protocol to represent controller data. The base modeling concepts in OPC UA are nodes and references. Every node is described with attributes like for example, id, name, description, value. To automatically generate graphical objects to be displayed on a screen, the implementation of the OPC UA protocol is browsed and interpreted.
Additional features and advantages will be disclosed in the following.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention and advantages thereof will now be described by way of non-limiting examples, with reference to the accompanying drawings, where:
FIG. 1 illustrates an industrial process to be monitored in an embodiment of the present invention, and
FIG. 2 illustrates the process of creating graphical objects of the industrial process depicted in FIG. 1 according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates an industrial process 100 to be monitored in accordance with an embodiment of the invention. This industrial process is exemplified in the form of a pipe 101 leading liquid, for instance gasoline, to a valve 102 . The valve determines how much if any of the gasoline should be delivered to a tank 103 via the pipe 101 . In this particular example, the level of gasoline in the tank is 10 units. From the tank, the gasoline is supplied to a motor 104 . It should be noted that this example is greatly exemplified and in real-life, an industrial process to be monitored is typically considerably more complex.
Now, to be able to monitor the industrial process 100 by using OPC UA, the components of the process is connected to a respective OPC server 105 , 106 , 107 for collecting OPC data from the components 102 , 103 , 104 . In case the components permit external control, OPC data to control the components can be sent to the respective OPC server. For instance, OPS server 105 may collect data relating to flow of gasoline through the valve 102 , but may also allow control of the flow through the valve by means of using OPC data for the control such that the level of gasoline in the tank 103 can be regulated. In this particular example, the tank 103 is a relatively passive process component, which does not offer any property control, but which delivers data pertaining to the gasoline level to the OPC server 106 . Finally, the OPC server 107 collects data from the motor 104 regarding motor speed. Further, the motor speed can be regulated by the OPC server 107 when appropriate OPC data is supplied.
The OPC servers are typically connected to a bus 108 for delivering measured process data to, and receiving process control data from, an operator work station 109 .
In order for an operator to be able to monitor the industrial process at his or her work station 109 , a graphical representation of the industrial process must be provided. This graphical representation would typically look very similar to the industrial process 100 as it is depicted in FIG. 1 .
In OPC UA, terminology has been established where physical objects can be defined by means of objects, attributes, structures, etc. The set of information that an OPC UA Server makes visible to its clients, such as the work station 109 , is referred to as AddressSpace. The OPC UA AddressSpace represents its contents as a set of Nodes connected by References. This is well-known terminology in the art and will not be explained in any further detail. Nodes in the AddressSpace are used to represent real objects, for instance pipe 101 , valve 102 , tank 103 and motor 104 of FIG. 1 .
In an embodiment of the present invention, graphical representation of an industrial process is attained by utilizing the feature in OPC UA that an object oriented protocol is used to represent OPC server data. The base modeling concepts in OPC UA are the above mentioned nodes and references. Every node is described with attributes like for example id, name, description, value, etc. To automatically generate graphical objects to be displayed on a screen, the implementation of the OPC UA protocol is browsed and interpreted.
Thus, a node type can be related to a graphic representation. In an exemplifying embodiment, one node can for instance represent the valve 102 of FIG. 1 , while another node can represent the tank 103 and still a further node can represent the motor 104 .
A set of graphical objects is created and stored in a graphical “library”. To create a graphical representation of the industrial process exemplified in FIG. 1 , four nodes would have to be used (“pipe”, “valve”, “tank” and “motor”), and the corresponding graphical objects would have to be created. Once this is done, any operator can easily use the established OPC UA terminology to make her own graphical representations of any industrial process. Further, the created graphical objects can be reused and distributed to other operators.
For instance, the operator (or any other person wishing to create the process graphics), can enter the node types in a script, and thus indicate which graphical objects she intends to include in a graphical representation.
Thereafter, the operator can indicate how the different nodes should be interconnected. To this end, the already established OPC UA concept of References could be used. Again, this could be entered in the script in an appropriate manner to indicate how a graphical object indicated by the above node types should be interconnected to any other indicated node type.
Then, the script is computer-interpreted such that each indicated OPC UA node of the script is associated with a respective one of the created graphical objects stored in library. Hence, each indicated node is associated with a corresponding graphical object. This interpretation is typically embodied by making a compilation of the source code of the script. Further, in the computer interpretation, a set of graphical objects representing the physical components of the monitored industrial process is generated. To this end, the associations of the OPC UA node with the graphical objects is utilized, and the indicated references will determine how each graphical object should be connected to another indicated graphical object. Thus, in this example, the valve 102 can be defined as an input element to the tank 103 while the motor 104 can be defined as an output element. Finally, the generated set of graphical objects is displayed.
FIG. 2 illustrates the process of creating graphical objects of the industrial process depicted in FIG. 1 according to an embodiment of the invention. The work station 109 of FIG. 1 is realized by means of a computer screen 110 at which the operator typically is located when supervising the industrial process 100 in FIG. 1 , and a computer 113 . As previously has been described, the operator enters appropriate OPC UA terms in a script 111 by means of a keyboard (not shown) to define the process to be graphically illustrated. In an embodiment of the invention, this is done by using the concept of OPC UA nodes and references.
Then, the operator pushes a “compile” button, wherein the text, or source code, entered in the script is compiled (i.e. computer-interpreted) in step 112 such that each indicated OPC UA node of the script is associated with a respective one of the created graphical objects stored in library. Hence, each indicated node is associated with a corresponding graphical object. Thereafter, when the computer 113 has finished the compilation, a set of graphical objects 114 representing the physical components of the monitored industrial process is generated and displayed.
In a further embodiment of the present invention, the concept of Attributes supported by OPC UA is employed. For example, with reference to FIG. 1 , a node corresponding to the tank 103 could provide a read-type attribute such that the actual level of the tank could be read at the OPC server 106 and presented to the operator on the generated graphical representation of the industrial process 100 at the work station 109 .
In a further embodiment, it is possible to assign a write-type attribute to a node. With reference to FIG. 1 , it would be desirable to control the flow through the valve 102 to attain a desired level of gasoline in the tank 103 . This could be done by providing the valve node with a write-type attribute such that an appropriate control signal is communicated to the valve 102 via OPC server 105 to set the tank level at a desired level.
The skilled person in the art realizes that the present invention by no means is limited to the examples described hereinabove. On the contrary, many modifications and variations are possible within the scope of the appended claims. | A method and device for generating a set of graphical objects to be displayed by using OPC UA (Unified Architecture) specification. The method includes indicating, by using OPC UA nodes, graphical objects to be displayed, the graphical objects representing physical components of a monitored process. Further, the method includes indicating, by using OPC UA references, how an indicated graphical object should be interconnected to another indicated graphical object when displayed. Next, the respective OPC UA node is associated with a corresponding predetermined graphical object, the set of graphical objects is generated from the associations and the individual graphical objects of the set is interconnected in accordance with the indicated interconnections. Finally, the generated set of graphical objects is displayed. | 6 |
CROSS-REFERENCE TO A RELATED APPLICATION
This application is related to Application Ser. No. 206,407 filed June 14, 1988, by Wash, and Application Ser. No. 206,646 filed June 14, 1988 by Wash, and Application Ser. No. 253,533 filed June 14, 1988, by Whitfield, which Applications are being filed contemporaneously with this application. The entire disclosures of each of these applications are incorporated by reference herein. Each of these applications is copending and commonly assigned.
FIELD OF THE INVENTION
This invention relates to electrical circuits suitable for encoding a binary data stream into a three-part code format.
INTRODUCTION TO THE INVENTION
A novel method for modulating a binary data stream into a code format suitable for encoding and decoding e.g., magnetic information or optical information, is disclosed in the above-cited Application Ser. No. 206,646 to Wash. The novel method features self-clocking, velocity insensitive encoding and decoding. The Wash disclosure states that preferred electrical circuits that may be employed for realizing the encoding scheme set forth in that disclosure are provided in the present application. This application, therefore, provides novel electrical circuits that may be advantageously employed, for example, for encoding a binary data stream into a three-part code format in accordance with the Wash disclosure. The novel electrical circuits encode the data and preserve the self-clocking, velocity insensitive features of the novel method.
SUMMARY OF THE INVENTION
In one aspect, the invention provides an electrical circuit suitable for encoding a three-part code format from a binary data stream, which circuit comprises:
(a) a clock means for generating information signals, the information signals
(1) demarking a bitcell; and
(2) demarking at least three logic transition locations within the bitcell; and
(b) a data encoder
(1) which inputs a binary data stream, and
(2) in coordination with the clock means information signals, places a logic transition in an assigned location, based on the current element in the binary data stream.
Preferably, the clock means comprises:
(a) a modulo-n counter, which
(1) is capable of accepting outside clock transitions, and
(2) in response to the outside clock transitions, generates repetitive groups of counter signals; and
(b) an x to y demultiplexer-decoder, which decoder, in response to the counter signals, generates decoder signals which are representative of the information signals.
In one preferred embodiment, the clock means comprises:
(a) a modulo-3 counter, which
(1) is capable of accepting outside clock transitions, the outside clock transitions having a frequency 3 times that of an input binary data stream, and
(2) in response to the outside clock transitions, generates repetitive groups of counter signals, the counter signals comprising 3 groups of binary pairs; and
(b) a 2 to 3 demultiplexer-decoder, which decoder, in response to the counter signals, generates three decoder signals [D clock 0 time 1 time], for each of three logic transition locations [D clock 0 time 1 time].
For this preferred embodiment, the serial data encoder preferably comprises:
(a) a logical AND circuit for determining if an input binary datum logic transition is to be assigned a 0 time location; and
(b) a logical OR circuit for determining if an input binary datum logic transition is to be assigned a 1 time location.
In another aspect, the invention provides an electrical circuit suitable for encoding a three-part code format from a binary data stream, which circuit comprises:
(a) means for defining a bitcell as the time t between two adjacent clock transitions, and writing a first clock transition at the beginning of the bitcell; and
(b) means for encoding a binary data transition after the first clock transition in the ratio of t d /t, where t d is the time duration between the first clock transition and the data transition, with the proviso that the ratio distinguishes a data 0 bit from a data 1 bit.
Preferably, the ratio t d /t <1/2 encodes a data 0 bit, and the ratio t d /t>1/2 encodes a data 1 bit.
Preferably, the clock transitions are the opposite polarity of the data transition.
BRIEF DESCRIPITON OF THE DRAWINGS
The invention is illustrated in the accompanying drawing, in which
FIG. 1 shows, in a generalized fashion, a three-part code format, and
FIG. 2 and 3 show the encoding of data bits 1 and 0 respectively in accordance with this format;
FIG. 4 shows in a generalized fashion, a second three-part code format that helps explain the present invention, and
FIGS. 5 and 6 show the encoding of data bits 1 and 0 respectively in accordance with the FIG. 4 three-part code format;
FIG. 7 shows another three-part code format that is employed by electrical circuits of the present invention;
FIG. 8 shows a preferred electrical circuit of the present invention;
FIG. 9 provides a Table I logic matrix generated by the FIG. 8 electrical circuit; and
FIG. 10 provides a generalized schematic on the operation of the FIG. 8 clock means.
DETAILED DESCRIPTION OF THE INVENTION
Important aspects of the Wash Ser. No. disclosure are first reviewed from a perspective that will facilitate a clear understanding of the electrical circuits of the present invention. To this end, attention is now directed to FIG. 1, which reproduces the Wash Ser. No. 206,407 FIG. 1 three-part code format comprising a [Clock (CL) 0 1] sequence. The sequence denotes time locations for logic transitions. As employed in this specification, a term "transition pulse" usually refers to only one edge i.e., either leading (low-to-high) or trailing (high-to-low) of a pulse.
The FIG. 1 three-part code format, in accordance with one aspect of the Wash disclosure, operates on an input binary data stream by the method steps of:
(1) defining a bitcell as the time t between two adjacent clock transitions;
(2) writing a first clock transition at the beginning of the bitcell; and
(3) encoding a binary data transition after the first clock transition, in the ratio of t d /t≅1/3 to encode a 0 bit, and in the ratio of t d /t≅2/3 to encode a 1 bit, where t d is the time duration from the first clock transition to the data transition.
In accordance with these steps, a data 1 bit is encoded as indicated by FIG. 2, and a data 0 bit is encoded as indicated by FIG. 3.
I have discovered that, for purposes of realizing the encoding schemes of FIGS. 2 and 3 in electrical circuits, it is advantageous to reformat the contents of FIG. 1, 2 and 3 in the manner shown in FIGS. 4, 5 and 6. In particular, FIG. 4 shows a three-part code format comprising a [DCL 0 time 1 time]* sequence. For this sequence, the time t d coincides with the location 0 time or 1 time, depending upon whether a data 0 bit or a data 1 bit is being encoded, respectively. This sequence is further explained by reference to FIG. 5. FIG. 5 shows an encoded data 1 bit. The encoding proceeds in accordance with the method steps set forth above. Thus, a clock transition is written at the beginning or DCL location of the bitcell. Here, the logic level goes from high to low. The logic level stays low through the location 0 time, and jumps at the data transition to a logic high at the location 1 time. The logic level stays high until the adjacent clock transition at the time t, as measured from the previous clock transition. A data 1 bit has thus been encoded, since t d /t=2/3 Note that the waveform of FIG. 5 is substantially the same as the waveform for FIG. 2, since both encode a data 1 bit by way of the same method steps.
To complete the explanation of the FIG. 4 format, consider the encoding of a data 0 bit (FIG. 6) The encoding proceeds in accordance with the method steps set forth above. Hence, FIG. 6 shows a clock transition that is written at the beginning or DCL location of the bitcell, where the logic level goes from high to low. The logic level stays low until the location 0 time, at which point the logic level jumps with the data transition at time t d to a logic high. The logic level stays high until the adjacent clock transition. A data 0 bit has thus been encoded, since t d /t=1/3. Note that the waveform of FIG. 6 is substantially the same as the waveform for FIG. 3, since both encode a data 0 bit by way of the same method steps. In summary, an intermediate low-to-high data transition occurs between two adjacent and successive clock transitions (high-to-low), near one of two predetermined locations, 0 time or 1 time, depending on whether the current data bit to be encoded is a data 0 bit or data 1 bit, respectively.
I have further discovered that for both the data 1 bit and the data 0 bit, the logic level is high for each data bit, 0 or 1, from the location "1 time" to the adjacent clock transition. This identity of a common high logic level is clear from inspection of FIGS. 5 and 6. This discovery, that the data 1 bit is only high at "1 time", and that the data 0 bit is high at 0 time and stays high until the adjacent D clock time, in turn suggests another three-part code format, shown in FIG. 7. FIG. 7 shows a [DCL D 1] sequence. The FIG. 7 format may first be distinguished from the FIG. 4 format, in that the "1 time" location of FIG. 4 has now been formalized as an invariant logic high, capitalizing on the last discovery that the logic level is high for this location for each data bit, 1 or 0. Secondly, the FIG. 7 format replaces the FIG. 4 "0 time" enumeration, by a corresponding Denumeration. Here, Dsignifies the logic transformation, "NOT Data". For example, a data 1 bit becomes, under the Dtransformation, a logic low at "0 time"; a data 0 bit becomes, under the Dtransformation, a logic high at "0 time". It should be clear, although not shown, that the encoding of a data 1 bit and a data 0 bit, by way of the three-part code format of FIG. 7, leads to the identical waveforms of FIGS. 5 and 6, for the data 1 bit and data 0 bit, respectively. The desirability and utility of the three-part code format of FIG. 7 will become clearer from the following analysis of a preferred electrical circuit of the present invention.
Attention, accordingly, is now directed to FIG. 8, which shows an electrical circuit 10 suitable for encoding a three-part code format from a binary data stream. The circuit 10 comprises a three-phase clock circuit 12, and a data encoder 14. In particular, the clock circuit 12 comprises a modulo-3 counter 16, a 2-3 demultiplexer-decoder 18, and an inverter 20. The clock circuit 12 is structurally completed by observing that the modulo-3 counter 16 accepts outside clock pulses from an outside clock 22, along a line 24. The modulo-3 counter 16 provides outputs along lines 26, 28 to the decoder 18, and receives an input along a line 30 which is an output from the decoder 18. The decoder 18 provides a set of three output information signals, namely [D clock 0 time 1 time] for input, along three lines 32, 34, 38 respectively, to the data encoder 14.
Turning now to the data encoder 14 in detail, it is observed that it is structurally completed as follows. The data encoder 14 accepts binary data from an outside line 40. The binary data is routed through an inverter 42, an AND gate 44, an OR gate 46 and a flip-flop 48. The connecting lines 50, 52, 54 and 56 provide the appropriate routing paths. The data encoder 14 also includes an inverter 58 which accepts from the clock circuit 12 the 1 time information from line 38, and inputs an inverted 1 time information signal along a line 60 to the OR gate 46.
The operation of the FIG. 8 electrical circuit 10 is now described. In summary, the clock circuit 12 generates three one-bit information signals, which signals demarcate the bitcell and demarcate three transition locations within a given bitcell i.e., [DCL 0 time 1 time] per FIGS. 4, 5 or 6 above; the data encoder 14, in coordination with the clock information signals, places the transitions in the proper locations based on the binary data from line 40.
The operation of the circuit 10 begins with the start of a new bitcell. This is effected by the clock circuit 12 generating the three information signals in accordance with Table I shown in FIG. 9. How the clock circuit 12 generates these information signals is disclosed below. Proceeding, therefore, the first row of Table I shows that at the beginning of the new bitcell, the DCL location,
______________________________________DCL = logic 0 (low)0 time = logic 1 (high)1 time = logic 1 (high)______________________________________
The clock 12 therefore outputs a logic low on line 32, a logic high on line 34, and a logic high on line 38.
Assume, now, that a data 1 bit is provided along the line 40 for input to the data encoder 14. The data 1 bit is first encoded at the location DCL. To do this, the data 1 bit is inverted by the inverter 42, and becomes a data 0 bit i.e., D. The data 0 bit, or D, in turn, becomes the first of the two inputs to the AND gate 44. The second input to the AND gate 44 is the inverted 0 time logic level on line 36, namely, a logic low. The AND gate 44 therefore outputs a logic low, given its two logic low inputs. Continuing, the AND gate 44 logic low output becomes the first of two inputs to the OR gate 46. The OR gate 46 second input is the inverted 1 time logic level on line 60, namely, a logic low. The OR gate 46, accordingly, outputs a logic low, given its two logic low inputs. This OR'd logic low output may be stored by the flip-flop 48, and represents the encoded portion of the data 1 bit for the DCL location. This result is in agreement with FIG. 5 above.
The next location of encoding the data 1 bit occurs at the 0 time location. Table I, row two, shows that the required clock circuit 12 information signals contemporaneous with the 0 time location are:
______________________________________DCL = logic 1 (high)0 time = logic 0 (low)1 time = logic 1 (high)______________________________________
The clock circuit 12, therefore, now outputs a logic high on line 32, a logic low on line 34, and a logic high on line 38. The data 1 bit has not changed, however, so that the line 50 input to the AND gate 44, D, is still a logic low. The second AND gate 44 input is the inverted 0 time logic, namely, a logic high. The logical AND operation determines if a data bit transition is to occur at the 0 time location. We know from FIG. 5 above, that at the 0 time location, a data bit 1 should have a logic low. This is in fact what the AND operation provides. The AND gate 44 outputs a logic low, given its low and high logic inputs. Continuing, the AND gate 44 logic low output becomes the first of two inputs to the OR gate 46. The second OR gate 46 input is the inverted 1 time logic on line 60, namely, a logic low. The OR gate 46, accordingly, outputs a logic low, given its two logic low inputs. This OR' d logic low output may be stored by the flip-flop 48, and represents the encoded portion of the data bit 1 for the 0 time location. This result is in agreement with FIG. 5 above.
The next and final location of encoding the data 1 bit occurs at the 1 time location. Table I, row three, shows that the required clock circuit 12 information signals contemporaneous with the 1 time location are:
______________________________________DCL = logic 1 (high)0 time = logic 1 (high)1 time = logic 0 (low)______________________________________
The clock circuit 12, therefore, now outputs a logic high on line 32, a logic high on line 34, and a logic low on line 38. The data 1 bit has not changed, however, so that the line 50 input to the AND gate 44, D, is still a logic low. The AND gate 44 second input is the inverted 0 time logic, namely, a logic low. The AND gate 44 therefore outputs a logic low, given its two logic low inputs. Continuing, the AND gate 44 logic low output becomes the first of two inputs to the OR gate 46. The OR gate 46 second input is the inverted 1 time logic on line 60, namely, a logic high. The logical OR gate 46 operation determines if a data bit transition is to occur at the 1 time location. We know from FIG. 5 above, that at the 1 time location, a data bit 1 should have a logic high. This is in fact what the OR gate 46 provides. The OR gate 46, accordingly, outputs a logic high, given its low and high logic inputs. This OR'd logic high output may be stored by the flip-flop 48, and represents the encoded portion of the data 1 bit for the 1 time location. This result is in agreement with FIG. 5 above. In summary, the data bit 1 has now been encoded by the circuit 10 so that it has a complete encoded waveform identical to FIG. 5 above.
The operation of the circuit 10 for encoding a data 0 bit, as compared to the disclosure for the data 1 bit, proceeds mutatis mutandis. For example, the clock circuit generates information signals in accordance with Table I. One important difference, however, is that D=1 throughout the encoding locations. This difference results in a data 0 bit encoding that is in agreement with FIG. 6 above.
The discussion reserved from above, on how the clock circuit 12 generates the information signals summarized in Table I, is now set forth. Recall that the clock circuit 12 comprises the modulo-3 counter 16, which accepts clocks pulses from the outside clock 22, and the 2-3 demultiplexer-decoder 18. In a preferred embodiment, shown symbolically in FIG. 10, the modulo-3 counter 16 receives an outside clock pulse, running at 3 times the frequency of the input data stream, and generates sequentially three binary pairs viz., ##STR1## This sequence of binary pairs, provided in turn as inputs via the line pair 26, 28 to the decoder 18, result in a sequence of binary triplets viz., ##STR2## The decoder 18 output in the FIG. 8 electrical circuit is actually the complement of this sequence viz., ##STR3## Note that this second matrix corresponds to Table I, and represents the information signals. In other embodiments, not shown, a decoder that provides the first sequence may be utilized, thus dispensing with the inverters 20 and 58, and necessitating an inverter (not shown) interrupting line 32. The clock circuit 12 operation is completed with the fact that the decoder 18, by way of the 1 time signal on line 30, resets the modulo-3 counter 16, at the end of a bitcell, in anticipation of the start of a new bitcell.
The operation of the FIG. 8 electrical circuit 10 is conditioned on the following criteria:
(1) the clock transitions are the opposite polarity of the data transition. In particular, the clock transitions are negative; the data transition is positive. In other circuit embodiments, not shown, these polarities may be reversed, while still uniquely differentiating the clock transitions from the data transition. This feature provides "self-clocking", which, in turn, permits velocity insensitive encoding and decoding.
(2) the information signals demark three transition locations, spaced equidistant. In other circuit embodiments, not shown, the transition locations may be spaced at any location determined by the method ratio t d /t, with the proviso that the transition location do not result in an indeterminacy in differentiating a data 0 bit from a data 1 bit. The indicated changes trade off data bit discrimination against encoding efficiency.
(3) the data encoder 14 places a data 1 bit logic transition at the 1 time location, and a data 0 bit logic transition at the 0 time location. In other circuit embodiments, not shown, these locations may be routinely reversed so that e.g., the data 1 bit logic transition is placed at the 0 time location, and the data 0 bit logic transition is placed at the 1 time location.
(4) the modulo-3 counter 16 receives an outside clock pulse stream running at 3 times the frequency of the input data stream. In other circuit embodiments, not shown, the counter 16 can receive outside clock pulses running integer multiples of the frequency of the input data stream.
(5 ) the circuit 10 makes use of AND gates, OR gates, inverters, clock circuit components etc. Conventional such components can be used for this purpose.
(6) although the present invention employs the AND gate circuit 44 and OR gate circuit 46 for determining if a data bit transition is to occur at a specified location, it is possible to provide alternative, equivalent logic. For example, the AND gate circuit 44 and/or the OR gate circuit 46 may be replaced by suitable NAND-gate modules. Those skilled in the art will have no difficulty, having regard to the disclosure herein and their own knowledge, in making and using the invention and in obtaining the advantages of the various embodiments.
The three-part code format can also be encoded by a software program running in a microprocessor, thus eliminating the need for discrete hardware. One drawback to this, however, is speed, since most microprocessors, without the addition of memory/buffer circuits and output hardware, will not be able to send out the three-part encoded data as fast as, for example, the FIG. 8 circuit 10. A suitable software encoding routine written in BASIC language is now listed:
__________________________________________________________________________10 REM ** THREE-PART ENCODING ROUTINE **20 DIM THREE-PART (DATAQTY*3) ENCODED ARRAY FOR DATA30 I=0 SET ARRAY POINTER TO 040 FOR I=1 TO DATAQTY LOOP THROUGH DATA50 THREE-PART (I)=0 CLOCK TRANSITION60 THREE-PART (I+1)= NOT DATA(J) DATA 0 TRANSITION70 THREE-PART (I+2)= 1 DATA 1 TRANSITION80 I=I+3 INCREMENT THREE-PART POINTER90 NEXT J__________________________________________________________________________ | Electrical circuits suitable for encoding a binary data stream into a tri-bit code format. The circuits are particularly valuable for situations where the encoding or information transfer rate is dependent on unpredicable and variable transfer rate velocities and accelerations. The circuits provide "self-clocking", which, in turn, permit velocity insensitive encoding. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a color image forming apparatus and method and an image processing program, which are applicable to a color print system that prints using color materials consisting of general process colors (cyan, magenta, yellow and black).
2. Description of the Related Art
A color print system using general process colors (cyan, magenta, yellow and black) forms full-color images by forming plates of individual colors using color materials and by combining the plates according to a subtractive mixture theory.
When forming a full-color image, unless the individual color plates are registered precisely, a blank space, generally called a registration gap, can occur between the plates, between image portions that ought to be adjacent to each other exactly. FIG. 5 is a conceptual illustration with reference to which the phenomenon will be described. FIG. 5 shows an example in which a letter image of a cyan plate is superimposed on a uniform background image of a magenta plate. The magenta plate has an image, from which the letter portion of the cyan plate is omitted. This is because mixing the magenta with cyan will result in blue. To represent the letters in cyan, therefore, the magenta plate has the portions corresponding to the letters omitted.
When the magenta plate and the cyan plate have their superimposed positions unmatched, the background color is seen around the letters of the cyan plate as shown in FIG. 5 , which is called a registration gap.
Conventionally, to eliminate the registration gap, a technique called trapping processing is applied to image portions in which the plates of individual colors are adjacent to each other. FIG. 6 is a conceptual illustration with reference to which the trapping processing method will be described. The trapping processing method reduces the area of the hollow portions of the magenta plate constituting the background so that the contours of the letter portions of the cyan plate are superimposed on the magenta plate with some width (the “trap width”) left in between.
Trapping processing can prevent the occurrence of a registration gap even if the superimposed positions of the magenta plate and cyan plate are displaced from each other as long as the displacement is within the trap width.
A concrete example of trapping processing is as follows. Specifically, an image designer can set an optimum trap width for each object, thereby being able to reflect it on a print image. There is a printer system with a function that applies a preset trap width to all portions in an image. When the printer system automatically carries out the trapping processing, the trapping processing is applied to portions that have no overlap margins (overlap widths/spaces) between plates of different colors. When no overlap margins are present between the plates of different colors, the drawing regions of the lower color plate are revised to provide the margins between the lower and upper color plates.
According to the conventional technique, it is necessary in trapping processing to adjust the trap width manually (see, Japanese Patent Application Lid-Open No. 2004-262011, for example), and otherwise only one value is applied to the entire image uniformly.
Such manual adjustment has a problem of being inefficient because the designer of the image data must carry out the trapping processing manually from image to image using application software capable of trapping processing setting.
When the printer system side uses the automatic trapping processing, the preset trap width is applied to all portions having no overlap margins between the color plates of different colors within the image. As a result, it has an adverse effect in that the trap width can become too large or too small in part. More specifically, when the cyan plate is adjacent to the magenta plate, since the superimposed portions become red because of mixing, too large a margin will result in an image of a cyan object with red edges. In contrast, too small a margin has the problem of being unable to absorb the entire registration gap.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a color image forming apparatus and method and an image processing program capable of implementing high-quality trapping processing, taking into consideration the type of an object and other information.
According to a first aspect of the present invention, that is provided a color image forming apparatus for forming, on a recording medium, an image composed of a group of objects contained in a print job with a plurality of color recording materials, said color image forming apparatus comprising: image format decision means for making a decision as to formats of an object by analyzing the object; size decision means for deciding sizes of the object; and control means for controlling trapping processing applied to the object in accordance with the decision results of said image format decision means and said size decision means.
According to a second aspect of the present invention, that is a color image forming apparatus for forming, on a recording medium, an image composed of a group of objects contained in a print job with a plurality of color recording materials, said color image forming apparatus comprising: image format decision means for making a decision as to formats of an object by analyzing the object; interrelationship decision means for deciding, for the object, an interrelationship between the object and another object that is superimposed on the one object; and control means for controlling trapping processing applied to the object in accordance with decision results of said interrelationship decision means.
According to a third aspect of the present invention, that is a color image forming apparatus for forming, on a recording medium, an image composed of a group of objects contained in a print job with a plurality of color recording materials, said color image forming apparatus comprising: image format decision means for making a decision as to formats of an object by analyzing the object; chroma or density information decision means for deciding information on chroma or density of the object; and control means for controlling trapping processing for the object in accordance with decision results of said image format decision means and said chroma or density information decision means.
According to a fourth aspect of the present invention, that is a color image forming method for forming, on a recording medium, an image composed of a group of objects contained in a print job with a plurality of color recording materials, said color image forming method comprising the steps of: making a decision as to formats of an object by analyzing the object; deciding sizes of the object; and controlling trapping processing applied to the object in accordance with decision results about the formats and the sizes of the object.
According to a fifth aspect of the present invention, that is a color image forming method for forming, on a recording medium, an image composed of a group of objects contained in a print job with a plurality of color recording materials, said color image forming method comprising the steps of: making a decision of formats of an object by analyzing the object; deciding, for the object, interrelationship between the object and another object superimposed on the object; and controlling trapping processing applied to the object in accordance with decision results of the interrelationship.
According to a sixth aspect of the present invention, that is a color image forming method for forming, on a recording medium, an image composed of a group of objects contained in a print job with a plurality of color recording materials, said color image forming method comprising the steps of: making a decision as to formats of an object by analyzing the object; deciding information on chroma or density of the object; and controlling trapping processing for the object in accordance with decision results about the formats of the object and the information on the chroma or density of the object.
According to a seventh aspect of the present invention, that is an image processing program applied to a color image forming apparatus for forming, on a recording medium, an image composed of a group of objects contained in a print job with a plurality of color recording materials, said image processing program being executed by a computer, said image processing program comprising the steps of: making a decision as to formats of an object by analyzing the object; deciding sizes of the object; and controlling trapping processing applied to the object in accordance with decision results about the formats and the sizes of the object.
According to a eighth aspect of the present invention, that is an image processing program applied to a color image forming apparatus for forming, on a recording medium, an image composed of a group of objects contained in a print job with a plurality of color recording materials, said image processing program being executed by a computer, said image processing program comprising the steps of: making a decision as to formats of an object by analyzing the object; deciding, for the object, an interrelationship between the object and another object that is superimposed on the one object; and controlling trapping processing applied to the object in accordance with decision results about the interrelationship.
According to a ninth aspect of the present invention, that is an image processing program applied to a color image forming apparatus for forming, on a recording medium, an image composed of a group of objects contained in a print job with a plurality of color recording materials, said image processing program being executed by a computer, said image processing program comprising the steps of: making a decision as to formats of an object by analyzing the object; deciding information on chroma or density of the object; and controlling trapping processing for the object in accordance with decision results about the formats of the object and the information on the chroma or density of the object.
The above and other objects, effects, features and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a configuration of a PostScript color printer applied to individual embodiments of the present invention in common;
FIG. 2 is a flowchart illustrating processing of a PostScript-compatible color printer in accordance with a first embodiment;
FIG. 3 is a flowchart illustrating processing of a PostScript-compatible color printer in accordance with a second embodiment;
FIG. 4 is a flowchart illustrating processing of a PostScript-compatible color printer in accordance with a third embodiment;
FIG. 5 is a drawing illustrating a registration gap; and
FIG. 6 is a drawing illustrating trapping processing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention will now be described with reference to the accompanying drawings.
FIG. 1 is a block diagram showing a configuration of a PostScript color printer applied to individual embodiments in common. In FIG. 1 , the reference numeral 1 designates a CPU for controlling the entire apparatus; 2 designates a ROM for storing processing procedures of the CPU 1 (including the processing procedures of FIGS. 2 , 3 and 4 ) and font data; and 3 designates a RAM used as a work area of the CPU 1 . The reference numeral 4 designates an operating panel on which a liquid crystal display and a variety of keys are disposed. The reference numeral 5 designates a nonvolatile memory (such as a RAM always supplied with battery power, or EEPROM or flash memory) for storing set information. The reference numeral 6 designates an interface for receiving as print data a print job composed of a page description language from an external unit such as a host computer. The PostScript color printer can be operated as a network printer. In this case, the interface 6 is connected to the network to receive the print data from the host computer. The reference numeral 7 designates a frame memory on which bit map images (of four colors Y, M, C and K) to be printed can be developed. The reference numeral 8 designates a printer engine for actually carrying out the print processing. The reference numeral 9 designates an engine interface for outputting the bit map image data of the individual color components, which are developed on the frame memory 7 , to the printer engine 8 . Although the following description is made under the assumption that the printer engine 8 is a laser beam printer engine, this is not essential. For example, the printer engine 8 may be a printer of the type that discharges ink droplets. In this case, the frame memory 7 may have a memory capacity required for a single or several times of scanning of a recording head. The print job received through the interface 6 is temporarily stored in the RAM 3 . The print job information stored temporarily in the RAM 3 is converted to a raster image (bit map image) through the processing of deciding the format of the objects and the processing including the trapping processing, which will be described later, and is stored in the frame memory 7 .
Embodiment 1
FIG. 2 shows a processing flow of a PostScript-compatible color printer of a first embodiment.
In the PostScript language, one of the page description languages, objects are roughly classified into three types: text; vector graphics; and raster image object. In the present embodiment, a decision is made as to which type of objects the object contained in the image information belongs to, text, vector graphics or raster image (step S 1 ). When a decision is made that the object is text, the processing proceeds to step S 2 , and when a decision is made that the object is vector graphics, the processing proceeds to step S 3 . At steps S 2 and S 3 , a decision is made as to whether the object has a small size or not (the latter possibility being sometimes referred to herein as “other size”).
At S 2 , a decision is made as to the point number representing the size of the text object passing through the foregoing decision. When the point number of the text object is less than 10 points (that is, small size), the processing proceeds to step S 4 , and when it is greater than 10 points, the processing proceeds to step S 6 . At step S 3 , a decision is made as to the size of the minimum width of the vector graphics object passing through the decision. When the size of the minimum width of the vector graphics is less than 0.5 mm (that is, small size), the processing proceeds to step S 5 , and when it is greater than 0.5 mm, the processing proceeds to step S 6 . As for concrete values of the small size, thin lines whose minimum thickness is equal to or less than 0.5 mm are appropriate for vector graphics objects, and letter objects less than 10 points are appropriate for text objects. When a decision is made that the size of the text or vector graphics object is small at step S 2 or S 3 , trapping processing is not carried out, and the processing proceeds to step S 4 or S 5 , and the image undergoes the same processing as overprinting, substantially.
At step S 6 , the color of the object of interest itself is compared with its ambient color, that is, the color adjacent to the object. As a result, when the two have no common plate color component, trapping processing is applied at step S 7 because there is a high possibility that a registration gap will occur. At step S 7 , in the case of a vector graphics object, a preset value is used as the trap width, which is usually set at about 50 μm. As for text objects, since there is a strong tendency that registration gaps around letters are particularly objectionable, the trap width is set at about 100 μm. Thus, for both vector graphics objects and text objects, the optimum trapping processing corresponding to the object sizes is executed.
At step S 6 , if a common plate color component is present, that is a color exists in common as between the color of the object of interest itself and the ambient color adjacent to the object, the processing is completed, without proceeding to step S 7 .
When the object passing through the decision at step S 1 is a raster image, trapping processing is not carried out. This is because raster images are usually composed of data obtained by scanning a silver salt photograph or data picked up by a digital camera. In other words, it is rare that these data have no overlap margin between the individual color plates, and adverse effects of trapping processing such as color changes at superimposed portions become conspicuous.
In the overprint processing at steps S 4 and S 5 , the corresponding image portions of the individual plates are processed in such a manner that they are exactly superimposed on each other (printing of only an image portion of a certain plate is not carried out, but printing is carried out in a manner that colors of the individual plates are mixed). This processing prevents a discrepancy occurring due to the interference of the trap width itself through the overprint processing.
Embodiment 2
FIG. 3 shows a processing flow of the PostScript color printer of a second embodiment in accordance with the present invention.
In the present embodiment, a decision is made as to which type of objects the object contained in the image information belongs to, text, vector graphics or raster image. Subsequently, referring to the relationships between the types of the individual objects passing through the decision and other objects superimposed on those objects, the optimum trapping processing is carried out. More specifically, the processing varies depending on whether (1) a raster image object is superimposed on a text object or vector graphics object passing through the decision, or (2) a vector graphics object is superimposed on a text object passing through the decision.
In the present embodiment, a decision is made at step S 1 as to which type of objects the object belongs to, text, vector graphics or raster image. When a decision is made that the object is a text object, the processing proceeds to step S 8 , and when a decision is made that the object is vector graphics, the processing proceeds to step S 9 .
At step S 8 , when the object superimposed on a text object passing through the decision at S 1 is also a text object or is a vector graphics object, normal trapping processing is carried out at step S 10 . At step S 8 , when the object superimposed on the text object is a raster image object, the processing is completed without carrying out trapping processing.
At step S 9 , when the object superimposed on the vector graphics object passing through the decision at step S 1 is a text object or another vector graphics object, normal trapping processing is carried out at step S 10 . At step S 9 , when the object superimposed on the vector graphics object is a raster image object, the processing is completed without carrying out trapping processing.
When the object passing through the decision at step S 1 is a raster image, the processing is completed without making a decision as to the superimposed object, and without carrying out trapping processing.
The present embodiment offers an advantage of being able to carry out trapping processing when a text object, which requires trapping processing most, is superimposed on a vector graphics object.
Embodiment 3
FIG. 4 shows a processing flow of the PostScript color printer of a third embodiment in accordance with the present invention.
In the present embodiment, a decision is made at step S 1 as to which type of objects the object contained in the image information belongs to, text, vector graphics or raster image. When a decision is made at step S 1 that the object is a text object, the processing proceeds to step S 11 ; and when a decision is made that the object is a vector graphics object, the processing proceeds to step S 12 . At step S 11 , a decision is made as to whether the color information of the text object is chromatic or achromatic color. When a decision is made at step S 11 that the color information of the text object is chromatic color, the processing proceeds to step S 13 , and when a decision is made that the color information is achromatic color, the processing proceeds to step S 14 . At step S 12 , a decision is made as to whether the color information of the vector graphics object is chromatic or achromatic color. When a decision is made at step S 12 that the color information of the vector graphics object is chromatic color, the processing proceeds to step S 13 , and when a decision is made that the color information is achromatic color, the processing proceeds to step S 14 .
At step S 13 , the text or vector graphics object passing through the decision of the chromatic color is subjected to trapping processing A. Generally, the trapping processing applied to the object with chromatic color causes the portions (trapping-width portions) of the object with a chromatic color superimposed on the background (the background being the object on which the object with a chromatic color is superimposed), obtained by the trapping to undergo color mixing, resulting in colors different from the original colors. This will give the object an edge if the trap width is large, thus undesirably changing the impression of the finished print image. Accordingly, in trapping processing A, the trap width is set at as small a value as possible, such as about 50 μm.
At step S 14 , the text or vector graphics object passing through the decision of an achromatic color is subjected to trapping processing B. The process colors (CMY) have a tendency to approach gray or achromatic color when mixed. Consequently, applying the trapping processing to the text or vector graphics object passing through the decision that the color information of that object is achromatic color will rarely cause conspicuous edges of a different color around the object. (The color of trapping regions created in the periphery of the object with an achromatic color is close to gray obtained by mixing the process colors.) Accordingly, in trapping processing B, the trap width is set at a rather large value, such as 100 μm, to prevent occurrence of a registration gap as much as possible.
The present embodiment offers the advantage of being able to carry out the optimum trapping processing by making a decision as to whether the object has chromatic or achromatic color.
In the foregoing embodiment, at steps S 11 and S 12 , a decision is made as to whether the object to be processed has chromatic or achromatic color. However, a decision may be made as to whether or not the density of the object to be processed is higher than a predetermined density. In this case, when the density of the object to be processed is higher than the predetermined value, the processing proceeds to step S 14 , and when the density of the object to be processed is not higher than the predetermined value, the processing proceeds to step S 13 .
Other Embodiments
It is possible to provide a system or apparatus with a recording medium storing software program code that can implement the functions of the foregoing embodiments. The foregoing embodiments can be achieved by a computer (or CPU or MPU) of the system or apparatus, which reads out the program code stored in such recording medium, and executes the program code. In this case, the program code itself read out of the recording medium implements the functions of the foregoing embodiments, and the program code can be written in a variety of recording media such as a CD, MD, memory card and MO.
In addition, according to the instructions of the program code the computer reads out, the operating system (OS) and the like working on the computer can execute part or all of the actual processing. This can also implement the functions of the foregoing embodiments.
Furthermore, it is also possible to write the program code read out of the recording medium to a memory in a function expansion card inserted into the computer or in a function expansion unit connected to the computer. According to the instructions of the written program code, the CPU and the like in the function expansion card or function expansion unit executes part or all of the actual processing, thereby being able to implement the functions of the foregoing embodiments.
The foregoing embodiments are described by way of example in which the present invention is applied to a PostScript color printer that processes a print job composed of a PostScript language, as an example of a print job composed of a page description language. As print jobs composed of other page description languages, there are jobs composed of PCL, LIPS, ESC/P, etc., and the present invention is also applicable to printers that process print jobs composed of these page description languages.
The present invention has been described in detail with respect to preferred embodiments, and it will now be apparent from the foregoing to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspect, and it is the intention, therefore, in the appended claims to cover all such changes and modifications as fall within the true spirit of the invention.
This application claims priority from Japanese Patent Application No. 2004-330954, filed Nov. 15, 2004, which is hereby incorporated by reference herein. | An image composed of a group of objects contained in a print job is formed on a recording medium with a plurality of color recording materials. Formats of an object are decided by analyzing the object. A size of the object is decided. Trapping processing applied to the object is controlled in accordance with decision results about the formats and the sizes of the object. This makes it possible to provide a color image forming apparatus capable of carrying out appropriate trapping automatically. | 7 |
BACKGROUND OF THE INVENTION
This invention relates to a yarn feed mechanism for a tufting machine, and more particularly to pattern-controlled yarn feed split or stub rolls for a multiple needle tufting machine.
Pattern controlled yarn feed rolls for multiple needle tufting machines are well known in the art, as illustrated in the following U.S. patents:
______________________________________2,966,866 J. L. Card Jan. 3, 19612,862,465 J. L. Card Dec. 2, 19583,847,098 W. W. Hammel, Jr. Nov. 12, 1974______________________________________
The J. L. Card U.S. Pat. No. 2,966,866 discloses a bank of four pairs of yarn feed rolls, each pair of which is selectively driven at a high speed or a low speed by the pattern control mechanism. All of the yarn feed rolls extend transversely the entire width of the machine and are journaled at both ends. Accordingly, the threading and unthreading of the respective yarn feed rolls in order to change the characteristics of the yarns, and therefore the patterns, such as the colors, is extremely time-consuming. Each yarn must be pulled back through the corresponding roll pairs from the needles and the yarns rearranged and individually re-inserted through the rolls and re-threaded in the needles.
The pattern control yarn feed rolls disclosed in the J. L. Card U.S. Pat. No. 2,862,465 project forward perpendicularly to the transverse row of needles, and each roll, because of its short length, is limited in the amount of yarn that the roll can carry. As a matter of fact, only the number of yarns equal to the repeat patterns are carried on each roll.
The J. L. Card U.S. Pat. No. 2,862,465, further discloses yarn guide tubes for carrying each independent thread from its corresponding yarn feed rolls to the respective needles. Moreover, the plurality of yarn feed tubes from each yarn feed roll span substantially the entire width of the machine so that the arrangement of the yarn feed tubes is rather complicated and expensive to manufacture.
The yarn feed module of the Hammel U.S. Pat. No. 3,847,098 discloses a plurality of pairs of short yarn feed rolls which are mounted to rotate about transverse axes. The rolls are closely spaced together end-to-end, and each roll is designed to carry only a limited number of yarns. Furthermore, each of the modules carries only one pair of feed rolls which project from the same side of the corresponding module.
U.S. Pat. No. 4,366,761 of Roy T. Card, issued Jan. 4, 1983, discloses dual shiftable needle bars for a tufting machine in which each of the needle bars is adapted to be shifted independently of the other needle bar in accordance with a programmed pattern to produce the graphics-type patterns such as those previously produced on Wilton type looms and as disclosed in FIGS. 7 and 8.
Tufting machines incorporating the dual shiftable needle bars as disclosed in the R. T. Card U.S. Pat. No. 4,366,761 have been used in conjunction with pattern-controlled yarn feed mechanisms incorporating a series of four rolls extending the length of the machine, such as those disclosed in the J. L. Card U.S. Pat. No. 2,966,866. The patterned tufted fabrics made by such machines have been favorably accepted where geometrical patterns and graphics designs are desired. However, the threading and re-threading of such four-roll, dual shiftable needle bar tufting machines has resulted in considerable down-time for each pattern change. Depending upon the pattern desired, the threading time for such four-roll machines ranges from 36 to 64 man hours, which substantially adds to the production time and cost of the patterned tufted products.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide in a multiple needle tufting machine, a pattern-controlled yarn feed mechanism incorporating transverse yarn feed rolls which are easily threaded and unthreaded.
The yarn feed mechanism made in accordance with this invention includes a plurality of split yarn feed rolls or stub rolls. The foreshortened yarn feed rolls are mounted in split or separated sets upon a plurality of transversely spaced supports on the machine. Each feed roll in each set is driven at a high speed or a low speed by one of a plurality of corresponding long yarn feed drive shafts extending the width of the machine. Each drive shaft is driven selectively by a pattern-controlled electromagnetic high speed clutch or a low speed clutch.
The yarn feed stub rolls made in accordance with this invention may be mounted on transversely spaced supports and disposed transversely on the front and the back of a tufting machine incorporating the dual shiftable needle bars of U.S. Pat. No. 4,366,761 for producing geometric and graphic patterns of the Wilton type, with a minimum of down-time for threading the yarn feed rolls.
The yarn feed stub rolls are designed to be utilized in a multiple needle tufting machine having a multiple number of independent yarn guide devices or yarn tube banks. Each yarn guide device spreads the yarns from a corresponding set of vertically spaced stub rolls over a limited repeat distance, that is to a limited number or groups of needles in the total needle row, in order to minimize the length and expanse of the yarn tubes, as well as to facilitate threading and unthreading of each set of yarn feed rolls.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevation of a multiple needle tufting machine incorporating the yarn feed mechanism made in accordance with this invention, with portions broken away;
FIG. 2 is a top plan view of the tufting machine disclosed in FIG. 1, with portions broken away;
FIG. 3 is a right end view of the tufting machine disclosed in FIG. 1;
FIG. 4 is a sectional elevation taken along the line 4--4 of FIG. 1;
FIG. 4A is an enlarged fragmentary, sectional elevation of the lower portion of the machine disclosed in FIG. 4;
FIG. 5 is an enlarged fragmentary vertical section taken along the line 5--5 of FIG. 1;
FIG. 6 is an enlarged fragmentary section taken along the line 6--6 of FIG. 1;
FIG. 7 is an enlarged section taken along the line 7--7 of FIG. 1 with some of the yarn shields in place for the top yarn feed rolls;
FIG. 8 is an enlarged section taken along the line 8--8 of FIG. 7;
FIG. 9 is an enlarged fragmentary plan section taken along the line 9--9 of FIG. 7; and
FIG. 10 is an enlarged fragmentary section taken along the line 10--10 of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in more detail, FIGS. 1-4 disclose a multiple needle tufting machine 10 made in accordance with this invention. The machine 10 includes a housing 11 and a bed frame 12 upon which is mounted a needle plate 13 for supporting a base fabric 14 adapted to be moved through the machine 10 from front-to-rear in the direction of the arrow 15 by the front fabric rollers 16 and the rear fabric rollers 17.
A motor, not shown, drives a rotary main drive shaft 18, which is connected by linkage, not shown, for reciprocably rotating a needle rocker shaft 19 carrying rocker arms 20 pivotally connected through link arms 21 to vertically reciprocable push rods 22. The lower end of each push rod 22 is fixedly connected to an elongated needle bar slide holder or foot 24 by a pair of parallel slide-ways, not shown, reciprocably receiving elongated slide bars or rods, each of which is fixed to a respective front needle bar 27 and a rear needle bar 28. The front needle bar 27 supports a plurality of uniformly spaced front needles 29 preferably aligned along the longitudinal axis of the needle bar 27. The rear needle bar 28 supports a plurality of uniformly spaced rear needles 30, also preferably aligned along the longitudinal axis of the rear needle bar 28.
The looper mechanism 34 in FIG. 4 is of a known construction and includes a front looper 35 and a rear looper 36 to cooperate with each respective front and rear needle 29 and 30. The loopers 35 and 36 are mounted on a hook bar 37 and connected by linkage to the main drive shaft 18 for reciprocable motion synchronously with the needles in order to form front and rear transverse rows of loop pile tufts.
The needle bars 27 and 28 are each independently shiftable by shift rods, such as the shift rod 32, controlled by pattern control mechanisms, not shown, in the manner described in the R. T. Card, U.S. Pat. No. 4,366,761. Each of the front and rear needle bars 27 and 28 may be independently shifted in accordance with the predetermined pattern in order to form various types of geometric or graphic designs in the base fabric 14, in a well known manner.
In order to form high loop pile and low loop pile in accordance with the principle of backrobbing previously formed loops, as taught in U.S. Pat. No. 2,966,866, a pattern-controlled yarn feed mechanism 40 incorporating a plurality of yarn feed rolls adapted to be independently driven at different speeds has been designed for attachment to the machine housing 11.
As best disclosed in FIGS. 1 and 2, a right clutch housing 41 and a left clutch housing 42 are mounted at each end of the machine 10 and supported in any convenient manner upon the top of the machine housing 11.
Mounted upon the front of the machine 10, by brackets 43 affixed to the upper portions of the machine housing 11, are a plurality of transversely spaced yarn feed supports or support housings 44. Each front support housing 44 includes a pair of transversely spaced side walls 45 and 46. Supported upon the exterior of the opposite side walls 45 and 46 are a right bank or set 47 of yarn feed rolls and a left bank or set 48 of yarn feed rolls, each yarn feed roll projecting outward away from its corresponding side wall 45 or 46 and terminating in a free unobstructed end.
As disclosed in the drawings, the right bank 47 includes a plurality of vertically spaced yarn feed stub rolls, such as the four pair of feed rolls 49, 50, 51, 52, 53, 54, 55, and 56. The yarn feed rolls in each pair 49-50, 51-52, 53-54, and 55-56 are preferably mounted parallel to each other in the same horizontal plane and spaced apart front-to-rear just sufficiently to provide an adequate wrap for each corresponding set of yarns, such as the yarn sets 57, 58, 59, and 60, as disclosed in FIG. 7.
The left bank 48 includes yarn feed rolls identical in size, number, and spacing to the yarn feed rolls in the right bank, and are identified by the same reference numerals with primes, such as yarn feed rolls 49', 50', 51', 53' and 55'. However, the left bank rolls, e.g. 49', project from the common support 44 in the opposite direction from the right bank rolls, e.g. 49, and terminate in free, unobstructed ends. Moreover, the left bank feed rolls, e.g. 49', are rotatably mounted in coaxial alignment with their corresponding yarn feed rolls, e.g. 49, in the right bank 47.
Moreover, in a preferred form of the invention, each of the corresponding yarn feed rolls on opposite side walls 45 and 46 are not only coaxially aligned, but are mounted on common driven roll shafts 61 and 62 (FIG. 2), which extend through the support housing 44 and are journaled in corresponding rotary bearings 63 and 64 on the opposite side walls 45 and 46. Thus, the top yarn feed roll 49 in the right bank 47 is fixed to and mounted upon the same roll shaft 61 as its coaxially aligned counterpart feed roll 49' in the left bank 48. In the same manner, the top yarn feed roll 50 is mounted on the same common shaft 62 as its corresponding left top yarn feed roll 50'.
The corresponding pairs of yarn feed rolls in each bank 47 and 48, such as the top rolls 49, 50, 49' and 50', are mounted at the same elevation and are cooperatively connected together for simultaneous rotary motion at the same speed in opposite directions by transmissions, such as the cooperating reversing gears 63 and 64 fixed upon the corresponding common shafts 61 and 62, as illustrated in the drawings. Thus, all four yarn feed rolls at each level, such as the top yarn feed rolls 49, 50, 49' and 50'; mounted on the same support housing 44, are all simultaneously driven at the same speed. However, yarn feed rolls at different levels may be driven at different speeds.
Fixedly attached to each common shaft 62 is a driven sprocket 65 coupled by a chain 66 to a drive sprocket 67. Each drive sprocket 67 is keyed to, or otherwise fixed to, a corresponding elongated yarn feed drive shaft 68, 69, 70, and 71. Each of the yarn feed drive shafts 69-71 extend through and are journaled for rotation in the rear portions of the front support housings 44. Moreover, the yarn feed drive shafts 68-71 may be formed in sections, as clearly disclosed in the drawings, so that each yarn feed drive shaft section is supported solely by the bearings 72 in the rear portion of a corresponding support housing 44. The yarn feed drive shaft sections are then joined together coaxially by the couplings 73.
The right end portion of each of the yarn feed drive shafts 68-71 extends through the inside wall of the right clutch housing 41 and is journaled in bearings 74 and is journaled in the exterior wall of the clutch housing 41 by bearings 75. The right end portion of each of the yarn feed drive shafts 68-71 carries a high-speed electromagnetic clutch 76 adapted to engage, when electrically energized, a driven sprocket 77 coupled by chain 78 to a drive sprocket 79 rigidly keyed upon a driven shaft 80 driven through a reduction gear 81 by a belt transmission 82 from the main drive shaft 18.
As illustrated in FIG. 1, all of the right end portions of the yarn feed drive shaft 68-71 extend parallel to each other in a vertically spaced arrangement, and the driven shaft 80 with its drive sprockets 79 is also located vertically above the yarn feed drive shafts 68-71. This vertical arrangement of the driven shaft 80 and the yarn feed drive shafts 68-71 is also shown in FIG. 6. However, in FIG. 2, the driven shaft 80 with the drive sprockets 79 has been offset forward, merely for illustrative purposes in order to clarify the disclosure of the chain linkage between the driven shaft 80 and the yarn feed drive shafts 68-71.
In a similar manner, the left end portions of the yarn feed drive shafts 68-71 extend through the left clutch housing 42 and are journaled in the inside bearings 83 and the outside bearings 84. Each of the yarn feed drive shafts carries and cooperates with a low speed clutch 86, each of which is adapted to engage, when electrically energized, a driven sprocket 87, which in turn is linked through chain 88 to a drive sprocket 89 on a driven shaft 90. The driven shaft 90 is keyed to a gear 91 which meshes with a gear 92 fixed upon a reducer driven shaft 93 carrying a reducer mechanism 94, which in turn is coupled through the pulley and belt transmission 95 to the main drive shaft 18. The gears 91 and 92 are utilized to reverse the direction of the shaft 90, since the reduction gear 94 is a double reducer having a reverse direction from the reducer mechanism 81, so that the yarn feed drive shafts 68-71 are driven in the same direction from each end.
As illustrated in FIG. 10, each of the low speed electromagnetic clutches 86 includes an electromagnetic coil 97 which is held in a stationary position, such as by the support arms 98 fixed to the side walls of the clutch housing 42. Keyed to the shaft 68 is a rotary clutch member 99. The sprocket 87 is fixed to an annular armature 100 and a rotary bearing or bushing 101 which is free to rotate about the shaft 68. However, when the coil 97 is energized, the clutch member 99 engages the armature 100 to cause the sprocket 87 to rotate with the shaft 68. All of the low-speed electromagnetic clutches 86 and the high-speed clutches 76 are preferably identical. The electromagnetic coils 97 are connected through leads 102 to a conventional pattern control mechanism 104 which may be pre-programmed in any desired manner, in order to selectively energize certain high-speed and low-speed clutches, which in turn drive the yarn feed rolls 49-56 at desired speeds, either high speed or low speed. The speeds of the yarn feed drive shafts is determined by the diameters of the sprockets 77 and 87.
However, the pattern control mechanism 104 is so programmed that only the high speed clutch 76, or a low speed clutch 86 will drive any particular yarn feed drive shaft 68-71. The pattern control mechanism 104 may be of any desired construction, such as that disclosed in either of the J. L. Card U.S. Pat. Nos. 2,966,866 or 2,862,465, or in the Hammel U.S. Pat. No. 3,847,098, or any more sophisticated pattern control mechanisms currently used.
As disclosed in FIGS. 1, 4, and 7, a plurality of front yarns 105 are fed from a yarn supply 106, such as a creel, and are fed through upper yarn guides 107 in separate sets to each bank of yarn feed rolls on the right and left sides of each support housing 44. In each bank of yarn feed rolls, each set of yarns is threaded about a corresponding pair of cooperating yarn feed rolls, such as the pair 49-50, or 53-54, as illustrated in FIGS. 4 and 7. Each set of yarns 105 is wrapped around the bottom of the rear yarn feed rolls 50, 52, 54, and 56, and then wrapped around the upper surface of the front yarn feed rolls in each pair, namely, the yarn feed rolls 49, 51, 53, and 55, (FIG. 7).
The yarns 105 from all four sets of yarns in each bank are then fed through a separate yarn feed tube bank 110, each of which includes a separate housing 111 and a plurality of yarn guide tubes 112. The upper ends of each of the yarn guide tubes 112 are mounted in the top of the housing 111 in a plurality of transverse rows (FIG. 2), while the lower ends of the tubes 112 are mounted in a lesser number of rows, such as one or two rows, over a greater transverse expanse than the upper ends of the tubes. In other words, looking at the yarn tube banks 110 from the front or rear, the yarn tubes 112 fan out transversely in opposite directions.
However, each of the yarn tube banks 110 carries the yarns only from a single vertical bank of yarn feed rolls so that the transverse expanse of the yarn feed is only a small portion of the entire width of the machine 10 and serves only a small group of transversely spaced needles 29 in the entire needle row. Thus, as illustrated in FIG. 1, there are six yarn tube banks 110, one tube bank for each of the six vertical banks of yarn feed rolls.
The structure of the yarn tube banks 110, including the housing 111 and the yarn tubes 112 is substantially the same as those disclosed in the J. L. Card U.S. Pat. No. 2,862,465 or the Hammel U.S. Pat. No. 3,847,098, except that the yarn tube banks 110 are substantially shorter so that they extend only a fraction of the entire width of the machine, as opposed to the full width expanse of the yarn tube banks in the above prior patents.
It will be further observed in FIGS. 1 and 2, that there is substantial spacing between the adjacent free ends of the yarn feed rolls in adjacent banks 47 and 48 on adjacent yarn support housings 44. Thus, because of the shorter yarn feed stub rolls 49-56 in the plurality of yarn feed banks, the free ends of the rolls, and the spacing between the free ends of the rolls, the threading of each tube bank 110 is considerably easier than it is for longer yarn feed rolls, particularly those which extend substantially the full width of the machine 10. The spacing between the free ends of the yarn feed rolls should be great enough that an operator may get his hand between the opposed feed rolls in order to withdraw the yarns in each set of rows axially from the free end of rolls and then to re-insert other yarns longitudinally or coaxially along the yarn feed rolls in order to change the patterns to be formed in the base fabric 14. As disclosed in the drawings, the spacing between the free ends of adjacent feed rolls is approximately equal to the length of each yarn feed stub roll.
In threading yarn feed rolls, the integrity of the front yarns 105 remains throughout the threading and unthreading process. In other words, the yarns are not cut between the front needles 29 and the yarn supply 106. The yarns are merely slipped coaxially off of the feed rolls and re-inserted and wrapped about the feed rolls in different configurations. For example, after one set of yarns is removed from the top feed rolls 49 and 50, some of the yarns from a lower set of feed rolls, such as 53 and 54 may be combined with yarns from other sets and re-threaded or wrapped upon the top feed rolls 49 and 50. Such re-threading of the yarns of all four pairs of the yarn feed rolls in each bank may be conducted in the same manner.
In order to facilitate the threading and unthreading of the yarn feed rolls, yarn shields 115, such as those disclosed in FIGS. 7 and 8, may be inserted in spaced relationship to the rolls in order to hold the yarns which have been removed from the feed rolls until they are needed for re-threading the same or other feed rolls.
Each of the yarn shields 115 is preferably an elongated piece of sheet material having an arcuate cross-section and about the same length as the corresponding feed roll. The inner end of each shield 115 is provided with an elongated coaxial support rod 116 which may be slip-fit into a corresponding tubular socket 117 formed on the outer surface of a side wall 45 and 46 of the corresponding yarn feed support housings 44. There will be one socket 117 for each yarn feed roll. As illustrated in FIG. 7, the rear sockets 117 are spaced vertically below the axis of the corresponding rear yarn feed rolls 50, 52, 54, and 56, while the front tubular support sockets 117 are mounted vertically above the axes of the front yarn feed rolls 49, 51, 53, and 55. The shields 115 are mounted concave toward the respective feed rolls, so that yarns 105 removed from a feed roll and located on a corresponding shield 115 have the same curvature of wrap as they do when mounted on the feed roll.
In removing yarns, such as 105, from a yarn feed roll, such as 49, the yarn shield 115 is manually moved axially, support rod 116 first, beneath the top set of yarns 57 and between the yarns 57 and the yarn feed roller 49. After the shield 115 has been moved toward the support housing 44 far enough that all of the yarns 57 engage the shield 115, the shield 115 is raised or moved radially away from the yarn feed roll 49 until the support rod 116 registers with its corresponding socket 117. The support rod 116 is then inserted into its socket 117 to hold the shield 115 in its operative position, disclosed in FIGS. 7 and 8, to support the yarns 57 on the shield 115 above the yarn feed roll 49. Since the surface of the shield 115 has a low coefficient of friction relative to the frictional surface of the yarn feed roll, the yarns 57 may easily be slipped axially off the free end of the yarn shield 115. After a different set of yarns 57 is selected for the yarn feed roll 49, the yarns are slid axially one-by-one along the shield 115 toward the housing 44, until they are all in place on the shield 115. The shield 115 is then moved axially away from the support housing 44 to withdraw the support rod 116 from its socket 117 and permit all the yarns 57 to slip off the shield 115 and lie wrapped about the corresponding yarn feed roll 49.
It will be noted in FIG. 7, that two of the yarn shields 115 have been inserted in their respective sockets 117. One shield 115 has been placed above the top feed roll 49 and the other shield has been placed below the top yarn feed roll 50 to facilitate the threading and unthreading of this pair of rolls. The yarn shields 115 have been removed from the other sockets 117 for the three lower pairs of feed rolls 51-52, 53-54, and 55-56, and the yarns 105 are wrapped around these respective feed rolls in position for feeding to the front needles 29.
The front yarns 105 leaving the bottom of the yarn tube banks 110 are guided in a conventional manner through the yarn puller rollers 120, and the yarn guides 121 and 122 to the front needles 29 (FIG. 4).
As best disclosed in FIGS. 7 and 9, a plurality of conventional yarn comb guides 123 may be mounted in the side walls 45 and 46 of the support housings 44 to guide the individual yarns 105 from the yarn supply 106 to the individual yarn feed rolls 50, 52, 54, and 56.
In the drawings, and particularly FIGS. 2, 3, and 4, a plurality of sets of rear yarns 125 may be fed through the upper yarn guides 126 to identical banks of yarn feed rolls 49-56 and 49'-56' as those on the front of the machine. The rear yarn feed rolls are mounted on rear yarn drive housings 144, which are identical to the front housings 44. The yarn feed rolls are driven by a plurality of vertically arranged yarn feed drive shafts 168, 169, 170, and 171, the opposite ends of which are journaled in the respective right and left clutch housings 41 and 42 and are driven through identical clutches to move each drive shaft at either a high or low speed. However, in the right clutch housing 41, each rear drive shaft, such as drive shaft 168, supports a low speed clutch 86, while the opposite end of each rear shaft in the left clutch housing 42 supports a high speed clutch 76. The clutches are adapted to be energized to selectively engage the corresponding driven sprockets, such as 77 and 87, and are driven from the main shaft 18 through sprocket and chain transmission and reduction gears of the same construction as their counterparts on the front of the machine 10.
The rear yarns 125 are fed through the respective rear yarn feed rolls in the same manner as the yarns 105 on the front of the machine and extend through identical yarn tube guides 110' on the rear of the machine and through corresponding yarn guides to the respective rear needles 30. The spacing between the yarn feed rolls on the rear of the machine is the same as those on the front of the machine to facilitate threading of the rear yarn feed rolls in the same manner as the threading of the front yarn feed rolls.
In the operation of the machine, various yarns 105 and 125 are threaded in sets about their corresponding banks of pairs of yarn feed rolls 49-56. In one example approximately 135 front yarns 105 are threaded over the eight feed rolls in each bank 47 and 48. Where six banks are used, approximately 810 front needles 29 are served by corresponding yarns to form six transverse repeat patterns.
The pattern control mechanism 104 is programmed in accordance with the desired pattern. After the machine 10 is started, the main drive shaft 18 simultaneously drives all of the corresponding elements in the same manner as the corresponding parts in any known tufting machine, such as the reciprocation of the needles 29 and 30 and their cooperating loopers 35 and 36.
All of the yarn feed drive shafts 68-71 and 168-171 are simultaneously driven through the pattern-controlled clutches 76 and 86 mounted in the clutch housing 41 and 42 at the ends of the machine so that all yarn feed rolls are simultaneously driven to feed yarn to the corresponding needles. The high or low pile tufts formed in the base fabric 14 are determined by the speed of the corresponding yarn feed rolls feeding the corresponding yarns, which are, in turn, controlled by the selective energization of the high and low speed clutches from the pattern control mechanism 104. If desired, the needle bars 27 and 28 are transversely shifted or remain stationary in accordance with the pattern drive controlling these needle bars, not shown, but as carried out in the prior U.S. Pat. No. 4,366,761.
The tufted loops formed in the base fabric 14 as it moves through the machine 10 will form geometric or graphic patterns even more varied than those disclosed in the prior U.S. J. L. Card Pat. No. 2,966,866, because of the multiple yarn feed rolls in combination with the dual shiftable needle bars.
It is also within the scope of this invention to use a single row of transversely spaced needles which are fixed with respect to a non-shiftable needle bar, and to utilize only the front yarn feed rolls, supports and clutch housings illustrated on the front of this machine 10. In other words, all of the rear supports and feed rolls, and their drives, would be removed in such a modification. In this event, patterns in high and low loop pile fabrics will be somewhat similar to those disclosed in the prior J. L. Card U.S. Pat. No. 2,966,866. However, when it is desired to change the patterns by rearranging the mix of the yarns in each set controlled by the different pairs of yarn feed rolls, such unthreading and rethreading can be accomplished in a fraction of the time which would be required for the threading and unthreading of rolls in the prior J. L. Card U.S. Pat. No. 2,966,866.
When it is desired to change the arrangement of the yarns, the machine is stopped, the operator merely places his hands between the free ends of adjacent yarn feed rolls and begins stripping the yarns coaxially of the yarn feed rolls away from their corresponding support housings and off the free ends. When the shields 115 are used, the shields 115 are first inserted between the yarns and the feed rolls engaging the yarns, and then into their corresponding sockets 117 in positions such as those disclosed in FIG. 7. The yarns remain stored on the arcuate shields 115 until they are needed again in rethreading the machine. In rethreading, yarns are slipped axially over the free ends of their corresponding shields, and the shields 115 are removed to permit the yarns to engage their corresponding feed rolls in new wrapped positions to establish the new patterns in the base fabric 14.
It is also within the scope of this invention to utilize other numbers of yarn feed rolls in each bank, such as a six-roll bank, a seven-roll, or even a nine-roll bank. It is also possible to utilize a two-roll bank, that is a bank in which there are two vertically spaced yarn feed rolls, and each roll cooperates through their reversing gears with another yarn roll, so that there are actually four instead of two rolls. Thus, in each bank disclosed in FIGS. 1, 2, and 7, these banks are referred to as four-roll banks, even though each bank includes eight or four pairs of rolls. | A yarn feed mechanism for a multiple needle tufting machine in which a plurality of yarn feed stub rolls are mounted on transversely spaced supports on the machine in such a manner that the stub rolls project in opposite directions from opposite sides of each support and have free ends which are spaced apart from the free ends of adjacent feed rolls to facilitate threading and unthreading the feed rolls. Each yarn feed support carries a plurality of first and second vertically spaced feed rolls on opposite sides of the support and each pair of coaxially aligned feed rolls are driven from a corresponding drive shaft adapted to be driven selectively at a high speed or a low speed. The yarn feed stub roll mechanism is particularly useful in the formation of relatively simple patterns, such as graphic or diamond-shaped patterns with multi-colored yarns such as those previously produced by Wilton Looms, to substantially reduce the down-time in threading and rethreading the yarn feed mechanism for different patterns. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Patent Application No. 61/415,484, filed Nov. 19, 2010 and U.S. Provisional Patent Application No. 61/418,941, filed Dec. 2, 2010, each of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present disclosure is in the technical field of asset management. More particularly, the present disclosure is in the technical field of remote asset control systems.
BACKGROUND OF THE INVENTION
[0003] Conventional remote asset control systems, such as building management systems, energy management systems, utility demand response and load control systems, enterprise network management systems, and the like. Typically, the management systems require assets such as a thermostat, load controller, energy display, electric meter, gas meter, water meter, fuel storage tank, battery bank, energy storage system, PV solar panel, hot water heater, pool pump, exhaust fan, motorized window shade, network router, wireless access point, network switch, boiler, lighting system, computer, computer peripheral, television, VCR, video game system, audio system, washing machine, dishwasher, clothes dryer, un-interruptible power supply, wind turbine, power distribution unit, other home automation appliance, other energy consuming appliance, other co-generation equipment, and the like.
[0004] These assets are accessible, through a communication network path using a combination of the Internet, a public or private local area network, a public or private wide area network, and a public or private wireless area network. The communication network paths use a combination of differing physical, network, and application protocol technologies such as Ethernet, power line carrier, coaxial cable, RS-232, RS-485, Internet Protocol, Ethernet, Bluetooth, or fiber.
[0005] Control commands are requests made to an asset for the purposes of reading or writing asset attributes such as to affect the state of the asset or other connected device. For example, a read and write of the configuration of a thermostat's locally displayed temperature scale may occur along with a reading of: the current room temperature; the software version; the firmware version; the electricity consumption; and the configured set points. If a communication network path failure occurs between the remote asset control system and the asset, suboptimal asset performance occurs because time critical control commands cannot be processed. The failed processing leads to inefficiencies, financial and other types of losses, and/or degraded performance.
SUMMARY OF THE INVENTION
[0006] For example, a large 11 kW oven used by a contract manufacturing facility for precisely reflowing solder on printed circuit boards is normally shutdown manually by employees on Friday evening and remains off until Monday morning. On one Friday evening the oven was not shutdown by employees. The manager, previously recognizing the potential that the employees may inadvertently leave the oven on, had subscribed to a monitoring service to detect and automate the shutdown of the oven in this case. However, a recent storm had damaged the cable modem providing Internet access to the contract manufacturer's facility. The monitoring service was using a conventional asset control system that relied on an Ethernet to Modbus/RS485 gateway at the oven location to communicate with the oven.
[0007] Due to the cable modem fault, the conventional remote asset system was unable to query the oven's status and turn off the oven via the Ethernet to Modbus/RS485 gateway and the contract manufacturer's electric bill incurred an additional 500 kWh of wasteful consumption above their normal usage. A remote asset control system as described within the present disclosure is able to detect that the oven was on and turn off the oven despite the cable modem fault by utilizing a schedule-based conditional composite asset policy enforced by a premise software-subsystem acting autonomously. The premise software-subsystem is able to query the oven for status and turn off the oven according to the schedule defined by the locally stored asset policy.
[0008] Further, as the number of communication network paths between the remote asset control system and the asset increases, the probability of communication network failures increases substantially. Therefore, suboptimal asset performance is likely to occur more frequently. Additionally, some forms of communication network paths are normally off. For example, cellular radio and satellite are only turned on at relatively infrequent intervals due to the high service costs. These communication network paths that are normally off are also problematic for remote asset control systems because such paths also prevent conventional asset control systems from issuing control commands to assets in a timely manner thus leading to suboptimal asset performance.
[0009] Commonly, utilities can forecast 24 hours in advance that supply will exceed demand. As part of a demand response program, the utility can command large numbers of AC load controllers to disconnect their loads, typically pool pumps, hot water heaters, and the like, for up to 4 hours. Conventional remote asset control systems typically wait until the load controllers need to be turned off before sending the control request. If the communication path to the load controller is down at that moment the load controller will not be turned off. The result is a problem for the utility since, if this communication failure were to happen in large scale, the utility may not be able to achieve the required load reduction, which in turn, may lead to rolling blackouts for their customers. However, a remote asset control system as described herein is able to, during the 24 hours leading up to the event, set a time-based conditional composite asset policy on a premise software-subsystem. The premise software-subsystem acts autonomously to enforce the policy and turn the load controllers off at the designated time enabling the utility to have a far greater confidence level that the required load reduction will be achieved.
[0010] The present disclosure also addresses the inability of conventional remote asset control systems to minimize gaps in asset telemetry. Asset telemetry gaps are interrupted portions of data collection. Asset telemetry, gathered by a remote asset control system, is typically processed by software applications that typically analyze individual asset performance such as: the ability to maintain room temperature; the state of an AC relay on a load controller during a utility demand response event; and detection of a manual thermostat set point override. Such information is used to analyze aggregate system performance. Typical performance parameters are a total amount of load shed and the number of customers opting out of a utility demand response event. By combining the telemetry of a plurality of assets, these parameters can be accurately determined.
[0011] Asset telemetry gaps reduce the ability of software applications to measure asset performance and aggregate system performance. The ability of software applications to further optimize asset performance and aggregate system performance is reduced as well. A conventional remote asset control system typically requires a working communication path to an asset at the time that telemetry needs to be collected otherwise the telemetry for that time is lost.
[0012] For example, a conventional remote asset control system communicating over the Internet to a customer premise having the ability to communicate to a ZigBee Smart Energy Profile 1.0 thermostat will not be able to collect thermostat telemetry, resulting in telemetry gaps, when the customer's internet service is not functioning. Further telemetry gaps can occur when the remote asset control system is offline for maintenance or when a maid unplugs the customer's broadband modem to make an outlet available for a vacuum, and the like. If a remote asset control system, as described in the present disclosure, is utilized, then the occurrence of telemetry gaps is greatly minimized because a premise software sub-system continues to collect telemetry from the thermostat regardless of the software sub-system's ability to communicate to the remote asset control system. In one embodiment, the remote asset control system in accordance with the subject technology is an embedded computer with an Ethernet connection to the Internet and a ZigBee Smart Energy Profile 1.0 interface, acting as an energy management system. When Internet connectivity between the remote asset control system and the software sub-system is restored, the historical telemetry collected during the communication outage is transferred to the remote asset control system.
[0013] The present disclosure is a remote asset control system for optimized asset performance having conditional policy-based asset control.
[0014] In one embodiment, the environment includes a remote asset control system that can create, modify, and delete asset policies within a grouping hierarchy that supports an asset policy inheritance scheme resulting in composite asset policies. The policy inheritance scheme makes it easier and more reliable for a software application to manage assets of similar ilk. The environment also has an asset policy transference and caching scheme, which moves policy enforcement to a software sub-system co-located with the asset thereby minimizing the potential for intermittent network communication to adversely affect asset performance. The software sub-system can conditionally enforce policies based upon internal, co-located, and remote events. And, where such events can be permission for an asset to operate at its highest energy or water consumption modes for short periods of time, but where the default, without permission, is to operate at lower levels of consumption.
[0015] Further, the environment can simplify asset replacement in the event of a hardware failure by allowing the software application to specify in advance the serial number, hardware address, and the like, of a replacement unit, thereby allowing the new unit to be immediately recognized and managed like the faulty asset which reduces the potential suboptimal performance. Still further, the environment can enumerate actual asset deviance as compared to the currently or previously enforced composite asset policies, allowing software applications to more quickly and easily identify faulty assets. Additionally, the environment allows real-time control asset policies that optimize communications when a human user expects low latency control and which operates in unison with the normal policy mechanisms. Furthermore, the environment allows atomic activation and deactivation of asset policies, which are part of the policy inheritance hierarchy, which ensures composite policy integrity at all times. The environment also has a multi-tiered telemetry caching and transference mechanism that maximizes the amount of telemetry available for software analytical operations which may enable further asset performance optimizations.
[0016] In another embodiment, the subject technology is directed to a system for facilitating a remote asset control system via a distributed computing network. The system includes a server in communication with premises via the distributed computing network. The server includes a memory storing an instruction set and data related to a plurality of asset policies, and a processor for running the instruction set, the processor being in communication with the memory and the distributed computing network, wherein the processor is operative to create the plurality of asset policies using an asset policy inheritance scheme that generates composite asset policies based upon a hierarchical group structure. The system also includes a plurality of the premises arranged in groups, each premise having at least one asset. Each asset includes a memory storing an instruction set and data related to a plurality of asset policies, and a processor for running the instruction set, the processor being in communication with the memory and the distributed computing network. The software sub-system processor is operative to receive and store the plurality of asset policies from the server, and control operation of the respective asset based upon the plurality of asset policies.
[0017] Each server processor may be further operative to store composite asset policies, and atomically activate and deactivate asset policies, which are part of the policy inheritance hierarchy, ensuring composite policy integrity. At least one of the plurality of asset policies may be a permission-based asset policy for throttling consumption by the respective asset. At least one of the plurality of asset policies may be a real-time control asset policy. At least two of the plurality of asset policies may be conditional policies that are active, each having a designated priority and the software sub-system processor is further operative to select one of the conditional policies based upon a preset criteria. The preset criteria can be a most aggressive energy saving mode. The software sub-system processor may be further operative to coordinate asset operation with co-located assets to improve efficiency. At least one of the plurality of asset policies may be a permission-based policy designed to improve safety. The server processor may be further operative to mark each of the asset policies as having a status of active or inactive and the software sub-system processor is further operative to precisely manipulate through an atomic request activation and deactivation of the plurality of asset polices based upon the status.
[0018] In another embodiment, the subject technology is directed to a system for facilitating a remote asset control system via a distributed computing network. The system includes a server in communication with a premise via the distributed computing network. The server includes a memory storing an instruction set and data related to a plurality of asset policies, and a processor for running the instruction set, the processor being in communication with the memory and the distributed computing network. The premise has at least one asset including: (i) a memory storing an instruction set and data related to a plurality of asset policies; and (ii) a processor for running the instruction set, the processor being in communication with the memory and the distributed computing network. The software sub-system processor is operative to: receive and store the plurality of asset policies from the server; autonomously control operation of the respective asset based upon the plurality of asset policies; and collect telemetry related to performance of the at least one asset.
[0019] The server processor may be further operative to poll the software sub-system and transfer the collected telemetry to the server. The server processor may be further operative to apply analytical algorithms to the collected telemetry to further optimize performance of the at least one asset. The server processor may be further operative to request asset deviance from asset policies.
[0020] Another embodiment of the subject technology is directed to a system for facilitating a remote asset control system via a distributed computing network including a server in communication with premises via the distributed computing network. The server includes a memory storing an instruction set and data related to a plurality of asset policies, and a processor for running the instruction set. The server processor is in communication with the memory and the distributed computing network, wherein the server processor is operative to create the plurality of asset policies using an asset policy inheritance scheme that generates composite asset policies based upon a hierarchical group structure. The system also has a plurality of the premises arranged in groups, each premise having at least one asset. Each asset includes a memory storing an instruction set and data related to a plurality of asset policies, and a processor for running the instruction set, the processor being in communication with the memory and the distributed computing network. The software sub-system processor is operative to receive and store the plurality of asset policies from the server, autonomously control operation of the respective asset based upon the plurality of asset policies, and collect telemetry related to performance of the at least one asset.
[0021] It should be appreciated that the subject technology can be implemented and utilized in numerous ways, including without limitation as a process, an apparatus, a system, a device, a method for applications now known and later developed or a computer readable medium. These and other unique features of the system disclosed herein will become more readily apparent from the following description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
[0022] FIG. 1 is a schematic diagram illustrating an environment having a remote asset control system in accordance with the subject technology.
[0023] FIG. 2 is a schematic diagram illustrating a software application requesting policy creation, policy modification, or policy deletion from the remote asset control system of FIG. 1 .
[0024] FIG. 3 is a schematic diagram illustrating policy inheritance and composite policy generation in the remote asset control system of FIG. 1 .
[0025] FIG. 4 is a schematic diagram illustrating composite policy transference from the remote asset control system to a software sub-system co-located with an asset in accordance with the subject technology.
[0026] FIG. 5 is a schematic diagram illustrating a software sub-system conditionally enforcing a composite policy based on inputs thereby optimizing performance of a co-located asset in accordance with the subject technology.
[0027] FIG. 6 is a schematic diagram illustrating a software application controlling an asset with minimal latency by creating and modifying a real-time policy on the remote asset control system in accordance with the subject technology.
[0028] FIG. 7 is a schematic diagram illustrating atomic policy activation and deactivation within a policy-based asset control system in accordance with the subject technology.
[0029] FIG. 8 is a schematic diagram illustrating telemetry caching and transfer between an asset, a sub-system, a remote asset control system, and a software application in accordance with the subject technology.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present disclosure overcomes many of the prior art problems associated with remotely controlling various assets such as devices that utilize power and other appliances. The advantages, and other features of the technology disclosed herein, will become more readily apparent to those having ordinary skill in the art from the following detailed description of certain preferred embodiments taken in conjunction with the drawings which set forth representative embodiments of the present invention and wherein like reference numerals identify similar structural elements.
[0031] Referring now to FIG. 1 , a schematic diagram illustrating an environment 10 for utilizing the subject remote asset control technology is shown.
[0032] The environment 10 includes a software application 100 , a remote asset control system 102 , communication network links 110 , 112 , 114 , and a software sub-system 104 co-located with an asset 108 in a premise 116 . The asset 108 is typically some type of appliance, meter or device that consumes or controls power consumption. The asset 108 may be in a residential, commercial, or industrial location. In brief overview, the remote asset control system 102 optimizes asset performance under a variety of circumstances such as network communication path failures.
[0033] For example, the asset 108 may be a thermostat, an electric, gas, or water meter, a solar panel, a hot water heater, a pool pump, a network router, a boiler, a lighting system, a computer, a television, a dishwasher, an un-interruptible power supply, a wind turbine and the like. To illustrate the subject technology, the following description is with respect to the asset 108 being a load controller or thermostat that controls an electrical load within the premise 116 , which could be a residential, commercial, or industrial location. The asset 108 may be hosted on two microcontrollers where first microcontroller handles the network communications and the second microcontroller handles the asset application logic and where a round robin operating environment is used in both microcontrollers.
[0034] In the environment 10 , the communication network links or paths 110 , 112 , 114 allow the software application 100 , the remote asset control system 102 , the software sub-system 104 and the asset 108 to be in communication. The communication network paths 110 , 112 , 114 are a combination of the Internet, a public or private local area network, a public or private wide area network, a public or private wireless area network, and the like. In a preferred embodiment, the software sub-system 104 creates a virtual private network over communication path 112 to the remote asset control system 102 , which enables fully bi-directional Internet Protocol communications regardless of the presence of an Internet Protocol communications firewall restricting network traffic flow into and out of premise 116 . As for communication path 114 , a wireless area network is preferred.
[0035] The software application 100 , the remote asset control system 102 , and the software sub-system 104 are preferably hosted in one physical location but may be distributed at various geographic locations. The software application 100 , the remote asset control system 102 , and software sub-system 104 , and the asset 108 will typically be implemented with a variety of programming languages such as Java or machine assembly language. In one embodiment, the software application 100 , the remote asset control system 102 , and software sub-system 104 are principally implemented in the Python language available from the Python Software Foundation in Wolfeboro Falls, N.H. A preferred embodiment of the asset 108 is implemented in C programming language.
[0036] The software sub-system 104 is managed like an asset using asset policies for the purposes of setting software versioning requirements, asset commissioning parameters, asset decommissioning, and asset replacement. The remote asset control system 102 sets asset policies specifically for the software sub-system 104 . An asset policy is a rule or combination of rules that govern the operation of the respective asset. For example, if software sub-system 104 implements a ZigBee Smart Energy Profile 1.0 Trust Center as defined by the ZigBee Alliance in San Ramon, Calif. and the asset 108 is ZigBee Smart Energy Profile 1.0 compatible load controller, then the software application 100 would create an asset policy containing the hardware address and installation code of the asset 108 for the software sub-system 104 thereby allowing the asset 108 to securely operate with the software sub-system 104 .
[0037] The premise 116 may be a single family dwelling unit, an apartment building, a campus comprised of multiple buildings, a high rise building, a residential multi-dwelling unit, or a commercial office space. The subject technology is particularly applicable to commercial buildings because commercial buildings have large energy and water loads to be managed, which better justifies the expense of installing new assets 108 that optimize usage.
[0038] The environment 10 will typically have a plurality of independent software applications that can communicate with the remote asset control system 102 . Further, the environment 10 will typically have a plurality of assets 108 communicating to a plurality of software sub-systems 104 at a plurality of premises 116 communicating to a plurality of remote asset control systems 102 . However, the following description is with respect to single components 100 , 102 , 104 , 108 for simplicity. The environment 10 is instantiated such that the software application 100 , the remote asset control system 102 , and the software sub-system 104 are further sub-divided into separate hierarchical elements that create additional distinct layers of communication interactions.
[0039] The environment 10 has policies described in more detail below (see items 120 , 122 , 124 , 126 , 128 , 130 , 140 , 142 , 151 , 166 , 168 , 172 , 174 , 176 , 178 , 186 of FIGS. 2-8 ). Policies are stored in a relational database or file in memory of the remote asset control system 102 and the software sub-system 104 . The software application 100 and the remote asset control system 102 transfer asset policies representations as an XML language encoding. The remote asset control system 102 and software sub-system 104 transfer asset policy representations as a Microsoft Windows-style INI encoding.
[0040] The asset policies define the expected behavior, settings, state, and other parameters of the thermostat asset 108 such as commissioning codes, thermostat heating and cooling set points, minimum firmware version of a load controller, on/off switch state, alarm temperature ranges, load controller duty cycle, electrical load shifting pattern, and electrical load balancing. The asset policies take into account various conditions such as time of day, the price of electricity, the relative stress level of the electrical grid, user preference, demand response event, business hours, and occupancy. The asset policies may represent the maximum variety of asset attributes under the maximum variety of conditions thereby enabling the software application 100 to best optimize asset performance under the maximum circumstances. An asset attribute is a characteristic of an asset that may be set by an asset policy. For example, a thermostat has a temperature setting, which is an attribute, and at various times the temperature setting varies according to the thermostat asset policy or policies.
[0041] Referring now to FIG. 2 , a schematic diagram illustrating the software application 100 requesting policy creation, policy modification, or policy deletion from the remote asset control system 102 is shown. The software application 100 communicates a request 118 via communication path 110 to the remote asset control system 102 to create the asset policy 120 . Example of requests 118 are a representational state transfer web service transaction, a SOAP web service transaction, an OpenADR transaction, a remote procedure call, a procedural call, and an object method invocation. The asset policy 120 will be marked as activated or deactivated as part of the request 118 . The asset policy 120 is stored in the remote asset control system 102 .
[0042] Referring now to FIG. 3 , a schematic diagram illustrating policy inheritance and composite policy generation in the remote asset control system 102 is shown. The remote asset control system 102 includes groups 131 , 133 , 135 . Groups 131 , 133 , 135 are logical asset encapsulation constructs, supporting hierarchical nesting, that enable assets of similar ilk to be managed in mass. For example, all of the thermostats for a national restaurant chain are assigned to a group and a single policy for that group would set the HVAC mode to Auto for all the thermostats. Group R 133 and group S 135 are hierarchically nested within group Q 131 . The group hierarchy and location of the asset policies within the group hierarchy define the policy inheritance structure.
[0043] Composite policies 128 , 130 are formed by merging higher level group hierarchy policies (e.g., asset policy 122 ) with policies (e.g., asset policies 124 , 126 ) at the same hierarchy group level. As can be seen, both asset composite policies 128 , 130 inherit asset policy A 122 since both group R 133 and group S 135 are sub-groups of group Q 131 . Composite asset policy AB 128 additionally inherits 136 asset policy B 124 . Likewise, composite asset policy AC 130 additionally inherits 138 asset policy C 126 . The exact manner and rules of policy inheritance are consistent with inheritance mechanisms of object based languages such as Java.
[0044] For example, if asset policy A 122 defines a minimum thermostat firmware requirement of v1.1 and a thermostat occupied cooling set point of 76° F. and asset policy B 124 defines a thermostat unoccupied cooling set point of 82° F. and a thermostat occupied cooling set point of 79° F. then the composite asset policy AB 128 will define a policy with minimum thermostat firmware requirement of v1.1, unoccupied cooling set point of 82° F. and a thermostat occupied cooling set point of 79° F. In this case the policy element for the occupied cooling set point in asset policy A 122 is overridden by the overlapping policy element in asset policy B 124 . Further, an arbitrary number of levels of the group hierarchy can contribute through inheritance to composite policies. The preferred embodiment of the present disclosure is for software application 100 to be able to create, modify, and delete arbitrary hierarchies of groups through a request using a representational state transfer web service transaction over an SSLv3 encrypted HTTP connection where the request is represented as an XML language encoding within the context of the request.
[0045] Referring now to FIG. 4 , a schematic diagram illustrating composite policy transference from the remote asset control system 102 to the software sub-system 104 is shown. The remote asset control system 102 has composite asset policy N 140 and makes a request 144 to transfer a representation of the policy to the software sub-system 104 via network communication path 112 . The software sub-system 104 stores composite asset policy N′ 142 which is a copy of composite asset policy N 140 . The remote asset control system 102 will periodically re-attempt to make request 144 until such time that the remote asset control system 102 can confirm that the software sub-system 104 has a valid copy of the policy N 140 or the software sub-system 104 will periodically query the remote asset control system 102 for composite asset policy N 140 .
[0046] The ability of the remote asset control system 102 and software sub-system 104 to complete the request to copy the policy N 140 is unaffected by the current ability of the software sub-system 104 to communicate via communication path 114 to the asset 108 . If the remote asset control system 102 is unable to copy the policy N 140 , then the remote asset control system 102 would reattempt to copy the policy N 140 again, for example every 2 minutes, until the copy was successful. The remote asset control system 102 and the software sub-system 104 maintain a plurality of composite asset policies pertaining to a plurality of assets.
[0047] Referring now to FIG. 5 , a schematic diagram illustrating the software sub-system 104 conditionally enforcing a previously copied composite policy 151 is shown. The composite policy 151 is based on inputs from an event monitor 153 thereby optimizing performance of the co-located asset 108 . The event monitor 153 is able to detect state changes from an internal event source 157 via internal communication path 156 , a premise event source 159 via premise communication path 154 , and a remote event source 150 via remote communication path 152 .
[0048] Event sources 150 , 157 , 159 generate inputs such as date and time based schedules, utility issued demand response events, utility signaled cost of electricity, and the operational status of a premise asset. The inputs are signaled asynchronously to the event monitor 153 or are polled periodically by the event monitor 153 . The internal event source 157 is typically a thread within the software sub-system's application process space, but may also be instantiated as an interrupt handler, process, function call, object, or state machine.
[0049] The premise event source 159 is typically another premise asset, such as another thermostat. The remote event source 150 is typically an Internet accessible server for signaling events and conditions generated by external sources which may alter the desired optimal operation of the assets. For example, an electric utility's public OpenADR server is publishing the real-time price of electricity which invokes a conditional policy on the software sub-system 104 causing a dishwasher to delay running when the price is above $0.20/kWh.
[0050] Inputs from the sources 150 , 157 , 159 are passed from the event monitor to the composite asset policy 151 along path 155 . These inputs determine which conditional elements of the composite asset policy 151 are enforced on the asset 108 by the software sub-system 104 making requests 158 via network communication path 114 to the asset 108 . For example, if composite asset policy 151 has a first conditional policy element that indicates that the thermostat occupied cooling set point is 75° F. during the hours of 9 am to 4:59 pm and a second conditional policy element that indicates that the thermostat occupied cooling set point is 82° F. during the hours of 5 pm to 8:59 am, then during the hours of 9 am to 4:59 pm, the software sub-system 104 will enforce the first conditional policy element and the occupied cooling set point is set to 75° F.
[0051] The internal event source 157 would periodically monitor time and send an event to the event monitor 153 when the current time changed to 5 pm. The event monitor 153 will then select the second conditional policy element and send request 158 to change the thermostat occupied cooling set point to 82° F., which is maintained until 9 am the following morning.
[0052] A composite asset policy will typically contain a plurality of conditional policy elements having a plurality of distinct event conditions that cause the conditional policy element to be enforced by the software sub-system 104 . The event monitor 153 may determine that multiple conditional elements of the composite asset policy 151 are active. As such conflicts between conditional policy elements may arise. During the creation of a policy on the remote asset control system 102 , the software application 100 will indicate a relative priority of the potentially conflicting conditional policy elements using a numbering system where 1 is a lowest priority and larger integer numbers indicate higher priority. Relative priority may also be identified by the type of policy element or the policy elements inheritance hierarchy.
[0053] The software sub-system 104 will resolve conflicting conditional policy elements by choosing the one with the highest relative priority. In the case that more than one conditional policy element are active and two ore more conditional policy elements are tied at the highest relative priority, then the software sub-system can break the tie by choosing the conditional policy element with the most aggressive energy saving mode, through random selection, by first conditional element within the composite asset policy, by the most conservative mode of operation, or combinations thereof depending on the type of asset.
[0054] Still referring to FIG. 5 , the asset 108 may have limited ability to store configuration data that allows the asset to function with limited autonomous operation when the communication network path 114 to the software sub-system 104 has failed. For example, if the asset 108 is a thermostat with the ability to configure an occupied cooling set point schedule, then the software sub-system 104 would be able to configure the thermostat schedule based on composite asset policy 151 . As a result, the thermostat occupied cooling set point is 75° F. during the hours of 9 am to 4:59 pm and the thermostat occupied cooling set point is 82° F. during the hours of 5 pm to 8:59 am. The thermostat asset 108 would be able to change the occupied cooling set point based on time independent of the ability of the software sub-system 104 to communicate to the asset via communication path 114 . The thermostat asset 108 would have an internal clock, which is typically synchronized with the software sub-system 104 . The thermostat asset 108 can not only automate simplistic time based schedules but also coordinate its operation with other co-located thermostats. For example, the thermostat asset 108 can reduce peak load by alternating the cooling of different zones in a non overlapping manner.
[0055] Still referring to FIG. 5 , the asset 108 may be a large electrical load such as an electric vehicle charging station, manufacturing equipment, warehouse lighting, or air conditioning units. The composite asset policy 151 permits the asset 108 to draw a maximum load for short periods of time. The asset 108 can exceed the time limit if the software sub-system's 104 event monitor 153 receives an event from one of the event sources 150 , 157 , 159 indicating that the asset 108 has permission to continue drawing a maximum load for an additional period of time. If an event granting permission is not received, then the software sub-system 104 causes the asset 108 to reduce consumption. The consumption reduction is preferably 25% of the maximum load, but may be as little as 0% and as much as 99% depending upon the asset 108 .
[0056] The asset 108 may consume electricity, gas, or water such as a gas-fired furnace and lawn sprinkler system. For example, electric utilities undersize pole transformers that convert medium voltages from transmission lines to those voltages appropriate for residential and small commercial buildings. In the past these undersized transformers normally, and safely, exceeded ideal internal temperatures towards the end of the day and at night. Due to significantly reduced demand, the transformers had time to cool down to normal operating temperatures. With the adoption rate of plug-in electric vehicles accelerating, increased over night charge may become a significant load during the night. Utilities are now concerned that the nightly cooling off period for these transformers will not happen or that the transformers may be overloaded.
[0057] Operating outside the ideal temperature range for extended periods of time or being overloaded will cause the transformers to fail prematurely and cause localized blackouts. A typical level 2 car charger can consume a significant amount of electricity. The expected clustering of electric vehicles in some neighborhoods makes it more likely that there may multiple electric vehicles serviced by the same transformer. To combat this problem, the utility can offer an electric vehicle charging kit to consumers. The consumers are offered a substantially discounted rate for charging their vehicles if they allow the utility to reduce or stop charging the electric vehicle when the utility determines that the transformer is not in its ideal temperature range or is near overloaded.
[0058] The kit includes an in-home energy management system that connects to the user's broadband Internet connection and also connects to a level 2 charging station via a ZigBee Smart Energy 1.0 compliant communication interface. A policy is set by the utility software systems on the remote asset control system 102 . Through the policy inheritance mechanism, a composite policy is created and transferred to the premise energy management systems deployed at several thousand homes within the utility's service territory. For example, the composite policy can allow charging up to 100% for up to 5 minutes with permission and up to 25% without permission.
[0059] The energy management system connects, via the Internet or utility backhaul, to a utility substation computer to determine if the co-located charging station is permitted to charge at up to 100%. The utility substation computer is able to monitor the transformer associated with the charging station, and determine if the temperature is within the desired range. When the transformer may be near overload, the utility substation computer can either grant or deny charging permission back to the energy management system.
[0060] At one specific customer location, the premise energy management system is granted permission by the utility sub-station computer to allow the charging station to go up to 100% usage for the next 5 minutes. The energy management system at a second customer location, also supplied by the same transformer, contacts the substation computer to check for permission to charge. The substation computer determines that the transformer's temperature is acceptable because the transformer is not near overload. The substation grants permission to the second customer location to charge at 100% for the next 5 minutes.
[0061] After a few minutes, the first energy management system contacts the utility substation computer requesting permission to charge at 100%. The utility substation computer determines that the transformer is outside the acceptable temperature range and denies permission to charge at up to 100%. The first energy management system sets the charging station to a 25% duty cycle. The first energy management system will request permission to charge at 100% again in a few minutes. Because of the reduced charging, the transformer's temperature is maintained in the normal range. Permission-based policies also help keep the transformer safe in the case that the Internet connection is down since all the charging stations will be reduced to 25% charging rate. The utility may also have the substation computer indicate a specific charge rate for the next period to the energy management system.
[0062] Referring now to FIG. 6 , a schematic diagram illustrating a software application 100 controlling an asset 108 with minimal latency by creating and modifying a real-time policy 166 on the remote asset control system 102 is shown. The system 10 has a human interface device 161 that permits require real-time control of the asset 108 . The human interface device 161 is typically actively controlled by a human user, but may also be running a software agent acting on behalf of the human user based upon pre-configured preferences. Real-time control typically means that the latency of control commands requested by the human interface device 161 until acted upon by the asset 108 is less than 1 second, but may be as much as 10 seconds or more. In one embodiment, the human interface device 161 is a mobile cellular smart phone, a computer, a personal data assistant, a land line telephone, a television, or a wireless remote control.
[0063] The sequence of events that enables the human interface device 161 to control the asset 108 in real-time is typically initiated by the human interface device 161 via communication path 163 . The human interface device 161 makes a request 165 to the software application 100 to create a real-time asset policy R 166 on remote asset control system 102 . The software application passes along a request 160 via communication path 110 .
[0064] On the real-time asset policy R 166 is on the remote asset control system 102 , the remote asset control system 102 copies the asset policy R 166 to the software sub-system 104 via communication path 112 with request 162 creating real-time asset policy R′ 168 . The software sub-system 104 now enforces real-time asset policy R′ 168 on asset 108 through request 164 on network communication path 114 . Communication paths 163 , 110 , 112 , 114 and request channels 165 , 160 , 162 , 164 are typically kept in a ready state for the purpose of minimizing the latency for subsequent control commands from the human interface device 161 to be acted upon by the asset 108 .
[0065] The human interface device 161 typically communicates to the software application 100 , but may also directly communicate to the remote asset control system 102 or the software sub-system 104 to further minimize the latency of control commands. The software application 100 may also request real-time control of the asset 108 as if the software application 100 itself were acting as a human interface device 161 . Request channels 165 , 160 , 162 , are preferably a representational state transfer web service, but may also be a SOAP web service, an OpenADR server, remote procedure call, procedural call, object method invocation, and the like, and where request channel 164 is preferably ZigBee Smart Energy Profile 1.0, but may also typically be Modbus, HomePlug AV, BACnet, RS-232, RS-485, and the like.
[0066] In one embodiment, the software application 100 presents a virtual thermostat control on the screen of a smart phone. The user expects that their control changes take effect in real-time on the actual physical thermostat asset 108 . The smart phone would indicate to the software application 100 that real-time control of the thermostat is desired. The software application 100 creates the real-time asset policy R 166 on the asset control the environment 102 which efficiently creates real-time asset policy R′ 168 on software sub-system 104 which in turn controls the asset 108 via network communication link 114 . When subsequent control commands are requested by the human interface device 161 , subsequent control commands are efficiently propagated to the thermostat asset 108 such that changes occur with minimal latency. A benefit of using a real-time asset policy as described is that other policies which may be in effect are automatically suppressed, which eliminates potential contention between the control commands that the human interface device is requesting and what would normally be the currently enforced policy.
[0067] Referring now to FIG. 7 , a schematic diagram illustrating atomic policy activation and deactivation within a policy-based asset control system 102 is shown. The hierarchical grouping and inheritance scheme described in FIG. 7 is consistent with those described for FIG. 3 . The exemplary environment 10 has asset policies 172 , 174 , 176 , 178 and a composite asset policy 186 . The asset policies 172 , 174 are initially active and asset policies 176 , 178 are initially inactive. The environment 10 also includes asset group Q 171 , which hierarchically contains group U 173 . Asset policies 172 , 176 belong to group Q 171 and asset policies 174 , 178 belong to group U 173 .
[0068] Initially, the composite asset policy 186 inherits asset policy W 172 and asset policy X 174 , but does not initially inherit policies Y, Z 176 , 178 because policies Y, Z 176 , 178 are currently marked as inactive. Then, the software application 100 sends a request 170 via network communication path 110 to the remote asset control system 102 to mark the asset policies 172 , 174 inactive. The asset policies 176 , 178 are also marked active, and composite asset policy 186 is atomically updated. The composite asset policy 186 does not enter a partially complete, incorrect, or corrupted state. The result is a business logic thread that enables an atomic transaction that activates or deactivates a plurality of policies affecting, via inheritance, a composite asset policy to lock the relational database in which the policies are stored until all the updates are completed. Such locking prevents other threads from reading the composite asset policy prematurely, but may also use file locks, semaphores, mutexes, critical sections, work queues, and the like to ensure the atomic nature of the transaction.
[0069] When creating policies on the remote asset control system 102 , the software application 100 simultaneously marks the policies as active or inactive. The ability of the software application 100 to precisely manipulate, through an atomic request 170 , the activation and deactivation of a plurality of polices 172 , 174 , 186 , 178 within a hierarchy of policy inheritance maintains the integrity of the composite asset policy 186 at all times.
[0070] Referring now to FIG. 8 , a schematic diagram illustrating telemetry caching and transfer between an asset 108 , a software sub-system 104 , a remote asset control system 102 , and a software application 100 is shown. The environment 10 has a telemetry source 192 on asset 108 , telemetry cache A 190 on software sub-system 104 , and telemetry cache A′ 188 on remote asset control system 102 . The software application 100 can request 194 , via network communication path 110 , present and historical telemetry regarding asset 108 from remote asset control system 102 .
[0071] The software sub-system 104 provides requests 198 to read from the telemetry source 192 . The requests 198 and other information are stored in telemetry cache A 190 . The preferred embodiment is for software sub-system to periodically poll, but data may also be asynchronously sent from the asset 108 . The telemetry of the polling cycles is stored within the telemetry cache A 190 to include a timestamp of when the telemetry was read and including a reference, pointer, name, and the like to the composite asset policy, conditions, and conditional policy elements being enforced at the time the telemetry was polled.
[0072] The software sub-system 104 stores the telemetry from a plurality of polling cycles in a manner that the data can be retrieved by the remote asset control system 102 . Further, the software sub-system 104 can poll for asset telemetry regardless of the current ability of the remote asset control system 102 to make requests 196 via network communication path 112 to the software sub-system 104 and regardless of the current ability of the software application 100 to make requests 194 to the remote asset the environment 102 via network communication path 110 . For example, even if the network communication path 112 is not working since the Internet Service Provider is performing network maintenance, the software sub-system 104 can continue to poll the asset 108 for telemetry and store it in telemetry cache A 190 .
[0073] Still referring still to FIG. 8 , the remote asset control system 102 is able to copy 196 telemetry cache A 190 from software sub-system 104 and create telemetry cache A′ 188 . Preferably, the remote asset control system 102 periodically polls the software sub-system 104 for data in the telemetry cache A 190 using Secure FTP. The telemetry of each polling cycle is stored within the telemetry cache A′ 188 as a relational database along with metadata including a timestamp of when the telemetry was copied from the software sub-system 104 .
[0074] The software sub-system 104 asynchronously transfers the telemetry cache A 190 to the remote asset control system 102 . The remote asset control system 102 polls for and copies telemetry cache A 190 regardless of the current ability of the software sub-system 104 to communicate with asset 108 via network communication path 114 and regardless of the current ability of the software application 100 to communicate to the remote asset control system 102 via network communication path 110 . For example, if the software application 100 is being updated to a new software release, during which time it is unable to communicate with the remote asset control system 102 , the remote asset control system 102 continues to poll the software sub-system 104 for telemetry cache A 190 and update telemetry cache A′ 188 .
[0075] Still referring to FIG. 8 , the software application 100 provides a request 194 for both current telemetry and historical telemetry from telemetry cache A′ 188 residing on the remote asset control system 102 . The software application makes a representational state transfer web service request with a query option indicating if the request is for the most recent telemetry or historical telemetry from telemetry cache A′ 190 . Further, the software application 100 may request 194 telemetry from the remote asset control system 102 , regardless of the current ability of the remote asset control system 102 to communicate with and retrieve telemetry from the software sub-system 104 via network communication path 112 and regardless of the current ability of the software sub-system 104 to communicate and retrieve telemetry from asset 108 via network communication path 114 . For example, if the software sub-system 104 is undergoing temporary system maintenance precluding communication with the remote asset control system 102 via network communication path 112 , the software application 100 is able to request telemetry from the remote asset control system 102 via network communication path 110 .
[0076] The caching of asset 108 telemetry by the software sub-system 104 eliminates a plurality of potential interruptions that may cause gaps in the recorded telemetry. Further, the secondary telemetry cache in the remote asset control system 102 maximizes the ability of the software application 100 to read telemetry. The result is minimal gaps in the recorded telemetry. By having thorough and accurate data, the telemetry is useful in analytical algorithms by the software application 100 to further optimize the performance of the asset 108 or plurality of assets 108 and the performance of the environment 10 generally.
[0077] Referring again to FIG. 7 , the software application 100 queries the remote asset control system 102 to only return telemetry concerning the asset 108 that is in violation of the composite asset policy currently enforced by software sub-system 104 . Thus, the software application 100 efficiently detects anomalies that may cause sub-optimal asset performance. For example, the AC relay of a load controller asset connected to an electric hot water heater is faulty and always latched in the “on” position. The software application 100 has created a policy for the load controller to turn off during a utility demand response event scheduled at 2 pm. At 2 pm, the software sub-system 104 commands the load controller to turn off, but due to the faulty AC relay, the load controller does not. The software application 100 is able to send an efficient request to the remote asset control system 102 returning only a listing of assets not performing as expected based upon enforced policy, e.g., the load controller would be reported as being in the “on” state when the load controller should have been in the “off” state.
[0078] When the number of assets being managed by the remote asset control system 102 is large, the method of requesting asset deviance from policy ensures that the software application 100 can more rapidly address the problem. For example, a repair crew is more quickly deployed to replace a faulty load controller, or additional load controller assets are turned off to compensate for the load reduction not achieved by the faulty load controller. Typically, the software application 100 sends a request to the remote asset control system 102 operating on a plurality of assets that are part of the same hierarchical group. Then, the remote asset control system 102 returns a list of assets not performing as expected based upon the current enforced policy.
[0079] One advantage of the subject technology is substantially optimized asset performance compared to conventional asset control systems because the co-located software sub-system continuously controls the assets by conditionally enforcing policy based upon a combination of remote, co-located, or internal inputs. The software application may set a permission-based policy that helps to ensure that assets reduce their consumption to a safe level when not explicitly permitted to use its highest consumption modes. This permission-based policy can help to make the electrical grid more reliable since the asset's default operational state is to operate in a mode that can typically be supported by a utility in less than ideal circumstances.
[0080] The software application also performs as if the software application were a conventional asset control system when the environment requires real-time asset control. Further, the software application of the subject technology has substantially fewer asset telemetry gaps compared to conventional remote asset control systems since the asset telemetry at multiple levels is cached and allows historical queries. The reduced asset telemetry gaps enable better analysis of asset performance which may be used in feedback to look for changes to policy for the asset to further optimize asset performance.
[0081] Further, a software application making a single policy change request to the present disclosure can change the control of a plurality of assets by virtue of policy inheritance, whereas a different software application would be required to make a plurality of individual requests to a conventional remote asset control system to achieve the same result. The advantage of the hierarchal policy organization of the present disclosure is to enhance the ability of the software application to consistently control assets of similar ilk. Further, the ability of the subject technology to allow a software application to atomically activate and deactivate policies ensures that corrupted, incomplete, or incorrect composite policies are never propagated to software sub-systems that could result in incorrect or sub-optimal asset performance.
[0082] Further, the subject technology allows software applications the advantage of setting policies regardless of the current ability of the policy-based asset control system to communicate to the software sub-system or the current ability of the software sub-system to communicate with the asset. Compared to conventional remote asset control systems, the software application does not need to track and continually retry requesting control commands until an asset becomes accessible and is able to process such a control request via a plurality of communication network paths.
[0083] For example, an electric utility wants to shave peak loads during times of high demand. The electric utility creates a demand response program for small commercial customers that gives electricity discounts to those who participate. Once enrolled, the electric utility replaces the customer's existing thermostats, installs a 30 A load controller on the electric hot water heater, and installs a premise energy management system. The electric utility installs similar systems of thermostats, load controllers, and premise energy management systems at the premises of several thousand customers in their service territory.
[0084] The utility's enterprise software, acting as a software application 100 , provides a web portal for their customers to create thermostat set point schedules helping to optimize daily energy efficiency. The electric utility also provides a mobile cellular smart phone application allowing real-time thermostat control to enable managers to remotely override the normal thermostat set point schedule. The utility's enterprise software translates the customer's daily thermostat set point preferences into policies on the remote asset control system 102 as described above. The remote asset control system 102 generates composite asset policies that are transferred to the premise energy management systems, a typical form of a software sub-system 104 .
[0085] The premise energy management system is able to autonomously manage the customer's thermostat set point daily schedules regardless of the ability of the utility enterprise software or the remote asset control system 102 to communicate to either the premise energy management system or the thermostat. Further, when a manager of a specific premise attempts to control the set points of a thermostat in real-time via the utility provided thermostat application on his mobile cellular smart phone, the utility enterprise software creates a real-time policy which minimizes the latency of control actions commanded from the manager's phone, while simultaneously and transparently overriding the daily thermostat set point schedule as desired.
[0086] Continuing with the electric utility application example, the electric utility forecasts that record high temperatures will cause electric demand to exceed electric supply. The electric utility issues a demand response event to the small commercial customers that are participating in the demand response program. The electric utility's enterprise software, nearly 24 hours in advance of the anticipated demand response, event creates a new group asset policy on the remote asset control system, that will be inherited by the individual policies of all the thermostat and load controller assets located at participating customer premises.
[0087] The new group asset policy will set back thermostats an additional 3° F. and turn off loads connected to the load controllers for 4 hours starting at 3 pm with a 15 minute start and end randomization. The remote asset control system 102 copies the atomically updated composite asset policy to each of the energy management systems at the customer's premise. The energy management systems operate normally and continue to manage the customer's thermostat set points according to the customer's preferred setting.
[0088] Then at 3 pm, plus up to an additional 15 minutes of randomization, the energy management system, at each premise, enforces the additional 3° F. thermostat set point offset and turns off the loads attached to the load controllers even though the connecting Internet service provider is down for many of the commercial customers participating in the utility demand response program. At the conclusion of the utility demand response event at 7 pm, plus an additional 15 minutes of randomization, the energy management system at each customer premise returns the thermostat set point back to the customer desired setting for their daily schedule and turn the loads attached to the load controllers back on.
[0089] If during the event, the customer opted out of the specific utility demand response event, the opt out was recorded by the premise energy management system. Later, if the Internet service provider has been able to restore service to its customers, the remote asset control system 102 is able to retrieve all of the historical telemetry gathered at periodic intervals. A typical interval would be 1 minute. The historical telemetry is cached by the energy management system for both the thermostat and load controller including timestamps and references to the composite asset policy, conditions, and conditional policy elements active for each telemetry reading.
[0090] The remote asset control system 102 retrieves the telemetry from all of the energy management systems for all the customers participating in the utility demand response program, enables the utility enterprise software to query for asset deviance from the load control event policy, and then quickly detects any customers that opted out of the utility load control event as well as any faults such as a load controller with a disabled AC relay. By recognizing the disabled load controller, the remote asset control system can automatically generate a utility service work ticket.
[0091] The next day while processing the work ticket, a technician identifies a new replacement load controller via a web interface of the software application. The technician specifies the new load controller, via its hardware address, as an alternate asset and schedules an electrician to make a service call. When the electrician replaces the faulty load controller with the new one, the new load controller is immediately managed according to the same polices as the original asset making the new load controller less likely to be managed incorrectly for future demand response events.
[0092] Still further, the utility enterprise software also reads all of the telemetry for all of the thermostats and load controllers so that a batch analysis normally taking 6 hours can begin. Because of the detailed telemetry gathered by the energy management systems, the batch analysis of the telemetry collected from the thermostats and load controllers indicates that a 10 minute start and end randomization is sufficient to allow the electrical grid to cope with the demand response event. Thus, the electric utility is able to further optimize the performance of the thermostat and load controller assets by reducing the start and end randomization time.
[0093] It will be appreciated by those of ordinary skill in the pertinent art that the functions of several elements may, in alternative embodiments, be carried out by fewer elements, or a single element. Similarly, in some embodiments, any functional element may perform fewer, or different, operations than those described with respect to the illustrated embodiments. Also, functional elements (e.g., modules, databases, interfaces, computers, servers, communication devices, and the like) shown as distinct for purposes of illustration may be incorporated within other functional elements in any particular implementation.
[0094] While the invention has been described with respect to preferred embodiments, those skilled in the art will readily appreciate that various changes and/or modifications can be made to the invention without departing from the spirit or scope of the invention. For example, each claim may depend from any or all claims, even in a multiple dependent manner, even though such has not been originally claimed. | A remote asset control system for optimized asset performance under a variety of circumstances, such as network communication path failures, software maintenance, software faults, hardware faults, hardware maintenance, computer system maintenance, computer system failure, undetected data errors, configuration errors, human error, power outages, malicious network attacks, and the like, having a means to create, modify, and delete asset policies, an object oriented asset policy inheritance scheme that generates composite asset policies, an asset policy transference and caching scheme, condition driven asset policy enforcement, permission-based asset policy mechanism for throttling energy or water consumption, asset replacement simplification, query capability to enumerate actual asset deviance as compared to the currently enforced composite asset policy, real-time control asset policies, atomic activation and deactivation of asset policies, which are part of the policy inheritance hierarchy, ensuring composite policy integrity, and multi-tiered telemetry caching and transference. | 7 |
[0001] This application claims priority of U.S. provisional application Ser. No. 61/201,394 filed Dec. 10, 2008.
FIELD OF THE INVENTION
[0002] The present invention relates to direction al drilling systems wherein a transmitter built into a sonde housing is used to transmit information concerning the drill head.
BACKGROUND OF THE INVENTION
[0003] Recently the world's leading manufacturer of radio transmitter beacons for use in horizontal directional boring, Digital Control Incorporated, or DCI, introduced a new locating system. The system reads the earth's magnetic field rather than gravity. With this information, the system is able to do a superior job of locating the buried drill head tooling when compared to conventional walkover receiver/transmitter systems. See for example the “compass effect” and non-magnetic drill tool housing 282 as described in U.S. Patent Application 20050077085, Apr. 14, 2005, the contents of which are incorporated by reference herein.
[0004] The superiority of the new SST (as it is trade-named) is realized when boring underneath busy streets, rivers or other locations where a walkover transmitter may be imperiled by traffic, need for a boat, or the signal may be affected by the existence of steel rebar between the receiver and the transmitter. However, to operate, the SST transmitter must be housed and located at a substantial distance (preferably at least about 10 feet) from any magnetic item, including alloy steel making up the housing or drill stem. Most steel alloys commonly used to make sonde housings are sufficiently magnetic to prevent the SST from sensing the earth's magnetic field accurately. To remedy this, non-magnetic variations of stainless steel can be used, including 15-15HS Max from Carpenter or Monel K-500 from Specialty Metals Corporation. These alloys are presently the only ones that have marginally enough tensile strength to handle stresses developed in drilling conditions, therefore the sonde housing design must be done with minimization of stress risers in mind.
[0005] Additionally, these alloys are extraordinarily difficult to fabricate into tooling as they have a low machineability rating. This means the design is best simplified to accommodate these difficulties. A general design to do that does exist in the industry. It is known as an end load, meaning the drill stem is removed from the transmitter housing to access the transmitter (sonde) for loading/unloading through the end of the housing.
[0006] Normally during loading, the sonde must be clocked, meaning oriented rotationally to the steering features on the bit mounted forward of the housing. One of the technical innovations of the SST transmitter is that it can be electronically clocked to the steering feature. This means the transmitter must remain solidly locked into a given orientation once it is installed; but it can be installed randomly in orientation to the steering feature.
[0007] End load housings normally restrain and clock the transmitter by having a slot in the transmitter face engage a tabbed feature in the housing. The transmitter is then trapped from the opposite end with a plug which maintains the tab/slot engagement and therefore the clock orientation.
[0008] The action of finding and engaging the slot and the tab is risk prone as it can't be inspected at the bottom of its blind bore, a bore possibly contaminated with dried mud. Should this engagement not be accomplished, the transmitter can drift in rotation during operation and the drill head will go off course, the ramifications of which are many, least of which is need to start the bore over.
SUMMARY OF THE INVENTION
[0009] A sonde assembly of the invention includes: a sonde housing in the form of a non-magnetic tube having windows therein for permitting a radio signal to be transmitted out the tube from the inside;
[0010] means such as a device enclosing a front end of the tube; a sonde slidingly disposed inside the non-magnetic tube and closely fitting in a sonde cavity thereof in engagement with a front end stop of the tube. The sonde comprises a sensor and a radio transmitter connected to the sensor to transmit a directional signal based on sensor input, which sensor and transmitter are disposed inside a non-magnetic cylinder.
[0011] A rear end cap is secured in a fixed position in a rear end opening of the non-magnetic tube, and a connector rigidly connects a rear end portion of the cylinder to a front end portion of the rear end cap. Upon securing of the rear end cap in a rear end opening of the sonde housing, the sonde is secured in a fixed position relative to the sonde housing. Preferably the sonde includes a sensor that senses the magnetic field of the earth.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In the accompanying drawing, wherein like numerals denote like elements.
[0013] FIG. 1 is a side view of a drill head using a sonde assembly of the invention,
[0014] FIG. 2 is a lengthwise sectional view of the drill head of FIG. 1 along the line A-A in FIG. 1 ,
[0015] FIG. 3 is an enlarged view of the circled area B in FIG. 2 ,
[0016] FIG. 4 is an enlarged view of the circled area C in FIG. 2 ,
[0017] FIG. 5 is an enlarged view of the circled area D in FIG. 4 ,
[0018] FIG. 6 is a partial side view of a sonde assembly of the invention;
[0019] FIG. 7 is a rear view, partly in section, of the sonde assembly of FIG. 6 ,
[0020] FIG. 8 is a top view of the sonde assembly of FIG. 6 ,
[0021] FIG. 9 is a side view partly in section, of the sonde assembly of FIG. 6 , and
[0022] FIG. 10 is an enlarged view of the circled area E in FIG. 9 .
DETAILED DESCRIPTION
[0023] A sonde mounting concept applied with the present invention as described herein eliminates risk of not engaging the tab into the slot by rigidly bolting the sonde to a plug which threadedly retains the sonde in its cavity. The concept is simple yet elegant. It eliminates risk of rotational drift, simplifies installation and provides the operator with complete confidence in the security of the sonde.
[0024] The details used are not limited to applications where a non magnetic housing is required. However, at this time, the only transmitter existing that can electronically clock is the SST unit that senses the earth's magnetic field for orientation. In the future, as gravity sensing transmitters evolve, such units may also be able to use electronic clocking, making this concept of this invention applicable for that technology as well.
[0025] In the accompanying drawings, Steering bill 906-5255 is a conventional flat bill made of non-magnetic steel. Such bills made of alloy steel have been used in the industry for over 15 years. Bill Adapter 906-5256 mounts that bill with bolts on an angled face to facilitate steering. The adapter joins to the housing via a conventional tapered API thread. The adapter has a central fluid passage 30 and a discharge nozzle 906-5259 to meter drilling mud to the bill area. Both adapter and housing are made of a non-magnetic metal (steel) for use in the present invention.
[0026] The Housing 906-5233 has nine longitudinal fluid passages 32 that direct the drill mud around the central sonde cavity. One of these passages is shown below the sonde cavity in FIG. 2 , and the others are configured like the one shown but arranged in a circular formation around the sonde cavity. The sonde cavity is vented to the outside ground pressure through three radio transmission slots (one visible in FIG. 1 ). These slots may be open, or they may be sealed with putty that will yield and leak should modest differential pressures develop between the sonde cavity and the adjacent soil. The transmitter cavity is, however, sealed from the flow of pressurized mud. These seals are located on plugs at each and of the cavity and around the data transmission cable that extends from the rear of the sonde and continues through the length of the drill stem up to the machine. The front plug assembly 906-5250 has a cushioned nose to provide a small amount of shock isolation as well as o-ring 906-5235 to seal. The plug threads into the housing body itself. It is considered a semi-permanent installation, only being removed to service the concentric sleeve 906-5249 or the elastic isolator 906-5251.
[0027] The Rear Plug 906-5237 is more involved in securing the transmitter than the front plug. It mounts to the rear face of the transmitter by means of (2) bolts threading into tapped holes in the rear sonde face. Note that the action of tightening these (2) mounting bolts compresses an o-ring and packing to seal the pressurized fluid from entering the sonde or sonde cavity. These two bolts are located 180° apart and can be seen as the smaller hexes in FIGS. 6 and 8 .
[0028] FIGS. 6-9 show the sub assembly of the SST transmitter with the housing removed, with the front on the left. Mounting the sub assembly of the SST transmitter and the rear plug and mounting bolts into the housing body is done by rotating the sub assembly as a unit to engage the threads at the rear of the sonde cavity. The external threads on the rear plug securely engage the threads at the rear of the sonde cavity. The assembly is driven via one of the three ½″ hexes (bosses on the rear face of the rear cap) with a socket and socket extension. The O-ring 906-5240 seals as the plug tightens up against the housing, and the sonde is restrained in all directions as well as sealed from pressurized mud flow.
[0029] In summary, the front plug remains in place sealing the front end of the sonde cavity. Use of a blind tube instead of a front plug is possible but involves practical difficulties in accessing and cleaning the sonde cavity. The rear plug has a large diameter threaded rear portion which allows attachment of the sub assembly to the sonde housing as described above, and a forwardly extending extension ending in an annular flange that abuts against the rear end face of the sonde housing. The bolts shown in FIGS. 6-9 extend through two holes in the annular flange of the extension into receiving threaded holes in the end of the cylinder that encloses the sonde. By this means the sub assembly, the sonde housing and rear cap, rotate as a unit.
[0030] The drill head is threadedly attached to a non magnetic drill stem extension often known as a collar. This extension provides at least 12 feet of distance between the back of the housing and the start of the magnetic steel stem.
[0031] Removal of the sonde from the cavity is done in reverse by removing the 12 foot drill stem collar from the rear of the housing and unthreading the rear plug. Along with the plug, the sonde will be extracted. The foregoing design has been tested and proved to be functional, easily used and manufacturable, making good use of the difficult to machine non magnetic stainless steel. 906-5250 has a cushioned nose to provide a small amount of shock isolation as well as o-ring 906-5235 to seal. The plug threads into the housing body itself. It is considered a semi-permanent installation, only being removed to service the concentric sleeve 906-5249 or the elastic isolator 906-5251.
[0032] The Rear Plug 906-5237 is more involved in securing the transmitter than the front plug. It mounts to the rear face of the transmitter by means of (2) bolts threading into tapped holes in the rear sonde face. Note that the action of tightening these (2) mounting bolts compresses an o-ring and packing to seal the pressurized fluid from entering the sonde or sonde cavity. These two bolts are located 180° apart and can be seen as the smaller hexes in FIG. 6 .
[0033] FIGS. 6-9 show the sub assembly of the SST transmitter with the housing removed, with the front on the left. Mounting the sub assembly of the SST transmitter and the rear plug and mounting bolts into the housing body is done by rotating the sub assembly as a unit to engage the threads at the rear of the sonde cavity. The external threads on the rear plug securely engage the threads at the rear of the sonde cavity. The assembly is driven via one of the three ½″ hexes (bosses on the rear face of the rear cap) with a socket and socket extension. The O-ring 906-5240 seals as the plug tightens up against the housing, and the sonde is restrained in all directions as well as sealed from pressurized mud flow.
[0034] In summary, the front plug remains in place sealing the front end of the sonde cavity. Use of a blind tube instead of a front plug is possible but involves practical difficulties in accessing and cleaning the sonde cavity. The rear plug has a large diameter threaded rear portion which allows attachment of the sub assembly to the sonde housing as described above, and a forwardly extending extension ending in an annular flange that abuts against the rear end face of the sonde housing. The bolts shown in FIGS. 6-9 extend through two holes in the annular flange of the extension into receiving threaded holes in the end of the cylinder that encloses the sonde. By this means the sub assembly, the sonde housing and rear cap, rotate as a unit.
[0035] The drill head is threadedly attached to a non magnetic drill stem extension often known as a collar. This extension provides at least 12 feet of distance between the back of the housing and the start of the magnetic steel stem.
[0036] Removal of the sonde from the cavity is done in reverse by removing the 12 foot drill stem collar from the rear of the housing and unthreading the rear plug. Along with the plug, the sonde will be extracted. The foregoing design has been tested and proved to be functional, easily used and manufacturable, making good use of the difficult to machine non magnetic stainless steel.
[0037] While certain embodiments of the invention have been illustrated for the purposes of this disclosure, numerous changes in the method and apparatus of the invention presented herein may be made by those skilled in the art, such changes being embodied within the scope and spirit of the present invention as defined in the appended claims. | A sonde assembly of the invention includes: a sonde housing in the form of a non-magnetic tube having windows therein for permitting a radio signal to be transmitted out the tube from the inside;
means such as a device enclosing a front end of the tube; a sonde slidingly disposed inside the non-magnetic tube and closely fitting in a sonde cavity thereof in engagement with a front end stop of the tube. The sonde comprises a sensor and a radio transmitter connected to the sensor to transmit a directional signal based on sensor input, which sensor and transmitter are disposed inside a non-magnetic cylinder. | 4 |
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